OBJECTIVETo study the protective mechanisms of the astragaloside against ischemia-reperfusion lung injury in rats.

METHODSIschemia-reperfusion lung injury was induced in SD rats. Astragalus armour glucoside was dissolved in 1% of sodium carboxymethyl cellulose at different concentrations (8, 6, and 3 mg/ml) was intragastrically administered in the rats at the dose of 1 ml/100 g. Cellular and subcellular structural changes in the lung tissue were observed at the end of the experiment using optical and transmission electron microscope, with the wet/dry ratio of the lung tissue and myeloperoxidase (MPO) activity measured.

RESULTSThe wet/dry ratio and myeloperoxidase activity in the lung tissue were significantly higher in the model group than in the sham-operated group (P<0.05), and were significantly lowered by the treatment with astragalus armour glucoside at different doses (P<0.01 or 0.05), and the effect was especially obvious in rats receiving a moderate dose. Pulmonary capillary expansion, erythrocyte leakage and exudate in the alveolar space with obvious pathological changes in the type I and II epithelial cells were observed in model group. Pulmonary capillary expansion was reduced in rats treated with high, medium and low dose of Astragalus armour glucoside, and the medium dose group showed the most obvious effect, in which no edema fluid in the alveolar space or erythrocyte leakage was found with also reduced type II lung epithelial cell degranulation.

CONCLUSIONAstragaloside has obvious antioxidant effect in rats with ischemia-reperfusion lung injury, and a medium dose produces the best effect.