Prooxidant activity and cellular effects of the phenoxyl radicals of dietary flavonoids and other polyphenolics
Prooxidant activity and cellular effects of the phenoxyl radicals of dietary flavonoids and other polyphenolics
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DOI：
10.1016/s0300-483x(02)00198-1
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发表时间：
2002-08-01
期刊：
影响因子：
4.5
通讯作者：
O'Brien, PJ
中科院分区：
文献类型：
--
作者：
Galati, G;Sabzevari, O;O'Brien, PJ
膳食中的水果、蔬菜、葡萄酒、香料和草药中的多酚类物质具有有益的抗氧化、抗炎和抗癌作用。然而，我们已经观察到，含有酚环的膳食多酚类物质被过氧化物酶代谢形成促氧化的苯氧基自由基，在某些情况下，这些自由基具有足够的活性，可以氧化谷胱甘肽或NADH，并伴有广泛的氧摄取和活性氧的形成。在谷胱甘肽存在下，多酚类物质经过氧化物酶代谢后，氧活化的催化效果顺序为：根黄素b>根黄素b> 1,2′-二羟基查尔酮b>对香豆酸b>柚皮素b>芹菜素>姜黄素>白藜芦醇>异硫素>辣椒素>山杉酚。抗坏血酸也被苯氧自由基氧化，但没有氧活化。具有儿茶酚环的多酚类物质也与抗坏血酸共氧化，可能是由半醌自由基介导的。对抗坏血酸协同作用的催化效果依次为：非塞汀、木犀草素、槲皮素、bbb、碘二醇、咖啡酸、去氢愈创木酸、bb1、儿茶素、bb2、杉木素、儿茶酚。NADH在没有氧摄取的情况下被化学计量氧化，这表明邻醌代谢物是负责任的。谷胱甘肽没有被共氧化，形成了谷胱甘肽缀合物，可能是由邻醌代谢物介导的。用含酚环的膳食多酚培养肝细胞，发现肝细胞GSH部分氧化为GSSG，而含有儿茶酚环的多酚通过形成GSH偶联物消耗GSH。饮食中含有酚环的多酚类物质也比含有儿茶酚环的多酚类物质更容易氧化人红细胞氧合血红蛋白并引起红细胞溶血。结果表明，含酚环的多酚类化合物通常比含儿茶酚环的多酚类化合物具有更强的抗氧化性。(C) 2002爱思唯尔科学爱尔兰有限公司版权所有。
Dietary polyphenolics in fruits, vegetables, wines, spices and herbal medicines have beneficial antioxidant, anti-inflammatory and anticancer effects. However, we have observed that dietary polyphenolics with phenol rings were metabolized by peroxidase to form prooxidant phenoxyl radicals which, in some cases were sufficiently reactive to cooxidize GSH or NADH accompanied by extensive oxygen uptake and reactive oxygen species formation. The order of catalytic effectiveness found for oxygen activation when polyphenolics were metabolized by peroxidase in the presence of GSH was phloretin > phloridzin > 4,2'-dihydroxy chalcone > p-coumaric acid > naringenin > apigenin > curcumin > resveratrol > isoliquiritigenin > capsaicin > kaempferol. Ascorbate was also cooxidized by the phenoxyl radicals but without oxygen activation. Polyphenolics with catechol rings also cooxidized ascorbate, likely mediated by semiquinone radicals. The order of catalytic effectiveness found for ascorbate cooxidation was fisetin, luteolin, quercetin, > eriodictyol, caffeic acid, nordihydroguaiaretic acid > catechin > taxifolin, catechol. NADH was stoichiometrically oxidized without oxygen uptake which, suggests that o-quinone metabolites were responsible. GSH was not cooxidized and GSH conjugates were formed, likely mediated by the o-quinone metabolites. Incubation of hepatocytes with dietary polyphenolics containing phenol rings was found to partially oxidize hepatocyte GSH to GSSG while polyphenolics, with a catechol ring were found to deplete GSH through formation of GSH conjugates. Dietary polyphenolics with phenol rings also oxidized human erythrocyte oxyhemoglobin and caused erythrocyte hemolysis more readily than polyphenolics with catechol rings. It is concluded that polyphenolics containing a phenol ring are generally more prooxidant than polyphenolics containing a catechol ring. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.