Effect of Combined Therapy of Lung and Intestine on VIP and p38 MAPK Signaling Pathways in Bronchial Asthma Mice / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe the therapeutic effects of the combined therapy of lung and intestine， a common treatment for pulmonary diseases in traditional Chinese medicine （TCM）， on bronchial asthma mice， and further detect the changes of vasoactive intestinal peptide （VIP） and p38 mitogen-activated protein kinase （p38 MAPK） signaling pathway-related proteins which are closely related to the pathogenesis of asthma， in order to elucidate the mechanism of the combined therapy of lung and intestine in the treatment of bronchial asthma. MethodA total of 60 Kunming mice were randomly divided into normal group， model group， dexamethasone group （0.5 mg·kg-1·d-1）， TCM group （2.73 g·kg-1·d-1）， and lung-intestine treatment group （6.825 g·kg-1·d-1）， 12 mice in each group. All mice except the normal group were sensitized by ovalbumin to induce bronchial asthma. After 30 days of intragastric administration， serum and lung tissue samples were obtained. The content of VIP， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α） in the serum of mice in each group was detected by enzyme-linked immunosorbent assay （ELISA）. The mRNA levels of TNF-α， IL-6， and p38 MAPK in lung tissues of mice were detected by real-time quantitative polymerase chain reaction （Real-time PCR）， and the protein levels of TNF-α， IL-6， p38 MAPK， and phosphorylated p38 MAPK （p-p38 MAPK） in lung tissues of mice were assayed by Western blot （WB）. ResultCompared with the normal group， the model group showed decreased content of serum VIP （P<0.05）， increased content of TNF-α and IL-6 （P<0.05）， up-regulated mRNA levels of TNF-α， IL-6， and p38 MAPK， and elevated protein levels of TNF-α， IL-6， and p-p38 MAPK/p38 MAPK in lung tissues （P<0.05）. Compared with the model group， the treatment groups exhibited increased content of serum VIP， TNF-α， and IL-6 （P<0.05）， down-regulated mRNA levels of TNF-α， IL-6， and p38 MAPK， and lower protein levels of TNF-α， IL-6， and p-p38 MAPK/p38 MAPK in lung tissues （P<0.05）. As compared with the lung-intestine treatment group， the serum TNF-α and IL-6 levels in the dexamethasone group were increased （P<0.05）， and the mRNA and protein levels of TNF-α and IL-6 in lung tissues were down-regulated （P<0.05）， while the levels of p38 MAPK， VIP mRNA， and p-p38 MAPK/p38 MAPK protein in lung tissues were up-regulated （P<0.05）. The serum VIP， TNF-α， and IL-6 levels in the TCM group were decreased （P<0.05）， and the mRNA levels of TNF-α， IL-6， p38 MAPK and protein levels of TNF-α， IL-6， p-p38 MAPK/p38 MAPK in lung tissues were up-regulated （P<0.05）， while the level of VIP mRNA in lung tissues was down-regulated （P<0.05）. ConclusionThrough increasing endogenous VIP and inhibiting the excessive activation of p38 MAPK signaling pathway， the combined therapy of lung and intestine can reduce the release of inflammatory factors， inhibit pulmonary inflammation response， and treat bronchial asthma.