- 期刊
兒茶素抑制日本腦炎病毒感染之研究
Study of Inhibitory Effects by Catechins in Japanese Encephalitis Virus Infection, The 22th Joint Annual Conferenceof Biomedical Sciences, Taiwan.
摘要
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。病毒主要侵犯腦部，受損部位色括腦、脊髓和腦膜，倖存者會有中樞神經系統受損之永久後遺症，目前並沒無有效的預防或治療藥物。兒茶素(catechins)是從綠茶中萃取出的化合物。從已知文獻中得知兒茶素中的的EGCG其有抑制病毒複製的功效。本論文主要探討兒茶素對日本腦炎病毒複製及發炎的抑制的效應，將有助於利用兒茶素當做抗病毒及抗發炎藥物或健康食品之應用。 本研究主要在in vitro的細胞培養上探討病毒感染與發炎的關係，以及小鼠成染日本腦炎病毒的動物模式，並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。更進一步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。 In vitro結果顯示兒茶素無論在綠猿猴腎細胞(Vero)或混合膠質細胞(mixed glia cell)都其有明顯的抑制日本腦炎病毒複製的效應。兒茶素亦可抑制病毒感染mixed glia cell後iNOS基因的表現。In vivo結果顯示，C3H/HeN小鼠在感染病毒後第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。餵食兒茶素之小鼠具有抑制日本腦炎病毒複製的效果。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大腦區域的OS及發炎細胞激素會大量表現，而且餵食兒茶素後小鼠大腦區域中iNOS、IL-6、TNF-α及RANTES的表現情形上也能看到被抑制的效果產生。
關鍵字
無資料並列摘要
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. Catechins are polyphenol compounds extracted from green tea. Some bio-functions of catechins have been reported induding anti-virus. This study aims to investigate the physiological effects of catechins (EGCG) administration when cell or mice infected by Japanese encephalitis virus. It will be assist in further application of the anti-virus and the anti-inflammation medicine or the health food. In vitro experiments indicated that catechins can significantly inhibit the replication of JEV in both Vero and nixed glia cells. Catechins can reduce iNOS mRNA transcription when infected by JEV in nixed glia cells. JEV infects C3HIHeN 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 2 cerebrum in mice, and induce inflammation in the brain of mice. We find that catechins can inhibit viral replication in brain of JEV infected mice. The high expression levels of iNOS and the inflammation-associated cytokines (IL-6、TNF-α and RANTES) in the brain of JEV infected mice can be reduced and detected by the real-time PCR and dot blot assay.