Reactive oxygen species (ROS) are involved in the pathogenesis of many pathological conditions, including male infertility. High concentrations of ROS derived from immature or abnormal sperm cells as well as white blood cells can impair the normal function of spermatozoa by (super)oxidizing the unsaturated fatty acids of their cell membranes as well as the fragmentation of sperm DNA and adversely affect their mobility. At the same time, however, normal ROS levels are vital for sperm maturation, activation, and acrosomal response. Reactive oxygen species can also come from external sources such as smoking and alcohol.
To protect spermatozoa from oxidative damage, semen plasma contains numerous enzymatic antioxidant systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and a number of non-enzymatic antioxidant systems such as, ascorbic and uric acid, alpha-tocopherol, pyruvate, glutathione, taurine, and hypotaurine. Endogenous antioxidant molecules can be further supplemented with various antioxidants derived from food, dietary supplements, and pharmaceuticals.
The imbalance between the overproduction of reactive oxygen species and reduced antioxidant capacity in semen leads to a condition called oxidative stress that is associated with idiopathic male infertility.
The antioxidant potential of biological fluids can be assessed either by quantifying the individual antioxidant molecules or by evaluating their overall cumulative action and overall effectiveness. This concept is known as Total Antioxidant Capacity (TAC).
The determination of the total antioxidant capacity allows the investigation of the antioxidant status of the semen and determines its ability to neutralize the reactive oxygen species.
The Total Antioxidant Capacity in the semen of infertile patients with asthenozoospermia, oligozoospermia, teratozoospermia, and their combinations - as well as in other pathological conditions - is often reduced to a statistically significant degree compared to normal fertile men. In addition, a positive correlation has been shown between TAC and sperm analysis parameters such as morphology, motility, and sperm concentration.
The measurement of the semen Total Antioxidant Capacity is especially useful in the investigation of conditions such as:
- Unexplained male infertility
- Patients with Oligozoospermia, Asthenozoospermia, Teratozoospermia and their combinations
- Increased rate of sperm DNA fragmentation
- Follow-up of patients treated with antioxidant supplements