English  |  正體中文  |  简体中文  |  Items with full text/Total items : 28611/40652
Visitors : 753696      Online Users : 56
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search
LoginUploadHelpAboutAdminister

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/14814

Title: 兒茶素抑制日本腦炎病毒感染之研究
tudy of inhibitory effects by catechins in Japanese encephalitis virus (JEV) infection
Authors: Meng-Yi Jhan
詹孟怡
Contributors: NTOU:Department of Food Science
國立臺灣海洋大學:食品科學系
Keywords: 兒茶素;日本腦炎病毒
catechins;JEV
Date: 2005
Issue Date: 2011-06-30T07:46:13Z
Abstract: 中文摘要 兒茶素(catechins)是從綠茶(green tea)中萃取出的化合物,其中最重要的成分有:(-)-epicatechin (EC)、(-)-epicatechin gallate(ECG)、(-)-epigallocatechin (EGC)、(-)-epigallocatechin gallate(EGCG)。由文獻得知EGCG具有抑制人類後天免疫不全病毒(human immunodeficiency virus, HIV)、流行性感冒病毒(influenza virus)、腺病毒(adenovirus)和EB病毒(Epstein-Barr virus)等病毒複製的功效,是近年來預防保健食品的熱門研究主題。 日本腦炎(Japanese encephalitis, JE)是經由日本腦炎病毒(Japanese encephalitis virus, JEV)感染所產生的急性腦炎,其流行地區分布極廣且包含了大部分的亞洲地區,台灣亦為主要流行區。日本腦炎病毒主要侵犯腦部,引起急性腦膜炎,受損部位包括腦、脊髓和腦膜,20~50%倖存者會有智力障礙、情緒依賴、動作遲緩、顫抖、自律神經失調、運動神經麻痺和精神病等症狀,大多為中樞神經系統受損之永久後遺症。日本腦炎病毒造成中樞神經損傷的機制目前仍不清楚,而目前日本腦炎病毒直接對神經細胞的影響以及在病毒刺激之下所誘發的細胞激素對中樞神經的影響之研究,大多侷限於in vitro的細胞培養上。本論文除了在in vitro的細胞培養上探討病毒感染與發炎的關係外,更利用小鼠感染日本腦炎病毒的動物模式進一步研究病毒與發炎細胞激素的蛋白質及基因在小鼠中樞神經系統各區中分布之情形與日本腦炎症狀的相關性。並探討兒茶素是否對於日本腦炎病毒感染的細胞或小鼠具有保護作用。 在細胞的實驗結果顯示兒茶素在高濃度時對細胞具有毒性,而濃度在125μg/ml時可減少50%細胞活性,而抑制日本腦炎病毒的效果無論是綠猿猴腎細胞(Vero)或混合膠質細胞(mixed glia cell)都可看見明顯的抑制病毒複製的效應,另外在抑制iNOS的效應上,兒茶素除了可抑制LPS誘導mixed glia cell產生之NO,也可抑制病毒感染mixed glia cell後iNOS基因的表現。在動物實驗結果顯示,C3H/HeN小鼠在感染日本腦炎病毒後第5天出現後肢癱瘓麻痺的情形,並於感染後第七天死亡。利用免疫墨點法(dot blot)分析顯示感染病毒第5天後的小鼠腦部可測得病毒外套膜蛋白的表現,比較小鼠中樞神經系統各區中病毒外套膜蛋白表現量後,發現病毒在大腦皮質感染最為嚴重。real-time PCR的結果也顯示病毒外套膜基因亦在大腦皮質表現最強烈,小腦及延腦較少。餵食兒茶素之小鼠只有些微抑制的效果。另外,real-time PCR及免疫墨點法的結果也顯示小鼠在感染日本腦炎病毒後iNOS及發炎細胞激素會大量表現,而且餵食兒茶素後小鼠中樞神經系統各區中iNOS、IL-6、TNF-α及RANTES的表現情形上也能看到些微被抑制的效果產生,但是IL-1β及IFN-γ則完全沒有被抑制。
Abstract Catechins are polyphenol compounds extracted from green tea. They are reported to have a variety of medicinal effects such as anti-tumor, anti-oxidation, anti-inflammation and anti-virus. Japanese encephalitis virus (JEV), a neurotropic flavivirus, is one of the major causes of acute encephalitis in human. Upon infected, it is commonly associated whit inflammatory reactions and neurological diseases. To date, there are no any effective medicines for Japanese encephalitis therapy. This study aims to investigate the physiological effects of catechins administration when infected by Japanese encephalitis virus (JEV). In vitro experiments indicated that catechins have cytotoxicity to Vero cells at high concentration (125μg/ml). However, catechins can significantly inhibit the replication of JEV in both Vero and nixed glia cells. Catechins not only inhibit NO production in nixed glia cells when induced by LPS, but also reduce iNOS mRNA transcription when infected by JEV in nixed glia cells. JEV infects C3H/HeN mice that demonstrates neurobehavioral abnormalities at the 5th day of post-infection and dies at the 7th day of post-infection. At the 5th day of post-infection, the expression of JEV envelope protein in brain regions can be detected by dot blotting and real-time PCR. JEV mainly replicates in the cerebrum in mice. We found out that catechins can only slightly inhibit viral replication, and the virus can also induce inflammation in the brain of mice. The high expression levels of iNOS and the productions of inflammation-associate cytokines in the brain of JEV infected mice can be detected by the real-time PCR and dot blot assay. The expression levels of iNOS、IL-6、TNF-α and RANTES in different brain regions of mice when fed with catechins is slightly inhibited, but IL-1β and IFN-γ are not.
URI: http://ethesys.lib.ntou.edu.tw/cdrfb3/record/#G0M93320062
http://ntour.ntou.edu.tw/ir/handle/987654321/14814
Appears in Collections:[食品科學系] 博碩士論文

Files in This Item:

File Description SizeFormat
index.html0KbHTML174View/Open


All items in NTOUR are protected by copyright, with all rights reserved.

 


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback