Curcumin Ameliorates Hydrocortisone-Induced Leydig Cell Injury and Testicular Dysfunction by Upregulating the Nrf2 Pathway

Curcumin has antifragmentation, antivirus, anti-infection, and antioxidation properties. Curcumin has been proven to prevent the peroxidation of sperm and testis membranes, thus enhancing sperm motility and reducing sperm abnormalities. This study aims to explore the role of curcumin in improving hydrocortisone (HCT)-induced Leydig cell injury by upregulating the Nrf2 pathway. Thirty male rats were divided into three groups: control group (CG, n = 10), model group (MG, n = 10), and curcumin treatment group (CTG, n = 10). CG rats were fed 2.5 mL/kg carboxymethyl cellulose as a blank control. MG rats were fed with 10 mg/kg HCT for 2 weeks. CTG rats were fed with 10 mg/kg HCT for 2 weeks and 100 mg/kg curcumin orally every day for 4 consecutive weeks. The ultrastructural score of Leydig cells was higher in the MG than in the CG (p < 0.05) and was lower in the CTG than in the MG (p < 0.05). The levels of Nrf2 and HO-1 were lower in the MG than in the CG (p < 0.05) and higher in the CTG than in the MG (p < 0.05). Curcumin can improve the biochemical and histological structural damage of rat testes induced by HCT by upregulating Nrf2 expression. This protective effect relies on the Nrf2 pathway inhibiting oxidative stress in the body, increasing testosterone levels and enzyme activity, thereby improving testicular dysfunction caused by interstitial cell damage.