A Chinese Traditional Therapy for Bleomycin-Induced Pulmonary Fibrosis in Mice

Abstract

Pulmonary fibrosis is a chronic and fatal disease of lung tissue with high incidence and mortality in the world. The exploration of effective treatment for pulmonary fibrosis remains an urgent challenge. In our study, Qingfei Xieding was investigated as a novel Chinese traditional patent medicine against pulmonary fibrosis. A pulmonary fibrosis mouse model was constructed by injecting with bleomycin sulfate. Following Qingfei Xieding administration, lung samples were collected to assess pulmonary phenotype changes by analyzing lung coefficient, wet/dry, and histopathologic section. Levels of nitric oxide (NO), hydroxyproline (HYP), malondialdehyde (MDA), and total antioxidant capacity were measured to evaluate the degree of oxidation. A single-cell gel electrophoresis (SCGE) assay was used to evaluate bleomycin-induced DNA damage. Western blotting and real-time quantitative PCR were performed to determine the abundance of inducible nitric oxide synthase (iNOS), connective tissue growth factor (CTGF), alpha smooth muscle actin (α-SMA), and fibronectin (FN). In the present study, Qingfei Xieding administration significantly attenuated bleomycin-induced pulmonary fibrosis in mice by reducing lung coefficient, wet/dry, NO, HYP, and MDA as well as the expression of iNOS, CTGF, α-SMA, FN, and DNA damage. The results indicated that Qingfei Xieding is effective to resist oxidative damage and histopathologic lesion, serving a protection role on bleomycin-induced pulmonary fibrosis.

Figure 1

Effect of Qingfei Xieding on histopathologic changes of lung-induced by bleomycin in mice. (a) Saline-water-treated rat; (b) BLM-water-treated rat; (c) BLM-Qingfei-treated rat; (d) saline-Qingfei-treated rat. Compared with the animals of the BLM-water group, lung histologic findings on the BLM-Qingfei group showed less fibrotic lesions. All panels were stained with HE and are shown at the same magnification. Scale bar, 100 μm.

Figure 2

Western blotting analysis for iNOS, CTGF, α-SMA, and FN expression in lung tissues. GAPDH, a housekeeping gene, was selected as the internal reference to determine the same sample loading.

Figure 3

Single-cell gel electrophoresis (SCGE) observed the DNA damage.

Figure 4

Relative transcriptional levels of iNOS, CTGF, α-SMA, and FN genes detected by qRT-PCR. Compared with the control group, the relative levels of the related genes were higher than those of the BLM model group. Qingfei Xieding down regulated the transcription of those pathway genes. ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗P < 0.001 (versus the model).