Paeoniflorin restores redox homeostasis in oxidatively challenged C2C12 myoblasts via activation of the Nrf2/HO-1 pathway

Abstract

Oxidative stress is a key contributor to myoblast injury and disrupts musculoskeletal homeostasis by impairing muscle differentiation. Paeoniflorin, a bioactive monoterpene glycoside derived from medicinal plants, e.g., Paeonia lactiflora, has demonstrated diverse pharmacological activities. This study explored paeoniflorin’s capacity to alleviate oxidative stress–induced damage in skeletal muscle precursor cells. C2C12 murine myoblasts were preincubated with noncytotoxic concentrations of paeoniflorin before hydrogen peroxide exposure to establish an oxidative stress model. Paeoniflorin significantly improved cell viability under oxidative conditions and reduced DNA damage, as demonstrated by decreased comet tail formation and γH2AX protein accumulation. It also attenuated apoptotic cell death by limiting caspase activation and preventing mitochondrial dysfunction, including cytochrome c release into the cytosol. Mechanistically, paeoniflorin suppressed intracellular reactive oxygen species (ROS) levels while enhancing activation of the redox-sensitive transcription factor nuclear factor erythroid 2–related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1). Importantly, inhibition of HO-1 activity using zinc protoporphyrin significantly diminished paeoniflorin’s antioxidative and cytoprotective effects, as evidenced by restored ROS accumulation, mitochondrial disruption, DNA damage, and apoptosis. Collectively, these findings indicate that paeoniflorin enhances resistance to oxidative stress in myoblasts through Nrf2/HO-1 pathway activation, thereby preserving genomic stability and mitochondrial function. These results support a potential role for paeoniflorin in maintaining muscle cell homeostasis under oxidative stress.