| [ Summary ] |
Recently, several lines of evidence have indicated that gastritis and gastroduodenal ulcers are related to Helicobacter pylori infection. Combination of a proton pump inhibitor, antibiotics and metronidazole is very useful for eradication of this bacterium. However, strains resistant to antibiotics and metronidazole appear frequently. Thus, we examined 27 natural medicines, which have traditionally been used in China, Indonesia, Vietnam and Japan, for in vitro antibacterial activity against H.pylori by the disc method. Among these, the methanol extract of Humulus luplus (female inflorescence), Magnolia Officinalis (bark) and Pachyrrhizus erosus (seeds) significantly inhibited the growth of H.pylori. A detailed study on H.lupulus, as well as activity-guided chemical analysis, led to isolation of an active compound, lupulone(1), from the hexane soluble fraction of its methanol extract. Lupulone(1) showed significant antibacterial activity against three clinically isolated strains including a macrolide resistant strain as well as two standard strains of H.pylori. |