Identification of naturally occurring flavonoids as anticancer agents: In silico studies

It is recognized that flavonoids have a variety of functions in nature, including anti-inflammatory, antibacterial, antioxidant, anticancer, anti-HIV and neuroprotective properties. In the present study, molecular docking experiment was performed on 15 naturally occurring flavonoids as anticancer agents. The analysis of results was performed on the basis of docking score, glide energy and interaction with amino acids. Each flavonoid showed a specific interaction with target protein. Naringin showed interactions with amino acids GLN131, ASP145, PHE80, VAL83, GLU8, ILE10, THR89 (docking score -12.48) involved with the protein PDB ID: 1gij (inhibitor of cyclin-dependent kinase 4). Naringin further showed interactions with THR887, THR886, LYS833, ASP836 amino acids (docking score -15.078) involved with PDB ID: 5jhb (inhibitor of PI3K and tubulin). Orientin showed interactions with amino acids ASN150, ASP163, LYS43, VAL101 (docking score -13.89) with PDB ID: 2euf as inhibitor of cyclin-dependent kinase 6. Quercetin showed interactions with amino acids PHE1047, LEU840, CYS919, GLU917 (docking score -11.7) with PDB ID: 4agd as inhibitor of VEGF receptor tyrosine kinase inhibitor. Epigallocatechin gallate showed interactions with amino acids LYS868, GLU885, THR916, ASP1046 using protein PDB ID: 3ewh (docking score -10.004) as inhibitor of Tie-2 kinase. The given flavonoid drugs interaction with cancer targets shows their possible potential against various forms of cancer. Epigallocatechin gallate when docked with 3ewh showed best docking score with important interaction required for anticancer activity. In molecular dynamic study, Epigallocatechin gallate in complex with VEGFR2 kinase protein (PDB ID: 3ewh) with RMSD indicates the protein remained stable through the simulation of 100ns with fluctuation in the range of 1.5-3.5 & Aring;. The provided docking results may be useful for the development of novel drug candidate for anticancer targets.