中文摘要：

目的：观察茶多糖的抗氧化和抗癌生物活性；方法：采用凝胶过滤法从江西省婺源县出产的粗老绿茶叶中提取、纯化茶多糖，通过β-胡萝卜素-亚油酸氧化体系的抑制试验、DPPH有机自由基清除试验及没食子酸自氧化作用产生超氧自由基的清除试验，研究该茶多糖的抗氧化作用；并采用人体结肠癌细胞（HCT-15、Caco-2）增殖抑制模型（MTT法）研究该茶多糖对人体结肠癌细胞的增殖抑制活性。结果：茶多糖具有明显的抗氧化作用；研究同时发现茶多糖在本实验条件下对不同人体结肠癌细胞增殖抑制活性存在明显差异，其中茶多糖对HCT-15细胞在较低浓度下（7．0μmol／L）便显现起好的增殖抑制活性。结论：茶多糖具有明显的抗氧化和抗癌生物活性。

英文摘要：

Objective： To study the antioxidant activity and anticancer activity of tea polysaccharide. Methods. Tea polysaccharide was extracted and purified by gel permeation chromatography from coarse old green tea leaves obtained from Wuyuan county of Jiangxi province in China. The antioxidant activity of the tea polysaccharide was evaluated by determining the change in absorbancy after heat-induced oxidation in a linoleic acid system with β-carotene, the decoloration of the 1,1-diphenyl-2-picrylhydrazyl and the elimination of superoxide generated from autoxidation of pyrogallol. On the other hand, the anticancer activities of tea polysaccharide at different concentrations were evaluated by MTT assay using two colon cancer cell lines （HCT-15,Caco-2）. Results. Tea polysaccharide possessed distinctive antioxidative activity. The anti-proliferation capabilities of the tea polysaccharide against the tested human colon cancer cell lines were different under the designed experiment conditions. The tea polysaccharide with high purity exhibited good anti-proliferation activity against HCT-15 at concentration of 7.0μmol/L. Conclusion ： Tea polysaccharide has remarkable antioxidative and anticancer bioactivities.