Duthie G G, Duthie S J, Kyle J A
Division of Cellular Integrity, Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK.
Nutr Res Rev. 2000 Jun;13(1):79-106. doi: 10.1079/095442200108729016.
Certain dietary antioxidants such as vitamin E and vitamin C are important for maintaining optimum health. There is now much interest in polyphenolic products of the plant phenylpropanoid pathway as they have considerable antioxidant activity in vitro and are ubiquitous in our diet. Rich sources include tea, wine, fruits and vegetables although levels are affected by species, light, degree of ripeness, processing and storage. This confounds the formulation of databases for the estimation of dietary intakes. Most attention to date has focused on the flavonoids, a generic term which includes chalcones, flavones, flavanones, flavanols and anthocyanins. There is little convincing epidemiological evidence that intakes of polyphenols are inversely related to the incidence of cancer whereas a number of studies suggest that high intakes of flavonoids may be protective against CHD. In contrast, numerous cell culture and animal models indicate potent anticarcinogenic activity by certain polyphenols mediated through a range of mechanisms including antioxidant activity, enzyme modulation, gene expression, apoptosis, upregulation of gap junction communication and P-glycoprotein activation. Possible protective effects against heart disease may be due to the ability of some polyphenols to prevent the oxidation of LDL to an atherogenic form although anti-platelet aggregation activity and vasodilatory properties are also reported. However, some polyphenols are toxic in mammalian cells. Thus, until more is known about their bioavailability, metabolism and intracellular location, increasing intakes of polyphenols by supplements or food fortification may be unwise.
某些膳食抗氧化剂，如维生素E和维生素C，对于维持最佳健康状态很重要。目前，人们对植物苯丙烷途径的多酚类产物非常感兴趣，因为它们在体外具有相当强的抗氧化活性，且在我们的饮食中普遍存在。丰富的来源包括茶、葡萄酒、水果和蔬菜，不过其含量受品种、光照、成熟度、加工和储存的影响。这使得用于估计膳食摄入量的数据库的制定变得复杂。迄今为止，大多数关注都集中在黄酮类化合物上，这是一个通用术语，包括查耳酮、黄酮、黄烷酮、黄烷醇和花青素。几乎没有令人信服的流行病学证据表明多酚摄入量与癌症发病率呈负相关，而一些研究表明，高黄酮摄入量可能对冠心病有保护作用。相比之下，大量细胞培养和动物模型表明，某些多酚通过一系列机制介导具有强大的抗癌活性，这些机制包括抗氧化活性、酶调节、基因表达、细胞凋亡、间隙连接通讯上调和P-糖蛋白激活。对心脏病可能的保护作用可能是由于一些多酚能够防止低密度脂蛋白氧化成致动脉粥样硬化的形式，尽管也有抗血小板聚集活性和血管舒张特性的报道。然而，一些多酚在哺乳动物细胞中是有毒的。因此，在对它们的生物利用度、代谢和细胞内定位了解更多之前，通过补充剂或食品强化来增加多酚摄入量可能是不明智的。
