Context: Development of a reliable and selective anti-inflammatory agent of cyclooxygenase-2 (COX-2), induced or up-regulated by inflammatory/injury stimulus such as IL-1β, TNF-α and LPS in the various types of organs, tissues and cells, with low side effects is a long-standing medicinal chemistry problem with significant social implications.
Objective: To target druggable enzymome COX-2 by exploiting NSAIDs and genipin (GEP) in anti-inflammatory infection.
Materials and methods: The compound aspirin GEP ester (AGE) was designed by computer-assisted screening, synthesized in the esterification of the acylate derivative and the methylate derivative with Et3N, and evaluated with 20, 40 and 60 mg/kg from days 18 to 24 after immunization in collagen-induced arthritis (CIA) rats by the sequential enzymatic experiments, western-blot analysis and pathological observation methods.
Results: AGE exhibited higher binding affinity with COX-1 and displayed the lowest estimated free energy with COX-2 than other ligands built by hanging NSAIDs with GEP, and was characterized by 1H NMR, 13C NMR and HRMS. AGE was competed against COX-2 with molecule-dependent potencies and selectivity (IC50: 0.36 mM; selectivity index: 275) in the sequential enzymatic experiments and decreased the expression of COX-2 in peripheral blood lymphocytes of CIA rats. AGE (40 and 60 mg/kg) could significantly relieve the secondary hind paw swelling and arthritis index, along with observing AGE attenuated histopathological changes of fibroblast like synovial tissue (FLST) and mesenteric lymph node lymphocytes (MLNL) in CIA rats.
Discussion and conclusion: AGE pharmacophore reported herein may be an effective strategy to develop a novel anti-inflammatory agent and potential inhibitor of COX-2.
Keywords: Aspirin genipin ester; genipin; pharmacophore.