OBJECTIVE: The aim of this study was to investigate the prophylactic effect and some mechanisms of action of triterpene acids of loquat (TAL) on bleomycin A5-induced pulmonary fibrosis rats. METHODS: A model of pulmonary fibrosis was induced by injecting rats with a single dose of bleomycin A5 (5 mg/kg) into the trachea. From the second day, rats in the preventive groups were treated with TAL (50, 150 or 450 mg/kg) or dexamethasone (1.2 mg/kg). On the 28th day after medication, the rats were killed and haematoxylin-eosin or masson staining was used to evaluate the degree of pulmonary fibrosis. Tumour necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1) levels in alveolar macrophage culture supernatant were detected by ELISA. The mRNA expression of TNF-α and TGF-β1 in alveolar macrophage was observed by RT-PCR. KEY FINDINGS: Lung histopathological examination showed TAL could ameliorate the structure of the lung and alleviate fibrogenesis. At the same time, TAL (150 or 450 mg/kg dose group) could reduce the expression of TNF-α and TGF-β1 in alveolar macrophage of rats with pulmonary fibrosis at either the protein or mRNA level. CONCLUSIONS: TAL had a positive prophylactic effect on lung fibrosis, which might have been related to its reduction on TNF-α or TGF-β1 expression in the alveolar macrophage of pulmonary fibrosis rats.
OBJECTIVE: The aim of this study was to investigate the prophylactic effect and some mechanisms of action of triterpene acids of loquat (TAL) on bleomycin A5-induced pulmonary fibrosisrats. METHODS: A model of pulmonary fibrosis was induced by injecting rats with a single dose of bleomycin A5 (5 mg/kg) into the trachea. From the second day, rats in the preventive groups were treated with TAL (50, 150 or 450 mg/kg) or dexamethasone (1.2 mg/kg). On the 28th day after medication, the rats were killed and haematoxylin-eosin or masson staining was used to evaluate the degree of pulmonary fibrosis. Tumour necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1) levels in alveolar macrophage culture supernatant were detected by ELISA. The mRNA expression of TNF-α and TGF-β1 in alveolar macrophage was observed by RT-PCR. KEY FINDINGS: Lung histopathological examination showed TAL could ameliorate the structure of the lung and alleviate fibrogenesis. At the same time, TAL (150 or 450 mg/kg dose group) could reduce the expression of TNF-α and TGF-β1 in alveolar macrophage of rats with pulmonary fibrosis at either the protein or mRNA level. CONCLUSIONS:TAL had a positive prophylactic effect on lung fibrosis, which might have been related to its reduction on TNF-α or TGF-β1 expression in the alveolar macrophage of pulmonary fibrosisrats.