Investigation of the Effects of Selenium Against 4-Nonylphenol-induced Toxicity in Rat Testis

The study aims to investigate whether selenium (Se) has a protective role against testicular toxicity induced by 4-nonylphenol (4-NP) in rats and reduces oxidative damage. For this purpose, 30 adult male Sprague-Dawley rats (250-300 g/90 days old) were divided into five equal groups: control, sham control, Se, 4-NP, and 4-NP + Se. The trial lasted 48 days, with 4-NP administered at 125 mg/kg/day and Se at 0.5 mg/kg/day. The general microscopic examination of the testicular tissue involved measuring the diameters of seminiferous tubules, epithelial heights, and the density of stage XIV tubules in sections stained with the triple staining method. Caspase 3 and CX43 expressions were observed immunohistochemically, and the numbers of live-dead and normal-abnormal spermatozoa were recorded. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were determined in blood serum and testicular tissue. At the end of the study, testicular toxicity due to 4-NP was demonstrated cytologically, histologically, histometrically, biochemically, and immunohistochemically. Se showed a positive effect against this toxicity, as evidenced by higher stage XIV tubule density in the 4-NP + Se group, lower caspase 3 levels compared to the 4-NP group, decreased MDA levels, increased SOD levels in serum and testicular tissue, and a higher count of live and normal spermatozoa. When used alone, Se may cause metabolic adverse effects, such as decreased live weight gain, reduced tubule diameter and epithelial height, and increased caspase 3 expression, depending on the dose and duration of use.