Objective:To investigate the protective effect of baicalin on acute lung injury(ALI) rats induced with lipopolysaccharide (LPS). Method: SD rats were randomly divided into 6 groups (n=10): control

ALI model

dexamethasone (5 mg·kg-1) and baicalin groups (50

100

200 mg·kg-1). After 1 h of the last administration

the model of ALI was established by intratracheal instillation of LPS. After 6 h of the LPS instillation

the serum was collected for determinating the interleukin (IL) -1β

IL-8 and tumor necrosis factor (TNF) -α levels. In addition

the ratios of lung wet to dry weight and water content were also measured. The activity of myeloperoxidase (MPO) and cyclooxygenase (COX) -2 in lung was determinated. Result: Compared with control group

ALI group exhibited a higher wet to dry radio and water content in lung (P＜0.05). Compared with ALI model group

baicalin significantly decreased the levels of IL-1β

IL-8 and TNF-α in serum (P＜0.05)

reduced the wet to dry ratio and water content in a dose-dependent manner (P＜0.05). Moreover

baicalin significantly decreased the activity of MPO and COX-2 in lung (P＜0.05). Conclusion: Baicalin had a protective effect on ALI rats induced with LPS and the mechanism maybe related to the suppression of inflammation.