Objective: The purpose of the study was to investigate the role of LPS (lipopolysaccharide) in acute lung injury (ALI) and protective effect of Xuanbai Chengqi(XBCQ) decoction. Method: Thirty two Wistar species male rats were randomly divided into 4 groups:normal control group

LPS treated group

dexamethasone group and XBCQ group

8 rats each group. LPS (6 mg·kg-1) was injected into the caudal vein of rats to perform ALI model. Normal controls and model group were given the same volume of physiological saline. The dosage of dexamethasone was 5 mg·kg-1ip. The dosage of XBCQ was 7 560 mg·kg-1ig. The experiment lasted for 3 d.CD14 and nuclear factor-κB(NF-κB) mRNA in lung tissue were measured by real time fluorescence quantitative PCR (RT-PCR). The pathological manifestation of the lung was observed. The mechanism was also analyzed. Result: Compared with normal group

the protein content of bronchoaleolar alveolar lavage fluid

body index of lung

expression of CD14 and NF-κB mRNA

expression of CD14 protein were greatly increased in LPS treated group. Compared with LPS treated group

the protein content of bronchoaleolar alveolar lavage fluid

body index of lung

expression of CD14 and NF-κB mRNA

expression of CD14 protein were decreased in XBCQ group(P<0.05 or P<0.01). Light microscope indicates large areas of pulmonary hemorrhage and necrosis were in model group. The pathological manifestations of XBCQ group were much more ameliorated than those of the model group. The inflammation of bronchiole was reduced. Conclusion: XBCQ decoction lessens the injury of lung tissue and has protective effects on rats with ALI induced by LPS. The mechanism is possibly related to the inhibition of the expressions of CD14 and NF-κB mRNA in injured lung tissues.