黄连碱对胆固醇代谢关键基因的调节作用

该文主要研究胆固醇和25-羟胆固醇诱导对HepG2细胞胆固醇代谢的影响和黄连中黄连碱的降胆固醇活性及调节机制.用生化法检测了总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白-胆固醇(LDL-c)和高密度脂蛋白-胆固醇(HDL-c)水平;用qRT-PCR和Western bolt技术检测了胆固醇代谢关键基因LDLR,HMGCR,CYP7A1 mRNA和蛋白的表达水平.结果显示胆固醇和25-羟基胆固醇诱导能导致LDLR,CYP7A1的mRNA和蛋白的表达下降从而使TC和LDL-c含量上升.黄连碱能上调LDLR和CYP7A1的mRNA和蛋白表达水平而下调HMGCR的mRNA和蛋白表达水平,从而降低TC,LDL-c水平.这些结果表明黄连碱具有潜在的降胆固醇的药理活性,其分子机制可能是通过调节胆固醇代谢的关键基因LDLR,CYP7A1和HMGCR的mRNA和蛋白表达而达到降胆固醇的效果.该研究为开发新的具有降胆固醇活性的天然药物奠定了良好的理论基础.     

Hypolipidemic Activity of Okra is Mediated Through Inhibition of Lipogenesis and Upregulation of Cholesterol Degradation

Little is known about the hypolipidemic activity of okra; therefore, we investigated the hypolipidemic activity of okra and its interaction with gene expression of several key components involved in lipid homeostasis. Male C57BL/6 mice were randomly divided into three groups and fed with hyperlipidemic diet or two hyperlipidemic diets supplemented with 1% or 2% okra powder for eight weeks. Results demonstrated that okra dose‐dependently decreased serum and hepatic total cholesterol and triglyceride, and enhanced fecal excretion of bile acids. Gene expression analysis revealed that okra upregulated cholesterol 7α‐hydroxylase (CYP7A1) expression, downregulated expression of sterol regulatory element‐binding protein 1c (SREBP1c) and fatty acid synthase (FAS), with no effect on sterol regulatory element‐binding protein 2 (SREBP2), 3‐hydroxy‐3‐methylglutaryl‐CoA reductase (HMGR), low‐density lipoprotein receptor (LDLR) and carnitine palmitoyltransferase‐1A (CPT1A). It was suggested that hypolipidemic activity of okra was mediated most likely by upregulation of cholesterol degradation through CYP7A1 and by inhibition of lipogenesis through SREBP1c and FAS. Okra raw and fractionated polysaccharide showed strong bile acid binding capacity in vitro, which may contribute to the hypolipidemic activity observed. In conclusion, okra has potential application in the management of hyperlipidemia and its associated metabolic disorders. Copyright © 2013 John Wiley & Sons, Ltd.     

黄连生物碱对金黄地鼠血脂代谢及低密度脂蛋白受体基因表达的影响

研究黄连生物碱对低密度脂蛋白受体（LDLR）基因表达和各项降脂指标的影响。通过实时荧光定量PCR检测给药后HepG2细胞和金黄地鼠肝脏中LDLR mRNA 的表达量,同时检测给药前后血清总胆固醇（TC）,甘油三酯（TG）,低密度脂蛋白胆固醇（LDL-c）,高密度脂蛋白胆固醇（HDL-c）含量。结果显示,给药后,与模型组相比,各药物组都有降血脂作用,其中黄连碱、巴马汀和药根碱能降低金黄地鼠血清中TC,TG和LDL-c水平（P<0.05,P<0.01）,升高HDL-c（P<0.01）,增加HepG2细胞和金黄地鼠肝脏中LDLR mRNA的表达量。表明黄连生物碱具有调节金黄地鼠血脂代谢的作用,且黄连碱的降脂效果最好。     

高效快速降脂动物模型研究

探讨斑马鱼作为降脂药物筛选模型的可行性以及盐酸小檗碱(BBR)对高脂斑马鱼的影响。用含4%胆固醇饲料喂养3月龄斑马鱼0,2,4,8,14,20,25,30 d,检测血清总胆固醇含量的变化;测定对照组、高胆固醇组、0.01%辛伐他汀组、0.1%BBR组和0.2%BBR组斑马鱼血清总胆固醇(TC)、总甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-c)和高密度脂蛋白胆固醇(HDL-c)的水平;RT-PCR检测肝脏HMGCR,LDLR和CYP7A1a mRNA的表达水平;油红O染色检测肝脏中脂肪含量的变化。结果显示4%胆固醇喂养斑马鱼后血清TC水平升高且有时间依赖性,20 d基本达到稳定水平;BBR组斑马鱼血清TC,TG和LDL-c水平显著下降,肝脏HMGCR mRNA的表达下降,LDLR和CYP7A1a mRNA的表达升高,脂肪含量减少。4%胆固醇饲料喂养斑马鱼20 d即可建立高脂斑马鱼模型,研究结果为进一步开展降脂药物的筛选奠定基础。     

Artichoke extract lowered plasma cholesterol and increased fecal bile acids in Golden Syrian hamsters

A study was conducted in hamsters to determine if artichoke leaf extract (ALE) could lower plasma total and non‐HDL cholesterol by increasing fecal excretion of neutral bile acids and sterols. Sixty‐four Golden Syrian hamsters (8 week old) were fed control diet or a similar diet containing ALE (4.5 g/kg diet) for 6 weeks. No significant changes for total cholesterol, HDL, non‐HDL cholesterol triglycerides or fecal neutral sterols and bile acids were found after 21 days for ALE‐fed animals compared with controls. But after 42 days, ALE‐fed male hamsters had significantly lower total cholesterol (15%), non‐HDL cholesterol (30%) and triglycerides (22%) and female hamsters fed ALE showed reductions of 15% for total cholesterol, 29% for non‐HDL cholesterol and 29% for triglycerides compared with controls. Total neutral sterol and bile acids concentrations increased significantly by 50% and 53% in fecal samples of ALE fed males, and 82.4% and 25% in ALE fed females compared with controls. The ALE lowered hamster plasma cholesterol levels by a mechanism involving the greater excretion of fecal bile acids and neutral sterols after feeding for 42 days. Copyright © 2011 John Wiley & Sons, Ltd.     

荜茇宁对高脂血症大鼠血脂代谢及其相关基因表达的影响

目的 观察荜茇宁对实验性高脂血症大鼠血脂代谢及其相关基因表达的影响.方法 饲喂高脂饲料建立高脂血症大鼠模型,荜茇宁分别按2.5、5、10 mg/kg给大鼠连续ig 4周.实验结束,取空腹血,检测血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、载脂蛋白Al(ApoAl)、载脂蛋白B(ApoB);利用反转录聚合酶链反应(RT-PCR)测定大鼠肝脏低密度脂蛋白受体(LDLR)、ApoB和3-羟基-3-甲基-戊二酰辅酶A还原酶(HMG-CoAR)mRNA的表达.结果 与模型组相比,荜茇宁能降低血清TC、TG、LDL-C、ApoB水平及ApoB/ApoAl的值(P<0.05),升高HDL-C、ApoAl(P<0.05),能增强高脂血症大鼠LDLR mRNA表达(P<0.05),降低ApoB mRNA表达(P<0.05),但对HMG-CoAR mRNA的影响不明显(P>0.05).结论 荜茇宁具有调节高脂血症大鼠血脂代谢的作用,其机制可能与提高LDLR基因转录水平,降低ApoB mRNA表达有关.     

褐藻糖胶调节大鼠脂质代谢紊乱的作用

目的研究褐藻糖胶(FPS)调节大鼠脂质代谢紊乱的作用。方法通过建立大鼠高脂血症模型,观察FPS对大鼠血脂水平、脂代谢酶、粪便中脂类含量、胆汁代谢、肝脏低密度脂蛋白受体(LDL-R)mRNA的影响。结果FPS能抑制高脂血症大鼠血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL-C)的浓度,升高高密度脂蛋白(HDL-C)的浓度和脂蛋白脂酶(LPL)、肝脂酶(HL)、卵磷脂胆固醇酰基转移酶(LCAT)的活性。FPS能增加粪便中胆固醇、甘油三酯、胆汁酸的含量,但对胆汁的分泌、胆汁中胆固醇和胆汁酸的浓度却无显著影响。逆转录聚合酶链反应(RT-PCR)实验显示,FPS能显著提高高脂血症大鼠肝脏LDL-R mRNA的表达水平。结论FPS可能通过抑制脂质(甘油三酯、胆固醇、胆汁酸)的吸收,激活脂代谢酶(LPL、HL、LCAT)的活性,促进肝脏低密度脂蛋白受体(LDL-R)mRNA的表达来调节脂质代谢紊乱。     

茵连化浊解毒汤对胆结石小鼠血生化指标、胆汁代谢谱的影响及其机制分析

目的 研究茵连化浊解毒汤对胆结石小鼠血生化指标、胆汁代谢谱的影响及机制.方法 选择C57BL/6雄性小鼠,随机分为对照组(普通饲料喂养)、模型组(高脂高热量高胆固醇饲料喂养)、实验组(高脂高热量高胆固醇饲料喂养并给予茵连化浊解毒汤干预).检测血生化指标、胆汁内代谢产物、肝脏内胆汁酸代谢蛋白的表达.结果 模型组小鼠血液中...     

温胆汤对高脂血症大鼠脂质代谢的影响

目的 :探讨温胆汤对高脂血症大鼠低密度脂蛋白受体基因表达的影响。方法 :在建立大鼠高脂血症模型基础上 ,观察温胆汤对大鼠血脂水平、总脂解酶 (LA)、脂蛋白脂酶 (LPL)和肝脂酶 (HL)活性以及肝脏低密度脂蛋白受体 (LDLR)基因表达的影响。结果 :温胆汤能显著抑制高脂模型大鼠血清总胆固醇 (TC)、血清总甘油三酯 (TG)浓度 ,提高LPL和LA活性 ,但对HL活性无明显影响 ;逆转录聚合酶链反应 (RT-PCR)实验显示高脂模型大鼠肝脏LDLRmRNA表达降低 ,温胆汤能显著上调高脂血症大鼠肝脏LDLRmRNA水平。结论 :温胆汤可能通过调节大鼠肝脏LDLR转录水平预防脂质代谢紊乱。     

潼白蒺藜药对调节高脂血症模型大鼠血脂作用及机制研究

目的：探究潼白蒺藜对高脂血症模型大鼠血脂水平的影响及机制,为药对协同降血脂的临床应用提供参考。方法：48只SPF级SD大鼠随机等分为正常对照组,高脂模型组,辛伐他汀组、潼白蒺藜药对组,并设白蒺藜组,潼蒺藜组对比。正常对照组采用基础饲料喂养,其余各组采用高脂饲料饲喂法建立高脂血症大鼠模型,造模的同时预防性给药,用潼蒺藜水提物、白蒺藜水提物、潼白蒺藜药对水提物和阳性对照药辛伐他汀分别灌胃,6周后检测大鼠体重及各脏器指数、并检测血清总胆固醇（Total cholesterol,TC）、甘油三酯（Triglyceride,TG）、高密度脂蛋白（high density lipoprotein-cholesterol,HDL-C）、低密度脂蛋白（high density lipoproteincholesterol,LDL-C）的含量,RT-PCR及western blot检测各组肝脏组织三羟基三甲基戊二酸单酰辅酶A还原酶（3-Hydroxy- 3-Methylglutaryl Coenzyme A Reductase,HMGCR）、胆固醇7a 羟化酶（Cytochrome P450 7A1,CYP7A1）、低密度脂蛋白受体（Low-Density Lipoprotein Receptor,LDL-R）mRNA及蛋白表达。结果：三组中药组均不同程度降低高脂模型大鼠血液TC、TG、LDL-C含量,提高HDL-C含量,其中潼白蒺藜药对更加显著（P<0.01）;三组中药组均能提高脂模型大鼠肝脏HMGCR、CYP7A1、LDL-R基因及蛋白表达,潼白蒺藜药对组疗效更为显著。结论：潼白蒺藜药对能显著调节机体的血脂水平,有效预防高脂血症,发挥协同增效作用,且其机制可能与调节HMGCR、CYP7A1、LDL-R表达有关。     

Bile acid‐binding activity of young persimmon (Diospyros kaki) fruit and its hypolipidemic effect in mice

The hypolipidemic effects and bile acid‐binding properties of young persimmon (Diospyros kaki) fruit were examined. In an animal experiment, male C57BL/6.Cr mice (n = 5) were fed an AIN‐76‐modified high fat diet supplemented with 2% or 5% (w/w) dried young persimmon fruit (YP) for 10 weeks. The intake of YP significantly enhanced fecal bile acid excretion and lowered the concentration of hepatic lipids and plasma cholesterol. Analysis of gene expression in liver tissue showed that 2% or 5% YP up‐regulated the expression of the sterol regulatory element‐binding protein‐2 gene. In the 5% group, there were increased expressions of the genes for cholesterol 7α‐hydroxylase and the low‐density lipoprotein receptor. Next, the bile acid‐binding ability of YP was analysed in vitro using cholic acid (CA). In 100–2000 µM CA solutions, 1% (w/v) YP adsorbed approximately 60% of CA, while dried mature persimmon fruit adsorbed approximately 20% of CA. The positive control, cholestyramine, adsorbed approximately 80% of CA in the 100–2000 µM CA solutions. A crude tannin extract from YP, which contained 54.7% condensed tannins, adsorbed approximately 78% of CA in the 2000 µM CA solutions. These results suggest that the ability of YP to bind bile acid contributes to its hypolipidemic effect in mice. Copyright © 2009 John Wiley & Sons, Ltd.     

茵杞调脂饮对非酒精性脂肪肝大鼠肝脏LXRα、CYP7A1基因表达的影响

目的研究茵杞调脂饮对非酒精性脂肪肝大鼠肝组织LXRα、CYP7A1基因表达的影响。方法48只大鼠随机分为正常组、模型组、茵杞调脂饮低、中、高剂量组及辛伐他汀组,12周后模型组灌胃生理盐水,药物组灌胃相应剂量药物,8周后检测血清TC、TG、HDL-C、LDL-C、FFA,肝组织TC、TG水平及LXRα、CYP7A1m RNA表达。结果与正常组比较,模型组大鼠TC、TG、LDL-C、FFA、LXRαmRNA水平明显升高,HDL-C、CYP7A1 mRNA水平明显下降(P<0.01),肝组织出现显著的细胞脂肪变性及脂滴沉着;与模型组比较,各药物组大鼠TC、TG、LDL-C、FFA、LXRαmRNA水平明显降低,HDL-C、CYP7A1 mRNA水平明显提升,肝细胞脂肪变性及脂滴沉着明显改善,且呈一定量效关系。结论茵杞调脂饮可调控脂肪合成,促进胆固醇排泄,下调炎性指标,改善血脂、氧化应激指标及肝组织病理变化,缓解非酒精性脂肪肝进展,其机制可能与调节LXRα、CYP7A1的表达有关。     

橄榄降脂胶囊对高脂血症大鼠血脂及其肝脏低密度脂蛋白受体基因表达的影响

目的:探讨中药橄榄降脂胶囊的降脂机制,为临床应用提供实验依据。方法:采用酶法检测大鼠血清总胆固醇(TC)、甘油三酯(TG);采用磷钨酸-镁沉淀法检测HDL-c、LDL-c,RT-PCR法测定肝低密度脂蛋白受体(LDLR)基因表达。结果:模型组大鼠TC、TG、LDL-c均显著高于正常组,HDL-c显著低于正常组(P<0.05)。与正常组比较,模型组大鼠肝LDLR mRNA表达降低,P<0.05。各治疗组肝LDLR mRNA表达升高,与模型组比较P<0.05。结论:橄榄降脂胶囊可能通过调节肝LDLR mRNA表达而纠正脂质代谢紊乱。     

A new TCM formula FTZ lowers serum cholesterol by regulating HMG-CoA reductase and CYP7A1 in hyperlipidemic rats

Ethnopharmacological relevance

Based on a theory of Chinese Medicine, Regulating Gan (liver) to lower lipids that is in brief to regulate the lipid metabolic related factors in the liver will improve serum lipid profile, we have developed Fufang Zhenzhu Tiao Zhi (FTZ) which includes eight herbs that are quality assured. FTZ has been developed with the potential to correct abnormal lipid metabolism. This Chinese herbal medicine has been prescribed for 20 years, which has been issued patent and clinically proven for use in the treatment of dyslipidemia.

Aim of the study

To investigate the cholesterol-lowering effect and the mode of action of FTZ extract on high lipid diet induced hyperlipidemic rats.

Materials and methods

The FTZ was prepared by alcohol and water extraction of eight herbs that have been quality-controlled according to the protocol. The cholesterol-lowering effect of FTZ was evaluated on SD rats fed with high-lipid diet. RT-PCR and western blot were used to analyze the gene expression of cholesterol metabolism-related enzymes including HMG-CoA reductase and cholesterol 7α-hydroxylase (CYP7A1) in the livers of the rats. The activity of HMG-CoA reductase and CYP7A1 were assessed by colorimetrical method and by quantification of the cholesterol metabolite of CYP7A1 using HPLC analysis respectively.

Results and conclusions

FTZ significantly decreased the levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), whilst elevated the serum high-density lipoprotein cholesterol (HDL-C) and decreased serum atherogenic index (A.I.) values in high lipid diet induced hyperlipidemic rats. Furthermore, FTZ showed significant antihyperlipidemic effect by at least three pathways in the high lipid diet induced hyperlipidemic rats: (1) upregulating the gene expression and activity of CYP7A1 which promotes the conversion of cholesterol into bile acid; (2) downregulating the gene expression and activity of HMG-CoA reductase to reduce de novo synthesis of cholesterol; (3) increasing the cholesterol excretion from feces. In these three pathways, HMG-CoA reductase and CYP7A1 are two pivotal enzymes in lipid cholesterol metabolism and are expressed mainly in hepatic cells, which support our new TCM treatment strategy: Modulating Liver to Treat Hyperlipemia.     

Reduction of plasma cholesterol by Curcuma comosa extract in hypercholesterolaemic hamsters.

The influence of the extract of Curcuma comosa Roxb. (Zingiberaceae) on lipid metabolism was investigated in hypercholesterolaemic hamsters. Intragastric administration of the ethyl acetate extract of C. comosa rhizome (0-500 mg/kg per day) to hypercholesterolaemic animals for 7 days decreased both plasma triglyceride and cholesterol levels in a dose-dependent manner. The reduction of plasma cholesterol levels was accompanied by a significant increase in the hepatic cholesterol content while the triglyceride content was not significantly changed. The increase of the hepatic cholesterol content was brought about by an expansion of the free cholesterol pool which specifically augments biliary cholesterol excretion. The C. comosa extract also increased plasma high density lipoprotein (HDL)-cholesterol and decreased plasma low density lipoprotein (LDL)-cholesterol. These results suggest that the C. comosa extract exerts a hypolipidaemic action by acceleration of lipid mobilization from extrahepatic tissue to the liver which subsequently increases excretion of cholesterol via the bile for excretion.     

Hypolipidemic activity and mechanisms of the total phenylpropanoid glycosides from Ligustrum robustum (Roxb.) Blume by AMPK‐SREBP‐1c pathway in hamsters fed a high‐fat diet

The aim of this study was to evaluate the hypolipidemic effect and mechanisms of total phenylpropanoid glycosides extracted from Ligustrum robustum (Roxb.) Blume (LRTPG) in hamsters fed a high‐fat diet and to discover bioactive components in HepG2 cell model induced by oleic acid. LRTPG of high (1.2 g/kg), medium (0.6 g/kg), and low (0.3 g/kg) doses was administrated daily for 21 consecutive days in hamsters. We found that in hamsters fed a high‐fat diet, LRTPG effectively reduced the concentrations of plasma triglycerides (TG), free fatty acid, total cholesterol, low‐density lipoprotein cholesterol, and hepatic TG and total cholesterol. And the compounds acteoside, ligupurpuroside A, ligupurpuroside C, and ligupurpuroside D significantly inhibited lipid accumulation in HepG2 cell at the concentration of 50 μmol/L. Mechanism research demonstrated that LRTPG increased the levels of phospho–AMP‐activated protein kinase and phospho‐sterol regulatory element binding protein‐1c in liver, further to suppress the downstream lipogenic genes as stearoyl‐CoA desaturase 1, glycerol‐3‐phosphate acyltransferase, 1‐acylglycerol‐3‐phosphate O‐acyltransferase 2, and diacylglycerol acyltransferase 2. In addition, LRTPG increased the hydrolysis of circulating TG by up‐regulating lipoprotein lipase activities. These results indicate that LRTPG prevents hyperlipidemia via activation of hepatic AMP‐activated protein kinase‐sterol regulatory element binding protein‐1c pathway.     

胎盘CYP3A4的表达及其与ICP关系的研究

目的探讨细胞色素P4503A4（CYP3A4）酶在正常晚孕和妊娠期肝内胆汁淤积症（intrahepatic cholestasis of pregnancy,ICP）胎盘的表达及其与母血和脐血总胆汁酸（total bile acids,TBA）水平的关系,进一步分析胎盘CYP3A4在ICP病理机制中的作用。方法采用实时荧光定量巢式PCR（RT—Nested PCR）法测定胎盘组织中CYP3A4 mRNA的表达量;采用速率法测定母血、脐血中总胆汁酸的水平。结果（1）对照组及ICP组胎盘组织中均有CYP3A4 mRNA的表达,ICP组胎盘组织中CYP3A4 mRNA表达量低干对照组（0．50（1．41）vs1．41（1．57））,差异有统计学意义（P〈0．05）;ICP地塞米松dexamethasone,DEX）治疗组CYP3A4 mRNA表达量高于未用DEX治疗组（0．59（1．27）VS0．21（1.09））,差异有统计学意义（P〈0．05）。（2）对照组及ICP组胎盘组织中CYP3A4 mRNA表达量与母、脐血中TBA水平之间均不具有相关性（n=-0．060～-0．330,P均〉0．05）。结论（1）ICP胎盘CYP3A4 mRNA的表达降低,使胎盘对胆汁酸的解毒作用减弱,这可能与ICP胎儿病理机制有关。（2）DEX是ICP胎盘CYP3A4的诱导剂,这可能是其治疗ICP的机制之一。