Evaluation Of Wushan Tea Polyphenol Extract Onantioxidant Activity And Protective Effect On Liverinjury And Gastric Injury

Wushan tea is a substitute tea made from the leaves of Malus hupehensis.It is a relatively common natural tea drink which has a variety of physiological functions such as antibacterial,anti-inflammatory,and nourishing the liver and protecting the stomach in Hubei and Sichuan.Polyphenols are the main active ingredients of Wushan tea.In this study,we extracted and purifiedthe polyphenols in Wushan tea,andevaluatedthe antioxidant activity in vitro of Wushan tea by in vitro chemical experiments and cell antioxidant experiments,and established mice liver injury and gastric injury models to verify efficacy and mechanism of action in vivo.The main findings are as follows:1.The polyphenols of Wushan tea was extracted by ethanol extraction,and were extracted by petroleum ether,ethyl acetate and n-butanol.Useing the best extractant which was selected according to the content of polyphenol and the antioxidant activity in vitro to extract the polyphenols of Wushan tea.Then,the extract was purified by HP-20 macroporous resin and its antioxidant activity in vitro was determined.The experimental results showed that the contents of polyphenols in the crude extracts and various parts of Wushan tea are in the following order: ethyl acetate phase > crude extract > butanol phase > water phase(the remaining)> petroleum ether phase,and ethyl acetate phase has the highest polyphenol content which was 378.1 mg/g,1.55 times that of the crude extract.According to the comparison of IC50 values,the order of chemical oxidation resistance in vitro was ethyl acetate phase > crude extract >butanol phase > water phase(the remaining)> petroleum ether phase,and ethyl acetate phase has the strongest antioxidant capacity in vitro.The polyphenols in ethyl acetate phase were purified by HP-20 macroporous adsorption resin,and the content after that increased to 637.5 mg/g obviously,compared with the IC50 value,the antioxidant activity of the purified extract was 2.24~2.88 times that of ethyl acetate,which was equivalent to 0.09~0.38 mg/m L vitamin C(VC).2.The protective effect of Wushan tea polyphenols extract on oxidative damage Hep G2 cells was explored by constructing H2O2 induced oxidative damage model of Hep G2 cells.The experimental results show that Wushan tea polyphenols extract can significantly improve the survival rate of Hep G2 cells induced by H2O2(58.10?67.24?90.16%);can improve the shrinkage and round off of oxidized damaged cells;can significantly reduce the content of ROS and MDA in Hep G2 cells,significantly increase the activities of SOD,GSH-Px,CAT and GSH;can reduce oxidative damage of cellular DNA molecules,alleviate the blockage in the early stage of DNA synthesis(G1 phase)and can reduce the proportion of early-stage apoptosis(20.57%)and late-stage apoptosis(26.65%)of oxidatively injured cells to 6.01% and 2.76%.The above results showed that the purified Wushan tea polyphenols extract has a certain protective effects on oxidative damage of Hep G2 cells.3.To explore the protective effect of Wushan tea extract on hepatic injury in mice,we construct a mice model of acute liver injury induced by CCl4.The experimental results show that gavage of Wushan tea extract canrelieve the increase of liver and spleen index and the pathological changes of liver tissue in mice to a certain degree;significantly reduce AST and ALT levels in serum;significantly reduce MDA levels in serum,increase SOD,CAT and GSH-Px enzyme activity in serum,and significantly increase the expression of SOD1,SOD2,CAT and GSH-Px in the liver of mice at the level of m RNA and protein,enhance the antioxidant capacity of mice to a certain extent and relieve the oxidative stress of the body;significantly reduce TNF-?,IL-6,IL-1? and IFN-? levels in serum and increase the expression of I?B?and decrease the expression of NF-?B,i NOS and COX-2 and alleviate inflammation in mice to a certain degree.The results showed that Wushan tea polyphenol extract can reduce the oxidative stress of mice by increasing the antioxidant capacity of mice,and then reduce the inflammatory response of the body to achieve the prevention of acute liver injury in mice.4.To explore the protective effect of Wushan tea extract on gastric injury in mice,we construct a mice model of acute gastric injury induced by hydrochloric acid/ethanol.The experimental results showed that Wushan tea extract can significantly reduce the serum gastrointestinal hormone MTL,SP content,increase the SS,VIP content,inhibit gastric juice over secretion and gastric juice p H value,significantly reduce the mice gastric lesion area,relieve pathological changes instomach tissue;and significantly reduced the content of MDA,improve the activities of SOD,CAT and GSH-Px in mice gastric tissue,enhance the antioxidant capacity of mice to a certain extent and relieve the oxidative stress of the body;significantly reduced the levels of TNF-?,IL-6,IL-12 and IFN-? in serum,alleviate inflammation in mice to a certain extent.The results showed that Wushan tea polyphenol extract can reduce the oxidative stress of mice by increasing the antioxidant capacity of mice,and then reduce the inflammatory response of the body to achieve the prevention of acute gastricinjury in mice.