Antibacterial action of tryptanthrin and kaempferol, isolated from the indigo plant (Polygonum tinctorium Lour.), against Helicobacter pylori-infected Mongolian gerbils - Kataoka,M.; Hirata,K.; Kunikata,T.; Ushio,S.; Iwaki,K.; Ohashi,K.; Ikeda,M.; Kurimoto,M. (Journal of Gastroenterology, 2001)