高氏柴胡防治C型肝炎病毒感染與應用安全性評估(1/2)

林俊清
高雄醫學大學
全球目前有1億七千萬人左右感染C型肝炎病毒而它所帶來的肝疾病(肝炎、肝硬化及肝癌)是全球嚴重的健康與醫療負擔，包括台灣。目前C型肝炎無預防疫苗，而現有的臨床治療藥物IFN/ribavirin對於最普遍的 genotype I 的治療效果並不理想 (約50%治癒率) 且副作用大，加上它龐大的醫療資金造成許多患者身體無法承受療程及經濟負擔。開發C型肝炎病毒及其引起的肝病治療藥物乃是優先考慮的一大問題，為了研發經濟、有效且副作用少的C型肝炎治療藥物，本計畫採取用適合本土發展之生藥，同時也開發台灣本土生藥資源。本研究團隊多年來致力於開發生藥分子醫學之研究，有悠久的歷史與經驗(近30年，290篇論文)，特別是本土的藥材資源開發具有眾多的貢獻與成果，尤其在保肝、抗肝纖維化、抗肝癌、及抗B型肝炎病毒的領域皆有許多成果。如今，本團隊也評估多年，在如何解決C型肝炎患者使用藥物產生的副作用與治療藥物太過昂貴的主要兩大問題中找出更有效的藥物，而本團隊在未建立一系列C型肝炎病毒模式前已證實台灣特有品種的高氏柴胡對於臨床病人檢體分離出的C型肝炎病毒感染具有良好的抑制作用(民國90年，國科會計畫編號：NSC 90-2317-B-037-001)，但受限於模式開發困難始終無法了解其明確具體的作用及機制，如今利用最新含有冷光病毒感染模式可深入探討高氏柴胡及其活性成分抗病毒的機轉，初步結果發現其主要作用在干擾病毒的侵入(entry)，而非複製及轉譯。另一方面高氏柴胡據報導指出其活性成分含量約為中國產的北柴胡5~20倍，為台灣特有優良品種，可為現前中國市場藥材過度開採，輸出之藥材原料年年減少也年年漲價，令許多廠商不堪負荷等問題帶來希望。在此提出3階段性的計畫為開發高氏柴胡及其成分抗C型肝炎病毒之藥療及本土栽培為目標: Phase I－觀察高氏柴胡及其相關活性成分對於直接控制病毒感染的藥效。在第一階段我們將以最新的C型肝炎病毒感染模式觀察藥物如何影響病毒感染週期(infection cycle)包括單病毒顆粒感染(free particle infection)、吸附(attachment)、融合(fusion)、細胞間的傳遞(cell-to-cell spread)及針對病毒的醣蛋白(glycoprotein)的改變。Phase II－觀察高氏柴胡及其成分對於影響宿主細胞導致病毒感染過程受控制。在此階段，將探討高氏柴胡及其成分是否誘導肝細胞免疫系統、脂肪合成與釋放(lipid system)的改變，達成抑制病毒感染過程包括病毒蛋白質的製造、病毒顆粒合成(particle assembly)及病毒釋放也同時探討是否對肝細胞有保護作用(自由基控制以及緩解發炎反應)。Phase III－評估高氏柴胡及其成分與IFN/ribavirin合併治療(體外試驗)及動物安全性。將測高氏柴胡及其成分與目前C型肝炎臨床用藥(IFN/ribavirin)是否有協同作用以達致低藥劑高效率的效果，另外也同時評估高氏柴胡及成分在老鼠體內注射後的安全性，結果可提供未來進入正式臨床前長期動物安全性試驗甚至人體試驗做參考。由此三階段計畫希望開發台灣本土栽植生藥新的標準治療方法或輔助臨床用藥之療法，來推動藥物經濟化，能為全世界需要干擾素(IFN)治療的肝炎患者提供新的希望，使人人都有能力接受治療。
關鍵字：高氏柴胡、本土生藥、C型肝炎病毒、抗病毒藥物

Assessment of efficacy and drug application safety of Bupleurum Kaoi against hepatitis C virus infection(1/2)

Chun-Ching Lin
School of Pharmacy, College of Pharmacy, Kaohsiung Medical University
Approximately 170 million people are infected with hepatitis C virus (HCV) worldwide. The hepatotropic virus causes significant morbidity and medical socio-economic burden globally, including Taiwan. At present, there is no vaccine available for immunization against HCV. In addition, treatment with standard therapy (interferon with ribavirin) on the most common genotype 1 infection is suboptimal (∼50%), which is also associated with high cost and serious side effects. It is therefore necessary to develop novel anti-HCV therapeutics that are inexpensive, highly efficient, and that results in minimal side effects with high patient adherence. Our laboratory has studied crude drug medicines, including local ones, for 30 years (290 SCI publications) and has made significant contributions in the field of liver protection, anti-liver fibrosis, anti-hepatoma, and anti-HBV drugs development. Identifying crude drug therapeutics against HCV infection is also among our recent research focus, and we have previously screened crude extractions from natural medicinal plants acclimated for culture in Taiwan against HCV. The initial screening data showed that the crude extraction of Bupleurum kaoi (B. kaoi) and the subsequently extracted active compound possess bioactivity against HCV infection. Recent herb culture incentives in Taiwan have mostly relocated to China, therefore losing the competitive market and increasing drug importation cost. Furthermore, due to resource limitation, China is imposing stringent export quota for natural crude drugs. B. kaoi is an endemic species unique to Taiwan that can be easily cultured locally and yield higher amounts of bioactive compounds than the commonly used B. chinensis species that is imported from China. Here, we propose a 3-phase study to evaluate the anti-HCV activities of B. kaoi and its active compounds, and investigate the associated antiviral mechanisms to identify novel therapeutics for treating HCV infection: Phase I－Antiviral assessment of B. kaoi and its active compounds on HCV infection cycle (including free particle infection, attachment, fusion, cell-to-cell spread, and viral-glycoprotein alterations); Phase II－Analyses of the anti-HCV effects from B. kaoi and its active compound through modulation of the host cell and host-virus interaction, and also investigate its liver protective activity on hepatocytes (these include host immunomodulation, host cell lipid system, ROS generation, and local inflammatory response that could affect viral assembly and release); and Phase III－Combinatorial therapy with IFN/Ribavirin and animal toxicity studies of B. kaoi and its active compound (examination on synergistic effects from co-therapy and evaluation of in vivo safety profile). Results generated from this grant will help develop B. kaoi and its active compound as novel anti-HCV therapeutics, and will serve as basis for subsequent clinical application. Furthermore, it will help promote the plant culture of B. kaoi and impact local industry and economy.
關鍵字：Bupleurum kaoi、local crude drug、hepatitis C virus、antiviral therapeutics