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Crooks I, Clements J, Curren R, Guo X, Hollings M, Lloyd M, Smart D, Thorne D, Weber E, Moore M. Key Challenges for In Vitro Testing of Tobacco Products for Regulatory Applications: Recommendations for the In Vitro Mouse Lymphoma Assay. Altern Lab Anim 2024; 52:42-59. [PMID: 38055860 DOI: 10.1177/02611929231219153] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
The Institute for In Vitro Sciences (IIVS) is sponsoring a series of workshops to develop recommendations for optimal scientific and technical approaches for conducting in vitro assays to assess potential toxicity within and across traditional tobacco and various tobacco and nicotine next-generation products (NGPs), including Heated Tobacco Products (HTPs) and Electronic Nicotine Delivery Systems (ENDS). This report was developed by a working group composed of attendees of the seventh IIVS workshop, 'Approaches and recommendations for conducting the mouse lymphoma gene mutation assay (MLA) and introduction to in vitro disease models', which was held virtually on 21-23 June 2022. This publication provides a background overview of the MLA, and includes the description of assay conduct and data interpretation, key challenges and recommended best practices for evaluating tobacco and nicotine products, with a focus on the evaluation of NGPs, and a summary of how the assay has been used to evaluate and compare tobacco and nicotine products.
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Affiliation(s)
- Ian Crooks
- B.A.T. (Investments) Limited, Southampton, UK
| | | | - Rodger Curren
- Institute for In Vitro Sciences, Gaithersburg, MD, USA
| | - Xiaoqing Guo
- National Center for Toxicological Research, Jefferson, AR, USA
| | | | - Mel Lloyd
- Labcorp Early Development Services, Harrogate, UK
| | - Daniel Smart
- Philip Morris International R&D, Philip Morris Products S.A., Neuchatel, Switzerland
| | | | - Elisabeth Weber
- Oekolab Ges. F. Umweltanalytik, A member of the JT International Group of Companies, Vienna, Austria
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2
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Lalonde G, Tsolakos N, Moir-Savitz TR, Easley AM, Gaworski CL, Oldham MJ. Subchronic inhalation of a novel electronic nicotine delivery system formulation and its corresponding base formulation. Hum Exp Toxicol 2024; 43:9603271241248631. [PMID: 38646969 DOI: 10.1177/09603271241248631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
BACKGROUND Fresh Menthol 3% Nicotine (FM3) is a novel JUUL e-liquid formulation. Its potential toxicity and that of the corresponding base formulation relative to a filtered air (FA) control was studied in a subchronic inhalation study conducted in general accordance with OECD 413. METHODS Aerosols generated with an intense puffing regime were administered to rats in a nose-only fashion at 1400 µg aerosol collected mass/L on a 6 hour/day basis for 90 days with a 42-day recovery. Exposure atmospheres met target criteria. Systemic exposure was confirmed by plasma measurement of nicotine. RESULTS No test article-related mortality, clinical signs (other than reversible lower body weight gains in males), clinical pathology or gross findings were noted during this study. No microscopic lesions related to base formulation exposure were identified. Minimal microscopic lesions were observed in the FM3 6-hour exposure group. Microscopic lesions observed in the FM3 6-hour exposure group comprised only minimal laryngeal squamous metaplasia in one male and one female animal. No microscopic lesions related to FM3 exposure remained after the recovery period. CONCLUSION Exposure atmosphere characterization indicated that conditions were achieved to permit thorough assessment of test articles and results indicate a low order of toxicity for the FM3 Electronic nicotine delivery systems (ENDS) formulation and its base formulation.
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3
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Desai RW, Demir K, Tsolakos N, Moir-Savitz TR, Gaworski CL, Weil R, Oldham MJ, Lalonde G. Comparison of the toxicological potential of two JUUL ENDS products to reference cigarette 3R4F and filtered air in a 90-day nose-only inhalation toxicity study. Food Chem Toxicol 2023; 179:113917. [PMID: 37451597 DOI: 10.1016/j.fct.2023.113917] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 06/13/2023] [Accepted: 06/22/2023] [Indexed: 07/18/2023]
Abstract
Electronic nicotine delivery systems (ENDS) are generally recognized as less harmful alternatives for those who would otherwise continue to smoke cigarettes. The potential toxicity of aerosols generated from JUUL Device and Virginia Tobacco (VT3) or Menthol (ME3) JUULpods at 3.0% nicotine concentration was assessed in rats exposed at target aerosol concentrations of 1400 μg/L for up to 6 h/day on a 5 day/week basis for at least 90 days (general accordance with OECD 413). 3R4F reference cigarette smoke (250 μg/L) and Filtered Air were used as comparators. JUUL ENDS product aerosol exposures at >5x the 3R4F cigarette smoke level resulted in greater plasma nicotine and cotinine levels (up to 2x). Notable cigarette smoke related effects included pronounced body weight reductions in male rats, pulmonary inflammation evidenced by elevated lactate dehydrogenase, pro-inflammatory cytokines and neutrophils in bronchoalveolar lavage fluid, increased heart and lung weights, and minimal to marked respiratory tract histopathology. In contrast, ENDS aerosol exposed animals had minimal body weight changes, no measurable inflammatory changes and minimal to mild laryngeal squamous metaplasia. Despite the higher exposure levels, VT3 and ME3 did not result in significant toxicity or appreciable respiratory histopathology relative to 3R4F cigarette smoke following 90 days administration.
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Affiliation(s)
| | | | - Nikos Tsolakos
- Protatonce Ltd, National Centre of Scientific Research Demokritos, Patriarchou Grigoriou E' & Neapoleos 27, Technological Park Lefkippos, Bldg 27, 15341, Ag. Paraskevi, Attiki, Greece
| | - Tessa R Moir-Savitz
- AmplifyBio, 1425 NE Plain City-Georgesville Rd, West Jefferson, OH, 43162, USA
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4
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Goel R, Bitzer ZT, Reilly SM, Bhangu G, Trushin N, Elias RJ, Foulds J, Muscat J, Richie JP. Effect of Charcoal in Cigarette Filters on Free Radicals in Mainstream Smoke. Chem Res Toxicol 2018; 31:745-751. [PMID: 29979036 PMCID: PMC6471497 DOI: 10.1021/acs.chemrestox.8b00092] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The addition of charcoal in cigarette filters may be an effective means of reducing many toxicants from tobacco smoke. Free radicals are a highly reactive class of oxidants abundant in cigarette smoke, and here we evaluated the effectiveness of charcoal to reduce free radical delivery by comparing radical yields from commercially available cigarettes with charcoal-infused filters to those without and by examining the effects of incorporating charcoal into conventional cigarette filters on radical production. Commercial cigarettes containing charcoal filters produced 40% fewer gas-phase radicals than did regular cellulose acetate filter cigarettes when smoked using the International Organization of Standardization (ISO, p = 0.07) and Canadian Intense (CI, p < 0.01) smoking protocols. While mean-particulate-phase radicals were 25-27% lower in charcoal cigarettes, differences from noncharcoal products were not significant ( p = 0.06-0.22). When cellulose acetate cigarette filters were modified to incorporate different types and amounts of activated charcoal, reductions in gas-phase (>70%), but not particulate-phase, radicals were observed. The reductions in gas-phase radicals were similar for the three types of charcoal. Decreases in radical production were dose-responsive with increasing amounts of charcoal (25-300 mg) with as little as 25 mg of activated charcoal reducing gas-phase radicals by 41%. In all studies, charcoal had less of an effect on nicotine delivery, which was decreased 33% at the maximal amount of charcoal tested (300 mg). Overall, these results support the potential consideration of charcoal in cigarette filters as a means to reduce exposure to toxic free radicals from cigarettes and other combustible tobacco products.
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Affiliation(s)
- Reema Goel
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - Zachary T. Bitzer
- Department of Food Science, College of Agricultural Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Samantha M. Reilly
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - Gurkirat Bhangu
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - Neil Trushin
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - Ryan J. Elias
- Department of Food Science, College of Agricultural Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Jonathan Foulds
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - Joshua Muscat
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - John P. Richie
- Department of Public Health Sciences, Pennsylvania State University Tobacco Center of Regulatory Science (TCORS), Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, United States
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5
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Phillips BW, Schlage WK, Titz B, Kogel U, Sciuscio D, Martin F, Leroy P, Vuillaume G, Krishnan S, Lee T, Veljkovic E, Elamin A, Merg C, Ivanov NV, Peitsch MC, Hoeng J, Vanscheeuwijck P. A 90-day OECD TG 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects of the aerosol from the carbon heated tobacco product version 1.2 (CHTP1.2) compared with cigarette smoke. I. Inhalation exposure, clinical pathology and histopathology. Food Chem Toxicol 2018; 116:388-413. [PMID: 29654848 DOI: 10.1016/j.fct.2018.04.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/28/2018] [Accepted: 04/07/2018] [Indexed: 01/25/2023]
Abstract
Within the framework of a systems toxicology approach, the inhalation toxicity of aerosol from a novel tobacco-heating potentially modified risk tobacco product (MRTP), the carbon-heated tobacco product (CHTP) 1.2, was characterized and compared with that of mainstream smoke (CS) from the 3R4F reference cigarette in a 90-day nose-only rat inhalation study in general accordance with OECD TG 413. CHTP1.2 is a heat-not-burn product using a carbon heat source to produce an aerosol that contains nicotine and tobacco flavor. At equal or twice the nicotine concentration in the test atmospheres, inhalation of CHTP1.2 aerosol led to a significantly lower exposure to harmful constituents and induced less respiratory tract irritation, systemic, and pathological effects compared with CS. Nasal epithelial changes were less pronounced in the CHTP1.2- than in the CS-exposed groups and reverted in the nicotine concentration-matched group after a recovery period. Lung inflammation was minimal in the CHTP1.2-treated groups compared with the moderate extent seen in the 3R4F groups. Many other toxicological endpoints evaluated did not show CHTP1.2 aerosol exposure-related effects, and no effects not seen for 3R4F were observed. These observations were consistent with findings from previous studies in which rats were exposed to MRTP aerosols containing similar nicotine concentrations.
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Affiliation(s)
- Blaine W Phillips
- PMI R&D, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Walter K Schlage
- Biology Consultant, Max-Baermann-Str. 21, 51429, Bergisch Gladbach, Germany
| | - Bjoern Titz
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Ulrike Kogel
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Davide Sciuscio
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Florian Martin
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Patrice Leroy
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Gregory Vuillaume
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Subash Krishnan
- PMI R&D, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Tom Lee
- PMI R&D, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Emilija Veljkovic
- PMI R&D, Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Ashraf Elamin
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Celine Merg
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Nikolai V Ivanov
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Manuel C Peitsch
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Julia Hoeng
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland
| | - Patrick Vanscheeuwijck
- PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchatel, Switzerland.
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6
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Morabito JA, Holman MR, Ding YS, Yan X, Chan M, Chafin D, Perez J, Mendez MI, Cardenas RB, Watson C. The use of charcoal in modified cigarette filters for mainstream smoke carbonyl reduction. Regul Toxicol Pharmacol 2017; 86:117-127. [PMID: 28238852 PMCID: PMC5448414 DOI: 10.1016/j.yrtph.2017.02.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 02/13/2017] [Accepted: 02/20/2017] [Indexed: 11/29/2022]
Abstract
Carbonyls are harmful and potentially harmful constituents (HPHCs) in mainstream cigarette smoke (MSS). Carbonyls, including formaldehyde and acrolein, are carcinogenic or mutagenic in a dose-dependent manner. Past studies demonstrate significant reduction of HPHCs by charcoal filtration. However, limits of charcoal filtration and cigarette design have not yet been investigated in a systematic manner. Objective data is needed concerning the feasibility of HPHC reduction in combustible filtered cigarettes. This systematic study evaluates the effect of charcoal filtration on carbonyl reduction in MSS. We modified filters of ten popular cigarette products with predetermined quantities (100-400 mg) of charcoal in a plug-space-plug configuration. MSS carbonyls, as well as total particulate matter, tar, nicotine, carbon monoxide (TNCO), and draw resistance were quantified. Significant carbonyl reductions were observed across all cigarette products as charcoal loading increased. At the highest charcoal loadings, carbonyls were reduced by nearly 99%. Tar and nicotine decreased modestly (<20%) compared to reductions in carbonyls. Increased draw resistance was significant at only the highest charcoal loadings. This work addresses information gaps in the science base that can inform the evaluation of charcoal filtration as an available technological adaptation to cigarette design which reduces levels of carbonyls in MSS.
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Affiliation(s)
| | | | - Yan S Ding
- Centers for Disease Control and Prevention, United States
| | - Xizheng Yan
- Centers for Disease Control and Prevention, United States
| | - Michele Chan
- Centers for Disease Control and Prevention, United States
| | - Dana Chafin
- Centers for Disease Control and Prevention, United States
| | - Jose Perez
- Centers for Disease Control and Prevention, United States
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7
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Wong ET, Kogel U, Veljkovic E, Martin F, Xiang Y, Boue S, Vuillaume G, Leroy P, Guedj E, Rodrigo G, Ivanov NV, Hoeng J, Peitsch MC, Vanscheeuwijck P. Evaluation of the Tobacco Heating System 2.2. Part 4: 90-day OECD 413 rat inhalation study with systems toxicology endpoints demonstrates reduced exposure effects compared with cigarette smoke. Regul Toxicol Pharmacol 2016; 81 Suppl 2:S59-S81. [DOI: 10.1016/j.yrtph.2016.10.015] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/04/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
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8
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Coffa BG, Coggins CRE, Werley MS, Oldham MJ, Fariss MW. Chemical, physical, and in vitro characterization of research cigarettes containing denicotinized tobacco. Regul Toxicol Pharmacol 2016; 79:64-73. [PMID: 27181452 DOI: 10.1016/j.yrtph.2016.05.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 05/04/2016] [Accepted: 05/11/2016] [Indexed: 12/18/2022]
Abstract
The use of very low nicotine tobacco cigarettes is currently being investigated as a possible harm reduction strategy. Here, we report the smoke chemistry, toxicity, and physical characteristics of very low nicotine cigarettes that were made using blended tobacco processed through a supercritical CO2 fluid extraction, which resulted in elimination of 96% of nicotine content (denicotinized (denic) tobacco). Three types of test cigarettes (TCs) were manufactured with tobacco filler containing 100% denic tobacco (TC100), 50% denic tobacco and 50% unextracted tobacco (TC50/50), and 100% unextracted tobacco (TC0). Mainstream smoke (MS) was generated for measurement of 46 analytes and cytotoxicity and mutagenicity determination. Analysis of physical characteristics of TCs demonstrated they were well made with <5% variability among cigarettes for most parameters measured. We observed significant changes in the levels of smoke constituents, including decreases in formaldehyde, nitrosamines, and phenol, and increases in aliphatic hydrocarbons, aliphatic nitrogen compounds, aromatic amines, halogen compounds, and metals. Use of denic tobacco resulted in changes in the chemical composition of MS, but these changes did not modify biological activity as measured in the mutagenicity and cytotoxicity assays.
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9
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Comparison of the impact of the Tobacco Heating System 2.2 and a cigarette on indoor air quality. Regul Toxicol Pharmacol 2016; 80:91-101. [PMID: 27311683 DOI: 10.1016/j.yrtph.2016.06.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 11/21/2022]
Abstract
The impact of the Tobacco Heating System 2.2 (THS 2.2) on indoor air quality was evaluated in an environmentally controlled room using ventilation conditions recommended for simulating "Office", "Residential" and "Hospitality" environments and was compared with smoking a lit-end cigarette (Marlboro Gold) under identical experimental conditions. The concentrations of eighteen indoor air constituents (respirable suspended particles (RSP) < 2.5 μm in diameter), ultraviolet particulate matter (UVPM), fluorescent particulate matter (FPM), solanesol, 3-ethenylpyridine, nicotine, 1,3-butadiene, acrylonitrile, benzene, isoprene, toluene, acetaldehyde, acrolein, crotonaldehyde, formaldehyde, carbon monoxide, nitrogen oxide, and combined oxides of nitrogen) were measured. In simulations evaluating THS 2.2, the concentrations of most studied analytes did not exceed the background concentrations determined when non-smoking panelists were present in the environmentally controlled room under equivalent conditions. Only acetaldehyde and nicotine concentrations were increased above background concentrations in the "Office" (3.65 and 1.10 μg/m(3)), "Residential" (5.09 and 1.81 μg/m(3)) and "Hospitality" (1.40 and 0.66 μg/m(3)) simulations, respectively. Smoking Marlboro Gold resulted in greater increases in the concentrations of acetaldehyde (58.8, 83.8 and 33.1 μg/m(3)) and nicotine (34.7, 29.1 and 34.6 μg/m(3)) as well as all other measured indoor air constituents in the "Office", "Residential" and "Hospitality" simulations, respectively.
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10
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Dalrymple A, Ordoñez P, Thorne D, Walker D, Camacho OM, Büttner A, Dillon D, Meredith C. Cigarette smoke induced genotoxicity and respiratory tract pathology: evidence to support reduced exposure time and animal numbers in tobacco product testing. Inhal Toxicol 2016; 28:324-38. [PMID: 27160659 PMCID: PMC4898166 DOI: 10.3109/08958378.2016.1170911] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/03/2016] [Accepted: 03/21/2016] [Indexed: 11/13/2022]
Abstract
Many laboratories are working to develop in vitro models that will replace in vivo tests, but occasionally there remains a regulatory expectation of some in vivo testing. Historically, cigarettes have been tested in vivo for 90 days. Recently, methods to reduce and refine animal use have been explored. This study investigated the potential of reducing animal cigarette smoke (CS) exposure to 3 or 6 weeks, and the feasibility of separate lung lobes for histopathology or the Comet assay. Rats were exposed to sham air or CS (1 or 2 h) for 3 or 6 weeks. Respiratory tissues were processed for histopathological evaluation, and Alveolar type II cells (AEC II) isolated for the Comet assay. Blood was collected for Pig-a and micronucleus quantification. Histopathological analyses demonstrated exposure effects, which were generally dependent on CS dose (1 or 2 h, 5 days/week). Comet analysis identified that DNA damage increased in AEC II following 3 or 6 weeks CS exposure, and the level at 6 weeks was higher than 3 weeks. Pig-a mutation or micronucleus levels were not increased. In conclusion, this study showed that 3 weeks of CS exposure was sufficient to observe respiratory tract pathology and DNA damage in isolated AEC II. Differences between the 3 and 6 week data imply that DNA damage in the lung is cumulative. Reducing exposure time, plus analyzing separate lung lobes for DNA damage or histopathology, supports a strategy to reduce and refine animal use in tobacco product testing and is aligned to the 3Rs (replacement, reduction and refinement).
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Affiliation(s)
| | - Patricia Ordoñez
- Vivotecnia Research S.L., Parque Científico de Madrid,
Tres Cantos,
Madrid,
Spain
| | - David Thorne
- British American Tobacco, R&D,
Southampton,
Hampshire,
UK
| | - David Walker
- British American Tobacco, R&D,
Southampton,
Hampshire,
UK
| | | | | | - Debbie Dillon
- British American Tobacco, R&D,
Southampton,
Hampshire,
UK
| | - Clive Meredith
- British American Tobacco, R&D,
Southampton,
Hampshire,
UK
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11
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Dalrymple A, Ordoñez P, Thorne D, Dillon D, Meredith C. An improved method for the isolation of rat alveolar type II lung cells: Use in the Comet assay to determine DNA damage induced by cigarette smoke. Regul Toxicol Pharmacol 2015; 72:141-9. [PMID: 25846365 DOI: 10.1016/j.yrtph.2015.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/26/2015] [Accepted: 03/30/2015] [Indexed: 11/28/2022]
Abstract
Smoking is a cause of serious diseases, including lung cancer, emphysema, chronic bronchitis and heart disease. DNA damage is thought to be one of the mechanisms by which cigarette smoke (CS) initiates disease in the lung. Indeed, CS induced DNA damage can be measured in vitro and in vivo. The potential of the Comet assay to measure DNA damage in isolated rat lung alveolar type II epithelial cells (AEC II) was explored as a means to include a genotoxicity end-point in rodent sub-chronic inhalation studies. In this study, published AEC II isolation methods were improved to yield viable cells suitable for use in the Comet assay. The improved method reduced the level of basal DNA damage and DNA repair in isolated AEC II. CS induced DNA damage could also be quantified in isolated cells following a single or 5 days CS exposure. In conclusion, the Comet assay has the potential to determine CS or other aerosol induced DNA damage in AEC II isolated from rodents used in sub-chronic inhalation studies.
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Affiliation(s)
- Annette Dalrymple
- British American Tobacco, Group R&D, Southampton, Hampshire SO15 8TL, UK.
| | - Patricia Ordoñez
- Vivotecnia Research S.L., Parque Científico de Madrid, C/Santiago Grisolía, 2 (PTM), 28760 Tres Cantos, Madrid, Spain
| | - David Thorne
- British American Tobacco, Group R&D, Southampton, Hampshire SO15 8TL, UK
| | - Debbie Dillon
- British American Tobacco, Group R&D, Southampton, Hampshire SO15 8TL, UK
| | - Clive Meredith
- British American Tobacco, Group R&D, Southampton, Hampshire SO15 8TL, UK
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Abstract
Driven by new regulatory demands to demonstrate risk reduction, the toxicity assessment of tobacco products increasingly employs innovative in vitro methods, including biphasic cell and tissue cultures exposed to whole cigarette smoke at the air-liquid interface, cell transformation assays, and genomic analyses. At the same time, novel tobacco products are increasingly compared to traditional cigarettes. This overview of in vitro toxicology studies of tobacco products reported in the last five years provides evidence to support the prioritisation of in vitro over in vivo methods by industry and their recommendation by regulatory authorities.
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13
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Toxicological assessment of kretek cigarettes part 5: Mechanistic investigations, inhalation toxicity. Regul Toxicol Pharmacol 2014; 70 Suppl 1:S54-65. [DOI: 10.1016/j.yrtph.2014.09.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 09/29/2014] [Indexed: 01/18/2023]
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14
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Schramke H, Roemer E, Dempsey R, Hirter J, Meurrens K, Berges A, Weiler H, Vanscheeuwijck P, Schorp M. Toxicological assessment of kretek cigarettes. Part 7: The impact of ingredients added to kretek cigarettes on inhalation toxicity. Regul Toxicol Pharmacol 2014; 70 Suppl 1:S81-9. [DOI: 10.1016/j.yrtph.2014.09.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 09/29/2014] [Indexed: 11/17/2022]
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15
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Investigating predictability of in vitro toxicological assessments of cigarettes: Analysis of 7years of regulatory submissions to Canadian regulatory authorities. Regul Toxicol Pharmacol 2014; 68:222-30. [DOI: 10.1016/j.yrtph.2013.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 12/20/2013] [Accepted: 12/20/2013] [Indexed: 11/21/2022]
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Mladjenovic N, Maertens RM, White PA, Soo EC. Mutagenicity of smoke condensates from Canadian cigarettes with different design features. Mutagenesis 2014; 29:7-15. [PMID: 24321849 DOI: 10.1093/mutage/get058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
There is currently limited knowledge regarding the impact of different cigarette designs on the toxicological properties of cigarette smoke condensate (CSC). This study used the Salmonella Mutagenicity Assay to examine the mutagenic activity of mainstream CSCs from 11 commercial Canadian cigarette brands with different design features or tobacco blend. The brands were selected to include design features that are common for cigarettes sold in the Canadian market, as well as cigarettes with alternate filters (charcoal or MicroBlue™), the super slim design, and cigarettes containing mixed blends of different tobacco types. CSCs were obtained using the International Organization for Standardization (ISO) and Health Canada Intense (HCI) smoking regimes, and mutagenic activity was assessed using Salmonella strains TA98, YG1041 and YG5185. Comparisons of the commercial brands to the Kentucky 3R4F, the Canadian Monitor 8 reference and a Canadian best seller revealed no significant reduction in CSC mutagenicity for cigarettes with alternate filters. However, the super slim design did afford some reduction in mutagenic potency. Nevertheless, since the study did not attempt to evaluate the impact of the cigarette designs on human health at the individual or population level, the super slim cigarettes cannot be considered 'reduced-harm' cigarettes.
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Affiliation(s)
- Nemanja Mladjenovic
- Science Division, Office of Research and Surveillance, Controlled Substances and Tobacco Directorate, Health Canada, 150 Tunney's Pasture DRWY, Ottawa, Ontario K1A 0K9, Canada
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Tsuji H, Fujimoto H, Matsuura D, Nishino T, Lee KM, Yoshimura H. Comparison of biological responses in rats under various cigarette smoke exposure conditions. J Toxicol Pathol 2013; 26:159-74. [PMID: 23914058 PMCID: PMC3695338 DOI: 10.1293/tox.26.159] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 02/19/2013] [Indexed: 11/19/2022] Open
Abstract
A variety of exposure regimens of cigarette smoke have been used in animal models of lung diseases. In this study, we compared biological responses of smoke exposure in rats, using different smoke concentrations (wet total particulate matter [WTPM]), daily exposure durations, and total days of exposure. As a range-finding acute study, we first compared pulmonary responses between SD and F344 strains after a single nose-only exposure to mainstream cigarette smoke or LPS. Secondly, F344 rats were exposed to cigarette smoke for 2 or 13 weeks under the comparable daily exposure dose (WTPM concentration x daily exposure duration; according to Haber's rule) but at a different WTPM concentration or daily exposure duration. Blood carboxylhemoglobin was increased linearly to the WTPM concentration, while urinary nicotine plus cotinine value was higher for the longer daily exposure than the corresponding shorter exposure groups. Gamma glutamyl transferase activity in bronchoalveolar lavage fluid (BALF) was increased dose dependently after 2 and 13 weeks of cigarette smoke exposure, while the neutrophil content in BALF was not increased notably. Smoke-exposed groups showed reduced body weight gain and increased relative lung and heart weights. While BALF parameters and the relative lung weights suggest pulmonary responses, histopathological examination showed epithelial lesions mainly in the upper respiratory organs (nose and larynx). Collectively, the results indicate that, under the employed study design, the equivalent daily exposure dose (exposure concentration x duration) induces equivalent pulmonary responses in rats.
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Affiliation(s)
- Hiroyuki Tsuji
- Product and Science Division, R&D Group, Japan Tobacco Inc., 6-2 Umegaka, Aoba-ku, Yokohama, Kanagawa 227-8512, Japan
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18
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Haussmann HJ. Use of hazard indices for a theoretical evaluation of cigarette smoke composition. Chem Res Toxicol 2012; 25:794-810. [PMID: 22352345 DOI: 10.1021/tx200536w] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The chemical composition of cigarette mainstream smoke (MS) has been quantitatively analyzed in multiple studies, often with the objective to toxicologically evaluate and compare various types of MS. Increases and decreases in yields of constituents between MS types can only be consolidated if these yields are compared on the basis of toxicological properties of the individual constituents. For the risk assessment of various complex mixtures including MS, a hazard index (HI) approach has been used that requires weighing of the exposure to individual MS constituents by cancer and noncancer potency values. The objective of the current study is to review the past uses of the HI concept for MS and smokeless tobacco and discuss strengths and limitations of using this concept. Published information as well as information made available on the Web was used. The HI concept has been applied to MS for determining and comparing theoretical lifetime risks, for consumer communication, for the prioritization of constituents for reduction, for ingredient assessment, and for the selection of constituents for regulation. The limitations of this approach are associated with the limited number of MS constituents with available yield data, the gaps and uncertainties in available potency values, the application to relatively high exposure concentrations, and the default assumption of additivity. The derived theoretical noncancer index is dominated by acrolein to an extent that there seems to be not much advantage in using the HI concept for noncancer assessments. The derived theoretical cancer index is dominated by genotoxic carcinogens of the MS vapor phase and may thus complement currently used toxicological assays in a tiered evaluation approach. As is the case for every other assay and interpretation model, the HI concept needs to be applied with its limitations and weaknesses in mind. Its best application is for comparative purposes. It should be kept in mind that the HI concept is a theoretical concept and does not provide actual risk information.
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Roemer E, Schorp MK, Piadé JJ, Seeman JI, Leyden DE, Haussmann HJ. Scientific assessment of the use of sugars as cigarette tobacco ingredients: a review of published and other publicly available studies. Crit Rev Toxicol 2012; 42:244-78. [PMID: 22263649 PMCID: PMC3296517 DOI: 10.3109/10408444.2011.650789] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 11/10/2011] [Accepted: 12/14/2011] [Indexed: 11/13/2022]
Abstract
Sugars, such as sucrose or invert sugar, have been used as tobacco ingredients in American-blend cigarettes to replenish the sugars lost during curing of the Burley component of the blended tobacco in order to maintain a balanced flavor. Chemical-analytical studies of the mainstream smoke of research cigarettes with various sugar application levels revealed that most of the smoke constituents determined did not show any sugar-related changes in yields (per mg nicotine), while ten constituents were found to either increase (formaldehyde, acrolein, 2-butanone, isoprene, benzene, toluene, benzo[k]fluoranthene) or decrease (4-aminobiphenyl, N-nitrosodimethylamine, N-nitrosonornicotine) in a statistically significant manner with increasing sugar application levels. Such constituent yields were modeled into constituent uptake distributions using simulations of nicotine uptake distributions generated on the basis of published nicotine biomonitoring data, which were multiplied by the constituent/nicotine ratios determined in the current analysis. These simulations revealed extensive overlaps for the constituent uptake distributions with and without sugar application. Moreover, the differences in smoke composition did not lead to relevant changes in the activity in in vitro or in vivo assays. The potential impact of using sugars as tobacco ingredients was further assessed in an indirect manner by comparing published data from markets with predominantly American-blend or Virginia-type (no added sugars) cigarettes. No relevant difference was found between these markets for smoking prevalence, intensity, some markers of dependence, nicotine uptake, or mortality from smoking-related lung cancer and chronic obstructive pulmonary disease. In conclusion, thorough examination of the data available suggests that the use of sugars as ingredients in cigarette tobacco does not increase the inherent risk and harm of cigarette smoking.
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Affiliation(s)
- Ewald Roemer
- Philip Morris International Management S.A., Operations Technical Services, Neuchâtel, Switzerland.
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20
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Discriminatory power of standard toxicity assays used to evaluate ingredients added to cigarettes. Regul Toxicol Pharmacol 2011; 62:49-61. [PMID: 22178773 DOI: 10.1016/j.yrtph.2011.11.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 11/24/2022]
Abstract
A tiered approach for testing ingredients in a cigarette matrix was developed and includes chemical-analytical testing and a standard battery of biological toxicity assays. These assays were adapted for comparative evaluation of mainstream smoke from experimental cigarettes with or without ingredients at various inclusion levels. This adaptation to test cigarette mainstream smoke may impact assay response. Since it is difficult to a priori determine discriminatory power, it was evaluated using a large experimental dataset from a multi-year program of cigarette ingredient testing performed at two separate laboratories. A statistical method, minimum detectable difference (MDD), was used as a measure of assay discriminatory power. MDD of cigarette smoke constituents ranged from 6% to 29% of the average. Salmonella mutagenicity and cytotoxicity test MDDs ranged from 20% to 81% and 18% to 49%, respectively. Body weight gain in 90-day nose-only inhalation studies yielded an MDD of 30-40%. Histopathological findings with severity scores between 0.5 and 1.5 had the lowest MDDs of 23% and higher. In general, discriminatory power decreased with increasing biological complexity and toxicological relevance of the assay. Beyond statistical analysis, however, a weight-of-the-evidence analysis by experienced researchers is required for toxicological assessment of a cigarette ingredient.
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Branton PJ, McAdam KG, Duke MG, Liu C, Curle M, Mola M, Proctor CJ, Bradley RH. Use of Classical Adsorption Theory to Understand the Dynamic Filtration of Volatile Toxicants in Cigarette Smoke by Active Carbons. ADSORPT SCI TECHNOL 2011. [DOI: 10.1260/0263-6174.29.2.117] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Peter J. Branton
- Group Research and Development, British American Tobacco, Regents Park Road, Millbrook, Southampton SO15 8TL, U.K
| | - Kevin G. McAdam
- Group Research and Development, British American Tobacco, Regents Park Road, Millbrook, Southampton SO15 8TL, U.K
| | - Martin G. Duke
- Group Research and Development, British American Tobacco, Regents Park Road, Millbrook, Southampton SO15 8TL, U.K
| | - Chuan Liu
- Group Research and Development, British American Tobacco, Regents Park Road, Millbrook, Southampton SO15 8TL, U.K
| | - Maria Curle
- Group Research and Development, British American Tobacco, Regents Park Road, Millbrook, Southampton SO15 8TL, U.K
| | - Michele Mola
- Group Research and Development, British American Tobacco, Regents Park Road, Millbrook, Southampton SO15 8TL, U.K
| | - Christopher J. Proctor
- Group Research and Development, British American Tobacco, Regents Park Road, Millbrook, Southampton SO15 8TL, U.K
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Purkis SW, Troude V, Duputié G, Tessier C. Limitations in the characterisation of cigarette products using different machine smoking regimes. Regul Toxicol Pharmacol 2010; 58:501-15. [PMID: 20807558 DOI: 10.1016/j.yrtph.2010.08.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 08/23/2010] [Accepted: 08/24/2010] [Indexed: 11/22/2022]
Abstract
It is recognised that no single machine smoking regime can represent the different behaviours of individual human smokers. It has been argued that the current ISO standard regime provides machine yields that are somewhat low for certain cigarette designs compared to human intake. Various cigarette machine smoking regimes have been proposed as options for regulatory use to provide data that reflect "average" or "maximum" yields as related to human intake. Some public health representatives have proposed that the intense regime mandated for testing in Canada with 100% of the ventilation holes in the cigarette filter blocked, should be used for product characterisation and that it is not necessary that it should reflect general human smoking behaviour. We believe that this is a flawed approach because our studies and those of other workers demonstrate that the conditions generated in the cigarette when using this intense machine smoking regime are extreme in comparison to the conditions found for regimes based more realistically on human smoking. In this paper, we provide data to show that smokers modify their smoking intensity over the course of smoking in response to changes in draw resistance, smoke concentrations and smoke temperatures. We compare changes in and interactions between these parameters during puffing when smoking cigarettes of different designs. Cigarettes were smoked using various machine smoking regimes previously proposed for smoke testing as well as a regime based on human smoking data from an 'in-house' study. Puffing parameters were derived from this study to represent the 'average smoker' under laboratory conditions and equivalent to the 90th percentile when the studied smokers smoked under natural conditions. Biomarker data from human uptake studies have shown that ventilation is an effective cigarette design tool to reduce total smoke constituent uptake in humans so demonstrating that any blocking of filter ventilation is far from 100%. Likewise, this current work also shows how smokers modify their smoking behaviour in ways not well reflected by the 100% ventilation blocking regime. It seems logical that any machine smoking regime chosen for future product regulation should reflect these findings for it to have valid public health relevance. In addition, it seems misguided to discourage product design features, such as ventilation, which clearly can provide products with reduced human smoke exposure, just to maintain the dogma, counter to the scientific evidence, that there must be a regulatory regime with 100% ventilation blocking.
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Affiliation(s)
- Stephen W Purkis
- Imperial Tobacco Limited, P.O. Box 244, Southville, Bristol BS99 7UJ, United Kingdom.
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Pauly JL, O'Connor RJ, Paszkiewicz GM, Cummings KM, Djordjevic MV, Shields PG. Cigarette filter-based assays as proxies for toxicant exposure and smoking behavior--a literature review. Cancer Epidemiol Biomarkers Prev 2010; 18:3321-33. [PMID: 19959679 DOI: 10.1158/1055-9965.epi-09-0925] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Cigarettes are being marketed with filters that differ in composition and design. The filters have different toxicant trapping efficiencies, and smoking stains reflect variations in smoking behavior. Presented herein are the results of a structured literature review that was done to identify cigarette filter-based assays that may serve as proxies for mouth-level exposure and assessing smoking methods. METHODS A search of the published scientific literature and internal tobacco company documents from 1954 to 2009 was carried out. RESULTS The literature search identified diverse schemes for assessing cigarette filters, including visual inspection and digital imaging of smoked-stained spent filters, and quantitative determinations for total particulate matter (TPM), nicotine, and solanesol. The results also showed that: (a) there are sufficient data to link filter-based chemical measures to standardized smoking machine-measured yields of tar and nicotine; (b) TPM eluted from filters or in chemical digest of filters can be used to estimate the efficiency of the filter for trapping smoke solids; (c) visual and digital inspection of spent filters is useful in finding indicators of variations in smoking behaviors; and (d) there is a correlation between solanesol and nicotine measured in filters and exposure biomarkers in smokers. CONCLUSIONS The cigarette filter may prove useful in estimating smoking behaviors such as filter vent blocking and puffing intensity, and may have utility as proxy measures of mouth-level smoke exposure in clinical trials. Additional investigations are needed to compare the different proposed assay schemes and the assay results with measurements of human biomarker assays of smoke exposure.
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Affiliation(s)
- John L Pauly
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
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