A Cellular Perspective on the Importance of Oxidative Stress Effects on Sperm

Infertility, especially in the last decade, has been rising as a global problem, affecting approximately 10-15% of the world's population. The abundance and origin of various types of infertility are different. Studies have shown that reactive oxygen species (ROS) are involved in infertility, in particular in male infertility. Although ROS is essential for normal physiological functions of sperm such as capacitation, hyper activation, acrosome reactions, and binding to the oocyte, excessive levels can be one of the main causes of defective sperm function, which not only impairs the health of sperm DNA, but also affects fertilization via oxidation of proteins, in particular the fatty acids of the sperm cell membrane. Also, the elevated ROS levels facilitate sperm DNA damage, which leads to activation of apoptotic pathway and cell death. Therefore, the quality of semen is functionally reduced. Since the oxidative damage to sperm DNA is associated with both miscarriage and development abnormalities in the offspring, it is essential to find new strategies to recognize the cellular and molecular biology of sperm. Therefore, considering different mechanisms of oxidative stress affecting sperm can contribute significantly to the etiology of male infertility.