Investigation of Novel Etoricoxib Analogues as Potential COX-II Inhibitors through a Bioisosteric Strategy, ADMET Evaluations, Docking Studies, and Molecular Dynamics Simulations.

Background: Inflammation is a natural process; however, chronic inflammation may result in numerous health issues. Etoricoxib (ETX), a selective cyclooxygenase-2 (COX-2) inhibitor, serves as an anti-inflammatory agent for various types of arthritis. However, prolonged use of ETX is associated with several adverse effects, including cardiovascular toxicity.

Objective: The current research aims to design an analogue of ETX having superior pharmacokinetic properties and safer toxicological profiles employing the bioisosteric approach.

Methods: The bioisosteres of various groups in ETX were produced utilizing the MolOpt online tool, resulting in the generation of novel ETX analogues. The pharmacokinetics (ADME) and toxicological profiles of the generated analogues were calculated by ADMETLab 3.0 server. The druglikeness (DL) and drugscore (DS) were calculated using OSIRIS property explorer (PEO). The molecular docking analysis of the ETX analogues against the target protein (PDB ID: 5KIR) was carried out using AutoDock Vina, and their results were visualized by Discovery Studio 2021. Molecular Dynamics (MD) simulation of the top three complexes was conducted using the Schrödinger suite. Binding free energy for the A098-5KIR, A188-5KIR, and D121- 5KIR complexes was conducted using MM-GBSA/PBSA method.

Results: A total of 1200 ETX bioisosteres were produced; among them, 51 were screened on the basis of ADMET profile, DL, and DS scores and selected for the docking study. A docking study revealed that 12 analogues show good interactions and docking scores. Furthermore, the molecular dynamics simulation of ligands A098, A188, and D121 demonstrated stability throughout the 100 ns simulation period.

Conclusion: The findings of the ADMET study, DL, DS, docking study, MD simulation, and binding free energy calculation indicate that the analogues A098, A188, and D121, which are bioisosteres of ETX, may serve as potential anti-inflammatory agents for inflammation-related disorders.