Inhibition of Epstein-Barr virus lytic cycle by ethyl acetate subfraction from Polygonum cuspidatum root

• Main Authors: Yi-Hsuan Kuan, 管易璇
• Other Authors: Tsuey-Pin Lin
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/96q63x

碩士 === 嘉南藥理科技大學 === 營養與保健科技研究所 === 99 === Polygonum cuspidatum is widely used as a medicinal herb in Asia. From the results of our previous studies, we found that ethanolic extract from the Polygonum cuspidatum root (PcE) inhibits EBV lytic cycle. The PcE was partitioned with n-hexane and ethyl acetate, and then PcE(H)EA was fractionated and purified by semi-preparative high performance liquid chromatography (HPLC) into F1, F2 and F3. F3 contained 68.2% emodin. F3 and emodin inhibit EBV lytic cycle, the concentration of F3 and emodin required to inhibit EBV immediate-early protein expression by 50% are 5.9 ?慊/ml and 3.9 ?慊/ml, respectively. These results demonstrated that emodin is a main compound involved in inhibition of F3 on EBV lytic cycle. The purpose of this study is to investigate the inhibitory effects of the ethyl acetate subfractions, F1 and F2 from Polygonum cuspidatum root on EBV lytic cycle. MTT assay was used to determine the viability of P3HR1 cells. Immunoblot, indirect immunofluorescence, flow cytometry analyses were performed for the determining of the expression of EBV lytic proteins. Results showed that the concentration of F1 and F2 required to inhibit EBV immediate-early protein expression by 50% are 23.3 ?慊/ml and 7.8 ?慊/ml, respectively. F1 and F2 decrease cell viability to 50% (CC50) at 93.1?n?慊/ml and 6.1 ?慊/ml, suggesting that F2 inhibited the expression of EBV lytic proteins was due to cell toxicity, F1 inhibits the expression of EBV lytic protein at the concentration of no cytotoxicity toward P3HR1 cells. Real-time quantitative PCR was used to analysis the replication of EBV DNA and the EBV virion producing, showing that F1 inhibited the replication of EBV DNA, EC50 is 55.5 ?慊/ml, reduces virion production by 44.5 % at the concentration of 50 ?慊/ml. This study finish that F1 inhibits EBV lytic proteins expression, thereby impeds the replication of EBV DNA and production of mature viral particle.