Effect of Houpu Mahuangtang on Airway Inflammation and Expression of TRPA1, TRPV1 mRNA and Protein in Asthmatic Mice / 中国实验方剂学杂志

ABSTRACT

<b>Objective:To investigate the effect of Houpu Mahuangtang on airway inflammation and expressions of gene and proteins of Transient receptor potential ankyrin 1, vanilloid 1 (TRPA1, TRPV1) in asthmatic mice. <b>Method:Sixty female Balb/c mice were randomly divided into six groups control group, model group, low, medium and high-dose Houpu Mahuangtang groups (7, 14, 28 g·kg^-1) and dexamethasone group (0.002 4 g·kg^-1), with 10 mice in each group. A mouse model of asthma was replicated by sensitizing and challenging with ovalbumin. The changes of enhanced pause (Penh) following acetylcholine chloride (ACh) inhalation were detected. The pathological changes of the lung tissues were observed. The number of eosinophils (EOS) in peripheral blood and the percentage of EOS in bronchoalveolar lavage fluid (BALF) were detected. Interleukin (IL)-4, IL-13, prostaglandin D₂ (PGD₂) and substance P (SP) were detected by enzyme-linked immuno sorbent assay (ELISA). The expressions of TRPA1 and TRPV1 gene and protein in lung tissues were detected by Quantitative Real-time polymerase chain reaction (Real-time PCR) and Western blot. <b>Result:Compared with control group, mice of model group showed significantly increased in Penh following ACh inhalation (<italic>P</italic><0.05, <italic>P</italic><0.01), EOS in blood and the percentage of EOS in BALF (<italic>P</italic><0.01). Histopathological changes in lungs showed inflammatory cell infiltration and bronchial mucosa damage. The levels of IL-4, IL-13, PGD₂ and SP in BALF and the expressions of TRPA1, TRPV1 mRNA and protein in lung tissues significantly increased (<italic>P</italic><0.05, <italic>P</italic><0.01). Compared with model group, treatment groups had significant effects in decreasing Penh, relieving lung injury, reducing EOS count in blood and the percentage of EOS in BALF (<italic>P</italic><0.05, <italic>P</italic><0.01), reducing IL-4, IL-13, PGD₂ and SP levels in BALF (<italic>P</italic><0.05, <italic>P</italic><0.01), as well as down-regulating TRPA1 and TRPV1 mRNA and protein expressions in lung tissues (<italic>P</italic><0.05, <italic>P</italic><0.01). <b>Conclusion:Houpu Mahuangtang could reduce airway inflammation, airway responsiveness. In addition to the reduction of levels of Th2 related cytokines, the mechanism of Houpu Mahuangtang might be related to the regulation of TRPA1, TRPV1 mRNA and protein expressions, and the decrease of associated neurofactor levels.