Antiviral effect of polyphenol-enriched extract of Rumex acetosa L. against influenza A virus

Although effective antiviral drugs are available for the treatment of influenza A virus (IAV) infection, the need for intensified drug discovery towards antiviral active compounds is obvious. A polyphenol-enriched extract of Rumex acetosa L. (Polygonaceae), standardized on galloylated oligomeric proanthocyanidins, was tested for antiviral activity against IAV in vitro using MTT, plaque reduction and hemagglutination assay. The extract inhibited IAV replication in a dose-dependent manner. IC50 and CC50 values, as determined by MTT assay, were 2.2 µg/ml and 79.2 µg/ml, resp., indicating a CC50/IC50 selectivity rat…