Protective effects of allantoin against ovalbumin (OVA)-induced lung inflammation in a murine model of asthma.

Asthma is characterized by difficulty in breathing because of the constriction of the smooth muscles of the bronchi, as a result of inflammation. In the present study, we focus on the protective effects of allantoin against ovalbumin (OVA)-induced lung inflammation in a murine allergic model, and assess cytokine release, eosinophilia, and mucus hypersecretion. Allantoin treatment led to significant reduction in the levels of Ig(immunoglobulin)E and T-helper-2-type cytokines, such as IL(interleukin)-4 and IL-5, in bronchoalveolar lavage (BAL) fluid. Airway inflammatory-cell infiltration was remarkably alleviated in allantoin-treated asthma groups, compared with the control group. Moreover, allantoin-treated asthma groups exhibited a marked decrease in cytokine mRNA expression in lung tissues, compared with the control group. The effectiveness of allantoin was similar to that of montelukast, used as a positive control. These results support the utility of allantoin as a protective agent against asthma.