Department of Toxicology, Maastricht University, Maastricht, The Netherlands.
Eur J Pharmacol. 2013 Sep 5;715(1-3):147-53. doi: 10.1016/j.ejphar.2013.05.029. Epub 2013 Jun 4.
Accumulating evidence suggests that foods rich in flavanols decrease the risk of developing cardiovascular diseases. Attenuation of oxidative stress was suggested to contribute to the cardiovascular benefit of flavanols. Up to now it was unclear whether flavanol metabolites can also protect cells from oxidative stress. The aim of the present study was to determine the potential contribution of several glucuronidated, methylated and sulfated metabolites of (-)-epicatechin (EC) and (+)-catechin (Cat) to the protection of human vascular endothelial cells (HUVECs) against oxidative stress. The relative potency of the tested compounds to scavenge superoxide anion radicals showed that a free catechol moiety in the molecule is important for the direct antioxidant activity. EC and Cat (0.5, 1, 10µM) were potent radical scavengers and provided protection against intracellular oxidative stress induced by hydrogen peroxide. Although the metabolites provided less intracellular protection compared to EC and Cat, the tested methylated and glucuronidated metabolites reduced oxidative stress significantly in HUVECs. Our results indicate that the metabolites have a relevant contribution in the intracellular protection of EC and Cat against oxidative stress. Also, the direct antioxidant activity plays an important role in this protection.
越来越多的证据表明，富含黄烷醇的食物可以降低患心血管疾病的风险。氧化应激的减轻被认为是黄烷醇对心血管有益的原因之一。到目前为止，还不清楚黄烷醇代谢物是否也能保护细胞免受氧化应激。本研究的目的是确定几种（-）-表儿茶素（EC）和（+）-儿茶素（Cat）的葡萄糖醛酸化、甲基化和硫酸化代谢物对保护人血管内皮细胞（HUVEC）免受氧化应激的潜在贡献。测试化合物清除超氧阴离子自由基的相对效力表明，分子中游离的儿茶酚部分对于直接抗氧化活性很重要。EC 和 Cat（0.5、1、10µM）是有效的自由基清除剂，并能提供针对过氧化氢诱导的细胞内氧化应激的保护。尽管与 EC 和 Cat 相比，代谢物提供的细胞内保护较少，但测试的甲基化和葡萄糖醛酸化代谢物可显著减轻 HUVEC 中的氧化应激。我们的结果表明，代谢物在 EC 和 Cat 抵抗氧化应激的细胞内保护中具有相关作用。此外，直接的抗氧化活性在这种保护中起着重要作用。
