Beneficial Effects of Resveratrol on Testicular Functions: Focus on Its Antioxidant Properties

Abstract

Male infertility is a pathological condition that affects many subjects and for which a progressive increase in cases has been observed in recent years. The mechanisms underlying male reproductive system dysfunction are not fully understood and the specific drugs use has not produced optimal results. Therefore, the focus on developing new therapeutic options to prevent or treat this dysfunction is continuously growing. Defective sperm function has been associated with oxidative stress (OS) due to reactive oxygen species (ROS) excessive production. OS is related to mitochondrial dysfunction, lipid peroxidation, DNA damage and fragmentation, and ultimately sperm cell death. Many defense mechanisms to protect from ROS injuries have been developed; natural antioxidants, such as vitamin C and E are able to interact with oxidizing radicals, neutralizing them. Interestingly, resveratrol (RSV), a natural polyphenol with proven health-promoting actions, has been found to be an effective free radical scavenger in several in vitro and in vivo models, providing protection against OS. In this review, we discussed mechanisms related to the modulation of redox homeostasis in the testis and how the alteration of these processes can determine a damage in testicular function; particularly, we focused on the antioxidant properties of RSV that could give beneficial effects in preserving male fertility.

Keywords: antioxidants; male infertility; oxidative stress; reactive oxygen species; resveratrol.

Figure 1

Physiological and pathological roles of ROS in the testis. The drawing represents a cross section of seminiferous tubule, where the spermatogenesis occurs. When ROS levels from both exogenous and endogenous sources are low (↓) they regulate spermatogonial stem cells self-renewal, sperm capacitation and hyperactivation, acrosomal reaction, and sperm–oocyte fusion processes; conversely, in seminiferous tubule the higher (↑) ROS levels cause OS leading to DNA fragmentation, lipid peroxidation, protein oxidation, and consequently cell death in different testicular cell types, resulting in male infertility. EGG: egg cell; SC: Sertoli cells; SSCs: spermatogonial stem cells; SPG: spermatogonia; SPT: spermatocytes; RS: round spermatids; SPZ: spermatozoa.