目的 探讨表没食子儿茶素没食子酸酯（epigallocatechin⁃3⁃gallate，EGCG）体外抑制埃可病 毒 9 型（Echovirus 9，ECHO9）的作用机制及其特异性底物热休克蛋白 70（Heat shock protein 70，Hsp70）在 其中的作用，为埃可病毒抑制剂的天然产物研发提供理论依据。方法 根据细胞毒性实验确定使用的 EGCG的最大工作浓度，采用病毒滴度 TCID50 检测法、细胞毒性检测法、Western blot 和实时荧光定量 PCR 方法（qPCR）分别检测 EGCG 在体外模型上对 ECHO9 的增殖、蛋白表达和基因转录的抑制效果。检测 RNAi 干扰Hsp70 的表达后病毒的生长曲线。结果 EGCG 对 Vero 细胞的毒性呈现明显的梯度依赖效应， 最大无毒浓度为25 μmol/L，且20 μmol/L的EGCG浓度下，细胞上清中病毒滴度抑制率达62%；同时Western blot结果显示EGCG使病毒G蛋白受到显著抑制；qPCR对细胞中埃可病毒G蛋白的转录本的检测结果表明 EGCG 使病毒 G 蛋白的转录效率下降了85.3%。RNAi干扰Hsp70后，病毒的滴度下降了两个数量级。结论 EGCG 体外对ECHO9有较好的抗病毒作用，且可能是通过抑制其特异性底物Hsp70实现的。

Objective To study the inhibitory effect of EGCG（epigallocatechin⁃3⁃gallate）on Echovirus 9 （ECHO 9）and effect of its substrate Hsp70（Heat shock protein 70）in vitro，and to provide basis for the research and development of new chemicals against ECHO 9 virus. Methods According to the maximum working concen⁃ tration of EGCG，the effects of EGCG on the proliferation，protein expression and gene transcriptional inhibition of ECHO 9 in vitro were detected by TCID50 assay，cytotoxicity assay，Western blot and real⁃time quantitative PCR， respectively. RNAi were used to knock down the expression of Hsp70 and the growth curves of virus were exam⁃ ined. Results Toxicity of EGCG on Vero cells showed an obvious gradient dependent effect，with the maximum non⁃toxic concentration of 25 μmol/L. The titer inhibition rate of virus in the cells supernatant reached 62% at the concentration of 20 μmol/L. Meanwhile，Western blot results showed that the virus G protein in EGCG treated cells was significantly inhibited. The results of qPCR on the transcription of virus G protein in cells showed that EGCG reduced the transcription efficiency of virus G protein by about 85.3% . Knocking down the expression level of Hsp70 reduced the titer of the virus by two orders of magnitude. Conclusions EGCG has a good antiviral effect on ECHO 9 in vitro，and may be achieved by inhibiting its specific substrate Hsp70.