Effect Of Apigenin On Atherosclerosis In ApoE Deficient Mice

Hyperlipidemia is one of the most common risk factors of atherosclerosis.From previous investigation, Matrix metalloproteinase-2(MMP-2)、matrixmetalloproteinase-3（MMP-3） and Matrix metalloproteinase-9(MMP-9)aberrantly expressed around atherosclerosis plaques, and Tissue-inhibitor ofmetalloproteinase-1(TIMP-1) is deemed to be important for regulating theactivity of MMPs. Other studies reveal that MMP-2and MMP-9can promotemigration and proliferation of smooth muscle, then acceleration the formationand disruption of atheromatous plaques. The high expression of TIMP-1canreduce intimal thickening of the artery, preventing the formation can stabilizeand reduce the Plaque of atherosclerotic. Therefore, matrix metalloproteinasesis of far-reaching importance for the study of atherosclerosis.Currently, a large number of studies have shown that some flavonoidscontained in food, such as naringenin, Pueraria total flavonoids, carrail pollen,can play an important role in preventing atherosclerosis. Apigenin (Apigenin,4’,5,7-trihydroxyflavone) is a kind of flavonoid that can be widely found inmany fruits, vegetables, legumes and tea. Celery is especially rich in apigenin.The impact of apigenin on the formation and stability of atherosclerotic plaquesin ApoE-deficient mice fed with high-fat diet is unclear. Objectives:This study is attempt to investigate the effect of apigenin onatherosclerosis in a animal model of ApoE-deficient mice.Methods:Thirty male ApoE-deficient mice(8-week-old) were adopted for model,which had been fed with normal feed for one week. Assigned into three groupsrandom. Mice in the control group were kept with high-fat diet. Apigeningroup was kept with of high-fat diet and Apigenin(10mg/kg.d Gavage). TheAtorvastatin group was kept with high-fat diet and original drug Atorvastatin(10mg/kg.d Gavage). After12weeks, the following items were measured:1、Body weight of three groups every10days.Carotid artery blood pressure atthe end of the Experiment;2、Triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol(LDL-C) and high density lipoprotein cholesterol (HDL-C);3、Plaque area at aortic root by HE staining.collagen content of the plaques byMasson staining;4、The expression of matrix metalloproteinases (MMP-2, MMP-3and MMP-9)and their tissue inhibitors (TIMP-1) by immunohistochemical analysis andwestern blot.Results：1、Body weight and Carotid arterial blood pressure of three groups was notaffected by the High-fat diet、Apigenin or Atorvastatin（P＞0.05）; 2、Compared to the control group, no significant difference was foundbetween the control group and the Apigenin group in triglycerides(P>0.05),while the high-density lipoprotein showed a significant difference (P<0.01); The total cholesterol and the low-density lipoprotein cholesterol ofApigenin group were reduced compared with the control group, there weresignificant differences (P <0.05).Atorvastatin group compared with the controlgroup, significantly reduced blood lipids (P <0.01);There were difference inTG、LDL-C、TC、HDL-C between Apigenin group and Atorvastatin group（P＜0.05）;3、 The atherosclerotic plaque size in the Apigenin group and atorvastatingroup was significantly reduced as compared to the control group (P <0.01or P＜0.05), and there was significant difference between Apigenin group andatorvastatin group in plaque area(P<0.05);4、Compared to the control group,the collagen content in atheroscleroticplaques of the Apigenin group was increased substantially (P<0.05).However,the collagen content in atherosclerotic plaques of atorvastatingroup was increased significantly (P <0.01).There was difference betweenApigenin group and atorvastatin group (P<0.05).5、Immunohistochemical results：compared to the control group,apigenin andAtorvastatin group, ApoE-/-mice aortic atherosclerotic plaques inMMP-2,MMP-3,MMP-9expression was significantly decreased, and thedifference was significant (P <0.05or P <0.01).Atorvastatin group expressed less MMP-2、MMP-3and MMP-9than Apigenin group,which has statisticallysignificant (P <0.05).Compared with mice with high-fat diet, the expression ofTIMP-1in atherosclerotic plaques in apigenin group had statisticallysignificant(P>0.05);which was significantly different in Atorvastatin group (P<0.01).There was difference between Apigenin group and atorvastatin groupin the expression of TIMP-1(P<0.05).6、Western blot: apigenin and Atorvastatin group, ApoE-/-mice aorticatherosclerotic plaques in MMP-2,MMP-3,MMP-9expression wassignificantly decreased compared with the control group, and the differencewas significant (P <0.05or P <0.01).Atorvastatin group expressed lessMMP-2、MMP-3and MMP-9than Apigenin group,which has statisticallysignificant (P <0.05).Compared with mice with high-fat diet, the expression ofTIMP-1in atherosclerotic plaques in apigenin group had statisticallysignificant(P<0.05);which was significantly different in Atorvastatin group (P<0.01).Also there was difference between Apigenin group and atorvastatingroup in the expression of TIMP-1(P<0.05).Conclusion:1、Apigenin can significantly reduce the atherosclerotic lesions, and its roleplays in part by lowering blood lipids;2、 Apigenin can increase the stability of atherosclerotic plaques,whichHomeostasis by regulating MMPs/TIMP-1.