乳清酸诱导大鼠脂肪肝的机制研究

目的研究乳清酸诱发大鼠脂肪肝的机制。方法将大鼠分成两组,对照组喂食AIN93标准饲料,模型组饲料中添加1%乳清酸。饲喂10d后,分别测定大鼠血清总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)、高密度脂蛋白胆固醇(high density lipoprotein-cholesterol,HDL-C)含量,以及肝脏TC、TG、磷脂含量。同时测定了肝脏中脂肪酸合成酶(FAS)、肉碱棕榈酰转移酶(CPT)、微粒体甘油三酯转运蛋白(MTP)的活性和其mRNA表达量,以及固醇调节元件结合蛋白(SREBP-1c)和过氧化物酶体增殖物激活受体(PPARα)的mRNA表达量。结果乳清酸可显著提高大鼠血清TG浓度和肝脏TC、TG含量。添加乳清酸后,大鼠肝脏中FAS活性及mRNA水平明显上调,而CPT、MPT活性及mRNA水平明显下调,同时作为转录调节因子的SREBP-1cmRNA表达量增加3.13倍,PPARα mRNA表达量无明显变化。结论1%乳清酸诱发大鼠脂肪肝与SREBP-1c的表达量升高引发的脂肪合成亢进有关,并与脂肪酸氧化分解受抑制及MTP活性和基因表达量降低有关。     

不同膳食油脂对高脂血症大鼠脂质代谢影响的比较研究

目的比较4种脂肪酸组成迥异的膳食油脂对高脂血症大鼠脂质代谢的影响,并初步探讨其作用机制。方法将OLETF大鼠28只分为4组,喂以AIN76基本配方饲料,基础油脂含量为8%,各组分别添加2%棕榈油、琉璃苣油、紫苏油和鱼油。4 w后,测定大鼠空腹血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(NEFA)、葡萄糖浓度,肝脏TG、TC、磷脂(PL)浓度以及肝脏脂质代谢相关酶脂肪酸合成酶(FAS)、苹果酸酶(ME)、葡萄糖6磷酸脱氢酶(G6PDH)和肉碱棕榈酰转移酶(CPT-1,CPT-2)的mRNA表达。结果与棕榈油组比,琉璃苣油组血清中NEFA、TG含量显著降低(P<0.05),TC、HDL-C含量明显升高(P<0.05)。紫苏油组血清中NEFA、TG含量显著降低(P<0.05)。鱼油组与其它组相比,各项指标含量均显著降低(P<0.05)。琉璃苣油和紫苏油组可明显降低肝脏TG和TC浓度(P<0.05),鱼油组显著降低肝脏TG浓度(P<0.05),对TC浓度无明显影响。此外,琉璃苣油、紫苏油和鱼油组可显著抑制肝脏脂肪合成相关酶的mRNA表达(P<0.05),同时显著增加脂肪酸分解酶mRNA表达(P<0.05)。结论相比于棕榈油组,摄食琉璃苣油、紫苏油和鱼油可通过抑制肝脏脂肪酸合成和促进脂肪酸分解,降低高脂血症大鼠血清和肝脏脂肪水平。     

大豆蛋白及其水解物对大鼠体内胆固醇代谢的影响

[目的]探讨大豆蛋白和大豆活性肽对高胆固酵模型大鼠血浆胆固酵及其有关血脂指标的影响,并对其可能的作用机理加以研究,同时也对大豆蛋白和大豆活性肽在降低胆固醇作用方面进行初步的比较.[方法]4周龄断乳雄性Wistar大鼠,经28d诱发高血胆固醇模型以后,按血浆总胆固醇浓度将动物均衡分为3组,分别喂饲含大豆活性肽、大豆蛋白和酪蛋白的纯合成高脂饲料56d后,断头处死动物.[结果]经28d诱导高脂模型后,实验模型大鼠的TC水平为(2.01±0.26)mmol/L(n=36),阴性对照组大鼠分别为(1.33±0.20)mmol/L(n=10).高血胆固醇模型大鼠的TC浓度是阴性对照组的1.51倍(P<0.05).高血胆固醇模型大鼠又经56d喂饲含有处理因素的饲科后,酪蛋白组、大豆蛋白组和大豆活性肽组大鼠体重(g)分别增加了198.5、133.1和119.3;TC(mmol/L)水平分别为6.41±0.57、3.99±0.28和3.01±0.37;TG(mmol/L)水平分别为3.73±0.70、2.58±0.86和1.09±0.34;与酪蛋白组相比,大豆蛋白组、大豆活性肽组动物体重及TC,TG含量显著降低(P<0.05);大豆活性肽、大豆蛋白的摄入可使大鼠肝脏HMG-CoA还原酶mRNA的表达增强,而对LDL-R mRNA的表达无影响.另外,与大豆蛋白组相比,大豆活性肽组大鼠体重及TC,TG含量显著降低(P<0.05).[结论]大豆蛋白、大豆活性肽的摄入可降低高血胆固醇模型大鼠TC、TG浓度,但对HDL-C水平无显著影响;经统计学检验,大豆活性肽降低胆固醇作用与大豆蛋白相比差异有统计学意义(P<0.05).大豆活性肽、大豆蛋白可影响大鼠肝脏HMG-CoA还原酶mRNA的表达可能是其降低胆固醇的机理之一.     

大豆活性肽降低大鼠血浆胆固醇机理的初步探讨

目的探讨膳食大豆活性肽对高胆固醇模型大鼠血浆胆固醇及其有关血脂指标的影响,并对其可能的作用机理加以研究。方法4周龄断乳雄性Wistar大鼠,经28d诱导高胆固醇模型以后,按血浆总胆固醇浓度将动物均衡分为2组,分别喂饲含酪蛋白和大豆活性肽的纯合成高脂饲料56d。结果经28d诱导高胆固醇模型后,高胆固醇模型大鼠的TC浓度是阴性对照组的1.51倍。又经56d喂饲含有处理因素的饲料后,酪蛋白组和大豆活性肽组大鼠体重分别增加了（198.5和119.3）g;血浆总胆固醇浓度水平分别为（6.41±0.57和3.01±0.37）mmol/L;TG水平分别为（3.73±0.70和2.13±0.61）mmol/L;粪胆汁酸含量分别为（0.75±0.13和0.96±0.17）mmol/d;与酪蛋白组相比,大豆活性肽组动物体重及TC,TG和apoB含量显著降低,而粪胆汁酸含量显著增加（P〈0.05）。大豆活性肽组可使大鼠肝脏HMG-CoA还原酶 mRNA,LDL-R mRNA的表达增强。结论膳食大豆活性肽摄入可降低高胆固醇模型大鼠TC、TG、apoB浓度、使粪胆汁酸排泄量增高,但对HDL-C,apoA水平无影响。另外,大豆活性肽可以增强大鼠肝脏HMG-CoA还原酶及LDL-R基因的表达,这可能是其降低血浆胆固醇的机理之一。大豆活性肽可影响血浆胆固醇水平,但其相应的作用机理还需进一步探讨。     

根皮苷对饲喂高脂高胆固醇饲料仓鼠肝脏中胆固醇代谢调控基因表达的影响

目的研究根皮苷对仓鼠血清胆固醇水平及肝脏中胆固醇代谢相关调控基因表达的影响。方法试验以饲喂高脂高胆固醇饲料仓鼠为动物模型,随机分为对照组和实验组(0.3%、0.6%和0.9%根皮苷),测定血清总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、甘油三酯(TG)水平。用实时定量荧光PCR(Real-time PCR)和Western blot方法检测肝脏中胆固醇代谢相关调控基因mRNA及蛋白表达水平。结果与对照组相比根皮苷(0.9%)能显著降低血清中TC(P<0.05)和TG(P<0.01)水平;饲喂根皮苷(0.6%,0.9%)能显著升高血清HDL-C水平(P<0.01)。RT–PCR分析显示,肝脏中LDL-R、LXR、CYP7A1基因表达上调,HMG-CoA-R基因表达下调。Western blot结果显示,与对照组相比给予0.6%、0.9%根皮苷后胆固醇合成限速酶HMG-CoA-R蛋白表达水平显著降低(P<0.05),0.9%根皮苷组CYP7A1表达水平显著升高(P<0.05)。结论根皮苷调控机体胆固醇代谢的机制可能是通过调控肝脏中胆固醇代谢相关基因的表达来实现的。     

钙摄入量对大鼠血浆胆固醇水平影响

目的 探讨钙摄入量对大鼠肝脏胆固醇代谢关键酶3-羟基-3-甲基戊二酰辅酶A还原酶(HMG-CoA还原酶)、7α-羟化酶(CYP7A)的mRNA表达影响.方法 雄性Wistar大鼠经14 d诱导高胆固醇血症模型后,分别喂饲不同钙含量的纯合成高脂饲料42 d.结果 经14 d诱导高胆固醇模型后,高脂模型组大鼠血浆胆固醇(TC)水平为(2.57±0.57)mmol/L(n=21),是常脂常钙组(1.49±0.14)mmol/L(n=8)的1.72倍.又经42 d喂饲含有处理因素的饲料后,各组大鼠摄食量和体重无变化;高脂高钙组心脏指数和肾脏指数分别显著低于、高于其他各组(P<0.05);随着钙含量增加,实验处理组大鼠骨密度也逐渐增加;高脂常钙组TC浓度为(2.32±0.75)mmol/L,比初始时下降了6.07%;高脂中钙组抑制TC增高能力强于常脂常钙组;除高脂高钙组外,钙摄入可使大鼠肝脏HMG-CoA还原酶mRNA的表达量呈现下降趋势,CYP7A mRNA的表达量呈现增强趋势.结论 适量钙摄入可通过影响HMD-CoA还原酶和CYP7A基因的表达来降低或改善血浆胆固醇水平.     

谷豆复合物、谷豆复合膳食纤维及单一谷物膳食纤维对脂代谢紊乱的影响

目的观察谷豆复合物、谷豆复合膳食纤维和全谷物玉米膳食纤维(DF)对脂代谢紊乱大鼠血脂及肝脏脂肪酸合成酶(FAS)活性,及其对大鼠肝组织固醇调节元件结合蛋白-1c(SREBP-1c)mRNA表达的影响,比较谷豆复合物、谷豆复合DF与单一谷物DF改善脂毒性效果。方法 50只SD大鼠适应性喂养1周后,随机分成阴性对照组、高脂模型组、谷豆复合物组、谷豆复合DF组和玉米DF组;以相应的饲料连续喂养8周后,测定各组大鼠总胆固醇(TC)、甘油三酯(TG)、空腹血糖(FBG)、高密度脂蛋白胆固醇(HDL-C)和FAS等指标,测定各组大鼠肝脏SREBP-1c mRNA的表达。结果与阴性对照组相比,高脂模型组的大鼠血清TC、TG水平显著升高(P0.05);与高脂模型组相比,谷豆复合物组、谷豆复合DF组和玉米DF组大鼠血清TC、TG水平显著降低(P0.05);HDL-C水平显著高于高脂模型组,大鼠肝脏脂肪酸合成酶活性及SREBP-1c的表达显著降低。结论谷豆复合膳食纤维可改善脂代谢紊乱大鼠的血脂水平,降低FAS活性及SREBP-1c的表达水平。     

孕期尼古丁暴露、高脂饮食和性别三种因素在胎源性高胆固醇血症发生过程中的交互作用研究

目的探讨尼古丁暴露(PNE)、高脂饮食(HFD)和性别在胎源性高胆固醇血症发生过程中的交互作用。方法孕鼠在GD11开始皮下注射尼古丁2 mg·kg~(-1)·d~(-1)直到自然生产,仔鼠从出生后4周开始断奶,雌雄分笼,在对照组和PNE组随机挑选仔鼠给予HFD饲料饲养(含89.5%玉米粉、10%猪油和0.5%TC),并在出生后24周处死大鼠,取血和肝脏检测。ELISA法检测血清皮质酮(CORT)水平,生化法检测血总胆固醇(TC)、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,实时定量PCR法检测胎盘、肝组织胆固醇代谢和胰岛素样生长因子1(IGF1)信号通路的相关基因mRNA表达。结果正常饮食和HFD下血胆固醇表型:正常饮食下,PNE雌、雄子代血TC均升高(P0.01),雄性血LDL-C升高(P0.01)。HFD下,PNE雌雄子代血TC、LDL-C均升高(P0.01)。正常饮食和HFD下肝脏胆固醇代谢:正常饮食下,PNE组Apo B、CYP7A1的mRNA表达升高(P0.01),雌性SR-B1和LDLR的mRNA表达降低(P0.05,P0.01)。高脂饮食下,PNE组HMGCR、CYP7A1、SR-B1的mRNA表达均下降(P0.05,P0.01),雄性LDLR的mRNA表达也降低(P0.05)。HFD可加重PNE所致的血TC、HDL-C水平升高,并进一步抑制肝脏HMGCR和SR-B1的mRNA表达。雄性PNE组子代血LDL-C水平以及肝脏SR-B1表达的变化较雌性PNE组明显。此外,雄性HFD组的HMGCR、CYP7A1和SR-B1的表达改变较雌性明显。结论HFD可加重PNE所致的成年子代胆固醇水平升高,且HFD可影响PNE子代肝脏胆固醇代谢基因的功能,部分存在性别差异。     

大豆蛋白对大鼠血脂代谢影响

目的探讨大豆蛋白在普通饮食和高脂饮食状态下对大鼠血清脂质水平的影响及作用机制。方法 48只清洁级SD大鼠,按体重随机分为4组,分别喂饲含酪蛋白和大豆蛋白的普通饲料和高脂饲料28 d后,脱颈椎处死动物,检测血脂指标及基因表达水平。结果大豆蛋白组大鼠血清胆固醇(TC)浓度(1.36±0.38)mmol/L,比酪蛋白组(1.97±0.42)mmol/L低31%(P0.05);大豆蛋白高脂组大鼠血清TC、甘油三酯(TG)和低密度脂蛋白胆固醇(LDL-C)浓度分别为(1.43±0.22),(0.53±0.14)和(0.25±0.06)mmol/L,分别比酪蛋白高脂组(2.03±0.31),(0.79±0.20),(0.31±0.06)mmol/L降低30%,33%和19%(P0.05)。大豆蛋白组大鼠肝脏3-羟基-3-甲基戊二酸辅酶A(HMG-CoA)还原酶及低密度脂蛋白受体(LDL-R)基因的表达均高于酪蛋白组。结论大豆蛋白通过影响HMG-CoA还原酶及LDL-R基因的表达调节血脂水平。     

木浆源甾醇对高脂高胆固醇仓鼠胆固醇代谢基因表达的影响

目的研究木浆源甾醇对高脂高胆固醇仓鼠肝脏中胆固醇代谢基因表达的影响。方法测定空白组、高脂组、实验组仓鼠的质量、脏器重量、血清中总胆固醇(total cholesterol,TC)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、甘油三酯(triglyceride,TG)水平。检测肝脏中胆固醇代谢相关调控基因m RNA表达水平及肝脏胆固醇含量和粪便固醇排泄量。结果木浆源甾醇可以极显著降低TC、TG、和Non HDL-C水平(P0.01),同时极显著降低肝脏中胆固醇含量和肝脏重量(P0.01),显著增加粪中固醇排泄量(P0.05)。实验组肝脏中SREBP2、CYP7A1、HMG-Co A-R和LDL-R m RNA表达水平显著上调(P0.05)。给予木浆源甾醇后可以改变肠道菌群多样性,增加有益菌减少有害菌数量。结论木浆源甾醇可能通过调控肝脏中胆固醇代谢相关基因的表达,抑制胆固醇的合成吸收并增加固醇的排泄,同时丰富肠道微生物多样性,增加有益菌数量,协同作用调控机体胆固醇的代谢。     

Dietary sea cucumber cerebroside alleviates orotic acid-induced excess hepatic adipopexis in rats

ABSTRACT: BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disease in industrialized countries. The present study was undertaken to explore the preventive effect of dietary sea cucumber cerebroside (SCC) extracted from Acaudina molpadioides in fatty liver rats. METHODS: Male Wistar rats were randomly divided into four groups including normal control group, NAFLD model group, and two SCC-treated groups with SCC at 0.006% and 0.03% respectively. The fatty liver model was established by administration of 1% orotic acid (OA) to the rats. After 10d, serum and hepatic lipid levels were detected. And the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were also determined. Besides, to gain the potential mechanism, the changes of key enzymes and gene expressions related to the hepatic lipid metabolism were measured. RESULTS: Dietary SCC at the level of 0.006% and 0.03% ameliorated the hepatic lipid accumulation in fatty liver rats. SCC administration elevated the serum triglyceride (TG) level and the ALT, AST activities in OA-fed rats. The activities of hepatic lipogenic enzymes including fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphatedehydrogenase (G6PDH) were inhibited by SCC treatment. And the gene expressions of FAS, ME, G6PDH and sterol-regulatory element binding protein (SREBP-1c) were also reduced in rats fed SCC. However, dietary SCC didn't affect the activity and mRNA expression of carnitine palmitoyltransferase (CPT) in liver. Besides, suppression of microsomal triglyceride transfer protein (MTP) activity was observed in SCC-feeding rats. CONCLUSIONS: These results suggested that dietary SCC could attenuate hepatic steatosis due to its inhibition of hepatic lipogenic gene expression and enzyme activity and the enhancement of TG secretion from liver.     

Corn silk extract improves cholesterol metabolism in C57BL/6J mouse fed high-fat diets

BACKGROUND/OBJECTIVESCorn silk (CS) extract contains large amounts of maysin, which is a major flavonoid in CS. However, studies regarding the effect of CS extract on cholesterol metabolism is limited. Therefore, the purpose of this study was to determine the effect of CS extract on cholesterol metabolism in C57BL/6J mouse fed high-fat diets.MATERIALS/METHODSNormal-fat group fed 7% fat diet, high-fat (HF) group fed 25% fat diet, and high-fat with corn silk (HFCS) group were orally administered CS extract (100 mg/kg body weight) daily. Serum and hepatic levels of total lipids, triglycerides, and total cholesterol as well as serum free fatty acid, glucose, and insulin levels were determined. The mRNA expression levels of acyl-CoA: cholesterol acyltransferase (ACAT), cholesterol 7-alpha hydroxylase (CYP7A1), farnesoid X receptor (FXR), lecithin cholesterol acyltransferase (LCAT), low-density lipoprotein receptor, 3-hyroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), adiponectin, leptin, and tumor necrosis factor α were determined.RESULTSOral administration of CS extract with HF improved serum glucose and insulin levels as well as attenuated HF-induced fatty liver. CS extracts significantly elevated mRNA expression levels of adipocytokines and reduced mRNA expression levels of HMG-CoA reductase, ACAT, and FXR. The mRNA expression levels of CYP7A1 and LCAT between the HF group and HFCS group were not statistically different.CONCLUSIONSCS extract supplementation with a high-fat diet improves levels of adipocytokine secretion and glucose homeostasis. CS extract is also effective in decreasing the regulatory pool of hepatic cholesterol, in line with decreased blood and hepatic levels of cholesterol though modulation of mRNA expression levels of HMG-CoA reductase, ACAT, and FXR.     

Dietary fat type and cholesterol quantity interact to affect cholesterol metabolism in guinea pigs.

Interactions of dietary fat saturation with dietary cholesterol on cholesterol homeostasis in guinea pigs were studied by feeding 15% (wt/wt) fat diets containing lard, olive oil or corn oil, with 0.00, 0.08, 0.17 or 0.33% added cholesterol. Plasma total and LDL cholesterol concentrations significantly increased with increasing dietary cholesterol, with pronounced increments occurring at the pharmacologic (0.33%) level. An interaction between fat type and dietary cholesterol was seen for HDL cholesterol concentrations. Saturated fat and the pharmacologic level of dietary cholesterol increased plasma HDL concentrations, whereas polyunsaturated fat minimized the dietary cholesterol-mediated increase. Interactions were also observed for hepatic cholesterol: dietary cholesterol increased both free and esterified hepatic cholesterol concentrations in all groups fed all the dietary fats, and fat type influenced the extent of hepatic cholesterol accumulation. Lard-fed animals accumulated the least hepatic cholesterol over the range of dietary cholesterol intakes. Dietary cholesterol suppressed hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity, with maximal suppression at all levels of cholesterol intake. Dietary cholesterol had a greater effect on plasma and hepatic cholesterol concentrations and hepatic HMG-CoA reductase activity than did fat type. The data indicated limited interactions of fat type and cholesterol quantity in altering mechanisms regulating plasma cholesterol homeostasis.     

Effect of corn gluten and its hydrolysate consumptions on weight reduction in rats fed a high-fat diet

This study examined the effects of corn gluten (CG) and its hydrolysate consumptions on weight reduction in rats fed a high-fat diet. Eight-month-old male Sprague-Dawley rats (n=40) were fed a high-fat diet (40% calorie as fat) for 4 weeks. They were then randomly divided into four groups and fed the isocaloric diets with different protein sources for 8 weeks. The protein sources were casein (control group), intact CG (CG group), CG hydrolysate A (CGHA group, 30% of protein as peptides and 70% as free amino acids) and CG hydrolysate P (CGHP group, 93% of protein as peptides and 7% as free amino acids). Body weight gain, adipose tissue weights, nitrogen balance, absorptions of energy, protein and fat, lipid profiles in plasma, liver and feces and hepatic activities of carnitine palmitoyl transferase (CPT), fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G6PDH) were assessed. The CGHA diet had the highest amount of BCAAs, especially leucine, and most of them existed as free amino acid forms. The CGHA group showed significant weight reduction and negative nitrogen balance. Protein absorption and apparent protein digestibility in the CGHA group were significantly lower than those in other groups. Adipose tissue weights were the lowest in the CGHA group. Activity of CPT tended to be higher in the CGHA group than in other groups and those of FAS, ME and G6PDH were significantly lower in the CGHA group than in other groups. In conclusion, the CGHA diet which had relatively high amounts of free amino acids and BCAAs, especially leucine, had a weight reduction effect by lowering adipose tissue weight and the activities of FAS, ME and G6PDH in experimental animals, but it seemed to be a negative result induced by lowering protein absorption, increasing urinary nitrogen excretion and protein catabolism.     

The role of dietary protein in hepatic lipogenesis in the young rat

1. The effect of varying dietary levels of casein (40-140 g/kg) on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PD), malic enzyme (EC 1.1.1.40; ME), citrate cleavage enzyme (EC 4.1.3.8; CCE), acetyl CoA carboxylase (EC 6.4.1.2; AcCx), glucokinase (EC 2.7.1.2; GK), and pyruvate dehydrogenase (PDH) was examined in young, growing rats. 2. The activities of AcCx, FAS, G6PD and in vivo fatty acid synthesis were generally found to increase with increased dietary protein. 3. The levels of GK and PDH were not related to dietary protein. 4. ME decreased with increasing dietary protein. 5. The results demonstrate a dissociation between hepatic fatty acid synthesis and ME and suggest that when rats consume low-protein diets the NADPH needed for fatty acid synthesis is generated primarily by ME but that as the level of dietary protein is increased the contribution of ME is reduced while that of the phosphogluconate pathway becomes more important.     

The effects of black garlic (Allium satvium) extracts on lipid metabolism in rats fed a high fat diet

BACKGROUD/OBEJECTIVESThe mechanism of how black garlic effects lipid metabolism remains unsolved. Therefore, the objectives of this study were to determine the effects of black garlic on lipid profiles and the expression of related genes in rats fed a high fat diet.MATERIALS/METHODSThirty-two male Sqrague-Dawley rats aged 4 weeks were randomly divided into four groups (n=8) and fed the following diets for 5 weeks: normal food diet, (NF); a high-fat diet (HF); and a high-fat diet + 0.5% or 1.5% black garlic extract (HFBG0.5 or HFBG1.5). Body weights and blood biochemical parameters, including lipid profiles, and expressions of genes related to lipid metabolism were determined.RESULTSSignificant differences were observed in the final weights between the HFBG1.5 and HF groups. All blood biochemical parameters measured in the HFBG1.5 group showed significantly lower values than those in the HF group. Significant improvements of the plasama lipid profiles as well as fecal excretions of total lipids and triglyceride (TG) were also observed in the HFBG1.5 group, when compared to the HF diet group. There were significant differences in the levels of mRNA of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and glucose-6-phosphate dehydrogenase (G6PDH) in the HFBG1.5 group compared to the HF group. In addition, the hepatic expression of (HMG-CoA) reductase and Acyl-CoA cholesterol acyltransferase (ACAT) mRNA was also significantly lower than the HF group.CONCLUSIONSConsumption of black garlic extract lowers SREBP-1C mRNA expression, which causes downregulation of lipid and cholestrol metahbolism. As a result, the blood levels of total lipids, TG, and cholesterol were decreased.     

Dietary defatted sesame flour decreases susceptibility to oxidative stress in hypercholesterolemic rabbits.

Plant glucosides possess antioxidative properties due to their ability to scavenge free radicals. Sesame seeds contain a class of these compounds, the sesaminol glucosides. To evaluate their antioxidative activity in vivo, we fed rabbits diets containing 1% cholesterol (Chol) with or without 10% defatted sesame flour (DSF) (containing 1% sesaminol glucosides) for 90 d. We determined the susceptibility of their tissues to oxidation ex vivo as well as serum total cholesterol (TC), phospholipid (PL), triglyceride (TG) and HDL cholesterol (HDL-C) concentrations. Serum TC, HDL-C, PL and TG levels were unaffected by the addition of DSF. The HDL-C in the Chol + DSF group was greater than in the Chol group at 45 d. Both were greater than in the groups that did not consume cholesterol. Liver TC and TG were significantly lower in rabbits fed the diet containing DSF plus 1% cholesterol than in those fed 1% cholesterol alone. Lipid peroxidation activity, measured as 2-thiobarbituric acid reactive substances (TBARS), was lower in the liver (P < 0.05) and serum (P = 0.06) of rabbits fed DSF plus cholesterol than in rabbits fed the cholesterol diet. Although we did not detect sesaminol glucosides in peripheral tissues, we observed abundant quantities of sesaminol in rabbits fed DSF, the principal metabolite. Our findings suggest that feeding DSF to rabbits does not protect cholesterol-induced hypercholesterolemia, but may decrease susceptibility to oxidative stress in rabbits fed cholesterol, perhaps due to the antioxidative activity of sesaminol.