Abstract:

Objective To discuss the effect of Jiegeng Yuanshen Tang（JGYST） on airway tissue inflammation and mucus secretion in the mice with allergic asthma， and to clarify the related mechanism. Methods Forty male C57BL/J mice were randomly divided into control group， JGYST group， ovalbumin （OVA） group， and OVA + JGYST group. The mice in OVA group and OVA +JGYST group were sensitized with 50 μg OVA via intraperitoneal injection twice weekly， followed by 20 μg OVA nasal drops daily for 7 d to induce asthma；the mice in OVA +JGYST group were gavaged with 200 μL JGYST 1 h before each OVA challenge， and the administration lasted for 7 d； the mice in control group were given equivalent dose of PBS via intraperitoneal injection， nasal drops， and gavage； the mice in JGYST group were given the same dose of PBS for intraperitoneal and nasal administration and gavaged with the same dose of JGYST. The pathomorphology of lung tissue of the mice in various groups was observed by HE staining and periodic acid-Schiff （PAS） staining， and the inflammation and PAS scores were calculated； flow cytometry method was used to detect the numbers of eosinophils， neutrophils， helper T lymphocyte 1 （Th1） cells， helper T lymphocyte 2 （Th2） cells， and dendritic cells （DCs）， as well as the percentage of mature DCs and level of reactive oxygen species （ROS） in lung tissue of the mice in various groups；real-time fluorescence quantitative PCR （RT-qPCR） method was used to detect the expression levels of interleukin-4 （IL-4）， interleukin-10 （IL-10）， and tumor necrosis factor-α （TNF-α） mRNA in lung tissue of the mice in various groups. Results The HE and PAS staining results showed that the mice in control group had intact airway and alveolar structure，without infiltration of inflammatory cells or mucus secretion； compared with control group， there was a large number of infiltrating inflammatory cells in airway tissue of the mice in OVA group，and the inflammation and PAS scores were increased （P<0.01）； compared with OVA group， the infiltration of inflammatory cells in airway tissue of the mice in JGYST group and OVA + JGYST group was decreased， and the inflammation and PAS scores were significantly decreased （P<0.01）. The flow cytometry results showed that compared with control group， the numbers of eosinophils， Th2 cells， and DCs in lung tissue of the mice in OVA group were increased （P<0.05 or P<0.01）， and the percentage of mature DCs and level of ROS were significantly increased （P<0.01）； compared with OVA group， the numbers of eosinophils， Th2 cells， and DCs in lung tissue of the mice in JGYST group and OVA + JGYST group were decreased （P<0.01）， and the percentage of mature DCs and level of ROS were significantly decreased （P<0.01）. The RT-qPCR results showed that compared with control group， the expression levels of IL-4， IL-10， and TNF-α mRNA in lung tissue of the mice in OVA group were increased （P<0.01）； compared with OVA group， the expression levels of IL-4 and TNF-α mRNA in lung tissue of the mice in JGYST group and OVA + JGYST group were decreased （P<0.01）， while the expression level of IL-10 mRNA was increased （P<0.01）. Conclusion JGYST can alleviate the airway tissue inflammation and mucus secretion in the mice with allergic asthma，and its mechanism may be related to reducing the number of Th2 cells and DCs， decreasing the ROS level and expression level of proinflammatory cytokine， and increasing the expression level of anti-inflammatory cytokine.

Key words: Jiegeng Yuanshen Tang, Asthma, Airway inflammation, Reactive oxygen species, Cytokine