The effect of luteolin on spermatological parameters, apoptosis, oxidative stress rate in freezing rabbit semen

The aim of the present study was to determine the effects of Luteolin (LUT) on semen quality, oxidative stress, apoptosis, acrosomal integrity, mitochondrial membrane potential and dead sperm ratio in rabbits. Ejaculates from six New Zealand rabbits were collected, evaluated and pooled. The pooling was divided into five groups as control (no additive) LUT 25 µM, LUT 50 µM, LUT 100 µM and LUT 200 µM and LUT added. It was then filled into a falcon tube with Tris-based extender at a final concentration of approximately 35 x 106 spermatozoa. Diluated rabbit semen samples were drawn into frozen and thawed. Frozen semen straws were thawed at 37°C in 30 seconds. According to our findings, no statistical difference was found between all doses of luteolin and the control group in the CASA (computer assisted sperm analysis) analysis performed at 4°C. However, total motility, progressive motility and rapid sperm percentage were found to be higher in the frozen and thawed rabbit semen at a dose of LUT 50 µM compared to the other groups (p⟨0.05). While amplitude of lateral head displacement (ALH) and beat cross-frequency (BCF) values were found at the lowest dose of LUT 200 µM, a statistically significant difference was observed between the other groups. When the flow cytometry results were examined, no statistical difference was found between the rate of dead sperm, acrosomal integrity, mitochondrial membrane potential and apoptosis rate. Morever, the H2 O2 percentage was found to be lower in all experimental groups compared to the control group (p⟨0.001). In conclusion, the addition of LUT in long-term storage of rabbit semen provided a protective effect for spermatozoa with its antioxidative properties against damage caused by cryopreservation.