Dietary curcumin supplementation relieves hydrogen peroxide-induced testicular injury by antioxidant and anti-apoptotic effects in roosters

Abstract

This study was aimed to investigate the effects of dietary curcumin supplementation on the hydrogen peroxide (H₂O₂)-induced testicular oxidative damage in breeder roosters. Thirty-two 20-week roosters were randomly divided into four groups: (1) basal diet (CON); (2) basal diet with H₂O₂ challenge (H₂O₂); (3) basal diet with 200 mg/kg curcumin (CUR); (4) basal diet with 200 mg/kg curcumin and H₂O₂ challenge (CUR + H₂O₂). The trial lasted for 8 weeks, H₂O₂ challenged groups got an intraperitoneal injection of H₂O₂ at the 50 and 53 days, while the CON and CUR groups received an injection of saline. The results showed that dietary curcumin supplementation significantly decreased abnormal sperm rates in the semen, notably improved seminiferous tubules, increased testis scores, and serum testosterone levels. Curcumin supplementation could also ameliorate the redox damage caused by H₂O₂, by enhancing the capacities of antioxidant enzymes (CAT, GSH-Px, SOD, and T-AOC), and reducing MDA levels. In addition, curcumin normalized the H₂O₂-induced negative effects, which included downregulations in spermatogenesis-related genes (STAR, HSD3-β1, SYCP3, AKT1) and antioxidant genes (HMOX-1, NQO-1), reduced protein expressions of Nrf2, PCNA, and Bcl-2, and increased protein expressions of Caspase 3 and Bax. Moreover, H₂O₂-induced decreased mRNA expressions of EIF2AK3, Caspase3, and BCL-2 were all reversed by dietary curcumin supplementation. In summary, dietary curcumin supplementation could relieve H₂O₂-induced oxidative damage and reproduction decline through the Nrf2 signaling pathway and anti-apoptotic effects in roosters.

Keywords: Antioxidant; Apoptosis; Curcumin; Hydrogen peroxide; Nrf2; Rooster.