Effect Of Ligustrazine On Airway Inflammation And Airway Remodeling In Asthmatic Mice By Regulating TGF-β1/Smad Signaling Pathway

Objective:To investigate the effect of ligustrazine on airway inflammation and airway remodeling in asthmatic mice by studying the regulation of ligustrazine on TGF-β1/Smad signaling Pathway in Asthma.Methods:In this experiment,40 healthy female BALB/c mice were randomly divided into 4 groups,10 mice in each group(n=10),marked as blank group,asthma group,ligustrazine group and dexamethasone group.During the course of asthma sensitization,according to the standard of 0.2ml per mouse,asthma group,ligustrazine group and dexamethasone group were sensitized by intraperitoneal injection of chicken ovalbumin(OVA)and aluminum hydroxide[Al2(OH)3] suspension for every 7 days,3 times in total.At the same time,blank group were given the same amount of normal saline by intraperitoneal injection as the control group.The excitation was started on the 14 th day of the experiment,asthma group,ligustrazine group and dexamethasone group were nasal drip continuously to construct chronic asthma model with 50μl of Ovalbumin(OVA,2mg/ml),at the same time,blank group were nasal drip continuously with the same amount of normal saline on the 14 th day of the experiment,and the excitation time was 6 days.At the same time of excitation,ligustrazine group was injected intraperitoneally with ligustrazine 30 minutes before nasal drip according to 80mg/kg standard,dexamethasone group were given intraperitoneal injection of dexamethasone 30 minutes before nasal drip according to 2mg/kg standard.On the 21 st day,the blood of the mice was collected by the method of orbital blood sampling,the blood of the mice was collected and centrifuged,collected the blood plasma by centrifugation,and detected the expression of relevant inflammatory factors in blood plasma by ELISA assay.All the mice were treated with the sacrifice of the broken spinal cord,the left lung tissue were embedded dewaxingthen and cut into sections then stained with HE and Masson,observed and analyzed the airway inflammation and airway remodeling of mice in each group under light microscope.At the same time,the right lung tissue of mice was ground to powder form under liquid nitrogen,and detected the expression level of related protein in mouse lung tissue by Western blotting method.Results:1.Compared with the blank group:(1)Asthma group,ligustrazine group and dexamethasone group had obvious signs of airway inflammation,mainly manifested by increased infiltration of inflammatory cells around the airway,thickening of the airway wall and airway smooth muscle,increased secretion of collagen,the results suggested that the model was constructed successfully.(2)The levels of IgE,IL-5,GATA-3 and TGF-β1 in serum of asthma group,ligustrazine group and dexamethasone group were significantly higher than those in blank group,the results suggest that airway inflammation induced by asthma can increase the expression of relevant inflammatory factors.(3)The expression of TGF-β1 and Smad2 protein in lung tissue of asthma group,ligustrazine group and dexamethasone group were increased,while the expression of Smad7 protein was decreased,the results suggest that TGF-β1/Smad signaling pathway plays an important role in the pathogenesis of asthma.2.Compared with the asthma group:(1)The airway inflammatory signs,infiltration of inflammatory cells around the airway,thickening of the airway wall and airway smooth muscle and secretion of collageninfiltration in ligustrazine group and dexamethasone group were lighter than those in asthma group,the results suggest that ligustrazine played a certain role in the treatment of asthma.(2)The levels of IgE,IL-5,GATA-3 and TGF-β1 in serum of ligustrazine group and dexamethasone group were lower than those in asthma group,the results suggest that ligustrazine can reduce the airway inflammation of asthma.(3)The expression of TGF-β1 and Smad2 protein in lung tissue of ligustrazine group and dexamethasone group were lower than those in asthma group,but the expression of Smad7 protein was higher.The results suggest that ligustrazine can regulate the TGF-β1/Smad signaling pathway.Conclusion:In this experiment,BALB/c mouse asthma model was successfully constructed by classical modeling.Ligustrazine can reduce airway inflammation in asthmatic mice and decrease the secretion of relevant inflammatory factors,thus reducing airway inflammation in asthma mice to a certain extent.Ligustrazin can reduce the thickening of bronchial smooth muscle layer and airway wall and the deposition of collagen,further studies showed that ligustrazine could regulate the activity of TGF-β1/Smad signaling pathway,decrease the expression of TGF-β1 and Smad protein,and alleviate the symptoms of bronchial asthma and the pathological process of airway remodeling.This study provides a theoretical and experimental basis for the clinical treatment of asthma with ligustrazine.