Male Infertility and Oxidative Stress: A Focus on the Underlying Mechanisms

Abstract

Reactive oxygen species (ROS) play a critical role in defining the functional competence of human spermatozoa. When generated in moderate amounts, ROS promote sperm capacitation by facilitating cholesterol efflux from the plasma membrane, enhancing cAMP generation, inducing cytoplasmic alkalinization, increasing intracellular calcium levels, and stimulating the protein phosphorylation events that drive the attainment of a capacitated state. However, when ROS generation is excessive and/or the antioxidant defences of the reproductive system are compromised, a state of oxidative stress may be induced that disrupts the fertilizing capacity of the spermatozoa and the structural integrity of their DNA. This article focusses on the sources of ROS within this system and examines the circumstances under which the adequacy of antioxidant protection might become a limiting factor. Seminal leukocyte contamination can contribute to oxidative stress in the ejaculate while, in the germ line, the dysregulation of electron transport in the sperm mitochondria, elevated NADPH oxidase activity, or the excessive stimulation of amino acid oxidase action are all potential contributors to oxidative stress. A knowledge of the mechanisms responsible for creating such stress within the human ejaculate is essential in order to develop better antioxidant strategies that avoid the unintentional creation of its reductive counterpart.

Positive Effect of a New Combination of Antioxidants and Natural Hormone Stimulants for the Treatment of Oligoasthenoteratozoospermia

“…Indeed, ROS abundance has been implicated in sperm abnormalities [ 35 , 36 ], while the exact impact on fertilization and pregnancy has long been the subject of considerable discussion. On the other end, reactive oxygen species mediate certain physiological processes such as sperm maturation, capacitation and acrosome reaction, two key events for the acquisition of fertilizing ability; therefore their fine balancing is fundamental to assure a proper redox microenvironment [ 37 ]. This is also supported by growing evidence demonstrating that the abuse of antioxidant treatments may induce sperm damage as a result of a reductive-stress-induced state.…”

The Synergetic Effect of Egyptian Portulaca oleracea L. (Purslane) and Cichorium intybus L. (Chicory) Extracts against Glucocorticoid-Induced Testicular Toxicity in Rats through Attenuation of Oxidative Reactions and Autophagy

“…Oxidative stress-related mechanisms are assumed responsible for altering male reproductive indices in about 40% of cases [ 19 , 27 ]. In addition to the excessive ROS formation, the scarcity of cytoplasmic antioxidants is the primary cause of oxidative stress [ 90 ]. Spermatozoa are vulnerable to ROS attack as they contain a considerable amount of polyunsaturated fatty acids and are rich in mitochondria.…”

“…Spermatozoa are vulnerable to ROS attack as they contain a considerable amount of polyunsaturated fatty acids and are rich in mitochondria. Therefore, Spermatozoa are more susceptible to oxidative stress, which may initiate lipid peroxidation, promote peroxidative damage, result in sperm motility loss, disrupt the androgen-producing Leydig cells, and increase oxidative DNA damage [ 84 , 90 , 91 ].…”

Recent Publication Trends in Radiotherapy and Male Infertility over Two Decades: A Scientometric Analysis

“…Exposure to low radiation doses reportedly decreases semen volume and leads to temporary oligozoospermia ( Mazur-Roszak et al, 2005 ). Moreover, radiation may induce reproductive toxicity in males ( Fukunaga et al, 2022 ) and can generate mitochondrial ROS in mammalian spermatozoa ( Aitken et al, 2022 ). Radiotherapy is also being used in the management of testicular cancer and prostate cancer.…”