Study On The Liver Protective Effects And Hypoglycemic And Synthesis Of The Oligosaccharide Repeating Unit Of Tea Polysaccharide

Tea is an ancient traditional drink in China. Tea has become a necessity indaily life. Tea polysaccharide is one of the most important active ingredient of tea. A large number of studies have shown that it has many biological functions such as anticoagulant. It can reduce blood sugar, hematic fat, blood perssure. It also can protect the liver and enhance the body’s immune function.To go into details of tea polysaccharide, the researchers on the one hand, though pharmacological experiments to explore the mechanism of biological activity, on the other hand, through the method of extraction and separation, and chemical synthesis for the activity of tea polysaccharide which plays a biological structure foundation, expecting to make better use of tea polysaccharide. In recent years, the active functions of tea polysaccharide in diabetes and liver protection have received extensive attention of the researchers, but its functional structure is still unclear.Based on the extracted tea polysaccharide from green tea, respectively by cell experiments and animal experiments, we manage to explore its function of reducing blood sugar and protecting the liver. We used Min6 cells which resist insulin, through the glucose consumption experiment, to explore the hypoglycemic effect of tea polysaccharide. The results show that 100 mg/L of tea polysaccharide can effectively increase the insulin consumption of Min6 cells. In another experiment, we tried to explore the liver protection effect of tea polysaccharide. First, Kunming mice were injected 6.4 g/kg bw of alcohol of acute alcoholic at one time, thus causing liver damage. At last, the results show that the 50mg/kg and 100 mg/kg and 200 mg/kg of tea polysaccharide can significantly reduce the acute alcoholic liver injury in mice- serum by reducing alanine aminotransferase(ALT) and aspertate aminotransferase(AST), and at the same time improve the activity of glutathione(GSH), and reduce lipid peroxidation end-products of malondialdehyde(MDA).All the above show that tea polysaccharide can play a role on liver protection by reducing oxidative stress.Studying the main biological structure of tea polysaccharide that improve insulin resistance and alcoholic liver injury will lead to more through research and wider usage.Many scientists have offerrd the main structure. After studying their papers, we synthesied compound 4-O-(α-L-rhamnopyranosyl)-D-galactopyranose, the repeating structural unit of tea polysaccharide, using NMR, mass spectrometry characterization. At the same time, alcoholicliver injury were studied and the results show that its vitro antioxidant activity, can reduce alcoholic liver injury by oxidative stress, so as to protect the liver function. This study is to establish structure-activity relationship of tea polysaccharide to improve insulin resistance and alcoholic liver injury and provides the material basis. At the same time, the improvement of insulin resistance and alcoholic liver injury were studied, results showed that the inhibition of oxidative stress in alcoholic liver injury, so as to achieve the role of protecting the liver. This study is to explore the way tea polysaccharide improves insulin resistance and alcoholic liver injury and also provides its main structure modification with material basis.