Oxidative stress and male infertility—a clinical perspective

Abstract

Oxidative stress occurs when the production of potentially destructive reactive oxygen species (ROS) exceeds the bodies own natural antioxidant defenses, resulting in cellular damage. Oxidative stress is a common pathology seen in approximately half of all infertile men. ROS, defined as including oxygen ions, free radicals and peroxides are generated by sperm and seminal leukocytes within semen and produce infertility by two key mechanisms. First, they damage the sperm membrane, decreasing sperm motility and its ability to fuse with the oocyte. Second, ROS can alter the sperm DNA, resulting in the passage of defective paternal DNA on to the conceptus. This review will provide an overview of oxidative biochemistry related to sperm health and will identify which men are most at risk of oxidative infertility. Finally, the review will outline methods available for diagnosing oxidative stress and the various treatments available.

Development of a specific method to evaluate 8-hydroxy,2-deoxyguanosine in sperm nuclei: relationship with semen quality in a cohort of 94 subjects

“…On the other hand, sperm anomalies deriving from a putative impairment of maturation and, in particular of chromatin packaging, would render spermatozoa more susceptible to ROS attack on DNA nucleotides. Overall the present investigation is consistent with the studies (Ni et al 1997, Shen et al 1999, Chen et al 2012 indicating that the association between OS and global semen quality is weak or even absent and that, similar to what has been reported for sperm DNA fragmentation (Cohen-Bacrie et al 2009), the detection of oxidative damage in semen could add diagnostic information to the routine semen analysis in the evaluation of male infertility (Tremellen 2008, Sakkas & Alvarez 2010.…”

“…This pathological condition has been involved in ageing and in many disorders, including male infertility (Tremellen 2008). In infertile subjects ROS levels increased and the antioxidant enzyme defences decrease with respect to donors or fertile men (Pasqualotto et al 2001).…”

“…Induction of sperm DNA breakage by OS may have important consequences, as the integrity of the sperm genome is a crucial trait for a safe and successful embryo development. In this scenario it has been proposed that the percentages of spermatozoa bearing signs of oxidative damage in the ejaculate might provide predictive information on male fertility status to add to the routine semen parameters (Tremellen 2008, Sakkas & Alvarez 2010, poorly predictive of reproduction outcomes (Lewis 2007).…”

The effects of three different exercise modalities on markers of male reproduction in healthy subjects: a randomized controlled trial

“…Oxidative stress in seminal plasma have been associated with negative changes in sperm concentration, motility and morphology (Khosrowbeygi & Zarghami 2007, Agarwal et al 2014 and can cause potential damage to the plasma membrane of the sperm cell and DNA integrity (Tremellen 2008) (Fraczek & Kurpisz 2015). These cytokines may adversely affect sperm cell function and the reproductive process (Sanocka et al 2003, Fraczek et al 2008, Fraczek & Kurpisz 2015.…”

“…Oxidative stress has been identified as an area of great attention because of the fact that ROS and their metabolites can lead to largely irreversible perturbations of semen parameters and sperm DNA integrity. The consequences are poor fertilization, poor embryonic development, pregnancy loss, birth defects and childhood cancer (De Iuliis et al 2006, Tremellen 2008, Aitken et al 2010, Agarwal et al 2014. To preserve cellular damage by overproduction of ROS, seminal plasma contains a number of enzymatic and non-enzymatic antioxidants, which act as free radical scavengers to eliminate surplus ROS and allow a balance between ROS generation and scavenging activity to be achieved.…”