抗肝脂質過氧化中藥新藥開發模式之建立

MODEL DEVELOPMENT OF NEW HERB FORMULAE AGAINST HEPATIC LIPID PEROXIDATION

林友鈞(Yu-Chun Lin)

指導教授 ： 楊玲玲

臺北醫學大學/藥學院/藥學研究所/博士(2006年)

摘要

環境污染物、肝炎病毒等致病因子，皆會引起過多的自由基及脂質過氧化而造成肝臟損害。而傳統中草藥富含許多有效成分，對自由基所誘發之肝臟損害具有保護的作用。本研究發現：(1) 傳統方劑中之葛根黃連黃芩湯具有抑制脂質過氧化的作用；(2)葛根黃連黃芩湯及其他藥材中之黃酮 (flavones)、黃酮醇 (flavonols)、雙氫黃酮 (flavanones)、雙氫黃酮醇 (flavanonols) 等類別之類黃酮 (flvonoids) 成分，以定量化構效分析 (QSAR) 進行抗脂質過氧化活性研究，結果顯示化學結構中官能基的取代與否及分子能量與類黃酮分子之抗脂質過氧化活性有密切的關係，並可建立一模組方程式： Y = 0.92X1－0.35X2－0.000051X3－0.0046X4－0.21X5＋3.26, r2=0.95, r2cv =0.93 (Y為抗脂質過氧化活性; X1 類黃酮為結構中A環5 /8 之取代基; X2 為B環3’ / 4’之取代基; X3為分子之高階分子軌道能; X4為靜電能; X5為鍵結能; r2為線性相關係數; r2cv 為交叉確信係數） 再經由不同抗肝脂質過氧化程度之類黃酮成分進行實測，以驗證本程式。此程式可用於預測藥材中flavones, flavonols, flavanones及flavanonols抗脂質過氧化的能力，並預測桑白皮藥材中桑根皮素 (morusin), 桑環素 (cyclomuberrin), 環桑色烯 (cyclomuberrochromene) 等成分具有良好之抗脂質過氧化的潛能；(3)將桑白皮加入葛根黃連黃芩湯中，可明顯提昇肝脂質過氧化之抑制率。 當藥物進入血液時會與血漿蛋白 (人類血清白蛋白; human serum albumin (HSA), 阿法爾酸性蛋白; α1- acid glycoprotein (AGP) 等) 結合，因此在中、西藥混用時，是否會與血漿蛋白的結合上產生相互的干擾是非常重要的。在葛根黃連黃芩湯之活性指標成分(黃芩：baicalein、葛根：daidzein、黃連：berberine、甘草：glycyrrhizic acid) 的研究發現：baicalein及daidzein分別加入HSA溶液時，分別降低9 %及21 % warfarin (WAR) 與HSA的結合率，增加游離態之藥物濃度。而berberine則降低81 % ibuprofen (IBU) 與HSA的結合率，也減少73 % disopyramide (DIP) 與AGP的結合率。另外glycyrrhizic acid分別減少28 % IBU及42 % salicylic acid (SAL) 與HSA的結合率。另外常用中藥方劑之四物湯亦減少HSA中37 % SAL的結合率。由以上結果我們建議各類中草藥在使用時，需注意與西藥在血清蛋白結合可能發生的交互作用，以免副作用的產生。 本研究發現葛根黃連黃芩湯具有抑制肝脂質過氧化活性。而程式模組可用於類黃酮成份之抗脂質過氧化活性。加入桑白皮之葛根黃連黃芩湯所得之新中藥方劑，可更明顯提昇肝脂質過氧化之抑制率。然而葛根黃連黃芩湯中baicalein及daidzein等成分會改變藥物與白蛋白的結合，增加游離藥物的量，改變藥物的血中有效濃度，因此在臨床使用葛根黃連黃芩湯時應特別注意與IBU, WAR, DIP等藥物，於血清蛋白結合可能發生的交互作用。而透過本系列研究模式之建立，可資應用於中藥方劑的改進及中藥新藥開發之參考。

關鍵字

葛根黃連黃芩湯 ； 抗肝脂質過氧化 ； 定量化構效分析 (QSAR) ； 桑白皮 ； 藥物交互作用

並列摘要

Heightened oxidative stress is an important mechanism in the pathogenesis of liver diseases caused by exposure to environmental toxins. Herbal supplements and Chinese medicine may contain ingredients that are protective against oxygen free radical-induced liver damage. In the present study, we discovered (1) Ge-Gen Huang –Lian Huang-Qin (GHH) Decoction, prescribed in traditional Chinese medicine for treating liver diseases, suppressed hepatic lipid peroxidation (LPO); (2) selected flavonoids (flavones, flavonols, flavanones and flavanonols) derived from GHH and other sources bear a quantitative structure activity relationship (QSAR) that fitted a model with the following equation: Y = 0.92X1－0.35X2－0.000051X3－0.0046X4－0.21X5＋3.26, r2=0.95, r2cv =0.93 (Y denotes antioxidant potency; a value of 1 is assigned to X1 if a functional group is present at both positions 5 and 8 of ring A in the flavonoid structure and X2, for positions 3’ and 4’ in ring B; X3, HOMO energy; X4, electrostatic energy; X5, bond energy; r2, linear regression coefficient; r2cv, cross validation coefficient) This equation predicted that the protective effects of flavones were more potent than flavonols, flavanones or flavanonols in tert-butyl hydroperoxide-induced LPO. QSAR studies indicate that the energy parameters are important factors in predicting the potency of flavones, flavonols, flavanones and flavanonols in suppressing LPO in liver. The same equation also applies to flavones from herbs not contained in GHH (e.g., morusin, cyclomuberrin, cyclomuberrochromene and others derived from Morus abla); and (3) combination of GHH and Morus abla conferred a greater effect in suppressing hepatic LPO. Adverse side effects may develop when Chinese medicine is administered along with prescription drugs. It is important to assess potential interaction of these 2 groups of medications. We noted in the present study that baicalein and daidzein, 2 flavonoids derived from GHH reduced the WAR binding levels by 9% and 21%, respectively. Berberine, also a GHH ingredient, reduced ibuprofen (IBU) binding to human serum albumin (HSA) by 81%. It also altered disopyramide (DIP) binding to α1-acid glycoprotein (AGP) by 73%. Glycyrrhizic acid, another GHH ingredient, reduced IBU binding to HSA by 28% and salicylic acid (SAL) binding by 42%. To further verify the clinical significance of the effects of Chinese medicine on drug binding to serum proteins. Siwu decoction, the most commonly prescribed herbal medicine, also examined for its effects on SAL, one of the most frequently prescribed medications, binding to HSA. Siwu decoction increased serum free SAL by 37%. These results suggest that various herbal formulae are likely to alter free drug levels, affecting their efficacy or causing unexpected side effects. In summary, we found that GHH was an effective regimen for reducing LPO in liver. The model was useful in predicting the potencies of flavones, major flavonoid gradients in GHH, in reducing liver LPO. Combination of GHH and Morus alba conferred a greater protective potency against LPO. However, flavonoids in GHH, such as baicalein and daidzein may alter drug binding to HSA, increasing or decreasing free drug levels. Co-administration of GHH with prescription drugs such as IBU, WAR and DIP should be made with caution. Results derived from the present study would be values in improving current and in developing new herb formulae.

並列關鍵字

Ge-Gen Huang –Lian Huang-Qin (GHH) Decoction ； Lipid peroxidation ； QSAR ； Morus alba ； Drug interaction

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