An in vitro antiviral evaluation of punicalagin toward influenza A virus

Abstract Background: Influenza complications are mild to serious, and can cause death in some cases. A great deal of attention has been paid in recent years to the development and use of new antiviral compounds for drug resistance in certain strains of the influenza virus and the clinical implications. This study was aimed to investigate the antiviral effect of punicalagin and associated mechanism against influenza A (H1N1) virus at cell culture. Methods and Results: The ant-influenza activity of punicalagin was studied in Madin-Darby Canine Kidney (MDCK) cells using influenza virus A/Puerto Rico/8/34 (H1N1) (PR8) by means of Hemagglutinin assay (HA) and 50% tissue culture infective dose (TCID50). Then, the inhibition of haemagglutination, virucidal activity, effect at different times, replication of viral RNA and expression of viral genes were investigated. Our results indicated that punicalagin decreased virus titers (P<0.05) with an inhibitory effect on virus hemagglutination and the activity of viral polymerase, but did not affect the replication of viral RNA. Punicalagin also inhibited the virus adsorption stage of influenza in terms of the different times addition assay. Conclusions: Punicalagin was effective against influenza infection most probably associated with inhibition of haemagglutination activity and virus binding. Further studies are needed to establish possible synergistic effects with existing anti-influenza, aiming to develop novel agents to treat severe influenza infection.