Effect of human dietary exposure levels of genistein during gestation and lactation on long-term reproductive development and sperm quality in mice.

The objective of the present study was to determine the long-term reproductive effects of gestational and lactational exposure (0, 0.1, 0.5, 2.5 and 10 mg/kg/day) to genistein on male mice at levels comparable to or greater than human dietary exposures. Testicular growth, sperm count and motility, and sperm fertilizing ability in vitro was assessed in male offspring on postnatal days (PND) 105 and 315. Selected genes were also examined by real-time PCR to determine whether genistein caused changes in gene expression similar to those previously observed with diethylstilbestrol (DES). No significant treatment-related effects on male offspring body weight, anogenital distance, seminal vesicle weight or testis weight were observed. There were also no significant effects on sperm count, the percent of motile sperm or the number of motile sperm at any age. The in vitro fertilizing ability of epididymal sperm was increased significantly in the high-dose group approximately 17% (P < 0.001) on PND 105 and 315. The results indicate that developmental exposure of mice to genistein at human exposure levels does not induce adverse effects on sperm quality or changes in testicular gene expression similar to DES.