RESUMO
INTRODUCTION: The testicular ischemia-reperfusion (I/R) injury is characterized by the excessive aggregation of un-scavenged reactive oxygen species, leading to the heightened levels of oxidative stress. This phenomenon plays a pivotal role in the pathophysiology of testicular torsion damage. OBJECTIVE: The current study aimed to detect the prophylactic and therapeutic effects of niacin on testicular I/R injury. STUDY DESIGN: Twenty-four healthy adult male Sprague Dawley rats were randomly allocated into three groups as follows: (1) sham group, (2) torsion/detorsion (T/D) group, and (3) treatment group which received 200 mg/kg niacin along with testicular T/D. Torsion/detorsion was induced by 2 h of torsion followed by 10 days of reperfusion period. In the treatment group, niacin was injected 30 min before the reperfusion period intraperitoneally and continued for 10 days by oral gavage. RESULTS: T/D was associated with marked decreases in terms of sperm count, viability, and kinematic parameters versus the sham group (P < 0.05), which niacin significantly reverted the kinematic parameters (P < 0.05). I/R injury caused a significant increase in the number of abnormal epididymal sperms compared to the sham group (P < 0.05). Niacin decreased the epididymal sperm abnormality significantly compared to the T/D group (P < 0.05). Tissue abnormalities in T/D group, such as edema, hyperemia, inflammation, and necrosis were completely visible histopathologically, while the histological changes in the niacin-treated group were better than those in the T/D group. Regarding the pathological parametric evaluations, I/R injury significantly reduced the mean testicular biopsy score (MTBS), germinal epithelial cell thickness (GECT), and mean seminiferous tubular diameter (MSTD), and increased the tubular hypoplasia/atrophy (THA) compared to the sham group (P < 0.05), which niacin treatment significantly improved the MTBS and GECT compared to the T/D group (P < 0.05). T/D significantly increased the oxidative stress index (OSI) and lipid peroxidation (MDA) (P < 0.05). Niacin significantly reduced the OSI and MDA levels compared to the T/D group (P < 0.05). DISCUSSION: The current study found that niacin has preventive/therapeutic effects against the elevation of oxidative stress markers and depletion of antioxidants during I/R injury. Following administration of niacin, a reduction in histologic injury was observed in rats. In our study, we showed the antioxidant properties of niacin and its capacity to protect against I/R damage. CONCLUSION: The findings of the present investigation revealed that niacin, as an antioxidant agent, can suppress the oxidative stress induced by testicular I/R injury, and can be used as a supplementary agent in the treatment of those undergoing testicular torsion surgery.