Research On The Mechanism Of Green Tea And Black Tea Made From Duan Jie Pekoe Inhibiting Proliferation And Migration Of HepG2 Cells

Tea originated in China.It is not only a kind of natural beverage.Since ancient times,there has been a tradition of using tea as a medicine.Although it cannot be said that“the medicine of all diseases,” but a large number of scientific research shows that tea has a very good anti-cancer effect.The purpose of this article is to explore the potential therapeutic mechanism of active ingredients in tea for hepatocellular carcinoma.The following three aspects are mainly studied:1.The DuanJie Pekoe,is a clone of the Yunnan big leaf species of tea tree.Through the sensory evaluation results and basic biochemical composition analysis,it can be concluded that the total amount of polyphenols in the DuanJie Pekoe green tea is 14.77%,which is much higher than the 5.62% of the black tea.Polyphenolic compounds are the main functional components of tea,especially catechins EGCG.A large number of studies have shown that EGCG can induce apoptosis,inhibit cancer cell metastasis and infection,and can also regulate various signaling pathways,thus affecting tumors,cell proliferation,metastasis,and invasion.The biochemical composition analysis showed that the content of EGCG was 44.86 mg/g in the DuanJie Pekoe green tea,and the total catechin content was106.20 mg/g.Due to the different production process(mainly the fermentation process)with the green tea,the DuanJie Pekoe Black tea is undergoing a large amount of conversion of polyphenols in the tea,resulting in the production of Theaflavins(TFs),Thearubigins(TRs)and tea browns(TB),etc.Tea pigments become the most important functional components of black tea.The total amount of tea pigments in the DuanJie Pekoe is 9.70%of the dry weight measured by biochemical composition.Black tea pigments exhibit good biological activity,such as scavenging free radicals,antioxidant activity,and anti-tumor activity.2.Next,the antioxidant capacity of DuanJie Pekoe tea was measured by the method of FRAP,DPPH and ABTS+ radical scavenging.The antioxidant activity of black tea and green tea was comprehensively compared.The antioxidant effect of tea is an important research of tea health function,and it is also an important mechanism of lipid-lowering and anti-cancer effects of tea.The results of this study show that: In general,the antioxidant capacity of DuanJie Pekoe Tea is: green tea> black tea,and the antioxidant activity of both teas is dose-dependent within a certain concentration range.3.In the end,the extract of DuanJie Pekoe Tea is studied to explore its effects and mechanism on inducing apoptosis,inhibiting the migration and invasion of human hepatoma cells,The main conclusions are as follows: After treated with DuanJie Pekoe green tea,HepG2 cells became round and chromatin was pyknosis,showing typical apoptotic morphological changes.The results of MTT assay and Coloning formation Assay showed that DuanJie Pekoe tea can inhibit the growth of HepG2 cells in a dose-and time-dependent manner.The mechanism may be inhibition of PI3K/AKT signaling pathway,activation of Caspase-3,up-regulation of pro-apoptotic protein Bax,and down-regulation of anti-apoptotic protein Bcl-2.It also revealed that DuanJie Pekoe tea mediates the cell apoptosis by the mitochondrial pathway(endogenous pathway).In addition,the Scratch Assay and Transwell experiment results showed that the extract of DuanJie Pekoe tea inhibited the migration and invasion of HepG2 cells in a dose-dependent manner,and the inhibition of green tea was more effective than black tea.