Antioxidant effect of Macrantha Satureja extraction on microscopic and biochemical parameters of bull sperm after freeze -thawing process

Oxidative damage due to production of reactive oxygen species during the freezing-thawing process is one of the main causes for the decline in fertility of sperm. The use of antioxidants to eliminate free radicals from the sperm diluents appears to be essential for sperm. The aim of this study was to investigate the antioxidant effect of different levels of Macrantha Satureja extracts on quality of post thawed sperm. Semen samples were collected from three Holstein bulls and diluted with a citrate-egg yolks diluents - with different levels (0, 2, 4, 8, 12, 16 and 20 ml/dl) of Macrantha Satureja extraction. After packing, cooling and freezing steps, straws stored in the liquid nitrogen tank. After freeze-thawing, the sperm motility, viability, plasma membrane integrity parameters and lipid peroxidation, were evaluated using Computer Assisted Semen Analysis, eosin-nigrosin staining, hypo-osmotic swelling test and malondialdehyde production respectively. The results showed that the extender supplemented with 4 ml/dl Macrantha Satureja extract have the best protective effect on freeze-thawed Holstein bull sperm and significantly improved all microscopic parameters. Inclusion of 4 ml/dl of extract, decreased the serum malondialdehyde compared to the other groups, however, this decrease was not statistically significant compared to control group. The result of this study confirms the positive effects of low doses of Macrantha Satureja extract on microscopic parameters of frozen-thawed bull sperm.