Essential lipid autacoids rewire mitochondrial energy efficiency in metabolic dysfunction-associated fatty liver disease.

BACKGROUND AND AIM: Injury to hepatocyte mitochondria is common in metabolic dysfunction-associated fatty liver disease. Here, we investigated whether changes in the content of essential fatty acid-derived lipid autacoids affect hepatocyte mitochondrial bioenergetics and metabolic efficiency. APPROACH AND RESULTS: The study was performed in transgenic mice for the fat-1 gene, which allows the endogenous replacement of the membrane omega-6-polyunsaturated fatty acid (PUFA) composition by omega-3-PUFA. Transmission electron microscopy revealed that hepatocyte mitochondria of fat-1 mice had more abundant intact cristae and higher mitochondrial aspect ratio. Fat-1 mice had increased expression of oxidative phosphorylation complexes I and II and translocases of both inner (translocase of inner mitochondrial membrane 44) and outer (translocase of the outer membrane 20) mitochondrial membranes. Fat-1 mice also showed increased mitofusin-2 and reduced dynamin-like protein 1 phosphorylation, which mediate mitochondrial fusion and fission, respectively. Mitochondria of fat-1 mice exhibited enhanced oxygen consumption rate, fatty acid ß-oxidation, and energy substrate utilization as determined by high-resolution respirometry, [1- 14 C]-oleate oxidation and nicotinamide adenine dinucleotide hydride/dihydroflavine-adenine dinucleotide production, respectively. Untargeted lipidomics identified a rich hepatic omega-3-PUFA composition and a specific docosahexaenoic acid (DHA)-enriched lipid fingerprint in fat-1 mice. Targeted lipidomics uncovered a higher content of DHA-derived lipid autacoids, namely resolvin D1 and maresin 1, which rescued hepatocytes from TNFα-induced mitochondrial dysfunction, and unblocked the tricarboxylic acid cycle flux and metabolic utilization of long-chain acyl-carnitines, amino acids, and carbohydrates. Importantly, fat-1 mice were protected against mitochondrial injury induced by obesogenic and fibrogenic insults. CONCLUSION: Our data uncover the importance of a lipid membrane composition rich in DHA and its lipid autacoid derivatives to have optimal hepatic mitochondrial and metabolic efficiency.

Variability of Omega-3/6 Fatty Acid Obtained Through Extraction-Transesterification Processes from Phaeodactylum tricornutum.

The effect of direct transesterification methods on the omega-3/6 composition of extracts from Phaeodactylum tricornutum was studied. The aim of this work was to identify an extraction method which allowed to obtain the most suitable profile of fatty acids in terms of its potential benefits to health, particularly if further used in the food industry. Seven methods using acids, alkalis, and heterogeneous-catalysts, (namely methods from 1 to 7, abbreviated as M1-M7) were performed to determine α-linolenic (ALA), linoleic (LA), docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. The composition of fatty acids was in all cases characterized by the major abundance of palmitic (23.95-34.08%), palmitoleic (30.94-35.56%), oleic acids (3.00-7.41%), and EPA (0.5-6.45%). Unsaturated fatty acids extraction yield was higher with a two-step transesterification process (M6, 63.65%). The total fatty acid methyl ester content (FAME) obtained with acid-transesterification (M1) reached about 21% wt, and 60% w/w total lipids. ALA higher relative content (ALA/LA ratio) was obtained when a lipid pre-extraction step was performed prior to acid-catalysis (M4). The transesterification method based on alkali-catalyst (M3, KOH catalyst) led to obtain higher DHA relative contents (DHA/EPA ratio up to 0.11), although its FAME content was 3.75-fold lower than that obtained with acid-transesterification (M1). Overall, this study shows that direct transesterification with alkali-catalyst (M3) improves the determination of PUFA content from the diatom through a more efficient transesterification-based extraction process, and thus allow to assess the value of the biomass more accurately for application in the food industry.

Microalgal Lipid Extracts Have Potential to Modulate the Inflammatory Response: A Critical Review.

Noncommunicable diseases (NCD) and age-associated diseases (AAD) are some of the gravest health concerns worldwide, accounting for up to 70% of total deaths globally. NCD and AAD, such as diabetes, obesity, cardiovascular disease, and cancer, are associated with low-grade chronic inflammation and poor dietary habits. Modulation of the inflammatory status through dietary components is a very appellative approach to fight these diseases and is supported by increasing evidence of natural and dietary components with strong anti-inflammatory activities. The consumption of bioactive lipids has a positive impact on preventing chronic inflammation and consequently NCD and AAD. Thus, new sources of bioactive lipids have been sought out. Microalgae are rich sources of bioactive lipids such as omega-6 and -3 polyunsaturated fatty acids (PUFA) and polar lipids with associated anti-inflammatory activity. PUFAs are enzymatically and non-enzymatically catalyzed to oxylipins and have a significant role in anti and pro-resolving inflammatory responses. Therefore, a large and rapidly growing body of research has been conducted in vivo and in vitro, investigating the potential anti-inflammatory activities of microalgae lipids. This review sought to summarize and critically analyze recent evidence of the anti-inflammatory potential of microalgae lipids and their possible use to prevent or mitigate chronic inflammation.

Omega-3 versus Omega-6 fatty acid availability is controlled by hydrophobic site geometries of phospholipase A2s.

Human phospholipase A2s (PLA2) constitute a superfamily of enzymes that hydrolyze the sn-2 acyl-chain of glycerophospholipids, producing lysophospholipids and free fatty acids. Each PLA2 enzyme type contributes to specific biological functions based on its expression, subcellular localization, and substrate specificity. Among the PLA2 superfamily, the cytosolic cPLA2 enzymes, calcium-independent iPLA2 enzymes, and secreted sPLA2 enzymes are implicated in many diseases, but a central issue is the preference for double-bond positions in polyunsaturated fatty acids (PUFAs) occupying the sn-2 position of membrane phospholipids. We demonstrate that each PLA2 has a unique preference between the specific omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the omega-6 arachidonic acid (AA), which are the precursors of most proinflammatory and anti-inflammatory or resolving eicosanoids and related oxylipins. Surprisingly, we discovered that human cPLA2 selectively prefers AA, whereas iPLA2 prefers EPA, and sPLA2 prefers DHA as substrate. We determined the optimal binding of each phospholipid substrate in the active site of each PLA2 to explain these specificities. To investigate this, we utilized recently developed lipidomics-based LC-MS/MS and GC/MS assays to determine the sn-2 acyl chain specificity in mixtures of phospholipids. We performed µs timescale molecular dynamics (MD) simulations to reveal unique active site properties, especially how the precise hydrophobic cavity accommodation of the sn-2 acyl chain contributes to the stability of substrate binding and the specificity of each PLA2 for AA, EPA, or DHA. This study provides the first comprehensive picture of the unique substrate selectivity of each PLA2 for omega-3 and omega-6 fatty acids.

Effects of menopausal hormone therapy on erythrocyte n-3 and n-6 PUFA concentrations in the Women's Health Initiative randomized trial.

BACKGROUND: The factors other than dietary intake that determine tissue concentrations of EPA and DHA remain obscure. Prior studies suggested that, in women, endogenous estrogen may accelerate synthesis of DHA from ɑ-linolenic acid (ALA), but the effects of exogenous estrogen on RBC n-3 (É·-3) PUFA concentrations are unknown. OBJECTIVE: We tested the hypothesis that menopausal hormone therapy (HT) would increase RBC n-3 PUFA concentrations. METHODS: Postmenopausal women (ages 50-79 y) were assigned to HT or placebo in the Women's Health Initiative (WHI) randomized trial. The present analyses included a subset of 1170 women (ages 65-79 y) who had RBC PUFA concentrations measured at baseline and at 1 y as participants in the WHI Memory Study. HT included conjugated equine estrogens (E) alone for women without a uterus (n = 560) and E plus medroxyprogesterone acetate (P) for those with an intact uterus (n = 610). RBC n-3 and n-6 (É·-6) PUFAs were quantified. RESULTS: Effects of E alone and E+P on PUFA profiles were similar and were thus combined in the analyses. Relative to the changes in the placebo group after 1 y of HT, docosapentaenoic acid (DPA; n-3) concentrations decreased by 10% (95% CI: 7.3%, 12.5%), whereas DHA increased by 11% (95% CI: 7.4%, 13.9%) in the HT group. Like DHA, DPA n-6 increased by 13% from baseline (95% CI: 10.0%, 20.3%), whereas linoleic acid decreased by 2.0% (95% CI: 1.0%, 4.1%; P values at least <0.01 for all). EPA and arachidonic acid concentrations were unchanged. CONCLUSIONS: HT increased RBC concentrations of the terminal n-3 and n-6 PUFAs (DHA and DPA n-6). These findings are consistent with an estrogen-induced increase in DHA and DPA n-6 synthesis, which is consistent with an upregulation of fatty acid elongases and/or desaturases in the PUFA synthetic pathway. The clinical implications of these changes require further study. The Women's Health Initiative Memory Study is registered at clinicaltrials.gov as NCT00685009. Note that the data presented here were not planned as part of the original trial, and therefore are to be considered exploratory.

The Dietary Replacement of Soybean Oil by Canola Oil Does Not Prevent Liver Fatty Acid Accumulation and Liver Inflammation in Mice.

A high-carbohydrate diet (HCD) is a well-established experimental model of accelerated liver fatty acid (FA) deposition and inflammation. In this study, we evaluated whether canola oil can prevent these physiopathological changes. We evaluated hepatic FA accumulation and inflammation in mice fed with a HCD (72.1% carbohydrates) and either canola oil (C group) or soybean oil (S group) as a lipid source for 0, 7, 14, 28, or 56 days. Liver FA compositions were analyzed by gas chromatography. The mRNA expression of acetyl-CoA carboxylase 1 (ACC1) was measured as an indicator of lipogenesis. The mRNA expression of F4/80, tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, and IL-10, as mediators of liver inflammation, were also measured. The C group stored less n-6 polyunsaturated FAs (n-6 PUFAs) and had more intense lipid deposition of monounsaturated FAs (MUFAs), n-3 PUFAs, and total FAs. The C group also showed higher ACC1 expression. Moreover, on day 56, the C group showed higher expressions of the inflammatory genes F4/80, TNF-α, IL-1ß, and IL-6, as well as the anti-inflammatory IL-10. In conclusion, a diet containing canola oil as a lipid source does not prevent the fatty acid accumulation and inflammation induced by a HCD.

A Low ω-6 to ω-3 PUFA Ratio (n-6:n-3 PUFA) Diet to Treat Fatty Liver Disease in Obese Youth.

BACKGROUND: Recent literature suggests that the Western diet's imbalance between high ω-6 (n-6) and low ω-3 (n-3) PUFA intake contributes to fatty liver disease in obese youth. OBJECTIVES: We tested whether 12 wk of a low n-6:n-3 PUFA ratio (4:1) normocaloric diet mitigates fatty liver and whether the patatin-like containing domain phospholipase 3 (PNPLA3) rs738409 variant affects the response. METHODS: In a single-arm unblinded study, obese youth 9-19 y of age with nonalcoholic fatty liver disease were treated with a normocaloric low n-6:n-3 PUFA ratio diet for 12 wk. The primary outcome was change in hepatic fat fraction (HFF%), measured by abdominal MRI. Metabolic parameters included alanine aminotransferase (ALT), lipids, measures of insulin sensitivity, and plasma oxidized linoleic acid metabolites (OXLAMs). Outcomes were also analyzed by PNPLA3 rs738409 genotype. Wilcoxon's signed rank test, the Mann-Whitney U test, and covariance pattern modeling were used. RESULTS: Twenty obese adolescents (median age: 13.3 y; IQR: 10.5-16.4 y) were enrolled and 17 completed the study. After 12 wk of dietary intervention, HFF% decreased by 25.8% (P = 0.009) despite stable weight. We observed a 34.4% reduction in ALT (P = 0.001), 21.9% reduction in triglycerides (P = 0.046), 3.28% reduction in LDL cholesterol (P = 0.071), and a 26.3% improvement in whole body insulin sensitivity (P = 0.032). The OXLAMs 9-hydroxy-octadecandienoic acid (9-HODE) (P = 0.011), 13-HODE (P = 0.007), and 9-oxo-octadecadienoic acid (9-oxoODE) (P = 0.024) decreased after 12 wk. HFF% declined in both the not-at-risk (CC/CG) and at-risk (GG) PNPLA3 rs738409 genotype groups, with significant (P = 0.016) HFF% reduction in the GG group. Changes in 9-HODE (P = 0.023), 9-oxoODE (P = 0.009), and 13-oxoODE (P = 0.003) differed between the 2 genotype groups over time. CONCLUSIONS: These data suggest that, independently of weight loss, a low n-6:n-3 PUFA diet ameliorates the metabolic phenotype of adolescents with fatty liver disease and that response to this diet is modulated by the PNPLA3 rs738409 genotype.This trial was registered at clinicaltrials.gov as NCT01556113.

Interaction between ω6 and ω3 fatty acids of different chain lengths regulates Atlantic salmon hepatic gene expression and muscle fatty acid profiles.

Atlantic salmon smolts (approx. 20-months old) were fed experimental diets with different combinations of omega-6:omega-3 fatty acids (FAs) (high-ω6, high-ω3, or balanced) and eicosapentaenoic acid plus docosahexaenoic acid (EPA + DHA) levels (0.3, 1.0 or 1.4%) for 12 weeks. Muscle FA (% total FA) reflected dietary C18-polyunsaturated FA; however, muscle EPA per cent and content (mg g-1) were not different in salmon fed high-ω3 or balanced diets. Muscle DHA per cent was similar among treatments, while DHA content increased in fish fed 1.4% EPA + DHA, compared with those fed 0.3-1.0% EPA + DHA combined with high-ω6 FA. Muscle 20:3ω6 (DGLA) content was highest in those fed high-ω6 with 0.3% EPA + DHA. Quantitative polymerase chain reaction analyses on liver RNA showed that the monounsaturated FA synthesis-related gene, scdb, was upregulated in fish fed 1.0% EPA + DHA with high-ω6 compared to those fed 0.3% EPA + DHA. In high-ω3-fed salmon, liver elovl2 transcript levels were higher with 0.3% EPA + DHA than with 1.0% EPA + DHA. In high-ω6-fed fish, elovl2 did not vary with EPA + DHA levels, but it was positively correlated with muscle ARA, 22:4ω3 and DGLA. These results suggest dietary 18:3ω3 elongation contributed to maintaining muscle EPA + DHA levels despite a two- to threefold change in dietary proportions, while 18:2ω6 with 0.3% EPA + DHA increased muscle DGLA more than arachidonic acid (ARA). Positive correlations between hepatic elovl2 and fabp10a with muscle ω6:ω3 and EPA + DHA + ARA, respectively, were confirmed by reanalysing data from a previous salmon trial with lower variations in dietary EPA + DHA and ω6:ω3 ratios. This article is part of the theme issue 'The next horizons for lipids as 'trophic biomarkers': evidence and significance of consumer modification of dietary fatty acids'.

Quantitative profiling of eicosanoids derived from n-6 and n-3 polyunsaturated fatty acids by twin derivatization strategy combined with LC-MS/MS in patients with type 2 diabetes mellitus.

Eicosanoids derived from n-6 and n-3 polyunsaturated fatty acids (PUFAs), serving as important signaling molecules, are implicated in many physiological and pathological processes, including Type 2 diabetes mellitus (T2DM). However, the quantification of endogenous eicosanoids is challenged by high structural similarity, low abundance in biological sample and poor electrospray ionization efficiency. In the current study, a sensitive and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to quantify 65 eicosanoids derived from n-6 and n-3 PUFAs in plasma samples using twin derivatization strategy with a pair of reagents, 5-(dimethylamino) naphthalene-1-sulfonyl piperazine (Dns-PP) and (diethylamino) naphthalene-1-sulfonyl piperazine (Dens-PP). Dns-PP-derivatized plasma sample was mixed with the equal volume of Dens-PP-derivatized eicosanoid internal standards for LC-MS/MS analysis in multiple reaction monitoring (MRM) mode. After Dns-PP derivatization, the ionization efficiency and separation performance were substantially improved, resulting in the enhanced sensitivity by 446- to 1009-folds compared to intact eicosanoids. The quantitative accuracy determined by twin derivatization method was found to be comparable with stable isotope labeled internal standards (SIL-IS) method. The newly proposed method was successfully employed to quantify the target eicosanoids in plasma samples from healthy controls and the patients with T2DM. N-6 PUFA-derived eicosanoids, PGF2α, PGD2, PGE2, PGA2, PGB2, 20-HETE and LTC4, significantly increased in plasma sample of T2DM patients. Oppositely, n-3 PUFA-derived eicosanoids, RvE1, 12(S)-HEPE and RvD1, remarkably decreased. Spearman's correlation analysis indicated the strong correlations between these highlighted eicosanoids and clinical parameters of T2DM. Collectively, the sensitive and reliable eicosanoid quantification method may facilitate to elucidate the characteristics of eicosanoid metabolism and understand the role of eicosanoids in the pathogenesis of T2DM and other diseases.

Variation in ω-3 and ω-6 Polyunsaturated Fatty Acids Produced by Different Phytoplankton Taxa at Early and Late Growth Phase.

Phytoplankton synthesizes essential ω-3 and ω-6 polyunsaturated fatty acids (PUFA) for consumers in the aquatic food webs. Only certain phytoplankton taxa can synthesize eicosapentaenoic (EPA; 20:5ω3) and docosahexaenoic acid (DHA; 22:6ω3), whereas all phytoplankton taxa can synthesize shorter-chain ω-3 and ω-6 PUFA. Here, we experimentally studied how the proportion, concentration (per DW and cell-specific), and production (µg FA L-1 day-1) of ω-3 and ω-6 PUFA varied among six different phytoplankton main groups (16 freshwater strains) and between exponential and stationary growth phase. EPA and DHA concentrations, as dry weight, were similar among cryptophytes and diatoms. However, Cryptomonaserosa had two-27 times higher EPA and DHA content per cell than the other tested cryptophytes, diatoms, or golden algae. The growth was fastest with diatoms, green algae, and cyanobacteria, resulting in high production of medium chain ω-3 and ω-6 PUFA. Even though the dinoflagellate Peridiniumcinctum grew slowly, the content of EPA and DHA per cell was high, resulting in a three- and 40-times higher production rate of EPA and DHA than in cryptophytes or diatoms. However, the production of EPA and DHA was 40 and three times higher in cryptophytes and diatoms than in golden algae (chrysophytes and synyrophytes), respectively. Our results show that phytoplankton taxon explains 56%-84% and growth phase explains ~1% of variation in the cell-specific concentration and production of ω-3 and ω-6 PUFA, supporting understanding that certain phytoplankton taxa play major roles in the synthesis of essential fatty acids. Based on the average proportion of PUFA of dry weight during growth, we extrapolated the seasonal availability of PUFA during phytoplankton succession in a clear water lake. This extrapolation demonstrated notable seasonal and interannual variation, the availability of EPA and DHA being prominent in early and late summer, when dinoflagellates or diatoms increased.

Chemo-enzymatic synthesis, characterization, in vitro antioxidant capacity and oxidative stability studies of novel phosphatidylcholines with ω-3/ω-6 PUFAs and phenolic acids.

Novel phosphatidylcholines containing PUFAs and phenolic acids were synthesized from egg phosphatidylcholine (PC), PUFAs (docosahexaenoic, arachidonic and linoleic acids) and phenolic acids (caffeic, ferulic and p-coumaric acids) as substrates. The structures of modified PCs were confirmed by spectral analysis and were evaluated for antioxidant activities. The modified PCs containing caffeic and ferulic acids exhibited excellent antioxidant activities compared with butylated hydroxytoluene (BHT) and α-tocopherol. The synthesized compounds were also evaluated for the oxidative stabilities in liposome and organic solvent. The modified PCs showed more oxidative stable compared with standard PUFA-PCs and PUFA-PCs + BHT. Results showed that the oxidative stability decreased with increasing degree of unsaturation in organic solvent whereas in liposomes, increased with increasing degree of unsaturation due to tight packed configuration. In this study, phenolic acids were found to render protections for PUFAs in modified PCs from oxidation. Modified PCs may have great potential for applications in food, cosmetic and pharmaceutical industries.

Consensus Mutagenesis and Ancestral Reconstruction Provide Insight into the Substrate Specificity and Evolution of the Front-End Δ6-Desaturase Family.

Marine algae are a major source of ω-3 long-chain polyunsaturated fatty acids (ω3-LCPUFAs), which are conditionally essential nutrients in humans and a target for industrial production. The biosynthesis of these molecules in marine algae requires the desaturation of fatty acids by Δ6-desaturases, and enzymes from different species display a range of specificities toward ω3- and ω6-LCPUFA precursors. In the absence of a molecular structure, the structural basis for the variable substrate specificity of Δ6-desaturases is poorly understood. Here we have conducted a consensus mutagenesis and ancestral protein reconstruction-based analysis of the Δ6-desaturase family, focusing on the ω3-specific Δ6-desaturase from Micromonas pusilla (MpΔ6des) and the bispecific (ω3/ω6) Δ6-desaturase from Ostreococcus tauri (OtΔ6des). Our characterization of consensus amino acid substitutions in MpΔ6des revealed that residues in diverse regions of the protein, such as the N-terminal cytochrome b5 domain, can make important contributions to determining substrate specificity. Ancestral protein reconstruction also suggests that some extant Δ6-desaturases, such as OtΔ6des, could have adapted to different environmental conditions by losing specificity for ω3-LCPUFAs. This data set provides a map of regions within Δ6-desaturases that contribute to substrate specificity and could facilitate future attempts to engineer these proteins for use in biotechnology.

Phytochemical composition and nutritional value of different plant parts in two cultivated and wild purslane (Portulaca oleracea L.) genotypes.

Purslane (Portulaca oleracea) is a weed naturally found in driveways, lawns, and fields and edible in many regions of Europe, Asia, the Middle East, Africa, and Australia. The purpose of this study was to compare the nutritional and phytochemical components of cultivated and wild purslane. Omega-3 contents of both purslane genotypes were comparable with 189.16 ± 25.52 mg/100 g dry weight and 188.48 ± 6.35 mg/100 g dry weight in cultivated and wild purslane leaves, respectively. Omega-6/omega-3 ratio (1:1-1:3) were low in both genotypes. However, high levels of oxalic acid were observed. Cultivated contained greater amounts of amino acids and vitamins than wild purslane. Of the 184 compounds identified in both genotypes by LC-MS/MS, including phenolic acids, organic acids, flavonoids, alkaloids, and betanin, more than 80 showed greater than two-fold abundance in the wild compared to cultivated purslane. Purslane has the potential to be cultivated as a food ingredient for nutraceutical applications.

Modification of the content of n-3 highly unsaturated fatty acid, chemical composition, and lipid nutritional indices in the meat of grass carp (Ctenopharyngodon idella) fed alfalfa (Medicago sativa) pellets.

A 120-d feeding trial was conducted to determine the effect of alfalfa (Medicago sativa) feeding on growth and chemical composition, fatty acid content, and nutritional and lipid indices of the meat of grass carp (Ctenopharyngodon idella). Two experimental diets were used: alfalfa pellet (AP) diet and artificial grain diet (GD). Final weight, feed conversion rate, and protein efficiency ratio were significantly greater in the GD group (P < 0.05). However, no differences in the length and condition factor were observed. The composition of the meat differed between treatments. The protein content was significantly greater in the AP group (P < 0.05), while the lipid and cholesterol contents were significantly greater in the GD group (P < 0.05). A greater proportion of saturated, n-6 polyunsaturated, and n-6 highly unsaturated fatty acids was obtained in the GD group. The AP group accumulated a greater concentration of eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosahexaenoic (DHA) acids (P < 0.05). The fatty acid composition of the meat determined a significant decrease in the thrombogenicity index and saturation index (S/P) in the AP group (P < 0.05). The Elongase index was greater in the GD group (P < 0.05). In contrast, the AP group had a greater index of Δ9 Desaturase and Δ5 + Δ6 Desaturase for n-3 and n-6 fatty acids (P < 0.05). These results suggest that alfalfa feeding decreases the growth of C. idella but improves the quality of meat by increasing the protein, EPA, and DHA contents. It also reduces cholesterol content and improves nutritional indices.

Oxidized Products of Omega-6 and Omega-3 Long Chain Fatty Acids Are Associated with Increased White Matter Hyperintensity and Poorer Executive Function Performance in a Cohort of Cognitively Normal Hypertensive Older Adults.

BACKGROUND: Cerebrovascular disease is a common cause of dementia in older adults, and potentially preventable with early intervention. Oxylipins are produced from the oxidation of long-chain polyunsaturated fatty acids (PUFA) possessing potent vascular effects. Oxylipins generated from the cytochrome P450 pathway are enzymatically converted to diols by soluble epoxide hydrolase (sEH); sEH products have been associated with small vessel ischemic disease. Little is known about oxylipins' impact on markers of dementia risk. OBJECTIVE: An exploratory examination of the association between omega-6 and omega-3 derived oxylipins, brain MRI, and cognition. METHODS: Thirty-seven non-demented participants with controlled hypertension (mean age 65.6 years) were enrolled in a dementia prevention study investigating fish oil and lipoic acid on preserving cognitive function. Baseline associations between plasma oxylipins, white matter hyperintensity (WMH), and Trails-B were examined using linear regression. P450-derived diol/epoxide ratio was an indirect measure of sEH activity. RESULTS: Omega-6 derived 9-HODE was associated with increased WMH (p = 0.017) and reduced grey matter volume (p = 0.02). Omega-6 P450-derived diol/epoxide ratio 9,10-DiHOME/9,10-EpOME was associated with increased WMH (p = 0.035) and poorer performance on Trails-B (p = 0.05); ratio14,15-DHET/14,15-EET was associated with increased WMH (p = 0.045). Omega-3 P450-derived diol/epoxide ratio 19,20-DiHDPE/19,20-EpDPE was associated with increased WMH (p = 0.04) and poorer performance on Trails-B (p = 0.04). Arachidonic acid was associated with better performance on Trails-B (p = 0.012); Omega-3 derived 16,17-EpDPE was associated with decreased WMH (p = 0.005). CONCLUSIONS: With the exception of arachidonic acid, it was specific oxylipin products, not their parent PUFAs, that were associated with unfavorable and favorable MRI and cognitive markers of dementia risk.

Essential fatty acids deficient diet modulates N-Acylethanolamide profile in rat's tissues.

No data are available on whether a diet deficient of the essential fatty acids is able to modulate tissue levels of endocannabinoids and congeners. Male rats fed for 12 weeks a diet deficient of essential fatty acids, palmitic and oleic acids (EFAD), replaced with saturated fatty acids (SAFA), showed lowered n-3 and n-6 PUFAs levels in plasma, liver and adipose tissue, with concomitant steep increase of oleic and mead acids, while in hypothalamus no changes in PUFA concentration were detected and only palmitoleic acid was found increased. We found a reduction of anandamide and palmitoylethanolamide in liver and brain, while oleoylethanolamide increased significantly in liver and adipose tissue, associated to a 50 % body weight decrease. Changes in N-acylethanolamide profile may contribute to body weight reduction distinctive of EFA deficiency.

[Oxylipins - biologically active substances of food].

Oxylipins are biologically active molecules that are formed in all aerobic organisms enzymatically or as a result of the action of free radicals and reactive oxygen species. The value of oxylipins for plants is comparable to the value of eicosanoids for animals and humans. In the human organism, the oxylipins' formation occurs through enzymatic or non-enzymatic oxygenation of various ω-6 and ω-3 polyunsaturated fatty acids (PUFAs) obtained from food. Being "local hormones", oxylipins are involved in the regulation of inflammation, pain response, cell adhesion, migration and proliferation, apoptosis, angiogenesis, regulation of blood pressure, blood coagulation, and blood vessel permeability. There is a hypothesis that the molecular structure of oxylipins allows them to be positioned as adaptogens and justifies the use of plants as potential sources of oxylipins in traditional medicine. The aim of this research is a brief analytical review of publications characterizing the adaptogenic potential and promising sources of oxylipins (plant, cyanobacteria, and algae). Results. The publications of the last decade indicate an increased interest in the oxylipins of plants, cyanobacteria, and algae. In total, about 150 oxylipins and their derivatives are known in plants and fungi. Of the plant sources of oxylipins, Peruvian poppy root (Lepidium meyenii), white bryony (Bryonia alba L.), blackcurrant seed oil (Ribes nigrum), and licorice (Glycyrrhiza glabra) are of particular interest. Some macroalgae are capable of non-enzymatically or enzymatically synthesizing a variety of oxylipins, including antiinflammatory prostaglandins, resolvins, an d leukotrienes. In addition, to common oxidized derivatives of fatty acids, macroalgae also contain a number of complex and unique oxylipins. Other sour ces of oxylipin producers include macroscopic gelatin colonies of freshwater cyanobacteria Aphanothece sacrum. As the analysis of the presented in the review publications showed, most anti-inflammatory and pro-resolvent oxylipins have antiproliferative properties, have adaptogenic potential, and can protect the body at the system level, contribu ting to the formation of favorable bacterial clearance. Conclusion. The results of numerous studies indicate that plants, algae, and even bacteria can be a promising source of oxylipins, both for their use in their native form and for the targeted isolation of oxylipins from them in order to conduct further studies of their adaptogenic potential, cardio- and geroprotective properties. In the future , establishing the adequate daily intake of these substances and the development on their basis of dietary preventive and specialized products for various purposes will be relevant.

Onion Peel Extract Increases Erythrocyte Membrane n-3 Fatty Acids in Overweight and Obese Korean Subjects.

The association between obesity and erythrocyte fatty acids (FAs) has been suggested; however, there have been no studies on the effects of onion peel extract (OPE) on the composition of erythrocyte FAs. This study aimed to investigate the effects of OPE on the composition of erythrocyte FAs in overweight and obese subjects. This was a randomized, double-blind, and placebo-controlled trial conducted in overweight and obese Korean subjects. The placebo and OPE groups were taking placebo capsule or OPE capsule twice per day for 12 weeks. Body composition and fat distribution were measured using dual-energy X-ray absorptiometry. The OPE group showed significantly reduced body weight, body mass index, body fat mass, and percentage of body fat mass. After 12 weeks, eicosapentaenoic acid and monounsaturated FAs of the placebo group were significantly lower at baseline. Consumption of OPE ameliorated the decreasing polyunsaturated n-3 polyunsaturated FA (PUFA) n-3 and increasing PUFA n-6, which prevented an increased n-6/n-3 ratio. The changes in arm fat percentage (ARFATP), trunk fat percentage, and total fat percentage (FATP) were negatively correlated with the change in PUFA n-3. In addition, increased erythrocyte docosahexaenoic acid was associated with decreased ARFATP and FATP. These results suggest that OPE has beneficial effects on obesity by regulating erythrocyte n-6/n-3 ratio and preventing fat accumulation in various body regions.

Characterization of Ternary Blends of Vegetable Oils with Optimal ω-6/ω-3 Fatty Acid Ratios.

An optimal ratio of omega-6 to omega-3 (ω-6/ω-3) polyunsaturated fatty acids (PUFA) in the diet prevents the pathogenesis of many inflammatory diseases. This study aimed to synthesize and characterize ternary oil blends with optimal ω-6/ω-3 ratios using olive (OL), sunflower (SU), and cress (CR) oils. The oxidative stability, thermal profile, fatty acid (FA) and tocopherol compositions, and the physicochemical properties of the blends were used to determine their quality. Oil mixtures were prepared with 2, 3, 4, and 5 ω-6/ω-3 ratios. FA composition and tocopherol content were the most important factors affecting the oxidation and thermal stabilities of the oils. All oil mixtures showed good quality indices. Thus, synthetized oil blends with high oxidative stability, high antioxidant content, optimal ω-6/ω-3 ratios, and recommended FA compositions can influence human health. The composition of healthy oil blends with optimal ω-6/ω-3 ratios was expressed mathematically and depicted graphically in a ternary diagram.

The changes in the release level of polyunsaturated fatty acids (ω-3 and ω-6) and lipids in the untreated and water-soaked chia seed.

Despite recent studies on health benefits of chia seed owing to its high content of ω-3 fatty acids, little work has been conducted on extractability of its nutrients. We examined the effect of soaking chia seed in water on the extractability of its omega fatty acids and lipids. State-of-the-art mass spectrometry techniques including GC-MS, LC-MS, and MALDI-MSI were utilized to identify and determine the spatial distribution of omega fatty acids and lipids in chia seed. Results showed that 24 h soaking in water improves the extractability of omega fatty acids and the ω-6:ω-3 ratio. Increase in the release levels of triacylglycerols and diacylglycerols and reduction in the release levels of phosphatidylcholines are envisaged to be the result of cell wall weakening and consequently availability of lipids for extraction. Results of MALDI-MSI show that highly abundant lipid species are mainly localised in the chia seed endosperm rather than its mucilage.