Department of Nutrition Science, Purdue University , West Lafayette, Indiana 47907, United States.
J Agric Food Chem. 2014 Feb 12;62(6):1294-300. doi: 10.1021/jf400097m. Epub 2014 Jan 29.
Recent findings indicate that soy isoflavones and their metabolites may play a role in mitigating postmenopausal bone loss. Equol, a metabolite of the soy isoflavone daidzein produced by intestinal bacteria, has shown some potential, but only 30-50% of the U.S. population is capable of converting dietary daidzein to equol. There are limited data on the pharmacokinetics of dietary racemic equol and its metabolites. This study was conducted to assess the levels of equol and its conjugates in plasma for a 24 h period resulting from oral administration of dietary daidzein and racemic equol in ovariectomized Sprague-Dawley rats. Plasma samples were analyzed for conjugated and free forms of equol using LC-MS/MS. The maximum plasma concentration (C(max)) and time to reach it (t(max)) for total equol (conjugated and unconjugated) were 8815 ± 2988 nmol/L and 2.17 ± 2.91 h and 3682 ± 2675 nmol/L and 20.67 ± 4.67 h, for dietary equol and daidzein, respectively. Although the majority of equol metabolites present were glucuronide conjugates (≥99%), there were low levels of equol monosulfate present. The changes in equol metabolism, specifically equol conjugates, due to the form of equol may play a role in the potential health benefits of equol.
最近的研究结果表明，大豆异黄酮及其代谢物可能在缓解绝经后骨丢失方面发挥作用。肠内细菌生成的大豆异黄酮染料木黄酮的代谢物雌马酚具有一定的潜力，但只有 30-50%的美国人口能够将膳食染料木黄酮转化为雌马酚。关于饮食雌马酚及其代谢物的药代动力学数据有限。本研究旨在评估口服膳食染料木黄酮和外消旋雌马酚后 24 小时内血浆中雌马酚及其缀合物的水平。使用 LC-MS/MS 分析血浆中雌马酚缀合物和游离形式的浓度。总雌马酚（缀合和未缀合）的最大血浆浓度（C(max)）和达到该浓度的时间（t(max)）分别为 8815±2988 nmol/L 和 2.17±2.91 h，以及 3682±2675 nmol/L 和 20.67±4.67 h，分别对应于饮食雌马酚和染料木黄酮。尽管大多数雌马酚代谢物为葡萄糖醛酸缀合物（≥99%），但仍存在低水平的雌马酚单硫酸盐。由于雌马酚的形式不同，雌马酚代谢物（特别是雌马酚缀合物）的变化可能在雌马酚的潜在健康益处中发挥作用。
