The effect of Qi'ao Decoction on ovalbumin induced and lipopolysaccharide enhanced severe asthma mice and its mechanism

Abstract Aim To evaluate the effect of Qi'ao Deocoction (QAD) on the inflammation and hyperresponsiveness of asthma mice. Methods 120 Balb/C mice were randomly divided into six groups: normal group, model group, dexamethasone group, high dose QAD group, medium dose QAD group and low dose QAD group. The asthma model was reproduced in Balb/C mice sensitized by ovalbumin, challenged by OVA and LPS. The mice of the normal group were sensitized, chanllenged and intranasally instilled by PBS. On day 28-34, 6.7, 13.4 and 26.8 g·kg −1 Qi'ao Decoction were administrated; 0.002 4 g·kg −1 dexamethasone solution was given to the dexamethasone group; normal and model groups were given the same amount of normal saline. Bronchoalveolar lavage fluid, airway hyperresponsiveness, lung histopathology and cytokines were then collected and analyzed. Results Compared with normal group, total cellular score, the number of macrophages, lymphocytes, eosinophils and neutrophils of model group significantly increased ( P P P P L before and after Ach (5 mg·mL −1 ) stimulation in the model group both overtook that in the normal group ( P L before and after Ach stimulation ( P P P P P P P P P > 0.05). Conclusion QAD can significantly inhibit airway inflammation and airway hyperresponsiveness of mice with severe asthma induced by ovalumin and lipopolysaccharide, adjust the balance of cytokines, and improve lung histopathological condition. So, it exhibits great effect on severe asthma.