Toxicity of aflatoxin: effects on spermatozoa, oocytes, and in vitro fertilization.

Aflatoxin B1 has been reported to have a deleterious effect on the reproductive capacity of laboratory and domestic animals. We wanted to elucidate the mechanistic aspect of this phenomenon by determining the toxic potential of aflatoxin B1 on the in vitro fertilizing ability of oocytes and epididymal sperm in albino rats. In vitro fertilization medium (IVFM) containing aflatoxin B1 at concentrations of 2.0, 4.0, 8.0, and 16.0 ppb was cultured with oocytes obtained from superovulated healthy fertile female rats and exposed to sperm cells. Epididymal sperm capacitated in IVFM, with or without aflatoxin B1, were exposed to oocytes, and the rates of fertilization in the two experiments were assessed. Aflatoxin B1 significantly reduced the mean number of ova fertilized, even at the lowest concentration. Exposure to aflatoxin caused a significant reduction in the motility of sperm cells. These results demonstrate the adverse effects of aflatoxin B1 on oocytes, spermatozoa, and in vitro fertilization.