The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou Institute of Cardiovascular Disease, 250 Changgangdong Road, Guangzhou, China.
Arch Toxicol. 2012 Nov;86(11):1681-90. doi: 10.1007/s00204-012-0874-7. Epub 2012 May 31.
Puerarin has multiple pharmacological effects and is widely prescribed for patients with cardiovascular diseases, including hypertension, cerebral ischemia, myocardial ischemia, diabetes mellitus, and arteriosclerosis. While puerarin is a useful therapeutic agent, its mechanisms of action have not been well defined. Understanding puerarin metabolism, in particular its interactions with metabolizing enzymes, will contribute to our understanding of its toxic and therapeutic effects and may help to elucidate potential negative drug-drug interactions. In this study, the major metabolite of puerarin was obtained from the urine of rats administered puerarin, by a semi-preparative high-performance liquid chromatography method. The major metabolite was identified as puerarin-7-O-glucuronide. In vitro, we used a UDP-glucuronosyltransferase (UGT) reaction screening method with 12 recombinant human UGTs to demonstrate that formation of puerarin-7-O-glucuronide was catalyzed by UGT1A1, 1A9, 1A10, 1A3, 1A6, 1A7, and 1A8. UGT1A1, 1A9, and 1A10 significantly catalyzed puerarin-7-O-glucuronide formation, and the activity of UGT1A1 was significantly higher than those of 1A9 and 1A10. The V (max) of UGT1A1 was two- to threefold higher than the levels of UGT1A9 or 1A10, with a lower K ( m ) value and a higher V (max)/K ( m ) value. The kinetics of puerarin-7-O-glucuronide formation catalyzed by UGT1A1 were similar to those of the pooled human liver microsomes (HLMs), with V (max) values of 186.3 and 149.2 pmol/min/mg protein, and K ( m ) values of 811.3 and 838.9 μM, respectively. Furthermore, bilirubin and β-estradiol, probe substrates for UGT1A1, significantly inhibited the formation of puerarin-7-O-glucuronide in HLMs.
葛根素具有多种药理作用，广泛用于治疗心血管疾病患者，包括高血压、脑缺血、心肌缺血、糖尿病和动脉硬化。虽然葛根素是一种有用的治疗药物，但它的作用机制尚未得到很好的定义。了解葛根素的代谢，特别是其与代谢酶的相互作用，将有助于我们了解其毒性和治疗效果，并可能有助于阐明潜在的负药物-药物相互作用。在这项研究中，通过半制备高效液相色谱法从大鼠给予葛根素后的尿液中获得葛根素的主要代谢物。主要代谢物被鉴定为葛根素-7-O-葡萄糖醛酸苷。在体外，我们使用 12 种重组人 UGT 进行 UDP-葡糖醛酸基转移酶 (UGT) 反应筛选方法，证明葛根素-7-O-葡萄糖醛酸苷的形成是由 UGT1A1、1A9、1A10、1A3、1A6、1A7 和 1A8 催化的。UGT1A1、1A9 和 1A10 显著催化葛根素-7-O-葡萄糖醛酸苷的形成，UGT1A1 的活性明显高于 1A9 和 1A10。UGT1A1 的 V(max) 是 UGT1A9 或 1A10 的两到三倍，具有较低的 K(m) 值和较高的 V(max)/K(m) 值。UGT1A1 催化的葛根素-7-O-葡萄糖醛酸苷形成的动力学与混合人肝微粒体 (HLMs) 相似，V(max) 值分别为 186.3 和 149.2 pmol/min/mg 蛋白，K(m) 值分别为 811.3 和 838.9 μM。此外，胆红素和β-雌二醇，UGT1A1 的探针底物，显著抑制 HLMs 中葛根素-7-O-葡萄糖醛酸苷的形成。
