INHIBITORY EFFECTS OF (-)-EPIGALLOCATECHIN GALLATE ON SPONTANEOUS HEPATOMA IN C3H HENCRJ MICE AND HUMAN HEPATOMA-DERIVED PLC/PRF/5 CELLS/

The inhibitory effect of (-)-epigallocatechin gallate (EGCG), a main c onstituent of Japanese green tea, on spontaneous hepatoma in C3H/HeNCr j mice was investigated. A total of 72 mice were divided into three gr oups; the control group without EGCG. and two experimental groups rece iving 0.05% (w/w) or 0.1% EGCG in drinking water. EGCG reduced the inc idence of hepatoma-bearing mice from 83.3% (control) to 56.0% (0.05% E GCG) and 52.2% (0.1% EGCG), and also reduced the average number of hep atomas per mouse from 1.83 (control) to 0.72 (0.05% EGCG) and 0.91 (0. 1% EGCG) at week 65. Ridit analysis of the distribution of the number of hepatomas in each group revealed that EGCG significantly increased the rate of mice without hepatoma in the two EGCG groups as compared t o the control. EGCG did not affect body weight gain, food consumption or any serum biochemical parameter. EGCG inhibited the growth and secr etion of alpha-fetoprotein by human hepatoma-derived PLC/PRF/5 cells w ithout decreasing their viability. These results indicate that EGCG ma y be a practical, nontoxic preventive agent against human hepatoma.