Effect of β-naphthoflavone on the metabolism of aflatoxin B 1 in hamsters

Abstract

The effect of β-naphthoflavone (BNF) pretreatment of hamsters on the hepatic metabolism of aflatoxin B 1 (AFB 1) has been examined in studies in vitro and in vivo. Pretreatment with BNF not only increased microsomal cytochrome P-450 by 50–80% but also increased microsome-mediated AFB 1 epoxidation as measured by AFB 1-DNA binding 2.6 fold without significantly affecting other hydroxylations. Neither cytosolic GSH S-transferases' activities nor AFB 1-GSH (AFB 1-SG) conjugation were affected. In vivo, hepatic AFB 1-DNA binding was also increased about 3–4-fold. These results in contrast to those observed in the rat indicate that induced species of cytochrome P-450 are primarily responsible for higher epoxidation of AFB 1 in the hamster.