Protective Effect of Emodin against Airway Inflammation in the Ovalbumin-Induced Mouse Model

Objective:To investigate whether emodin exerts protective effects on mouse with allergic asthma.Methods:A mouse model of allergic airway inflammation was employed.The C57BL/6 mice sensitized and challenged with ovalbumin(OVA) were intraperitoneally administered 10 or 20 mg/kg emodin for 3 days during OVA challenge.Animals were sacrificed 48 h after the last challenge.Inflammatory cell count in the bronchoalveolar lavage fluid(BALF) was measured.The levels of interleukin(IL)-4,IL-5,IL-13 and eotaxin in BALF and level of immunoglobulin E(IgE) in serum were measured with enzyme-linked immuno sorbent assay kits.The mRNA expressions of IL-4,IL-5,heme oxygenase(HO)-1 and matrix metalloproteinase-9(MMP-9) were determined by real-time quantitative polymerase chain reaction.Results:Emodin induced significant suppression of the number of OVA-induced total inflammatory cells in BALF.Treatment with emodin led to significant decreases in the levels of IL-4,IL-5,IL-13 and eotaxin in BALF and total IgE level in serum.Histological examination of lung tissue revealed marked attenuation of allergen-induced lung eosinophilic inflammation.Additionally,emodin suppressed IL-4,IL-5 and MMP-9 mRNA expressions and induced HO-1mRNA expression.Conclusion:Emodin exhibits anti-inflammatory activity in the airway inflammation mouse model,supporting its therapeutic potential for the treatment of allergic bronchial asthma.