Seminal plasma reduces exogenous oxidative damage to human sperm, determined by the measurement of DNA strand breaks and lipid peroxidation

Exposure of spermatozoa to reactive oxygen species (ROS) has been associate d with cellular injury, that includes DNA damage and lipid peroxidation. In addition, sperm preparation techniques such as centrifugation, commonly us ed prior to in vitro fertilization and scientific studies, are associated w ith the generation of ROS and an increase in the level of DNA damage. The p reservation, therefore, of sperm in vitro that might decrease the potential for oxidative DNA damage to arise and allow for an improvement in semen qu ality used for artificial insemination, is of importance. Seminal plasma is a rich source of antioxidants, which, potentially, safeguards sperm from o xidative attack during storage and once ejaculated. We have investigated th e protection of human spermatozoa from ROS afforded by seminal plasma. Sper m were exposed to exogenous ROS by incubating the cells with hydrogen perox ide in the presence of ferrous sulfate and ADP. Aliquots of seminal plasma were added to the incubation mixture in differing amounts, and the generati on of DNA strand breaks and thiobarbituric acid reactive species (TBARS), i ndicative of lipid peroxidation, determined. Incubation of sperm with exoge nous ROS resulted in a significant generation of DNA strand breaks and lipi d peroxidation compared to basal levels of damage (P < 0.05). Addition of s eminal plasma to the incubation media produced a significant decrease in DN A strand breaks and TEARS (P<0.05), when the amount of plasma added exceede d 60% v/v. The results indicate that spermatozoal oxidative damage induced by exogenous ROS, specifically DNA damage and Lipid peroxidation, is reduce d by the presence of seminal plasma. (C) 2000 Elsevier Science B.V. All rig hts reserved.