The Effects And Mechanisms Of Theabrownin On Atherosclerosis In ApoE^-/- Mice

Objective:To investigate the effects of theabrownin on the formation of atherosclerosis in ApoE-/-mice and explore the mechanism of itMethods:1.A total of 40 SPF male ApoE-/-mice which were 4 week old were randomly divided into 4 groups after 1 week adaptive feeding.The mice in control group were fed with normal diet for 12 weeks,and then fed with 0.3ml normal saline for 4 weeks;the mice in model group were fed with Western diet for 12 weeks,and then fed with 0.3 ml normal saline for 4 weeks;the mice in the statin group and the theabrownin group were fed with Western diet for 12 weeks,and then intragastric administration of 10 mg/kg atorvastatin calcium tablets and 675 mg/kg theabrownin respectively for 4 weeks2.Weights of each mouse were measured once a week.After 4 weeks of drug intervention,collected venous blood and detected the levels of cholesterol,triglyceride and LDL through ELISA3.After 16 weeks,the aortas,which was taken and spread on the sealing membrane,stained with oil red O,and then measured the ratio of atherosclerotic plaque area to aortic surface area.The ascending aortas were paraffin embedded,sectioned and stained with hematoxylin eosin,and then were observed and photographed under microscope.Finally,the ratio of atherosclerotic plaque area to cross-sectional area of aortic wall was measured.4.After 16 weeks,the ascending aortas were taken out,paraffin embedded,sectioned and immunohistochemical methods were used to measure the positive signal area of CD68 and CD90 in the aortas.Finally,the ratio between the positive signal areas and atherosclerotic plaques were calculated5.Measured transcription of MCP-1 and IL-6 in aorta by qRT-PCR.Results:1.The weight of mice in each group increased gradually.The weight of mice fed with high-fat diet was higher than that in the control group,among which the weight of mice in the model group increased mostly.After being treated with theabrownin,the weight of mice was not significantly lower than that in the model group(P>0.05).The levels of TC,TG and LDL in the theabrownin group were lower than those in the model group(P<0.05)2.In the model group,we saw lots of atherosclerotic plaques on the aortic wall after oil red O staining.Compared with the model group,the specific volume of atherosclerotic plaque area and aortic surface area in theabrownin group decreased(P<0.05).Compared with the model group,the ratio of the plaque area to cross-sectional area of the aortic wall in the mice treated with theabrownin also decreased significantly(P<0.05)3.After being fed with high-fat diet,a large number of macrophages and T lymphocytes infiltrated in atherosclerotic plaques of model group.Compared with the model group,the infiltration degree of macrophages and T-lymphocytes in the atherosclerotic plaques of theabrownin group reduced(P<0.05)4.According to the results of qRT-PCR,the transcription level of MCP-1 and IL-6 in the model group increased significantly compared with the control group After the treatment of theabrownin,the transcription level of the above-mentioned inflammatory factors was significantly lower than that in the model group(P<0.05)Conclusion:Theabrownin can reduce atherosclerosis of ApoE-/-fed with high fat diet.Its mechanism may be related to the decrease of blood lipid level,infiltration of macrophages and T lymphocytes in atherosclerotic plaque,and transcription level of MCP-1 and IL-6.