SPECIES COMPARISON OF INVITRO METABOLISM OF AFLATOXIN-B1

  • 1 January 1977
    • journal article
    • research article
    • Vol. 37  (6) , 1649-1656
Abstract
The metabolism of [14C]aflatoxin B1 by 9000 .times. g supernatant fraction of livers of duck, rat, mouse, monkey and humans was compared by incubating the compound and liver fractions in the presence of cofactors and air for 30 min. The incubation medium was extracted with chloroform, and the soluble metabolites were separated on thin layer plates and quantified. Radioactivity remaining in the aqueous phase was determined to quantify metabolism to water soluble derivatives. Duck, monkey and human livers were most active in total conversion, each metabolizing .apprx. 80% of available substrate in 30 min. Rat and mouse livers had lower activities, metabolizing 15-20%. Duck liver produced 60% chloroform insoluble derivatives, but all other species produced larger quantities of chloroform soluble than insoluble metabolites. Aflatoxin Q1 was the principle chloroform soluble metabolite produced by monkey, human and rat liver, whereas duck liver produced aflatoxicol in that fraction. Aflatoxin P1 was produced by monkey, human and mouse liver, but not by duck and rat. The chromatographic region containing aflatoxins M1 and B2a contained low levels of radioactivity in all species except human. No consistent pattern of metabolism emerged which could be correlated with species differences in response to aflatoxin B1 toxicity or carcinogenicity.