title: Studies on the use of plant extracts in assessing the effects of plant metabolism on the mutagenicity and toxicity of pesticides.
abstract: We have carried out studies on the effects of plant metabolism on the mutagenicity of agricultural chemicals. Our approach is to use a cell-free plant extract, as a source of metabolic enzymes, in a standard Ames test. Using a number of test compounds, we observe that plant metabolism can alter the mutagenicity of several pesticides, and can in some instances give rise to metabolites apparently unique from those which are formed in animal cells. A number of parameters of the assay have been examined, and we find that the assay temperature and preincubation of the pesticide with the extract can significantly alter the outcome of the test. We also have devised a method of controlling for the effects that natural extracts can have on the spontaneous reversion rate of the Salmonella tester strains, in an effort to distinguish slight mutagenic responses from the effects of nutrients (e.g. histidine for his- bacteria) in the assay.
authors.affiliation: Department of Molecular Biology and Genetics, University of Guelph, Ont., Canada.
authors.forename: I A
authors.initials: IA
authors.lastname: Rasquinha
authors.forename: A G
authors.initials: AG
authors.lastname: Wildeman
authors.forename: R N
authors.initials: RN
authors.lastname: Nazar
mesh_terms: D000818:Animals; D001711:Biotransformation; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D009152:Mutagenicity Tests / Q000379:methods*; D010575:Pesticides / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity; D010936:Plant Extracts / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012486:Salmonella typhimurium / Q000187:drug effects*; D013696:Temperature
chemical_list: D010575:Pesticides; D010936:Plant Extracts