Curcumin in a tris‐based semen extender improves cryosurvival of Hariana bull spermatozoa.

In this study, the cryoprotective potential of natural antioxidant curcumin in Hariana bull semen was evaluated as an additive in a tris‐based extender with the assessment of motility and motion parameters of spermatozoa, membrane intactness, progesterone‐receptor binding, protein carbonyl content, cervical mucus penetration, cryocapacitation‐associated and apoptotic‐like changes. The collected ejaculates were divided into five groups in the tris‐based extender (control without curcumin‐I, 10 µM‐II, 25 µM‐III, 50 µM‐IV and 75µM‐V) and were cryopreserved. Groups II and III containing 10 and 25 µM curcumin substantially (p <.05) improved the post‐thaw sperm parameters like viability, motility, and velocity parameters; intact acrosome and membrane; lowered protein carbonyl content; DNA fragmentation and cryocapacitation‐associated changes in comparison to control. It was interesting to note that early apoptotic‐like changes in sperm cells were significantly (p <.05) decreased in Group II along with an increase in a higher population of sperm cells having high mitochondrial transmembrane potential. Higher progesterone‐receptor binding, Vanguard distance and in vitro capacitation response were observed only in Group II (10µM) compared to other groups. In conclusion, curcumin in a semen extender manifests cryoprotective effects and may be incorporated at 10 µM concentration in a Hariana bull semen extender for better post‐thaw sperm quality. [ABSTRACT FROM AUTHOR]