Testing Rhodiola sachalinensis saccharide as cryoprotectant for bovine spermatozoa

Rhodiola sachalinensis saccharide (RSS) was extracted from the rhizome of Herba Rhodiolae and was expected as a novel cryoprotectant. The aim of this study was to test the effects of RSS on motility of bull sperm and the activities of superoxide dismutase (SOD), lactate dehydrogenase (LDH), and glutamic oxaloacetic transaminase (GOT) in bull sperm during cryopreservation. Rhodiola sachalinensis saccharide was added at the concentrations of 0.02, 0.04, 0.06, 0.08, and 0.10 mg/mL to the extenders, which were used to store bovine semen. It was found that the RSS-added extends resulted in a higher percentage of cryopreserved sperm motility, mitochondrial activity, and membrane and acrosome integrity than those of RSS-free extenders. The SOD, LDH, and GOT activities were all decreased during the process of freezing and thawing. The extenders supplemented with RSS improved the SOD, LDH, and GOT activities after cryopreservation compared with the RSS-free groups. In conclusion, RSS conferred great cryoprotective capacity to the basic extender for bull spermatozoa during the process of freezing-thawing, and the optimal concentration of RSS for the extender was 0.06 mg/mL.