Apoptosis-inducing activity of high molecular weight fractions of tea extracts

High molecular weight fractions of green tea, black tea, oolong tea, and pu -erh tea were found to induce apoptosis in human monoblastic leukemia U937 cells by examination of their ability to inhibit cell proliferation and to induce apoptotic body formation and DNA ladder formation. These tea fractio ns were also shown to induce apoptosis in stomach cancer MKN-45 cells. In a ddition to known antitumor-promoting activity of tea high molecular weight fractions, their apoptosis-inducing activity may contribute to canter chemo preventive effects of tea.