Chronic obstructive pulmonary disease (COPD) can lead to chronic and obstructive bronchitis and emphysema resulting in decreased bronchial lumen size. This study evaluated the effect of CrataBL, a protein isolated from the bark of Crataeva tapia, on lung mechanics, inflammation, and remodeling after elastase-induced pulmonary alterations in mice. The use of CrataBL led to decreased mechanical alterations, alveolar septum disruption (Lm), number of macrophage and neutrophil cells in the BALF, and TNF-alpha, MMP-9, MMP-12, TIMP-1, eNOS, and iNOS positive cells in the airways and alveolar walls compared to the animals in the ELA group. Moreover, a reduction in MUC-5-positive cells in the airway walls was observed. In conclusion, CrataBL attenuates changes in lung mechanics, inflammation, extracellular lung remodeling, and oxidative stress responses induced by the administration of elastase and decreased the volume fraction of isoprostane, collagen, and elastic fibers in the airways and alveolar walls compared to the animals in the ELA groups. Therefore, CrataBL is a potential therapeutic tool in the treatment of COPD. (C) 2015 Elsevier Ltd. All rights reserved.