SUBCHRONIC FEEDING STUDY OF THE MYCOTOXIN FUMONISIN B1 IN B6C3F1 MICEAND FISCHER-344 RATS

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium moniliforme, a common fungus which occurs naturally on corn, and other Fusarium speci es. FB1 and other fumonisins are now recognized as having potentially important animal and human health implications. However, few toxicolog ical data are currently available. Male and female B6C3F1 mice and Fis cher 344 rats were fed diets containing O, 1, 3, 9, 27, or 81 ppm FB1 (greater than or equal to 98% purity) for 13 weeks. No differences in behavior or appearance, body weight or food consumption between contro l and FB1-fed groups were found. In mice, hepatopathy and altered seru m chemical profiles indicative of hepatotoxicity were found in females fed the 81 ppm diet. No adverse effects were found in female mice fed less than or equal to 27 ppm FB1 or in male mice at any dietary level studied. In rats, nephrosis involving the outer medulla was found in males fed greater than or equal to 9 ppm and, to a lesser degree, in f emales fed 81 ppm FB1, while decreased kidney weight was found in both sexes at dietary levels greater than or equal to 9 ppm FB1. Although the liver is a target organ of FB1 in rats, hepatotoxicity was not fou nd in rats fed diets containing up to 81 ppm FB 1 for 90 days. Thus, F B1 was toxic to both species following subchronic oral exposure, altho ugh significant interspecies differences in the no observed effect lev els and organ-specific responses were found. (C) 1995 Society of Toxic ology.