Novel chalcone candidates as potential in vitro and in vivo anti-inflammatory agents: Synthesis, in silico docking,...

Managing inflammation with the commonly used nonsteroidal anti-inflammatory drugs (NSAIDs) represents a critical challenge in modern medicine because of its strong influence on the cyclooxygenase-1 (COX-1) enzyme might induce substantial adverse effects. Therefore, there is urgent necessity for the exploration of safer alternatives, particularly cyclooxygenase-2 (COX-2) inhibitors. This study aimed to address this issue through the synthesis and evaluation of 19 new chalcone derivatives (2a-m and 4a-f) for their in vitro anti-inflammatory activity against various biotargets including iNOS, COX-2, 5-LOX, PGE2, and TNFα. Moreover, these compounds showed moderate to strong anti-inflammatory activity in the carrageenan rat paw edema test. Compounds 2a, 2f, 2 h, 2 m, and 4b are promising candidates for the treatment of inflammatory diseases. In particular, compound 4b was demonstrated to be the most effective derivative as a nitric oxide release inhibitor, exhibiting a 61.7 % inhibition rate. It exhibited substantial selectivity for COX-2 (IC₅₀ = 1.933 μM) compared to COX-1 (IC₅₀ = 5.526 μM). Compound 4b exhibited notable inhibitory activity against 5-LOX (IC₅₀ = 2.112 μM) and demonstrated considerable inhibitory activity against iNOS, PGE2, and TNF-α biotargets in LPS-stimulated RAW cells, with IC₅₀ values of 114.18, 37.13, and 58.15 nM, respectively. The in vivo anti-inflammatory effects demonstrated the significant efficacy of compound 4b, as evidenced by a notable edema inhibition rate of 37.05 %, along with minimal ulcerogenic activity observed in the histopathological findings. In silico experiments demonstrated that the intermolecular contacts of the most active chemical 4b with the biotargets COX-2, 5-LOX, and iNOS were analyzed by docking, revealing significant binding interactions. The stability of the interactions between compound 4b and the targets COX-2, 5-LOX, and iNOS was assessed using a standard 100 ns atomistic dynamic simulation method. Various parameters derived from MD simulation trajectories were adjusted and validated to confirm the stability of the generated complexes under dynamic settings. Ultimately, compound 4b exhibited favorable physicochemical properties and satisfactory drug-likeness, indicating its potential as an oral anti-inflammatory agent, warranting additional structure-activity relationship investigation and optimization.