Inhibitory effect of betotastine besilate on antigen-induced airway eosinophil infiltration and peripheral blood eosinophilia in mice.

Eosinophilic inflammations has been recognized as a characteristic of allergic diseases. The effect of betotastine besilate (betotastine, CAS 125602-71-3, TAU-284), a new potent antihistamine drug, on the model of eosinophilic inflammation which shows eosinophil infiltration into the airway and peripheral blood eosinophilia was examined. The mice sensitized with ovalbumin (OVA) were challenged with aerosolized OVA 12 days after the first sensitization. One day after the challenge, the numbers of leukocytes and eosinophils in bronchoalveolar lavage fluid (BALF) were increased and the increase lasted up to 10 days after the challenge. Additionally, peripheral blood eosinophilia was also observed and the change peaked on the third day after the challenge. Betotastine (10 mg/kg, b.i.d., p.o.) inhibited the increase of eosinophil number in BALF on the third day after the challenge and that in peripheral blood from 1 to 3 days after the challenge. These results suggest that betotastine is an effective drug against eosinophilic inflammation of allergic diseases.