Introduction: Trace minerals nutrition have significant impact on reproductive health and performance. Development of male reproductive tissue requires an optimal level of selenium (Se) in testis, and a small deviation, either deficiency or excess, leads to abnormal development. Selenium is a constituent of selenoproteins including GPx1, GPx3, mGPx4, cGPx4, and GPx5 that protect against oxidative damage to spermatozoa throughout the process of sperm maturation. A factor of central importance in male fertility is oxidative damage to spermatozoa, and Se helps to protect from this damage and consequently plays an important role in maintaining male fertility. Thus, Se and selenoproteins ensure viability of spermatozoa as well as providing protection against reactive oxygen species. In this study the role of Se and various selenoproteins in male reproductive performance is reviewed.
Methods: MEDLINE, Cochrane and Google scholar have been searched between Jan 1, 2015, and Jan 1, 2022, with imposing English language restrictions, for observational and clinical trial studies evaluated the impact of selenium in men reproductive performance. “Selenium”, “male reproduction” and “selenoproteins” have been used as keywords in this study.
Results: Previous studies confirmed that spermatogenesis is a Se dependent process regardless of the source of Se. Elevated levels of lipid peroxidation, malondialdehyde, and reactive oxygen species have been observed in male mice consuming both Se deficient (0.2 ppm sodium selenite) and Se excessive (1.0 ppm sodium selenite) diets, which resulted in harmful effects to semen quality by decreasing the fraction of motile spermatozoa, spermatozoa concentration, and number of motile spermatozoa and by increasing tailless and headless spermatozoa. A diet deficient in selenium (0.2 ppm sodium selenite) has been shown to reduce glutathione peroxidase (GSH-Px or GPx) activity in human studies, while its excess (1.0 ppm sodium selenite) intake resulted in increased GPx activity, impairing male reproductive potential.
Conclusion: The mammalian system needs a continuous supply of certain trace element, one of which is Se. Results from this review showed that presence of adequate Se in the male reproductive tract is essential for normal spermatogenesis, and Se has a fundamental role in mammalian sperm maturation. However, further longitudinal studies and well-designed randomized control trials assessing confounders are needed.
Keywords: Selenium; Male reproduction; Selenoproteins