不同年龄阶段小鼠脑聚集二十二碳六烯酸及脂肪酸去饱和酶的变化

【目的】 探讨生命早期不同年龄阶段脑摄取、聚集二十二碳六烯酸(DHA)(C22:6n-3)及相关去饱和酶的变化。 【方法】 使用6~8周龄清洁级C57BL/6J雌性小鼠,分别给予n-3 多不饱和脂肪酸(n-3 PUFAs)缺乏饲料和含n-3 PUFAs饲料喂养6周,然后雌雄合笼交配繁殖,新生仔鼠分别于生后7、21 d和42 d时取血、脑和肝脏。采用甲酯化-气相色谱分析对血浆、脑和肝脏中脂肪酸谱进行分析;采用荧光定量PCR方法对脑和肝脏中脂肪酸去饱和酶1(FADS1)和脂肪酸去饱和酶2(FADS2)基因mRNA表达进行检测。 【结果】 对不同年龄小鼠组织脂肪酸的比较发现,脑中DHA和总n-3 PUFAs含量在两种不同饲料组均随年龄增加而升高;而肝中的含量则随年龄增加而降低。与n-3 PUFAs缺乏组相比,饲料中添加n-3 PUFAs可使仔鼠生后7、21 d和42 d时脑和肝脏中DHA和总n-3 PUFAs含量均显著升高;升高的程度在脑组织中随年龄增加而降低,而在肝脏组织中则不随年龄变化。对不同年龄段FADS表达的比较发现,FADS1和FADS2 mRNA在脑组织中的表达量于42 d时显著高于7 d和21 d,而在肝组织中的表达量于各年龄段之间无显著性差异。与n-3 PUFAs缺乏组相比,饲料中添加n-3 PUFAs可使仔鼠生后7 d和21 d时脑组织FADS1和FADS2表达水平显著降低,而42 d时的表达无变化;肝组织中这两种酶mRNA水平在7 d和21 d时无变化,42 d时FADS1显著降低。 【结论】 发育期脑对DHA的聚集需求随着年龄增大而逐渐减少;FADS在脑中的表达水平随年龄增大而升高。同时,饲料n-3 PUFAs缺乏状态对脑聚集DHA以及FADS的影响在年龄小时更明显。     

Lipase inhibitor orlistat decreases incorporation of eicosapentaenoic and docosahexaenoic acids in rat tissues

Orlistat is a gastric and pancreatic lipases inhibitor that is often prescribed to obese subjects. Orlistat has been shown to decrease the absorption of biologically important lipophilic micronutrients such as liposoluble vitamins. We hypothesized that long-term administration of orlistat may lower the incorporation of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in blood lipids and tissues. This hypothesis was tested in rats fed a diet supplemented with fish oil as a source of n-3 LC-PUFA. Male Wistar rats (n = 18) were divided into 3 groups and fed experimental high-fat diets containing fish oil (control diet) or fish oil plus orlistat (200 and 400 mg/kg of diet) over the course of 3 weeks. Fat absorption and the level of eicosapentaenoic acid (EPA) and docosahexaenoic acid, among other fatty acids, in red blood cells, plasma, liver, and spleen, were measured at the end of the experimental period. The results show that at 200 mg and 400 mg/kg of diet orlistat lowers fat absorption by 9% (P = .008) and 54% (P = .008). Orlistat given at the higher level induced a reduction of the incorporation of EPA in red blood cell (−45%; P = .006) and in plasma (−34%; P = .026) compared to the control group. Our results confirmed that administration of orlistat reduces incorporation of n-3 LC-PUFA in blood lipids and tissues in a rat model.     

Docosahexaenoic acid (DHA): an ancient nutrient for the modern human brain

Modern humans have evolved with a staple source of preformed docosahexaenoic acid (DHA) in the diet. An important turning point in human evolution was the discovery of high-quality, easily digested nutrients from coastal seafood and inland freshwater sources. Multi-generational exploitation of seafood by shore-based dwellers coincided with the rapid expansion of grey matter in the cerebral cortex, which characterizes the modern human brain. The DHA molecule has unique structural properties that appear to provide optimal conditions for a wide range of cell membrane functions. This has particular implications for grey matter, which is membrane-rich tissue. An important metabolic role for DHA has recently been identified as the precursor for resolvins and protectins. The rudimentary source of DHA is marine algae; therefore it is found concentrated in fish and marine oils. Unlike the photosynthetic cells in algae and higher plants, mammalian cells lack the specific enzymes required for the de novo synthesis of alpha-linolenic acid (ALA), the precursor for all omega-3 fatty acid syntheses. Endogenous synthesis of DHA from ALA in humans is much lower and more limited than previously assumed. The excessive consumption of omega-6 fatty acids in the modern Western diet further displaces DHA from membrane phospholipids. An emerging body of research is exploring a unique role for DHA in neurodevelopment and the prevention of neuropsychiatric and neurodegenerative disorders. DHA is increasingly being added back into the food supply as fish oil or algal oil supplementation.     

Benefits of Structured and Free Monoacylglycerols to Deliver Eicosapentaenoic (EPA) in a Model of Lipid Malabsorption

In the present study, we used a preclinical model of induced lipolytic enzyme insufficiency, and hypothesized that the use of monoacylglycerols (MAG) will enhance their bioavailability and delivery to the tissues. Experimental diets containing 20% lipids were fed to rats for 21 days with or without Orlistat. The control diet of fish oil (FO), a source of EPA and DHA, was tested against: structured (A) vanillin acetal of sn-2 MAG (Vanil + O) and (B) diacetyl derivative of sn-2 MAG (Acetyl + O) and (C) free MAG (MAG + O). FA profiles with an emphasis on EPA and DHA levels were determined in plasma, red blood cells (RBC), liver, spleen, brain and retina. We observed significant reduction of lipid absorption when rats co-consumed Orlistat. As expected, the FO groups with and without Orlistat showed the biggest difference. The Vanil + O, Acetyl + O and MAG + O groups, demonstrated higher levels of EPA (5.5 ± 1.9, 4.6 ± 1.6 and 5.6 ± 0.6, respectively) in RBC compared with FO + O diets (3.3 ± 0.2, 2.6 ± 0.2). Levels of EPA incorporation, in plasma, were similar to those obtained for RBC, and similar trends were observed for the collected tissues and even with DHA levels. These observations with two MAG derivatives providing the fatty acid esterified in the sn-2 position, show that these molecules are efficient vehicles of EPA in malabsorption conditions which is in line with our hypothesis. Free MAG, characterized as having exclusively sn-1(3) isomers of EPA, demonstrated better absorption efficiencies and accretion to tissues when compared to structured MAG. The study demonstrated that structured and free MAG can be used efficiently as an enteral vehicle to supply bioactive fatty acids such as EPA and DHA in lipid malabsorption where diminished lipolytic activity is the underlying cause.     

Flaxseed flour (Linum usitatissinum) consumption improves bone quality and decreases the adipocyte area of lactating rats in the post-weaning period

The aim of this work was to evaluate the effects of flaxseed flour in the intake on adiposity and femur structure of the lactating rats during the post-weaning period. After weaning, the lactating rats were divided into control (C, n?=?6) and experimental (F, n?=?6) groups treated with a diet containing flaxseed flour. Serum hormone and fatty acids composition, morphology of intra-abdominal adipocytes, computed tomography and biomechanical analyses of femur were determined. Food intake, body mass and hormone analysis have shown similar results. The F group showed the following (p?相似文献   

Fatty acid profiles,antioxidant status,and growth of preterm infants fed diets without or with long-chain polyunsaturated fatty acids

Summary. Long-chain polyunsaturated fatty acids (LCP) are considered conditionally essential nutrients for the infant born prematurely, and attempts are being made to match fatty acid profiles of formula and breast fed infants. In this double-blind, randomized study we investigated the effects of a formula enriched with both n-6 and n-3 LCP on plasma fatty acid profiles, antioxidant status and growth of premature infants. 29 infants received either a formula devoid of LCP or a LCP supplemented formula (0.5 g/100 g fat linoleic acid metabolites, 0.8 g/100 g fat -linolenic acid metabolites). 17 breast fed infants served as a control group. At study entry as well as two and four weeks later, plasma and urine samples were collected, growth data obtained and food tolerance was documented. At the end of the four week study period, plasma docosahexaenoic acid (DHA) levels of supplemented infants were significantly higher than those of unsupplemented infants and similar to those of infants fed human milk. Plasma n-6 LCP concentrations including arachidonic acid (AA) were similar between groups. The plasma -tocopherol levels of breast fed and supplemented infants were similar and tended to be lower than in infants fed the formula devoid of LCP. Urinary malondialdehyde (MDA) excretion of formula fed infants was significantly higher compared to infants fed human milk, but did not differ between the two formula groups. Parameters of growth and milk tolerance did not differ between groups. Our results demonstrate that plasma LCP levels similar to those of breast fed infants can be achieved with the LCP supplemented formula used in this trial, without evidence of adverse effects of the LCP enrichment.AA arachidonic acid - ALA -linolenic acid - DGLA dihomo--linolenic acid - DHA docosahexaenoic acid - EPA eicosapentaenoic acid - F formula devoid of LCP - GLA -linolenic acid - HM human milk - LA linoleic acid - LCP long-chain polyunsaturated fatty acids - LCP-F formula enriched with LCP - MDA malondialdehyde - PC phosphatidylcholine - PCA postconceptional age - PE phosphatidylethanolamine - PUFA polyunsaturated fatty acid     

Self-Reported DHA Supplementation during Pregnancy and Its Association with Obesity or Gestational Diabetes in Relation to DHA Concentration in Cord and Maternal Plasma: Results from NELA,a Prospective Mother-Offspring Cohort

Maternal supplementation of docosahexaenoic acid (DHA) during pregnancy has been recommended due to its role in infant development, but its effect on materno-fetal DHA status is not well established. We evaluated the associations between DHA supplementation in pregnant women with obesity or gestational diabetes mellitus (GDM) and maternal and neonatal DHA status. Serum fatty acids (FA) were analyzed in 641 pregnant women (24 weeks of gestation) and in 345 venous and 166 arterial cord blood samples of participants of the NELA cohort. Obese women (n = 47) presented lower DHA in serum than those lean (n = 397) or overweight (n = 116) before pregnancy. Linoleic acid in arterial cord was elevated in obese women, which indicates lower fetal retention. Maternal DHA supplementation (200 mg/d) during pregnancy was associated with enhanced maternal and fetal DHA levels regardless of pre-pregnancy body mass index (BMI), although higher arterial DHA in overweight women indicated an attenuated response. Maternal DHA supplementation was not associated with cord venous DHA in neonates of mothers with GDM. The cord arteriovenous difference was similar for DHA between GDM and controls. In conclusion, maternal DHA supplementation during pregnancy enhanced fetal DHA status regardless of the pre-pregnancy BMI while GDM may reduce the effect of DHA supplementation in newborns.     

Linseed oil and marine oil as sources of (n-3) fatty acids in rat heart

Rats were fed a fat mixture containing a low level of (n-3) polyunsaturated fatty acids, linseed oil or marine oil. The arachidonic acid in cardiac tissue was depressed by (n-3) linolenic acid and further depressed by (n-3) polyunsaturated fatty acids of marine oil. Docosahexaenoic acid was the principal replacement for arachidonic acid.     

Dietary supplementation with a combination of α-lipoic acid,acetyl-l-carnitine,glycerophosphocoline, docosahexaenoic acid,and phosphatidylserine reduces oxidative damage to murine brain and improves cognitive performance

Alzheimer disease has a complex etiology composed of nutritional and genetic risk factors and predispositions. Moreover, genetic risk factors for cognitive decline may remain latent pending age-related decline in nutrition, suggesting the potential importance of early nutritional intervention, including preventative approaches. We hypothesized that a combination of multiple nutritional additives may be able to provide neuroprotection. We demonstrate herein that dietary supplementation with a mixture of ALA, ALCAR, GPC, DHA, and PS reduced reactive oxygen species in normal mice by 57% and prevented the increase in reactive oxygen species normally observed in mice lacking murine ApoE when maintained on a vitamin-free, iron-enriched, oxidative-challenge diet. We further demonstrate that supplementation with these agents prevented the marked cognitive decline otherwise observed in normal mice maintained on this challenge diet. These findings add to the growing body of research indicating that key dietary supplementation may delay the progression of age-related cognitive decline.     

Long-chain polyunsaturated fatty acid supplementation had no effect on body weight but reduced energy intake in overweight and obese women

Longer-chain polyunsaturated fatty acids may have greater appetite-suppressing effects than shorter-chain, monosaturated, and saturated fatty acids. Because fish oils are predominantly composed of n-3 long-chain polyunsaturated fatty acid and may assist in the treatment of obesity comorbidities, their effect on body weight and body mass index is of interest. We hypothesized that daily supplementation with docosahexaenoic acid (DHA)–rich oil would reduce energy intake and body weight in overweight and obese women compared with supplementation with oleic acid (OA) rich oil. A double-blinded, randomized, parallel intervention was conducted. Body mass index (in kilograms per meter squared), body weight (in kilograms), body fat (in percent), and lean tissue (in kilograms) were measured at baseline and 12 weeks after intervention with DHA or OA. Diet diaries were also completed at these time points for estimation of energy and macronutrient intake. Subjects reported significantly lower energy (P = .020), carbohydrate (g) (P = .037), and fat (g) (P = .045) intake after DHA compared with OA. Body mass or composition was not affected by treatment, although a fall in body weight in the DHA group approached statistical significance (P = .089). Daily ingestion of DHA over a 12-week period may reduce energy intake in overweight and obese females, but longer-term and adequately powered studies using subjects of both sexes are needed. Other factors that should be considered include the following: the choice of control, the body mass index category of subjects, and ways of improving the compliancy and accuracy of dietary assessment.     

Dietary conjugated linoleic acid and long-chain n-3 fatty acids in mammary and prostate cancer protection: a review

The role of dietary fatty acids on cancer is still controversial. To examine the current literature on the protective role of conjugated linoleic acid (CLA) and marine long-chain fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] and the risk of breast and prostate cancer, data from 41 case-control and cohort studies and relevant in vitro and animal experiments were included in this 2000–2010 revision. Epidemiological studies on CLA intake or its tissue concentration related to breast and prostate tumorigenesis are not conclusive; EPA and DHA intake have shown important inverse associations just in some studies. Additional research on the analysed association is required.     

Comparison of fatty acid and proximate compositions of the body and claw of male and female blue crabs (Callinectes sapidus) from different regions of the Mediterranean coast

Fatty acid and proximate compositions of the body and claw of male and female blue crabs from Akyatan Lagoon and Hurma strait were investigated. Male blue crab meat had a higher protein and fat content, and lower moisture and ash content, than that of the female from Akyatan Lagoon. Moreover, there were variations of protein and fat amounts in both female crab meats between Akyatan Lagoon and Hurma strait. The dominant saturated fatty acids were palmitic acid (16:0; range from ～12% to 15%) and stearic acid (18:0; range from ～7.5% to 16.1%) for all samples. The total monounsaturated fatty acid content in the body of female crabs from Akyatan Lagoon was higher than those of Hurma Strait (22.04% versus 7.55%). There were no statistically significant differences (P >0.05) between eicosapentaenoic acid concentrations in body meat of the male crab than those of female crab meat from Akyatan Lagoon (P<0.05). Docosahexaenoic acid contents were different between the body meat of male crabs from Akyatan Lagoon and those of female crabs from Hurma strait. The total n3 was detected as 27.33% in body meat whereas it was 24.39% in claw meat of the male crab from Akyatan Lagoon. Those values were almost similar in the body and claw meat of female crab from Akyatan Lagoon.     

Dietary supplementation with conjugated linoleic acid plus n-3 polyunsaturated fatty acid increases food intake and brown adipose tissue in rats

The effect of supplementation with 1% conjugated linoleic acid and 1% n-3 long chain polyunsaturated fatty acids (CLA/n-3) was assessed in rats. Food intake increased with no difference in body weights. White adipose tissue weights were reduced whereas brown adipose tissue and uncoupling protein-1 expression were increased. Plasma adiponectin, triglyceride and cholesterol levels were reduced while leptin, ghrelin and liver weight and lipid content were unchanged. Hypothalamic gene expression measurements revealed increased expression of orexigenic and decreased expression of anorexigenic signals. Thus, CLA/n-3 increases food intake without affecting body weight potentially through increasing BAT size and up-regulating UCP-1 in rats.     

配方奶添加长链多聚不饱和脂肪酸对足月儿生长发育的影响

[目的]拟探讨配方乳添加等量AA与DHA对中国部分地区足月婴儿生长发育的影响. [方法]271名足月健康新生儿,随机分配进入添加AA DHA配方喂养组(frisolac advanced,FA组)、未添加AA DHA配方喂养组(frisolac H,FH组),并选择26名纯母乳喂养儿(fully breast feding,BF组)为对照组.所有参与的婴儿在满3和6个月时邀请入院检测体重、身长、头围、智能发育指数(MDI),运动发育指数(PDI),并采集外周静脉血检测血浆长链多聚不饱和脂肪酸(LCPUFA)与血红蛋白. [结果]尽管两种配方喂养婴儿血清LCPUFA含量差异有显著性,但两组配方喂养婴儿在满3和6个月时体重、身长、头围、MDI、PDI差异无显著性.然而,本研究显示纯母乳喂养婴儿在6个月时体重和身长低于混合喂养婴儿(BF组 FA组),且BF组婴儿在6个月时血浆AA、DHA及与血红蛋白低于BF FA组婴儿. [结论]尽管添加AA∶DHA=1∶1的配方可以显著地增加婴儿血浆AA和DHA水平,但并不表明对现有的标准婴儿配方乳添加AA DHA可促进婴儿生长发育.     

Demographic and lifestyle factors associated with body mass index among children and adolescents

Cases of overweight and obesity among adults, adolescents, and children are escalating in the United States. Using data from the Continuing Survey of Food Intake for Individuals (CSFII) 1994–1996 and 1998, and the National Health and Nutrition Examination Survey III (NHANES), we developed multivariate regression models to examine the association between demographic and lifestyle variables (gender, race/ethnicity, age, family income, diet, and television viewing) and the body mass index (BMI) of children aged 6–11 years, and adolescents aged 12–19 years for CSFII and aged 12–16 years for NHANES. In the children's model, the statistically significant demographic predictors of BMI were age, race, gender, and family income. Among adolescents, the demographic predictors were age, race, and gender. Among the lifestyle variables, dietary factors were not associated with BMI in children. On the contrary, carbohydrates (less added sugars) had a statistically significant inverse relationship to BMI among adolescents. In both children and adolescents, television viewing was markedly associated with BMI, and participation in team sports was negatively associated with BMI. The overall process by which overweight develops is complex, and our four models explained only a small portion of total variance of BMI. The CSFII models explained 8.5% of the variance for children and 11.4% of the variance for adolescents. The NHANES models explained 8.8% of the variance for children and 12.5% of the variance for adolescents. Demographic variables accounted for roughly one-half of the explained variance for both children and adolescents. The rest of the explained variance was accounted for by television viewing, diet, and family income.     

生育和不育男性精液维生素B_(12)、叶酸、活性氧和精子质量的比较

为了探讨精液维生素 B1 2 (VB1 2 )、叶酸和活性氧 (ROS)对精子质量和生殖功能的影响。收集成年男性不育者 44名 (不育组 )和经证实配偶已怀孕的健康成年男性 176名 (生育组 )的精液 ,根据 WHO推荐方法检测精子质量指标 ,并测定精液 VB1 2 、叶酸和 ROS水平。结果显示二组 VB1 2 和叶酸没有显著性差异 (P>0 .0 5 ) ,不育组 ROS和形态异常精子都显著高于生育组 (P<0 .0 1) ,ROS与精子形态异常呈正相关 (P<0 .0 1) ,VB1 2 和叶酸与 ROS均呈负相关 (P<0 .0 1)。结论认为精液 ROS升高 ,可能促使精子形态异常 ,从而影响男性生殖功能。     

Prenatal Maternal Docosahexaenoic Acid (DHA) Supplementation and Newborn Anthropometry in India: Findings from DHANI

Long-chain omega-3 fatty acid status during pregnancy may influence newborn anthropometry and duration of gestation. Evidence from high-quality trials from low- and middle-income countries (LMICs) is limited. We conducted a double-blind, randomized, placebo-controlled trial among 957 pregnant women (singleton gestation, 14–20 weeks’ gestation at enrollment) in India to test the effectiveness of 400 mg/day algal docosahexaenoic acid (DHA) compared to placebo provided from enrollment through delivery. Among 3379 women who were screened, 1171 were found eligible; 957 were enrolled and were randomized. The intervention was two microencapsulated algal DHA (200 × 2 = 400 mg/day) or two microencapsulated soy and corn oil placebo tablets to be consumed daily from enrollment (≤20 weeks) through delivery. The primary outcome was newborn anthropometry (birth weight, length, head circumference). Secondary outcomes were gestational age and 1 and 5 min Appearance, Pulse, Grimace, Activity, and Respiration (APGAR) score. The groups (DHA; n = 478 and placebo; n = 479) were well balanced at baseline. There were 902 live births. Compliance with the intervention was similar across groups (DHA: 88.5%; placebo: 87.1%). There were no significant differences between DHA and placebo groups for birth weight (2750.6 ± 421.5 vs. 2768.2 ± 436.6 g, p = 0.54), length (47.3 ± 2.0 vs. 47.5 ± 2.0 cm, p = 0.13), or head circumference (33.7 ± 1.4 vs. 33.8 ± 1.4 cm, p = 0.15). The mean gestational age at delivery was similar between groups (DHA: 38.8 ± 1.7 placebo: 38.8 ± 1.7 wk, p = 0.54) as were APGAR scores at 1 and 5 min. Supplementing mothers through pregnancy with 400 mg/day DHA did not impact the offspring‘s birthweight, length, or head circumference.