Effect of fumonisin B-1 on rat hepatic P450 system

The effects of the mycotoxin fumonisin B-1 (FB1) on the hepatic cytochrome P450 system were investigated in male rats dosed daily by oral gavage with 3 mg FB1 per kg body weight for 9 consecutive days. FB1 treatment resulted in a reduced weight gain. At the same time, CYP2E activity was increased, w hich is considered to mark the metabolic changes inherent to growth retarda tion in young rats. Treatment with FB1 also resulted in a selective inhibit ion of CYP2Cl1 and to a lesser extent, CYP1A2 in liver microsomes obtained from treated animals, whereas it did not affect significantly the activity of CYP2A1/2A2, CYP2B1/2B2. CYP3A1/3A2 and CYP4A. The significant inhibition of CYP2Cl1 is considered to reflect a suppressed activity of protein kinas e activity resulting from the inhibition of sphingolipid biosynthesis cause d by FB1. (C) 2000 Elsevier Science B.V. All rights reserved.