Antiallergic Effects of Caffeic Acid in Blomia Tropicalis Murine Model of Experimental Asthma

Background: Atopic asthma is a chronic airway inflammatory disorder, which is characterized by reversible airway obstruction, airway hyperresponsiveness and production of Th2-dominated response with the production of cytokines IL-4, IL-5 and IL-13. The most common drugs used to treat allergic respiratory diseases, control their symptoms, but also induce long-term side effects. Therefore, in order to mitigate these effects, new treatments with alternative drugs must be pursued to improve asthma control. Among several compounds investigated by the scientific community, caffeic acid (CA), a phenolic acid has shown important biological properties, such as antioxidant and anti-inflammatory. In this study we investigated the antiallergic effects of caffeic acid on inflammatory cytokines, in vitro, and in a murine model of experimental asthma induced by the Blomia tropicalis extract (Bt). Methods: We measured the concentration of cytokines (IL-4, IL-5 and IL-13) on spleen cell culture supernatants in vitro, using 25, 50 or 100 μM of CA. For in vivo experiments, AJ mice were sensitized (100 µg/ animal s.c) and challenged (10μg/ animal i.n) with Bt. Sensitized A/J mice were treated or not with CA (10, 100 or 200mg/Kg) or with 3mg/kg of Dexametazone (Dex) and the following parameters were analyzed: number of total cells in bronchoalveolar lavage (BAL); eosinophil peroxidase activity (EPO) in BAL; serum level of specific IgE, IgG1 and IgG2a; and histopathological changes in the lungs. Results: The CA oral treatment caused a reduction in total number of cells in BAL, EPO in lungs, serum level of specific IgG1 and histopathological changes showed attenuate allergic inflammation in the lungs. Additionally, we observed a significant decrease of Th2-type cytokines (IL-4, IL-5 and IL-13) on spleen cell culture supernatants.