Sperm Quality, Antioxidant Capacity, Transcriptional Profile and Antifreeze-Related Genes of Frozen Rabbit Semen in Relation to Alpha Lipoic Acid Implication

The aim of this study was to estimate the impact of alpha-lipoic acid (ALA) as an antioxidant at different levels (0.25, 0.5, and 1 mmol) on the post-thawed rabbit sperm parameters, in comparison to 200 µmol Trolox (vitamin E analogue). Key parameters included sperm quality, antioxidant defense status, mitochondrial activity, ROS levels, and expression level of selected antioxidant-associated genes and antifreeze related gene assessed using RT-qPCR. Semen samples from fifteen mature bucks were pooled based on a minimum progressive motility of 70%. Assessments were conducted post-thaw using TCG extender, focusing on motility, quality, and antioxidant-related expression. Results showed that the group of using (ALA 0.25 mmol) had a positive influence on post-thawed sperm progressive motility with significant difference (p ≤ 0.05) between other groups. Moreover, (ALA 0.25 mmol) group significantly (p ≤ 0.05) improved antioxidants enzymes activity in compared to all groups while malondialdehyde MDA value reduced in (ALA 0.25 mmol) group in comparison with other groups. The (ALA 0.25 mmol) group exhibited significantly (p ≤ 0.05) higher mitochondrial membrane potential activity, lower ROS accumulation and DNA fragmentation levels than other groups, Antioxidant-related genes and HSP90 were up-regulated in sperm cryopreserved with ( ALA 0.25 mmol) group in compared to other groups (p ≤ 0.05). This study concluded that supplementation of alpha lipoic acid with low concentration (0.25 mmol) in buck semen promotes sperm quality characteristics, reduces ROS, upregulates antioxidants and antifreeze related genes post freezing.