牛磺酸影响甘油三酯代谢的研究进展

牛磺酸是一种广泛存在于哺乳动物组织中的小分子含硫氨基酸,结构简单且不参与蛋白质合成。牛磺酸可由甲硫氨酸和半胱氨酸合成,在鱼贝类等海产品中含量丰富,具有多种生理功能。动物实验和临床实验表明牛磺酸可显著改善肥胖,降低血清甘油三酯水平,减少肝脏脂肪蓄积。本文从细胞实验、动物实验、临床实验和流行病学调查4个方面总结了牛磺酸对脂肪代谢的影响,并主要从促进脂肪分解代谢、抑制脂肪合成、减少炎症反应和氧化应激、提高脂联素水平、与胆汁酸结合等方面归纳了牛磺酸影响脂肪代谢的作用机理,为进一步研究牛磺酸促进脂肪代谢的作用机制提供参考,也为开发以牛磺酸为功能因子、具有减肥、改善血脂及脂肪肝功能的保健品提供理论依据。     

牛磺酸降血糖作用研究进展

牛磺酸是机体组织细胞中含量丰富的一种小分子含硫氨基酸,有广泛的生理调节作用。大量动物实验证实牛磺酸具有良好的降血糖效果,临床试验证明牛磺酸能降低糖尿病患者血糖水平。本文概述了牛磺酸对不同类型糖尿病葡萄糖代谢的影响,并从抗氧化、抗炎、保护胰岛β细胞、促进胰岛素分泌、改善胰岛素抵抗等方面归纳总结了其发挥降血糖作用的主要作用机制,为牛磺酸降血糖作用机制的深入研究,也为牛磺酸在功能食品领域的进一步开发利用提供参考。     

牛磺酸影响胆固醇代谢的研究进展

牛磺酸是小分子含硫氨基酸,为常见食物成分之一,富含于海产品中。动物实验证实牛磺酸可显著降低饮食性高胆固醇血症动物的胆固醇水平,临床试验也显示牛磺酸能降低血清总胆固醇及动脉粥样硬化指数,表明牛磺酸具有良好的抗动脉粥样硬化作用,因此被认为是心血管细胞保护剂。本文从体内和体外两方面的研究情况介绍了牛磺酸对胆固醇代谢的影响,并主要从胆固醇/胆汁酸稳态的角度,总结归纳了牛磺酸对血液循环中胆固醇的清除、对胆固醇向胆汁酸的生物转化、以及对胆汁酸排出等多条作用途径的影响,为牛磺酸降胆固醇作用机制的深入研究、也为牛磺酸在功能食品领域的进一步开发利用提供参考。     

乳制品和钙摄入量对人体和动物体重及体成分的影响

膳食调查、动物实验和某些人体研究初步证明，在除去膳食总热量的影响之后，膳食钙是一个影响体重和体脂肪含量的独立因素。高脂肪、高糖、低钙膳食促进体脂肪的合成，而在同样的热能摄入量下，膳食钙摄入量的增加，特别是酸奶和其他乳制品的摄入量，与体脂肪比例和体重呈负相关关系。关于钙摄入、胞外钙浓度与胰岛素分泌和体脂肪代谢调控作用的理论已经初步建立。动物实验表明，仅用无机钙补充剂不能与摄入乳制品达到同样的体重控制效果，因此认为乳制品中存在的其他活性成分，以及乳制品中的蛋白质与碳水化合物比例也在减少脂肪积累和控制体重方面有重要作用。     

牛肝中牛磺酸对免疫抑制小鼠免疫及抗氧化能力的影响

为了研究牛磺酸对动物免疫调节作用和抗氧化能力的影响,本实验通过物理方法从牛肝中提取天然牛磺酸,并对不同年龄的小鼠腹腔注射环磷酰胺建立免疫抑制小鼠模型,再给免疫抑制小鼠腹腔注射不同剂量的牛磺酸,并且比较牛磺酸对不同年龄免疫抑制小鼠的免疫调节作用和抗氧化能力的影响,并对免疫指标与总抗氧化能力(total antioxidant capacity,T-AOC)进行相关性分析。结果表明:高、低剂量牛磺酸对不同年龄免疫抑制小鼠的免疫调节作用和抗氧化能力均有改善,且幼年组与老年组灌胃牛磺酸的免疫调节作用和抗氧化能力均达到正常水平或优于正常水平,并经相关性分析,小鼠抗氧化能力升高免疫能力也随之升高。     

甜菜碱及其营养功能

甜菜碱是在甜菜糖蜜中发现的季铵型生物碱,是动物体代谢中间产物,具有提供甲基、调节体内渗透压、促进脂肪代谢和蛋白质合成等作用。应用于饲料中能明显改善生产效果,促进动物生长,提高抗应激能力,提高抗球虫疗效,是一种安全高效的营养性饲料添加剂。     

益生菌改善代谢综合症研究进展

益生菌是广泛应用于食品中的对人体健康有益的活的微生物。近年随着代谢综合征发病率逐年升高,越来越多的研究显示益生菌良好的改善代谢综合征的作用。肠道菌群失调与代谢综合征的发生发展密切相关,而益生菌则可逆转这种肠道菌群分布。动物实验和临床实验均显示,益生菌(尤其是乳杆菌和双歧杆菌),具有良好的改善代谢综合征的功效,表现出减肥、降血脂、降血压和降血糖等作用。研究显示益生菌通过抑制脂肪合成和加强脂肪分解,保护胰岛β细胞和提高胰岛素敏感性而加快葡萄糖转运,增加胆固醇转化和增加胆汁酸排出、释放血管紧张素转化酶抑制肽等途径发挥对代谢综合征的调节作用。本文就益生菌改善代谢综合征的研究进行综述,为益生菌在功能食品领域的进一步研发与利用提供参考。     

天然牛磺酸对急性抑郁模型小鼠的干预作用

以天然牛磺酸为试验材料,通过建立2种急性抑郁动物模型,研究牛磺酸对抑郁模型动物的干预效果。以ICR小鼠为实验动物,设牛磺酸低(0.5 g/kg bw)、中(1 g/kg bw)、高(2 g/kg bw)剂量组,同时设溶剂对照组、模型对照和阳性(氟西汀)对照组。通过建立行为绝望动物模型,探讨天然牛磺酸对行为绝望小鼠的干预效果;通过行为学、血清和脑组织中相关生化指标,分析牛磺酸对利血平诱导的急性抑郁的干预机制。结果表明:牛磺酸中、高剂量组可显著改善行为绝望小鼠的抑郁样行为,并缓解利血平诱导的小鼠眼睑下垂,同时升高抑郁小鼠脑组织五羟色胺、去甲肾上腺素和多巴胺水平,降低单胺氧化酶活性,提高脑源性神经营养因子含量,降低促肾上腺皮质激素释放因子、促肾上腺皮质激素、皮质醇水平,改善相关生化指标。研究表明:牛磺酸对行为绝望模型和利血平诱导抑郁模型均具有干预抑郁的作用,作用机制可能与增加单胺类神经递质,参与调节肾上腺功能的紊乱有关。     

植物多糖的功能性及其在肉制品中的应用研究进展

植物多糖作为天然的植物提取物,具有抗氧化、抑菌的能力以及降血糖、抗肿瘤等多种生物活性,因此成为医学和食品等领域的研究热点。将植物多糖应用于肉制品中可改善产品的质构、风味、色泽等,部分植物多糖可使加工后的肉制品具有功能特性。植物多糖还可替代部分脂肪,减少肉制品中的脂肪含量,起到促进健康的作用。文章对植物多糖的多种功能特性以及在肉制品中添加多糖对产品感官、理化性质等方面的影响进行综述,以期为后续的研究提供参考。     

月见草油透皮吸收对小鼠体重增长抑制效果的研究

以雄性BALB/C小鼠为实验对象,通过测定体重、身长、体脂质量、血脂生化指标、肝脏脂肪代谢相关基因的mRNA表达水平和观察脂肪细胞大小,评价月见草油透皮吸收后对小鼠体重增长的抑制效果。结果表明:与橄榄油组相比较,月见草油能显著抑制小鼠体重增长,明显降低生殖器周围脂肪质量、脂肪系数以及Lee’s指数;月见草油组小鼠的脂肪细胞直径明显变小;涂抹月见草油可降低血清中TG、TC和LDL含量,减少肝脏脂肪合成相关基因ACC、FAS、LPL、SREBP1-C和HMGCR mRNA表达水平,上调脂肪分解相关基因HSL、CPT1和LDL-R mRNA表达。月见草油透皮吸收后,可以通过调控肝脏脂肪代谢途径,促进机体脂肪氧化分解,抑制雄性小鼠的体重增长,降低血清中血脂含量。     

Taurine is Involved in Energy Metabolism in Muscles,Adipose Tissue,and the Liver

Energy metabolism is a basic and general process, by which the body acquires and uses energy to maintain normal function, and taurine plays a vital role in energy metabolism. Taurine deficiency may cause a weak energy metabolism and energy metabolism dysfunction. Taurine biosynthetic ability is limited, and its supplementation in the diet can strengthen energy metabolism in muscle performance, cardiac function, liver activity, and adipose tissue. Combining taurine with other drugs may have a superior effect in energy metabolism. In many metabolic disorders, taurine, or the combination of taurine with other drugs, also functions as a repair treatment for damaged tissues, and acts as a promoter for the balance of energy metabolism. The present study discusses the potential roles of taurine in energy metabolism.     

牛磺酸对大鼠的减重降脂作用

目的:探讨牛磺酸饮水对高脂血症大鼠减重降脂的作用。方法:根据血清总胆固醇(TC)和体重将SD大鼠随机分为对照组、高脂模型组和牛磺酸(低、高)剂量组。对照组摄食普通饲料,其余三组摄食高脂饲料,牛磺酸组饮用牛磺酸水溶液。饲养12周后处死动物,检测血清TC、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、甘油三酯(TG)水平,血清谷胱甘肽过氧化物酶(GSH-PX)和超氧化物歧化酶(SOD)活力;粪便中总胆汁酸(TBA)含量;肝脏TC、TG、游离脂肪酸(FFA)、还原型谷胱甘肽(GSH)、肝糖原的含量和GSH-PX酶活力。结果:高剂量牛磺酸显著降低高脂饮食大鼠的体重,两个剂量牛磺酸都可以显著降低大鼠附睾脂肪垫指数;高剂量牛磺酸显著降低大鼠血清TC、LDL-C、肝脏FFA和肝糖原水平,两个剂量牛磺酸对肝脏TC和TG均无显著影响,但都可显著增加粪便TBA含量;两个剂量牛磺酸都可以显著升高大鼠血清GSH-PX和肝脏GSH-PX、还原型GSH。结论:牛磺酸主要通过促进胆固醇转化为胆汁酸,并随粪便排出、加强脂质代谢减少肝脏FFA堆积、提高机体抗氧化能力等途径发挥减重降脂功效,但其减重降脂机制还需深入研究。     

Role of taurine in the pathogenesis of obesity

Taurine is a sulfur‐containing amino acid that is present in mammalian tissues in millimolar concentrations. Taurine is involved in a diverse array of biological and physiological functions, including bile salt conjugation, osmoregulation, membrane stabilization, calcium modulation, anti‐oxidation, and immunomodulation. The prevalence of obesity and being overweight continues to rise worldwide at an alarming rate. Obesity is associated with a higher risk of metabolic and cardiovascular diseases, cancer, and other clinical conditions. Ingestion of taurine has been shown to alleviate metabolic diseases such as hyperlipidemia, diabetes, hypertension, and obesity in animal models. A global epidemiological survey showed that 24‐h urinary taurine excretion, as a marker of dietary taurine intake, was inversely associated with BMI, blood pressure, and plasma cholesterol in humans. In addition, taurine chloramine, an endogenous product derived from activated neutrophils, has been reported to suppress obesity‐induced oxidative stress and inflammation in adipocytes. Synthetic activity and concentration of taurine in adipose tissues and plasma have been shown to decrease in humans and animals during the development of obesity, suggesting a relationship between taurine deficiency and obesity. In this review, I summarize the effects of taurine on the progression of obesity in animal models and humans. Furthermore, I discuss possible mechanisms underlying the antiobesity effects of taurine.     

Taurine: A Regulator of Cellular Redox Homeostasis and Skeletal Muscle Function

Taurine is a nonproteinogenic ß‐aminosulfonic acid. Important dietary sources of taurine are fish and seafood. Taurine interacts with ion channels, stabilizes membranes, and regulates the cell volume. These actions confirm its high concentrations in excitable tissues like retina, neurons, and muscles. Retinal degeneration, cardiomyopathy, as well as skeletal muscle malfunction are evident in taurine‐deficient phenotypes. There is evidence that taurine counteracts lipid peroxidation and increases cellular antioxidant defense in response to inflammation. In activated neutrophils, taurine reacts with hypochloric acid to form taurine chloramine, which triggers the Kelch‐like ECH‐associated protein 1–nuclear factor E2‐related factor 1 (Keap1–Nrf2) pathway. Consequently, Nrf2 target genes, such as heme oxygenase‐1 and catalase, are induced. Furthermore, taurine may prevent an overload of reactive oxygen species (ROS) directly by an inhibition of ROS generation within the respiratory chain. Taurine affects mitochondrial bioenergetics and taurine‐deficient mice exhibit an impaired exercise performance. Moreover, some studies demonstrate that taurine enhances the glycogen repletion in the postexercise recovery phase. In the case of taurine deficiency, many studies observed a phenotype known in muscle senescence and skeletal muscle disorders. Overall, taurine plays an important role in cellular redox homeostasis and skeletal muscle function.     

Effects of dietary taurine on egg production,egg quality and cholesterol levels in Japanese quail

BACKGROUND: Taurine is a semi‐essential amino acid and has many biological properties. The objective of this study was to determine the effect of dietary supplementation with taurine on egg production, egg quality, and cholesterol level in serum and egg yolk of quails. A total of 108 quails aged 6 weeks were randomly allocated to three dietary treatments. Each treatment consisted of four replicates of nine quails. The diets were supplemented with 0, 100, and 500 mg kg^?1 of taurine for 8 weeks. RESULTS: Dietary 500 mg kg^?1 taurine significantly affected egg production rate and feed conversion ratio, but had no significant effects on body weight gain, feed consumption, or egg weight. Dietary taurine had no significant effect on egg quality parameters studied. Serum triglyceride concentration was reduced significantly with supplementation of taurine at 100 and 500 mg kg^?1. Egg yolk cholesterol content was reduced significantly, and the contents of serum taurine and egg yolk taurine were increased significantly with taurine supplementation at 500 mg kg^?1. CONCLUSION: Results of the present study indicated that adding 500 mg kg^?1 taurine reduced yolk cholesterol concentration and increased yolk taurine content without adverse effects on performance and egg quality of laying quails. Copyright © 2010 Society of Chemical Industry     

共轭亚油酸降脂及分子机理研究进展

共轭亚油酸是一类具有两个共轭双键的十八碳多不饱和脂肪酸混合物的总称,具有确切的减肥降脂活性与可验证的临床安全性,使其成为国际减肥市场的宠儿。简要回顾了共轭亚油酸减肥降脂的研究成果,并从调控能量代谢、脂代谢、骨骼肌代谢和糖代谢,介导脂肪细胞的分化与凋亡以及调节肠道微生物群6个方面总结了共轭亚油酸减肥降脂的作用机制,同时对其存在问题及发展机会做了分析与讨论。共轭亚油酸作为减肥降脂的天然产物,具有更大、更广阔的发展潜力。     

Role of zinc in lipid and fatty acid metabolism and in membranes

This review addresses the role of zinc in the metabolism of lipids including cholesterol, phospholipids, triglyceride, fatty acids, lipoproteins, and essential fatty acids and it discusses to a limited extent the role of zinc in membranes as well as zinc's known effects on receptors. The evidence which is compiled demonstrates two main features of the interactions of zinc in lipid and fatty acid metabolism; 1) that zinc intimately affects many aspects of lipid metabolism through established enzymes but also has modulatory effects whose mechanism is not obvious or established, and 2) many of the observations are superficially contradictory and do not lend themselves to ready explanation. These are the features of a field whose time has come and which beckons further research to clarify these issues.     

Protective effects of taurine on human hair follicle grown in vitro

Taurine is a naturally occurring beta-amino acid produced by methionine and cysteine metabolism. It is involved in a variety of physiological functions, including immunomodulatory and antifibrotic. Taking advantage of the ability of human hair follicle grown in vitro to recapitulate most of the characteristic features of normal hair follicle in vivo, we studied (i) taurine uptake by isolated human hair follicles; (ii) its effects on hair growth and survival rate; and (iii) its protective potential against transforming growth factor (TGF)-beta1, an inhibitor of in vitro hair growth and a master switch of fibrotic program. We showed that taurine was taken up by the connective tissue sheath, proximal outer root sheath and hair bulb, promoted hair survival in vitro and prevented TGF-beta1-induced deleterious effects on hair follicle.     

乳甘油三酯的组成结构及其消化吸收和代谢特性

甘油三酯(triacylglycerols,TAGs)是膳食中最重要的脂质成分,不仅为人体提供能量同时也是多种必需脂肪酸的重要来源。甘油三酯的消化、吸收和代谢受到多种因素的影响。大量研究结果证实除脂肪酸的组成以外,甘油三酯的组成和结构对脂肪酸的吸收和代谢也有显著的影响。乳甘油三酯与其他膳食脂肪相比具有特殊的组成和结构,这些特异性使得乳甘油三酯具有许多特殊的生理和营养学功能。本文详细阐述了人乳、牛乳和山羊乳甘油三酯的结构特征,甘油三酯消化、吸收和脂肪酸代谢过程,以及甘油三酯分子内结构对其代谢的作用的影响,以期为甘油三酯代谢、营养及功能特性研究提供参考。