Effects of Erythronium sibiricum bulb polysaccharides on oxidative stress in asthmatic mice

ObjectiveTo explore the effect of Erythronium sibiricum bulb polysaccharides on asthma and its mechanism based on oxidative stress.MethodsFifty female BALB/c mice were randomly divided into the negative control group， asthma model group， dexamethasone group， low and high-dose Erythronium sibiricum bulb polysaccharides groups. Except the negative control group， the asthma model was established by sensitizing with chicken egg albumin （OVA）. The number and classification of inflammatory cells in bronchoalveolar lavage fluid （BALF） were determined by a whole blood analyzer. Hematoxylin-eosin （HE）， Periodate acid-Schiff （PAS） and Masson staining were used to observe the lung pathology of asthmatic mice. The contents of malondialdehyde （MDA） and the activity of superoxide dismutase （SOD） in serum were detected by colorimetry. Determination of protein expression and mRNA abundance of nuclear factor erythroid2-related factor 2（Nrf2）， HemeoxygenasE1 （HO-1） and Vascular endothelial growth factor （VEGF） in the lung were detected by immunohistochemistry and real-time fluorescence determination polymerase chain reaction （RT-PCR）.ResultsCompared with the negative control group， the numbers of total inflammatory cells， neutrophils， monocytes and eosinophils in the BALF of the model group were significantly increased （P<0.05）， as well as the inflammatory infiltration of lung tissue was obvious. Meanwhile， the collagen deposition and mucus secretion increased along with the hyperplasia of the cup cell. The MDA content was increased （P<0.05） while the SOD activity was inhibited （P<0.05） in the serum of asthmatic mice. The protein expression and mRNA abundance of Nrf2， HO-1 and VEGF in lung tissues were increased （P<0.05） in the model group. Compared with the model group， after administration of Erythronium sibiricum bulb polysaccharides， the results of inflammatory cell classification and counting indicated that the total number of inflammatory cells， neutrophils， monocytes and eosinophils were significantly decreased （P<0.05）， and the pathological lung conditions were improved. The protein expression levels and mRNA abundance of Nrf2 and HO-1 in lung tissues were increased （P<0.05） while the protein expression and mRNA abundance of VEGF were significantly down-regulated （P<0.05） compared to the model group.ConclusionErythronium sibiricum bulb polysaccharides can relieve airway inflammation and airway remodeling in asthma， which may take effect by activating the Nrf2/HO-1 pathway and inhibiting the expression of VEGF.