Therapeutic Effects of Kangzhi Syrup in a Guinea Pig Model of Ovalbumin-Induced Cough Variant Asthma

Abstract

Purpose. This study aimed to investigate the possible effects and underlying mechanisms of Kangzhi syrup on ovalbumin- (OVA-) induced cough variant asthma (CVA) in guinea pigs. Methods. All 48 guinea pigs were randomly assigned to four experimental groups: normal, OVA model with or without Kangzhi syrup (OVA and OVA + KZ), and OVA with Dexamethasone (OVA + DM). After sensitizing the guinea pigs, a cough challenge was performed by the inhalation of capsaicin. The antitussive effect, inflammatory cells, cytokines in bronchoalveolar lavage fluid (BALF) and lung tissue, and morphological changes were examined. Results. Compared with model group, Kangzhi syrup effectively exerted an antitussive effect (p<0.0001) and reduced the pneumonic anaphylacticitis by inhibiting the infiltration of total inflammatory cells (p<0.0001) and reducing the percentage of eosinophil in BALF (p<0.0001). Moreover, evidence from morphological studies also demonstrated that Kangzhi syrup inhibited the infiltration of inflammatory cells and ameliorated the structure changes. NF-κB and TGF-β1 expression were attenuated in the OVA + KZ group versus the OVA group (p<0.0001). Additionally, a semiquantitative analysis of TGF-β1 expression also demonstrated that the Kangzhi syrup attenuated this profibrogenic growth factor (p<0.001). Conclusions. The results demonstrated that Kangzhi syrup exerted a considerable antitussive effect in CVA animal model, which depended on its marked impact on the anti-anaphylactic inflammation. Additionally, it could ameliorate the airway remodeling by inhibiting NF-κB and TGF-β1 signal pathway.