Effect Of Baicalin On The Expressions Of Matrix Metalloproteinase-9 And Tissue Inhibitor Of Metalloproteinase-1 In Asthmatic Rats

Objective: To investigate the role of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase (TIMP-1) in the airway remodeling of bronchial asthma, and to explore the effect of baicalin on the expressional levels of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in asthmatic rats.Method: Thirty healthy male Wistar rats with the weight of 180 ~ 220 grams were randomly divided into five groups. Which were consisted of normal control group(n=6)challenge with normal saline, asthmatic model group(n=6)with ovalbumin conjuncted with A1(OH)3 , baicalin intervention(n=6)treating with baicalin before activating ; ligustrazine intervention group(n=6)treating with the intraperitoneal injection ligustrazine before activating; combined therapy group(n=6)with the intraperitoneal injection baicalin with Ligustrazine before activating. The rats were sensitized and challenged by ovalbumin to establish the asthmatic model.. Lung tissues were sliced and stained with HE. The following morphologic parameters were measured by image analysis system: the ratio of airway wall luminal and outer diameter, the thickness of airway smooth muscle (WAm). The expressions of MMP-9 and TIMP-1 and collagen typeâ…£in lung tissues were observed by immunohistochemistry combined with the computerized micro-image analysis. Statistical analysis was performed with SPSS10 software.Results: (1) it was found that airway wall thickened, smooth muscle hypertrophied, and airway remodelled in asthmatic rats. (2) : Both asthmatic group and every therapeutic group were higher than the normal control group(P < 0.05)in the ratio of airway wall luminal and outer diameter and the thickness of smooth muscle, the baicalin group were lower than the asthmatic group(P < 0.05), but still higher than the ligustrazine group(P < 0.05);the ligustrazine group were lower than the asthmatic group(P < 0.05); the baicalin combined with ligustrazine group were lower than that in the liguatrazine group(P < 0.05).(3) Both the asthmatic group and every intervention group were higher than the normal control grou(pP < 0.05); the baicalin group were lower than the asthmatic group(P < 0.05); the ligustrazine group were lower than the asthmatic group(P < 0.05), but still higher than the baicalin group(P < 0.05); the baicalin combined with ligustrazine group were lower than that in the baicalin group(P < 0.05). (4) The baicalin group were lower than the asthmatic group(P < 0.05) in the expression of TIMP-1 in lung tissue , but still higher than the normal control group(P < 0.05); the ligustrazine group were lower than those in the asthmatic group(P < 0.05), but still higher than the baicalin group(P < 0.05); the baicalin combined with ligustrazine group were lower than that in the normal control group(P < 0.05). (5) Both the asthmatic group and every therapy group were higher than the normal control group in the deposition of collagen typeâ…£in the airway wall(P < 0.05); the baicalin group were lower than the asthmatic group(P < 0.05), but still higher than the ligustrazine group(P < 0.05);the ligustrazine group were lower than the asthmatic group(P < 0.05); the baicalin combined with ligustrazine group were lower than that in the liguatrazine group(P < 0.05). (6) There were significant positive correlations between MMP-9 levels and the thickness of airway smooth muscle(r=0.406,P < 0.05),between TIMP-9 levels and the thickness of airway smooth muscle(r=0.513,P < 0.01), and between collagen typeâ…£levels and the thickness of airway smooth muscle(r=0.474,P < 0.02).Conclusion: The high expression of matrix metalloproteinase -9 and tissue inhibitor of metalloproteinase-1 might play an important role in developing airway fibrosis and remodeling. Imbalance between MMP-9 and TIMP-1 was a biomarker of airway remodeling. Baicalin can decrease the deposition of collagen typeâ…£and suppress the airway remodeling by influencing the balance between matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1. this function can be improved through combined with ligustrazine.