Flow cytometry study of post-thawed bulk spermatozoa: Mito-TEMPO improves cryopreservation performance by controlling apoptosis rate, DNA fragmentation and ROS production.

Sperm cryopreservation is used to spread qualified semen for artificial insemination, but the freezing process reduces sperm quality. This study assessed the efficacy of Mito-TEMPO on post-thawed goat sperm quality. Semen samples divided to five equal groups and after dilution, received different doses of Mito-TEMPO (0, 1, 10, 100 and 1000 μM), and cryopreserved in liquid nitrogen. After thawing, flow cytometry analysis was performed to evaluate sperm mitochondria membrane potential, viability, apoptotic-like changes, DNA fragmentation and ROS concentration. According to the results, Mito-TEMPO (10 and 100 μM) improved (P ≤ 0.05) sperm viability and decreased (P ≤ 0.05) apoptotic-like changes and ROS concentration compared to the other groups. Mitochondria membrane potential was higher (P ≤ 0.05) in groups received 1, 10 and 100 μM Mito-TEMPO. The lowest (P ≤ 0.05) DNA fragmentation was observed in group received 10 μM Mito-TEMPO. In conclusion, mitochondria-targeted antioxidant Mito-TEMPO could be an efficient cryo-additive to enhance flowcytometric quality parameters of post-thawed bulk semen.