绿茶多酚对自由基诱导的红细胞膜过氧化的抑制作用

Protective Effects of Green Tea Polyphenols Against Free Radical Initiated Peroxidation on Erythrocyte Ghosts

采用水溶性偶氮引发剂2,2′-偶氮二(2-脒基丙烷)二盐酸盐(AAPH)在37℃引发人血红细胞膜的过氧化,通过测定氧气吸收及维生素E的消耗研究了过氧化过程的动力学,并对从绿茶中提取的主要多酚类化合物的抗氧化活性做了定量研究.使用的绿茶多酚有:(-)-表儿茶素(EC),(-)-表棓儿茶素(EGC),(-)-表儿茶素棓酸酯(ECG)和(-)-表棓儿茶素棓酸酯(EGCG).结果表明,这些绿茶多酚能够显著缩短过氧化反应的动力学链长,有效地抑制红细胞膜的过氧化.抗氧化活性顺序为:EC>ECG>EGCG>EGC.

Peroxidation of human erythrocyte ghosts was initiated by a water-soluble fine radical initiator 2,2 ' -azo (2-amidinopropane) dihydrochloride (AAPH). The peroxidation was monitored by oxygen uptake and consumption of vitamin E. It was found that the peroxidation was inhibited by the principal polyphenolic components extracted from green tea leaves, i. e. ( - ) epicatechin (EC), ( -) -epigallocatechin (EGC), ( - )-epicatechin gallate (ECG), and ( - )-epigallocatechin gallate (EGCG). Kinetic analysis of the antioxidation process demonstrated that these green tea polyphenols could significantly shorten the kinetic chain length of the peroxidation and inhibit the peroxidation of erythrocyte ghosts with the activity sequence of EC > ECG > EGCG > EGC.