隐孔菌多糖对小鼠内毒素性肺损伤的保护作用

Protective effects of cryptoporus polysaccharide on lipopolysaccharide-induced lung injuries in mice

目的研究隐孔菌多糖(cryptoporus polysaccharide,CP)对脂多糖(LPS)诱导小鼠急性肺损伤(ALI)的影响。方法LPS气管内滴入诱导小鼠ALI模型,设立对照组、模型组、隐孔菌多糖(1、10、30mg·kg-1)组和地塞米松(0·5mg·kg-1)组,检测支气管肺泡灌洗液(BALF)和肺组织中中性粒细胞的浸润情况、比色法测定伊文氏兰渗出量及BALF中的中性粒细胞髓过氧化物酶(MPO)、超氧根阴离子自由基(O2·)含量,观察肺组织病理及肺湿重/干重比值改变,ELISA法检测肺组织中TNF-α和IL-10含量。结果隐孔菌多糖(1、10、30mg·kg-1)尾静脉给药能够抑制BALF MPO活性,改善ALI小鼠BALF及肺组织中的炎症细胞的聚集和肺水肿程度,降低肺组织中TNF-α水平及升高IL-10/TNF-α比值。结论隐孔菌多糖通过抑制中性粒细胞黏附、趋化、减轻肺水肿等改善LPS诱导的小鼠ALI。

Aim To investigate the effect of cryptoporus polysaccharide （CP） on lipopolysaccharide （LPS） -induced lung injuries in vivo in mice. Methods Acute lung injury was induced in ICR mice by instilling intratracheally with LPS, and animals were assigned to six groups：control, model,CP（ 1, 10, 30 mg ·kg^-1 ）and dexameathone （0. 5 mg · kg^-1 ）. The infiltration of neutrophils in brochoalveolar lavage fluid （BALF） and lung tissue was detected by cell count and morphological analysis. Evans Blue extravasation, the activities of myeloperoxidase （MPO） and superoxide anion（ O2^- ） were measured by colorimetry. Pathologi- cal sections were observed and wet weight/dry weight ratio was measured, tumor necrosis factor-α and interleukin-10 in the lung tissue were detected with ELISA. Results CP （ 1,10,30 mg ·kg^-2, iv） could decrease MPO activity in BALF, ameliorate lung edema and the aggregation of inflammatory cells in BALF and lung tis- sue, and it could decrease TNF-α level, increase the ratio of IL-10/TNF-α in lung tissue as well. Conclusion These studies demonstrate protective effects of CP on EPS-induced lung injuries in mice through the inhibition of cell adhesion and chemotaxis of neutro- phils and relief of lung edema.