Evaluation of the Reproductive Toxicity of Dietary Fumonisin B1 in Rats

The toxicity of dietary fumonisin B1 (FB1), a mycotoxin from the common maize fungus Fusarium verticillioides, on serum gonadotropins, ovarian histopathology, and fertility were examined in female Wistar rats. Thirty-nine female rats were randomly assigned to two test diets containing 10.0 and 20.0 mg FB1/kg and a control diet. After 14 days of feeding, blood samples were obtained by intracardiac puncture from 4 rats in each treatment for gonadotropins evaluation, and were then killed by cervical dislocation to collect samples of ovaries for histopathology. Also, each of the remaining nine females in each treatment was mated to one healthy adult male rat. The serum LH concentrations of rats fed diets containing 10 and 20 mg FB1/kg were significantly lower (P 0.05) than those fed the control diet, while the serum FSH level of rats fed diet containing 20 mg FB1/kg only was significantly lower (P 0.05) compared with the controls. Dietary FB1 however failed to induce histopathological changes in the ovaries of the rats. Fertility, gestation lengths and foetal weights of the rats decreased significantly (P 0.05) with increased dietary FB1. The concentration of daily dietary FB1/kgBW of 1.74 in this study is less than five times the estimated probable daily fumonisin intake of 355 μg/kg BW for person eating ‘mouldy’ maize in the high oesophageal cancer area of the Transkei region, South Africa. The apparent significant “safety factor” of about five times relative to human FB1 exposure may be a cause for concern in areas where maize is a dietary staple