Protective effect of Rhodiola rosea polysaccharides on cryopreserved boar sperm

• RPs improved sperm motility and mitochondrial activity.
• RPs improved sperm acrosomal integrity and plasma membrane integrity.
• RPs improved sperm superoxide dismutase and glutathione peroxidase activity.
• RPs decreased sperm malonaldehyde level.

Cryopreservation brings sublethal damage to sperm, resulting in reduced fertile life of sperm. Rhodiola rosea polysaccharides (RPs) have antiviral, antioxidant and antitumor activities. In the present study, the cryoprotective effect of RPs on boar sperm quality parameters after frozen–thawed process was investigated. Boar sperm was cryopreserved in the extender with RPs added at concentrations of 0 (used as control), 2, 4, 6, 8 and 10 mg/L and their effects on the quality of frozen–thawed boar sperm were assessed. Addition of RPs significantly improved sperm motility, mitochondrial activity, acrosomal integrity, plasma membrane integrity, superoxide dismutase and glutathione peroxidase activity and decreased sperm malonaldehyde level (p < 0.05). The results indicated that the addition of RPs to the freezing extender decreased the cryodamage to the boar sperm.