槲皮素及其代谢物抑制氧化应激与炎症

Quercetin and One of Its Metabolites Inhibit Reactive Oxygen-species and Inflammation

以人脐静脉内皮细胞为试材,用棕榈酸(PA)建立氧化应激与炎症模型,考察槲皮素和其代谢物槲皮素-3-O-葡萄糖醛酸对内皮细胞氧化应激与炎症的抑制作用。结果表明:PA刺激诱发了内皮细胞内的氧化应激反应,导致胞内ROS的增加和线粒体膜电位的下降。槲皮素和槲皮素-3-O-葡萄糖醛酸能有效减少ROS的过量生成并逆转线粒体膜电位下降,从而发挥抑制内皮氧化应激的功能。PA刺激引起内皮细胞中IKKβ与NF-κB的活化并导致炎性因子IL-6和TNF-α的蛋白合成,槲皮素和槲皮素-3-O-葡萄糖醛酸能有效下调IKKβ与NF-κB的磷酸化水平,降低IL-6和TNF-α的蛋白合成,从而发挥抑制内皮炎性反应的功能。因此,槲皮素和槲皮素-3-O-葡萄糖醛酸可以有效抑制内皮细胞的氧化应激与炎性反应。预示含有槲皮素的植物原料与人类健康的关系可能与槲皮素代谢物抑制内皮氧化应激与炎性反应有关。

Human umbilical vein endothelial cells were pretreated with quercetin and its metabolite quercetin-3-O- glucuronide for 30 min, and then incubated with 100 μmol/L palmitic acid. Palmitic acid stimulation led to reactive oxygen species （ROS） production with collapse of mitochondrial membrane potential （ △ψm）. Quercetin and quercetin- 3-O-glucuronide inhibited ROS overproduction and effectively restored △ψm, demonstrating their chemoprotection of mitochondrial function through antioxidative actions. Also, quercetin and quercetin-3-O-glucuronide inhibited ROS- associated inflammation by inhibition of interleukin-6 and tumor necrosis factor-α production with suppression of IKKβ/ NF-kB phosphorylation. Therefore, quercetin and quercetin-3-O-glucuronide can inhibit oxidative stress and inflammation. The results of this study indicate that the relationship between food containing quercetin and human health may be due to the anti-oxidative stress and anti-inflammation activities of its metabolite in the endothelial cells.