Arbutus andrachne Extracts Exhibit In Vitro Neuraminidase (N9) Inhibitory Activity: A Potential Herbal Strategy Against Avian Influenza.

The rise in emerging viral outbreaks has intensified the need for novel antiviral therapies and highlighted the untapped potential of natural products. Influenza viruses, particularly avian strains, continue to evolve rapidly, yet the antiviral properties of Jordan's native plants remain largely unexplored. This study focused on avian influenza and screened twelve endemic plant species, using ethanol to selectively extract polar phytochemicals likely to interact with the hydrophilic active site of neuraminidase (NA). Among these, Arbutus andrachne leaf and fruit extracts emerged as potent in vitro inhibitors of recombinant N9 neuraminidase, a key enzyme in influenza replication, with IC50 values of 31.6 µg/mL and 32.9 µg/mL, respectively. LC-MS analysis identified hyperoside as the major shared flavonoid in both extracts, which may contribute to the observed inhibitory activity. These findings support the potential of A. andrachne as a natural source for herbal preparations with antiviral activity.