Eicosapentaenoic acid enhances nitric oxide production by cultured human endothelial cells

Algerian Prickly Pear Seed By-Products: Fatty Acids Composition, Antioxidant, Enzyme Inhibitory Activities towards Tyrosinase, Urease, α-Amylase, and Cholinesterase, along with the Ability to Protect from Thermal Protein Denaturation

Prickly pear seed is a source of the most expensive oil in the world, which is rich in vitamins and polyunsaturated fatty acids. Its extraction generates a large quantity of press cake. These two by-products need to be valued. The current study aimed to assess the fatty acid composition of oil and the phytochemical composition of press cake. In addition, the antioxidant and the inhibition of thermal protein denaturation effects of both Algerian seed by-products were evaluated with their inhibitory action against the activities of urease, tyrosinase, α-amylase, and cholinesterase enzymes. The GC MS analysis result revealed the richness of our oil in linoleic (74%) and palmitic (13%) acids methyl esters, respectively. The chemical composition of press cake was characterized by a high value of dry matter (94.94 ± 0.05%), especially the carbohydrates (85.13 ± 0.94%). The results of antioxidant activity presented by IC50 and A0.5 ranged from 7.51 ± 0.03 to 88.10 ± 0.92 µg/mL. Furthermore, the IC50 values were 40.19 ± 1.21 and 61.18 ± 0.03 µg/mL in thermal protein denaturation assay, and ranging from 22.97 ± 0.72 to 385.99 ± 0.27 µg/mL for the inhibition of enzymatic activities. These results indicate that the studied oil can be one of the strongest oils for its impressive effects and also encourage us to reuse its press cake in feed livestock.

Omega-3-Rich Tuna Oil Derived from By-Products of the Canned Tuna Industry Enhances Memory in an Ovariectomized Rat Model of Menopause

To increase the value of the by-products of the canned tuna industry, the memory enhancement effect and the possible mechanisms of omega-3-rich tuna oil in bilateral ovariectomized (OVX) rats were assessed. Female rats were orally given tuna oil at doses of 140, 200, and 250 mg/kg of body weight (BW) for 28 days before OVX and for 21 days continually after OVX. Memory performance was assessed every week, whereas the parameters regarding mechanisms of action were assessed at the end of the study. All doses of tuna oil enhanced memory, docosahexaenoic acid (DHA) levels, and superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities but decreased cortisol, acetylcholinesterase (AChE), malondialdehyde (MDA), and inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Medium and high doses of tuna oil suppressed monoamine oxidase (MAO) but increased eNOS activity. A high dose of tuna oil suppressed gamma-aminotransferase (GABA-T) but increased glutamic acid decarboxylase (GAD) and sirtuin-1. A medium dose of tuna oil decreased homocysteine (Hcys) and C-reactive protein. No change in telomere or estradiol was observed in this study. Our results suggest the memory-enhancing effect of tuna oil in an OVX rat model of menopause. The main mechanisms may involve a reduction in oxidative stress, inflammation, and neurotransmitter regulation.

Effects of Combining Docosahexaenoic Acid and Eicosapentaenoic Acid with Sesame Lignan on Vascular Endothelial Function

Vascular endothelial cells produce vasoactive substances, such as nitric oxide (NO), to regulate vascular relaxation and contraction. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) enhance NO production in endothelial cells, and sesamin, a sesame lignan contained in sesame seeds, also promotes NO production. This study examined DHA, EPA, and sesamin's combined effects since it was expected that combining them would further enhance NO production in endothelial cells. Using a human umbilical vein endothelial cell (HUVEC), the NO amount secreted in the culture supernatant was analyzed. Sesamin metabolite (SC1) was used in the experiments because it is a major metabolite in human blood after sesamin absorption. When cells were treated with DHA or EPA alone, they increased NO production in a concentration-dependent manner, whereas no change in NO production was observed for SC1. NO production increased when DHA and EPA were treated in combination with SC1, although the low DHA and EPA concentrations showed no difference in NO production. In the concentrations in which the combined effect was observed, SC1 activated eNOS via calcium signaling, whereas DHA and EPA activated eNOS via alterations in the membrane lipid environment. The combined effect of the two pathways was considered to have enhanced the eNOS activity. These results suggested that combining DHA, EPA, and sesamin might improve vascular endothelial function.

Effects of omega-3 fatty acid on major cardiovascular outcomes: A systematic review and meta-analysis

BACKGROUND

The effects of omega-3 fatty acid on cardiovascular health obtained inconsistent results. A systematic review and meta-analysis were therefore conducted to assess the effects of omega-3 fatty acid supplementation for primary and secondary prevention strategies of major cardiovascular outcomes.

METHODS

The databases of PubMed, Embase, and the Cochrane library were systematically searched from their inception until September 2020. Relative risks (RRs) with 95% confidence intervals were used to assess effect estimates by using the random-effects model.

RESULTS

Twenty-eight randomized controlled trials involving 136,965 individuals were selected for the final meta-analysis. Omega-3 fatty acid was noted to be associated with a lower risk of major cardiovascular events (RR, 0.94; 95% CI, 0.89-1.00; P = .049) and cardiac death (RR, 0.92; 95% CI, 0.85-0.99; P = .022). However, no significant differences was noted between omega-3 fatty acid and the control for the risks of all-cause mortality (RR, 0.97; 95% CI, 0.92-1.03; P = .301), myocardial infarction (RR, 0.90; 95% CI, 0.80-1.01; P = .077), and stroke (RR, 1.02; 95% CI, 0.94-1.11; P = .694).

CONCLUSIONS

Major cardiovascular events and cardiac death risks could be avoided with the use of omega-3 fatty acid. However, it has no significant effects on the risk of all-cause mortality, myocardial infarction, and stroke.

Involvement of Fatty Acids and Their Metabolites in the Development of Inflammation in Atherosclerosis

Despite all the advances of modern medicine, atherosclerosis continues to be one of the most important medical and social problems. Atherosclerosis is the cause of several cardiovascular diseases, which are associated with high rates of disability and mortality. The development of atherosclerosis is associated with the accumulation of lipids in the arterial intima and the disruption of mechanisms that maintain the balance between the development and resolution of inflammation. Fatty acids are involved in many mechanisms of inflammation development and maintenance. Endothelial cells demonstrate multiple cross-linkages between lipid metabolism and innate immunity. In addition, these processes are linked to hemodynamics and the function of other cells in the vascular wall, highlighting the central role of the endothelium in vascular biology.

The case for adding eicosapentaenoic acid (icosapent ethyl) to the ABCs of cardiovascular disease prevention

The high-purity eicosapentaenoic acid (EPA) prescription fish oil-derived omega-3 fatty acid (omega-3), icosapent ethyl (IPE), was recently approved by the United States Food and Drug Administration (FDA) for cardiovascular disease (CVD) prevention in high-risk patients. This approval is based on the 25% CVD event risk reduction observed with IPE in the pre-specified primary composite endpoint (cardiovascular [CV] death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or hospitalization for unstable angina) in the landmark Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT). Notably, this reduction in CVD event risk with IPE was an incremental benefit to well-controlled low-density lipoprotein cholesterol; patients in REDUCE-IT had elevated triglyceride (TG) levels (135-499 mg/dL) and either had a history of atherosclerotic CVD or diabetes with additional CV risk factors. Given the CVD event risk reduction in REDUCE-IT, within a year following trial results, several global medical societies added IPE to their clinical guidelines. IPE is a stable, highly purified, FDA-approved prescription EPA ethyl ester. In contrast, mixed omega-3 products (docosahexaenoic acid + EPA combinations) have limited or no evidence for CVD event risk reduction, and nonprescription fish oil dietary supplements are not regulated as medicine by the FDA. We offer our perspective and rationale for why this evidence-based EPA-only formulation, IPE, should be added to the 'E' in the ABCDEF methodology for CV prevention. We provide multiple lines of evidence regarding an unmet need for CVD prevention beyond statin therapy, IPE clinical trials, IPE cost-effectiveness analyses, and proposed pleiotropic (non-lipid) mechanisms of action of EPA, as well as other relevant clinical considerations. See Figure 1 for the graphical abstract.[Figure: see text].

Randomization to Omega-3 Fatty Acid Supplementation and Endothelial Function in COPD: The COD-Fish Randomized Controlled Trial

Rationale

Studies suggest a pathogenic role of endothelial dysfunction in chronic obstructive lung disease (COPD). Omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation improves endothelial function in other diseases but has not been examined in COPD.

Objective

We hypothesized that n-3 PUFA supplementation would improve systemic endothelial function in COPD. We performed a pilot randomized, placebo-controlled, double-blind, phase 2 superiority trial (NCT00835289).

Methods

Adults with moderate and severe stable COPD (79% with emphysema on computed tomography [CT]) were randomized to high-dose fish oil capsules or placebo daily for 6 months. The primary endpoint was percentage change in brachial artery flow-mediated dilation (FMD) from baseline to 6 months. Secondary endpoints included peripheral arterial tonometry, endothelial microparticles (EMPs), 6-minute walk distance, respiratory symptoms, and pulmonary function.

Results

Thirty-three of 40 randomized participants completed all measurements. Change in FMD after 6 months did not differ between the fish oil and placebo arms (-1.1%, 95% CI -5.0-2.9, p=0.59). CD31⁺ EMPs increased in the fish oil arm (0.9%, 95% CI 0.1-1.7, p=0.04). More participants in the fish oil arm reported at least a 4-point improvement in the St George's Respiratory Questionnaire (SGRQ) compared to placebo (8 versus 1; p=0.01). There were no significant changes in other secondary endpoints. There were 4 serious adverse events determined to be unrelated to the study (3 in the fish oil arm and 1 in the placebo arm).

Conclusion

Randomization to n-3 PUFAs for 6 months did not change systemic endothelial function in COPD. Changes in EMPs and SGRQ suggest n-3 PUFAs might have biologic and clinical effects that warrant further investigation.

Reduced neuropathy target esterase in pre-eclampsia suppresses tube formation of HUVECs via dysregulation of phospholipid metabolism

Recently, studies have shown that neuropathy target esterase (NTE) is essential to placental and normal blood vessel development. However, whether it is involved in abnormal placenta angiogenesis of pre-eclampsia remains unknown. Thus, our aim was to observe the expression of NTE in pre-eclamptic placentas and its effects and mechanism of NTE on the migration and the tube formation of human umbilical vein endothelial cells (HUVECs). Immunohistochemical staining showed that the NTE protein was intensely located in blood vessels of the normal pregnant placenta. However, western blot revealed that the expression level of NTE protein was significantly reduced in pre-eclamptic placenta. The results indicated that overexpression of NTE significantly promoted the migration and the tube formation of HUVECs compared with those of the control and scramble short hairpin RNA (shRNA) group. Conversely, NTE shRNA obviously inhibited the migration and the tube formation of HUVECs. Additionally, chromatography assay evidenced that NTE overexpression significantly reduced the level of phosphatidylcholine (PC) of HUVECs, but NTE shRNA obviously increased the level of PC of HUVECs. Furthermore, exogenous PC and lysophosphatidylcholine (LPC) significantly inhibited the tube formation of HUVECs in a dose-dependent manner. Collectively, our results suggest that reduced NTE in placenta may contribute to abnormal placenta angiogenesis of pre-eclampsia via the dysregulation of PC and LPC metabolism.

Protective Effects and Molecular Signaling of n-3 Fatty Acids on Oxidative Stress and Inflammation in Retinal Diseases

Oxidative stress and inflammation play crucial roles in the development and progression of retinal diseases. Retinal damage by various etiologies can result in retinopathy of prematurity (ROP), diabetic retinopathy (DR), and age-related macular degeneration (AMD). n-3 fatty acids are essential fatty acids and are necessary for homeostasis. They are important retinal membrane components and are involved in energy storage. n-3 fatty acids also have antioxidant and anti-inflammatory properties, and their suppressive effects against ROP, DR, and AMD have been previously evaluated. α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and their metabolites have been shown to alleviate retinal oxidative stress and inflammation involving various biological signaling pathways. In this review, we summarize the current understanding of the n-3 fatty acids effects on the mechanisms of these retinal diseases and how they exert their therapeutic effects, focusing on ALA, EPA, DHA, and their metabolites. This knowledge may provide new remedial strategies for n-3 fatty acids in the prevention and treatment of retinal diseases associated with oxidative stress and inflammation.

Habitual Fish Consumption, n-3 Fatty Acids, and Nuclear Magnetic Resonance Lipoprotein Subfractions in Women

Background

Supplementation with omega‐3 (n‐3) fatty acid or dietary fish may protect against atherosclerosis, but the potential mechanisms are unclear. Prior studies found modest triglyceride‐lowering effects and slight increases in LDL (low‐density lipoprotein) cholesterol. Limited evidence has examined n‐3 effects on more detailed lipoprotein biomarkers.

Methods and Results

We conducted a study of 26 034 healthy women who reported information on fish and n‐3 intake from a 131‐item food‐frequency questionnaire. We measured plasma lipids, apolipoproteins, and nuclear magnetic resonance spectroscopy lipoproteins and examined their associations with dietary intake of fish, total n‐3, and the n‐3 subtypes (eicosapentaenoic, docosahexaenoic, and α‐linolenic acids). Top‐ versus bottom‐quintile intake of fish and n‐3 were significantly associated with lower triglyceride and large VLDL (very‐low‐density lipoprotein) particles. Fish intake, but not total n‐3, was positively associated with total cholesterol, LDL cholesterol, apolipoprotein B, and larger LDL size, but only α‐linolenic acid was associated with lower LDL cholesterol. Total n‐3, docosahexaenoic acid, and α‐linolenic acid intake were also positively associated with larger HDL (high‐density lipoprotein) size and large HDL particles. High eicosapentaenoic acid intake was significantly associated with only a decreased level of VLDL particle concentration and VLDL triglyceride content. The n‐3 fatty acids had some similarities but also differed in their associations with prospective cardiovascular disease risk patterns.

Conclusions

Higher consumption of fish and n‐3 fatty acids were associated with multiple measures of lipoproteins that were mostly consistent with cardiovascular prevention, with differences noted for high intake of eicosapentaenoic acid versus docosahexaenoic acid and α‐linolenic acid that were apparent with more detailed lipoprotein phenotyping. These hypothesis‐generating findings warrant further study in clinical trials.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000479.

Omega-3 and Omega-6 polyunsaturated fatty acids stimulate vascular differentiation of mouse embryonic stem cells

Polyunsaturated fatty acids (PUFAs) and their metabolites may influence cell fate regulation. Herein, we investigated the effects of linoleic acid (LA) as ω-6 PUFA, eicosapentaenoic acid (EPA) as ω-3 PUFA and palmitic acid (PA) on vasculogenesis of embryonic stem (ES) cells. LA and EPA increased vascular structure formation and protein expression of the endothelial-specific markers fetal liver kinase-1, CD31 as well as VE-cadherin, whereas PA was without effect. LA and EPA increased reactive oxygen species (ROS) and nitric oxide (NO), activated endothelial NO synthase (eNOS) and raised intracellular calcium. The calcium response was inhibited by the intracellular calcium chelator BAPTA, sulfo-N-succinimidyl oleate which is an antagonist of CD36, the scavenger receptor for fatty acid uptake as well as by a CD36 blocking antibody. Prevention of ROS generation by radical scavengers or the NADPH oxidase inhibitor VAS2870 and inhibition of eNOS by L-NAME blunted vasculogenesis. PUFAs stimulated AMP activated protein kinase-α (AMPK-α) as well as peroxisome proliferator-activated receptor-α (PPAR-α). AMPK activation was abolished by calcium chelation as well as inhibition of ROS and NO generation. Moreover, PUFA-induced vasculogenesis was blunted by the PPAR-α inhibitor GW6471. In conclusion, ω-3 and ω-6 PUFAs stimulate vascular differentiation of ES cells via mechanisms involving calcium, ROS and NO, which regulate function of the energy sensors AMPK and PPAR-α and determine the metabolic signature of vascular cell differentiation.

Meta-analysis Comparing Combined Use of Eicosapentaenoic Acid and Statin to Statin Alone

Role of omega-3-Fatty acids, especially eicosapentaenoic acid (EPA), in reducing cardiovascular events is not clear. We conducted a meta-analysis including trial sequential analysis (TSA) of all available randomized controlled trials (RCTs) assessing the impact of EPA + statin on cardiovascular risk reduction. The aim is to appraise cardiovascular risk reduction with EPA and statin taken together. A comprehensive search of PubMed and EMBASE databases was conducted for all RCTs that compared EPA + Statin versus statin alone and included outcomes related to cardiovascular health. We calculated a comprehensive odds ratio (ORs) and 95% confidence intervals (CIs) using a random-effects model. We included 5 RCTs totaling 27,415 patients. Our results demonstrated that EPA + statin resulted in 18% reduction in the incidence of MACE (OR = 0.78; 95% CI: 0.65 to 0.93, I² = 54%, p value <0.01) and 30% reduction in myocardial infarction (MI) (OR = 0.71; 95% CI: 0.61 to 0.82, I² = 0% p value <0.01) as compared with statin alone. With respect to MACE, the number needed to treat was 49. The statistical significance for reduction in the incidence of MACE with EPA+ statin was further augmented with trial sequential analysis. However, combined therapy of EPA + statin demonstrated no significant association on incidence of stroke when compared with statin alone or all-cause mortality. In conclusion, this meta-analysis demonstrated that EPA significantly reduced the incidence of MACE when combined with statin therapy, which is mainly driven by a significant reduction in myocardial infarction.

Marine-Derived Omega-3 Polyunsaturated Fatty Acids and Heart Failure: Current Understanding for Basic to Clinical Relevance

Heart failure (HF) is a rapidly growing global public health problem. Since HF results in high mortality and re-hospitalization, new effective treatments are desired. Although it remains controversial, omega 3 polyunsaturated fatty acids (n-3 PUFAs), such as the eicosapentaenoic acid and docosahexaenoic acid, have been widely recognized to have benefits for HF. In a large-scale clinical trial regarding secondary prevention of HF by n-3 PUFA (GISSI-HF trial), the supplementation of n-3 PUFA significantly reduced cardiovascular mortality and hospitalization. Other small clinical studies proposed that n-3 PUFA potentially suppresses the ventricular remodeling and myocardial fibrosis, which thereby improves the ventricular systolic and diastolic function both in ischemic and non-ischemic HF. Basic investigations have further supported our understanding regarding the cardioprotective mechanisms of n-3 PUFA against HF. In these reports, n-3 PUFA has protected hearts through (1) anti-inflammatory effects, (2) intervention of cardiac energy metabolism, (3) modification of cardiac ion channels, (4) improvement of vascular endothelial response, and (5) modulation of autonomic nervous system activity. To clarify the pros and cons of n-3 PUFA on HF, we summarized recent evidence regarding the beneficial effects of n-3 PUFA on HF both from the clinical and basic studies.

Effect of Eicosapentaenoic Acid Supplementation on Paraoxonase 2 Gene Expression in Patients with Type 2 Diabetes Mellitus: a Randomized Double-blind Clinical Trial

Type 2 diabetes mellitus (T2DM) is recognized as one of the most prevalent metabolic diseases, and it is mostly associated with oxidative stress, atherosclerosis and dyslipidemia. Paraoxonase 2 (PON2) due to its antioxidant properties may play a role in the atherosclerosis development. Although long-chain omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) have been shown to reduce the risk of cardiovascular disease, the exact mechanism of action is still unknown. Our goal in this study was to determine the effect of EPA administration on gene expression of PON2 in patients with T2DM. Present study was a randomized, controlled double-blind trial. Thirty-six patients with T2DM were randomly allocated to receive 2 g/day EPA (n = 18) or placebo (n = 18) for 8 weeks. There were no significant differences between 2 groups concerning demographic or biochemical variables, and dietary intakes as well (p > 0.05). However, patients received EPA showed a significant increase in the gene expression of PON2 compared with placebo group (p = 0.027). In addition, high-density lipoprotein cholesterol increased and fasting blood sugar decreased significantly after EPA supplementation compared with control group. Taken together, supplementation with 2 g/day EPA could be atheroprotective via the upregulation of PON2 in patients with T2DM.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03258840.

Omega-3 Fatty Acid Supplementation Improves Endothelial Function in Primary Antiphospholipid Syndrome: A Small-Scale Randomized Double-Blind Placebo-Controlled Trial

Endothelial cells are thought to play a central role in the pathogenesis of antiphospholipid syndrome (APS). Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation has been shown to improve endothelial function in a number of diseases; thus, it could be of high clinical relevance in APS. The aim of this study was to evaluate the efficacy of n-3 PUFA supplementation on endothelial function (primary outcome) of patients with primary APS (PAPS). A 16-week randomized clinical trial was conducted with 22 adult women with PAPS. Patients were randomly assigned (1:1) to receive placebo (PL, n = 11) or n-3 PUFA (ω-3, n = 11) supplementation. Before (pre) and after (post) 16 weeks of the intervention, patients were assessed for endothelial function (peripheral artery tonometry) (primary outcome). Patients were also assessed for systemic markers of endothelial cell activation, inflammatory markers, dietary intake, international normalized ratio (INR), and adverse effects. At post, ω-3 group presented significant increases in endothelial function estimates reactive hyperemia index (RHI) and logarithmic transformation of RHI (LnRHI) when compared with PL (+13 vs. -12%, p = 0.06, ES = 0.9; and +23 vs. -22%, p = 0.02, ES = 1.0). No changes were observed for e-selectin, vascular adhesion molecule-1, and fibrinogen levels (p > 0.05). In addition, ω-3 group showed decreased circulating levels of interleukin-10 (-4 vs. +45%, p = 0.04, ES = -0.9) and tumor necrosis factor (-13 vs. +0.3%, p = 0.04, ES = -0.95) and a tendency toward a lower intercellular adhesion molecule-1 response (+3 vs. +48%, p = 0.1, ES = -0.7) at post when compared with PL. No changes in dietary intake, INR, or self-reported adverse effects were observed. In conclusion, 16 weeks of n-3 PUFA supplementation improved endothelial function in patients with well-controlled PAPS. These results support a role of n-3 PUFA supplementation as an adjuvant therapy in APS. Registered at http://ClinicalTrials.gov as NCT01956188.

Treatment with omega-3 polyunsaturated fatty acids does not improve endothelial function in patients with type 2 diabetes and very high cardiovascular risk: A randomized, double-blind, placebo-controlled study (Omega-FMD)

BACKGROUND AND AIMS

Numerous recent studies conducted in different clinical settings have focused on the benefits of omega-3 polyunsaturated fatty acids (n-3 PUFAs) in the prevention of cardiovascular diseases. There is limited evidence that patients with type 2 diabetes (T2D) and very high cardiovascular risk can also benefit from a high dose of n-3PUFAs, especially those on optimal medical therapy as recommended by the guidelines. The aim of the present study was to assess the impact of high-dose n-3 PUFA treatment on endothelial function in patients with T2D and established atherosclerotic cardiovascular disease (ASCVD).

METHODS

We conducted a prospective randomized double-blind, placebo-controlled, 2-center study, in which endothelial function was measured using flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD). Serum fatty acids composition was measured by gas chromatography. All measurements were done at baseline and after 3 months of treatment with PUFAs at a dose of 2 g/d (n = 36) or placebo (n = 38).

RESULTS

The majority of the study population was treated with optimal medical therapy. Despite significantly higher concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid in the n-3 PUFA group after 3-month treatment, we did not observe significant changes in endothelial function indices (FMD and NMD). However, in regression analysis, only baseline FMD was associated with EPA concentration before 3 months of n-3 PUFA treatment.

CONCLUSIONS

Three months of high-dose n-3 PUFA treatment in very high-risk patients with ASCVD and T2D did not improve the endothelial function indices.

Eicosapentaenoic acid triggers Ca2+ release and Ca2+ influx in mouse cerebral cortex endothelial bEND.3 cells

Eicosapentaenoic acid (EPA), an omega-3 fatty acid abundant in fish oil, protects endothelial cells (EC) from lipotoxicity and triggers EC NO release. The latter is related to an elevation of cytosolic Ca2+. Although EPA has been shown to cause human EC cytosolic Ca2+ elevation, the mechanism is unclear. Microfluorimetric imaging was used here to measure free cytosolic Ca2+ concentration. EPA was shown to cause intracellular Ca2+ release in mouse cerebral cortex endothelial bEND.3 cells; interestingly, the EPA-sensitive intracellular Ca2+ pool(s) appeared to encompass and was larger than the Ca2+ pool mobilized by sarcoplasmic-endoplasmic reticulum Ca2+-ATPase inhibition by cyclopiazonic acid. EPA also opened a Ca2+ influx pathway pharmacologically distinct from store-operated Ca2+ influx. Surprisingly, EPA-triggered Ca2+ influx was Ni2+-insensitive; and EPA did not trigger Mn2+ influx. Further, EPA-triggered Ca2+ influx did not involve Na+-Ca2+ exchangers. Thus, our results suggest EPA triggered unusual mechanisms of Ca2+ release and Ca2+ influx in EC.

Relationship of non-cardiac biomarkers with periprocedural myocardial injury in patients undergoing percutaneous coronary intervention

percutaneous coronary intervention (PCI) is one of the dominant methods for revascularization in patient with coronary artery disease (CAD), which accompanied with high incidence of periprocedural myocardial injury (PMI) evaluated by postprocedural cardiac biomarker elevation. For the convenience of risk stratification of PMI following PCI, the aim of present review provides a unique opportunity to summarize the relationship of non-cardiac biomarkers with PMI by extensively searching in the MEDLINE to identify all the relevant studies. In conclusion, we found that PCI related PMI might be correlated positively to those non-cardiac biomarkers such as low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol, total cholesterol, triglyceride, the ratios of LDL-C to high-density lipoprotein cholesterol (HDL-C), the ratios of HDL-C to apolipoprotein A-I, the ratio of eicosapentaenoic acid to arachidonic acid, lectin-like oxidized low-density lipoprotein receptor-1, C-reactive protein, high on-treatment platelet reactivity, platelet-monocyte aggregates, N-term pro-B-type natriuretic peptide, hemoglobin and albuminuria. Inversely, no relationships of PMI with those non-cardiac biomarkers such as mean platelet volume, platelet distribution width, platelet-larger cell ratio, uric acid, eosinophils count and the genetic variant of methylenetetrahydrofolate reductase (MTHFR) 677 C>T polymorphism. Moreover, there were controversial associations between PMI and those non-cardiac biomarkers such as high-density lipoprotein cholesterol, glycosylated hemoglobin, homocysteine and the polymorphism Leu33Pro of platelet glycoprotein IIbIIIa. However, almost all studies failed to provide definite mechanism of its findings, and further reaches are needed to focus on the potential mechanisms of association between non-cardiac biomarkers and PMI related to PCI.

Omega 3 Fatty Acids Supplementation and Oxidative Stress in HIV-Seropositive Patients. A Clinical Trial

HIV-seropositive patients show high incidence of coronary heart disease and oxidative stress has been described as relevant key in atherosclerosis development. The aim of this study was to assess the effect of omega 3 fatty acids on different markers of oxidative stress in HIV-seropositive patients. We performed a randomized parallel controlled clinical trial in The Instituto Mexicano del Seguro Social, a public health hospital. 70 HIV-seropositive patients aged 20 to 55 on clinical score A1, A2, B1 or B2 receiving highly active antiretroviral therapy (HAART) were studied. They were randomly assigned to receive omega 3 fatty acids 2.4 g (Zonelabs, Marblehead MA) or placebo for 6 months. At baseline and at the end of the study, anthropometric measurements, lipid profile, glucose and stress oxidative levels [nitric oxide catabolites, lipoperoxides (malondialdehyde plus 4-hydroxialkenals), and glutathione] were evaluated. Principal HAART therapy was EFV/TDF/FTC (55%) and AZT/3TC/EFV (15%) without difference between groups. Treatment with omega 3 fatty acids as compared with placebo decreased triglycerides (-0.32 vs. 0.54 mmol/L; p = 0.04), but oxidative stress markers were not different between groups.

From sodium intake restriction to nitrate supplementation: Different measures with converging mechanistic pathways?

Endothelial nitric oxide synthase is at the centre of endothelial physiology producing nitric oxide which dilates blood vessels, inhibits platelet aggregation and smooth muscle cell proliferation and reduces adhesion molecule production. The laminar shear stress is a common test used usually as the flow mediated dilatation test (FMD) which is sensitive to saturated fat, sodium and potassium although with the latter ion it is possible potassium has direct effects on ion channels in the smooth muscle cell as well as the endothelial cell. High blood pressure and blood cholesterol both reduce nitric oxide production, the latter probably by increasing caveolin-1 which binds nitric oxide synthase. Saturated fat reduces nitric oxide by elevating LDL cholesterol and caveolin-1 while insulin stimulates nitric oxide synthase activity by serine phosphorylation. Polyphenols from tea, coffee and cocoa and virgin olive oil enhance FMD and eNOS activity is essential for this activity. Wine polyphenols produce mixed results and it is not clear at present that they are beneficial. Blackberries and other polyphenol-rich fruit also enhance FMD. Dietary nitrate from beetroot and green leafy vegetables is converted to nitrite by salivary microbes and then to nitric oxide and this acts directly on the smooth muscle to lower blood pressure particularly in a low oxygen environment. Dietary nitrate also improves work efficiency and improves flow mediated dilatation.

Postprandial Dysmetabolism and Oxidative Stress in Type 2 Diabetes: Pathogenetic Mechanisms and Therapeutic Strategies

Postprandial dysmetabolism in type 2 diabetes (T2D) is known to impact the progression and evolution of this complex disease process. However, the underlying pathogenetic mechanisms still require full elucidation to provide guidance for disease prevention and treatment. This review focuses on the marked redox changes and inflammatory stimuli provoked by the spike in blood glucose and lipids in T2D individuals after meals. All the causes of exacerbated postprandial oxidative stress in T2D were analyzed, also considering the consequence of enhanced inflammation on vascular damage. Based on this in-depth analysis, current strategies of prevention and pharmacologic management of T2D were critically reexamined with particular emphasis on their potential redox-related rationale.

Cytokines, angiogenic, and antiangiogenic factors and bioactive lipids in preeclampsia

Preeclampsia is a low-grade systemic inflammatory condition in which oxidative stress and endothelial dysfunction occurs. Plasma levels of soluble receptor for vascular endothelial growth factor (VEGFR)-1, also known as sFlt1 (soluble fms-like tyrosine kinase 1), an antiangiogenic factor have been reported to be elevated in preeclampsia. It was reported that pregnant mice deficient in catechol-O-methyltransferase (COMT) activity show a preeclampsia-like phenotype due to a deficiency or absence of 2-methoxyoestradiol (2-ME), a natural metabolite of estradiol that is elevated during the third trimester of normal human pregnancy. Additionally, autoantibodies (AT1-AAs) that bind and activate the angiotensin II receptor type 1 a (AT1 receptor) also have a role in preeclampsia. None of these abnormalities are consistently seen in all the patients with preeclampsia and some of them are not specific to pregnancy. Preeclampsia could occur due to an imbalance between pro- and antiangiogenic factors. VEGF, an angiogenic factor, is necessary for the transport of polyunsaturated fatty acids (PUFAs) to endothelial cells. Hence reduced VEGF levels decrease the availability of PUFAs to endothelial cells. This leads to a decrease in the formation of anti-inflammatory and angiogenic factors: lipoxins, resolvins, protectins, and maresins from PUFAs. Lipoxins, resolvins, protectins, maresins, and PUFAs suppress insulin resistance; activation of leukocytes, platelets, and macrophages; production of interleukin-6 and tumor necrosis factor-α; and oxidative stress and endothelial dysfunction; and enhance production of prostacyclin and nitric oxide (NO). Estrogen enhances the formation of lipoxin A4 and NO. PUFAs also augment the production of NO and inhibit the activity of angiotensin-converting enzyme and antagonize the actions of angiotensin II. Thus, PUFAs can prevent activation of angiotensin II receptor type 1 a (AT1 receptor). Patients with preeclampsia have decreased plasma phospholipid concentrations of arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), the precursors of lipoxins (from AA), resolvins (from EPA and DHA), and protectins (from DHA) and prostaglandin E1 (PGE1 from DGLA: dihomo-γ-linolenic acid) and prostacyclin (PGI2 derived from AA). Based on these evidences, it is proposed that preeclampsia may occur due to deficiency of PUFAs and their anti-inflammatory products: lipoxins, resolvins, protectins, and maresins.

Endothelial dysfunction in cirrhosis: Role of inflammation and oxidative stress

This review describes the recent developments in the pathobiology of endothelial dysfunction (ED) in the context of cirrhosis with portal hypertension and defines novel strategies and potential targets for therapy. ED has prognostic implications by predicting unfavourable early hepatic events and mortality in patients with portal hypertension and advanced liver diseases. ED characterised by an impaired bioactivity of nitric oxide (NO) within the hepatic circulation and is mainly due to decreased bioavailability of NO and accelerated degradation of NO with reactive oxygen species. Furthermore, elevated inflammatory markers also inhibit NO synthesis and causes ED in cirrhotic liver. Therefore, improvement of NO availability in the hepatic circulation can be beneficial for the improvement of endothelial dysfunction and associated portal hypertension in patients with cirrhosis. Furthermore, therapeutic agents that are identified in increasing NO bioavailability through improvement of hepatic endothelial nitric oxide synthase (eNOS) activity and reduction in hepatic asymmetric dimethylarginine, an endogenous modulator of eNOS and a key mediator of elevated intrahepatic vascular tone in cirrhosis would be interesting therapeutic approaches in patients with endothelial dysfunction and portal hypertension in advanced liver diseases.

n-3 PUFA induce microvascular protective changes during ischemia/reperfusion

Ischemia/reperfusion (I/R) injury can occur in consequence of myocardial infarction, stroke and multiple organ failure, the most prevalent cause of death in critically ill patients. I/R injury encompass impairment of endothelial dependent relaxation, increase in macromolecular permeability and leukocyte-endothelium interactions. Polyunsaturated fatty acids (n-3 PUFA), such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) found in fish oil have several anti-inflammatory properties and their potential benefits against I/R injury were investigated using the hamster cheek pouch preparation before and after ischemia. Before the experiments, hamsters were treated orally with saline, olive oil, fish oil and triacylglycerol (TAG) and ethyl ester (EE) forms of EPA and DHA at different daily doses for 14 days. Fish oil restored the arteriolar diameter to pre ischemic values during reperfusion. At onset and during reperfusion, Fish oil and DHA TAG significantly reduced the number of rolling leukocytes compared to saline and olive oil treatments. Fish oil, EPA TAG and DHA TAG significantly prevented the rise on leukocyte adhesion compared to saline. Fish oil (44.83 ± 3.02 leaks/cm(2)), EPA TAG (31.67 ± 2.65 leaks/cm(2)), DHA TAG (41.14 ± 3.63 leaks/cm(2)), and EPA EE (30.63 ± 2.25 leaks/cm(2)), but not DHA EE (73.17 ± 2.82 leaks/cm(2)) prevented the increase in macromolecular permeability compared to saline and olive oil (134.80 ± 1.49 and 121.00 ± 4.93 leaks/cm(2), respectively). On the basis of our findings, we may conclude that consumption of n-3 polyunsaturated fatty acids, especially in the triacylglycerol form, could be a promising therapy to prevent microvascular damage induced by ischemia/reperfusion and its consequent clinical sequelae.

Effects of intake of fish or fish oils on the development of diabetes

The association between fish and fish oils intake and diabetes remains largely unknown. Here we systematically reviewed published articles (clinical trials, prospective cohort studies, systematic reviews and meta-analyses) about the effects of intake of fish or fish oils on the development of diabetes. An intake of fish oils seems not to affect insulin sensitivity, insulin secretion, beta-cell function or glucose tolerance. There is a considerable statistical heterogeneity in the overall summary estimates of the association between fish or fish oils consumption and the development of type 2 diabetes, which is partly explained by geographical differences. Marine n-3 polyunsaturated fatty acids have beneficial effects on the prevention of type 2 diabetes in Asian populations.

Role of CYP1A1 in modulating the vascular and blood pressure benefits of omega-3 polyunsaturated fatty acids

The mechanisms that mediate the cardiovascular protective effects of omega 3 (n-3) polyunsaturated fatty acids (PUFAs) have not been fully elucidated. Cytochrome P450 1A1 efficiently metabolizes n-3 PUFAs to potent vasodilators. Thus, we hypothesized that dietary n-3 PUFAs increase nitric oxide (NO)-dependent blood pressure regulation and vasodilation in a CYP1A1-dependent manner. CYP1A1 wild-type (WT) and knockout (KO) mice were fed an n-3 or n-6 PUFA-enriched diet for 8 weeks and were analyzed for tissue fatty acids and metabolites, NO-dependent blood pressure regulation, NO-dependent vasodilation of acetylcholine (ACh) in mesenteric resistance arterioles, and endothelial NO synthase (eNOS) and phospho-Ser1177-eNOS expression in the aorta. All mice fed the n-3 PUFA diet showed significantly higher levels of n-3 PUFAs and their metabolites, and significantly lower levels of n-6 PUFAs and their metabolites. In addition, KO mice on the n-3 PUFA diet accumulated significantly higher levels of n-3 PUFAs in the aorta and kidney without a parallel increase in the levels of their metabolites. Moreover, KO mice exhibited significantly less NO-dependent regulation of blood pressure on the n-3 PUFA diet and significantly less NO-dependent, ACh-mediated vasodilation in mesenteric arterioles on both diets. Finally, the n-3 PUFA diet significantly increased aortic phospho-Ser1177-eNOS/eNOS ratio in the WT compared with KO mice. These data demonstrate that CYP1A1 contributes to eNOS activation, NO bioavailability, and NO-dependent blood pressure regulation mediated by dietary n-3 PUFAs.

Eicosapentaenoic acid protects against palmitic acid-induced endothelial dysfunction via activation of the AMPK/eNOS pathway

Recent studies have shown that free fatty acids are associated with chronic inflammation, which may be involved in vascular injury. The intake of eicosapentaenoic acid (EPA) can decrease cardiovascular disease risks, but the protective mechanisms of EPA on endothelial cells remain unclear. In this study, primary human umbilical vein endothelial cells (HUVECs) treated with palmitic acid (PA) were used to explore the protective effects of EPA. The results revealed that EPA attenuated PA-induced cell death and activation of apoptosis-related proteins, such as caspase-3, p53 and Bax. Additionally, EPA reduced the PA-induced increase in the generation of reactive oxygen species, the activation of NADPH oxidase, and the upregulation of inducible nitric oxide synthase (iNOS). EPA also restored the PA-mediated reduction of endothelial nitric oxide synthase (eNOS) and AMP-activated protein kinase (AMPK) phosphorylation. Using AMPK siRNA and the specific inhibitor compound C, we found that EPA restored the PA-mediated inhibitions of eNOS and AKT activities via activation of AMPK. Furthermore, the NF-κB signals that are mediated by p38 mitogen-activated protein kinase (MAPK) were involved in protective effects of EPA. In summary, these results provide new insight into the possible molecular mechanisms by which EPA protects against atherogenesis via the AMPK/eNOS-related pathway.

The effects of dietary fish oil on exercising skeletal muscle vascular and metabolic control in chronic heart failure rats

Impaired vasomotor control in chronic heart failure (CHF) is due partly to decrements in nitric oxide synthase (NOS) mediated vasodilation. Exercising muscle blood flow (BF) is augmented with polyunsaturated fatty acid (PUFA) supplementation via fish oil (FO) in healthy rats. We hypothesized that FO would augment exercising muscle BF in CHF rats via increased NO-bioavailability. Myocardial infarction (coronary artery ligation) induced CHF in Sprague-Dawley rats which were subsequently randomized to dietary FO (20% docosahexaenoic acid, 30% eicosapentaenoic acid, n = 15) or safflower oil (SO, 5%, n = 10) for 6-8 weeks. Mean arterial pressure (MAP), blood [lactate], and hindlimb muscles BF (radiolabeled microspheres) were determined at rest, during treadmill exercise (20 m·min(-1), 5% incline) and exercise + N(G)-nitro-l-arginine-methyl-ester (l-NAME) (a nonspecific NOS inhibitor). FO did not change left ventricular end-diastolic pressure (SO: 14 ± 2; FO: 11 ± 1 mm Hg, p > 0.05). During exercise, MAP (SO: 128 ± 3; FO: 132 ± 3 mm Hg) and blood [lactate] (SO: 3.8 ± 0.4; FO: 4.6 ± 0.5 mmol·L(-1)) were not different (p > 0.05). Exercising hindlimb muscle BF was lower in FO than SO (SO: 120 ± 11; FO: 93 ± 4 mL·min(-1)·100 g(-1), p < 0.05) but was not differentially affected by l-NAME. Specifically, 17 of 28 individual muscle BF's were lower (p < 0.05) in FO demonstrating that PUFA supplementation with FO in CHF rats does not augment muscle BF during exercise but may lower metabolic cost.

Atherosclerosis, dyslipidemia, and inflammation: the significant role of polyunsaturated Fatty acids

Phospholipids play an essential role in cell membrane structure and function. The length and number of double bonds of fatty acids in membrane phospholipids are main determinants of fluidity, transport systems, activity of membrane-bound enzymes, and susceptibility to lipid peroxidation. The fatty acid profile of serum lipids, especially the phospholipids, reflects the fatty acid composition of cell membranes. Moreover, long-chain n-3 polyunsatured fatty acids decrease very-low-density lipoprotein assembly and secretion reducing triacylglycerol production. N-6 and n-3 polyunsatured fatty acids are the precursors of signalling molecules, termed "eicosanoids," which play an important role in the regulation of inflammation. Eicosanoids derived from n-6 polyunsatured fatty acids have proinflammatory actions, while eicosanoids derived from n-3 polyunsatured fatty acids have anti-inflammatory ones. Previous studies showed that inflammation contributes to both the onset and progression of atherosclerosis: actually, atherosclerosis is predominantly a chronic low-grade inflammatory disease of the vessel wall. Several studies suggested the relationship between long-chain n-3 polyunsaturated fatty acids and inflammation, showing that fatty acids may decrease endothelial activation and affect eicosanoid metabolism.

Therapeutic impact of eicosapentaenoic acid on ischemic brain damage following transient focal cerebral ischemia in rats

Long-chain n-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), have been shown to reduce ischemic neuronal injury. We investigated the effects of ethyl-EPA (EPA-E) on ischemic brain damage using a rat transient focal cerebral ischemia model. Male Sprague-Dawley rats (n=105) were subjected to 90 min of focal cerebral ischemia. EPA-E (100mg/kg/day) or vehicle was administered once a day for 3, 5 or 7 days prior to ischemia. Different withdrawal intervals of 3, 5, and 7 days prior to ischemia following 7-day pretreatment with EPA-E or vehicle were also examined. In addition, post-ischemic administration of EPA-E was investigated. Pretreatment with EPA-E for 7 and 5 days, but not 3 days, showed significant infarct volume reduction and neurological improvements when compared with vehicle pretreatment. In addition, withdrawal of EPA-E administration for 3 days, but not 5 and 7 days, also demonstrated significant infarct volume reduction and neurological improvements when compared with vehicle treatment. Post-ischemic treatment of EPA-E did not show any neuroprotection. Immunohistochemistry revealed that 7-day pretreatment with EPA-E significantly reduced cortical expression of 8-hydroxydeoxyguanosine (maker for oxidative DNA damage), 4-hydroxy-2-nonenal (maker for lipid peroxidation), phosphorylated adducin (marker for Rho-kinase activation) and von Willebrand factor (endothelial marker) when compared with vehicle pretreatment. In addition, phosphorylated adducin expression co-localized with von Willebrand factor immunoreactivity. The present study established the neuroprotective effect of EPA-E on ischemic brain damage following transient focal cerebral ischemia in rats, which may be involved in the suppression of oxidative stress and endothelial Rho-kinase activation.

Effect of eicosapentaenoic acid on central systolic blood pressure

Central systolic blood pressure (C-SBP) has been shown to be a better predictor of cardiovascular risk than brachial SBP. In this study, the effects of eicosapentaenoic acid (EPA) on C-SBP were compared with pravastatin. Twenty-four patients with hyperlipidemia were assigned 13 to receive 1800 mg/day EPA (EPA group) and 11 to receive 10 mg/day pravastatin (pravastatin group) for 3 months. In the EPA group, there were no changes in the LDL-cholesterol level. However, the radial augmentation index (AI) and C-SBP decreased after treatment by 5.7% (p < 0.01) and 8.7% (p < 0.001), respectively. Moreover, systolic and diastolic brachial BPs decreased by 7.1% and 8.0%, respectively (p < 0.01 for both). In the pravastatin group, the LDL-cholesterol level decreased by 29.5% (p < 0.001). However, there were no significant changes in brachial BP, AI and C-SBP between. These results suggested that EPA but not pravastatin may reduce cardiac afterload by reducing vascular reflected waves and lowering C-SBP.

Administration of highly purified eicosapentaenoic acid to statin-treated diabetic patients further improves vascular function

We prospectively examined the additional effects of highly purified eicosapentaenoic acid (EPA) particularly on the vascular function of diabetic patients with hypercholesterolemia receiving statin therapy. We enrolled 28 patients with type 2 diabetes complicated by dyslipidemia who had been treated with statins for at least one year. The patients were randomly assigned to 2 groups: administration of statin alone (group S: n = 13) and addition of EPA to the current statin therapy (group SE: n = 15). The highly purified EPA was administered at a dose of 1,800 mg/day for 6 months. To evaluate vascular function, the duration of reactive hyperemia (DRH), which is the time required for forearm blood flow to return to the basal level after inducing reactive hyperemia, was measured using strain gauge plethysmography. There were no significant differences in the clinical background factors between the 2 groups. Low-density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol levels significantly decreased after 6 months only in group SE. Compared with the baseline data, no significant change in DRH was observed after 6 months in group S. By contrast, DRH was significantly prolonged after 6 months in group SE, indicating that the addition of highly purified EPA improved vascular function. Our results showed that in patients with type 2 diabetes and receiving statin therapy whose LDL-C level was less than 100 mg/dL, the addition of highly purified EPA for 6 months significantly improved vascular function.

Omega-3 fatty acids and cardiovascular disease: effects on risk factors, molecular pathways, and clinical events

We reviewed available evidence for cardiovascular effects of n-3 polyunsaturated fatty acid (PUFA) consumption, focusing on long chain (seafood) n-3 PUFA, including their principal dietary sources, effects on physiological risk factors, potential molecular pathways and bioactive metabolites, effects on specific clinical endpoints, and existing dietary guidelines. Major dietary sources include fatty fish and other seafood. n-3 PUFA consumption lowers plasma triglycerides, resting heart rate, and blood pressure and might also improve myocardial filling and efficiency, lower inflammation, and improve vascular function. Experimental studies demonstrate direct anti-arrhythmic effects, which have been challenging to document in humans. n-3 PUFA affect a myriad of molecular pathways, including alteration of physical and chemical properties of cellular membranes, direct interaction with and modulation of membrane channels and proteins, regulation of gene expression via nuclear receptors and transcription factors, changes in eicosanoid profiles, and conversion of n-3 PUFA to bioactive metabolites. In prospective observational studies and adequately powered randomized clinical trials, benefits of n-3 PUFA seem most consistent for coronary heart disease mortality and sudden cardiac death. Potential effects on other cardiovascular outcomes are less-well-established, including conflicting evidence from observational studies and/or randomized trials for effects on nonfatal myocardial infarction, ischemic stroke, atrial fibrillation, recurrent ventricular arrhythmias, and heart failure. Research gaps include the relative importance of different physiological and molecular mechanisms, precise dose-responses of physiological and clinical effects, whether fish oil provides all the benefits of fish consumption, and clinical effects of plant-derived n-3 PUFA. Overall, current data provide strong concordant evidence that n-3 PUFA are bioactive compounds that reduce risk of cardiac death. National and international guidelines have converged on consistent recommendations for the general population to consume at least 250 mg/day of long-chain n-3 PUFA or at least 2 servings/week of oily fish.

N-3 Polyunsaturated fatty acid therapy improves endothelial function and affects adiponectin and resistin balance in the first month after myocardial infarction

INTRODUCTION

N-3 Polyunsaturated fatty acids (n-3 PUFA) exert clinical beneficial effects in patients after acute myocardial infarction (AMI). However, their exact mechanisms of action are not well recognized yet. Our aim was to evaluate effects of early introduced n-3 PUFA supplementation on endothelial function and serum adipokine concentrations in patients with AMI.

MATERIAL AND METHODS

Thirty-eight patients with AMI and successful coronary stent implantation were randomized to the study group (PUFA group: n = 19; standard therapy + PUFA 1 g daily) and the control group (control group: n = 19; standard therapy). The study group patients were given n-3 PUFA (Omacor 1 g daily) starting from the 3(rd) day of AMI. Ultrasound vascular indexes (flow-mediated dilatation [FMD], nitroglycerine-mediated dilation [NMD]) and serum concentrations of adiponectin and resistin (ELISA) were evaluated before and after 30 days of pharmacotherapy.

RESULTS

Comparison of the mean delta values (baseline/after 30 days of therapy) between groups revealed significant differences for delta FMD (PUFA 7.6 ±12.4% vs. control -1.7 ±10.5%, p = 0.019) and delta resistin concentrations (PUFA 1.0 ±3.8pg/ml vs. control -1.6 ±2.9pg/ml, p = 0.028). Multiple linear regression analysis for all subjects revealed the n-3 PUFA supplementation (r = 10.933, p = 0.004) and waist circumference (r = -0.467, p = 0.01) as independent factors associated with delta FMD values (R-adjusted 0.29; p = 0.002).

CONCLUSIONS

Early and short-term n-3 PUFA supplementation in AMI with successful primary PCI and optimal pharmacotherapy improves endothelial function. However, increased resistin serum levels observed after 1-month n-3 PUFA supplementation merits further investigations.

The link between erectile and cardiovascular health: the canary in the coal mine

Lifestyle and nutrition have been increasingly recognized as central factors influencing vascular nitric oxide (NO) production and erectile function. This review underscores the importance of NO as the principal mediator influencing cardiovascular health and erectile function. Erectile dysfunction (ED) is associated with smoking, excessive alcohol intake, physical inactivity, abdominal obesity, diabetes, hypertension, and decreased antioxidant defenses, all of which reduce NO production. Better lifestyle choices; physical exercise; improved nutrition and weight control; adequate intake of or supplementation with omega-3 fatty acids, antioxidants, calcium, and folic acid; and replacement of any testosterone deficiency will all improve vascular and erectile function and the response to phosphodiesterase-5 inhibitors, which also increase vascular NO production. More frequent penile-specific exercise improves local endothelial NO production. Excessive intake of vitamin E, calcium, l-arginine, or l-citrulline may impart significant cardiovascular risks. Interventions discussed also lower blood pressure or prevent hypertension. Certain angiotensin II receptor blockers improve erectile function and reduce oxidative stress. In men aged <60 years and in men with diabetes or hypertension, erectile dysfunction can be a critical warning sign for existing or impending cardiovascular disease and risk for death. The antiarrhythmic effect of omega-3 fatty acids may be particularly crucial for these men at greatest risk for sudden death. In conclusion, by better understanding the complex factors influencing erectile and overall vascular health, physicians can help their patients prevent vascular disease and improve erectile function, which provides more immediate motivation for men to improve their lifestyle habits and cardiovascular health.

Impact of omega-3 polyunsaturated fatty acids on coronary plaque instability: an integrated backscatter intravascular ultrasound study

OBJECTIVE

To assess the impact of omega-3 polyunsaturated fatty acids (ω3 PUFAs) on coronary plaque instability.

METHODS

Serum content of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) was measured in 336 of 368 consecutive patients suspected of having coronary artery disease who underwent coronary angiography. Conventional and integrated backscatter intravascular ultrasound (IB-IVUS) parameters were analyzed in 116 patients with 128 coronary plaques, using a 43-MHz (motorized pullback 0.5mm/s) intravascular catheter (View It, Terumo Co., Japan). Lipid-rich plaques were classified into two categories according to their components.

RESULTS

Patients with acute coronary syndrome had significantly lower levels of ω3 PUFAs (especially of EPA and DPA) than those without it. IB-IVUS analyses showed that ω3 PUFAs correlated inversely with % lipid volume and positively with % fibrous volume. Patients with low EPA levels, low DPA levels, and low DHA levels had a significantly higher % lipid volume (p=0.048, p=0.008, and p=0.036, respectively) and a significantly lower % fibrous volume (p=0.035, p=0.008, and p=0.034, respectively) than those with high levels of these fatty acids. Even after adjustment for confounders, the presence of both low EPA and low DPA levels proved to be an independent predictor for lipid-rich plaques in any of the two categories.

CONCLUSIONS

A lower serum content of ω3 PUFAs (especially of EPA and DPA) was significantly associated with lipid-rich plaques, suggesting the contribution to the incidence of acute coronary syndrome.

Mediterranean diet and cardioprotection: the role of nitrite, polyunsaturated fatty acids, and polyphenols

The continually increasing rate of myocardial infarction (MI) in the Western world at least partly can be explained by a poor diet lacking in green vegetables, fruits, and fish and enriched in food that contains saturated fat. In contrast, a number of epidemiologic studies provide strong evidence highlighting the cardioprotective benefits of the Mediterranean diet enriched in green vegetables, fruits, fish, and grape wine. Regular consumption of these products leads to an accumulation of nitrate/nitrite/NO, polyunsaturated fatty acids (PUFA), and polyphenolic compounds, such as resveratrol, in the human body. Studies have confirmed that these constituents are bioactive exogenous mediators, which induce strong protection against MI. The aim of this review is to provide a critical, in-depth analysis of the cardioprotective pathways mediated by nitrite/NO, PUFA, and phenolic compounds of grape wines discovered in the recent years, including cross-talk between different mechanisms and compounds. Overall, these findings may facilitate the design and synthesis of novel therapeutic tools for the treatment of MI.