RÉSUMÉ
Objective To investigate the effects of astragalus polysaccharides on radio-pulmonary lesion.Methods 48 Wistar rats were divided into normal group, model group, astragalus polysaccharides treated group and dexamethasone treated group, each had 12 rats.Models of radio-pulmonary lesion of rats in later three groups were established by whole-thorax irradiation 20 Gy, then normal group was pretending to irradiation.Rats in normal group and model group were given 0.9% NaCl, astragalus polysaccharides treated group and dexamethasone treated group were given astragalus polysaccharides(8mg/mL) and dexamethasone(0.05mg/mL), accordingly.All rats were with 8 weeks, at 2 w and 8 w post-injury, 6 rats in each group were selected randomly and anesthesia to death.The erythrocytes and leukocytes in blood and bronchoalveolar lavage fluid ( BALF) in each group were detected and histological examination of lung tissues were performed by Haematoxylin and Eosin staining to study general morphology.Results Radiation-induced lung injury rat model were successfully constructed, general observation showed that irradiated rats gradually appear listlessness, reduce the volume of activities, arched, hair removal and other symptoms, astragalus polysaccharide (APS) and dexamethasone treated rats had gradual improvement than model group.Compared with control group, erythrocytes and leukocytes counts in serum of model group at 2 w and 8 w post-injury were significantly decreased(P <0.05), the numbers of erythrocytes and leukocytes in BALF were significantly increased(P <0.05). Compared with model group group, the leukocytes, erythrocytes and neutrophils counts in serum of astragalus polysaccharides treated group and dexamethasone treated group were all increased(P <0.05), respectively, and the number of leukocytes and erythrocytes in BLAF were significantly decreased(P<0.05).All the indexes between two groups had no significant difference.The pathological changes of lung tissues showed that rats in model group had rupture alveolar wall, widened alveolar interval, pulmonary interstitial hyperplasia, and the alveolar space and interstitial lung stroma had a large number of inflammatory cells exudation.The symptoms in astragalus polysaccharides treated group and dexamethasone treated group were all alleviated, and there was no significant difference between the two groups.Conclusion Astragalus polysaccharides have therapeutic effect on radio-pulmonary lesion in rats, and the therapeutic effects of astragalus polysaccharides are roughly similar to dexamethasone.Further research is needed to elucidate the mechanism behind the effects of astragalus polysaccharides in order to develop appropriate treatment.