SCREENINGS TEST OF TRADITIONAL MEDICINAL HERBS FOR BACTERICIDAL ACTIVITY AND THEIR EFFECTS DETERMINATION

Multidrug resistant pathogenic bacteria are an increasing problem that leads to be the difficulty and high cost of treatment. Therefore a novel effective antibiotic is needed. Thai traditional medicinal herbs may be a source of novel drug which have potential antibacterial effect. This study investigated the antibacterial activity of twenty seven Thai medicinal herbal extract using agar diffusion method for screening test and serial dilution method to determined minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). We found that three of them, Garcinia mangostana extract , Mesua ferrea extract and Kaempferia galangal extract showed high antibacterial activity. Among them, Garcinia mangostana extract showed the most potency in inhibition on selected indicator strains. It has strong antibacterial activity against MRSA with low MIC which was at 3.91-7.81 µg/ml and MBC was at 3.91-15.63 µg/ml. Mesua ferrea extract and Kaempferia galangal extract showed MIC and MBC at 15.63-62.50 µg/ml and 125-250 µg/ml respectively. Garcinia mangostana Linn. would be a promising novel antimicrobial agent for MRSA infection. Further study is needed to investigate the bacterial response at molecular level.