表没食子儿茶素没食子酸酯稳定性研究

Study on the Stability of(-)-Epigallocatechin-3-gallate

目的:解析表没食子儿茶素没食子酸酯((-)-epigallocatechin-3-gallate,EGCG)氧化聚合的环境条件,及其稳定性变化对体外培养细胞系氧化还原平衡的影响,为深入探讨EGCG在细胞培养体系及活体中的作用机制奠定基础。方法:在无细胞体系中,设置不同的环境条件,溶液环境(H 2O、RPMI1640、DMEM)、温度(37和74℃)、EGCG浓度(0、20、40、80、320μmol/L)、反应时间(3、6、12、24 h)、pH(5和9)等,通过检测OD 578值变化评估EGCG在不同条件下氧化聚合的差异;分析EGCG氧化聚合变化对受试细胞内外H 2O 2水平的影响。结果:发现RPMI1640和DMEM培养液较H 2O更利于EGCG的氧化聚合,高温高EGCG浓度及碱性条件促进EGCG氧化聚合,同时EGCG的氧化聚合随反应时间延长而加剧。在含有细胞的培养体系中EGCG也会发生自动氧化聚合并产生H 2O 2,导致细胞内外的H 2O 2浓度升高,但胞内H 2O 2浓度呈现先上升后下降的趋势。结论:溶液环境和pH变化是引起EGCG氧化聚合的关键因素,在细胞培养中20μmol/L的EGCG可通过氧化聚合效应发挥更好的抗氧化活性。

Objective:To analyze the environmental conditions of(-)-epigallocatechin-3-gallate(EGCG)oxidative polymerization and the effects of changes in its stability on the redox balance of the test cells,and to lay the foundation for an in-depth study of the role of EGCG in cell culture systems and living organisms.Methods:The research set different conditions of solution environment,EGCG concentration,temperature,time,pH,to evaluate the difference of EGCG oxidative polymerization under different conditions by detecting the change of OD 578 value.Result:The results showed that RPMI1640 and DMEM medium were more favorable for EGCG oxidation polymerization than H 2O.High temperature and high EGCG concentration and alkaline conditions promoted EGCG oxidation polymerization.At the same time,the oxidative polymerization of EGCG intensified with the extension of the reaction time.In a cell-containing culture system,EGCG also underwent auto-oxidative polymerization and produced H 2O 2,which increased the H 2O 2 concentration inside and outside the cell.However,the intracellular H 2O 2 concentration showed a trend of first increase and then decrease.Conclusion:Solution environment and pH changes are the key factors that cause EGCG oxidative polymerization.20μmol/L EGCG is more conducive to exert antioxidant activity through oxidative polymerization effect in cell culture.