Effect of Ketotifen on the Production of Reactive Oxygen Species from Human Eosinophils Primed by Eotaxin

Ketotifen is an antiallergic drug and may have direct inhibitory effects on eosinophils. To investigate the anti-eosinophilic effect of ketotifen, we examined the effect of ketotifen on the production of reactive oxygen species (ROS) from eotaxin-primed human eosinophils. Ketotifen at 10(-10)-10(-6) mol/l significantly reduced the production of ROS evoked by A23187 from eosinophils primed by eotaxin. In contrast, ketotifen at 10(-5) mol/l significantly augmented the production in the absence of eotaxin. We demonstrated that appropriate concentrations of ketotifen may have direct inhibitory effects on eosinophil oxidative metabolism primed by eotaxin. Ketotifen may contribute to the treatment of allergic disease through its anti-eosinophilic effects.