PSJ Web Site
J-STAGE
  Software Requirements
Microsoft Internet Explorer 5.01 or higher and Netscape Navigator 4.75 or higher are recommended.


J.Health Sci., 54(1), 81-88, 2008

Inhibitory and Killing Activities of Medicinal Plants against Multiple Antibiotic-resistant Helicobacter pylori

Supayang Piyawan Voravuthikunchai*, a and Hazel Mitchellb

aNatural Products Research Center and Department of Microbiology, Faculty of Science, Prince of Songkla University, 15 Kanchanawanich Road, Hat Yai, Songkhla 90112, Thailand and bThe Australian Helicobacter Reference Laboratory, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Biological Sciences Building Upper Kensington Campus. Cnr Botany/High Sts Randwick, Sydney, NSW 2052, Australia

Multiple antibiotic-resistant Helicobacter pylori (H. pylori), one of the major causes of gastric cancer, is now increasingly reported. The aim of this study was to screen medicinal plants widely used in Thailand as possible sources of medicines that can be used to treat H. pylori infection. Twenty-four extracts from 13 kinds of Thai herbs were tested for their antibacterial activity against 20 strains of antibioticresistant H. pylori. Inhibition of growth was tested by the paper disc agar diffusion method. Most strains of H. pylori examined were proved to be susceptible to seven medicinal plants; i.e., Peltophorum pterocarpum, Piper betle, Punica granatum (P. granatum), Quercus infectoria (Q. infectoria), Tamarindus indica, Uncaria gambir, and Walsura robusta. Among these extracts, P. granatum and Q. infectoria exhibited the greatest inhibitory potencies. Minimal inhibitory concentrations (MIC) were determined by the agar dilution method in Petri dishes with a Millipore filter membrane, and minimal bactericidal concentrations (MBC) were assessed with the extract that gave a significant MIC value against each bacterial strain by placing the Millipore filter membrane onto a fresh Isosensitest agar plate. Ethanolic extracts of P. granatum and Q. infectoria significantly reduced the growth of all strains of H. pylori, with the best MIC values at 0.8 and 3.1 mg/ml, and the best MBC values at 3.1 and 6.2 mg/ml, respectively. Effective fractions partially purified from both plant species yielded MICs and MBCs that were at least 10-fold less compared with the crude extracts. From the data obtained, it is hoped that P. granatum and Q. infectoria will become useful sources with which to develop new therapeutic agents for H. pylori infection.