Effect of Xiaoqinglong decoction on mucus hypersecretion in the airways and cilia function in a murine model of asthma

Abstract

Objective: Xiaoqinglong decoction (XQL) has been used in traditional Chinese medicine as a prescription for asthma treatment. We explored the effects of XQL on mucus hypersecretion and ciliophagy in the airways of mice in which asthma had been induced by ovalbumin (OVA). Methods: Thirty-six mice were sensitized by OVA injection (i.p.) on day-0 and day-14 and challenged with 1% OVA on day 18–22. Then, they were divided into three groups: model, carbocysteine and XQL. From day-15 to day-22, the XQL group was administered XQL (10 g/kg, p.o.) 1 hour before each aerosol challenge with OVA. To evaluate the effect of XQL on mucus hypersecretion, AB-PAS staining, measurement of serum levels of interleukin (IL)-13, bronchoalveolar lavage fluid (BALF) analyses, ciliophagy analyses, as well as co-expression of Light Chain 3 (LC3) and acetylated α-tubulin by immunofluorescence staining were undertaken. Results: Treatment with XQL (10 g/kg) attenuated mucus secretion in the airways, and reduced the positive areas of AB-PAS staining in histopathologic lung tissues (P < .05). IL-13 expression in serum (P < .01), OVA-induced inflammatory changes, and the number of white blood cells (P < .01) in BALF samples were also reduced. However, the effect on mucus secretion was less apparent in the carbocysteine group compared with the XQL group. XQL treatment also improved the cilia length and elicited a substantial reduction in ciliophagy and LC3 expression in the tracheal epithelium. Conclusion: XQL can attenuate cilia shortening, aid the clearance function of ciliated epithelial cells, and reduce mucus production in an OVA-induced asthma model in mice. XQL can inhibit mucus hypersecretion and could be a new type of pharmacotherapy.

Keywords

• Asthma
• Xiaoqinglong decoction
• Mucus
• Ciliophagy
• IL-13