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AIM: To investigate the effect of berberine (Ber) on Helicobacter pylori (Hp)-induced human gastric epithelial cells (GES-1) injury and the underlying mechanism .METHODS: Berberine (5, 10 and 20 μmol/L) and PD98059 (20 μmol/L), a selective inhibitor of extracellular regulated protein kinases (ERK)1/2 signaling pathway, were added to Hp-infected GES-1 cells.The cell activity and apoptosis, the levels of interleukin (IL)-1βand IL-8, lactic dehydrogenase ( LDH) activity and the protein levels of Bax , Bcl-2 and p-ERK1/2 in the GES-1 cells were determined by MTT assay, flow cytometry, ELISA, colorimetry and Western blot, respectively.RESULTS: Compared with control group, Hp significantly inhibited the cell activity , increased the apoptotic rate , LDH activity, IL-1βand IL-8 levels, the Bax and p-ERK1/2 protein levels but decreased the Bcl-2 protein level in GES-1 cells (P<0.05).However, these effects of Hp were reversed by berberine at medium-dose and high-dose, as compared with the Hp-infected GES-1 cells ( P<0.05).Moreover, the protective effects of berberine were significantly enhanced by the co-incubation of berberine with PD98059, as compared with the berberine at higher dose (P<0.05).CONCLUSION:Berberine may attenuate Hp-in-duced human gastric epithelial GES-1 cells injury by anti-inflammation, promoting cell growth and anti-apoptosis via the in-hibition of ERK1/2 signaling pathway .
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Objective To explore the effects of extracellular regulated protein kinase 1/2 (ERK1/2) signal pathway on cardiomyocyte apoptosis and tumor necrosis factor-α (TNF-α) expression at different glucose-lowing rates,and the influence of glucose-lowing rate on cardiomyocyte injury and inflammatory secretion function,as well as its mechanism.Methods Cardiomyocytes of Wistar neonate rat were maintained in medium supplemented with 25 mmol/L glucose for 72 h.Then the medium was changed to different concentrations of glucose and all cells were divided into five groups.Group A was control group whose medium supplemented with 25 mmol/L glucose.Medium of group B,C,D,E was supplemented with 20,15,10,5 mmol/L glucose (glucose-lowing rate was 5,10,15,20 mmol/L) respectively.Survival rate of cardiomyocyte was measured by CCK8 kit.Cardiomyocyte apoptosis was measured by flow cytometry instrument and laser confocal microscope after Annexin V-PI.TNF-α was measured by ELISA.ERK1/2 protein and phosphorylation were measured by Western blot.Cardiomyocyte apoptosis and TNF-α levels were measured again after U0126 was added.Results At the same time point,along with the glucose-lowing rate increased,survival rate of cardiomyocyte in group A was increased and those in group C,D,E were decreased (P＜ 0.05).TNF-α concentration was increased in group B,C,D and decreased in group E.After 24 h,apoptosis rate decreased in group B and increased in group C,D,E (P＜0.05).ERK1/2 phosphorylation level increased in group B,D,and E(P＜0.05).The ERK1/2 phosphorylation level in group B was the lowest.After U0126 was added,survival rates of cardiomyocyte in all groups were increased (P＜0.01) while TNF-α concentrations were decreased (P＜0.05).In every group,survival rate of eardiomyocyte after 48 h was lower than that after 3 h and 24 h,while TNF-α concentration was higher (P＜0.05).Conclusion Influence of glucose-lowering rate for cardiomyocyte apoptosis and TNF-o is caused by ERK1/2 pathway.In the glucose-lowering course,ERK1/2 pathway promotes cardiomyocytes apoptosis and TNF-α secretion is related with not only osmotic pressure,but also ERK1/2 signal pathway activation as well.