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Sommer N, Franzen K, Andreas S, Pankow W, Kunstmann W, Hanewinkel R. [Harmful health effects of flavors in e-cigarettes]. Dtsch Med Wochenschr 2024; 149:646-653. [PMID: 38458230 DOI: 10.1055/a-2260-5003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2024]
Abstract
BACKGROUND Almost all e-cigarettes contain flavorings that make the product more attractive. In the evaluation of e-cigarettes on health, flavors have so far played a subordinate role. METHOD Selective literature search in PubMed, supplemented by legal regulations on the use of flavors in e-cigarettes. RESULTS Flavors make it easier to start using e-cigarettes and have a consumption-promoting effect. Deeper inhalation increases nicotine uptake and the absorption of toxic substances from the e-cigarette liquid. For some flavors, pathological effects have been demonstrated in addition to other toxic components of the e-cigarette. To date, no toxicological analyses are available for the vast majority of flavors contained in e-cigarettes. CONCLUSIONS The proven consumption-promoting effect and the health risks that can be extrapolated from preclinical data are significant for the political discussion of a ban on flavors for e-cigarettes, analogous to the ban on flavors in tobacco products already in force.
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Affiliation(s)
- Natascha Sommer
- Medizinische Klinik II, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Gießen and Marburg Lung Center (UGMLC), Mitglied des Deutschen Zentrums für Lungenforschung (DZL), Justus-Liebig-Universität Gießen
| | - Klaas Franzen
- Universitätsklinikum Schleswig-Holstein, Medizinische Klinik III, Pneumologie, Campus Lübeck, Airway Research Center North (ARCN), Deutsches Zentrum für Lungenforschung (DZL), Lübeck/Großhansdorf
| | - Stefan Andreas
- Lungenfachklinik Immenhausen, Immenhausen, Klinik für Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Deutsches Zentrum für Lungenforschung
| | - Wulf Pankow
- Philipps-Universität Marburg - Fachbereich Medizin
| | | | - Reiner Hanewinkel
- IFT-Nord gGmbH, Institut für Therapie- und Gesundheitsforschung, Kiel
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2
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Wang T, Hua Y, Liu L, Leng B. Analysis of atypical glandular cells in ThinPrep Pap smear and follow-up histopathology. Proc AMIA Symp 2024; 37:403-407. [PMID: 38628324 PMCID: PMC11018051 DOI: 10.1080/08998280.2024.2324656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/31/2024] [Indexed: 04/19/2024] Open
Abstract
Background Diagnosing atypical glandular cells (AGC) is a significant challenge in cytomorphology. Methods A retrospective study was undertaken to assess the prevalence of AGC and the subsequent histological outcomes over 5 years at a single institution. Results A total of 159,649 ThinPrep Pap tests, including 395 cases of AGC, were retrieved, of which 330 AGC cases had follow-up histopathology. Among these 330 cases, 43.9% were classified as AGC not otherwise specified, followed by AGC-endocervical cells at 33.3%. The most frequently observed histological findings at follow-up included CIN1 and benign mucosa with reactive changes, followed by high-grade squamous intraepithelial lesion and cervical squamous cell carcinoma. The overall 5-year insignificant AGC rate was 0.12%, and the overall 5-year significant AGC rate was 0.08%. Notably, 36.7% of AGC cases tested positive for high-risk human papillomavirus. Interestingly, the level of experience did not significantly impact the rates for significant or insignificant AGC diagnosis. However, senior cytopathologists had a higher AGC report rate compared to their junior peers. Conclusion The AGC diagnostic rate at our institution falls within the range given by the College of American Pathologists. A significant number of cases had follow-up histologic results available, and the overall 5-year insignificant AGC rate was 0.12%.
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Affiliation(s)
- Tengfei Wang
- Department of Pathology, Baylor Scott and White Health, Temple, Texas, USA
| | - Yinan Hua
- Department of Pathology, Baylor Scott and White Health, Temple, Texas, USA
| | - Lina Liu
- Department of Pathology, Baylor Scott and White Health, Temple, Texas, USA
| | - Bing Leng
- Department of Pathology, Baylor Scott and White Health, Temple, Texas, USA
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Cooper SY, Olszewski NA, Tetteh-Quarshie S, Hill SP, Ghodsi S, González-Castro A, Willis CV, Henderson BJ. The Impact of High or Low Doses of Nicotine in a Mouse Model of Vapor Self-Administration. Nicotine Tob Res 2024; 26:316-323. [PMID: 37531402 PMCID: PMC10882436 DOI: 10.1093/ntr/ntad136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/18/2023] [Accepted: 07/31/2023] [Indexed: 08/04/2023]
Abstract
INTRODUCTION A wide variety of nicotine concentrations and formulations are available to users of electronic nicotine delivery systems (ENDS). This is increasingly true when considering the many flavors available with ENDS products. To date, there have been few preclinical investigations into the impact of nicotine doses, with and without flavors, on vaping-related behaviors. This present study evaluated how nicotine concentrations relevant to tank-based and pod-based ENDS, with and without flavors, impact reinforcement-related behavior in a mouse model. AIMS AND METHODS Adult male and female C57/BL6J mice were used in vapor-inhalation self-administration assays. Mice were assigned e-liquids containing 6 mg/mL or 60 mg/mL nicotine. Additional mice were assigned these nicotine doses with green apple or menthol flavorants. Mice were trained on fixed-ratio 1 for 10, 2-hour sessions, then five sessions at FR3, three progressive ratio sessions, and two FR3 sessions. RESULTS We observed male mice exhibited higher reinforcement-related behavior to menthol-flavored 6 mg/mL nicotine when compared to female mice. Males were only observed to have a menthol-induced enhancement of self-administration at 6 mg/mL nicotine and not 60 mg/mL nicotine. However, female mice exhibited significant menthol-induced increases in reinforcement-related behaviors with 60 mg/mL nicotine. CONCLUSIONS These data provide evidence that males and females exhibit different dose sensitivities to nicotine. These sex-dependent differences in nicotine sensitivity also indicate that flavor-induced enhancement in nicotine intake is dependent on the different doses for each sex. IMPLICATIONS There has been much discussion recently regarding the impact of flavors on vaping-related behavior. Our current study may support prior investigations that suggest flavors enhance the palatability of nicotine-containing products. However, this current study provides evidence that males and females exhibit different sensitivities to nicotine.
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Affiliation(s)
- Skylar Y Cooper
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV, USA
| | - Nathan A Olszewski
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV, USA
| | - Samuel Tetteh-Quarshie
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV, USA
| | - Sean P Hill
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV, USA
| | - Saaman Ghodsi
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV, USA
| | - Astrid González-Castro
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV, USA
| | - Clay V Willis
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV, USA
| | - Brandon J Henderson
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV, USA
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Henderson BJ, Tetteh-Quarshie S, Olszewski NA. Modulators of nicotine reward and reinforcement. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2024; 99:355-386. [PMID: 38467487 DOI: 10.1016/bs.apha.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Nicotine has been well-characterized for its ability to alter neurophysiology to promote rewarding and reinforcing properties. However, several exogenous chemicals possess properties that modulate or enhance nicotine's ability to alter neurophysiology. This chapter focuses on nicotine's impact on behavior through changes in neurophysiology and several chemical entities that in-turn modulate nicotine's ability to act as a neuromodulator.
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Affiliation(s)
- Brandon J Henderson
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, WV, United States.
| | - Samuel Tetteh-Quarshie
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, WV, United States
| | - Nathan A Olszewski
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, WV, United States
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Wang T, Zreik R, Leng B. The Landscape of Primary Gastric Leiomyosarcoma in Texas Population: Analysis of Texas Cancer Registry Data. Cureus 2023; 15:e49403. [PMID: 38149139 PMCID: PMC10749797 DOI: 10.7759/cureus.49403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2023] [Indexed: 12/28/2023] Open
Abstract
Introduction Primary gastric leiomyosarcoma is an extremely rare disease. There have been no previous studies regarding gastric leiomyosarcoma in the Texas population. Methods Anonymous data of gastric leiomyosarcoma from the Texas Cancer Registry (TCR) was used. Information collected included the primary tumor site, age at diagnosis, gender, race/ethnicity, diagnosis and treatments, tumor size, lymph node and metastasis status, grade and stage, body weight and height, public health regions and payer, metropolitan status, neighborhood poverty level, smoking status, survival interval, and cause of death for statistical analysis. Result Thirty-three cases from 2003-2019 were selected. Primary gastric leiomyosarcoma was more commonly diagnosed in patients over 50 years of age, females, and individuals of white race. The diagnosis was primarily based on histology, and the disease was typically treated with surgery and chemotherapy. At the time of diagnosis, 45.5% of patients were in the late stage, and 48.5% of patients died from gastric leiomyosarcoma with a mean survival interval of 15.3 months. BMI scores showed a positive correlation with survival intervals. Surveillance, Epidemiology and End Results (SEER) tumor staging was associated with the prognosis of gastric leiomyosarcoma. Conclusion There were multiple disparities among patients with primary gastric leiomyosarcoma in the Texas population. The SEER summary stage was associated with the prognosis of gastric leiomyosarcoma.
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Affiliation(s)
- Tengfei Wang
- Pathology, Baylor Scott & White Health, Temple, USA
| | - Riyam Zreik
- Pathology, Baylor Scott & White Health, Temple, USA
| | - Bing Leng
- Pathology, Baylor Scott & White Health, Temple, USA
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Jabba SV, Erythropel HC, Woodrow JG, Anastas PT, O'Malley S, Krishnan-Sarin S, Zimmerman JB, Jordt SE. Synthetic cooling agent in oral nicotine pouch products marketed as 'Flavour-Ban Approved'. Tob Control 2023:tc-2023-058035. [PMID: 37380351 PMCID: PMC10753027 DOI: 10.1136/tc-2023-058035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 06/09/2023] [Indexed: 06/30/2023]
Abstract
BACKGROUND US sales of oral nicotine pouches (ONPs) have rapidly increased, with cool/mint-flavoured ONPs the most popular flavour category. Restrictions on sales of flavoured tobacco products have either been implemented or proposed by several US states and localities. Zyn, the most popular ONP brand, is marketing Zyn Chill and Zyn Smooth as 'Flavour-Ban Approved' or 'unflavoured', probably to evade flavour bans and increase product appeal. At present, it is unclear whether these ONPs are indeed free of flavour additives that can impart pleasant sensations such as cooling. METHODS Sensory cooling and irritant activities of 'Flavour-Ban Approved' Zyn ONPs, Chill and Smooth, along with minty varieties (Cool Mint, Peppermint, Spearmint, Menthol), were analysed by Ca2+ microfluorimetry in HEK293 cells expressing the cold/menthol (TRPM8) or menthol/irritant receptor (TRPA1). Flavour chemical content of these ONPs was analysed by gas chromatography/mass spectrometry. RESULTS Zyn Chill ONP extracts robustly activated TRPM8, with much higher efficacy (39%-53%) than the mint-flavoured ONPs. In contrast, mint-flavoured ONP extracts elicited stronger TRPA1 irritant receptor responses than Chill extracts. Chemical analysis demonstrated that Chill exclusively contained WS-3, an odourless synthetic cooling agent, while mint-flavoured ONPs contained WS-3 together with mint flavourants. CONCLUSIONS ONP products marketed as 'Flavour-Ban Approved' or 'unflavoured' contain flavouring agents, proving that the manufacturer's advertising is misleading. Synthetic coolants such as WS-3 can provide a robust cooling sensation with reduced sensory irritancy, thereby increasing product appeal and use. Regulators need to develop effective strategies for the control of odourless sensory additives used by the industry to bypass flavour bans.
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Affiliation(s)
- Sairam V Jabba
- Department of Anesthesiology, Duke University School of Medicine, Durham, North Carolina, USA
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Hanno C Erythropel
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Chemical and Environmental Engineering, Yale University, New Haven, Connecticut, USA
| | | | - Paul T Anastas
- Center for Green Chemistry & Green Engineering, Yale University, New Haven, Connecticut, USA
- Department of Forestry and Environmental Studies, Yale University, New Haven, Connecticut, USA
| | - Stephanie O'Malley
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Suchitra Krishnan-Sarin
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Julie B Zimmerman
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Chemical and Environmental Engineering, Yale University, New Haven, Connecticut, USA
| | - Sven Eric Jordt
- Department of Anesthesiology, Duke University School of Medicine, Durham, North Carolina, USA
- Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
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Shi Z, Wang AL, Fairchild VP, Aronowitz CA, Lynch KG, Loughead J, Langleben DD. Addicted to green: priming effect of menthol cigarette packaging on brain response to smoking cues. Tob Control 2023; 32:e45-e52. [PMID: 34599084 PMCID: PMC8971144 DOI: 10.1136/tobaccocontrol-2021-056639] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 08/11/2021] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Mentholated tobacco cigarettes are believed to be more addictive than non-menthol ones. Packaging of most menthol cigarette brands includes distinctive green hues, which may act as conditioned stimuli (ie, cues) and promote menthol smoking. To examine the cue properties of menthol cigarette packaging, we used a priming paradigm to assess the effect of packaging on the neural substrates of smoking cue reactivity. We hypothesised that menthol packaging will exert a specific priming effect potentiating smoking cue reactivity in menthol compared with non-menthol smokers. METHODS Forty-two menthol and 33 non-menthol smokers underwent functional MRI while viewing smoking and neutral cues. The cues were preceded (ie, primed) by briefly presented images of menthol or non-menthol cigarette packages. Participants reported craving for cigarettes in response to each cue. RESULTS Menthol packaging induced greater frontostriatal and occipital smoking cue reactivity in menthol smokers than in non-menthol smokers. Menthol packaging also enhanced the mediation by neural activity of the relationship between cue exposure and cigarette craving in menthol but not non-menthol smokers. Dynamic causal modelling showed stronger frontostriatal-occipital connectivity in response to menthol packaging in menthol compared with non-menthol smokers. The effects of non-menthol packaging did not differ between categories of smokers. CONCLUSIONS Our findings demonstrate heightened motivational and perceptual salience of the green-hued menthol cigarette packaging that may exacerbate menthol smokers' susceptibility to smoking cues. These effects could contribute to the greater addiction severity among menthol smokers and could be considered in the development of science-based regulation and legal review of tobacco product marketing practices.
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Affiliation(s)
- Zhenhao Shi
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - An-Li Wang
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | | | - Catherine A Aronowitz
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Kevin G Lynch
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - James Loughead
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Daniel D Langleben
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
- Annenberg Public Policy Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Synthetic Cooling Agent in Oral Nicotine Pouch Products Marketed as "Flavor-Ban Approved". BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.23.529797. [PMID: 36865160 PMCID: PMC9980044 DOI: 10.1101/2023.02.23.529797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Background US sales of oral nicotine pouches (ONPs) have rapidly increased, with cool/mint-flavored ONPs the most popular. Restrictions on sales of flavored tobacco products have either been implemented or proposed by several US states and localities. Zyn, the most popular ONP brand, is marketing Zyn-"Chill" and Zyn-"Smooth" as "Flavor-Ban Approved", probably to evade flavor bans. At present it is unclear whether these ONPs are indeed free of flavor additives that can impart pleasant sensations such as cooling. Methods Sensory cooling and irritant activities of "Flavor-Ban Approved" ONPs, Zyn-"Chill" and "Smooth", along with "minty" varieties (Cool Mint, Peppermint, Spearmint, Menthol), were analyzed by Ca2+ microfluorimetry in HEK293 cells expressing the cold/menthol (TRPM8) or menthol/irritant receptor (TRPA1). Flavor chemical content of these ONPs was analyzed by GC/MS. Results Zyn-"Chill" ONP extracts robustly activated TRPM8, with much higher efficacy (39-53%) than the mint-flavored ONPs. In contrast, mint-flavored ONP extracts elicited stronger TRPA1 irritant receptor responses than Zyn-"Chill" extracts. Chemical analysis demonstrated the presence of WS-3, an odorless synthetic cooling agent, in Zyn-"Chill" and several other mint-flavored Zyn-ONPs. Conclusions Synthetic cooling agents such as WS-3 found in 'Flavor-Ban Approved' Zyn-"Chill" can provide a robust cooling sensation with reduced sensory irritancy, thereby increasing product appeal and use. The label "Flavor-Ban Approved" is misleading and may implicate health benefits. Regulators need to develop effective strategies for the control of odorless sensory additives used by the industry to bypass flavor bans.
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Havermans A, Mallock N, Zervas E, Caillé-Garnier S, Mansuy T, Michel C, Pennings JLA, Schulz T, Schwarze PE, Solimini R, Tassin JP, Vardavas CI, Merino M, Pauwels CGGM, van Nierop LE, Lambré C, Bolling AK. Review of industry reports on EU priority tobacco additives part A: Main outcomes and conclusions. Tob Prev Cessat 2022; 8:27. [PMID: 35860504 PMCID: PMC9255285 DOI: 10.18332/tpc/151529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 02/01/2023]
Abstract
The European Union Tobacco Products Directive (EU TPD) mandates enhanced reporting obligations for tobacco manufacturers regarding 15 priority additives. Within the Joint Action on Tobacco Control (JATC), a review panel of independent experts was appointed for the scientific evaluation of the additive reports submitted by a consortium of 12 tobacco manufacturers. As required by the TPD, the reports were evaluated based on their comprehensiveness, methodology and conclusions. In addition, we evaluated the chemical, toxicological, addictive, inhalation facilitating and flavoring properties of the priority additives based on the submitted reports, supplemented by the panel's expert knowledge and some independent literature. The industry concluded that none of the additives is associated with concern. Due to significant methodological limitations, we question the scientific validity of these conclusions and conclude that they are not warranted. Our review demonstrates that many issues regarding toxicity, addictiveness and attractiveness of the additives have not been sufficiently addressed, and therefore concerns remain. For example, menthol facilitates inhalation by activation of the cooling receptor TRPM8. The addition of sorbitol and guar gum leads to a significant increase of aldehydes that may contribute to toxicity and addictiveness. Titanium dioxide particles (aerodynamic diameter <10 µm) are legally classified as carcinogenic when inhaled. For diacetyl no report was provided. Overall, the industry reports were not comprehensive, and the information presented provides an insufficient basis for the regulation of most additives. We, therefore, advise MS to consider alternative approaches such as the precautionary principle.
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Affiliation(s)
- Anne Havermans
- Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, Netherlands
| | - Nadja Mallock
- German Federal Institute for Risk Assessment, Berlin, Germany
| | - Efthimios Zervas
- Hellenic Thoracic Society, Athens, Greece.,School of Applied Arts and Sustainable Design, Hellenic Open University, Athens, Greece
| | | | - Thibault Mansuy
- French Agency for Food, Environmental and Occupational Health and Safety, Paris, France
| | - Cécile Michel
- French Agency for Food, Environmental and Occupational Health and Safety, Paris, France
| | - Jeroen L A Pennings
- Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, Netherlands
| | - Thomas Schulz
- German Federal Institute for Risk Assessment, Berlin, Germany
| | | | | | | | | | - Miguel Merino
- Andalusia Agency For Agriculture and Fisheries Development, Seville, Spain
| | - Charlotte G G M Pauwels
- Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, Netherlands
| | - Lotte E van Nierop
- Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, Netherlands
| | - Claude Lambré
- National Institute of Health and Medical Research, Paris, France
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Johnson NL, Patten T, Ma M, De Biasi M, Wesson DW. Chemosensory Contributions of E-Cigarette Additives on Nicotine Use. Front Neurosci 2022; 16:893587. [PMID: 35928010 PMCID: PMC9344001 DOI: 10.3389/fnins.2022.893587] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/06/2022] [Indexed: 11/13/2022] Open
Abstract
While rates of smoking combustible cigarettes in the United States have trended down in recent years, use of electronic cigarettes (e-cigarettes) has dramatically increased, especially among adolescents. The vast majority of e-cigarette users consume "flavored" products that contain a variety of chemosensory-rich additives, and recent literature suggests that these additives have led to the current "teen vaping epidemic." This review, covering research from both human and rodent models, provides a comprehensive overview of the sensory implications of e-cigarette additives and what is currently known about their impact on nicotine use. In doing so, we specifically address the oronasal sensory contributions of e-cigarette additives. Finally, we summarize the existing gaps in the field and highlight future directions needed to better understand the powerful influence of these additives on nicotine use.
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Affiliation(s)
- Natalie L. Johnson
- Department of Pharmacology and Therapeutics, Center for Smell and Taste, Center for Addiction Research and Education, University of Florida, Gainesville, FL, United States
| | - Theresa Patten
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Pharmacology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Minghong Ma
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Mariella De Biasi
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Pharmacology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Daniel W. Wesson
- Department of Pharmacology and Therapeutics, Center for Smell and Taste, Center for Addiction Research and Education, University of Florida, Gainesville, FL, United States
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Anter A, Ahmed ASF, Hammad ASA, Almalki WH, Abdel Hafez SMN, Kasem AW, El-Moselhy MA, Alrabia MW, Ibrahim ARN, El-Daly M. The Severity of Acute Kidney and Lung Injuries Induced by Cecal Ligation and Puncture Is Attenuated by Menthol: Role of Proliferating Cell Nuclear Antigen and Apoptotic Markers. Front Med (Lausanne) 2022; 9:904286. [PMID: 35814769 PMCID: PMC9260148 DOI: 10.3389/fmed.2022.904286] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/16/2022] [Indexed: 11/24/2022] Open
Abstract
Objective Sepsis-induced acute lung injury (ALI) and acute kidney injury (AKI) are major causes of mortality. Menthol is a natural compound that has anti-inflammatory and antioxidative actions. Since exaggerated inflammatory and oxidative stress are characteristics of sepsis, the aim of this study was to evaluate the effect of menthol against sepsis-induced mortality, ALI, and AKI. Methods The cecal ligation and puncture (CLP) procedure was employed as a model of sepsis. Rats were grouped into sham, sham-Menthol, CLP, and CLP-Menthol (100 mg/kg, p.o). Key Findings A survival study showed that menthol enhanced the survival after sepsis from 0% in septic group to 30%. Septic rats developed histological evidence of ALI and AKI. Menthol markedly suppressed sepsis induced elevation of tissue TNF-a, ameliorated sepsis-induced cleavage of caspase-3 and restored the antiapoptotic marker Bcl2. Significance We introduced a role of the proliferating cell nuclear antigen (PCNA) in these tissues with a possible link to the damage induced by sepsis. PCNA level was markedly reduced in septic animals and menthol ameliorated this effect. Our data provide novel evidence that menthol protects against organ damage and decreases mortality in experimental sepsis.
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Affiliation(s)
- Aliaa Anter
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
| | - Al-Shaimaa F. Ahmed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
- *Correspondence: Al-Shaimaa F. Ahmed,
| | - Asmaa S. A. Hammad
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
| | - Waleed Hassan Almalki
- Department of Pharmacology and Toxicology, Umm Al-Qura University, Makkah, Saudi Arabia
| | | | - AlShaimaa W. Kasem
- Department of Pathology, Faculty of Medicine, Minia University, Minya, Egypt
| | - Mohamed A. El-Moselhy
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
- Department of Clinical Pharmacy and Pharmacology, Ibn Sina National College for Medical Studies, Jeddah, Saudi Arabia
| | - Mohammad W. Alrabia
- Department of Microbiology and Medical Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ahmed R. N. Ibrahim
- Department of Clinical Pharmacy, College of Pharmacy, King Khalid University, Abha, Saudi Arabia
- Department of Biochemistry, Faculty of Pharmacy, Minia University, Minya, Egypt
| | - Mahmoud El-Daly
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, Minya, Egypt
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Bagdas D, Kebede N, Zepei AM, Harris L, Minanov K, Picciotto MR, Addy NA. Animal Models to Investigate the Impact of Flavors on Nicotine Addiction and Dependence. Curr Neuropharmacol 2022; 20:2175-2201. [PMID: 35611777 PMCID: PMC9886843 DOI: 10.2174/1570159x20666220524120231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 04/17/2022] [Accepted: 05/22/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Tobacco use in humans is a long-standing public health concern. Flavors are common additives in tobacco and alternative tobacco products, added to mask nicotine's harsh orosensory effects and increase the appeal of these products. Animal models are integral for investigating nicotine use and addiction and are helpful for understanding the effects of flavor additives on the use of nicotine delivery products. OBJECTIVE This review focuses on preclinical models to evaluate the contribution of flavor additives to nicotine addiction. MATERIALS AND METHODS An electronic literature search was conducted by authors up to May 2022. Original articles were selected. RESULTS The behavioral models of rodents described here capture multiple dimensions of human flavored nicotine use behaviors, including advantages and disadvantages. CONCLUSION The consensus of the literature search was that human research on nicotine use behavior has not caught up with fast-changing product innovations, marketing practices, and federal regulations. Animal models are therefore needed to investigate mechanisms underlying nicotine use and addiction. This review provides a comprehensive overvie.
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Affiliation(s)
- Deniz Bagdas
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
- Yale Tobacco Center of Regulatory Science, Yale School of Medicine, New Haven, CT, USA
| | - Nardos Kebede
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Andy Ma Zepei
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Lilley Harris
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Karina Minanov
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Marina R. Picciotto
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
- Yale Tobacco Center of Regulatory Science, Yale School of Medicine, New Haven, CT, USA
| | - Nii A. Addy
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
- Yale Tobacco Center of Regulatory Science, Yale School of Medicine, New Haven, CT, USA
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
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13
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Bagdas D, Rupprecht LE, Nunes EJ, Schillinger E, Immanuel JJ, Addy NA. Evaluation of Flavor Effects on Oral Nicotine Liking and/or Disliking Using the Taste Reactivity Test in Rats. Nicotine Tob Res 2021; 24:753-760. [PMID: 34918123 DOI: 10.1093/ntr/ntab241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/01/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Tobacco product flavors may change the sensory properties of nicotine, such as taste and olfactory cues, which may alter nicotine reward and aversion and nicotine taking behavior. The hedonic or aversive value of a taste stimulus can be evaluated by examining affective orofacial movements in rodents. AIMS AND METHODS We characterized taste responses to various oral nicotine concentrations using the taste reactivity test in rats. We also evaluated the impact of menthol and benzaldehyde (cherry, almond) flavorants on both ingestive and aversive responses to oral nicotine. Adult Sprague-Dawley rats (n = 5-10 per sex per group) were implanted with intraoral catheters and received 20 infusions (200 µl/ea). Nicotine (1-100 µg/mL) was evaluated in taste reactivity test to determine taste responses to nicotine. Later, the effects of menthol (50 µg/mL) and benzaldehyde (100 µg/mL) on the taste responses to nicotine were determined. RESULTS Nicotine at low concentrations (3 µg/mL in males, 1 µg/mL in females) elicited significantly greater ingestive responses compared with water, whereas higher nicotine concentrations (≥30 µg/mL in males, ≥10 µg/mL in females) elicited significant aversive reactions. Thus, intraoral nicotine induced both hedonic and aversive responses in a concentration- and sex-dependent manner. Females were more sensitive to nicotine's concentration. The addition of menthol or benzaldehyde significantly increased the hedonic responses to nicotine, and significantly decreased the aversive nicotine responses. CONCLUSIONS Oral nicotine induces both hedonic and aversive taste responses, which may represent liking and disliking. Menthol and benzaldehyde can alter the orosensory experience of nicotine, which may influence nicotine's abuse liability. IMPLICATIONS Our work represents a model to study impact of flavors on oral nicotine liking and disliking responses in rats. Moreover, our findings show that menthol and benzaldehyde alter the orosensory experience of nicotine, suggesting that both could influence nicotine's abuse liability.
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Affiliation(s)
- Deniz Bagdas
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA.,Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Laura E Rupprecht
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA.,Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Eric J Nunes
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA.,Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Emma Schillinger
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Judah J Immanuel
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Nii A Addy
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA.,Yale Tobacco Center of Regulatory Science, Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA.,Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT, USA.,Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
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14
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Lu SJ, Li L, Duffy BC, Dittmar MA, Durocher LA, Panawennage D, Delaney-Baldwin ER, Spink DC. Investigation of Vaping Fluids Recovered From New York State E-Cigarette or Vaping Product Use-Associated Lung Injury Patients. Front Chem 2021; 9:748935. [PMID: 34778204 PMCID: PMC8579054 DOI: 10.3389/fchem.2021.748935] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/08/2021] [Indexed: 11/30/2022] Open
Abstract
E-cigarette or vaping product use-associated lung injury (EVALI) is a serious pulmonary condition that is associated with the extended use of certain vaping products. EVALI was first characterized in the summer of 2019 and has since been reported in all 50 U.S. states. From August 2019 through June 2021, the New York State Department of Health has reported more than 197 confirmed cases emanating from all regions of the state. The Wadsworth Center at the New York State Department of Heath received vaping cartridges recovered from EVALI patients for chemical analysis of their contents. Untargeted analytical methods using gas chromatography-mass spectrometry and liquid chromatography-high-resolution mass spectrometry as well as targeted analyses for a variety of analytes including cannabinoids, pesticides, vitamin E acetate (VEA) and mycotoxins were used to characterize the composition of the vaping fluids and several commercial vaping fluid additives. From the analyses of the 284 e-cigarette devices recovered from patients, 82 were found to be nicotine-containing pods, and 202 devices containing cannabis oil, apparently from unauthorized or black-market dealers. The fluids from the cannabis-oil cartridges tended to have lower levels of THCs (Δ9-tetrahydrocannabinol + Δ8-tetrahydrocannabinol) and total cannabinoids compared with those of commercially produced formulations and contained significant levels of diluents including VEA, medium-chain triglycerides, polyethylene glycol, and castor oil. VEA was the diluent most frequently detected, which was present in 132 (65.3%) of the vaping fluids that contained cannabis oil. When present, VEA ranged from 2.0 to 67.8% of the total mass of the oil with a mean content of 37.0%. In some cases, two or three diluents were detected in the same sample. The ratio of VEA to THCs varied widely, from 0.07 to 5.34. VEA and specifically the high ratios of VEA to THCs in black-market vaping fluids may be causative in EVALI. The safety of additional components and additives that are present in vaping fluids are likewise of concern.
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Affiliation(s)
- Shijun Jimmy Lu
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, United States.,Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY, United States
| | - Lingyun Li
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Bryan C Duffy
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Mark A Dittmar
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Lorie A Durocher
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Deepika Panawennage
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Em R Delaney-Baldwin
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - David C Spink
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY, United States.,Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, NY, United States
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15
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Nicotine self-administration with menthol and audiovisual cue facilitates differential packaging of CYP2A6 and cytokines/chemokines in rat plasma extracellular vesicles. Sci Rep 2021; 11:17393. [PMID: 34462474 PMCID: PMC8405708 DOI: 10.1038/s41598-021-96807-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
In this study, we investigated whether intravenously self-administered nicotine with menthol and audiovisual cue modulates nicotine-metabolizing CYP2A6, oxidative stress modulators, and cytokines/chemokines in plasma extracellular vesicles (EVs) in rats. We assigned rats to self-administered nicotine with: (a) audiovisual cue (AV), (b) menthol, and (c) menthol and AV cue. We found increased levels of CD9 in plasma EVs after self-administered nicotine with menthol and AV cue. Moreover, expression of CYP2A6 in plasma EVs was significantly increased after self-administered nicotine in response to menthol and AV cue. However, despite an upward trend on SOD1 and catalase, increase was not found to be statistically significant, while total antioxidant capacity was found to be significantly increased in plasma and plasma EVs obtained after self-administered nicotine with menthol and AV cue. Among cytokine and chemokine profiling, we found a significant increase in the levels of MCP-1 after self-administered nicotine with menthol and AV cue and complete packaging of IL-1β in EVs. Taken together, the study provides evidence that nicotine in response to menthol and AV cues can package altered levels of CYP2A6, and cytokines/chemokines in plasma EVs that may contribute to cell–cell communication, nicotine metabolism, and inflammation upon cigarette smoking.
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16
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Cooper SY, Akers AT, Journigan VB, Henderson BJ. Novel Putative Positive Modulators of α4β2 nAChRs Potentiate Nicotine Reward-Related Behavior. Molecules 2021; 26:4793. [PMID: 34443380 PMCID: PMC8398432 DOI: 10.3390/molecules26164793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 11/18/2022] Open
Abstract
The popular tobacco and e-cigarette chemical flavorant (-)-menthol acts as a nonselective, noncompetitive antagonist of nicotinic acetylcholine receptors (nAChRs), and contributes to multiple physiological effects that exacerbates nicotine addiction-related behavior. Menthol is classically known as a TRPM8 agonist; therefore, some have postulated that TRPM8 antagonists may be potential candidates for novel nicotine cessation pharmacotherapies. Here, we examine a novel class of TRPM8 antagonists for their ability to alter nicotine reward-related behavior in a mouse model of conditioned place preference. We found that these novel ligands enhanced nicotine reward-related behavior in a mouse model of conditioned place preference. To gain an understanding of the potential mechanism, we examined these ligands on mouse α4β2 nAChRs transiently transfected into neuroblastoma-2a cells. Using calcium flux assays, we determined that these ligands act as positive modulators (PMs) on α4β2 nAChRs. Due to α4β2 nAChRs' important role in nicotine dependence, as well as various neurological disorders including Parkinson's disease, the identification of these ligands as α4β2 nAChR PMs is an important finding, and they may serve as novel molecular tools for future nAChR-related investigations.
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Affiliation(s)
- Skylar Y. Cooper
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA; (S.Y.C.); (A.T.A.); (V.B.J.)
| | - Austin T. Akers
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA; (S.Y.C.); (A.T.A.); (V.B.J.)
| | - Velvet Blair Journigan
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA; (S.Y.C.); (A.T.A.); (V.B.J.)
- Department of Pharmaceutical Sciences, School of Pharmacy, Marshall University, Huntington, WV 25701, USA
| | - Brandon J. Henderson
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA; (S.Y.C.); (A.T.A.); (V.B.J.)
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17
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Karelitz JL, Perkins KA. Acute subjective sensory perceptions predict relative reinforcing effects of smoked nicotine. Addict Behav 2021; 117:106835. [PMID: 33517233 DOI: 10.1016/j.addbeh.2021.106835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 12/30/2020] [Accepted: 01/11/2021] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Smoking is believed partially reinforcing via immediate sensory perceptions. Yet, unknown is whether a cigarette's relative reinforcing efficacy can be predicted by these perceptions and whether this relationship may vary due to constituents known to alter those perceptions. METHODS Sensory perceptions of acute smoking were examined as predictors of subsequent cigarette choice behavior. Also tested was whether nicotine content or menthol affected this relationship. Adult dependent smokers (N = 37) participated in five sessions comparing cigarettes varying in nicotine contents (NIC; 1.3, 2.3, 5.5, 11.2, and 17.4 mg/g), relative to the very lowest nicotine content, 0.4 mg/g (VLNC). Non-menthol (n = 17) and menthol (n = 20) cigarettes-matched on nicotine-were provided based on participant preference. One NIC was compared versus VLNC per session (single-blinded); NIC content order was randomized across sessions on separate days. Perceptions (e.g., "liking", "satisfying") were measured immediately after initial sampling of NIC or VLNC, followed by a validated puff-by-puff choice procedure to determine preference for each NIC versus VLNC. RESULTS NIC perceptions (difference from VLNC) and puff choices increased with nicotine. Menthol moderated associations between perceptions and nicotine; and between puff choices and nicotine. Perceptions were predictive of puff choice-greater magnitude of difference in perceptions between VLNC and NIC led to more NIC puff choices. When testing perceptions' prediction of puff choices, neither the main effect of menthol or interaction of Perceptions X Nicotine Condition were significant. CONCLUSIONS Consistent with assumed-but rarely tested-causes of smoking reinforcement, sensory perceptions from a cigarette predict its relative reinforcing efficacy.
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18
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Cooper SY, Akers AT, Henderson BJ. Flavors Enhance Nicotine Vapor Self-administration in Male Mice. Nicotine Tob Res 2021; 23:566-572. [PMID: 32860507 PMCID: PMC7885783 DOI: 10.1093/ntr/ntaa165] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 08/24/2020] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Although the use of combustible cigarettes has decreased in many urban regions of America, the use of electronic nicotine delivery systems (ENDS) has dramatically increased. ENDS, or electronic cigarettes (e-cigarettes), differ from combustible cigarettes given that there are no restrictions on flavorant additives in e-liquids. With 95% of ENDS users vaping flavored e-liquids, it is critical to understand how flavors alter vaping-related behaviors. We have previously shown that menthol and green apple flavors enhance nicotine reward-related behavior in a mouse model and in the present study have investigated how menthol and green apple flavors alter e-Vape self-administration behavior in male mice. METHODS Adult C57/BL6J male mice were used in vapor-inhalation self-administration assays. Mice were assigned vaping e-liquids (6 mg/mL nicotine with or without menthol or green apple flavor) to escalate on a fixed-ratio 1 (FR1) schedule in daily 3-hour sessions to examine initiation-related behaviors. Following escalation, mice were transitioned to a FR3 and progressive ratio schedules in 3-hour sessions to examine reinforcement-related behaviors. RESULTS Here we observed that male mice exhibited increased rates of self-administration escalation on a FR1 schedule when assigned to flavored e-liquids. Upon transition to FR3, mice continued to exhibit enhanced levels of reinforcement with flavored e-liquids. We also observed that mice self-administer zero-nicotine green apple flavored e-liquids. CONCLUSIONS These data provide additional evidence that ENDS flavors enhance vaping-related initiation and reinforcement-related behavior and promote the need to continue investigating the role ENDS flavors play in vaping-related behaviors. IMPLICATIONS There has been much discussion recently regarding the impact of flavors on vaping-related behavior. Our study here shows that flavors significantly enhance the acquisition and reinforcement of vaping-related behavior. This suggests that flavors in electronic nicotine delivery systems significantly increase the risk of addiction-related behaviors among users of vaping products.
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Affiliation(s)
- Skylar Y Cooper
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV
| | - Austin T Akers
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV
| | - Brandon J Henderson
- Department of Biomedical Sciences, Joan C Edwards School of Medicine at Marshall University, Huntington, WV
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19
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Wickham RJ. The Biological Impact of Menthol on Tobacco Dependence. Nicotine Tob Res 2021; 22:1676-1684. [PMID: 31867627 DOI: 10.1093/ntr/ntz239] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/17/2019] [Indexed: 12/19/2022]
Abstract
In the 1920s, tobacco companies created a marketing campaign for what would one day be their most profitable series of products: mentholated tobacco cigarettes. Menthol provides the smoker with a pleasant mint flavor in addition to a cooling sensation of the mouth, throat, and lungs, giving relief from the painful irritation caused by tobacco smoke. Promising a healthier cigarette using pictures of doctors in white coats and even cartoon penguins, tobacco companies promoted these cigarettes to young, beginner smokers and those with respiratory health concerns. Today, smoking tobacco cigarettes causes one in five US Americans to die prematurely, crowning it as the leading cause of preventable death. In contrast to the dubious health claims by tobacco companies, mentholated cigarettes are in fact more addictive. Smokers of mentholated cigarettes have lower successful quit rates and in some cases are resistant to both behavioral and pharmacological treatment strategies. There is now considerable evidence, especially in the last 5 years, that suggest menthol might influence the addictive potential of nicotine-containing tobacco products via biological mechanisms. First, menthol alters the expression, stoichiometry, and function of nicotinic receptors. Second, menthol's chemosensory properties operate to mask aversive properties of using tobacco products. Third, menthol's chemosensory properties aid in serving as a conditioned cue that can both enhance nicotine intake and drive relapse. Fourth, menthol alters nicotine metabolism, increasing its bioavailability. This review discusses emerging evidence for these mechanisms, with an emphasis on preclinical findings that may shed light on why menthol smokers exhibit greater dependence. IMPLICATIONS Mentholated cigarettes have been shown to have greater addictive potential than their nonmentholated counterparts. Evidence is pointing toward multiple mechanisms of action by which menthol may alter tobacco dependence. Understanding menthol's biological functions as it pertains to nicotine dependence will be helpful in crafting novel pharmacotherapies that might better serve menthol smokers. In addition, a better understanding of menthol's pharmacology as it relates to tobacco dependence will be valuable for informing policy decisions on the regulation of mentholated cigarettes.
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Affiliation(s)
- Robert J Wickham
- Department of Psychology, Elizabethtown College, Elizabethtown, PA
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20
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Denlinger-Apte RL, Cassidy RN, Carey KB, Kahler CW, Bickel WK, O'Connor R, Thussu S, Tidey JW. The impact of menthol flavoring in combusted tobacco on alternative product purchasing: A pilot study using the Experimental Tobacco Marketplace. Drug Alcohol Depend 2021; 218:108390. [PMID: 33213974 PMCID: PMC7750267 DOI: 10.1016/j.drugalcdep.2020.108390] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 10/01/2020] [Accepted: 10/24/2020] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Menthol cigarette smokers may switch to other combusted products like menthol little cigars and cigarillos (LCCs) or switch to non-combusted products like menthol vapes if menthol cigarettes are banned or otherwise restricted. This pilot study used a behavioral economics task to understand (a) menthol cigarette demand across a range of increasing prices in the context of available alternative products and (b) how the availability of menthol LCCs affected cigarette demand and alternative product substitution. METHODS Menthol smokers completed the Experimental Tobacco Marketplace task during two sessions. Cigarettes, LCCs, smokeless tobacco, vapes, and medicinal nicotine were available from an online store. The price of menthol cigarettes increased across trials while the prices of the alternative products remained constant. Menthol LCCs were available in one session and excluded in the other. Cross-price elasticity beta estimates identified significant product substitutes. RESULTS When menthol LCCs were available, increasing the price of menthol cigarettes led to substitution with non-menthol cigarettes (β = 0.65, 95%CI = 0.34, 0.96), menthol little cigars (β = 0.39, 95%CI = 0.08, 0.70), and menthol vapes (β = 0.26, 95%CI = 0.16, 0.35). When menthol LCCs were not available, increasing the price of menthol cigarettes led to substitution with non-menthol cigarettes (β = 0.59, 95% CI = 0.08, 1.11), non-menthol cigarillos (β = 0.62, 95%CI = 0.19, 1.04), and menthol vapes (β = 0.13, 95%CI = 0.08, 0.18). CONCLUSIONS As the price of menthol cigarettes increased, demand for menthol cigarettes decreased and demand for combusted and non-combusted products increased, indicating significant substitution for menthol cigarettes. Policies targeting menthol combusted tobacco could result in some menthol smokers switching to non-combusted products like vaping devices.
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Affiliation(s)
- Rachel L Denlinger-Apte
- Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA.
| | - Rachel N Cassidy
- Department of Behavioral and Social Sciences, Brown University School of Public Health, Providence, RI, 02912, USA.
| | - Kate B Carey
- Department of Behavioral and Social Sciences, Brown University School of Public Health, Providence, RI, 02912, USA.
| | - Christopher W Kahler
- Department of Behavioral and Social Sciences, Brown University School of Public Health, Providence, RI, 02912, USA.
| | - Warren K Bickel
- Fralin Biomedical Research Institute, Virginia Tech, Roanoke, VA, 24016, USA.
| | - Richard O'Connor
- Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, NY, 14263, USA. Richard.O'
| | - Shreeya Thussu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA
| | - Jennifer W Tidey
- Department of Behavioral and Social Sciences, Brown University School of Public Health, Providence, RI, 02912, USA.
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21
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Jao NC, Tan MM, Matthews PA, Simon MA, Schnoll R, Hitsman B. Menthol Cigarettes, Tobacco Dependence, and Smoking Persistence: The Need to Examine Enhanced Cognitive Functioning as a Neuropsychological Mechanism. Nicotine Tob Res 2020; 22:466-472. [PMID: 30551213 DOI: 10.1093/ntr/nty264] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 12/11/2018] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Despite the overall decline in the prevalence of cigarette use in the United States, menthol cigarette use among smokers is rising, and evidence shows that it may lead to more detrimental effects on public health than regular cigarette use. One of the mechanisms by which nicotine sustains tobacco use and dependence is due to its cognitive enhancing properties, and basic science literature suggests that menthol may also enhance nicotine's acute effect on cognition. AIMS AND METHODS The purpose of this review is to suggest that the cognitive enhancing effects of menthol may be a potentially important neuropsychological mechanism that has yet to be examined. In this narrative review, we provide an overview of basic science studies examining neurobiological and cognitive effects of menthol and menthol cigarette smoking. We also review studies examining menthol essential oils among humans that indicate menthol alone has acute cognitive enhancing properties. Finally, we present factors influencing the rising prevalence of menthol cigarette use among smokers and the importance of this gap in the literature to improve public health and smoking cessation treatment. CONCLUSIONS Despite the compelling evidence for menthol's acute cognitive enhancing and reinforcing effects, this mechanism for sustaining tobacco dependence and cigarette use has yet to be examined and validated among humans. On the basis of the basic science evidence for menthol's neurobiological effects on nicotinic receptors and neurotransmitters, perhaps clarifying menthol's effect on cognitive performance can help to elucidate the complicated literature examining menthol and tobacco dependence. IMPLICATIONS Menthol cigarette use has continued to be a topic of debate among researchers and policy makers, because of its implications for understanding menthol's contribution to nicotine dependence and smoking persistence, as well as its continued use as a prevalent flavoring in tobacco and nicotine products in the United States and internationally. As international tobacco regulation policies have begun to target menthol cigarettes, research studies need to examine how flavoring additives, specifically menthol, may acutely influence neurobiological and cognitive functioning as a potential mechanism of sustained smoking behavior to develop more effective treatments.
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Affiliation(s)
- Nancy C Jao
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Marcia M Tan
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Phoenix A Matthews
- Department of Health Systems Science, University of Illinois at Chicago, Chicago, IL
| | - Melissa A Simon
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL.,Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Chicago, IL.,Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Robert Schnoll
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA
| | - Brian Hitsman
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL
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22
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Cooper SY, Henderson BJ. The Impact of Electronic Nicotine Delivery System (ENDS) Flavors on Nicotinic Acetylcholine Receptors and Nicotine Addiction-Related Behaviors. Molecules 2020; 25:E4223. [PMID: 32942576 PMCID: PMC7571084 DOI: 10.3390/molecules25184223] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/11/2020] [Accepted: 09/13/2020] [Indexed: 12/18/2022] Open
Abstract
Over the past two decades, combustible cigarette smoking has slowly declined by nearly 11% in America; however, the use of electronic cigarettes has increased tremendously, including among adolescents. While nicotine is the main addictive component of tobacco products and a primary concern in electronic cigarettes, this is not the only constituent of concern. There is a growing market of flavored products and a growing use of zero-nicotine e-liquids among electronic cigarette users. Accordingly, there are few studies that examine the impact of flavors on health and behavior. Menthol has been studied most extensively due to its lone exception in combustible cigarettes. Thus, there is a broad understanding of the neurobiological effects that menthol plus nicotine has on the brain including enhancing nicotine reward, altering nicotinic acetylcholine receptor number and function, and altering midbrain neuron excitability. Although flavors other than menthol were banned from combustible cigarettes, over 15,000 flavorants are available for use in electronic cigarettes. This review seeks to summarize the current knowledge on nicotine addiction and the various brain regions and nicotinic acetylcholine receptor subtypes involved, as well as describe the most recent findings regarding menthol and green apple flavorants, and their roles in nicotine addiction and vaping-related behaviors.
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Affiliation(s)
| | - Brandon J. Henderson
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25703, USA;
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Bagdas D, Jackson A, Carper M, Chen RYT, Akinola LS, Damaj MI. Impact of menthol on nicotine intake and preference in mice: Concentration, sex, and age differences. Neuropharmacology 2020; 179:108274. [PMID: 32827516 DOI: 10.1016/j.neuropharm.2020.108274] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 08/09/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022]
Abstract
Menthol has been shown to contribute to the appeal of tobacco products in humans. However, factors such as sex, age and menthol concentration remain unclear in the interaction between menthol and nicotine. To understand these factors, we utilized a mouse model to determine the impact of menthol on oral nicotine consumption. A range of menthol concentrations (oral and systemic) were tested with or without oral nicotine using the two-bottle choice paradigm in adolescent and adult female and male C57BL/6J mice. Moreover, genetically modified mice were used to investigate the role of α7 nicotinic acetylcholine receptors (nAChRs) on the effects of menthol. Menthol addition to nicotine solution increased oral nicotine consumption in C57BL/6J mice in a sex- and menthol concentration-dependent manner. At lower menthol concentrations, female mice demonstrated an enhancement of nicotine consumption and male mice showed a similar behavior at higher menthol concentrations. Menthol drinking alone was only significantly different by sex at 60 μg/ml menthol concentration where female mice had higher menthol intake than males. Menthol administered both orally and systemically (intraperitoneal) increased oral nicotine consumption. Adolescent female mice had a higher nicotine intake at lower menthol concentrations compared to their adult counterparts. While α7 nAChR wild type mice consumed more mentholated nicotine solution than nicotine only solution, this effect was abolished in KO mice. Effects of menthol are concentration-, sex-, age-, and α7 nAChR-dependent. Oral and intraperitoneal menthol increases nicotine intake, suggesting that sensory, peripheral, and/or central mechanisms are involved in effects of menthol on oral nicotine consumption.
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Affiliation(s)
- Deniz Bagdas
- Department of Psychiatry, School of Medicine, Yale University, New Haven, CT, USA; Yale Tobacco Center of Regulatory Science, Yale University, New Haven, CT, USA; The Center for the Study for Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA.
| | - Asti Jackson
- Department of Psychiatry, School of Medicine, Yale University, New Haven, CT, USA; Yale Tobacco Center of Regulatory Science, Yale University, New Haven, CT, USA
| | - Moriah Carper
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA
| | - Rita Yu-Tzu Chen
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA
| | - Lois S Akinola
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA
| | - M Imad Damaj
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA; The Center for the Study for Tobacco Products, Virginia Commonwealth University, Richmond, VA, USA
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Green Apple e-Cigarette Flavorant Farnesene Triggers Reward-Related Behavior by Promoting High-Sensitivity nAChRs in the Ventral Tegmental Area. eNeuro 2020; 7:ENEURO.0172-20.2020. [PMID: 32747456 PMCID: PMC7433896 DOI: 10.1523/eneuro.0172-20.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/04/2020] [Accepted: 06/11/2020] [Indexed: 11/21/2022] Open
Abstract
While combustible cigarette smoking has declined, the use of electronic nicotine delivery systems (ENDS) has increased. ENDS are popular among adolescents, and chemical flavorants are an increasing concern because of the growing use of zero-nicotine flavored e-liquids. Despite this, little is known regarding the effects of ENDS flavorants on vaping-related behavior. Following previous studies demonstrating the green apple flavorant, farnesol, enhances nicotine reward and exhibits rewarding properties without nicotine, this work focuses on the green apple flavorant, farnesene, for its impact on vaping-related behaviors. Using adult C57BL/6J mice, genetically modified to contain fluorescent nicotinic acetylcholine receptors (nAChRs), and farnesene doses of 0.1, 1.0, and 10 mg/kg, we observed farnesene-alone produces reward-related behavior in both male and female mice. We then performed whole-cell patch-clamp electrophysiology and observed farnesene-induced inward currents in ventral tegmental area (VTA) putative dopamine (pDA) neurons that were blocked by the nAChR antagonist, DhβE. While the amplitudes of farnesene-induced currents are ∼30% of nicotine's efficacy, this indicates the potential for some ENDS flavorants to stimulate nAChR function. Additionally, farnesene enhances nicotine's potency for activating nAChRs on VTA dopamine neurons. This may be because of changes in nAChR stoichiometry as our data suggest a shift toward high-sensitivity α4β2 nAChRs. Consequently, these data show that the green apple flavorant, farnesene, causes reward-related behavior without nicotine through changes in nAChR stoichiometry that results in an enhanced effect of nicotine on VTA dopamine neurons. These results demonstrate the importance of future investigations into ENDS flavorants and their effects on vaping-related behaviors.
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Huynh YW, Raimondi A, Finkner A, Kuck JD, Selleck C, Bevins RA. Menthol blunts the interoceptive discriminative stimulus effects of nicotine in female but not male rats. Psychopharmacology (Berl) 2020; 237:2395-2404. [PMID: 32448943 PMCID: PMC7354904 DOI: 10.1007/s00213-020-05542-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 04/27/2020] [Indexed: 01/29/2023]
Abstract
RATIONALE Menthol is a widely used tobacco constituent that has shown to enhance nicotine's reinforcing effects. OBJECTIVE To determine whether injected menthol also alters nicotine's stimulus effects, we used a drug discrimination task. METHODS A total of 57 adult Sprague-Dawley rats (28M, 29F) received 20 positive and 20 negative days (intermixed) of discrimination training. On positive days, rats received a group-specific menthol and nicotine injection (VEH + 0.1 NIC, 1 M + 0.1 NIC, 5 M + 0.1 NIC, VEH + 0.4 NIC, 1 M + 0.4 NIC, 5 M + 0.4 NIC; mg/kg) before eight 15-s cue light presentations (conditioned stimulus (CS)), each followed by 4-s sucrose access. On negative days, all rats were injected with vehicle and saline before eight non-reinforced CS presentations. Next, rats underwent generalization testing with 30 dose combinations of menthol and nicotine. The change in drug-mediated anticipatory goal tracking during the CS was calculated as a difference score (CS minus pre-CS responding). RESULTS All groups readily acquired drug discrimination. However, difference scores for the 5M + 0.1 NIC group were lower for females. Additionally, females had lower scores for 0.05, 0.1, and 0.4 mg/kg nicotine generalization tests. The lowest nicotine dose discriminable from saline was 0.05 mg/kg for females but 0.025 mg/kg for males. Co-administration with 5 or 10 mg/kg menthol weakened discrimination performance between 0.1 and 0.4 mg/kg and between 0.1 and 0.05 mg/kg nicotine for 0.1 mg/kg nicotine training groups. CONCLUSIONS Female rats that were trained with 0.1 mg/kg nicotine were more sensitive to menthol's modulatory effects on nicotine's stimulus effects. This highlights the importance of taking sex and training dose into account when evaluating the interoceptive stimulus effects of nicotine and menthol.
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Affiliation(s)
- Y Wendy Huynh
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Anthony Raimondi
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Andrew Finkner
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Jordan D Kuck
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Carly Selleck
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA
| | - Rick A Bevins
- Department of Psychology, University of Nebraska-Lincoln, 238 Burnett Hall, Lincoln, NE, 68588-0308, USA.
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Menthol cigarette smoking is associated with greater subjective reward, satisfaction, and "throat hit", but not greater behavioral economic demand. Addict Behav 2020; 101:106108. [PMID: 31648140 DOI: 10.1016/j.addbeh.2019.106108] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/14/2022]
Abstract
AIMS The cooling and minty flavor of menthol in cigarettes has been hypothesized to mask the harshness of inhaled cigarette smoke, contributing to menthol's appeal and subjective reinforcement and linking menthol use to smoking initiation, progression, nicotine dependence, and difficulty quitting. This study examined differences between menthol and non-menthol smokers on behavioral economic indices of reinforcing efficacy (i.e., demand) and subjective response to smoking (i.e., satisfaction, reward, "throat hit," aversion) and the association between measurements of reinforcement and subjective response. DESIGN 600 current adult smokers were recruited from an online smoking cessation program. Following website enrollment, individuals completed a self-report measurement of subjective response to smoking (reward, satisfaction, aversion, "throat hit"), and a modified cigarette purchase task (CPT) to assess behavioral economic cigarette demand. FINDINGS In bivariate and adjusted ANOVA models, menthol smokers reported greater subjective reward, satisfaction, and positive sensations in the throat ("throat hit") from smoking compared to non-menthol smokers; and those outcomes were also correlated with greater nicotine dependence and lower likelihood of a past-year quit attempt. Although cigarette demand was associated with smoking level, subjective smoking reward, and nicotine dependence, there were no differences in smoking demand between menthol vs. non-menthol smokers. CONCLUSIONS The pleasurable aspects of menthol vs non-menthol smoking may be a mechanism linking it to greater nicotine dependence and difficulty quitting. A menthol ban could decrease population-level cigarette consumption by restricting smokers' access to a highly rewarding cigarette flavoring.
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Denlinger-Apte RL, Kotlyar M, Koopmeiners JS, Tidey JW, Luo X, Benowitz NL, Jensen JA, Ikuemonisan JO, Pacek LR, Smith TT, Vandrey R, Donny EC, Hatsukami DK. Effects of Very Low Nicotine Content Cigarettes on Smoking Behavior and Biomarkers of Exposure in Menthol and Non-menthol Smokers. Nicotine Tob Res 2019; 21:S63-S72. [PMID: 31867637 PMCID: PMC6939781 DOI: 10.1093/ntr/ntz160] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/25/2019] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Because 30% of cigarettes sold in the United States are characterized as menthol cigarettes, it is important to understand how menthol preference may affect the impact of a nicotine reduction policy. METHODS In a recent trial, non-treatment-seeking smokers were randomly assigned to receive very low nicotine cigarettes (VLNC; 0.4 mg nicotine/g tobacco) or normal nicotine cigarettes (NNC; 15.5 mg/g) for 20 weeks. On the basis of preference, participants received menthol or non-menthol cigarettes. We conducted multivariable regression analyses to examine whether menthol preference moderated the effects of nicotine content on cigarettes per day (CPD), breath carbon monoxide (CO), urinary total nicotine equivalents (TNE), urinary 2-cyanoethylmercapturic acid (CEMA), and abstinence. RESULTS At baseline, menthol smokers (n = 346) reported smoking fewer CPD (14.9 vs. 19.2) and had lower TNE (52.8 vs. 71.6 nmol/mg) and CO (17.7 vs. 20.5 ppm) levels than non-menthol smokers (n = 406; ps < .05). At week 20, significant interactions indicated that menthol smokers had smaller treatment effects than non-menthol smokers for CPD (-6.4 vs. -9.3), TNE (ratio of geometric means, 0.22 vs. 0.10) and CEMA (ratio, 0.56 vs. 0.37; ps < .05), and trended toward a smaller treatment effect for CO (-4.5 vs. -7.3 ppm; p = .06). Odds ratios for abstinence at week 20 were 1.88 (95% confidence interval [CI] = 0.8 to 4.4) for menthol and 9.11 (95% CI = 3.3 to 25.2) for non-menthol VLNC smokers (p = .02) relative to the NNC condition. CONCLUSIONS Although menthol smokers experienced reductions in smoking, toxicant exposure, and increases in quitting when using VLNC cigarettes, the magnitude of change was smaller than that observed for non-menthol smokers. IMPLICATIONS Results of this analysis suggest that smokers of menthol cigarettes may respond to a nicotine reduction policy with smaller reductions in smoking rates and toxicant exposure than would smokers of non-menthol cigarettes.
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Affiliation(s)
- Rachel L Denlinger-Apte
- Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, NC
| | - Michael Kotlyar
- Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, MN
| | - Joseph S Koopmeiners
- Masonic Cancer Center and Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN
| | - Jennifer W Tidey
- Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, NC
- Department of Behavioral and Social Sciences, Brown University School of Public Health, Providence, RI
| | - Xianghua Luo
- Masonic Cancer Center and Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN
| | - Neal L Benowitz
- Department of Medicine, University of California San Francisco, San Francisco, CA
| | - Joni A Jensen
- Masonic Cancer Center and Department of Psychiatry, University of Minnesota, Minneapolis, MN
| | - Joshua O Ikuemonisan
- Masonic Cancer Center and Department of Psychiatry, University of Minnesota, Minneapolis, MN
| | - Lauren R Pacek
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC
| | - Tracy T Smith
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC
| | - Ryan Vandrey
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD
| | - Eric C Donny
- Baptist Comprehensive Cancer Center and Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC
| | - Dorothy K Hatsukami
- Masonic Cancer Center and Department of Psychiatry, University of Minnesota, Minneapolis, MN
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Avelar AJ, Akers AT, Baumgard ZJ, Cooper SY, Casinelli GP, Henderson BJ. Why flavored vape products may be attractive: Green apple tobacco flavor elicits reward-related behavior, upregulates nAChRs on VTA dopamine neurons, and alters midbrain dopamine and GABA neuron function. Neuropharmacology 2019; 158:107729. [PMID: 31369741 DOI: 10.1016/j.neuropharm.2019.107729] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 07/22/2019] [Accepted: 07/28/2019] [Indexed: 01/15/2023]
Abstract
While nicotine is the primary addictive component in tobacco products, additional flavors have become a concern with the growing popularity of electronic nicotine delivery systems (ENDS). For this reason, we have begun to investigate popular tobacco and ENDS flavors. Here, we examined farnesol, a chemical flavorant used in green apple and fruit flavors in ENDS e-liquids, for its ability to produce reward-related behavior. Using male and female 3-6 month old C57BL/6 J mice and farnesol doses of 0.1, 1, and 10 mg/kg we identified a sex-dependent effect in a conditioned place preference assay: farnesol-alone produces reward-related behavior in only male mice. Despite this sex-dependent effect, 1.0 mg/kg farnesol enhances locomotor activity in both male and female mice. To understand farnesol's effect on reward-related behavior, we used whole-cell patch-clamp electrophysiology and confocal microscopy to investigate changes in putative dopamine and GABA neurons. For these approaches, we utilized genetically modified mice that contain fluorescent nicotinic acetylcholine receptors (nAChRs). Our electrophysiological assays with male mice revealed that farnesol treatment increases ventral tegmental area (VTA) dopamine neuron firing frequency and this may be due to a decrease in inhibitory tone from GABA neurons. Our microscopy assays revealed that farnesol treatment produces a significant upregulation of α6* nAChRs in male mice but not female mice. This was supported by an observed increase in α6* nAChR function in additional electrophysiology assays. These data provide evidence that popular tobacco flavorants may alter smoking-related behavior and promote the need to examine additional ENDS flavors.
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Affiliation(s)
- Alicia J Avelar
- Department of Biomedical Sciences, Marshall University, Joan C Edwards School of Medicine, Huntington, WV, USA
| | - Austin T Akers
- Department of Biomedical Sciences, Marshall University, Joan C Edwards School of Medicine, Huntington, WV, USA
| | - Zachary J Baumgard
- Department of Biomedical Sciences, Marshall University, Joan C Edwards School of Medicine, Huntington, WV, USA
| | - Skylar Y Cooper
- Department of Biomedical Sciences, Marshall University, Joan C Edwards School of Medicine, Huntington, WV, USA
| | - Gabriella P Casinelli
- Department of Biomedical Sciences, Marshall University, Joan C Edwards School of Medicine, Huntington, WV, USA
| | - Brandon J Henderson
- Department of Biomedical Sciences, Marshall University, Joan C Edwards School of Medicine, Huntington, WV, USA.
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Nesil T, Narmeen S, Bakhti-Suroosh A, Lynch WJ. Effect of menthol on nicotine intake and relapse vulnerability in a rat model of concurrent intravenous menthol/nicotine self-administration. Psychopharmacology (Berl) 2019; 236:1219-1232. [PMID: 30483833 PMCID: PMC6536373 DOI: 10.1007/s00213-018-5128-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 11/19/2018] [Indexed: 11/30/2022]
Abstract
RATIONALE Epidemiological data suggest that menthol may increase vulnerability to cigarette/nicotine use and relapse. While menthol's sensory properties are often attributed as the underlying cause of the enhanced vulnerability, an alternative possibility is that they are mediated via pharmacological interactions with nicotine. OBJECTIVE This study addressed the possibility that menthol enhances nicotine intake and relapse vulnerability via pharmacological interactions with nicotine using a concurrent intravenous menthol/nicotine self-administration procedure. METHODS Following acquisition, adolescent rats were given 23-h/day access to nicotine (0.01 mg/kg/infusion), nicotine plus menthol (0.16, 0.32, or 0.64 mg/kg/infusion), or menthol alone (0.16, 0.32, 0.64 mg/kg/infusion) for a total of 10 days. Nicotine-seeking was assessed using an extinction/cue-induced reinstatement procedure following 10 days of forced abstinence. We also assessed the effect of menthol (0.32 mg/kg/infusion) on progressive ratio responding for nicotine (0.01 mg/kg/infusion). RESULTS Menthol decreased PR responding for nicotine but did not affect self-administration under extended access conditions. The low dose of menthol tended to decrease subsequent extinction responding, and was not different from menthol alone, whereas the high dose decreased reinstatement responding. Although not significant, the highest levels of extinction responding were observed in a minority of rats in the moderate and high menthol-nicotine groups; rats in these groups also took longer to extinguish. CONCLUSIONS Taken together, these results demonstrate that pharmacological interactions of menthol with nicotine reduce, rather than increase, nicotine's reinforcing effects and some measures of relapse vulnerability. Importantly, however, moderate and high menthol doses may increase some aspects of relapse vulnerability in a minority of individuals.
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MESH Headings
- Animals
- Behavior, Addictive/chemically induced
- Behavior, Addictive/psychology
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Conditioning, Operant/drug effects
- Conditioning, Operant/physiology
- Extinction, Psychological/drug effects
- Extinction, Psychological/physiology
- Infusions, Intravenous
- Male
- Menthol/administration & dosage
- Menthol/toxicity
- Nicotine/administration & dosage
- Nicotine/toxicity
- Nicotinic Agonists/administration & dosage
- Nicotinic Agonists/toxicity
- Rats
- Rats, Sprague-Dawley
- Recurrence
- Reinforcement, Psychology
- Self Administration
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Affiliation(s)
- Tanseli Nesil
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, 22902, USA
| | - Syeda Narmeen
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, 22902, USA
| | - Anousheh Bakhti-Suroosh
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, 22902, USA
| | - Wendy J Lynch
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, 22902, USA.
- Department of Psychiatry and Neurobehavioral Sciences, PO Box 801402, Charlottesville, VA, 22904, USA.
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Social and anxiety-like behaviors contribute to nicotine self-administration in adolescent outbred rats. Sci Rep 2018; 8:18069. [PMID: 30584246 PMCID: PMC6305389 DOI: 10.1038/s41598-018-36263-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 11/19/2018] [Indexed: 01/06/2023] Open
Abstract
Both emotional and social traits interact with genetic factors to influence smoking behavior. We previously established a socially acquired nicotine intravenous self-administration model where social learning of a nicotine-associated odor cue reversed conditioned flavor aversion and promoted nicotine intake. In this study, we first phenotyped ~800 adolescent heterogeneous stock rats in open field, novel object interaction, social interaction, elevated plus maze, and marble burying behaviors. These rats were then phenotyped on socially acquired nicotine self-administration. We found 243 significant correlations between different behavioral tests. Principal component regression analysis found that ~10-20% of the variance in nicotine-related measures, such as intake during the first or the last three fixed-ratio sessions, the progressive ratio session, and reinstatement behavior, can be explained by variations in behavioral traits. Factors corresponding to social behavior and anxiety were among the strongest predictors of nicotine intake and reinstatement of nicotine-seeking behavior. We also found many sex differences in behavioral measures. These data indicated that the genetic diversity of this population, in combination with social behaviour and anxiety, are significant contributors to the divergent nicotine self-administration behavior and indicated a high probability of discovering sex-specific genetic mechanisms for nicotine intake in future genome-wide association studies.
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Henderson BJ, Grant S, Chu BW, Shahoei R, Huard SM, Saladi SSM, Tajkhorshid E, Dougherty DA, Lester HA. Menthol Stereoisomers Exhibit Different Effects on α4β2 nAChR Upregulation and Dopamine Neuron Spontaneous Firing. eNeuro 2018; 5:ENEURO.0465-18.2018. [PMID: 30627659 PMCID: PMC6325563 DOI: 10.1523/eneuro.0465-18.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 12/08/2018] [Indexed: 11/21/2022] Open
Abstract
Menthol contributes to poor cessation rates among smokers, in part because menthol enhances nicotine reward and reinforcement. Mentholated tobacco products contain (-)-menthol and (+)-menthol, in varying proportions. We examined these two menthol stereoisomers for their ability to upregulate α4β2 nAChRs and to alter dopamine neuron firing frequency using long-term, low-dose (≤500 nm) exposure that is pharmacologically relevant to smoking. We found that (-)-menthol upregulates α4β2 nAChRs while (+)-menthol does not. We also found that (-)-menthol decreases dopamine neuron baseline firing and dopamine neuron excitability, while (+)-menthol exhibits no effect. We then examined both stereoisomers for their ability to inhibit α4β2 nAChR function at higher concentrations (>10 µm) using the Xenopus oocyte expression system. To probe for the potential binding site of menthol, we conducted flooding simulations and site-directed mutagenesis. We found that menthol likely binds to the 9´ position on the TM2 (transmembrane M2) helix. We found that menthol inhibition is dependent on the end-to-end distance of the side chain at the 9´ residue. Additionally, we have found that (-)-menthol is only modestly (∼25%) more potent than (+)-menthol at inhibiting wild-type α4β2 nAChRs and a series of L9´ mutant nAChRs. These data reveal that menthol exhibits a stereoselective effect on nAChRs and that the stereochemical effect is much greater for long-term, submicromolar exposure in mice than for acute, higher-level exposure. We hypothesize that of the two menthol stereoisomers, only (-)-menthol plays a role in enhancing nicotine reward through nAChRs on dopamine neurons.
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Affiliation(s)
- Brandon J. Henderson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia 25703
| | - Stephen Grant
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Betty W. Chu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Rezvan Shahoei
- Department of Physics, National Institutes of Health Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Stephanie M. Huard
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Shyam S. M. Saladi
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Emad Tajkhorshid
- Department of Biochemistry, National Institutes of Health Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Dennis A. Dougherty
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Henry A. Lester
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
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32
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Zhang M, Harrison E, Biswas L, Tran T, Liu X. Menthol facilitates dopamine-releasing effect of nicotine in rat nucleus accumbens. Pharmacol Biochem Behav 2018; 175:47-52. [PMID: 30201386 DOI: 10.1016/j.pbb.2018.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 09/05/2018] [Accepted: 09/07/2018] [Indexed: 11/19/2022]
Abstract
Menthol is a significant flavoring additive in tobacco products. Accumulating clinical evidence suggests that menthol may promote tobacco smoking and nicotine dependence. Our previous studies demonstrated that menthol enhanced nicotine reinforcement in rats. However, it is unclear whether menthol interacts with nicotine at the neurochemical level. The present study used intracranial microdialysis to examine whether and the ways in which menthol affects nicotine-induced dopamine release in rats in the nucleus accumbens core (NAc), a terminal field of brain reward circuitry. To make comparisons with our previous work that showed an enhancing effect of menthol on nicotine self-administration behavior, male Sprague-Dawley rats were first trained in 20 daily 1-h sessions to press a lever for intravenous nicotine self-administration (15 μg/kg/infusion). Dopamine levels were then measured in the right NAc using intracranial microdialysis coupled with high-performance liquid chromatography. Five minutes before microdialysis, the rats received an intraperitoneal injection of menthol (0, 1, 2.5, and 5 mg/kg), a subcutaneous injection of nicotine (0.2 mg/kg or its vehicle), or both. Menthol alone did not affect dopamine levels in dialysates, whereas nicotine alone elevated dopamine levels. Combined nicotine and menthol administration significantly increased dopamine levels compared with nicotine alone. These data indicate a facilitating effect of menthol on nicotine-induced dopamine release in the NAc. These findings shed light on our understanding of the neurobiological mechanisms that underlie the menthol-induced enhancement of nicotine reinforcement.
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Affiliation(s)
- Meiyu Zhang
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA; Experimental Research Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China
| | - Erin Harrison
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Lisa Biswas
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Thuy Tran
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Xiu Liu
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA.
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Valentine GW, DeVito EE, Jatlow PI, Gueorguieva R, Sofuoglu M. Acute effects of inhaled menthol on the rewarding effects of intravenous nicotine in smokers. J Psychopharmacol 2018; 32:986-994. [PMID: 29788802 PMCID: PMC6329876 DOI: 10.1177/0269881118773972] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE This double-blind, placebo controlled study examined whether menthol inhaled from an electronic cigarette (e-cigarette) would change subjective and withdrawal alleviating effects of intravenous nicotine in young adult smokers. METHODS A total of 32 menthol-preferring smokers and 25 non-menthol-preferring smokers participated in the study that consisted of a random sequence of three different inhaled menthol conditions (0.0%, 0.5%, and 3.2%) across three test sessions (a single menthol condition per session). In each test session (performed at least 24 hours apart), a random order of saline, and two different nicotine infusions of 0.25 mg and 0.5 mg/70 kg of bodyweight were administered, one hour apart, concurrent with menthol inhalation. RESULTS While menthol did not alter the positive subjective effects of nicotine, menthol significantly enhanced aversive effects of nicotine in non-menthol-preferring smokers and reduced smoking urges in menthol-preferring smokers. In addition, menthol-preferring smokers reported blunted positive subjective responses to nicotine and less severe nicotine withdrawal after overnight nicotine deprivation. Finally, compared to non-menthol-preferring smokers, menthol-preferring smokers had a significantly lower baseline nicotine metabolite ratio indicating slower nicotine metabolism within our sample of menthol-preferring smokers. CONCLUSIONS Our findings did not support an enhancement of nicotine's positive subjective effects from inhaled menthol. However, as compared to non-menthol-preferring smokers, menthol-preferring smokers had blunted positive subjective responses to nicotine and reduced overnight withdrawal severity that may be partly due to inhibition of nicotine metabolism from chronic exposure to inhaled menthol. Collectively, these results reveal a more complex and nuanced role of inhaled menthol in smokers than previously recognized.
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Affiliation(s)
- Gerald W Valentine
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA,VA Connecticut Healthcare System, West Haven, CT, USA
| | - Elise E DeVito
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA,VA Connecticut Healthcare System, West Haven, CT, USA
| | - Peter I Jatlow
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA,Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT USA
| | - Ralitza Gueorguieva
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - Mehmet Sofuoglu
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA,VA Connecticut Healthcare System, West Haven, CT, USA
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D’Silva J, Cohn AM, Johnson AL, Villanti AC. Differences in Subjective Experiences to First Use of Menthol and Nonmenthol Cigarettes in a National Sample of Young Adult Cigarette Smokers. Nicotine Tob Res 2018; 20:1062-1068. [PMID: 29059351 PMCID: PMC6093322 DOI: 10.1093/ntr/ntx181] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 08/11/2017] [Indexed: 11/12/2022]
Abstract
Purpose Menthol has been hypothesized to ease the harshness of cigarette smoke. Thus, sensory experiences at first cigarette use may be one mechanism by which menthol facilitates progression to regular smoking. This study examined differences in subjective experiences to the first use of a menthol versus nonmenthol cigarette among new young adult smokers. Methods Data were drawn from waves 5-8 of the Truth Initiative Young Adult Cohort Study, a national sample of 18-34 year olds assessed every 6 months. Analyses included a subset of young adult current smokers (n = 251) who initiated smoking in the past 6 months. Subjective responses to first cigarette use were assessed across menthol and nonmenthol initiators in bivariate analyses and adjusted models controlling for smoking correlates. Results Fifty-two percent of new young adult smokers used a menthol cigarette at first use. First use of a menthol cigarette was higher in those aged 18-24 (vs. 25-34). Most black smokers (93.1%) were menthol initiators compared to 43.9% of white smokers. More than half of menthol and nonmenthol initiates felt relaxed or calm, dizzy, lightheaded, liking the taste and a rush or buzz at first use. Menthol initiators were less likely in bivariate and multivariable analyses to experience feeling nauseated at first use (adjusted odds ratio = 0.45; p = .020) compared to nonmenthol initiators. Conclusions While few differences were found between menthol and nonmenthol initiators in their subjective experiences, fewer menthol initiates felt nauseated at first cigarette use. Future research needs to identify additional mechanisms linking menthol initiation to smoking progression. Implications Menthol initiators were more likely to be younger (18-24 vs. 25-34), and black (vs. white) compared to nonmenthol initiators. Our finding that menthol initiators were less likely to feel nauseated at first cigarette use compared to nonmenthol initiators suggests that menthol may reduce aversion to early cigarette use among young smokers and thus has the potential to facilitate continued experimentation. Interventions and policy approaches to reduce tobacco use initiation and progression are urgently needed in young people.
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Affiliation(s)
- Joanne D’Silva
- Schroeder Institute at Truth Initiative, Washington, DC
- Department of Behavioral and Community Health, University of Maryland School of Public Health, College Park, MD
| | - Amy M Cohn
- Battelle Memorial Institute, Arlington, VA
- Department of Oncology, Georgetown University Medical Center, Washington, DC
| | | | - Andrea C Villanti
- Schroeder Institute at Truth Initiative, Washington, DC
- Vermont Center on Behavior and Health, Department of Psychiatry, University of Vermont, Burlington, VT
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Smith TT, Rupprecht LE, Denlinger-Apte RL, Weeks JJ, Panas RS, Donny EC, Sved AF. Animal Research on Nicotine Reduction: Current Evidence and Research Gaps. Nicotine Tob Res 2018; 19:1005-1015. [PMID: 28379511 DOI: 10.1093/ntr/ntx077] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 03/31/2017] [Indexed: 01/21/2023]
Abstract
A mandated reduction in the nicotine content of cigarettes may improve public health by reducing the prevalence of smoking. Animal self-administration research is an important complement to clinical research on nicotine reduction. It can fill research gaps that may be difficult to address with clinical research, guide clinical researchers about variables that are likely to be important in their own research, and provide policy makers with converging evidence between clinical and preclinical studies about the potential impact of a nicotine reduction policy. Convergence between clinical and preclinical research is important, given the ease with which clinical trial participants can access nonstudy tobacco products in the current marketplace. Herein, we review contributions of preclinical animal research, with a focus on rodent self-administration, to the science of nicotine reduction. Throughout this review, we highlight areas where clinical and preclinical research converge and areas where the two differ. Preclinical research has provided data on many important topics such as the threshold for nicotine reinforcement, the likelihood of compensation, moderators of the impact of nicotine reduction, the impact of environmental stimuli on nicotine reduction, the impact of nonnicotine cigarette smoke constituents on nicotine reduction, and the impact of nicotine reduction on vulnerable populations. Special attention is paid to current research gaps including the dramatic rise in alternative tobacco products, including electronic nicotine delivery systems (ie, e-cigarettes). The evidence reviewed here will be critical for policy makers as well as clinical researchers interested in nicotine reduction. IMPLICATIONS This review will provide policy makers and clinical researchers interested in nicotine reduction with an overview of the preclinical animal research conducted on nicotine reduction and the regulatory implications of that research. The review also highlights the utility of preclinical research for research questions related to nicotine reduction.
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Affiliation(s)
- Tracy T Smith
- University of Pittsburgh Cancer Institute, Pittsburgh, PA.,Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA
| | - Laura E Rupprecht
- Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA
| | - Rachel L Denlinger-Apte
- Department of Behavioral and Social Sciences, School of Public Health, Brown University, Providence, RI
| | - Jillian J Weeks
- Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA
| | - Rachel S Panas
- Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA
| | - Eric C Donny
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA
| | - Alan F Sved
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA.,Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA
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Thompson MF, Poirier GL, Dávila-García MI, Huang W, Tam K, Robidoux M, Dubuke ML, Shaffer SA, Colon-Perez L, Febo M, DiFranza JR, King JA. Menthol enhances nicotine-induced locomotor sensitization and in vivo functional connectivity in adolescence. J Psychopharmacol 2018; 32:332-343. [PMID: 28747086 DOI: 10.1177/0269881117719265] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Mentholated cigarettes capture a quarter of the US market, and are disproportionately smoked by adolescents. Menthol allosterically modulates nicotinic acetylcholine receptor function, but its effects on the brain and nicotine addiction are unclear. To determine if menthol is psychoactive, we assessed locomotor sensitization and brain functional connectivity. Adolescent male Sprague Dawley rats were administered nicotine (0.4 mg/kg) daily with or without menthol (0.05 mg/kg or 5.38 mg/kg) for nine days. Following each injection, distance traveled in an open field was recorded. One day after the sensitization experiment, functional connectivity was assessed in awake animals before and after drug administration using magnetic resonance imaging. Menthol (5.38 mg/kg) augmented nicotine-induced locomotor sensitization. Functional connectivity was compared in animals that had received nicotine with or without the 5.38 mg/kg dosage of menthol. Twenty-four hours into withdrawal after the last drug administration, increased functional connectivity was observed for ventral tegmental area and retrosplenial cortex with nicotine+menthol compared to nicotine-only exposure. Upon drug re-administration, the nicotine-only, but not the menthol groups, exhibited altered functional connectivity of the dorsal striatum with the amygdala. Menthol, when administered with nicotine, showed evidence of psychoactive properties by affecting brain activity and behavior compared to nicotine administration alone.
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Affiliation(s)
- Matthew F Thompson
- 1 Center for Comparative NeuroImaging, University of Massachusetts Medical School, Worcester, MA, USA.,2 Department of Biology, Clark University, Worcester, MA, USA
| | - Guillaume L Poirier
- 1 Center for Comparative NeuroImaging, University of Massachusetts Medical School, Worcester, MA, USA
| | - Martha I Dávila-García
- 3 Department of Pharmacology, Howard University College of Medicine, Washington, DC, USA
| | - Wei Huang
- 1 Center for Comparative NeuroImaging, University of Massachusetts Medical School, Worcester, MA, USA
| | - Kelly Tam
- 1 Center for Comparative NeuroImaging, University of Massachusetts Medical School, Worcester, MA, USA
| | - Maxwell Robidoux
- 1 Center for Comparative NeuroImaging, University of Massachusetts Medical School, Worcester, MA, USA
| | - Michelle L Dubuke
- 4 Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA.,5 Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, Worcester, MA, USA
| | - Scott A Shaffer
- 4 Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA.,5 Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, Worcester, MA, USA
| | - Luis Colon-Perez
- 6 Department of Psychiatry, University of Florida College of Medicine, Gainesville, FL, USA
| | - Marcelo Febo
- 6 Department of Psychiatry, University of Florida College of Medicine, Gainesville, FL, USA
| | - Joseph R DiFranza
- 1 Center for Comparative NeuroImaging, University of Massachusetts Medical School, Worcester, MA, USA.,7 Department of Family Medicine and Community Health, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jean A King
- 1 Center for Comparative NeuroImaging, University of Massachusetts Medical School, Worcester, MA, USA.,8 Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA.,9 Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
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Alasmari F, Crotty Alexander LE, Drummond CA, Sari Y. A computerized exposure system for animal models to optimize nicotine delivery into the brain through inhalation of electronic cigarette vapors or cigarette smoke. Saudi Pharm J 2018; 26:622-628. [PMID: 29989025 PMCID: PMC6035328 DOI: 10.1016/j.jsps.2018.02.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 02/26/2018] [Indexed: 12/25/2022] Open
Abstract
Pre-clinical studies investigated the effects of chronic exposure to nicotine on lungs, kidneys and brains using animal models. Most of these studies delivered nicotine into the circulatory and central nervous systems (CNS) through intraperitoneal injection or oral consumption methods. Few studies used inhalation machine system for nicotine delivery into brains in rodents to mimic human exposure to cigarettes. However, finding a more accurate and clinically relevant method of nicotine delivery is critical. A computerized inhalation machine has been designed (SciReq) and is currently employed in several institutions. The computerized machine delivers electronic (e)-cigarette vapor as well as tobacco smoke to rodents using marketed e-cigarette devices or tobacco cigarettes. This provides evidence about clinical effects of nicotine delivery by traditional methods (combustible cigarettes) and new methodologies (e-cigarettes) in physiological systems. Potential neurobiological mechanisms for the development of nicotine dependence have been determined recently in mice exposed to e-cigarette vapors in our laboratory using SciReq system. In this review article, the discussion focuses on the efficiency and practical applicability of using this computerized inhalation exposure system in inducing significant changes in brain protein expression and function as compared to other nicotine delivery methods. The SciReq inhalation system utilized in our laboratory and others is a method of nicotine delivery to the CNS, which has physiological relevance and mimics human inhalant exposures. Translation of the effects of inhaled nicotine on the CNS into clinical settings could provide important health considerations.
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Affiliation(s)
- Fawaz Alasmari
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, USA
| | - Laura E Crotty Alexander
- Pulmonary and Critical Care Section, VA San Diego Healthcare System, 3350 La Jolla Village Dr, MC 111J, San Diego, CA 92161, USA.,Department of Medicine, Division of Pulmonary and Critical Care, University of California at San Diego (UCSD), La Jolla, CA 92093, USA
| | | | - Youssef Sari
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, USA
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DeVito EE, Krishnan-Sarin S. E-cigarettes: Impact of E-Liquid Components and Device Characteristics on Nicotine Exposure. Curr Neuropharmacol 2018; 16:438-459. [PMID: 29046158 PMCID: PMC6018193 DOI: 10.2174/1570159x15666171016164430] [Citation(s) in RCA: 154] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/09/2017] [Accepted: 10/13/2017] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Electronic cigarette (e-cigarette) use has increased substantially in recent years. While e-cigarettes have been proposed as a potentially effective smoking cessation tool, dualuse in smokers is common and e-cigarettes are widely used by non-smokers, including youth and young-adult non-smokers. Nicotine, the primary addictive component in cigarettes, is present at varying levels in many e-liquids. E-cigarettes may lead to initiation of nicotine use in adult and youth non-smokers, re-initiation of nicotine dependence in ex-smokers or increased severity of nicotine dependence in dual-users of cigarettes and e-cigarettes. As such, there are important clinical and policy implications to understanding factors impacting nicotine exposure from e-cigarettes. However, the broad and rapidly changing range of e-liquid constituents and e-cigarette hardware which could impact nicotine exposure presents a challenge. Recent changes in regulatory oversight of e-cigarettes underscore the importance of synthesizing current knowledge on common factors which may impact nicotine exposure. METHODS This review focuses on factors which may impact nicotine exposure by changing e-cigarette use behavior, puff topography, altering the nicotine yield (amount of nicotine exiting the e-cigarette mouth piece including nicotine exhaled as vapor) or more directly by altering nicotine absorption and bioavailability. RESULTS Topics reviewed include e-liquid components or characteristics including flavor additives (e.g., menthol), base e-liquid ingredients (propylene glycol, vegetable glycerin), components commonly used to dissolve flavorants (e.g., ethanol), and resulting properties of the e-liquid (e.g., pH), e-cigarette device characteristics (e.g., wattage, temperature, model) and user behavior (e.g., puff topography) which may impact nicotine exposure. CONCLUSION E-liquid characteristics and components, e-cigarette hardware and settings, and user behavior can all contribute substantially to nicotine exposure from e-cigarettes.
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Affiliation(s)
- Elise E. DeVito
- Yale University School of Medicine, Department of Psychiatry, New Haven, CT, USA
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Effects of menthol and its interaction with nicotine-conditioned cue on nicotine-seeking behavior in rats. Psychopharmacology (Berl) 2017; 234:3443-3453. [PMID: 28918457 PMCID: PMC5693741 DOI: 10.1007/s00213-017-4736-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 08/24/2017] [Indexed: 10/18/2022]
Abstract
RATIONALE Increasing clinical evidence suggests that menthol, a significant flavoring additive in tobacco products, may contribute to smoking and nicotine dependence. Relapse to smoking behavior presents a formidable challenge for the treatment of tobacco addiction. An unresolved issue is whether the mentholation of tobacco products precipitates relapse to tobacco use in abstinent smokers. OBJECTIVES The present study examined the effects of menthol on the perseverance and relapse of nicotine-seeking behavior in rats. METHODS Male Sprague-Dawley rats were trained to press a lever for intravenous nicotine self-administration (0.03 mg/kg/infusion) under a fixed-ratio five schedule of reinforcement. Each nicotine infusion was signaled by the presentation of a sensory stimulus that was established as a discrete nicotine-conditioned cue. Five minutes prior to the sessions, the rats received an intraperitoneal injection of menthol (0.1 mg/kg) or vehicle. In the subsequent extinction test sessions, nicotine was unavailable with or without menthol and/or the nicotine-conditioned cue. The reinstatement tests were performed the following day after the extinction criterion was met. Menthol was also tested on food-seeking responses. In a subset of nicotine-trained rats, a transient receptor potential melastatin 8 (TRPM8) antagonist RQ-00203078 was given prior to menthol administration. RESULTS Continued administration of menthol sustained responses on the previously active and nicotine-reinforced lever in the extinction tests. The readministration of menthol after extinction reinstated active lever responses. In both the extinction and the reinstatement tests, a combination of pre-session menthol administration and cue representation during the session produced a more robust behavioral effect than either menthol or the cue alone. No such effects of menthol was observed in food trained rats. RQ-00203078 did not change menthol effect on nicotine seeking. CONCLUSION These data demonstrated that menthol specifically sustained and reinstated nicotine-seeking behavior, and this effect was independent of TRPM8 activity. These findings suggest that menthol in most tobacco products, even not menthol labeled, may contribute to the perseverance of and relapse to tobacco-seeking behavior.
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Krishnan-Sarin S, Green BG, Kong G, Cavallo DA, Jatlow P, Gueorguieva R, Buta E, O’Malley SS. Studying the interactive effects of menthol and nicotine among youth: An examination using e-cigarettes. Drug Alcohol Depend 2017; 180:193-199. [PMID: 28915478 PMCID: PMC5659733 DOI: 10.1016/j.drugalcdep.2017.07.044] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/25/2017] [Accepted: 07/30/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Tobacco products containing menthol are widely used by youth. We used e-cigarettes to conduct an experimental evaluation of the independent and interactive effects of menthol and nicotine among youth. PROCEDURES Pilot chemosensory experiments with fourteen e-cigarette users identified low (barely perceptible, 0.5%) and high (similar to commercial e-liquid, 3.5%) menthol concentrations. Sixty e-cigarette users were randomized to a nicotine concentration (0mg/ml, 6mg/ml, 12mg/ml) and participated in 3 laboratory sessions. During each session, they received their assigned nicotine concentration, along with one of three menthol concentrations in random counterbalanced order across sessions (0, 0.5%, 3.5%), and participated in three fixed-dose, and an ad-lib, puffing period. Urinary menthol glucuronide and salivary nicotine levels validated menthol and nicotine exposure. We examined changes in e-cigarette liking/wanting and taste, coolness, stimulant effects, nicotine withdrawal and ad-lib use. RESULTS Overall, the high concentration of menthol (3.5%) significantly increased e-cigarette liking/wanting relative to no menthol (p<0.001); there was marginal evidence of nicotine* menthol interactions (p=0.06), with an increase in liking/wanting when 3.5% menthol was combined with 12mg/ml nicotine, but not 6mg/ml nicotine. Importantly, both 0.5% and 3.5% menthol concentrations significantly improved taste and increased coolness. We did not observe nicotine or menthol-related changes in stimulant effects, nicotine withdrawal symptoms or ad-lib use. CONCLUSIONS Menthol, even at very low doses, alters the appeal of e-cigarettes among youth. Further, menthol enhances positive rewarding effects of high nicotine-containing e-cigarettes among youth.
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Affiliation(s)
| | - Barry G. Green
- The John B. Pierce Laboratory and Department of Surgery, Yale University School of Medicine
| | - Grace Kong
- Department of Psychiatry, Yale University School of Medicine
| | - Dana A. Cavallo
- Department of Psychiatry, Yale University School of Medicine
| | - Peter Jatlow
- Department of Laboratory Medicine, Yale University School of Medicine
| | | | - Eugenia Buta
- Department of Biostatistics, Yale University School of Public Health
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Henderson BJ, Wall TR, Henley BM, Kim CH, McKinney S, Lester HA. Menthol Enhances Nicotine Reward-Related Behavior by Potentiating Nicotine-Induced Changes in nAChR Function, nAChR Upregulation, and DA Neuron Excitability. Neuropsychopharmacology 2017; 42:2285-2291. [PMID: 28401925 PMCID: PMC5645749 DOI: 10.1038/npp.2017.72] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/28/2017] [Accepted: 04/01/2017] [Indexed: 12/17/2022]
Abstract
Understanding why the quit rate among smokers of menthol cigarettes is lower than non-menthol smokers requires identifying the neurons that are altered by nicotine, menthol, and acetylcholine. Dopaminergic (DA) neurons in the ventral tegmental area (VTA) mediate the positive reinforcing effects of nicotine. Using mouse models, we show that menthol enhances nicotine-induced changes in nicotinic acetylcholine receptors (nAChRs) expressed on midbrain DA neurons. Menthol plus nicotine upregulates nAChR number and function on midbrain DA neurons more than nicotine alone. Menthol also enhances nicotine-induced changes in DA neuron excitability. In a conditioned place preference (CPP) assay, we observed that menthol plus nicotine produces greater reward-related behavior than nicotine alone. Our results connect changes in midbrain DA neurons to menthol-induced enhancements of nicotine reward-related behavior and may help explain how smokers of menthol cigarettes exhibit reduced cessation rates.
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Affiliation(s)
- Brandon J Henderson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA,Department of Biomedical Sciences, Marshall University, Joan C Edwards School of Medicine, Huntington, WV, USA
| | - Teagan R Wall
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Beverley M Henley
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Charlene H Kim
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Sheri McKinney
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Henry A Lester
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA,Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard MC 156-29, Pasadena, CA 91125-2900, USA, Tel: +626 395 4946, Fax: +626 564 8709, E-mail:
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Evaluating oral flavorant effects on nicotine self-administration behavior and phasic dopamine signaling. Neuropharmacology 2017; 128:33-42. [PMID: 28943284 DOI: 10.1016/j.neuropharm.2017.09.029] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 08/31/2017] [Accepted: 09/19/2017] [Indexed: 12/26/2022]
Abstract
Understanding how tobacco product flavor additives, such as flavorants in electronic cigarettes, influence smoking behavior and addiction is critical for informing public health policy decisions regarding tobacco product regulation. Here, we developed a combined intraoral (i.o.) and intravenous (i.v.) self-administration paradigm in rats to determine how flavorants influence self-administration behavior. By combining i.o. flavorant delivery with fast scan cyclic voltammetry (FSCV) or i.v. nicotine self-administration in adult, male rats, we examined whether flavors alter phasic dopamine (DA) signaling and nicotine self-administration. Oral administration of 10% sucrose or 0.32% saccharin, but not 0.005% menthol, increased phasic DA release in the nucleus accumbens (NAc). Oral sucrose or saccharin, when combined with i.v. nicotine delivery, also led to increased self-administration behavior. Specifically, combined i.o. sucrose and i.v. nicotine decreased responding compared to sucrose alone, and increased responding compared to nicotine alone. In contrast, i.o. flavorants did not alter motivational breakpoint in a progressive ratio task. Oral menthol, which did not alter i.v. nicotine administration, reversed oral nicotine aversion (50 and 100 mg/L) in a two-bottle choice test. Here, we demonstrate that i.o. appetitive flavorants that increase phasic DA signaling also increase self-administration behavior when combined with i.v. nicotine delivery. Additionally, oral menthol effects were specific to oral nicotine, and were not observed with i.v. nicotine-mediated reinforcement. Together, these preclinical findings have important implications regarding menthol and sweet flavorant additive effects on tobacco product use and can be used to inform policy decisions on tobacco product flavorant regulation.
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Han W, Wang T, Chen H. Social learning promotes nicotine self-administration by facilitating the extinction of conditioned aversion in isogenic strains of rats. Sci Rep 2017; 7:8052. [PMID: 28808247 PMCID: PMC5556091 DOI: 10.1038/s41598-017-08291-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/10/2017] [Indexed: 11/25/2022] Open
Abstract
Both social environment and genetic factors are critical for smoking initiation and nicotine addiction. We reported that rats developed conditioned flavor (i.e., taste and odor) aversion to intravenously self-administered (IVSA) nicotine, and that social learning promoted nicotine IVSA with flavor cues. We thus tested the hypothesis that socially acquired nicotine IVSA is a heritable trait by using female rats of six inbred strains and six F1 hybrids. Each strain was tested for 10 daily IVSA sessions. We found that the intake of nicotine (15 and 30 μg/kg/inf) varied among these strains by 33.7–56.6-fold. The heritability of nicotine intake was estimated to be 0.54–0.65. Further, there was a strong correlation in nicotine intake (R2 = 0.85, p < 0.0001) between the two nicotine doses. Another cohort of rats was given three daily IVSA sessions followed by five sessions that tested conditioned flavor aversion. Nicotine intake was highly correlated with the extinction of the conditioned aversion (R2 = 0.58, p < 0.005). These data showed that nicotine intake in the socially acquired nicotine self-administration model is controlled by genetic factors and that the role of social learning is likely in facilitating the extinction of conditioned aversive response to nicotine.
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Affiliation(s)
- Wenyan Han
- Department of Pharmacology, University of Tennessee Health Science Center, 71 S. Manassas St., Room 205 Translational Science Research Building, Memphis, TN, 38163, USA
| | - Tengfei Wang
- Department of Pharmacology, University of Tennessee Health Science Center, 71 S. Manassas St., Room 205 Translational Science Research Building, Memphis, TN, 38163, USA
| | - Hao Chen
- Department of Pharmacology, University of Tennessee Health Science Center, 71 S. Manassas St., Room 205 Translational Science Research Building, Memphis, TN, 38163, USA.
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Longley M, Willis EL, Tay CX, Chen H. An open source device for operant licking in rats. PeerJ 2017; 5:e2981. [PMID: 28229020 PMCID: PMC5312574 DOI: 10.7717/peerj.2981] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 01/11/2017] [Indexed: 11/20/2022] Open
Abstract
We created an easy-to-use device for operant licking experiments and another device that records environmental variables. Both devices use the Raspberry Pi computer to obtain data from multiple input devices (e.g., radio frequency identification tag readers, touch and motion sensors, environmental sensors) and activate output devices (e.g., LED lights, syringe pumps) as needed. Data gathered from these devices are stored locally on the computer but can be automatically transferred to a remote server via a wireless network. We tested the operant device by training rats to obtain either sucrose or water under the control of a fixed ratio, a variable ratio, or a progressive ratio reinforcement schedule. The lick data demonstrated that the device has sufficient precision and time resolution to record the fast licking behavior of rats. Data from the environment monitoring device also showed reliable measurements. By providing the source code and 3D design under an open source license, we believe these examples will stimulate innovation in behavioral studies. The source code can be found at http://github.com/chen42/openbehavior.
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Affiliation(s)
- Matthew Longley
- Undergraduate Program, University of Memphis , Memphis , TN , United States
| | - Ethan L Willis
- Maters' Program, Department of Bioinformatics, University of Memphis , Memphis , TN , United States
| | - Cindy X Tay
- Undergraduate Program, Duke University , Durham , NC , United States
| | - Hao Chen
- Department of Pharmacology, University of Tennessee Health Science Center , Memphis , TN , United States
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Alexander LA, Trinidad DR, Sakuma KLK, Pokhrel P, Herzog TA, Clanton MS, Moolchan ET, Fagan P. Why We Must Continue to Investigate Menthol's Role in the African American Smoking Paradox. Nicotine Tob Res 2016; 18 Suppl 1:S91-101. [PMID: 26980870 DOI: 10.1093/ntr/ntv209] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The disproportionate burden of tobacco use among African Americans is largely unexplained. The unexplained disparities, referred to as the African American smoking paradox, includes several phenomena. Despite their social disadvantage, African American youth have lower smoking prevalence rates, initiate smoking at older ages, and during adulthood, smoking rates are comparable to whites. Smoking frequency and intensity among African American youth and adults are lower compared to whites and American Indian and Alaska Natives, but tobacco-caused morbidity and mortality rates are disproportionately higher. Disease prediction models have not explained disease causal pathways in African Americans. It has been hypothesized that menthol cigarette smoking, which is disproportionately high among African Americans, may help to explain several components of the African American smoking paradox. PURPOSE This article provides an overview of the potential role that menthol plays in the African American smoking paradox. We also discuss the research needed to better understand this unresolved puzzle. METHODS We examined prior synthesis reports and reviewed the literature in PubMed on the menthol compound and menthol cigarette smoking in African Americans. RESULTS The pharmacological and physiological effects of menthol and their interaction with biological and genetic factors may indirectly contribute to the disproportionate burden of cigarette use and diseases among African Americans. CONCLUSIONS Future studies that examine taste sensitivity, the menthol compound, and their effects on smoking and chronic disease would provide valuable information on how to reduce the tobacco burden among African Americans. IMPLICATIONS Our study highlights four counterintuitive observations related to the smoking risk profiles and chronic disease outcomes among African Americans. The extant literature provides strong evidence of their existence and shows that long-standing paradoxes have been largely unaffected by changes in the social environment. African Americans smoke menthols disproportionately, and menthol's role in the African American smoking paradox has not been thoroughly explored. We propose discrete hypotheses that will help to explain the phenomena and encourage researchers to empirically test menthol's role in smoking initiation, transitions to regular smoking and chronic disease outcomes in African Americans.
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Affiliation(s)
- Linda A Alexander
- College of Public Health, University of Kentucky College of Public Health, Lexington, KY
| | - Dennis R Trinidad
- Department of Family Medicine and Public Health, University of California, San Diego, La Jolla, CA
| | - Kari-Lyn K Sakuma
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR
| | - 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
| | | | | | - Pebbles Fagan
- University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI;
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LeSage MG, Staley M, Muelken P, Smethells JR, Stepanov I, Vogel RI, Pentel PR, Harris AC. Abuse liability assessment of an e-cigarette refill liquid using intracranial self-stimulation and self-administration models in rats. Drug Alcohol Depend 2016; 168:76-88. [PMID: 27627814 PMCID: PMC5257285 DOI: 10.1016/j.drugalcdep.2016.08.628] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/14/2016] [Accepted: 08/22/2016] [Indexed: 01/19/2023]
Abstract
BACKGROUND The popularity of electronic cigarettes (ECs) has increased dramatically despite their unknown health consequences. Because the abuse liability of ECs is one of the leading concerns of the Food and Drug Administration (FDA), models to assess it are urgently needed to inform FDA regulatory decisions regarding these products. The purpose of this study was to assess the relative abuse liability of an EC liquid compared to nicotine alone in rats. Because this EC liquid contains non-nicotine constituents that may enhance its abuse liability, we hypothesized that it would have greater abuse liability than nicotine alone. METHODS Nicotine alone and nicotine dose-equivalent concentrations of EC liquid were compared in terms of their acute effects on intracranial self-stimulation (ICSS) thresholds, acquisition of self-administration, reinforcing efficacy (i.e., elasticity of demand), blockade of these behavioral effects by mecamylamine, nicotine pharmacokinetics and nicotinic acetylcholine receptor binding and activation. RESULTS There were no significant differences between formulations on any measure, except that EC liquid produced less of an elevation in ICSS thresholds at high nicotine doses. CONCLUSIONS Collectively, these findings suggest that the relative abuse liability of this EC liquid is similar to that of nicotine alone in terms of its reinforcing and reinforcement-enhancing effects, but that it may have less aversive/anhedonic effects at high doses. The present methods may be useful for assessing the abuse liability of other ECs to inform potential FDA regulation of those products.
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Affiliation(s)
- MG LeSage
- Department of Medicine, Minneapolis Medical Research Foundation, Minneapolis, MN,Department of Medicine, University of Minnesota, Minneapolis, MN,Department of Psychology, University of Minnesota, Minneapolis, MN, 55455
| | - M Staley
- Department of Medicine, Minneapolis Medical Research Foundation, Minneapolis, MN
| | - P Muelken
- Department of Medicine, Minneapolis Medical Research Foundation, Minneapolis, MN
| | - JR Smethells
- Department of Medicine, Minneapolis Medical Research Foundation, Minneapolis, MN,Department of Psychiatry, University of Minnesota, Minneapolis, MN, 55455
| | - I Stepanov
- Masonic Cancer, Center University of Minnesota, Minneapolis, MN
| | - RI Vogel
- Masonic Cancer Center Biostatistics and Bioinformatics Core ,University of Minnesota Minneapolis, MN
| | - PR Pentel
- Department of Medicine, Minneapolis Medical Research Foundation, Minneapolis, MN,Department of Medicine, University of Minnesota, Minneapolis, MN
| | - AC Harris
- Department of Medicine, Minneapolis Medical Research Foundation, Minneapolis, MN,Department of Medicine, University of Minnesota, Minneapolis, MN,Department of Psychology, University of Minnesota, Minneapolis, MN, 55455
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Sterling K, Fryer C, Pagano I, Jones D, Fagan P. Association between menthol-flavoured cigarette smoking and flavoured little cigar and cigarillo use among African-American, Hispanic, and white young and middle-aged adult smokers. Tob Control 2016; 25:ii21-ii31. [PMID: 27856997 DOI: 10.1136/tobaccocontrol-2016-053203] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/07/2016] [Indexed: 11/03/2022]
Abstract
OBJECTIVES Flavour additives in cigarettes and little cigars and cigarillos (LCCs), which influence smokers' risk perceptions, may reinforce dual flavoured tobacco use. We examined the association among mentholated cigarette use, risk perceptions for flavour additives in LCCs and flavoured LCC smoking behaviour. METHODS Data from a national probability sample of 964 young and middle-aged adult current cigarette smokers were analysed. Multinomial logistic regression models examined the relationship among mentholated cigarette smoking, risk perceptions and current flavoured LCC use for the analytic sample and gender and race/ethnicity. RESULTS Daily menthol cigarette smokers, compared to occasional, non-menthol smokers, had increased odds of flavoured LCC smoking (OR=1.75, 95% CI 1.02 to 2.98). This relationship was found for males, blacks/African-Americans and Hispanics/Latinos (p<0.05). Positive perceptions of menthol-flavoured additives in LCCs was associated with increased odds of flavoured LCC use among the analytic sample, males and blacks/African-Americans (p<0.05). Positive perceptions for clove-flavoured, spice-flavoured and alcohol-flavoured additives were also associated with flavoured LCC use among the analytic sample (p<0.05). CONCLUSIONS Use of menthol-flavoured cigarettes and positive perceptions about menthol-flavoured and other flavour additives in LCCs may contribute to dual use with flavoured LCCs among adult cigarette smokers, specifically those from vulnerable populations.
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Affiliation(s)
- K Sterling
- School of Public Health, Georgia State University, Atlanta, Georgia, USA
| | - C Fryer
- University of Maryland, College Park, Maryland, USA
| | - I Pagano
- University of Hawaii at Manoa, Honolulu, Hawaii, USA
| | - D Jones
- School of Public Health, Georgia State University, Atlanta, Georgia, USA
| | - P Fagan
- Univeristy of Arkansas for Medical Sciences, Fay W. Boozman College of Public Health, USA
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Advances in Behavioral Laboratory Methods that Inform Tobacco Regulatory Science: A TCORS Working Group Special Issue. TOB REGUL SCI 2016; 2:294-300. [PMID: 29152546 DOI: 10.18001/trs.2.4.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Objective The 2009 Family Smoking Prevention and Tobacco Control Act (TCA) created unprecented enabling conditions for establishing national regulatory policy that reduces the burden of public health and societal problems associated with tobacco product use. The Center for Tobacco Products (CTP), created by the FDA to implement the TCA, developed a first-of-its-kind FDA/National Institutes of Health (NIH) collaborative program to fund Tobacco Centers of Regulatory Science (TCORS). Methods To assist the TCORS with addressing research priorites, working groups (WGs) comprised of FDA-CTP liasions and TCORS investigators were formed. Under the direction of the Center for Evaluation and Coordination of Trainin and Research (CECTR), the TCORS WGs seek to develop tangible work products in their respective areas of focus. Results The focus of the behavioral pharmacology WG evolved from publishing a narrow paper on behavioral methods in electronic cigarette research to a collection of papers on advances in behavioral laboratory methods that may inform tobacco regulatory science. Conclusion This Special Issue contains articles that address all of the CTP research priorities and demonstrates how advances in behavioral laboratory methods made by TCORS investigators can inform FDA efforst to regulate tobacco products.
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Abstract
OBJECTIVES Menthol, a flavoring agent, is found in approximately 90% of cigarettes, but at much higher levels in menthol than non-menthol cigarettes. Menthol is reportedly included in cigarettes for its cooling and soothing effects, but also additional actions that affect smokers' receipt and processing of nicotine. In this study we investigated the response to short-term abstinence and acute nicotine delivery in menthol-preferring and non-menthol-preferring smokers. METHODS Nicotine dependent participants (N = 134) participated in an intravenous nicotine delivery session following overnight smoking abstinence. Participants were intravenously administered a placebo and 2 escalating nicotine doses. We compare subjective and physiological responses to nicotine and smoking urges, withdrawal, and cognitive performance following overnight abstinence and post-nicotine between regular 'menthol' smokers and 'non-menthol' cigarette smokers. RESULTS Relative to non-menthol-preferring smokers, menthol-preferring smokers re a smaller reduction in smoking urges from overnight abstinence baseline to post-nicotine end-of-session and rated less subjective differences between nicotine doses. CONCLUSIONS Differences between menthol-preferring and non-menthol-preferring smokers' responses to abstinence or acute nicotine could reflect pre-existing individual differences that may have in initial development of menthol preferences, or could have arisen secondarily to pro use of menthol versus non-menthol cigarettes.
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50
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Biswas L, Harrison E, Gong Y, Avusula R, Lee J, Zhang M, Rousselle T, Lage J, Liu X. Enhancing effect of menthol on nicotine self-administration in rats. Psychopharmacology (Berl) 2016; 233:3417-27. [PMID: 27473365 PMCID: PMC4990499 DOI: 10.1007/s00213-016-4391-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/08/2016] [Indexed: 01/19/2023]
Abstract
RATIONALE Tobacco smoking is a leading preventable cause of premature death in the USA. Menthol is a significant flavoring additive in tobacco products. Clinical evidence suggests that menthol may promote tobacco smoking and nicotine dependence. However, it is unclear whether menthol enhances the reinforcing actions of nicotine and thus facilitates nicotine consumption. This study employed a rat model of nicotine self-administration to examine the effects of menthol on nicotine-taking behavior. METHODS Male Sprague-Dawley rats were trained in daily 1-h sessions to press a lever for intravenous nicotine self-administration under a fixed-ratio 5 schedule of reinforcement. In separate groups, rats self-administered nicotine at four different doses (0.0075, 0.015, 0.03, and 0.06 mg/kg/infusion). Five minutes prior to the two test sessions, menthol (5 mg/kg) or its vehicle was administered intraperitoneally in all rats in a counterbalanced design within each group. In separate rats that self-administered 0.015 mg/kg/infusion nicotine, menthol dose-response function was determined. Menthol was also tested on food self-administration. RESULTS An inverted U-shaped nicotine dose-response curve was observed. Menthol pretreatment shifted the nicotine dose-response curve to the left. The facilitating effect of menthol on the self-administration of 0.015 mg/kg/infusion nicotine was dose-dependent, whereas it produced similar effects at doses above the threshold of 2.5 mg/kg. Menthol tended to suppress the self-administration of food pellets. CONCLUSIONS These data demonstrate that menthol enhances the reinforcing effects of nicotine, and the effect of menthol was specific to nicotine. The findings suggest that menthol directly facilitates nicotine consumption, thereby contributing to tobacco smoking.
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Affiliation(s)
- Lisa Biswas
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Erin Harrison
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Yongzhen Gong
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Ramachandram Avusula
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Jonathan Lee
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Meiyu Zhang
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Thomas Rousselle
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Janice Lage
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Xiu Liu
- Department of Pathology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
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