Effect of Betulin on Inflammatory Biomarkers and Oxidative Status of Ova-Induced Murine Asthma

Asthma is a chronic, serious allergic inflammatory disease in the airway. The inflammation in the airway is induced by the allergic T-helper 2 cells (Th2 cells), which leads to unfettered production of inflammatory cytokines. The accretion of inflammatory cells in the airway also speeds up the secretion of reactive oxygen species (ROS) and suppresses antioxidative processes. Hence, the present work aimed to study the antiasthmatic efficacy of betulin and its effect in suppressing the inflammatory markers of ovalbumin (OVA) challenged asthmatic mice. The observed results revealed that the levels of inflammatory cells including neutrophils, eosinophils, lymphocytes, and macrophages were effectively decreased by betulin treatment; furthermore, the inflammatory markers IL-4, IL-5, IL-13, and TNF-α levels were notably suppressed by betulin administration in OVA-challenged asthmatic mice. Similarly, the oral administration of betulin showed a reduction in IgE level and elevation in the IFN-γ level in bronchoalveolar lavage fluid (BALF). The elevated levels of antioxidant enzymes like catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD) were observed in betulin treated mice. Furthermore, reduced levels of reactive oxygen species like NO2, NO3, and MDA were noted in the betulin treated group. Consistently, airway hyperreactivity (AHR) was depleted in the betulin administered group compared with the OVA-challenged asthmatic group. Betulin treatment was revealed to have noteworthy antiasthmatic effects mediated by the suppression of production of inflammatory cells and the expression of other inflammatory markers. Furthermore, the elevation in the level of antioxidant markers helped to disclose the original regulatory mode of betulin on asthma treatment.