利用HPLC分析方法預測中草藥與藥物之交互作用：探討furanocoumarins對肝臟代謝酵素CYP3A4所引起交互作用之研究

Predicting Herb-drug Interactions by HPLC Analysis: Furanocoumarin-based Metabolic Interactions with CYP3A4

林盈谷(Ying-Ku Lin)

指導教授 ： 何秀娥

臺北醫學大學/藥學院/藥學系(博士班)/博士(2008年)

摘要

本研究以逆相高效液相層析 (RP-HPLC) 方法預測中草藥與藥物因代謝而發生交互作用之可能性。以二十九種結構相關且已知會抑制藥物代謝phase-I細胞色素P450 3A4 (CYP3A4) 的furanocoumarins為模式藥物利用RP-HPLC進行預測中草藥與藥物之交互作用。將其中五個furanocoumarins標準品利用已經確效的RP-HPLC系統分析，將所得的容量因子 (capacity factor) 值與用Molsuite 2000 molecular modeling pro plus software (ChemSW®) 軟體計算出的furanocoumarins分配係數 (log P) 進行關聯分析。利用此關聯曲線可求得這系列furanocoumarins之容量因子。結果顯示絕大部分的furanocoumarins其容量因子介於1.65和10.57之間 (滯留時間10到40分鐘)，也就是相當於RP-HPLC分析時分離層3到8 (fraction 3~8) 之間。每一個分離層利用對nifedipine氧化反應的抑制之程度來表示酵素CYP3A4受抑制之程度。在定量性預測中草藥與藥物交互作用時，Ru 被定義為層析反應單位的總合，可利用方程式Ru = R / 7.79 ?e 105表示，其中R代表每一個層析峰或是任一個分離層內所有層析峰其面積的總合 (sum of the peak area)。結果顯示，CYP3A4酵素抑制百分比 (y) 與層析反應單位的總合 (Ru，x) 呈乙狀 (sigmoidal) 的關係，方程式為 y = 85.36 x (14.86 + x)-1其相關係數為0.63。這乙狀的曲線可以分為低、中和高風險三個範圍，用來代表中草藥或複方濃縮中草藥粉與藥物發生代謝交互作用的風險程度。經由本研究"風險類別"的預測分類結果，可以提供有用的資訊來評估中草藥與藥物之交互作用。

關鍵字

中草藥與藥物交互作用 ； 代謝酵素CYP3A4 ； 層析分析

並列摘要

An attempt made in this study was to predict the potential for metabolic interactions of herbal extracts of drugs based on their chromatographic profiles in reverse-phase high-performance liquid chromatography (RP-HPLC) analysis. Twenty-nine structurally related furanocoumarin compounds with known effect on cytochrome P450 3A4 (CYP3A4), which is important for phase-I drug metabolism, were selected as a model system, and analyzed using an RP-HPLC system developed for this study. Log values of the partition coefficients (log P) of these furanocoumarin derivatives calculated using Molsuite 2000 molecular modeling pro plus software (ChemSW®) were used to interpolate the capacity factors from a validated correlation curve constructed using five standard references that covered the elution time range in the RP-HPLC analysis system developed in the lab. The obtained correlations were then used to estimate the capacity factor for all of the furanocoumarin derivatives collected from the literatures with reported herb-drug interaction activity in CYP3A4. The capacity factors for most of the furanocoumarins were between 1.65 and 10.57 (with retention times of 10~40 min), a range approximately equivalent to fractions 3 to 8 (Fr3~8) in the RP-HPLC fraction analysis. Each fraction was examined for its inhibition of microsomal nifedipine oxidation represented as the CYP3A4 inhibitory potency. Ru was designated the total response unit and expressed as Ru = R / 7.79 ?e 105; this was calculated for each single peak or each fraction in terms of the sum of the peak area (R) for all chromatographic peaks appearing in the chromatographic analysis. A sigmoidal relationship was established between the CYP3A4 inhibitory potency (y) and the RP-HPLC peak response unit (Ru，x) as y = 85.36 x (14.86 + x)-1 with a correlation coefficient of 0.63. The sigmoidal curve could be divided into three ranges designated low, medium, and high risk that were used to indicate the relative inhibitory potency of the metabolic interactions of herbs or traditional Chinese herb medicines with CYP3A4. These predictive classifications provide information and might be useful for “risk category” decisions concerning herb-drug interactions.

並列關鍵字

Herb-drug Interactions ； CYP3A4 ； Chromatographic analysis

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