Antiviral Drug Discovery from Typha angustifolia Pollen: Computational Analysis Targeting Flaviviridae Polymerases and Entry Proteins

For centuries, Traditional Chinese Medicine has been a subject of extensive research for its healing properties, including its effects against viruses. The pollen of Typha angustifolia emerges as a notable natural source of antiviral agents, with earlier investigations focusing on its antioxidant and anti-inflammatory properties, which are associated with flavonoids and phenolics that facilitate electron transfer. These bioactive compounds could potentially disrupt viral entry and replication, thereby necessitating further studies.

Molecular docking analysis was conducted on 11 compounds from T. angustifolia targeting the entry protein of dengue virus, the NS5B polymerase of hepatitis C virus, and the RdRp of Japanese encephalitis virus. The binding affinity was evaluated through LibDock score assessments, and simulations of molecular dynamics (RMSD and RMSF) were performed to analyze the stability of the complexes.

Naringenin was consistently identified as one of the highest binders for all three viral proteins, achieving the top score for the RdRp of Japanese encephalitis (129.288). Isorhamnetin showed the greatest binding affinity for the hepatitis C NS5B polymerase (120.827), exceeding that of sofosbuvir (120.629), while isorhamnetin-3-O-rutinoside displayed strong binding to the dengue viral entry protein (97.0838). Molecular dynamics confirmed the stability of ligand-protein interactions, underlined by sustained van der Waals and electrostatic forces.

These findings underscore naringenin as a versatile antiviral candidate, with other flavonoids exhibiting specific effectiveness that could facilitate multitarget inhibition approaches. This polypharmacological potential of flavonoids aligns with their established antiviral properties, although confirmatory experimental studies are critical.

Naringenin emerged as the most potent and reliable antiviral agent among the compounds of T. angustifolia, particularly against the RdRp of Japanese encephalitis. These computational insights validate T. angustifolia pollen as a promising natural antiviral resource, warranting further validation through in vitro and in vivo studies.