P-55: Trolox (Vitamin E) Improves SpermQuality in Oligospermia during Cryopreservation

Background: Since the deleterious effects of reactive oxygen species (ROS) during sperm cryopreservation can be overcome by antioxidants, post-thaw human sperm quality may perhaps profit from adding antioxidants to the extender media prior to cryopreservation. This study evaluated the effects of different concentrations of Trolox supplementation to cryo-protective media on post-thaw motility and the apoptosis-like events associated with cryopreservation procedure that includes trans-location of phosphatidyl serine (PS) to the cell surface, alterations in mitochondrial membrane potential (MMP), and DNA integrity of normozoospermic and Oligoozoospermic semen samples. Materials and Methods: Spermatozoa from 20 normozoospermic men and 20 patients with Oligoozoospermia were cryopreserved with cryo-protective agent containing 0, 20, 40, and 80 μmol Trolox. Pre and post cryopreservation period, sperm motility was evaluated by computer-assisted sperm analysis (CASA). Flow cytometry was utilized to investigate the MMP, PS externalization and DNA fragmentation before and after freezing-thawing. Results: The results of this study indicated that addition of 40 μmol Trolox significantly (p<0.05) increased the percentage of post-thaw motile spermatozoa in normozoospermic semen sample compared to another group. There was no motile sperm in Trolox supplemented frozen-thawed Oligoozoospermic group. Sperm frozen in extender with Trolox had greater MMP, lower DNA fragmentation and externalization of PS in both groups, though the most effective dose of Trolox in normozoospermic and Oligoozoospermic semen samples were different. Conclusion: These findings support the use of Trolox as freezing extender supplement to improve the quality of cryopreserved human sperm, measured in terms of early apoptosis changes and DNA integrity, before and after freezing-thawing in both normozoospermic men and Oligoozoospermic patients.