The protective effects of melatonin against cryopreservation-induced oxidative stress in human sperm

Abstract

Reactive oxygen species (ROS) production and lipid peroxidation during cryopreservation harm sperm membrane and as a result reduce the recovery of motile sperm. The antioxidant effects of melatonin on different cells have been widely reported. This study was aimed to evaluate changes in post-thaw motility, viability, and intracellular ROS and malondialdehyde (MDA) in response to the addition of melatonin to human sperm freezing extender. Semen of 43 fertile men was collected and each sample was divided into eight equal aliquots. An aliquot was analyzed freshly for viability, motility, and intracellular ROS and MDA. Melatonin was added to the recommended human freezing extender to yield six different final concentrations: 0.001, 0.005, 0.01, 0.05, 0.1, and 1 mM. A control group without melatonin was also included. Two weeks after cryopreservation, samples were thawed and pre-freeze analyses repeated. Obtained results showed that cryopreservation significantly ( P <0.05) reduces viability and motility, but increases intracellular ROS and MDA of human sperm. The semen extender supplemented with various doses of melatonin (except for 0.001 mM) significantly ( P <0.05) increased motility and viability, but decreased intracellular ROS and MDA levels of cryopreserved sperm after the thawing process, as compared with the control group. We also found that the most effective concentration of melatonin in protecting human spermatozoa from cryopreservation injuries was 0.01 mM. These findings suggest that melatonin exerts its cryoprotective effects on spermatozoa possibly by counteracting intracellular ROS, and thereby reduces MDA generation. This finally leads to increase of post-thaw viability and motility of cryopreserved spermatozoa.

Melatonin Scavenger Properties against Oxidative and Nitrosative Stress: Impact on Gamete Handling and In Vitro Embryo Production in Humans and Other Mammals

“…Melatonin can decrease mitochondrial ROS production when sperm is exposed to oxidative stress [128]. Thus, it is a powerful antioxidant and anti-apoptotic agent in ejaculated human spermatozoa by the inhibition of caspase-3 and caspase-9 activities [80,128,129]. Melatonin can prevent mitochondrial ROS formation under basal conditions and at an early time point upon oxidative stress induced by H 2 O 2 exposure [130], increasing MnSOD expression [85], glutathione peroxidase [131], and glutathione reductase [132]; preventing DNA fragmentation [129], and therefore, improving sperm quality [130].…”

The autophagy-related protein LC3 is processed in stallion spermatozoa during short-and long-term storage and the related stressful conditions

“…Efforts have been made to improve the composition of extenders used for both refrigeration and cryopreservation, by adding antioxidants, cryoprotectants, and other similar reagents (Ball and Vo, 2001;Ball et al, 2001;Guthrie et al, 2002;Aboagla and Terada, 2003;Pena et al, 2011;Lagares et al, 2012;Morillo-Rodriguez et al, 2012;Karimfar et al, 2015). More recently, the study of molecular mechanisms controlling cell survival or cell death has emerged as a successful approach to improve semen conservation and to extend the lifespan of the sperm in vitro (Watson, 2000;Ortega Ferrusola et al, 2010;Cordova et al, 2014).…”

Melatonin Scavenger Properties against Oxidative and Nitrosative Stress: Impact on <em>In Vitro</em> Embryo Production in Mammals

“…Also, it suppress the expression of p53 and Bax, upregulates SOD1, Gpx4, BCL2L1 and SOX2. [90] Human Sperm 0.01 mM in freezing extender before cryopreservation of sperm from infertile men Increases motility and viability, decreases ROS and MDA levels [91] Porcine Oocyte 10-7 M during in vitro maturation under heat stress Improve polar body and blastocyst rate impaired by heat stress. Also it preserves normal levels of steroid hormone, reduces ROS, enhances GSH production and inhibits apoptosis.…”

“…Melatonin can decrease mitochondrial ROS production when sperm are exposed to oxidative stress [120], being a powerful antioxidant and anti-apoptotic agent in ejaculated human spermatozoa by inhibition of caspase-3 and caspase-9 activities [91,120,121]. Even more, melatonin can prevent mitochondrial ROS formation under basal conditions and at early time point upon oxidative stress induced by H2O2 exposure [122], increasing MnSOD expression [71], preventing DNA fragmentation [121] and therefore improving sperm quality [122].…”

“…Even more, melatonin can prevent mitochondrial ROS formation under basal conditions and at early time point upon oxidative stress induced by H2O2 exposure [122], increasing MnSOD expression [71], preventing DNA fragmentation [121] and therefore improving sperm quality [122]. As well as, melatonin supplementation of semen extenders increases sperm motility, viability, decreases ROS levels and lipid peroxidation [91], increasing sperm quality after the freezing-thawing processes [123]. This antioxidant compound can protect from testicular injury induced by oxidative stress after cadmium (Cd) exposure [84].…”