AIM To explore the effects of glycyrrhetinic acid on the gastric ulcer rats infected by Helicobacter pylori (Hp) and its action mechanism.METHODS Gastric ulcer rat models were induced by acetic acid stress and then followed by Hp infection.After treatment with low and high doses of glycyrrhetinic acid,the ulcer index,gastric acid and proteinase activities in gastric ulcer rats were analyzed.The effects of glycyrrhetinic acid on the expressions of BCL2 and Caspase-3,the GSK3β activity in gastric mucosa and gastric epithelial cells,and the cell apoptosis level were then detected.RESULTS Glycyrrhetinic acid reduced the ulcer index,gastric acid and proteinase activities in rats.Besides,the expression of BCL2 was significantly up-regulated by glycyrrhetinic acid in gastric mucosa and gastric epithelial cells,whereas the expression of Caspase-3,level of cell apoptosis,and GSK3β activity were significantly reduced.After the treatment with GSK3 β activator LY294002,the level of BCL2 was down-regulated,Caspase-3 expression was increased,and the level of cell apoptosis was enhanced.CONCLUSION Glycyrrhetinic acid promotes the healing of gastric ulcer infected by Hp via regulating GSK3β activity and inhibiting apoptosis of gastric epithelial cells.

[ ABSTRACT] AIM:To investigate the effect of artemisinin on lipopolysaccharide ( LPS)-induced intestinal epi-thelial barrier damage in IEC-6 cells and its molecular mechanism.METHODS:Cultured IEC-6 cells were divided to 5 groups:control group, LPS (100 mg/L) group and LPS +Artemisinin (30, 50 and 100μmol/L) groups.The cytotoxici-ty was detected by MTT assay.The releases of TNF-α, IL-1βand IL-6 in the IEC-6 cells were measured by ELISA.The transepithelial electrical resistance ( TER) was detected by electrical resistance tester, and the horseradish peroxidase (HRP) flux permeability were analyzed by a microplate reader.The expression of tight junction proteins, ZO-1, claudin-1 and occludin, and the expression of TLR4/MyD88/NF-κB at mRNA and protein levels were determined by RT-qPCR and Western blot.RESULTS:Artemisinin alone (up to 100 μmol/L) or in combination with LPS (100 mg/L) was not toxic to IEC-6 cells.Compared with control group, the releases of TNF-α, IL-1βand IL-6 in the culture supernatant of IEC-6 cells significantly increased after treatment with LPS.The expression of TLR4/MyD88/NF-κB was activated by LPS.LPS down-regulated the protein expression of ZO-1, claudin-1 and occludin.However, artemisinin treatment decreased the re-leases of TNF-α, IL-1βand IL-6 in the culture supernatant of IEC-6 cells.The expression of TLR4/MyD88/NF-κB at mR-NA and protein levels was gradually reduced after treatment with artemisinin.In addition, artemisinin upregulated the pro-tein expression of ZO-1, claudin-1 and occludin significantly (P<0.01) in a dose-dependent manner.CONCLUSION:Artemisinin attenuates LPS-induced intestinal epithelial barrier damage by inhibiting TLR4/MyD88/NF-κB activation in the IEC-6 cells.