多不饱和脂肪酸对大鼠大脑细胞膜脂肪酸组成的影响

研究多不饱和脂肪酸(PUFAs)对发育期大鼠大脑细胞膜脂肪酸类别与含量的变化。将56只初断乳雄性SD大鼠随机分为阴性组、必需脂肪酸(EFA)缺乏组、鱼油组[300mg/(kg·d)]、紫苏组[2.45mL/(kg·d)]、α-亚油酸组[1.32g/(kg·d)]、核桃组[2.45mL/(kg·d)]与红花组[1.65g/(kg·d)]。连续饲养8周,提取大脑组织总细胞膜,并使用气相色谱-质谱联用技术检测其脂肪酸的种类与含量。结果表明,各组大鼠脂肪酸组成无差别;与阴性组比较,各组均能显著提高n-3PUFAs的含量;紫苏组、核桃组和红花组能显著降低n-6PUFAs的含量,增加饱和脂肪酸的含量;紫苏组、核桃组、红花组和鱼油组能显著降低单不饱和脂肪酸的含量。说明PUFAs能改变大鼠大脑细胞膜的含量,但对其类别影响不大;短期缺乏EFA对细胞膜脂肪酸的类别与含量无影响。     

Influence of vitamin B6 supplementation on polyunsaturated fatty acids concentration in serum and liver of rats fed a diet restricted in protein

The influence of vitamin B6 on fatty acids content in serum and liver of rats receiving low protein diets was studied. Addition of B6 decreased linoleic acid (LA) and increased alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) in serum of rats fed a protein-deficient diet (9% energy from proteins) for 3 months. Further restriction of dietary protein (4.5% of energy from protein) caused an increase of the DHA concentration and sum of polyunsaturated fatty acids (PUFAs). In the liver of undernourished rats significant changes of PUFA composition were noticed, although without any significant influence of vitamin B6.     

Combination effect of phospholipids and n-3 polyunsaturated fatty acids on rat cholesterol metabolism

This study evaluated phospholipids (PLs) containing n-3 polyunsaturated fatty acids (n-3 PUFAs) for their specific inherent effects and effects due to a combination of the presence of glycerophosphate structure and n-3 PUFAs on cholesterol metabolism in rats. Rats were fed a diet of AIN-93G containing soybean oil (SO, 7%), SO (5.8%)+fish oil (1.2%), SO (5.2%)+soybean PLs (1.8%), SO (5.2%)+PLs containing n-3 PUFAs (1.8%), and SO (4.0%)+fish oil (1.2%)+soybean PLs (1.8%). Diets with PLs containing n-3 PUFAs, and soybean PLs in combination with fish oil, resulted in decreased serum and liver cholesterol levels through enhancement of fecal cholesterol excretion and suppression of liver sterol regulatory element binding protein-2 mRNA expression compared with the diet containing soybean oil alone. This study shows that soybean PLs with added triacylglycerol that included n-3 PUFAs have the same effects on cholesterol metabolism as PLs containing n-3 PUFAs, and that these could be of benefit to people.     

Increasing omega fatty acid content in cow's milk through diet manipulation: Effect on milk flavor

Milk with an increased content of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and conjugated linoleic acid (CLA) was obtained by incorporating fish oil into the feed of cows. The 4 feed treatments used were a control diet of 57% forage and 43% concentrate mix with EnerGII fat supplement at 1.65% of dietary DM, or EnerGII in the basal diet was partially replaced with 1) 0.21% partially ruminally inert calcium salts of 71% fish oil given at 0.41% of DM; 2) 0.41% inert calcium salts of 71% fish oil given at 0.83% of DM; or 3) 0.83% inert calcium salts of 43% fish oil given at 0.83% of DM. The cows were milked after 5 and 8 wk and the EPA, DHA, and CLA contents in the pasteurized whole milk were determined. The presence of off-flavors in the milk was investigated after 3 and 10 d of storage. Twelve judges were trained to evaluate the presence of grassy, fishy, oily, oxidized, and rancid off-flavors. Although levels of EPA, DHA, vaccenic acid, and CLA increased for all 4 treatments, a trained sensory panel detected no difference in milk flavor between treatments and the control, with little or no intensity of off-flavors. Results suggest that feeding fish oil and EnerGII at varying levels enhanced CLA, EPA, DHA, and total n-3 fatty acids in milk over the length of the experiment without negatively affecting milk flavor. This creates the potential for a more marketable and healthful product.     

Effect of lycopene on biomarkers of oxidative stress in rats supplemented with ω−3 polyunsaturated fatty acids

Eicosapentaenoic (C20:5 n−3, EPA) and docosahexaenoic (C22:6 n−3, DHA) fatty acids are highly susceptible to lipid oxidation and may contribute to oxidative stress. The purpose of this study was to evaluate if a diet rich in EPA and DHA could promote higher oxidation in both plasma and brain tissue of rats and if lycopene supplementation could revert the oxidation biomarkers to their baseline levels. Wistar rats were divided into four groups (7 rats/group): SOY group received AIN93M diet containing 8% soybean oil for 21 days; OMEGA group received 8% fish oil containing 2% EPA and 1% DHA instead of soybean oil for 21 days; OMEGA-L0.5 and OMEGA-L50 groups were fed a diet containing 8% fish oil for 11 days followed by lycopene supplementation (5 and 500 mg/kg diet, respectively) for 10 more days. The brain homogenate oxidation measured by TBARS suggested that supplementation with EPA and DHA reduced the oxidation rate and this effect was suppressed by lycopene at both concentrations. Antioxidant capacity measured by DPPH method in plasma of groups supplemented with EPA and DHA was nil while in SOY group it was 21.4%. Lycopene was not detected in the plasma of the animals. It is likely that antioxidants present in plasma have been depleted to keep malondialdehyde concentration measured by TBARS unchanged. Both plasma malondialdehyde concentration and antioxidant activity of groups with and without lycopene supplementation did not differ. Hence, diets rich in EPA and DHA did not promote higher oxidation in rat brain homogenate but reduced plasma antioxidant capacity. Lycopene did not show antioxidant plasma protection at both doses. Taking into account that plasma α-tocopherol concentration did not change among the groups and that rats synthesize ascorbic acid, additional research should be carried out to identify the oxidative results observed in this study.     

The importance of the long-chain polyunsaturated fatty acid n-6/n-3 ratio in development of non-alcoholic fatty liver associated with obesity

Non-alcoholic fatty liver disease (NAFLD) is the most important cause of chronic liver disease that is characterized by hepatocyte triacylglycerol accumulation (steatosis), which can progress to inflammation, fibrosis, and cirrhosis (steatohepatitis). Overnutrition triggers the onset of oxidative stress in the liver due to higher availability and oxidation of fatty acids (FA), with development of hyperinsulinemia and insulin resistance (IR), and n-3 long-chain polyunsaturated FA (n-3 LCPUFA) depletion, with enhancement in the n-6/n-3 LCPUFA ratio favouring a pro-inflammatory state. These changes may lead to hepatic steatosis by different mechanisms, namely, (i) IR-dependent higher peripheral lipolysis and FA flux to the liver, (ii) n-3 LCPUFA depletion-induced changes in DNA binding activity of sterol regulatory element-binding protein 1c (SREBP-1c) and peroxisome proliferator-activated receptor α (PPAR-α) favouring lipogenesis over FA oxidation, and (iii) hyperinsulinemia-induced activation of lipogenic factor PPAR-γ. Supplementation with n-3 LCPUFA appears to reduce nutritional hepatic steatosis in adults, however, other histopathologic features of NAFLD remain to be studied.     

The role of meat as a source of n-3 polyunsaturated fatty acids in the human diet

It is considered that consumption of very long chain (VLC, carbon chain length ?20) n − 3 PUFAs in most Western populations is sub-optimal and benefits in relation to chronic disease would be gained from increased consumption. This review examines the current contribution that meat makes to dietary intake of VLC n − 3 PUFA and given its current low contribution, how ruminant meat may be enriched. Enrichment both directly with VLC n − 3 fatty acids and indirectly by increasing intake by the animals of α-linolenic acid (ALNA; C18:3 n − 3) are considered. Since it now appears that dietary ALNA is a very limited source of VLC n − 3 PUFA in humans, the indirect route is controversial but since some forages are rich sources of ALNA this route has many sustainability and environmental attractions. Consideration is also given to the increased concentrations of trans and conjugated fatty acids that will arise from enriching ruminant meat with PUFA.     

膳食中n-3多不饱和脂肪酸对2型糖尿病患者血糖和胰岛素敏感性的影响

2型糖尿病是世界上最常见的慢性疾病之一。膳食中的n-3多不饱和脂肪酸可能会减少亚洲人的2型糖尿病风险, 中国2型糖尿病患者血浆磷脂n-3不饱和脂肪酸与胰岛素敏感性呈正相关。而欧美的前瞻性研究均发现, 鱼类的摄入和n-3多不饱和脂肪酸的摄入会增加2型糖尿病的发病风险, 在西方白种人群中进行的n-3多不饱和脂肪酸干预的随机对照试验也并未发现n-3多不饱和脂肪酸能够改善患者胰岛素抵抗水平或血糖水平, n-3多不饱和脂肪酸甚至可轻微地降低患者胰岛素的敏感性。本文综述了目前n-3多不饱和脂肪酸摄入量与2型糖尿病风险之间的关系。     

Omega 3 polyunsaturated fatty acids and the treatment of depression

Depression is a common, recurrent, and debilitating illness that has become more prevalent over the past 100 years. This report reviews the etiology and pathophysiology of depression, and explores the role of omega 3 polyunsaturated fatty acids (n-3 PUFA) as a possible treatment. In seeking to understand depression, genetic factors and environmental influences have been extensively investigated. Research has led to several hypotheses for the pathophysiological basis of depression but a definitive pathogenic mechanism, or group thereof, has hitherto remained equivocal. To date, treatment has been based on the monoamine hypothesis and hence, selective serotonin reuptake inhibitors have been the most widely used class of medication. In the last decade, there has been considerable interest in n-3 PUFAs and their role in depression. These fatty acids are critical for development and function of the central nervous system. Increasing evidence from epidemiological, laboratory, and randomized placebo-controlled trials suggests deficiency of dietary n-3 PUFAs may contribute to development of mood disorders, and supplementation with n-3 PUFAs may provide a new treatment option. Conclusions based on systematic reviews and meta-analyses of published trials to date vary. Research into the effects of n-3 PUFAs on depressed mood is limited. Furthermore, results from such have led to conflicting conclusions regarding the efficacy of n-3 PUFAs in affecting reduction in symptoms of depression. PUFAs are generally well tolerated by adults and children although mild gastrointestinal effects are reported. There is mounting evidence to suggest that n-3 PUFAs play a role in depression and deserve greater research efforts.     

Effects of anti-atherosclerosis diet containing omega 3 fatty acids on the lipid spectrum of blood and cell membranes in patients with ischemic heart disease and essential hypertension

A total of 27 patients received an anti-atherosclerotic diet containing fatty fish Greenland halibut, 100 g/day. Significant reduction of the total cholesterol level, cholesterol levels of very low and low density proteins, triglycerides, atherogenic index, elevation of blood fibrinolytic activity in the presence of lowered levels of arachidonic acid and an increased relative content of omega 3 polyunsaturated fatty acids (PUFA) were recorded in membranes of red blood cells and platelets. The results of the investigations conducted have shown that even rather low doses of omega 3 PUFA introduced in the presence of the hypolipidemic diet are conductive to the alimentary correction of the blood serum lipid spectrum of the fatty-acid content in cellular membrane structural lipids.     

Effects of a high fat diet on long-chain fatty acids composition in rats serum and liver

A reliable and sensitive technique had presented to monitor the content of long-chain fatty acids (LCFAs) in biological materials. The purpose of this study was to report a method for separation and quantification of LCFAs by capillary gas chromatography (GC) with better recovery. With this method, we detected some changes of LCFAs in the serum and liver of rat fed with high fat diet. The result showed that the levels of C22:0, C22:6, C26:0 of serum of the high fat group were higher than that of the control group (P < 0.01); and the levels of C22:6, C26:0 of liver of the high fat group were higher than that of the control group (P < 0.01), but the levels of C22:0 and C24:0 of liver of the high fat group were lower than that of the control group (P < 0.01). It indicated that a high fat diet had an adverse effect upon normal metabolism.     

Effect of diets with different content of polyunsaturated fatty acids on ATPase activity in different rat tissues

The authors studied the effect of the diets with varying content of polyunsaturated fatty acids (PUFA) on ATPase activity in the heart, kidneys and lungs of Wistar rats. During 3 weeks the rats received different diets. Group I was kept on the diet poor in PUFA, Group II on the diet rich in linoleic acid, and Group III on the diet rich in linolenic acid. The content of PUFA in food has no effect on ATPase activity in the lungs. The maximal activity of Mg-ATPase in the heart was seen in the Group III rats, while the minimal in the Group I rats (P less than 0.05). On the contrary, Na, K-ATPase activity was minimal in the Group III rats (P-0.05). Examination of ATPase activity in the kidneys has demonstrated no substantial difference between Groups II and III as regards Mg-ATPase activity, whereas Mg-ATPase activity in the Group I animals was significantly reduced (P less than 0.02). As Na, K-ATPase activity in the kidneys increased (Group II, P-0.05) excretion of Na and K with urine considerably diminished.     

Effect of boiling and frying on the content of essential polyunsaturated fatty acids in muscle tissue of four fish species

Frozen samples of common fish species, sea trout (Salmo trutta), from Norway and Siberia, herring (Clupea harengus pallasi), rock sole (Lepidopsetta bilineata) and cod (Gadus morhua maris-albi), collected from a wholesale market in Krasnoyarsk city (Siberia, Russia) were analyzed. Special attention was paid to long-chain essential polyunsaturated fatty acids: eicosapentaenoic, 20:5ω3 (EPA) and docosahexaenoic, 22:6ω3 (DHA). Heat-treatment (cooking and frying) did not in general significantly decrease the contents of EPA and DHA compared to raw fish species, except for a modest reduction in Norwegian trout during frying. Boiled trout appeared to be a more valuable fish dish for obtaining the officially recommended appropriate daily intake of EPA + DHA for humans. Herring and sole had intermediate values, while boiled cod had a comparatively low value.     

Role of polyunsaturated fatty acids in diet therapy of children with allergic diseases

135 pediatric patients receiving hypoallergic diet were included into the study group. The control group consisted of 20 children. The impact of PUFA omega-3 biologically active supplements (polyen, prima-Oil) was studied in hypoallergic rations. Biochemical indices were simultaneously investigated. The revealed dynamic changes of fatty acid spectrum in plasma and red cell membranes, cellular and humoral immunity status and eicosanoids synthesis were followed by positive clinical changes. Diets enriched with biologically active supplementation (PUPA omega-3) can be recommended for application in pediatric practice.     

The fatty acid,phospholipid and cholesterol content of control and polyunsaturated lamb aorta

Lambs trained to drink liquid supplements containing various levels of sunflower oil showed increased incorporation of linoleic acid into the aortic phospholipids with associated decreases in the percentage of C18:3ω3, C20:3ω9, C20:5ω3 and the C22ω3 fatty acids, while there was no significant change in the percentage of C20: 4ω6 fatty acid. The levels of cholesterol, total phospholipid and phospholipid fractions, did not vary significantly with increasing oil intake.     

马齿苋多不饱和脂肪酸对高脂血症大鼠的降脂作用

研究马齿苋多不饱和脂肪酸对高脂血症大鼠脂质代谢的影响。从60只大鼠中随机取10只以普通饲料喂养作空白组(NG),其余50只喂食高脂饲料构建高脂血症模型,并将其分为高脂模型组(HLP)、非诺贝特阳性对照组(FB, 0.033 3 g/(kg·d))、马齿苋多不饱和脂肪酸高[PUFAs-H, 0.666g/(kg·d)]、中[PUFAs-M, 0.333 g/(kg·d)]、低剂量组[PUFAs-L, 0.167 g/(kg·d)]。灌胃给药28 d后,测定大鼠体质量、血清中血脂水平及抗氧化指标,同时测定大鼠肝脏中总胆固醇(TC)、甘油三酯(TG)含量,并通过HE染色、油红O染色观察其肝脏状态。与HLP组相比,PUFAs-L、PUFAs-M、PUFAs-H组均可降低大鼠体质量、血清中TC、TG、低密度脂蛋白胆固醇(LDL-C)、丙二醛(MDA)及肝脏中TC、TG含量(P<0.05),升高高密度脂蛋白胆固醇(HDL-C)、超氧化物歧化酶(SOD)含量(P<0.05);HE染色与油红O染色结果一致,与HLP组相比,各实验组能明显改善肝脏组织状态。马齿苋PUFAs能够调节高脂血症大鼠...     

The influence of the dietary polyunsaturated fatty acids on the phagocyte's functional activity in rats

The influence of dietary polyunsaturated fatty acids on the superoxid anion production by peritoneal macrophages and phagocytosis by blood neutrophiles in male Wistar rats weighting 127.0 +/- 3.2 r was investigated after 3 months feeding. Rats fed isocaloric purified diets contained 24% fat representing combinations of lard, sunflower oil and fish oil (eiconol) providing the ratios of w6/w3 fatty acids equal 49.0; 6.1; 1.1. The increasing of superoxide formed by peritoneal macrophages and phagocytic activity of neutrophiles in the group received diet with the minimal ratios of w6/w3 fatty acids compared to that in rats fed diet with ratio 49.0 was noted. The increased activity of mononuclear-phagocytic system was confirmed by morphological investigation of peripheral lymphoid organs.     

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。