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Lipids in Health and Disease Jun 2020The relation between dietary and circulating linoleic acid (18:2 n-6, LA), glucose metabolism and liver function is not yet clear. Associations of dietary and...
BACKGROUND
The relation between dietary and circulating linoleic acid (18:2 n-6, LA), glucose metabolism and liver function is not yet clear. Associations of dietary and circulating LA with glucose metabolism and liver function markers were investigated.
METHODS
Cross-sectional analyses in 633 black South Africans (aged > 30 years, 62% female, 51% urban) without type 2 diabetes at baseline of the Prospective Urban Rural Epidemiology study. A cultural-sensitive 145-item food-frequency questionnaire was used to collect dietary data, including LA (percentage of energy; en%). Blood samples were collected to measure circulating LA (% total fatty acids (FA); plasma phospholipids), plasma glucose, glycosylated hemoglobin (HbA1c), serum gamma-glutamyl transferase (GGT), alanine (ALT) and aspartate aminotransferase (AST). Associations per 1 standard deviation (SD) and in tertiles were analyzed using multivariable regression.
RESULTS
Mean (±SD) dietary and circulating LA was 6.8 (±3.1) en% and 16.0 (±3.5) % total FA, respectively. Dietary and circulating LA were not associated with plasma glucose or HbA1c (β per 1 SD: - 0.005 to 0.010, P > 0.20). Higher dietary LA was generally associated with lower serum liver enzymes levels. One SD higher circulating LA was associated with 22% lower serum GGT (β (95% confidence interval): - 0.25 (- 0.31, - 0.18), P < 0.001), but only ≤9% lower for ALT and AST. Circulating LA and serum GGT associations differed by alcohol use and locality.
CONCLUSION
Dietary and circulating LA were inversely associated with markers of impaired liver function, but not with glucose metabolism. Alcohol use may play a role in the association between LA and liver function.
TRIAL REGISTRATION
PURE North-West Province South Africa study described in this manuscript is part of the PURE study. The PURE study is registered in ClinicalTrials.gov (Identifier: NCT03225586; URL).
Topics: Adult; Aged; Biomarkers; Black People; Female; Glucose; Glycated Hemoglobin; Humans; Linoleic Acid; Liver; Liver Diseases; Male; Middle Aged; Phospholipids; South Africa; gamma-Glutamyltransferase
PubMed: 32546275
DOI: 10.1186/s12944-020-01318-3 -
Journal of Oleo Science Jul 2019Camellia oleifera, C. japonica and C. sinensis are three representative crops of the genus Camellia. In this work, we systematically investigated the lipid...
Camellia oleifera, C. japonica and C. sinensis are three representative crops of the genus Camellia. In this work, we systematically investigated the lipid characteristics of these seed oils collected from different regions. The results indicated significant differences in acid value (AV), peroxide value (PV), iodine value (IV), saponification value (SV) and relative density of the above-mentioned camellia seed oils (p < 0.05). The C. japonica seed oils showed the highest AV (1.7 mg/g), and the C. sinensis seed oils showed the highest PV (17.4 meq/kg). The C. japonica seed oils showed the lowest IV (79.9 g/100 g), SV (192.7 mg/g) and refractive index (1.4633) of all the oils, while the C. sinensis seed oils showed the lowest relative density (0.911 g/cm). The major fatty acids in the camellia seed oils were palmitic acid (16:0), oleic acid (18:1) and linoleic acid (18:2); the oleic acid in C. oleifera and C. japonica seed oils accounted for more than 80% of the total fatty acids. The oleic acid levels in the C. oleifera and C. japonica oils were higher than those in the C. sinensis seed oils, while the linoleic acid levels in the former were lower than those in the latter one. Differences also exist in the triacylglycerol (TAG) composition, although the most abundant TAG molecular species in the camellia seed oils was trioleoylglycerol (OOO). Seven sterol species, squalene and α-tocopherol were detected in the camellia seed oils, however, the contents of tocopherol and unsaponifiable molecules in the C. oleifera and C. japonica seed oils were significantly lower than those in the C. sinensis seed oil. These results demonstrated that the varieties of Camellia affected the seed oil lipid characteristics.
Topics: Camellia; Chemical Phenomena; Linoleic Acid; Oleic Acid; Palmitic Acid; Phytosterols; Plant Oils; Seeds; Squalene; Triglycerides; Triolein; alpha-Tocopherol
PubMed: 31178460
DOI: 10.5650/jos.ess18234 -
Nutrients Oct 2019Good sources of the long-chain n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) include cold-water fish and seafood; however, vegan diets... (Review)
Review
Good sources of the long-chain n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) include cold-water fish and seafood; however, vegan diets (VGNs) do not include animal-origin foods. Typically, US omnivores obtain enough dietary EPA and DHA, but unless VGNs consume algal n-3 supplements, they rely on endogenous production of long-chain fatty acids. VGN diets have several possible concerns: (1) VGNs have high intakes of linoleic acid (LA) as compared to omnivore/non-vegetarian diets. (2) High intakes of LA competitively interfere with the endogenous conversion of alpha-linolenic acid (ALA) to EPA and DHA. (3) High somatic levels of LA/low ALA indicate a decreased ALA conversion to EPA and DHA. (4) Some, not all VGNs meet the Dietary Reference Intake Adequate Intake (DRI-AI) for dietary ALA and (5) VGN diets are high in fiber, which possibly interferes with fat absorption. Consequently, health professionals and Registered Dietitians/Registered Dietitian Nutritionists working with VGNs need specific essential fatty acid diet guidelines. The purpose of this review was: (1) to suggest that VGNs have a DRI-AI Special Consideration requirement for ALA and LA based on VGN dietary and biochemical indicators of status and (2) to provide suggestions to ensure that VGNs receive adequate intakes of LA and ALA.
Topics: Diet, Vegan; Docosahexaenoic Acids; Eicosapentaenoic Acid; Humans; Linoleic Acid; Nutritional Status; Nutritive Value; Recommended Dietary Allowances; alpha-Linolenic Acid
PubMed: 31590264
DOI: 10.3390/nu11102365 -
The Journal of Nutritional Biochemistry Apr 2016Docosahexaenoic acid (DHA) is thought to be important for brain function. The main dietary source of DHA is fish, however, DHA can also be synthesized from precursor...
Docosahexaenoic acid (DHA) is thought to be important for brain function. The main dietary source of DHA is fish, however, DHA can also be synthesized from precursor omega-3 polyunsaturated fatty acids (n-3 PUFA), the most abundantly consumed being α-linolenic acid (ALA). The enzymes required to synthesize DHA from ALA are also used to synthesize longer chain omega-6 (n-6) PUFA from linoleic acid (LNA). The large increase in LNA consumption that has occurred over the last century has led to concern that LNA and other n-6 PUFA outcompete n-3 PUFA for enzymes involved in DHA synthesis, and therefore, decrease overall DHA synthesis. To assess this, rats were fed diets containing LNA at 53 (high LNA diet), 11 (medium LNA diet) or 1.5% (low LNA diet) of the fatty acids with ALA being constant across all diets (approximately 4% of the fatty acids). Rats were maintained on these diets from weaning for 8 weeks, at which point they were subjected to a steady-state infusion of labeled ALA and LNA to measure DHA and arachidonic acid (ARA) synthesis rates. DHA and ARA synthesis rates were generally highest in rats fed the medium and high LNA diets, while the plasma half-life of DHA was longer in rats fed the low LNA diet. Therefore, increasing dietary LNA, in rats, did not impair DHA synthesis; however, low dietary LNA led to a decrease in DHA synthesis with tissue concentrations of DHA possibly being maintained by a longer DHA half-life.
Topics: Animals; Fatty Acids, Unsaturated; Linoleic Acid; Rats
PubMed: 27012633
DOI: 10.1016/j.jnutbio.2015.11.016 -
Cell Communication and Signaling : CCS Oct 2019Linoleic acid is the major fatty acid moiety of cardiolipin, which is central to the assembly of components involved in mitochondrial oxidative phosphorylation (OXPHOS).... (Clinical Trial)
Clinical Trial
BACKGROUND
Linoleic acid is the major fatty acid moiety of cardiolipin, which is central to the assembly of components involved in mitochondrial oxidative phosphorylation (OXPHOS). Although linoleic acid is an essential nutrient, its excess intake is harmful to health. On the other hand, linoleic acid has been shown to prevent the reduction in cardiolipin content and to improve mitochondrial function in aged rats with spontaneous hypertensive heart failure (HF). In this study, we found that lower dietary intake of linoleic acid in HF patients statistically correlates with greater severity of HF, and we investigated the mechanisms therein involved.
METHODS
HF patients, who were classified as New York Heart Association (NYHA) functional class I (n = 45), II (n = 93), and III (n = 15), were analyzed regarding their dietary intakes of different fatty acids during the one month prior to the study. Then, using a mouse model of HF, we confirmed reduced cardiolipin levels in their cardiac myocytes, and then analyzed the mechanisms by which dietary supplementation of linoleic acid improves cardiac malfunction of mitochondria.
RESULTS
The dietary intake of linoleic acid was significantly lower in NYHA III patients, as compared to NYHA II patients. In HF model mice, both CI-based and CII-based OXPHOS activities were affected together with reduced cardiolipin levels. Silencing of CRLS1, which encodes cardiolipin synthetase, in cultured cardiomyocytes phenocopied these events. Feeding HF mice with linoleic acid improved both CI-based and CII-based respiration as well as left ventricular function, together with an increase in cardiolipin levels. However, although assembly of the respirasome (i.e., CI/CIII/CIV complex), as well as assembly of CII subunits and the CIII/CIV complex statistically correlated with cardiolipin levels in cultured cardiomyocytes, respirasome assembly was not notably restored by dietary linoleic acid in HF mice. Therefore, although linoleic acid may significantly improve both CI-based and CII-based respiration of cardiomyocytes, respirasomes impaired by HF were not easily repaired by the dietary intake of linoleic acid.
CONCLUSIONS
Dietary supplement of linoleic acid is beneficial for improving cardiac malfunction in HF, but is unable to completely cure HF.
Topics: Aged; Animals; Cardiolipins; Electron Transport Complex II; Electron Transport Complex III; Electron Transport Complex IV; Female; Heart Failure; Humans; Linoleic Acid; Male; Mice; Mitochondria, Heart; Oxidative Phosphorylation; Protein Subunits
PubMed: 31619261
DOI: 10.1186/s12964-019-0445-0 -
Journal of Dairy Science Jun 2003A gas chromatographic procedure was used for analysis of conjugated linoleic acid (CLA) isomers cis-9, trans-11-octadecadienoic; trans-10, cis-12 octadecadienoic; and...
A gas chromatographic procedure was used for analysis of conjugated linoleic acid (CLA) isomers cis-9, trans-11-octadecadienoic; trans-10, cis-12 octadecadienoic; and trans-9, trans-11-octadecadienoic (c9t11, t10c12, t9t11) produced by lactobacilli. Four different cultures, two strains each of Lactobacillus acidophilus and Lactobacillus casei were tested for their ability to produce CLA from free linoleic acid in MRS broth supplemented with linoleic acid. Different concentrations of linoleic acid (0, 0.05, 0.1, 0.2 and 0.5 mg/ml) were added to MRS broth, inoculated with the lactobacilli, and incubated at 37 degrees C. Viable counts and amounts of individual isomers of CLA (c9t11, t10c12, t9t11) were measured at 0, 24, 48, and 72 h. All the cultures were able to produce free CLA in media supplemented with linoleic acid. Maximum production of CLA (80.14 to 131.63 microg/ml) was observed at 24 h of incubation in broth containing 0.02% of free linoleic acid. No significant (P > 0.05) increases in total CLA levels were observed after 24 h of incubation. The ability of the cultures to produce CLA in skim milk supplemented with 0.02% free linoleic acid also was studied. In this medium, the total amounts of free CLA after 24 h of incubation ranged from 54.31 to 116.53 microg/ml. The use of lactic acid bacteria able to form free CLA in cultured dairy products may have potential health or nutritional benefits. Free CLA in the products likely would be more readily available for absorption from the digestive tract than if it were incorporated into the cells of the starter culture.
Topics: Animals; Chromatography, Gas; Chromatography, High Pressure Liquid; Humans; Intestines; Lactobacillus acidophilus; Lacticaseibacillus casei; Linoleic Acid; Milk
PubMed: 12836928
DOI: 10.3168/jds.S0022-0302(03)73781-3 -
BMC Gastroenterology May 2022Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy with poor prognosis. Intrahepatic bile duct stone (IBDS) is one of the key...
BACKGROUND
Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy with poor prognosis. Intrahepatic bile duct stone (IBDS) is one of the key causes to ICC occurrence and can increase morbidity rate of ICC about forty times. However, the specific carcinogenesis of IBDS is still far from clarified. Insight into the metabolic phenotype difference between IBDS and ICC can provide potential mechanisms and therapeutic targets, which is expected to inhibit the carcinogenesis of IBDS and improve the prognosis of ICC.
METHODS
A total of 34 participants including 25 ICC patients and 9 IBDS patients were recruited. Baseline information inclusive of liver function indicators, tumor biomarkers, surgery condition and constitution parameters etc. from patients were recorded. ICC and IBDS pathological tissues, as well as ICC para-carcinoma tissues, were collected for GC-MS based metabolomics experiments. Multivariate analysis was performed to find differentially expressed metabolites and differentially enriched metabolic pathways. Spearman correlation analysis was then used to construct correlation network between key metabolite and baseline information of patients.
RESULTS
The IBDS tissue and para-carcinoma tissue have blurred metabolic phenotypic differences, but both of them essentially distinguished from carcinoma tissue of ICC. Metabolic differences between IBDS and ICC were enriched in linoleic acid metabolism pathway, and the level of 9,12-octadecadienoic acid in IBDS tissues was almost two times higher than in ICC pathological tissues. The correlation between 9,12-octadecadienoic acid level and baseline information of patients demonstrated that 9,12-octadecadienoic acid level in pathological tissue was negative correlation with gamma-glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP) level in peripheral blood. These two indicators were all cancerization marker for hepatic carcinoma and disease characteristic of IBDS.
CONCLUSION
Long-term monitoring of metabolites from linoleic acid metabolism pathway and protein indicators of liver function in IBDS patients has important guiding significance for the monitoring of IBDS carcinogenesis. Meanwhile, further insight into the causal relationship between linoleic acid pathway disturbance and changes in liver function can provide important therapeutic targets for both IBDS and ICC.
Topics: Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Carcinogenesis; Cholangiocarcinoma; Humans; Linoleic Acid
PubMed: 35637430
DOI: 10.1186/s12876-022-02354-2 -
Prostaglandins, Leukotrienes, and... 2012Linoleic acid (LA) is the most abundant polyunsaturated fatty acid in human diets, a major component of human tissues, and the direct precursor to the bioactive oxidized... (Randomized Controlled Trial)
Randomized Controlled Trial
Linoleic acid (LA) is the most abundant polyunsaturated fatty acid in human diets, a major component of human tissues, and the direct precursor to the bioactive oxidized LA metabolites (OXLAMs), 9- and 13 hydroxy-octadecadienoic acid (9- and 13-HODE) and 9- and 13-oxo-octadecadienoic acid (9- and 13-oxoODE). These four OXLAMs have been mechanistically linked to pathological conditions ranging from cardiovascular disease to chronic pain. Plasma OXLAMs, which are elevated in Alzheimer's dementia and non-alcoholic steatohepatitis, have been proposed as biomarkers useful for indicating the presence and severity of both conditions. Because mammals lack the enzymatic machinery needed for de novo LA synthesis, the abundance of LA and OXLAMs in mammalian tissues may be modifiable via diet. To examine this issue in humans, we measured circulating LA and OXLAMs before and after a 12-week LA lowering dietary intervention in chronic headache patients. Lowering dietary LA significantly reduced the abundance of plasma OXLAMs, and reduced the LA content of multiple circulating lipid fractions that may serve as precursor pools for endogenous OXLAM synthesis. These results show that lowering dietary LA can reduce the synthesis and/or accumulation of oxidized LA derivatives that have been implicated in a variety of pathological conditions. Future studies evaluating the clinical implications of diet-induced OXLAM reductions are warranted.
Topics: Adult; Dietary Fats; Female; Headache; Humans; Linoleic Acid; Linoleic Acids; Linoleic Acids, Conjugated; Male; Middle Aged; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Young Adult
PubMed: 22959954
DOI: 10.1016/j.plefa.2012.08.004 -
Cellular Physiology and Biochemistry :... 2019The omega 6 fatty acid (FA) linoleic acid (LA) is required for embryonic development; however, omega 6 FAs can alter cellular metabolism via inflammation or modulation...
BACKGROUND/AIMS
The omega 6 fatty acid (FA) linoleic acid (LA) is required for embryonic development; however, omega 6 FAs can alter cellular metabolism via inflammation or modulation of mitochondrial function. Fetal LA is obtained from the maternal diet, and FAs are transported to the fetus via placental FA transporters (FATPs) and binding proteins (FABPs), but specific proteins responsible for LA transport in placental trophoblasts are unknown. Dietary LA consumption is increasing, but the effect of elevated LA on trophoblast function is not clear.
METHODS
Swan71 trophoblasts were exposed to physiological and supraphysiological concentrations of LA for 24 hours. Quantification of mRNA was determined using real time PCR, and protein concentration was determined by Western blot analysis. Cell viability, citrate synthase activity and mitochondrial respiration were determined.
RESULTS
Exposure to 300 and 500 μM LA increased FATP1 and FATP4 mRNA expression. 500 μM LA increased FATP1 and FATP4 protein expression. Exposure to 500 μM increased FABP5 mRNA expression, while exposure to 100 to 500 μM LA decreased FABP3 mRNA expression. 300 and 500 μM LA decreased FABP3 protein expression. Cell viability was decreased by exposure to LA (100 to 1000 μM). Citrate synthase activity and routine mitochondrial respiration were significantly decreased by exposure to 300 and 500 μM LA, and maximal respiration and spare respiratory capacity were decreased by exposure to 100 to 500 μM LA. 300 and 500 μM LA increased reactive oxygen species generation in human trophoblasts. Moreover, exposure to 300 and 500 μM LA decreased IL-6 secretion. Exposure to 500 μM LA increased IL-8, NF-κB and PPAR-γ mRNA expression, but decreased NF-κB protein expression. 300 μM LA decreased IL-8 protein expression. Further, exposure to 100 to 500 μM LA increased prostaglandin E2 and leukotriene B₄ release.
CONCLUSION
Exposure to LA decreases cell viability, alters mRNA expression of FA transport related proteins, mitochondrial respiration and function, and inflammatory responses in trophoblasts. These findings may have implications on placental function when women consume high levels of LA.
Topics: Cell Line; Cell Survival; Dinoprostone; Gene Expression Regulation; Humans; Linoleic Acid; Mitochondria; Mitochondrial Proteins; Oxygen Consumption; Trophoblasts
PubMed: 30790507
DOI: 10.33594/000000007 -
Acta Biochimica Polonica Feb 2020Lactobacillus plantarum YW11 capability to convert linoleic acid into conjugated linoleic acid and other metabolites was studied in a dose-dependent manner by...
Lactobacillus plantarum YW11 capability to convert linoleic acid into conjugated linoleic acid and other metabolites was studied in a dose-dependent manner by supplementing LA at different concentrations. L. plantarum YW11 displayed a uniform distinctive growth curve of CLA and other metabolites at concentrations of LA ranging from 1% (w/v) to 10% (w/v), with slightly increased growth at higher LA concentrations. The biotransformation capability of L. plantarum YW11 evaluated by GC-MS revealed a total of one CLA isomer, i.e. 9-cis,11-trans-octadecadienoic acid, also known as the rumenic acid (RA), one linoleic acid isomer (linoelaidic acid), and LA metabolites: (E)-9-octadecenoic acid ethyl ester, trans, trans-9,12-octadecadienoic acid, propyl ester and stearic acid. All the metabolites of linoleic acid were produced from 1 to 10% LA supplemented MRS media, while surprisingly the only conjugated linoleic acid compound was produced at 10% LA. To assess the presence of putative enzymes, responsible for conversion of LA into CLA, in silico characterization was carried out. The in silico characterization revealed presence of four enzymes (10-linoleic acid hydratase, linoleate isomerase, acetoacetate decarboxylase and dehydrogenase) that may be involved in the production of CLA (rumenic acid) and LA isomers. The biotransformation ability of L. plantarum YW11 to convert LA into RA has great prospects for biotechnological and industrial implications that could be exploited in the future scale-up experiments.
Topics: Biotransformation; Computer Simulation; Food Microbiology; Gas Chromatography-Mass Spectrometry; Humans; Isomerism; Lactobacillus plantarum; Linoleic Acid; Linoleic Acids, Conjugated
PubMed: 32031769
DOI: 10.18388/abp.2020_5095