Protective Effect of Gastrodia elata Polysaccharide GEP-2 Against Oxidative Stress in Intestinal Epithelial NCM460 Cells

Oxidative stress in intestinal epithelial cells has been increasingly recognized as a key factor in various intestinal disorders. <i>Gastrodia elata</i> polysaccharide-2 (GEP-2), a water-soluble polysaccharide known for its antioxidant properties, has shown potential against intestinal injury. However, its effects on intestinal epithelial cells and the molecular mechanisms involved are not yet fully understood. In this study, we established a hydrogen peroxide (H₂O₂)-induced oxidative stress model using human colonic epithelial cells (NCM460) to evaluate the protective effects of GEP-2. We assessed cell viability, antioxidant enzyme activities, reactive oxygen species (ROS) levels, and mitochondrial membrane potential (MMP). The results demonstrated that GEP-2 pretreatment significantly improved the viability of NCM460 cells subjected to H₂O₂ damage. Additionally, it could enhance the antioxidant defense, reduce the levels of ROS, malondialdehyde (MDA), and maintain the MMP. Transcriptomic analysis identified 169 differentially expressed genes upregulated in the glutathione metabolism. JAK-STAT pathway and downregulated in inflammation. Furthermore, it was shown that GEP-2 treatment activated the Nuclear factor erythroid 2-related factor 2 (Nrf2)/quinone oxidoreductase 1 (NQO1)-mediated antioxidant response and promoted the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway. Therefore, GEP-2 exerts multi-targeted cell protection by coordinating the Nrf2/NQO1 antioxidant axis and the JAK/STAT survival signaling pathway, providing a theoretical basis for the development of novel antioxidants.