Hybrids of selective COX-2 inhibitors and active derivatives of edaravone as COX-2 selective NSAIDs with free radical scavenging activity: Design, synthesis and biological activities

Novel hybrids of selective COX-2 inhibitors (coxibs) and active derivatives of free radical scavenger edaravone were designed to overcome the risk of cardiovascular events and stroke increased by NSAIDs (nonsteroidal anti-inflammatory drugs) in this study. All the hybrids were assayed for the COX-2 inhibitory and DPPH (2, 2-diphenyl-1-picrylhydrazyl) free radical scavenging activities in vitro. Finally, we found a series of hybrids with good inhibitory activity and selectivity of COX-2 and excellent free radical scavenging activity in vitro. The most promising compound 6a (WYZ90) exhibited very potent COX-2 inhibitory activity (COX-2, IC₅₀ = 75 nM), weak COX-1 inhibitory activity (COX-1, IC₅₀ = 5734 nM), better free radical scavenging activity (DPPH, IC₅₀ = 19.9 μM) than edaravone, moderate drug-likeness and ADME properties in silico, acceptable pharmacokinetic properties (T_1/2 = 4.16 h, 10 mg/kg, o.p.) and oral bioavailability (F% = 36.03 %) in mice. In addition, compound WYZ90 showed similar analgesic activity to the selective COX-2 Inhibitor celecoxib in acetic acid-induced mice and better antioxidant activity in Fe²⁺-induced lipid peroxidation in mouse liver tissue homogenate than edaravone. In conclusion, this study provided a novel class of coxibs containing edaravone moiety as COX-2 selective NSAIDs with free radical scavenging activity and the candidate compound WYZ90 showed not only similar selective COX-2 inhibitory and analgesic activity to celecoxib but also better free radical scavenging and antioxidant activity than edaravone.

Edaravone; Free radical scavenger; NSAIDs; Selective COX-2 inhibitor.