Protective Effects of Morin Against Bleomycin-Induced Pulmonary Fibrosis in Mice

Background: Idiopathic pulmonary fibrosis (IPF) is a fatal and incurable lung disease. Morin, a natural product with antioxidant and anti-inflammatory activity, could reduce lung inflammation induced by lipopolysaccharide (LPS) and liver fibrosis in previous studies. Objectives: The aim of this study was to evaluate the antifibrotic activity of morin in the pulmonary fibrosis induced by bleomycin in mice. Methods: Pulmonary fibrosis was induced by the intratracheal instillation of bleomycin (3 mg/kg) in C57Bl/6J mice. Morin (10, 20, and 40 mg/kg, p.o.) was given to mice from day 0 to 21 after bleomycin administration. The mice were sacrificed on day 21 to measure the total number of cells, the percentage of leukocytes in bronchoalveolar lavage fluid (BALF), lung hydroxyproline content, lung index, and oxidative stress markers. Histopathological changes were evaluated by the microscopic examination of sections stained with hematoxylin-eosin and Masson’s trichrome. Results: Our data showed that treatment with morin significantly attenuated the infiltration of inflammatory cells, hydroxyproline content, lung index, and oxidative stress that were elevated in fibrotic lungs. In addition, morin could reduce the pathological changes induced by bleomycin. Conclusions: Based on the study, morin, probably by its anti-inflammatory and antioxidant activities, can attenuate pulmonary fibrosis induced by bleomycin in mice.