Inhibitory effects of emodin, baicalin, schizandrin and berberine on hef A gene: Treatment of Helicobacter pylori-induced multidrug resistance

AIM: To investigate the inhibitory effects of emodin, baicalin, etc.on the hefA gene of multidrug resistance(MDR) in Helicobacter pylori(H.pylori).METHODS: The double dilution method was used to screen MDR H.pylori strains and determine the minimum inhibitory concentrations(MICs) of emodin, baicalin, schizandrin, berberine, clarithromycin, metronidazole, tetracycline, amoxicillin and levofloxacin against H.pylori strains.After the screened MDR stains were treated with emodin, baicalin, schizandrin or berberine at a 1/2 MIC concentration for 48 h, changes in MICs of amoxicillin, tetracycline, levofloxacin, metronidazole and clarithromycin were determined.MDR strains with reduced MICs of amoxicillin were selected to detect the hefA mR NA expression by realtime quantitative PCR.RESULTS: A total of four MDR H.pylori strains were screened.Treatment with emodin, baicalin, schizandrin and berberine significantly decreased the MICs of amoxicillin and tetracycline against some strains, decreased by 1 to 2 times, but did not significantly change the MICs of clarithromycin, levofloxacin, and metronidazole against MDR strains.In the majority of strains with reduced MICs of amoxicillin, hef A m RNA expression was decreased; one-way ANOVA(SPSS 12.0) used for comparative analysis, P < 0.05.CONCLUSION: Emodin, baicalin, schizandrin and berberine significantly decreased the MICs of amoxicillin and tetracycline against some H.pylori strains, possibly by mechanisms associated with decreasing hefA mR NA expression.

Molecular mechanisms of apoptosis in hepatocellular carcinoma cells induced by ethanol extracts of Solanum lyratum Thumb through the mitochondrial pathway

AIM To explore the induction effects and mechanism of Solanum lyratum Thumb(ST) on human hepatocellularcarcinoma SMMC-7721 cells through the mitochondrial pathway.METHODS The experiments were conducted on three groups: an experimental group (with ST ethanol extracts' concentration being 2.5, 5 and 10 mg/L), a negative control group (with only nutrient solution, 0 mg/L ST ethanol extracts), and a positive control group (2.5 mg/L DDP). The inhibition rate of cell proliferation was checked by using the methyl thiazolyl tetrazolium method, and cell apoptosis was tested by TUNEL method. Furthermore, RT-PCR was used to examine m RNA expression of Fas, Fas L, caspase-8, caspase-3, p53 and Bcl-2 genes.RESULTS Compared with the negative control group, the inhibition and apoptosis rates of the experimental group with different concentrations of ST extracts on human hepatocellular carcinoma SMMC-7721 cells significantly increased(P<0.05). Besides, the m RNA expression of Fas L and Bcl-2 significantly decreased(P<0.05) while the m RNA expression of Fas, caspase-8, caspase-3 and p53 increased significantly. When compared with the positive control group, the experimental groups with 5 mg/L ST ethanol extracts showed effects similar to the positive control group.CONCLUSION ST ethanol extracts induced the apoptosis of hepatocellular carcinoma SMMC-7721 cells through up-regulated Fas, caspase-8, caspse-3 and p53, and down-regulated Fas L and Bcl-2 in the mitochondrial pathway.

Helicobacter pylori isolates from ethnic minority patients in Guangxi:Resistance rates,mechanisms,and genotype

AIM: To investigate the rate of Helicobacter pylori (H. pylori) resistance to clarithromycin among ethnic minority patients in Guangxi, explore the underlying mechanisms, and analyze factors influencing genotype distribution of H. pylori isolates.