Epstein-Barr 病毒 (EBV) 是人類的皰疹病毒，主要感染人類的 B 淋巴細胞以及上皮細胞。已證實與許多惡性腫瘤相關，如巴克氏淋巴瘤 (Burkitt’s lymphoma) 及鼻咽癌 (Nasopharyngeal carcinoma) 等，先前實驗室發現虎杖乙醇萃取物具有抑制 EB 病毒由丁酸鈉 (SB) 所誘導溶裂循環，因此，本研究的目的將探討虎杖乙酸乙酯分離物對 EB 病毒活性的影響。研究計畫將以 MTT 方法分析虎杖乙酸乙酯分離物對 P3HR1 細胞存活的影響。以西方墨點法分析 EB 病毒溶裂蛋白質和磷酸化 ERK 的表現；以即時定量 PCR 分析病毒溶裂循環基因的轉錄及病毒複製的情形，結果顯示虎杖乙酸乙酯分離物 F1、F3、F3a 及其主成分白藜蘆醇? (piceid) 與大黃素 (emodin) 能抑制 SB 所誘導的極早期基因，BRLF1 和 BZLF1的轉錄。也發現降低 EB 病毒溶裂蛋白質表現，包括了 Rta、Zta 和 EA-D，以及 EB 病毒 DNA 複製。這些研究證實，虎杖乙酸乙酯分離物 F1、F3、F3 與主成分 emodin 及 piceid 可以有效地抑制 EB 病毒溶裂基因轉錄，降低溶裂蛋白質的表現，進而減少 EB 病毒複製。此外，F1、F3、F3a 及 emodin 促進 SB 所抑制的 ERK 磷酸化，進而可能影響細胞內 EB 病毒進入溶裂循環。 Epstein-Barr virus (EBV) is a human herpesvirus, which infects lymphoid and epithelial cells. EBV is associated with several malignant diseases such as Burkitt’s lymphoma and Nasopharyngeal carcinoma. Our earlier study found that the ethanolic extract of Polygonum cuspidatum roots inhibits the expression of EBV lytic proteins. The purpose of this study is to investigate further the anti-EBV effect of the ethyl acetate fraction from Polygonum cuspidatum. MTT assay was used to determine the viability of P3HR1 cells; immunoblot and flow cytometry analyses, the expression of EBV lytic proteins and phosphorylation-ERK; real-time quantitative PCR, the transcription of lytic genes and EBV DNA replication. Result showed that the ethyl acetate fraction F1, F3, F3a and major compounds, piceid and emodin inhibit the transcription of EBV immediated-early genes, BRLF1 and BZLF1 genes, and decrease the expression of lytic proteins, including Rta, Zta and EA-D, and EBV DNA replication. These results suggest that the ethyl acetate fraction from P. cuspidatum effectively inhibits the transcription of EB virus lytic genes, reduced lytic protein expression and decreased its DNA replication. The study shows that F1, F3, F3a and emodin inhibit the EBV lytic cycle.
