虎杖是一種在亞洲廣泛使用的中草藥。先前在我們實驗室研究發現，虎杖根乙醇萃取物 (PcE)可以抑制 EB病毒的溶裂循環。本研究進一步將 PcE 經由正己烷及乙酸乙酯分劃，再藉由半製備高效液相層析儀 (HPLC)分離純化得到 F1q、F1a、F2a、F2b和F3a分離物，而 F1a含有 51.8%的白藜蘆醇苷 1.2%的白藜蘆醇，而 F2a經由核磁共振分析，鑑定 F2a為蔥醌醣苷 B (anthraglycoside B)，F3a主要為大黃素 (emodin)，而 F1q、F2b尚未了解是何種物質。進一步以 MTT方法測定 F1a和白藜蘆醇苷對 P3HR-1細胞存活的影響。以西方墨點法及流式細胞儀分析 EB病毒溶裂期蛋白質的表現。結果顯示 F1a抑制 50% EB病毒溶裂期蛋白質所需濃度 (EC50) 是大於 50 g/ml，而白藜蘆醇苷 EC50是 109.1 M ，而F1a對 P3HR1細胞半數致死率濃度 (CC50)大於 200 g/ml，而白藜蘆醇苷的 CC50 為 507.9 Μ。這些結果證明白藜蘆醇苷在不具細胞毒性濃度能有效抑制 EB病毒溶裂期蛋白質表現。接著以 Real-time qPCR方法分析白藜蘆醇苷對 EB病毒 DNA的複製，結果顯示白藜蘆醇苷抑制 50% EB病毒 DNA複製所需的濃度為 89.9 M。本研究結果證實，白藜蘆醇苷能有效的抑制 EB病毒的溶裂蛋白質表現並降低 EB病毒 DNA複製能力。 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) inhibited EBV lytic cycle. This study was to partition the PcE with n-hexane and ethyl acetate and purified by semi-preparative high performance liquid chromatography (HPLC) into F1q, F1a, F2a, F2b and F3a. F1a contained 51.8% piceid and 1.2% resveratrol. F2a was identified as anthraglycoside B by NMR. The major compound of F3a was emodin. F1q and F2b were unknown. Further study was to explore the effect of F1a on the viability of P3HR1cells by MTT assay. Immunoblot and flow cytometry analyses were performed for the determining of the expression of EBV lytic proteins. Results showed that the concentration of F1a to inhibit EBV immediate-early proteins expression by 50% (EC50) was above 50 g/ml, and piceid was 109.1 M. The concentrations of F1a decreased cell viability to 50% (CC50) were higher than 200 g/ml, and piceid was 507.9 M. These results demonstrated that piceid inhibited the expression of EBV lytic proteins at the concentration of no cytotoxicity toward P3HR1 cells. Real-time quantitative PCR was used to assay the replication of EBV DNA, showing that the concentration of piceid to inhibit EBV DNA replication by 50% was 89.9 M. This study demonstrated that piceid inhibited EBV lytic proteins expression, thereby impeded the replication of EBV DNA.
