Background. CrataBLis a protein isolated fromCrataeva tapiabark. It has been shown to exhibit several biological properties, including anti-inflammatory, analgesic, antitumor, and insecticidal activities. There are no studies evaluating the role ofCrataBLin experimental asthma models.Aim. To evaluate the effects ofCrataBLon lung mechanics, inflammation, remodeling, and oxidative stress activation of mice with allergic pulmonary inflammation.Materials and Methods. BALB/c mice (6-7 weeks old, 25-30g) were divided into four groups: nonsensitized and nontreated mice (C group, n=8); ovalbumin- (OVA-) sensitized and nontreated mice (OVA group, n=8); nonsensitized andCrataBL-treated mice (C+CR group, n=8); OVA-sensitized andCrataBL-treated mice (OVA+CR group, n=8). We evaluated hyperresponsiveness to methacholine, bronchoalveolar lavage fluid (BALF), pulmonary inflammation, extracellular matrix remodeling, and oxidative stress markers.Results. CrataBLtreatment in OVA-sensitized mice (OVA+CR group) attenuated the following variables compared to OVA-sensitized mice without treatment (OVA group) (all p<0.05): (1) respiratory system resistance (Rrs) and elastance (Ers) after methacholine challenge; (2) total cells, macrophages, polymorphonuclear cells, and lymphocytes in BALF; (3) eosinophils and volume fraction of collagen and elastic fibers in the airway and alveolar wall according to histopathological and morphometry analysis; (4) IL-4-, IL-5-, IL-13-, IL-17-, IFN-γ-, MMP-9-, TIMP-1-, TGF-β-, iNOS-, and NF-kB-positive cells and volume of 8-iso-PGF2αin airway and alveolar septa according to immunohistochemistry; and (5) IL-4, IL-5, and IFN-γaccording to an ELISA.Conclusion. CrataBLcontributes to the control of hyperresponsiveness, pulmonary inflammation, extracellular matrix remodeling, and oxidative stress responses in an animal model of chronic allergic pulmonary inflammation.