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标题：Protective Effect of Green Tea Extract against Reperfusion Injury in Rats
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作者：Nobuaki YAGI ; Toshikazu YOSHIKAWA ; Yuji NAITO 等
期刊名称：Journal of Clinical Biochemistry and Nutrition
印刷版ISSN：0912-0009
电子版ISSN：1880-5086
出版年度：1999
卷号：27
期号：2
页码：89-101
DOI：10.3164/jcbn.27.89
出版社：The Society for Free Radical Research Japan
摘要：The effect of green tea extract on acute gastric mucosal damage induced by ischemia-reperfusion injury was investigated in rats. Ischemia-reperfusion injury was produced by applying a small vascular clamp to the celiac artery for 30min followed by removal of the clamp with reperfusion for 60min. An anti-ulcer effect of the green tea extract was demonstrated in this model. The increase seen in the lipid peroxide level in the gastric mucosa after ischemia-reperfusion was significantly inhibited by the extract. Tissue-associated myeloperoxidase activity, an index of neutrophil accumulation, was increased significantly in the gastric mucosa after reperfusion; this increase of activity was significantly inhibited by the green tea extract and paralleled the increase in the total area of gastric erosions. An electron spin resonance spin trapping study showed that the extract scavenged superoxide radicals generated by the hypoxanthine-xanthine oxidase system and that diphenyl- p -picryl-hydrazyl radicals were also eliminated in a concentration-dependent manner. In an in vitro study, the green tea extract significantly inhibited the increase in lipid peroxide in brain homogenates. Incubation of whole blood cells with interleukin-8 increased the expression of CD11b/CD18 by neutrophils, whereas co-incubation with the extract did not cause this upregulation. Human umbilical vein endothelial cells stimulated with interleukin-1β showed increased expression of E-selectin and intercellular adhesion molecule-1, but co-incubation with the extract significantly inhibited this upregulation. These results suggest that the protective effect of green tea extract against ischemia/reperfusion-induced gastric mucosal injury may be related to its antioxidant activity and inhibition of neutrophil accumulation.
关键词：green tea extract;ischemia-reperfusion injury;superoxide radical;hydroxyl radical;adhesion molecule;neutrophil accumulation