Anti-neuraminidase Activity of Chemical Constituents of Balanophora Involucrata.

Balanophora involucrata J. D. Hooker has been known to possess potential anti-inflammatory and antibacterial activities; however, the antiviral activity has not been evaluated by now. In order to find new neuraminidase Inhibitors (NAIs), the neuraminidase (NA) inhibition activity was evaluated of different extractions from B. involucrate. In this study, NA inhibition assay in vitro was used to find out which extract of Balanophora involucrate exhibit inhibitory activity against neuraminidase. Then, we employed NA inhibition assay, UPLC/Q-TOF-MS/MS and molecular docking techniques to identify the specific compounds responsible for the anti-influenza activity of the extract, and to explore the potential natural neuraminidase inhibitors. The ethyl acetate extract of Balanophora involucrata exhibited significant inhibitory activity against neuraminidase with IC50 at 159.5 μg/mL. Twenty compounds were identified according to the MS/MS spectra; among them two compounds, quercitrin and phloridzin showed obvious inhibitory activity against neuraminidase, with the IC50 at 311.76 μmol/L and 347.32 μmol/L, respectively. This study suggested that Balanophora involucrata can be a potential natural source of neuraminidase inhibitors and may further aid for human in fighting ferocious influenza viruses.