In Vitro Studies of Antioxidants for Male Reproductive Health

The detrimental effects of oxidants on spermatozoa were suggested close to 70 years ago with the demonstration that oxygen is sperm toxic. Later studies confirmed the susceptibility of spermatozoa to oxidative stress and the fact that human spermatozoa and semen leukocytes can generate reactive oxygen species (ROS). These observations have led to studies on the role of antioxidants in protecting spermatozoa from oxidative stress in vitro. The purpose of this chapter is to discuss the rationale for antioxidant therapy in male infertility and evaluate the data on the efficacy of in vitro antioxidant preparations on sperm function. A review of the literature demonstrates a beneficial effect of in vitro antioxidants in protecting spermatozoa from exogenous oxidants and cryopreservation (and subsequent thawing). However, the protective effect of in vitro antioxidants on sperm preparations subjected to endogenous ROS and gentle sperm processing has not been established.