Epigallocatechin 3‐gallate improves the quality of bull semen cryopreservation.

To determine the effects of epigallocatechin‐3‐gallate (EGCG) on the cryopreservation of bovine semen, epigallocatechin‐3‐gallate dissolved with double distilled water to 0.2, 0.4, 0.6 and 0.8 mg/ml were added to the cryopreservation diluent of the bull semen. Then, we used computer‐assisted analysis of semen kinematic parameters, staining method to detect membrane function, acrosome integrity, enzyme‐linked immunosorbent assay to detect catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), malondialdehydes (MDA) and reactive oxygen levels. The results showed that adding 0.6 mg/L of epigallocatechin‐3‐gallate could improve the cryopreserved sperm quality, which significantly increased the total motility, distance average path, distance straight line, distance curved line, average path velocity, curvilinear‐velocity, straight‐line velocity, amplitude of lateral head displacement and beat/cross frequency, as well as sperm CAT, GSH‐Px and SOD levels (p < 0.05), whilst reducing the reactive oxygen species and MDA levels (p < 0.05). Hence, these results indicate that the addition of 0.6 mg/ml of EGCG has a protective effect on the cryopreservation of the bovine semen. [ABSTRACT FROM AUTHOR]