Risk assessment for aflatoxin: I. Metabolism of aflatoxin B1 by different species.

A comparison of the generation and detoxification of reactive aflatoxin B1 metabolites in different species may elucidate why animal species vary widely in sensitivity to aflatoxin B1 carcinogenicity, in addition to offering some perspective on how sensitive man may be to the carcinogenic effects of this mycotoxin. Scientific literature comparing the ability of cellular fractions from different species to metabolize aflatoxin B1 is reviewed. However, in vitro studies exclude components for multiple metabolic pathways, eliminating the possibility of competition between metabolic activation and detoxification. Quantification of metabolic activation by different species from these studies is therefore limited. The species-specific carcinogenic potency of aflatoxin B1 may be reflected in levels of aflatoxin B1-DNA adducts generated in vivo. The current paucity of quantitative information on human DNA adduct levels does not permit comparisons between different species on this basis.