title: Forward mutation of S. typhimurium by smokeless tobacco extracts.
abstract: Mutagenicity of 4 popular brands of smokeless tobaccos was studied using a S. typhimurium forward mutation assay. Aqueous extracts of 4 brands and dichloromethane and methanol extracts of 1 of the 4 brands of smokeless tobacco's did not induce significant mutagenicity either in the presence or absence of metabolic activation. Aqueous and organic extracts were however mutagenic when treated with physiological levels of sodium nitrite (0.25 mM) at acidic pH and without metabolic activation. The results indicate that smokeless tobacco contain polar and non-polar chemicals which become mutagenic to S. typhimurium under nitrosation conditions.
authors.affiliation: Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge 02139.
authors.forename: L
authors.initials: L
authors.lastname: Shirnamé-Moré
mesh_terms: D001711:Biotransformation; D006863:Hydrogen-Ion Concentration; D000432:Methanol; D008752:Methylene Chloride; D009152:Mutagenicity Tests; D009154:Mutation; D015538:Nitrosation; D010936:Plant Extracts / Q000633:toxicity; D010947:Plants, Toxic; D012486:Salmonella typhimurium; D012977:Sodium Nitrite / Q000378:metabolism; D014030:Tobacco, Smokeless / Q000378:metabolism / Q000633:toxicity*
chemical_list: D010936:Plant Extracts; D008752:Methylene Chloride; D012977:Sodium Nitrite; D000432:Methanol