The dietary intake of flavonoids seems to be inversely related to cardiovascular mortality. The consumption of isoflavonoids is increasing in the general population, especially due to the use of food supplements and a variety of isoflavonoid-rich foods. However, detailed studies on the vascular influence of individual pure isoflavonoids are mostly missing. For this study, 16 isoflavonoids were initially screened for their vasorelaxant properties on rat aortas. The 2 most potent of them, biochanin A and glycitein, were further tested for the mechanism of action on porcine coronary arteries. They both induced an endothelium independent vascular relaxation, with EC50 below 6 and 17 µM, respectively. Biochanin A, but not glycitein, was able to block the vasoconstriction caused by KCl, CaCl2, serotonin, and U46619 in a dose-dependent manner. Another series of experiments suggested that the major mechanism of action of biochanin A was the inhibition of L-type calcium channels. Moreover, biochanin A in relatively small concentrations (2 - 4 µM) interfered with the cGMP, but not cAMP, pathway in isolated coronary arteries. These results indicate that some isoflavonoids, in particular biochanin A, are able to have vasodilatory effects in micromolar concentrations, which is of potential clinical interest for the management of cardiovascular pathologies.

中文翻译：

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Biochanin A 是 16 种异黄酮中最有效的，通过钙通道和 cGMP 依赖性通路诱导冠状动脉松弛

类黄酮的膳食摄入似乎与心血管死亡率呈负相关。一般人群中异黄酮的消费量正在增加，特别是由于使用食品补充剂和各种富含异黄酮的食物。然而，关于单个纯异黄酮对血管影响的详细研究大多缺失。在这项研究中，最初筛选了 16 种异黄酮类化合物对大鼠主动脉的血管舒张特性。其中最有效的两种，biochanin A 和黄豆黄素，进一步测试了对猪冠状动脉的作用机制。它们都诱导了内皮非依赖性血管舒张，EC50 分别低于 6 和 17 µM。Biochanin A 能够以剂量依赖性方式阻断由 KCl、CaCl2、5-羟色胺和 U46619 引起的血管收缩，但黄豆黄素不能。另一系列实验表明，biochanin A 的主要作用机制是抑制 L 型钙通道。此外，相对较小浓度 (2 - 4 µM) 的 biochanin A 会干扰 cGMP，但不会干扰离体冠状动脉中的 cAMP 通路。这些结果表明，一些异黄酮，特别是生物链素 A，能够在微摩尔浓度下产生血管舒张作用，这对于心血管疾病的管理具有潜在的临床意义。