The Efficacy Of Sarcandra Glabra Extract Alone Or Combined With Antibiotics Against Helicobacter Pylori In Vitro

Background and objective:Helicobacter pylori(H.pylori) is thought to be responsible for a number of prevalent gastrointestinal diseases.Eradication of H.pylori can prevent the development of H.pylori related diseases.However, antimicrobial resistance has limited the efficiency of current anti-H.pylori therapies consisting an acid-suppressive drug or a bismuth component with two or more antibiotics. Prolonging the duration,increasing the dosage and adding other antibiotics( such as sequential regimen,concomitant regimen and hybrid regimen) has been considered to improve the eradication rate of H.pylori. But the eradication rates with these regimens have generally declined to unacceptable levels because of increasing resistance to antibiotics. Consequently, the development of new drugs such as traditional Chinese medicine has been a focus. Sarcandra glabra is a natural traditional Chinese medicine grass coral which has anti- inflammatory and broad-spectrum antibacterial effect. But whether Sarcandra glabra can help eradicate H.pylori has not been reported. So we conducted this research to evaluate the effect of sarcandra glabra extract(SGE) on H.pylori(drug resistant strains especially) and the interaction between SGE and other six antibiotics recommended by consensus with agar dilution method. Moreover, we also observed the extravasation of H.pylori after administrated with SGE to find out the possible anti-H.pylori mechanisms and furnish the theoretic foundation and experimental evidence for further research.Method:1、H.pylori isolates: A total of 32 H.pylori isolates which are resistant to six antibiotics(A-amoxicillin,C-Clarithromycin,M-metronidazole,L-Levofloxacin,T-tetracycline and F- furazolidone)recommended by consensus were selected form 653 isolates which has been already conducted susceptibility test(E-test or Kirby Bauer drug sensitivity test) over a period of 4 years(2010 to2013). Among these 32 H.pylori isolates, 8 isolates were resistant to three or more antibiotics. 16 H.pylori strains were double resistance. 8 isolates were monoresistance.2、The minimal inhibitory concentrations(MICs) of antibiotics were determined using agar dilution method.3、The MICs of SGE were detected with agar dilution method.4、Interaction between SGE and other six antibiotics: Different concentrations of two kinds of antibacterial drugs were diluted with checkerboard method and the MICs of SGE when combined with antibiotics or administrated alone were detected by agar plate method. Fractional inhibitory concentration index(FICI) was calculated to evaluate the interaction. FICI≤0.5 indicates synergism, 0.5<FICI≤1indicates additive,1<FICI≤2 indicates independent action and FICI>2 indicates antagonism.5、The effect of SGE on H.pylori outer membrane: 1 multiple drug resistance isolate and 1 sensitive isolated were selected. The level of glucose and activity of aspartate amino transferase were assessed after the two isolates incubated for 24 h at concentrations of 95 ug/ml of SGE. The experiment was repeated twice.Results:1、The MIC values to SGE ranged from 11.9~47.5μg/ml.2 、 The interaction between SGE and other six antibiotics :(1)SGE+A :FICI≤0.5(80%),0.5<FICI≤1(20%);(2)SGE +M:FICI≤0.5(70%),0.5<FICI≤1(30%);(3)SGE+L:FICI≤0.5(60%),0.5<FICI≤1(40%);(4)SGE+F:FICI≤0.5(90%),0.5<FICI≤1(10%);(5)SGE+T:FICI≤0.5(90%),0.5<FICI≤1(10%);(6)SGE +C:FICI ≤0.5(80%),0.5<FICI≤1(20%)。3 、 The level of glucose and activity of aspartate amino transferase were significantly different higher in SGE group than in control group(P < 0.01) no matter using resistant isolate or sensitive isolate.Conclusion:1、SGE has significant inhibitory effect on antibiotic resistant H.pylori strains in vitro.2、Synergism and additivity of SGE combined with antibiotics were the maininteractions, synergism mostly.3、SGE can damage the H.pylori outer membrane barrier, which may be the mechanism of anti-H.pylori effect and the synergism combined with antibiotics.