腸病毒71型是屬於微小RNA病毒科的腸病毒屬的成員。自從1998年來台灣多次發生腸病毒71型的感染與流行，其主要感染對象為五歲以下兒童，輕微感染時出現手足口症、咽唊炎等症狀，腸病毒71型的嚴重性在於造成致死性的肺水腫，以及侵犯中樞神經系統，造成腦膜炎、無菌性腦膜炎以及小兒麻痺樣症候群等症狀。為了快速尋找能夠抑制腸病毒71型的藥物，在我們的研究中測試了二十二種中草藥萃取液，發現魚腥草萃取液能夠中和腸病毒71型感染Vero細胞所引起的細胞病變現象。根據中和試驗得知，魚腥草萃取液有效中和一半腸病毒71型所引起的細胞病變死亡的濃度(IC50)為125.92±27.837 g/mL。我們進一步觀察發現魚腥草萃取液抑制腸病毒71型感染主要是影響病毒蛋白的產生。並且發現魚腥草萃取液處理之後可有效抑制病毒感染後所引起的細胞凋亡的現象。綜合以上結果，我們認為可由魚腥草萃取液中分離出有效抑制腸病毒71型的成分，進一步發展為抗腸病毒71型的藥物。

Enterovirus 71 (EV71) is a positive-stranded RNA virus in the genus Enterovirus of the family Picornaviridae. EV71 infection can cause hand, foot, and mouth disease (HFMD), herpangina and associated with fatal pulmonary edema as well as severe neurological complications, including encephalitis, meningitis, and a poliomyelitis-like syndrome in children. Several major outbreaks of EV71 have occurred in recent years in Taiwan. In this study we screened 22 Chinese medicine extracts for anti-EV71 activity. We found Houttuynia cordata Thunb. can neutralize the EV71-induced cytopathic effect (CPE) in Vero cells. The 50% inhibitory concentration of H. cordata on EV71 was approximately 125.92±27.837 g/mL. A plaque reduction assay showed that H. cordata can reduce the plaque formation. H. cordata was able to reduce viral protein synthesis and also abate the apoptotic process in enterovirus 71-infected Vero cells. We concluded that H. cordata possesses antiviral activity and has a potential for development as an anti-enterovirus 71 agent.

目 錄
指導教授推薦書…………………………………………………………
口試委員會審定書………………………………………………………
授權書……………………………………………………………...…....iii
誌謝…………………………………………………………...…………iv
中文摘要…………………………………………………………………v
英文摘要…………………………………………………………….…..vi
中文目錄………………………………………………………...……...vii
英文目錄………………………………………………..……………...viii
第一章 前言…………………………………………………………….1
第二章 研究目的………………………………………………..……..9
第三章 材料與方法……………..……………………………..……..10
第四章 結果………………………………………………………….21
第五章 討論………………………….……...…………………..…….29
圖表…………………………………………………………………..….33
參考文獻………………………………………………………………57

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