Zinc protects sperm from being damaged by reactive oxygen species in assisted reproduction techniques

The aim of this study was to explore the effect of zinc on hydrogen peroxide-induced sperm damage in assisted reproduction techniques. First, sperms were selected from semen samples of 20 healthy men prepared by density gradient centrifugation. Selected sperm were treated with either 0.001% H(2)O(2), 12.5 nM ZnCL(2), 0.001% H(2)O(2) + 12.5 nM ZnCL(2) or 0.9% NaCl(2) (control). After this treatment, the motility, viability, membrane integrity and DNA fragmentation of sperms in each group were analysed by Goodline sperm detection system, optical microscopy and sperm DNA fragmentation assay. Poorer motility, vitality, membrane integrity and more DNA damage were found in sperms treated by H(2)O(2), compared with control. When sperms were treated with both H(2)O(2) and zinc, however, all indicators were improved compared with H(2)O(2) alone. There was a close association between oxidative stimulation and sperm injury; zinc could inhibit hydrogen peroxide-induced damage of sperm in assisted reproductive technology. However, the presence of zinc in culture medium can decrease the sperm quality without addition of peroxide.