Aflatoxins are metabolites of Aspergillus sp fungi which are contamina
nts of animal and human diets. Both phase I and phase II drug metaboli
zing enzymes are involved in the biological activity of aflatoxins. Cy
tochrome P450 plays a central role in the bioactivation to epoxyde, it
also forms products that are less toxic than the parent compounds. Gl
utathione S-tranferases are identified as the major epoxide detoxifica
tion system. The relative efficacy of competing pathways of aflatoxins
biotransformation is a critical factor in the susceptibility to their
toxic effects. In addition, modulation of biotransformation, and thus
toxicity, can result from a variety of dietary and drug treatments.