基于代谢相互作用的补骨脂-甘草配伍的适宜性研究

Psoralea corylifolia is a common traditional Chinese medicine (TCM) and has been reported to have clinical adverse reaction recently. The reason may be due to improper use. Licorice is one of widely used detoxicant, and often compatibility with Psoralea corylifolia in clinic practice. Our pilot study found that the main component of Psoralea corylifolia, bakuchiol has potential nephrotoxicity in human renal tubular epithelial (Human Kidney-2, HK-2) cells, and the cytotoxicity were reduced by the metabolism of CYP enzymes. We proposed the hypothesis that the compatibility of Psoralea corylifolia with Licorice might have potential herb-herb interactions via inhibition of CYP450 metabolic enzymes, resulted in enhanced the risk of toxic effect. This project is a preliminary study to investigate the compatibility of Psoralea corylifolia with Licorice based on the metabolic interactions. We plan to study in two levels: 1) For in vivo study, to examine and compare the toxic effects of single herb decoction and the mixed decoction of the two herb medicines using rat. 2) For in vitro study, to investigate the combined cytotoxic effect of bakuchiol and glycyrrhetinic acid, using HK-2 cells in presence of human liver microsomes （HLM）, to explore the mechanism of combined toxicity based on CYP 450 metabolism. The study can provide new evidences for safe and rational application of Psoralea corylifolia and Licorice in clinic.

常用中药补骨脂近年已有临床不良反应的报道，使用不当是原因之一。甘草为常用解毒药，与补骨脂伍用率较高。我们前期工作发现，补骨脂主要成分之一补骨脂酚具有肾细胞毒性，但经CYP450酶代谢后毒性降低。补骨脂与甘草配伍可能产生基于CYP450酶抑制的中药间相互作用, 从而增高发生毒性反应的风险。本项目拟从代谢相互作用角度初步探讨补骨脂与甘草配伍的适宜性。在整体动物层次，研究大鼠经口给与单味药材补骨脂及其与甘草配伍的毒性效应；在细胞层次，用人肾小管上皮（HK-2）细胞和人肝微粒体共培养模型，研究补骨脂酚与甘草次酸配伍的细胞毒性，基于CYP450 代谢探讨其配伍毒性机制，为中药在临床更合理的应用提供新的科学依据。

本研究基于代谢相互作用探讨补骨脂-甘草配伍的适宜性。.体内研究显示：.1. 一次大剂量经口给予补骨脂（约相当于临床剂量的40倍），可引起大鼠肾损伤，未见明显肝毒性；.2. 补骨脂与甘草配伍单次给药，增加了补骨脂酚在大鼠体内的吸收，抑制了补骨脂酚的代谢，增大了补骨脂酚在大鼠体内的暴露量，出现增强其肾损伤趋势。.3. 补骨脂长期给药28天可对大鼠肝脏造成一定损伤，但与甘草配伍后并没有增强或减弱补骨脂对大鼠的肝损伤。.4. 给药第14天起即发现高剂量的补骨脂及补骨脂-甘草配伍对大鼠肾脏造成损伤，28天时各给药组均观察到肾毒性，但补骨脂与甘草配伍后并没有加重或减轻补骨脂的肾脏毒性。.5. 补骨脂毒性的主要靶器官为肝、肾。且补骨脂引起的肝、肾损伤是可逆的，停药7天后可恢复正常。.体外研究发现：.1. 甘草主要吸收入血的活性代谢物甘草次酸，减弱或逆转人肝微粒体（HLM）对补骨脂酚肾细胞毒性的代谢减毒，表型出增强其肾细胞毒性；甘草的另一成分甘草酸铵对补骨脂酚的代谢减毒没有影响。.2. 甘草次酸能抑制HLM中参与代谢补骨脂酚的主要CYP同工酶活性，从而抑制HLM对补骨脂酚的代谢，显著减弱HLM对补骨脂酚的代谢减毒作用，导致补骨脂酚的肾细胞毒性增强。.研究结果提示，当补骨脂与甘草配伍应用时，可能会因为CYP酶的抑制而导致代谢相互作用，增高补骨脂酚出现肝、肾毒性的风险。建议临床应用时考虑酌情减量，长期用药时监测患者的肝、肾功能。