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Food Chemistry Sep 2022The physicochemical properties and interactions of the complex of oleic acid (OA) and β-cyclodextrin (β-CD) were studied by experimental and computational methods....
The physicochemical properties and interactions of the complex of oleic acid (OA) and β-cyclodextrin (β-CD) were studied by experimental and computational methods. Differential scanning calorimetry and X-ray diffraction confirmed the successful preparation of OA/β-CD inclusion complex. The stability of the complex was improved, exhibiting a 61.2 °C higher degradation temperature and a lower peroxide value than OA. Raman and Fourier transform infrared spectroscopy studies revealed that the carboxyl group of OA entered into the β-CD cavity to form hydrogen bonds, which was confirmed by conformational search and weak interactions analysis. Dispersion energy from van der Waals (-290.79 kJ/mol) contributed 87.3% to total interaction energy (-253.88 kJ/mol). Topological analysis showed that four moderate hydrogen bonds were formed between OA and β-CD with the bond energy ranging from -76.05 to -30.25 kJ/mol. This work provided theoretical basis for the development of nutritional supplements containing unsaturated fatty acids encapsulated by β-CD.
Topics: Calorimetry, Differential Scanning; Models, Theoretical; Oleic Acid; Solubility; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction; beta-Cyclodextrins
PubMed: 35417841
DOI: 10.1016/j.foodchem.2022.132910 -
Molecules (Basel, Switzerland) Sep 2023Non-alcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide, mainly manifested by hepatic steatosis. Hepatic lipids may be derived from...
Non-alcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide, mainly manifested by hepatic steatosis. Hepatic lipids may be derived from dietary intake, plasma free fatty acid (FFA) uptake, or hepatic de novo lipogenesis (DNL). Currently, cellular and animal models of hepatocellular steatosis are widely used to study the pathogenesis of NAFLD and to investigate therapeutic agents. However, whether there are differences between the in vivo and in vitro models of the mechanisms that cause lipid accumulation has not been reported. We used OA/PA-induced NCTC 1469 cells and high-fat-diet-fed C57BL/6J mice to simulate a hepatocyte steatosis model of NAFLD and to detect indicators related to FFA uptake and DNL. In addition, when serological indicators were analysed in the mouse model, it was found that serum FASN levels decreased. The results revealed that, in the cellular model, indicators related to DNL were decreased, FASN enzyme activity was unchanged, and indicators related to FFA uptake were increased, including the high expression of CD36; while, in the animal model, indicators related to both FFA uptake and de novo synthesis were increased, including the high expression of CD36 and the increased protein levels of FASN with enhanced enzyme activity. In addition, after an analysis of the serological indicators in the mouse model, it was found that the serum levels of FASN were reduced. In conclusion, the OA/PA-induced cellular model can be used to study the mechanism of FFA uptake, whereas the high-fat-diet-induced mouse model can be used to study the mechanism of FFA uptake and DNL. Combined treatment with CD36 and FASN may be more effective against NAFLD. FASN in the serum can be used as one of the indicators for the clinical diagnosis of NAFLD.
Topics: Mice; Animals; Mice, Inbred C57BL; Oleic Acid; Palmitic Acid; Non-alcoholic Fatty Liver Disease; Diet, High-Fat; Hepatocytes; Disease Models, Animal; CD36 Antigens; Fatty Acids, Nonesterified
PubMed: 37764494
DOI: 10.3390/molecules28186714 -
Methods in Molecular Biology (Clifton,... 2023The endocannabinoid 2-arachidonoylglycerol (2-AG) exerts its physiological action by binding to and functionally activating type-1 (CB) and type-2 (CB) cannabinoid...
The endocannabinoid 2-arachidonoylglycerol (2-AG) exerts its physiological action by binding to and functionally activating type-1 (CB) and type-2 (CB) cannabinoid receptors. It is thought to be produced through the action of sn-1 selective diacylglycerol lipase (DAGL) that catalyzes 2-AG biosynthesis from sn-2-arachidonate-containing diacylglycerols. Different methodological approaches for measuring DAGL activity in biological samples are now available. Here, a highly sensitive radiometric assay to assess DAGL activity, by using 1-oleoyl[1-C]-2-arachidonoylglycerol as the substrate, is reported. All the steps required to perform lipid extraction, fractionation by thin-layer chromatography (TLC), and quantification of radiolabeled [C]-oleic acid via scintillation counting are described in detail.
Topics: Diglycerides; Endocannabinoids; Lipoprotein Lipase; Oleic Acid; Receptors, Cannabinoid
PubMed: 36152195
DOI: 10.1007/978-1-0716-2728-0_23 -
Journal of Oleo Science 2024Unsaturated fatty acids, such as oleic and linoleic acids, are easily oxidized by exposure to temperature and light in the presence of air to form unsaturated fatty acid... (Comparative Study)
Comparative Study
Unsaturated fatty acids, such as oleic and linoleic acids, are easily oxidized by exposure to temperature and light in the presence of air to form unsaturated fatty acid hydroperoxides as primary oxidation products. However, the catabolic rates of unsaturated fatty acid hydroperoxides in the human body remain unknown. In this study, ethyl esters of C-labeled linoleic acid (*C18:2-EE) and oleic acid (*C18:1-EE) and their hydroperoxides (*C18:2-EE-OOH and *C18:1-EE-OOH, respectively) prepared by the photo-oxidation of *C18:2-EE and *C18:1-EE, respectively, were administered to mice and their catabolic rates were determined by measuring the expired CO levels. *C18:2-EE-OOH and *C18:1-EE-OOH were β-oxidized faster than *C18:2-EE and *C18:1-EE, respectively. Notably, rapid β-oxidation of *C18:2-EE-OOH and *C18:1-EE-OOH was similar to that of medium-chain fatty acids, such as octanoic acid. Then, degradation products of C18:2-EE-OOH and C18:1-EE-OOH were analyzed under gastric conditions by gas chromatography/mass spectrometry. Major decomposition products of C18:2-EE-OOH and C18:1-EE-OOH were medium-chain compounds, such as octanoic acid ethyl ester, 9-oxo-nonanoic acid ethyl ester, and 10-oxo-8-decenoic acid ethyl esters, indicating that C18:2-EE-OOH and C18:1-EE-OOH isomers formed during photo-oxidation were decomposed under acidic conditions. These findings support previous reports that dietary lipid hydroperoxides are not absorbed into the intestine as lipid hydroperoxides but as degradation products. This is the first study to suggest that dietary lipid hydroperoxides decompose during gastric digestion to form medium-chain compounds that are directly absorbed into the liver via the portal vein and rapidly catabolized via β-oxidation.
Topics: Animals; Oxidation-Reduction; Oleic Acid; Linoleic Acid; Carbon Dioxide; Carbon Isotopes; Mice; Male; Hydrogen Peroxide
PubMed: 38825538
DOI: 10.5650/jos.ess23236 -
Experimental Eye Research Apr 2024The accumulation of oleic acid (OA) in the meibum from patients with meibomian gland dysfunction (MGD) suggests that it may contribute to meibomian gland (MG) functional...
The accumulation of oleic acid (OA) in the meibum from patients with meibomian gland dysfunction (MGD) suggests that it may contribute to meibomian gland (MG) functional disorder, as it is a potent stimulator of acne-related lipogenesis and inflammation in sebaceous gland. Therefore, we investigate whether OA induces lipogenesis and inflammasome activation in organotypic cultured mouse MG and human meibomian gland epithelial cells (HMGECs). Organotypic cultured mouse MG and HMGECs were exposed to OA or combinations with specific AMPK agonists 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). Lipogenic status, ductal keratinization, squamous metaplasia, NLRP3/ASC/Caspase-1 inflammasome activation, proinflammatory cytokine IL-1β production, and AMPK pathway phosphorylation in MG were subsequently examined by lipid staining, immunofluorescence staining, immunohistochemical staining, ELISA assay, and Western blot analyses. We found that OA significantly induced lipid accumulation, ductal keratinization, and squamous metaplasia in organotypic cultured MG, as evidenced by increased lipids deposition within acini and duct, upregulated expression of lipogenic proteins (SREBP-1 and HMGCR), and elevation of K10/Sprr1b. Additionally, OA induced NLRP3/ASC/Caspase-1 inflammasome activation, cleavage of Caspase-1, and production of downstream proinflammatory cytokine IL-1β. The findings of lipogenesis and NLRP3-related proinflammatory response in OA-stimulated HMGECs were consistent with those in organotypic cultured MG. OA exposure downregulated phospho-AMPK in two models, while AICAR treatment alleviated lipogenesis by improving AMPK/ACC phosphorylation and SREBP-1/HMGCR expression. Furthermore, AMPK amelioration inhibited activation of the NLRP3/ASC/Caspase-1 axis and secretion of IL-1β, thereby relieving the OA-induced proinflammatory response. These results demonstrated that OA induced lipogenic disorder and NLRP3 inflammasome activation in organotypic cultured mouse MG and HMGECs by suppressing the AMPK signaling pathway, indicating OA may play an etiological role in MGD.
Topics: Humans; Mice; Animals; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Sterol Regulatory Element Binding Protein 1; Oleic Acid; Meibomian Glands; AMP-Activated Protein Kinases; Lipogenesis; Epithelial Cells; Caspase 1; Cytokines; Metaplasia; Carcinoma, Squamous Cell; Interleukin-1beta
PubMed: 38453039
DOI: 10.1016/j.exer.2024.109851 -
Journal of Neuroscience Research May 2024Diets rich in saturated fats are more detrimental to health than those containing mono- or unsaturated fats. Fatty acids are an important source of energy, but they also...
Diets rich in saturated fats are more detrimental to health than those containing mono- or unsaturated fats. Fatty acids are an important source of energy, but they also relay information regarding nutritional status to hypothalamic metabolic circuits and when in excess can be detrimental to these circuits. Astrocytes are the main site of central fatty acid β-oxidation, and hypothalamic astrocytes participate in energy homeostasis, in part by modulating hormonal and nutritional signals reaching metabolic neurons, as well as in the inflammatory response to high-fat diets. Thus, we hypothesized that how hypothalamic astrocytes process-specific fatty acids participates in determining the differential metabolic response and that this is sex dependent as males and females respond differently to high-fat diets. Male and female primary hypothalamic astrocyte cultures were treated with oleic acid (OA) or palmitic acid (PA) for 24 h, and an untargeted metabolomics study was performed. A clear predictive model for PA exposure was obtained, while the metabolome after OA exposure was not different from controls. The observed modifications in metabolites, as well as the expression levels of key metabolic enzymes, indicate a reduction in the activity of the Krebs and glutamate/glutamine cycles in response to PA. In addition, there were specific differences between the response of astrocytes from male and female mice, as well as between hypothalamic and cerebral cortical astrocytes. Thus, the response of hypothalamic astrocytes to specific fatty acids could result in differential impacts on surrounding metabolic neurons and resulting in varied systemic metabolic outcomes.
Topics: Animals; Astrocytes; Oleic Acid; Female; Palmitic Acid; Hypothalamus; Male; Mice; Mice, Inbred C57BL; Sex Characteristics; Cells, Cultured
PubMed: 38741550
DOI: 10.1002/jnr.25339 -
The Journal of Physiology Sep 2023Well-regulated placental palmitic acid (PA) and oleic acid (OA) metabolism is vital for optimal placental function and fetal development, but dysregulation occurs with...
Well-regulated placental palmitic acid (PA) and oleic acid (OA) metabolism is vital for optimal placental function and fetal development, but dysregulation occurs with gestational diabetes (GDM). We hypothesized that such dysregulation might arise from increased maternofetal glucose, leptin or insulin concentrations present in GDM, and that dysregulated PA and OA lipid metabolism could be moderated by myo-inositol, a natural polyol and potential GDM intervention. Placental explants from 21 women were incubated with stable isotope-labelled C-PA or C-OA for 48 h. Explants were treated with glucose (5, 10 mm) or leptin (13 nm) or insulin (150 nm) in combination with myo-inositol (0.3, 30, 60 μm). Forty-seven C-PA lipids and 37 C-OA lipids were measured by liquid chromatography-mass spectrometry (LCMS). Compared with controls (5 mm glucose), glucose (10 mm) increased 19 C-OA lipids and nine C-PA lipids, but decreased C-OA phosphatidylethanolamine 38:5 and C-PA phosphatidylethanolamine 36:4. The effects of leptin and insulin were less prominent than glucose, with leptin increasing C-OA acylcarnitine 18:1, and insulin increasing four C-PA triacylglycerides. Most glucose, leptin and insulin-induced alterations in lipids were attenuated by co-incubation with myo-inositol (30 or 60 μm), with attenuation also occurring in all subgroups stratified by GDM status and fetal sex. However, glucose-induced increases in acylcarnitine were not attenuated by myo-inositol and were even exaggerated in some instances. Myo-inositol therefore appears to generally act as a moderator, suppressing the perturbation of lipid metabolic processes by glucose, leptin and insulin in placenta in vitro. Whether myo-inositol protects the fetus and pregnancy from unfavourable outcomes requires further research. KEY POINTS: Incubation of placental explants with additional glucose, or to a lesser extent insulin or leptin, alters the placental production of C-lipids from C-palmitic acid (PA) and C-oleic acid (OA) in vitro compared with untreated controls from the same placenta. Co-incubation with myo-inositol attenuated most alterations induced by glucose, insulin or leptin in C-lipids, but did not affect alterations in C-acylcarnitines. Alterations induced by glucose and leptin in C-PA triacylglycerides and C-PA phospholipids were influenced by fetal sex and gestational diabetes status, but were all still attenuated by myo-inositol co-incubation. Insulin differently affected C-PA triacylglycerides and C-PA phospholipids depending on fetal sex, with alterations also attenuated by myo-inositol co-incubation.
Topics: Pregnancy; Female; Humans; Insulin; Oleic Acid; Palmitic Acid; Phosphatidylethanolamines; Leptin; Diabetes, Gestational; Placenta; Glucose
PubMed: 37602663
DOI: 10.1113/JP285036 -
Journal of Plant Physiology Aug 2024The oil palm (Elaeis guineensis) is emerging as the world's most important and prolific oilseed crop, celebrated for its impressive oil yield. However, the molecular...
The oil palm (Elaeis guineensis) is emerging as the world's most important and prolific oilseed crop, celebrated for its impressive oil yield. However, the molecular intricacies that govern lipid metabolism and fatty acid accumulation in oil palm fruits remain relatively underexplored. This study reveals a significant correlation between the expression of EgGRP2A, a transcription factor, and the expression of EgFATA in the oil palm. Yeast one-hybrid analysis and electrophoretic mobility shift assays (EMSA) reveal and confirm the binding interactions between EgGRP2A and the promoter region of EgFATA. Subsequent experiments in oil palm protoplasts show that transient overexpression of EgGRP2A leads to a marked upregulation of EgFATA expression. Conversely, downregulation of EgGRP2A in transgenic oil palm embryoids leads to a significant reduction in EgFATA expression. Metabolite profiling in the transgenic embryoids reveals a significant reduction in unsaturated fatty acids, particularly oleic acid. These findings promise profound insights into the regulatory orchestration of EgFATA and the synthesis of fatty acids, particularly oleic acid, in the oil palm. Furthermore, the results lay the foundation for future breeding and genetic improvement efforts aimed at increasing oleic acid content in oil palm varieties.
Topics: Arecaceae; Oleic Acid; Plant Proteins; Transcription Factors; Gene Expression Regulation, Plant; Plants, Genetically Modified
PubMed: 38772323
DOI: 10.1016/j.jplph.2024.154263 -
Nutrients Jan 2023In 2010, the Mediterranean diet was recognized by UNESCO as an Intangible Cultural Heritage of Humanity. Olive oil is the most characteristic food of this diet due to... (Review)
Review
In 2010, the Mediterranean diet was recognized by UNESCO as an Intangible Cultural Heritage of Humanity. Olive oil is the most characteristic food of this diet due to its high nutraceutical value. The positive effects of olive oil have often been attributed to its minor components; however, its oleic acid (OA) content (70-80%) is responsible for its many health properties. OA is an effective biomolecule, although the mechanism by which OA mediates beneficial physiological effects is not fully understood. OA influences cell membrane fluidity, receptors, intracellular signaling pathways, and gene expression. OA may directly regulate both the synthesis and activities of antioxidant enzymes. The anti-inflammatory effect may be related to the inhibition of proinflammatory cytokines and the activation of anti-inflammatory ones. The best-characterized mechanism highlights OA as a natural activator of sirtuin 1 (SIRT1). Oleoylethanolamide (OEA), derived from OA, is an endogenous ligand of the peroxisome proliferator-activated receptor alpha (PPARα) nuclear receptor. OEA regulates dietary fat intake and energy homeostasis and has therefore been suggested to be a potential therapeutic agent for the treatment of obesity. OEA has anti-inflammatory and antioxidant effects. The beneficial effects of olive oil may be related to the actions of OEA. New evidence suggests that oleic acid may influence epigenetic mechanisms, opening a new avenue in the exploration of therapies based on these mechanisms. OA can exert beneficial anti-inflammatory effects by regulating microRNA expression. In this review, we examine the cellular reactions and intracellular processes triggered by OA in T cells, macrophages, and neutrophils in order to better understand the immune modulation exerted by OA.
Topics: Oleic Acid; Olive Oil; Oleic Acids; Anti-Inflammatory Agents; Diet, Mediterranean
PubMed: 36615882
DOI: 10.3390/nu15010224 -
Proceedings of the National Academy of... Mar 2022Neural stem cells, the source of newborn neurons in the adult hippocampus, are intimately involved in learning and memory, mood, and stress response. Despite...
Neural stem cells, the source of newborn neurons in the adult hippocampus, are intimately involved in learning and memory, mood, and stress response. Despite considerable progress in understanding the biology of neural stem cells and neurogenesis, regulating the neural stem cell population precisely has remained elusive because we have lacked the specific targets to stimulate their proliferation and neurogenesis. The orphan nuclear receptor TLX/NR2E1 governs neural stem and progenitor cell self-renewal and proliferation, but the precise mechanism by which it accomplishes this is not well understood because its endogenous ligand is not known. Here, we identify oleic acid (18:1ω9 monounsaturated fatty acid) as such a ligand. We first show that oleic acid is critical for neural stem cell survival. Next, we demonstrate that it binds to TLX to convert it from a transcriptional repressor to a transcriptional activator of cell-cycle and neurogenesis genes, which in turn increases neural stem cell mitotic activity and drives hippocampal neurogenesis in mice. Interestingly, oleic acid-activated TLX strongly up-regulates cell cycle genes while only modestly up-regulating neurogenic genes. We propose a model in which sufficient quantities of this endogenous ligand must bind to TLX to trigger the switch to proliferation and drive the progeny toward neuronal lineage. Oleic acid thus serves as a metabolic regulator of TLX activity that can be used to selectively target neural stem cells, paving the way for future therapeutic manipulations to counteract pathogenic impairments of neurogenesis.
Topics: Animals; Cell Proliferation; Hippocampus; Ligands; Mice; Neurogenesis; Oleic Acid; Orphan Nuclear Receptors; Receptors, Cytoplasmic and Nuclear
PubMed: 35333654
DOI: 10.1073/pnas.2023784119