HR Attenuates Phlegm And MUC5AC Expression Via MMP-9/P38Signaling Pathway In The Mice Models

ObjectiveAcute bronchitis, chronic obstructive pulmonary disease and asthma are common respiratory disease. They usually appears as cough, sputum, etc. HR is a compound preparation, it’s used to antitussive and expectorant in clinical. It’s proved as antitussive in pharmacodynamics, but its expectorant effects and mechanisms are unclear. The purpose of this project was to evaluate the role of HR in expectorant effects and probe its the possible mechanisms.Methods1. To begin with, we established a traditional animal model—the tracheal phenol red secretion in mice. Evaluating HR whether it has expectorant effect.2. Secondly, we established a lipopolysaccharide (LPS) induced acute airway inflammation model in mice. LPS was instilled to induce the acute airway inflammation in mice. Ink was in-stilled to the airway in mice, to evaluate HR on mucociliary clearance with LPS induced acute airway inflammation in mice. Mucopolysaccharide expression was determined by carbazole colorimetry, to evaluate whether HR can reduce mucopolysaccharide expression level. MUC5AC mRNA expression in lung tissue was determined by real-time PCR, and MUC5AC protein expression in BALF was determined by ELISA, to evaluate effects of HR on MUC5AC mRNA and protein expression with LPS induced the acute airway inflammation in mice.3. Thirdly, we established an ovalbumin (OVA) induced asthma model in mice. The lung tissue was paraffin-embedded sections, and slices were stained by PAS, to observe effect of HR on mucus-secreting goblet cells in lung tissue. MUC5AC mRNA expression of lung tissue was de-termined by real-time PCR, to evaluate effects of HR on MUC5AC mRNA expression with OVA induced asthma model in mice.4. Finally, we also established a cigarette smoking(CS)-induced acute airway inflammation model in mice. To evaluate HR enhances mucociliary clearance in CS-induced acute airway in-flammation in mice. Mucopolysaccharide expression was determined by carbazole colorimetry, to evaluate whether HR can reduce mucopolysaccharide expression level. MUC5AC mRNA expression of lung tissue was determined by real-time PCR, and MUC5AC protein expression in BALF was determined by ELISA, to evaluate effects of HR on MUC5AC protein expression. And MMP-9and p-p38protein expression were determined by SABC immunohistochemical staining, to evaluate expectorant activity and signaling pathway of HR.Results1.Effect of HR on tracheal phenol red secretion in mice. Mice were given HR by intragastric, once a day for4days. HR300mg/kg and600mg/kg, positive control drug NH4Cl1g/kg exhib-ited an increase in eliminating tracheal phenol red activity.2.HR enhances mucociliary clearance with LPS induced acute airway inflammation in mice. Mice were given HR by intragastric, once a day for4days. HR30,100,300,600mg/kg exhibited an increase in mucociliary clearance in a dose-dependent manner. But HR300,600mg/kg sig-nificant exhibited an increase in mucociliary clearance compared with the model group. Posi-tive control drug Erdosteine300mg/kg also exhibited an increase in mucociliary clearance com-pared with the model group.3. HR reduces MUC5AC mRNA expression in the lung tissue, mucopolysaccharide and MUC5AC level in BALF with LPS induced airway inflammation in mice. Mice were given HR by intragastric, once a day for4days. HR30,100,300,600mg/kg significant reduced mucopoly-saccharide and MUC5AC level in BALF, and MUC5AC mRNA expression in the lung tissue by real-time PCR in a dose-dependent manner. This result was consistent with MUC5AC pro-tein level in BALF.4. HR reduces MUC5AC mRNA expression and mucus-secreting goblet cells in airway in oval-bumin-induced asthma model. Mice were given HR by intragastric, once a day for11days. HR10,30,100mg/kg reduced mucus-secreting goblet cells in lung tissues in a dose-dependent man-ner. Effect of HR100mg/kg was comparable with those of Dex0.5mg/kg. HR10,30,100mg/kg significant reduced MUC5AC mRNA expression in the lungs by real-time PCR. Dex0.5mg/kg also significant reduced MUC5AC mRNA expression in the lung.5. HR enhances mucociliary clearance in CS-induced acute airway inflammation in mice. Mice were given HR by intragastric, once a day for6days. HR100,300,600mg/kg significant exhib-ited an increase in mucociliary clearance compared with the model group. Positive control drug Erdosteine300mg/kg also exhibited an increase in mucociliary clearance compared with the model group, which was comparable with those of HR300mg/kg.6. HR reduces MUC5AC mRNA expression in the lung tissue, mucopolysaccharide and MUC5AC level in BALF with CS-induced acute airway inflammation in mice. Mice were given HR by intragastric, once a day for6days. HR30,100,300mg/kg significantly reduced mucopolysaccharide in a dose-dependent manner, and decreased MUC5AC protein level in BALF. These results were consistent with MUC5AC mRNA expression.7. HR decreased p-p38and MMP-9, but not p-ERK, JNK, NF-κB expression in the lung tissue with CS-induced acute airway inflammation in mice. These results suggested that HR inhibits MUC5AC expression via suppressing p38MAPK/MMP-9signaling pathway probably.ConclusionsOur results exhibited HR increased airway mucociliary clearance, decreased MUC5AC mRNA and protein expression, reduced mucopolysaccharide levels. The mechanism of its action was relevant to reduce MUC5AC expression by p38MAPK/MMP-9signaling pathway.