Impact of oxidative stress and one-carbon metabolism on male infertility; a mini-review to current trends

Abstract

It is difficult to determine male factor in infertility of couples, due to its various overlaps with female factors. Numerous factors may cause infertility in males, including sperm concentration, motility and morphology. A wide range of studies have been carried out on oxidative stress and its role in male infertility. In physiological situations, a slight amount of reactive oxygen species (ROS) is produced in spermatozoa. However, many factors decrease ROS concentration in seminal plasma finally. ROS, through decreasing sperm motility, and the fusing ability of sperm, decreases fertility. An oxidative attack is neutralized by androgen metabolism in the body. This is carried out by the one carbon cycle which is related to homocysteine metabolism pathway. This cycle provides active methyl groups for transmethylation. Homocysteine has two chief metabolism pathways namely glutathione and methylation process inhibition. Any perturbation in metabolism pathways leads to glutathione decrease and released homocysteine amount which itself leads to the inhibition of methylation processes and DNA damage. One of the methods for treating infertility is to reduce the amount of ROS; thus antioxidants may be used for that matter.