Evaluation of tempol effects on semen quality during human sperm cryopreservation.

Introduction: Cryopreservation causes physical and chemical damages and it can effect on sperm vitality, motility and lipid composition of sperm membrane. Increase of imbalance between production of reactive oxygen species (ROS) and semen antioxidant levels may responsible for this damage. Tempol considered as antioxidant with ability to penetrate membrane and reduce stress oxidative, especially hydrogen peroxide. Therefore aim of this study for the first time was to evaluate effect of Tempol during human sperm cryopreservation on sperm parameters and ROS level. Materials and Methods: Semen sample from 42 normozoospermic men were collected and divided two groups. In control group, semen samples were cryopreserved accordingly vitrolife protocol. In test group, Tempol (5uM) was added in sperm freeze solution. Motility, viability and stress oxidative assessed with computer-aided sperm analysis (CASA), eosin-nigrosin staining, and H2DCFDA (2'7'-dichlorodihydrofluorescein diacetate) probe respectively. Data was analyzed with SPSS 18.5 software Results: Sperm motility and viability were significantly (p<0.05) higher in the test group (33.61±2.6, 45.63±1.95) compared to control group (33.94±2.52, 23.10±2.17) after freeze and thawed sample. In addition in Tempol group, stress oxidative insignificantly lower than control group (38.29±4.6 vs. 45.99±4.4 p>0.05). Conclusion: Tempol may preserve sperm motility and vitality after cryopreservation via inhibition of sperm membrane peroxidation. Tempol with anti-oxidant activity like super oxide dismutase function may decrease the level of ROS and hydrogen peroxide generation than control group. [ABSTRACT FROM AUTHOR]