Anti-tumor Effect of Green Tea Catechin on Cancer Cell Lines

Park, Jeong Hyun; Shon, Ho Sang; Sung, Hoon Ki; Liu, Yin; Kim, Joo Young; Sung, Eon Ki; Lee, Yung Chang

Abstract

In this research, the author investigated antitumor effects of green tea catechin on cancer cell lines in various concentrations and durations. Additionally, antitumor mechanism of catechin associated with apoptosis and necrosis, especially their onset and duration were invesigated. Cancer cell lines, L1210 (lymphocytic leukemia), L929 (fibrosarcoma), HepG2 (hepatoblastoma) were used. In each group, intensity of morphological changes and cell damage was observed under inverted, light, confocal and electron microscopes, and MTT and flowcytometric analysis, gel electrophoresis were used to elucidate the effects of catechin after exposure to 1, 10, 100 and 500 microgram/ml catechin until 72 hours. In all cancer cell lines, catechin induced cellular injury and inhibition of proliferation in concentration- and duration-dependent manner. The effects of catechin were the strongestt in L1210 cells and L929 and HepG2 cells in order. Dual phenomena, of apoptosis and necrosis, were shown after catechin treatment. In necrotic cells, cellular swelling, cell organelles destruction, nuclear disintegration and random DNA fragmentation were observed. In apoptotic cells, apoptotic bodies, nuclear and cytoplasmic condensations, periodic DNA fragmentation were seen. In L1210 cells, necrotic and apoptotic cells were co-existed earlier, after exposure to catechin 100 microgram/ml and then apoptosis predom-inated later. In the same concentration, catechin induced apoptosis of L929 cells. but after exposure to 500 microgram/ml catechin, They were involved with apoptosis and necrosis simultaneously. On the other hand, HepG2 cells were damaged less than other cell lines but were involved with necrosis and inhibition of G2/M phase after treatment with 500 microgram/ml catechin. These results suggested that anti-tumor mechanism of catechin, associated with apoptosis, necrosis and cell cycle arrest, were quite different according to cancer type, concentration and duration of catechin treatment. Therefore, much more research would be essential for clinical application of catechin and this study would be the basic source for further study of green tea.