文章基本信息

标题：Effect of Plant Phenolics on the Formation of the Spin-Adduct of Hydroxyl Radical and the DNA Strand Breaking by Hydroxyl Radical
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作者：Kazuyuki HIRAMOTO ; Natsuko OJIMA ; Ken-ichi SAKO 等
期刊名称：Biological and Pharmaceutical Bulletin
印刷版ISSN：0918-6158
电子版ISSN：1347-5215
出版年度：1996
卷号：19
期号：4
页码：558-563
DOI：10.1248/bpb.19.558
出版社：The Pharmaceutical Society of Japan
摘要：The effect of plant phenolics, including flavonoids and green tea polyphenolics, on hydroxyl radical was examined by a common method using an electron spin resonance (ESR) technique with 5, 5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trapping agent. The intensity of the ESR signals of DMPO-OH adduct formed by the interaction of DMPO with Fenton reagent was reduced in the presence of each phenolic in a dose-dependent manner. However, the decrease in the intensity of the signals was due partly to the enhanced disappearance of the spin adduct by the phenolics, as has been previously shown. This spin trapping method was unreliable for evaluation of the effect of the phenolics against hydroxyl radical. Hydroxyl radical induced-DNA single-strand breaks may be a better index for evaluation of the activity of the phenolics regarding hydroxyl radical. The effect of the phenolics on DNA single-strand breaks induced by Fenton reagent was examined. While sesamol and esculetin were inhibitory, most polyphenolics, especially (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG), were rather stimulatory. The results indicate that sesamol and esculetin scavenged hydroxyl radical, and EGC and EGCG generated hydroxyl radical under the conditions where hydroxyl radical was generating.
关键词：hydroxyl radical;plant phenolic;ESR-spin trapping;DNA strand breaking