-
Asia Pacific Journal of Clinical... 2019Docosahexaenoic acid (DHA) is a 22-carbon omega 3 PUFA highly enriched in the neuronal cell membranes and rod outer segment membranes. When DHA is depleted from these... (Review)
Review
Docosahexaenoic acid (DHA) is a 22-carbon omega 3 PUFA highly enriched in the neuronal cell membranes and rod outer segment membranes. When DHA is depleted from these cell membranes it is replaced nearly quantitatively by a 22-carbon omega 6 PUFA, docosapentaenoic acid, which has similar, but less potent, biophysical and physiological properties to DHA. It is speculated that omega 6-docosapentaenoic acid is a buffer to prevent the possible catastrophic effects of DHA depletion on brain and visual function. The primary insult from the loss of DHA from cell membrane glycerophospholipids, and replacement by omega 6-docosapentaenoic acid, is on the flexibility/compression of the membrane lipids which affects the optimal function of integral membrane proteins (receptors, voltage-gated ion channels and enzymes). This leads to effects on second messenger systems, and subsequently affects neurotransmitter concentrations due to 'weakened' signals from the initiating receptors. Remembering there are more than 80 billion neurones and many times more synaptic connections between neurons, a very small loss of "efficiency" in signal due to altered properties of membrane proteins would likely result in meaningful changes in brain and visual function. Additionally, impairment of neurotransmission could be due, in part, to sub-optimal brain energy metabolism (glucose entry into the brain), which is significantly reduced in omega 3 deficiency. Many studies report that dietary omega 3 deficiency results in changes in learning, coping with stress, behavioural changes, and responses in visual function. It is thus concluded that DHA is an essential fatty acid for optimal neuronal function.
Topics: Animals; Brain; Cell Membrane; Docosahexaenoic Acids; Humans; Neurons; Retinal Rod Photoreceptor Cells
PubMed: 31826363
DOI: 10.6133/apjcn.201912_28(4).0002 -
Molecules (Basel, Switzerland) Jun 2024Research over the last 25 years related to structural elucidations and biological investigations of the specialized pro-resolving mediators has spurred great interest in... (Review)
Review
Research over the last 25 years related to structural elucidations and biological investigations of the specialized pro-resolving mediators has spurred great interest in targeting these endogenous products in total synthesis. These lipid mediators govern the resolution of inflammation as potent and stereoselective agonists toward individual G-protein-coupled receptors, resulting in potent anti-inflammatory activities demonstrated in many human disease models. Specialized pro-resolving mediators are oxygenated polyunsaturated products formed in stereoselective and distinct biosynthetic pathways initiated by various lipoxygenase and cyclooxygenase enzymes. In this review, the reported stereoselective total synthesis and biological activities of the specialized pro-resolving mediators biosynthesized from the polyunsaturated fatty acid n-3 docosapentaenoic acid are presented.
Topics: Humans; Fatty Acids, Unsaturated; Animals; Prostaglandin-Endoperoxide Synthases; Anti-Inflammatory Agents; Inflammation
PubMed: 38930898
DOI: 10.3390/molecules29122833 -
Journal of Nutritional Science and... 2015Metabolic syndrome is a cluster of metabolic disorders that contribute to increased cardiovascular morbidity and mortality. Although the pathogenesis of metabolic... (Review)
Review
Metabolic syndrome is a cluster of metabolic disorders that contribute to increased cardiovascular morbidity and mortality. Although the pathogenesis of metabolic syndrome is complicated, dietary lipids have been recognized as contributory factors in the development and the prevention of cardiovascular risk clustering. We investigated the physiological functions and molecular actions of functional lipids, especially omega3-polyunsaturated fatty acid (PUFA)-containing lipids, in the development of metabolic syndrome using obese model animals. Feeding of omega3-PUFA-containing lipids, such as eicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid, tetracosahexaenoic acid, and omega3-phosphatidylcholine, alleviated hepatic lipid accumulation through the suppression of lipogenic gene expression in the liver. Additionally, dietary omega3-PUFA-containing lipids increased serum adiponectin levels in obese animal models. Their molecular actions in the prevention and alleviation of metabolic syndrome could be attributed to the regulation of the activity or abundance of several transcriptional factors in the liver and adipose tissue. Dietary functional lipids would be useful to prevent or alleviate metabolic syndrome in obese animals. In particular, the function of omega3-containing lipids as dietary adiponectin inducers deserves attention with respect to alleviation of metabolic syndrome by dietary manipulation.
Topics: Adiponectin; Adipose Tissue; Animals; Diet; Fatty Acids, Omega-3; Functional Food; Humans; Liver; Metabolic Syndrome; Obesity; Transcription Factors
PubMed: 26598838
DOI: 10.3177/jnsv.61.S159 -
Current Opinion in Clinical Nutrition... Mar 2021Docosapentaenoic acid (DPA) is a minor omega-3 fatty acid (FA) which has been frequently overlooked in lipid research. This review examines the biochemical and... (Review)
Review
PURPOSE OF REVIEW
Docosapentaenoic acid (DPA) is a minor omega-3 fatty acid (FA) which has been frequently overlooked in lipid research. This review examines the biochemical and physiological outcomes of human trials which have used pure preparations of DPA (n - 3 DPA) and also recent developments in specialized proresolving lipid mediators (SPMs) derived from n - 3 DPA.
RECENT FINDINGS
There have been only been two human studies and eleven animal studies with pure n - 3 DPA. The doses of n - 3 DPA used in the human trials have been 1-2 g/day. n - 3 DPA abundance is increased in blood lipid fractions within 3-4 days of supplementation. n - 3 DPA has the potential for unique properties, with a greater similarity in biological functioning with docosahexaenoic acid (DHA), than eicosapentaenoic acid (EPA). Despite the typically low levels of n - 3 DPA in most tissue lipids relative to EPA and DHA, unique SPMs, such as resolvins, maresins and protectins of the n - 3 DPA type, are involved in resolution of inflammation and regulating immune function.
SUMMARY
We suggest that measurement of blood levels of n - 3 DPA gives no indication of its broad biological roles, but that the true functionality of this enigmatic n - 3 polyunsaturated fatty acid (PUFA) remains obscure until more is known about the properties of the unique DPA-derived SPMs.
Topics: Animals; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Humans
PubMed: 33315722
DOI: 10.1097/MCO.0000000000000722 -
European Journal of Pharmacology Aug 2016Recent years have seen the description and elucidation of a new class of anti-inflammatory and pro-resolving lipid mediators. The arachidonic acid (AA)-derived compounds... (Review)
Review
Recent years have seen the description and elucidation of a new class of anti-inflammatory and pro-resolving lipid mediators. The arachidonic acid (AA)-derived compounds in this class are called lipoxins and have been described in great detail since their discovery thirty years ago. The new players are mediators derived from fish oil omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), called resolvins, protectins and maresins. Taken together, these mediators are also called specialized pro-resolution mediators (SPMs). As compared to the AA/EPA/DHA-derived compounds, research regarding mediators formed from the n-3 and n-6 docosapentaenoic acids (DPAn-3 and DPAn-6) is sparse. However, mono- di- and trihydroxy derivates of the DPAs have anti-inflammatory properties as well, even though mechanisms of their anti-inflammatory action have not been fully elucidated. This review aims to summarize current knowledge regarding the DPA-derived SPMs and their actions.
Topics: Animals; Drug Discovery; Fatty Acids, Unsaturated; Humans
PubMed: 26546723
DOI: 10.1016/j.ejphar.2015.11.002 -
Progress in Lipid Research Jul 2023This review is about the role of arachidonic acid (ArA) in foetal and early growth and development. In 1975 and '76, we reported the preferential incorporation of ArA... (Review)
Review
This review is about the role of arachidonic acid (ArA) in foetal and early growth and development. In 1975 and '76, we reported the preferential incorporation of ArA into the developing brain of rat pups, its conservation as a principal component in the brains of 32 mammalian species and the high proportion delivered by the human placenta for foetal nutrition, compared to its parent linoleic acid (LA). ArA is quantitatively the principal acyl component of membrane lipids from foetal red cells, mononuclear cells, astrocytes, endothelium, and placenta. Functionally, we present evidence that ArA, but not DHA, relaxes the foetal mesenteric arteries. The placenta biomagnifies ArA, doubling the proportion of the maternal level in cord blood. The proportions of ArA and its allies (di-homo-gamma-linolenic acid (DGLA), adrenic acid and ω6 docosapentaenoic acid) are similar or higher than the total of ω3 fatty acids in human milk, maintaining the abundant supply to the developing infant. Despite the evidence of the importance of ArA, the European Food Standard Agency, in 2014 rejected the joint FAO and WHO recommendation on the inclusion of ArA in infant formula, although they recommended DHA. The almost universal dominance of ArA in the membrane phosphoglycerides during human organogenesis and prenatal growth suggests that the importance of ArA and its allies in reproductive biology needs to be re-evaluated urgently.
Topics: Pregnancy; Female; Humans; Animals; Rats; Arachidonic Acid; Docosahexaenoic Acids; Linoleic Acid; Infant Formula; Glycerophospholipids; Mammals
PubMed: 36746351
DOI: 10.1016/j.plipres.2023.101222 -
Nutrients Dec 2020Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 polyunsaturated fatty acids (PUFAs) consumed in low abundance in the Western diet. Increased... (Review)
Review
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 polyunsaturated fatty acids (PUFAs) consumed in low abundance in the Western diet. Increased consumption of n-3 PUFAs may have beneficial effects for a wide range of physiological outcomes including chronic inflammation. However, considerable mechanistic gaps in knowledge exist about EPA versus DHA, which are often studied as a mixture. We suggest the novel hypothesis that EPA and DHA may compete against each other through overlapping mechanisms. First, EPA and DHA may compete for residency in membrane phospholipids and thereby differentially displace n-6 PUFAs, which are highly prevalent in the Western diet. This would influence biosynthesis of downstream metabolites of inflammation initiation and resolution. Second, EPA and DHA exert different effects on plasma membrane biophysical structure, creating an additional layer of competition between the fatty acids in controlling signaling. Third, DHA regulates membrane EPA levels by lowering its rate of conversion to EPA's elongation product n-3 docosapentaenoic acid. Collectively, we propose the critical need to investigate molecular competition between EPA and DHA in health and disease, which would ultimately impact dietary recommendations and precision nutrition trials.
Topics: Animals; Arachidonic Acid; Diet; Diet, Western; Dietary Supplements; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Humans; Inflammation; Phospholipids
PubMed: 33276463
DOI: 10.3390/nu12123718 -
The Journal of Allergy and Clinical... Nov 2023Aspirin-exacerbated respiratory disease (AERD) is associated with high levels of cysteinyl leukotrienes, prostaglandin D, and low levels of prostaglandin E. Further,...
BACKGROUND
Aspirin-exacerbated respiratory disease (AERD) is associated with high levels of cysteinyl leukotrienes, prostaglandin D, and low levels of prostaglandin E. Further, 15-hydroxyeicosatetraenoic acid (15-HETE) levels may have predictive value in therapeutic outcomes of aspirin desensitization. Accumulation of nasal group 2 innate lymphoid cells (ILC2s) has been demonstrated during COX-1 inhibition in AERD, although the relationships between tissue ILC2 accumulation, reaction symptom severity, and novel lipid biomarkers are unknown.
OBJECTIVE
We sought to determine whether novel lipid mediators are predictive of nasal ILC2 accumulation and symptom scores during COX-1 inhibitor challenge in patients with AERD.
METHODS
Blood and nasal scraping samples from patients with AERD were collected at baseline and COX-1 inhibitor reaction and then processed for flow cytometry for nasal ILC2s and serum for lipidomic analysis.
RESULTS
Eight patients with AERD who were undergoing aspirin desensitization were recruited. Of the 161 eicosanoids tested, 42 serum mediators were detected. Baseline levels of 15-HETE were negatively correlated with the change in numbers of airway ILC2s (r = -0.6667; P = .0428). Docosahexaenoic acid epoxygenase metabolite 19,20-dihydroxy-4Z,7Z,10Z,13Z,16Z-docosapentaenoic acid (19,20-diHDPA) was positively correlated with both changes in airway ILC2s (r = 0.7143; P = .0305) and clinical symptom scores (r = 0.5000; P = .0081).
CONCLUSION
Low levels of baseline 15-HETE predicted a greater accumulation of airway ILC2s in patients with AERD who were receiving COX-1 inhibition. Further, increases in the cytochrome P pathway metabolite 19,20-dihydroxy-4Z,7Z,10Z,13Z,16Z-docosapentaenoic acid (19,20-diHDPA) were associated with increased symptoms and nasal ILC2 accumulation. Future studies to assess how these mediators might control ILC2s may improve the understanding of AERD pathogenesis.
Topics: Humans; Immunity, Innate; Lymphocytes; Asthma, Aspirin-Induced; Hydroxyeicosatetraenoic Acids; Cyclooxygenase Inhibitors; Sinusitis; Nasal Mucosa; Prostaglandins; Eicosanoids; Aspirin; Nasal Polyps
PubMed: 37543185
DOI: 10.1016/j.jaci.2023.06.028 -
Nutrients Dec 2022Docosahexaenoic acid (DHA) is a major constituent of neural and visual membranes and is required for optimal neural and visual function. DHA is derived from food or by... (Review)
Review
Docosahexaenoic acid (DHA) is a major constituent of neural and visual membranes and is required for optimal neural and visual function. DHA is derived from food or by endogenous synthesis from α-linolenic acid (ALA), an essential fatty acid. Low blood levels of DHA in some westernised populations have led to speculations that child development disorders and various neurological conditions are associated with sub-optimal neural DHA levels, a proposition which has been supported by the supplement industry. This review searched for evidence of deficiency of DHA in human populations, based on elevated levels of the biochemical marker of -3 deficiency, docosapentaenoic acid (22:5-6). Three scenarios/situations were identified for the insufficient supply of DHA, namely in the brain of new-born infants fed with high-linoleic acid (LA), low-ALA formulas, in cord blood of women at birth who were vegetarians and in the milk of women from North Sudan. Twenty post-mortem brain studies from the developed world from adults with various neurological disorders revealed no evidence of raised levels of 22:5-6, even in the samples with reduced DHA levels compared with control subjects. Human populations most likely at risk of -3 deficiency are new-born and weanling infants, children and adolescents in areas of dryland agriculture, in famines, or are refugees, however, these populations have rarely been studied. This is an important topic for future research.
Topics: Infant, Newborn; Infant; Pregnancy; Adult; Child; Humans; Female; Adolescent; Animals; Docosahexaenoic Acids; Fatty Acids, Essential; Brain; Milk; Parturition; alpha-Linolenic Acid
PubMed: 36615819
DOI: 10.3390/nu15010161 -
Journal of Bioscience and Bioengineering Mar 2022ω3-Docosapentaenoic acid (ω3-DPA), an ω3-polyunsaturated fatty acid (ω3-PUFA), is expected to have beneficial physiological functions to humans; however, because of...
ω3-Docosapentaenoic acid (ω3-DPA), an ω3-polyunsaturated fatty acid (ω3-PUFA), is expected to have beneficial physiological functions to humans; however, because of its rarity in nature, it has not been fully analyzed. We isolated an ω3-DPA producing microorganism strain T7 from brackish areas in Japan. Although most oleaginous microorganisms rarely accumulate ω3-DPA (<5% of total lipid), strain T7 accumulated ω3-DPA with more than 20% of total fatty acids. The strain T7 was identified as a related species of Aurantiochytrium. In Aurantiochytrium sp. T7, ω3-DPA production reached 164 mg/L culture broth, and the ω3-DPA content reached 23.5% of the total fatty acids when cultivated in a medium containing 2% glucose as the carbon source and 1% yeast extract as the nitrogen source, with a salinity equivalent to 50% of that of seawater and a pH in the acidic range (pH < 5.5). Aurantiochytrium sp. T7 is a promising producer of high-purity ω3-DPA containing-lipid for the functional analysis of ω3-DPA whose physiological function has hardly been elucidated, and a useful strain for investigating the novel metabolic pathway of fatty acids.
Topics: Culture Media; Docosahexaenoic Acids; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Humans; Stramenopiles
PubMed: 34893429
DOI: 10.1016/j.jbiosc.2021.10.011