Parisa Alipoor Janafard
Hosein Daghigh Kia

Despite significant improvements in sperm cryopreservation, this process affects the quality of sperm by generating reactive oxygen species and reduction of antioxidant activity. Caffeine, as a cyclic nucleotide phosphodiesterase inhibitor has antioxidant and free radical scavenging properties. Therefore, the aim of this study was to investigate the effect of caffeine in the soybean lecithin extender on the performance of freezethawed sperm in Ghezel ram. Semen collection was performed using artificial vagina twice a week. Collected samples were diluted using Tris based extender with different levels of caffeine (0, 0.5, 1, 2, 4 mM/L). After cooling and freezing of semen samples, they were kept in liquid nitrogen. After thawing, membrane integrity, lipids peroxidation, total antioxidant capacity, glutathione peroxidase and superoxide dismutase activities parameters in seminal plasma were evaluated. To analyze the obtained data, we first examined them in terms of normality. Then data analysis was performed with SAS software (9.4) using GLM procedure. The results showed that addition of 1 mM/L caffeine increased glutathione peroxidase activity and total antioxidant capacity in comparison with other groups (P <0.05). However, the addition of caffeine had no significant effect on the superoxide dismutase activity, and MDA concentration. In conclusion,addition of 1 mM/L caffeine in Tris-lecithin based extender can improve quality of freeze-thawed spermatozoa due to increases glutathione peroxidase activity and total antioxidant capacity, which could reduce the oxidative damages of sperm during freeze-thawing process.

Methyl xanthine, Caffeine,Cryopreservation, Antioxidant, glutathione peroxidase