Background: Cryopreservation of human sperm is a funda- mental technique in reproductive medicine. Extensive research has explored the protective role of antioxidants in cryopreserva- tion, particularly their ability to enhance post-thaw semen qual- ity. Selenium, a vital trace element, supports male reproductive health by strengthening antioxidant defenses, improving sperm parameters, and mitigating oxidative stress. This study aims to evaluate the impact of selenium on biochemical markers in sperm from asthenozoospermic men during freeze-thaw cycles. Materials and Methods: Semen samples were collected from thirty asthenozoospermic men at the Roya Infertility Treatment Center in Qom. Each sample was divided into three groups: (1) Control (fresh semen), (2) Freeze (sperm frozen in standard medium), and (3) Freeze + Selenium (sperm frozen in medium supplemented with 2 µg/mL selenium). Levels of tumor necro- sis factor-alpha (TNF-α), interleukin-10 (IL-10), malondialde- hyde (MDA), and antioxidant enzymes—superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX)— along with total antioxidant capacity (TAC), were assessed via ELISA. Results: Compared to the control group, the Freeze group exhibited a significant increase in TNF-α and MDA levels, alongside a marked decline in antioxidant enzymes and IL- 10 (P<0.05). In contrast, the Freeze + Selenium group dem- onstrated a significant rise in antioxidant enzymes and IL-10, coupled with a reduction in MDA and TNF-α levels relative to the Freeze group (P<0.05). Conclusion: Supplementing cryopreservation media with se- lenium appears to alleviate cryodamage, significantly enhanc- ing antioxidant enzyme activity while reducing oxidative and inflammatory markers (MDA and TNF-α). These findings suggest that selenium may play a protective role in preserving sperm quality during freeze-thaw processes.
