Implementing in vitro and in silico approaches to evaluate anti-influenza virus activity of different Bangladeshi plant extracts

Emergence of antiviral drug resistance in influenza virus remains a major public health concern worldwide. Nowadays, different herbs receive renewed attention because of their enormous antiviral potential. In this study, we investigated the antiviral activity of Camellia sinensis, Persicaria hydropiper, Persicaria orientale, Persicaria lapathifolia, Persicaria stagnina, Mucuna pruriens and Chenopodium album against different influenza strains using both in vitro and in silico approaches. Antiviral effect of plant extracts was evaluated by cytopathic effect (CPE) inhibition assay on influenza infected MDCK (Madin Darby Canine Kidney) cell line. Later, the herb demonstrating antiviral activity was virtually screened for their available bioactive compounds and multiple in silico tools were performed to prioritize and establish these compounds as potential inhibitor. The methanol, but not the n-hexane and ethyl acetate extracts of C. sinensis, P. hydropiper, M. pruriens and C. album exhibited anti-influenza effect with EC₅₀ values within 32–46 µg/ml. Importantly, the extracts remained effective against both amantadine-resistant and -sensitive influenza isolates. The molecular docking analysis showed that flavonoids, steroid and derivatives had strong binding affinity to the target proteins which may remain responsible for the anti-influenza characteristics of plant extracts. Pharmacokinetic properties, bioavailability and drug-likeness score revealed that ferulic acid, sinapic acid, campesterol, cryptomeridiol, eupatin and genistein could be attractive leads as potential influenza inhibitors. Taken together, the botanical ingredients of these herbs could be used as valuable candidates for developing novel therapeutics to control influenza related illnesses.