Influence of cetirizine and loratadine on granulocyte-macrophage colony-stimulating factor and interleukin-8 release in A549 human airway epithelial cells stimulated with interleukin-1beta.

Background And Purpose: In addition to being antagonists of histamine receptors, some antihistamines modulate the pathogenesis of allergic inflammation by reducing mediator release, adhesion molecule expression and, consequently, recruitment of inflammatory cells. The aim of this study was to explore the effects of 2 second-generation antihistamines, cetirizine and loratadine, on granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-8 (IL-8) secretions in human airway epithelial cells.

Methods: A549 cells were pre-incubated with cetirizine (1, 5, 10 microM) or loratadine (1 microM) individually for 16 h followed by stimulation with IL-1beta for 8 h. The levels of GM-CSF and IL-8 were measured by an enzyme-linked immunosorbant assay.

Results: Cetirizine (10 microM) and loratadine significantly reduced the release of GM-CSF, by 37% and 40%, respectively (p<0.05). Cetirizine (5, 10 microM) inhibited the production of IL-8 by 19% (p<0.05). However, cetirizine (1 microM) and loratadine (1 microM) did not appreciably inhibit IL-8 release.

Conclusions: These observations indicate that these 2 second-generation antihistamines inhibit the release of GM-CSF and IL-8 beyond their antagonistic histamine H1 receptor activity and may thus exert clinically relevant anti-inflammatory effects in inflammatory airway disorders.