Unlocking the potential of propolis: Concentration-dependent effects on Ossimi Ram (Ovis aries) semen quality

Reproductive biotechnology requires successful and efficient cryopreservation of semen since it is a crucial technique for artificial insemination, which preserves and multiplies the superior genetic origins of animals. Propolis, a natural antioxidant produced by honeybees, was examined in this study. Tris-citric-glucose-soybean lecithin extender supplemented with propolis ethanolic extract (P, μg/mL) at 0 (Control), 25 (T1), 50 (T2), 100 (T3), and 200 (T4) was used. The extended semen, prepared in a 1:20 ratio (semen: extender) at 37 °C, was equilibrated for 2 hours at 5 °C and packaged in straws (0.25 ml) before storage in liquid nitrogen at -196 °C. Visual characteristics (e.g., motility, livability, abnormality), DNA integrity, lipid peroxidation, and total antioxidant capacity of semen after thawing with P extract were thoroughly investigated. The results revealed that the low concentration (T1, 25 and T2, 50 µg/ml P) decreased lipid peroxidation, apoptotic sperm, improved sperm characteristics, and maintained the highest sperm cell viability. This resulted in improved reproductive performance and DNA integrity during cryopreservation of Ossimi ram semen. However, the high concentration (T3, 100 and T4, 200 µg/ml P) had the opposite effect and showed a low impact on maintaining cryopreserved Ossimi ram semen. In conclusion, Propolis shows potential for enhancing cryopreservation efficiency, but an optimal dosage is crucial to avoid adverse effects.