Cholecalciferol alleviates testicular dysfunction in experimental hyperthyroidism via antioxidant, anti-inflammatory and antiapoptotic effects

This study aimed to investigate the possible protective effect of cholecalciferol against testicular dysfunction in L-thyroxine-induced hyperthyroid rat model. Twenty-four adult male rats were divided into three groups: control, hyperthyroid, and hyperthyroid cholecalciferol treated. At the end of four weeks, serum samples were collected for measurement of thyroid hormones, testosterone, and serum inflammatory markers (interleukin-6 and tumour necrosis factor-alpha). Thereafter, malondialdehyde and antioxidant enzymes were assessed in the testicular homogenate. Also, histological and immunohistochemical studies of the testicular tissues were done. The current results showed lower serum testosterone and testes weight in hyperthyroid rats than control group, with significantly elevated serum inflammatory markers, and disturbed oxidant/antioxidant status in the testicular tissues. This was associated with structural abnormalities. Immunohistochemical study showed upregulation of caspase-3 and downregulation of proliferating cell nuclear antigen (PCNA) in hyperthyroid rats. Cholecalciferol supplementation significantly improved the testicular dysfunction and the testicular pathological features in the hyperthyroid rats. It significantly decreased the levels of serum inflammatory markers and malondialdehyde levels. Also, cholecalciferol supplementation increased the activity of the antioxidant enzymes in the testicular tissue, downregulated caspase-3 and upregulated PCNA in the testicular tissues. Cholecalciferol could ameliorate pathophysiological changes in rat testes of hyperthyroid rats.