Anti-influenza A virus activity of epigallocatechin gallate

Aim To explore the anti-influenza A virus activity of epigallocatechin gallate(EGCG) and its mechanism.Methods Inhibition of viral-entry by EGCG was determined with luciferase assay in MDCK cells infected with A/Thailand/Kan353/2004 H5N1 pseudovirus.Nneuraminidase inhibition assay was further used to investigate the mechanism of anti-influenza activity.Anti-influenza activity of EGCG was further confirmed in MDCK cells infected with influenza A virus FM_1 strain with different medications,including treated,prophylactic medications.Results EGCG inhibited the entry of H5N1 pseudovirus into MDCK cells with IC50 of 145.10 μmol·L-1.EGCG also inhibited the activity of neuraminidase with IC50 of 417.20 μmol·L-1.EGCG also showed anti-influenza viral effect on FM_1 virus in MDCK cells.IC50 was 6.88 μmol·L-1 when added before inoculation with influenza A virus FM_1 strain,while IC50 was 14.83 μmol·L-1 when added after the virus inoculation.TI was 58.02 and 26.92,respectively.Conclusions EGCG can inhibit influenza A virus in vitro.The mechanism of EGCG includes at least the virus entry and neuraminidase activity inhibition.