Background: Glucocorticoids (GC) are potent inhibitors of peripheral blood eosinophil, basophil, and airway epithelial cell function.
Objectives: We compared in vitro the inhibitory activity of synthetic GC used for topical treatment in asthma and rhinitis on basophil histamine release (HR), eosinophil viability, and expression of vascular cell adhesion molecule-1 (VCAM-1) in the human bronchial epithelial cell line BEAS-2B.
Methods: Cells were treated for 24 hours with increasing concentrations (range 10(-13) to 10(-6) mol/L) of fluticasone propionate (FP), mometasone furoate (MF), budesonide (BUD), beclomethasone dipropionate (BDP), triamcinolone acetonide (TAA), hydrocortisone (HC), or dimethyl sulfoxide diluent before challenge. HR was measured by a fluorometric assay, viability of purified eosinophils was assessed by erythrosin B dye exclusion, and expression of VCAM-1 was measured by flow cytometry.
Results: GC induced a concentration-dependent inhibition of anti-IgE-induced HR. Maximum inhibition ranged from 59. 7% to 81%, with a rank order of GC potency of FP > MF > BUD > BDP congruent with TAA >> HC. Three-day treatment of eosinophils with GC concentration-dependently inhibited IL-5-induced eosinophil viability, with a rank of potency almost identical to that observed with basophil HR. The rank order of potency of GC for inhibition of the expression of VCAM-1 in BEAS-2B cells was MF congruent with FP >> BUD > TAA > HC congruent with BDP. Inhibitory concentration of 50% values revealed that epithelial cells were the most sensitive and eosinophils were the least sensitive.
Conclusions: These data, combined with information on pharmacodynamics of these drugs in vivo, may be useful in estimating GC local anti-inflammatory effects.