There is a dynamic interplay between pro- and anti-oxidant substances in human ejaculate. Reactive Oxygen Species (ROS) in low, controlled levels in the extracellular space play an important physiological role, modulating gene and protein activities vital for sperm proliferation, differentiation, and function. Excessive Reactive Oxygen Species (ROS) generation can overwhelm protective mechanism and initiate changes in lipid and/or protein layers of sperm plasma membranes. Additionally, changes in DNA can be induced.
Oxidative Stress (OS) is defined as a cellular condition associated with an imbalance between the production of free radicals, mainly ROS, and their scavenging capacity by antioxidants. When the production of ROS exceeds the available antioxidant defence, significant oxidative damage occurs to many cellular organelles by damaging lipids, proteins, DNA, and carbohydrates, thus ultimately leading to cell death. The OS-induced sperm damage has been suggested to be a significant contributing factor in 30–80% of all cases of male infertility. The generation of ROS can be exacerbated by environmental, infectious, and lifestyle aetiologies.
Luminol is used for quantification of redox activities of spermatozoa in the laboratory.