Protective effect of phenylethanoid glycosides extracted from phlomis younghusbandii on acute high altitude pulmonary edema in rats / 解放军医学杂志

ABSTRACT

Objective To investigate the protective effect of phenylethanoid glycosides (PhGCs) extracted from Phlomis younghusbandii on acute high altitude pulmonary edema (HAPE) in rats. MethodsSeventy male Wistar rats were randomly divided into 7 groups (10 each) normoxia control group (NG, distilled water), normoxia+PhGCs group (NG+PhGCs, 400mg/ kg), hypoxia model group (HG, distilled water), dexamethasone (Dex, 4mg/kg), and three groups of PhGCs in high (PhGCs-H, 400mg/kg), middle (PhGCs-M, 200mg/kg) and low (PhGCs-L, 50mg/kg) dosage. PhGCs extracted from Phlomis younghusbandii were administered prophylactically to rats for 3 days, and HAPE was induced by the hypobaric hypoxia exposure for 72 hours in an animal decompression chamber with the chamber pressure of 267mmHg to simulate an altitude of 8000m. The water content of rat lung tissue was determined with wet/dry specific gravity method, and histopathologic changes were observed with HE staining. The enzymatic activities of SOD and GSH, and the contents of MDA in lung tissue were determined with spectrophotometry, and the contents of IL-1β, TNF-α in serum and lung tissue were determined with ELISA. ResultsCompared with NG group, no obvious difference was found in the water content of rat lung tissue in NG+PhGCs group, but the water content increased obviously in HG group (P<0.05). Compared with NG group, lung tissue congestion and edema were found in HG group, with a heavy inflammatory cell infiltration, widening of alveolar interval, and thickening of alveolar wall were found. The enzymatic activities of SOD and GSH were notablely depressed, and the contents of MDA in lung tissue, and the contents of IL-1β and TNF-α in serum and lung tissue remarkably increased (P<0.05). Compared with HG group, the water content of rat lung tissue in each PhGCs group decreased obviously. Inflammatory cells infiltration, widening of alveolar interval, and thickening of alveolar wall, the enzymatic activity of SOD and GSH increased, and the contents of IL-1β, TNF-α and MDA decreased significantly in PhGCs groups (P<0.05). Conclusion PhGCs extracted from Phlomis younghusbandii may alleviate the oxidative stress and inflammatory response of acute lung injury induced by acute hypoxia. PhGC showed a protective effect against acute HAPE in a rat model.