The triterpenoid lupeol attenuates allergic airway inflammation in a murine model

Asthma is a chronic inflammatory disease of the airways associated with a Th2 immune response. Despite their side effects, corticosteroids are the most used and effective drugs for treatment of asthma. In this work we investigated the efficacy of lupeol, a triterpenoid isolated from Diplotropis ferruginea Benth. (Fabaceae), in the treatment of bronchial asthma in BALB/c mice immunized with ovalbumin. Administration of lupeol caused the reduction of cellularity and eosinophils in the bronchoalveolar lavage fluid. Treatment with lupeol also reduced the production of mucus and overall inflammation in the lung. Levels of Type II cytokines IL-4, IL-5 and IL-13 were significantly reduced in mice treated with lupeol, an effect that was similar to that observed in dexamethasone-treated mice. In contrast, IgE production was not significantly altered after treatment with lupeol. In conclusion, our results demonstrate that lupeol attenuates the alterations' characteristics of allergic airway inflammation. The investigation of the mechanisms of action of this molecule may contribute for the development of new drugs for the treatment of asthma.