THE INFLUENCE OF DIETARY-FAT ON HEPATIC BIOACTIVATION OF AFLATOXIN B-1 IN RATS

Fischer 344 rats were fed a low-fat high carbohydrate (HC) diet, an is ocaloric fat-containing (IC) diet, a hypercaloric fat-containing (HF) diet or a commercial rodent chow. The effects of these diets were stud ied on the binding of aflatoxin B (AFB(1)) to exogenous DNA, and on th e activities of hepatic glutathione transferases (GSTs), cytochromes 2 B1 and 1A1. Microsome-mediated binding of[H-3]AFB(1), to exogenous DNA was significantly lower in the HC-rats than in the chow and IC-fed ra ts. No significant differences were noted between HF and either HC or IC rats. There was no significant difference in hepatic GST activity o f rats fed the different diets. Our results suggest that high-carbohyd rate low-fat diets reduce microsome mediated epoxidation of AFB(1) to a larger extent than high-fat diets. In general, high fat diets increa sed cytochrome 1A1 and 2B1 activities relative to chow and high carboh ydrate diet. This suggests greater detoxification of AFB(1), thus redu cing the amount of AFB(1) available for hepatic macromolecular binding .