ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by dyspnea and progressive loss of lung function. In this study, the preventive and therapeutic effects of methanolic extract of Glycyrrhiza glabra on pulmonary fibrosis were investigated. Pulmonary fibrosis was induced by administration of bleomycin (BLM) into the left lung of rats. Methyl-prednisolone (M-pred, 4 mg/kg) and methanolic extract of G. glabra (500 mg/kg) were injected intraperitoneally from the 1st to 14th days in the preventive group and from the 14th to 28th days in the therapeutic group once every day. Pulmonary inflammatory and fibrotic indices were evaluated by hematoxylin and eosin (H&E) and Masson's trichrome, respectively. The level of hydroxyproline as an index of pulmonary fibrosis and malondialdehyde (MDA) as an oxidative stress biomarker and catalase were measured by the related ELISA Kits. Pulmonary inflammatory and fibrotic indices in the G. glabra and M-pred groups significantly reduced compared with BLM group. G. glabra decreased the level of hydroxyproline in pulmonary tissue similar to M-pred. MDA reduced in G. glabra and M-pred groups compared with BLM group. The activity of catalase increased in the G. glabra preventive group. According to the results, G. glabra prevented and treated pulmonary fibrosis and inflammation in rats. Therefore, G. glabra may be suggested for the prevention and treatment of pulmonary fibrosis and inflammation.
Subject(s)
Glycyrrhiza/chemistry , Inflammation/drug therapy , Plant Extracts/pharmacology , Pulmonary Fibrosis/drug therapy , Animals , Bleomycin/toxicity , Catalase/metabolism , Disease Models, Animal , Hydroxyproline/metabolism , Inflammation/pathology , Male , Malondialdehyde/metabolism , Methanol/chemistry , Methylprednisolone/pharmacology , Oxidative Stress/drug effects , Pulmonary Fibrosis/pathology , RatsABSTRACT
OBJECTIVE: Pulmonary fibhrosis is a disease of the connective tissues in the respiratory system. Nigella sativa has been used for the treatment of pulmonary diseases like asthma. This study investigated the early and late preventive effect of methanolic extract of N. sativa on a bleomycin- induced pulmonary fibrosis model. MATERIALS AND METHODS: This study was carried out using 52 rats. Pulmonary fibrosis was induced by a single endotracheal injection of bleomycin (5 mg/kg). Extract of N. sativa (500 mg/kg per day) or methylprednisolone succinate (4 mg/kg per day) was injected intraperitoneally in two periods (i.e. days 1-14 as early preventive group and days 15-28 days as late preventive group). The lung tissues were histologically examined at the end of each period and inspected for the amount of hydroxyproline and biomarkers of oxidative stress. RESULTS: The pulmonary inflammation and fibrosis were significantly decreased in groups treated with methylprednisolone and N. sativa extract compared to bleomycin group in both early and late prevention groups (p<0.001). The hydroxyproline concentration in pulmonary tissue was significantly decreased in N. sativa and methylprednisolone groups compared to the bleomycin group in both prevention groups (p<0.001). Significant reductions in lipid peroxidation (p<0.001) and increases in catalase activity were also observed in N. sativa and methylprednisolone groups compared to bleomycin group. CONCLUSION: This study suggested that N. Sativa extract is effective for early and late prevention of pulmonary fibrosis and inflammation. However, more studies are needed to identify its anti-inflammatory and anti-fibrotic mechanisms in the respiratory system.
