Effect and Mechanism of Sangmei Zhike Granule on Airway Inflammation in Rats with Cough Variant Asthma / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore the effect and mechanism of Sangmei Zhike granule （SMZK） on airway inflammation in rats with cough variant asthma（CVA）. MethodSix-week-old male SD rats were randomly divided into normal group， model group， and SMZK （2.48 g·kg-1） group. The rats in the model group and the SMZK group received intraperitoneal injection of a mixed solution containing 10% ovalbumin （OVA） and aluminium hydroxide on the 1st and 8th days and aerosol inhalation of 1% OVA solution from the 15th day for CVA model induction. The intervention lasted for two weeks from the 15th day. At the end of animal manipulation， the lung function was detected and inflammatory cells in the peripheral blood were counted. The serum interleukin-4 （IL-4）， interleukin-5 （IL-5）， and interleukin-10 （IL-10） levels were determined. Hematoxylin-eosin （HE） staining was performed on the lungs. Western blot was used to detect the protein expression of nuclear factor kappa-B （NF-κB） and its inhibitor α（IκBα） in lung tissues. ResultCompared with the normal group， the model group showed reduced forced expiratory volume in the first 0.1 second （FEV0.1），FEV0.1/forced vital capacity （FVC），and forced expiratory flow 50% （FEF50%） （P<0.05， P<0.01）， increased white blood cells and eosinophils （P<0.01）， and up-regulated serum IL-4， IL-5， and IL-10 （P<0.01）. As revealed by HE staining， the model group displayed shed epithelial cells of the bronchus， airway stenosis， hyperplasia and expansion of mucous glands， disarrangement of layer structures， disorderly arranged cells， and extensive infiltration of inflammatory cells. The protein expression of NF-κB p65 was higher （P<0.01） and that of IκBα was lower （P<0.01） in the lung tissues of the model group than that in the normal group. Compared with the model group， the SMZK group showed increased FEV0.1，FEV0.1/FVC，and FEF50% （P<0.05）， decreased white blood cells and eosinophils in the peripheral blood （P<0.01）， and declining serum IL-4， IL-5， IL-10 （P<0.01）. HE staining demonstrated mild bronchial mucosal injury and relieved inflammatory cell infiltration， gland hyperplasia， and epithelial degeneration and necrosis in the SMZK group. The protein expression of NF-κB p65 was decreased （P<0.05） and that of IκBα was increased （P<0.05） in lung tissues of the SMZK group than that in the model group. ConclusionSMZK can improve lung function and inhibit airway inflammation in rats with CVA. The underlying mechanism may be related to the regulation of IκBα/NF-κB protein expression in the lungs.