1
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Cox A, Brown KC, Bender C, Valentovic MA. The e-liquid flavoring cinnamaldehyde induces cellular stress responses in human proximal tubule (HK-2) kidney cells. Biomed Pharmacother 2024; 175:116666. [PMID: 38677246 DOI: 10.1016/j.biopha.2024.116666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 04/22/2024] [Accepted: 04/24/2024] [Indexed: 04/29/2024] Open
Abstract
Flavored e-liquid use has become popular among e-cigarette users recently, but the effects of such products outside the lung are not well characterized. In this work, acute exposure to the popular flavoring cinnamaldehyde (CIN) was performed on human proximal tubule (HK-2) kidney cells. Cells were exposed to 0-100 µM CIN for 24-48 h and cellular stress responses were assessed. Mitochondrial viability via MTT assay was significantly decreased at 20 µM for 24 and 48 h exposure. Seahorse XFp analysis showed significantly decreased mitochondrial energy output at 20 µM by 24 h exposure, in addition to significantly reduced ATP Synthase expression. Seahorse analysis also revealed significantly decreased glycolytic function at 20 µM by 24 h exposure, suggesting inability of glycolytic processes to compensate for reduced mitochondrial energy output. Cleaved caspase-3 expression, a mediator of apoptosis, was significantly increased at the 24 h mark. C/EBP homologous protein (CHOP) expression, a mediator of ER-induced apoptosis, was induced by 48 h and subsequently lost at the highest concentration of 100 µM. This decrease was accompanied by a simultaneous decrease in its downstream target cleaved caspase-3 at the 48 h mark. The autophagy marker microtubule-associated protein 1 A/1B light chain 3 (LC3B-I and LC3B-II) expression was significantly increased at 100 µM by 24 h. Autophagy-related 7 (ATG7) protein and mitophagy-related proteins PTEN-induced putative kinase 1 (PINK1) and PARKIN expression were significantly reduced at 24 and 48 h exposure. These results indicate acute exposure to CIN in the kidney HK-2 model induces mitochondrial dysfunction and cellular stress responses.
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Affiliation(s)
- Ashley Cox
- Department of Biomedical Sciences, Toxicology Research Cluster, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, United States
| | - Kathleen C Brown
- Department of Biomedical Sciences, Toxicology Research Cluster, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, United States
| | - Christopher Bender
- Department of Biomedical Sciences, Toxicology Research Cluster, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, United States
| | - Monica A Valentovic
- Department of Biomedical Sciences, Toxicology Research Cluster, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, United States.
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2
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Saruwatari S, Takada M, Mutoh J, Kishikawa N, Kuroda N, Wada M. LC-MS/MS analysis of components in smoke from e-cigarettes that use guarana extract as the caffeine source. ANAL SCI 2024; 40:959-963. [PMID: 38507147 DOI: 10.1007/s44211-024-00535-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/15/2024] [Indexed: 03/22/2024]
Abstract
Currently, e-cigarette products to inhale caffeine (Caf) are commercially available and widely used. Guarana extract (GE) is used as the caffeine source in some e-cigarette products. In this study, an LC-MS/MS analysis of components in the smoke from e-cigarettes with GE was performed. The concentration ranges of Caf and the minor components theophylline (TP), theobromine (TB), and paraxanthine (PX) in e-liquid and cigarette smoke extract (CSE) of five e-cigarette products were determined. The concentration ranges of e-liquid and CSE were 2.17-8.62 mg/mL and 0.17-1.17 µg/puff for Caf, 0.09-37.58 µg/mL and 0.03-11.88 ng/puff for TB, 50.28-185.26 ng/mL and 0.00-0.05 ng/puff for TP, and 0.44-4.09 µg/mL and 0.03-0.20 ng/puff for PX, respectively. By comparing the peak area ratios of e-liquid and CSE, we clarified that the heat degradation of Caf to its related components in GE products was accelerated. Epicatechin, which is another typical component in GE, was determined for CSE, but not for e-liquid.
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Affiliation(s)
- Suzuna Saruwatari
- Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, 1-1-1 Daigakudori, Sanyo-Onoda, Yamaguchi, 756-0884, Japan
| | - Makoto Takada
- Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, 1-1-1 Daigakudori, Sanyo-Onoda, Yamaguchi, 756-0884, Japan
- Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nakamura, Johnan, Fukuoka, Fukuoka, 814-0180, Japan
| | - Junpei Mutoh
- Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, 1-1-1 Daigakudori, Sanyo-Onoda, Yamaguchi, 756-0884, Japan
| | - Naoya Kishikawa
- Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan
| | - Naotaka Kuroda
- Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan
| | - Mitsuhiro Wada
- Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, 1-1-1 Daigakudori, Sanyo-Onoda, Yamaguchi, 756-0884, Japan.
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3
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Hernandez A, Belfleur L, Migaud M, Gassman NR. A tipping point in dihydroxyacetone exposure: mitochondrial stress and metabolic reprogramming alter survival in rat cardiomyocytes H9c2 cells. Chem Biol Interact 2024; 394:110991. [PMID: 38582340 PMCID: PMC11069339 DOI: 10.1016/j.cbi.2024.110991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 03/20/2024] [Accepted: 04/02/2024] [Indexed: 04/08/2024]
Abstract
Exogenous exposures to the triose sugar dihydroxyacetone (DHA) occur from sunless tanning products and electronic cigarette aerosol. Once inhaled or absorbed, DHA enters cells, is converted to dihydroxyacetone phosphate (DHAP), and incorporated into several metabolic pathways. Cytotoxic effects of DHA vary across the cell types depending on the metabolic needs of the cells, and differences in the generation of reactive oxygen species (ROS), cell cycle arrest, and mitochondrial dysfunction have been reported. We have shown that cytotoxic doses of DHA induced metabolic imbalances in glycolysis and oxidative phosphorylation in liver and kidney cell models. Here, we examine the dose-dependent effects of DHA on the rat cardiomyocyte cell line, H9c2. Cells begin to experience cytotoxic effects at low millimolar doses, but an increase in cell survival was observed at 2 mM DHA. We confirmed that 2 mM DHA increased cell survival compared to the low cytotoxic 1 mM dose and investigated the metabolic differences between these two low DHA doses. Exposure to 1 mM DHA showed changes in the cell's fuel utilization, mitochondrial reactive oxygen species (ROS), and transient changes in the glycolysis and mitochondrial energetics, which normalized 24 h after exposure. The 2 mM dose induced robust changes in mitochondrial flux through acetyl CoA and elevated expression of fatty acid synthase. Distinct from the 1 mM dose, the 2 mM exposure increased mitochondrial ROS and NAD(P)H levels, and sustained changes in LDHA/LDHB and acetyl CoA-associated enzymes were observed. Although the cells were exposed to low cytotoxic (1 mM) and non-cytotoxic (2 mM) acute doses of DHA, significant changes in mitochondrial metabolic pathways occurred. Further, the proliferation increase at the acute 2 mM DHA dose suggests a metabolic adaption occurred with sustained consequences in survival and proliferation. With increased exogenous exposure to DHA through e-cigarette aerosol, this work suggests cell metabolic changes induced by acute or potentially chronic exposures could impact cell function and survival.
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Affiliation(s)
- Arlet Hernandez
- Department of Pharmacology and Toxicology, The University of Alabama at Birmingham, 1720 2nd Ave S, Birmingham, AL, 35294, USA
| | - Luxene Belfleur
- Department of Pharmacology, Whiddon College of Medicine, University of South Alabama, 1660 Springhill Ave, Mobile, AL, 36604, USA
| | - Marie Migaud
- Department of Pharmacology, Whiddon College of Medicine, University of South Alabama, 1660 Springhill Ave, Mobile, AL, 36604, USA
| | - Natalie R Gassman
- Department of Pharmacology and Toxicology, The University of Alabama at Birmingham, 1720 2nd Ave S, Birmingham, AL, 35294, USA.
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4
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Cox A, Brown KC, Valentovic MA. The E-liquid flavoring vanillin alters energy and autophagic pathways in human proximal tubule (HK-2) epithelial cells. Chem Biol Interact 2024; 394:111003. [PMID: 38608998 DOI: 10.1016/j.cbi.2024.111003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/04/2024] [Accepted: 04/07/2024] [Indexed: 04/14/2024]
Abstract
The use of flavored e-liquids in electronic nicotine delivery systems (ENDS) has become very popular in recent years, but effects of these products have not been well characterized outside the lung. In this study, acute exposure to the popular flavoring vanillin (VAN) was performed on human proximal tubule (HK-2) kidney cells. Cells were exposed to 0-1000 μM VAN for 24 or 48 h and cellular stress responses were determined. Mitochondrial viability using MTT assay showed a significant decrease between the control and 1000 μM group by 48 h. Seahorse XFp analysis showed significantly increased basal respiration, ATP production, and proton leak after 24 h exposure. By 48 h exposure, these parameters remained significantly increased in addition to non-mitochondrial respiration and maximal respiration. Glycolytic activity after 24 h exposure showed significant decreases in glycolysis, glycolytic capacity, glycolytic reserve, and non-glycolytic acidification. The autophagy markers microtubule-associated protein 1A/1B light chain 3 (LC3B-I and LC3B-II) were probed via western blotting. The ratio of LC3B-II/LC3B-I was significantly increased after 24 h exposure to VAN, but by 48 h this ratio significantly decreased. The mitophagy marker PINK1 showed an increasing trend at 24 h, and its downstream target Parkin was significantly increased between the control and 750 μM group only. Finally, the oxidative stress marker 4-HNE was significantly decreased after 48 h exposure to VAN. These results indicate that acute exposure to VAN in the kidney HK-2 model can induce energy and autophagic changes within the cell.
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Affiliation(s)
- Ashley Cox
- Department of Biomedical Sciences, Toxicology Research Cluster, Marshall University Joan C. Edwards School of Medicine, Huntington, WV, 25701, USA
| | - Kathleen C Brown
- Department of Biomedical Sciences, Toxicology Research Cluster, Marshall University Joan C. Edwards School of Medicine, Huntington, WV, 25701, USA
| | - Monica A Valentovic
- Department of Biomedical Sciences, Toxicology Research Cluster, Marshall University Joan C. Edwards School of Medicine, Huntington, WV, 25701, USA.
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5
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Strongin RM, Sharma E, Erythropel HC, Kassem NOF, Noël A, Peyton DH, Rahman I. Chemical and physiological interactions between e-liquid constituents: cause for concern? Tob Control 2024:tc-2023-058546. [PMID: 38658055 DOI: 10.1136/tc-2023-058546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 04/11/2024] [Indexed: 04/26/2024]
Abstract
Studies of Electronic Nicotine Delivery Systems (ENDS) toxicity have largely focused on individual components such as flavour additives, base e-liquid ingredients (propylene glycol, glycerol), device characteristics (eg, model, components, wattage), use behaviour, etc. However, vaping involves inhalation of chemical mixtures and interactions between compounds can occur that can lead to different toxicities than toxicity of the individual components. Methods based on the additive toxicity of individual chemical components to estimate the health risks of complex mixtures can result in the overestimation or underestimation of exposure risks, since interactions between components are under-investigated. In the case of ENDS, the potential of elevated toxicity resulting from chemical reactions and interactions is enhanced due to high operating temperatures and the metallic surface of the heating element. With the recent availability of a wide range of e-liquid constituents and popularity of do-it-yourself creation of e-liquid mixtures, the need to understand chemical and physiological impacts of chemical combinations in ENDS e-liquids and aerosols is immediate. There is a significant current knowledge gap concerning how specific combinations of ENDS chemical ingredients result in synergistic or antagonistic interactions. This commentary aims to review the current understanding of chemical reactions between e-liquid components, interactions between additives, chemical reactions that occur during vaping and aerosol properties and biomolecular interactions, all of which may impact physiological health.
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Affiliation(s)
| | | | - Hanno C Erythropel
- Chemical and Environmental Engineering, Yale University, New Haven, Connecticut, USA
| | - Nada O F Kassem
- CBEACH, San Diego State University Research Foundation, San Diego, California, USA
| | - Alexandra Noël
- Department of Comparative Biomedical Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - D H Peyton
- Chemistry, Portland State University, Portland, Oregon, USA
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester, Rochester, New York, USA
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6
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El-Hellani A, Adeniji A, Erythropel HC, Wang Q, Lamb T, Mikheev VB, Rahman I, Stepanov I, Strongin RM, Wagener TL, Brinkman MC. Comparison of emissions across tobacco products: A slippery slope in tobacco control. Tob Induc Dis 2024; 22:TID-22-57. [PMID: 38560551 PMCID: PMC10980913 DOI: 10.18332/tid/183797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 02/07/2024] [Accepted: 02/10/2024] [Indexed: 04/04/2024] Open
Abstract
In this narrative review, we highlight the challenges of comparing emissions from different tobacco products under controlled laboratory settings (using smoking/vaping machines). We focus on tobacco products that generate inhalable smoke or aerosol, such as cigarettes, cigars, hookah, electronic cigarettes, and heated tobacco products. We discuss challenges associated with sample generation including variability of smoking/vaping machines, lack of standardized adaptors that connect smoking/vaping machines to different tobacco products, puffing protocols that are not representative of actual use, and sample generation session length (minutes or number of puffs) that depends on product characteristics. We also discuss the challenges of physically characterizing and trapping emissions from products with different aerosol characteristics. Challenges to analytical method development are also covered, highlighting matrix effects, order of magnitude differences in analyte levels, and the necessity of tailored quality control/quality assurance measures. The review highlights two approaches in selecting emissions to monitor across products, one focusing on toxicants that were detected and quantified with optimized methods for combustible cigarettes, and the other looking for product-specific toxicants using non-targeted analysis. The challenges of data reporting and statistical analysis that allow meaningful comparison across products are also discussed. We end the review by highlighting that even if the technical challenges are overcome, emission comparison may obscure the absolute exposure from novel products if we only focus on relative exposure compared to combustible products.
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Affiliation(s)
- Ahmad El-Hellani
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, United States
- Center for Tobacco Research, The Ohio State University Comprehensive Cancer Center, Columbus, United States
| | - Ayomipo Adeniji
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, United States
- Center for Tobacco Research, The Ohio State University Comprehensive Cancer Center, Columbus, United States
| | - Hanno C. Erythropel
- Department of Chemical and Environmental Engineering, School of Engineering & Applied Science, Yale University, New Haven, United States
- Yale Center for the Study of Tobacco Product Use and Addiction (YCSTP), Department of Psychiatry, Yale School of Medicine, New Haven, United States
| | - Qixin Wang
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, United States
| | - Thomas Lamb
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, United States
| | - Vladimir B. Mikheev
- Battelle Public Health Center for Tobacco Research, Battelle Memorial Institute, Columbus, United States
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, United States
| | - Irina Stepanov
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota Twin Cities, Minneapolis, United States
- Masonic Cancer Center, University of Minnesota Twin Cities, Minneapolis, United States
| | - Robert M. Strongin
- Department of Chemistry, Portland State University, Portland, United States
| | - Theodore L. Wagener
- Center for Tobacco Research, The Ohio State University Comprehensive Cancer Center, Columbus, United States
- Department of Internal Medicine, The Ohio State University, Columbus, United States
| | - Marielle C. Brinkman
- Center for Tobacco Research, The Ohio State University Comprehensive Cancer Center, Columbus, United States
- Division of Epidemiology, College of Public Health, The Ohio State University, Columbus, United States
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7
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Fenech A, Baatjes N, Gunasuntharam K. Fifteen-minute consultation: What paediatricians need to know about vaping. Arch Dis Child Educ Pract Ed 2024; 109:60-65. [PMID: 36600454 DOI: 10.1136/archdischild-2022-324752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022]
Abstract
The prevalence of vaping among children and young people (CYP) is on the rise. This is perhaps a result of perceiving vaping as 'harmless', especially after an extensive public acceptance through the UK Government's promotion of vaping in smoking cessation as well as lax regulations on advertisements. More awareness and research of the effects of vaping is necessary and a call for immediate public health strategies to be implemented in the UK. This article highlights essential facts about vaping, signs of addiction and cessation support for CYP as part of health promotion.
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Affiliation(s)
- Amanda Fenech
- Evelina London Community Services, Sunshine House, Guy's and St Thomas' NHS Foundation Trust, London, UK
- Paediatric Department, Mater Dei Hospital, Msida, Malta
| | - Nikki Baatjes
- Evelina London Community Services, Sunshine House, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Kavitha Gunasuntharam
- Evelina London Community Services, Sunshine House, Guy's and St Thomas' NHS Foundation Trust, London, UK
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8
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Glantz S, Lempert LK. Vuse Solo e-cigarettes do not provide net benefits to public health: a scientific analysis of FDA's marketing authorisation. Tob Control 2024; 33:e108-e115. [PMID: 36764683 PMCID: PMC10409877 DOI: 10.1136/tc-2022-057296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 11/04/2022] [Indexed: 02/12/2023]
Abstract
In October 2021, the US Food and Drug Administration (FDA) authorised marketing of RJ Reynolds Vapor Company's (RJR) Vuse Solo e-cigarette through FDA's Premarket Tobacco Product Application (PMTA) pathway. FDA concluded that RJR demonstrated Vuse products met the statutory standard of providing a net benefit to public health. A review of FDA's scientific justification reveals deficiencies: (1) not adequately considering Vuse's popularity with youth and evidence that e-cigarettes expanded the nicotine market and stimulate cigarette smoking; (2) trading youth addiction for unproven adult benefit without quantifying these risks and benefits; (3) not considering design factors that appeal to youth; (4) not addressing evidence that e-cigarettes used as consumer products do not help smokers quit and promote relapse in former smokers; (5) not discussing evidence that dual use is more dangerous than smoking; (6) narrowly focusing on the fact that e-cigarettes deliver lower levels of some toxicants without addressing direct evidence on adverse health effects; (7) downplaying significant evidence of other substantial harms; (8) not acting on FDA's own study showing no all-cause mortality benefit of reducing (but not stopping) cigarette use; and (9) improperly considering e-cigarettes' high abuse liability and potential for high youth addiction and undermining tobacco cessation. Because marketing these products is not appropriate for the protection of the public health, FDA should reconsider its Vuse marketing order as statutorily required and not use it as a template for other e-cigarette PMTAs. Policymakers outside the USA should anticipate that tobacco companies will use FDA's decision to try to weaken tobacco control regulation of e-cigarettes and promote their products.
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Affiliation(s)
| | - Lauren Kass Lempert
- Center for Tobacco Control Research and Education, University of California San Francisco, San Francisco, California, USA
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9
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Martin A, Tempra C, Yu Y, Liekkinen J, Thakker R, Lee H, de Santos Moreno B, Vattulainen I, Rossios C, Javanainen M, Bernardino de la Serna J. Exposure to Aldehyde Cherry e-Liquid Flavoring and Its Vaping Byproduct Disrupt Pulmonary Surfactant Biophysical Function. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:1495-1508. [PMID: 38186267 PMCID: PMC10809783 DOI: 10.1021/acs.est.3c07874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 12/16/2023] [Accepted: 12/18/2023] [Indexed: 01/09/2024]
Abstract
Over the past decade, there has been a significant rise in the use of vaping devices, particularly among adolescents, raising concerns for effects on respiratory health. Pressingly, many recent vaping-related lung injuries are unexplained by current knowledge, and the overall implications of vaping for respiratory health are poorly understood. This study investigates the effect of hydrophobic vaping liquid chemicals on the pulmonary surfactant biophysical function. We focus on the commonly used flavoring benzaldehyde and its vaping byproduct, benzaldehyde propylene glycol acetal. The study involves rigorous testing of the surfactant biophysical function in Langmuir trough and constrained sessile drop surfactometer experiments with both protein-free synthetic surfactant and hydrophobic protein-containing clinical surfactant models. The study reveals that exposure to these vaping chemicals significantly interferes with the synthetic and clinical surfactant biophysical function. Further atomistic simulations reveal preferential interactions with SP-B and SP-C surfactant proteins. Additionally, data show surfactant lipid-vaping chemical interactions and suggest significant transfer of vaping chemicals to the experimental subphase, indicating a toxicological mechanism for the alveolar epithelium. Our study, therefore, reveals novel mechanisms for the inhalational toxicity of vaping. This highlights the need to reassess the safety of vaping liquids for respiratory health, particularly the use of aldehyde chemicals as vaping flavorings.
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Affiliation(s)
- Alexia Martin
- National
Heart and Lung Institute, Imperial College
London, Sir Alexander Fleming Building, London SW7 2AZ, U.K.
| | - Carmelo Tempra
- Institute
of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague 6 160 00, Czech Republic
| | - Yuefan Yu
- National
Heart and Lung Institute, Imperial College
London, Sir Alexander Fleming Building, London SW7 2AZ, U.K.
| | - Juho Liekkinen
- Department
of Physics, University of Helsinki, Helsinki 00560, Finland
| | - Roma Thakker
- National
Heart and Lung Institute, Imperial College
London, Sir Alexander Fleming Building, London SW7 2AZ, U.K.
| | - Hayoung Lee
- National
Heart and Lung Institute, Imperial College
London, Sir Alexander Fleming Building, London SW7 2AZ, U.K.
| | - Berta de Santos Moreno
- National
Heart and Lung Institute, Imperial College
London, Sir Alexander Fleming Building, London SW7 2AZ, U.K.
| | - Ilpo Vattulainen
- Department
of Physics, University of Helsinki, Helsinki 00560, Finland
| | - Christos Rossios
- National
Heart and Lung Institute, Imperial College
London, Sir Alexander Fleming Building, London SW7 2AZ, U.K.
| | - Matti Javanainen
- Institute
of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague 6 160 00, Czech Republic
- Institute
of Biotechnology, University of Helsinki, Helsinki 00790, Finland
| | - Jorge Bernardino de la Serna
- National
Heart and Lung Institute, Imperial College
London, Sir Alexander Fleming Building, London SW7 2AZ, U.K.
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10
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Oldham MJ, Jeong L, Gillman IG. An Approach to Flavor Chemical Thermal Degradation Analysis. TOXICS 2023; 12:16. [PMID: 38250972 PMCID: PMC10819574 DOI: 10.3390/toxics12010016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024]
Abstract
Toxicological evaluations of flavor chemicals for use in inhalation products that utilize heat for aerosol generation are complicated because of the potential effect heat may have on the flavor chemical. The objective was to develop a thermal degradation technique to screen flavor chemicals as part of a toxicological testing program for their potential use in ENDS formulations. Based upon published data for acetaldehyde, acrolein, and glycidol from ENDS products (common thermal degradants of propylene glycol and glycerin), the pyrolizer temperature was adjusted until a similar ratio of acetaldehyde, acrolein, and glycidol was obtained from a 60/40 ratio (v/v) of glycerin/propylene glycol via GC/MS analysis. For each of 90 flavor chemicals, quantitative measurements of acetaldehyde, acrolein, and glycidol, in addition to semiquantitative non-targeted analysis tentatively identifying chemicals from thermal degradation, were obtained. Twenty flavor chemicals transferred at greater than 99% intact, another 26 transferred at greater than 95% intact, and another 15 flavor chemicals transferred at greater than 90% intact. Most flavor chemicals resulted in fewer than 10-12 tentatively identified thermal degradants. The practical approach to the thermal degradation of flavor chemicals provided useful information as part of the toxicological evaluation of flavor chemicals for potential use in ENDS formulations.
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11
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Wu S, Kim E, Zhao R. Acetal Formation of Flavoring Agents with Propylene Glycol in E-Cigarettes: Impacts on Indoor Partitioning and Thirdhand Exposure. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:21284-21294. [PMID: 38065550 DOI: 10.1021/acs.est.3c08514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
The widespread use of flavored e-cigarettes has led to a significant rise in teenage nicotine use. In e-liquids, the flavor carbonyls can form acetals with unknown chemical and toxicological properties. These acetals can cause adverse health effects on both smokers and nonsmokers through thirdhand exposure. This study aims to explore the impacts of these acetals formed in e-cigarettes on indoor partitioning and thirdhand exposure. Specifically, the acetalization reactions of commonly used flavor carbonyls in laboratory-made e-liquids were monitored using proton nuclear magnetic resonance (1H NMR) spectroscopy. EAS-E Suite and polyparameter linear free energy relationships (PP-LFERs) were employed to estimate the partitioning coefficients for species. Further, a chemical two-dimensional partitioning model was applied to visualize the indoor equilibrium partitioning and estimate the distribution of flavor carbonyls and their acetals in the gas phase, aerosol phase, and surface reservoirs. Our results demonstrate that a substantial fraction of carbonyls were converted into acetals in e-liquids and their chemical partitioning was significantly influenced. This study shows that acetalization is a determinant factor in the exposure and toxicology of harmful carbonyl flavorings, with its impact extending to both direct exposure to smokers and involuntary exposure to nonsmokers.
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Affiliation(s)
- Shuang Wu
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Erica Kim
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Ran Zhao
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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12
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Strongin RM, Sharma E, Erythropel HC, El-Hellani A, Kassem NOF, Mikheev VB, Noël A, Peyton DH, Springer ML. Emerging ENDS products and challenges in tobacco control toxicity research. Tob Control 2023; 33:110-115. [PMID: 35715171 PMCID: PMC9758272 DOI: 10.1136/tobaccocontrol-2022-057268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 06/03/2022] [Indexed: 11/04/2022]
Abstract
Electronic nicotine delivery systems (ENDS) continue to rapidly evolve. Current products pose unique challenges and opportunities for researchers and regulators. This commentary aims to highlight research gaps, particularly in toxicity research, and provide guidance on priority research questions for the tobacco regulatory community. Disposable flavoured ENDS have become the most popular device class among youth and may contain higher nicotine levels than JUUL devices. They also exhibit enhanced harmful and potentially harmful constituents production, contain elevated levels of synthetic coolants and pose environmental concerns. Synthetic nicotine and flavour capsules are innovations that have recently enabled the circumvention of Food and Drug Administration oversight. Coil-less ENDS offer the promise of delivering fewer toxicants due to the absence of heating coils, but initial studies show that these products exhibit similar toxicological profiles compared with JUULs. Each of these topic areas requires further research to understand and mitigate their impact on human health, especially their risks to young users.
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Affiliation(s)
| | - Eva Sharma
- Behavioral Health and Health Policy, Westat, Rockville, Maryland, USA
| | - Hanno C Erythropel
- Chemical and Environmental Engineering, Yale University, New Haven, Connecticut, USA
| | - Ahmad El-Hellani
- Center for Tobacco Research and the Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, Ohio, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Nada O F Kassem
- Division of Health Promotion and Behavioral Science, San Diego State University Research Foundation, San Diego, California, USA
| | - Vladimir B Mikheev
- Battelle Public Health Center for Tobacco Research, Battelle Memorial Institute, Columbus, Ohio, USA
| | - Alexandra Noël
- Department of Comparative Biomedical Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - David H Peyton
- Chemistry, Portland State University, Portland, Oregon, USA
| | - Matthew L Springer
- Division of Cardiology, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
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13
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Niu J, Zhu J. Thermal reaction products and formation pathways of two monoterpenes under in situ thermal desorption conditions that mimic vaping coil temperatures. Sci Rep 2023; 13:21650. [PMID: 38066090 PMCID: PMC10709557 DOI: 10.1038/s41598-023-49174-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 12/05/2023] [Indexed: 12/18/2023] Open
Abstract
Vaping has become more popular and different brands and types of vaping devices have rapidly emerged. However, little is known about the potential health risks of human inhalation exposures to the volatile chemicals in the vapour, which includes both directly vaporised components of vaping liquid and their reaction products formed during vaping processes. This study investigated reaction products of two monoterpenes (α-pinene and terpinolene) that are used as flavouring agents in vaping liquids with a focus on the identification of reaction products and their formation pathways. The thermal desorption was conducted under an in situ condition that is in the range of heating coil temperature in vaping by thermally desorbing the chemicals at a temperature range of 100-300 °C. Additional clean air was introduced during the thermal desorption. 36 and 29 reaction products were identified from α-pinene and terpinolene, respectively, at a relative concentration of 0.01% and greater in the desorbed mixture. 3-Carene was the dominant reaction product of α-pinene, while reaction products of terpinolene was dominated by p-isopropenyltoluene. Several reaction pathways including ring opening, allylic oxidation, cyclo-etherification, Wagner-Meerwein rearrangement, epoxidation, cleavage and removal of partial structure, and dehydration were involved in the formation of various reaction products. These pathways and resulting relative concentrations of residual parent compound and reaction products were influenced by both temperature and amount of air present during thermal desorption. The study results demonstrate possible existence of reaction products from thermally labile chemicals like monoterpenes in vaping aerosols and can help inform policies regulating vaping devices and products to protect public health.
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Affiliation(s)
- Jianjun Niu
- Exposure and Biomonitoring Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa, Canada
| | - Jiping Zhu
- Exposure and Biomonitoring Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa, Canada.
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14
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Deng H, Tang S, Yang F, Chen D, Bian Z, Wang Y, Tang G, Lee HK. Recent advances in the analysis of electronic cigarette liquids and aerosols: Sample preparation and chromatographic characterization. J Chromatogr A 2023; 1712:464495. [PMID: 37952386 DOI: 10.1016/j.chroma.2023.464495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/21/2023] [Accepted: 11/06/2023] [Indexed: 11/14/2023]
Abstract
Electronic cigarette (e-cigarette) usage has risen dramatically worldwide in recent years. It has been publicized as a safer alternative to the conventional combustible cigarette. This, however, has not yet been supported by robust toxicological research evidence. Analysis of the chemical compositions of e-liquids and generated aerosols is an important step in evaluating the toxicity effects of e-cigarettes. Currently, a broad spectrum of analytical methods have been employed for qualitative and quantitative analysis of chemical compositions of e-cigarette liquids and aerosols. The aim of this article is to review the advances in the chromatographic characterization of chemical composition of the latter in the recent five years. In addition, sample preparation methods for e-liquids and aerosols are surveyed and discussed. A study of the relevant literature indicates that, expectedly, gas chromatography and liquid chromatography with a variety of detection systems, particularly mass spectrometry, have been the main analytical techniques used in this field. Sample preparation procedures primarily include headspace sampling, dilute-and-shoot approach, liquid-liquid extraction and sorbent-based extraction for e-liquids and for aerosols (the latter usually with laboratory-built collection devices). Some challenges of current e-cigarette analytical research, and an overview on prospective work are also presented.
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Affiliation(s)
- Huimin Deng
- China National Tobacco Quality Supervision and Test Center, High and New Technology Industries Development Zone, No.6 Cuizhu Street, Zhengzhou 450001, China
| | - Sheng Tang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu Province 212003, China
| | - Fei Yang
- China National Tobacco Quality Supervision and Test Center, High and New Technology Industries Development Zone, No.6 Cuizhu Street, Zhengzhou 450001, China
| | - Dan Chen
- Yunnan Institute of Tobacco Quality Inspection & Supervision, Kunming 650106, China; School of Materials Science and Engineering, Peking University, Beijing 100871, China
| | - Zhaoyang Bian
- China National Tobacco Quality Supervision and Test Center, High and New Technology Industries Development Zone, No.6 Cuizhu Street, Zhengzhou 450001, China
| | - Ying Wang
- China National Tobacco Quality Supervision and Test Center, High and New Technology Industries Development Zone, No.6 Cuizhu Street, Zhengzhou 450001, China
| | - Gangling Tang
- China National Tobacco Quality Supervision and Test Center, High and New Technology Industries Development Zone, No.6 Cuizhu Street, Zhengzhou 450001, China.
| | - Hian Kee Lee
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu Province 212003, China; Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
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15
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Pinkston R, Penn AL, Noël A. Increased oxidative stress responses in murine macrophages exposed at the air-liquid interface to third- and fourth-generation electronic nicotine delivery system (ENDS) aerosols. Toxicol Rep 2023; 11:40-57. [PMID: 37405056 PMCID: PMC10315815 DOI: 10.1016/j.toxrep.2023.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 06/06/2023] [Accepted: 06/14/2023] [Indexed: 07/06/2023] Open
Abstract
Background New fourth generation electronic nicotine delivery system (ENDS) devices contain high levels of nicotine salt (up to 60 mg/mL), whose cellular and molecular effects on immune cells are currently unknown. Here, we used a physiologically-relevant in vitro air-liquid interface (ALI) exposure model to assess the toxicity of distinct ENDS, a 3rd-generation electronic-cigarette (e-cig) and two 4th-generation ENDS devices (JUUL and Posh Plus). Methods Murine macrophages (RAW 264.7) were exposed at the ALI to either air, Menthol or Crème Brûlée-flavored ENDS aerosols generated from those devices for 1-hour per day for 1 or 3 consecutive days. Cellular and molecular toxicity was evaluated 24 h post-exposure. Results 1-day of Menthol-flavored JUUL aerosol exposure significantly decreased cell viability and significantly increased lactate dehydrogenase (LDH) levels compared to air controls. Further, JUUL Menthol elicited significantly increased reactive oxygen species (ROS) and nitric oxide (NO) production compared to air controls. Posh Crème Brûlée-flavored aerosols displayed significant cytotoxicity - decreased cell viability and increased LDH levels -after 1- and 3-day exposures, while the Crème Brûlée-flavored aerosol produced by the 3rd-generation e-cig device only displayed significant cytotoxicity after 3 days compared to air controls. Further, both Posh and third-generation e-cig Crème Brûlée flavored-aerosols elicited significantly increased ROS plus high levels of 8-isoprostane after 1 and 3 days compared to air controls, indicating increased oxidative stress. Posh and third-generation e-cig Crème Brûlée flavored-aerosols elicited reduction in NO levels after one day, but elicited increase in NO after 3 days. Genes in common dysregulated by both devices after 1 day included α7nAChR, Cyp1a1, Ahr, Mmp12, and iNos. Conclusion Our results suggest that ENDS Menthol and Crème Brûlée-flavored aerosol exposures from both 3rd- and 4th-generation ENDS devices are cytotoxic to macrophages and cause oxidative stress. This can translate into macrophage dysfunction. Although 4th-generation disposable ENDS devices have no adjustable operational settings and are considered low-powered ENDS devices, their aerosols can induce cellular toxicity compared to air-exposed control cells. This study provides scientific evidence for regulation of nicotine salt-based disposable ENDS products.
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Affiliation(s)
- Rakeysha Pinkston
- Department of Environmental Toxicology, Southern University and A & M College, Baton Rouge, LA 70813, USA
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, 1909 Skip Bertman Drive, Baton Rouge, LA 70803, USA
| | - Arthur L Penn
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, 1909 Skip Bertman Drive, Baton Rouge, LA 70803, USA
| | - Alexandra Noël
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, 1909 Skip Bertman Drive, Baton Rouge, LA 70803, USA
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16
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Sahu R, Shah K, Malviya R, Paliwal D, Sagar S, Singh S, Prajapati BG, Bhattacharya S. E-Cigarettes and Associated Health Risks: An Update on Cancer Potential. Adv Respir Med 2023; 91:516-531. [PMID: 37987300 PMCID: PMC10660480 DOI: 10.3390/arm91060038] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/03/2023] [Accepted: 11/08/2023] [Indexed: 11/22/2023]
Abstract
The potential cancer risk associated with electronic-cigarette (e-cigarette) use is ongoing and remains a subject of debate. E-Cigarettes work by heating a liquid that usually contains nicotine, flavorings, and other chemicals. When the liquid is heated, users inhale an aerosol into their lungs. While e-cigarettes are generally considered less harmful than traditional tobacco products, they still contain potentially harmful chemicals, which can damage DNA and lead to cancer. Several studies have investigated the potential cancer risk associated with e-cigarette use, while other studies have suggested that e-cigarette aerosol may contain carcinogenic chemicals that could increase the risk of lung and bladder cancer in humans. However, these studies are limited in their scope and do not provide conclusive evidence. Overall, the long-term cancer risk associated with e-cigarette use remains uncertain, more research is needed to fully understand the potential risks and benefits of e-cigarettes. However, this review will allow the investigator to get more recent updates about e-cigarettes.
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Affiliation(s)
- Rakesh Sahu
- Department of Pharmacy, School of Medical and Allied Sciences, Galgotias University, Greater Noida 201310, India; (R.M.); (D.P.); (S.S.)
- Department of Pharmaceutical Chemistry, Institute of Pharmaceutical Research, GLA University, Mathura 281406, India;
| | - Kamal Shah
- Department of Pharmaceutical Chemistry, Institute of Pharmaceutical Research, GLA University, Mathura 281406, India;
| | - Rishabha Malviya
- Department of Pharmacy, School of Medical and Allied Sciences, Galgotias University, Greater Noida 201310, India; (R.M.); (D.P.); (S.S.)
| | - Deepika Paliwal
- Department of Pharmacy, School of Medical and Allied Sciences, Galgotias University, Greater Noida 201310, India; (R.M.); (D.P.); (S.S.)
| | - Sakshi Sagar
- Department of Pharmacy, School of Medical and Allied Sciences, Galgotias University, Greater Noida 201310, India; (R.M.); (D.P.); (S.S.)
| | - Sudarshan Singh
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Bhupendra G. Prajapati
- Shree S. K. Patel College of Pharmaceutical Education and Research, Ganpat University, Kherva 384012, India
| | - Sankha Bhattacharya
- Department of Pharmaceutics, School of Pharmacy & Technology Management, SVKM’S NMIMS Deemed-to-Be University, Shirpur 425405, India;
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17
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Sachdeva J, Karunananthan A, Shi J, Dai W, Kleinman MT, Herman D, Kloner RA. Flavoring Agents in E-cigarette Liquids: A Comprehensive Analysis of Multiple Health Risks. Cureus 2023; 15:e48995. [PMID: 38111420 PMCID: PMC10726647 DOI: 10.7759/cureus.48995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2023] [Indexed: 12/20/2023] Open
Abstract
The availability of a wide range of flavored e-cigarettes is one of the primary reasons for vaping initiation and persistent use among adolescents and young people. This plethora of flavors available on the market are crafted using different flavoring agents such as cinnamaldehyde, vanillin, benzaldehyde, ethyl maltol, menthol, and dimethylpyrazine. Recent studies have brought to light the potential risks associated with e-cigarette flavoring agents and their effects on various organ systems, both with and without nicotine. Research has demonstrated that flavoring agents can induce inflammation, endothelial dysfunction, epithelial barrier disruption, oxidative stress, DNA damage, electrophysiological alterations, immunomodulatory effects, and behavioral changes, even independently of nicotine. Notably, these negative outcomes adversely affect cardiovascular system by reducing cell viability, decreasing endothelial nitric oxide synthase, nitric oxide bioavailability, soluble guanylyl cyclase activity and cyclic guanosine monophosphate accumulation, impairing endothelial proliferation and tube formation, and altering vasoreactivity resulting in vascular dysfunction. In the heart, these agents decrease parasympathetic activity, induce depolarization of resting membrane potential, loss of rhythmicity, increase isovolumic relaxation time, and change in ventricular repolarization and ventricular tachyarrhythmias. It is found that the specific response elicited by flavoring agents in different organ systems varies depending on the flavor used, the concentration of the flavoring agent, and the duration of exposure. However, the literature on the effects of flavoring agents is currently limited, emphasizing the need for more preclinical and randomized clinical trials to gain a deeper understanding and provide further evidence of the harmful effects of flavored e-cigarette use. In summary, recent research suggests that flavoring agents themselves can have detrimental effects on the body. To fully comprehend these effects, additional preclinical and clinical studies are needed to explore the risks associated with flavored e-cigarette usage.
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Affiliation(s)
- Jaspreet Sachdeva
- Cardiovascular Sciences, Huntington Medical Research Institutes, Pasadena, USA
| | | | - Jianru Shi
- Cardiovascular Sciences, Huntington Medical Research Institutes, Pasadena, USA
| | - Wangde Dai
- Cardiovascular Sciences, Huntington Medical Research Institutes, Pasadena, USA
| | - Michael T Kleinman
- Environmental and Occupational Health, College of Health Sciences, University of California, Irvine, USA
| | - David Herman
- Environmental and Occupational Health, College of Health Sciences, University of California, Irvine, USA
| | - Robert A Kloner
- Cardiovascular Sciences, Huntington Medical Research Institutes, Pasadena, USA
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18
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Leventhal AM, Tackett AP, Whitted L, Jordt SE, Jabba SV. Ice flavours and non-menthol synthetic cooling agents in e-cigarette products: a review. Tob Control 2023; 32:769-777. [PMID: 35483721 PMCID: PMC9613790 DOI: 10.1136/tobaccocontrol-2021-057073] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 04/19/2022] [Indexed: 01/21/2023]
Abstract
E-cigarettes with cooling flavours have diversified in ways that complicate tobacco control with the emergence of: (1) Ice-hybrid flavours (eg, 'Raspberry Ice') that combine cooling and fruity/sweet properties; and (2) Products containing non-menthol synthetic cooling agents (eg, Wilkinson Sword (WS), WS-3, WS-23 (termed 'koolada')). This paper reviews the background, chemistry, toxicology, marketing, user perceptions, use prevalence and policy implications of e-cigarette products with ice-hybrid flavours or non-menthol coolants. Scientific literature search supplemented with industry-generated and user-generated information found: (a) The tobacco industry has developed products containing synthetic coolants since 1974, (b) WS-3 and WS-23 are detected in mass-manufactured e-cigarettes (eg, PuffBar); (c) While safe for limited oral ingestion, inhalational toxicology and health effects from daily synthetic coolant exposure are unknown and merit scientific inquiry and attention from regulatory agencies; (d) Ice-hybrid flavours are marketed with themes incorporating fruitiness and/or coolness (eg, snow-covered raspberries); (e) WS-23/WS-3 concentrates also are sold as do-it-yourself additives, (f) Pharmacology research and user-generated and industry-generated information provide a premise to hypothesise that e-cigarette products with ice flavours or non-menthol cooling agents generate pleasant cooling sensations that mask nicotine's harshness while lacking certain aversive features of menthol-only products, (g) Adolescent and young adult use of e-cigarettes with ice-hybrid or other cooling flavours may be common and cross-sectionally associated with more frequent vaping and nicotine dependence in convenience samples. Evidence gaps in the epidemiology, toxicology, health effects and smoking cessation-promoting potential of using these products exist. E-cigarettes with ice flavours or synthetic coolants merit scientific and regulatory attention.
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Affiliation(s)
- Adam M Leventhal
- Institute for Addiction Science, University of Southern California, Los Angeles, California, USA
| | - Alayna P Tackett
- Department of Preventive Medicine, Keck School of Medicine University of Southern California, Los Angeles, California, USA
| | - Lauren Whitted
- Department of Preventive Medicine, Keck School of Medicine University of Southern California, Los Angeles, California, USA
| | - Sven Eric Jordt
- Anesthesiology, Duke University School of Medicine, Durham, North Carolina, USA
- Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Sairam V Jabba
- Anesthesiology, Duke University School of Medicine, Durham, North Carolina, USA
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19
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Augustini ALRM, Borg C, Sielemann S, Telgheder U. Making Every Single Puff Count-Simple and Sensitive E-Cigarette Aerosol Sampling for GCxIMS and GC-MS Analysis. Molecules 2023; 28:6574. [PMID: 37764350 PMCID: PMC10536117 DOI: 10.3390/molecules28186574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/31/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
The analysis of the aerosol from tobaccoless electronic cigarettes (e-cigarettes) is an important part of understanding their impact on human health, yet sampling aerosol from e-cigarettes is still considered a challenge. It lacks a standard method for research and quality control and there are a variety of methods. However, few are simple and inexpensive, and none have been suggested for the use with gas chromatography coupled ion mobility spectrometry (GCxIMS). This work presents and evaluates such a setup made from standard lab equipment to quickly collect a quantitative sample from the aerosol of a single puff (5 s totaling 125 mL). The aerosol condensates directly in the cooled headspace (HS) vial, which is analyzed in the HS-GCxIMS or mass spectrometer (HS-GC-MS). The combined use of GC-MS and GCxIMS allows the simple and sensitive identification of unknown substances in complex mixtures and the identification of degradation products in the aerosols. A calibration of 26 flavor compounds (0.2-20 µg/g) was created using single puffs of a spiked, flavorless commercial refill solution and 2-alkanones as internal standards. This sensitive but easily reproducible setup enables a wide range of further investigations, even for labs that were previously unable to afford it.
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Affiliation(s)
- Alexander L. R. M. Augustini
- Department Hamm 2, Hamm-Lippstadt University of Applied Sciences, Marker Allee 76-78, 59063 Hamm, Germany; (A.L.R.M.A.)
- Faculty of Chemistry, Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany
| | - Christopher Borg
- Department Hamm 2, Hamm-Lippstadt University of Applied Sciences, Marker Allee 76-78, 59063 Hamm, Germany; (A.L.R.M.A.)
| | - Stefanie Sielemann
- Department Hamm 2, Hamm-Lippstadt University of Applied Sciences, Marker Allee 76-78, 59063 Hamm, Germany; (A.L.R.M.A.)
| | - Ursula Telgheder
- Faculty of Chemistry, Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany
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20
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Soule EK, Sousan S, Pender J, Thomas L, Gold E, Fresquez S, Mooring R, Coombs V, Gogineni A, Tiet A. Secondhand electronic cigarette aerosol in vehicles impacts indoor air quality. Drug Alcohol Depend 2023; 250:110889. [PMID: 37478503 PMCID: PMC10528711 DOI: 10.1016/j.drugalcdep.2023.110889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 06/26/2023] [Accepted: 07/04/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND Electronic cigarette (ECIG) use in vehicles represents a public health concern due to the potential for exposure to high concentrations of particulate matter (PM) and other toxicants. This study examined the impact of ECIG use on air quality in vehicles. METHODS People who reported current ECIG use (n=60; mean age=20.5, SD=2.3) completed a brief survey and a 30-min ECIG use session in their own vehicle. Using a protocol similar to clinical laboratory studies involving tobacco use, participants took 10 directed puffs (i.e., a directed bout with one puff every 30s for 5min) followed by a 25-min ad libitum period in which participants took as many puffs as desired. PM 2.5µm in diameter or smaller (PM2.5) were measured using aerosol monitors set up to sample air from the breathing zone of the passenger seat and total puffs were recorded. The association between peak PM2.5 concentration and puff count was examined. RESULTS Participants took a median 18 total puffs during the sessions. Median PM2.5 concentrations increased from 4.78µg/m3 at baseline to 107.40µg/m3 after the directed bout. Median peak PM2.5 concentration was 464.48µg/m3 and ranged from 9.56µg/m3 to 143,503.91µg/m3 (IQR=132.72-1604.68). After removing two extreme outliers for puff count and PM2.5 concentrations, puff count was significantly correlated with peak PM2.5 concentration during the ad libitum bout (r=0.32, p=0.015). CONCLUSIONS ECIG use in vehicles impacts air quality negatively and may pose health risks to those present in vehicles when ECIG use is occurring.
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Affiliation(s)
- Eric K Soule
- Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC27858, USA; Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, VA27858, USA.
| | - Sinan Sousan
- Department of Public Health, Brody School of Medicine, East Carolina UniversityGreenville, NC27858, USA; North Carolina Agromedicine Institute, Greenville, NC27858, USA
| | - Jack Pender
- Department of Chemistry, Thomas Harriot College of Arts & Sciences, East Carolina University, Greenville, NC27858, USA
| | - Luke Thomas
- Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC27858, USA
| | - Emily Gold
- Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC27858, USA
| | - Sarah Fresquez
- Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC27858, USA
| | - Ronald Mooring
- Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC27858, USA
| | - Vivien Coombs
- Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC27858, USA
| | - Anish Gogineni
- Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC27858, USA
| | - Alex Tiet
- Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC27858, USA
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21
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Rose JJ, Krishnan-Sarin S, Exil VJ, Hamburg NM, Fetterman JL, Ichinose F, Perez-Pinzon MA, Rezk-Hanna M, Williamson E. Cardiopulmonary Impact of Electronic Cigarettes and Vaping Products: A Scientific Statement From the American Heart Association. Circulation 2023; 148:703-728. [PMID: 37458106 DOI: 10.1161/cir.0000000000001160] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Vaping and electronic cigarette (e-cigarette) use have grown exponentially in the past decade, particularly among youth and young adults. Cigarette smoking is a risk factor for both cardiovascular and pulmonary disease. Because of their more limited ingredients and the absence of combustion, e-cigarettes and vaping products are often touted as safer alternative and potential tobacco-cessation products. The outbreak of e-cigarette or vaping product use-associated lung injury in the United States in 2019, which led to >2800 hospitalizations, highlighted the risks of e-cigarettes and vaping products. Currently, all e-cigarettes are regulated as tobacco products and thus do not undergo the premarket animal and human safety studies required of a drug product or medical device. Because youth prevalence of e-cigarette and vaping product use was as high as 27.5% in high school students in 2019 in the United States, it is critical to assess the short-term and long-term health effects of these products, as well as the development of interventional and public health efforts to reduce youth use. The objectives of this scientific statement are (1) to describe and discuss e-cigarettes and vaping products use patterns among youth and adults; (2) to identify harmful and potentially harmful constituents in vaping aerosols; (3) to critically assess the molecular, animal, and clinical evidence on the acute and chronic cardiovascular and pulmonary risks of e-cigarette and vaping products use; (4) to describe the current evidence of e-cigarettes and vaping products as potential tobacco-cessation products; and (5) to summarize current public health and regulatory efforts of e-cigarettes and vaping products. It is timely, therefore, to review the short-term and especially the long-term implications of e-cigarettes and vaping products on cardiopulmonary health. Early molecular and clinical evidence suggests various acute physiological effects from electronic nicotine delivery systems, particularly those containing nicotine. Additional clinical and animal-exposure model research is critically needed as the use of these products continues to grow.
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22
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Klupinski TP, Strozier ED, Koebel DD, Lucas EA. Detection of the Synthetic Coolant Menthone 1,2-Glycerol Ketal in an e-Liquid and in Electronic Waterpipe Aerosols Therefrom. Chem Res Toxicol 2023; 36:1355-1360. [PMID: 37439580 PMCID: PMC10529952 DOI: 10.1021/acs.chemrestox.3c00089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The presence and toxicological risks of synthetic coolants in electronic nicotine delivery systems (ENDS) have not been thoroughly studied. We identified the synthetic coolant menthone 1,2-glycerol ketal (MGK) in a menthol-flavored e-liquid at a concentration of ∼170 μg/mL. We also detected MGK in aerosols resulting from heating the e-liquid with an electronic waterpipe. MGK was initially detected in the e-liquid by two-dimensional gas chromatography-time-of-flight mass spectrometry. To avoid potential analytical artifacts that could result from heating samples in the injection port of the gas chromatograph, quantitation of MGK in the e-liquid was accomplished using a liquid chromatography-tandem mass spectrometry method. Following recent reports identifying other synthetic coolants in e-liquids, these results add knowledge about inhalation exposures from ENDS use and suggest the importance of future research to study the potential inhalation toxicity related to the use of MGK-containing e-liquids in ENDS devices. Furthermore, the results demonstrate the ability to quantify ketals in e-liquids using liquid chromatography methods.
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Affiliation(s)
| | | | - David D Koebel
- Battelle, 505 King Ave., Columbus, Ohio 43201, United States
| | - Eric A Lucas
- Battelle, 505 King Ave., Columbus, Ohio 43201, United States
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23
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Bautista M, Mogul AS, Fowler CD. Beyond the label: current evidence and future directions for the interrelationship between electronic cigarettes and mental health. Front Psychiatry 2023; 14:1134079. [PMID: 37645635 PMCID: PMC10460914 DOI: 10.3389/fpsyt.2023.1134079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 07/31/2023] [Indexed: 08/31/2023] Open
Abstract
Electronic cigarette use has dramatically increased over the last decade. With this recent technological development and wide range of constituents in various products, putative adverse effects on the brain and body have been largely unexplored. Here, we review current evidence linking electronic nicotine cigarette use with potential health consequences and provide evidence supporting an association between drug use and depression in humans. We also examine the biological effects of individual constituents in electronic cigarette aerosols, which include labeled ingredients, such as propylene glycol, vegetable glycerin, nicotine, and flavorants, as well as unlabeled ingredients found in the aerosols, such as carbonyls and heavy metals. Lastly, we examine the effects of electronic cigarette use on endogenous metabolism via changes in cytochrome P450 enzymes, which can thereby impact therapeutic outcomes. While the current evidence offers insight into the potential effects of electronic cigarette use on biological processes, further studies are necessary to determine the long-term clinical relevance of aerosol inhalation.
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Affiliation(s)
| | | | - Christie D. Fowler
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
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Soule EK, Sousan S, Pender J, Thomas A, Patel N. Electronic cigarette use and cigarette smoking in vehicles among adults who use electronic cigarettes and cigarettes in the USA. Tob Control 2023:tc-2022-057898. [PMID: 37451861 PMCID: PMC10787805 DOI: 10.1136/tc-2022-057898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 06/28/2023] [Indexed: 07/18/2023]
Affiliation(s)
- Eric K Soule
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
- Center for the Study of Tobacco Products, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Sinan Sousan
- Department of Public Health, East Carolina University, Greenville, North Carolina, USA
- North Carolina Agromedicine Institute, Greenville, North Carolina, USA
| | - Jack Pender
- Department of Chemistry, East Carolina University, Greenville, North Carolina, USA
| | - Alisha Thomas
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
| | - Neal Patel
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
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Jabba SV, Erythropel HC, Woodrow JG, Anastas PT, O'Malley S, Krishnan-Sarin S, Zimmerman JB, Jordt SE. Synthetic cooling agent in oral nicotine pouch products marketed as 'Flavour-Ban Approved'. Tob Control 2023:tc-2023-058035. [PMID: 37380351 PMCID: PMC10753027 DOI: 10.1136/tc-2023-058035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 06/09/2023] [Indexed: 06/30/2023]
Abstract
BACKGROUND US sales of oral nicotine pouches (ONPs) have rapidly increased, with cool/mint-flavoured ONPs the most popular flavour category. Restrictions on sales of flavoured tobacco products have either been implemented or proposed by several US states and localities. Zyn, the most popular ONP brand, is marketing Zyn Chill and Zyn Smooth as 'Flavour-Ban Approved' or 'unflavoured', probably to evade flavour bans and increase product appeal. At present, it is unclear whether these ONPs are indeed free of flavour additives that can impart pleasant sensations such as cooling. METHODS Sensory cooling and irritant activities of 'Flavour-Ban Approved' Zyn ONPs, Chill and Smooth, along with minty varieties (Cool Mint, Peppermint, Spearmint, Menthol), were analysed by Ca2+ microfluorimetry in HEK293 cells expressing the cold/menthol (TRPM8) or menthol/irritant receptor (TRPA1). Flavour chemical content of these ONPs was analysed by gas chromatography/mass spectrometry. RESULTS Zyn Chill ONP extracts robustly activated TRPM8, with much higher efficacy (39%-53%) than the mint-flavoured ONPs. In contrast, mint-flavoured ONP extracts elicited stronger TRPA1 irritant receptor responses than Chill extracts. Chemical analysis demonstrated that Chill exclusively contained WS-3, an odourless synthetic cooling agent, while mint-flavoured ONPs contained WS-3 together with mint flavourants. CONCLUSIONS ONP products marketed as 'Flavour-Ban Approved' or 'unflavoured' contain flavouring agents, proving that the manufacturer's advertising is misleading. Synthetic coolants such as WS-3 can provide a robust cooling sensation with reduced sensory irritancy, thereby increasing product appeal and use. Regulators need to develop effective strategies for the control of odourless sensory additives used by the industry to bypass flavour bans.
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Affiliation(s)
- Sairam V Jabba
- Department of Anesthesiology, Duke University School of Medicine, Durham, North Carolina, USA
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Hanno C Erythropel
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Chemical and Environmental Engineering, Yale University, New Haven, Connecticut, USA
| | | | - Paul T Anastas
- Center for Green Chemistry & Green Engineering, Yale University, New Haven, Connecticut, USA
- Department of Forestry and Environmental Studies, Yale University, New Haven, Connecticut, USA
| | - Stephanie O'Malley
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Suchitra Krishnan-Sarin
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Julie B Zimmerman
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Chemical and Environmental Engineering, Yale University, New Haven, Connecticut, USA
| | - Sven Eric Jordt
- Department of Anesthesiology, Duke University School of Medicine, Durham, North Carolina, USA
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
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Golpe MC, Ramil M, Rodríguez I. Comprehensive characterization of volatile and semi-volatile compounds in e-liquids for electronic cigarette using gas chromatography accurate mass spectrometry. J Chromatogr A 2023; 1703:464114. [PMID: 37269573 DOI: 10.1016/j.chroma.2023.464114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/16/2023] [Accepted: 05/28/2023] [Indexed: 06/05/2023]
Abstract
The consumption of electronic cigarettes is a habit with an increasing prevalence, particularly among youths. Knowing the composition of e-liquids used in these devices represents the first step to understand the potential impact of e-smoking in the health of consumers. Herein, a non-target screening methodology was applied to the identification of volatile and semi-volatile compounds in a set of e-liquids from different suppliers, with different flavors, and containing different kinds of additives, such as nicotine or cannabidiol. To this end, samples were characterized by gas chromatography accurate mass spectrometry, using a time-of-flight mass analyzer. Combination of deconvoluted electronic ionization mass spectra with linear retention index values, obtained for two columns with different selectivity, permitted the identification of more than 250 chemicals with different confidence levels. Among them, respiratory pro-inflammatory compounds, acetals of propylene glycol and glycerin with aldehydes, nicotine-related and non-related alkaloids, and psychoactive cannabinoids were confirmed as concerning compounds in e-liquid samples. Concentration ratios between propylene glycol acetals and parent aldehydes varied in the range from 2% (ethyl vanillin) to more than 80% (case of benzaldehyde). The ratios between the concentrations of delta-9-tetrahydrocannabinol and cannabidiol in e-liquids stayed in the range from 0.02% to 0.3%.
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Affiliation(s)
- M Cobo Golpe
- Department of Analytical Chemistry, Nutrition and Food Sciences. Research Institute on Chemical and Biological Analysis (IAQBUS). Universidade de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - M Ramil
- Department of Analytical Chemistry, Nutrition and Food Sciences. Research Institute on Chemical and Biological Analysis (IAQBUS). Universidade de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - I Rodríguez
- Department of Analytical Chemistry, Nutrition and Food Sciences. Research Institute on Chemical and Biological Analysis (IAQBUS). Universidade de Santiago de Compostela, 15782-Santiago de Compostela, Spain.
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Tommasi S, Blumenfeld H, Besaratinia A. Vaping Dose, Device Type, and E-Liquid Flavor are Determinants of DNA Damage in Electronic Cigarette Users. Nicotine Tob Res 2023; 25:1145-1154. [PMID: 36780924 PMCID: PMC10202635 DOI: 10.1093/ntr/ntad003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/26/2022] [Accepted: 01/05/2023] [Indexed: 02/15/2023]
Abstract
INTRODUCTION Despite the widespread use of electronic cigarettes, the long-term health consequences of vaping are largely unknown. AIMS AND METHODS We investigated the DNA-damaging effects of vaping as compared to smoking in healthy adults, including "exclusive" vapers (never smokers), cigarette smokers only, and nonusers, matched for age, gender, and race (N = 72). Following biochemical verification of vaping or smoking status, we quantified DNA damage in oral epithelial cells of our study subjects, using a long-amplicon quantitative polymerase chain reaction assay. RESULTS We detected significantly increased levels of DNA damage in both vapers and smokers as compared to nonusers (p = .005 and p = .020, respectively). While the mean levels of DNA damage did not differ significantly between vapers and smokers (p = .522), damage levels increased dose-dependently, from light users to heavy users, in both vapers and smokers as compared to nonusers. Among vapers, pod users followed by mod users, and those who used sweet-, mint or menthol-, and fruit-flavored e-liquids, respectively, showed the highest levels of DNA damage. The nicotine content of e-liquid was not a predictor of DNA damage in vapers. CONCLUSIONS This is the first demonstration of a dose-dependent formation of DNA damage in vapers who had never smoked cigarettes. Our data support a role for product characteristics, specifically device type and e-liquid flavor, in the induction of DNA damage in vapers. Given the popularity of pod and mod devices and the preferability of sweet-, mint or menthol-, and fruit-flavored e-liquids by both adult- and youth vapers, our findings can have significant implications for public health and tobacco products regulation. IMPLICATIONS We demonstrate a dose-dependent formation of DNA damage in oral cells from vapers who had never smoked tobacco cigarettes as well as exclusive cigarette smokers. Device type and e-liquid flavor determine the extent of DNA damage detected in vapers. Users of pod devices followed by mod users, and those who use sweet-, mint or menthol-, and fruit-flavored e-liquids, respectively, show the highest levels of DNA damage when compared to nonusers. Given the popularity of pod and mod devices and the preferability of these same flavors of e-liquid by both adult- and youth vapers, our findings can have significant implications for public health and tobacco products regulation.
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Affiliation(s)
- Stella Tommasi
- Department of Population and Public Health Sciences, USC Keck School of Medicine, University of Southern California, M/C 9603, Los Angeles, CA 90033, USA
| | - Hannah Blumenfeld
- Department of Population and Public Health Sciences, USC Keck School of Medicine, University of Southern California, M/C 9603, Los Angeles, CA 90033, USA
| | - Ahmad Besaratinia
- Department of Population and Public Health Sciences, USC Keck School of Medicine, University of Southern California, M/C 9603, Los Angeles, CA 90033, USA
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Jabba SV, Erythropel HC, Anastas PT, Zimmerman JB, Jordt SE. Synthetic Cooling Agent and Candy Flavors in California-marketed "non-Menthol" Cigarettes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.15.540890. [PMID: 37292602 PMCID: PMC10245676 DOI: 10.1101/2023.05.15.540890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
RATIONALE The ban of menthol cigarettes is one of the key strategies to promote smoking cessation in the United States. Menthol cigarettes are preferred by young beginning smokers for smoking initiation. Almost 90% of African American smokers use menthol cigarettes, a result of decades-long targeted industry marketing. Several states and municipalities already banned menthol cigarettes, most recently California, effective on December 21, 2022. In the weeks before California's ban took effect, the tobacco industry introduced several "non-menthol" cigarette products in California, replacing previously mentholated brands. Here, we hypothesize that tobacco companies replaced menthol with synthetic cooling agents to create a cooling effect without using menthol. Similar to menthol, these agents activate the TRPM8 cold-menthol receptor in sensory neurons innervating the upper and lower airways. METHODS Calcium microfluorimetry in HEK293t cells expressing the TRPM8 cold/menthol receptors was used to determine sensory cooling activity of extracts prepared from these "non-menthol" cigarette brands, and compared to standard menthol cigarette extracts of the same brands. Specificity of receptor activity was validated using TRPM8-selective inhibitor, AMTB. Gas chromatography mass spectrometry (GCMS) was used to determine presence and amounts of any flavoring chemicals, including synthetic cooling agents, in the tobacco rods, wrapping paper, filters and crushable capsule (if present) of these "non-menthol" cigarettes. RESULTS Compared to equivalent menthol cigarette extracts, several California-marketed "non-menthol" cigarette extracts activated cold/menthol receptor TRPM8 at higher dilutions and with stronger efficacies, indicating substantial pharmacological activity to elicit robust cooling sensations. Synthetic cooling agent, WS-3, was detected in tobacco rods of several of these "non-menthol" cigarette brands. Crushable capsules added to certain "non-menthol" crush varieties contained neither WS-3 nor menthol but included several "sweet" flavorant chemicals, including vanillin, ethyl vanillin and anethole. CONCLUSION Tobacco companies have replaced menthol with the synthetic cooling agent, WS-3, in California-marketed "non-menthol" cigarettes. WS-3 creates a cooling sensation similar to menthol, but lacks menthol's characteristic "minty" odor. The measured WS-3 content is sufficient to elicit cooling sensations in smokers, similar to menthol, that facilitate smoking initiation and act as a reinforcing cue. Regulators need to act quickly to prevent the tobacco industry from bypassing menthol bans by substituting menthol with synthetic cooling agents, and thereby thwarting smoking cessation efforts.
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Kosarac I, Katuri GP, Kubwabo C, Siddique S, Mischki TK. Quantitation and Stability of Nicotine in Canadian Vaping Liquids. TOXICS 2023; 11:378. [PMID: 37112605 PMCID: PMC10144332 DOI: 10.3390/toxics11040378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/05/2023] [Accepted: 04/14/2023] [Indexed: 06/19/2023]
Abstract
Electronic cigarettes (e-cigarettes, vaping products) have become increasingly popular, with recent increases in use associated with closed systems delivering higher concentrations of nicotine. Most vaping products designed as an alternative to combustible cigarettes contain nicotine. A number of published studies have examined the reported concentrations of nicotine in vaping liquids (e-liquids) and found discrepancies between labelled and measured levels. Some discrepancy can also be explained by the lack of stability of nicotine in these types of products. Recently, a chemical analysis method for the quantitative determination of low and high levels of nicotine in vaping liquids was developed. This method uses dilution with acetonitrile prior to analysis with gas chromatograph mass spectrometry (GC-MS) in single ion monitoring mode (SIM). The developed method was validated using a laboratory-prepared vaping liquid as well as commercially available, nicotine-free products fortified with nicotine in the laboratory. The method detection limit (MDL) and the limit of quantitation (LOQ) for nicotine were calculated to be 0.002 mg/mL and 0.006 mg/mL, respectively. The newly developed method was applied to quantify nicotine in commercially available vaping liquids of various flavour profiles and across a wide range of nicotine concentrations, including those with nicotine salts. Furthermore, a subset of vaping liquids were analyzed to elucidate nicotine stability in various product subtypes. After a period of six months of accelerated storage to mimic one year, the overall mean percent of the original nicotine concentration remaining in the salt-based vaping products was 85% (minimum 64%, maximum 99%) while in the free-base nicotine products it was 74% (minimum 31%, maximum 106%). Nicotine stability in vaping liquids was found to be influenced by the nicotine form (pH) of formulation and its chemical composition. Non-targeted, qualitative analysis of chemical composition of vaping products showed that most constituents were identified and found to be remaining in the products following stability trials; however, three new compounds were tentatively identified in some vaping liquids at the end of the stability trials. Stability studies and the accurate quantitation of nicotine in vaping products can help inform product standards related to the safety, quality and utility of vaping products as a smoking cessation tool.
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Affiliation(s)
- Ivana Kosarac
- Tobacco Control Directorate, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Guru P. Katuri
- Tobacco Control Directorate, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Cariton Kubwabo
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Shabana Siddique
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Trevor K. Mischki
- Tobacco Control Directorate, Health Canada, Ottawa, ON K1A 0K9, Canada
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Zhang H, Cui H, Xia X, Zhang F, Hayat K, Zhang X, Ho CT. Controlled Selective Formation of Amadori Compounds from α/ε Mono- or Di-glycation of Lysine with Xylose. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:5358-5371. [PMID: 36944085 DOI: 10.1021/acs.jafc.3c00388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Three Amadori rearrangement products (Xyl-α-Lys-ARP, Xyl-ε-Lys-ARP, and diXyl-α,ε-Lys-ARP) were observed in the xylose-lysine (Xyl-Lys) Maillard reaction model. They were separated and characterized by liquid chromatography with tandem mass spectrometry and NMR. The crucial roles of reaction temperature, pH, molar ratio of Xyl to Lys, and reaction time in the formation of different Xyl-Lys-ARPs were investigated. The proportion of Xyl-α-Lys-ARP among all Xyl-Lys-ARPs was increased to 48.41% (its concentration was 25.31 μmol/mL) after the reaction at pH = 5.5 and a molar ratio of 3:1 (Xyl: Lys) for 9 min, while only Xyl-ε-Lys-ARP was generated at a higher pH (7.5) and a lower molar ratio of 1:5. Moreover, the much higher activation energy (84.08 kJ/mol) of diXyl-α,ε-Lys-ARP than Xyl-α-Lys-ARP (34.19 kJ/mol) and Xyl-ε-Lys-ARP (32.32 kJ/mol) indicated a pronounced promoting effect on diXyl-α,ε-Lys-ARP formation by high temperatures. A complete conversion from Xyl-α-Lys-ARP and Xyl-ε-Lys-ARP to diXyl-α,ε-Lys-ARP was achieved through the reaction time prolongation and Xyl concentration increase at a higher temperature; the concentration of diXyl-α,ε-Lys-ARP was 39.05 μmol/mL at a molar ratio of 5:1 for 40 min. Accordingly, the selective preparation of Xyl-α-Lys-ARP, Xyl-ε-Lys-ARP, and diXyl-α,ε-Lys-ARP could be achieved through adjusting the Xyl-Lys ratio, pH, and reaction time.
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Affiliation(s)
- Han Zhang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu, P. R. China
| | - Heping Cui
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu, P. R. China
| | - Xue Xia
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu, P. R. China
| | - Foxin Zhang
- Anhui QiangWang Flavouring Food Co. Ltd., Fuyang 236500, Anhui, P. R. China
| | - Khizar Hayat
- Department of Kinesiology, Nutrition, and Health, Miami University, Oxford, Ohio 45056, United States
| | - Xiaoming Zhang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu, P. R. China
| | - Chi-Tang Ho
- Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, New Jersey 08901, United States
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Synthetic Cooling Agent in Oral Nicotine Pouch Products Marketed as "Flavor-Ban Approved". BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.23.529797. [PMID: 36865160 PMCID: PMC9980044 DOI: 10.1101/2023.02.23.529797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Background US sales of oral nicotine pouches (ONPs) have rapidly increased, with cool/mint-flavored ONPs the most popular. Restrictions on sales of flavored tobacco products have either been implemented or proposed by several US states and localities. Zyn, the most popular ONP brand, is marketing Zyn-"Chill" and Zyn-"Smooth" as "Flavor-Ban Approved", probably to evade flavor bans. At present it is unclear whether these ONPs are indeed free of flavor additives that can impart pleasant sensations such as cooling. Methods Sensory cooling and irritant activities of "Flavor-Ban Approved" ONPs, Zyn-"Chill" and "Smooth", along with "minty" varieties (Cool Mint, Peppermint, Spearmint, Menthol), were analyzed by Ca2+ microfluorimetry in HEK293 cells expressing the cold/menthol (TRPM8) or menthol/irritant receptor (TRPA1). Flavor chemical content of these ONPs was analyzed by GC/MS. Results Zyn-"Chill" ONP extracts robustly activated TRPM8, with much higher efficacy (39-53%) than the mint-flavored ONPs. In contrast, mint-flavored ONP extracts elicited stronger TRPA1 irritant receptor responses than Zyn-"Chill" extracts. Chemical analysis demonstrated the presence of WS-3, an odorless synthetic cooling agent, in Zyn-"Chill" and several other mint-flavored Zyn-ONPs. Conclusions Synthetic cooling agents such as WS-3 found in 'Flavor-Ban Approved' Zyn-"Chill" can provide a robust cooling sensation with reduced sensory irritancy, thereby increasing product appeal and use. The label "Flavor-Ban Approved" is misleading and may implicate health benefits. Regulators need to develop effective strategies for the control of odorless sensory additives used by the industry to bypass flavor bans.
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Holt AK, Poklis JL, Peace MR. The history, evolution, and practice of cannabis and E-cigarette industries highlight necessary public health and public safety considerations. JOURNAL OF SAFETY RESEARCH 2023; 84:192-203. [PMID: 36868647 PMCID: PMC10829760 DOI: 10.1016/j.jsr.2022.10.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/29/2022] [Accepted: 10/25/2022] [Indexed: 06/18/2023]
Affiliation(s)
- Alaina K Holt
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, United States; Integrative Life Sciences Doctoral Program, Virginia Commonwealth University, Richmond, VA, United States.
| | - Justin L Poklis
- Department of Pharmacology & Toxicology, Virginia Commonwealth University, Richmond, VA, United States.
| | - Michelle R Peace
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, United States.
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Majid S, Weisbrod RM, Fetterman JL, Keith RJ, Rizvi SHM, Zhou Y, Behrooz L, Robertson RM, Bhatnagar A, Conklin DJ, Hamburg NM. Pod-based e-liquids impair human vascular endothelial cell function. PLoS One 2023; 18:e0280674. [PMID: 36701344 PMCID: PMC9879485 DOI: 10.1371/journal.pone.0280674] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 01/05/2023] [Indexed: 01/27/2023] Open
Abstract
Pod-based electronic (e-) cigarettes more efficiently deliver nicotine using a protonated formulation. The cardiovascular effects associated with these devices are poorly understood. We evaluated whether pod-based e-liquids and their individual components impair endothelial cell function. We isolated endothelial cells from people who are pod users (n = 10), tobacco never users (n = 7), and combustible cigarette users (n = 6). After a structured use, pod users had lower acetylcholine-mediated endothelial nitric oxide synthase (eNOS) activation compared with never users and was similar to levels from combustible cigarette users (overall P = 0.008, P = 0.01 pod vs never; P = 0.96 pod vs combustible cigarette). The effects of pod-based e-cigarettes and their constituents on vascular cell function were further studied in commercially available human aortic endothelial cells (HAECs) incubated with flavored JUUL e-liquids or propylene glycol (PG):vegetable glycerol (VG) at 30:70 ratio with or without 60 mg/mL nicotine salt for 90 min. A progressive increase in cell death with JUUL e-liquid exposure was observed across 0.0001-1% dilutions; PG:VG vehicle with and without nicotine salt induced cell death. A23187-stimulated nitric oxide production was decreased with all JUUL e-liquid flavors, PG:VG and nicotine salt exposures. Aerosols generated by JUUL e-liquid heating similarly decreased stimulated nitric oxide production. Only mint flavored e-liquids increased inflammation and menthol flavored e-liquids enhanced oxidative stress in HAECs. In conclusion, pod e-liquids and their individual components appear to impair endothelial cell function. These findings indicate the potential harm of pod-based devices on endothelial cell function and thus may be relevant to cardiovascular injury in pod type e-cigarette users.
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Affiliation(s)
- Sana Majid
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States of America
| | - Robert M. Weisbrod
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States of America
| | - Jessica L. Fetterman
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States of America
| | - Rachel J. Keith
- University of Louisville School of Medicine, Louisville, KY, United States of America
| | - Syed H. M. Rizvi
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States of America
| | - Yuxiang Zhou
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States of America
| | - Leili Behrooz
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States of America
| | | | - Aruni Bhatnagar
- University of Louisville School of Medicine, Louisville, KY, United States of America
| | - Daniel J. Conklin
- University of Louisville School of Medicine, Louisville, KY, United States of America
| | - Naomi M. Hamburg
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, United States of America
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Dempsey R, Rodrigo G, Vonmoos F, Gunduz I, Belushkin M, Esposito M. Preliminary toxicological assessment of heated tobacco products: A review of the literature and proposed strategy. Toxicol Rep 2023; 10:195-205. [PMID: 36748021 PMCID: PMC9898577 DOI: 10.1016/j.toxrep.2023.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/20/2022] [Accepted: 01/18/2023] [Indexed: 01/21/2023] Open
Abstract
Heated tobacco products (HTP) have become increasingly common in many countries worldwide. The principle of heating tobacco, without combustion, to produce a nicotine-containing aerosol with remarkably reduced levels of other known toxins, compared to combusted tobacco cigarettes, is now well established. As these products are intended as alternatives to traditional combusted products, during the early stages of their development, it is important for manufacturers to ensure that the design of the product does not lead to any unintentionally increased or new risk for the consumer, compared to the traditional products that consumers seek to replace. There is limited guidance from tobacco product regulations concerning the requirements for performing such preliminary toxicological assessments. Here, we review the published literature on studies performed on HTPs in the pursuit of such data, outline a proposed approach that is consistent with regulatory requirements, and provide a logical approach to the preliminary toxicological assessment of HTPs.
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Affiliation(s)
- Ruth Dempsey
- RD Science Speaks Consultancy Sàrl, Le Mont sur Lausanne, Switzerland,Corresponding authors.
| | - Gregory Rodrigo
- PMI R&D, Philip Morris Products S.A., Rue des Usines 56, 2000 Neuchâtel, Switzerland,Corresponding authors.
| | - Florence Vonmoos
- PMI R&D, Philip Morris Products S.A., Rue des Usines 56, 2000 Neuchâtel, Switzerland
| | - Irfan Gunduz
- PMI R&D, Philip Morris Products S.A., Rue des Usines 56, 2000 Neuchâtel, Switzerland
| | - Maxim Belushkin
- PMI R&D, Philip Morris Products S.A., Rue des Usines 56, 2000 Neuchâtel, Switzerland
| | - Marco Esposito
- PMI R&D, Philip Morris Products S.A., Rue des Usines 56, 2000 Neuchâtel, Switzerland
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35
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Gschwend G, Jenkins C, Jones A, Kelso C, Morgan J. A Wide Range of Flavoring-Carrier Fluid Adducts Form in E-Cigarette Liquids. Chem Res Toxicol 2023; 36:14-22. [PMID: 36597559 DOI: 10.1021/acs.chemrestox.2c00200] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A range of flavoring molecules are used in electronic cigarette liquids (e-liquids), some of which have been shown to form cyclic acetal adducts with e-liquid solvent components propylene glycol (PG) and vegetable glycerine (VG). The objective of this study was to identify the range of flavoring molecules which form adducts in e-liquid products. Common e-liquid flavoring molecules (N = 36) from a range of chemical class groups were exposed to PG, VG, or methanol and analyzed by GC-MS over a time frame of 4 weeks to identify possible reaction products. Adduct formation was observed, with 14 of the flavoring molecules reacting with methanol, 10 reacting with PG, and 10 reacting with VG. Furfural PG and VG acetals, valeraldehyde PG and VG acetals, veretraldehyde PG and VG acetals, p-anisaldehyde PG and VG acetals, and piperonal VG acetal were confirmed for the first time. Adducts formed by reaction with ketone-containing flavoring molecules were also observed for the first time. The presence of these acetals was confirmed in 32% of commercial e-liquid products analyzed (N = 142). This study has established a range of flavoring molecules which are able to react with solvent components PG and VG in e-liquids under standard storage conditions. These newly identified adducts need to be further assessed to determine their toxicological safety.
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Affiliation(s)
- Grace Gschwend
- School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Caitlin Jenkins
- School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Alison Jones
- School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia.,School of Public Health, University of Western Australia, Perth, WA 6907, Australia
| | - Celine Kelso
- School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia.,Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.,Molecular Horizons, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Jody Morgan
- Molecular Horizons, University of Wollongong, Wollongong, NSW 2522, Australia.,School of Chemistry, Faculty of Science, University of Sydney, Sydney, NSW 2006, Australia
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36
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Fix BV, OConnor RJ, Goniewicz ML, Leigh NL, Cummings M, Hitchman SC, Fong GT, El Nahas G, Hammond D, McNeill A, Borland R, King B, Palumbo MN. Characterisation of vaping liquids used in vaping devices across four countries: results from an analysis of selected vaping liquids reported by users in the 2016 ITC Four Country Smoking and Vaping Survey. Tob Control 2023; 32:51-59. [PMID: 34021061 PMCID: PMC9326900 DOI: 10.1136/tobaccocontrol-2020-056338] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVES This study presents an analysis of vaping products (VPs) purchased in the USA, Canada, England and Australia and assesses whether differences in regulations were associated with differences in the chemical composition of the VPs. METHODS April-September 2017, a total of 234 VP refill liquids and prefilled cartridges were purchased in convenience samples of retail locations in each country. Products were chosen from brands and styles most commonly reported by current VP users in the 2016 ITC Four Country Smoking and Vaping Survey. All products were tested for nicotine, tobacco-specific nitrosamines (TSNAs), minor tobacco alkaloids, organic acids and flavouring chemicals. RESULTS Consistent with the laws in Canada and Australia at the time of product purchase, nicotine was not detected in any of the VPs (n=10 in Canada; n=15 in Australia). US liquids (n=54) had a mean nicotine concentration of 16.2 mg/mL, (range=0.0-58.6) and English liquids (n=166) had a mean concentration of 11.9 mg/mL ((range=0.0-31.2) F(3244)=12.32, p<0.001). About 5% of English samples exceeded the UK's 20 mg/mL nicotine limit. Substantial country differences were observed in levels ofTSNAs, with the USA being higher than elsewhere. Of all products tested, 18.8% contained at least one organic acid. Liquids purchased in England contained far more identifiable flavouring chemicals than those in the other countries. CONCLUSIONS VP composition, particularly with respect to nicotine and flavouring, varies by country, likely reflecting both marketplace preferences and country-specific regulations. There are differences between nicotine levels claimed on the package and actual levels, particularly in England.
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Affiliation(s)
- Brian Vincent Fix
- Dept. of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | - Richard J OConnor
- Dept. of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | | | - Noel L Leigh
- Dept. of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | - Michael Cummings
- Psychiatry & Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | - Geoffrey T Fong
- Psychology, University of Waterloo, Waterloo, Ontario, Canada
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Georges El Nahas
- Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - David Hammond
- School of Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada
| | - Ann McNeill
- UK Centre for Tobacco Control Studies, National Addiction Centre, Institute of Psychiatry, King's College London, London, UK
| | - Ron Borland
- School of Psychological Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Bill King
- Vichealth Centre for Tobacco Control, cancer council victoria, Carlton, Victoria, Australia
| | - Mary N Palumbo
- Dept. of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
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37
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Alhadyan SK, Sivaraman V, Onyenwoke RU. E-cigarette Flavors, Sensory Perception, and Evoked Responses. Chem Res Toxicol 2022; 35:2194-2209. [PMID: 36480683 DOI: 10.1021/acs.chemrestox.2c00268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The chemosensory experiences evoked by flavors encompass a number of unique sensations that include olfactory stimuli (smell), gustatory stimuli (taste, i.e., salty, sweet, sour, bitter, and umami (also known as "savoriness")), and chemesthesis (touch). As such, the responses evoked by flavors are complex and, as briefly stated above, involve multiple perceptive mechanisms. The practice of adding flavorings to tobacco products dates back to the 17th century but is likely much older. More recently, the electronic cigarette or "e-cigarette" and its accompanying flavored e-liquids emerged on to the global market. These new products contain no combustible tobacco but often contain large concentrations (reported from 0 to more than 50 mg/mL) of nicotine as well as numerous flavorings and/or flavor chemicals. At present, there are more than 400 e-cigarette brands available along with potentially >15,000 different/unique flavored products. However, surprisingly little is known about the flavors/flavor chemicals added to these products, which can account for >1% by weight of some e-liquids, and their resultant chemosensory experiences, and the US FDA has done relatively little, until recently, to regulate these products. This article will discuss e-cigarette flavors and flavor chemicals, their elicited responses, and their sensory effects in some detail.
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Affiliation(s)
- Shatha K Alhadyan
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Vijay Sivaraman
- Department of Biological and Biomedical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Rob U Onyenwoke
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States.,Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, North Carolina 27707, United States
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38
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Noël A, Ghosh A. Carbonyl Profiles of Electronic Nicotine Delivery System (ENDS) Aerosols Reflect Both the Chemical Composition and the Numbers of E-Liquid Ingredients-Focus on the In Vitro Toxicity of Strawberry and Vanilla Flavors. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:16774. [PMID: 36554655 PMCID: PMC9779252 DOI: 10.3390/ijerph192416774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Propylene glycol (PG) and glycerin (G) are the most widely used humectants in electronic nicotine delivery system (ENDS) devices. Carbonyls are present in aerosols produced when ENDS devices heat PG and G. Whether aerosolized PG and G are innocuous to the lungs has not been established. Here, we determined the chemical profiles of ENDS aerosols containing three humectant ratios (30/70, 50/50 and 70/30, PG/VG), for three flavors (strawberry, vanilla and Catalan cream) containing either 12 or 18 mg/mL of nicotine. Additionally, we examined the in vitro toxicity of the strawberry- and vanilla-flavored ENDS aerosol in human lung epithelial cells (BEAS-2B) exposed at the air-liquid interface for 1 h. For strawberry- and vanilla-flavored aerosols produced by a 3rd-generation ENDS device with the same PG/G ratio, the e-liquid nicotine content of 12 and 18 mg/mL did not transfer to the aerosol with substantial differences in concentrations. Our data also indicate the presence of carbonyls in all three flavored e-cig aerosols analyzed, with levels exceeding 1 µg/puff for acetone, butyraldehyde, and acetaldehyde, in strawberry-, vanilla, and Catalan cream-flavored e-cig aerosols, respectively. Furthermore, closed-system ENDS of the fourth generation emitted trace levels of carbonyls in the aerosols (<0.3 µg/puff), while open-system tank-style ENDS of the third generation produced elevated levels of harmful chemicals, including acrolein (>1 µg/puff), formaldehyde (>5 µg/puff), and m- & p-tolualdehyde (>4 µg/puff). Moreover, under non-cytotoxic conditions, BEAS-2B cells exposed to strawberry-flavored aerosols exhibited significantly increased reactive oxygen and nitric oxide species (ROS/NOS) levels in cell media compared to air controls, while vanilla-flavored ENDS aerosols up-regulated the expression of pro-inflammatory and oxidative stress markers. Our data suggest (a) that ENDS aerosol chemical composition will vary based upon the presence and concentration of the initial e-liquid ingredients, with a pronounced impact of the flavoring components; and (b) short-term exposures to flavored ENDS aerosols may impair lung cells' redox signaling in a flavor-specific manner.
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Hernandez A, Sonavane M, Smith KR, Seiger J, Migaud ME, Gassman NR. Dihydroxyacetone suppresses mTOR nutrient signaling and induces mitochondrial stress in liver cells. PLoS One 2022; 17:e0278516. [PMID: 36472985 PMCID: PMC9725129 DOI: 10.1371/journal.pone.0278516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
Dihydroxyacetone (DHA) is the active ingredient in sunless tanning products and a combustion product from e-juices in electronic cigarettes (e-cigarettes). DHA is rapidly absorbed in cells and tissues and incorporated into several metabolic pathways through its conversion to dihydroxyacetone phosphate (DHAP). Previous studies have shown DHA induces cell cycle arrest, reactive oxygen species, and mitochondrial dysfunction, though the extent of these effects is highly cell-type specific. Here, we investigate DHA exposure effects in the metabolically active, HepG3 (C3A) cell line. Metabolic and mitochondrial changes were evaluated by characterizing the effects of DHA in metabolic pathways and nutrient-sensing mechanisms through mTOR-specific signaling. We also examined cytotoxicity and investigated the cell death mechanism induced by DHA exposure in HepG3 cells. Millimolar doses of DHA were cytotoxic and suppressed glycolysis and oxidative phosphorylation pathways. Nutrient sensing through mTOR was altered at both short and long time points. Increased mitochondrial reactive oxygen species (ROS) and mitochondrial-specific injury induced cell cycle arrest and cell death through a non-classical apoptotic mechanism. Despite its carbohydrate nature, millimolar doses of DHA are toxic to liver cells and may pose a significant health risk when higher concentrations are absorbed through e-cigarettes or spray tanning.
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Affiliation(s)
- Arlet Hernandez
- Department of Pharmacology and Toxicology, The University of Alabama at Birmingham, Birmingham AL, United States of America
| | - Manoj Sonavane
- Department of Pharmacology and Toxicology, The University of Alabama at Birmingham, Birmingham AL, United States of America
| | - Kelly R. Smith
- University of South Alabama Mitchell Cancer Institute, Mobile, Alabama, United States of America
| | - Jensyn Seiger
- University of South Alabama Mitchell Cancer Institute, Mobile, Alabama, United States of America
| | - Marie E. Migaud
- University of South Alabama Mitchell Cancer Institute, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama Whiddon College of Medicine, Mobile, AL, United States of America
| | - Natalie R. Gassman
- Department of Pharmacology and Toxicology, The University of Alabama at Birmingham, Birmingham AL, United States of America
- * E-mail:
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40
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Augustini ALRM, Sielemann S, Telgheder U. Quantitation of Flavor Compounds in Refill Solutions for Electronic Cigarettes Using HS-GCxIMS and Internal Standards. Molecules 2022; 27:molecules27228067. [PMID: 36432167 PMCID: PMC9698780 DOI: 10.3390/molecules27228067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
New regulations on the use of flavor compounds in tobaccoless electronic cigarettes require comprehensive analyses. Gas chromatography coupled ion mobility spectrometry is on the rise as an analytical technique for analyzing volatile organic compounds as it combines sensitivity, selectivity, and easy usage with a full-range screening. A current challenge is the quantitative GCxIMS-analysis. Non-linear calibration methods are predominantly used. This work presents a new calibration method using linearization and its corresponding fit based on the relation between the reactant and analyte ions from the chemical ionization. The analysis of e-liquids is used to compare the presented calibration with an established method based on a non-linear Boltzmann fit. Since e-liquids contain matrix compounds that have been shown to influence the analyte signals, the use of internal standards is introduced to reduce these effects in GCxIMS-analysis directly. Different matrix mixtures were evaluated in the matrix-matched calibration to improve the quantitation further. The system's detection and quantitation limits were determined using a separate linear calibration. A matrix-matched calibration series of 29 volatile compounds with 12 levels were used to determine the concentration of these substances in a spiked, flavorless e-liquid and a banana-flavored e-liquid, validating the quality of the different calibrations.
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Affiliation(s)
- Alexander L. R. M. Augustini
- Hamm-Lippstadt University of Applied Sciences, Marker Allee 76-78, 59063 Hamm, Germany
- Faculty of Chemistry, Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany
| | - Stefanie Sielemann
- Hamm-Lippstadt University of Applied Sciences, Marker Allee 76-78, 59063 Hamm, Germany
- Correspondence:
| | - Ursula Telgheder
- Faculty of Chemistry, Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany
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41
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Non-Targeted Chemical Characterization of JUUL-Menthol-Flavored Aerosols Using Liquid and Gas Chromatography. SEPARATIONS 2022. [DOI: 10.3390/separations9110367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The aerosol constituents generated from JUUL Menthol pods with 3.0% and 5.0% nicotine by weight (Me3 and Me5) are characterized by a non-targeted approach, which was developed to detect aerosol constituents that are not known to be present beforehand or that may be measured with targeted methods. Three replicates from three production batches (n = 9) were aerosolized using two puffing regimens (intense and non-intense). Each of the 18 samples were analyzed by gas chromatography electron ionization mass spectrometry and by liquid chromatography electrospray ionization high-resolving power mass spectrometry. All chemical constituents determined to differ from control were identified and semi-quantified. To have a complete understanding of the aerosol constituents and chemistry, each chemical constituent was categorized into one of five groups: (1) flavorants, (2) harmful and potentially harmful constituents, (3) leachables, (4) reaction products, and (5) chemical constituents that were unable to be identified or rationalized (e.g., chemical constituents that could not be categorized in groups (1–4). Under intense puffing, 74 chemical constituents were identified in Me3 aerosols and 68 under non-intense puffing, with 53 chemical constituents common between both regimens. Eighty-three chemical constituents were identified in Me5 aerosol using an intense puffing regimen and seventy-five with a non-intense puffing regimen, with sixty-two chemical constituents in common. Excluding primary constituents, reaction products accounted for the greatest number of chemical constituents (approximately 60% in all cases, ranging from about 0.05% to 0.1% by mass), and flavorants—excluding menthol—comprised the second largest number of chemical constituents (approximately 25%, ranging consistently around 0.01% by mass). The chemical constituents detected in JUUL aerosols were then compared to known constituents from cigarette smoke to determine the relative chemical complexities and commonalities/differences between the two. This revealed (1) a substantial decrease in the chemical complexity of JUUL aerosols vs. cigarette smoke and (2) that there are between 55 (Me3) and 61 (Me5) unique chemical constituents in JUUL aerosols not reported in cigarette smoke. Understanding the chemical complexity of JUUL aerosols is important because the health effects of combustible cigarette smoke are related to the combined effect of these chemical constituents through multiple mechanisms, not just the effects of any single smoke constituent.
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42
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E-cigarette aerosol exposure of pulmonary surfactant impairs its surface tension reducing function. PLoS One 2022; 17:e0272475. [PMID: 36350850 PMCID: PMC9645651 DOI: 10.1371/journal.pone.0272475] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/27/2022] [Indexed: 11/11/2022] Open
Abstract
Introduction E-cigarette (EC) and vaping use continue to remain popular amongst teenage and young adult populations, despite several reports of vaping associated lung injury. One of the first compounds that EC aerosols comes into contact within the lungs during a deep inhalation is pulmonary surfactant. Impairment of surfactant’s critical surface tension reducing activity can contribute to lung dysfunction. Currently, information on how EC aerosols impacts pulmonary surfactant remains limited. We hypothesized that exposure to EC aerosol impairs the surface tension reducing ability of surfactant. Methods Bovine Lipid Extract Surfactant (BLES) was used as a model surfactant in a direct exposure syringe system. BLES (2ml) was placed in a syringe (30ml) attached to an EC. The generated aerosol was drawn into the syringe and then expelled, repeated 30 times. Biophysical analysis after exposure was completed using a constrained drop surfactometer (CDS). Results Minimum surface tensions increased significantly after exposure to the EC aerosol across 20 compression/expansion cycles. Mixing of non-aerosolized e-liquid did not result in significant changes. Variation in device used, addition of nicotine, or temperature of the aerosol had no additional effect. Two e-liquid flavours, menthol and red wedding, had further detrimental effects, resulting in significantly higher surface tension than the vehicle exposed BLES. Menthol exposed BLES has the highest minimum surface tensions across all 20 compression/expansion cycles. Alteration of surfactant properties through interaction with the produced aerosol was observed with a basic e-liquid vehicle, however additional compounds produced by added flavourings appeared to be able to increase inhibition. Conclusion EC aerosols alter surfactant function through increases in minimum surface tension. This impairment may contribute to lung dysfunction and susceptibility to further injury.
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43
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Omaiye EE, Luo W, McWhirter KJ, Pankow JF, Talbot P. Ethyl maltol, vanillin, corylone and other conventional confectionery-related flavour chemicals dominate in some e-cigarette liquids labelled 'tobacco' flavoured. Tob Control 2022; 31:s238-s244. [PMID: 36328460 PMCID: PMC9664106 DOI: 10.1136/tc-2022-057484] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/14/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND The increased popularity of electronic cigarettes (e-cigarettes) has been linked to the abundance of flavoured products that are attractive to adolescents and young adults. In the last decade, e-cigarette designs have evolved through four generations that include modifications in battery power, e-cigarette liquid (e-liquid) reservoirs and atomiser units. E-liquids have likewise evolved in terms of solvent use/ratios, concentration and number of flavour chemicals, use of nicotine salts and acids, the recent increased use of synthetic cooling agents and the introduction of synthetic nicotine. Our current objective was to evaluate and compare the evolving composition of tobacco-flavoured e-liquids over the last 10 years. METHODS Our extensive database of flavour chemicals in e-liquids was used to identify trends and changes in flavour chemical composition and concentrations. RESULTS Tobacco-flavoured products purchased in 2010 and 2011 generally had very few flavour chemicals, and their concentrations were generally very low. In tobacco-flavoured refill fluids purchased in 2019 and Puff Bar Tobacco e-cigarettes, the total number and concentration of flavour chemicals were higher than expected. Products with total flavour chemicals >10 mg/mL contained one to five dominant flavour chemicals (>1 mg/mL). The most frequently used flavour chemicals in tobacco e-liquids were fruity and caramellic. CONCLUSIONS There is a need for continuous surveillance of e-liquids, which are evolving in often subtle and harmful ways. Chemical constituents of tobacco flavours should be monitored as they clearly can be doctored by manufacturers to have a taste that would appeal to young users.
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Affiliation(s)
- Esther E Omaiye
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California, USA
| | - Wentai Luo
- Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, USA
| | - Kevin J McWhirter
- Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, USA
| | - James F Pankow
- Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, USA
| | - Prue Talbot
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California, USA
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Mohammadi L, Han DD, Xu F, Huang A, Derakhshandeh R, Rao P, Whitlatch A, Cheng J, Keith RJ, Hamburg NM, Ganz P, Hellman J, Schick SF, Springer ML. Chronic E-Cigarette Use Impairs Endothelial Function on the Physiological and Cellular Levels. Arterioscler Thromb Vasc Biol 2022; 42:1333-1350. [PMID: 36288290 PMCID: PMC9625085 DOI: 10.1161/atvbaha.121.317749] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/14/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND The harmful vascular effects of smoking are well established, but the effects of chronic use of electronic cigarettes (e-cigarettes) on endothelial function are less understood. We hypothesized that e-cigarette use causes changes in blood milieu that impair endothelial function. METHODS Endothelial function was measured in chronic e-cigarette users, chronic cigarette smokers, and nonusers. We measured effects of participants' sera, or e-cigarette aerosol condensate, on NO and H2O2 release and cell permeability in cultured endothelial cells (ECs). RESULTS E-cigarette users and smokers had lower flow-mediated dilation (FMD) than nonusers. Sera from e-cigarette users and smokers reduced VEGF (vascular endothelial growth factor)-induced NO secretion by ECs relative to nonuser sera, without significant reduction in endothelial NO synthase mRNA or protein levels. E-cigarette user sera caused increased endothelial release of H2O2, and more permeability than nonuser sera. E-cigarette users and smokers exhibited changes in circulating biomarkers of inflammation, thrombosis, and cell adhesion relative to nonusers, but with distinct profiles. E-cigarette user sera had higher concentrations of the receptor for advanced glycation end products (RAGE) ligands S100A8 and HMGB1 (high mobility group box 1) than smoker and nonuser sera, and receptor for advanced glycation end product inhibition reduced permeability induced by e-cigarette user sera but did not affect NO production. CONCLUSIONS Chronic vaping and smoking both impair FMD and cause changes in the blood that inhibit endothelial NO release. Vaping, but not smoking, causes changes in the blood that increase microvascular endothelial permeability and may have a vaping-specific effect on intracellular oxidative state. Our results suggest a role for RAGE in e-cigarette-induced changes in endothelial function.
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Affiliation(s)
- Leila Mohammadi
- Division of Cardiology (L.M., D.D.H., R.D., P.R., P.G., M.L.S.), University of California, San Francisco
| | - Daniel D Han
- Division of Cardiology (L.M., D.D.H., R.D., P.R., P.G., M.L.S.), University of California, San Francisco
- Now with School of Medicine and Dentistry, University of Rochester, NY (D.D.H.)
| | - Fengyun Xu
- Department of Anesthesia and Perioperative Care (F.X., J.H.), University of California, San Francisco
| | - Abel Huang
- Division of Occupational and Environmental Medicine (A.H., A.W., S.F.S.), University of California, San Francisco
| | - Ronak Derakhshandeh
- Division of Cardiology (L.M., D.D.H., R.D., P.R., P.G., M.L.S.), University of California, San Francisco
| | - Poonam Rao
- Division of Cardiology (L.M., D.D.H., R.D., P.R., P.G., M.L.S.), University of California, San Francisco
- Now with CHRISTUS Good Shepherd Internal Medicine Residency Program, Longview, TX (P.R.)
| | - Adam Whitlatch
- Division of Occupational and Environmental Medicine (A.H., A.W., S.F.S.), University of California, San Francisco
| | - Jing Cheng
- Division of Oral Epidemiology and Dental Public Health (J.C.), University of California, San Francisco
| | - Rachel J Keith
- Department of Medicine, University of Louisville Medical School, KY (R.J.K.)
| | - Naomi M Hamburg
- Department of Medicine, Boston University School of Medicine, MA (N.M.H.)
| | - Peter Ganz
- Division of Cardiology (L.M., D.D.H., R.D., P.R., P.G., M.L.S.), University of California, San Francisco
| | - Judith Hellman
- Department of Anesthesia and Perioperative Care (F.X., J.H.), University of California, San Francisco
| | - Suzaynn F Schick
- Division of Occupational and Environmental Medicine (A.H., A.W., S.F.S.), University of California, San Francisco
- Center for Tobacco Control Research and Education (S.F.S., M.L.S.), University of California, San Francisco
| | - Matthew L Springer
- Division of Cardiology (L.M., D.D.H., R.D., P.R., P.G., M.L.S.), University of California, San Francisco
- Center for Tobacco Control Research and Education (S.F.S., M.L.S.), University of California, San Francisco
- Cardiovascular Research Institute (M.L.S.), University of California, San Francisco
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45
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El-Hellani A, Soule EK, Daoud M, Salman R, El Hage R, Ardati O, El-Kaassamani M, Yassine A, Karaoghlanian N, Talih S, Saliba N, Shihadeh A. Assessing toxicant emissions from e-liquids with DIY additives used in response to a potential flavour ban in e-cigarettes. Tob Control 2022; 31:s245-s248. [PMID: 36328456 PMCID: PMC9664124 DOI: 10.1136/tc-2022-057505] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/15/2022] [Indexed: 11/22/2022]
Abstract
SIGNIFICANCE Electronic cigarettes (e-cigarettes) aerosolise liquids that contain nicotine, propylene glycol, glycerol and appealing flavours. In the USA, regulations have limited the availability of flavoured e-cigarettes in pod-based systems, and further tightening is expected. In response, some e-cigarette users may attempt to make their e-liquids (do-it-yourself, DIY). This study examined toxicant emissions from several aerosolised DIY e-liquids. METHODS DIY additives were identified by reviewing users' responses to a hypothetical flavour ban, e-cigarette internet forums and DIY mixing internet websites. They include essential oils, cannabidiol, sucralose and ethyl maltol. E-liquids with varying concentrations and combinations of additives and tobacco and menthol flavours were prepared and were used to assess reactive oxygen species (ROS), carbonyl and phenol emissions in machine-generated aerosols. RESULTS Data showed that adding DIY additives to unflavoured, menthol-flavoured or tobacco-flavoured e-liquids increases toxicant emissions to levels comparable with those from commercial flavoured e-liquids. Varying additive concentrations in e-liquids did not have a consistently significant effect on the tested emissions, yet increasing power yielded significantly higher ROS, carbonyl and phenol emissions for the same additive concentration. Adding nicotine to DIY e-liquids with sucralose yielded increase in some emissions and decrease in others, with freebase nicotine-containing e-liquid giving higher ROS emissions than that with nicotine salt. CONCLUSION This study showed that DIY additives can impact aerosol toxicant emissions from e-cigarettes and should be considered by policymakers when restricting commercially available flavoured e-liquids.
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Affiliation(s)
- Ahmad El-Hellani
- Division of Environmental Health Sciences, The Ohio State University College of Public Health, Columbus, Ohio, USA
- Virginia Commonwealth University Center for the Study of Tobacco Products, Richmond, Virginia, USA
| | - Eric K Soule
- Virginia Commonwealth University Center for the Study of Tobacco Products, Richmond, Virginia, USA
- Department of Health Education and Promotion, East Carolina University, Greenville, North Carolina, USA
| | - Mohammad Daoud
- Department of Chemistry, American University of Beirut Faculty of Arts and Sciences, Beirut, Lebanon
| | - Rola Salman
- Virginia Commonwealth University Center for the Study of Tobacco Products, Richmond, Virginia, USA
- Department of Mechanical Engineering, American University of Beirut Faculty of Engineering and Architecture, Beirut, Lebanon
| | - Rachel El Hage
- Virginia Commonwealth University Center for the Study of Tobacco Products, Richmond, Virginia, USA
- Department of Chemistry, American University of Beirut Faculty of Arts and Sciences, Beirut, Lebanon
| | - Ola Ardati
- Department of Chemistry, American University of Beirut Faculty of Arts and Sciences, Beirut, Lebanon
| | - Malak El-Kaassamani
- Department of Chemistry, American University of Beirut Faculty of Arts and Sciences, Beirut, Lebanon
| | - Amira Yassine
- Department of Chemistry, American University of Beirut Faculty of Arts and Sciences, Beirut, Lebanon
| | - Nareg Karaoghlanian
- Virginia Commonwealth University Center for the Study of Tobacco Products, Richmond, Virginia, USA
- Department of Mechanical Engineering, American University of Beirut Faculty of Engineering and Architecture, Beirut, Lebanon
| | - Soha Talih
- Virginia Commonwealth University Center for the Study of Tobacco Products, Richmond, Virginia, USA
- Department of Mechanical Engineering, American University of Beirut Faculty of Engineering and Architecture, Beirut, Lebanon
| | - Najat Saliba
- Virginia Commonwealth University Center for the Study of Tobacco Products, Richmond, Virginia, USA
- Department of Chemistry, American University of Beirut Faculty of Arts and Sciences, Beirut, Lebanon
| | - Alan Shihadeh
- Virginia Commonwealth University Center for the Study of Tobacco Products, Richmond, Virginia, USA
- Department of Mechanical Engineering, American University of Beirut Faculty of Engineering and Architecture, Beirut, Lebanon
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46
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Wong ET, Luettich K, Cammack L, Chua CS, Sciuscio D, Merg C, Corciulo M, Piault R, Ashutosh K, Smith C, Leroy P, Moine F, Glabasnia A, Diana P, Chia C, Tung CK, Ivanov N, Hoeng J, Peitsch M, Lee KM, Vanscheeuwijck P. Assessment of inhalation toxicity of cigarette smoke and aerosols from flavor mixtures: 5-week study in A/J mice. J Appl Toxicol 2022; 42:1701-1722. [PMID: 35543240 PMCID: PMC9545811 DOI: 10.1002/jat.4338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 04/20/2022] [Accepted: 05/05/2022] [Indexed: 11/10/2022]
Abstract
Most flavors used in e-liquids are generally recognized as safe for oral consumption, but their potential effects when inhaled are not well characterized. In vivo inhalation studies of flavor ingredients in e-liquids are scarce. A structure-based grouping approach was used to select 38 flavor group representatives (FGR) on the basis of known and in silico-predicted toxicological data. These FGRs were combined to create prototype e-liquid formulations and tested against cigarette smoke (CS) in a 5-week inhalation study. Female A/J mice were whole-body exposed for 6 h/day, 5 days/week, for 5 weeks to air, mainstream CS, or aerosols from (1) test formulations containing propylene glycol (PG), vegetable glycerol (VG), nicotine (N; 2% w/w), and flavor (F) mixtures at low (4.6% w/w), medium (9.3% w/w), or high (18.6% w/w) concentration or (2) base formulation (PG/VG/N). Male A/J mice were exposed to air, PG/VG/N, or PG/VG/N/F-high under the same exposure regimen. There were no significant mortality or in-life clinical findings in the treatment groups, with only transient weight loss during the early exposure adaptation period. While exposure to flavor aerosols did not cause notable lung inflammation, it caused only minimal adaptive changes in the larynx and nasal epithelia. In contrast, exposure to CS resulted in lung inflammation and moderate-to-severe changes in the epithelia of the nose, larynx, and trachea. In summary, the study evaluates an approach for assessing the inhalation toxicity potential of flavor mixtures, thereby informing the selection of flavor exposure concentrations (up to 18.6%) for a future chronic inhalation study.
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Affiliation(s)
- Ee Tsin Wong
- PMI R&DPhilip Morris International Research Laboratories Pte LtdSingapore
| | | | - Lydia Cammack
- PMI R&DPhilip Morris International Research Laboratories Pte LtdSingapore
| | - Chin Suan Chua
- PMI R&DPhilip Morris International Research Laboratories Pte LtdSingapore
| | | | - Celine Merg
- PMI R&DPhilip Morris Products S.ANeuchâtelSwitzerland
| | | | - Romain Piault
- PMI R&DPhilip Morris Products S.ANeuchâtelSwitzerland
| | | | | | - Patrice Leroy
- PMI R&DPhilip Morris Products S.ANeuchâtelSwitzerland
| | - Fabian Moine
- PMI R&DPhilip Morris Products S.ANeuchâtelSwitzerland
| | | | | | - Cecilia Chia
- PMI R&DPhilip Morris International Research Laboratories Pte LtdSingapore
| | - Ching Keong Tung
- PMI R&DPhilip Morris International Research Laboratories Pte LtdSingapore
| | | | - Julia Hoeng
- PMI R&DPhilip Morris Products S.ANeuchâtelSwitzerland
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47
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Scharf P, Rizzetto F, Xavier LF, Farsky SHP. Xenobiotics Delivered by Electronic Nicotine Delivery Systems: Potential Cellular and Molecular Mechanisms on the Pathogenesis of Chronic Kidney Disease. Int J Mol Sci 2022; 23:ijms231810293. [PMID: 36142207 PMCID: PMC9498982 DOI: 10.3390/ijms231810293] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 11/20/2022] Open
Abstract
Chronic kidney disease (CKD) is characterized as sustained damage to the renal parenchyma, leading to impaired renal functions and gradually progressing to end-stage renal disease (ESRD). Diabetes mellitus (DM) and arterial hypertension (AH) are underlying diseases of CKD. Genetic background, lifestyle, and xenobiotic exposures can favor CKD onset and trigger its underlying diseases. Cigarette smoking (CS) is a known modified risk factor for CKD. Compounds from tobacco combustion act through multi-mediated mechanisms that impair renal function. Electronic nicotine delivery systems (ENDS) consumption, such as e-cigarettes and heated tobacco devices, is growing worldwide. ENDS release mainly nicotine, humectants, and flavorings, which generate several byproducts when heated, including volatile organic compounds and ultrafine particles. The toxicity assessment of these products is emerging in human and experimental studies, but data are yet incipient to achieve truthful conclusions about their safety. To build up the knowledge about the effect of currently employed ENDS on the pathogenesis of CKD, cellular and molecular mechanisms of ENDS xenobiotic on DM, AH, and kidney functions were reviewed. Unraveling the toxic mechanisms of action and endpoints of ENDS exposures will contribute to the risk assessment and implementation of proper health and regulatory interventions.
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48
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Kerber PJ, Peyton DH. Kinetics of Aldehyde Flavorant-Acetal Formation in E-Liquids with Different E-Cigarette Solvents and Common Additives Studied by 1H NMR Spectroscopy. Chem Res Toxicol 2022; 35:1410-1417. [PMID: 35830545 PMCID: PMC10861150 DOI: 10.1021/acs.chemrestox.2c00159] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Flavorants, nicotine, and organic acids are common additives found in the e-liquid carrier solvent, propylene glycol (PG) and/or glycerol (GL), at various concentrations. Some of the most concentrated and prevalent flavorants in e-liquids include trans-cinnamaldehyde, vanillin, and benzaldehyde. Aldehyde flavorants have been shown to react with PG and GL to form flavorant-PG and -GL acetals that have unique toxicity properties in e-liquids before aerosolization. However, there is still much that remains unknown about the effects of different e-cigarette solvents, water, nicotine, and organic acids on the rate of acetalization in e-liquids. We used 1H NMR spectroscopy to determine the first-order initial rate constant, half-life, and % acetal formed at equilibrium for flavorant-acetal formation in simulated e-liquids. Herein, we report that acetalization generally occurs at a faster rate and produces greater yields in e-liquids with higher ratios of GL (relative to PG). trans-Cinnamaldehyde acetals formed the fastest in 100% PG-simulated e-liquids, followed by benzaldehyde and vanillin based on their half-lives and rate constants. The acetal yield was greatest for benzaldehyde in PG e-liquids, followed by trans-cinnamaldehyde and vanillin. Acetalization in PG e-liquids containing aldehyde flavorants was inhibited by water and nicotine but catalyzed by benzoic acid. Flavorant-PG acetal formation was generally delayed in the presence of nicotine, even if benzoic acid was present at 2-, 4-, or 10-fold the nicotine concentration, as compared to the PG e-liquids with 2.5 mg/mL flavorant. Thus, commercial e-liquids with aldehyde flavorants containing a higher GL ratio (relative to PG), little water, no nicotine, nicotine with excess organic acids, or organic acids without nicotine would undergo acetalization the fastest and with the highest yield. Many commercial e-liquids must therefore contain significant amounts of flavorant acetals.
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Affiliation(s)
- Paul J Kerber
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
| | - David H Peyton
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
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49
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Vivarelli F, Granata S, Rullo L, Mussoni M, Candeletti S, Romualdi P, Fimognari C, Cruz-Chamorro I, Carrillo-Vico A, Paolini M, Canistro D. On the toxicity of e-cigarettes consumption: Focus on pathological cellular mechanisms. Pharmacol Res 2022; 182:106315. [PMID: 35724819 DOI: 10.1016/j.phrs.2022.106315] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/09/2022] [Accepted: 06/14/2022] [Indexed: 10/18/2022]
Abstract
Tobacco smoking remains without a doubt one of the leading causes of premature death worldwide. In combination with conventional protocols for smoking cessation, e-cigarettes have been proposed as a useful tool to quit smoking. Advertised as almost free of toxic effects, e-cigarettes have rapidly increased their popularity, becoming a sought-after device, especially among young people. Recently some health concerns about e-cigarette consumption are being raised. It is well known that they can release several toxic compounds, some of which are carcinogenic to humans, and emerging results are now outlining the risks related to the onset of respiratory and cardiovascular diseases and even cancer. The present review shows the emerging evidence about the role of technical components of the devices, the e-liquid composition as well as customization by consumers. The primary topics we discuss are the main toxicological aspects associated with e-cigarette consumption, focusing on the molecular pathways involved. Here it will be shown how exposure to e-cigarette aerosol induces stress/mitochondrial toxicity, DNA breaks/fragmentation following the same pathological pathways triggered by tobacco smoke, including the deregulation of molecular signalling axis associated with cancer progression and cell migration. Risk to fertility and pregnancy, as well as cardiovascular risk associated with e-cigarette use, have also been reported.
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Affiliation(s)
- Fabio Vivarelli
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy.
| | - Silvia Granata
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; Department of Medicine and Surgery - University of Milano - Bicocca
| | - Laura Rullo
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Matilde Mussoni
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Sanzio Candeletti
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Patrizia Romualdi
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Carmela Fimognari
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Ivan Cruz-Chamorro
- Instituto de Biomedicina de Sevilla, IBiS (Universidad de Sevilla, HUVR, Junta de Andalucía, CSIC), 41013 Seville, Spain; Departamento de Bioquímica Médica y Biología Molecular e Inmunología, Universidad de Sevilla, 41009 Seville, Spain
| | - Antonio Carrillo-Vico
- Instituto de Biomedicina de Sevilla, IBiS (Universidad de Sevilla, HUVR, Junta de Andalucía, CSIC), 41013 Seville, Spain; Departamento de Bioquímica Médica y Biología Molecular e Inmunología, Universidad de Sevilla, 41009 Seville, Spain
| | - Moreno Paolini
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy.
| | - Donatella Canistro
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
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50
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Kerber PJ, Duell AK, Powers M, Strongin RM, Peyton DH. Effects of Common e-Liquid Flavorants and Added Nicotine on Toxicant Formation during Vaping Analyzed by 1H NMR Spectroscopy. Chem Res Toxicol 2022; 35:1267-1276. [PMID: 35735356 PMCID: PMC10861143 DOI: 10.1021/acs.chemrestox.2c00110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A broad variety of e-liquids are used by e-cigarette consumers. Additives to the e-liquid carrier solvents, propylene glycol and glycerol, often include flavorants and nicotine at various concentrations. Flavorants in general have been reported to increase toxicant formation in e-cigarette aerosols, yet there is still much that remains unknown about the effects of flavorants, nicotine, and flavorants + nicotine on harmful and potentially harmful constituents (HPHCs) when aerosolizing e-liquids. Common flavorants benzaldehyde, vanillin, benzyl alcohol, and trans-cinnamaldehyde have been identified as some of the most concentrated flavorants in some commercial e-liquids, yet there is limited information on their effects on HPHC formation. E-liquids containing flavorants + nicotine are also common, but the specific effects of flavorants + nicotine on toxicant formation remain understudied. We used 1H NMR spectroscopy to evaluate HPHCs and herein report that benzaldehyde, vanillin, benzyl alcohol, trans-cinnamaldehyde, and mixtures of these flavorants significantly increased toxicant formation produced during e-liquid aerosolization compared to unflavored e-liquids. However, e-liquids aerosolized with flavorants + nicotine decreased the HPHCs for benzaldehyde, vanillin, benzyl alcohol, and a "flavorant mixture" but increased the HPHCs for e-liquids containing trans-cinnamaldehyde compared to e-liquids with flavorants and no nicotine. We determined how nicotine affects the production of HPHCs from e-liquids with flavorant + nicotine versus flavorant, herein referred to as the "nicotine degradation factor". Benzaldehyde, vanillin, benzyl alcohol, and a "flavorant mixture" with nicotine showed lower HPHC levels, having nicotine degradation factors <1 for acetaldehyde, acrolein, and total formaldehyde. HPHC formation was most inhibited in e-liquids containing vanillin + nicotine, with a degradation factor of ∼0.5, while trans-cinnamaldehyde gave more HPHC formation when nicotine was present, with a degradation factor of ∼2.5 under the conditions studied. Thus, the effects of flavorant molecules and nicotine are complex and warrant further studies on their impacts in other e-liquid formulations as well as with more devices and heating element types.
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Affiliation(s)
- Paul J Kerber
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
| | - Anna K Duell
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
| | - Marley Powers
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
| | - Robert M Strongin
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
| | - David H Peyton
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, United States
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