The Evaluation of Rosemary (Rosmarinus Officinalis) Leaf Extract Inclusion in Freezing Medium on Quality Parameters of Buffalo Bull Spermatozoa

BACKGROUND: The discrepancy between the endogenous antioxidants concentrations and free radicals results in oxidative stress and cellular injury. OBJECTIVE: To appraise the usefulness of Rosemarinus officinalis (RO) aqueous extract in protecting buffalo spermatozoa during freezing / thawing process. MATERIALS AND METHODS: Qualifying ejaculates from four well-restrained bulls were evaluated initially and then diluted in a freezing medium supplemented with RO-0.00, RO0.50%, RO-1.00%, RO-2.00%, and RO-4.00%, cooled to 4ºC in 2 h, equilibrated for 4 h at 4ºC, packed in straws, and cryopreserved, and thawed at 37ºC for 30 s followed by evaluation. RESULTS: We found that freezing medium supplemented with RO-2.00% improves progressive motility (%) compared to the control. Similarly, a lower rate of apoptosis-like changes (%) was recorded with RO4.00% than the control, RO-0.50% and RO-1.00%. This response was accompanied by an increment in viable spermatozoa. Semen samples supplemented with RO-2.00% and RO-4.00% displayed higher TAC (total antioxidant capacity, μM/L) and ATP (nmol/million) content than the control. In addition, semen samples supplemented with RO-2.00% displayed lower concentrations of ROS (reactive oxygen species, 10 4 RLU/20 min/25 million) than the control and RO-0.05%. Also LPO (lipid peroxidation, μM/L) with RO-2.00% and RO-4.00% was lower than the control. CONCLUSION: The inclusion of rosemary aqueous extract ameliorates motility features, structural and functional parameters, viability, TAC and ATP content of bull sperm. Conversely, the inclusion of rosemary aqueous extract alleviates apoptosis-like changes, ROS and LPO in comparison to the control. Further studies are required to determine the mechanism of action of rosemary aqueous extract in ameliorating semen quality and fertility of buffalo spermatozoa.