Does Lagenaria siceraria seed oil-enriched extender regulate sperm quality, oxidant/antioxidant markers, and sperm mitochondrial enzymes in chilled diluted rabbit semen?

This study investigated the cryoprotective effects of Lagenaria siceraria seed oil (BG) on rabbit sperm quality during a 72-hour period of chilled storage at 4 °C. While a prevalent method for preserving rabbit semen, cryopreservation can elicit cold shock and other stressors, resulting in a decline in sperm quality. Thereafter, the researchers hypothesized that BG, potentially due to its antioxidant properties, could mitigate these detrimental effects. For the experiment, semen samples were diluted in extender and assigned to treatment groups receiving BG at concentrations of 0 (BG0), 100 (BG100), 200 (BG200), or 400 (BG400) µL/mL, followed by storage at 4 °C. Sperm quality parameters (motility, viability, membrane integrity, and morphology) were assessed at 24-, 48-, and 72-hour time points of storage. Results indicated a quadratic improvement in sperm motility, viability, and membrane integrity with the addition of 100 or 200 µL/mL of BG across all time points (P < 0.01). A quadratic relationship was observed between BG supplementation levels and the concentrations of GPx and SOD, indicating a dose-dependent increase. BG treatment at all concentrations led to elevated total antioxidant capacity (TAC) compared to the control, with peak TAC values at 200 and 400 µL/mL BG. Conversely, nitric oxide (NO) levels significantly decreased (P < 0.001) with increasing BG dosage. BG treatment significantly decreased malondialdehyde, H₂O₂, and protein carbonyl levels compared to the control (P < 0.01). Additionally, succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) activities were significantly and quadratically improved at BG concentrations of 200 and 400 µL/mL relative to the 100 µL/mL concentration. In conclusion, supplementing rabbit semen extenders with BG significantly enhanced sperm quality during 72-hour chilled storage by attenuating oxidative stress, bolstering antioxidant capacity, and promoting mitochondrial enzyme activity. These findings suggest that BG is a promising additive for improving the preservation of chilled rabbit semen, potentially benefiting artificial insemination and rabbit breeding programs.