几种茶多糖降血糖活性的研究

研究和对比白茶多糖（White tea polysaccharide,WTP）、绿茶多糖（Green tea polysaccharide,GTP）和红茶多糖（Black tea polysaccharide,BTP）的成分、降血糖效果及机理。分别选取寿眉、龙井、白琳工夫作为白茶、绿茶和红茶的代表,测定分析茶多糖提取物的成分和分子量。以链脲佐菌素诱导小鼠糖尿病模型,二甲双胍作为阳性对照,研究茶多糖降血糖效果,qPCR测定小鼠肝脏中相关基因表达水平。结果表明,所选白茶、绿茶和红茶多糖的绝对重均分子量分别为18 180、19 470、8 745 Da。所选茶多糖提取物均具有降血糖功效,白茶、绿茶和红茶多糖干预组小鼠的血糖下降率分别为53.2%、52.8%及61.6%。茶多糖均可改善小鼠葡萄糖耐量,调节糖代谢相关基因表达,并且存在一定差异。

Comparative Study on the Structure and Hypoglycemic Activity of Several Tea Polysaccharides

To study and compare the composition, blood sugar lowering effect and composition of WTP, GTP and BTP. Shoumei, Longjing and Bailingongfu were selected as representatives of white tea, green tea and black tea, and the composition, molecular weight of tea polysaccharides were determined. The mice diabetes model was induced by streptozotocin, metformin was used as a positive control to study the hypoglycemic effect of tea polysaccharides, and qPCR was used to determine the expression level of related genes in mice liver. The results showed that the molecular weights of WTP, GTP and BTP are 18 180 Da, 19 470 Da and 8 745 Da, respectively. The selected tea polysaccharides have hypoglycemic effect, the fasting blood glucose decline rates of WTP, GTP and BTP were 53.2%, 52.8% and 61.6%, respectively. Tea polysaccharides can all improve glucose tolerance, down-regulate the expression of Foxo1, G6Pc, PEPCK and TXNIP genes in mice and there are some differences.