Ascorbic acid reduces redox potential in human spermatozoa subjected to heat-induced oxidative stress

Oxidation-reduction potential (ORP) is a new measure of oxidative stress. It is a balance between the total available oxidants and reductants. This study measures the efficiency of ascorbic acid (AA) against oxidative stress induced by either heat alone or heat and hydrogen peroxide in sperm suspensions using the MiOXSYS System. Two concentrations of ascorbic acid (400 and 600mol/L) were tested against heat- and heat plus hydrogen peroxide-induced oxidative stress in sperm suspensions after 2 and 4hr of incubation. Sperm motility and static oxidation reduction potential (sORP) were measured at 2 and 4hr of incubation at three different temperatures. A significant decrease in sORP was observed as a function of AA concentration. The 600mol/L AA had more pronounced reduction in sORP compared to 400mol/L AA (p=.001). Significant decreases in sperm motility ranging from 4.89% to 14.02% were observed both as a function of incubation time and addition of H2O2 (p<.001). Ascorbic acid is efficacious to reduce heat-induced oxidative stress in sperm preparations in vitro. The supplementation of ascorbic acid may be advantageous for semen preparations in IUI, IVF and ICSI.