Specific Activity of Superoxide Dismutase in Stallion Seminal Plasma Is Related to Sperm Cryotolerance

Abstract

While the removal of seminal plasma is a routine practice prior to equine sperm cryopreservation, this fluid contains the main source of antioxidant enzymes able to scavenge these reactive oxygen species. Therefore, stallion seminal plasma components may have an impact on ejaculate freezability. Against this background, this study was designed to investigate whether the activities of the main stallion seminal plasma antioxidant enzymes are related to sperm cryotolerance. With this purpose, 16 ejaculates were collected from 14 healthy stallions, and each ejaculate was split into two aliquots. The first one was used to evaluate the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GSR) in seminal plasma. The second aliquot was extended and then processed for cryopreservation. Sperm motility and viability were evaluated before and after cryopreservation, and ejaculates were classified as of good (GFE) or poor freezability (PFE) based on total motile and viable spermatozoa at post-thaw. We observed that, while the specific activities of CAT, GPX, and GSR were similar between GFE and PFE, that of SOD was significantly (p < 0.05) higher in GFE than in PFE. We can thus conclude that, in stallions, the specific activity of SOD in the seminal plasma of a given ejaculate might be related to its freezability.

The Importance of Oxidative Stress in Determining the Functionality of Mammalian Spermatozoa: A Two-Edged Sword

“…For this reason, there is intense interest in the use of antioxidants to promote cryosurvival. Recent studies have, for example, indicated that the specific activity of SOD in seminal plasma is related to the freezability of stallion, jackass and dog spermatozoa [74,75]. Loss of SOD from human semen samples is also thought to be a key factor in determining their ability to survive cryostorage [76].…”

The characteristics of proteome and metabolome associated with contrasting sperm motility in goat seminal plasma

“…Some studies have demonstrated that superoxide dismutase 1 is tightly associated with sperm quality, including sperm motility 38 – 40 . In some previous studies, superoxide dismutase was found to exist in seminal plasma, and may be associated with sperm fertility and cryotolerance 41 , 42 . But, in this study, superoxide dismutase 1 was found to be more abundant in the low motility group.…”

Quercetin Improves the Apoptotic Index and Oxidative Stress in Post-Thaw Dog Sperm

“…Herein, the observed reduction in oxidative stress by the application of quercetin in dog sperm coincides with the results found in the rats, Red Jungle fowl and the roosters where supplementation with quercetin reduced oxidative stress (Naja et al 2020, Rakha et al 2020, Yelumalai et al 2019). The mechanism employed by quercetin to ameliorate oxidative stress in post-thaw sperm is thought to occur via an increase in the sperm total antioxidant capacity and the amelioration of lipid peroxidation (Papas et al 2019). Quercetin has also caused improvements in advanced DNA integrity, owing to reduced ROS levels, as reported in bulls (Avdatek et al 2018), which could have contributed to fertility.…”

“…In sperm cryopreservation, due to discarding the seminal plasma, sperms lack essential antioxidants that defeat ROS (Kashou et al 2013), and further oxidative stress develops, which potentiates cryo-induced stress, damage, and subsequent apoptosis (Fraser et al 2011, Iwasaki &Gagnon 1992, Papas et al 2019). The cryopreservation of cells promotes the oxidation of phospholipids in the cell membrane, increases intracellular ROS, and thus leads to DNA fragmentation and cell membrane damage (El- Said et al 2014, Su et al 2019).…”