title: Evaluation of aflatoxin B1 mutagenesis: addition of glutathione and glutathione-S-transferase to the Salmonella mutagenicity assay.
abstract: The effects of glutathione (GSH) and the combination of GSH and glutathione-S-transferase (GST) on aflatoxin B1 (AFB1) mutagenesis in the Salmonella mutagenicity assay using Salmonella typhimurium strains TA98 and TA100 were tested. Ten concentrations of AFB1 (0-1.0 micrograms/plate) were added to a liver microsomal homogenate (S9 mix) or to S9 mix containing GSH or S9 mix containing the combination of GSH + GST. One-third of the samples were plated directly. Two-thirds were incubated for 30 min at 37 degrees C prior to plating, and of those, half included bacteria. All samples were plated according to Ames et al [1975]. The results show that the addition of GSH and GSH + GST affected AFB1 mutagenesis by forming the AFB1-GSH conjugate and decreasing the availability of AFB1-8,9-epoxide. The effect of GST on GSH activity varied with the strain because of the different amounts of S9 mix used. The formation of the AFB1-GSH conjugate was verified by using reverse-phase high-performance liquid chromatography for quantitation of AFB1 and detection of AFB1-GSH.
mesh_terms: D016604:Aflatoxin B1; D000348:Aflatoxins / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001711:Biotransformation; D005978:Glutathione / Q000494:pharmacology*; D005982:Glutathione Transferase / Q000494:pharmacology*; D008862:Microsomes, Liver / Q000378:metabolism; D009152:Mutagenicity Tests; D009153:Mutagens; D009154:Mutation; D051381:Rats; D012486:Salmonella typhimurium / Q000187:drug effects
chemical_list: D000348:Aflatoxins; D009153:Mutagens; D016604:Aflatoxin B1; D005982:Glutathione Transferase; D005978:Glutathione