The Role of the Natural Antioxidant Mechanism in Sperm Cells

Alicja Kowalczyk

doi:10.1007/s43032-021-00795-w

Abstract

Molecular studies of the causes of male infertility revealed a significant contribution of oxidative stress. When excessive amounts of reactive oxygen species (ROS) are produced or antioxidant activity fails, the equilibrium between oxidation and reduction is disrupted, causing oxidative stress (OS). High levels of ROS can have an adverse effect on sperm function through the initiation of DNA damage, lipid peroxidation, loss of membrane integrity and increased permeability, inactivation of cellular enzymes, and cell apoptosis. In addition to endogenous factors such as immature sperm, leukocytes, and varicocele, potential causes of excessive ROS can also be found exogenously in males with testicular hyperthermia or exposed to environmental toxicity. To maintain the optimal functioning of sperm cells, it is, therefore, necessary to balance the redox potential, i.e., to balance ROS by antioxidants. The purpose of this review is to present the antioxidant defense systems in semen.

Highlights

Molecular studies of the underlying causes of male infertility have revealed a significant share of oxidative stress (OS), which is defined as an imbalance in the redox state of the body caused either by too high levels of oxidants or, by too little antioxidants
The purpose of this review is to present the antioxidant defense systems in semen
Research in recent years has shown that oxidative stress, caused by reactive oxygen species and free radicals, can underlie the occurrence of many reproductive disorders and is directly related to infertility or complete sterility

Summary

Introduction

Molecular studies of the underlying causes of male infertility have revealed a significant share of oxidative stress (OS), which is defined as an imbalance in the redox state of the body caused either by too high levels of oxidants or, by too little antioxidants. DNA damage caused by oxidation breaks the chromosome, leading to mutations [11]. Several studies have confirmed the important role of intact sperm DNA in normal embryonic development [14–16]. According to Virro et al [17], it has been shown that changes in the paternal genome can influence the development of embryos even with direct injection of semen into the oocyte via ICSI. Other researchers have found that higher levels of DNA fragmentation in sperm are associated with lower rates of blastocyst formation [17]. Nasr-Esfahani et al [18] showed that sperm-derived embryos with high levels of DNA damage are less likely to reach later developmental stages or blastocysts. The fragmentation of sperm DNA showed a negative correlation with the rates of blastulation and pregnancy even in the case of good quality oocytes, and high levels of DNA damage favored the arrest of embryo development [19]

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