Moxibustion prevents tripterygium glycoside-induced oligoasthenoteratozoospermia in rats via reduced oxidative stress and modulation of the Nrf2/HO-1 signaling pathway

Oligoasthenoteratozoospermia (OAT) decreases male fertility, seriously affecting the production of offspring. This study clarified the preventive impact of different moxibustion frequencies on OAT and selected the optimal frequency to elucidate the underlying mechanism. An OAT rat model was constructed by gavage of tripterygium glycosides (TGS) suspension. Daily moxibustion (DM) or alternate-day moxibustion (ADM) was administered on the day of TGS suspension administration. Finally, we selected DM for further study based on sperm quality and DNA fragmentation index, testicular and epididymal morphology, and reproductive hormone level results. Subsequently, the oxidative stress (OS) status was evaluated by observing the OS indices levels; malondialdehyde (MDA), 8-hydroxy-deoxyguanosine (8-OHdG), total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) in testicular tissue using colorimetry and enzyme-linked immunosorbent assay. Furthermore, heme oxygenase 1 (HO-1) and nuclear factor erythropoietin-2-related factor 2 (Nrf2) were evaluated using Western blotting. Immunohistochemistry was employed to locate and assess the expression of HO-1 and Nrf2 protein, while quantitative real-time polymerase chain reaction was utilized to detect their mRNA expression. MDA and 8-OHdG levels decreased following DM treatment, while T-SOD and T-AOC increased, suggesting that DM may prevent TGS-induced OAT in rats by decreasing OS in the testis. Furthermore, protein and mRNA expression of Nrf2 and HO-1 in the testis were elevated, indicating that DM may reduce OS by activating the signaling pathway of Nrf2/HO-1. Therefore, DM could prevent OAT in rats via the Nrf2/HO-1 pathway, thereby presenting a promising therapeutic approach against OAT.