Antioxidant and Hypoglycemic Activity of Polysaccharide from Tea

Abstract

Tea polysaccharide had high antioxidant activity and it could be used to cure diabetes. Antioxidant activity of tea poly-saccharide (TPS) fromthree kinds of tea (green tea, oolong tea and black tea) were compared the result indicated that oolong tea，polysaccharide (OTPS) had the highest antioxidant activity. In order to explicate the mechanismof antioxidant and hypoglycemicactivity, the streptozotocin (STZ)-induced diabetes mice model (DM) was established. The influence of OTPS on blood-glucose,content of MDAand NO, and activities of GSH-PX, SOD, NOS in serum kidney and liver were investigated. The result showed，that after four weeks injection of OTPS to DM mice, the blood-glucose of thre treatment group reduced by 14.5%, 21.5% and33.3%, respectively, comparing to the model control. The reduction efect of OTPS increased with the rise of dose. The activity ofSODandGSH-PXelevatedsignificantly, whiletheactivityof NOSdecreased. Thecontent of MDAandNOreducedsignificantly.The above results imply that antioxidant activity was enhanced. Comparing to XKWtreatment, the effect of a dose of 300mg/(kgbw) OTPS was much better. The research showed that the OTPS had a significant efect on reducing blood glucose, and could en-hance the antioxidant activity of DM mice.Key words- Polysaccharide, Tea, Antioxidant, Activity, Diabetes, Blood glucose