Anti-helicobacter pylori effects of propolis ethanol extract on clarithromycin and metronidazole resistant strains

Antimicrobial resistance for Helicobacter pylori infection still become problem in Indonesia especially for metronidazole and clarithromycin resistance that is commonly used in the national regiment therapy. Finding a new antimicrobial agent against this bacterium is still a challenge to face. Propolis extract is well known substance which has antimicrobial effect against some gram-negative bacteria. However, the effect against H. pylori remain unknown. We analysed the antimicrobial effect of propolis extract against H. pylori in clarithromycin and metronidazole Resistant Strains. Anti-H. pylori effect of ethanol propolis extract was tested on 10 types of H. pylori strains isolated from dyspeptic patients in Indonesia. Ethanol propolis extracts (PRO) show inhibitory activity at concentrations of 5% and 10% on all strains H. pylori. Determination minimum inhibitory concentration (MIC) value of propolis extract used microdilution method, the MIC values were in the range of 1024-8192 μg/mL. Determination of the minimum bactericidal concentration (MBC) value is performed by scratch method based on the results of the microdilution test and produces an MBC value in the range of 1024 - 16348 μg/mL. The required concentration of propolis extract for the bactericidal effect against H. pylori was the same or eight-fold higher than the corresponding value. The combination of propolis extract and metronidazole based through paper tape method showed an additive effect, as well as the combination of propolis extract and clarithromycin. This extract might be can become alternative treatment against H. pylori infection that resistance for metronidazole and clarithromycin treatment.