Ginsenoside Re Attenuates D-Galactose-Induced Aging-like Oxidative Stress in Cultured Bovine Oocytes via Activation of the SIRT1/Nrf2 Signaling Pathway

Maternal aging is associated with increased oxidative stress and decreased mitochondrial function, which deteriorate oocyte quality. Ginsenoside Re (GRe), an antioxidant derived from Panax ginseng, has been reported to alleviate cellular damage and extend healthy lifespan. In this study, we investigated the protective effects of GRe on in vitro-matured bovine oocytes and elucidated the underlying mechanisms. Oocyte aging-like oxidative stress conditions were induced by adding 20 mg/mL D-galactose (D-gal) to the in vitro maturation (IVM) medium; GRe treatment involved supplementing the medium with various GRe concentrations (25, 50, and 100 μg/mL). GRe treatment significantly improved maturation, with 50 μg/mL GRe showing the most pronounced effect. This recovery was accompanied by reduced accumulation of reactive oxygen species and improved mitochondrial capacity and biogenesis, mediated by SIRT1/Nrf2 signaling. Consequently, GRe improved embryonic developmental ability. These findings suggest that GRe may improve oocyte quality in the context of aging and associated oxidative stress.