Study On The Mechanism Of Qingzhi Tongmai Granules On Abnormal Lipid Metabolism And Anti-atherosclerosis In Rats

Objective: The purpose of this study was to explore the effect of Qingzhi Tongmai granules on blood lipid level of atherosclerosis model rats,and to further explore its related molecular mechanism of anti-atherosclerosis.Materials and methods: 1.144 SPF SD male rats were selected as the research object in this experiment,and were randomly divided into 12 groups with 12 cases in each group,i.e.a normal group,a model group,and 10 TCM group(Qingzhi Tongmai granules group).Except for the normal group,atherosclerosis models were established for the other groups.The specific method was to inject vitamin D3+ compound high-fat feed for 8 weeks.Rats in the normal group were injected with the same amount of normal saline and fed with conventional feed.In the 4th week after the experiment,the rats in the TCM group were given drugs according to different proportions measured by the uniform design scheme.In this study,intragastric administration was used as the main route,and the administration proportion was 10ml/kg.Normal group and model group were given the same amount of normal saline.2.A total of 8 rats died due to factors such as technique of intragastric administration and autoimmunity of rats,so it was finally decided to take 10 rats from each group for the next test.Nine weeks after the experiment,the rats in each group were sampled.Extracted blood from abdominal aorta,separate it to obtain serum,took out the aorta and liver to make frozen sections of aorta and liver tissue.The pathomorphology and lipid deposition of aorta and liver were observed by HE staining respectively.Detected the levels of cholesterol(TC),triglyceride(TG),low density lipoprotein(LDL),high density lipoprotein(HDL),apolipoprotein AI(Apo AI),apolipoprotein B(Apo B)and apolipoprotein AI/ apolipoprotein B(Apo AI/ Apo B)in rat serum;Detected the following substances that affect cholesterol synthesis and uptake in liver tissues with q PCR and Western blot methods: the expression levels of low density lipoprotein receptor(LDLr),scavenger receptor BI(SR-BI),3-hydroxy-3-methylglutaric acid monoacyl coenzyme A reductase(HMGCR),cholesterol 7α-hydroxylase(CYP7A1)genes and related proteins.Detected the expression levels of ATP binding casstte transporter A1(ABCA1),ATP binding casstte transporter G1(ABCG1),liver X-receptor-α(LXRα),peroxisome proliferators-activated receptors(PPARγ)genes and related proteins,all of these affect cholesterol efflux and reverse cholesterol transport(RCT).Results: 1.The blood lipid test results showed that compared with the normal group,the levels of TC,TG and LDL in the model group were significantly increased(p < 0.01),and the level of HDL-C was significantly decreased(p < 0.01),suggesting that the model was successfully established.The TC levels in groups 3,8,9 and 12 decreased(p < 0.05),HDL-C levels in groups 8,10,11 and 12 increased(p < 0.05),LDL-C levels in groups 3,8,9,10,11 and 12 decreased(p < 0.05).The contents of TC,TG and LDL-C in the other groups decreased and HDL-C increased slightly,but there was no statistical significance.Based on the above results,selected group 8 and group 12 together with normal group and model group for subsequent study.Compared with the normal group,Apo AI in the model group decreased significantly,Apo B increased,and Apo AI/ Apo B decreased significantly(P < 0.01).Group 8 and group 12 can increase Apo AI,decrease Apo B,and increase Apo AI/ Apo B,with statistically significant difference compared with model group(P < 0.01).2.The results of atherosclerotic lesions and liver lipid deposition show that,compared with the model group,the aortic intima of rats in the TCM group was intact,the area of AS plaque was significantly reduced,and lipid droplets in the liver were significantly reduced.HE staining results showed reduction of aortic wall thickening,decreased infiltration of foam cells and inflammatory cells,and significantly reduction of the degree of hepatic steatosis in the rats of TCM group.Only some hepatocytes showed hydropic degeneration.The deposition of lipid droplets in liver tissue was reduced,and most hepatocytes were close to normal morphology.3.The results of molecules related to cholesterol synthesis and uptake showed that compared with the model group,the expression of liver cholesterol receptor LDLr and SR-BI protein in the TCM group were significantly increased(p < 0.05).The expression of HMGCR protein,a key enzyme in liver cholesterol synthesis,was significantly decreased(p < 0.05).The expression of CYP7A1 protein,a key rate-limiting enzyme in liver cholesterol synthesis,was significantly increased(p < 0.01).4.The results of molecules related to cholesterol efflux and reverse cholesterol transport showed that the expressions of ABCA1 and ABCG1 protein,the key molecules of cholesterol efflux,were significantly increased in the TCM group compared with the model group(p < 0.05).The expression of LXRα and PPARγ protein,the key factors in reverse cholesterol transport,were significantly increased(P < 0.01).Conclusion: 1.Qingzhi Tongmai granules can effectively reduce blood lipid and regulate apolipoprotein-related indicators.The lipid-lowering effect in group 8 and group 12 were superior than other TCM groups,which indicates that Qingzhi Tongmai granules can regulate lipid metabolism disorder.2.Qingzhi Tongmai granules can reduce lipid deposition in the lesion area of atherosclerotic plaque on aortic intima and reduce hepatic steatosis and lipid droplet deposition,which indicates that Qingzhi Tongmai granules can improve atherosclerosis and hepatic lipid deposition.3.The mechanism of Qingzhi Tongmai granules in preventing and treating atherosclerosis may be to inhibit expression of HMGCR protein(a key enzyme for cholesterol synthesis in liver tissue),increase the expression levels of liver cholesterol receptor LDLr and SR-BI protein,CYP7A1 protein(a key rate-limiting enzymes for cholesterol synthesis),ABCA1 and ABCG1 protein(the key molecules in cholesterol efflux),LXRα and PPARγ protein(the key factors in reverse cholesterol transport),thereby reducing the synthesis and intake of cholesterol,accelerating the outflow rate of cholesterol to peripheral tissues,promoting the reverse cholesterol transport,delaying the formation of atherosclerotic hard plaque,and thus playing an anti-atherosclerosis role.