植物分离蛋白对卵巢切除大鼠血脂代谢的影响

目的:研究大米分离蛋白和大豆分离蛋白对因雌性激素缺乏引起的高胆固醇血症的影响.方法:将24只Wistar成年雌鼠随机分为4组.3组大鼠进行双侧卵巢切除手术,分别喂食添加20%酪蛋白(对照组)、大米分离蛋白或大豆分离蛋白的饲料.另1组进行卵巢伪切除手术,喂食添加20%酪蛋白的对照饲料,喂养4周后解剖,测定血清和肝脏中胆固醇、甘油三酯浓度以及粪中胆汁酸排泄量和蛋白表观消化率等指标.结果:卵巢切除明显增加成年雌鼠血清和肝脏中胆固醇和甘油三酯浓度.与酪蛋白组相比,饲料中添加大豆分离蛋白能显著降低卵巢切除大鼠血浆总胆固醇和低密度脂蛋白及胆固醇浓度(p＜0.05),但对血浆甘油三酯浓度无显著影响,同时明显降低肝重、肝脏中总脂、总胆固醇、游离胆固醇及甘油三酯总量,以及增加排粪量和胆汁酸排泄量,大豆分离蛋白表观消化率也明显比酪蛋白和大米分离蛋白高.大米分离蛋白对血脂没有明显降低效果,但肝脏总脂、总胆固醇、游离胆固醇和甘油三酯浓度明显低于酪蛋白饲料组,而排粪量、粪中胆汁酸排泄量和蛋白表观消化率则与酪蛋白组无显著差异.结论:抗消化蛋白对因雌性激素缺乏引起的高胆固醇血症有明显降低效果,可能的作用机制是由于该蛋白的低消化性干扰,肠道中胆汁酸代谢,增加粪中胆汁酸的排泄量来降低肝脏和血浆中胆固醇浓度.     

湿热处理多孔玉米淀粉对大鼠脂质代谢的影响

目的：探讨湿热处理多孔玉米淀粉对大鼠脂质代谢的影响。方法：32 只雌性Sprague-Dawley（SD）大鼠随机分为4 组,其中1 组为对照组饲喂基础饲料,另外3 组为高脂组,分别为高脂空白组、多孔淀粉组（porousstarch,PS）和湿热处理多孔淀粉组（heat moisture treatment starch,HTMPS）,饲喂基础饲料,适应1 周后,对照组饲喂基础饲料,高脂组分别饲喂相应高脂饲料。饲喂4 周后解剖,检测大鼠血脂、肝脂及小肠和粪便中胆汁酸等指标。结果：饲喂多孔淀粉和湿热处理多孔淀粉组大鼠血清总胆固醇（total cholesterol,TC）、甘油三酯（triglyceride,TG）、非高密度脂蛋白胆固醇（non-high-density lipoprotein cholesterol,non-HDL-C）、抗动脉硬化指数（atherosclerosis index,AI）、甘油三酯/高密度脂蛋白胆固醇（TG/HDL-C）、肝脏TC、肝脏总TC和腹部脂肪含量显著下降（P＜0.05）,粪便中粪醇、胆固醇等中性固醇排泄量增加,粪便中胆汁酸排泄量显著增加（P＜0.05）。PS组与HTMPS组相比,大鼠血浆中TC、AI、腹部脂肪含量、肝脏总脂肪含量较低,粪便中胆汁酸及小肠内容物中胆汁酸较高。结论：多孔淀粉降血脂降胆固醇效果优于湿热处理多孔玉米淀粉,可降低高脂饮食造成的高脂血症风险,对预防心血管疾病有一定的作用。     

无斑鹞鲼蛋白质对大鼠胆固醇代谢的影响

目的：探讨无斑鹞鲼蛋白（Aetobatus flagelum protein,AFP）对高胆固醇模型大鼠胆固醇代谢的影响,并对其可能的作用机制加以研究。方法：5 周龄雄性Sprague-Dawley（SD）大鼠,适应性饲养1 周后,按体质量随机分为酪蛋白对照组、5% AFP组、10% AFP组,分别给予高胆固醇饲料及分别添加5%和10% AFP的高胆固醇饲料。28 d后测定大鼠血清总胆固醇（total cholesterol,TC）、高密度脂蛋白胆固醇（high density lipoprotein cholesterol,HDL-C）水平,肝脏TC、游离胆固醇水平,粪便中胆汁酸和中性固醇含量以及肝脏3-羟基-3-甲基戊二酸单酰辅酶A（3-hydroxy-3-methyl glutaryl coenzyme A reductase,HMG-CoA）、胆固醇酰基转移酶2（acyl coenzyme Acholesterolacyltransferase 2,ACAT2）、胆固醇7α-羟化酶1（cholesterol 7α-hydroxylase 1,CYP7A1）的mRNA表达量。结果：与酪蛋白对照组相比,无斑鹞鲼蛋白可显著降低大鼠血清和肝脏中的TC含量（P＜0.05）,明显增加血清HDL-C含量（P＜0.05）,极显著降低大鼠动脉粥样硬化指数（P＜0.01）。此外,无斑鹞鲼蛋白可明显增加大鼠粪便中胆汁酸和中性固醇的排出量（P＜0.05）,并可降低大鼠肝脏中ACAT2 mRNA的表达量（P＜0.05）,增加CYP7A1 mRNA的表达量（P＜0.05）,而对HMG-CoA mRNA的作用不显著。结论：无斑鹞鲼蛋白可明显降低大鼠血清和肝脏中的TC含量,降低大鼠血清动脉粥样硬化指数,其作用机制主要与增加肝脏内胆固醇的分解代谢以及促进粪便中性固醇和胆汁酸的排出有关。     

黑米通过上调小鼠肝脏CYP7A1的表达调控胆固醇代谢

目的:研究黑米对小鼠血脂以及肝脏中胆固醇代谢相关基因及蛋白表达的影响。方法:雄性C57BL/6J小鼠随机分为4组,以玉米淀粉为碳水化合物来源的高脂高胆固醇膳食组为对照,实验组分别在高脂饲料中添加白米(精)和黑米(低剂量C+BL和高剂量C+BH)代替玉米淀粉。测定血清总胆固醇(TC)、甘油三酯(TG)和高密度脂蛋白胆固醇(HDL-C)水平,Real-time PCR(RT-PCR)法检测肝脏中胆固醇代谢调控相关基因HMG-Co A-R、LXR-α、SREBP-2、LDL-R、CYP7A1等的m RNA表达水平,Western blot法检测LDL-R和CYP7A1的蛋白表达水平。结果:白米组血清中TC、TG、HDL-C含量较对照组无统计学差异,但黑米组血清中TC和TG含量较对照组降低,且HDL-C显著升高(P0.05)。RT-PCR结果显示,与高脂组相比,黑米添加组LXR-α、SREBP-2、CYP7A1 m RNA表达水平均上调(P0.05)。与高脂组相比,C+BH组小鼠CYP7A1蛋白表达显著上调(p0.05)。结论:黑米调节机体胆固醇代谢平衡可能是通过升高血清中HDL-C含量,上调肝脏中胆固醇向胆汁酸转化酶CYP7A1的表达。     

牛磺酸对高胆固醇血症大鼠胆固醇/胆汁酸代谢的影响

为探讨在无外源性胆酸盐的务件下牛磺酸对高胆固醇血症大鼠胆固醇,胆汁酸代谢的影响,以8周龄雄性Wistar大鼠为试验对象,根据大鼠的体重和血清胆固醇水平随机分为对照组、高脂饲料组和牛磺酸组,分别给予基础饲料、高脂饲料以及添加了1%牛磺酸的高脂饲料.21 d后测定大鼠血清总胆固醇(TC)、高密度脂蛋白胆固醇、肝脏TC、门静脉血和胆汁中胆固醇与胆汁酸含量、粪便中中性固醇与胆汁酸含量以及肝脏CYP7Al、空肠ABCG5,ABCG8和曰肠BABP的mRNA表达.结果显示:牛磺酸可显著降低高胆固醇血症大鼠的血清和肝脏TC水平,明显增加粪便中性固醇和胆汁酸的排出量.提示牛磺酸是通过抑制胆固醇吸收、促进粪便中性固醇和胆汁酸排出而起到降胆固醇作用.     

黑米对雌性小鼠血脂调节的影响

黑米富含花色苷,花色苷具有降血脂、抗氧化、抗炎等多种功效。实验研究黑米对雌性小鼠血清胆固醇水平(TC、TG、HDL-C)以及肝脏中胆固醇代谢相关基因(LDL-R、LXR-α、CYP7A1、SREBP-2、HMG-CoA-R)调控表达的影响。以喂养高脂高胆固醇膳食的雌性C57BL/6J小鼠为动物模型,以喂食高脂高胆固醇膳食组为对照组(C组),三个实验组分别在小鼠高脂饲料中添加白米(C+W组)和黑米(B+L和B+H组)。测定血清总胆固醇(TC)、甘油三酯(TG)和高密度脂蛋白胆固醇(HDL-C)水平以及肝脏胆固醇代谢调控相关基因HMG-CoA-R、LXR-α、SREBP-2、LDL-R、CYP7A1等的mRNA表达。与高脂对照组相比,黑米可显著降低血清中总胆固醇和甘油三酯的水平;RT-PCR结果显示,与高脂组相比,黑米添加组LXR-α、SREBP-2、LDL-R、CYP7A1 mRNA表达量均上调,HMG-CoA-R mRNA表达量下调。     

硫酸化羊肚菌多糖调控胆固醇代谢作用

黑脉羊肚菌多糖（polysaccharides from Morchella angusticeps Peck,PMEP）已被证实可以降低胆固醇。本研究旨在比较PMEP及其硫酸化多糖（sulfated PMEP,SPMEP）对高胆固醇饮食大鼠的降胆固醇活性。结果表明：高剂量的PMEP和SPMEP可使大鼠的血清总胆固醇质量浓度分别降低15%和23%,表明SPMEP比PMEP具有更强的降胆固醇活性。PMEP和SPMEP降低血清胆固醇质量浓度伴随着肝脏3-羟基-3-甲基戊二酰CoA还原酶表达显著下调及7α-羟化酶表达显著上调（P＜0.05）。此外,PMEP和SPMEP都可以显著降低肝脏胆固醇质量浓度（P＜0.05）,同时显著提高粪便和肠道胆汁酸的总量（P＜0.05）。结论：PMEP通过硫酸化修饰可以增强对大鼠的降胆固醇活性。     

桑叶水提物预防小鼠高脂血症的作用研究

目的探讨桑叶水提取物(mulberry leaf water extract,MWE)的降血脂功效,为桑叶保健品降血脂的开发利用提供依据。方法在饲喂高脂饲料的同时,给予小鼠不同剂量的桑叶水提取物,28 d后摘眼球取血,测定不同试验组小鼠血清血脂水平、载脂蛋白A1(Apo A1)和载脂蛋白B(Apo B)含量、小鼠肝脏中3-羟基-3-甲基戊二酰辅酶A还原酶(HMGR)、胆固醇-7α-羟化酶(CYP7A1)和卵磷脂胆固醇酰基转移酶(LCAT)活性和总胆汁酸(total bile acid,TBA)含量以及粪便含水率和TBA含量。结果与高脂组小鼠相比,MWE可降低高脂饮食小鼠肝脏系数及脂肪系数,并降低高脂饮食小鼠血脂水平,使肝脏HMG-COA和LCAT活性降低,提高CYP7A1活性,并抑制肝脏胆汁酸的积累,促进胆汁酸的排出。结论 MWE对高脂小鼠具有显著的降血脂功效,可有效减少脂肪积累,促进胆固醇代谢从而预防动脉硬化的发生。     

发酵麦胚对高脂模型大鼠胆固醇水平的调节

目的:探讨发酵麦胚对高脂模型大鼠胆固醇水平的调节及可能的作用机制。方法:雄性SD大鼠,根据体质量和血清胆固醇水平随机分组,每组10只,空白组自由取食基础饲料和饮水,模型组、液低组、液中组、液高组、渣低组、渣中组、渣高组自由取食高脂饲料和饮水,每天固定时间灌胃,空白组和模型组灌胃同体积水,其他组分别灌胃221、442、884 mg/(kg·d)的发酵液冻干粉和沉淀物冻干粉。60 d后测血清总胆固醇(total cholesterol,TC)含量、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)含量、肝脏TC含量、胆固醇7α-羟化酶(cholesterol 7α-hydroxylase,CYP7A1)活性、排便量和粪便胆汁酸含量。结果:模型组血清TC含量极显著高于空白组(P0.01),高胆固醇血症模型构建成功;液低组、渣中组大鼠血清TC含量分别显著(P0.05)和极显著(P0.01)低于模型组;各受试组肝脏TC含量、排便量和粪便胆汁酸排出量均高于模型组,但未达显著水平(P0.05)。结论:发酵麦胚降血清胆固醇效果明确,且具有时间效应和剂量效应关系;其作用途径可能与促进血清胆固醇向肝脏转运、增加胆固醇向胆汁酸转化以及增加排便量有关。     

多孔淀粉对卵巢切除大鼠脂质代谢的影响

目的:研究多孔淀粉对卵巢切除大鼠脂质代谢的影响。方法:将24只雌性SD大鼠按体质量随机分为3组,其中一组进行伪切除手术,其余两组进行双侧卵巢切除手术,手术后恢复1周,分别饲喂相应饲料。4周后,检测大鼠血脂、肝脂、粪便中中性固醇含量和胆汁酸含量以及肠道中典型微生物数量、短链脂肪酸浓度等指标。结果:多孔淀粉的替代添加可以显著降低大鼠血浆中甘油三酯(triglyceride,TG)、TG与高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C)的比值(TG/HDL-C)、肝脏中总胆固醇(total cholesterol,TC)、TG和脂肪总质量,显著减少腹部脂肪堆积(P0.05);显著增加粪便中中性固醇和胆汁酸的排泄量(P0.05);同时促进肠道中益生菌增殖和短链脂肪酸浓度的提高。结论:多孔淀粉对雌激素缺乏引起的高脂血症具有较好的降脂、降胆固醇效果,对内源性脂质代谢紊乱具有较好的缓解作用。     

Fish protein decreases serum cholesterol in rats by inhibition of cholesterol and bile acid absorption

Fish protein has been shown to decrease serum cholesterol content by inhibiting absorption of cholesterol and bile acid in laboratory animals, though the mechanism underlying this effect is not yet fully understood. The purpose of this study was to elucidate the mechanism underlying the inhibition of cholesterol and bile acid absorption following fish protein intake. Male Wistar rats were divided into 2 dietary groups of 7 rats each, 1 group receiving a diet consisting of 20% casein and the other receiving a diet consisting of 10% casein and 10% fish protein. Both experimental diets also contained 0.5% cholesterol and 0.1% sodium cholate. After the rats had been on their respective diets for 4 wk, their serum and liver cholesterol contents and fecal cholesterol, bile acid, and nitrogen excretion contents were measured. Fish protein consumption decreased serum and liver cholesterol content and increased fecal cholesterol and bile acid excretion and simultaneously increased fecal nitrogen excretion. In addition, fish protein hydrolyzate prepared by in vitro digestion had lower micellar solubility of cholesterol and higher binding capacity for bile acids compared with casein hydrolyzate. These results suggest that the hypocholesterolemic effect of fish protein is mediated by increased fecal cholesterol and bile acid excretion, which is due to the digestion products of fish protein having reduced micellar solubility of cholesterol and increased bile acid binding capacity.     

High Amylose Cornstarch Decreases Plasma Triacylglycerol Concentration, but not Plasma Cholesterol, in a Dose-Dependent Manner

ABSTRACT:  The effect of dietary high amylose cornstarch (HACS) on plasma lipids was studied in ovariectomized rats (OVX-rats). OVX-rats were fed cholesterol-free purified diets containing either 0%, 5%, 10%, 20%, or 30%HACS as a percentage of total carbohydrate for 28 d. Plasma triacylglycerol (TAG) concentration and apparent starch digestibility were found to decrease as the dietary level of HACS increased. On the other hand, the amount of small intestinal bile acids, cecal tissue weight, the amount of cecal short-chain fatty acids, primary:secondary ratio of fecal bile acids, and fecal weight were found to increase. However, plasma total cholesterol concentration, excretion of fecal bile acids, cholesterol 7α-hydroxylase activity, liver lipids, body weight gain, liver weight, and the weight of cecal contents were not affected by the diets. The amount of propionic acid in the cecal content increased as the dietary level of HACS increased. HACS might lower lipogenesis in liver and adipose tissue and lower very low density lipoprotein secretion by increasing propionic acid production, consequently leading to a decreased plasma TAG concentration.     

Selection of potential probiotic lactobacilli for cholesterol-lowering properties and their effect on cholesterol metabolism in rats fed a high-lipid diet

The objectives of this study were to screen probiotic characteristics of lactobacilli isolated from traditionally homemade koumiss products in Xinjiang and Inner Mongolia of China, and to determine and compare the effect of the Lactobacillus strains in vivo on lipid metabolism in rats fed with a high-lipid diet. Three out of 68 strains of Lactobacillus isolated from the koumiss were screened for bile-salt resistance, acid tolerance, and different hypocholesterolemic properties. The cholesterol-lowering effects of the 3 screened strains were estimated in rats fed a high-lipid diet by determination of serum lipids, liver, and fecal cholesterol, fecal total bile acids, and short-chain fatty acids. After a 4-wk feeding period, in comparison with the control group, the groups LIP-1 and MG9-2 had a significant reduction in serum total cholesterol, triglyceride and low-density lipoprotein cholesterol, and significantly increased high-density lipoprotein, the group E7301 had similar effects on serum lipids, but the change was not significant. The groups LIP-1, MG9-2 and E7301 had a significant reduction in liver cholesterol content and an increase in fecal cholesterol content compared with the control group. Total bile acid excretion was significantly higher in rats fed MG9-2 than the other groups. Rats fed diets containing lactic acid bacteria strains had significantly higher propionic acid and butyric acid concentrations in the feces compared with the control. Results indicated that the 3 screened Lactobacillus strains were able to lower cholesterol in vitro, and reduce cholesterol effectively in vivo. The mechanisms behind the hypocholesterolemic effect of 3 strains are likely to be diverse and will need further investigation.     

Lipid-Lowering Effect of Eriocitrin, the Main Flavonoid in Lemon Fruit, in Rats on a High-Fat and High-Cholesterol Diet

ABSTRACT:  Eriocitrin (eriodictyol 7- O -β-rutinoside) is the main flavonoid in lemon fruit. In this study, eriocitrin was investigated for its lowering effect on serum and hepatic lipids in high-fat and high-cholesterol fed rats. Rats in the control group ( N = 6) were fed a 20% lard and 1% cholesterol diet for 21 d, and rats in the 0.35% eriocitrin group ( N = 6) and 0.70% eriocitrin group ( N = 6) were fed a diet supplemented with eriocitrin 0.35% and 0.70%, respectively. The content of hepatic total cholesterol and triglyceride in the eriocitrin group was no different from that of the control group. The total cholesterol, VLDL+LDL, triglyceride, and phospholipid in the serum of the 0.35% eriocitrin group showed significantly lower concentrations than the control group ( P < 0.05), although there was no difference in the HDL concentrations among the groups. The lowering effect of eriocitrin for serum total cholesterol was thought to be caused by a decrease in VLDL+LDL. The 0.35% eriocitrin group was shown to have a significant increase in excretion of fecal bile acid ( P < 0.05) and a tendency for enhanced hepatic m-RNA levels of LDL receptor in comparison with the control group.     

植物乳杆菌DMDL 9010制剂调控SD大鼠脂质水平的研究

探讨植物乳杆菌DMDL 9010(Lactobacillus plantarum DMDL 9010)对SD大鼠脂质水平的影响。以无菌水、1 mg/mL阿托伐他汀水溶液、高剂量(109 CFU/mL)和低剂量(107 CFU/mL)L. plantarum DMDL 9010菌悬液连续灌胃SD大鼠10周,监测大鼠体重和血清、肝脏、粪便的脂质水平变化。结果显示:高剂量(109 CFU/mL)L.plantarum DMDL 9010能显著降低大鼠血清总胆固醇(TC)(23.03%)、低密度脂蛋白(28.00%)和动脉硬化指数(34.04%)(p<0.05),显著降低大鼠肝脏TC(33.20%)和甘油三酯(TG)(40.86%)(p<0.05),增加粪便TC(31.07%)和胆汁酸(TBA)(70.18%)排泄(p<0.05),肝脏病理切片观察表明,L. plantarum DMDL 9010能改善肝细胞脂肪变性。得出L. plantarum DMDL 9010以剂量依赖的方式降低血清和肝脏的TC和TG,提高粪便TC和TBA排泄,从而有效调控其脂质水平,为开发预防和治疗高胆固醇血症的益生菌制剂提供了可能。     

牛磺酸对高胆固醇血症小鼠胆固醇/胆汁酸吸收与排出的影响

为探讨牛磺酸对高胆固醇血症小鼠胆固醇/胆汁酸代谢的影响,本文以10周龄雄性C57BL/6小鼠为实验对象,根据体重和血清胆固醇水平随机分为6组,对照组(N)、高胆固醇膳食组(C)、高胆固醇/胆盐膳食组(CB)以及分别与这三组相对应的牛磺酸添加组(NT、CT、CBT).给与各组相应膳食1周后,测定血清和肝脏胆固醇含量,粪胆汁酸和中性固醇含量,以及胆固醇/胆汁酸稳态相关因子肝脏ABCG5/ABCG8、BSEP,空肠ABCG5/ABCG8,回肠BABP、BAT mRNA表达.结果显示:分别与C、CB组相比较,CT、CBT组小鼠血清和肝脏胆固醇显著降低(P<0.05)、粪胆汁酸量明显增加(P<0.05)、粪中性固醇量无显著变化;与N组相比较,C/CT/CB/CBT四组小鼠肝脏ABCG5/ABCG8、BSEP,空肠ABCC5/ABCG8 mRNA表达增加,但四组问无显著差异;与N组相比较,C/CT/CB/CBT四组小鼠回肠BATmRNA表达明显减少,CT组比C组进一步降低.以上结果提示,牛磺酸增加了高胆固醇血症小鼠粪胆汁酸的排出,并不影响粪中性固醇的排出,并且在无外源性胆盐的条件下显示抑制回肠BAT mRNA表达的倾向.