Effects of azelastine on neutrophil chemotaxis, phagocytosis and oxygen radical generation

The effects of azelastine, an orally active anti-allergic drug, on several inflammatory parameters of human neutrophils, including human neutrophil chemotaxis, phagocytosis and generation of reactive oxygen species (ROS), was examined. ROS generated in a cell-free, xanthine-xanthine oxidase system was also assessed. The species investigated were superoxide radical anion (O2-), hydrogen peroxide (H2O2) and hydroxyl radical (OH.). Azelastine significantly inhibited human neutrophil phagocytosis and the generation of O2-, H2O2, OH. by human neutrophils. However, the drug did not markedly affect human neutrophil chemotaxis or the ROS levels generated in the xanthine-xanthine oxidase system. The present study indicates that azelastine may exert an anti-inflammatory action by inhibiting human neutrophil phagocytosis as well as oxygen radical generation at the sites of inflammation.