2-Substituted Benzoxazoles as Potent Anti-Inflammatory Agents: Synthesis, Molecular Docking and In vivo Anti-Ulcerogenic Studies

Abstract

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) are the commonly used therapeutic interventions of inflammation and pain that competitively inhibit the cyclooxygenase (COX) enzymes. Several side effects like gastrointestinal and renal toxicities are associated with the use of these drugs. The therapeutic anti-inflammatory benefits of NSAIDs are produced by the inhibition of COX-2 enzymes, while undesirable side effects arise from the inhibition of COX-1 enzymes.

Objective: In the present study, a new series of 2-substituted benzoxazole derivatives 2(a-f) and 3(ae) were synthesized in our lab as potent anti-inflammatory agents with outstanding gastro-protective potential. The new analogs 2(a-f) and 3(a-e) were designed depending upon the literature review to serve as ligands for the development of selective COX-2 inhibitors.

Methods: The synthesized analogs were characterized using different spectroscopic techniques (FTIR, ¹HNMR, ¹³CNMR) and elemental analysis. All synthesized compounds were screened for their binding potential in the protein pocket of COX-2 and evaluated for their anti-inflammatory potential in animals using the carrageenan-induced paw edema method. Further 5 compounds were selected to assess the in vivo anti-ulcerogenic activity in an ethanol-induced anti-ulcer rat model.

Results: Five compounds (2a, 2b, 3a, 3b and 3c) exhibited potent anti-inflammatory activity and significant binding potential in the COX-2 protein pocket. Similarly, these five compounds demonstrated a significant gastro-protective effect (**p<0.01) in comparison to the standard drug, Omeprazole.

Conclusion: Depending upon our results, we hypothesize that 2-substituted benzoxazole derivatives have excellent potential to serve as candidates for the development of selective anti-inflammatory agents (COX-2 inhibitors). However, further assessments are required to delineate their underlying mechanisms.

Keywords: 2-Substituted benzoxazole; COX-2 inhibitor; anti-inflammatory; coxibs; docking; ethanol.