Does Antioxidant Mitoquinone (MitoQ) Ameliorate Oxidative Stress in Frozen–Thawed Rooster Sperm?

SIMPLE SUMMARY: The cryopreservation of sperm cells is widely used in many animal species. In commercial stocks, frozen–thawed rooster semen is unreliable for artificial insemination. During cryopreservation, spermatozoa experience mitochondrial oxidative damage, causing oxidative damage to the spermatozoa. As a selective mitochondrial antioxidant, mitoquinone (MitoQ) has proven to be effective in ameliorating mitochondrial dysfunction and reducing oxidative stress in mitochondria. In this study, we attempted to determine whether MitoQ ameliorates oxidative stress in frozen–thawed rooster sperm, thereby improving sperm quality. We found that an adequate amount of MitoQ (150 nM) not only ameliorated post-thawed sperm quality and motility parameters by restoring ATP level and preventing membrane damage, but also improved the redox balance and antiapoptotic activity. These results can offer some new perspectives to improve the efficacy of the current rooster semen cryopreservation technology. ABSTRACT: In this study, we aimed to determine the benefit of mitoquinone (MitoQ) in rooster semen extenders on sperm quality, motility parameters, antioxidant capacities, and apoptotic changes in post-thawed rooster semen. A total of 85 ejaculates from 18 roosters were collected and then divided into five equal aliquots and cryopreserved in extenders with 1.0% soy lecithin nanoparticles that contained various concentrations of MitoQ (0 nM (M0), 50 nM (M50), 100 nM (M100), 150 nM (M150), and 200 nM (M200)). By using a computer-assisted semen analyzer, sperm motility parameters were assessed after freeze thawing. The M150 group had significantly higher percentages of total motility, progressive motility, viability, acrosome membrane integrity, and mitochondrial activity than the other groups (p < 0.05). Compared to other groups, M100 and M150 groups produced a higher percentage of plasma membrane integrity and ATP contents (p < 0.05). Additionally, the lowest levels of ROS and MDA in spermatozoa were observed in M150 group (p < 0.05), whereas the highest levels of ROS and MDA were observed in sperm in the controls or the M200 group (p < 0.05). Significantly higher values of SOD, GPx, and Cas-3 were found in the M150 group compared to other groups (p < 0.05). Overall, these results demonstrate that MitoQ at 150 nM not only ameliorates post-thawed sperm quality and motility parameters by restoring ATP levels and preventing membrane damage, but also improves redox balance and antiapoptotic activities.