桔梗在升陷汤中发挥引经作用的药代动力学机制与物质基础

It is a Traditional Chinese Medicine (TCM) theory that Platycodonis Radix (PG) acts as a "guiding medicine" which could change other drug's direction or/and location, and then made them concentrated in specially appointed direction or/and location. PG plays an important and specific role in Shengxian Decoction (SXT), a famous TCM formula, which is widely applied to treat chronic heart failure (CHF). In the previous research, a metabonomics approach in rats has been investigated to study 1) the therapeutic effect and mechanism of SXT on CHF, 2) the role of PG in SXT on intervention effect on CHF, which successfully demonstrated that application of PG in SXT could promote the therapeutic effects on CHF rats but treatment with only PG had no beneficial effects. To further explain the "guiding action", firstly, a quantitative HPLC-MS/MS method was established and validated to pharmacokinetics studies of both SXT and decreased SXT (PG removed, SXT-PG), including integrative pharmacokinetic parameters of multi-compounds and component-component interactions. Secondly, a qualitative HPLC-MS/MS method was developed and applied to serum pharmacochemistry studies of both SXT and SXT-PG. Pharmacokinetics and serum pharmacochemistry research of SXT and SXT-PG revealed differences, which could be used to reflect the "guiding" role of PG. At last, a qualitative HPLC-MS/MS method was established to study the chemical composition profile and metabolism profile of PG, which could reveal the ingredients accountable for "guiding action". This study established systematic method for identification of main constituents and determination of main active constituents in Shengxian Decoction in rat serum, and provided a scientific explanation of "guiding action" for PG.

桔梗，中医理论认为能引导方剂中诸药药力上行，在升陷汤中作为引经药。本课题组前期基于代谢组学对升陷汤的有效性进行评价和作用机制研究，并通过对比升陷汤全方和缺桔梗方的功效，发现缺方抗慢性心衰功效不如全方，而桔梗本身无明显活性，提示桔梗在升陷汤中具有重要的作用和地位。基于此，本课题拟采用药代动力学研究办法，通过对比升陷汤全方和缺桔梗方中在健康大鼠中主要药效成分的药动学参数以及各药效成分在主要组织器官中的分布趋势及排泄规律，从药物体内过程相互作用的层次上实现对桔梗载药上行功能的科学解释，进一步探索桔梗发挥引经作用的"时-效关系"；采用血清药物化学研究办法，建立表征、鉴定及测定升陷汤中桔梗主要入血成分的HPLC-MS/MS方法，并通过对比升陷汤和升陷汤缺失桔梗的方剂在健康大鼠中血清药物化学成分的区别，阐明升陷汤中桔梗的药性物质基础。

本课题通过血清药物化学、药代动力学等研究方法，考察升陷汤中的引经药桔梗的存在与缺失对升陷汤中其他活性成分的影响，探索桔梗发挥引经作用的“时-效关系”，为方剂学配伍机制研究提供方法学模式。.首先基于HPLC-DAD、HPLC-ELSD及HPLC-MS/MS等技术完成了升陷汤全方、缺方及桔梗指纹图谱建立及18种活性成分的含量测定，含量最高为知母皂苷B-II，而后是新芒果苷、柴胡皂苷A、柴胡皂苷、芒果苷等。 其次基于UHPLC-Q-TOF-MS技术，考察在相同时间点大鼠体内血浆、尿液、粪便、胆汁等样本内升陷汤活性成分的代谢过程途径差异，发现桔梗配伍后，主要影响升陷汤中组方皂苷及黄酮类活性成分的体内过程，增加上述有效成分的吸收，且明显改变原型与代谢产物的排泄过程，代谢产物较原型增加。最后基于HPLC-MS/MS开展升陷汤全方、缺方和桔梗在大鼠体内的吸收、分布、代谢和排泄等药代动力学特征研究：桔梗显著促进有效成分新芒果苷、知母皂苷BII、升麻素苷、芦丁、毛蕊异黄酮在大鼠体内的血浆浓度和组织分布，并能促进所检测18种物质经尿液、粪便和胆汁的排泄，累积排泄量之和占总排泄量的百分比分别为58.36%、1.97%和39.70%。“时-效关系”研究结果表明，新芒果苷在全方组30 min时（缺方组15min）体内分布浓度达最大，桔梗使其在肺中的浓度显著增加；知母皂苷BⅡ全方组在30 min时（缺方组15min）体内各组织分布浓度达最大，桔梗增加了其在肺、肝、肌肉中的富集；升麻素全方组15 min（缺方组15 min）体内各组织分布浓度达最大，桔梗增加了升麻素苷在肺中的聚集；芦丁全方组4 h（缺方组8 h）在心脏中浓度最高，桔梗增加了芦丁在心脏的富集作用；毛蕊异黄酮全方组30 min在肺和肝中达到最高分布浓度（缺方组15 min），桔梗增加了毛蕊异黄酮在肺和肝的富集；均起到了将有效成分向重要器官尤其是肺的引经作用。