Total polysaccharide of Y upingfeng protects against bleomycin-induced pulmonary fibrosis via inhibiting transforming growth factor-β1-mediated type I collagen abnormal deposition in rats.

Objective This study was to explore the antifibrotic effect and the possible mechanism of total polysaccharides of Y upingfeng ( YPF- P) on bleomycin ( BLM)-induced pulmonary fibrosis in rats. Methods Pulmonary fibrosis was induced in Sprague- Dawley rats by BLM (5 mg/kg), killed 14 and 28 days after BLM administration by abdominal aorta exsanguination and removed the lungs. Lung coefficient was counted at the same time. Besides, H&E and Masson's trichrome staining for histopathological changes of lung tissues were observed. Additionally, western blotting and immunohistochemical staining techniques were used to detect expression of transforming growth factor-β1 ( TGF-β1), type I collagen ( Col- I) and α-smooth muscle actin (α- SMA). Finally, the levels of Col- I and hydroxyproline ( HYP) in lung tissues were also utilized. Key findings YPF- P alleviated the increase of lung coefficient induced by BLM instillation in pulmonary fibrosis rat, pathologic changes and collagen distribution were obviously ameliorated, while the increase of α- SMA-positive cells and TGF-β1 expression was prevented after YPF- P treatment. Moreover, the contents of HYP and Col- I were decreased in YPF- P group. Conclusions YPF- P had antifibrotic effect in experiment, which may reduce the synthesis and promote the deposition of Col- I via suppressing the increase of TGF-β1-mediated activation of myofibroblasts. [ABSTRACT FROM AUTHOR]