Background: Asthenozoospermia which involves approximately 19% of infertility cases, is one of the most prevalent causes of male infertility. Sperm cryopreservation is used routinely in assisted reproductive technology, accompanied by cell damage, such as apoptosis. In freezing, the occurrence of cold shock, formation of intracellular ice, production of reactive oxygen species (ROS), and apoptosis induction could be held responsible for disturbance in sperm function. An effective strategy to maintain the quality of cryopreserved sperms could be adding an antioxidant to the cryopreservation medium. Alpha lipoic acid (ALA) is a potent antioxidant and could inhibit apoptosis by reducing ROS levels. Objective: Considering the necessity of cryopreservation in asthenozoospermic patients, in this study, we decided to investigate the effects of ALA on the expression of the anti-apoptotic genes of cryopreserved sperms in these patients. Materials and Methods: 30 semen samples were collected from asthenozoospermic patients been referred to the infertility treatment center of Qom University Jihad from July to December 2021. Each semen sample was divided into 3 groups: control (fresh); freeze, treated with cryo-protectant alone; and freeze+ ALA, treated with cryoprotectant 0.5 mM ALA solution. In the freezing groups, samples were cryopreserved with human sperm freezing medium and rapid freezing method. In each sample, the expression of the anti- apoptotic genes Bcl-2 and HSP70 was assessed using Real-time PCR. The number of changes in gene expression was determined by the ΔΔCt formula, and finally, the results were reported as fold change. Results: The expression levels of Bcl-2 and HSP70 genes increased significantly (2.64 and 2.85 times, respectively) in the freeze group compared to the control group (p < 0.001). Meanwhile, the expression levels of Bcl-2 and HSP70 genes increased significantly in the freeze+ ALA group compared to the control counterpart (8.13 and 5.23 times, respectively) (p < 0.001). Conclusion: Our findings revealed that the utilization of ALA and cryoprotective medium reduces apoptosis by increasing the expression of the anti-apoptotic genes Bcl-2 and HSP70.
