[Resveratrol protects human sperm against cryopreservation-induced injury].

Objective: To investigate the effects of resveratrol in the cryopreservation medium on the quality and function of post-thaw sperm.

Methods: Semen samples were obtained from 50 normozoospermic and 50 oligoasthenozoospermic men, liquefied and then cryopreserved in the glycerol-egg yolk-citrate (GEYC) medium with or without 30 μmol/L resveratrol. Sperm motility, viability and acrosome reaction (AR) were examined before and after thawing. Sperm lipid peroxidation and the level of reactive oxygen species (ROS) were measured using commercial malondialdehyde (MDA) and the ROS assay kit. Sperm mitochondrial membrane potential (MMP) and DNA damage were determined by Rhodamine 123 staining and TUNEL.

Results: The percentage of progressively motile sperm (PMS), total sperm motility, sperm viability, MMP and AR were significantly decreased (P <0.05) while the levels of sperm ROS, MDA and DNA fragmentation index (DFI) remarkably increased in both the normozoospermia and oligoasthenozoospermia groups after cryopreservation as compared with those in the fresh ejaculate (P <0.05). In comparison with the non-resveratrol control, the post-thaw sperm cryopreserved with 30 μmol/L resveratrol showed markedly higher PMS (［32.7 ± 4.8］ vs ［43.1 ± 6.3］ %, P <0.05), total motility (［44.8 ± 6.9］ vs ［56.9 ± 7.4］ %, P <0.05), viability (［52.3 ± 6.1］ vs ［67.5 ± 5.6］ %, P <0.05), MMP (［56.5 ± 7.0］ vs ［63.4 ± 7.5］ %, P <0.05) and AR (［16.6 ± 3.8］ vs ［26.3 ± 4.7］ %, P <0.05) but lower ROS, MDA and DFI (all P <0.05) in the normozoospermia group, and so did the post-thaw sperm in the oligoasthenozoospermia group, with a particularly lower DFI (［28.5 ± 4.8］ vs ［36.3 ± 5.7］%, P <0.01).

Conclusions: Resveratrol in the cryopreservation medium can improve the quality and function of post-thaw human sperm by reducing cryopreservation-induced sperm injury and the level of ROS.