Cell biology and Raman spectroscopy jointly reveal the dual antioxidative mechanisms of ginsenosides under...

Oxidative stress driven by oxidative macromolecular damage and redox signaling disruption, is a core pathological contributor to multiple sub-healthy states. While ginsenosides are well-documented for their antioxidant properties, the coupling between their membrane-level biophysical interactions and intracellular pathway regulation remains poorly defined. Using cell biology and surface-enhanced Raman spectroscopy, this study elucidates a dual-mechanism framework by which two representative ginsenosides, Ro and Rg1, protect PC12 cells against oxidative damage induced by organic and inorganic peroxides: (1) Nrf2/GPx4 axis activation: Both ginsenosides act as co-substrates in the GPx4 catalytic cycle and upregulate the Nrf2/GPx4 signaling axis, which attenuates mitochondrial membrane depolarization, reduces intracellular ROS and MDA accumulation, and enhances the activity of endogenous antioxidant enzymes including SOD and GR. (2) Structure-dependent membrane interaction: The relatively hydrophobic ginsenoside Ro preferentially partitions into cholesterol-rich ordered membrane domains (lipid rafts), undergoes internalization to ROS-enriched intracellular compartments, and effectively suppresses radical chain propagation and lipid peroxidation. In contrast, the hydrophilic Rg1 is largely retained at the membrane-water interface, with predominant endosomal sequestration or efflux, leading to comparatively weaker antioxidant efficacy. These findings establish a coupled membrane-transcriptional regulatory basis for the dietary and therapeutic applications of ginseng-derived compounds and provide new insight into the cellular bioactivity of saponins.