基于细胞色素P450酶代谢调控的补骨脂抗绝经后骨质疏松作用机制研究

Psoralea corylifolia (PC) is a commonly used traditional Chinese medicine with kidney-enrich and strengthening functions. Modern pharmacology has demonstrated that PC treatments postmenopausal osteoporosis by increasing serum concentration and bone mineral density. However, it is still not clear how PC contributes to the level of estrogen. In our preliminary experiment, it was found that PC had low exposure in vivo, but it could influence the activity of CYP1A1 and CYP1B1 enzymes, which were related to estrogen metabolism. Therefore, we speculated that PC played its role in prevention and treatment of osteoporosis by raising estrogen levels while affecting CYP450 enzyme. Based on the above point of view, multi-component pharmacokinetic of PC in rats was firstly investigated, then the inhibitory activity of PC on CYP1A1 and CYP1B1 in vitro was tested. Furthermore, after administration of PC extract, the change of serum estrogen levels and the mRNA expression of CYP1A1, CYP1B1 in ovariectomized rats were also investigated, which could illuminate the pharmacological mechanism of PC from a CYP450 perspective. This study reveals the pharmacokinetic characteristics and anti-osteoporosis mechanism of PC, as well as provides scientific evidences for PC in treatment of postmenopausal osteoporosis in clinical.

补骨脂为我国传统补肾助阳中药，其可以通过提高血清雌激素水平，增加骨密度，发挥抗绝经后骨质疏松作用。但是目前补骨脂提高雌激素水平的作用机制还不明确。申请者在前期研究中发现，补骨脂在体内的暴露量低，但却可以影响参与代谢雌激素的CYP1A1和CYP1B1酶，因此推测其可能是通过抑制CYP450酶，提高雌激素水平，从而发挥抗绝经后骨质疏松作用。本课题首先通过测定补骨脂在大鼠体内的多成分药代动力学，然后测试补骨脂及主要活性成分在体外对CYP1A1、CYP1B1的抑制活性，最终通过比较骨质疏松模型大鼠灌胃补骨脂前后雌激素及其代谢物的含量变化，以及大鼠肝脏中CYP1A1、CYP1B1 mRNA表达水平的变化，从CYP450酶角度阐明补骨脂防治绝经后骨质疏松的作用机制。该研究成果在一定程度揭示了补骨脂的药代动力学特征及抗绝经后骨质疏松作用机理，也为其应用于临床治疗骨质疏松提供科学依据。

补骨脂为我国传统补肾助阳中药，其可以通过提高血清雌激素水平，增加骨密度，发挥抗绝经后骨质疏松作用。但是目前补骨脂提高雌激素水平的作用机制还不明确。本课题主要完成了以下工作：①采用UPLC-MS/MS方法对大鼠单次和多次给药后血浆中补骨脂素、补骨脂定、新补骨脂异黄酮、补骨脂甲素、补骨脂乙素、补骨脂酚和norbakuchinic acid（补骨脂酚的主要代谢产物）的药动学进行研究，同时描绘了其它16个原型成分及主要代谢产物的峰面积响应随时间变化曲线，结果发现同一结构类型的化合物体内代谢特征基本一致。②采用底物探针法，通过检测7-乙氧基-试卤灵及试卤灵含量发现补骨脂乙素、补骨脂定、新补骨脂异黄酮、异补骨脂二氢黄酮和补骨脂二氢黄酮甲醚对CYP1A1和CYP1B1（参与雌激素代谢的主要CYP450亚型）有较强的抑制活性。③采用底物探针法，本研究还发现补骨脂乙素、异补骨脂二氢黄酮和补骨脂二氢黄酮甲醚对其他CYP重组酶和UGT重组酶也表现出较一定的抑制活性，且CYP重组酶和UGT重组酶参与上述化合物的体内代谢。④通过质粒转染HeLa1A1细胞实验发现BCRP、MRP1或MRP4转运体是导致补骨脂乙素和补骨脂二氢黄酮甲醚的葡萄糖醛酸酯代谢产物排泄的重要因素。本研究在一定程度揭示了补骨脂的多成分药代动力学特征以及抗绝经后骨质疏松药效物质，为其应用于临床治疗骨质疏松提供科学依据。