Recent studies have suggested that antihistamines, widely used in the treatment of symptoms of patients with allergic rhinitis, may also possess antiinflammatory properties. The mechanisms underlying this property, however, are not clearly understood. We have cultured epithelial cells from nasal biopsy specimens from patients with seasonal allergic rhinitis outside the pollen season and studied the effect of 0 to 10-3 mol/L fexofenadine, the main active metabolite of terfenadine, on eosinophil-induced changes in electrical resistance (measure of permeability) and release of proinflammatory mediators from these cells. Additionally, we have studied the effect of this drug on eosinophil cherootaxis and adherence to endothelial cells induced by conditioned medium from these human nasal epithelial cell (HNEC) cultures. Incubation of HNEC in the presence of eosinophils treated with opsonized latex beads significantly decreased the electrical resistance of these cultures, an effect that was abrogated by treatment of the cultures with 10-9 to 10-3 mol/L fexofenadine. Similarly, incubation of HNEC in the presence of eosinophils treated with latex beads also significantly increased the basal release of the chemokine 'regulated upon activation, normal T cell expressed and secreted' (RANTES) (from 96.0 to 613.0 fg/μg cellular protein; p < 0.05), IL-8 (from 42.0 to 198.5 pg/μg cellular protein; p < 0.05), granulocyte-macrophage colony-stimulating factor (GM- CSF) (from 0.54 to 3.4 pg/μg cellular protein; p < 0.05), and soluble intercellular adhesion molecule-1 (sICAM-1) (from 7.8 to 18.4 pg/μg cellular protein; p < 0.05) from HNEC. The eosinophil-induced release of IL-8, GM- CSF, and sICAM-1 from the HNEC was significantly attenuated by treatment with fexofenadine. Analysis of the effects of conditioned medium from HNEC demonstrated that this significantly increased both eosinophil chemotaxis and adherence to endothelial cells. Addition of 10-6 to 10-3 mol/L fexofenadine to the conditioned medium significantly attenuated eosinophil chemotaxis and adherence to endothelial cells. These results suggest that fexofenadine may reduce nasal inflammation by modulating the release of proinflammatory mediators and adhesion molecules from HNEC.
Abdelaziz, M. M., Devalia, J. L., Khair, O. A., Bayram, H., Prior, A. J., & Davies, R. J. (1998). Effect of fexofenadine on eosinophil-induced changes in epithelial permeability and cytokine release from nasal epithelial cells of patients with seasonal allergic rhinitis. Journal of Allergy and Clinical Immunology, 101(3), 410–420. https://doi.org/10.1016/S0091-6749(98)70256-8