EGCG抗兔晶状体上皮细胞增殖机制中p38激酶作用的研究

目的:研究p38激酶在绿茶提取物中的表没食子儿茶素没食子酸酯[(-)-Epigallocatechin-3-gallate,EGCG]抗晶状体上皮细胞增殖机制中的作用。 方法:用噻唑蓝比色法(MTT比色法)研究p38的特异性抑制剂SB203580对EGCG抑制晶状体上皮细胞增殖作用的影响;用Western Blot法研究EGCG对p38激酶的磷酸化和非磷酸化水平的影响。 结果:(1)预先加入25μmol/L,50μmol/L的SB203580孵育1h后,100μmol/L EGCG对晶状体上皮细胞增殖的抑制率低于对照组,但这种差别没有统计学上的意义(P>0.05);200μmol/L EGCG组对晶状体上皮细胞的抑制率低于对照组,有统计学的意义(P<0.05);(2)在晶状体上皮细胞,磷酸化的p38基础水平很低。p38的磷酸化水平随EGCG浓度的增加逐渐增加,而非磷酸化的p38的水平与基础水平一样保持不变。以200μmol/L EGCG作用15min来研究其对p38的磷酸化和非磷酸化影响的时-效规律发现,加药后初期,p38的磷酸化水平很高,随后逐渐下降。同时,非磷酸化p38的水平保持不变。 结论:(1)EGCG对晶状体上皮细胞的增殖抑制作用可能通过p38通路;(2)EGCG对p38影响主要在于调节蛋白激酶的磷酸化与去磷酸化水平,不影响总蛋白含量。眼科学报 2003;19:236-238。

Role of p38MAPKs Pathway in the Growth Inhibition of Rabbit Lens Epithelial Cells Induced by EGCG

PURPOSE: Study the role of p38MAPKs pathway in the growth inhibition of rabbit lens epithelial cells(LECs) induced by green tea extract (-)-Epigallocatechin-3-gallate (EGCG). METHODS: (1) MTT colormetric assay was used to study the effect of p38 specific inhibitors SB203580 on LECs growth. (2) MTT colormetric was used to study the effect of SB203580 on LECs growth inhibition induced by EGCG. (3) Western blotting methods was used to study the effect of EGCG on the kinase phosphorylation- and nonphosphorylation-level of p38. RESULTS: (1) When LECs were preincubated with 25 mumol/L, 50 mumol/L SB203580 for 1 h, 100 mumol/L EGCG had little influence on LECs proliferation. It showed great protects effect significantly when increased to 200 mumol/L. (2) Basic phosphorylation-level of p38 were very weak in LECs, but it increased with EGCG concentration increased and reached maximum at 200 mumol/L. 15 min after 200 mumol/L was added, the phosphorylation-level was the highest and began to fall, but even at the end of our test, it still stayed higher than that of basic level. The nonphosphorylation-level of p38 remained stable in all test. CONCLUSIONS: The LECs proliferation inhibition induced by EGCG is through p38 pathway at lease partially.