[Effect of compound panax notoginsenoside granules on TGF-β1/Smads signaling pathway in rats with bleomycin-induced pulmonary fibrosis].

OBJECTIVE

To investigate the intervention effects and mechanisms of the compound panax notoginsenoside granules (CPNG) on bleomycin-induced pulmonary fibrosis in rats.

METHODS

Sixty male Sprague-Dawley rats were randomly divided into 6 groups, including normal control group, model group, prednisolone group, and CPNG (high, middle and low-dose) groups. Each group included 10 Sprague-Dawley rats. Except the control group, pulmonary fibrosis model rats were injected with bleomycin (5 mg/kg) via trachea. On the second day of the bleomycin injection, the rats in each treatment group were given prednisolone (3.33 mg/kg) and corresponding doses of CPNG (100, 50, 25 mg/kg) by nasogastric feeding daily; the normal control group and the model group were given the equal volume distilled water daily. Twenty-eight days later, all rats were executed and the lung tissues were subjected to the histopathological examination via HE and Masson staining. The hydroxyproline (HYP) in lung tissues was assessed by alkaline hydrolysis. The expressions of TGF-β1, Smad2, and Smad7 proteins were analyzed by Western blotting.

RESULTS

Compared with the model group, the histopathological results revealed that CPNG dramatically decreased the severity of lung inflammation and fibrosis in rats (P<0.01). Compared with the control group, the HYP in lung tissues was reduced in all of the CPNG groups (P<0.01). Moreover, CPNG inhibited the expressions of TGF-β1 or Smad2 proteins (P<0.01), but enhanced the expression of Smad7 protein in the rat lung tissues (P<0.01).

CONCLUSIONS

CPNG has the prevention and treatment effect on the bleomycin-induced pulmonary fibrosis in rats, and it might be attributed to the regulation on the TGF-β1/Smads signaling pathway.