Evaluation of supplementation of cryopreservation medium with gallic acid as an antioxidant in quality of post-thaw human spermatozoa.

Human sperm cryopreservation is a way to preserve sperm in the clinic. But, the production of reactive oxygen species (ROS) during cryopreservation, has certain negative impacts on the quality of sperm and its reproductive capacity. The goal of this study is to see how sperm cryopreserved in media enriched with gallic acid alter post-thaw morphology, motility, viability, DNA structure, and plasma membrane lipid peroxidation. Four groups were considered for performing this study: (1) Fresh sperm before cryopreservation; (2) cryopreserved control sperm without any supplementation; (3) cryopreserved sperm using freezing media supplemented with 50 μg/ml gallic acid and (4) cryopreserved sperm using freezing media supplemented with 100 μg/ml gallic acid. This study's results indicated that the addition of doses of 50 μg/ml gallic acid to cryopreservation medium significantly improved sperm morphology, motility, vitality, and DNA integrity and reduced DNA fragmentation and lipid peroxidation as compared to the medium without any gallic acid supplementation (p < 0.05); but, the concentration of 100 μg/ml gallic acid had no significant effects on the mentioned sperm parameters (p > 0.05). This study's findings represent the possibility of enhancing sperm characteristics and lowering detrimental effects of ROS on sperm DNA structure during cryopreservation by supplementing sperm freezing medium with gallic acid as a natural antioxidant. Therefore, Gallic acid may help improve the quality and subsequently fertilization potential of cryopreserved human sperm.