Protective Effects of Ascorbate and Catalase on Human Spermatozoa During Cryopreservation

Abstract

Human semen cryopreservation in the clinical management of male infertility is complicated by cryodamage to spermatozoa. We aimed to clarify the full pattern of cryodamage and evaluate the protective effects of ascorbate and catalase on cryopreserved spermatozoa. Semen samples were collected from 30 fertile males. Each sample was divided into 6 groups: fresh semen, cryopreserved semen without treatment, and samples cryopreserved with ascorbate (300 or 600 mM) or catalase (200 or 400 IU/mL). Spermatozoa were examined for their viability, motility, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), apoptosis (positive for annexin V and negative for propidium iodide [ie, Ann, and DNA damage (Olive tail moment [OTM]) in the presence or absence of ascorbate or catalase during cryopreservation. In comparison with the fresh spermatozoa, there was a significant decrease in the viability, motility, and MMP but increase in Ann + /PI 2 and OTM in the cryopreserved spermatozoa (P , .01 and P , .05, respectively). Concurrently, ROS levels in the postthaw spermatozoa also increased significantly, and this elevation was well correlated with the quality variations of postthaw spermatozoa (P , .01 for all). Ascorbate (300 mM) and catalase (200 and 400 IU/mL) reduced the ROS levels in postthaw spermatozoa significantly, compared with those in the control (P , .05). Furthermore, these antioxidants also prevented those characteristics from being adversely affected (P , .05). This study demonstrated that cryopreservation results in cryodamage to human spermatozoa, possibly through the mechanism of ROS. Appropriate ascorbate or catalase supplementation of cryoprotective medium restrains ROS levels and the resultant cryodamage.

Effect of catalase, superoxide dismutase and reduced glutathione in LDL extender on ovine cryopreserved sperm viability

“…During the cryopreservation, the plasma and mitochondrial membranes are equally vulnerable; however, the reduction in the motility is associated with problems in the mitochondrial structure. Catalase improved the motility and viability of human sperm, inhibiting DNA damages and protecting the mitochondrial function, indicating that this antioxidant is useful for decrease the ROS levels (LI et al, 2010). Our results could be indicating that some antioxidants used here (as catalase and superoxide dismutase) were a litter more efficient for the mitochondrial protection than other, as showed by the better values of some kinetics parameters.…”

Antioxidant therapy in male infertility: fact or fiction?

“…107,108 Several studies have also examined the role of antioxidants in protecting sperm DNA from injury following cryopreservation and thawing. Most studies have shown that antioxidants (vitamin C, catalase, resveratrol and genistein) can protect the sperm DNA from oxidative injury during cryopreservation and subsequent thawing [109][110][111][112] ( Table 6). In contrast, Taylor et al reported that the antioxidant vitamin E does not protect sperm DNA during cryopreservation.…”

Sperm preparation before freezing improves sperm motility and reduces apoptosis in post-freezing-thawing sperm compared with post-thawing sperm preparation

“…For example, dead spermatozoa or leukocytes in pre-freezing semen detrimentally affect the sperm survival rate and the fertility potential after thawing through the ROS generation process [6]. A number of studies have demonstrated that supplemental addition of antioxidative to cryoprotective medium, e.g., ascorbate or catalase, minimize DNA damage and preserve sperm integrity; however, the benefit of these supplementations is still debated [25,26]. In this study, we hypothesized that sperm preparation before freezing, compared with sperm preparation after freezing-thawing, would improve post-thawed sperm, i.e., sperm motility, sperm vitality and non-apoptotic sperm.…”