In vitro antiviral effects of Peganum harmala seed extract and its total alkaloids against Influenza virus

- Peganum harmala L. extract and its total alkaloids showed the inhibitory effect against influenza A virus replication.
- The extract could inhibit viral RNA replication and viral polymerase activity.
- Antiviral activity of the extract against influenza virus is most probably associated with inhibiting viral RNA transcription.
- The crud extract and its total alkaloid should be further characterized to be developed as anti-influenza A virus agent.

This research was aimed to evaluate the in vitro antiviral effect and the mechanism of the effect of Peganum. harmala seeds extract against influenza A virus infection using Madin-Darby canine kidney (MDCK) cells. In this research, ethyl alcohol extract of P. harmala seeds and its total alkaloids was prepared. The potential antiviral activity of the extract and its total alkaloids against influenza A/Puerto Rico/8/34 (H1N1; PR8) virus was assessed. The mode of action of the extract to inhibit influenza replication was investigated using virucidal activity, hemagglutination inhibition assay, time of addition assays, RNA replication, western blot analysis and RNA polymerase blocking assay. The crud extract of P. harmala seed and its total alkaloids showed the best inhibitory effect against influenza A virus replication in MDCK cells using MTT assay, TCID50 method and hemagglutination assay. Our results indicated that the extract inhibits viral RNA replication and viral polymerase activity but did not effect on hemagglutination inhibition and virucidal activity. This study showed that, in vitro antiviral activity of P. harmala seed extract against influenza virus is most probably associated with inhibiting viral RNA transcription. Therefore, this extract and its total alkaloid should be further characterized to be developed as anti-influenza A virus agent.