Liraglutide modulates cyclooxygenase and α7 acetylcholine receptors: in vitro and in silico insights into its anti-inflammatory role in LPS-induced inflammation in RAW 264.7 macrophages

Liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist, is well-established for its metabolic benefits, including glycemic control and weight loss. Beyond these roles, it exhibits significant anti-inflammatory properties, though the mechanisms remain underexplored. This study investigates the anti-inflammatory effects of liraglutide in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. Results demonstrate that increasing concentrations of liraglutide suppresses LPS-elevated prostaglandin E2 (PGE2), 6-keto prostaglandin F1α (6-keto-PGF_1α, a stable prostacyclin metabolite) and thromboxane A2 (TXA2), similar to that observed with conventional anti-inflammatory agents, ibuprofen and celecoxib. Mechanistic exploration reveals that liraglutide's anti-inflammatory action is dually-modulated by cyclooxygenase (COX) and nicotinic acetylcholine receptor (nAChR) signaling. The application of non-selective, non-competitive nAChR antagonist or selective and potent α7-nAChR antagonist, mecamylamine (MEC) and methyllycaconitine (MLA), respectively, highlights the involvement of cholinergic pathways in liraglutide's activity. Based on in silico molecular docking analyses, liraglutide exhibits favorable binding affinities to COX-1, COX-2, prostacyclin synthase (PGIS), and α7nAChRs, supporting its potential multi-target anti-inflammatory effects. These findings suggest that the therapeutic potential of liraglutide may go beyond metabolic regulation and may be promising for conditions in which metabolic and inflammatory pathways converge, including inflammation and modulation of cholinergic signaling.