茶多酚对二甲肼诱发小鼠大肠肿瘤的抑制作用

用二甲肼诱发ＩＣＲ小鼠大肠癌，同时服用０．４％茶多酚２０周。结果发现茶多酚组结肠肿瘤发生率少于阳性对照组，平均肿瘤数及腺癌百分比均低于阳性对照组；花多酚组小鼠肝微粒体细胞色素Ｐ４５０含量低于阴性对照组和阳性对照组，而肝组织超氧化物歧化酶活性高于阳性对照组，仍低于阴性对照组；茶多酚对小鼠结肠粘膜上皮细胞的增殖指数无明显影响。结果表明，茶多酚对实验性大肠癌有显著的预防作用，其作用机理可能与降低肝脏细胞

Inhibition of Colorectal Carcinoma Induced by 1,2-Dimethylhydrazine in Mice with Tea Polyphe-nols

olorectal cancer was induced by subcutaneous injection.of 1 ,2-dimethylhydrazine(DMH)inmice,and the animals were administered orally with 0.4%of tea polyphenols(TP)simultaneously for20 weeks to study its preventive effects,Results showed incidence of coiorectal cancer in mice adminis-tered with TP was significantly lower than in positive controls(P<0.05),and average nurnber of tu-mor foci and proportion of adenocarcinolna were significantly fewer in TP group than in positive controls(P<0.01).Level of cytochrome P_(450)(CP_(450))in liver microsome of the mice administered with TP waslower than that both in negative and positive controls (P<0.01),and activities of superoxide dismutase(SOD) in liver tissue were higher than those We in positive controls (P<0.01), but lower than in negativecontrols(P<0.01 ).Proliferative index of epithelial cells in mice was not obviously influenced by TP,Itsuggested that TP could have preventive effects on experimental colorental cancer with a possible mecha-nism of lowering CP_(450) and increasing the activity of SOD in the liver.