红曲与葡萄籽原花青素混合剂对动脉粥样硬化大鼠血脂的影响

目的:探讨红曲与葡萄籽原花青素(GSPE)混合剂对大鼠高脂血症的改善及对血清氧化性低密度脂蛋白的影响.方法:将60只大鼠按总胆固醇(TC)水平随机分为基础对照组、模型对照组及混合剂低、中、高三个剂量组,采用30万IUVD3/kg·d连续3d灌胃后,配合高脂饲料,复制大鼠动脉粥样硬化模型.空白对照组饲喂基础饲料,其余实验组饲喂高脂饲料;空白组及模型组灌胃蒸馏水,三个剂量组灌胃不同剂量混合剂,连续10周.在实验第2、4、6、8、10周测定血清总胆固醇(TC)、甘油三脂、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇(ox-LDL)、氧化性低密度脂蛋白及血清SOD、MDA、GSH-Px、T-AOC水平.结果:三个剂量组大鼠血清血脂水平(TC、TG、LDL-c)及ox-LDL明显降低,血清抗氧化能力(SOD、GSH-Px、T-AOC)提高,中、高剂量组效果优于低剂量组.结论:红曲及葡萄籽原花青素能缓解大鼠高脂血症,降低ox-LDL水平,提高机体抗氧化能力,延缓动脉粥样硬化的发生.     

n-6/n-3多不饱和脂肪酸比例对HepG2细胞脂代谢的影响

本文研究了不同比例n-6/n-3多不饱和脂肪酸对HepG2细胞影响,通过体外培养细胞60μM不同比例LA/ALA培养24 h,通过反转录PCR研究不同比例LA/ALA对HepG2细胞SREBP-1、FAS、HMG-CR、LDLr和Apo B蛋白等脂代谢相关基因及蛋白表达量的影响。结果表明在组1(LA)、组2(10:1 LA/ALA)、组3(5:1 LA/ALA)、组4(1:1 LA/ALA)、组5(1:5 LA/ALA)、组6(1:10LA/ALA)和组7(ALA)7组比例中,1:1 LA/ALA比例处理细胞效果最佳,此比例脂肪酸通过下调HepG2细胞SREBP-1和FAS基因的表达来降低细胞TG的含量;下调HMG-CR基因的表达,上调LDLr基因的表达来降低细胞TC和LDL-C含量;通过上调SR-B1基因表达增加胆固醇逆转运,从而实现对HepG2脂代谢的有效调控。此多不饱和脂肪酸体外营养评价模型,为n-6/n-3多不饱和脂肪酸最佳营养比例推荐及食用植物油中多不饱和脂肪酸比例营养评估提供理论依据。     

翅果油对小鼠抗氧化能力及脂质代谢的影响

以昆明小鼠为模拟对象,研究了摄入翅果油对小鼠抗氧化能力和脂质代谢的影响。实验选取30只6周龄昆明小鼠,随机分为3组,分别为对照组、花生油组和翅果油组,持续喂养6周后,分别测定其体重、抗氧化能力和脂质代谢水平。结果表明:与花生油相比,翅果油可显著降低小鼠体重、血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、丙二醛(MDA)含量及肝脏组织载脂蛋白Apo E基因表达量,显著提高血清和肝脏的总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性及肝脏组织肉碱棕榈酰转移酶-Ⅰ(CPT-Ⅰ)表达量、血清高密度脂蛋白胆固醇(HDL-C)含量。研究表明,富含不饱和脂肪酸和V_E的翅果油有助于提高小鼠机体抗氧化能力和血脂调节能力,是非常适宜食用的安全健康油品。     

燕麦β-葡聚糖抗氧化及降血脂作用的研究

目的:探讨燕麦β-葡聚糖对高脂血症大鼠的血脂及抗氧化作用的影响.方法:48只雄性大鼠随机分为4组:正常对照组、高脂对照组、高脂β-葡聚糖处理组(高、低剂量),喂养9周,测定血清总胆固醇(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);超氧化物歧化酶fSOD)活性、总抗氧化能力(T-AOC)、丙二醛(MDA)和脑脂褐质含量等指标.结果:燕麦B一葡聚糖能够降低TC、TG、LDL-C水平,升高HDL-C的水平;同时能明显提高血清SOD酶活性和T-AOC水平,并降低脑脂褐质及MDA含量.结论:燕麦β-葡聚糖对高脂血症大鼠的血脂水平升高和脂质过氧化均有一定的抑制作用.     

黄粉虫油对高脂血症小鼠血脂水平及抗氧化能力的影响

目的：探讨黄粉虫油对高脂血症小鼠血脂水平及抗氧化能力的影响。方法：以高脂饲料喂养雄性ICR小鼠,建立高脂血症模型,以不同剂量(5、10、20mL/(kg·d))的黄粉虫油对小鼠进行灌胃,观察各实验组小鼠血脂水平和肝脏抗氧化能力的变化情况。结果：黄粉虫油能显著降低高脂血症小鼠血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)浓度,升高高密度脂蛋白胆固醇(HDL-C)的浓度,同时动脉粥样硬化指数(AI) 亦显著降低;黄粉虫油能降低小鼠肝脏丙二醛(MDA)含量,增加肝脏过氧化氢酶(CAT)、超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)的活性,提高肝脏总抗氧化(T-AOC)能力。结论：黄粉虫油具有调节血脂和增强抗氧化功能的作用。     

不同n-6/n-3PUFA比率对载脂蛋白E缺失小鼠脂质成分的影响

目的探讨不同n-6/n-3多不饱和脂肪酸(polyunsaturated fatty acid,PUFA)饮食对载脂蛋白E缺失(apolipoprotein E deficient,apo E-/-)小鼠血脂水平及脂质成分的影响,以冀为高脂血症患者的日常膳食提供参考。方法 8周龄雄性apo E-/-小鼠随机分为5组(n=12),在基础鼠粮基础上添加紫苏籽油和红花油,使n-6/n-3 PUFA比率为:组1 1.28,组2 5.03,组3 9.98,组4 68.26,总脂肪量5%,对照组饮食基础鼠粮,干预6周后检测血清脂质水平,气相色谱-质谱联用仪分析血清和肝脏组织中脂肪酸组成。结果与其余各组相比,组4血清甘油三酯(TG)水平升高;与对照组相比,4种饮食干预均显著降低血清低密度脂蛋白胆固醇酯(LDL-C)水平,其中组3饮食降低程度最大;组4与组1相比,血清和肝脏组织中n-6脂肪酸分别增加了28%和48%,花生四烯酸(arachidonic acid,AA)分别增加了118%和122%,亚油酸(linoleic acid,LA)分别增加了19%和29%;总n-3 PUFA分别降低了39%和44%,二十碳五烯酸(EPA)分别降低了63%和65%。结论随着饮食中n-6/n-3 PUFA比率的增加,血清和肝脏组织中n-6 PUFA含量增加,n-3 PUFA含量降低。n-6/n-3 PUFA比率9.98饮食可最大程度降低血清LDL-C水平,可作为高脂血症患者的日常膳食参考。     

n-3多不饱和脂肪酸的药理作用

目的综述n-3多不饱和脂肪酸的药理作用。方法对国内外有代表性的文献加以归纳总结。结果与结论n-3多不饱和脂肪酸具有调血脂,降胆固醇,抑制血小板聚集,抗氧化,影响中枢神经系统和调节免疫功能的作用。     

番茄水提取物对动脉粥样硬化大鼠的影响

研究番茄水提取物(AEL)对高脂诱导动脉粥样硬化(AS)大鼠的影响及可能作用机制。采用高脂饲料喂饲和腹腔注射VD3建立大鼠AS模型2。4周后处死大鼠,检测血清血脂、抗氧化水平及全血黏度,观察主动脉作病理学变化。结果显示AEL给药组明显降低总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)和丙二醛(MDA)含量,明显升高高密度脂蛋白胆固醇(HDL-C)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、一氧化氮(NO)水平,明显降低动脉硬化指数(AI)及全血黏度,不同程度减缓主动脉粥样斑块的形成。AEL具有减缓大鼠动脉粥样硬化形成的作用,其可能与降低TC、TG、LDL-C及全血黏度,提高HDL-C水平及抗氧化有关。     

大豆磷脂和VE抗氧化、调节血脂功能的研究

为了探讨大豆磷脂和VE抗氧化、调节血脂的功能,分别建立抗氧化和调节血脂两个试验动物模型。每个模型均分成不同剂量组,经灌胃同一功能性食品溶液(其成分为大豆磷脂和VE)30 d后,取抗氧化模型组小鼠血检验其过氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽(GSH)3个指标的含量,取调节血脂模型组大鼠血检验其血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)3个指标的含量。结果表明大豆磷脂和VE具有较明显的抗氧化、调节血脂的功能。     

海参消化道多糖降血脂功能的研究

目的:为了充分利用海参加工的下脚料,研究海参消化道多糖对小鼠血脂及抗脂质过氧化的作用,为今后的开发利用奠定基础.方法:利用高脂饲料建立高脂血症模型,通过给予小鼠不同剂量的海参消化道多糖,5周后眼球取血,测定血清总胆固醇(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),同时测定超氧化物歧化酶(SOD)、谷胱甘肤过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量.结果:高、中、低剂量海参消化道多糖均能显著地降低高脂血症小鼠的血清总胆固醇(TC)、甘油三酯、低密度脂蛋白胆固醇水平,提高高密度脂蛋白胆固醇和动脉硬化指数(HDL-C/TC)值以及谷胱甘肤过氧化物酶的活性,并降低丙二醛的含量.结论:海参消化道多糖具有降血脂、抗氧化功能,对冠心病和动脉粥样硬化有一定的预防作用.     

Endogenous production of n-3 and n-6 fatty acids in mammalian cells

Polyunsaturated fatty acids (PUFA) are important components of mammalian diets, and the beneficial effects of n-3 PUFA on human development and cardiovascular health have been well documented. Caenorhabditis elegans is one of the few animals known to be able to produce linoleic (LA, 18:2n-6) and alpha-linolenic (ALA, 18:3n-3) essential fatty acids. These essential PUFA are generated by the action of desaturases that successively direct the conversion of monounsaturated fatty acids (MUFA) to PUFA. The cDNA coding sequences of the C. elegans Delta(12) and n-3 fatty acid desaturases were each placed under the control of separate constitutive eukaryotic promoters and simultaneously introduced into HC11 mouse mammary epithelial cells by adenoviral transduction. Phospholipids from transduced cells showed a significant decrease in the ratios of both MUFA:PUFA and n-6:n-3 fatty acids relative to control cultures. The fatty acid profile of transduced cellular phospholipids revealed significant decreases in MUFA and arachidonic acid (20:4n-6), and increases in LA, ALA, and eicosapentaenoic acid (20:5n-3). The fatty acid composition of triacylglycerols derived from transduced cells was similarly, but less dramatically, affected. These results demonstrate the functionality of C. elegans fatty acid desaturase enzymes in mammalian cells. Expression of these desaturases in livestock might act to counterbalance the saturating effect that rumen microbial biohydrogenation has on the fatty acid profile of ruminant products, and allow for the development of novel, land-based dietary sources of n-3 PUFA.     

Production response of multiparous Holstein cows treated with bovine somatotropin and fed diets enriched with n-3 or n-6 fatty acids

Multiparous cows (n = 59) were blocked by expected calving date and previous milk yield and assigned randomly to treatments to determine the effects of bovine somatotropin (bST; Posilac, Monsanto Animal Agricultural Group, St. Louis, MO) and source of dietary fat on production responses. Diets were provided from calving and included whole, high-oil sunflower seeds [SS; 10% of dietary dry matter (DM); n-6:n-3 ratio of 4.6] as a source of linoleic acid (18:2) or a mixture of Alifet-High Energy and Alifet-Repro (AF; Alifet USA, Cincinnati, OH; 3.5 and 1.5% of dietary DM, respectively; n-6/n-3 ratio of 2.6) as a source of protected n-3 fatty acids. Diets contained 181 versus 188 g of crude protein and 183 versus 186 g of acid detergent fiber/kg of DM and 1.54 versus 1.66 Mcal of net energy for lactation at the actual DM intake for SS versus AF, respectively. Cows received 0 or 500 mg of bST every 10 d from 12 to 70 d in milk (DIM) and at 14-d intervals through 280 DIM. The 2 × 2 factorial combination of diet (SS or AF) with or without bST administration resulted in treatments designated as SSY, SSN, AFY, and AFN, respectively. Data were analyzed as repeated measures using mixed model procedures to determine the effects of diet, bST, and their interactions. Yield of 3.5% fat-corrected milk was not altered by diet, but was increased by 4.0 ± 1.9 kg/d from 12 to 70 DIM and by 5.1 ± 1.2 kg/d from 12 to 280 DIM by bST. Treatment did not affect DM intake or energy balance (EB) nadir. There was an interaction of bST and diet on EB because AF decreased the impact of bST on overall EB and allowed AFY cows to reach a positive EB earlier than SSY cows. Gross feed efficiency adjusted for body weight change was greater for bST-treated cows (1.03 vs. 1.15 ± 0.03 kg of fat-corrected milk/Mcal of net energy for lactation). Circulating insulin-like growth factor-I concentrations were increased by bST (85 vs. 125 ± 8 ng/mL). Body weight, body condition score, and backfat thickness were reduced by bST, but differences between treated and nontreated cows did not differ by 280 DIM. Results indicate cows responded to bST administration in early lactation, but the magnitude of the response was greater after 70 DIM. Source of dietary fat had a minimal effect on most production measurements, but relative to SS, AF decreased the impact of bST on overall EB. Results support the premise that bST administration prolongs the delay in postpartum tissue replenishment.     

甘油酯型n-3多不饱和脂肪酸富集方法研究进展北大核心CSCD

n-3多不饱和脂肪酸(n-3 PUFA)具有多种生理活性,其主要有3种存在形式,其中甘油酯型n-3 PUFA因其生物利用度高和不易被氧化而优于游离型和乙酯型。然而,目前鲜有对甘油酯型n-3 PUFA进行高纯度富集的方法。为了对甘油酯型n-3 PUFA的高值化更加深入的研究提供参考,综述了富集甘油酯型n-3 PUFA的3种常见方法(物理一步法、两步法和酶一步法)及优缺点。物理一步法可以避免产物氧化,但得率较低;两步法工艺复杂,并有可能产生环境污染;而酶一步法具有简单、高效等优点,成为学者们关注的焦点。现有脂肪酶对甘油酯型n-3 PUFA的富集能力有限,还需进一步发掘富集能力更强的选择性脂肪酶。     

n-3 polyunsaturated fish fatty acids in a fish-oil-supplemented bread

White bread enriched in n-3 fatty acids in the form of gelatine-coated fish oil and marketed in Denmark since 1990 under the name of ‘Omega Bread’, was found to be a reliable and significant source of higher n-3 polyunsaturated fatty acids (with 20 and 22 C atoms). The bread from six bakeries contained 40-55 mg per 100 g more n-3 fatty acids. By eating 200 g daily of this bread one gets some 25-30% of the amount of higher n-3 polyunsaturated fatty acids present in 30 g of mixed fish. The daily ingestion of this amount of fish over a period of 20 years is known to reduce mortality from coronary heart disease by more than 50%. The supplement of n-3 polyunsaturated fatty acids obtained by eating Omega Bread daily in place of other types of white bread is expected to reduce coronary heart disease. In addition, such an increased daily ingestion of n-3 polyunsaturated fatty acids over a long-term period may possibly have other beneficial health effects. It is recommended that the intake of higher n-3 fatty acids in industrialised Western societies should be increased by more than can be obtained by a daily ration of Omega Bread. It is therefore advisable that consumption of Omega Bread is combined with an increased intake of fish and/or fish oil capsules and/or fish-oil-enriched substitutes for butter and margarine.     

Enhanced n-3 phospholipid content reduces inflammatory responses in bovine endothelial cells

Uncontrolled inflammation contributes to the increased incidence and severity of infectious diseases in periparturient dairy cattle. The objective of this study was to determine if increasing n-3 fatty acid (FA) content and altering the profile of vasoactive eicosanoids could attenuate endothelial cell inflammatory responses. Bovine aortic endothelial cells (BAEC) were cultured with free FA mixtures that mimic the plasma NEFA composition during the first week of lactation of dairy cows or with a free FA mixture supplemented with a higher proportion of n-3 FA, including eicosapentaenoic and docosahexaenoic acids. The effects of increasing the docosahexaenoic and eicosapentaenoic acid content of BAEC on the expression of proinflammatory mediators and eicosanoid biosynthesis was assessed. Culturing BAEC with enriched concentrations of n-3 FA decreased the expression of proinflammatory cytokines, adhesion molecules, and reactive oxygen species with a concomitant increase in the biosynthesis of proresolving eicosanoids, including resolvins, protectins, and lipoxins. This study showed for the first time that increasing the n-3 FA content of endothelial cell phospholipids could alter the expression of eicosanoids and control the magnitude of inflammatory responses. Future studies are necessary to elucidate the mechanisms by which resolvins, protectins, and lipoxins may modify endothelial inflammatory pathways necessary to reduce the severity and duration of disease in periparturient cows.     

n-3脂肪酸鸡蛋营养价值分析

n-3类脂肪酸健康功效明确,其中EPA和DHA对降低心血管疾病风险等方面有较强作用,但人群摄入量往往不足.研究表明,通过对母鸡饲料进行n-3脂肪酸强化能有效地增加蛋黄内EPA和DHA的含量,其中DHA强化鸡蛋比未强化鸡蛋含量高2.4～10倍.每人每天食用1～2个n-3脂肪酸鸡蛋可使得机体每日摄入的EPA和DHA达到膳食推荐量.而由于n-3脂肪酸的引入,相应的安全性评估也应加强,包括需从n-3脂肪酸的摄入量、n-3脂肪酸鸡蛋里的深海鱼污染物和胆固醇含量等几个方面进行评价.     

Production of n-3 polyunsaturated fatty acid concentrate from sardine oil by immobilized Candida rugosa lipase

ABSTRACT:  This study was conducted to develop an immobilized-enzyme system to entrap lipase in chitosan-alginate-CaCl₂ beads for the purpose of concentrating n-3 polyunsaturated fatty acids (n-3 PUFAs) from sardine oil. Lipase was immobilized by an ionotropic gelatin method analyzed for characteristics. Optimum pH of immobilized lipase shifted from pH 7.0 to 6.0 and immobilized lipase showed higher stability against pH and temperature changes. Original sardine oil contained 38.1% n-3 PUFAs (25.2% 20:5n3 and 7.20% 22:6n3), and the concentration was significantly increased to 65.3% (40.2% 20:5n3 and 15.5% 22:6n3) with free lipase and to 64.8% (39.6% 20:5n3 and 15.3% 22:6n3) with immobilized lipase after 90 min of repeated hydrolysis. Fatty acid content of the free fatty acid (FFA) fraction of hydrolyzed oil showed that lipase preferably hydrolyzed 16:0, 16:1n7 and 18:0 accounting for 76.6% and 69.5% of total FFAs (after 1st and 2nd hydrolysis, respectively). This study shows that use of immobilized lipase systems for increasing n-3 PUFA concentration in sardine oil provides new processing opportunities for the industry.     

Endogenous production and elevated levels of long-chain n-3 fatty acids in the milk of transgenic mice

n-3 Polyunsaturated fatty acids (n-3 PUFA) are important for the normal development and functioning of all organisms. Mammals lack the n-3 fatty acid desaturase required for the synthesis of α-linolenic acid (18:3n-3), and are therefore dependent on dietary sources to obtain this essential fatty acid. Currently, the richest source of dietary long-chain n-3 PUFA, eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3), are triacylglycerides extracted from rapidly declining marine resources. The nematode Caenorhabditis elegans synthesizes a wide range of PUFA and possesses the only known example of an n-3 fatty acid desaturase enzyme in the animal kingdom. Transgenic mice expressing the C. elegans n-3 desaturase under the control of the lactation-induced goat β-casein mammary gland promoter were generated via pronuclear microinjection. Significant increases in n-3 PUFA, decreases in n-6 PUFA, and an overall decrease in the n-6:n-3 PUFA ratio were observed in the milk produced by transgenic mice. Neonate mice consuming milk from transgenic females accumulated increased levels of docosahexaenoic acid in their brains. This transgenic model may provide useful information to address some basic questions of neonatal nutrition, and demonstrates one of the steps that would be required to increase the n-3 PUFA content of milk and dairy products endogenously. Increasing the proportion of n-3 PUFA in milk fat would help to improve the nutritional composition of an important component of the North American diet.     

Enrichment of eggs in n-3 polyunsaturated fatty acids by feeding hens with different amount of linseed oil in diet

The production of n-3 polyunsaturated fatty acid enriched eggs by addition of linseed oil to the laying hens' diet has been evaluated in terms of production parameters and n-6/n-3 ratio. A total of 150 18weeks old Lohmann Brown laying hens were housed in cages and fed with basal diet and four experimental diets containing 1%, 2%, 3% or 4% of linseed oil added to the basal diet. The effect of the altered level of linseed oil on hens laying performance, fatty acid content and composition and cholesterol content in egg yolk has been evaluated during 13weeks of experiment. Egg weight, yolk fat content, yolk weight, yolk percentage and shape index were not influenced by dietary treatment. The ratio between n-6 and n-3 polyunsaturated fatty acids in eggs decreased in first 5weeks and then remained stable until the end of the experiment for all experimental groups. Different contents of linseed oil in feed highly influenced the n-6/n-3 ratio (P<0.0001). Addition of linseed oil did not influence the cholesterol content in yolks (P=0.5200) while the only factor affecting the cholesterol content was the hens age (P<0.0001).     

Significance of Increasing n-3 PUFA Content in Pork on Human Health

Evidence for the health-promoting effects of food rich in n-3 polyunsaturated fatty acids (n-3 PUFA) is reviewed. Pork is an important meat source for humans. According to a report by the US Department of Agriculture (http://www.ers.usda.gov/topics), the pork consumption worldwide in 2011 was about 79.3 million tons, much higher than that of beef (48.2 million tons). Pork also contains high levels of unsaturated fatty acids relative to ruminant meats (Enser, M., Hallett, K., Hewett, B., Fursey, G. A. J. and Wood, J. D. (1996) Enser, M., Hallett, K., Hewett, B., Fursey, G. A. J. and Wood, J. D. (1996). Fatty acid content and composition of English beef, lamb and pork at retail. Meat Sci. 44:443–458.[Crossref], [Web of Science ®] , [Google Scholar]. Fatty acid content and composition of English beef, lamb, and pork at retail. Meat Sci. 44:443–458). The available literature indicates that the levels of eicosatetraenoic and docosahexaenoic in pork may be increased by fish-derived or linseed products, the extent of which being dependent on the nature of the supplementation. Transgenic pigs and plants show promise with high content of n-3 PUFA and low ratio of n-6/n-3 fatty acids in their tissues. The approaches mentioned for decreasing n-6/n-3 ratios have both advantages and disadvantages. Selected articles are critically reviewed and summarized.