The evaluation of the protective effect of selenium-L-methionine on testicular tissue damage induced by radiation

BACKGROUND: Radiation induces pronounced and widespread histopathological damage in the testes, which exhibit a high degree of radiosensitivity; consequently, the utilization of effective radioprotective agents has become increasingly crucial for mitigating radiation-associated toxic outcomes, particularly infertility. PURPOSE: The present investigation aimed to comprehensively evaluate the capacity of selenium-L-methionine to mitigate radiation-induced histopathological and molecular alterations within testicular tissue, thereby assessing its potential as a radioprotective agent. MATERIAL AND METHODS: Rats were randomized into four groups: Group 1 (control), Group 2 (rad group), which received a single 10 Gy irradiation on day 2; Group 3 (sel group), which received intraperitoneal selenium-L-methionine (4 mg/kg) for six consecutive days; and Group 4 (rad+sel group), which received the same selenium-L-methionine regimen followed by 10 Gy irradiation 30 minutes after the second day's administration. On the seventh day, all animals were euthanized, and testicular tissue and blood samples were collected for biochemical and histopathological analyses. RESULTS: In the testicular tissues of the radiation-exposed groups, deformed and abnormal seminiferous tubule structures, a reduction in germ cell numbers, and sloughing of tubular epithelial cells were observed. Seminiferous tubule diameters, Johnsen's testicular biopsy scores, epididymal sperm motility, and the expression levels of Connexin 43, HSP70, PCNA, StAR, CAT, and SOD were decreased in the irradiated group, whereas TGFB1, IL-6, and MMP9 levels were increased. Selenium-L-methionine treatment largely reversed these radiation-induced changes. CONCLUSIONS: The addition of selenium-L-methionine to radiotherapy yielded promising radioprotective outcomes, and this therapeutic effect positions selenium-L-methionine as a potential novel radioprotective agent. Furthermore, the immunohistochemical markers used in the study-including MMP9, Connexin 43, HSP70, PCNA, and StAR served as sensitive indicators for detecting radiation-induced damage in testicular tissue. Nevertheless, larger-scale and long-term studies are required to validate these findings and to further substantiate the potential use of selenium-L-methionine as a radioprotective agent in clinical practice.