| Objective: In this paper,the optimal ultrasonic extraction process of total triterpene acid of Ganoderma lucidum spore powder was first studied.Then,we explored the regulating lipid effect and anti-atherosclerosis effect and its effect mechanism of total triterpene acid extract on hyperlipidemia rabbit induced by high-fat diet.Method: 1.Study on extraction process: The effects of three conditions of extraction time,material-liquid ratio and ethanol concentration on the extraction rate of total triterpene acid were studied by orthogonal experiment,and the optimal extraction process was determined.2.Pharmacodynamic study of total triterpene acid extract: Experimental animals Japanese big ear rabbits are divided into high,medium and low dose groups,positive control group(atorvastatin),high fat model group and normal group.In addition to the normal group of animals given normal feed,the remaining groups were fed with high-fat feed,and bovine serum albumin was injected intravenously at the end of the fourth week to form an atherosclerosis model.Animals in each group were collected blood at the pre-determined detection time points before and after the experiment,then determine the levels of serum triglyceride(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),and serum aminotransferase including alanine aminotransferase(ALT),aspartate aminotransferase(AST),and creatine kinase(CK)activities;animal feces were collected at the final stage of the experiment and the bile acid content was determined.At the end of the 14 th week,the animals were sacrificed,and the cholesterol 7?-hydroxylase(CYP7A1)activity in liver microsomes,TG,TC,LDL-C and HDL-C levels in the thoracic aorta were measured,TG,TC levels in the liver also were measured;Calculate the area of abdominal aortic plaque and conduct histopathological examination of aorta and liver;Western blotting to check the expression of liver X receptor alpha(LXR?)and its downstream target gene ATP binding cassette transporter(ABC)A1/G1/G5/G8 in liver,aorta and small intestine;Foam cells were transfected with LXR?siRNA,and the liquid scintillation counting method was used to detect the cholesterol efflux of the foam cells,and the ABCA1/G1 expression of the cells was checked.Results: The best extraction process was obtained by orthogonal test: the best extraction process of total triterpene acid of Ganoderma lucidum spores was material-liquid ratio 1:70,ethanol concentration 98%,ultrasonic extraction time 15 min,and the total triterpene extraction rate was 4.307%.Pharmacodynamic test: Ganoderma lucidum spores total triterpene acid extract can significantly reduce TC and LDL-C levels in serum and tissues,increase HDL-C levels,and significantly reduce arterial plaque area,showing lipid-regulating and anti-atherosclerosis activity;Ganoderma lucidum spores total triterpene acid extractincreased the expression of LXR? and ABCA1/G1,ABCG5/8,CYP7A1 in the liver of experimental animals,and increased the expression of LXR? and ABCG5/8 in the small intestine,and significantly increased the content of bile acids in animal feces;After silencing the expression of LXR? in foam cells,the expression of LXR? downstream genes such as ABCA1/G1 was significantly down-regulated,and the ability of the extract to promote the efflux of cholesterol by foam cells was suppressed.Conclusion: In the rabbit model of hyperlipidemia induced by high-fat diet,Ganoderma lucidum spores total triterpene acid extract has the effect of regulating blood lipids and anti-atherosclerosis,mainly reducing the level of serum TC and LDL-C,but its no obvious reducing TG effect.The mechanism may be through up-regulating the expression of LXR?,so that up-regulating expression of LXR? downstream target genes related to cholesterol reverse transport and bile acid synthesis such as ABCA1,ABCG1,ABCG5,ABCG8,CYP7A1,etc. |
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