Evaluation of methoxyflavones as dengue NS2B-NS3 protease inhibitors: an in silico and in vitro studies

Dengue is one of the most prevalent viruses transmitted by the Aedes aegypti mosquitoes. Currently, no specific medication is available to treat dengue diseases. The NS2B-NS3 protease is vital during post-translational processing, which is a key target in this study. Due to methoxy group substitution, methoxyflavones are more bioavailable and metabolically stable than hydroxylated flavones. To date, research on the anti-dengue activity of methoxyflavones is limited. Hence, this work aims to determine the inhibitory activity of methoxyflavones against the dengue NS2B-NS3. Methoxyflavones derivatives were screened using molecular docking. The result showed a strong binding interaction of compound 1 and compound 2 with NS2B-NS3 protease. Both compounds exhibited comparable binding energy as the reference compound, quercetin, with values lower than - 8.1 kcal/mol. Molecular dynamics simulation using GROMACS revealed the stability and stiffness of the complexes over a 100 ns time scale. In addition, an in vitro assay for NS2B-NS3 protease inhibition revealed inhibitory effects of compounds 1 and 2 with IC50 values of 316.80 µM and 463.30 µM, respectively. The ADMET analyses showed favorable pharmacokinetics profiles that comply with Lipinski's Rule of Five. Collectively, our findings suggest that compounds 1 and 2 inhibit dengue NS2B-NS3 activity. These findings hold promise of methoxyflavones as starting compounds for potential dengue treatment, highlighting the need for further investigation.