Ameliorative effect of selenium nanoparticles combined with post-conditioning on testicular ischemia–reperfusion injury in rats

Testicular torsion is a serious urological emergency that quickly cuts off blood flow to the testis, causing ischemia and subsequent reperfusion injury when blood flow restarts. This leads to oxidative stress, inflammation, and cell death, which can cause irreversible tissue damage and impairment of spermatogenesis. Although surgical detorsion is the standard treatment, post-ischemic injury remains a major obstacle to saving the testis. Selenium nano particles SeNps show strong antioxidant, anti-inflammatory, and anti-apoptotic effects, making them promising for treating ischemia-reperfusion (I/R) injury. Additionally, ischemic post-conditioning (PC) has shown protective effects in various organs, including the heart, brain, and testes, reducing reperfusion-triggered oxidative damage, lowering cell death, and improving tissue resistance to I/R injury. Investigate the synergistic effects of selenium nanoparticles and post-conditioning against testicular ischemia-reperfusion injury via testicular torsion in rats. Twenty-eight adult male rats were randomly allocated into four groups (n = 7 each): sham (SH), ischemia-reperfusion (IR), post-conditioning (PC), and selenium nanoparticles plus post-conditioning (SeNp/PC). All animals underwent right orchidectomy. In the left testis (except SH), ischemia was induced by 720° clockwise torsion of the spermatic cord for 3 h, followed by 24 h of reperfusion. In PC and SeNp/PC groups, post-conditioning was applied at the onset of reperfusion through 10 alternating cycles of reperfusion and ischemia (10 s each). Selenium nanoparticles were administered intraperitoneally at 0.5 mg/kg, 5 min before reperfusion in the SeNp/PC group. Subsequently, hormonal assays, oxidative stress biomarkers, blood profile, vascular regulation markers, apoptotic and inflammatory mediators, as well as histopathological and immunohistochemical analyses were performed. Ischemia-reperfusion (IR) injury led to increased oxidative stress markers (malondialdehyde), higher apoptotic activity (Caspase-3), and significant upregulation of inflammatory mediators (IL-6 and TNF-α). These changes were reduced by post-conditioning (PC) and were further improved with selenium nanoparticles combined with PC (SeNp/PC) compared to the SH group. Conversely, antioxidant enzymes (catalase and reduced glutathione) and reproductive hormones (testosterone, FSH, and LH) significantly increased in both PC and SeNp/PC groups relative to IR. Additionally, levels of endothelial nitric oxide synthase (eNOS), heat shock protein 70 (HSP70), and vascular endothelial growth factor (VEGF) were markedly elevated. Histological assessments (H&E and PAS staining) showed preserved testicular structure, with near-complete spermatogenesis observed in SeNp/PC-treated rats. Johnsen's scores were 8-10, 2-3, 6-9, and 9-10 for SH, IR, PC, and SeNp/PC groups, respectively. Furthermore, SeNp/PC treatment resulted in reduced expression of pro-apoptotic Bax and inflammatory NF-κB markers. SeNp with PC boosts the alleviation of injury resulting from ischemia-reperfusion injury in the rat testis.