Docosahexaenoic acid (DHA) and cardiovascular disease risk factors

Stimulus-response signaling dynamics characterize macrophage polarization states

The functional state of cells is dependent on their microenvironmental context. Prior studies described how polarizing cytokines alter macrophage transcriptomes and epigenomes. Here, we characterized the functional responses of 6 differentially polarized macrophage populations by measuring the dynamics of transcription factor nuclear factor κB (NF-κB) in response to 8 stimuli. The resulting dataset of single-cell NF-κB trajectories was analyzed by three approaches: (1) machine learning on time-series data revealed losses of stimulus distinguishability with polarization, reflecting canalized effector functions. (2) Informative trajectory features driving stimulus distinguishability ("signaling codons") were identified and used for mapping a cell state landscape that could then locate macrophages conditioned by an unrelated condition. (3) Kinetic parameters, inferred using a mechanistic NF-κB network model, provided an alternative mapping of cell states and correctly predicted biochemical findings. Together, this work demonstrates that a single analyte's dynamic trajectories may distinguish the functional states of single cells and molecular network states underlying them. A record of this paper's transparent peer review process is included in the supplemental information.

The effect of conjugated linoleic acid supplementation in comparison with omega-6 and omega-9 on lipid profile: a graded, dose-response systematic review and meta-analysis of randomized controlled trials

Conjugated linoleic acid (CLA) is a geometrical isomer of linoleic acid, which has anti-inflammatory, anti-diabetic, anti-cancer, and anti-obesity properties. However, the studies reported inconstant results about the CLA-related effects on lipid profiles. As a result, meta-analysis and systematic review were performed to survey the CLA supplementation-related effect on lipid profile including high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol (TC), and triglycerides (TG). To identify the relevant research, a systematic comprehensive search was initiated on the medical databases such as Scopus and PubMed/Medline until December 2022. The overall effect size was estimated by weighted mean difference (WMD) and 95% confidence interval (CI) in a random effect meta-analysis. In the final quantitative analysis, the meta-analysis considered 35 randomized controlled trials (RCTs) with 1,476 participants (707 controls and 769 cases). The pooled results demonstrated that CLA supplementation, compared with olive oil, significantly increased serum TG levels (WMD: 0.05 mmol/L; 95% CI: 0.01 to 0.1; p = 0.04; I2 = 0.0%, p = 0.91). With regard to TC level, CLA supplementation compared with placebo significantly reduced TC concentrations (WMD: -0.08 mmol/L; 95% CI: -0.14 to -0.02; p < 0.001; I2 = 82.4%). Moreover, the non-linear dose-response analysis indicated a decreasing trend of TC serum level from the 15th week of CLA supplementation compared with olive oil (Pnon-linearity = 0.01). The present meta-analysis and systematic review of 35 RCTs showed that the CLA intervention was able to raise the level of TG in comparison to olive oil; however, it can decrease TC level compared with placebo and olive oil.

Indexing of Fatty Acids in Poultry Meat for Its Characterization in Healthy Human Nutrition: A Comprehensive Application of the Scientific Literature and New Proposals

Chicken meat is becoming the most consumed in the world for both economic and nutritional reasons; regarding the latter, the lipid profile may play positive or negative roles in the prevention and treatment of diseases. In this study, we define the state of the art of lipid-based nutritional indexes and used the lipid content and fatty acid profile (both qualitative and quantitative) of breast meat of two poultry genotypes with different growth rates and meat traits. Further, we summarize and review the definitions, implications, and applications of nutritional indexes used in recent years and others of our own design to provide a useful tool to researchers working in the field of meat quality (not only in poultry) to select the most appropriate index for their own scientific purposes. All indexes show advantages and disadvantages; hence, a rational choice should be applied to consider the nutritional effect of meat on human health and for a possible assessment of the most suitable rearing systems (genotype, feeding, farming system or postmortem handling).

Encapsulation of Docosahexaenoic Acid Oil Substantially Improves the Oxylipin Profile of Rat Tissues

Docosahexaenoic acid (DHA) is a major n-3 polyunsaturated fatty acid (PUFA) particularly involved in cognitive and cardiovascular functions. Due to the high unsaturation index, its dietary intake form has been considered to improve oxidation status and to favor bioaccessibility and bioavailability as well. This study aimed at investigating the effect of DHA encapsulated with natural whey protein. DHA was dietary provided as triacylglycerols to achieve 2.3% over total fatty acids. It was daily supplied to weanling rats for four weeks in omelet as food matrix, consecutively to a 6-hour fasting. First, when DHA oil was encapsulated, consumption of chow diet was enhanced leading to promote animal growth. Second, the brain exhibited a high accretion of 22.8% DHA, which was not improved by dietary supplementation of DHA. Encapsulation of DHA oil did not greatly affect the fatty acid proportions in tissues, but remarkably modified the profile of oxidized metabolites of fatty acids in plasma, heart, and even brain. Specific oxylipins derived from DHA were upgraded, such as Protectin Dx in heart and 14-HDoHE in brain, whereas those generated from n-6 PUFAs were mainly mitigated. This effect did not result from oxylipins measured in DHA oil since DHA and EPA derivatives were undetected after food processing. Collectively, these data suggested that dietary encapsulation of DHA oil triggered a more efficient absorption of DHA, the metabolism of which was enhanced more than its own accretion in our experimental conditions. Incorporating DHA oil in functional food may finally improve the global health status by generating precursors of protectins and maresins.

The ALGOVUE Clinical Trial: Effects of the Daily Consumption of Eggs Enriched with Lutein and Docosahexaenoic Acid on Plasma Composition and Macular Pigment Optical Density

Background. Carotenoids and docosahexaenoic acid (DHA) were identified as essential components for eye health and are both naturally present in eggs. Objective. We aimed to evaluate the effect of the daily consumption of two eggs enriched with lutein/zeaxanthin and DHA on macular pigment optical density (MPOD) and on circulating xanthophyll and fatty acid concentrations in healthy participants. Methods. Ninety-nine healthy volunteers consumed either two standard eggs or two enriched eggs per day for 4 months. MPOD was measured at baseline (V0) and at follow-up (V4) using a modified confocal scanning laser ophthalmoscope (primary outcome). Blood samples were collected to determine total plasma and lipoprotein fatty acids and lutein/zeaxanthin compositions at V0 and V4 (secondary outcomes). Results. A slight but significant increase in MPOD was observed for all study participants consuming two eggs per day for 4 months at all eccentricities (0.5°, 1°, 2°, and 4°). Plasma and lipoprotein lutein, zeaxanthin, and DHA concentrations significantly increased in both groups but were greater in the enriched group (for the enriched group (V0 vs. V4): lutein, 167 vs. 369 ng/mL; zeaxanthin, 17.7 vs. 29.2 ng/mL; DHA, 1.89 vs. 2.56% of total fatty acids). Interestingly, lutein from high-density lipoprotein (HDL) was strongly correlated with MPOD at 0.5 and 1° eccentricities (rho = 0.385, p = 0.008, and rho = 0.461, p = 0.001, respectively). Conclusions. MPOD was slightly increased in both groups. Lutein, zeaxanthin, and DHA plasma concentrations were strongly enhanced in the enriched group compared with the standard group. A significant correlation was found between MPOD level and lutein concentration in HDL.

Docosahexaenoic Acid Inhibits Expression of Fibrotic Mediators in Mice With Chronic Pancreatitis

Background

Chronic pancreatitis (CP) is an irreversible progressive disease that destroys exocrine parenchyma, which are replaced by fibrous tissue. As pancreatic fibrosis is a key feature of CP, reducing fibrotic protein content in the pancreas is crucial for preventing CP. Studies suggest that NF-κB facilitates the expression of fibrotic mediators in pancreas and protein kinase C-δ (PKC-δ) regulates NF-κB activation in stimulated pancreatic acinar cells. Docosahexaenoic acid (DHA) is an omega-3 fatty acid having anti-inflammatory and anti-fibrotic effects. It has been shown to inhibit NF-κB activity in cerulein-stimulated pancreatic acinar cells which is a cellular model of CP. In the present study, we investigated if DHA inhibits expression of fibrotic mediators by reducing PKC-δ and NF-κB expression in mouse pancreatic tissues with CP.

Methods

For six weeks, mice were weekly induced for acute pancreatitis to develop CP. Furthermore, acute pancreatitis was induced by hourly intraperitoneal injections of cerulein (50 μg/kg × 7). Mice were administered DHA (10 μM) via drinking water before and after CP induction.

Results

Cerulein-induced pancreatic damages like decreased pancreatic weight/total body weight, leukocyte infiltration, necrosis of acinar cells, and vacuolization were found to be inhibited by DHA. Additionally, DHA inhibited cerulein-induced fibrotic mediators like alpha-smooth muscle actin and fibronectin in pancreas. DHA reduced expression of PKC-δ and NF-κB p65 in pancreatic tissues of cerulein-treated mice.

Conclusions

DHA may be beneficial in preventing CP by suppressing pancreatic expression of fibrotic mediators.

Evaluation of the Performance of Lipidyzer Platform and Its Application in the Lipidomics Analysis in Mouse Heart and Liver

Lipids play important roles in cell signaling, energy storage, and as major structural components of cell membranes. To date, little work has been conducted to show the extent of tissue specificity of lipid compositions. Here, the recently acquired Lipidyzer platform was employed in this pilot study: (i) to assess the performance of the Lipidyzer platform, (ii) to explore lipid profiles in liver and cardiac tissue in mice, (iii) to examine sex-specific differences in lipids in the liver tissue, and (iv) to evaluate biological variances in lipidomes present in animals. In total, 787 lipid species from 13 lipid classes were measured in the liver and heart. Lipidomics data from the Lipidyzer platform were very reproducible with the coefficient of variations of the quality control (QC) samples, ∼10%. The total concentration of the cholesterol esters (CE) lipid class, and specifically CE(16:1) and CE(18:1) species, showed sex differences in the liver. Cardiac tissue had higher levels of phospholipids containing docosahexaenoic acid, which could be related to heart health status and function. Our results demonstrate the usefulness of the Lipidyzer platform in identifying differences in lipid profile at the tissue level and between male and female mice in specific tissues.

Non-enzymatic conversion of primary oxidation products of Docosahexaenoic acid into less toxic acid molecules

Docosahexaenoic acid (DHA) is long chain omega-3 fatty acid with known health benefits and clinical significance. However, 4-hydroxy hexenal (HHE), an enzymatic oxidation product of DHA has recently been reported to have health-damaging effects. This conflict raises major concern on the long-term clinical use of these fatty acids. Even though the enzymatic and non-enzymatic conversion of HHE to nontoxic acid molecules is possible by the aldehyde detoxification systems, it has not yet studied. To address this, primary oxidation products of DHA in lipoxidase system were subjected to non-enzymatic conversion at physiological temperature over a period of 1 week. The reaction was monitored using HPLC, IR spectroscopy and biochemical assays (based on the loss of conjugated dienes, lipid peroxides aldehydes). Short term and long term cytotoxicity of the compounds generated at various time points were analyzed. IR and HPLC spectra revealed that the level of aldehydes in the primary oxidation products reduced over time, generating acids and acid derivatives within a week period. In short term and long term cytotoxicity analysis, initial decomposition products were found more toxic than the 1-week decomposition products. Further, when primary oxidation products were subjected to aldehyde dehydrogenase mediated oxidation, it generated products that are also less toxic. The study suggests the possible non-enzymatic conversion of primary oxidation products of DHA to less cytotoxic acid molecules. Exploration of the physiological roles of these acid molecules may explain the biological potential of omega-3 fatty acids.

Combining Desorption Electrospray Ionization Mass Spectrometry Imaging and Machine Learning for Molecular Recognition of Myocardial Infarction

Lipid profile changes in heart muscle have been previously linked to cardiac ischemia and myocardial infarction, but the spatial distribution of lipids and metabolites in ischemic heart remains to be fully investigated. We performed desorption electrospray ionization mass spectrometry imaging of hearts from in vivo myocardial infarction mouse models. In these mice, myocardial ischemia was induced by blood supply restriction via a permanent ligation of left anterior descending coronary artery. We showed that applying the machine learning algorithm of gradient boosting tree ensemble to the ambient mass spectrometry imaging data allows us to distinguish segments of infarcted myocardium from normally perfused hearts on a pixel by pixel basis. The machine learning algorithm selected 62 molecular ion peaks important for classification of each 200 μm-diameter pixel of the cardiac tissue map as normally perfused or ischemic. This approach achieved very high average accuracy (97.4%), recall (95.8%), and precision (96.8%) at a spatial resolution of ∼200 μm. In addition, we determined the chemical identity of 27 species, mostly small metabolites and lipids, selected by the algorithm as the most significant for cardiac pathology classification. This molecular signature of myocardial infarction may provide new mechanistic insights into cardiac ischemia, assist with infarct size assessment, and point toward novel therapeutic interventions.

Synthesis of 2-docosahexaenoylglycerol by enzymatic ethanolysis

Synthesis of 2-docosahexaenoylglycerol with high nutritional value was conducted by enzymatic ethanolysis of algal oil. The effects of lipase type, substrate molar ratio of algal oil to ethanol, reaction time, reaction temperature and lipase load on the content of 2-monoacylglycerols (2-MAGs) in the crude product were investigated. Under the optimal conditions, 27-31% 2-MAGs were obtained in the ethanolysis reaction. Lipozyme 435 exhibited 1,3-specific selectivity and maintained stable operational stability after 7 successive reuse cycles. The enzymatic ethanolysis catalyzed by Lipozyme 435 could both synthesize 2-MAGs and concentrate DHA. Further purification of 2-MAGs was performed with solvent extraction by 85% ethanol aqueous solution and hexane, obtaining 95% 2-MAGs in a yield of 67%. The contents of DHA in 2-MAGs product and 2-MAGs fraction were 74.76% and 75.66%, respectively, which were about 26% higher than that in the algal oil. Therefore, this method is efficient and environmental-friendly for synthesis of 2-docosahexaenoylgylcerol.

Algae as nutritional and functional food sources: revisiting our understanding

Global demand for macroalgal and microalgal foods is growing, and algae are increasingly being consumed for functional benefits beyond the traditional considerations of nutrition and health. There is substantial evidence for the health benefits of algal-derived food products, but there remain considerable challenges in quantifying these benefits, as well as possible adverse effects. First, there is a limited understanding of nutritional composition across algal species, geographical regions, and seasons, all of which can substantially affect their dietary value. The second issue is quantifying which fractions of algal foods are bioavailable to humans, and which factors influence how food constituents are released, ranging from food preparation through genetic differentiation in the gut microbiome. Third is understanding how algal nutritional and functional constituents interact in human metabolism. Superimposed considerations are the effects of harvesting, storage, and food processing techniques that can dramatically influence the potential nutritive value of algal-derived foods. We highlight this rapidly advancing area of algal science with a particular focus on the key research required to assess better the health benefits of an alga or algal product. There are rich opportunities for phycologists in this emerging field, requiring exciting new experimental and collaborative approaches.

DHA and EPA Content and Fatty Acid Profile of 39 Food Fishes from India

Docosahexaenoic acid (DHA) is the principal constituent of a variety of cells especially the brain neurons and retinal cells and plays important role in fetal brain development, development of motor skills, and visual acuity in infants, lipid metabolism, and cognitive support and along with eicosapentaenoic acid (EPA) it plays important role in preventing atherosclerosis, dementia, rheumatoid arthritis, Alzheimer's disease, and so forth. Being an essential nutrient, it is to be obtained through diet and therefore searching for affordable sources of these ω-3 polyunsaturated fatty acids (PUFA) is important for consumer guidance and dietary counseling. Fish is an important source of PUFA and has unique advantage that there are many food fish species available and consumers have a wide choice owing to availability and affordability. The Indian subcontinent harbors a rich fish biodiversity which markedly varies in their nutrient composition. Here we report the DHA and EPA content and fatty acid profile of 39 important food fishes (including finfishes, shellfishes, and edible molluscs from both marine water and freshwater) from India. The study showed that fishes Tenualosa ilisha, Sardinella longiceps, Nemipterus japonicus, and Anabas testudineus are rich sources of DHA and EPA. Promotion of these species as DHA rich species would enhance their utility in public health nutrition.

Docosahexaenoic acid prevented tumor necrosis factor alpha-induced endothelial dysfunction and senescence

We investigated how docosahexaenoic acid (DHA) regulated tumor necrosis factor-alpha (TNF-α)-induced senescence and dysfunction in endothelial cells (EC). We used RT-PCR to examine the expression of several genes related to senescence and dysfunction in EC. TNF-α-induced p21 protein levels were investigated by Western blot (WB) and fluorescence antibody techniques. TNF-α induced the senescence marker β-galactosidase and the expression of several senescence and endothelial dysfunction-related genes, e.g., CDKN1A, SHC1 and GLB1. DHA attenuated TNF-α-induced senescence-related gene expression and p21 protein expression. DHA attenuated TNF-α-induced gene expression related to dysfunction of EC, such as plasminogen activator inhibitor 1 (SERPINE1), lectin-like oxidized low-density lipoprotein receptor-1 (OLR1), thromboxane A2 receptor (TXA2R) and p38 MAPK (MAPK14). DHA reversed the TNF-α-mediated reduction of endothelial nitric oxide synthase (NOS3) gene expression. TNF-α-mediated upregulation of these genes was inhibited by allopurinol and apocynin. These results indicated that DHA regulated the expression of several genes that are associated with senescence and dysfunction of EC.

Understanding the cholesterol metabolism-perturbing effects of docosahexaenoic acid by gas chromatography-mass spectrometry targeted metabonomic profiling

PURPOSE

Over the past few decades, docosahexaenoic acid (DHA) has gained special attention for management of cholesterol-associated metabolic disorders and neurodegenerative diseases such as Alzheimer's disease (AD) owing to its neuroprotective, anti-inflammatory and hypolipidemic properties. Several epidemiological studies have reported the effect of DHA in reducing the risk of developing AD by lowering cholesterol. Hypercholesterolemia is a pro-amyloidogenic factor influencing the enzymatic processing of amyloid-β precursor protein (AβPP) to toxic β-amyloid. However, the mechanism by which DHA modulates the cholesterol pathway has not been established. Thus, the objective of this study was to investigate the mechanism of regulation of cholesterol metabolism by DHA in an AβPP₆₉₅ overexpressing AD cell model.

METHODS

A gas chromatography/mass spectrometry method was developed and validated for the targeted profiling of 11 cholesterol metabolites in DHA-treated Chinese hamster ovary wild-type (CHO-wt) and AβPP₆₉₅ overexpressing (CHO-AβPP₆₉₅) cells. The differential metabolite profiles between DHA- and vehicle-treated groups were further analyzed using fold change values of the ratio of concentration of metabolites in CHO-AβPP₆₉₅ to CHO-wt cells. Effect of DHA on key rate-limiting enzymatic activities within the cholesterol pathway was established using biochemical assays.

RESULTS

Our results showed that DHA reduced the levels of key cholesterol anabolites and catabolites in CHO-AβPP₆₉₅ cells as compared to CHO-wt cells. Further enzymatic studies revealed that the cholesterol-lowering effect of DHA was mediated by regulating HMG-CoA reductase and squalene epoxidase enzyme activities.

CONCLUSION

We demonstrate for the first time the dual effects of DHA in inhibiting HMG-CoA reductase and squalene epoxidase and modulating the sterol biosynthesis axis of the cholesterol pathway in AβPP₆₉₅ overexpressing AD. Our novel findings underscore the potential of DHA as a multi-target hypocholesterolemic agent for the prophylaxis of AD and other cholesterol-associated diseases.

Docosahexaenoic Acid Levels in Blood and Metabolic Syndrome in Obese Children: Is There a Link?

Prevalence of metabolic syndrome is increasing in the pediatric population. Considering the different existing criteria to define metabolic syndrome, the use of the International Diabetes Federation (IDF) criteria has been suggested in children. Docosahexaenoic acid (DHA) has been associated with beneficial effects on health. The evidence about the relationship of DHA status in blood and components of the metabolic syndrome is unclear. This review discusses the possible association between DHA content in plasma and erythrocytes and components of the metabolic syndrome included in the IDF criteria (obesity, alteration of glucose metabolism, blood lipid profile, and blood pressure) and non-alcoholic fatty liver disease in obese children. The current evidence is inconsistent and no definitive conclusion can be drawn in the pediatric population. Well-designed longitudinal and powered trials need to clarify the possible association between blood DHA status and metabolic syndrome.

Docosahexaenoic acid inhibits the invasion of MDA-MB-231 breast cancer cells through upregulation of cytokeratin-1

Docosahexaenoic acid (DHA), the main member of the omega-3 essential fatty acid family, has been shown to reduce the invasion of the triple-negative breast cancer cell line MDA-MB-231, but the mechanism involved remains unclear. In the present study, a proteomic approach was used to define changes in protein expression induced by DHA. Proteins from crude membrane preparations of MDA-MB-231 cells treated with 100 µM DHA were separated by two-dimensional electrophoresis (2-DE) and differentially expressed proteins were identified using MALDI-TOF mass spectrometry. The main changes observed were the upregulation of Keratin, type Ⅱ cytoskeletal 1 (KRT1), catalase and lamin-A/C. Immunocytochemistry analyses confirmed the increase in KRT1 induced by DHA. Furthermore, in vitro invasion assays showed that siRNA against KRT1 was able to reverse the DHA-induced inhibition of breast cancer cell invasion. In conclusion, KRT1 is involved in the anti-invasive activity of DHA in breast cancer cells.

Effect of dietary marine microalgae (schizochytrium) powder on egg production, blood lipid profiles, egg quality, and Fatty Acid composition of egg yolk in layers

Two hundred and sixteen Institut de Sélection Animale (ISA) brown layers (40 wks of age) were studied for 6 wks to examine the effect of microalgae powder (MAP) on egg production, egg quality, blood lipid profile, and fatty acid concentration of egg yolk. Dietary treatments were as follows: i) CON (basal diet), ii) 0.5% MAP (CON+0.5% Schizochytrium powder), and iii) 1.0% MAP (CON+1.0% Schizochytrium powder). From 44 to 46 wks, egg production was higher in 1.0% MAP treatment than in control treatment (linear, p = 0.034); however, there was no difference on the egg production from 40 to 43 wks (p>0.05). Serum triglyceride and total cholesterol were significantly reduced in the groups fed with MAP, compared to those in groups fed with control diets (Quadratic, p = 0.034 and p = 0.039, respectively). Inclusion of 0.5% MAP in the diet of layers improved egg yolk color, compared with hens fed with basal diet at 46 wks (quadratic, p = 0.044). Eggshell thickness was linearly increased in MAP-fed treatments at 46th wk (p<0.05). Concentration of yolk docosahexaenoic acid (DHA; C22:6n-3) was increased in treatment groups fed with MAP (linear, p<0.05). The n-6 fatty acids, n-6/n-3 fatty acid, and unsaturated fatty acid/saturated fatty acid were decreased in treatment groups fed with MAP (linear, p<0.05). These results suggest that MAP improved the egg production and egg quality, and may affect serum lipid metabolites in the layers. In addition, MAP increases yolk DHA levels, and deceases n-6/n-3 fatty acid ratio.

Study of the effects of a diet supplemented with active components on lipid and glycemic profiles

OBJECTIVES

Currently, there are numerous studies on risk factors for cardiovascular disease and the potential for functional foods to bring benefits or improve people's health. However, most of these studies are conducted with middle-aged individuals. The aim of this study was to evaluate the effects of supplementing a typical diet with some functional components, which are substances that when consumed in small quantities can improve people's welfare.

METHODS

The participants in this study were young; slightly overweight; had normal glucose tolerance; and had lipid values indicating dyslipidemia or close dyslipidemia. Following a 4-wk run-in phase, participants followed either a diet containing foods enriched with ω-3 fatty acids, β-glucans, phytosterols, and vitamin E or an isoenergetic diet without the active components. Sixteen individuals (age range 20 to 37 y) were randomly assigned to one of two groups. At the end of treatment, while fasting, plasma concentrations of triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol were measured. Furthermore, blood glucose was evaluated after fasting and after a meal enriched with β-glucans.

RESULTS

There was a statistically significant reduction (α < 0.05) across the lipid profile. A meal rich in β-glucans produced a glycemic response significantly lower than the nonenriched meal.

CONCLUSION

The dietary supplements used in this work, based on the integration of functional components into the usual diet of the population, have proved effective in reducing peak levels of postprandial glucose and the risk for dyslipidemia. Therefore, these functional components proved a valuable aid in the prevention of cardiovascular diseases and metabolic disorders.

Omega-3 supplementation combined with anti-vascular endothelial growth factor lowers vitreal levels of vascular endothelial growth factor in wet age-related macular degeneration

PURPOSE

To determine the influence of omega-3 supplementation on vitreous vascular endothelial growth factor A (VEGF-A) levels in patients with exudative age-related macular degeneration (wet AMD) receiving intravitreal anti-VEGF treatment.

DESIGN

Prospective, randomized, open-label, single-center, clinical trial, consecutive interventional case series.

METHODS

The study included 3 cohorts with wet AMD and a control group with epiretinal membrane or macular hole. Twenty wet AMD patients being treated with anti-VEGF were randomized to daily supplementation of antioxidants, zinc, and carotenoids with omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid; group 1, n = 10) or without omega-3 fatty acids (group 2, n = 10). They were compared with an anti-VEGF treatment-naïve wet AMD group (group 3, n = 10) and an epiretinal membrane or macular hole group (group 4, n = 10). Primary outcome was vitreal VEGF-A levels (at the time of anti-VEGF injection). Secondary outcomes were plasma VEGF-A and central foveal thickness. Patients with new submacular hemorrhage or any other treatment within 3 months were excluded. Final analyses included 9, 6, 7, and 8 patients in groups 1 through 4, respectively.

RESULTS

Patients receiving omega-3s (group 1) had significantly lower levels of vitreal VEGF-A (141.11 ± 61.89 pg/mL) when compared with group 2 (626.09 ± 279.27 pg/mL; P = .036) and group 3 (735.48 ± 216.43 pg/mL; P = .013), but similar levels to group 4 (235.81 ± 33.99 pg/mL; P=.215). All groups showed similar values for plasma VEGF-A and central foveal thickness measurements.

CONCLUSIONS

This study demonstrated that omega-3 supplementation combined with anti-VEGF treatment is associated with decreased vitreal VEGF-A levels in wet AMD patients.

Docosahexaenoic acid decreases TNF-α-induced lectin-like oxidized low-density lipoprotein receptor-1 expression in THP-1 cells

Docosahexaenoic acid (DHA) prevents atherosclerosis and may decrease monocyte/macrophage activation by tumor necrosis factor (TNF)-α. Here, we sought to determine the protective effects of DHA against TNF-α-induced stimulation of lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (LOX-1) expression, which is associated with atherosclerosis. Using reverse transcription polymerase chain reaction, we found that TNF-α induced the expression of LOX-1 (OLR1), NADPH oxidase 2 (Nox2), p47phox (NCF1), very late antigen-4 (ITGA4), and lymphocyte function-associated antigen (ITGAL) genes. Additionally, DHA attenuated TNF-α-induced acetylated (Ac)-LDL uptake and reactive oxygen species (ROS) production, as measured using fluorescently labeled LDL and H2DCFDA, respectively, and reduced the expression levels of these genes. Moreover, the PI3 kinase inhibitor LY294002 blocked these effects of DHA. These results indicated that DHA inhibited several events associated with redox regulation in a PI3K-dependent manner, thereby mediating the expression of LOX-1 in monocytes/macrophages.

The effect of conjugated linoleic acids and omega-3 fatty acids supplementation on lipid profile in atherosclerosis

Background:

Cardiovascular diseases (CVD) are the most serious cause of mortality in developed and developing countries. Epidemiological studies indicated that dyslipidemia is the major risk factor of CVD. Dyslipidemia can be modified either by proper lifestyle or medical intervention or by the combination of both. Conjugated linoleic acids (CLA) and ω3 fatty acids have beneficial effects on plasma lipids and lipoproteins. The aim of this study was to evaluate the effect of CLA and omega-3 fatty acids (ω-3 fatty acids) supplementation on lipid profile in atherosclerosis patient.

Materials and Methods:

This study was a 2-month clinical randomized trial. Ninety atherosclerotic patients with angiographically diagnosed coronary atherosclerosis who were referred to Emam Reza Heart Clinic of Shiraz University of Medical Sciences from February to march 2011 were selected if they fulfilled the inclusion criteria. The participants were randomly classified into 3 groups receiving 3 g/d CLA or 1 920 mg/d ω3 or placebo for 2 months. High-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglycerides (TG), and total cholesterol were measured before and after the intervention. This study was a two-month clinical randomized trial.

Results:

Data were analyzed using SPSS software (SPSS Inc, Chicago, version19). Although CLA did not appear to have a significant effect on TG, ω3 supplementation significantly reduced TG level. Consumption of CLA and ω3 supplementation did not significantly affect HDL cholesterol, LDL cholesterol, and total cholesterol.

Conclusions:

ω3 supplementation significantly reduced TG level but CLA and ω3 did not show significant changes in other indices of lipid profile in atherosclerotic patients.

Relationship between the lipidome, inflammatory markers and insulin resistance

The objectives of the present study were to (1) examine the effects of the phenotypic factors age, gender and BMI on the lipidomic profile and (2) investigate the relationship between the lipidome, inflammatory markers and insulin resistance.

Bioequivalence of two omega-3 fatty acid ethyl ester formulations: a case of clinical pharmacology of dietary supplements

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Omega-3 fatty acids are dietary components, present in the body with variable blood concentrations. • Bioavailability evaluations of ethyl ester preparations are hampered by the difficulty in achieving similar concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the preparations being compared. This may require questionable corrections for baseline concentrations. • If repeated doses are given, this may lead to errors because of variable dietary fish intake. If a single dose is selected, this needs to be large, since omega-3 LC-PUFA are present in many compartments.

WHAT THIS STUDY ADDS

• We selected subjects with uniform omega-3 background concentrations, to obtain comparable results at the end of treatment. • Testing bioequivalence of two formulations with different EPA : DHA ratios led to single dose intakes of 12 g, which were well tolerated. • In spite of clear differences in EPA : DHA ratios between the two preparations, plasma ratios did not differ and bioequivalence could be well ascertained.

AIM

To evaluate the bioequivalence of two omega-3 long chain polyunsaturated fatty acid (n-3 LC-PUFA) ethyl ester preparations, previously shown not to be bioequivalent in healthy subjects, with the objective of providing a guideline for future work in this area.

METHOD

A randomized double-blind crossover protocol was chosen. Volunteers with the lowest blood concentrations of n-3 LC-PUFA were selected. They received the ethyl esters in a single high dose (12 g) and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) blood concentrations were analyzed after fingerprick collection at intervals up to 24 h.

RESULTS

Differently from a prior study, the pharmacokinetic analysis indicated a satisfactory bioequivalence: for the AUC(0,24 h) 90% CI of the ratio between the two formulations were in the range for bioequivalence (for EPA 0.98, 1.04 and for DHA 0.99, 1.04) and the same was true for C(max) and t(max) (90% CI were 0.95, 1.14 and 1.10, 1.25 for EPA and 0.88, 1.02 and 0.84, 1.24 for DHA).

CONCLUSION

This study shows that, in order to obtain reliable bioequivalence data of products present in the daily diet, certain conditions should be met. Subjects should have low, homogeneous baseline concentrations and not be exposed to food items containing the product under evaluation, e.g. fish. Finally, as in the case of omega-3 fatty acids, selected doses should be high, eventually with appropriate conditions of intake.

The association of n-3 fatty acids with serum High Density Cholesterol (HDL) is modulated by sex but not by Inuit ancestry

OBJECTIVE

To explore the association between dietary n-3 fatty acids and serum lipids in a population with a high intake of marine food. Specifically to test interaction with sex and ethnicity.

METHODS

Information was obtained from 2280 Inuit who participated in a countrywide health survey in Greenland in 2005-2009. n-3 intake was estimated from an FFQ and analyses of Red Blood Cell (RBC) membranes. Serum total, HDL and LDL cholesterol and triglyceride were analysed. Obesity was measured. Information on ethnicity, smoking, alcohol consumption, and physical activity was obtained from an interview.

RESULTS

In linear regression models adjusted for age, sex, obesity, ethnicity, alcohol, and smoking serum HDL, LDL and triglyceride were associated with n-3 intake estimated as eicosapentaenoic acid (EPA) in RBC membranes. For HDL the interaction between EPA and sex was significant (p < 0.001). No significant interactions were observed for EPA and ethnicity.

CONCLUSION

A positive association of EPA with serum HDL and LDL and a negative association with triglyceride was observed among both men and women. For HDL, the association was stronger for men. The association of EPA with serum HDL was similar among Inuit with full Inuit ancestry and those with part Inuit ancestry. Diet and overweight are both realistic candidates for a population based intervention against dyslipidemia. Further studies of ethnic differences in the effect of n-3 fatty acids on cardiovascular risk factors are recommended.

Efficient display of active Geotrichum sp. lipase on Pichia pastoris cell wall and its application as a whole-cell biocatalyst to enrich EPA and DHA in fish oil

Geotrichum sp. lipase (GSL) was first displayed on the cell wall of Pichia pastoris on the basis of the a-agglutinin anchor system developed in Saccharomyces cerevisiae . Surface display levels were monitored using Western blotting, immunofluorescence miscroscopy, and fluorescence-activated cell sorting analysis. Lipase activity of the yeast whole cells reached a maximum at 273 ± 2.4 U/g of dry cells toward olive oil after 96 h of culture at 30 °C, with optimal pH and temperature at 7.5 and 45 °C, respectively. Displayed GSL exhibited relatively high stability between pH 6.0 and 8.0 and retained >70% of the maximum activity. The surface-displayed lipase retained 80% of its original activity after incubation at 45 °C for 4 h. Moreover, the GSL-displaying yeast whole cells were then used as a biocatalyst to enrich eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil on the basis of selective hydrolysis. As a result, EPA and DHA increased from 1.53 and 24.1% in the original fish oil to 1.85 and 30.86%, which were increases of 1.21- and 1.29-fold, respectively. The total yield of EPA and DHA reached 46.62%.

DHA derivatives of fish oil as dietary supplements: a nutrition-based drug discovery approach for therapies to prevent metabolic cardiotoxicity

INTRODUCTION

During the early 1970s, Danish physicians Jorn Dyerberg and colleagues observed that Greenland Eskimos consuming fatty fishes exhibited low incidences of heart disease. Fish oil is now one of the most commonly consumed dietary supplements. In 2004, concentrated fish oil was approved as a drug by the FDA for the treatment of hyperlipidemia. Fish oil contains two major omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). With advancements in lipid concentration and purification techniques, EPA- or DHA-enriched products are now commercially available, and the availability of these components in isolation allows their individual effects to be examined. Newly synthesized derivatives and endogenously discovered metabolites of DHA exhibit therapeutic utility for obesity, metabolic syndrome and cardiovascular disease.

AREAS COVERED

This review summarizes our current knowledge on the distinct effects of EPA and DHA to prevent metabolic syndrome and reduce cardiotoxicity risk. Since EPA is an integral component of fish oil, we will briefly review EPA effects, but our main theme will be to summarize effects of the DHA derivatives that are available today. We focus on using nutrition-based drug discovery to explore the potential of DHA derivatives for the treatment of obesity, metabolic syndrome and cardiovascular diseases.

EXPERT OPINION

The safety and efficacy evaluation of DHA derivatives will provide novel biomolecules for the drug discovery arsenal. Novel nutritional-based drug discoveries of DHA derivatives or metabolites may provide realistic and alternative strategies for the treatment of metabolic and cardiovascular disease.

Similarities and differences between the effects of EPA and DHA on markers of atherosclerosis in human subjects

We have reviewed effects of long chain (LC) n-3 PUFA on markers of atherosclerosis in human subjects with a focus on individual effects of EPA and DHA. Initial results from epidemiological studies suggested that LC n-3 PUFA from fish oils (FO) reduced incidence of CVD; those results have been confirmed in interventional studies. Dietary intervention with n-3 PUFA decreased fasting and postprandial TAG, number of remnant-like chylomicron particles, large VLDL, and total and small dense LDL particles. It increased mean size of LDL particles by increasing number of large and decreasing those of small dense particles. With some exceptions, n-3 PUFA decreased blood pressure (BP) and heart rate (HR), flow-mediated dilation (FMD) and plasma concentrations of inflammatory markers. n-3 PUFA also decreased circulating adhesion molecules and intima-media thickness (IMT) in some but not other studies. For IMT, results varied with the sex and artery being examined. EPA effects on FMD are endothelial cell dependent, while those of DHA seem to be endothelial cell independent. Individually, both EPA and DHA decreased TAG and inflammatory markers, but only DHA decreased HR, BP and number of small dense LDL particles. Results varied because of dose and duration of n-3 PUFA, EPA:DHA, health status of subjects and other reasons. Future studies are needed to determine optimal doses of EPA and DHA individually, their synergistic, additive or antagonistic effects, and to understand underlying mechanisms. In conclusion, n-3 PUFA decreased several risk factors for atherosclerosis without any serious adverse effects.

A meta-analysis shows that docosahexaenoic acid from algal oil reduces serum triglycerides and increases HDL-cholesterol and LDL-cholesterol in persons without coronary heart disease

Certain algae contain the (n-3) fatty acid DHA, yet the relation between algal oil supplementation and cardiovascular disease risk factors has not been systematically examined. Our objective was to examine the relation between algal oil supplementation and cardiovascular disease risk factors. We conducted a systematic review of randomized controlled trials published between 1996 and 2011 examining the relation between algal oil supplementation and cardiovascular disease risk factors and performed a meta-analysis of the association between algal oil DHA supplementation and changes in the concentrations of TG, LDL-cholesterol (LDL-C), and HDL-cholesterol (HDL-C). We identified 11 randomized controlled trials with 485 healthy participants that evaluated the relation between algal oil DHA supplementation and TG, LDL-C, and HDL-C. The median dose of algal DHA was 1.68 g/d. The pooled estimate for the change in TG concentration was -0.20 mmol/L (95% CI: -0.27 to -0.14), 0.23 mmol/L (95% CI: 0.16-0.30) for LDL-C, and 0.07 mmol/L (95% CI: 0.05-0.10) for HDL-C. DHA supplementation from algal oil, a marine source of (n-3) fatty acids not extracted from fish, may reduce serum TG and increase HDL-C and LDL-C in persons without coronary heart disease.

Effect of n-3 fatty acids on patients with advanced lung cancer: a double-blind, placebo-controlled study

PUFA from fish oil appear to have anti-inflammatory and anti-oxidative effects and improve nutritional status in cancer patients. With this as background, the aim of the present study was to investigate the effect of EPA plus DHA on inflammatory condition, and oxidative and nutritional status in patients with lung cancer. In our multicentre, randomised, double-blind trial, thirty-three patients with a diagnosis of advanced inoperable non-small-cell lung cancer and undergoing chemotherapy were divided into two groups, receiving four capsules/d containing 510 mg of EPA and 340 mg of DHA, or 850 mg of placebo, for 66 d. At the start of chemotherapy (T0), after 8 d (T1), 22 d (T2) and 66 d (T3), biochemical (inflammatory and oxidative status parameters) and anthropometric parameters were measured in both groups. A significant increase of body weight in the n-3 group at T3v. T0 was observed. Concerning inflammation, C-reactive protein and IL-6 levels differed significantly between the n-3 and placebo groups at T3, and progressively decreased during chemotherapy in the n-3 group, evidencing n-3 PUFA anti-inflammatory action. Concerning oxidative status, plasma reactive oxygen species levels increased in the placebo group v. the n-3 group at the later treatment times. Hydroxynonenal levels increased in the placebo group during the study, while they stabilised in the n-3 group. Our data confirm that the continual assumption of EPA plus DHA determined an anti-inflammatory and anti-oxidative action which could be considered a preliminary goal in anti-cachectic therapy.

Fish oil, selenium and mercury in relation to incidence of hypertension: a 20-year follow-up study

OBJECTIVES

Long-chain omega-3 polyunsaturated fatty acids (LCω3PUFAs), selenium (Se) and mercury (Hg) are three important components in fish. The cardioprotective effect of LCω3PUFA intake has been recognized; however, the hypothesis that this benefit may be greatest with high Se and low Hg levels has not been investigated.

DESIGN

A cohort of 4508 American adults aged 18-30, without hypertension at baseline in 1985, were enrolled. Six follow-ups were conducted at examinations in 1987, 1990, 1992, 1995, 2000 and 2005. Diet was assessed by a validated interviewer-administered quantitative food frequency questionnaire at exams in 1985, 1992 and 2005. Incident hypertension was defined as first occurrence at any follow-up examination of systolic blood pressure (BP) ≥ 140 mmHg, diastolic BP ≥ 90 mmHg or taking antihypertensive medication. Toenail clippings were collected in 1987, and Se and Hg levels were quantified by instrumental neutron-activation analysis.

RESULT

Participants in the highest LCω3PUFA intake quartile had a significantly lower incidence of hypertension (hazard ratio: 0.65; 95% CI: 0.53-0.79; P(trend) < 0.01) compared to those in the lowest quartile after adjustment for potential confounders. Docosahexaenoic acid showed a greater inverse association than eicosapentaenoic acid. The inverse association of LCω3PUFA intake with hypertension appeared more pronounced at higher Se and lower Hg levels, although interaction tests were statistically nonsignificant.

CONCLUSIONS

Our findings indicated that LCω3PUFA intake was inversely associated with incidence of hypertension. The prior hypothesis that the potential antihypertensive effect of LCω3PUFA intake varies depending on joint levels of Se and Hg received modest support and cannot be ruled out.