Suppressive Effects of the Anti-allergic Drugs, Tranilast and Azelastine, on the Lysophosphatidylserine-Dependent Activation of Rat Mast Cells

Anti-allergic drugs, tranilast and azelastine, were examined for their effects on lysophosphatidylserine (lysoPS)-dependent histamine release from rat mast cells. Although both compounds suppressed the histamine release in a dose-dependent manner, the inhibition was affected by lysoPS concentration differently. In the presence of an increasing concentration of lysoPS, the suppressive effect of tranilast decreased. The inhibition by azelastine, however, was independent of the concentration of lysoPS. The findings suggest that these two drugs inhibit lysoPS-dependent histamine release through essentially different routes.