School of Pharmacy, China Medical University, Taichung, Taiwan.
J Ethnopharmacol. 2012 Dec 18;144(3):671-6. doi: 10.1016/j.jep.2012.10.009. Epub 2012 Oct 13.
The rhizome of Polygonum cuspidatum SIEB. et ZUCC. (Polygonaceae, PC), a widely used Chinese medicine, is commonly prescribed for the treatments of amenorrhea, arthralgia, jaundice, abscess, scald and bruises.
PC contains various polyphenols including stilbenes, anthraquinones and flavonoids. This study investigated the pharmacokinetics and tissue distribution of emodin and resveratrol in PC.
Male Sprague-Dawley rats were orally administered PC (2 and 4 g/kg) and blood samples were withdrawn at the designed time points via cardiopuncture. Moreover, after 7-dose administrations of PC (4 g/kg), brain, liver, lung, kidney and heart were collected. The concentrations of resveratrol and emodin in the plasma and tissues were assayed by HPLC before and after hydrolysis with β-glucuronidase and sulfatase.
The glucuronides/sulfates of emodin and resveratrol were exclusively present in the plasma. In liver, kidney, lung and heart, the glucuronides/sulfates of resveratrol were the major forms. For emodin, its glucuronides/sulfates were the major forms in kidney and lung, whereas considerable concentration of emodin free form was found in liver. Neither free forms nor conjugated metabolites of resveratrol and emodin were detected in brain.
The sulfates/glucuronides of resveratrol and emodin were the major forms in circulation and most assayed organs after oral intake of PC. However, the free form of emodin was predominant in liver.
虎杖（蓼科虎杖属，PC）的根茎是一种广泛应用的中药，常用于治疗闭经、关节痛、黄疸、脓肿、烫伤和瘀伤。
PC 含有各种多酚类物质，包括芪类、蒽醌类和黄酮类。本研究旨在研究大黄素和白藜芦醇在 PC 中的药代动力学和组织分布。
雄性 Sprague-Dawley 大鼠口服给予 PC（2 和 4 g/kg），并通过心脏穿刺在设计的时间点采集血样。此外，在给予 PC（4 g/kg）7 个剂量后，收集脑、肝、肺、肾和心脏。用 HPLC 测定血浆和组织中白藜芦醇和大黄素在水解前后（用β-葡萄糖醛酸酶和硫酸酯酶水解）的浓度。
大黄素和白藜芦醇的葡萄糖醛酸/硫酸盐仅存在于血浆中。在肝、肾、肺和心中，白藜芦醇的葡萄糖醛酸/硫酸盐是主要形式。对于大黄素，其葡萄糖醛酸/硫酸盐是肾和肺中的主要形式，而肝中则发现相当浓度的大黄素游离形式。在脑中均未检测到游离形式或结合代谢物的白藜芦醇和大黄素。
口服 PC 后，白藜芦醇和大黄素的硫酸盐/葡萄糖醛酸是循环和大多数检测器官中的主要形式。然而，游离形式的大黄素在肝中占优势。
