Protective effect of dioscin against intestinal ischemia/reperfusion injury via adjusting miR-351-5p-mediated oxidative stress.

Oxidative stress plays important roles in intestinal ischemia-reperfusion (II/R) injury, and exploration of effective lead compounds against II/R injury via regulating oxidative stress is necessary. In this study, the effects and possible mechanisms of dioscin against hypoxia-reoxygenation (H/R) injury in IEC-6 cells and II/R injury in mice were investigated. The results showed that dioscin markedly increased cell viability, and reduced ROS level caused by H/R injury in IEC-6 cells. in vivo, dioscin significantly reduced the levels of MDA, MPO and chiu' score, increased SOD level, and improved pathological changes caused by II/R injury in mice. Mechanism investigation showed that dioscin markedly up-regulated the expression levels of Sirt6 by decreasing miR-351-5p levels, decreased the expression levels of p-FoxO3α via activating AMPK, and increased the expression levels of MnSOD and CAT. In addition, miR-351-5p mimic in IEC-6 cells and agomir in mice increased ROS levels and aggravated II/R injury. MiR-351-5p inhibitor in IEC-6 cells and antagomir in mice alleviated these actions by adjusting Sirt6 signal pathway. MiR-351-5p interference experiment further confirmed that dioscin increased Sirt6 expression level by down- regulating miR-351-5p level to inhibit oxidative stress and reduce II/R injury. Furthermore, we also demonstrated that dioscin inhibited the expression level of miR-351-5p via reducing TRBP expression level during the generation of miR-351-5p mature body. Dioscin showed protective effect against II/R injury via adjusting miR- 351-5/Sirt6 signal to reduce oxidative stress, which should be considered as one potent candidate to treat II/R injury. In addition, miR-351-5/Sirt6 could be one effective drug target against II/R injury.