Glycyrrhetinic Acid Attenuates H2O2-induced Oxidation Damage and Apoptosis in Intestinal Epithelial Cells via Activation of PI3K/Akt Signaling Pathway

AbstractOxidative stress inflicts gut dysfunction, which has been recognized as a key driver of intestinal diseases. Therefore, promoting intestinal epithelial cells survival in an oxidative stress environment is vital for the maintenance of human and animal health. Here, we tried to reveal the underlying molecular mechanism that glycyrrhetic acid (GA) protects intestinal porcine epithelial cells (IPEC-J2) cells from oxidative stress-induced cell apoptosis in this study. The results showed that GA could rescue the cell viability through CCK8 assay, and decreased cell apoptosis determined by flow cytometry. GA increases the levels of antioxidant enzymes and downregulate the release of MDA and ROS in H2O2-induced IPEC-J2 cells by cellular barrier assay and ROS immunofluorescence. Next, RNA-sequencing analysis demonstrated that GA could inhibit cell apoptosis through activating the PI3K/Akt signaling pathway. Further verification found that GA could downregulate the mRNA expression and the protein levels of Cytc and p53, while upregulate the protein levels of p-PI3K, p-Akt and Bcl2, as well as upregulating the expression level of p-Akt by immunofluorescence analysis. We speculated that GA could activate the intracellular PI3K/Akt signaling by binding to the membrane receptor VIPR1 through molecular docking analysis. Collectively, these results indicate that the mechanism of rescue cell viability by exerting GA antioxidant effect, which provided a potential strategy for alleviating oxidative stress in human/animals.