Pomegranate peel extract inhibits internalization and replication of the influenza virus: An in vitro study

Influenza virus, which is associated with high level of morbidity and mortality, has been recently considered a public health concern; however, the methods of choice to control and treat it are limited. Our previous study showed anti-influenza virus activity of pomegranate peel extract (PPE). In this study, the mechanism through which PPE acts against influenza virus A/Puerto Rico/8/34 (H1N1; PR8) was investigated.

Ethyl alcohol extract of pomegranate (Punica granatum L.) peel was prepared, and the action mechanism of PPE in inhibiting influenza replication was studied by time-of-drug-addition assay, virucidal activity, RNA replication, hemagglutination inhibition assay, viral mRNA expression, and western blot analysis.

PPE inhibited viral polymerase activity, viral RNA replication, and viral protein expression but could not affect hemagglutination inhibition and virucidal activity. According to time-of-drug-addition assay results, PPE inhibited the virus adsorption and early steps of influenza replication.

This study demonstrated that the antiviral effect of PPE on influenza virus is most probably associated with inhibition of viral adsorption and viral RNA transcription.