Suppression of Helicobacter pylori-induced gastritis by green tea extract in Mongolian gerbils
Author: Satoshi Matsubara and Hideyuki Shibata and Fumiyasu Ishikawa and Teruo Yokokura and Mami Takahashi and Takashi Sugimura and Keiji Wakabayashi
Since urease of Helicobacter pylori is essential for its colonization, we focused attention on foodstuffs which inhibit the activity of this enzyme. Among plant-derived 77 foodstuff samples tested, some tea and rosemary extracts were found to clearly inhibit H. pylori urease in vitro. In particular, green tea extract (GTE) showed the strongest inhibition of H. pylori urease, with an IC50 value of 13 μg/ml. Active principles were identified to be catechins, the hydroxyl group of 5′-position appearing important for urease inhibition. Furthermore, when H. pylori-inoculated Mongolian gerbils were given GTE in drinking water at the concentrations of 500, 1000, and 2000 ppm for 6 weeks, gastritis and the prevalence of H. pylori-infected animals were suppressed in a dose-dependent manner. Since the acquisition by H. pylori of resistance to antibiotics has become a serious problem, tea and tea catechins may be very safe resources to control H. pylori-associated gastroduodenal diseases.