茶叶防癌有效成分的筛选一茶多酚类

Screening of active anticarcinogenic ingredients in tea-tea polyphonls

选用一组体外短测指标对茶水冻干物、茶多酚及表没食子儿茶素表没食子酸酯（ＥＧＣＧ），表儿茶素表没食子酸酯（ＥＣＧ），表没食子儿茶素（ＥＧＣ）和表儿茶素（ＥＣ）四种儿茶素的防癌作用进行了检测。研究结果表明，茶木冻干物、茶多酚及四种儿茶素在代表起动阶段的基因突变及微核形成两项指标中，均表现出一定的抑制作用，并有剂量－反应关系。在四种儿茶素中，ＥＣＧ对微核形成的抑制率明显高于其它三种儿茶素。在促癌阶段方面，ＥＣＧ和ＥＧＣＧ对ＴＰＡ抑制Ｖ７９细胞代谢协作具有明显的阻断作用。这两种儿茶素的抗促癌作用在ＢＡＬＢ／Ｃ３Ｔ３细胞转化试验中得到了进一步的证实。以上受试物对癌细胞的体外生长均有抑制作用，但并无特异性。本文结果表明，Ｖ７９细胞基因正向突变和细胞周期阻断法微核试验作为起始阶段指标、Ｖ７９细胞代谢协作试验作为促癌阶段、Ｈｅｌａ细胞存活率及软琼脂生长能力的测定作为癌细胞增殖指标，适用于茶中防癌有效成分的筛检。

Using short-term tes in vitro for screening anticarcinogenic compounds has been an attracting area for cancer chemoprevention, but no systematic studies have been earried out on the efficacy of those teats. In this study,V79 cells gene forward mutation test,V79 cells cytokinesis block micronuclei test,V79 cells metabolic cooperation test and Hela cells growth ability test in soft agar were selected to detect the antimutagenic and cancer cell proliferation inhibition effects of Chinese tea. The active components was analyzed as well. The results show that the water extract of tea(WET) and tea polyphenols(TP) are both effective in inhibiting the mutagenesis of Mitomycin C(MMC), which indicates their effects on the initiation stage. However, the four catechins(EGCG,ECG,EGC and EC) tested also showed inhibition effect on mutagenesis induceds by MMC. Among the four catechins, ECG seems to be more effective in the micronuclei test. Inthe V79 cells metabolic coopoeration test, ECG and EGCG showed strong antipromotion effects. This effects of ECG and EGCG were confirmed in the BALB/C 3T 3 cell transformation test, It is concluded that the four tests mentioned above could be used as a batch of short term tests in screening the antimutagenic and cancer inhibition compounds of Chinese tea.