Computer-aided study of selective flavonoids against chikungunya virus replication using molecular docking and DFT-based approach

Chikungunya fever has a high morbidity rate in humans and is caused by chikungunya virus (CHIKV). Currently, there is no vaccination or treatment available to show an effective efficacy against this disease. This study targets four non-structural proteins of CHIKV using 650 flavonoids from various medicinal plants, inhabited in Pakistan and India. The compounds are initially screened on the basis of their effective pharmacological properties and are docked against the four proteins. A threshold of - 8.5 kcal/mol is applied to screen and reduce the number of flavonoids for further analysis. The reactivity of screened flavonoids is analyzed using the density functional theory (DFT). Cirsimaritin, apigenin, tamarixetin, and 5,7,3 ',4 '-tetrahydroxyflavone from Andrographis paniculata have shown a high binding affinity against nsP1. Rhamnetin, tamarixetin and medioresinol have shown a strong binding affinity against nsP2. Four flavonoids, i.e. 5,7,3 ',4 '-tetrahydroxyflavone, 5,7,4 '-trihydroxyflavone, tamarixetin and rhamnetin, showed a high binding affinity for nsP3 while apigenin depicted a strong binding affinity for nsP4. Pharmacological properties of these flavonoids illustrate an effective disposition in humans. The results manifest that the screened eight flavonoids can be analyzed against CHIKV for in vitro and in vivo cell replication, due to their effective pharmacological properties, strong inhibition and high reactivity.