Effect of Valerian Extract on Experimental Pulmonary Fibrosis in Rats

Objective To evaluate the effects and mechanism of valerian extract on bleomycin-induced pulmonary fibrosis in rats. Methods Wistar rats(irrespective of sex)were given a single intratracheal instillation of bleomycin at a dose of 5 mg·kg-1 to make a model of pulmonary fibrosis.65 survival rats were randomly divided into four groups: high-dose,low-dose(n=16,each)groups of Valerian,Colchicine group(n=16)and Model group(n=17).Each group was given the valeian extract at 100 mg ·kg-1 and 20 mg ·kg-1,100 μg ·kg-1 of colchicine and 10 mL· kg-1 of N.S.daily since the second day of model establishment.6 rats were killed in each group on day 7,10 rats were killed on day 28.Rats in control group(n=8) were instilled with saline intractracheally at a dose of 10 mL· kg-1and treated with N.S.10 mL· kg-1.Rats in the control group were all killed on day 28.The right lower pulmonary lobes were harvested for HE-staining,and observed by Masson-staining.Expression of TGF-β1 was examined by immunohistochemistry and HYP was measured. Results 3 rats(18.75%) were dead during experiment in the model group.Compared with the model,rats in valerian and colchicine groups showed attenuated alveolitis and lower expression of TGF-β1on 7 d(P0.05).The pulmonary fibrosis in valerian and colchicine groups was ameliorated on 28 d,and the contents of HYP was decreased as well,in comparison with those in the model group. Conclusion Valerian extract could reduce the degree of alveolitis and fibrosis induced by bleomycin which may be due to suppression of TGF-β1.