Superiority of a Non -Enzymatic Antioxidant Over Enzymatic Antioxidants in Improving the Post Thaw Function of Labrador Dog Semen

Abstract

In the current study the effect of supplementation of non-enzymatic and enzymatic antioxidants to the Tris-citric acid-fructose egg yolk plasma extender on sperm attributes and antioxidant defence system in frozen-thaw semen was compared. Supplementation of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) to the extender significantly (p < 0.05) improved motility, viability, PMI, AI and high IMMP compared to control. Malonaldehyde (LPO) concentration was significantly (p < 0.05) high in GSH supplemented extender followed by CAT/glutathione peroxidase (GPX), SOD and control. Significantly (p < 0.05) high H2O2 scavenging activity of spermatozoa was observed in GPX supplemented extender followed by SOD, CAT, control and GSH. NO2-concentration (µM/109 spermatozoa) was significantly (p < 0.05) less in GSH, CAT, GPX supplemented extenders compared to control. SO2-scavenging activity of spermatozoa was significantly high in GSH/GPX than SOD/CAT/control. SOD, CAT, GPX and GRE activity of spermatozoa was significantly (p < 0.05) high in GSH supplemented extender. Spermatozoa cryopreserved in SOD and CAT supplemented extenders indicated significantly (p < 0.05) higher SOD activity compared to control. GPX activity of spermatozoa was also significantly (p < 0.05) high in GPX/CAT supplemented extenders. Cryoinjury to the spermatozoa was protected to a maximum level in GSH supplemented extender followed by CAT, SOD, GPX and control. Study concluded that GSH is superior over antioxidant enzymes in protecting the spermatozoa from cryoinjury. Based on these observations, higher fertility rate is expected of canine semen cryopreserved in GSH supplemented TCFEYP extender compared to TCFEYP.