Effects of dietary vitamin E on male reproductive system

Vitamin E (毩-tocopherol) is fat soluble organic compound and commonly present in the cell membranes. This vitamin has the strong antioxidant properties and inhibits the lipid peroxidation created by the free hydroxyl and superoxide radicals. This vitamin protects the cell membrane of sperm cell from damages of ROS. In vitro studies have proved that the use of vitamin E improves the motility and fertilizing ability of sperm in the egg penetration of hamster[1]. Similarly, in vivo studies, supplementation of vitamin E was found to be effective in reduced number and motility of sperms caused by reactive oxygen species (ROS)[2]. The supplementation of this vitamin through oral route has significant beneficial effects on motility of sperms through the reduction of malondealdehyde (MDA), which is known as the end product of lipid peroxidation[3]. The shortage of vitamin E may damage the reproductive organs like damages in the spermatogenesis, testicular dysfunction and shrinkage of semeneferous tubules. The use of this vitamin enhances the functions of testes in the form of increased in weight of testes and epididymis. Besides the antioxidants properties of this vitamin, antioxidant enzymes like superoxide dismutase (SOD) and glutathione peroxidase are enhanced due to use of this vitamin[4]. The deficiency of this vitamin leads to testicular degeneration in poultry, rats and hamster[5] as well as the lower production of germ cells[6]. The seminiferous tubules making the framework of testes are degenerated due to deficiency of vitamin E[7]. Selenium is known as essential for the testicular function and sperm motility[8]. Lack of selenium causes the testicular malfunctioning like atrophy of semineferous tubules, abnormal spermatogenesis, immature sperms and reduction in volume of testes[9]. Vitamin E possesses the enhanced effects on the sperm motility when given with selenium[10]. There is lot of information about the use of vitamin E in various doses during the cryopreservation of semen. However, there is limited information about the use of vitamin E in diet as well as through oral routes in the bodies of various species. Keeping in view the male infertility due to deficiency of this antioxidant as well their beneficial use in this review was focused.