鱼油ω-3 PUFAs的功能特性研究进展

由各种水产副产物精制提取的鱼油可广泛应用于食品、药品以及动物饲料的加工。鱼油中的二十二碳六烯酸和二十碳五烯酸是ω-3多不饱和脂肪酸(ω-3 polyunsaturated fatty acids,ω-3 PUFAs)的主要功能活性成分,食品鱼油具有健康促进作用。该文结合国内外研究进展,重点综述近年来鱼油ω-3多不饱和脂肪酸的主要功能特性,并针对鱼油主要功能特性的不足进行分析,以期为鱼油功能活性成分在医药和食品领域的深度开发提供参考。

Plasma Phospholipid Omega-3 Fatty Acids and Freshwater Fish Consumption in the Brazilian Amazon

Background: Amazonian riverside communities consume large quantities of freshwater fish, comparable to marine fish consumption of Inuit, Scandinavian and Japanese populations. Few studies have considered the relation of high freshwater fish consumption and intake of omega-3 fatty acids (FA). Objective: The objective of the present study was to determine the profile of the concentrations of plasma phospholipid FAs and its relation with freshwater fish intake in 12 riverside communities in the Tapajós River basin (State of Pará, Brazilian Amazon). Design: This cross-sectional study included 333 adults (15 - 86 years old). Fish meal frequency was determined using a 7-day interview-administered dietary recall questionnaire. Fish were categorized as piscivorous and non-piscivorous fish on trophic level. Plasma phospholipid FAs were measured by capillary gas-liquid chromatography. Results: Participants consumed 5 to 6 fish meals a week, with twice as many non-piscivorous fish than piscivorous fish (4.4 fish/week vs 2.2 fish/week, respectively). The omega-3 FA levels in plasma phospholipids were low (EPA + DHA = 31.21 mg/L;%EPA + DHA = 2.59%). Omega-3 FAs increased with frequency of fish intake, and particularly with piscivorous fish, controlling for sociodemographic, anthropometric and lifestyle characteristics. DHA levels were greater in women than in men. Conclusions: Omega-3 FA in this Amazonian population increased with fish consumption, but although they consumed freshwater fish almost daily, the concentrations of omega-3 FA were relatively low and comparable to fish-eater communities for which fish is not a dietary mainstay. It is possible that nutrients present in marine, but not in certain freshwater fish species, may facilitate absorption of omega-3 FA. Sex and/or gender differences must be taken into account when assessing the relationship between fish consumption and plasma phospholipid omega-3 FA levels.

Effects of ω-3 fatty acids on toll-like receptor 4 and nuclear factor-κB p56 in lungs of rats with severe acute pancreatitis

AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.

Transgenic Pigs Carrying a Synthesized Fatty Acid Desaturase Gene Yield High Level of ω-3 PUFAs

Polyunsaturated fatty acids （PUFAs） are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease and diabetes. In this study, we aimed to investigate whether the sFat-1 gene from Caenorhabditis briggsae could be functionally expressed in transgenic pigs, and whether the transgenic could synthesize high quality ω-3 PUFAs endogenously. In this study, a gene construct consisting of CMV promoter and 1.9 kb cDNA of ω-3 fatty acid desaturase gene （sFat-1） from C. briggsae was injected into the male pronucleus of pig embryos by microinjection. The piglets were screened for the transgene by PCR, Southern blot and reverse transcription-PCR analysis. Pigs that give positive results were mated with wild-type pigs to produce the next generation and the transmission of transgene was examined by PCR analysis. Fatty acids compositions of various tissues in the transgenic pigs were then analyzed by gas chromatograph. A total of 878 embryos were transferred into 42 recipients, among which 29 successfully got pregnant and gave birth to a total of 162 piglets, and 8 of them were identified to be transgenic. Fatty acid compositions in the transgenic pigs were altered, and the levels of ω-6：ω-3 ratios were decreased from 14.53 in the control to 2.62 in Fat-1 transgenic pigs. A number of primary sFat-1-transgenic pigs were bred in this study, which lays the foundation for cultivation of new varieties of transgenic pigs.

Usefulness of ω-3 fatty acid supplementation in addition to mesalazine in maintaining remission in pediatric Crohn's disease: A double-blind, randomized, placebo-controlled study

AIM： To assess the value of long-chain w-3 fatty acids （FAs） supplementation in addition to amino-salicylic-acid （5-ASA） in pediatric patients with Crohn＇s disease （CD）. METHODS： Thirty-eight patients （20 males and 18 females, mean age 10.13 years, range 5-16 years） with CD in remission were randomized into two groups and treated for 12 too. Group Ⅰ （18 patients） received 5-ASA （50 mg/kg/d）＋w-3 FAs as triglycerides in gastroresistant capsules, 3 g/d （eicosapentanoic acid, EPA, 400 mg/g, docosahexaenoic acid, DHA, 200 mg/g）. Group Ⅱ （20 patients） received 5-ASA （50 mg/kg/d）＋olive oil placebo capsules. Patients were evaluated for fatty acid incorporation in red blood cell membranes by gas chromatography at baseline 6 and 12 mo after the treatment. RESULTS： The number of patients who relapsed at 1 year was significantly lower in group I than in group Ⅱ （P〈0.001）. Patients in group I had a significant increase in the incorporation of EPA and DHA （P〈0.001） and a decrease in the presence of arachidonic acids. CONCLUSION： Enteric-coated w-3 FAs in addition to treatment with 5-ASA are effective in maintaining remission of pediatric CD.

Effect of ω-3 Polyunsaturated Fatty Acid on Toll-like Receptors in Patients with Severe Multiple Trauma

This study examined the effects of ω-3 polyunsaturated fatty acid（ω-3PUFA） on the expression of toll-like receptor 2（TLR2）,toll-like receptor 4（TLR4） and some related inflammatory factors in peripheral blood mononuclear cells（PBMCs） of patients with early-stage severe multiple trauma.Thirty-two patients who were admitted to the Department of Traumatic Surgery,Tongji Hospital（Wuhan,China） between May 2010 and November 2010,and diagnosed as having severe multiple trauma with a injury severity score（ISS） no less than 16,were enrolled in the study and divided into two groups at random（n=16 in each）：ω-3PUFA group and control group in which routine parenteral nutrition supplemented with ω-3PUFA or not was administered to the patients in two groups for consecutive 7 days.Peripheral blood from these patients was collected within 2 h of admission（day 0）,and 1,3,5 and 7 days after the nutritional support.PBMCs were isolated and used for detection of the mRNA and protein expression of TLR2 and TLR4 by using real-time PCR and flow cytometry respectively,the levels of NF-κB by quantum dots-based immunofluorescence assay,the levels of TNF-α,IL-2,IL-6 and COX-2 by ELISA,respectively.The results showed that the mRNA and protein expression of TLR2 and TLR4 in PBMCs was significantly lower in ω-3PUFA group than in control group 5 and 7 days after nutrition support（both P0.05）.The levels of TNF-α,IL-2,IL-6 and COX-2 were found to be substantially decreased in PBMCs in ω-3PUFA group as compared with control group at 5th and 7th day（P0.05 for all）.It was concluded that ω-3PUFA can remarkably decrease the expression of TLR2,TLR4 and some related inflammatory factors in NF-κB signaling pathway in PBMCs of patients with severe multiple trauma,which suggests that ω-3PUFA may suppress the excessive inflammatory response meditated by the TLRs/NF-κB signaling pathway.

A Diet with 3% of Energy from a Mixture of Omega-3 Fatty Acids Significantly Increases in Vivo Lipid Peroxidation in Postmenopausal Women

Dietary omega-3 (n - 3) polyunsaturated fatty acids (PUFA) are recommended by public health organizations to reduce the risk of cardiovascular disease, and several epidemiological studies have suggested there is an inverse association between n - 3 intake and human cancers. However, n - 3 are susceptible to an increase in lipid peroxidation in the human body. As part of a crossover dietary intervention study of a diet (20% of energy from fat) with or without an additional 3% of energy from a mixture of n - 3 (with 5.36 g α-linolenic acid and 1.45 g eicosapentaenoic acid and docosahexaenoic acid per 2000 kcal per day), we measured total in vivo lipid peroxidation in healthy postmenopausal women (n = 15). Our results indicated that the diet with 3% of energy from n - 3 significantly increased the urinary concentrations of total polar lipophilic aldehydes and related compounds produced via lipid peroxidation (p α, β-unsaturated hydroxy aldehydes 4-hydroxy-2-trans - hexenal (p trans -decenal (p < 0.05) compared to the diet with less than 1% of energy from n - 3. This is also the first study to document the presence of 4-hydroxy-2-trans -decenal in the urine of individuals consuming n - 3. These results demonstrate that an increase in 3% of energy from dietary n – 3 increases in vivo lipid peroxidation.

脂肪酶催化醇解制备富含n-3 PUFAs的甘油酯

n-3 PUFAs具有多种生理活性。以鱼油为原料,采用脂肪酶催化醇解法对其中的n-3 PUFAs进行富集,得到富含n-3 PUFAs的甘油酯。结果表明:来自米曲霉的脂肪酶Eversa Transform 2.0(ET 2.0)对n-3 PUFAs表现出良好的醇解特异性。通过单因素实验确定最佳工艺条件为:甲醇体积分数40%,m_(甲醇)∶m_(鱼油)=1.6∶1,温度35℃,脂肪酶添加量4%,反应时间2 h。在此条件下,鱼油甘油酯中n-3 PUFAs的含量从39.88%上升至67.87%,EPA和DHA的含量从36.61%上升至65.22%,n-3 PUFAs的得率为56.33%。脂肪酶在最佳反应条件下对不同底物的富集效果是:金枪鱼油甘油酯中n-3 PUFAs的含量从38.81%上升到61.35%,藻油甘油酯中n-3 PUFAs的含量从45.96%上升到64.09%。上述方法获得的富含n-3 PUFAs甘油酯在食品和制药行业有很大的应用潜力。

分子蒸馏技术分步法制备酶促酯交换反应的高含量ω-3 PUFA鱼油甘油酯

研究采用分子蒸馏技术分步法处理多级酶促鱼油酯交换反应产物,获得高含量ω-3多不饱和脂肪酸(polyunsaturated fatty acid,PUFA)甘油酯。首先通过一级分子蒸馏分离鱼油酯交换产物中的甘油酯和副产物,当蒸馏压强5 Pa、蒸馏温度140℃、刮板转速240 r/min和进料速率0.2 mL/min时,得率为47.13%的一级重相ω-3 PUFA含量达到53.76%,高温气相色谱及核磁共振氢谱都证明一级重相不含乙酯型鱼油;其次,当蒸馏压强5 Pa、蒸馏温度110℃、刮板转速240 r/min和冷凝温度20℃时,分子蒸馏可以将一级轻相中的ω-3 PUFA含量从60.73%富集到78.01%,此一级轻相富集相参与二级酶促酯交换反应和分子蒸馏分离后,获得得率为46.23%并含有51.38%ω-3 PUFA的二级重相。若一级轻相直接参与二级酯交换反应和分离,其二级重相ω-3 PUFA含量仅为42.37%。采用多级酶促酯交换反应和多步分子蒸馏方法可以制备不同ω-3 PUFA含量等级的甘油酯型鱼油产品,并实现原料和副产物的最大化利用。

The effects of season on fatty acid composition and ω3/ω6 ratios of northern pike(Esox lucius L.,1758) muscle lipids

In the present study, the effects of season on fatty acid composition, total lipids, and ω3/ω6 ratios of northern pike muscle lipids in Klzlhrmak River （Klrlkkale, Turkey） were investigated. A total of 35 different fatty acids were determined in gas chromatography. Among these, palmitic, oleic, and palmitoleic acids had the highest proportion. The main polyunsaturated fatty acids （PUFAs） were found to be docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid. There were more PUFAs than monounsaturated fatty acids （MUFA） in all seasons. Similarly, the percentages of ω3 fatty acids were higher than those of total ω6 fatty acids in the fatty acid composition. ω3/ω6 ratios were calculated as 1.53, 1.32, 1.97, and 1.71 in spring, summer, autumn and winter, respectively. Overall, we found that the fatty acid composition and ω3/ω6 fatty acid ratio in the muscle of northern pike were significantly influenced by season.

The Global Research Progress of Enzymatic Processing of Oils with Omega 3 Polyunsaturated Fatty Acids

This paper has reviewed that Omega 3 polyunsaturated fatty acids (PUFAs), as an essential fatty acids (EFAs), mainly come from fish oil of marine products, has positive effects on treatment and/or prevention of several diseases. In this review, the recent developments by 2019 in the field of enzymatic modification of oils rich in omega 3 PUFAs have summarized. Several different products, such as structured lipids with a variety of FA compositions, nutritional aspects, omega 3 PUFA concentrates and phospholipids,have discussed from the point of process technology as well as possible applications. Enhancing omega 3 PUFA content in diet involves a number of strategies aiming to modify the content of such FAs in fats and oils. Due to the mild reaction conditions used, especially the lipase specificity, the position as well as content of omega 3 PUFAs in lipid molecules being of importance from the point of bioavailability, enzymatic processing of omega 3 PUFA oil is safe, efficient and preferred over chemical treatments.

Cytochrome P450 monooxygenase-mediated eicosanoid pathway:A potential mechanistic linkage between dietary fatty acid consumption and colon cancer risk

Human consumption of linoleic acid(LA,18:2ω-6,abundant in vegetable oils)is very high.Animal experiments showed that excessive LA intake increased azoxymethane-induced colon tumorigenesis,however,the impact of excessive LA on colon cancer in human is not conclusive,making it difficult to make dietary recommendations for optimal intake of LA.Understanding the molecular mechanisms of LA on colon tumorigenesis could help to clarify its health effect,and facilitate development of mechanismbased strategies for preventing colon cancer.Recent studies show that the previously unappreciated cytochrome P450 monooxygenase-mediated eicosanoid pathway is upregulated in colon cancer and plays critical roles in its pathogenesis,and could contribute to the effects of dietary LA,as well asω-3 fatty acids,on colon tumorigenesis.In this review,we will discuss recent studies about the roles of cytochrome P450 monooxygenases in fatty acid metabolism and its roles in colonic inflammation and colon cancer,and how this information could help us to clarify the health impacts of dietary fatty acids.

亚麻籽和鱼油对蛋鸡蛋黄n-3多不饱和脂肪酸含量与肝脏脂肪酸代谢的影响

本试验旨在研究饲粮中添加亚麻籽和鱼油对蛋鸡蛋黄n-3多不饱和脂肪酸含量、肝脏脂肪酸组成及其合成代谢基因表达的影响。选择28周龄海兰褐壳蛋鸡96只,随机分为4组,每组24只。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加10%亚麻籽、10%亚麻籽+5%鱼油和5%鱼油。饲养21 d后连续收集7 d鸡蛋,然后每组随机选取4只鸡屠宰取样。结果表明,与对照组相比:1)添加亚麻籽和鱼油均显著增加蛋黄中n-3多不饱和脂肪酸含量(P<0.05),其中单独添加鱼油的蛋黄中二十二碳六烯酸(DHA)和二十碳五烯酸含量最高;2)试验组肝脏单不饱和脂肪酸比例均显著降低(P<0.05),肝脏n-3多不饱和脂肪酸比例均显著增加(P<0.05);3)单独添加鱼油显著降低肝脏脂肪酸延长酶1、脂肪酸延长酶2和去饱和酶(脂肪酸去饱和酶1、脂肪酸去饱和酶2和硬脂酰辅酶A去饱和酶1)基因表达水平(P<0.05)。由此可见,蛋鸡饲粮中单独添加亚麻籽或鱼油可以富集蛋黄n-3多不饱和脂肪酸沉积;添加亚麻籽促进肝脏α-亚麻酸转化生成DHA过程,表现为上调脂肪酸延长酶和去饱和酶基因表达,添加鱼油显示相反结果。

ω-3脂肪酸对脓毒症病人治疗的影响

目的:探讨ω-3脂肪酸对脓毒症病人的免疫调节和抗炎作用。方法:将18例病人随机分为鱼油治疗组和常规治疗组。鱼油治疗组病人为常规治疗加鱼油,并于治疗前和治疗后第5天用流式细胞仪检测单核细胞HLA-DR表达率,同时检测炎症反应指标,包括C反应蛋白(CRP)、IL-6和肿瘤坏死因子α(TNF-α),观察病情严重程度(APACHEⅡ评分)和氧合指数(PaO2/FiO2)的变化。结果:相对于常规治疗组,鱼油治疗组病人血清CRP、IL-6和TNF-α均明显下降;氧合指数改善;单核细胞HLA-DR表达率、APACHEⅡ评分较常规治疗组无显著性差异。结论:应用ω-3脂肪酸可使脓毒症病人血清炎症介质表达减少,但对单核细胞HLA-DR的表达未见调节作用。

ω-3多不饱和脂肪酸逆转肠外营养所致肝损害的实验室观察

目的:从临床实验室和组织学观察ω-3多不饱和脂肪酸(ω-3PUFA)对成人肠外营养相关肝损害(PNALD)的作用。方法:选取15例长期行PN导致胆汁淤积(直接胆红素≥34μmol/L)的成人短肠综合征病人。动态观察病人应用ω-3PUFA前和治疗1个月内肝功能和血清游离脂肪酸谱的变化。同时行肝穿刺活检,观察治疗前和治疗1个月后的肝组织学改变。结果:ω-3PUFA治疗1个月后,80%(12/15)病人直接胆红素水平恢复正常,所有病人肝功能指标和血清游离脂肪酸谱均得到改善,从肝组织学上亦证实了这种效果。结论:ω-3PUFA能很好地逆转成人PNALD,并改善病人的血脂状况。

ω-3多不饱和脂肪酸对重症急性胰腺炎病人早期炎性反应的影响

目的:观察含有不同ω-3/ω-6比例脂肪酸的PN,能否改变重症急性胰腺炎(SAP)病人血脂肪酸谱,进而改善机体早期炎性反应和器官功能。方法:40例SAP病人随机分为研究组和对照组,每组20例。使用等氮、等热量PN,共5 d,其中非蛋白质热量117 kJ(28 kcal)/(kg.d)、氮量0.2 g/(kg.d)。对照组用中长链脂肪乳剂,研究组用添加ω-3多不饱和脂肪酸的中长链脂肪乳剂,分别在试验前和试验第6天早晨抽取静脉血,检测血游离脂肪酸谱、IL-6、WBC、C反应蛋白(CRP)等,同时记录生命体征和肺、肾等器官功能指标。结果:研究组CRP水平明显降低,氧合指数得到改善,IL-6有所下降。另外,还观察到研究组病人全身炎性反应综合征(SIRS)比率、急性呼吸窘迫综合征(ARDS)患病率以及合并急性肾功能衰竭病人行连续性血液净化(CBP)时间均有所下降。结论:添加ω-3多不饱和脂肪酸的PN,能降低SAP病人机体早期炎症反应,改善肺功能,缩短CBP时间。

ω-3多不饱和脂肪酸影响炎症和免疫功能的基础研究

作为营养药理素,ω-3多不饱和脂肪酸具有调节炎症和免疫功能的作用,这与其能够产生不同的脂类代谢产物、调控细胞内信号转导途径有关。本文作者就ω-3多不饱和脂肪酸的分类、组成以及对炎症和免疫功能作用的分子机制作一综述。

富含n-3多不饱和脂肪酸功能性原料在家禽生产中的应用研究进展

亚麻籽、鱼油、微藻等功能性原料富含大量n-3多不饱和脂肪酸(n-3 PUFA),常添加到家禽饲粮中富集n-3 PUFA禽产品。不同原料具有不同的脂肪酸组成及其他营养物质,在养殖中对家禽生长发育会产生不同的影响。本文从家禽生产性能、禽产品品质、n-3 PUFA及其他成分含量、感官评价、氧化稳定性等方面,对利用不同原料富集n-3 PUFA保健禽产品的研究进行了综述,为不同功能性原料更好地应用于家禽养殖生产提供科学依据。

ω-3 LCPUFAs模拟热加工鱼肉脂肪氧化形成风味物质的研究

为探索热加工过程中鱼肉脂肪氧化形成风味物质的过程,以鱼肉典型脂肪酸--ω-3 LCPUFAs(EPA、DPA、DHA)为代表,分别采用脂肪氧化酶处理和加热处理,采用固相微萃取-气相色谱-质谱联用技术分析。结果显示:经两种方式处理,3种脂肪酸共产生8大类107种风味特性各不相同的成分,其中具有土腥味和鱼腥味等鱼肉特征风味成分包括2-辛酮、2-壬酮、3-辛烯-2-酮、反-2-戊醇、3-辛醇、1-辛烯-3-醇、十二醇。产物中含量最大的成分是芳香族化合物,其它产物含量大致顺序为醛、酮、醇或烷烃、呋喃或酯,脂肪氧化型产物(醛、酮、醇、呋喃)占总含量的6.0%~63.7%。3种脂肪酸产物总含量顺序为EPA>DHA>DPA,推测3种脂肪酸稳定性顺序为DPA>DHA>EPA。两种处理方式相比,加热处理形成比例更高的脂肪氧化型产物,而低温脂肪氧化酶处理主要形成芳香族化合物。提示受热作用更利于鱼肉形成风味良好的产物。

分子蒸馏法富集鱼油ω-3脂肪酸

研究分子蒸馏富集深海鱼油中ω-3脂肪酸的工艺方法。实验结果表明,采用MD—S80分子蒸馏设备,110℃,10Pa,进料流量为0．5g／min时对鱼油ω-3脂肪酸富集效果最好。通过二级分子蒸馏,可以得到总ω-3脂肪酸含量为63％,得率为13．46％的鱼油乙酯。