RESUMO
Relative sensory irritation responses for Swiss-Webster mice exposed nose-only to mainstream tobacco smoke were evaluated for several cigarette types using a smoking regimen consisting of a 35-ml puff, 2 s in duration, taken once per minute. The degree of sensory irritation for each cigarette type was evaluated as the smoke concentration inducing a 50% reduction in breathing frequency. The smoke concentration inducing 50% respiratory depression is called the RD(50) value. Study findings suggest that mainstream tobacco smoke from the Eclipse cigarette, which primarily heats rather than burns tobacco, yielded an RD(50) that was significantly higher (approximately twofold) than a tobacco-burning leading ultralight or the 2R4F or 1R5F reference cigarettes. This is indicative of reduced upper airways irritation by Eclipse that may be due to its distinct design. Study findings suggest that the irritating nature of mainstream tobacco smoke from different cigarette types can be evaluated effectively in terms of smoke concentration using the relative sensory irritation assessment. These findings constitute the first report about use of the RD(50) sensory irritation response during comparative evaluations of mainstream tobacco smoke.
Assuntos
Irritantes/toxicidade , Nicotiana/toxicidade , Insuficiência Respiratória/induzido quimicamente , Taxa Respiratória/efeitos dos fármacos , Sistema Respiratório/efeitos dos fármacos , Fumar/efeitos adversos , Animais , Exposição por Inalação , Camundongos , Ventilação Pulmonar/efeitos dos fármacos , Testes de Função Respiratória , Insuficiência Respiratória/fisiopatologia , Sistema Respiratório/fisiopatologia , Volume de Ventilação Pulmonar/efeitos dos fármacosRESUMO
The mouse dermal assay has long been used to assess the dermal tumorigenicity of cigarette smoke condensate (CSC). This mouse skin model has been developed for use in carcinogenicity testing utilizing the SENCAR mouse as the standard strain. Though the model has limitations, it remains as the most relevant method available to study the dermal tumor promoting potential of mainstream cigarette smoke. In the typical SENCAR mouse CSC bioassay, CSC is applied for 29 weeks following the application of a tumor initiator such as 7,12-dimethylbenz[a]anthracene (DMBA). Several endpoints are considered for analysis including: the percentage of animals with at least one mass, latency, and number of masses per animal. In this paper, a relatively straightforward analytic model and procedure is presented for analyzing the time course of the incidence of masses. The procedure considered here takes advantage of Bayesian statistical techniques, which provide powerful methods for model fitting and simulation. Two datasets are analyzed to illustrate how the model fits the data, how well the model may perform in predicting data from such trials, and how the model may be used as a decision tool when comparing the dermal tumorigenicity of cigarette smoke condensate from multiple cigarette types. The analysis presented here was developed as a statistical decision tool for differentiating between two or more prototype products based on the dermal tumorigenicity.
Assuntos
Testes de Carcinogenicidade/métodos , Modelos Biológicos , Nicotiana/toxicidade , Neoplasias Cutâneas/induzido quimicamente , Poluição por Fumaça de Tabaco/efeitos adversos , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Teorema de Bayes , Carcinógenos/toxicidade , Feminino , Camundongos , Camundongos Endogâmicos SENCAR , Neoplasias Cutâneas/epidemiologiaRESUMO
A tiered testing strategy has been employed to evaluate the potential for new ingredients, tobacco processes, and technological developments to alter the mainstream smoke or biological activity that results from burning cigarette tobacco. The foundation of this evaluation strategy is comparative testing, typically including chemical and biological assessments. In the manufacture of cigarettes, diammonium phosphate (DAP) and urea have been historically used as ingredients added to tobacco, to reconstituted tobacco sheet, and to other processed tobaccos. As part of ongoing stewardship efforts, a toxicological assessment of cigarettes with and without DAP and urea was conducted. Chemical and biological analyses were conducted for test cigarettes added 0.5% DAP and 0.2% urea in the final blend and also for those added 1.0% DAP and 0.41% urea in the final blend compared to reference cigarettes without added DAP or urea. Principal components of this evaluation included a determination of selected mainstream smoke constituent yields, an Ames assay in Salmonella typhimurium strains TA98 and TA100, a sister chromatid exchange assay in Chinese hamster ovary cells, a 13-week inhalation study of mainstream cigarette smoke in Sprague-Dawley rats, and a 30-week dermal tumor-promotion evaluation of mainstream cigarette smoke condensate in SENCAR mice. Comparative evaluations demonstrated that the addition of DAP and urea to cigarettes at up to 1% and 0.41%, respectively, does not alter the biological activity compared to reference cigarettes without DAP or urea.
Assuntos
Carcinógenos/toxicidade , Qualidade de Produtos para o Consumidor , Mutagênicos/toxicidade , Nicotiana/química , Fosfatos/toxicidade , Ureia/toxicidade , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Células CHO , Cocarcinogênese , Cricetinae , Cricetulus , Feminino , Exposição por Inalação , Masculino , Tamanho do Órgão/efeitos dos fármacos , Especificidade de Órgãos , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Troca de Cromátide Irmã/efeitos dos fármacos , Neoplasias Cutâneas/induzido quimicamente , Alcatrões/química , Alcatrões/toxicidade , Indústria do Tabaco/normas , Testes de ToxicidadeRESUMO
This study compared the toxicological responses of Sprague-Dawley rats exposed nose-only to mainstream smoke (MS) from Test cigarettes (1, 2, and 3) to those of Control cigarettes without banded cigarette paper technologies (BCPT). Test cigarettes 1 and 2 had bands based on one technology (different band weight application) while Test cigarette 3 had bands based on another technology. The banded papers are representative of current marketed technologies. Rats were exposed to humidified HEPA filtered air (Sham) or to MS at concentrations of 0.06, 0.20, or 0.80 mg wet total particulate matter per liter air. Each exposure group contained 30 animals/sex (sentinel had 20 animals/sex). The study had two phases (13 weeks each): MS exposure (1 h/day, 5 days/week) and recovery without smoke exposure. Endpoints included clinical observations, respiratory physiology, hematology, serum chemistry, blood carboxyhemoglobin (COHb), serum nicotine, body/organ weights, gross pathology, and histopathology. Comparisons conducted were: Sham exposed vs. all cigarettes, Control cigarette vs. all Test cigarettes, and Test 1 vs. Test 2. Control and Test MS had comparable effects on respiratory physiology, COHb, serum nicotine, serum chemistry, and hematology. While some minor differences were observed, Control and Test MS had comparable effects on clinical signs, body/organ weights, and gross pathology/histopathology. Consequently, exposure of rats to equivalent MS concentrations from the four cigarettes induced similar toxicological responses in this study.
Assuntos
Pneumopatias/etiologia , Fumar/efeitos adversos , Animais , Análise Química do Sangue , Carboxihemoglobina/metabolismo , Feminino , Testes Hematológicos , Histocitoquímica , Exposição por Inalação , Pneumopatias/sangue , Pneumopatias/patologia , Masculino , Nicotina/sangue , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Testes de Função Respiratória , Fumar/sangue , Estatísticas não ParamétricasRESUMO
A subchronic, nose-only inhalation study was conducted to compare the effects of mainstream smoke from a reference cigarette containing conventional reconstituted tobacco sheet at 30% of the finished blend to mainstream smoke from cigarettes containing 10% or 15% cast sheet (a specific type of reconstituted tobacco sheet) substituted for part of the conventional reconstituted tobacco. Male and female Sprague-Dawley rats were exposed for 1 h/day, 5 d/wk, for 13 wk to mainstream smoke at 0, 0.06, 0.20, or 0.80 mg wet total particulate matter per liter of air. Clinical signs, body and organ weights, clinical chemistry, hematology, carboxyhemoglobin (COHb), serum nicotine, plethysmography, gross pathology, and histopathology were determined. Exposure to cigarette smoke induced a number of changes in respiratory physiology, histopathology, and serum nicotine and COHb levels when compared to sham animals. When corresponding dose groups of reference and cast sheet mainstream smokes were compared, no biological differences were noted. At the end of the exposure period, subsets of rats from each group were maintained without smoke exposures for an additional 13 wk (recovery period). At the end of the recovery period, there were no statistically significant differences in histopathological findings observed between the reference and either cast sheet cigarette. Substitution of 10% or 15% cast sheet tobacco for conventional reconstituted tobacco sheet does not alter the inhalation toxicology of the mainstream smoke when compared to mainstream smoke from a reference cigarette containing conventional reconstituted tobacco sheet.
Assuntos
Exposição por Inalação/análise , Nicotiana , Fumar , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Feminino , Masculino , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , Fumar/efeitos adversos , Fumar/patologia , Volume de Ventilação Pulmonar/efeitos dos fármacos , Volume de Ventilação Pulmonar/fisiologia , Fatores de TempoRESUMO
A tiered testing strategy has been employed to evaluate the potential of tobacco processes, ingredients, or technological developments to change the biological activity resulting from burning cigarette tobacco. The strategy is based on comparative chemical and biological testing. The introduction of banded cigarette papers in cigarettes to meet New York state "Fire Safety Standards for Cigarettes" constitutes an example of a technological development evaluated utilizing this tiered testing strategy that included a comparison of the chemical and biological effects of cigarettes with and without the banded cigarette paper technologies (BCPT) (representative of current marketed technologies). Specific testing included mainstream cigarette smoke chemistry studies; in vitro studies included genotoxicity (Ames and sister chromatid exchange) and cytotoxicity studies (neutral red); in vivo studies included a 13-week inhalation study in Sprague-Dawley rats and a 30-week dermal tumor promotion study in SENCAR mice. Collectively, data indicated that cigarettes with and without BCPT had a similar toxicological profile in this test battery.
Assuntos
Nicotiana/toxicidade , Papel , Fumaça/efeitos adversos , Tecnologia , Indústria do Tabaco/métodos , Administração por Inalação , Administração Tópica , Animais , Células CHO/efeitos dos fármacos , Células CHO/metabolismo , Células CHO/patologia , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Feminino , Imunossupressores/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos SENCAR , Vermelho Neutro , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Troca de Cromátide Irmã/efeitos dos fármacos , Troca de Cromátide Irmã/genética , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologia , Fumaça/análise , Alcatrões/química , Alcatrões/toxicidade , Nicotiana/química , Testes de ToxicidadeRESUMO
Previous studies demonstrated that repetitive application of cigarette smoke condensate (CSC) to 7,12-dimethylbenz[a]anthracene (DMBA)-initiated SENCAR mouse skin for 29 weeks at doses of 10, 20 and 40 mg "tar"/application results in time- and dose-dependent dermal tumor formation. To evaluate CSC-induced tumor promotion in other mouse skin models, male DBA/2 mice were treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) (300 microg) or DMBA (75 or 150 microg) followed by promotion with 1R4F CSC at concentrations ranging from 9 to 45 mg "tar"/application. Both MNNG and DMBA have previously been shown to adequately initiate tumor development. Study end-points included clinical signs, body weights, and mass tracking. Neither the DMBA-initiated/acetone-promoted control groups, nor DMBA-initiated/CSC-promoted groups produced grossly observable skin tumors. For MNNG-initiated groups, a total of four tumors were observed. Based on these findings, it would appear the DBA/2 mouse was unresponsive to CSC dermal tumor promotion. It is not possible, based on the study design employed, to determine the underlying basis for the apparent resistance exhibited by this mouse strain to CSC-induced tumor promotion.
Assuntos
Nicotiana/efeitos adversos , Neoplasias Cutâneas/etiologia , Fumaça/efeitos adversos , 9,10-Dimetil-1,2-benzantraceno , Animais , Peso Corporal , Masculino , Metilnitronitrosoguanidina , Camundongos , Camundongos Endogâmicos DBA , Camundongos Endogâmicos SENCAR , Hidrocarbonetos Policíclicos Aromáticos/toxicidadeRESUMO
A tiered testing strategy has been developed to evaluate the potential for new ingredients, tobacco processes, and technological developments to alter the biological activity that results from burning tobacco. A series of studies was initially conducted with cigarettes containing 3% high fructose corn syrup (HFCS) as an alternate tobacco casing material to corn syrup/invert sugar, including determination of selected mainstream cigarette smoke (MS) constituent yields, Ames assay, sister chromatid exchange (SCE) assay in Chinese hamster ovary (CHO) cells, a 30-week dermal tumor-promotion evaluation of cigarette smoke condensate (CSC) in SENCAR mice, and a 13-week subchronic inhalation study of MS in Sprague-Dawley rats. A second series of studies was conducted with cigarettes containing 3%, 4% and 5% HFCS including MS chemistry, Ames assay, SCE assay in CHO cells, and a neutral red cytotoxicity assays. Collectively, mainstream smoke chemistry, genotoxicity, dermal tumor-promotion, and inhalation toxicity studies demonstrated no differences between cigarettes with 3% HFCS and cigarettes with 3% corn syrup/invert sugar. Also, mainstream smoke chemistry and genotoxicity of cigarettes with 4% and 5% HFCS were not different from cigarettes with 3% HFCS. In conclusion, the addition of up to 5% HFCS to cigarette does not alter the mainstream smoke chemistry or biological activity of mainstream smoke or mainstream smoke condensate as compared to cigarettes with 3% corn syrup/invert sugar with regard to the parameters investigated and presented.
Assuntos
Frutose/toxicidade , Nicotiana/efeitos dos fármacos , Fumar , Edulcorantes/toxicidade , Administração por Inalação , Animais , Células CHO , Testes de Carcinogenicidade , Cricetinae , Cricetulus , Camundongos , Camundongos Endogâmicos SENCAR , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Troca de Cromátide Irmã/efeitos dos fármacos , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologia , Fumaça/análise , Nicotiana/químicaRESUMO
UNLABELLED: A comprehensive 2-year oral chronic toxicity/carcinogenicity study was conducted with smokeless tobacco using modern toxicological test methods and well-accepted standards. The study included a 1-year interim subgroup to assess toxicity at that intermediate time point. Test groups consisted of a tobacco blend (B) used in snus, and an aqueous tobacco extract of that tobacco blend (E) administered at 0.2, 2, or 5 mg nicotine/kg body weight/day via dosed feed to male and female Wistar Han rats. The dosages were selected to simulate potential exposure in humans ingesting smokeless tobacco or an aqueous extract of smokeless tobacco (the latter intended to simulate a snus extract, to enable bridging these data to snus epidemiology data). The following endpoints were evaluated: clinical observations, body weights, feed consumption (FC), ophthalmic exams, toxicokinetics, clinical pathology, gross pathology, and histopathology. During the 2-year study, clear treatment-related, dose-responsive effects included: (1) increases in plasma nicotine and cotinine (indicating that animals were appropriately exposed to levels relevant to human exposure) and (2) decreases in body weights with some alterations in FC. At the 2-year time point, two tumor types (in the highest B doses) displayed statistically significantly increased incidence trends vs. CONTROLS: (1) uterine carcinoma in females and (2) epididymal mesothelioma in males. Three tumor types displayed statistically significantly decreased incidence trends: (1) mammary gland adenomas in females, (2) skin basal cell carcinomas in females, and (3) thyroid follicular cell adenomas in males. These increases (and decreases) in tumor trends were interpreted as not being treatment-related because: (1) there were no preneoplastic or related non-neoplastic histopathological findings in the treated rats at the 1-year or 2-year time points to suggest that any of these neoplastic findings were treatment-related and (2) the tumor morphologies and incidences were generally within the expected range of historical controls for Wistar Han rats. Findings from this study indicate that chronic exposure of male and female Wistar Han rats to either a tobacco blend used in snus, or a tobacco extract of that blend does not lead to increased toxicity or carcinogenicity, based on the specified outcomes measured.
Assuntos
Neoplasias/induzido quimicamente , Extratos Vegetais/toxicidade , Tabaco sem Fumaça/toxicidade , Animais , Testes de Carcinogenicidade , Feminino , Masculino , Ratos , Ratos Wistar , NicotianaRESUMO
Hypothesizing that their respective genetic backgrounds would confer an increased sensitivity to lung tumorigenesis, the plausibility of selected rodent models for the inhalation testing of mainstream tobacco smoke (MTS) was evaluated. Strain A/J and rasH2 transgenic (Tg) mice were exposed to MTS from Kentucky 1R4F research cigarettes using either a whole-body or nose-only exposure regimen. The whole-body regimen consisted of a 20-week exposure period [0.200 mg wet total particulate matter/liter (WTPM/l), 6 h/day, 5 days/week]; nose-only dosing proceeded for 28 weeks [0.040, 0.125, or 0.400 mg WTPM/l, 3 h/day, 5 days/week]. Both regimens included a 16-week recovery period. Gross and microscopic examinations of the lungs were used to evaluate tumor formation, with experimental results supporting the following conclusions: 1. Evaluation of MTS-induced tumorigenicity based on gross evaluation versus microscopic confirmation provides strikingly disparate results, indicating that serial sectioning is necessary for a definitive assessment of lung tumors. 2. While the dosing regimens employed do not allow for a definitive comparison, whole-body exposure appeared to be more effective for inducing statistical changes in tumor multiplicity and incidence compared to nose-only exposure. 3. Exposure-related stress, evidenced as reductions in both body weight gain and background tumor formation, represents a potential confounder during inhalation testing of MTS tumorigenicity, with additional investigation warranted to validate the specificity of exposure-related responses. 4. Comparative findings between A/J and rasH2 Tg mice suggest that the former may be overly sensitive to exposure-related stress, potentially influencing tumorigenic responses.
Assuntos
Genes ras/genética , Neoplasias Pulmonares/induzido quimicamente , Fumaça/efeitos adversos , Fumar/patologia , Administração Intranasal , Animais , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Pulmão/patologia , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos A , Camundongos TransgênicosRESUMO
A tiered testing strategy has been developed to evaluate the potential of tobacco processes, ingredients, or technological developments to change the biological activity resulting from burning tobacco. The strategy is based on comparative chemical and biological testing. Dry ice expanded tobacco (DIET) is an example of a common tobacco expansion process currently used in the manufacture of cigarettes to increase tobacco filling capacity. As part of the toxicological evaluation of DIET, test cigarettes containing DIET were compared with control cigarettes containing tobacco expanded with a traditional expansion agent (Freon-11, also known as trichlorofluoromethane). Testing included mainstream cigarette smoke chemistry studies, genotoxicity studies (Ames and sister chromatid exchange, SCE), a 13-week inhalation study in Sprague-Dawley rats, and a 30-week dermal tumor promotion study in SENCAR mice. Cigarettes containing DIET or Freon-11 expanded tobacco were similar in biological activity.
Assuntos
Gelo-Seco , Nicotiana/toxicidade , Fumar/efeitos adversos , Indústria do Tabaco/métodos , Administração por Inalação , Animais , Células CHO , Carboxihemoglobina/metabolismo , Testes de Carcinogenicidade , Clorofluorcarbonetos de Metano , Cricetinae , Feminino , Masculino , Camundongos , Camundongos Endogâmicos SENCAR , Testes de Mutagenicidade , Nicotina/sangue , Ratos , Ratos Sprague-Dawley , Troca de Cromátide Irmã , Fumar/sangue , Nicotiana/químicaRESUMO
A tiered testing strategy has been developed to evaluate the potential of tobacco processes, ingredients, or technological developments to change the biological activity resulting from burning tobacco. The strategy is based on comparative chemical and biological testing. Expanded shredded tobacco stems (ESS) constitute an example of a common tobacco components expansion process currently used in the manufacture of cigarettes to increase the tobacco blend filling capacity. As part of the toxicological evaluation of ESS, test cigarettes containing 9.5%, 18.5%, and 25% ESS were compared to control cigarettes containing 0% ESS. Testing included mainstream cigarette smoke chemistry studies, genotoxicity studies (Ames and sister chromatid exchange), a 13-week inhalation study in Sprague-Dawley rats, and a 30-week dermal tumor promotion study in SENCAR mice. Collectively, data indicated that cigarettes with and without ESS had a similar toxicological profile in this test battery.
Assuntos
Nicotiana/toxicidade , Plantas Tóxicas , Fumaça/efeitos adversos , Fumar , Indústria do Tabaco/métodos , Animais , Células CHO , Testes de Carcinogenicidade , Cricetinae , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos SENCAR , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Troca de Cromátide Irmã/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/patologia , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologia , Fumaça/análiseRESUMO
Numerous chemical and toxicological studies indicate that smoke from ECLIPSE, a cigarette that primarily heats rather than burns tobacco, is simplified and reduced in specific chemicals believed to be associated with smoking-related diseases, and demonstrates reduced smoke toxicity and biological activity in vitro when compared to conventional tobacco burning cigarettes. These data led to the hypothesis that cigarette smoke condensate (CSC) from ECLIPSE should have lower tumorigenicity than 1R4F condensate in the SENCAR mouse dermal tumor promotion assay. Female SENCAR mice were initiated with a single topical application of 7,12-dimethylbenz[a]anthracene (DMBA) followed by promotion with ECLIPSE or 1R4F CSC. Dermal application of 10, 20, or 40 mg ECLIPSE or 1R4F CSC three times/week for 29 weeks did not alter body weights, survival or other indicators of subchronic toxicity. In DMBA-initiated mice, there were significant increases in both the number of microscopically confirmed tumor-bearing animals and total number of microscopically confirmed dermal tumors at all 1R4F CSC doses and the high-dose ECLIPSE CSC. However, the number of ECLIPSE tumor-bearing animals were reduced 83%, 93% and 67% at the low-, mid- and high-doses, respectively, compared to the 1R4F. Similarly, the total number of dermal tumors was reduced 91%, 94% and 87% at the low-, mid- and high-dose, respectively, compared to the 1R4F CSC. ECLIPSE CSC demonstrated dramatic reductions in dermal tumor promotion potential compared to 1R4F CSC.
Assuntos
Mutagênicos/efeitos adversos , Nicotiana/efeitos adversos , Neoplasias Cutâneas/induzido quimicamente , Pele/efeitos dos fármacos , Fumaça/efeitos adversos , 9,10-Dimetil-1,2-benzantraceno/administração & dosagem , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Administração Tópica , Animais , Bioensaio , Carcinógenos/administração & dosagem , Carcinógenos/toxicidade , Relação Dose-Resposta a Droga , Feminino , Temperatura Alta , Humanos , Camundongos , Camundongos Endogâmicos SENCAR , Testes de Mutagenicidade , Mutagênicos/administração & dosagem , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/patologiaRESUMO
A tiered testing strategy has been developed to evaluate the potential for new ingredients, tobacco processes, and technological developments to increase or reduce the biological activity that results from burning tobacco. In the manufacture of cigarettes, honey is used as a casing ingredient to impart both aroma and taste. The primary objective of this document is to summarize and interpret chemical and toxicological studies that have been conducted to evaluate the potential impact of honey on the biological activity of either mainstream cigarette smoke or cigarette smoke condensate. As part of ongoing stewardship efforts, cigarettes produced with honey (5% wet weight) as an alternative to invert sugar in tobacco casing material were subjected to extensive evaluation. Principal components of this evaluation were a determination of selected mainstream smoke constituent yields, Ames assay, sister chromatid exchange assay in Chinese hamster ovary cells, a 30-wk dermal tumor promotion evaluation of cigarette smoke condensate in SENCAR mice, and a 13-wk inhalation study of cigarette smoke in Sprague-Dawley rats. Comparative analytical evaluations demonstrated that the substitution of honey for invert sugar as a casing material in cigarettes had no significant impact on mainstream smoke chemistry. In addition, in vitro and in vivo studies demonstrated that cigarettes containing tobacco cased with honey had comparable biological activity to cigarettes containing invert sugar. Collectively, these data demonstrate that the use of honey as an alternative casing material in the manufacture of cigarettes does not alter the potential toxicity of cigarette smoke condensate (CSC) or cigarette smoke; therefore the use of honey as an ingredient added to cigarette tobacco is acceptable from a toxicological perspective.
Assuntos
Mel/toxicidade , Nicotiana , Fumar , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Administração por Inalação , Animais , Peso Corporal/efeitos dos fármacos , Testes de Carcinogenicidade , Carcinógenos/toxicidade , Feminino , Técnicas In Vitro , Masculino , Testes de Mutagenicidade , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Troca de Cromátide Irmã/efeitos dos fármacos , Neoplasias Cutâneas/induzido quimicamente , Fumaça/análise , Acetato de Tetradecanoilforbol/toxicidadeRESUMO
This manuscript presents data from 90-day toxicology studies designed to characterize the subchronic effects of a smokeless tobacco blend and an aqueous extract of that blend when administered to rodents in NTP-2000 feed. Positive control (nicotine tartrate) and treatment groups were matched for a range of nicotine levels. The doses evaluated were 0.3, 3, and 6 mg nicotine/kg body weight/day in Wistar Hannover rats and 6, 60, and 120 mg nicotine/kg/day in CD-1 mice. Variables evaluated included plasma nicotine and cotinine, body weights, feed consumption, clinical observations, clinical and anatomic pathology (including organ weights), and histopathology. Plasma nicotine and cotinine levels were dose-responsive. Key effects such as body weight reductions and organ weight changes occurred in rats and mice predominantly at the highest doses of test articles and positive control in the absence of treatment-related gross or histopathological changes. Organ weight changes were attributed mainly to the lower body weights of treated vs. control groups. The blend- and extract-induced effects generally paralleled each other and the nicotine-induced effects. Based on these studies, the doses evaluated spanned the no observable adverse effect level, the lowest observable adverse effect level and the maximum tolerated dose.
Assuntos
Extratos Vegetais/toxicidade , Tabaco sem Fumaça/toxicidade , Testes de Toxicidade Subcrônica , Animais , Peso Corporal/efeitos dos fármacos , Cotinina/sangue , Relação Dose-Resposta a Droga , Determinação de Ponto Final , Feminino , Masculino , Dose Máxima Tolerável , Camundongos , Camundongos Endogâmicos , Nicotina/sangue , Tamanho do Órgão/efeitos dos fármacos , Especificidade de Órgãos , Extratos Vegetais/química , Extratos Vegetais/farmacocinética , Ratos , Ratos Wistar , Tabaco sem Fumaça/química , Tabaco sem Fumaça/farmacocinéticaRESUMO
A tiered testing strategy based on a comparative chemical and biological testing program has been developed to evaluate the potential of tobacco processes, ingredients, or other technological developments to change the biological activity that results from burning tobacco. Cast sheet tobacco is a specific type of reconstituted tobacco sheet that can be used in the manufacture of cigarettes. The comparative chemical and biological testing program was used to compare the mainstream smoke and cigarette smoke condensate (CSC) from a Reference cigarette that did not contain cast sheet to that collected from Test cigarettes containing cast sheet at a final blend level of either 10% or 15%. Testing included mainstream cigarette smoke chemistry studies, in vitro studies (Ames assay, sister chromatid exchange assay, and neutral red cytotoxicity assay), and in vivo toxicology studies (13-week rat nose-only inhalation assay and 30-week mouse dermal tumor promotion assay). Certain statistically significant differences were observed in the chemical and biological studies when the Reference cigarette was compared to each of the Test cigarettes. However, when viewed collectively, the chemical and biological studies demonstrated that inclusion of cast sheet up to 15% in the final blend did not increase the inherent biological activity of mainstream cigarette smoke or CSC.
Assuntos
Nicotiana/química , Nicotiana/toxicidade , Preparações de Plantas/química , Preparações de Plantas/toxicidade , Fumar/efeitos adversos , Animais , Células CHO , Cricetinae , Cricetulus , Feminino , Camundongos , Camundongos Endogâmicos SENCAR , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Troca de Cromátide Irmã/efeitos dos fármacos , Fumaça/efeitos adversosRESUMO
A subchronic, nose-only inhalation study compared the effects of mainstream smoke from a 1R4F research cigarette to that of a 2R4F research cigarette. Male and female rats were exposed for 1 h/day, 5 days/wk, for 13 wk to mainstream smoke at 0, 0.06, 0.20, or 0.80 mg wet total particulate matter per liter of air. Clinical signs, body and organ weights, clinical chemistry, hematology, carboxyhemoglobin, serum nicotine, pulmonary plethysmography, gross pathology, and histopathology were determined. When histological changes resulting from exposure to smoke from the two types of cigarettes were compared, no biologically significant differences were observed. At the end of the exposure period, subsets of rats from each group were maintained without smoke exposures for an additional 13 wk (recovery period). At the end of the recovery period, there were no statistically significant differences in histopathological findings observed between the 1R4F and the 2R4F cigarettes. The complete toxicological assessment in this comparative inhalation study of 1R4F and 2R4F cigarettes suggests no overall biologically significant differences between the rats exposed to the two cigarettes.
Assuntos
Nicotiana/toxicidade , Fumaça/efeitos adversos , Animais , Contagem de Células Sanguíneas , Análise Química do Sangue , Peso Corporal/efeitos dos fármacos , Carboxihemoglobina/metabolismo , Feminino , Umidade , Exposição por Inalação/efeitos adversos , Longevidade/efeitos dos fármacos , Masculino , Nicotina/sangue , Tamanho do Órgão/efeitos dos fármacos , Pletismografia , Ratos , Padrões de Referência , Sistema Respiratório/patologia , TemperaturaRESUMO
A subchronic, nose-only inhalation study compared the effects of mainstream smoke from a cigarette containing 100% flue-cured tobacco cured by a direct-fired process to that of a cigarette containing 100% flue-cured tobacco cured by a heat exchanger process. The tobaccos and mainstream smoke from tobaccos cured by the heat exchanger process have been shown to have significantly lower levels of tobacco-specific nitrosamines than tobaccos cured by a direct-fired process. Male and female rats were exposed for 1 h/day, 5 days/wk, for 13 wk to mainstream smoke at 0, 0.06, 0.20, or 0.80 mg wet total particulate matter per liter of air. Clinical signs, body and organ weights, clinical chemistry, hematology, carboxyhemoglobin, serum nicotine, plethysmography, gross pathology, and histopathology were determined. When histologic changes resulting from exposure to smoke from the two types of cigarettes were compared, the only significant difference was increased epithelial hyperplasia of the anterior nasal cavity in males in the high-exposure group for the heat-exchanger cigarette. At the end of the exposure period, subsets of rats from each group were maintained without smoke exposures for an additional 13 wk (recovery period). At the end of the recovery period, there were no statistically significant differences in histopathological findings observed between the heat-exchanger-cured tobacco cigarette when compared to the direct-fired cured tobacco cigarette. The complete toxicological assessment in this study of heat exchanger and direct-fired tobaccos suggests no overall biologically significant differences between the two cigarettes.
Assuntos
Nicotiana , Nitrosaminas/análise , Respiração/efeitos dos fármacos , Poluição por Fumaça de Tabaco/análise , Animais , Análise Química do Sangue , Peso Corporal/efeitos dos fármacos , Peso Corporal/etnologia , Monóxido de Carbono/análise , Carboxihemoglobina/análise , Feminino , Exposição por Inalação/análise , Masculino , Mucosa Nasal/efeitos dos fármacos , Mucosa Nasal/patologia , Nicotina/sangue , Tamanho do Órgão , Pletismografia , Ratos , Ratos Sprague-Dawley , Fumaça/análise , Volume de Ventilação Pulmonar/efeitos dos fármacos , Fatores de TempoRESUMO
ECLIPSE cigarettes utilize a special form of continuous glass filament (CGF) as an insulator around the carbon heat source. The average numbers of CGFs on the external barrel and cigarette filter end were determined subsequent to manufacture, subsequent to real-world consumer handling and subsequent to simulated consumer handling. The following were not statistically significantly different: the average number of CGFs on the external barrel of cigarettes retrieved from the test market compared to the average external barrel counts from cigarettes subsequent to manufacture or when subjected to simulated consumer handling, and the average number of CGFs on the external barrel of cigarettes subsequent to manufacture compared to the average external barrel counts from cigarettes subjected to simulated consumer handling. The average number of CGFs on the filter end of cigarettes retrieved from the test market was statistically significantly higher than average cigarette filter end counts from cigarettes subsequent to manufacture. The average number of CGFs on the cigarette filter end of cigarettes retrieved from the test market was statistically significantly lower than average cigarette filter end counts from cigarettes subjected to simulated consumer handling. Overall, results from this study suggest that consumer handling does increase the average numbers of CGFs on the external surfaces of the cigarette. Further, the results of this study demonstrate that for the purpose of CGF quantification, the simulated consumer handling protocol used in this study (i.e., based on laboratory measurements of forces) is a reasonably good model for actual consumer handling of cigarettes. Based on the minimal number of CGFs that could be transferred to the smoker and the deposition pattern governed by their physical characteristics, the potential to deposit CGFs from these cigarettes to the lungs of smokers is extremely remote. Therefore, no convincing information exists to suggest that smokers would be exposed to CGFs from any ECLIPSE-related source at a biologically significant level.