Antiviral Activity of Berbamine Against Influenza A Virus Infection

Berbamine (BBM) is a bibenzyl isoquinoline present in the traditional Chinese herbal medicine <i>Berberis amurensisis</i> Rupr. The present study demonstrates that BBM exerts strong antiviral efficacy against influenza A virus (IAV) infection. We examined the anti-IAV effect of BBM using green fluorescent protein (GFP)-expressing influenza A and H1N1 IAV. The fluorescence microscopy, fluorescence-activated cell sorting analysis, and plaque assay showed that BBM significantly hinders IAV infection. The immunofluorescence analysis confirmed the anti-influenza activity of BBM. From the time-of-addition and hemagglutination inhibition results, it is elucidated that the antiviral effect of BBM is closely related to its inhibitory effect against viral binding and entry at an early infection stage. Our findings imply that BBM has the potential to be developed as a potent antiviral drug against influenza viral infection.