In vivo conversion of linoleic acid to arachidonic acid in human adults

Athletes Can Benefit from Increased Intake of EPA and DHA-Evaluating the Evidence

Fatty fish, which include mackerel, herring, salmon and sardines, and certain species of algae (e.g., Schizochytrium sp., Crytthecodiniumcohnii and Phaeodactylumtricornutum) are the only naturally rich sources of the omega-3 polyunsaturated fatty acids (n-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are the most biologically active members of the n-3 PUFA family. Limited dietary sources and fluctuating content of EPA and DHA in fish raise concerns about the status of EPA and DHA among athletes, as confirmed in a number of studies. The beneficial effects of EPA and DHA include controlling inflammation, supporting nervous system function, maintaining muscle mass after injury and improving training adaptation. Due to their inadequate intake and beneficial health-promoting effects, athletes might wish to consider using supplements that provide EPA and DHA. Here, we provide an overview of the effects of EPA and DHA that are relevant to athletes and discuss the pros and cons of supplements as a source of EPA and DHA for athletes.

Dietary linoleic acid lowering alone does not lower arachidonic acid or endocannabinoids among women with overweight and obesity: A randomized, controlled trial

The linoleic acid (LA)-arachidonic acid (ARA)-inflammatory axis suggests dietary LA lowering benefits health because it lowers ARA and ARA-derived endocannabinoids (ECB). Dietary LA reduction increases concentrations of omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and DHA derived ECB. The aim of this study was to examine targeted reduction of dietary LA, with and without EPA and DHA, on plasma EPA and DHA and ECB (2-arachidonoyl glycerol [2-AG], anandamide [AEA], and docosahexaenoyl ethanolamide [DHA-EA]). Healthy, pre-menopausal women (n = 62, BMI 30 ± 3 kg/m2 , age 35 ± 7 years; mean ± SD) were randomized to three 12-week controlled diets: (1) high LA, low omega-3 EPA and DHA (H6L3); (2) low LA, low omega-3 EPA and DHA (L6L3); or (3) low LA, high omega-3 EPA and DHA (L6H3). Baseline plasma fatty acids and ECB were similar between diets. Starting at 4 weeks, L6L3 and L6H3 lowered plasma LA compared to H6L3 (p < 0.001). While plasma ARA changed from baseline by 8% in L6L3 and -8% in L6H3, there were no group differences. After 4 weeks, plasma EPA and DHA increased from baseline in women on the L6H3 diet (ps < 0.001) and were different than the H6L3 and L6L3 diets. No differences were found between diets for AEA or 2-AG, however, in L6L3 and L6H3, AEA increased by 14% (ps < 0.02). L6H3 resulted in 35% higher DHA-EA (p = 0.013) whereas no changes were seen with the other diets. Lowering dietary LA did not result in the expected changes in fatty acids associated with the LA-ARA inflammatory axis in women with overweight and obesity.

n-6 fatty acid biomarkers and incident atrial fibrillation: an individual participant-level pooled analysis of 11 international prospective studies

BACKGROUND

The presence of atrial fibrillation (AF) is associated with an over 2-fold increased risk of stroke, heart failure, and cardiovascular mortality. Long chain n-6 PUFAs have been suggested to have a variety of beneficial biologic effects that may reduce AF development; however, prior studies evaluating this relationship are limited.

OBJECTIVES

We prospectively evaluated the association between circulating levels of linoleic acid (LA) and arachidonic acid (AA) with incident AF.

METHODS

We used participant-level data from a global consortium of 11 prospective cohort studies with measurements of LA and AA in adults (aged ≥18 y). Participating studies conducted de novo analyses using a prespecified analytical plan with harmonized definitions for exposures, outcomes, covariates, and subgroups. Associations were pooled using inverse-variance weighted meta-analysis.

RESULTS

Among 41,335 participants, 6173 incident cases of AF were ascertained, with median follow-up time of 14 y. In multivariable analysis, per interquintile range (difference between the 10th and 90th percentiles for each fatty acid), circulating n-6 levels were not associated with incident AF. For LA, the hazard ratio per interquintile range was 0.96 (95% confidence interval [CI]: 0.89, 1.04), and for AA, 1.02 (95% CI: 0.94, 1.10), with little evidence of heterogeneity between cohorts. Associations were similarly nonsignificant across subgroups of age, race, and biomarker fraction.

CONCLUSIONS

Biomarkers of n-6 fatty acids including LA and AA are not associated with incident AF. These findings suggest that overall effects of n-6 PUFAs on influencing AF development are neutral.

Arachidonic acid modulates the cellular energetics of human pluripotent stem cells and protects the embryoid bodies from embryotoxicity effects in vitro

Arachidonic acid (AA), an ω-6 polyunsaturated fatty acid involved in signalling pathways that drive cell fate decisions, has an enhancing role in the immunomodulatory effect on mesenchymal stem cells and the vasculogenesis of embryonic stem cells. 3D embryoid bodies (EBs) from pluripotent stem cells (PSCs) have been used as in vitro models for embryotoxicity for various compounds/drugs. Valproic acid (VA), a common anti-epileptic drug, is known to be embryotoxic and cause malformations in embryos. As early embryogenesis depends on AA, we investigated the embryo protective effects of AA against the embryotoxic drug VA in this study. The effects of AA on the proliferation and cell cycle parameters of PSCs were studied. In particular, the potential of AA to abrogate VA-induced embryotoxicity in vitro was evaluated using ROS detection and antioxidant assays. In response to AA, we observed modulation in cell proliferation of induced pluripotent stem cells (iPSCs) and pluripotent NTERA-2 embryonal carcinoma (EC) cells. The present study substantiates the cytoprotective effects of AA against VA. These results imply that AA plays a critical role in the proliferation and differentiation of iPSCs and EC cells and protects the EBs from cytotoxic damage, thereby ensuring normal embryogenesis. Thus, the bioactive lipid AA may be explored for supplementation to benefit pregnant women treated with long-term anti-epileptic drugs to prevent in-utero fetal growth malformations.

The impact of subchronic ozone exposure on serum metabolome and the mechanisms of abnormal bile acid and arachidonic acid metabolisms in the liver

Ambient ozone (O₃) pollution can induce respiratory and cardiovascular toxicity. However, its impact on the metabolome and the underlying mechanisms remain unclear. This study first investigated the serum metabolite changes in rats exposed to 0.5 ppm O₃ for 3 months using untargeted metabolomic approach. Results showed chronic ozone exposure significantly altered the serum levels of 34 metabolites with potential increased risk of digestive, respiratory and cardiovascular disease. Moreover, bile acid synthesis and secretion, and arachidonic acid (AA) metabolism became the most prominent affected metabolic pathways after O₃ exposure. Further studies on the mechanisms found that the elevated serum toxic bile acid was not due to the increased biosynthesis in the liver, but the reduced reuptake from the portal vein to hepatocytes owing to repressed Ntcp and Oatp1a1, and the decreased bile acid efflux in hepatocytes as a results of inhibited Bsep, Ostalpha and Ostbeta. Meanwhile, decreased expressions of detoxification enzyme of SULT2A1 and the important regulators of FXR, PXR and HNF4α also contributed to the abnormal bile acids. In addition, O₃ promoted the conversion of AA into thromboxane A2 (TXA2) and 20-hydroxyarachidonic acid (20-HETE) in the liver by up-regulation of Fads2, Cyp4a and Tbxas1 which resulting in decreased AA and linoleic acid (LA), and increased thromboxane B2 (TXB2) and 20-HETE in the serum. Furthermore, apparent hepatic chronic inflammation, fibrosis and abnormal function were found in ozone-exposed rats. These results indicated chronic ozone exposure could alter serum metabolites by interfering their metabolism in the liver, and inducing liver injury to aggravate metabolic disorders.

Geographic variations and determinants of EPA plus DHA and EPA alone in pregnant and lactating women from China

EPA and DHA are essential for maternal and fetal health, but epidemiological data are sparse in China. We examined the trends of EPA alone and a combination of EPA plus DHA in pregnant and lactating women in three distinct geographic regions in China and explored their potential influencing factors. A total of 1015 healthy women during mid-pregnancy, late pregnancy or lactation were recruited from Weihai (coastland), Yueyang (lakeland) and Baotou (inland) cities of China between May and July of 2014. Maternal EPA and DHA concentrations (percentage of total fatty acids) in plasma and erythrocytes were measured by capillary GC. Adjusted EPA plus DHA concentrations in both plasma and erythrocytes significantly declined from mid-pregnancy (2·92 %, 6·95 %) to late pregnancy (2·20 %, 6·42 %) and lactation (2·40 %, 6·29 %) (P_trend < 0·001); and both concentrations were highest in coastland, followed by lakeland, and lowest in inland (P < 0·001). Regarding EPA alone, the concentrations were higher in women during lactation or late pregnancy and in women in coastland and inland areas. Moreover, concentrations of EPA or EPA plus DHA were higher in women with older age, higher education, higher annual family income per capita and higher dietary intake of marine aquatic product and mutton. In lactating women, erythrocyte EPA concentration was higher in those having breast-feeding partially v. exclusively. In conclusion, maternal plasma and erythrocyte concentrations of EPA plus DHA or EPA alone differed with geographic regions, physiological periods and maternal characteristics, indicating a need of population-specific health strategies to improve fatty acids status in pregnant and lactating women.

Pentadecanoylcarnitine is a newly discovered endocannabinoid with pleiotropic activities relevant to supporting physical and mental health

As an emerging dietary essential fatty acid, pentadecanoic acid (C15:0) is expected to have bioactive metabolites with broad health benefits. Here, we evaluated pentadecanoylcarnitine, an endogenous C15:0 metabolite, for dose dependent cell-based activities, including measurement of its effects on 148 clinically relevant biomarkers across twelve primary human cell systems mimicking various disease states. Mechanisms of action for pentadecanoylcarnitine were also assessed across 78 cell-based target assays. Pentadecanoylcarnitine had dose-dependent anti-inflammatory activities, including lower IL-1α, ITAC, MCP-1, and IP-10, across five cell systems relevant to treating cardiovascular, immune, neoplastic, pulmonary, and skin diseases. Targeted assays showed pentadecanoylcarnitine as a full-acting cannabinoid 1 and 2 receptor agonist (EC50 3.7 and 3.2 µM, 111% and 106% maximum activity compared to the positive control, respectively). Pentadecanoylcarnitine also had 5-HT1A and 5-HT1B receptor agonist and histamine H1 and H2 receptor antagonist activities. In summary, pentadecanoylcarnitine, a second discovered full-acting endocannabinoid, had broad pleiotropic activities relevant to regulating inflammation, pain, mood, and sleep. This study's findings further the need to evaluate the potential health impacts of C15:0 nutritional deficiencies caused by population-wide avoidance of all dietary saturated fats, including C15:0.

α-linolenic acid interconversion is sufficient as a source of longer chain ω-3 polyunsaturated fatty acids in humans: An opinion

α-linolenic acid (αLNA) conversion into the functionally important ω-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), has been regarded as inadequate for meeting nutritional requirements for these PUFA. This view is based on findings of small αLNA supplementation trials and stable isotope tracer studies that have been interpreted as indicating human capacity for EPA and, in particular, DHA synthesis is limited. The purpose of this review is to re-evaluate this interpretation. Markedly differing study designs, inconsistent findings and lack of trial replication preclude robust consensus regarding the nutritional adequacy of αLNA as a source of EPC and DHA. The conclusion that αLNA conversion in humans is constrained is inaccurate because it presupposes the existence of an unspecified, higher level of metabolic activity. Since capacity for EPA and DHA synthesis is the product of evolution it may be argued that the levels of EPA and DHA it maintains are nutritionally appropriate. Dietary and supra-dietary EPA plus DHA intakes confer health benefits. Paradoxically, such health benefits are also found amongst vegetarians who do not consume EPA and DHA, and for whom αLNA conversion is the primary source of ω-3 PUFA. Since there are no reported adverse effects on health or cognitive development of diets that exclude EPA and DHA, their synthesis from αLNA appears to be nutritionally adequate. This is consistent with the dietary essentiality of αLNA and has implications for developing sustainable nutritional recommendations for ω-3 PUFA.

Intracellular and extracellular untargeted metabolomics reveal the effect of acute uranium exposure in HK-2 cells

Uranium exposure poses a serious threat to the health of occupational populations and the public. Although metabolomics is a promising research approach to study the toxicological mechanisms of uranium exposure, in vitro studies using human cells are scarce. Applying cultured cell metabolomics, we exhaustively analyzed the intracellular and extracellular differential metabolites upon uranium exposure and characterized the possible biological effects of uranium exposure on human kidney cells. Uranium exposure significantly induced disturbance in the amino acid biosynthesis and linoleic acid metabolism of the cells. Cells exposed to uranium produce excessive amounts of arachidonic acid, which has the potential to cause oxidative stress and damage cells. The results provide new evidence for an oxidative stress mechanism of uranium-induced renal cell injury. Cell metabolomics has proven to be a useful diagnostic tool to study the molecular mechanisms of uranium poisoning.

Cytochrome P450 epoxygenase-derived EPA and DHA oxylipins 17,18-epoxyeicosatetraenoic acid and 19,20-epoxydocosapentaenoic acid promote BAT thermogenesis and WAT browning through the GPR120-AMPKα signaling pathway

The mechanisms whereby fish oil rich in EPA and DHA promotes BAT thermogenesis and WAT browning are not fully understood. Thus, this study aimed to investigate the effects of cytochrome P450 (CYP) epoxygenase-derived EPA and DHA oxylipins 17,18-EpETE and 19,20-EpDPE on BAT thermogenesis and WAT browning and explore the underlying mechanism. Stromal vascular cells (SVCs) were subjected to 17,18-EpETE or 19,20-EpDPE treatment and mice were treated with the CYP epoxygenase inhibitor, the thermogenic marker genes were detected and the involvement of GPR120 and AMPKα were assessed. The in vitro results indicated that 17,18-EpETE and 19,20-EpDPE induced brown and beige adipocyte thermogenesis, with increased expression of thermogenic marker gene UCP1 in differentiated SVCs. Meanwhile, the expression of GPR120 and phosphorylation of AMPKα were increased in response to these two oxylipins. However, the inhibition of GPR120 and AMPKα inhibited the promotion of adipocyte thermogenesis. In addition, in the presence of CYP epoxygenase inhibitor MS-PPOH, EPA and DHA had no effect on increasing UCP1 expression in differentiated SVCs. Consistent with the in vitro results, the in vivo findings demonstrated that fish oil had no body fat-lowering effects and no effects on enhancing energy metabolism, iBAT thermogenesis and iWAT browning in mice fed HFD after intraperitoneal injection of CYP epoxygenase inhibitor SKF-525A. Moreover, fish oil had no effect on the elevation of GPR120 expression and activation of AMPKα in iBAT and iWAT in mice fed HFD after intraperitoneal injection of SKF-525A. In summary, our results showed that CYP epoxygenase-derived EPA and DHA oxylipins 17,18-EpETE and 19,20-EpDPE promoted BAT thermogenesis and WAT browning through the GPR120-AMPKα signaling pathway, which might contribute to the thermogenic and anti-obesity effects of fish oil.

Heme-oxygenase and lipid mediators in obesity and associated cardiometabolic diseases: Therapeutic implications

Obesity-mediated metabolic syndrome remains the leading cause of death worldwide. Among many potential targets for pharmacological intervention, a promising strategy involves the heme oxygenase (HO) system, specifically its inducible form, HO-1. This review collects and updates much of the current knowledge relevant to pharmacology and clinical medicine concerning HO-1 in metabolic diseases and its effect on lipid metabolism. HO-1 has pleotropic effects that collectively reduce inflammation, while increasing vasodilation and insulin and leptin sensitivity. Recent reports indicate that HO-1 with its antioxidants via the effect of bilirubin increases formation of biologically active lipid metabolites such as epoxyeicosatrienoic acid (EET), omega-3 and other polyunsaturated fatty acids (PUFAs). Similarly, HO-1and bilirubin are potential therapeutic targets in the treatment of fat-induced liver diseases. HO-1-mediated upregulation of EET is capable not only of reversing endothelial dysfunction and hypertension, but also of reversing cardiac remodeling, a hallmark of the metabolic syndrome. This process involves browning of white fat tissue (i.e. formation of healthy adipocytes) and reduced lipotoxicity, which otherwise will be toxic to the heart. More importantly, this review examines the activity of EET in biological systems and a series of pathways that explain its mechanism of action and discusses how these might be exploited for potential therapeutic use. We also discuss the link between cardiac ectopic fat deposition and cardiac function in humans, which is similar to that described in obese mice and is regulated by HO-1-EET-PGC1α signaling, a potent negative regulator of the inflammatory adipokine NOV.

Endocannabinoid System and Its Regulation by Polyunsaturated Fatty Acids and Full Spectrum Hemp Oils

The endocannabinoid system (ECS) consists of endogenous cannabinoids, their receptors, and metabolic enzymes that play a critical homeostatic role in modulating polyunsaturated omega fatty acid (PUFA) signaling to maintain a balanced inflammatory and redox state. Whole food-based diets and dietary interventions linked to PUFAs of animal (fish, calamari, krill) or plant (hemp, flax, walnut, algae) origin, as well as full-spectrum hemp oils, are increasingly used to support the ECS tone, promote healthy metabolism, improve risk factors associated with cardiovascular disorders, encourage brain health and emotional well-being, and ameliorate inflammation. While hemp cannabinoids of THC and CBD groups show distinct but complementary actions through a variety of cannabinoid (CB1 and CB2), adenosine (A2A), and vanilloid (TRPV1) receptors, they also modulate PUFA metabolism within a wide variety of specialized lipid mediators that promote or resolve inflammation and oxidative stress. Clinical evidence reviewed in this study links PUFAs and cannabinoids to changes in ECS tone, immune function, metabolic and oxidative stress adaptation, and overall maintenance of a well-balanced systemic function of the body. Understanding how the body coordinates signals from the exogenous and endogenous ECS modulators is critical for discerning the underlying molecular mechanisms of the ECS tone in healthy and disease states. Nutritional and lifestyle interventions represent promising approaches to address chronic metabolic and inflammatory disorders that may overlap in the population at risk. Further investigation and validation of dietary interventions that modulate the ECS are required in order to devise clinically successful second-generation management strategies.

Explorative Combined Lipid and Transcriptomic Profiling of Substantia Nigra and Putamen in Parkinson's Disease

Parkinson’s disease (PD) is characterized by the loss of dopaminergic neurons from the substantia nigra (SN) that project to the dorsal striatum (caudate-putamen). To better understand the molecular mechanisms underlying PD, we performed combined lipid profiling and RNA sequencing of SN and putamen samples from PD patients and age-matched controls. SN lipid analysis pointed to a neuroinflammatory component and included elevated levels of the endosomal lipid Bis (Monoacylglycero)Phosphate 42:8, while two of the three depleted putamen lipids were saturated sphingomyelin species. Remarkably, we observed gender-related differences in the SN and putamen lipid profiles. Transcriptome analysis revealed that the top-enriched pathways among the 354 differentially expressed genes (DEGs) in the SN were “protein folding” and “neurotransmitter transport”, and among the 261 DEGs from putamen “synapse organization”. Furthermore, we identified pathways, e.g., “glutamate signaling”, and genes, encoding, e.g., an angiotensin receptor subtype or a proprotein convertase, that have not been previously linked to PD. The identification of 33 genes that were common among the SN and putamen DEGs, which included the α-synuclein paralog β-synuclein, may contribute to the understanding of general PD mechanisms. Thus, our proof-of-concept data highlights new genes, pathways and lipids that have not been explored before in the context of PD.

Tricarboxylic Acid Cycle Activity and Remodeling of Glycerophosphocholine Lipids Support Cytokine Induction in Response to Fungal Patterns

Increased glycolysis parallels immune cell activation, but the role of pyruvate remains largely unexplored. We found that stimulation of dendritic cells with the fungal surrogate zymosan causes decreases of pyruvate, citrate, itaconate, and α-ketoglutarate, while increasing oxaloacetate, succinate, lactate, oxygen consumption, and pyruvate dehydrogenase activity. Expression of IL10 and IL23A (the gene encoding the p19 chain of IL-23) depended on pyruvate dehydrogenase activity. Mechanistically, pyruvate reinforced histone H3 acetylation, and acetate rescued the effect of mitochondrial pyruvate carrier inhibition, most likely because it is a substrate of the acetyl-CoA producing enzyme ACSS2. Mice lacking the receptor of the lipid mediator platelet-activating factor (PAF; 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine) showed reduced production of IL-10 and IL-23 that is explained by the requirement of acetyl-CoA for PAF biosynthesis and its ensuing autocrine function. Acetyl-CoA therefore intertwines fatty acid remodeling of glycerophospholipids and energetic metabolism during cytokine induction.

Ginseng gintonin, aging societies, and geriatric brain diseases

Background

A dramatic increase in aging populations and low birth rates rapidly drive aging societies and increase aging-associated neurodegenerative diseases. However, functional food or medicinal formulations to prevent geriatric brain disorders are not readily available. Panax ginseng is a candidate, since ginseng has long-been consumed as a rejuvenating agent. However, the underlying molecular mechanisms and the components of ginseng that are responsible for brain rejuvenation and human longevity are unknown. Accumulating evidence shows that gintonin is a candidate for the anti-aging ingredient of ginseng, especially in brain senescence.

Methods

Gintonin, a glycolipoprotein complex, contains three lipid-derived G protein-coupled receptor ligands: lysophosphatidic acids (LPAs), lysophosphatidylinositols (LPIs), and linoleic acid (LA). LPA, LPI, and LA act on six LPA receptor subtypes, GPR55, and GPR40, respectively. These G protein-coupled receptors are distributed within the nervous and non-nervous systems of the human body.

Results

Gintonin-enriched fraction (GEF) exhibits anti-brain senescence and effects against disorders such as Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD). Oral administration of gintonin in animal models of d-galactose-induced brain aging, AD, HD, and PD restored cognitive and motor functions. The underlying molecular mechanisms of gintonin-mediated anti-brain aging and anti-neurodegenerative diseases include neurogenesis, autophagy stimulation, anti-apoptosis, anti-oxidative stress, and anti-inflammatory activities. This review describes the characteristics of gintonin and GEF, and how gintonin exerts its effects on brain aging and brain associated-neurodegenerative diseases.

Conclusion

Finally, we describe how GEF can be applied to improve the quality of life of senior citizens in aging societies.

Role of omega-6 and omega-3 fatty acids in fetal programming

Maternal nutrition plays a critical role in fetal development and can influence adult onset of disease. Linoleic acid (LA) and alpha-linolenic acid (ALA) are major omega-6 (n-6) and n-3 polyunsaturated fatty acids (PUFA), respectively, that are essential in our diet. LA and ALA are critical for the development of the fetal neurological and immune systems. However, in recent years, the consumption of n-6 PUFA has increased gradually worldwide, and elevated n-6 PUFA consumption may be harmful to human health. Consumption of diets with high levels of n-6 PUFA before or during pregnancy may have detrimental effects on fetal development and may influence overall health of offspring in adulthood. This review discusses the role of n-6 PUFA in fetal programming, the importance of a balance between n-6 and n-3 PUFAs in the maternal diet, and the need of further animal models and human studies that critically evaluate both n-6 and n-3 PUFA contents in diets.

An Integrated Fecal Microbiome and Metabolomics in T2DM Rats Reveal Antidiabetes Effects from Host-Microbial Metabolic Axis of EtOAc Extract from Sophora flavescens

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease. Sophora flavescens (S. flavescens), also named Kushen, is a famous Chinese herbal medicine that has been used to prevent and cure T2DM both in folk medicine and in medical institution. However, its mechanism of action remains unclear. In this study, the pharmacodynamic effects of S. flavescens EtOAc extract (SFE) on high-fat diet and low-dose streptozotocin-induced T2DM rats were examined. Fecal metabolomics analysis and 16S rRNA gene sequencing were applied to determine the influence of T2DM and SFE treatment on gut microbiota and host metabolism. Based on the consistency of the results of metabolic pathways in metabolomics analysis and phylogenetic investigation of communities by reconstruction of unobserved state (PICRUSt) analysis of 16S rRNA gene sequencing, the level of metabolites and the operational taxonomic units of gut bacteria were combined, and Spearman's analysis was implemented. Our data showed that SFE significantly decreased fasted blood glucose levels and improved lipid profile, glycosylated serum protein, glycosylated hemoglobin index, and pancreas damage. Metabolomics and 16S rRNA gene sequencing analysis indicated gut bacteria disorder, disturbed lipid metabolism, carbohydrate metabolism, and especially amino acid metabolism in T2DM and that SFE can regulated these metabolic pathways through the influence on gut bacteria. Spearman's analysis indicated that the amino acid metabolism that included tryptophan, branched chain amino acid, aromatic amino acid, beta-alanine, and glycine, serine and threonine metabolism, lipid metabolism, including lysophosphatidylcholines and lysophosphatidylethanolamines, primary bile acid and linoleic acid metabolism, carbohydrate metabolism, and nucleotide metabolism positively correlated with Faecalibacterium, Flexispira, Phascolarctobacterium, Prevotella, Roseburia, and [Prevotella]. In addition, arginine and proline metabolism, steroid hormone, steroid biosynthesis, and sphingolipid metabolism positively correlated with Lactobacillus, Oscillospira, Parabacteroides, Ruminococcus, and Streptococcus. Taken together, we speculated that SFE may have an effect on T2DM by mediating host-microbial metabolic axis. Exploration of SFE treatment for T2DM by multiomics is expected to provide a reference for clinical treatment.

Altered Lipid Tumor Environment and Its Potential Effects on NKT Cell Function in Tumor Immunity

Natural killer T (NKT) cells are CD1d restricted T cells that mostly recognize lipid antigens. These cells share characteristics with both adaptive and innate immune cells and have multiple immunoregulatory roles. In a manner similar to innate immune cells, they respond quickly to stimuli and secrete large amounts of cytokines, amplifying and modulating the immune response. As T cells, they express T cell receptors (TCRs) and respond in an antigen-specific manner like conventional T cells. There are at least two subtypes of NKT cells, type I and type II, that differ in the nature of their TCR, either semi-invariant (type I) or diverse (type II). The two sub-types generally have opposing functions in tumor immunity, with type I promoting and type II suppressing tumor immunity, and they cross-regulate each other, forming an immunoregulatory axis. The tumor has multiple mechanisms by which it can evade immune-surveillance. One such mechanism involves alteration in tumor lipid repertoire and accumulation of lipids and fatty acids that favor tumor growth and evade anti-tumor immunity. Since NKT cells mostly recognize lipid antigens, an altered tumor lipid metabolic profile will also alter the repertoire of lipid antigens that can potentially affect their immune-modulatory function. In this review, we will explore the effects of alterations in the lipid metabolites on tumor growth, antigen cross-presentation, and overall effect on anti-tumor immunity, especially in the context of NKT cells.

Polyunsaturated Phospholipid Modified Membrane Degradation Catalyzed by a Secreted Phospholipase A2

To optimize the compositions of the lipid-based nanomedicine and to advance understanding of the roles of polyunsaturated phospholipids in biological membranes, this study examined the effects of polyunsaturated phospholipids on the degradation of giant unilamellar vesicles catalyzed by a secreted phospholipase A2 (sPLA₂) using fluorescence microscopy. Molecular interfacial packing, interaction, and degradation of the films containing various mixing ratios of saturated and polyunsaturated phospholipids were quantified using a Langmuir trough integrated with synchrotron X-ray surface scattering techniques. It was found that a high molar fraction (0.63 and above) of polyunsaturated phospholipids not only enhanced the rate of sPLA₂-catalyzed vesicle degradation but also changed the vesicle deformation process and degradation product morphology. Hydrolysis of the saturated phospholipids generated highly ordered liquid crystal domains, which was reduced or prohibited by the presence of the polyunsaturated phospholipids in the reactant film.

n-3 PUFAs reduce tumor load and improve survival in a NASH-tumor mouse model

Background

With 9.1% of all cancer deaths, hepatocellular carcinoma is the second leading cause of cancer deaths worldwide. Due to the increasing prevalence of metabolic syndrome, nonalcoholic fatty liver disease (NAFLD) has evolved into a major risk factor for hepatocellular carcinoma development. Herein, we investigated whether a dietary n-3 polyunsaturated fatty acid (PUFA) supplementation improves the outcome of progressive NAFLD.

Methods

Feeding three high-fat diets, differing in n-3 and n-6 PUFA contents and ratios (n-3/n-6: 1:8, 1:1, 5:1), the impact of n-3 PUFAs and n-3/n-6 PUFA ratios on NAFLD-related liver fibrosis and tumorigenesis was analyzed in 12- and 20-week-old streptozotocin/high-fat diet (STZ/HFD)-treated mice.

Results

Feeding of n-3 PUFA-rich diets (1:1 and 5:1) resulted in increased hepatic n-3 PUFA content and n-3/n-6 PUFA ratio with decreased hepatic lipid accumulation. In 20-week-old mice, n-3 PUFA-rich diets alleviated tumor load significantly, with reduced liver/body weight index, tumor size, and tumor number. Finally, these effects were accompanied by a significant improvement of survival of these mice.

Conclusions

Herein, we showed that increased n-3 PUFA content and n-3/n-6 PUFA ratios lead to improved survival and attenuated tumor progression in STZ/HFD-treated mice. Thus, n-3 PUFAs could be the basis for new therapeutic options against NAFLD-related tumorigenesis.

Linoleic acid in diets of mice increases total endocannabinoid levels in bowel and liver: modification by dietary glucose

AIM

Linoleic acid (LA) is an essential fatty acid involved in the biosynthesis of arachidonic acid and prostaglandins. LA is known to induce obesity and insulin resistance. In this study, two concentrations of LA with or without added glucose (G) were fed to mice to investigate their effects on endocannabinoid (EC) biology.

MATERIALS AND METHODS

Four groups of C57BL/6 mice were provided with diets containing 1% or 8% LA with or without added G (LAG) for 8 weeks. Body weights, food intake, circulating glucose and insulin levels were measured throughout the study. Following euthanasia, plasma, bowel and hepatic ECs, monoacylglycerol lipase and fatty acid amide hydroxylase protein levels (enzymes responsible for EC degradation) and transcriptional activity of PPARα in liver were quantified. Liver was probed for evidence of insulin receptor activity perturbation.

RESULTS

Increasing dietary LA from 1% to 8% significantly increased circulating, small bowel and hepatic ECs. 1%LAG fed mice had lowest feed efficiency, and only liver levels of both ECs were reduced by addition of G. Addition of G to 1% LA diets resulted in elevated monoacylglycerol lipase and fatty acid amide hydroxylase protein levels (p < 0.001 and p < 0.001, respectively) in liver due to increased transcriptional activity of PPARα (p < 0.05). The reduced EC levels with addition of G also correlated with a measure of enhanced insulin action.

CONCLUSION

In conclusion, body weight of mice is influenced by the source of calorie intake. Furthermore, tissue EC/g are dependent on tissue-specific synthesis and degradation that are modulated by dietary LA and G which also influence food efficiency, and down-stream insulin signalling pathways. The findings could potentially be useful information for weight management efforts in humans.

Muscle and serum metabolomes are dysregulated in colon-26 tumor-bearing mice despite amelioration of cachexia with activin receptor type 2B ligand blockade

Cancer-associated cachexia reduces survival, which has been attenuated by blocking the activin receptor type 2B (ACVR2B) ligands in mice. The purpose of this study was to unravel the underlying physiology and novel cachexia biomarkers by use of the colon-26 (C26) carcinoma model of cancer cachexia. Male BALB/c mice were subcutaneously inoculated with C26 cancer cells or vehicle control. Tumor-bearing mice were treated with vehicle (C26+PBS) or soluble ACVR2B either before (C26+sACVR/b) or before and after (C26+sACVR/c) tumor formation. Skeletal muscle and serum metabolomics analysis was conducted by gas chromatography-mass spectrometry. Cancer altered various biologically functional groups representing 1) amino acids, 2) energy sources, and 3) nucleotide-related intermediates. Muscle metabolomics revealed increased content of free phenylalanine in cancer that strongly correlated with the loss of body mass within the last 2 days of the experiment. This correlation was also detected in serum. Decreased ribosomal RNA content and phosphorylation of a marker of pyrimidine synthesis revealed changes in nucleotide metabolism in cancer. Overall, the effect of the experimental C26 cancer predominated over blocking ACVR2B ligands in both muscle and serum. However, the level of methyl phosphate, which was decreased in muscle in cancer, was restored by sACVR2B-Fc treatment. In conclusion, experimental cancer affected muscle and blood metabolomes mostly independently of blocking ACVR2B ligands. Of the affected metabolites, we have identified free phenylalanine as a promising biomarker of muscle atrophy or cachexia. Finally, the decreased capacity for pyrimidine nucleotide and protein synthesis in tumor-bearing mice opens up new avenues in cachexia research.

Multiple endocannabinoid-mediated mechanisms in the regulation of energy homeostasis in brain and peripheral tissues

The endocannabinoid (eCB) system is widely expressed in many central and peripheral tissues, and is involved in a plethora of physiological processes. Among these, activity of the eCB system promotes energy intake and storage, which, however, under pathophysiological conditions, can favour the development of obesity and obesity-related disorders. It is proposed that eCB signalling is evolutionary beneficial for survival under periods of scarce food resources. Remarkably, eCB signalling is increased both in hunger and in overnutrition conditions, such as obesity and type-2 diabetes. This apparent paradox suggests a role of the eCB system both at initiation and at clinical endpoint of obesity. This review will focus on recent findings about the role of the eCB system controlling whole-body metabolism in mice that are genetically modified selectively in different cell types. The current data in fact support the notion that eCB signalling is not only engaged in the development but also in the maintenance of obesity, whereby specific cell types in central and peripheral tissues are key sites in regulating the entire body's energy homeostasis.

Sperm motility and lipid composition in internally fertilizing ocellate river stingray Potamotrygon motoro

All extant groups of Elasmobranches have internal fertilization and the structure of the male reproductive organs is very specific: sperm passes from the internal organs via the cloaca, but the male copulating organ (clasper) is distant from the cloaca. This suggests that sperm can contact the surrounding medium before fertilization. Because of this involvement with the environment, external signaling in sperm motility activation could occur in these species even though their fertilization mode is internal. In this case, spermatozoa of Elasmobranches should hypothetically possess a specific structure and membrane lipid composition which supports physiological functions of the sperm associated with environmental tonicity changes occurring at fertilization. Additionally, sperm motility properties in these taxa are poorly understood. The current study examined sperm lipid composition and motility under different environmental conditions for the ocellate river stingray, Potamotrygon motoro, an endemic South America freshwater species. Sperm samples were collected from six mature males during the natural spawning period. Sperm motility was examined in seminal fluid and fresh water by light video microscopy. Helical flagellar motion was observed in seminal fluid and resulted in spermatozoon progression; however, when diluted in fresh water, spermatozoa were immotile and had compromised structure. Lipid class and fatty acid (FA) composition of spermatozoa was analyzed by thin layer and gas chromatography. Spermatozoa FAs consisted of 33 ± 1% saturated FAs, 28 ± 1% monounsaturated FAs (MUFAs), and 41 ± 1% polyunsaturated FAs (PUFAs), and a high content of n-6 FAs (32 ± 2%) was measured. These results allowed us to conclude that sperm transfer from P. motoro male into female should occur without coming into contact with the hypotonic environment so as to preserve potent motility. In addition, this unusual reproductive strategy is associated with specific spermatozoa structure and lipid composition. Low level of docosahexaenoic acid and relatively low PUFA/MUFA ratio probably account for the relatively low fluidity of freshwater stingray membrane and can be the main reason for its low tolerance to hypotonicity.

Omega-6/omega-3 fatty acid intake of children and older adults in the U.S.: dietary intake in comparison to current dietary recommendations and the Healthy Eating Index

BACKGROUND

Omega-6 and omega-3 fatty acids (FAs) and their ratio have been shown to affect cognitive function in children and older adults. With these analyses, we aimed to describe omega-6 and omega-3 FA intake among children and older adults in light of FA intake recommendations and with consideration of overall diet.

METHODS

Data were merged from two cross-sectional studies with 219 children 7 to 12 years old and one longitudinal study with 133 adults 65 to 79 years old. Demographic data, anthropometric data, and Healthy Eating Index scores were used to study relations among the omega-6 to omega-3 FA ratio and age, education, body mass index, and diet quality. FA intake, demographic, and anthropometric data were examined using partial correlations, t-tests, and analysis of variance.

RESULTS

Most children and adults consumed at least the recommended amount of alpha-linolenic acid (LNA; omega-3) for their age and gender without consuming high amounts of linoleic acid (LA; omega-6), but did not consume sufficient eicosapentaenoic acid (EPA; omega-) and docosahexaenoic acid (DHA; omega-3). The average omega-6 to omega-3 ratios in both groups were lower than previously reported. Eating lower ratios was associated with healthier diets and consuming adequate amounts of several other nutrients. No demographic or anthropometric variables were related to FA intake in children. Adults with a college degree had significantly lower ratios than those without a college degree.

CONCLUSIONS

American children and older adults are able to consume more balanced omega-6 to omega-3 ratios than has been indicated by commodity data. However, very few American children met even the lowest recommendations for EPA and DHA intake. Research is needed to clarify recommendations for the optimal ratio across development, which may aid in increasing EPA and DHA intake and improving health outcomes in the United States.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02199808 13 July 2014, NCT01823419 (retrospectively registered) 20 March 2013, and NCT01515098 18 January 2012.

Effects of a low and a high dietary LA/ALA ratio on long-chain PUFA concentrations in red blood cells

There is a debate about the optimal dietary ratio of LA and ALA to promote an efficient conversion of ALA to EPA and DHA, which have implications for human health.

Effects of a 12-week high-α-linolenic acid intervention on EPA and DHA concentrations in red blood cells and plasma oxylipin pattern in subjects with a low EPA and DHA status

The essential omega-3 fatty acid alpha-linolenic acid (ALA, 18:3n3) can be converted into EPA and DHA.

Complete assessment of whole-body n-3 and n-6 PUFA synthesis-secretion kinetics and DHA turnover in a rodent model

Previous assessments of the PUFA biosynthesis pathway have focused on DHA and arachidonic acid synthesis. Here, we determined whole-body synthesis-secretion kinetics for all downstream products of PUFA metabolism, including direct measurements of DHA and n-6 docosapentaenoic acid (DPAn-6, 22:5n-6) turnover, and compared n-6 and n-3 homolog kinetics. We infused labeled α-linolenic acid (ALA, 18:3n-3), linoleic acid (LNA, 18:2n-6), DHA, and DPAn-6 as ²H₅-ALA, ¹³C₁₈-LNA, ¹³C₂₂-DHA, and ¹³C₂₂-DPAn-6. Eight 11-week-old Long Evans rats fed a 10% fat diet were infused with the labeled PUFAs over 3 h, and plasma enrichment of labeled products was measured every 30 min. The DHA synthesis-secretion rate (94 ± 34 nmol/day) did not differ from other PUFA products (range, 21.8 ± 4.3 nmol/day to 408 ± 116 nmol/day). Synthesis-secretion rates of n-6 and n-3 PUFA homologs were similar, except 22:4n-6 and DPAn-6 had lower synthesis rates. However, daily turnover from newly synthesized DHA (0.067 ± 0.023%) was 56-fold to 556-fold slower than all other PUFA turnover and was 130-fold slower than that determined directly from the total plasma unesterified DHA pool. In conclusion, n-6 and n-3 PUFA synthesis-secretion kinetics suggest that differences in turnover, not in synthesis-secretion rates, primarily determine PUFA plasma levels.

Role of exercise-induced calmodulin protein kinase (CaMK)II activation in the regulation of omega-6 fatty acids and lipid metabolism genes in rat skeletal muscle

Activation of calmodulin dependent protein kinase (CaMK)II by exercise is beneficial in controlling membrane lipids associated with type 2 diabetes and obesity. Regulation of lipid metabolism is crucial in the improvement of type 2 diabetes and obesity associated symptoms. The role of CaMKII in membrane associated lipid metabolism was the focus of this study. Five to six weeks old male Wistar rats were used in this study. GC×GC-TOFMS technique was used to determine the levels of polyunsaturated fatty acids (linoleic acid, arachidonic acid and 11,14-eicosadienoic acid). Carnitine palmitoyltransferase (Cpt-1) and acetyl-CoA carboxylase (Acc-1) genes expression were assessed using quantitative real time PCR (qPCR). From the results, CaMKII activation by exercise increased the levels of arachidonic acid and 11,14-eicosadienoic acid while a decrease in the level of linolenic acid was observed in the skeletal muscle. The results indicated that exercise-induced CaMKII activation increased CPT-1 expression and decreased ACC-1 expression in rat skeletal muscle. All the observed increases with activation of CaMKII by exercise were aborted when KN93, an inhibitor of CaMKII was injected in exercising rats. This study demonstrated that CaMKII activation by exercise regulated lipid metabolism. This study suggests that CaMKII can be a vital target of therapeutic approach in the management of diseases such as type 2 diabetes and obesity that have increased to epidemic proportions recently.

The potential relevance of docosahexaenoic acid and eicosapentaenoic acid to the etiopathogenesis of childhood neuropsychiatric disorders

Over the last 15 years, considerable interest has been given to the potential role of omega-3 polyunsaturated fatty acids (PUFAs) for understanding pathogenesis and treatment of neurodevelopmental and psychiatric disorders. This review aims to systematically investigate the scientific evidence supporting the hypothesis on the omega-3 PUFAs deficit as a risk factor shared by different pediatric neuropsychiatric disorders. Medline PubMed database was searched for studies examining blood docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) status in children with neuropsychiatric disorders. Forty-one published manuscripts were compatible with the search criteria. The majority of studies on attention-deficit/hyperactivity disorder (ADHD) and autism found a significant decrease in DHA levels in patients versus healthy controls. For the other conditions examined-depression, juvenile bipolar disorder, intellectual disabilities, learning difficulties, and eating disorders (EDs)-the literature was too limited to draw any stable conclusions. However, except EDs, findings in these conditions were in line with results from ADHD and autism studies. Results about EPA levels were too inconsistent to conclude that EPA could be associated with any of the conditions examined. Finally, correlational data provided, on one hand, evidence for a negative association between DHA and symptomatology, whereas on the other hand, evidence for a positive association between EPA and emotional well-being. Although the present review underlines the potential involvement of omega-3 PUFAs in the predisposition to childhood neuropsychiatric disorders, more observational and intervention studies across different diagnoses are needed, which should integrate the collection of baseline PUFA levels with their potential genetic and environmental influencing factors.

Dietary linoleic acid interacts with FADS1 genetic variability to modulate HDL-cholesterol and obesity-related traits

BACKGROUND & AIMS

Blood levels of polyunsaturated fatty acids (PUFAs) are under control of endogenous synthesis via Δ5- and Δ6-desaturases, encoded by the FADS1 and FADS2 genes, respectively and of diet. Genome-wide associations studies (GWAS) reported associations between polymorphisms in FADS1-FADS2 and variations in plasma concentrations of PUFAs, HDL- and LDL-cholesterol and triglycerides. However, it is not established whether dietary PUFAs intake modulates these associations. We assessed whether dietary linoleic acid (LA) or α-linolenic acid (ALA) modulate the association between the FADS1 rs174547 polymorphism (a GWAS hit) and lipid and anthropometric phenotypes.

METHODS

Dietary intakes of LA and ALA, FADS1 rs174547 genotypes, lipid and anthropometric variables were determined in three French population-based samples (n = 3069). These samples were stratified according to the median dietary LA (<9.5 and ≥9.5 g/d) and ALA (<0.80 and ≥0.80 g/d) intakes. The meta-analysis was performed using a random-effect.

RESULTS

Our meta-analysis confirmed the association between rs174547 and plasma lipid levels and revealed an association with waist circumference and body mass index. These associations were not modified by dietary ALA intake (all p-interaction > 0.05). In contrast, the associations with HDL-cholesterol levels, waist circumference and BMI were modulated by the dietary intake of LA (p interaction < 0.05). In high LA consumers only, the rs174547 minor allele was significantly associated with lower HDL-cholesterol levels (β = -0.05 mmol/L, p = 0.0002). Furthermore, each copy of the rs174547 minor allele was associated with a 1.58 cm lower waist circumference (p = 0.0005) and a 0.46 kg m^-2 lower BMI (p = 0.01) in the low LA intake group, but not in the high LA intake group.

CONCLUSIONS

The present study suggests that dietary LA intake may modulate the association between the FADS gene variants and HDL-cholesterol concentration, waist circumference and BMI. These gene-nutrient interactions, if confirmed, suggest that subjects carrying the rs174547 minor allele might benefit from low dietary LA intakes.

Effect of dietary quebracho tannin extract on milk fatty acid composition in cows

The aim of this study was to examine the capacity of quebracho tannin extract (QTE) to modulate the fatty acid (FA) profile in the milk fat of cows. Fifty Holstein cows yielding 33.2 ± 8.2 kg/d of milk were divided into 2 groups. The cows were fed a basal diet with a forage-concentrate ratio of 66:34 on a dry matter (DM) basis. Diets tested were control (CON, basal diet without QTE) and basal diet plus 15 or 30 g of QTE/kg of DM (QTE₁₅ and QTE₃₀, respectively). Two treatments could be tested simultaneously and were arranged along 6 periods. The milk FA profile was characterized by increments in the proportion of linoleic (LA) and α-linolenic acid (α-LNA) (QTE₁₅ = 10 and 6.1%; QTE₃₀ = 28 and 25%, respectively) compared to CON, which might indicate reduced ruminal biohydrogenation (BH) of both dietary LA and α-LNA. Vaccenic acid (VA) in the milk fat was reduced (QTE₁₅ 8.9% and QTE₃₀ 12%) compared to CON, which may be linked to inhibited BH of LA and α-LNA. Rumenic acid (RA), a conjugated LA (cis-9,trans-11 conjugated linoleic acid) and an important human health promoter, was unfortunately decreased (QTE₁₅ 8.3% and QTE₃₀ 16%) in the milk compared with CON, probably because of inhibited ruminal BH of LA. However, reduced RA in the milk was probably due to reduced availability of VA produced in the rumen and the consequently low VA available to be desaturated to RA in the mammary gland by Δ⁹-desaturase. The proportions of total polyunsaturated FA were increased with QTE₁₅ and QTE₃₀ by 4.7 and 15% compared to CON, respectively, and the long-chain FA proportions were also increased (QTE₁₅ 2.0% and QTE₃₀ 8.2%). Moreover, myristic and palmitic acid were reduced by QTE₃₀ (9.6 and 3.3%, respectively) compared to CON, which also contributed to increasing the nutritional quality of milk because they are recognized to increase high-density lipoprotein in humans. Branched-chain FA in milk was reduced with QTE treatments, which indicates inhibited ruminal BH and microbial activity. In general, our findings suggest that dietary QTE have the potential to modulate FA profile of milk fat, and this effect is dosage dependent. Because QTE influenced the FA profile of milk fat both positively and negatively, further research is needed before concluding that QTE may improve the nutritional quality of cow milk fat in human diets.

Cardiovascular diseases, depression disorders and potential effects of omega-3 fatty acids

Cardiovascular disease (CVD) and depressive disorders (DD) are two of the most prevalent health problems in the world. Although CVD and depression have different origin, they share some common pathophysiological characteristics and risk factors, such as the increased production of proinflammatory cytokines, endothelial dysfunction, blood flow abnormalities, decreased glucose metabolism, elevated plasma homocysteine levels, oxidative stress and disorder in vitamin D metabolism. Current findings confirm the common underlying factors for both pathologies, which are related to dramatic dietary changes in the mid-19th century. By changing dietary ratio of omega-6 to omega-3 fatty acids from 1:1 to 15-20:1 some changes in metabolism were induced, such as increased pro-inflammatory mediators and modulations of different signaling pathways following pathophysiological response related to both, cardiovascular diseases and depressive disorders.

Erythrocyte fatty acid composition of Nepal breast-fed infants

PURPOSE

Essential fatty acids play a critical role in the growth and development of infants, but little is known about the fatty acid status of populations in low-income countries. The objective was to describe the fatty acid composition of red blood cells (RBC) in breastfeed Nepali infants and a subsample of their mothers and to identify the main sources of fatty acids in the mother's diet, as well as the fatty acid composition of breast milk.

METHODS

RBC fatty acid composition was analyzed in a random sample of 303 infants and 72 mother, along with 68 breastmilk samples. Fatty acid profiles of the most important dietary fat sources were analyzed. Information on mother's diet and intake of fat was collected by three 24-h dietary recalls.

RESULTS

In infant RBC's, docosahexaenoic acid (DHA) was the main n-3 fatty acid, and arachidonic acid (AA) was the major n-6 fatty acid. Total n-6 PUFA was three times higher than total n-3 PUFA. Height-for-age (HAZ) was positively associated with DHA status and AA status in multivariable models. The concentration of all fatty acids was higher in children, compared to mothers, except Total n-6 PUFA and Linoleic acid (LA) where no differences were found. The mother's energy intake from fat was 13% and cooking oil (sesame, mustard, soybean or sunflower oil) contributed 52% of the fat intake.

CONCLUSIONS

RBC-DHA levels in both infants and mother was unexpected high taking into account few dietary DHA sources and the low DHA concentrations in breastmilk.

Bipolar disorder moderates associations between linoleic acid and markers of inflammation

Dietary polyunsaturated fatty acids (PUFA) and inflammatory proteins associate with immune activation and have been implicated in the pathophysiology of mood disorders. We have previously reported that individuals with bipolar disorder (BPD) have decreased PUFA intake, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA); and decreased PUFA concentration of plasma EPA and linoleic acid (LA). We have also reported an association between plasma LA and its metabolites and burden of disease measures in BPD. In the current cross-sectional study we collected blood samples and diet records from both bipolar (n = 91) and control subjects (n = 75) to quantify plasma cytokine concentrations and dietary LA intake, respectively. Using multiple linear regression techniques, we tested for case control differences in plasma cytokine levels and associations between cytokines and dietary LA intake, adjusting for sex, age, BMI, and total energy intake. We found significantly higher plasma levels of interleukin 18 (IL-18) (p = 0.036), IL-18 binding protein (IL-18BP) (p = 0.001), soluble tumor necrosis factor receptor (sTNFR) 1 (p = 0.006), and sTNFR2 (p = 0.007) in BPD compared with controls. Moreover, BPD significantly moderated the associations of dietary LA intake with plasma levels of IL-18, sTNFR1 and sTNFR2, which were inverse associations in bipolar individuals and positive associations in controls (p for dietary LA x BPD diagnosis interaction < 0.05 for all three). These findings suggest potential dysregulation of LA metabolism in BPD, which may extend to a modified influence of dietary LA on specific inflammatory pathways in individuals with BPD compared to healthy controls.

Golden Needle Mushroom: A Culinary Medicine with Evidenced-Based Biological Activities and Health Promoting Properties

Flammulina velutipes (enoki, velvet shank, golden needle mushroom or winter mushroom), one of the main edible mushrooms on the market, has long been recognized for its nutritional value and delicious taste. In recent decades, research has expanded beyond detailing its nutritional composition and delved into the biological activities and potential health benefits of its constituents. Many bioactive constituents from a range of families have been isolated from different parts of the mushroom, including carbohydrates, protein, lipids, glycoproteins, phenols, and sesquiterpenes. These compounds have been demonstrated to exhibit various biological activities, such as antitumour and anticancer activities, anti-atherosclerotic and thrombosis inhibition activity, antihypertensive and cholesterol lowering effects, anti-aging and antioxidant properties, ability to aid with restoring memory and overcoming learning deficits, anti-inflammatory, immunomodulatory, anti-bacterial, ribosome inactivation and melanosis inhibition. This review aims to consolidate the information concerning the phytochemistry and biological activities of various compounds isolated from F. velutipes to demonstrate that this mushroom is not only a great source of nutrients but also possesses tremendous potential in pharmaceutical drug development.

Linoleic acid and the pathogenesis of obesity

The modern Western diet has been consumed in developed English speaking countries for the last 50 years, and is now gradually being adopted in Eastern and developing countries. These nutrition transitions are typified by an increased intake of high linoleic acid (LA) plant oils, due to their abundance and low price, resulting in an increase in the PUFA n-6:n-3 ratio. This increase in LA above what is estimated to be required is hypothesised to be implicated in the increased rates of obesity and other associated non-communicable diseases which occur following a transition to a modern Westernised diet. LA can be converted to the metabolically active arachidonic acid, which has roles in inducing inflammation and adipogenesis, and endocannabinoid system regulation. This review aims to address the possible implications of excessive LA and its metabolites in the pathogenesis of obesity.

Distribution of omega-6 and omega-3 polyunsaturated fatty acids in the whole rat body and 25 compartments

The steady state compositions of omega-6 and omega-3 polyunsaturated fatty acids (PUFA) throughout the various viscera and tissues within the whole body of rats have not previously been described in a comprehensive manner. Dams consumed diets containing 10wt% fat (15% linoleate and 3% α-linolenate). Male offspring (n=9) at 7-week of age were euthanized and dissected into 25 compartments. Total lipid fatty acids for each compartment were quantified by GC/FID and summed for the rat whole body; total n-6 PUFA was 12wt% and total n-3 PUFA was 2.1% of total fatty acids. 18:2n-6 accounted for 84% of the total n-6 PUFA, 20:4n-6 was 12%, 18:3n-3 was 59% of the total n-3 PUFA, 20:5n-3 was 2.1%, and 22:6n-3 was 32%. The white adipose tissue contained the greatest amounts of 18:2n-6 (1.5g) and 18:3n-3 (0.2g). 20:4n-6 was highest in muscle (60mg) and liver (57mg), while 22:6n-3 was greatest in muscle (46mg), followed by liver (27mg) and carcass (20mg). In terms of fatty acid composition expressed as a percentage, 18:2n-6 was the highest in the heart (13wt%), while 18:3n-3 was about 1.3wt% for skin, white adipose tissue and fur. 20:4n-6 was highest (21-25wt%) in the circulation, kidney, and spleen, while 22:6n-3 was highest in the brain (12wt%), followed by the heart (7.9wt%), liver (5.9wt%), and spinal cord (5.1wt%). Selectivity was greatest when comparing 22:6n-3 in brain (12%) to white adipose (0.08%) (68-fold) and 22:5n-6 in testes (15.6%) compared to white adipose (0.02%), 780-fold.

Australia's nutrition transition 1961-2009: a focus on fats

Since the 1960s, Australian diets have changed considerably, influenced by a burgeoning multicultural cuisine, increase in urbanisation and food technology advances. This has been described as a 'nutrition transition', resulting in the adoption of a Western diet pattern, with a shift away from unrefined foods towards a diet higher in both plant-derived high PUFA and total fats and refined carbohydrates. Utilising the 1961-2009 annual food supply data from the UN FAO, the present study investigated changes in the intake of macronutrient and specific fatty acid in the Australian population, including that of the PUFA linoleic acid (LA), due to its hypothesised role in inflammation and risk for obesity. Cumulative change over time for the contribution of specific nutrients to total available energy (TAE) was calculated, as was linearity of change. Over the time period analysed, the cumulative change in TAE from carbohydrate was -9.35 and +16.67 % from lipid. The cumulative change in TAE from LA was +120.48 %. Moreover, the cumulative change in the contribution of LA to total PUFA availability was +7.1 %. Utilising the average g/d per capita of LA from selected dietary sources, the change in the contribution of specific foodstuffs was assessed, with total plant oils having a cumulative change of +627.19 % to LA availability, equating to a cumulative change of +195.61 % in contribution to total LA availability. The results of the present study indicate that LA availability in Australia has increased over the previous five decades as a result of the availability of increased plant oils, as has total fat, possibly contributing to the increasing rates of obesity and obesity-associated co-morbidities.

Diet-induced changes in n-3- and n-6-derived endocannabinoids and reductions in headache pain and psychological distress

Omega-3 and omega-6 fatty acids are biosynthetic precursors of endocannabinoids with antinociceptive, anxiolytic, and neurogenic properties. We recently reported that targeted dietary manipulation-increasing omega-3 fatty acids while reducing omega-6 linoleic acid (the H3-L6 intervention)-reduced headache pain and psychological distress among chronic headache patients. It is not yet known whether these clinical improvements were due to changes in endocannabinoids and related mediators derived from omega-3 and omega-6 fatty acids. We therefore used data from this trial (N = 55) to investigate 1) whether the H3-L6 intervention altered omega-3- and omega-6-derived endocannabinoids in plasma and 2) whether diet-induced changes in these bioactive lipids were associated with clinical improvements. The H3-L6 intervention significantly increased the omega-3 docosahexaenoic acid derivatives 2-docosahexaenoylglycerol (+65%, P < .001) and docosahexaenoylethanolamine (+99%, P < .001) and reduced the omega-6 arachidonic acid derivative 2-arachidonoylglycerol (-25%, P = .001). Diet-induced changes in these endocannabinoid derivatives of omega-3 docosahexaenoic acid, but not omega-6 arachidonic acid, correlated with reductions in physical pain and psychological distress. These findings demonstrate that targeted dietary manipulation can alter endocannabinoids derived from omega-3 and omega-6 fatty acids in humans and suggest that 2-docosahexaenoylglycerol and docosahexaenoylethanolamine could have physical and/or psychological pain modulating properties.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01157208) PERSPECTIVE: This article demonstrates that targeted dietary manipulation can alter endocannabinoids derived from omega-3 and omega-6 fatty acids and that these changes are related to reductions in headache pain and psychological distress. These findings suggest that dietary interventions could provide an effective, complementary approach for managing chronic pain and related conditions.

Protective effect of arachidonic acid and linoleic acid on 1-methyl-4-phenylpyridinium-induced toxicity in PC12 cells

Background

Parkinson’s disease is a neurodegenerative disorder that is being characterized by the progressive loss of dopaminergic neurons of the nigrostriatal pathway in the brain. The protective effect of omega-6 fatty acids is unclear. There are lots of contradictions in the literature with regard to the cytoprotective role of arachidonic acid. To date, there is no solid evidence that shows the protective role of omega-6 fatty acids in Parkinson’s disease. In the current study, the potential of two omega-6 fatty acids (i.e. arachidonic acid and linoleic acid) in alleviating 1-methyl-4-phenylpyridinium (MPP⁺)-induced cytotoxicity in PC12 cells was examined.

Methods

Cultured PC12 cells were either treated with MPP⁺ alone or co-treated with one of the omega-6 fatty acids for 1 day. Cell viability was then assessed by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Results

Cells treated with 500 μM MPP⁺ for a day reduced cell viability to ~70% as compared to control group. Linoleic acid (50 and 100 μM) significantly reduced MPP⁺-induced cell death back to ~85-90% of the control value. The protective effect could be mimicked by arachidonic acid, but not by ciglitazone.

Conclusions

Both linoleic acid and arachidonic acid are able to inhibit MPP⁺-induced toxicity in PC12 cells. The protection is not mediated via peroxisome proliferator-activated receptor gamma (PPAR-γ). Overall, the results suggest the potential role of omega-6 fatty acids in the treatment of Parkinson’s disease.

Food for thought: dietary changes in essential fatty acid ratios and the increase in autism spectrum disorders

The last decades have shown a spectacular and partially unexplained rise in the prevalence of autism spectrum disorders (ASD). This rise in ASD seems to parallel changes in the dietary composition of fatty acids. This change is marked by the replacement of cholesterol by omega-6 (n-6) fatty acids in many of our food products, resulting in a drastically increased ratio of omega-6/omega-3 (n-6/n-3). In this context, we review the available knowledge on the putative role of fatty acids in neurodevelopment and describe how disturbances in n-6/n-3 ratios may contribute to the emergence of ASDs. Both clinical and experimental research is discussed. We argue that a change in the ratio of n-6/n-3, especially during early life, may induce developmental changes in brain connectivity, synaptogenesis, cognition and behavior that are directly related to ASD.

Association between high dietary intake of the n-3 polyunsaturated fatty acid docosahexaenoic acid and reduced risk of Crohn's disease

BACKGROUND

There are plausible mechanisms for how dietary docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, could prevent Crohn's disease (CD).

AIM

To conduct a prospective study to investigate the association between increased intake of DHA and risk of CD.

METHODS

Overall, 229 702 participants were recruited from nine European centres between 1991 and 1998. At recruitment, dietary intakes of DHA and fatty acids were measured using validated food frequency questionnaires. The cohort was monitored through to June 2004 to identify participants who developed incident CD. In a nested case-control analysis, each case was matched with four controls; odds ratios (ORs) were calculated for quintiles of DHA intake, adjusted for total energy intake, smoking, other dietary fatty acids, dietary vitamin D and body mass index.

RESULTS

Seventy-three participants developed incident CD. All higher quintiles of DHA intake were inversely associated with development of CD; the highest quintile had the greatest effect size (OR = 0.07; 95% CI = 0.02-0.81). The OR trend across quintiles of DHA was 0.54 (95% CI = 0.30-0.99, Ptrend  = 0.04). Including BMI in the multivariate analysis, due to its correlation with dietary fat showed similar associations. There were no associations with the other dietary fatty acids studied.

CONCLUSION

There were inverse associations, with a biological gradient between increasing dietary docosahexaenoic acid intakes and incident Crohn's disease. Further studies in other populations should measure docosahexaenoic acid to determine if the association is consistent and the hypothesis tested in randomised controlled trials of purely docosahexaenoic acid supplementation.

New method for the extraction of volatile lipid oxidation products from shrimp by headspace-solid-phase microextraction-gas chromatography-mass spectrometry and evaluation of the effect of salting and drying

A new method based on headspace-solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed, aimed at evaluating the formation of volatile lipid oxidation products (VLOPs) in shrimp during the salting and drying process. Of the four fibers evaluated, the fiber coated with divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) was the most adequate for the quantification of the VLOPs. The best analytical conditions were obtained by homogenization in an ultraturrax followed by extraction at 40 °C for 30 min. The optimized method allowed for the rapid and simple extraction of the VLOPs, with low detection (≤0.15 ng g(-1)) and quantification (≤0.50 ng g(-1)) limits and satisfactory precision (≤12.67%) and extraction efficiency (≥94.28%). The salting and drying negatively affected shrimp quality, reducing the fatty acid content and increasing the VLOPs, especially hexanal.

Omega-6 fatty acids and greater likelihood of suicide risk and major depression in early pregnancy

OBJECTIVE

To estimate the prevalence of suicide risk (SR) and major depressive episodes (MDEs) in early pregnancy, as well as the relationship of serum fatty acid status to these outcomes.

METHODS

Cross-sectional analyses were performed on data from 234 pregnant women enrolled in a prospective cohort study in Rio de Janeiro, Brazil. SR and MDE were defined according to the Mini International Neuropsychiatric Interview. Fatty acid compositions were determined for serum samples obtained between the 6th and 13th gestational week. Fatty acid data were expressed as the percent of total fatty acids, converted to Z scores and then entered as continuous variables in logistic regression models.

RESULTS

The prevalence of SR was 19.6% and that of MDE was 17.0%. In the adjusted logistic regressions, a higher likelihood of SR was observed among women with higher arachidonic acid levels [AA (20:4, n-6): OR=1.45, 95%CI 1.02-2.07] and adrenic acid levels [AdA (22:4, n-6): OR=1.43, 95%CI 1.01-2.04]. A higher likelihood of MDE was also observed among women with higher AA levels [OR=1.47, 95%CI 1.03-2.10] and AdA levels [OR=1.59, 95%CI 1.09-2.32].

CONCLUSION

Higher serum levels of AA and AdA were associated with a greater likelihood of SR and MDE among pregnant Brazilian women.