Protective effect of rhubarb on endotoxin-induced acute lung injury.

To approach the mechanism of lipopolysaccharide (LPS) in causing acute lung injury (ALI) and the protective effect of rhubarb and dexamethasone, lung specimens were examined with macroscopy, microscopy, electron microscopy and the biological markers of ALI including lung wet/dry weight, the rate of neutrophils and protein content in the pulmonary alveolar lavage fluid, pulmonary capillary permeability and pulmonary alveolar permeability index were observed. The mechanism of the ALI is mainly due to direct injury of alveolar epithelium and pulmonary vascular endothelium. Rhubarb and dexamethasone could significantly reduce the edema of the lung tissue, decrease the red blood cell exudation, neutrophil infiltration and plasma protein exudation in the alveoli and all the biological markers in comparison with the ALI model rats, indicating they have protective action on vascular endothelium and alveolar epithelium.