House dust mites (HDM) are one of the commonest aeroallergens worldwide. With understanding the heterogeneity of asth-matic inflammation, the role of innate immunity has been highlighted in asthma pathogenesis. Based on this trend, murine models of allergic airways disease for asthma research have recently switched from the use of surrogate allergen ovalbumin together with adjuvant to use of the HDM extract. This has accelerated understanding of how adaptive and innate immunity generate downstream pathology. In this study, we have investigated the effects of a glutathione-based antioxidant, L-2-ox-othiazolidine-4-carboxylic acid (OTC) on the HDM-induced airway inflammation and hyperresponsiveness. HDM-sensitized and -challenged mice showed the typical allergic airway inflammation and hyperresponsivenss, the increased levels of Th2 cytokines, IL-17, IL-1β, and TNF-α in lungs, and increased levels of GSSG and decreased lev! els of GSH in lung tissues. Very interestingly, the administration of OTC restored the levels of GSH, decreased the numbers of airway inflammatory cells in BAL fluids, the peribronchial and perivascular inflammation in lung tissues, the increase in the levels of inflammatory cytokines, and bronchial hyperresponsiveness in HDM-sensitized and -challenged mice. These findings suggest that antioxidant treatment using OTC is very effective in a more clinically relevant murine model, i.e. HDM-induced asthma model, for bron-chial asthma.