The effects of asthma medications on reactive oxygen species production in human monocytes.

OBJECTIVE Asthma is a chronic inflammatory airway disease induced by many environmental factors. The inhalation of allergens and pollutants promotes the production of reactive oxygen species (ROS) leading to airway inflammation, hyper-responsiveness, and remodeling in allergic asthma. The effects of asthma medications on ROS production are unclear. The present study investigated the anti-ROS effects of current asthma medications including inhaled corticosteroid (ICS; budesonide and fluticasone), leukotriene receptor antagonist (LTRA; montelukast), long-acting β2 agonists (LABAs; salmeterol and formoterol), and a new extra-LABA (indacaterol). METHODS The human monocyte cell line THP-1 cells were pre-treated with different concentrations of the asthma medications at different time points after hydrogen peroxide (H2O2) stimulation. H2O2 production was measured with DCFH-DA by flow cytometry. RESULTS Montelukast, fluticasone, and salmeterol suppressed H2O2-induced ROS production. Indacaterol enhanced H2O2-induced ROS production. Budesonide and formoterol alone had no anti-ROS effects, but the combination of these two drugs significantly suppressed H2O2-induced ROS production. CONCLUSIONS Different asthma medications have different anti-ROS effects on monocytes. The combination therapy with LABA and ICS seemed not to be the only choice for asthma control. Montelukast may also be a good supplemental treatment for the poorly controlled asthma because of its powerful anti-ROS effects. Our findings provide a novel therapeutic view in asthma.