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Wang Q, Sundar I, Li D, Lucas J, Muthumalage T, McDonough S, Rahman I. E-cigarette-Induced Pulmonary Inflammation and Dysregulated Repair are Mediated by nAChR α7 Receptor: Role of nAChR α7 in ACE2 Covid-19 receptor regulation. RESEARCH SQUARE 2020:rs.2.23829. [PMID: 32702718 PMCID: PMC7336696 DOI: 10.21203/rs.2.23829/v2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Electronic cigarette (e-cig) vaping is increasing rapidly in the United States, as e-cigs are considered less harmful than combustible cigarettes. However, limited research has been conducted to understand the possible mechanism that mediate, toxicity and pulmonary health effects of e-cigs. We hypothesized that sub-chronic e-cig exposure induces inflammatory response and dysregulated repair/extracellular matrix (ECM) remodeling, which occur through the α7 nicotinic acetylcholine receptor (nAChR α7). Adult wild-type (WT), nAChRα7 knockout (KO), and lung epithelial cell-specific KO (nAChRα7 CreCC10) mice were exposed to e-cig aerosol containing propylene glycol (PG) with or without nicotine. Bronchoalveolar lavage fluids (BALF) and lungs tissues were collected to determine e-cig induced inflammatory response and ECM remodeling, respectively. Sub-chronic e-cig exposure with nicotine increased the inflammatory cellular influx of macrophages and T-lymphocytes including increased pro-inflammatory cytokines in BALF and increased ACE2 Covid-19 receptor, whereas nAChR α7 KO mice show reduced inflammatory responses associated with decreased ACE2 receptor. Interestingly, matrix metalloproteinases (MMPs), such as MMP2, MMP8, and MMP9 were altered both at the protein and mRNA transcript levels in female and male, but WT mice exposed to PG alone showed a sex-dependent phenotype. Moreover, MMP12 was increased significantly in male mice exposed to PG with or without nicotine in a nAChR α7-dependent manner. Additionally, sub-chronic e-cig exposure with or without nicotine altered the abundance of ECM proteins, such as collagen and fibronectin significantly in a sex-dependent manner, but without the direct role of nAChR α7 gene. Overall, sub-chronic e-cig exposure with or without nicotine affected lung inflammation and repair responses/ECM remodeling, which were mediated by nAChR α7 in a sex-dependent manner.
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102
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Traboulsi H, Cherian M, Abou Rjeili M, Preteroti M, Bourbeau J, Smith BM, Eidelman DH, Baglole CJ. Inhalation Toxicology of Vaping Products and Implications for Pulmonary Health. Int J Mol Sci 2020; 21:E3495. [PMID: 32429092 PMCID: PMC7278963 DOI: 10.3390/ijms21103495] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/28/2020] [Accepted: 05/12/2020] [Indexed: 12/17/2022] Open
Abstract
E-cigarettes have a liquid that may contain flavors, solvents, and nicotine. Heating this liquid generates an aerosol that is inhaled into the lungs in a process commonly referred to as vaping. E-cigarette devices can also contain cannabis-based products including tetrahydrocannabinol (THC), the psychoactive component of cannabis (marijuana). E-cigarette use has rapidly increased among current and former smokers as well as youth who have never smoked. The long-term health effects are unknown, and emerging preclinical and clinical studies suggest that e-cigarettes may not be harmless and can cause cellular alterations analogous to traditional tobacco smoke. Here, we review the historical context and the components of e-cigarettes and discuss toxicological similarities and differences between cigarette smoke and e-cigarette aerosol, with specific reference to adverse respiratory outcomes. Finally, we outline possible clinical disorders associated with vaping on pulmonary health and the recent escalation of acute lung injuries, which led to the declaration of the vaping product use-associated lung injury (EVALI) outbreak. It is clear there is much about vaping that is not understood. Consequently, until more is known about the health effects of vaping, individual factors that need to be taken into consideration include age, current and prior use of combustible tobacco products, and whether the user has preexisting lung conditions such as asthma and chronic obstructive pulmonary disease (COPD).
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Affiliation(s)
- Hussein Traboulsi
- Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada; (H.T.); (M.A.R.); (M.P.); (J.B.); (B.M.S.)
| | - Mathew Cherian
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (M.C.); (D.H.E.)
| | - Mira Abou Rjeili
- Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada; (H.T.); (M.A.R.); (M.P.); (J.B.); (B.M.S.)
- Respiratory Epidemiology and Clinical Research Unit, McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Matthew Preteroti
- Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada; (H.T.); (M.A.R.); (M.P.); (J.B.); (B.M.S.)
- Department of Pathology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Jean Bourbeau
- Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada; (H.T.); (M.A.R.); (M.P.); (J.B.); (B.M.S.)
- Respiratory Epidemiology and Clinical Research Unit, McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - Benjamin M. Smith
- Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada; (H.T.); (M.A.R.); (M.P.); (J.B.); (B.M.S.)
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (M.C.); (D.H.E.)
- Respiratory Epidemiology and Clinical Research Unit, McGill University Health Centre, Montreal, QC H4A 3J1, Canada
| | - David H. Eidelman
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (M.C.); (D.H.E.)
| | - Carolyn J. Baglole
- Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada; (H.T.); (M.A.R.); (M.P.); (J.B.); (B.M.S.)
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada; (M.C.); (D.H.E.)
- Department of Pathology, McGill University, Montreal, QC H3A 2B4, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC H3G 1Y6, Canada
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103
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Ho J, Sciuscio D, Kogel U, Titz B, Leroy P, Vuillaume G, Talikka M, Martin E, Pospisil P, Lebrun S, Xia W, Lee T, Chng YX, Phillips BW, Veljkovic E, Guedj E, Xiang Y, Ivanov NV, Peitsch MC, Hoeng J, Vanscheeuwijck P. Evaluation of toxicity of aerosols from flavored e-liquids in Sprague-Dawley rats in a 90-day OECD inhalation study, complemented by transcriptomics analysis. Arch Toxicol 2020; 94:2179-2206. [PMID: 32367274 PMCID: PMC7303093 DOI: 10.1007/s00204-020-02759-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/22/2020] [Indexed: 01/08/2023]
Abstract
The use of flavoring substances is an important element in the development of reduced-risk products for adult smokers to increase product acceptance and encourage switching from cigarettes. In a first step towards characterizing the sub-chronic inhalation toxicity of neat flavoring substances, a study was conducted using a mixture of the substances in a base solution of e-liquid, where the standard toxicological endpoints of the nebulized aerosols were supplemented with transcriptomics analysis. The flavor mixture was produced by grouping 178 flavors into 26 distinct chemical groups based on structural similarities and potential metabolic and biological effects. Flavoring substances predicted to show the highest toxicological effect from each group were selected as the flavor group representatives (FGR). Following Organization for Economic Cooperation and Development Testing Guideline 413, rats were exposed to three concentrations of the FGR mixture in an e-liquid composed of nicotine (23 µg/L), propylene glycol (1520 µg/L), and vegetable glycerin (1890 µg/L), while non-flavored and no-nicotine mixtures were included as references to identify potential additive or synergistic effects between nicotine and the flavoring substances. The results indicated that the inhalation of an e-liquid containing the mixture of FGRs caused very minimal local and systemic toxic effects. In particular, there were no remarkable clinical (in-life) observations in flavored e-liquid-exposed rats. The biological effects related to exposure to the mixture of neat FGRs were limited and mainly nicotine-mediated, including changes in hematological and blood chemistry parameters and organ weight. These results indicate no significant additive biological changes following inhalation exposure to the nebulized FGR mixture above the nicotine effects measured in this sub-chronic inhalation study. In a subsequent study, e-liquids with FGR mixtures will be aerosolized by thermal treatment and assessed for toxicity.
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Affiliation(s)
- Jenny Ho
- PMI S&I, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore, Singapore
| | - Davide Sciuscio
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Ulrike Kogel
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Bjoern Titz
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Patrice Leroy
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Gregory Vuillaume
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Marja Talikka
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Elyette Martin
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Pavel Pospisil
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Stefan Lebrun
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Wenhao Xia
- PMI S&I, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore, Singapore
| | - Tom Lee
- PMI S&I, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore, Singapore
| | - Yun Xuan Chng
- PMI S&I, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore, Singapore
| | - Blaine W Phillips
- PMI S&I, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore, Singapore
| | - Emilija Veljkovic
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Emmanuel Guedj
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Yang Xiang
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Nikolai V Ivanov
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Manuel C Peitsch
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Julia Hoeng
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland
| | - Patrick Vanscheeuwijck
- PMI S&I, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000, Neuchâtel, Switzerland.
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104
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Lin VY, Fain MD, Jackson PL, Berryhill TF, Wilson LS, Mazur M, Barnes SJ, Blalock JE, Raju SV, Rowe SM. Vaporized E-Cigarette Liquids Induce Ion Transport Dysfunction in Airway Epithelia. Am J Respir Cell Mol Biol 2020; 61:162-173. [PMID: 30576219 DOI: 10.1165/rcmb.2017-0432oc] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cigarette smoking is associated with chronic obstructive pulmonary disease and chronic bronchitis. Acquired ion transport abnormalities, including cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction, caused by cigarette smoking have been proposed as potential mechanisms for mucus obstruction in chronic bronchitis. Although e-cigarette use is popular and perceived to be safe, whether it harms the airways via mechanisms altering ion transport remains unclear. In the present study, we sought to determine if e-cigarette vapor, like cigarette smoke, has the potential to induce acquired CFTR dysfunction, and to what degree. Electrophysiological methods demonstrated reduced chloride transport caused by vaporized e-cigarette liquid or vegetable glycerin at various exposures (30 min, 57.2% and 14.4% respectively, vs. control; P < 0.0001), but not by unvaporized liquid (60 min, 17.6% vs. untreated), indicating that thermal degradation of these products is required to induce the observed defects. We also observed reduced ATP-dependent responses (-10.8 ± 3.0 vs. -18.8 ± 5.1 μA/cm2 control) and epithelial sodium channel activity (95.8% reduction) in primary human bronchial epithelial cells after 5 minutes, suggesting that exposures dramatically inhibit epithelial ion transport beyond CFTR, even without diminished transepithelial resistance or cytotoxicity. Vaporizing e-cigarette liquid produced reactive aldehydes, including acrolein (shown to induce acquired CFTR dysfunction), as quantified by mass spectrometry, demonstrating that respiratory toxicants in cigarette smoke can also be found in e-cigarette vapor (30 min air, 224.5 ± 15.99; unvaporized liquid, 284.8 ± 35.03; vapor, 54,468 ± 3,908 ng/ml; P < 0.0001). E-cigarettes can induce ion channel dysfunction in airway epithelial cells, partly through acrolein production. These findings indicate a heretofore unknown toxicity of e-cigarette use known to be associated with chronic bronchitis onset and progression, as well as with chronic obstructive pulmonary disease severity.
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Affiliation(s)
| | | | | | - Taylor F Berryhill
- 2Pharmacology/Toxicology and Targeted Metabolomics and Proteomics Laboratory
| | - Landon S Wilson
- 2Pharmacology/Toxicology and Targeted Metabolomics and Proteomics Laboratory
| | | | - Stephen J Barnes
- 2Pharmacology/Toxicology and Targeted Metabolomics and Proteomics Laboratory
| | | | | | - Steven M Rowe
- 1Department of Medicine.,3Gregory J. Fleming Cystic Fibrosis Center.,4Department of Pediatrics, and.,5Department of Cell Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
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105
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Effects of combustible tobacco smoking and novel tobacco products on oxidative stress: Different sides of the same coin? CURRENT OPINION IN TOXICOLOGY 2020. [DOI: 10.1016/j.cotox.2020.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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106
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Fowles J, Barreau T, Wu N. Cancer and Non-Cancer Risk Concerns from Metals in Electronic Cigarette Liquids and Aerosols. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17062146. [PMID: 32213824 PMCID: PMC7142621 DOI: 10.3390/ijerph17062146] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/09/2020] [Accepted: 03/19/2020] [Indexed: 12/28/2022]
Abstract
We evaluated metal concentrations in e-liquids and e-aerosols from eight studies and estimated the range of corresponding cancer and non-cancer risks. Chromium and nickel were the leading contributors to cancer risk, with minor contributions from cadmium, lead, and arsenic. The increased cancer risks, assuming exposure to 2 mL/day, ranged from 5.7 to 30,000 additional cancers in a million e-cigarette users. The average cancer risk was 3 in 1000. Cancer risks in the mid to upper end of these ranges exceed acceptable levels. The hazard quotient (HQ) approach was used to evaluate non-cancer risks. Hazard quotients exceeding 1.0 indicate the possibility for non-cancer adverse health effects. Estimated exposures at the maximum reported concentrations of nickel, chromium, and manganese resulted in HQ values of 161, 1.1, and 1.0, respectively, with additional contributions from lead. The average concentration of nickel resulted in an HQ value of 14. We conclude from these studies that exposure to metals in e-cigarette liquids and aerosols may pose a significant cancer and non-cancer health risk at the mid and upper end of the reported ranges. The device design and heating elements appear to be the main source of metals in e-aerosols. The large range of metals within and across e-cigarette brands indicate the need for improvements in product design, enforced product safety regulations and manufacturing quality control. Implementation of such measures could reduce metal exposure in e-cigarette users.
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107
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Herr C, Tsitouras K, Niederstraßer J, Backes C, Beisswenger C, Dong L, Guillot L, Keller A, Bals R. Cigarette smoke and electronic cigarettes differentially activate bronchial epithelial cells. Respir Res 2020; 21:67. [PMID: 32164736 PMCID: PMC7068890 DOI: 10.1186/s12931-020-1317-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/10/2020] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The use of electronic cigarettes (ECIGs) is increasing, but the impact of ECIG-vapor on cellular processes like inflammation or host defense are less understood. The aim of the present study was to compare the acute effects of traditional cigarettes (TCIGs) and ECIG-exposure on host defense, inflammation, and cellular activation of cell lines and primary differentiated human airway epithelial cells (pHBE). METHODS We exposed pHBEs and several cell lines to TCIG-smoke or ECIG-vapor. Epithelial host defense and barrier integrity were determined. The transcriptome of airway epithelial cells was compared by gene expression array analysis. Gene interaction networks were constructed and differential gene expression over all groups analyzed. The expression of several candidate genes was validated by qRT-PCR. RESULTS Bacterial killing, barrier integrity and the expression of antimicrobial peptides were not affected by ECIG-vapor compared to control samples. In contrast, TCIGs negatively affected host defense and reduced barrier integrity in a significant way. Furthermore ECIG-exposure significantly induced IL-8 secretion from Calu-3 cells but had no effect on NCI-H292 or primary cells. The gene expression based on array analysis distinguished TCIG-exposed cells from ECIG and room air-exposed samples. CONCLUSION The transcriptome patterns of host defense and inflammatory genes are significantly distinct between ECIG-exposed and TCIG-treated cells. The overall effects of ECIGs on epithelial cells are less in comparison to TCIG, and ECIG-vapor does not affect host defense. Nevertheless, although acute exposure to ECIG-vapor induces inflammation, and the expression of S100 proteins, long term in vivo data is needed to evaluate the chronic effects of ECIG use.
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Affiliation(s)
- Christian Herr
- Department of Internal Medicine V - Pulmonology, Allergology and Critical Care Medicine, Saarland University, D-66421, Homburg, Germany.
| | - Konstantinos Tsitouras
- Department of Internal Medicine V - Pulmonology, Allergology and Critical Care Medicine, Saarland University, D-66421, Homburg, Germany
| | - Julia Niederstraßer
- Department of Internal Medicine V - Pulmonology, Allergology and Critical Care Medicine, Saarland University, D-66421, Homburg, Germany
| | - Christina Backes
- Clinical Bioinformatics, Saarland University, University Hospital, 66123, Saarbrücken, Germany
| | - Christoph Beisswenger
- Department of Internal Medicine V - Pulmonology, Allergology and Critical Care Medicine, Saarland University, D-66421, Homburg, Germany
| | - Li Dong
- Department of Clinical Laboratory, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
| | - Loïc Guillot
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre de Recherche Saint-Antoine (CRSA), 75012, Paris, France
| | - Andreas Keller
- Clinical Bioinformatics, Saarland University, University Hospital, 66123, Saarbrücken, Germany
| | - Robert Bals
- Department of Internal Medicine V - Pulmonology, Allergology and Critical Care Medicine, Saarland University, D-66421, Homburg, Germany
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108
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Noël A, Hansen S, Zaman A, Perveen Z, Pinkston R, Hossain E, Xiao R, Penn A. In utero exposures to electronic-cigarette aerosols impair the Wnt signaling during mouse lung development. Am J Physiol Lung Cell Mol Physiol 2020; 318:L705-L722. [PMID: 32083945 DOI: 10.1152/ajplung.00408.2019] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Currently, more than 9 million American adults, including women of childbearing age, use electronic-cigarettes (e-cigs). Further, the prevalence of maternal vaping now approaching 10% is similar to that of maternal smoking. Little, however, is known about the effects of fetal exposures to nicotine-rich e-cig aerosols on lung development. In this study, we assessed whether in utero exposures to e-cig aerosols compromised lung development in mice. A third-generation e-cig device was used to expose pregnant BALB/c mice by inhalation to 36 mg/mL of nicotine cinnamon-flavored e-cig aerosols for 14-31 days. This included exposures for either 12 days before mating plus during gestation (preconception groups) or only during gestation (prenatal groups). Respective control mice were exposed to filtered air. Subgroups of offspring were euthanized at birth or at 4 wk of age. Compared with respective air-exposed controls, both preconception and prenatal exposures to e-cig aerosols significantly decreased the offspring birth weight and body length. In the preconception group, 7 inflammation-related genes were downregulated, including 4 genes common to both dams and fetuses, denoting an e-cig immunosuppressive effect. Lung morphometry assessments of preconception e-cig-exposed offspring showed a significantly increased tissue fraction at birth. This result was supported by the downregulation of 75 lung genes involved in the Wnt signaling, which is essential to lung organogenesis. Thus, our data indicate that maternal vaping impairs pregnancy outcomes, alters fetal lung structure, and dysregulates the Wnt signaling. This study provides experimental evidence for future regulations of e-cig products for pregnant women and developmentally vulnerable populations.
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Affiliation(s)
- Alexandra Noël
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Shannon Hansen
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Anusha Zaman
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Zakia Perveen
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Rakeysha Pinkston
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana.,Health Research Center, Department of Environmental Toxicology, Southern University and A&M College, Baton Rouge, Louisiana
| | - Ekhtear Hossain
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Rui Xiao
- Department of Anesthesiology, Columbia University Medical Center, New York, New York
| | - Arthur Penn
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
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109
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Nemmar A, Al-Salam S, Beegam S, Yuvaraju P, Zaaba NE, Yasin J, Ali BH. Waterpipe Tobacco Smoke Inhalation Triggers Thrombogenicity, Cardiac Inflammation and Oxidative Stress in Mice: Effects of Flavouring. Int J Mol Sci 2020; 21:E1291. [PMID: 32075078 PMCID: PMC7072969 DOI: 10.3390/ijms21041291] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 12/29/2019] [Accepted: 01/02/2020] [Indexed: 12/26/2022] Open
Abstract
The consumption of water-pipe smoking (WPS) has been promoted by the use of flavoured tobacco. However, little is known about the impact of flavouring on the cardiovascular toxicity induced by WPS inhalation. Here, we compared the cardiovascular effects and underlying mechanism of actions of plain (P) (unflavoured) versus apple-flavoured (AF) WPS (30 minutes/day, 5 days/week for 1 month) in mice. Control mice were exposed to air. Both P- and AF-WPS inhalation induced an increase in systolic blood pressure, thrombogenicity and plasma concentration of fibrinogen and von Willebrand factor. In heart homogenates, AF-WPS inhalation caused an increase of 8-isoprostane and a decrease in the levels of reduced glutathione (GSH) and superoxide dismutase (SOD). Nevertheless, P-WPS decreased only the activity of SOD. The concentrations of tumour necrosis factor α and interleukin 1β were increased only in heart homogenates of mice exposed to AF-WPS. Although both P- and AF-WPS increased the concentration of troponin I in heart homogenates and induced DNA damage, the concentration of cleaved caspase 3 was only increased in mice exposed to AF-WPS. Immunohistochemical analysis of the hearts showed that both P- and AF- WPS inhalation decreased the expression of SOD. Moreover, the expression of nuclear factor erythroid-derived 2-like 2 at nuclear level in the heart was higher in both AF-WPS and P-WPS compared with control group, and the effect observed in AF-WPS group was more significant than that seen in P-WPS group. Likewise, the concentration of heme oxygenase-1 was significantly increased in both P-WPS and AF-WPS groups compared with control group, and the effect seen in AF-group was higher than that observed in P-WPS group. In conclusion, our findings showed that both P- and AF-WPS induce thrombogenicity and cardiac injury, and that this toxicity is potentiated by the presence of flavouring.
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Affiliation(s)
- Abderrahim Nemmar
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, UAE; (S.B.); (P.Y.); (N.E.Z.)
- Zayed Center for Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, UAE
| | - Suhail Al-Salam
- Department of Pathology, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, UAE;
| | - Sumaya Beegam
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, UAE; (S.B.); (P.Y.); (N.E.Z.)
| | - Priya Yuvaraju
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, UAE; (S.B.); (P.Y.); (N.E.Z.)
| | - Nur Elena Zaaba
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, UAE; (S.B.); (P.Y.); (N.E.Z.)
| | - Javed Yasin
- Department of Internal Medicine, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, UAE;
| | - Badreldin H. Ali
- Department of Pharmacology and Clinical Pharmacy, College of Medicine & Health Sciences, Sultan Qaboos University, P.O. Box 35, Muscat 123, Al-Khod, Oman;
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110
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Go YY, Mun JY, Chae SW, Chang J, Song JJ. Comparison between in vitro toxicities of tobacco- and menthol-flavored electronic cigarette liquids on human middle ear epithelial cells. Sci Rep 2020; 10:2544. [PMID: 32054887 PMCID: PMC7018737 DOI: 10.1038/s41598-020-59290-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 01/17/2020] [Indexed: 12/20/2022] Open
Abstract
Since electronic-cigarettes (e-cigarettes) are considered less toxic than conventional tobacco smoking, the use of e-cigarettes has increased, and the market for e-cigarette liquids (e-liquids) is continuously increasing. However, many studies showed that e-cigarettes may cause various harmful effects in lung, oral and heart. In this study, we investigated the effects of e-liquids on otitis media (OM) using human middle ear epithelial cells (HMEECs). Menthol-flavored e-liquid induced significant cell death in HMEECs (IC50: 1.45 ± 0.14%) and tobacco-flavored e-liquid led to increase in inflammatory cytokine levels and higher mucin production. Flavored e-liquids decreased the mRNA levels of genes encoding epithelial sodium channels (ENaCs) in HMEECs. Apoptosis and autophagy reactions were induced by exposure of HMEECs to menthol- and tobacco-flavored e-liquids. Tobacco-flavored e-liquids caused a greater increase in the levels of autophagosome marker, LC3-II, compared to menthol-flavored e-liquids, which was followed by cell death. These results demonstrate that flavored e-liquids cause cytotoxicity via apoptosis, autophagy, inflammatory response, and mucin production in HMEECs. The flavors present in e-liquids might be a risk factor for the development of otitis media.
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Affiliation(s)
- Yoon Young Go
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea
| | - Ji Yoen Mun
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea
| | - Sung-Won Chae
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea
| | - Jiwon Chang
- Department of Otorhinolaryngology-Head and Neck Surgery, Hallym University College of Medicine, Seoul, Korea.
| | - Jae-Jun Song
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
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111
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Bozier J, Chivers EK, Chapman DG, Larcombe AN, Bastian NA, Masso-Silva JA, Byun MK, McDonald CF, Crotty Alexander LE, Ween MP. The Evolving Landscape of e-Cigarettes: A Systematic Review of Recent Evidence. Chest 2020; 157:1362-1390. [PMID: 32006591 DOI: 10.1016/j.chest.2019.12.042] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 01/12/2023] Open
Abstract
Smoking continues to be a burden to economies and health-care systems across the world. One proposed solution to the problem has been e-cigarettes; however, because they are a relatively new product in the market, little is known about their potential health impacts. Furthermore, e-cigarettes continue to evolve at a rapid rate, making it necessary to regularly review and summarize available studies. Although e-cigarettes are marketed as a smoking cessation tool by some manufacturers, the reality is that many nonsmokers, including youth, are using them. This review focuses on two major demographic groups (smokers and nonsmokers) and evaluates the most recent data (early 2017 to mid 2019) regarding the potential health effects of e-cigarettes. We assessed peer-reviewed studies on the health impacts of e-cigarettes, with a particular focus on common questions asked by policy makers, clinicians, and scientists: (1) What are the effects of e-cigarettes compared with air/not smoking?; (2) Is there any direct evidence of harm or benefit to humans?; (3) Is there a risk from secondhand exposure?; (4) What are the risks and/or benefits of e-cigarettes compared with tobacco cigarette use?; (5) Are there risks or benefits to specific populations (eg, people with COPD or asthma, pregnant women [and their offspring])?; (6) What are the effects of flavoring chemicals?; (7) What are the effects of including nicotine in e-liquids?; (8) How often is nicotine concentration labeling incorrect?; and (9) What are the risks when e-cigarettes explode?
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Affiliation(s)
- Jack Bozier
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia; Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia
| | | | - David G Chapman
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia; Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia
| | - Alexander N Larcombe
- Telethon Kids Institute, Perth, WA, Australia; School of Public Health, Curtin University, Perth, WA, Australia
| | - Nicole A Bastian
- Discipline of Obstetrics and Gynaecology, School of Medicine, Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia
| | - Jorge A Masso-Silva
- Department of Medicine, Division of Pulmonary Critical Care & Sleep, University of California San Diego, San Diego, CA
| | - Min Kwang Byun
- Department of Medicine, Division of Pulmonary Critical Care & Sleep, University of California San Diego, San Diego, CA; Division of Pulmonology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Christine F McDonald
- Department of Respiratory and Sleep Medicine, Austin Health, Heidelberg, VIC, Australia; Institute for Breathing and Sleep, Heidelberg, VIC, Australia; School of Medicine, University of Melbourne, VIC, Australia
| | - Laura E Crotty Alexander
- Department of Medicine, Division of Pulmonary Critical Care & Sleep, University of California San Diego, San Diego, CA; Pulmonary Critical Care Section, Veterans Affairs San Diego Healthcare System, San Diego, CA
| | - Miranda P Ween
- School of Medicine, University of Adelaide, Adelaide, SA, Australia; Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia.
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112
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Merecz-Sadowska A, Sitarek P, Zielinska-Blizniewska H, Malinowska K, Zajdel K, Zakonnik L, Zajdel R. A Summary of In Vitro and In Vivo Studies Evaluating the Impact of E-Cigarette Exposure on Living Organisms and the Environment. Int J Mol Sci 2020; 21:ijms21020652. [PMID: 31963832 PMCID: PMC7013895 DOI: 10.3390/ijms21020652] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/03/2020] [Accepted: 01/15/2020] [Indexed: 12/11/2022] Open
Abstract
Worldwide use of electronic cigarettes has been rapidly expanding over recent years, but the long-term effect of e-cigarette vapor exposure on human health and environment is not well established; however, its mechanism of action entails the production of reactive oxygen species and trace metals, and the exacerbation of inflammation, which are associated with potential cytotoxicity and genotoxicity. The present study examines the effects of selected liquid chemicals used in e-cigarettes, such as propylene glycol/vegetable glycerin, nicotine and flavorings, on living organisms; the data collected indicates that exposure to e-cigarette liquid has potentially detrimental effects on cells in vitro, and on animals and humans in vivo. While e-liquid exposure can adversely influence the physiology of living organisms, vaping is recommended as an alternative for tobacco smoking. The study also compares the impact of e-cigarette liquid exposure and traditional cigarette smoke on organisms and the environmental impact. The environmental influence of e-cigarette use is closely connected with the emission of airborne particulate matter, suggesting the possibility of passive smoking. The obtained data provides an insight into the impact of nicotine delivery systems on living organisms and the environment.
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Affiliation(s)
- Anna Merecz-Sadowska
- Department of Economic Informatics, University of Lodz, 90-214 Lodz, Poland; (K.M.); (L.Z.); (R.Z.)
- Correspondence: ; Tel.: +48-663-626-667
| | - Przemyslaw Sitarek
- Department of Biology and Pharmaceutical Botany, Medical University of Lodz, 90-151 Lodz, Poland;
| | | | - Katarzyna Malinowska
- Department of Economic Informatics, University of Lodz, 90-214 Lodz, Poland; (K.M.); (L.Z.); (R.Z.)
- Department of Allergology and Respiratory Rehabilitation, Medical University of Lodz, 90-725 Lodz, Poland;
| | - Karolina Zajdel
- Department of Medical Informatics and Statistics, Medical University of Lodz, 90-645 Lodz, Poland;
| | - Lukasz Zakonnik
- Department of Economic Informatics, University of Lodz, 90-214 Lodz, Poland; (K.M.); (L.Z.); (R.Z.)
| | - Radoslaw Zajdel
- Department of Economic Informatics, University of Lodz, 90-214 Lodz, Poland; (K.M.); (L.Z.); (R.Z.)
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113
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Macedonia TV, Krefft SD, Rose CS. Persistent Severe Fixed Airways Obstruction in a High-Dosing E-cigarette User. J Gen Intern Med 2020; 35:345-349. [PMID: 31705470 PMCID: PMC6957624 DOI: 10.1007/s11606-019-05462-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 08/01/2019] [Accepted: 09/26/2019] [Indexed: 12/29/2022]
Abstract
Electronic Nicotine Delivery Systems (ENDS), commonly referred to as "e-cigs," were first introduced in the United States in 2007. Since then, their use has grown substantially, with the largest market among adolescents and young adults. ENDS are often perceived by the public as safe alternatives to traditional cigarettes and as aids in smoking cessation. Little is known about inhalational hazards of e-cigs. We describe the case of a 45-year-old man who developed acute respiratory symptoms associated with onset of severe fixed airways obstruction 9 months after he quit traditional cigarettes and began high-dose vaping. Lung biopsy showed respiratory bronchiolitis. Analysis of his heated e-cigarette solution identified a mixture containing vanillin, aldehydes, alcohols and other chemicals, the inhalation effects of which have not been well-studied. This case report adds to the growing literature describing potentially severe lung health effects of vaping and provides a framework for taking a clinical vaping history so that the health consequences of e-cigarettes may be better understood.
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Affiliation(s)
- Tony V Macedonia
- University of Colorado School of Medicine Anschutz Medical Campus, Aurora, CO, USA.,Division of Environmental and Occupational Health Sciences , National Jewish Health, Denver, CO, USA
| | - Silpa D Krefft
- Division of Environmental and Occupational Health Sciences , National Jewish Health, Denver, CO, USA.,Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, CO, USA.,Department of Environmental and Occupational Health, Colorado School of Public Health, Aurora, CO, USA.,Division of Pulmonary and Critical Care Medicine, Veterans Administration EasternColorado Health Care System, Denver, CO, USA
| | - Cecile S Rose
- Division of Environmental and Occupational Health Sciences , National Jewish Health, Denver, CO, USA. .,Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, CO, USA. .,Department of Environmental and Occupational Health, Colorado School of Public Health, Aurora, CO, USA.
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114
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Muthumalage T, Lamb T, Friedman MR, Rahman I. E-cigarette flavored pods induce inflammation, epithelial barrier dysfunction, and DNA damage in lung epithelial cells and monocytes. Sci Rep 2019; 9:19035. [PMID: 31836726 PMCID: PMC6910911 DOI: 10.1038/s41598-019-51643-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/01/2019] [Indexed: 12/16/2022] Open
Abstract
E-cigarette flavored pods are increasing in use among young adults. Although marketed as a safer alternative to conventional cigarettes, the health effects of e-cigarette flavored pods are unknown. We hypothesized that e-cigarette flavored pods would cause oxidative stress, barrier dysfunction, and an inflammatory response in monocytes and lung epithelial cells. JUUL pod flavors (Fruit Medley, Virginia Tobacco, Cool Mint, Crème Brulee, Cool Cucumber, Mango, and Classic Menthol) and similar pod flavors (Just Mango-Strawberry Coconut and Caffé Latte) were tested. These pod flavors generated significant amounts of acellular ROS and induced significant mitochondrial superoxide production in bronchial epithelial cells (16-HBE). Lung epithelial cells (16-HBE, BEAS-2B) and monocytes (U937) exposed to various pod aerosols resulted in increased inflammatory mediators, such as IL-8 or PGE2. JUUL pod flavors, Crème Brulee and Cool Cucumber, caused epithelial barrier dysfunction in 16-HBE cells. Moreover, tested flavors also showed DNA damage upon exposure in monocytes. We determined the chemical constituents present in various flavors. Our data suggest that these constituents in flavored pods induce oxidative stress, inflammation, epithelial barrier dysfunction, and DNA damage in lung cells. These data provide insights into the regulation of e-cigarette flavored pods, as well as constituents in these flavors.
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Affiliation(s)
- Thivanka Muthumalage
- Department of Environmental Medicine, University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA
| | - Thomas Lamb
- Department of Environmental Medicine, University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA
| | - Michelle R Friedman
- Department of Chemistry & Biochemistry, College of Brockport, State University of New York, NY, New York, USA
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, School of Medicine & Dentistry, Rochester, NY, USA.
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115
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Lawyer GR, Jackson M, Prinz M, Lamb T, Wang Q, Muthumalage T, Rahman I. Classification of flavors in cigarillos and little cigars and their variable cellular and acellular oxidative and cytotoxic responses. PLoS One 2019; 14:e0226066. [PMID: 31825984 PMCID: PMC6905550 DOI: 10.1371/journal.pone.0226066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 11/12/2019] [Indexed: 01/10/2023] Open
Abstract
Flavored tobacco products are increasing in popularity but remain unregulated, with the exception of the ban on flavored conventional cigarettes. Lack of regulation of cigarillos and little cigars allows vendors to have their own version of popular flavors, each with different chemical components. A new classification system was created for flavored cigars in order to easily communicate our results with the scientific community. To understand the physicochemical characteristics of flavored little cigars and cigarillo smoke, size distribution and concentration of particulate matter in smoke were determined. Acellular reactive oxygen species generation was measured as an indirect measurement of the potential to cause oxidative stress in cells. In addition, cigarillo smoke extract treatment on bronchial epithelial (Beas-2b) cells were assessed to determine the flavor-induced cellular toxicity. Flavored cigars/cigarillos showed significant variability in the tested parameters between flavors as well as brands of the same flavor, but most of the cigars showed higher potential of generating oxidative stress, than research grade cigarettes. Flavored cigars produced maximum particle concentrations at 1.0μm and 4.0 μm compared with 3R4F reference research cigarettes. A differential cytotoxic response was observed with cigarillo smoke extract treatments, with “fruits/candy” and “drinks” being the most toxic, but were not more cytotoxic than smoke from cigarettes. These cigarillos with flavors must be well characterized for toxicity in order to prevent adverse effects caused by exposure to flavor chemicals. Our study provides insight into understanding the potential health effects of flavor-infused cigars/cigarillos and the need for the regulation of those flavoring chemicals in these products. Future research is directed to determine the flavoring toxicity of little cigars and cigarillos in vivo studies.
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Affiliation(s)
- Gina R Lawyer
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Monica Jackson
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Melanie Prinz
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Thomas Lamb
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Qixin Wang
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Thivanka Muthumalage
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Irfan Rahman
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, United States of America
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116
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Fonseca Fuentes X, Kashyap R, Hays JT, Chalmers S, Lama von Buchwald C, Gajic O, Gallo de Moraes A. VpALI-Vaping-related Acute Lung Injury: A New Killer Around the Block. Mayo Clin Proc 2019; 94:2534-2545. [PMID: 31767123 DOI: 10.1016/j.mayocp.2019.10.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 10/14/2019] [Indexed: 01/21/2023]
Abstract
The use of electronic cigarettes, known as vaping, has become increasingly popular over the past decade, particularly in the adolescent and young adult population, often exposing users to harmful chemicals. Vaping has been associated with a heterogeneous group of pulmonary disease. Recently, a multistate epidemic has emerged surrounding vaping-related acute lung injury, prompting the Centers for Disease Control and Prevention to list an official health advisory. In this review, we describe the current literature on the epidemiology, clinical significance, as well as recommended evaluation and treatment of vaping-related lung injury.
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Affiliation(s)
| | - Rahul Kashyap
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN
| | - J Taylor Hays
- Department of General Internal Medicine, Nicotine Dependence Center, Mayo Clinic, Rochester, MN
| | - Sarah Chalmers
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
| | | | - Ognjen Gajic
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN
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117
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Wavreil FD, Heggland SJ. Cinnamon-flavored electronic cigarette liquids and aerosols induce oxidative stress in human osteoblast-like MG-63 cells. Toxicol Rep 2019; 7:23-29. [PMID: 31871899 PMCID: PMC6909334 DOI: 10.1016/j.toxrep.2019.11.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 12/26/2022] Open
Abstract
As noncombustible nicotine delivery devices, electronic cigarettes (e-cigarettes) are the most popular tobacco product among youth. The widespread popularity of e-cigarettes combined with possible health consequences suggest a need to further research health hazards associated with e-cigarette use. Since conventional tobacco use is a risk factor for osteoporosis, this study investigates the impact of nicotine-free, cinnamon-flavored e-cigarette liquid (e-liquid) on bone-forming osteoblasts compared to flavorless e-liquid. Human tumor-derived osteoblast-like MG-63 cells were exposed for 24 h or 48 h to 0.0.4 %, 0.04 %, 0.4 % or 1 % of unvaped e-liquid or 0.0025 %, 0.025 %, 0.25 %, 1 % or 2.5 % of aerosol condensate in addition to a culture medium only control. Changes in cell viability were assessed by MTT assay, and the expression of a key bone protein, collagen type I, was analyzed by immunofluorescence. Production of reactive oxygen species (ROS) was detected by fluorometry to assess oxidative stress. Cell viability decreased in a dose-dependent manner, and ROS production increased, which was most pronounced with cinnamon-flavored e-liquids. There were no detectable changes in collagen type I protein following exposure to any of the aerosol condensates. This study demonstrates osteoblast-like cells are sensitive to both e-liquids and aerosol condensates and suggests the cytotoxicity of cinnamon-flavored e-liquids might be associated with oxidative stress rather than changes in collagen type I protein expression. This in vitro study provides insight into the potential impacts of e-cigarette use on bone cells.
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Affiliation(s)
| | - Sara J. Heggland
- Department of Biology, The College of Idaho, 2112 Cleveland Blvd, Caldwell, ID, 83605, USA
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118
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Rowell TR, Keating JE, Zorn BT, Glish GL, Shears SB, Tarran R. Flavored e-liquids increase cytoplasmic Ca 2+ levels in airway epithelia. Am J Physiol Lung Cell Mol Physiol 2019; 318:L226-L241. [PMID: 31693394 DOI: 10.1152/ajplung.00123.2019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
E-cigarettes are noncombustible, electronic nicotine-delivery devices that aerosolize an e-liquid, i.e., nicotine, in a propylene glycol-vegetable glycerin vehicle that also contains flavors. While the effects of nicotine are relatively well understood, more information regarding the potential biological effects of the other e-liquid constituents is needed. This is a serious concern, because e-liquids are available in >7,000 distinct flavors. We previously demonstrated that many e-liquids affect cell growth/viability through an unknown mechanism. Since Ca2+ is a ubiquitous second messenger that regulates cell growth, we characterized the effects of e-liquids on cellular Ca2+ homeostasis. To better understand the extent of this effect, we screened e-liquids for their ability to alter cytosolic Ca2+ levels and found that 42 of 100 flavored e-liquids elicited a cellular Ca2+ response. Banana Pudding (BP) e-liquid, a representative e-liquid from this group, caused phospholipase C activation, endoplasmic reticulum (ER) Ca2+ release, store-operated Ca2+ entry (SOCE), and protein kinase C (PKCα) phosphorylation. However, longer exposures to BP e-liquid depleted ER Ca2+ stores and inhibited SOCE, suggesting that this e-liquid may alter Ca2+ homeostasis by short- and long-term mechanisms. Since dysregulation of Ca2+ signaling can cause chronic inflammation, ER stress, and abnormal cell growth, flavored e-cigarette products that can elicit cell Ca2+ responses should be further screened for potential toxicity.
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Affiliation(s)
- Temperance R Rowell
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina.,Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina
| | - James E Keating
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - Bryan T Zorn
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina
| | - Gary L Glish
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - Stephen B Shears
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Robert Tarran
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina.,Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina
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119
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Muthumalage T, Rahman I. Cannabidiol differentially regulates basal and LPS-induced inflammatory responses in macrophages, lung epithelial cells, and fibroblasts. Toxicol Appl Pharmacol 2019; 382:114713. [PMID: 31437494 PMCID: PMC6917034 DOI: 10.1016/j.taap.2019.114713] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/16/2019] [Accepted: 08/17/2019] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Cannabidiol (CBD) containing products are available in a plethora of flavors in oral, sublingual, and inhalable forms. Immunotoxicological effects of CBD containing liquids were assessed by hypothesizing that CBD regulates oxidative stress and lipopolysaccharide (LPS) induced inflammatory responses in macrophages, epithelial cells, and fibroblasts. METHODS Epithelial cells (BEAS-2B and NHBE), macrophages (U937), and lung fibroblast cells (HFL-1) were treated with varying CBD concentrations or exposed to CBD aerosols. Generated reactive oxygen species (ROS) and inflammatory mediators were measured. Furthermore, monocytes and epithelial cells were stimulated with LPS in combination with CBD or dexamethasone to understand the anti-inflammatory effects of CBD. RESULTS CBD showed differential effects on IL-8 and MCP-1, and acellular and cellular ROS levels. CBD significantly attenuated LPS-induced NF-κB activity, IL-8, and MCP-1 release from macrophages. Cytokine array data depicted a differential cytokine response due to CBD. Inflammatory mediators, IL-8, serpin E1, CXCL1, IL-6, MIF, IFN-γ, MCP-1, RANTES, and TNF-α were induced, whereas MCP-1/CCL2, CCL5, eotaxin, and IL-2 were reduced. CBD and dexamethasone treatments reduced the IL-8 level induced by LPS when the cells were treated individually, but showed antagonistic effects when used in combination via MCPIP (monocytic chemotactic protein-induced protein). CONCLUSION CBD differentially regulated basal pro-inflammatory response and attenuated both LPS-induced cytokine release and NF-κB activity in monocytes, similar to dexamethasone. Thus, CBD has a differential inflammatory response and acts as an anti-inflammatory agent in pro-inflammatory conditions but acts as an antagonist with steroids, overriding the anti-inflammatory potential of steroids when used in combination.
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Affiliation(s)
- Thivanka Muthumalage
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, USA
| | - Irfan Rahman
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY, USA.
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120
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Krishnan-Sarin S, O’Malley SS. The science of flavour in tobacco products. WORLD HEALTH ORGANIZATION TECHNICAL REPORT SERIES 2019; 1015:125-142. [PMID: 36743396 PMCID: PMC9896977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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121
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Tobore TO. On the potential harmful effects of E-Cigarettes (EC) on the developing brain: The relationship between vaping-induced oxidative stress and adolescent/young adults social maladjustment. J Adolesc 2019; 76:202-209. [DOI: 10.1016/j.adolescence.2019.09.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 09/07/2019] [Accepted: 09/22/2019] [Indexed: 12/20/2022]
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122
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Abstract
Electronic cigarettes (e-cigarettes) are alternative, non-combustible tobacco products that generate an inhalable aerosol containing nicotine, flavors, propylene glycol, and vegetable glycerin. Vaping is now a multibillion dollar industry that appeals to current smokers, former smokers, and young people who have never smoked. E-cigarettes reached the market without either extensive preclinical toxicology testing or long term safety trials that would be required of conventional therapeutics or medical devices. Their effectiveness as a smoking cessation intervention, their impact at a population level, and whether they are less harmful than combustible tobacco products are highly controversial. Here, we review the evidence on the effects of e-cigarettes on respiratory health. Studies show measurable adverse biologic effects on organ and cellular health in humans, in animals, and in vitro. The effects of e-cigarettes have similarities to and important differences from those of cigarettes. Decades of chronic smoking are needed for development of lung diseases such as lung cancer or chronic obstructive pulmonary disease, so the population effects of e-cigarette use may not be apparent until the middle of this century. We conclude that current knowledge of these effects is insufficient to determine whether the respiratory health effects of e-cigarette are less than those of combustible tobacco products.
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Affiliation(s)
- Jeffrey E Gotts
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Sven-Eric Jordt
- Department of Anesthesiology, Duke University, Durham, NC, USA
- Yale Center for the Study of Tobacco Products and Addiction, Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Rob McConnell
- Department of Preventive Medicine, University of Southern California, CA, USA
| | - Robert Tarran
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
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123
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Berkelhamer SK, Helman JM, Gugino SF, Leigh NJ, Lakshminrusimha S, Goniewicz ML. In Vitro Consequences of Electronic-Cigarette Flavoring Exposure on the Immature Lung. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16193635. [PMID: 31569724 PMCID: PMC6801380 DOI: 10.3390/ijerph16193635] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/23/2019] [Accepted: 09/25/2019] [Indexed: 12/17/2022]
Abstract
Background: The developing lung is uniquely susceptible and may be at increased risk of injury with exposure to e-cigarette constituents. We hypothesize that cellular toxicity and airway and vascular responses with exposure to flavored refill solutions may be altered in the immature lung. Methods: Fetal, neonatal, and adult ovine pulmonary artery smooth muscle cells (PASMC) were exposed to popular flavored nicotine-free e-cigarette refill solutions (menthol, strawberry, tobacco, and vanilla) and unflavored solvents: propylene glycol (PG) or vegetable glycerin (VG). Viability was assessed by lactate dehydrogenase assay. Brochodilation and vasoreactivity were determined on isolated ovine bronchial rings (BR) and pulmonary arteries (PA). Results: Neither PG or VG impacted viability of immature or adult cells; however, exposure to menthol and strawberry flavored solutions increased cell death. Neonatal cells were uniquely susceptible to menthol flavoring-induced toxicity, and all four flavorings demonstrated lower lethal doses (LD50) in immature PASMC. Exposure to flavored solutions induced bronchodilation of neonatal BR, while only menthol induced airway relaxation in adults. In contrast, PG/VG and flavored solutions did not impact vasoreactivity with the exception of menthol-induced relaxation of adult PAs. Conclusion: The immature lung is uniquely susceptible to cellular toxicity and altered airway responses with exposure to common flavored e-cigarette solutions.
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Affiliation(s)
- Sara K Berkelhamer
- Department of Pediatrics, University at Buffalo, SUNY, Buffalo, NY 14203, USA.
| | - Justin M Helman
- Department of Pediatrics, University at Buffalo, SUNY, Buffalo, NY 14203, USA.
| | - Sylvia F Gugino
- Department of Pediatrics, University at Buffalo, SUNY, Buffalo, NY 14203, USA.
| | - Noel J Leigh
- Department of Health Behavior, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
| | | | - Maciej L Goniewicz
- Department of Health Behavior, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
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124
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Ween MP, Hamon R, Macowan MG, Thredgold L, Reynolds PN, Hodge SJ. Effects of E‐cigarette E‐liquid components on bronchial epithelial cells: Demonstration of dysfunctional efferocytosis. Respirology 2019; 25:620-628. [DOI: 10.1111/resp.13696] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 06/16/2019] [Accepted: 07/23/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Miranda P. Ween
- Department of Thoracic MedicineRoyal Adelaide Hospital Adelaide SA Australia
- School of MedicineUniversity of Adelaide Adelaide SA Australia
| | - Rhys Hamon
- Department of Thoracic MedicineRoyal Adelaide Hospital Adelaide SA Australia
- School of MedicineUniversity of Adelaide Adelaide SA Australia
| | - Matthew G. Macowan
- Department of Thoracic MedicineRoyal Adelaide Hospital Adelaide SA Australia
- School of MedicineUniversity of Adelaide Adelaide SA Australia
| | - Leigh Thredgold
- Department of Occupational and Environmental Health, School of Public HealthUniversity of Adelaide Adelaide SA Australia
| | - Paul N. Reynolds
- Department of Thoracic MedicineRoyal Adelaide Hospital Adelaide SA Australia
- School of MedicineUniversity of Adelaide Adelaide SA Australia
| | - Sandra J. Hodge
- School of MedicineUniversity of Adelaide Adelaide SA Australia
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125
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Worku D, Worku E. A narrative review evaluating the safety and efficacy of e-cigarettes as a newly marketed smoking cessation tool. SAGE Open Med 2019; 7:2050312119871405. [PMID: 31452888 PMCID: PMC6700846 DOI: 10.1177/2050312119871405] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/01/2019] [Indexed: 12/28/2022] Open
Abstract
Introduction: E-cigarettes are an alternative to traditional tobacco-based cigarettes. While having considerable societal awareness, conflicting evidence exists to support their claims that they are an effective smoking cessation tool and are safe. Currently >7000 flavours exist with evidence that they exhibit detrimental cellular and tissue effects. A literature review was conducted utilising PubMed and Google Scholar Databases identifying papers between 2014 and 2019. The aims of this study were to accurately gauge the safety and efficacy of e-cigarettes as a smoking cessation tool. Methods: Search terms including ‘electronic cigarettes’ and ‘vaping’ were used to identify suitable references. A total of 314 articles were identified from which papers were excluded due to risk of bias, insufficient detail or were duplicate from which 58 papers were used in the final review. Results: Evidence shows that e-cigarettes can have detrimental effects on several cell lines and animal models with their flavourings and nicotine content implicated; this has, however, not translated into major health outcomes after 3.5 years follow-up but has been linked to chronic lung disease and cardiovascular disease. While advertised as an effective smoking cessation tool, no consensus can be made regarding their effectiveness although the first robust randomised controlled trial reports some success. This, however, is offset by the fact that the most common e-cigarette use is as a dual user and that there is evidence of threefold increased risk of future tobacco smoking. Conclusion: Future research is needed to evaluate the long-term health outcomes and efficacy of e-cigarettes as a smoking cessation tool with greater discussion between patients and clinicians regarding this smoking cessation tool.
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Affiliation(s)
| | - Elliott Worku
- Royal Brisbane and Women's Hospital Foundation, Herston, QLD, Australia
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126
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Cirillo S, Vivarelli F, Turrini E, Fimognari C, Burattini S, Falcieri E, Rocchi MBL, Cardenia V, Rodriguez-Estrada MT, Paolini M, Canistro D. The Customizable E-cigarette Resistance Influences Toxicological Outcomes: Lung Degeneration, Inflammation, and Oxidative Stress-Induced in a Rat Model. Toxicol Sci 2019; 172:132-145. [PMID: 31388676 DOI: 10.1093/toxsci/kfz176] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/12/2019] [Accepted: 07/19/2019] [Indexed: 12/26/2022] Open
Abstract
AbstractDespite the knowledge gap regarding the risk-benefit ratio of the electronic cigarette (e-cig), its use has grown exponentially, even in teenagers. E-cig vapor contains carcinogenic compounds (eg, formaldehyde, acetaldehyde, and acrolein) and free radicals, especially reactive oxygen species (ROS) that cause toxicological effects, including DNA damage. The role of e-cig voltage customization on molecule generation has been reported, but the effects of the resistance on e-cig emissions and toxicity are unknown. Here, we show that the manipulation of e-cig resistance influences the carbonyls production from nonnicotine vapor and the oxidative and inflammatory status in a rat model. Fixing the voltage at the conventional 3.5 V, we observed that the amount of the selected aldehydes increased as the resistance decreased from 1.5 to 0.25 Ω. Under these conditions, we exposed Sprague Dawley rats to e-cig aerosol for 28 days, and we studied the pulmonary inflammation, oxidative stress, tissue damage, and blood homeostasis. We found a perturbation of the antioxidant and phase II enzymes, probably related to the increased ROS levels due to the enhanced xanthine oxidase and P450-linked monooxygenases. Furthermore, frames from scanning electron microscope showed a disorganization of alveolar and bronchial epithelium in 0.25 Ω group. Overall, various toxicological outcomes, widely recognized as smoke-related injuries, can potentially occur in e-cig consumers who use low-voltage and resistance device. Our study suggests that certain “tips for vaping safety” cannot be established, and encourages further independent investigations to help public health agencies in regulating the e-cig use.
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Affiliation(s)
- Silvia Cirillo
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum—University of Bologna, 40126 Bologna
| | - Fabio Vivarelli
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum—University of Bologna, 40126 Bologna
| | - Eleonora Turrini
- Department for Life Quality Studies, Alma Mater Studiorum—University of Bologna, 47921 Rimini
| | - Carmela Fimognari
- Department for Life Quality Studies, Alma Mater Studiorum—University of Bologna, 47921 Rimini
| | - Sabrina Burattini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino
| | - Elisabetta Falcieri
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino
| | | | - Vladimiro Cardenia
- Department of Agricultural, Forest and Food Sciences, University of Turin
| | - Maria Teresa Rodriguez-Estrada
- Department of Agricultural and Food Sciences, Alma Mater Studiorum—University of Bologna, 40127 Bologna
- Interdepartmental Centre for Industrial Agrofood Research, Alma Mater Studiorum—University of Bologna, 47521 Cesena, Italy
| | - Moreno Paolini
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum—University of Bologna, 40126 Bologna
| | - Donatella Canistro
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum—University of Bologna, 40126 Bologna
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127
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Thimraj TA, Sompa SI, Ganguly K, Ernstgård L, Johanson G, Palmberg L, Upadhyay S. Evaluation of diacetyl mediated pulmonary effects in physiologically relevant air-liquid interface models of human primary bronchial epithelial cells. Toxicol In Vitro 2019; 61:104617. [PMID: 31381966 DOI: 10.1016/j.tiv.2019.104617] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/03/2019] [Accepted: 08/01/2019] [Indexed: 12/17/2022]
Abstract
Diacetyl is an artificial flavouring agent, known to cause bronchiolitis obliterans. Diacetyl-induced pulmonary effects were assessed in human primary bronchial epithelial cells (PBEC) cultured at air-liquid interface (ALI). The PBEC-ALI models were exposed to clean air (sham) and diacetyl vapour (1, 3, 10 and 30 ppm) for 30 min. At 6 and 24 h post-exposure, cell medium was sampled for assessment of cytotoxicity measurement, and CXCL8, MMP9 secretion by ELISA. Pro-inflammatory, oxidative stress, tissue injury/repair, anti-protease and beta-defensin markers were assessed using qRT-PCR. Additionally, epidermal growth factor receptor ligands (amphiregulin) and anti-protease (SLPI) were analysed at 6 h, 8 h and 24 h post exposure to 1 and 10 ppm diacetyl. No significant cytotoxicity was observed at any exposure level. MMP9 was significantly increased in both apical and basal media at 24 h. Both SLPI and amphiregulin secretion were significantly increased following exposure to 10 ppm diacetyl. Exposure of PBEC-ALI model to diacetyl vapour resulted in significantly altered transcript expression of pro-inflammatory, oxidative stress, anti-protease, tissue injury/repair markers. Changes in transcript expression of significantly altered markers were more prominent 24 h post-exposure compared to 6 h. This study warrants further mechanistic investigations to elucidate the pulmonary effects of inhaled diacetyl vapour using physiologically relevant in vitro models.
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Affiliation(s)
- Tania A Thimraj
- Integrative Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Shanzina I Sompa
- Integrative Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Koustav Ganguly
- Integrative Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Lena Ernstgård
- Integrative Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Gunnar Johanson
- Integrative Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Lena Palmberg
- Integrative Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Swapna Upadhyay
- Integrative Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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128
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Polosa R, O'Leary R, Tashkin D, Emma R, Caruso M. The effect of e-cigarette aerosol emissions on respiratory health: a narrative review. Expert Rev Respir Med 2019; 13:899-915. [PMID: 31375047 DOI: 10.1080/17476348.2019.1649146] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Introduction: Due to the uptake in the use of e-cigarettes (ECs), evidence on their health effects is needed to inform health care and policy. Some regulators and health professionals have raised concerns that the respirable aerosols generated by ECs contain several constituents of potential toxicological and biological relevance to respiratory health. Areas covered: We critically assess published research on the respiratory system investigating the effects of ECs in preclinical models, clinical studies of people who switched to ECs from tobacco cigarettes, and population surveys. We assess the studies for the quality of their methodology and accuracy of their interpretation. To adequately assess the impact of EC use on human health, addressing common mistakes and developing robust and realistic methodological recommendations is an urgent priority. The findings of this review indicate that ECs under normal conditions of use demonstrate far fewer respiratory risks than combustible tobacco cigarettes. EC users and smokers considering ECs have the right to be informed about the relative risks of EC use, and to be made aware that findings of studies published by the media are not always reliable. Expert opinion: Growing evidence supports the relative safety of EC emission aerosols for the respiratory tract compared to tobacco smoke.
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Affiliation(s)
- Riccardo Polosa
- Centro per la Prevenzione e Cura del Tabagismo (CPCT), Azienda Ospedaliero-Universitaria "Policlinico-V. Emanuele", Università of Catania , Catania , Italy.,Center of Excellence for the acceleration of HArm Reduction (CoEHAR), University of Catania , Catania , Italy
| | - Renée O'Leary
- Canadian Institute for Substance Use Research , Victoria , Canada
| | - Donald Tashkin
- David Geffen School of Medicine at the University of California, Los Angeles (UCLA) , Los Angeles , CA , USA
| | - Rosalia Emma
- Dipartimento di Medicina Clinica e Sperimentale (MEDCLIN), University of Catania , Catania , Italy.,Dipartimento di Scienze biomediche e biotecnologiche (BIOMETEC), University of Catania , Catania , Italy
| | - Massimo Caruso
- Dipartimento di Medicina Clinica e Sperimentale (MEDCLIN), University of Catania , Catania , Italy.,Dipartimento di Scienze biomediche e biotecnologiche (BIOMETEC), University of Catania , Catania , Italy
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129
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Czekala L, Simms L, Stevenson M, Tschierske N, Maione AG, Walele T. Toxicological comparison of cigarette smoke and e-cigarette aerosol using a 3D in vitro human respiratory model. Regul Toxicol Pharmacol 2019; 103:314-324. [DOI: 10.1016/j.yrtph.2019.01.036] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 10/27/2022]
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130
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Soneji SS, Knutzen KE, Villanti AC. Use of Flavored E-Cigarettes Among Adolescents, Young Adults, and Older Adults: Findings From the Population Assessment for Tobacco and Health Study. Public Health Rep 2019; 134:282-292. [PMID: 30857471 DOI: 10.1177/0033354919830967] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVES The use of flavored electronic cigarettes (e-cigarettes) is common among e-cigarette users, but little is known about the potential harms of flavorings, the extent to which the concurrent use of multiple flavor types occurs, and the correlates of flavor type use. The objective of this study was to assess the types of e-cigarette flavors used by adolescent (aged 12-17), young adult (aged 18-24), and older adult (aged ≥25) e-cigarette users. METHODS We assessed the prevalence of flavored e-cigarette use within the past month by flavor types and concurrent use of multiple flavor types among past-month e-cigarette users sampled during Wave 2 (2014-2015) of the Population Assessment for Tobacco and Health Study among 414 adolescents, 961 young adults, and 1711 older adults. We used weighted logistic regression models for the use of fruit-, candy-, mint/menthol-, tobacco-, or other-flavored e-cigarettes and concurrent use of multiple flavor types. Covariates included demographic characteristics, e-cigarette use frequency, cigarette smoking status, current use of other tobacco products, and reasons for e-cigarette use. RESULTS The leading e-cigarette flavor types among adolescents were fruit, candy, and other flavors; among young adults were fruit, candy, and mint/menthol; and among older adults were tobacco or other flavors, fruit, and mint/menthol. Compared with older adults, adolescents and young adults were more likely to use fruit-flavored e-cigarettes (adjusted odds ratio [aOR] = 3.35; 95% confidence interval [CI], 2.56-4.38; and aOR = 2.31; 95% CI, 1.77-3.01, respectively) and candy-flavored e-cigarettes (aOR = 3.81; 95% CI, 2.74-5.28; and aOR = 2.95; 95% CI, 2.29-3.80, respectively) and concurrently use multiple flavor types (aOR = 4.58; 95% CI, 3.39-6.17; and aOR = 2.28; 95% CI, 1.78-2.91, respectively). CONCLUSIONS Regulation of sweet e-cigarette flavors (eg, fruit and candy) may help reduce the use of e-cigarettes among young persons without substantially burdening adult e-cigarette users.
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Affiliation(s)
- Samir S Soneji
- 1 Dartmouth Geisel School of Medicine, Dartmouth-Hitchcock Norris Cotton Cancer Center, Lebanon, NH, USA.,2 Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth Geisel School of Medicine, Lebanon, NH, USA
| | - Kristin E Knutzen
- 2 Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth Geisel School of Medicine, Lebanon, NH, USA
| | - Andrea C Villanti
- 3 Vermont Center on Behavior and Health, Department of Psychiatry, University of Vermont Larner College of Medicine, Burlington, VT, USA
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131
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Clapp PW, Lavrich KS, van Heusden CA, Lazarowski ER, Carson JL, Jaspers I. Cinnamaldehyde in flavored e-cigarette liquids temporarily suppresses bronchial epithelial cell ciliary motility by dysregulation of mitochondrial function. Am J Physiol Lung Cell Mol Physiol 2019; 316:L470-L486. [PMID: 30604630 PMCID: PMC6459291 DOI: 10.1152/ajplung.00304.2018] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 01/23/2023] Open
Abstract
Aldehydes in cigarette smoke (CS) impair mitochondrial function and reduce ciliary beat frequency (CBF), leading to diminished mucociliary clearance (MCC). However, the effects of aldehyde e-cigarette flavorings on CBF are unknown. The purpose of this study was to investigate whether cinnamaldehyde, a flavoring agent commonly used in e-cigarettes, disrupts mitochondrial function and impairs CBF on well-differentiated human bronchial epithelial (hBE) cells. To this end, hBE cells were exposed to diluted cinnamon-flavored e-liquids and vaped aerosol and assessed for changes in CBF. hBE cells were subsequently exposed to various concentrations of cinnamaldehyde to establish a dose-response relationship for effects on CBF. Changes in mitochondrial oxidative phosphorylation and glycolysis were evaluated by Seahorse Extracellular Flux Analyzer, and adenine nucleotide levels were quantified by HPLC. Both cinnamaldehyde-containing e-liquid and vaped aerosol rapidly yet transiently suppressed CBF, and exposure to cinnamaldehyde alone recapitulated this effect. Cinnamaldehyde impaired mitochondrial respiration and glycolysis in a dose-dependent manner, and intracellular ATP levels were significantly but temporarily reduced following exposure. Addition of nicotine had no effect on the cinnamaldehyde-induced suppression of CBF or mitochondrial function. These data indicate that cinnamaldehyde rapidly disrupts mitochondrial function, inhibits bioenergetic processes, and reduces ATP levels, which correlates with impaired CBF. Because normal ciliary motility and MCC are essential respiratory defenses, inhalation of cinnamaldehyde may increase the risk of respiratory infections in e-cigarette users.
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Affiliation(s)
- Phillip W Clapp
- Curriculum in Toxicology, School of Medicine, University of North Carolina , Chapel Hill, North Carolina
- Center for Environmental Medicine, Asthma, and Lung Biology, School of Medicine, University of North Carolina , Chapel Hill, North Carolina
| | - Katelyn S Lavrich
- Curriculum in Toxicology, School of Medicine, University of North Carolina , Chapel Hill, North Carolina
| | | | - Eduardo R Lazarowski
- Department of Medicine, University of North Carolina , Chapel Hill, North Carolina
| | - Johnny L Carson
- Center for Environmental Medicine, Asthma, and Lung Biology, School of Medicine, University of North Carolina , Chapel Hill, North Carolina
- Department of Pediatrics, University of North Carolina , Chapel Hill, North Carolina
| | - Ilona Jaspers
- Curriculum in Toxicology, School of Medicine, University of North Carolina , Chapel Hill, North Carolina
- Center for Environmental Medicine, Asthma, and Lung Biology, School of Medicine, University of North Carolina , Chapel Hill, North Carolina
- Department of Pediatrics, University of North Carolina , Chapel Hill, North Carolina
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132
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Hua M, Omaiye EE, Luo W, McWhirter KJ, Pankow JF, Talbot P. Identification of Cytotoxic Flavor Chemicals in Top-Selling Electronic Cigarette Refill Fluids. Sci Rep 2019; 9:2782. [PMID: 30808901 PMCID: PMC6391497 DOI: 10.1038/s41598-019-38978-w] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 01/03/2019] [Indexed: 01/28/2023] Open
Abstract
We identified the most popular electronic cigarette (EC) refill fluids using an Internet survey and local and online sales information, quantified their flavor chemicals, and evaluated cytotoxicities of the fluids and flavor chemicals. "Berries/Fruits/Citrus" was the most popular EC refill fluid flavor category. Twenty popular EC refill fluids were purchased from local shops, and the ingredient flavor chemicals were identified and quantified by gas chromatography-mass spectrometry. Total flavor chemical concentrations ranged from 0.6 to 27.9 mg/ml, and in 95% of the fluids, total flavor concentration was greater than nicotine concentration. The 20 most popular refill fluids contained 99 quantifiable flavor chemicals; each refill fluid contained 22 to 47 flavor chemicals, most being esters. Some chemicals were found frequently, and several were present in most products. At a 1% concentration, 80% of the refill fluids were cytotoxic in the MTT assay. Six pure standards of the flavor chemicals found at the highest concentrations in the two most cytotoxic refill fluids were effective in the MTT assay, and ethyl maltol, which was in over 50% of the products, was the most cytotoxic. These data show that the cytotoxicity of some popular refill fluids can be attributed to their high concentrations of flavor chemicals.
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Affiliation(s)
- My Hua
- Environmental Toxicology Graduate Program, University of California, Riverside, Riverside, CA, United States
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA, United States
| | - Esther E Omaiye
- Environmental Toxicology Graduate Program, University of California, Riverside, Riverside, CA, United States
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA, United States
| | - Wentai Luo
- Department of Chemistry and Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, United States
| | - Kevin J McWhirter
- Department of Chemistry and Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, United States
| | - James F Pankow
- Department of Chemistry and Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, United States
| | - Prue Talbot
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA, United States.
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133
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Li D, Sundar IK, McIntosh S, Ossip DJ, Goniewicz ML, O'Connor RJ, Rahman I. Association of smoking and electronic cigarette use with wheezing and related respiratory symptoms in adults: cross-sectional results from the Population Assessment of Tobacco and Health (PATH) study, wave 2. Tob Control 2019; 29:140-147. [PMID: 30760629 DOI: 10.1136/tobaccocontrol-2018-054694] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 12/13/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Wheezing is a symptom of potential respiratory disease and known to be associated with smoking. Electronic cigarette use ('vaping') has increased exponentially in recent years. This study examined the cross-sectional association of vaping with wheezing and related respiratory symptoms and compare this association with smokers and dual users. METHODS The Population Assessment of Tobacco and Health study wave 2 data collected from October 2014 to October 2015 with 28 171 adults were used. The cross-sectional association of vaping with self-reported wheezing and related respiratory symptoms relative to smokers and dual users of tobacco and electronic cigarettes were studied using multivariable logistic and cumulative logistic regression models with consideration of complex sampling design. RESULTS Among the 28 171 adult participants, 641 (1.2%) were current vapers who used e-cigarettes exclusively, 8525 (16.6%) were current exclusive smokers, 1106 (2.0%) were dual users and 17 899 (80.2%) were non-users. Compared with non-users, risks of wheezing and related respiratory symptoms were significantly increased in current vapers (adjusted OR (aOR)=1.67, 95% CI: 1.23 to 2.15). Current vapers had significantly lower risk in wheezing and related respiratory symptoms compared with current smokers (aOR=0.68, 95% CI: 0.53 to 0.87). No significant differences were found between dual users and current smokers in risk of wheezing and related respiratory symptoms (aOR=1.06, 95% CI: 0.91 to 1.24). CONCLUSIONS Vaping was associated with increased risk of wheezing and related respiratory symptoms. Current vapers had lower risk in wheezing and related respiratory symptoms than current smokers or dual users but higher than non-users. Both dual use and smoking significantly increased the risk of wheezing and related respiratory symptoms.
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Affiliation(s)
- Dongmei Li
- Department of Clinical & Translational Research, University of Rochester Medical Center, Rochester, New York, USA
| | - Isaac K Sundar
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Scott McIntosh
- Department of Public Health Sciences, University of Rochester Medical Center, Rochester, New York, USA
| | - Deborah J Ossip
- Department of Public Health Sciences, University of Rochester Medical Center, Rochester, New York, USA
| | - Maciej Lukasz Goniewicz
- Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | - Richard J O'Connor
- Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, USA
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134
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Otero CE, Noeker JA, Brown MM, Wavreil FDM, Harvey WA, Mitchell KA, Heggland SJ. Electronic cigarette liquid exposure induces flavor-dependent osteotoxicity and increases expression of a key bone marker, collagen type I. J Appl Toxicol 2019; 39:888-898. [PMID: 30690755 DOI: 10.1002/jat.3777] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 11/09/2022]
Abstract
Electronic cigarettes (e-cigarettes) are nicotine delivery devices advertised as a healthier alternative to conventional tobacco products, but their rapid rise in popularity outpaces research on potential health consequences. As conventional tobacco use is a risk factor for osteoporosis, this study examines whether exposure to electronic liquid (e-liquid) used in e-cigarettes affects bone-forming osteoblasts. Human MG-63 and Saos-2 osteoblast-like cells were treated for 48 hours with 0.004%-4.0% dilutions of commercially available e-liquids of various flavors with or without nicotine. Changes in cell viability and key osteoblast markers, runt-related transcription factor 2 and Col1a1, were assessed. With all e-liquids tested, cell viability decreased in a dose-dependent manner, which was least pronounced in flavorless e-liquids, most pronounced in cinnamon-flavored e-liquids and occurred independently of nicotine. Col1a1, but not runt-related transcription factor 2, mRNA expression was upregulated in response to coffee-flavored and fruit-flavored e-liquids. Cells treated with a non-cytotoxic concentration of fruit-flavored Mango Blast e-liquid with or without nicotine showed significantly increased collagen type I protein expression compared to culture medium only. We conclude that the degree of osteotoxicity is flavor-dependent and occurs independently of nicotine and that flavored e-liquids reveal collagen type I as a potential target in osteoblasts. This study elucidates potential consequences of e-cigarette use in bone.
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Affiliation(s)
- Claire E Otero
- Department of Biology, The College of Idaho, 2112 Cleveland Blvd, Caldwell, ID, 83605, USA
| | - Jacob A Noeker
- Department of Biology, The College of Idaho, 2112 Cleveland Blvd, Caldwell, ID, 83605, USA
| | - Mary M Brown
- Department of Biology, The College of Idaho, 2112 Cleveland Blvd, Caldwell, ID, 83605, USA
| | - Florence D M Wavreil
- Department of Biology, The College of Idaho, 2112 Cleveland Blvd, Caldwell, ID, 83605, USA
| | - Wendy A Harvey
- Biomolecular Research Center, Boise State University, Boise, ID, 83725, USA
| | - Kristen A Mitchell
- Department of Biological Sciences, Boise State University, Boise, ID, 83725, USA
| | - Sara J Heggland
- Department of Biology, The College of Idaho, 2112 Cleveland Blvd, Caldwell, ID, 83605, USA
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136
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Cigarette smoke condensate may disturb immune function with apoptotic cell death by impairing function of organelles in alveolar macrophages. Toxicol In Vitro 2018; 52:351-364. [DOI: 10.1016/j.tiv.2018.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 01/24/2023]
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137
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Noël A, Verret CM, Hasan F, Lomnicki S, Morse J, Robichaud A, Penn AL. Generation of Electronic Cigarette Aerosol by a Third-Generation Machine-Vaping Device: Application to Toxicological Studies. J Vis Exp 2018:58095. [PMID: 30199038 PMCID: PMC6231858 DOI: 10.3791/58095] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Electronic-cigarette (e-cig) devices use heat to produce an inhalable aerosol from a liquid (e-liquid) composed mainly of humectants, nicotine, and flavoring chemicals. The aerosol produced includes fine and ultrafine particles, and potentially nicotine and aldehydes, which can be harmful to human health. E-cig users inhale these aerosols and, with the third-generation of e-cig devices, control design features (resistance and voltage) in addition to the choice of e-liquids, and the puffing profile. These are key factors that can significantly impact the toxicity of the inhaled aerosols. E-cig research, however, is challenging and complex mostly due to the absence of standardized assessments and to the numerous varieties of e-cig models and brands, as well as e-liquid flavors and solvents that are available on the market. These considerations highlight the urgent need to harmonize e-cig research protocols, starting with e-cig aerosol generation and characterization techniques. The current study focuses on this challenge by describing a detailed step-by-step e-cig aerosol generation technique with specific experimental parameters that are thought to be realistic and representative of real-life exposure scenarios. The methodology is divided into four sections: preparation, exposure, post-exposure analysis, plus cleaning and maintenance of the device. Representative results from using two types of e-liquid and various voltages are presented in terms of mass concentration, particle size distribution, chemical composition and cotinine levels in mice. These data demonstrate the versatility of the e-cig exposure system used, aside from its value for toxicological studies, as it allows for a broad range of computer-controlled exposure scenarios, including automated representative vaping topography profiles.
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Affiliation(s)
- Alexandra Noël
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University;
| | - Christina M Verret
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University
| | - Farhana Hasan
- Department of Environmental Sciences, College of the Coast & Environment, Louisiana State University
| | - Slawomir Lomnicki
- Department of Environmental Sciences, College of the Coast & Environment, Louisiana State University
| | - John Morse
- SCIREQ Scientific Respiratory Equipment Inc
| | | | - Arthur L Penn
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University
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138
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Scott A, Lugg ST, Aldridge K, Lewis KE, Bowden A, Mahida RY, Grudzinska FS, Dosanjh D, Parekh D, Foronjy R, Sapey E, Naidu B, Thickett DR. Pro-inflammatory effects of e-cigarette vapour condensate on human alveolar macrophages. Thorax 2018; 73:1161-1169. [PMID: 30104262 PMCID: PMC6269646 DOI: 10.1136/thoraxjnl-2018-211663] [Citation(s) in RCA: 200] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/16/2018] [Accepted: 06/11/2018] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Vaping may increase the cytotoxic effects of e-cigarette liquid (ECL). We compared the effect of unvaped ECL to e-cigarette vapour condensate (ECVC) on alveolar macrophage (AM) function. METHODS AMs were treated with ECVC and nicotine-free ECVC (nfECVC). AM viability, apoptosis, necrosis, cytokine, chemokine and protease release, reactive oxygen species (ROS) release and bacterial phagocytosis were assessed. RESULTS Macrophage culture with ECL or ECVC resulted in a dose-dependent reduction in cell viability. ECVC was cytotoxic at lower concentrations than ECL and resulted in increased apoptosis and necrosis. nfECVC resulted in less cytotoxicity and apoptosis. Exposure of AMs to a sub-lethal 0.5% ECVC/nfECVC increased ROS production approximately 50-fold and significantly inhibited phagocytosis. Pan and class one isoform phosphoinositide 3 kinase inhibitors partially inhibited the effects of ECVC/nfECVC on macrophage viability and apoptosis. Secretion of interleukin 6, tumour necrosis factor α, CXCL-8, monocyte chemoattractant protein 1 and matrix metalloproteinase 9 was significantly increased following ECVC challenge. Treatment with the anti-oxidant N-acetyl-cysteine (NAC) ameliorated the cytotoxic effects of ECVC/nfECVC to levels not significantly different from baseline and restored phagocytic function. CONCLUSIONS ECVC is significantly more toxic to AMs than non-vaped ECL. Excessive production of ROS, inflammatory cytokines and chemokines induced by e-cigarette vapour may induce an inflammatory state in AMs within the lung that is partly dependent on nicotine. Inhibition of phagocytosis also suggests users may suffer from impaired bacterial clearance. While further research is needed to fully understand the effects of e-cigarette exposure in humans in vivo, we caution against the widely held opinion that e-cigarettes are safe.
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Affiliation(s)
- Aaron Scott
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - Sebastian T Lugg
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - Kerrie Aldridge
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - Keir E Lewis
- College of Medicine, Swansea University, Swansea, UK
| | - Allen Bowden
- Analytical Facility, School of Chemistry, University of Birmingham, Birmingham, UK
| | - Rahul Y Mahida
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - Frances Susanna Grudzinska
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - Davinder Dosanjh
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - Dhruv Parekh
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - Robert Foronjy
- Division of Pulmonary and Critical Care Medicine,Department of Medicine, SUNY Downstate Medical Center, Brooklyn, New York, USA
| | - Elizabeth Sapey
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - Babu Naidu
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
| | - David R Thickett
- Birmingham Acute Care Research Group Institute of Inflammation and Ageing (IIA), University of Birmingham, Birmingham, UK
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139
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Vreeke S, Peyton DH, Strongin RM. Triacetin Enhances Levels of Acrolein, Formaldehyde Hemiacetals, and Acetaldehyde in Electronic Cigarette Aerosols. ACS OMEGA 2018; 3:7165-7170. [PMID: 30087908 PMCID: PMC6068691 DOI: 10.1021/acsomega.8b00842] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/13/2018] [Indexed: 05/13/2023]
Abstract
The health effects of inhaled electronic cigarette (e-cigarette) flavoring compounds are largely unknown. Earlier reports of their chemical reactivity have been conflicting, with some claiming, for example, that the degradation of flavoring chemicals in e-cigarettes to aldehydes is statistically insignificant. It is thus important to understand how these molecules react to afford enhanced aerosol products. The purpose of the current study was to investigate the origin of formaldehyde, acrolein, and acetaldehyde in e-cigarettes that contain the popular additive, triacetin (TA). By using 13C labeling and a combination of 1H NMR and 13C NMR, we were able to identify that ester hydrolysis of TA occurs to form acetic acid (HOAc) during aerosolization. The released HOAc acts as a catalyst in the degradation of propylene glycol (PG) and glycerol (GLY), increasing the formation of formaldehyde hemiacetals, acrolein, and acetaldehyde. A solution of 10% TA in 1:1 PG/GLY e-liquid was aerosolized using two different e-cigarettes at two wattages. Each device exhibited a significant increase in aldehyde levels, of up to 185% compared to the aerosol from a 1:1 PG/GLY e-liquid. In addition, the GLY formaldehyde hemiacetal was more predominant within the presence of HOAc, indicating that GLY may be relatively more prone to degradation from protonation.
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Affiliation(s)
- Shawna Vreeke
- Department of Chemistry, Portland
State University, 1719
SW 10th Avenue, Portland, Oregon 97201, United
States
| | - David H. Peyton
- Department of Chemistry, Portland
State University, 1719
SW 10th Avenue, Portland, Oregon 97201, United
States
| | - Robert M. Strongin
- Department of Chemistry, Portland
State University, 1719
SW 10th Avenue, Portland, Oregon 97201, United
States
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140
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Wang JB, Olgin JE, Nah G, Vittinghoff E, Cataldo JK, Pletcher MJ, Marcus GM. Cigarette and e-cigarette dual use and risk of cardiopulmonary symptoms in the Health eHeart Study. PLoS One 2018; 13:e0198681. [PMID: 30044773 PMCID: PMC6059385 DOI: 10.1371/journal.pone.0198681] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 05/23/2018] [Indexed: 12/20/2022] Open
Abstract
E-cigarettes are promoted as healthier alternatives to conventional cigarettes. Many cigarette smokers use both products. It is unknown whether the additional use of e-cigarettes among cigarette smokers (dual users) is associated with reduced exposure to tobacco-related health risks. Cross-sectional analysis was performed using baseline data from the Health eHeart Study, among English-speaking adults, mostly from the United States. Cigarette use (# cigarettes/day) and/or e-cigarette use (# days, # cartridges, and # puffs) were compared between cigarette only users vs. dual users. Additionally, we examined cardiopulmonary symptoms/ conditions across product use: no product (neither), e-cigarettes only, cigarettes only, and dual use. Among 39,747 participants, 573 (1.4%) reported e-cigarette only use, 1,693 (4.3%) reported cigarette only use, and 514 (1.3%) dual use. Dual users, compared to cigarette only users, reported a greater median (IQR) number of cigarettes per day, 10.0 (4.0-20.0) vs. 9.0 (3.0-15.0) (p < .0001), a lower (worse) median (IQR) SF-12 general health score, 3.3 (2.8-3.8) vs. 3.5 (2.8-3.9) (p = .0014), and a higher (worse) median (IQR) breathing difficulty score in the past month, 2.0 (1.0-2.0) vs. 1.0 (1.0-2.0) (p = .001). Of the 19 cardiopulmonary symptoms/ conditions, having a history of arrhythmia was significantly different between cigarette only users (14.2%) and dual users (17.8%) (p = .02). In this sample, dual use was not associated with reduced exposure to either (i) cigarettes, compared to cigarette only users or (ii) e-cigarettes, compared to e-cigarette only users. E-cigarette only use, compared to no product use, was associated with lower general health scores, higher breathing difficulty scores (typically and past month), and greater proportions of those who responded 'yes' to having chest pain, palpitations, coronary heart disease, arrhythmia, COPD, and asthma. These data suggest the added use of e-cigarettes alone may have contributed to cardiopulmonary health risks particularly respiratory health risks.
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Affiliation(s)
- Julie B. Wang
- 24K Data, Washington, DC, United States of America
- Division of Cardiology, School of Medicine, University of California, San Francisco, United States of America
- Physiological Nursing, School of Nursing, University of California, San Francisco, United States of America
| | - Jeffrey E. Olgin
- Division of Cardiology, School of Medicine, University of California, San Francisco, United States of America
| | - Gregory Nah
- Division of Cardiology, School of Medicine, University of California, San Francisco, United States of America
| | - Eric Vittinghoff
- Department of Epidemiology and Biostatistics, University of California, San Francisco, United States of America
| | - Janine K. Cataldo
- Physiological Nursing, School of Nursing, University of California, San Francisco, United States of America
| | - Mark J. Pletcher
- Department of Epidemiology and Biostatistics, University of California, San Francisco, United States of America
| | - Gregory M. Marcus
- Division of Cardiology, School of Medicine, University of California, San Francisco, United States of America
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141
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Fagan P, Pokhrel P, Herzog TA, Moolchan ET, Cassel KD, Franke AA, Li X, Pagano I, Trinidad DR, Sakuma KLK, Sterling K, Jorgensen D, Lynch T, Kawamoto C, Guy MC, Lagua I, Hanes S, Alexander LA, Clanton MS, Graham-Tutt C, Eissenberg T. Sugar and Aldehyde Content in Flavored Electronic Cigarette Liquids. Nicotine Tob Res 2018; 20:985-992. [PMID: 29182761 PMCID: PMC6037055 DOI: 10.1093/ntr/ntx234] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 11/01/2017] [Indexed: 11/14/2022]
Abstract
Introduction Sugars are major constituents and additives in traditional tobacco products, but little is known about their content or related toxins (formaldehyde, acetaldehyde, and acrolein) in electronic cigarette (e-cigarette) liquids. This study quantified levels of sugars and aldehydes in e-cigarette liquids across brands, flavors, and nicotine concentrations (n = 66). Methods Unheated e-cigarette liquids were analyzed using liquid chromatography mass spectrometry and enzymatic test kits. Generalized linear models, Fisher's exact test, and Pearson's correlation coefficient assessed sugar, aldehyde, and nicotine concentration associations. Results Glucose, fructose and sucrose levels exceeded the limits of quantification in 22%, 53% and 53% of the samples. Sucrose levels were significantly higher than glucose [χ2(1) = 85.9, p < .0001] and fructose [χ2(1) = 10.6, p = .001] levels. Formaldehyde, acetaldehyde, and acrolein levels exceeded the limits of quantification in 72%, 84%, and 75% of the samples. Acetaldehyde levels were significantly higher than formaldehyde [χ2(1) = 11.7, p = .0006] and acrolein [χ2(1) = 119.5, p < .0001] levels. Differences between nicotine-based and zero-nicotine labeled e-cigarette liquids were not statistically significant for sugars or aldehydes. We found significant correlations between formaldehyde and fructose (-0.22, p = .004) and sucrose (-0.25, p = .002) and acrolein and fructose (-0.26, p = .0006) and sucrose (-0.21, p = .0006). There were no significant correlations between acetaldehyde and any of the sugars or any of the aldehydes and glucose. Conclusions Sugars and related aldehydes were identified in unheated e-cigarette liquids and their composition may influence experimentation in naïve users and their potential toxicity. Implications The data can inform the regulation of specific flavor constituents in tobacco products as a strategy to protect young people from using e-cigarettes, while balancing FDA's interest in how these emerging products could potentially benefit adult smokers who are seeking to safely quit cigarette smoking. The data can also be used to educate consumers about ingredients in products that may contain nicotine and inform future FDA regulatory policies related to product standards and accurate and comprehensible labeling of e-cigarette liquids.
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Affiliation(s)
- Pebbles Fagan
- Department of Health Behavior and Health Education, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR
- Center for the Study of Tobacco Products, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, VA
| | - Pallav Pokhrel
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Thaddeus A Herzog
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | | | - Kevin D Cassel
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Adrian A Franke
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Xingnan Li
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Ian Pagano
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Dennis R Trinidad
- Family Medicine and Public Health, University of California, San Diego, La Jolla, CA
| | - Kari-lyn K Sakuma
- College of Public Health and Human Sciences, Department of Health Promotion and Behavior, Oregon State University, Waldo Corvallis, OR
| | - Kymberle Sterling
- School of Public Health, Department of Health Promotion and Behavior, Georgia State University, Atlanta, GA
| | - Dorothy Jorgensen
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Tania Lynch
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Crissy Kawamoto
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Mignonne C Guy
- Department of African American Studies, Virginia Commonwealth University, Richmond, VA
- Center for the Study of Tobacco Products, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, VA
| | - Ian Lagua
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Sarah Hanes
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Linda A Alexander
- Department of Social and Behavioral Sciences, College of Public Health, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV
| | | | - Camonia Graham-Tutt
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI
| | - Thomas Eissenberg
- Department of Psychology, Virginia Commonwealth University, Richmond, VA
- Center for the Study of Tobacco Products, College of Humanities and Sciences, Virginia Commonwealth University, Richmond, VA
| | - Addictive Carcinogens Workgroup
- Department of Health Behavior and Health Education, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR
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142
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Vasanthi Bathrinarayanan P, Brown JEP, Marshall LJ, Leslie LJ. An investigation into E-cigarette cytotoxicity in-vitro using a novel 3D differentiated co-culture model of human airways. Toxicol In Vitro 2018; 52:255-264. [PMID: 29940344 DOI: 10.1016/j.tiv.2018.06.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 06/20/2018] [Accepted: 06/21/2018] [Indexed: 12/21/2022]
Abstract
Currently there is a lack of consensus on the possible adverse health effects of E-cigarettes (ECs). Important factors including cell model employed and exposure method determine the physiological relevance of EC studies. The present study aimed to evaluate EC cytotoxicity using a physiologically relevant in-vitro multicellular model of human airways. Human bronchial epithelial cells (CALU-3) and pulmonary fibroblasts (MRC-5) were co-cultured at air-liquid-interface for 11-14 days post which they were exposed to whole cigarette smoke (WCS) or EC vapour (ECV) at standard ISO-3308 regime for 7 m using a bespoke aerosol delivery system. ECV effects were further investigated at higher exposure times (1 h-6 h). Results showed that while WCS significantly reduced cell viability after 7 m, ECV decreased cell viability only at exposure times higher than 3 h. Furthermore, ECV caused elevated IL-6 and IL-8 production despite reduced cell viability. ECV exposure also produced a marked increase in oxidative stress. Finally, WCS but not ECV exposure induced caspase 3/7 activation, suggesting a caspase independent death of ECV exposed cells. Overall, our results indicate that prolonged ECV exposure (≥3 h) has a significant impact on pro-inflammatory mediators' production, oxidative stress and cell viability but not caspase 3/7 activity.
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Affiliation(s)
- Pranav Vasanthi Bathrinarayanan
- Aston Institute of Materials Research, School of Engineering and Applied Science, Aston University, Birmingham B4 7ET, United Kingdom
| | - James E P Brown
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, United Kingdom; Aston Medical Research Institute, Aston University, Birmingham B4 7ET, United Kingdom
| | - Lindsay J Marshall
- Research and Toxicology Department, Humane Society International, 5, Underwood Street, London, United Kingdom
| | - Laura J Leslie
- Aston Institute of Materials Research, School of Engineering and Applied Science, Aston University, Birmingham B4 7ET, United Kingdom.
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143
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Huang SJ, Xu YM, Lau ATY. Electronic cigarette: A recent update of its toxic effects on humans. J Cell Physiol 2018; 233:4466-4478. [PMID: 29215738 DOI: 10.1002/jcp.26352] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/29/2017] [Indexed: 02/05/2023]
Abstract
Electronic cigarettes (e-cigarettes), battery-powered and liquid-vaporizing devices, were invented to replace the conventional cigarette (c-cigarette) smoking for the sake of reducing the adverse effects on multiple organ systems that c-cigarettes have induced. Although some of the identified harmful components in e-cigarettes were alleged to be measured in lower quantity than those in c-cigarettes, researchers unveiled that the toxic effects of e-cigarettes should not be understated. This review is sought for an attempt to throw light on several typical types of e-cigarette components (tobacco-specific nitrosamines, carbonyl compounds, and volatile organic compounds) by revealing their possible impacts on human bodies through different action mechanisms characterized by alteration of specific biomarkers on cellular and molecular levels. In addition, this review is intended to draw the limelight that like c-cigarettes, e-cigarettes could also be accompanied with toxic effects on whole human body, which are especially apparent on respiratory system. From head to foot, from physical aspect to chemical aspect, from genotype to phenotype, potential alterations will take place upon the intake of the liquid aerosol.
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Affiliation(s)
- Shu-Jie Huang
- Laboratory of Cancer Biology and Epigenetics, Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, Guangdong, People's Republic of China
| | - Yan-Ming Xu
- Laboratory of Cancer Biology and Epigenetics, Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, Guangdong, People's Republic of China
| | - Andy T Y Lau
- Laboratory of Cancer Biology and Epigenetics, Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, Guangdong, People's Republic of China
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144
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Behar RZ, Luo W, McWhirter KJ, Pankow JF, Talbot P. Analytical and toxicological evaluation of flavor chemicals in electronic cigarette refill fluids. Sci Rep 2018; 8:8288. [PMID: 29844439 PMCID: PMC5974410 DOI: 10.1038/s41598-018-25575-6] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/19/2018] [Indexed: 01/18/2023] Open
Abstract
Thousands of electronic cigarette refill fluids are commercially available. The concentrations of nicotine and the solvents, but not the flavor chemicals, are often disclosed on product labels. The purpose of this study was to identify and quantify flavor chemicals in 39 commercial refill fluids that were previously evaluated for toxicity. Twelve flavor chemicals were identified with concentrations ≥1 mg/ml: cinnamaldehyde, menthol, benzyl alcohol, vanillin, eugenol, p-anisaldehyde, ethyl cinnamate, maltol, ethyl maltol, triacetin, benzaldehyde, and menthone. Transfer of these flavor chemicals into aerosols made at 3V and 5V was efficient (mean transfer = 98%). We produced lab-made refill fluids containing authentic standards of each flavor chemical and analyzed the toxicity of their aerosols produced at 3V and 5V using a tank Box Mod device. Over 50% of the refill fluids in our sample contained high concentrations of flavor chemicals that transferred efficiently to aerosols at concentrations that produce cytotoxicity. When tested with two types of human lung cells, the aerosols made at 5V were generally more toxic than those made at 3V. These data will be valuable for consumers, physicians, public health officials, and regulatory agencies when discussing potential health concerns relating to flavor chemicals in electronic cigarette products.
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Affiliation(s)
- Rachel Z Behar
- Cell Molecular and Developmental Biology Graduate Program, University of California, Riverside, CA, 92521, United States.,UCR Stem Cell Center, University of California, Riverside, CA, 92521, United States.,Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, United States
| | - Wentai Luo
- Department of Civil and Environmental Engineering, Portland State University, PO Box 751, Portland, OR, 97207-0751, United States
| | - Kevin J McWhirter
- Department of Civil and Environmental Engineering, Portland State University, PO Box 751, Portland, OR, 97207-0751, United States
| | - James F Pankow
- Department of Civil and Environmental Engineering, Portland State University, PO Box 751, Portland, OR, 97207-0751, United States
| | - Prue Talbot
- UCR Stem Cell Center, University of California, Riverside, CA, 92521, United States. .,Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, United States.
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145
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Analytical and toxicological evaluation of flavor chemicals in electronic cigarette refill fluids. Sci Rep 2018. [PMID: 29844439 DOI: 10.1038/s41598‐018‐25575‐6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Thousands of electronic cigarette refill fluids are commercially available. The concentrations of nicotine and the solvents, but not the flavor chemicals, are often disclosed on product labels. The purpose of this study was to identify and quantify flavor chemicals in 39 commercial refill fluids that were previously evaluated for toxicity. Twelve flavor chemicals were identified with concentrations ≥1 mg/ml: cinnamaldehyde, menthol, benzyl alcohol, vanillin, eugenol, p-anisaldehyde, ethyl cinnamate, maltol, ethyl maltol, triacetin, benzaldehyde, and menthone. Transfer of these flavor chemicals into aerosols made at 3V and 5V was efficient (mean transfer = 98%). We produced lab-made refill fluids containing authentic standards of each flavor chemical and analyzed the toxicity of their aerosols produced at 3V and 5V using a tank Box Mod device. Over 50% of the refill fluids in our sample contained high concentrations of flavor chemicals that transferred efficiently to aerosols at concentrations that produce cytotoxicity. When tested with two types of human lung cells, the aerosols made at 5V were generally more toxic than those made at 3V. These data will be valuable for consumers, physicians, public health officials, and regulatory agencies when discussing potential health concerns relating to flavor chemicals in electronic cigarette products.
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146
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Bitzer ZT, Goel R, Reilly SM, Elias RJ, Silakov A, Foulds J, Muscat J, Richie JP. Effect of flavoring chemicals on free radical formation in electronic cigarette aerosols. Free Radic Biol Med 2018; 120:72-79. [PMID: 29548792 PMCID: PMC5940571 DOI: 10.1016/j.freeradbiomed.2018.03.020] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 03/09/2018] [Accepted: 03/12/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Flavoring chemicals, or flavorants, have been used in electronic cigarettes (e-cigarettes) since their inception; however, little is known about their toxicological effects. Free radicals present in e-cigarette aerosols have been shown to induce oxidative stress resulting in damage to proliferation, survival, and inflammation pathways in the cell. Aerosols generated from e-liquid solvents alone contain high levels of free radicals but few studies have looked at how these toxins are modulated by flavorants. OBJECTIVES We investigated the effects of different flavorants on free radical production in e-cigarette aerosols. METHODS Free radicals generated from 49 commercially available e-liquid flavors were captured and analyzed using electron paramagnetic resonance (EPR). The flavorant composition of each e-liquid was analyzed by gas chromatography mass spectroscopy (GCMS). Radical production was correlated with flavorant abundance. Ten compounds were identified and analyzed for their impact on free radical generation. RESULTS Nearly half of the flavors modulated free radical generation. Flavorants with strong correlations included β-damascone, δ-tetradecalactone, γ-decalactone, citral, dipentene, ethyl maltol, ethyl vanillin, ethyl vanillin PG acetal, linalool, and piperonal. Dipentene, ethyl maltol, citral, linalool, and piperonal promoted radical formation in a concentration-dependent manner. Ethyl vanillin inhibited the radical formation in a concentration dependent manner. Free radical production was closely linked with the capacity to oxidize biologically-relevant lipids. CONCLUSIONS Our results suggest that flavoring agents play an important role in either enhancing or inhibiting the production of free radicals in flavored e-cigarette aerosols. This information is important for developing regulatory strategies aimed at reducing potential harm from e-cigarettes.
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Affiliation(s)
- Zachary T Bitzer
- Department of Food Science, Pennsylvania State University, College of Agricultural Sciences, University Park, PA, USA
| | - Reema Goel
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, 500 University Dr., Mail Code: CH69, Hershey, PA 17033, USA
| | - Samantha M Reilly
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, 500 University Dr., Mail Code: CH69, Hershey, PA 17033, USA
| | - Ryan J Elias
- Department of Food Science, Pennsylvania State University, College of Agricultural Sciences, University Park, PA, USA
| | - Alexey Silakov
- Department of Chemistry, Pennsylvania State University, Eberley College of Science, University Park, PA, USA
| | - Jonathan Foulds
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, 500 University Dr., Mail Code: CH69, Hershey, PA 17033, USA
| | - Joshua Muscat
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, 500 University Dr., Mail Code: CH69, Hershey, PA 17033, USA
| | - John P Richie
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, 500 University Dr., Mail Code: CH69, Hershey, PA 17033, USA.
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147
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Kaur G, Muthumalage T, Rahman I. Mechanisms of toxicity and biomarkers of flavoring and flavor enhancing chemicals in emerging tobacco and non-tobacco products. Toxicol Lett 2018; 288:143-155. [PMID: 29481849 PMCID: PMC6549714 DOI: 10.1016/j.toxlet.2018.02.025] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/19/2018] [Accepted: 02/21/2018] [Indexed: 01/11/2023]
Abstract
Tobacco products containing flavorings, such as electronic nicotine delivery devices (ENDS) or e-cigarettes, cigars/cigarillos, waterpipes, and heat-not-burn devices (iQOS) are continuously evolving. In addition to increasing the exposure of teenagers and adults to nicotine containing flavoring products and flavoring enhancers, chances of nicotine addiction through chronic use and abuse also increase. These flavorings are believed to be safe for ingestion, but little information is available about their effects on the lungs. In this review, we have discussed the in vitro and in vivo data on toxicity of flavoring chemicals in lung cells. We have further discussed the common flavoring agents, such as diacetyl and menthol, currently available detection methods, and the toxicological mechanisms associated with oxidative stress, inflammation, mucociliary clearance, and DNA damage in cells, mice, and humans. Finally, we present potential biomarkers that could be utilized for future risk assessment. This review provides crucial parameters important for evaluation of risk associated with flavoring agents and flavoring enhancers used in tobacco products and ENDS. Future studies can be designed to address the potential toxicity of inhaled flavorings and their biomarkers in users as well as in chronic exposure studies.
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Affiliation(s)
- Gurjot Kaur
- Human and Environmental Toxicology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Thivanka Muthumalage
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA.
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148
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Abstract
Electronic cigarettes (ECs) have been growing rapidly in popularity among youth and adults in the United States over the last decade. This increasing prevalence is driven partially by the ability to customize devices, flavors, and nicotine content and the general notion that ECs are harmless, particularly in comparison with conventional cigarettes. In vitro and in vivo murine models have demonstrated a number of harmful biological effects of e-liquids and their aerosols. However, limited clinical data exist on whether these effects translate into detrimental long-term outcomes in human subjects. The short-term harmful respiratory effects of EC use demonstrated in nonsmokers argue against their use. However, slightly more favorable data exist for the respiratory benefits of substituting conventional cigarettes with ECs and the short-term efficacy of ECs as smoking cessation tools. Nonetheless, available research is severely limited in regard to long-term outcomes and by study designs fraught with bias, pointing to the need for additional research efforts with well-designed longitudinal studies to guide US Food and Drug Administration regulatory efforts. The hurdle presented by diverse device designs and e-liquid permutations, which contribute to the inconsistency of available data, also highlights the need for legislative standardization of ECs.
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Affiliation(s)
- Amika K Sood
- Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC.
| | - Matthew J Kesic
- Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Michelle L Hernandez
- Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC
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149
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Muthumalage T, Prinz M, Ansah KO, Gerloff J, Sundar IK, Rahman I. Inflammatory and Oxidative Responses Induced by Exposure to Commonly Used e-Cigarette Flavoring Chemicals and Flavored e-Liquids without Nicotine. Front Physiol 2018; 8:1130. [PMID: 29375399 PMCID: PMC5768608 DOI: 10.3389/fphys.2017.01130] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 12/21/2017] [Indexed: 12/14/2022] Open
Abstract
Background: The respiratory health effects of inhalation exposure to e-cigarette flavoring chemicals are not well understood. We focused our study on the immuno-toxicological and the oxidative stress effects by these e-cigarette flavoring chemicals on two types of human monocytic cell lines, Mono Mac 6 (MM6) and U937. The potential to cause oxidative stress by these flavoring chemicals was assessed by measuring the production of reactive oxygen species (ROS). We hypothesized that the flavoring chemicals used in e-juices/e-liquids induce an inflammatory response, cellular toxicity, and ROS production. Methods: Two monocytic cell types, MM6 and U937 were exposed to commonly used e-cigarette flavoring chemicals; diacetyl, cinnamaldehyde, acetoin, pentanedione, o-vanillin, maltol and coumarin at different doses between 10 and 1,000 μM. Cell viability and the concentrations of the secreted inflammatory cytokine interleukin 8 (IL-8) were measured in the conditioned media. Cell-free ROS produced by these commonly used flavoring chemicals were also measured using a 2′,7′dichlorofluorescein diacetate probe. These DCF fluorescence data were expressed as hydrogen peroxide (H2O2) equivalents. Cytotoxicity due to the exposure to selected e-liquids was assessed by cell viability and the IL-8 inflammatory cytokine response in the conditioned media. Results: Treatment of the cells with flavoring chemicals and flavored e-liquid without nicotine caused cytotoxicity dose-dependently. The exposed monocytic cells secreted interleukin 8 (IL-8) chemokine in a dose-dependent manner compared to the unexposed cell groups depicting a biologically significant inflammatory response. The measurement of cell-free ROS by the flavoring chemicals and e-liquids showed significantly increased levels of H2O2 equivalents in a dose-dependent manner compared to the control reagents. Mixing a variety of flavors resulted in greater cytotoxicity and cell-free ROS levels compared to the treatments with individual flavors, suggesting that mixing of multiple flavors of e-liquids are more harmful to the users. Conclusions: Our data suggest that the flavorings used in e-juices can trigger an inflammatory response in monocytes, mediated by ROS production, providing insights into potential pulmonary toxicity and tissue damage in e-cigarette users.
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Affiliation(s)
- Thivanka Muthumalage
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Melanie Prinz
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Kwadwo O Ansah
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Janice Gerloff
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Isaac K Sundar
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
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150
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Hamacher J, Hadizamani Y, Borgmann M, Mohaupt M, Männel DN, Moehrlen U, Lucas R, Stammberger U. Cytokine-Ion Channel Interactions in Pulmonary Inflammation. Front Immunol 2018; 8:1644. [PMID: 29354115 PMCID: PMC5758508 DOI: 10.3389/fimmu.2017.01644] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/10/2017] [Indexed: 12/12/2022] Open
Abstract
The lungs conceptually represent a sponge that is interposed in series in the bodies’ systemic circulation to take up oxygen and eliminate carbon dioxide. As such, it matches the huge surface areas of the alveolar epithelium to the pulmonary blood capillaries. The lung’s constant exposure to the exterior necessitates a competent immune system, as evidenced by the association of clinical immunodeficiencies with pulmonary infections. From the in utero to the postnatal and adult situation, there is an inherent vital need to manage alveolar fluid reabsorption, be it postnatally, or in case of hydrostatic or permeability edema. Whereas a wealth of literature exists on the physiological basis of fluid and solute reabsorption by ion channels and water pores, only sparse knowledge is available so far on pathological situations, such as in microbial infection, acute lung injury or acute respiratory distress syndrome, and in the pulmonary reimplantation response in transplanted lungs. The aim of this review is to discuss alveolar liquid clearance in a selection of lung injury models, thereby especially focusing on cytokines and mediators that modulate ion channels. Inflammation is characterized by complex and probably time-dependent co-signaling, interactions between the involved cell types, as well as by cell demise and barrier dysfunction, which may not uniquely determine a clinical picture. This review, therefore, aims to give integrative thoughts and wants to foster the unraveling of unmet needs in future research.
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Affiliation(s)
- Jürg Hamacher
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Internal Medicine V - Pneumology, Allergology, Respiratory and Environmental Medicine, Faculty of Medicine, Saarland University, Saarbrücken, Germany.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Yalda Hadizamani
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Michèle Borgmann
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland
| | - Markus Mohaupt
- Internal Medicine, Sonnenhofspital Bern, Bern, Switzerland
| | | | - Ueli Moehrlen
- Paediatric Visceral Surgery, Universitäts-Kinderspital Zürich, Zürich, Switzerland
| | - Rudolf Lucas
- Department of Pharmacology and Toxicology, Vascular Biology Center, Medical College of Georgia, Augusta, GA, United States
| | - Uz Stammberger
- Lungen- und Atmungsstiftung Bern, Bern, Switzerland.,Novartis Institutes for Biomedical Research, Translational Clinical Oncology, Novartis Pharma AG, Basel, Switzerland
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