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

Summary 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 Mi OXSYS System. Two concentrations of ascorbic acid (400 and 600 μmol/L) were tested against heat‐ and heat plus hydrogen peroxide‐induced oxidative stress in sperm suspensions after 2 and 4 hr of incubation. Sperm motility and static oxidation reduction potential ( sORP ) were measured at 2 and 4 hr of incubation at three different temperatures. A significant decrease in sORP was observed as a function of AA concentration. The 600 μmol/L AA had more pronounced reduction in sORP compared to 400 μmol/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 H 2 O 2 ( 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.