Inhibition of Chemical Mediator Release from Human Leukocytes and Lung in Vitro by A Novel Antiallergic Agent, Kb-2413

Abstract
The effect of KB-2413 on IgE-mediated histamine and LTC4, release from leukocytes obtained from asthmatic patients who were sensitive to mites, and from human lung tissues passively sensitized with IgE myeloma serum was studied. KB-2413 inhibited the IgE-mediated chemical mediator release concentration dependently at a range of 10-4 to 3±10-3 M. KB-2413 did not enhance histamine release at a higher concentration unlike ketotifen. These findings suggest that the inhibitory effect of KB-2413 on the release of chemical mediators contributes to the anti-allergic activity of this compound.