The Effect Of Jiawei Liuan Decoction On Airway Remodeling And The Expression Of MMP-9 And TIMP-1 In Rats With Cough Variant Asthma

Objective:To observe the effects of Modified Liuan Decoction on airway remodeling and the expression of MMP-9 and TIMP-1 genes in cough variant asthma(CVA)rats by successfully replicating a cough variant asthma model.To verify the hypothesis that Modified Liuan Decoction can treat CVA by reducing the expression of MMP-9 and TIMP-1 genes,regulating the balance between MMP-9 and TIMP-1,and alleviating airway remodeling.To further discuss the role and mechanism of Modified Liuan Decoction in the treatment of CVA.Methods:Sixty Wistar rats were randomly divided into six groups:blank group,CVA model group,Montelukast sodium group,low-dose Modified Liuan Decoction group,medium-dose Modified Liuan Decoction group and high-dose group with 10 rats in each group.With the exception of the blank group,the other groups were sensitized by intra-peritoneal injection of 10%ovalbumin(OVA)and a 1ml mixed solution of Al(OH)3 on the 1st and 8th days.From the 15th day onwards,a normal saline solution with 1%OVA was given twice a day for a period of 10 days through the process of ultrasonic excitation,30 minutes before the stimulation.The other 2 groups were given the same dosage of normal saline solution by gastrointestinal administration.On the 26th day,the number of coughs was measured.Lung tissue samples were then collected for HE and Masson staining to observe the infiltration of inflammatory cells and histological changes.In addition,collagen volume was measured.The expression of MMP-9 and TIMP-1 in the lung tissue was measured by the real-time fluorescence quantitative PCR method.Result:1.The effect of Modified Liuan Decoction on the number of coughs in rats:Compared with the blank group,the number of coughs in the model group was significantly higher(P<0.05).Compared with the model group,the number of coughs in each dosage group of Modified Liuan Decoction and Montelukast Sodium group decreased,there was statistical difference between the groups(P<0.05),and the middle dosage group of Modified Liuan Decoction had the least number of coughs.Compared with the montelukast sodium group,the cough frequency of each dosage group of Modified Liuan Decoction decreased,but there was no significant difference between the two groups(P>0.05).2.The effect of Modified Liuan Decoction on the general changes of lung tissue in rats:Compared with the blank group,the lung tissue in the model group was dark red,hyperemia and edema were obvious.Fresh and old spots of bleeding were scattered on the surface of the model group.There was an obvious increase in volume,with blunt edges and poor elasticity.Compared with the model group,the lung tissue in the Modified Liuan Decoction group and Montelukast sodium group was a bright red color,with a marked reduction in hyperemia and edema.There were occasional old bleeding points observed,but there was no significant increase in volume and elasticity was normal.3.Pathological results of HE staining of lung tissue:The model group showed an infiltration of a large number of inflammatory cells in the trachea and its surroundings,with eosinophils,lymphocytes,neutrophils more commonly seen.In addition,there was thickening of the bronchial wall,edema,alveolar collapse,widening of the bronchial wall interval,partial alveolar dilatation observed.Exfoliated epithelial cells and a mucus emboli can be seen in the alveolar cavity and trachea respectively.Compared with the model group,there was significant improvement in the above pathological conditions in the Montelukast sodium group and the Modified Liuan Decoction groups.4.Pathological results of Masson staining of lung tissue:Collagen deposition under the airway epithelium in the model group was significantly increased,and a visible thick dense layer was observed.Compared with blank group,there was a significant increase in collagen deposition,which has a statistically significant difference(P<0.05).Collagen deposition around the trachea in the Montelukast sodium group and the Modified Liuan Decoction group was significantly reduced compared with model group,with a statistically significant difference(P<0.05).There was an obvious decrease in the volume fraction of collagen in the high dose group of Modified Liuan Decoction.There were no significant differences between all the dosage groups of Modified Liuan Decoction and the Montelukast sodium group(P>0.05).5.The effect of Modified Liuan Decoction on the relative expression of MMP-9 gene in the rat lung tissue:The expression of MMP-9 gene in the model group was significantly higher than that in the blank group,with a statistically significant difference(P<0.05).Compared with the model group,the expression of MMP-9 gene in each dose group of Modified Liuan Decoction and the Montelukast Sodium group decreased significantly,and the difference was statistically significant(P<0.05).Of which,the expression of MMP-9 in each dose group was significantly lower than that in the model group.There were no significant differences between the Montelukast sodium group and all the dosage groups of Modified Liuan Decoction(P>0.05).6.The effect of Jiawei Luan Decoction on the relative expression of TIMP-1 gene in lung tissue:The expression of TIMP-1 in model group was significantly higher than that in blank group(P<0.05);the expression of TIMP-1 in Montelukast sodium group and Jiawei Luan Decoction group was significantly lower than that in model group(P<0.05),and the expression of TIMP-1 in medium-dose group of Jiawei Luan Decoction was significantly lower than that in model group.There was no significant difference between the dosage groups of montelukast sodium and Modified Liuan Luan Decoction(P>0.05).7.The effect of Modified Liuan Decoction on the ratio of MMP-9/TIMP-1 in lung tissue:Compared with the blank group,the ratio of MMP-9/TIMP-1 in the model group was significantly increased,with a statistically significant difference(P<0.05).Compared with the model group,the ratio of MMP-9/TIMP-1 in the medium-and high-dose groups of Modified Liuan Decoction was reduced,with no statistically significant difference(P>0.05).Compared with the model group,the ratio of MMP-9/TIMP-1 in the low dosage groups of Modified Liuan Decoction was reduced,with a statistically significant difference(P>0.05).The ratio of MMP-9/TIMP-1 decreased with statistical significance(P<0.05).Conclusion:1.Airway remodeling exists in cough variant asthma rats,with the expression levels of MMP-9 and TIMP-1 genes and the ratio of MMP-9/TIMP-1 higher than those in normal rats.2.Modified Liuan Decoction can reduce airway inflammation,airway hyperresponsiveness and collagen deposition.It may regulate the balance of MMP-9/TIMP-1 ratio by down-regulating the expression of MMP-9 and TIMP-1 genes in the lung tissue of CVA rats,thereby inhibiting airway remodeling.3.There were no significant differences in the relative expression of MMP-9 and TIMP-1 genes and the ratio of MMP-9/TIMP-1 between Modified Liuan Decoction and Montelukast sodium groups.In terms of inhibiting the expression of the MMP-9 gene,the low-dose group of Modified Liuan Decoction performed the best.In terms of inhibiting the expression of the TIMP-1 gene,the medium-dose group of Modified Liuan Decoction performed the best.In terms of adjusting the imbalance of the MMP-9/TIMP-1 ratio,the low-dose group of Modified Liuan Decoction performed the best.