Effect of Quercetin on Capacitation Status and Lipid Peroxidation of Stallion Spermatozoa

Lower fertility of preserved stallion semen may be caused by damage to the spermatozoa or premature capacitation during storage. We investigated the use of the flavonoid, quercetin, with a standard skim milk extender for storage of stallion spermatozoa to prevent premature capacitation and acrosome reaction and to reduce the damage to spermatozoa from lipid peroxidation. Several concentrations of quercetin (0.05, 0.1, 0.2, 0.3 mM) were mixed with skim milk-glucose extender, and the antioxidant effectiveness was assessed using xanthine–xanthine oxidase challenge for 21 h. The effect of quercetin on capacitation status of sperm was assessed during a 4 h incubation at 33°C, and a storage trial at 5°C for 6 days. In addition, the ability of sperm stored in quercetin extender to undergo capacitation and acrosome reaction was assessed using heparin and A23187. Lipid peroxidation in the sperm after challenge was inhibited by any concentration of quercetin in the medium, while 0.1 and 0.3 mM quercetin were most e...