Objective: To observe the therapeutic effect and mechanism of Mongolian Dongqingye-7 capsule for the pulmonary fibrosis induced by pingyangmycin in rats. Method: Totally 90 healthy SD rats were randomly divided into sham-operation group and model group after 1 week of adaptive breeding. Gap injection of pingyangmycin was done by using tracheal cartilage ring to establish the pulmonary fibrosis models in rats. Postoperative day 7

the rats were divided into Mongolian Dongqingye-7 capsule groups (120

240

480 mg·kg-1)

dexamethasone group (0.3 mg·kg-1)

sham-operation group and model group with same amount of normal saline. 7

14

28 days after the treatment

blood was taken to detect total antioxidant capacity (T-AOC);right lung was taken to detect transforming growth factor-β1 (TGF-β1) and hydoroxyproline(Hyp) content

while the left lung was fixed. Result: On day 7

14

28

as compared with the sham-operation group

the TGF-β1 protein expressions were significantly increased (P<0.05

P<0.01);lung coefficient was increased significantly (P<0.01);Hyp content in lung tissues was increased significantly (P<0.05

P<0.01);and total antioxidant capacity in serum was decreased significantly (P<0.05

P<0.01) in the model group at each observation point. As compared with the model group

TGF-β1 protein expression was decreased significantly in Mongolian drug groups (P<0.05

P<0.01)

and significantly decreased on day 14 and day 28 in hormone group (P<0.05);lung coefficient was significantly decreased in both Mongolian drug groups and hormone group (P<0.05

P<0.01);Hyp content in liver tissues was significantly decreased on days 7

14

28 in Mongolian drug high dose group and the hormone group (P<0.05

P<0.01)

and significantly decreased on days 14 and 28 days in Mongolian drug low dose group and mid dose group (P<0.05

P<0.01);total antioxidant capacity in serum was significantly increased on day 14 and day 28 in Mongolian drug mid dose group

high dose group and hormone group (P<0.05

P<0.01)

and significantly increased on day 28 in Mongolian drug low dose group (P<0.01). Conclusion: Mongolian Dongqingye-7 capsule has certain therapeutic effects for the pulmonary fibrosis induced by pingyangmycin in rats

and its preliminary analysis shows that the mechanism may be related to the expression of TGF-β1.