Effect of endurance exercise training on aflatoxin B<inf>1</inf>hepatotoxicity in rats

Abstract

Effect of endurance exercise training on hepatotoxicity induced by aflatoxin B1(AFB1) was studied in rats. Rats were subjected to swimming with 1%BW resistance for 30 min, 5 days/week for 14 weeks before administration of AFB1. Endurance exercise training induced high physical fitness as shown by reduction in resting heart rate and increase in the activities of mitochondrial succinate dehydrogenase and citrate synthase in the gastrocnemius muscle. Water-immersed rats had similar basal physical fitness when compared with that of the untrained rats. Endurance exercise training as per the above schedule followed by a single i.p. injection of AFB1(2 mg/kg BW) caused a significant increase in the activities of serum alanine aminotransferase (ALT) by 6.6 fold and aspartate aminotransferase (AST) by 1.8 fold and increased the severity of histopathologic hepatic necrosis at 24h after AFB1administration. Endurance exercise training potentiated AFB1-induced hepatotoxicity by increasing the activity of the hepatic monooxygenase enzymes aniline hydroxylase and p- nitroanisole-O- demethylase. These results suggest that potentiation of AFB1- hepatotoxicity by endurance exercise training may be due to an increase in the metabolic formation of AFB1-8,9-oxide, which, in turn, causes a marked increase in AFB1binding to hepatic DNA and proteins.