Adult male Wistar rats were enrolled in a study to test the acute hepatic effects
of 50 mg/kg fumonisin B1 in feed for 5 days. Fumonisin B1 depressed growth
and feed intake, and absolute and relative liver weight showed a significant increase.
The proportions of C17:0, C18:3 n3, C22:5 n3 and C22:6 n3 fatty acids
decreased in the hepatic phospholipid fraction. All proportional decreases modified
the hepatocellular membrane lipids into a more rigid state. The fatty acid profile
modifications were partly compensated for by endogenous glutathione (preventing
the formation of conjugated dienes and trienes as initial phase lipid peroxidation
indicators), while the enzymatic antioxidant defence system (glutathione peroxidase)
was unaltered. In contrast, hepatic malondialdehyde, the cytotoxic product
of end-phase lipid peroxidation showed a concentration increase even after 5 days
of feeding. The results indicate a rather strong and rapid hepatic effect of FB1,
immediately impairing membrane phospholipids, even before the enzymatic antioxidant
defence is activated
