Human Sperm Quality and Metal Toxicants: Protective Effects of some Flavonoids on Male Reproductive Function

Abstract

Background Metals can cause male infertility through affection of spermatogenesis and sperm quality. Strong evidences confirm that male infertility in metal-exposed humans is medi- ated via various mechanisms such as production of reactive oxygen species (ROS). Flavonoids have antioxidant and metal chelating properties which make them suitable candidates for neu- tralizing adverse effects of metals on semen quality. In the current study, we have evaluated the effects of five types of flavonoids (rutin, naringin, kaempferol, quercetin, and catechin) on recovery of sperm motility and prevention of membrane oxidative damage from aluminum chloride (AlCl3), cadmium chloride (CdCl2), and lead chloride (PbCl4). Materials and Methods In this experimental study, motility and lipid peroxidation of metal- exposed sperm was investigated in the presence of different concentrations of five kinds of flavonoids. Malondialdehyde (MDA) production was assessed as a lipid peroxidation marker. Results Aluminum chloride (AlCl3), cadmium chloride (CdCl2), and lead chloride (PbCl4) diminished sperm motility. Treatment of metal-exposed sperm with rutin, nar- ingin, and kaempferol attenuated the negative effects of the metals on sperm motility. Quercetin and catechin decreased the motility of metal-exposed sperm. Conclusion Based on the MDA production results, only AlCl3 significantly induced lipid peroxidation. Treatment with rutin, naringin, and kaempferol significantly decreased MDA production.

Keywords

• metal toxicity
• sperm motility
• lipid peroxidation
• flavonoids
• semen quality