Abstract:

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.

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