Ethyl-2-oxo-2H-chromene-3-carboxylate exhibits anti-allergic effects by inhibiting IgE-mediated mast cell activation and passive cutaneous anaphylaxis in mice

An allergy is an exaggerated immune response to an otherwise harmless substance. These reactions are triggered largely by mast cell activation and the subsequent release of inflammatory mediators. Although current allergy therapies effectively relieve symptoms, they are generally accompanied by side effects, highlighting the need for safer alternatives. In this study, we investigated the anti-allergic effect of ethyl-2-oxo-2H-chromene-3-carboxylate (EtCC), a coumarin derivative. Rat basophilic leukemia (RBL-2H3) cells and a passive cutaneous anaphylaxis (PCA) model were used for in vitro and in vivo evaluations, respectively. In RBL-2H3 cells sensitized with dinitrophenyl (DNP)-specific-immunoglobulin (Ig) E and stimulated with DNP-human serum albumin (HSA), EtCC inhibited histamine and beta-hexosaminidase release, and downregulated mRNA expression of interleukin (IL)-4, IL-13, and TNF-α. EtCC also suppressed phosphorylation of MAPK, AKT, and NF-kB. In vivo, EtCC attenuated ear edema and Evans blue extravasation in a PCA model. These findings demonstrate that EtCC effectively suppresses mast-cell-mediated allergic responses, suggesting its potential as a novel allergy treatment.