Dynamic changes at high-protein dietary pattern of major fatty acids in healthy lactating women: A systematic review and meta-analysis

BACKGROUND

Fatty acids (FAs) in human milk are important nutrients for infants. They play important roles in energy supply, nervous system development, and metabolic function maintenance. However, how the composition of major milk FAs change with lactation stages remains controversial.

OBJECTIVES

To systematically review the concentration range of major FAs in human milk at various lactation stages.

METHODS

A total of 12 papers involving 50 sets of data with 3507 participants were reviewed according to the PRISMA checklist and flow diagram. The inclusion criteria was the literatures had the FAs contents in breast milk of healthy lactation mothers at three lactation stages and the dietary patterns could be calculated. The exclusion criteria were: the studies were duplicates, were unrelated to dietary patterns or breast milk composition, and/or the study populations were unhealthy. We searched PubMed, the China National Knowledge Infrastructure, WanFang, and Web of science. Agency for Health Care Research and Quality (AHRQ) was used to assess the bias of studies. The mean values of polyunsaturated fatty acids (PUFAs) including docosahexaenoic acid (DHA), arachidonic acid (AA), eicosapentaenoic acid (EPA), α-linolenic acid (ALA), linoleic acid (LA), monounsaturated fatty acids (MUFAs), and saturated fatty acids (SFAs, including lauric acid and palmitic acid), in human milk at three lactation stages (colostrum 1-7 d, transitional milk 8-14 d, mature milk 15 d-3 mo) of healthy lactating women were investigated in terms of the high protein dietary pattern. Publication biases were evaluated by Egger's test.

RESULTS

According to the percentage in total fat of colostrum, transitional milk, and mature milk (% wt/wt), respectively, the results showed that PUFA (25.72%, 24.92%, and 22.69%), AA (0.85%, 0.76%, and 0.59%), DHA (0.53%, 0.47%, and 0.39%), EPA (0.15%, 0.10%, and 0.10%), and MUFA (37.39%, 37.21%, and 36.14%) contents in breast milk decreased with lactation, while another two PUFA forms, LA (17.47%, 17.82%, and 17.48%), and ALA (1.09%, 1.39%, and 1.24%) arrived at a peak in the transitional milk and then decreased in the mature milk, SFA (37.46%, 38.64%, and 40.52%), and lauric acid contents (2.78%, 4.91%, and 4.97%) increased with the lactation stages.

CONCLUSION

These findings could shed light on the dynamic change progress of major FA metabolism, potentially enhancing the knowledge of lactation biology, and improving infant feeding practices to meet their needs.

Association between dietary polyunsaturated fatty acids and their concentration in blood plasma, red blood cell and semen of dogs

Background: In dogs, dietary omega 3 polyunsaturated fatty acids (n-3 PUFA) affect the fatty acid (FA) profile of blood plasma, erythrocyte membrane (EM) and semen, but their correlation has not yet been investigated. Aim: In this study, we evaluated the association between dietary PUFA and their profile in blood plasma, EM and semen of dogs, with the possibility to predict the semen profile using the values of the three first. Methods: Twelve male dogs received the same standard commercial diet for four weeks. The FA profile was analyzed by gas chromatography in paired diet, blood (plasma and EM determinations) and semen samples. Data were analyzed with SAS Proc Corr version 9.4. Pearson´s correlation coefficient (significant if p < 0.05) was used to assess the association of dietary FA profiles with those in blood plasma, EM and semen. Results: There was a positive correlation between dietary eicosapentaenoic acid (EPA) and blood plasma (r = 0.97), EM (r = 0.94) and semen (r = 0.92) EPA, and between dietary docosahexaenoic acid (DHA) and arachidonic acid (ARA) and semen DHA (r = 0.93) and ARA (r = 0.92), respectively. There was negative correlation between dihomo-gamma-linolenic acid (DGLA) in the diet and EM DGLA (r = -0.94). Conclusion: The dietary EPA is correlated with blood plasma, EM and semen EPA concentrations, and dietary DHA and ARA are correlated with semen DHA and ARA concentrations in dogs. These findings suggest that dietary EPA, DHA and ARA concentrations could be useful predictive markers for such concentrations in the semen of dogs.

Investigation of Maternal Diet and FADS1 Polymorphism Associated with Long-Chain Polyunsaturated Fatty Acid Compositions in Human Milk

Increasing the amount of long-chain polyunsaturated fatty acids (LCPUFA) in human milk is an important strategy for infant growth and development. We investigated the associations of LCPUFA compositions in human milk with maternal diet (especially fish and shellfish intake), with fatty acid Δ5 desaturase gene (FADS1) polymorphisms, and with gene-diet interactions. The present study was performed as part of an adjunct study of the Japan Environment and Children’s Study. The participants were 304 lactating females, who provided human milk 6−7 months after delivery. Fatty acids in human milk were analyzed by gas chromatography, and dietary surveys were conducted using a brief self-administered diet history questionnaire. We also analyzed a single nucleotide polymorphism of FADS1 (rs174547, T/C). There was a significant difference in arachidonic acid (ARA) composition in human milk among the genotype groups, and the values were decreasing in the order of TT > TC > CC. The concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were also different between TT and CC genotype, indicating a tendency for decreasing values in the same order. The composition of ARA showed significant gene−dietary interactions in multiple regression analysis, and the positive correlation between fish and shellfish intake and ARA composition in human milk was significant only in the CC genotype. Moreover, the factor most strongly associated with EPA and DHA composition in human milk was fish and shellfish intake. Therefore, it was suggested that increasing fish and shellfish intake in mothers may increase EPA and DHA composition in human milk, while increasing fish and shellfish intake in CC genotype mothers may lead to increased ARA composition in human milk.

Total Fatty Acid and Polar Lipid Species Composition of Human Milk

Human milk lipids are essential for infant health. However, little is known about the relationship between total milk fatty acid (FA) composition and polar lipid species composition. Therefore, we aimed to characterize the relationship between the FA and polar lipid species composition in human milk, with a focus on differences between milk with higher or lower milk fat content. From the Norwegian Human Milk Study (HUMIS, 2002–2009), a subset of 664 milk samples were analyzed for FA and polar lipid composition. Milk samples did not differ in major FA, phosphatidylcholine, or sphingomyelin species percentages between the highest and lowest quartiles of total FA concentration. However, milk in the highest FA quartile had a lower phospholipid-to-total-FA ratio and a lower sphingomyelin-to-phosphatidylcholine ratio than the lowest quartile. The only FAs associated with total phosphatidylcholine or sphingomyelin were behenic and tridecanoic acids, respectively. Milk FA and phosphatidylcholine and sphingomyelin species containing these FAs showed modest correlations. Associations of arachidonic and docosahexaenoic acids with percentages of phosphatidylcholine species carrying these FAs support the conclusion that the availability of these FAs limits the synthesis of phospholipid species containing them.

Depletion of essential fatty acids in muscle is associated with shorter survival of cancer patients undergoing surgery-preliminary report

Emerging studies are reporting associations between skeletal muscle abnormalities and survival in cancer patients. Cancer prognosis is associated with depletion of essential fatty acids in erythrocytes and plasma in humans. However the relationship between skeletal muscle membrane fatty acid composition and survival is unknown. This study investigates the relationship between fatty acid content of phospholipids in skeletal muscle and survival in cancer patients. Rectus abdominis biopsies were collected during cancer surgery from 35 patients diagnosed with cancer. Thin-layer and gas chromatography were used for quantification of phospholipid fatty acids. Cutpoints for survival were defined using optimal stratification. Median survival was between 450 and 500 days when patients had arachidonic acid (AA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in muscle phospholipid below the cut-point compared to 720-800 days for patients above. Cox regression analysis revealed that low amounts of AA, EPA and DHA are risk factors for death. The risk of death remained significant for AA [HR 3.5 (1.11-10.87), p = 0.03], EPA [HR 3.92 (1.1-14.0), p = 0.04] and DHA [HR 4.08 (1.1-14.6), p = 0.03] when adjusted for sex. Lower amounts of essential fatty acids in skeletal muscle membrane is a predictor of survival in cancer patients. These results warrant investigation to restore bioactive fatty acids in people with cancer.

Thromboelastography with platelet mapping: Limited predictive ability in detecting preinjury antiplatelet agent use

BACKGROUND

Preinjury antiplatelet agent (APA) use in trauma patients can increase traumatic hemorrhage and worsen outcomes. Thromboelastography with platelet mapping (TEGPM) has characterized platelet function via arachidonic acid (AA) and adenosine diphosphate (ADP) inhibition in nontrauma settings, but limited data exist in the acute trauma population.

METHODS

A prospective observational study of adult trauma patients with suspected preinjury APA use who received TEGPM testing from 2017 to 2020 was performed. Patients on anticoagulants were excluded. Patients were grouped according to preinjury APA regimen: 81 mg or 325 mg of aspirin daily, 81 mg of aspirin and 75 mg of clopidrogrel daily, 75 mg of clopidrogrel daily, or no antiplatelet. Ability of TEGPM to detect APA use was assessed using predictive statistics and area under receiver operating characteristic curves (AUROCs).

RESULTS

A total of 824 patients were included with most patients taking 81 mg of aspirin (n = 558). Patients on no antiplatelet were younger and had higher baseline platelet counts, while patients on 75 mg of clopidrogrel were more likely to be admitted after ground level fall. All other baseline characteristics were balanced. Admission TEG values were similar between groups. Median AA inhibition was higher in patients on aspirin containing regimens (p < 0.0001). Median ADP inhibition was higher in patients on clopidogrel containing regimens and those taking 325 mg of aspirin (p < 0.0001). Arachidonic acid inhibition accurately detected preinjury APA use and aspirin use (AUROC, 0.89 and 0.84, respectively); however, ADP inhibition performed poorly (AUROC, 0.58). Neither AA nor ADP inhibition was able to discern specific APA regimens or rule out APA use entirely.

CONCLUSION

High AA inhibition accurately detects preinjury APA use in trauma patients. High ADP inhibition after trauma is common, limiting its utility to accurately identify preinjury APA use. Further study is needed to identify assays that can reliably detect and further characterize preinjury APA use in trauma populations.

LEVEL OF EVIDENCE

Diagnostic test, level II.

Polyunsaturated Phospholipids Increase Cell Resilience to Mechanical Constraints

If polyunsaturated fatty acids (PUFAs) are generally accepted to be good for health, the mechanisms of their bona fide benefits still remain elusive. Membrane phospholipids (PLs) of the cardiovascular system and skeletal muscles are particularly enriched in PUFAs. The fatty acid composition of PLs is known to regulate crucial membrane properties, including elasticity and plasticity. Since muscle cells undergo repeated cycles of elongation and relaxation, we postulated in the present study that PUFA-containing PLs could be central players for muscle cell adaptation to mechanical constraints. By a combination of in cellulo and in silico approaches, we show that PUFAs, and particularly the ω-3 docosahexaenoic acid (DHA), regulate important properties of the plasma membrane that improve muscle cell resilience to mechanical constraints. Thanks to their unique property to contortionate within the bilayer plane, they facilitate the formation of vacuole-like dilation (VLD), which, in turn, avoid cell breakage under mechanical constraints.

Association of plasma polyunsaturated fatty acids with arterial blood pressure: A Mendelian randomization study

High polyunsaturated fatty acids (PUFAs) intake is recommended for primary and secondary prevention of cardiovascular disease (CVD). However, the association of PUFAs with blood pressure (BP) is still controversial. In the present study, two-sample Mendelian randomization (MR) analysis was performed to investigate the causal relationship of PUFAs with BP, including systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP).Genetic instruments and summary statistics for two-sample MR analysis were obtained from 3 large-scale genome-wide association studies (GWASs). Eight single nucleotide polymorphisms (SNPs) significantly (P < 5 × 10-8) related to 6 PUFAs were used as instrumental variables. Conventional inverse-variance weighted method was adopted to evaluate the causality of PUFAs with BP; the Weighted Median, MR-egger, and Leave-one-out method were used for sensitivity analyses.As a result, there was no evidence of a causal association between all PUFAs and SBP. In addition, arachidonic acid (AA, β = -0.04, P < .001) and eicosapentaenoic acid (EPA, β = -0.47, P = .02) were negatively associated with DBP, while linoleic acid (LA, β = 0.03, P = .005) and α-linolenic acid (ALA, β = 3.83, P < .001) were positively associated with DBP. There was no evidence of a causal relationship between either docosapentaenoic acid (DPA) or docosahexaenoic acid (DHA) with DBP.In conclusion, a genetic predisposition to plasma polyunsaturated fatty acid (PUFA) had a divergent effect on DBP, independent of SBP. It suggested that it is helpful for lower DBP level to supplemental intake of AA and EPA or promote the conversion of LA and ALA to AA and EPA respectively, which need to be further validated with randomized controlled studies.

Minimizing marine ingredients in diets of farmed Atlantic salmon (Salmo salar): effects on liver and head kidney lipid class and fatty acid composition

Limited fish meal and fish oil supplies have necessitated research on alternatives for aquafeeds. Seven dietary treatments with different protein and lipid sources were formulated for farmed Atlantic salmon, and their effects on liver and head kidney lipid class, fatty acid, and elemental composition were studied. Fish meal, fish oil, and EPA + DHA content ranged from 5-35%, 0-12%, and 0.1-3%, respectively. Elemental analysis showed that the C to N ratio was higher in the head kidney than in the liver, which is consistent with higher content of total lipids in the head kidney compared with the liver. There was a greater susceptibility to dietary lipid alterations in the liver compared with the head kidney despite liver having a greater proportion of phospholipid and a much lower proportion of triacylglycerol. So long as fish oil levels were 5% or more of the diet, arachidonic acid (ARA) and docosahexaenoic acid (DHA) proportions were the same for each tissue as with feeding the marine diet with 12% fish oil; however, livers and head kidneys from fish fed the lowest amount of fish meal and fish oil had the lowest levels of eicosapentaenoic (EPA) and DHA and the highest ARA levels. Removal of fish oil and reduction of fish meal to 5% in diets of farmed Atlantic salmon affected elemental and lipid compositions of the liver and head kidney tissues potentially increasing susceptibility to inflammation. However, with 10% of the diet comprising fish meal and fish oil, lipid contents were comparable with fish fed marine-based diets.

Genetic variants in FADS1 and ELOVL2 increase level of arachidonic acid and the risk of Alzheimer's disease in the Tunisian population

Polyunsaturated fatty acids (PUFAs) are closely related to various physiological conditions. In several age-related diseases including Alzheimer's disease (AD) altered PUFAs metabolism has been reported. However, the mechanism behind PUFAs impairment and AD developpement remains unclear. In humans, PUFAs biosynthesis requires delta-5 desaturase (D5D), delta-6 desaturase (D6D) and elongase 2 activities; which are encoded by fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2), and elongation of very-long-chain fatty acids-like 2 (ELOVL2) genes, respectively. In the present work, we aim to assess whether genetic variants in FADS1, FADS2 and ELOVL2 genes influence plasma and erythrocyte PUFA composition and AD risk. A case-control study was carried out in 113 AD patients and 161 healthy controls.Rs174556, rs174617, and rs3756963 of FADS1, FADS2, and ELOVL2 genes, respectively were genotyped using PCR-RFLP. PUFA levels were quantified using Gas Chromatography. Genotype distributions of rs174556 (FADS1) and rs3756963 (ELOVL2) were different between case and control groups. The genotype TT of rs174556 and rs3756963 single nucleotide polymorphism (SNP) increases significantly the risk of AD in our population. PUFA analysis showed higher plasma and erythrocyte arachidonic acid (AA) level in patients with AD, whereas only plasma docosahexaenoic acid (DHA) was significantly decreased in AD patients. The indexes AA/Dihomo-gamma-linolenic acid (DGLA) and C24:4n-6/Adrenic acid (AdA) were both higher in the AD group. Interestingly, patients with TT genotype of rs174556 presented higher AA level and AA/DGLA index in both plasma and erythrocyte. In addition, higher AA and AA/DGLA index were observed in erythrocyte of TT genotype ofrs3756963 carrier's patients. Along with, positive correlation between AA/DGLA index, age or Gamma-linolenic acid (GLA)/ Linoleic acid (LA) index was seen in erythrocyte and /or plasma of AD patients. After adjustment for confounding factors, the genotype TT of rs174556, erythrocyte AA and AA/DGLA index were found to be predictive risk factors for AD while plasma DHA was found associated with lower AD risk. Both rs174556 and rs3756963 influence AD risk in the Tunisian population and they are likely associated with high AA level. The combination of the two variants increases further the susceptibility to AD. We suggest that FADS1 and ELOVL2 variants could likely regulate the efficiency of AA biosynthesis which could be at the origin of inflammatory derivate.

Metabolic Fingerprinting Links Oncogenic PIK3CA with Enhanced Arachidonic Acid-Derived Eicosanoids

Oncogenic transformation is associated with profound changes in cellular metabolism, but whether tracking these can improve disease stratification or influence therapy decision-making is largely unknown. Using the iKnife to sample the aerosol of cauterized specimens, we demonstrate a new mode of real-time diagnosis, coupling metabolic phenotype to mutant PIK3CA genotype. Oncogenic PIK3CA results in an increase in arachidonic acid and a concomitant overproduction of eicosanoids, acting to promote cell proliferation beyond a cell-autonomous manner. Mechanistically, mutant PIK3CA drives a multimodal signaling network involving mTORC2-PKCζ-mediated activation of the calcium-dependent phospholipase A2 (cPLA2). Notably, inhibiting cPLA2 synergizes with fatty acid-free diet to restore immunogenicity and selectively reduce mutant PIK3CA-induced tumorigenicity. Besides highlighting the potential for metabolic phenotyping in stratified medicine, this study reveals an important role for activated PI3K signaling in regulating arachidonic acid metabolism, uncovering a targetable metabolic vulnerability that largely depends on dietary fat restriction. VIDEO ABSTRACT.

Human milk fatty acid profile across lactational stages after term and preterm delivery: A pooled data analysis

BACKGROUND

Lipids in human milk (HM) provide the majority of energy for developing infants, as well as crucial essential fatty acids (FA). The FA composition of HM is highly variable and influenced by multiple factors. We sought to increase understanding of the variation in HMFA profiles and their development over the course of lactation, and after term and preterm delivery, using a pooled data analysis.

OBJECTIVE

To review the literature and perform a pooled data analysis to qualitatively describe an extensive FA profile (36 FAs) in term and preterm colostrum, transitional - and mature milk up to 60 days postpartum.

DESIGN

A Medline search was conducted for HMFA profile data following term or preterm delivery. The search was confined to English language papers published between January 1980 and August 2018. Studies reporting original data, extensive FA profiles in HM from healthy mothers were included. Weighted least squares (WLS) means were calculated from the pooled data using random or fixed effect models.

RESULTS

Our pooled data analysis included data from 55 studies worldwide, for a total of 4374 term milk samples and 1017 preterm milk samples, providing WLS means for 36 FAs. Patterns in both term and preterm milk were apparent throughout lactation for some FAs: The most abundant FAs (palmitic, linoleic and oleic acid) remained stable over time, whereas several long-chain polyunsaturated FAs (including ARA and DHA) seemed to decrease and short- and medium-chain FAs increased over time.

CONCLUSIONS

High heterogeneity between individual studies was observed for the reported levels of some FAs, whereas other FAs were remarkably consistent between studies. Our pooled data suggests that specific FA categories fluctuate according to distinct patterns over the course of lactation; many of these patterns are comparable between term and preterm milk.

Lipid mass spectrometry: A path traveled for 50 years

In the middle of the 1960s, I began graduate school and at the same time started on the path of using mass spectrometry to gain insight into various aspects of lipid biochemistry. This was not a straight path but one that went from organic geochemistry, to lunar sample analysis, to a pursuit of the structure of an elusive and very active, lipid mediator slow reacting substance of anaphylaxis (SRS-A). The discovery of the structure of SRS-A opened important questions about phospholipid biochemistry and the arachidonate cycle in cells. I have written this reflection to highlight the various advances in mass spectrometry that occurred during this time that had a great impact on our ability to study lipid biochemistry. I specifically applied these new advances to studies of leukotriene biosynthesis in vivo, leukotriene metabolism, and arachidonate-containing phospholipids that are essential in providing arachidonic acid for the 5-lipoxygenase pathway. Along the way, imaging mass spectrometry was shown to be a powerful tool to probe lipids as they exist in tissue slices. We found this as just one of the ways to use the emerging technology of lipidomics to study human pathophysiology. Our studies of neutral lipids and oxidized phospholipids were especially challenging due to the total number of molecular species that could be found in cells. Many challenges remain in using mass spectrometry for lipid studies, and a few are presented.

Higher Accumulation of Docosahexaenoic Acid in the Vermilion of the Human Lip than in the Skin

The vermilion of the human lip is a unique facial area because of certain distinguishing features from the adjacent tissues such as the white lip (skin) and oral mucosa. However, the distinction in terms of molecular distribution between the vermilion and skin has remained unexplored. Therefore, we aimed to map the human lip by mass spectrometry imaging to gain understanding of the free fatty acid distribution in the vermilion. The lip specimens trimmed off during cheiloplasty were analyzed using desorption electrospray ionization-mass spectrometry imaging. Distributions of two monounsaturated fatty acids and three polyunsaturated fatty acids were observed in the human lip tissue: palmitoleic acid (POA) and oleic acid (OA) and linoleic acid (LA), arachidonic acid (AA), and docosahexaenoic acid (DHA), respectively. Although POA, OA, LA, and AA were differentially distributed across the vermilion and skin, DHA showed a higher accumulation in the epithelium of the vermilion compared to that in the skin. Our results clearly demonstrated the difference in fatty acid distributions between the vermilion and skin. The highly abundant DHA in the epithelium of the vermilion may have an antioxidant role and may thus protect the lip from aging. Our findings can provide a novel strategy for treating lip disorders.

Fatty-Acid Uptake in Prostate Cancer Cells Using Dynamic Microfluidic Raman Technology

It is known that intake of dietary fatty acid (FA) is strongly correlated with prostate cancer progression but is highly dependent on the type of FAs. High levels of palmitic acid (PA) or arachidonic acid (AA) can stimulate the progression of cancer. In this study, a unique experimental set-up consisting of a Raman microscope, coupled with a commercial shear-flow microfluidic system is used to monitor fatty acid uptake by prostate cancer (PC-3) cells in real-time at the single cell level. Uptake of deuterated PA, deuterated AA, and the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were monitored using this new system, while complementary flow cytometry experiments using Nile red staining, were also conducted for the validation of the cellular lipid uptake. Using this novel experimental system, we show that DHA and EPA have inhibitory effects on the uptake of PA and AA by PC-3 cells.

Altered brain levels of arachidonic acid-derived inflammatory eicosanoids in a rodent model of anorexia nervosa

Increasing evidence underline the role of inflammation in the behavioral, emotional and cognitive dysregulations displayed in anorexia nervosa (AN). Among the inflammatory mediators acting at both peripheral and central levels, growing attention receives a class of lipids derived from arachidonic acid (AA), called eicosanoids (eiCs), which exert a complex, multifaceted role in a wide range of neuroinflammatory processes, peripheral inflammation, and generally in immune system function. To date, little is known about their possible involvement in the neurobiological underpinnings of AN. The present study evaluated whether the activity-based model of AN (ABA) may alter AA-metabolic pathways by changing the levels of AA-derived eiCs in specific brain areas implicated in the development of the typical anorexic-like phenotype, i.e. in prefrontal cortex, cerebral cortex, nucleus accumbens, caudate putamen, amygdala, hippocampus, hypothalamus and cerebellum. Our results point to brain region-specific alterations of the cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 epoxygenase (CYP) metabolic pathways rendering altered levels of AA-derived eiCs (i.e. prostaglandins, thromboxanes and hydroxyeicosatetraenoic acids) in response to induction of and recovery from the ABA condition. These changes, supported by altered messenger RNA (mRNA) levels of genes coding for enzymes involved in eiCs-related methabolic pathways (i.e., PLA₂, COX-2, 5-LOX and 15-LOX), underlie a widespread brain dysregulation of pro- and anti-inflammatory eiC-mediated processes in the ABA model of AN. These data suggest the importance of eiCs signaling within corticolimbic areas in regulating key neurobehavioral functions and highlight eiCs as biomarker candidates for monitoring the onset and development of AN, and/or as possible targets for pharmacological management.

Early nutrition in combination with polymorphisms in fatty acid desaturase gene cluster modulate fatty acid composition of cheek cells' glycerophospholipids in school-age children

Variants in the human genes of fatty acid (FA) desaturase 1 (FADS1), 2 (FADS2) and 3 (FADS3) are associated with PUFA blood levels. We explored if maternal prenatal supplementation and children's genetic variation in seventeen SNP of the FADS1, FADS2 and FADS3 gene cluster influence twenty-one of the most relevant cheek cells' derived FA in glycerophospholipids (GPL-FA). The study was conducted in 147 Spanish and German mother-children pairs participating in the Nutraceuticals for a Healthier Life (NUHEAL) study at 8, 9 and 9·5 years. Linear and mixed model longitudinal regression analyses were performed. Maternal fish-oil (FO) or FO+5-methyltetrahydrofolate (5-MTHF) supplementation during pregnancy was associated with a significant decrease of arachidonic acid (AA) concentrations in cheek cell GPL in the offspring, from 8 to 9·5 years; furthermore, maternal FO+5-MTHF supplementation was associated with higher n-6 docosapentaenoic acid concentrations in their children at age 8 years. FADS1 rs174556 polymorphism and different FADS2 genotypes were associated with higher concentrations of linoleic and α-linolenic acids in children; moreover, some FADS2 genotypes determined lower AA concentrations in children's cheek cells. It is suggested an interaction between type of prenatal supplementation and the offspring genetic background driving GPL-FA levels at school age. Prenatal FO supplementation, and/or with 5-MTHF, seems to stimulate n-3 and n-6 FA desaturation in the offspring, increasing long-chain PUFA concentrations at school age, but depending on children's FADS1 and FADS2 genotypes. These findings suggest potential early nutrition programming of FA metabolic pathways, but interacting with children's FADS polymorphisms.

Human Milk Composition and Dietary Intakes of Breastfeeding Women of Different Ethnicity from the Manawatu-Wanganui Region of New Zealand

Human milk is nutrient rich, complex in its composition, and is key to a baby’s health through its role in nutrition, gastrointestinal tract and immune development. Seventy-eight mothers (19–42 years of age) of Asian, Māori, Pacific Island, or of European ethnicity living in Manawatu-Wanganui, New Zealand (NZ) completed the study. The women provided three breast milk samples over a one-week period (6–8 weeks postpartum), completed a three-day food diary and provided information regarding their pregnancy and lactation experiences. The breast milk samples were analyzed for protein, fat, fatty acid profile, ash, selected minerals (calcium, magnesium, selenium, zinc), and carbohydrates. Breast milk nutrient profiles showed no significant differences between the mothers of different ethnicities in their macronutrient (protein, fat, carbohydrate, and moisture) content. The breast milk of Asian mothers contained significantly higher levels of polyunsaturated fatty acids (PUFAs), omega-3 (n-3) and omega-6 (n-6) fatty acids, docosahexaenoic acid (DHA), and linoleic acids. Arachidonic acid was significantly lower in the breast milk of Māori and Pacific Island women. Dietary intakes of protein, total energy, saturated and polyunsaturated fat, calcium, phosphorus, zinc, iodine, vitamin A equivalents, and folate differed between the ethnic groups, as well as the number of serves of dairy foods, chicken, and legumes. No strong correlations between dietary nutrients and breast milk components were found.

Fish oil supplemental dose needed to reach 1g% DHA+EPA in mature milk

INTRODUCTION

Erythrocyte (RBC) DHA+EPA is considered optimal at 8g%. Mothers with lifetime high fish intakes exhibiting this status produce milk with about 1g% DHA+EPA. We established DHA+EPA supplemental dosages needed to augment RBC DHA+EPA to 8g% and milk DHA+EPA to 1g%.

MATERIALS AND METHODS

Pregnant women were randomly allocated to DHA+EPA dosages of: 225+90 (n=9), 450+180 (n=9), 675+270 (n=11) and 900+360 (n=7) mg/day. Samples were collected at 20 and 36 gestational weeks and 4 weeks postpartum.

RESULTS

Linear regression revealed needed dosages rounded at 750mg/day to reach 8g% RBC DHA+EPA and 1000mg/day for 1g% milk DHA+EPA. RBC DHA+EPA increment depended on baseline values. There was no effect on milk AA, but milk EPA/AA ratio increased.

CONCLUSION

Women with an RBC DHA+EPA status of 5.5g% need 750 and 1000mg DHA+EPA/day to reach 8g% RBC DHA+EPA at the pregnancy end and 1g% mature milk DHA+EPA, respectively.

Comparative effects of high oleic acid vs high mixed saturated fatty acid obesogenic diets upon PUFA metabolism in mice

Emerging evidence indicates that the fatty acid composition of obesogenic diets influences physiologic outcomes. There are scant data regarding how the content of non-essential fatty acids like monounsaturated fatty acids (MUFA) and saturated fatty acids (SFAs) impact the metabolism of polyunsaturated fatty acids (PUFAs). In this work, we tested the hypothesis that obesogenic diets enriched in oleic acid (OA; 18:1n-9) reduce polyunsaturated fatty acid (PUFA) levels vs an obesogenic diet enriched in SFAs. Adult male mice were fed for eight weeks either (1) a control 16% fat energy (en) diet with 5.7% en OA and 4.4% en SFA, (2) a 50% fat en diet with 33% en OA and 9.9% en SFA, or (3) a 50% en diet with a high SFA diet with 33% en SFA and 9.1% en OA. Dietary levels and intake of linoleic acid (LA; 18:2n-6) and α-linolenic acid (ALA; 18:3n-3) were constant between the experimental groups. Several peripheral organs (liver, heart, kidney, and adipose) were analyzed for lipid composition and oxylipin analysis was performed for liver and adipose. Our data demonstrate that a high OA diet reduced tissue content of LA and ALA (≥30%) in phospholipid and neutral lipid fractions, reduced the content of some LA-derived and ALA-derived oxylipins in liver and adipose, and conversely, elevated hepatic content of PGF_2α. In all tissues examined, except for adipose, levels of arachidonic acid (ARA; 20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3) were either elevated or unaffected by the obesogenic diets. Our data indicate that the non-essential fatty content of obesogenic diets impacts PUFA content in peripheral tissues and influences the levels of bioactive oxylipins.

Dietary Intakes of Arachidonic Acid and Docosahexaenoic Acid in Early Life - With a Special Focus on Complementary Feeding in Developing Countries

BACKGROUND

In developing countries, dietary intakes of arachidonic acid (ARA) and docosahexaenoic acid (DHA) in early life are lower than current recommended levels. This review specifically focusses on the contribution that complementary feeding makes to ARA and DHA intakes in medium- to low-income countries. The aims of the review are (1) to determine the availability of ARA and DHA food sources in developing countries, (2) to estimate the contribution of complementary feeding to dietary intakes of ARA and DHA in infants aged 6-36 months, and (3) to relate the dietary ARA and DHA intake data to key socioeconomic and health indicators.

SUMMARY

The primary dietary data was collected by the Food and Agriculture Organisation (FAO) using Food Balance Sheets, and fatty acid composition was based on the Australian food composition tables. There is evidence of wide variation in per capita dietary intake for both DHA and ARA food sources, with low intakes of meat and seafood products being highly prevalent in most low-income countries. In children aged 6-36 months, the supply of ARA and DHA from the longer duration of breastfeeding in low-income countries is counterbalanced by the exceptionally low provision of ARA and DHA from complementary foods. The lowest tertile for ARA intake is associated with higher percentages of childhood stunting, birth rate, infant mortality, and longer duration of breast feeding. Key Message: In developing countries, intakes of DHA and ARA from complementary foods are low, and public health organisations need to adopt pragmatic strategies that will ensure that there is a nutritional safety net for the most vulnerable infants.

Phospholipid Fatty Acid Composition and Diamine Oxidase Activity of Intestinal Mucosa From Rats Treated With Irinotecan Hydrochloride (CPT-11) under Vegetable Oil–Enriched Diets: Comparison Between Perilla Oil and Corn Oil

BACKGROUND

Irinotecan hydrochloride (CPT-11), a topoisomerase I inhibitor highly effective for various cancers, has its dosage limited by diffuse mucosal damage with increased prostaglandin (PG) E(2). However, an analysis of intestinal phospholipid fatty acid composition after CPT-11 treatment has not been reported. This study aimed to evaluate intestinal phospholipid fatty acid composition in relation to intestinal mucosal integrity and plasma and mucosal PGE(2) levels after CPT-11 treatment. The effect of dietary vegetable oil supplementation, perilla oil vs corn oil, was also evaluated.

METHODS

Intestinal phospholipid fatty acid composition, PGE(2) level, mucosal diamine oxidase (DAO) activity, diarrhea, and blood tests were evaluated in rats injected with CPT-11 under a conventional diet. The same parameters were compared among 3 different dietary vegetable oil supplementations: perilla oil, corn oil, and a 1:3, respectively, mixture with a semisynthetic diet during 14 days.

RESULTS

CPT-11 treatment caused severe diarrhea, and intestinal mucosal fatty acid composition changed with increased PGE(2) level and decreased DAO activity. Decreases in eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and EPA/arachidonic acid (AA) ratio in colonic mucosa were observed. Perilla oil increased omega-3 polyunsaturated fatty acids, alpha-linolenic acid, EPA, and EPA/AA ratio and decreased plasma PGE(2). But the amounts used were not enough to attenuate intestinal damage from CPT-11 treatment.

CONCLUSIONS

CPT-11 induced changes of intestinal mucosal fatty acid composition with increased PGE(2) level and decreased intestinal integrity; perilla oil shows the possibility of being able to attenuate those changes.

Fatty acids profile in preterm Colostrum of Tunisian women. Association with selected maternal characteristics

Fatty acids (FA), especially arachidonic (AA, 20:4ω6) and docosahexaenoic (DHA, 22:6ω3) acids are critical for the health and development of infants. Colostrum FA composition has been examined in 101 lactating Tunisian women delivering prematurely using gas chromatography. Among polyunsaturated FA, linoleic acid predominated whereas each of the other polyunsaturated FA accounted for 1% or less of total FA. Colostrum AA and DHA contents were lower in women aged above 34 years compared to those less than 34 years. Preeclampsia was associated with lower DHA (0.40±0.22 vs. 0.53±0.27; p=0.018), but higher AA (1.14±0.44 vs. 0.93±0.30; p<0.006) and AA:DHA ratio (4.31±4.04 vs. 2.29±2.79; p<0.001). In multivariate analysis, colostrum DHA correlated with plasma DHA (β, 0.417; p=0.002), maternal age (β, -0.290; p=0.028) and preeclampsia (β, -0.270; p=0.042). Preterm colostrum FA profile in Tunisian women is comparable to those of other populations. Colostrum AA and DHA levels are altered in aged and pre-eclamptic women.

Astrocyte arachidonate and palmitate uptake and metabolism is differentially modulated by dibutyryl-cAMP treatment

Astrocytes play a vital role in brain lipid metabolism; however the impact of the phenotypic shift in astrocytes to a reactive state on arachidonic acid metabolism is unknown. Therefore, we determined the impact of dibutyryl-cAMP (dBcAMP) treatment on radiolabeled arachidonic acid ([1-(14)C]20:4n-6) and palmitic acid ([1-(14)C]16:0) uptake and metabolism in primary cultured murine cortical astrocytes. In dBcAMP treated astrocytes, total [1-(14)C]20:4n-6 uptake was increased 1.9-fold compared to control, while total [1-(14)C]16:0 uptake was unaffected. Gene expression of long-chain acyl-CoA synthetases (Acsl), acyl-CoA hydrolase (Acot7), fatty acid binding protein(s) (Fabp) and alpha-synuclein (Snca) were determined using qRT-PCR. dBcAMP treatment increased expression of Acsl3 (4.8-fold) and Acsl4 (1.3-fold), which preferentially use [1-(14)C]20:4n-6 and are highly expressed in astrocytes, consistent with the increase in [1-(14)C]20:4n-6 uptake. However, expression of Fabp5 and Fabp7 were significantly reduced by 25% and 45%, respectively. Acot7 (20%) was also reduced, suggesting dBcAMP treatment favors acyl-CoA formation. dBcAMP treatment enhanced [1-(14)C]20:4n-6 (2.2-fold) and [1-(14)C]16:0 (1.6-fold) esterification into total phospholipids, but the greater esterification of [1-(14)C]20:4n-6 is consistent with the observed uptake through increased Acsl, but not Fabp expression. Although total [1-(14)C]16:0 uptake was not affected, there was a dramatic decrease in [1-(14)C]16:0 in the free fatty acid pool as esterification into the phospholipid pool was increased, which is consistent with the increase in Acsl3 and Acsl4 expression. In summary, our data demonstrates that dBcAMP treatment increases [1-(14)C]20:4n-6 uptake in astrocytes and this increase appears to be due to increased expression of Acsl3 and Acsl4 coupled with a reduction in Acot7 expression.

The European Food Safety Authority recommendation for polyunsaturated fatty acid composition of infant formula overrules breast milk, puts infants at risk, and should be revised

The European Food Safety Authority (EFSA) has concluded from a limited review of the literature that although docosahexaenoic acid (DHA) is required for infant formula, arachidonic acid is not required "even in the presence of DHA" (EFSA Journal, 12 (2014) 3760). This flawed opinion is grounded in human trials which tested functionality of DHA in neural outcomes and included arachidonic acid ostensibly to support growth. The EFSA report mistakes a nutrient ubiquitous in the diets of newborn infants, through breast milk and with wide-ranging health and neurodevelopmental effects, for an optional drug targeted to a particular outcome that is properly excluded when no benefit is found for that particular outcome. Arachidonic acid has very different biological functions compared to DHA, for example, arachidonic acid has unique functions in the vasculature and in specific aspects of immunity. Indeed, the overwhelming majority of trials include both DHA and arachidonic acid, and test development specific to DHA such as neural and visual development. DHA suppresses membrane arachidonic acid concentrations and its function. An infant formula with DHA and no arachidonic acid runs the risk of cardio and cerebrovascular morbidity and even mortality through suppression of the favorable oxylipin derivatives of arachidonic acid. The EFSA recommendation overruling breast milk composition should be revised forthwith, otherwise being unsafe, ungrounded in most of the evidence, and risking lifelong disability.

Lipid Fraction and Intracellular Metabolite Analysis Reveal the Mechanism of Arachidonic Acid-Rich Oil Accumulation in the Aging Process of Mortierella alpina

The mechanism of arachidonic acid (ARA) content increase during aging of Mortierella alpina was elucidated. Lipid fraction analysis showed that ARA content increased from 46.9% to 66.4% in the triacylglycerol (TAG) molecule, and ARA residue occupation increased in the majority of TAG molecules during the aging process. For the first time, intracellular metabolite analysis was conducted to reveal the pathways closely associated with ARA biosynthesis during aging. The main reason for the increased ARA content was not only at the expense of other fatty acids degradation but also at the expense of further ARA biosynthesis during aging. Furthermore, translocation played a vital role in ARA redistribution among the glycerol moiety, and mycelium did not die immediately with key pathways activated to maintain a relatively stable intracellular environment. This study lays a foundation for further improvement of ARA content in the oil product obtained from M. alpina.

Increased PUFA Content and 5-Lipoxygenase Pathway Expression Are Associated with Subcutaneous Adipose Tissue Inflammation in Obese Women with Type 2 Diabetes

Obese women with type 2 diabetes mellitus (T2DM) have more inflammation in their subcutaneous white adipose tissue (sWAT) than age-and-BMI similar obese women with normal glucose tolerance (NGT). We aimed to investigate whether WAT fatty acids and/or oxylipins are associated with the enhanced inflammatory state in WAT of the T2DM women. Fatty acid profiles were measured in both subcutaneous and visceral adipose tissue (vWAT) of 19 obese women with NGT and 16 age-and-BMI similar women with T2DM. Oxylipin levels were measured in sWAT of all women. Arachidonic acid (AA) and docosahexaenoic acid (DHA) percentages were higher in sWAT, but not vWAT of the T2DM women, and AA correlated positively to the gene expression of macrophage marker CD68. We found tendencies for higher oxylipin concentrations of the 5-LOX leukotrienes in sWAT of T2DM women. Gene expression of the 5-LOX leukotriene biosynthesis pathway was significantly higher in sWAT of T2DM women. In conclusion, AA and DHA content were higher in sWAT of T2DM women and AA correlated to the increased inflammatory state in sWAT. Increased AA content was accompanied by an upregulation of the 5-LOX pathway and seems to have led to an increase in the conversion of AA into proinflammatory leukotrienes in sWAT.

The Edible Marine Alga Gracilariopsis chorda Alleviates Hypoxia/Reoxygenation-Induced Oxidative Stress in Cultured Hippocampal Neurons

Age-related neurological disorders are of growing concern among the elderly, and natural products with neuroprotective properties have been attracting increasing attention as candidates for the prevention or treatment of neurological disorders induced by oxidative stress. In an effort to explore natural resources, we collected some common marine seaweed from the Korean peninsula and Indonesia and screened them for neuroprotective activity against hypoxia/reoxygenation (H/R)-induced oxidative stress. Of the 23 seaweeds examined, the ethanol extract of Gracilariopsis chorda (GCE) provided maximum neuroprotection at an optimum concentration of 15 μg/mL, followed by Undaria pinnatifida. GCE increased cell viability after H/R, decreased the formation of reactive oxygen species (measured by 2',7'-dichlorodihydrofluorescein diacetate [DCF-DA] staining), and inhibited the double-stranded DNA breaks (measured by H2AX immunocytochemistry), apoptosis (measured by Annexin V/propidium iodide staining), internucleosomal DNA fragmentation (measured by DNA laddering), and dissipation of mitochondrial membrane potential (measured by JC-1 staining). Using reverse-phase high-pressure liquid chromatography, we quantitated the arachidonic acid (AA) in GCE, which provides neuroprotection against H/R-induced oxidative stress. This neuroprotective effect of AA was comparable to that of GCE. These findings suggest that the neuroprotective effect of GCE against H/R-induced neuronal death is due, at least in part, to the AA content that suppresses neuronal apoptosis.

[ANALYSIS OF ARACHIDONIC ACID RELATIVE CONTENT CHANGES IN ERYTHROCYTES AND PLATELETS PHOSPHOLIPIDS MEMBRANES FEATURES IN CORONARY HEART DISEASE WITH ATRIAL FIBRILLATION PATIENTS]

Erythrocytes and platelets phospholipid membranes fatty acid spectrum was detected in coronary heart disease and atrial fibrillation patients and in patients with coronary heart disease without atrial fibrillation. 87 patients were investigated. Significant decrease in the arachidonic acid relative content in coronary heart disease patients compared with healthy individuals was related. As well as a significant decrease in the arachidonic acid relative content in coronary heart disease and atrial fibrillation patients compared with coronary heart disease patients without atrial fibrillation was related too. These dates may indicate that decreasing relative content arachidonic acid can be possible pathogenetic link in the development of arrhythmias.

Arachidonic acid production by Mortierella alpina using raw crop materials

BACKGROUND

Arachidonic acid (ARA) is one of the three essential fatty acids, and it is important for human body to keep healthy and is widely used. At present, expensive materials such as glucose and yeast extract are generally reported to be optimal for ARA production. A new cost-effective fermentation process including cheaper material for ARA production is of great significance.

METHODS

Feasibility of using corn meal and powdered soybean for fungal growth and lipid accumulation was evaluated by means of single factor test. N-hexadecane concentration was optimized, and the effect of temperature on biomass and ARA content was examined.

RESULTS

Mortierella alpina made better use of the aforementioned material as carbon and nitrogen sources for both hyphae growth and ARA production compared with glucose and yeast extract. Maximal levels of 10.9 g/L ARA and 26.1 g/L total lipids were obtained when 66 g/L corn meal, 54 g/L soybean meal and 6% (v/v) n-hexadecane were supplemented. A temperature-shift strategy involved three steps, namely, 30°C (3 days) - 25°C (4 days) - 20°C (4 days), which further improved ARA production by 24.7%.

CONCLUSIONS

Several factors such as carbon and nitrogen sources, temperature and dissolved oxygen had great influence on biomass and microbial oil production. Mortierella alpina preferred corn and soybean meal compared with glucose and yeast extract, which would surely alleviate the high cost of ARA production. Based on this study, the new process is both low cost and practicable.

Arachidonic and linoleic acid derivatives impact oocyte ICSI fertilization--a prospective analysis of follicular fluid and a matched oocyte in a 'one follicle--one retrieved oocyte--one resulting embryo' investigational setting

Objective

To evaluate human oocyte ability to undergo fertilization and subsequent preimplantation embryonic development in relation to a wide panel of follicular fluid (FF) arachidonic acid derivatives (AAD) and linoleic acid derivatives (LAD) of prospectively selected patients undergoing intracytoplasmic sperm injection (ICSI).

Methodology

Study was designed as a two center (a university clinic and a private clinic) prospective study. 54 women of 181 consecutive couples undergoing ICSI were prospectively found to be eligible for analysis. 'One follicle – one retrieved oocyte – one resulting embryo' approach was used. Each individual follicle was aspirated independently and matched to an oocyte growing in this particular follicular milieu. FF samples were assessed for AAD and LAD by high-performance liquid chromatography; additionally, activity of secretory phospholipase A (sPLA₂) was determined by enzyme-linked immunosorbent assay.

Principal Findings

Increased activity of sPLA₂ and significantly higher AAD and LAD levels were found in FF of oocytes that did not show two pronuclei or underwent degeneration after ICSI in comparison to oocytes with the appearance of two pronuclei. Receiver operating characteristics curve analysis identified acids with the highest sensitivity and specificity: 5oxo-hydroxyeicosatetraenoic, 16-hydroxyeicosatetraenoic, 9-hydroxyoctadecadieneoic and 12-hydroxyeicosatetraenoic. No significant differences between AAD and LAD related to embryo quality were found.

Conclusions/Significance

Our study demonstrates for the first time that elevated concentrations of AAD and LAD in FF at the time of oocyte retrieval significantly decrease the ability of oocytes to form pronuclei after ICSI. This may serve as a new tool for non-invasive assessment of oocyte developmental capacity. However, levels of AAD and LAD are not associated with subsequent embryo quality or pregnancy rate, and therefore more studies are needed to determine their usefulness in human IVF procedure.

Unexpected similarity in RBC DHA and AA levels between bottlenose dolphins and humans

BACKGROUND

The Omega-3 Index [red blood cell (RBC) content of eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA)] is inversely related to risk of cardiovascular disease in humans. In the U.S., the average Omega-3 Index is about 4-6% of RBC fatty acids, whereas in Japan it is 9-10%. The range of physiologically-possible levels for the Omega-3 Index in other mammals is unknown.

OBJECTIVE

To compare the RBC fatty acid composition of a common piscivorous mammal, the bottlenose dolphin (Tursiops truncatus), with that of (U.S.) humans, and to examine the extent to which dietary fatty acid patterns were reflected in RBCs.

METHODS

RBCs were isolated from routine blood samples collected from 35 healthy dolphins at two display facilities and were analyzed by gas chromatography. For humans, historic, deidentified RBC fatty acid data from our laboratory were used (n=11,329; mean age 58).

RESULTS

The mean Omega-3 Index of the dolphins was 19.9% compared with 6.0% for humans. EPA levels were 15.3% vs 1.2%, respectively, but DHA levels were virtually identical (4.6% vs 4.8%). Linoleic acid (LNA) levels were much lower in dolphins vs humans (0.5% vs 12.5%) whereas arachidonic acid (ARA) levels were similar (12.3% vs 14.5%). In a subgroup of humans with an Omega-3 Index in the >99.2 percentile, the mean index was similar to that of the dolphins. Based on an analysis of their food, the dolphins consumed about 60g of EPA+DHA per day as compared to about 0.1g in humans.

CONCLUSION

Dolphins have an Omega-3 Index that is (only) 3-4× higher than that of U.S. adults despite their intake of EPA+DHA being about 165× higher (as a percent of kcal). RBC, EPA and LNA levels are relatively more reflective of dietary intakes than are DHA and ARA levels. The mechanisms by which certain fatty acid levels appear to be fixed and others may vary in RBC membranes are unknown.

Laser-written nanoporous silicon diffraction gratings for biosensors

Surface-relief diffraction gratings and planar diffraction gratings directly written on nanoporous silicon layers using 514 nm continuous-wave lasers at very low power (less than 20 mW) were demonstrated. Diffraction-based biosensing application to detect arachidonic acid was experimentally demonstrated at incident light wavelength of 632.8 nm. A comparison in sensing applications was made between the two types of gratings to show the distinct advantage of the planar grating with selective functionalization. Laser-written planar gratings enable directly immobilizing biomolecules in the laser oxidized area of nanoporous silicon, resulting in a new patterned functionalization technique for biosensing applications. The functionalization technique can not only simplify the functionalization procedure in biosensing but also it has potential to increase the sensitivity of sensors by accurately defining grating patterns using the laser direct writing technique.

Enzymatic synthesis of extra virgin olive oil based infant formula fat analogues containing ARA and DHA: one-stage and two-stage syntheses

Structured lipids (SLs) with high palmitic acid content at the sn-2 position enriched with arachidonic acid (ARA) and docosahexaenoic acid (DHA) were produced using extra virgin olive oil, tripalmitin, ARA and DHA single cell oil free fatty acids. Four types of SLs were synthesized using immobilized lipases, Novozym 435 and Lipozyme TL IM, based on one-stage (one-pot) and two-stage (sequential) syntheses. The SLs were characterized for fatty acid profile, triacylglycerol (TAG) molecular species, melting and crystallization profiles, tocopherols, and phenolic compounds. All the SLs had >50 mol % palmitic acid at the sn-2 position. The predominant TAGs in all SLs were PPO and OPO. The total tocopherol content of SL1-1, SL1-2, SL2-1, and SL2-2 were 70.46, 68.79, 79.64, and 79.31 μg/g, respectively. SL1-2 had the highest melting completion (42.0 °C) and crystallization onset (27.6 °C) temperatures. All the SLs produced in this study may be suitable as infant formula fat analogues.

Oxidized fatty acid analysis by charge-switch derivatization, selected reaction monitoring, and accurate mass quantitation

A highly sensitive, specific, and robust method for the analysis of oxidized metabolites of linoleic acid (LA), arachidonic acid (AA), and docosahexaenoic acid (DHA) was developed using charge-switch derivatization, liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) with selected reaction monitoring (SRM) and quantitation by high mass accuracy analysis of product ions, thereby minimizing interferences from contaminating ions. Charge-switch derivatization of LA, AA, and DHA metabolites with N-(4-aminomethylphenyl)-pyridinium resulted in a 10- to 30-fold increase in ionization efficiency. Improved quantitation was accompanied by decreased false positive interferences through accurate mass measurements of diagnostic product ions during SRM transitions by ratiometric comparisons with stable isotope internal standards. The limits of quantitation were between 0.05 and 6.0pg, with a dynamic range of 3 to 4 orders of magnitude (correlation coefficient r(2)>0.99). This approach was used to quantitate the levels of representative fatty acid metabolites from wild-type (WT) and iPLA2γ(-/-) mouse liver identifying the role of iPLA2γ in hepatic lipid second messenger production. Collectively, these results demonstrate the utility of high mass accuracy product ion analysis in conjunction with charge-switch derivatization for the highly specific quantitation of diminutive amounts of LA, AA, and DHA metabolites in biologic systems.

Exhaled breath condensate: a promising source for biomarkers of lung disease

Exhaled breath condensate (EBC) has been increasingly studied as a noninvasive research method for sampling the alveolar and airway space and is recognized as a promising source of biomarkers of lung diseases. Substances measured in EBC include oxidative stress and inflammatory mediators, such as arachidonic acid derivatives, reactive oxygen/nitrogen species, reduced and oxidized glutathione, and inflammatory cytokines. Although EBC has great potential as a source of biomarkers in many lung diseases, the low concentrations of compounds within the EBC present challenges in sample collection and analysis. Although EBC is viewed as a noninvasive method for sampling airway lining fluid (ALF), validation is necessary to confirm that EBC truly represents the ALF. Likewise, a dilution factor for the EBC is needed in order to compare across subjects and determine changes in the ALF. The aims of this paper are to address the characteristics of EBC; strategies to standardize EBC sample collection and review available analytical techniques for EBC analysis.

Influence of Dietary Conjugated Linoleic Acid and Fat Source on Body Fat and Apoptosis in Mice*

OBJECTIVE

To determine whether altered dietary essential fatty acid (linoleic and arachidonic acid) concentrations alter sensitivity to conjugated linoleic acid (CLA)-induced body fat loss or DNA fragmentation.

RESEARCH METHODS AND PROCEDURES

Mice were fed diets containing soy oil (control), coconut oil [essential fatty acid deficient (EFAD)], or fish oil (FO) for 42 days, and then diets were supplemented with a mixture of CLA isomers (0.5% of the diet) for 14 days. Body fat index, fat pad and liver weights, DNA fragmentation in adipose tissue, and fatty acid profiles of adipose tissue were determined.

RESULTS

The EFAD diet decreased (p < 0.05) linoleic and arachidonic acid in mouse adipose tissue but did not affect body fat. Dietary CLA caused a reduction (p < 0.05) in body fat. Mice fed the EFAD diet and then supplemented with CLA exhibited a greater reduction (p < 0.001) in body fat (20.21% vs. 6.94% in EFAD and EFAD + CLA-fed mice, respectively) compared with mice fed soy oil. Dietary FO decreased linoleic acid and increased arachidonic acid in mouse adipose tissue. Mice fed FO or CLA were leaner (p < 0.05) than control mice. FO + CLA-fed mice did not differ in body fat compared with FO-fed mice. Adipose tissue apoptosis was increased (p < 0.001) in CLA-supplemented mice and was not affected by fat source.

DISCUSSION

Reductions in linoleic acid concentration made mice more sensitive to CLA-induced body fat loss only when arachidonic acid concentrations were also reduced. Dietary essential fatty acids did not affect CLA-induced DNA fragmentation.

Fatty acid compositions of preterm and term colostrum, transitional and mature milks in a sub-Saharan population with high fish intakes

BACKGROUND

There are no data on the fatty acid (FA) compositions of preterm and term milks for sub-Saharan African populations with advancing lactation. However, it is generally acknowledged that our ancestors evolved in sub-Saharan East-Africa, where they inhabited the land-water ecosystems.

METHODS

We compared the FA-compositions of preterm (28-36 weeks) and term (37-42) colostrum (2-5 day), transitional (6-15) and mature (16-56) milks in rural African women with stable dietary habits and lifelong high freshwater fish intakes.

RESULTS

From colostrum to mature milk: the median docosahexaenoic acid (DHA) content decreased from 1.11 to 0.75; and arachidonic acid (AA) from 0.93 to 0.69 g% in preterm milk. In term milk, DHA decreased from 0.81 to 0.53 and AA from 1.08 to 0.55 g%. Medium-chain saturated-FA (MCSAFA) increased from 16.9 to 33.7, and 7.92-29.0 g%, while mono-unsaturated FA (MUFA) decreased from 32.5 to 22.6, and 40.0-26.5 g%, in preterm and term milk, respectively. Consistent with the literature, preterm colostrum contained higher DHA and MCSAFA, and lower MUFA compared to term colostrum. These differences vanished rapidly with advancing lactation. MUFA and MCSAFA were inversely related.

CONCLUSIONS

The presently found DHA in preterm colostrum and mature milks and AA in premature mature milk proved the highest reported in the literature so far, as derived from analysis with capillary GC-columns. We confirmed the much higher MCSAFA and lower MUFA contents in milk of rural African, compared to Westernized women. The milk FA composition of this traditional population might show us the FA composition on which our species evolved and consequently to which our genome has become adapted to optimally support (infant) health.

Supplementation of DHA-rich microalgal oil or fish oil during the suckling period in mildly n-3 fatty acid-deficient rat pups

Long-chain polyunsaturated fatty acids (LC-PUFA), particularly arachidonic acid (ARA) and docosahexaenoic acid (DHA), are considered critical for the development of infants and are commonly supplemented in infant formulae. In this study, two common sources of n-3 LC-PUFA, fish oil (FO) and DHA-rich microalgal oil (DMO), were fed to rat pups of mildly n-3 PUFA-deficient dams to compare changes in LC-PUFA of tissue phospholipids. The milk from dams fed a n-3 PUFA-deficient diet contained less n-3 LC-PUFA than that of dams fed a control diet (AIN-93G). The pups' were given orally 1 mg/g weight of either FO or DMO for 17 days between the ages of 5 and 21 days, the pups were weaned, and sacrificed 1 week later for analysis of fatty acid compositions of brain, heart, kidney, spleen, and thymus phospholipids. Although both FO and DMO brought about a recovery in the tissue DHA levels compared to those of the control group (pups from AIN-93G-fed dams), DMO was more effective at restoring tissue LC-PUFA status because it was richer in DHA than FO. FO had a slightly lower PUFA level than that required to bring the LC-PUFA status completely to normal levels in this experiment, and EPA did not accumulate in tissues under the conditions tested here. These results demonstrate the effectiveness of ingesting either FO or DMO in the pre-weaning period for improving mild n-3 PUFA deficiency.

Characterization of free radicals formed from COX-catalyzed DGLA peroxidation

Like arachidonic acid (AA), dihomo-γ-linolenic acid (DGLA) is a 20-carbon ω-6 polyunsaturated fatty acid and a substrate of cyclooxygenase (COX). Through free radical reactions, COX metabolizes DGLA and AA to form well-known bioactive metabolites, namely, the 1 and 2 series of prostaglandins (PGs1 and PGs2), respectively. Unlike PGs2, which are viewed as proinflammatory, PGs1 possess anti-inflammatory and anticancer activities. However, the mechanisms linking the PGs to their bioactivities are still unclear, and radicals generated in COX-DGLA have not been detected. To better understand PG biology and determine whether different reactions occur in COX-DGLA and COX-AA, we have used LC/ESR/MS with a spin trap, α-(4-pyridyl-1-oxide)-N-tert-butyl nitrone (POBN), to characterize the carbon-centered radicals formed from COX-DGLA in vitro, including cellular peroxidation. A total of five types of DGLA-derived radicals were characterized as POBN adducts: m/z 266, m/z 296, and m/z 550 (same as or similar to COX-AA) and m/z 324 and m/z 354 (exclusively from COX-DGLA). Our results suggest that C-15 oxygenation to form PGGs occurs in both COX-DGLA and COX-AA; however, C-8 oxygenation occurs exclusively in COX-DGLA. This new finding will be further investigated for its association with various bioactivities of PGs, with potential implications for inflammatory diseases.

Ultra-pressure liquid chromatography/tandem mass spectrometry targeted profiling of arachidonic acid and eicosanoids in human colorectal cancer

Cumulative evidence shows that eicosanoids such as prostaglandins, leukotrienes, thromboxanes and hydroxy eicosatetraenoic acids play an important role in associating inflammation with human colorectal cancer (CRC). In this study an ultra-pressure liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method was developed and validated for the targeted profiling of eight relevant eicosanoids and the major metabolic precursor, arachidonic acid (AA), in human colon. Multiple reaction monitoring (MRM) experiments were performed in negative electrospray ionization mode. The metabolites were separated using a C(18) column consisting of 1.7 µm ethylene-bridged hybrid particles (100 × 2.1 mm i.d.) and gradient elution (50 to 95% of solvent B) with a mobile phase comprising water (0.1% formic acid) [solvent A] and acetonitrile (0.1% formic acid) [solvent B] at a flow rate of 0.4 mL/min. The analysis time for each sample was 5.5 min. Our UPLC/MS/MS method demonstrated satisfactory validation results in terms of selectivity, sensitivity, matrix effect, linearity, extraction efficiency, intra- and inter-day precision, accuracy and autosampler stability. The method was applied for the clinical profiling of matched pairs of cancerous and normal colon mucosae obtained from eight colorectal cancer patients. Endogenous levels of AA and selected eicosanoids such as prostaglandin E(2) (PGE(2)), prostacyclin (PGI(2)) [assayed as its stable hydrolytic product 6-keto-prostaglandin(1α) (6-k PGF(1α))] and 12-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12-HETE) were found to be significantly different (p <0.05; paired t-test) between cancerous and normal mucosae.

DHA improves cognition and prevents dysfunction of entorhinal cortex neurons in 3xTg-AD mice

Defects in neuronal activity of the entorhinal cortex (EC) are suspected to underlie the symptoms of Alzheimer's disease (AD). Whereas neuroprotective effects of docosahexaenoic acid (DHA) have been described, the effects of DHA on the physiology of EC neurons remain unexplored in animal models of AD. Here, we show that DHA consumption improved object recognition (↑12%), preventing deficits observed in old 3xTg-AD mice (↓12%). Moreover, 3xTg-AD mice displayed seizure-like akinetic episodes, not detected in NonTg littermates and partly prevented by DHA (↓50%). Patch-clamp recording revealed that 3xTg-AD EC neurons displayed (i) loss of cell capacitance (CC), suggesting reduced membrane surface area; (ii) increase of firing rate versus injected current (F-I) curve associated with modified action potentials, and (iii) overactivation of glutamatergic synapses, without changes in synaptophysin levels. DHA consumption increased CC (↑12%) and decreased F-I slopes (↓21%), thereby preventing the opposite alterations observed in 3xTg-AD mice. Our results indicate that cognitive performance and basic physiology of EC neurons depend on DHA intake in a mouse model of AD.

Observation of an unusual electronically distorted semiquinone radical of PCB metabolites in the active site of prostaglandin H synthase-2

The activation of the metabolites of airborne polychlorinated biphenyls (PCBs) into highly reactive radicals is of fundamental importance. We found that human recombinant prostaglandin H synthase-2 (hPGHS-2) biotransforms dihydroxy-PCBs, such as 4-chlorobiphenyl-2',5'-hydroquinone (4-CB-2',5'-H(2)Q), into semiquinone radicals via one-electron oxidation. Using electron paramagnetic resonance (EPR) spectroscopy, we observed the formation of the symmetric quartet spectrum (1:3:3:1 by area) of 4-chlorobiphenyl-2',5'-semiquinone radical (4-CB-2',5'-SQ()(-)) from 4-CB-2',5'-H(2)Q. This spectrum changed to an asymmetric spectrum with time: the change can be explained as the overlap of two different semiquinone radical species. Hindered rotation of the 4-CB-2',5'-SQ()(-) appears not to be a major factor for the change in lineshape because increasing the viscosity of the medium with glycerol produced no significant change in lineshape. Introduction of a fluorine, which increases the steric hindrance for rotation of the dihydroxy-PCB studied, also produced no significant changes. An in silico molecular docking model of 4-CB-2',5'-H(2)Q in the peroxidase site of hPGHS-2 together with ab initio quantum mechanical studies indicate that the close proximity of a negatively charged carboxylic acid in the peroxidase active site may be responsible for the observed perturbation in the spectrum. This study provides new insights into the formation of semiquinones from PCB metabolites and underscores the potential role of PGHS-2 in the metabolic activation of PCBs.

Comparative fatty acid profiles of wild and farmed tropical freshwater fish rohu (Labeo rohita)

The proximate composition of the whole body and the fatty acid composition of the liver, muscle, eye and brain of wild and cultured rohu (Labeo rohita) were analyzed. The cultured species was found to have significantly (P < 0.05) higher lipid contents than its wild counterpart. The saturated (SFA) and monounsaturated (MUFA) fatty acid contents were significantly higher in the cultured species, whereas the n-6 and n-3 polyunsaturated fatty acid (PUFA) levels were higher in the wild species. Fatty acids C16:0 and C18:1 n-9 were the principal fatty acids of the SFAs and MUFAs, respectively, identified in the analyses. Docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid were the predominant PUFAs in both groups, and all three were found to be present at significantly (P < 0.05) higher levels in the wild species. Erucic acid (C22:1 n-9), which was the predominant fatty acid (30.76%) in the feed, was detected only at low levels in muscle (0.30%), liver (1.04%) and eye (1.28%) of cultured fish tissue.

Near-infrared spectroscopy and partial least-squares regression for determination of arachidonic acid in powdered oil

Near-infrared (NIR) spectroscopy was evaluated as a rapid method of predicting arachidonic acid content in powdered oil without the need for oil extraction. NIR spectra of powdered oil samples were obtained with an NIR spectrometer and correlated with arachidonic acid content determined by a modification of the AOCS Method. Partial Least-Squares regression was applied to calculate models for the prediction of arachidonic acid. The model developed with the raw spectra had the best performance in cross-validation (n = 72) and validation (n = 21) with a correlation coefficient of 0.965, and the root mean square error of cross-validation and prediction were both 0.50. The results show that NIR, a well-established and widely applied technique, can be applied to determine the arachidonic acid content in powdered oil.

Individual variation and intraclass correlation in arachidonic acid and eicosapentaenoic acid in chicken muscle

Chicken meat with reduced concentration of arachidonic acid (AA) and reduced ratio between omega-6 and omega-3 fatty acids has potential health benefits because a reduction in AA intake dampens prostanoid signaling, and the proportion between omega-6 and omega-3 fatty acids is too high in our diet. Analyses for fatty acid determination are expensive, and finding the optimal number of analyses to give reliable results is a challenge. The objective of the present study was i) to analyse the intraclass correlation of different fatty acids in five meat samples, of one gram each, within the same chicken thigh, and ii) to study individual variations in the concentrations of a range of fatty acids and the ratio between omega-6 and omega-3 fatty acid concentrations among fifteen chickens. Fifteen newly hatched broilers were fed a wheat-based diet containing 4% rapeseed oil and 1% linseed oil for three weeks. Five muscle samples from the mid location of the thigh of each chicken were analysed for fatty acid composition. The intraclass correlation (sample correlation within the same animal) was 0.85-0.98 for the ratios of total omega-6 to total omega-3 fatty acids and of AA to eicosapentaenoic acid (EPA). This indicates that when studying these fatty acid ratios, one sample of one gram per animal is sufficient. However, due to the high individual variation between chicken for these ratios, a relatively high number of animals (minimum 15) are required to obtain a sufficiently high power to reveal significant effects of experimental factors (e.g. feeding regimes). The present experiment resulted in meat with a favorable concentration ratio between omega-6 and omega-3 fatty acids. The AA concentration varied from 1.5 to 2.8 g/100 g total fatty acids in thigh muscle in the fifteen broilers, and the ratio between AA and EPA concentrations ranged from 2.3 to 3.9. These differences among the birds may be due to genetic variance that can be exploited by breeding for lower AA concentration and/or a more favorable AA/EPA ratio to produce meat with health benefits.

[The effect of toxic components in tobacco smoke on the fatty acid profile of dental pulp]

The aim of the present study was to characterize fatty acid profile of dental pulp in non-smokers' and tobacco-smokers' with acute serous pulpitis. The fatty acid composition in the pulp of molars, pre-molars and chisel tooth in 80 tobacco-smokers and 60 non-smokers were analyzed by Gas-Chromatography with glass capillary colums. Linolic acid was revealed in both - tobacco-smokers and non-smokers; the concentration of linolic acid in tooth pulp of non-smokers was significantly higher. Non-smokers' tooth pulp contained linolic, linolenic and arachidonic acids; tobacco-smokers' - only linolic acid. The linolenic and arachidonic acids in pulp of tobacco-smokers were not discovered.

Simultaneous determination of 2-arachidonoylglycerol, 1-arachidonoylglycerol and arachidonic acid in mouse brain tissue using liquid chromatography/tandem mass spectrometry

Endocannabinoids (ECs), such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG), modulate a number of physiological processes, including pain, appetite and emotional state. Levels of ECs are tightly controlled by enzymatic biosynthesis and degradation in vivo. However, there is limited knowledge about the enzymes that terminate signaling of the major brain EC, 2-AG. Identification and quantification of 2-AG, 1-AG and arachidonic acid (AA) is important for studying the enzymatic hydrolysis of 2-AG. We have developed a sensitive and specific quantification method for simultaneous determination of 2-AG, 1-AG and AA from mouse brain and adipose tissues by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using a simple brain sample preparation method. The separations were carried out based on reversed phase chromatography. Optimization of electrospray ionization conditions established the limits of detection (S/N = 3) at 50, 25 and 65 fmol for 2-AG, 1-AG and AA, respectively. The methods were selective, precise (%R.S.D. < 10%) and sensitive over a range of 0.02-20, 0.01-10 and 0.05-50 ng/mg tissue for 2-AG, 1-AG and AA, respectively. The quantification method was validated with consideration of the matrix effects and the mass spectrometry (MS) responses of the analytes and the deuterium labeled internal standard (IS). The developed methods were applied to study the hydrolysis of 2-AG from mouse brain extracts containing membrane bound monoacylglycerol lipase (MAGL), and to measure the basal levels of 2-AG, 1-AG and AA in mouse brain and adipose tissues.

[Changes in lipid composition of human plasma and erythrocyte membranes due to sodium hydroxybutyrate and normobaric hyperoxia during bed rest]

Gas chromatography was employed to study effects of sodium hydroxybutyrate (GHBA) and normobaric hyperoxia on the fatty-acid composition of total lipids of blood plasma and erythrocyte membranes in 5 normal male volunteers in the baseline data collection period and during 14-d bed rest. Both in plasma and erythrocyte membranes saturated palmitic acid was found increased and polyunsaturated linoleic acid and arachidonic acid reduced.