Intervention Study Of Caulis Spatholobi On The Expression Levels Of MMP-9 And TIMP-1 In Atherosclerotic Rabbit Models

Objective: To investigate the expression of MMP-9 and TIMP-1 in atherosclerotic rabbits and the effect of Caulis Spatholobi extract on them.Methods: Forty rabbits were randomly divided into 5 groups by digital table: normal,model,low Spatholobus suberectus,medium Spatholobus suberectus and high Spatholobus suberectus,each group with 8 rabbits.All rabbits were fed with water ad libitum for 60 days.The normal group was fed in conventional diet.The model Spatholobus suberectus intervention group was with fat diet(120 g/d,divided into two times)for modeling.At the same time,the Spatholobus suberectus intervention group was given Spatholobus suberectus extract 5.2g/animal/day,10.4g/animal/day and 20.8g/animal/day according to the low,medium and high doses.We collected blood samples from the marginal ear vein after fasting for 10-12 h on days 0,30 and 60 of the experiment,and measured five blood lipids in plasma and various parameters of hemorheology by colorimetry to analyze the lipid composition.At the end of the experiment,blood samples were collected to detect the expression levels of serum CRP,serum MMP-9,and TIMP-1 in rabbits by enzyme-linked immunosorbent assay,and the aortas were harvested and stained with HE to observe the pathomorphological changes of the aortas of rabbits in each group,and then we used SPSS 22.0 to analysis the data.Results:1.The indexes of low,medium and high dose of Spatholobus suberectus(TG,TC,LDL-C,VLDL-C)at the end of the experiment were higher than those in the normal group but significantly lower than those in the model group,the difference was statistically significant(P<0.05).2.Compared with the model group,the whole blood viscosity of the medium and high dose group of Caulis Spatholobi was directly lower than that of the model group on days 30 and 60,and the difference was statistically significant(P<0.05).3.Compared with the normal group,the CRP expression level in the model group was highly increased(P<0.05),compared with the model group,the CRP expression in the medium dose group of Caulis Spatholobi was significantly decreased,and the difference was statistically significant(P<0.05);4.In the model-dose group the serum MMP-9 expression level was significantly increased compared with the normal-dose group,but the serum TIMP-1 expression level was decreased,and the MMP-9/TIMP-1 ratio was increased,and the difference was significant(P<0.05);compared with the model group,the MMP-9 and TIMP-1 expression levels in the low and high dose groups of Caulis Spatholobi extract were not significantly different(P>0.05);5.The pathological results suggested that the aortic pathological damage of vascular wall was apparently reduced in the low,medium and high dose groups of Caulis Spatholobi extract,and necrosis and scars were not observed in the plaques,especially in the medium and high dose groups of Caulis Spatholobi compared with the model group.Conclusion:(1)Caulis Spatholobi extract can reduce blood lipid and improve hemorheology in atherosclerotic rabbits.(2)Spatholobus suberectus extract was able to reduce the serum CRP and MMP-9's expression and increase the expression level of TIMP-1 in atherosclerotic rabbits,thereby decreasing the MMP-9/TIMP-1 ratio,reducing inflammatory cell infiltration,enhancing the stability of plaques,and delaying the formation of AS.(3)Spatholobus suberectus extract was able to reduce the pathological damage of the vascular wall of the thoracic aorta in atherosclerotic model rabbits.