Fipronil-induced decrease in the epididymal sperm count: oxidative effect and protection by vitamin E.

The toxic effects of the insecticide fipronil on the sperm production and oxidative damage in the testis were evaluated, as well as the protective action of vitamin E. Male rats received vehicle or fipronil 5 mg/kg and fipronil 5 mg/kg + vitamin E 100 mg/kg for 14 days. Thereafter, the sperm concentration in the epididymis and parameters of oxidative damage in the homogenate of testicles were assessed. Fipronil reduced epidydimal sperm count. The activity of the glutathione peroxidase enzyme increased and that of catalase was reduced in the testis. Also, a reduction in GSH and an increase in the concentration of malondialdehyde were observed in the animals treated with fipronil. The vitamin E reestablished the analysed parameters to levels similar to those of the control group. We concluded that fipronil decreased sperm production in rats because of its oxidant activity and that this effect was reversed by vitamin E.