Eicosapentaenoic acid improves endothelial function and nitric oxide bioavailability in a manner that is enhanced in combination with a statin

Sea Change for Marine Omega-3s: Randomized Trials Show Fish Oil Reduces Cardiovascular Events

Recently, 3 large randomized controlled trials (RCTs) have assessed the effects of supplementation with marine omega-3 fatty acids on the occurrence of cardiovascular disease (CVD) events. We reviewed this evidence and considered it in the context of the large and growing body of data on the CV health effects of marine omega-3s. One RCT examining 8179 patients, most with coronary heart disease (CHD), reported that 4 grams/day of a highly purified omega-3 product containing eicosapentaenoic acid (EPA) reduced the risk for major adverse CV events by 25% (P<.001). Two other recent RCTs in primary prevention populations showed that approximately 1 gram/day of purified fish oil containing 840 mg/day of EPA and docosahexaenoic acid (DHA) significantly reduced risks of CHD and CV death, especially in individuals who did not consume fish and seafood frequently. The American Heart Association (AHA) continues to emphasize the importance of marine omega-3s as a nutrient for potentially reducing risks of congestive heart failure, CHD, ischemic stroke, and sudden cardiac death. Marine omega-3s should be used in high doses for patients with CHD on statins who have elevated triglycerides and at about 1 gram/day for primary prevention for individuals who do not consume at least 1.5 fish or seafood meals per week.

Eight weeks of fish oil supplementation does not prevent sitting-induced leg endothelial dysfunction

Prolonged sitting impairs leg endothelial function and this impairment is thought to be mediated by a sustained reduction in blood flow-induced shear stress. However, whether nutritional strategies can be used to prevent sitting-induced leg endothelial dysfunction remains unknown. Herein, we tested the hypothesis that 8 weeks of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation would prevent endothelial dysfunction associated with sitting. Nineteen healthy men were randomly assigned to a placebo group or EPA+DHA group in a double-blind fashion. The EPA+DHA group was administered EPA-rich fish oil, containing 600 mg EPA and 260 mg DHA per day for 8 weeks. The placebo group received matching capsules for the same duration of time. Popliteal artery flow-mediated dilation (FMD) was measured at baseline and before and after a 3-h sitting period. During sitting, blood pressure, popliteal artery diameter, and blood velocity were measured every hour. Throughout the sitting period, popliteal artery blood flow and shear rate were markedly and similarly reduced in both groups (P < 0.05). However, counter to the hypothesis, 3 h of sitting impaired popliteal artery FMD to the same extent in both groups (P < 0.05). In conclusion, daily EPA and DHA supplementation is not effective at preventing the detrimental effects of prolonged sitting on leg endothelial function. Novelty We provide evidence that sitting-induced leg endothelial dysfunction in young healthy subjects cannot be remediated by a nutritional strategy known to produce cardiovascular benefits. This could be partially due to the low total dose of EPA and DHA administered.

Anti-Inflammatory and Anti-Apoptotic Effects of Stybenpropol A on Human Umbilical Vein Endothelial Cells

Inflammation is a key mediator in the progression of atherosclerosis (AS). Benzoinum, a resin secreted from the bark of Styrax tonkinensis, has been widely used as a form of traditional Chinese medicine in clinical settings to enhance cardiovascular function, but the active components of the resin responsible for those pharmaceutical effects remain unclear. To better clarify these components, a new phenylpropane derivative termed stybenpropol A was isolated from benzoinum and characterized via comprehensive spectra a nalysis. We further assessed how this phenylpropane derivative affected treatment of human umbilical vein endothelial cells (HUVECs) with tumor necrosis factor-α (TNF-α). Our results revealed that stybenpropol A reduced soluble intercellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), interleukin-8 (IL-8), and interleukin-1β (IL-1β) expression by ELISA, inhibited apoptosis, and accelerated nitric oxide (NO) release in TNF-α-treated HUVECs. We further found that stybenpropol A decreased VCAM-1, ICAM-1, Bax, and caspase-9 protein levels, and increased the protein levels of Bcl-2, IKK-β, and IκB-α. This study identified a new, natural phenylpropane derivative of benzoinum, and is the first to reveal its cytoprotective effects in the context of TNF-α-treated HUVECs via regulation of the NF-κB and caspase-9 signaling pathways.

An omega-3 fatty acid plasma index ≥4% prevents progression of coronary artery plaque in patients with coronary artery disease on statin treatment

BACKGROUND AND AIMS

Higher blood levels of the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been associated with fewer cardiovascular events and lower mortality in prospective studies. Our aim was to determine a target level of EPA and DHA to prevent progression of coronary artery plaque.

METHODS

218 subjects with stable coronary artery disease on statins were randomized to high-dose EPA and DHA (3.36 g daily) or no omega-3 for 30 months. Coronary plaque volume was measured by coronary computed tomographic angiography. Plasma phospholipid levels of EPA, DHA and total fatty acids were measured by gas chromatography mass spectrometry. The omega-3 fatty acid index was calculated as EPA+DHA/total fatty acid.

RESULTS

Mean (SD) age was 62.9 (7.8) years; mean (SD) LDL-C level 78.6 (27.3) mg/dL and median triglyceride level 122 mg/dL. Subjects assigned to EPA and DHA had increased plasma EPA and DHA levels variably from 1.85% to 13.02%. Plasma omega-3 fatty acid index ≥4% prevented progression of fibrous, noncalcified, calcified and total plaque in nondiabetic subjects whereas those in the lowest quartile (<3.43%) had significant progression of fibrous, calcified and total plaque. No difference was observed in diabetic subjects.

CONCLUSIONS

EPA and DHA added to statins prevented coronary plaque progression in nondiabetic subjects with mean LDL-C <80 mg/dL, when an omega-3 index ≥4% was achieved. Low omega-3 index <3.43% identified nondiabetic subjects at risk of coronary plaque progression despite statin therapy. These findings highlight the importance of measuring plasma levels of omega-3 fatty acids early and at trial conclusion. Targeting an omega-3 index ≥4% maximizes cardiovascular benefit.

The Role of n-3 Fatty Acids in Cardiovascular Disease: Back to the Future

Cardiovascular disease (CVD) remains the major cause of death and disability worldwide, and residual risk after implementing all current therapies is still high. In this context, the latest (2016) European Cardiology Society/European Atherosclerosis Society guidelines recommend that triglyceride (TG)-lowering drugs should be used in high-risk patients with TGs levels >2.3 mmol/L (200 mg/dL), after lifestyle measures fail to lower them. After several neutral CVD outcome trials with n-3 fatty acids, the Reduction of Cardiovascular Events with EPA–Intervention Trial met its primary end point, that is, among patients with elevated TGs levels despite the use of statins, the risk of ischemic events, including cardiovascular death, was significantly lower in those who received 4 g of icosapent ethyl daily. In this review, we comment on the findings of previous and recently published randomized controlled CVD outcome trials assessing n-3 fatty acids supplementation. Both efficacy and safety, as well as future perspectives, are discussed.

New Insights into Mechanisms of Action for Omega-3 Fatty Acids in Atherothrombotic Cardiovascular Disease

PURPOSE OF REVIEW

Treatment of hypercholesterolemia with statins results in significant reductions in cardiovascular risk; however, individuals with well-controlled low-density lipoprotein cholesterol (LDL-C) levels, but persistent high triglycerides (TG), remain at increased risk. Genetic and epidemiologic studies have shown that elevated fasting TG levels are associated with incident cardiovascular events. At effective doses, omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower TG levels but may have additional atheroprotective properties compared to other TG-lowering therapies such as niacin and fibrates. The purpose of this review is to evaluate mechanisms related to the potential benefits of omega-3 fatty acids in atherothrombotic disease.

RECENT FINDINGS

Large randomized clinical trials are currently under way to test the cardiovascular benefits of omega-3 fatty acids at a pharmacologic dosage (4 g/day). A large randomized trial with a prescription EPA-only formulation was shown to reduce a composite of cardiovascular events by 25% in statin-treated patients with established cardiovascular disease or diabetes and other CV risk factors. EPA and DHA have distinct tissue distributions as well as disparate effects on membrane structure and lipid dynamics, rates of lipid oxidation, and signal transduction pathways. Compared to other TG-lowering therapies, EPA has been found to inhibit cholesterol crystal formation, inflammation, and oxidative modification of atherogenic lipoprotein particles. The anti-inflammatory and endothelial benefits of EPA are enhanced in combination with a statin. Omega-3 fatty acids like EPA only at a pharmacologic dose reduce fasting TG and interfere with mechanisms of atherosclerosis that results in reduced cardiovascular events. Additional mechanistic trials will provide further insights into their role in reducing cardiovascular risk in subjects with well-managed LDL-C but elevated TG levels.

New fatty dihydropyridines present cardioprotective potential in H9c2 cardioblasts submitted to simulated ischemia and reperfusion

Nifedipine is a calcium channel blocker dihydropyridine that has been used in the treatment of hypertension. The production of reactive species and calcium overload are the main contributors to myocardial ischemia-reperfusion (I / R) injury. We investigated the ability of novel dihydropyridines (DHPs) to improve the effect of protecting against the injury induced by ischemia and reperfusion in cardioblasts when compared to nifedipine. Forty three DHPs were created varying the fatty chains derived from palmitic acid, stearic acid and oleic acids and aromatic moiety in addition to the addition of chemical elements such as chlorine, nitrogen dioxide, furfural, hydroxyl and methoxy. Cytotoxicity and inhibition of linoleic oxidation were evaluated for all new DHPs and also for nifedipine. The alpha-tocopherol and butylated hydroxytoluene (BHT) were used as antioxidants controls. The compounds with the best antioxidant potential were used in the ischemia and reperfusion (I / R) induction test in cardioblasts (H9c2). Cardioblasts were treated 24 h after assembly of plates and submitted to the ischemia simulation (30 min), after which, normoxia and cellular nutrition conditions were reestablished, simulating reperfusion (additional 30 min). Right after, cell viability, apoptosis, necrosis, and the generation of reactive oxygen species (ROS) were evaluated. Cell viability during I / R was not altered in cells treated with nifedipine, BHT and the new DHP composed of palmitic acid with hydroxyl group in the aromatic substituent. The other new DHPs increased cell viability during I / R simulation and reduced levels of reactive species compared to the I / R group, demonstrating the antioxidant capacity of the new DHPs. Therefore, DHPS with palmitic and oleic acids in the C3 and C5 position with NO2 or Cl in aromatic moiety, presented the highest antioxidant potential (linoleic oxidant test). The new DHPs increased cell viability during I / R simulation and reduced levels of reactive species compared to the ischemia and reperfusion group, demonstrating the antioxidant capacity of the new DHPs. Taken together, these results indicate that those new DHPs have a greater cardioprotective antioxidant capacity to face the damages of ischemia and reperfusion.