Allergic bronchial eosinophilia: a therapeutic approach for the selection of potential bronchial anti-inflammatory drugs.

Aeroallergen-induced infiltration of eosinophils in the bronchoalveolar lavage fluid (BALF) in guinea pigs was used as a marker of bronchial inflammation. Drugs were administered orally 4 h after aeroallergen challenge. Allergic bronchial eosinophilia in guinea pigs was inhibited by orally administered dexamethasone and methylprednisolone. Terfenadine (a newer H1-receptor antagonist), theophylline (a nonspecific phosphodiesterase inhibitor), and salbutamol (a beta 2-agonist) did not influence allergic eosinophilic infiltration. Many of these agents, administered prophylactically, have been reported to suppress allergic eosinophilic infiltration in the BALF of guinea pigs. Methylprednisolone, a steroid, inhibits allergic bronchial eosinophilia regardless of the time of administration; that is, 2 h before or 4 h after aeroallergen challenge. The therapeutic approach used in this study may facilitate drug discovery for bronchial inflammation/asthma.