Effect of valerian extract treatment on experimental pulmonary fibrosis in rats

OBJECTIVE To evaluate the effects and mechanism of valerian extract treatment on bleomycin-induced pulmonary fibrosis of rats.METHODS Healthy Wistar rats(irrespective of sex)were given with a single intratracheal instillation of bleomycin at a dose of 5 mg·kg-1 to make model of pulmonary fibrosis.49 survival rats were randomly divided into 3 groups: high-dose groups(n=16),low-dose groups(n=16)of Valerian and model group(n=17).Valerian group was given respectively with the Valerian extract at 100 mg·kg-1and 20 mg·kg-1 after second day(once every day).Model group was given 10 mL·kg-1saline after second day(once every day).And in each groups,6 rats were killed on day 7,10 rats were killed on day 28 after instillation respectively.Rats in control group(n=8) were instilled with saline intractracheally and saline was given everyday at a dose of 10 mL·kg-1.Control group was 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 The left lower pulmonary lobes were got for assay of HYP.RESULTS No obvious patho-transformation in control group.The alveolitis in valerian groups were ameliorated compared with model group on 7d,the expressions of TGF-β1 were weaker than model group and the mean integrated optical densities of TGF-β1 were lower than model group(P0.05).The contents of HYP in all groups had no significant differences.The pulmonary fibrosis in the valerian groups were ameliorated compared with model group on 28d,the contents of HYP in valerian groups were lower than model group(P0.05).The expressions of TGF-β1 were lower than model group.CONCLUSION Valerian extract could reduce the degree of alveolitis and fibrosis induced by bleomycin through depression of TGF-β1.