Salvianolic acid B attenuates oxidative stress-induced injuries in enterocytes by activating Akt/GSK3β signaling and preserving mitochondrial function

The cellular and tissue damage induced by oxidative stress (OS) contribute to a variety of human diseases, which include gastrointestinal diseases. Salvianolic acid B (Sal B), which is a natural polyphenolic acid in Salvia miltiorrhiza, exhibits prominent antioxidant properties. However, its precise function and molecular mechanisms in protecting normal intestine epithelium from OS-induced damage are still poorly defined. In this study, we tried to clarify this relationship. Here, we found Sal B addiction in the rat intestinal epithelial cell, IEC-6, prevented H2O2-induced cell viability decrease and apoptosis induction, ameliorated H2O2-induced intestinal epithelial barrier dysfunction and mitochondrial dysfunction, and suppressed H2O2-induced production of ROS to varying degrees, ranging from 10% to 30%. Moreover, by employing an ischemia reperfusion model of rats, we also discovered that Sal B treatment reversed ischemia and a reperfusion-caused decrease in villus height and crypt depth, decreased proliferation of enterocytes, and increased the apoptotic index in the jejunum and ileum. Mechanistically, Sal B treatment up-regulated the phosphorylated level of Akt and GSK3β in enterocytes in vitro and in vivo, and PI3K inhibitor LY294002 treatment abrogated the protective effects of Sal B. Meanwhile, the inactivation of GSK3β reversed the oxidative stress-induced apoptosis and mitochondrial dysfunction in IEC-6 cells. Together, our results demonstrated that the damage of intestinal epithelial cells in in vitro and in vivo models were both attenuated by Sal B treatment, and such antioxidant activity might very possibly be attributed to the activation of Akt/GSK3β signaling.