Glycyrrhizin suppresses oxidative stress injury in ulcerative colitis through Nrf2/HO-1 signaling pathway
Objective To investigate the effect of glycyrrhizin(GL)on oxidative stress in ulcerative colitis(UC)and its relation with nuclear factor erythroid-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway.Methods HT-29 cells were randomly divided into normal group,model group and low,medium and high GL concentration group.The oxidative stress model was induced in HT-29 cells by adding 0.8 mmol/L H2O2 in culture media,and the model cells were treated with 0.5,1.0,and 2.0 mmol/L concentration of GL for 24 h.The cell viability was detected by cell counting kit-8 method,the level of reactive oxygen species(ROS)was detected,and the protein expressions of HO-1,Kelch-like ECH-associated protein 1(Keap1),and Nrf2 were detected by Western blot.Twenty-four SD rats were divided into normal,model and GL intervention groups,with 8 rats in each group.The UC was induced by adding 5％dextran sulfate sodium salt in drinking water in model and GL intervention groups.The disease activity index(DAI)and tissue damage index(TDI)of rats were observed;rats were sacrificed at the end of the experiment,the length of colon was measured,and the levels of superoxide dismutase(SOD)and malondialdehyde(MDA)in colon tissues were detected;and the expressions of HO-1,Keap1 and Nrf2 in colon tissues were detected by Western blot.Results Compared with the model cell group,the cell survival rate was increased in the low,medium and high GL concentration groups(all P＜0.05),the intracellular ROS level was decreased(P＜0.05),the expression of HO-1 and Nrf2 was increased in medium and high GL concentration groups(all P＜0.05);while the expression of Keap1 in the medium and high GL concentration groups decreased(both P＜0.05).Compared with the model rats,DAI and TDI decreased(both P＜0.05),colon length was longer(P＜0.05),SOD level in colon tissue increased(P＜0.05),MDA level decreased(P＜0.05),Nrf2 and HO-1 expression significantly increased(both P＜0.05),and Keap1 protein expression decreased in the GL intervention rats(P＜0.05).Conclusion GL may suppress oxidative stress-induced injury by modulating the Nrf2/HO-1 signaling pathway,to exert therapeutic effects on ulcerative colitis.
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维普
