Eicosapentaenoic acid reduces membrane fluidity, inhibits cholesterol domain formation, and normalizes bilayer width in atherosclerotic-like model membranes

EPA Induces an Anti-Inflammatory Transcriptome in T Cells, Implicating a Triglyceride-Independent Pathway in Cardiovascular Risk Reduction

Twice-daily intake of purified eicosapentaenoic acid (EPA) reduces atherosclerotic cardiovascular disease risk in patients with high triglycerides, but its exact mechanism remains unclear. We exposed non-activated CD4+ T cells to 100μM EPA, oleic acid, palmitic acid, or control, and conducted RNA and ATAC-sequencing after 48 hours. EPA exposure downregulated immune response-related genes like HLA-DRA, CD69, and IL2RA, and upregulated oxidative stress prevention genes like NQO1. Transcription factor footprinting showed decreased GATA3 and PU.1, and increased REV-ERB. These effects were specific to EPA, suggesting it induces an anti-inflammatory transcriptomic landscape in CD4+ T cells, contributing to its observed cardiovascular benefits.

The role for ω-3 polyunsaturated and short chain fatty acids in hypertension: An updated view on the interaction with gut microbiota

As of 2024, arterial hypertension is still considered the leading modifiable cardiovascular risk factor and, due to high rates of undertreatment and poor blood pressure control, the major contributor to human morbidity and mortality. Development of new treatment options and better interventions in lifestyle correction have become a priority of experimental and clinical research. In the last decades, dietary supplementation of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and generation of gut microbiota-derived short chain fatty acids (SCFAs) have surged as potential and promising interventions for hypertension and cardiovascular prevention. ω-3 PUFAs are considered "essential" fatty acids that can be obtained only from dietary sources. Although previous intervention trials were not consistent in reporting a significant benefit of ω-3 PUFAs, the recent REDUCE-IT trial has provided robust evidence in support of their role in cardiovascular prevention. Recent studies have also identified the intestinal microbiota as a potential player in the pathophysiology and progression of hypertension. Although this might occur through many pathways, generation of SCFAs that is highly dependent on dietary fiber intake is primarily involved, providing an additional target for the development of novel therapeutic strategies. For these reasons, some scientific societies currently recommend dietary supplementation of ω-3 PUFAs and fiber-containing foods in patients with hypertension. In this narrative review, we summarize the results of studies that examined the effects of ω-3 PUFAs and SCFAs on blood pressure, highlighting the mechanisms of action on the vascular system and their possible impact on hypertension, hypertension-related organ damage and, ultimately, cardiovascular outcomes.

Erythrocyte Membrane Fluidity and Omega-3 Fatty Acid Intake: Current Outlook and Perspectives for a Novel, Nutritionally Modifiable Cardiovascular Risk Factor

Omega-3 fatty acids reduce triglycerides and have several positive effects on different organs and systems. They are also found in the plasma membrane in variable amounts in relation to genetics and diet. However, it is still unclear whether omega-3 supplementation can reduce the occurrence of major cardiovascular events (MACEs). Two trials, REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial), with highly purified EPA, and STRENGTH (Effect of High-Dose Omega-3 Fatty Acids vs. Corn Oil on Major Adverse Cardiovascular Events in Patients at High Cardiovascular Risk), with a combination of EPA and DHA, have produced different outcomes, triggering a scientific debate on possible explanations for the discrepancies. Furthermore, doubts have arisen as to the anti-inflammatory and anti-aggregating activity of these compounds. Recent studies have, however, highlighted interesting effects of EPA and DHA on erythrocyte membrane fluidity (EMF). EMF is governed by a complex and dynamic biochemical framework, with fatty acids playing a central role. Furthermore, it can be easily measured in erythrocytes from a blood sample using fluorescent probes. Recent research has also shown that EMF could act as a possible cardiovascular risk factor biomarker. This review aims to synthetize the latest evidence on erythrocyte membrane fluidity, exploring its potential role as a biomarker of residual cardiovascular risk and discussing its clinical relevance. Further, we aim to dissect the possible biological mechanisms that link omega-3 modifiable membrane fluidity to cardiovascular health.

Small-Molecule Modulators of Lipid Raft Stability and Protein-Raft Partitioning

Development of an understanding of membrane nanodomains colloquially known as "lipid rafts" has been hindered by a lack of pharmacological tools to manipulate rafts and protein affinity for rafts. We screened 24,000 small molecules for modulators of the affinity of peripheral myelin protein 22 (PMP22) for rafts in giant plasma membrane vesicles (GPMVs). Hits were counter-screened against another raft protein, MAL, and tested for impact on raft , leading to two classes of compounds. Class I molecules altered the raft affinity of PMP22 and MAL and also reduced raft formation in a protein-dependent manner. Class II molecules modulated raft formation in a protein-independent manner. This suggests independent forces work collectively to stabilize lipid rafts. Both classes of compounds altered membrane fluidity in cells and modulated TRPM8 channel function. These compounds provide new tools for probing lipid raft function in cells and for furthering our understanding of raft biophysics.

Role of DHA in a Physicochemical Study of a Model Membrane of Grey Matter

The present study investigates a multicomponent lipid system that simulates the neuronal grey matter membrane, employing molecular acoustics as a precise, straightforward, and cost-effective methodology. Given the significance of omega-3 polyunsaturated fatty acids in the functionality of cellular membranes, this research examines the effects of reducing 1-palmitoyl-2-docosahexaenoylphosphatylcholine (PDPC) content on the compressibility and elasticity of the proposed membrane under physiological conditions. Our results align with bibliographic data obtained through other techniques, showing that as the proportion of PDPC increases in the grey matter membrane model, the system's compressibility decreases, and the membrane's elasticity increases, as evidenced by the reduction in the bulk modulus. These results could be interpreted in light of the emerging model of lipid rafts, in which esterified DHA infiltrates and remodels their architecture. We contend that the results obtained may serve as a bridge between biophysics and cellular biology.

Exploring the role and therapeutic potential of lipid metabolism in acute kidney injury

Acute kidney injury (AKI) is a prevalent condition, yet no specific treatment is available. Extensive research has revealed the pivotal role of lipid-related alterations in AKI. Lipid metabolism plays an essential role in the sustenance of the kidneys. In addition to their energy-supplying function, lipids contribute to the formation of renal biomembranes and the establishment of the renal microenvironment. Moreover, lipids or their metabolites actively participate in signal transduction, which governs various vital biological processes, such as proliferation, differentiation, apoptosis, autophagy, and epithelial-mesenchymal transition. While previous studies have focused predominantly on abnormalities in lipid metabolism in chronic kidney disease, this review focuses on lipid metabolism anomalies in AKI. We explore the significance of lipid metabolism products as potential biomarkers for the early diagnosis and classification of AKI. Additionally, this review assesses current preclinical investigations on the modulation of lipid metabolism in the progression of AKI. Finally, on the basis of existing research, this review proposes future directions, highlights challenges, and presents novel targets and innovative ideas for the treatment of and intervention in AKI.

Effects of omega-3 fatty acids on coronary revascularization and cardiovascular events: a meta-analysis

AIMS

Benefits of pharmacologic omega-3 fatty acid administration in cardiovascular prevention are controversial. Particularly, effects on coronary revascularization are unclear; also debated are specific benefits of eicosapentaenoic acid (EPA). We investigated incident coronary revascularizations, myocardial infarction (MI), stroke, heart failure (HF), unstable angina, and cardiovascular death, in subjects randomized to receive EPA or EPA + docosahexaenoic acid (EPA + DHA) vs. control.

METHODS AND RESULTS

Meta-analysis of randomized controlled trials (RCTs) was conducted after MEDLINE, Embase, Scopus, Web of Science, and Cochrane Library search. Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines were followed for abstracting data and assessing data quality and validity. Data were pooled using a random effects model. Eighteen RCTs with 134 144 participants (primary and secondary cardiovascular prevention) receiving DHA + EPA (n = 52 498), EPA alone (n = 14 640), or control/placebo (n = 67 006) were included. Follow-up ranged from 4.5 months to 7.4 years. Overall, compared with controls, omega-3 supplementation reduced the risk of revascularization [0.90, 95% confidence interval (CI) 0.84-0.98; P = 0.001; P-heterogeneity = 0.0002; I2 = 68%], MI (0.89, 95% CI 0.81-0.98; P = 0.02; P-heterogeneity = 0.06; I2 = 41%), and cardiovascular death (0.92, 95% CI 0.85-0.99; P = 0.02; P-heterogeneity = 0.13; I2 = 33%). Lower risk was still observed in trials where most participants (≥60%) were on statin therapy. Compared with DHA + EPA, EPA alone showed a further significant risk reduction of revascularizations (0.76, 95% CI 0.65-0.88; P = 0.0002; P-interaction = 0.005) and all outcomes except HF.

CONCLUSION

Omega-3 fatty acid supplementation reduced the risk of cardiovascular events and coronary revascularization, regardless of background statin use. Eicosapentaenoic acid alone produced greater benefits. The role of specific omega-3 molecules in primary vs. secondary prevention and the potential benefits of reduced revascularizations on overall health status and cost savings warrant further research.

Nontargeted Lipidomics of Sorghum Grain Reveals Novel Fatty Acid Esters of Hydroxy Fatty Acids and Cultivar Differences in Lipid Profiles

Sorghum, a globally grown gluten-free cereal, is used mainly as an animal feed in developed countries regardless of its potential for human consumption. In this study, we utilized nontargeted lipidomics to thoroughly analyze, compare, and characterize whole-grain lipids in six sorghum cultivars (cv) grown in a single field trial in Australia: Buster, Bazley, Cracker, Liberty, MR43, and Tiger. In total, 194 lipid molecular species representing five major lipid classes were identified. Multivariate analysis unveiled distinct lipid profiles among the cultivars. The most distinct lipid profile belonged to cv. MR43. The lower ω-6 to ω-3 ratio and optimal P/S ratio in cv. Bazley reflect this as a valuable source of balanced essential fatty acids in the diet. The novel bioactive lipids known as FAHFAs (fatty acid esters of hydroxy fatty acids) were identified and characterized in sorghum grains. These findings further emphasize the potential of whole-grain sorghum as a basis for new health-promoting food products.

Omega-3 fatty acids in the treatment of heart failure

Omega-3 polyunsaturated fatty acids (Ω-3 PUFAs) have garnered increased attention as a therapeutic option in cardiovascular disease. Most of the research to date has focused on their lipid altering effects and clinical benefits in patients with coronary artery disease, however, there are data supporting their use in the treatment of heart failure. We review the mechanisms through which Ω-3 PUFAs exert their positive effects on the cardiovascular system and highlight the observational and treatment studies that assessed their effects in patients with heart failure.

Randomized Trial for Evaluation in Secondary Prevention Efficacy of Combination Therapy-Statin and Eicosapentaenoic Acid (RESPECT-EPA)

BACKGROUND

Low plasma levels of eicosapentaenoic acid (EPA) are associated with cardiovascular events. This trial aimed to assess the clinical benefits of icosapent ethyl in patients with coronary artery disease, a low EPA/arachidonic acid (AA) ratio, and statin treatment.

METHODS

In this prospective, multicenter, randomized, open-label, blinded end-point study, patients with stable coronary artery disease and a low EPA/AA ratio (<0.4) were randomized to EPA (1800 of icosapent ethyl administered daily) or control group. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, unstable angina pectoris, and coronary revascularization. The secondary composite end points of coronary events included sudden cardiac death, fatal and nonfatal myocardial infarction, unstable angina requiring emergency hospitalization and coronary revascularization, or coronary revascularization.

RESULTS

Overall, 3884 patients were enrolled at 95 sites in Japan. Among them, 2506 patients had a low EPA/AA ratio, and 1249 and 1257 patients were randomized to the EPA and control group, respectively. The median EPA/AA ratio was 0.243 (interquartile range, 0.180-0.314) and 0.235 (interquartile range, 0.163-0.310) in the EPA and control group, respectively. Over a median period of 5 years, the primary end point occurred in 112 of 1225 patients (9.1%) and 155 of 1235 patients (12.6%) in the EPA and control group, respectively (hazard ratio, 0.79 [95% CI, 0.62-1.00]; P=0.055). Meanwhile, the secondary composite end point of coronary events in the EPA group was significantly lower (81/1225 [6.6%] versus 120/1235 [9.7%] patients; hazard ratio, 0.73 [95% CI, 0.55-0.97]). Adverse events did not differ between the groups, but the rate of new-onset atrial fibrillation was significantly higher in the EPA group (3.1% versus 1.6%; P=0.017).

CONCLUSIONS

Icosapent ethyl treatment resulted in a numerically lower risk of cardiovascular events that did not reach statistical significance in patients with chronic coronary artery disease, a low EPA/AA ratio, and statin treatment.

REGISTRATION

URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN000012069.

Eicosapentaenoic Acid Improves Endothelial Nitric Oxide Bioavailability Via Changes in Protein Expression During Inflammation

BACKGROUND

Endothelial cell (EC) dysfunction involves reduced nitric oxide (NO) bioavailability due to NO synthase uncoupling linked to increased oxidation and reduced cofactor availability. Loss of endothelial function and NO bioavailability are associated with inflammation, including leukocyte activation. Eicosapentaenoic acid (EPA) administered as icosapent ethyl reduced cardiovascular events in REDUCE-IT (Reduction of Cardiovascular Events With Icosapent Ethyl-Intervention Trial) in relation to on-treatment EPA blood levels. The mechanisms of cardiovascular protection for EPA remain incompletely elucidated but likely involve direct effects on the endothelium.

METHODS AND RESULTS

In this study, human ECs were treated with EPA and challenged with the cytokine IL-6 (interleukin-6). Proinflammatory responses in the ECs were confirmed by ELISA capture of sICAM-1 (soluble intercellular adhesion molecule-1) and TNF-α (tumor necrosis factor-α). Global protein expression was determined using liquid chromatography-mass spectrometry tandem mass tag. Release kinetics of NO and peroxynitrite were monitored using porphyrinic nanosensors. IL-6 challenge induced proinflammatory responses from the ECs as evidenced by increased release of sICAM-1 and TNF-α, which correlated with a loss of NO bioavailability. ECs pretreated with EPA modulated expression of 327 proteins by >1-fold (P<0.05), compared with IL-6 alone. EPA augmented expression of proteins involved in NO production, including heme oxygenase-1 and dimethylarginine dimethylaminohydrolase-1, and 34 proteins annotated as associated with neutrophil degranulation. EPA reversed the endothelial NO synthase uncoupling induced by IL-6 as evidenced by an increased [NO]/[peroxynitrite] release ratio (P<0.05).

CONCLUSIONS

These direct actions of EPA on EC functions during inflammation may contribute to its distinct cardiovascular benefits.

Impact of dietary n-6/n-3 fatty acid ratio of atherosclerosis risk: A review

Atherosclerosis is a causative factor associated with cardiovascular disease (CVD). Over the past few decades, extensive research has been carried out on the relationship between the n-6/n-3 fatty acid ratio of ingested lipids and the progression of atherosclerosis. However, there are still many uncertainties regarding the precise nature of this relationship, which has led to challenges in providing sound dietary advice to the general public. There is therefore a pressing need to review our current understanding of the relationship between the dietary n-6/n-3 fatty acid ratio and atherosclerosis, and to summarize the underlying factors contributing to the current uncertainties. Initially, this article reviews the association between the n-6/n-3 fatty acid ratio and CVDs in different countries. A summary of the current understanding of the molecular mechanisms of n-6/n-3 fatty acid ratio on atherosclerosis is then given, including inflammatory responses, lipid metabolism, low-density lipoprotein cholesterol oxidation, and vascular function. Possible reasons behind the current controversies on the relationship between the n-6/n-3 fatty acid ratio and atherosclerosis are then provided, including the precise molecular structures of the fatty acids, diet-gene interactions, the role of fat-soluble phytochemicals, and the impact of other nutritional factors. An important objective of this article is to highlight areas where further research is needed to clarify the role of n-6/n-3 fatty acid ratio on atherosclerosis.

Clinical characteristics and treatment compounds of obesity-related kidney injury

Disorders in energy homeostasis can lead to various metabolic diseases, particularly obesity. The obesity epidemic has led to an increased incidence of obesity-related nephropathy (ORN), a distinct entity characterized by proteinuria, glomerulomegaly, progressive glomerulosclerosis, and renal function decline. Obesity and its associated renal damage are common in clinical practice, and their incidence is increasing and attracting great attention. There is a great need to identify safe and effective therapeutic modalities, and therapeutics using chemical compounds and natural products are receiving increasing attention. However, the summary is lacking about the specific effects and mechanisms of action of compounds in the treatment of ORN. In this review, we summarize the important clinical features and compound treatment strategies for obesity and obesity-induced kidney injury. We also summarize the pathologic and clinical features of ORN as well as its pathogenesis and potential therapeutics targeting renal inflammation, oxidative stress, insulin resistance, fibrosis, kidney lipid accumulation, and dysregulated autophagy. In addition, detailed information on natural and synthetic compounds used for the treatment of obesity-related kidney disease is summarized. The synthesis of detailed information aims to contribute to a deeper understanding of the clinical treatment modalities for obesity-related kidney diseases, fostering the anticipation of novel insights in this domain.

Omega-3 fatty acids for cardiovascular event lowering

Low-density lipoprotein cholesterol (LDL-C) is the main target for therapeutics aimed at reducing the risk of atherosclerotic cardiovascular disease (ASCVD) and downstream cardiovascular (CV) events. However, multiple studies have demonstrated that high-risk patient populations harbour residual risk despite effective LDL-C lowering. While data support the causal relationship between triglycerides and ASCVD risk, triglyceride-lowering therapies such as omega-3 fatty acids have shown mixed results in CV outcomes trials. Notably, icosapent ethyl, a purified formulation of eicosapentaenoic acid (EPA), has garnered compelling evidence in lowering residual CV risk in patients with hypertriglyceridaemia and treated with statins. In this review, we summarize studies that have investigated omega-3-fatty acids for CV event lowering and discuss the clinical implementation of these agents based on trial data and guidelines.

ω‑3 fatty acids in atherosclerotic cardiovascular disease (Review)

Atherosclerotic cardiovascular disease (ASCVD) is one of the most common chronic diseases in the world. Epidemiological evidence and clinical trials have shown that ω-3 fatty acids have a variety of promoting effects in reducing the risk of ASCVD, but different conclusions of large randomized controlled trials make their clinical use in the prevention and treatment of ASCVD controversial. The present review focuses on the pharmacological mechanism, clinical trials and evidence value of clinical applications of ω-3 fatty acids in order to provide theoretical and practical evidence for the clinical application strategy, and follow-up research and development of ω-3 fatty acids as anti-ASCVD drugs.

Recommendations for nutritional supplements for dry eye disease: current advances

Dry eye disease (DED) represents a prevalent ocular surface disease. The development of effective nutritional management strategies for DED is crucial due to its association with various factors such as inflammation, oxidative stress, deficiencies in polyunsaturated fatty acids (PUFAs), imbalanced PUFA ratios, and vitamin insufficiencies. Extensive research has explored the impact of oral nutritional supplements, varying in composition and dosage, on the symptoms of DED. The main components of these supplements include fish oils (Omega-3 fatty acids), vitamins, trace elements, and phytochemical extracts. Beyond these well-known nutrients, it is necessary to explore whether novel nutrients might contribute to more effective DED management. This review provides a comprehensive update on the therapeutic potential of nutrients and presents new perspectives for combination supplements in DED treatment.

Omega-3 (n-3) Fatty Acid-Statin Interaction: Evidence for a Novel Therapeutic Strategy for Atherosclerotic Cardiovascular Disease

Managing atherosclerotic cardiovascular disease (ASCVD) often involves a combination of lifestyle modifications and medications aiming to decrease the risk of cardiovascular outcomes, such as myocardial infarction and stroke. The aim of this article is to discuss possible omega-3 (n-3) fatty acid-statin interactions in the prevention and treatment of ASCVD and to provide evidence to consider for clinical practice, highlighting novel insights in this field. Statins and n-3 fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) are commonly used to control cardiovascular risk factors in order to treat ASCVD. Statins are an important lipid-lowering therapy, primarily targeting low-density lipoprotein cholesterol (LDL-C) levels, while n-3 fatty acids address triglyceride (TG) concentrations. Both statins and n-3 fatty acids have pleiotropic actions which overlap, including improving endothelial function, modulation of inflammation, and stabilizing atherosclerotic plaques. Thus, both statins and n-3 fatty acids potentially mitigate the residual cardiovascular risk that remains beyond lipid lowering, such as persistent inflammation. EPA and DHA are both substrates for the synthesis of so-called specialized pro-resolving mediators (SPMs), a relatively recently recognized feature of their ability to combat inflammation. Interestingly, statins seem to have the ability to promote the production of some SPMs, suggesting a largely unrecognized interaction between statins and n-3 fatty acids with relevance to the control of inflammation. Although n-3 fatty acids are the major substrates for the production of SPMs, these signaling molecules may have additional therapeutic benefits beyond those provided by the precursor n-3 fatty acids themselves. In this article, we discuss the accumulating evidence that supports SPMs as a novel therapeutic tool and the possible statin-n-3 fatty acid interactions relevant to the prevention and treatment of ASCVD.

Omega-3 supplementation changes the physical properties of leukocytes but not erythrocytes in healthy individuals: An exploratory trial

n3-PUFA impact health in several ways, including cardiovascular protection and anti-inflammatory effects, but the underlying mechanisms are not fully understood. In this exploratory study involving 31 healthy subjects, we aimed to investigate the effects of 12 weeks of fish-oil supplementation (1500 mg EPA+DHA/day) on the physical properties of multiple blood cell types. We used deformability cytometry (DC) for all cell types and Laser-assisted Optical Rotational Red Cell Analysis (Lorrca) to assess red blood cell (RBC) deformability. We also investigated the correlation between changes in the physical properties of blood cells and changes in the Omega-3 Index (O3I), defined as the relative content of EPA+DHA in RBCs. Following supplementation, the mean±SD O3I increased from 5.3 %±1.5 % to 8.3 %±1.4 % (p < 0.001). No significant changes in RBC properties were found by both techniques. However, by DC we observed a consistent pattern of physical changes in lymphocytes, neutrophils and monocytes. Among these were significant increases in metrics correlated with the cells' deformability resulting in less stiff cells. The results suggest that leukocytes become softer and have an increased ability to deform under induced short-term physical stress such as hydrodynamic force in the circulation. These changes could impact immune function since softer leukocytes can potentially circulate more easily and could facilitate a more rapid response to systemic inflammation or infection. In conclusion, fish-oil supplementation modulates some physical properties of leukocyte-subfractions, potentially enhancing their biological function. Further studies are warranted to explore the impact of n3-PUFA on blood cell biology, particularly in disease states associated with leukocyte dysregulation.

Effect of omega-3 fatty acids supplementation on the prognosis of coronary artery disease: A meta-analysis of randomized controlled trials

AIMS

To evaluate whether omega-3 fatty acids (ɷ-3 FAs) supplementation can improve cardiovascular outcomes in patients with established coronary artery disease (CAD).

DATA SYNTHESIS

Five electronic databases were searched for randomized controlled trials that evaluated the effect of ɷ-3 FAs on cardiovascular outcomes in patients with CAD. The language was restricted to English. The risk ratio was pooled. Subgroup analyses were conducted to evaluate whether study-level variables might act as effect modifiers. A total of 12 studies involving 29913 patients were included. ɷ-3 FAs had no effects on major adverse cardiovascular events (MACEs) (RR, 0.93; 95 % CI: 0.85 to 1.01, P = 0.09). While ɷ-3 FAs reduced the incidences of all-cause death (RR, 0.90; 95 % CI: 0.83 to 0.97, P = 0.005), cardiovascular death (RR, 0.82; 95 % CI: 0.75 to 0.90, P < 0.0001), myocardial infarction (RR, 0.77; 95 % CI: 0.68 to 0.86, P < 0.0001), revascularization (RR, 0.80; 95 % CI: 0.69 to 0.93, P = 0.003), sudden cardiac death (RR, 0.67; 95 % CI: 0.52 to 0.86, P = 0.002) and hospitalization for heart failure or unstable angina pectoris (RR, 0.75; 95 % CI: 0.58 to 0.97, P = 0.03) in CAD. It did not statistically reduce the risk of stroke (RR, 0.96; 95 % CI: 0.77 to 1.21, P = 0.76). The favorable effects of ɷ-3 FAs on MACEs were significant in subgroups of intervention with EPA and baseline triglyceride ≥1.7 mmol/L.

CONCLUSION

ɷ-3 FAs supplementation, especially EPA, appears to be an effective adjunct therapy for improving the prognosis of CAD.

REGISTRATION NUMBER

PROSPERO CRD42022311237.

Do patients benefit from omega-3 fatty acids?

Omega-3 fatty acids (O3FAs) possess beneficial properties for cardiovascular (CV) health and elevated O3FA levels are associated with lower incident risk for CV disease (CVD.) Yet, treatment of at-risk patients with various O3FA formulations has produced disparate results in large, well-controlled and well-conducted clinical trials. Prescription formulations and fish oil supplements containing low-dose mixtures of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have routinely failed to prevent CV events in primary and secondary prevention settings when added to contemporary care, as shown most recently in the STRENGTH and OMEMI trials. However, as observed in JELIS, REDUCE-IT, and RESPECT-EPA, EPA-only formulations significantly reduce CVD events in high-risk patients. The CV mechanism of action of EPA, while certainly multifaceted, does not depend solely on reductions of circulating lipids, including triglycerides (TG) and LDL, and event reduction appears related to achieved EPA levels suggesting that the particular chemical and biological properties of EPA, as compared to DHA and other O3FAs, may contribute to its distinct clinical efficacy. In vitro and in vivo studies have shown different effects of EPA compared with DHA alone or EPA/DHA combination treatments, on atherosclerotic plaque morphology, LDL and membrane oxidation, cholesterol distribution, membrane lipid dynamics, glucose homeostasis, endothelial function, and downstream lipid metabolite function. These findings indicate that prescription-grade, EPA-only formulations provide greater benefit than other O3FAs formulations tested. This review summarizes the clinical findings associated with various O3FA formulations, their efficacy in treating CV disease, and their underlying mechanisms of action.

The role of polyunsaturated fatty acids in the neurobiology of major depressive disorder and suicide risk

Long-chain polyunsaturated fatty acids (LC-PUFAs) are obtained from diet or derived from essential shorter-chain fatty acids, and are crucial for brain development and functioning. Fundamentally, LC-PUFAs' neurobiological effects derive from their physicochemical characteristics, including length and double bond configuration, which differentiate LC-PUFA species and give rise to functional differences between n(omega)-3 and n-6 LC-PUFAs. LC-PUFA imbalances are implicated in psychiatric disorders, including major depression and suicide risk. Dietary intake and genetic variants in enzymes involved in biosynthesis of LC-PUFAs from shorter chain fatty acids influence LC-PUFA status. Domains impacted by LC-PUFAs include 1) cell signaling, 2) inflammation, and 3) bioenergetics. 1) As major constituents of lipid bilayers, LC-PUFAs are determinants of cell membrane properties of viscosity and order, affecting lipid rafts, which play a role in regulation of membrane-bound proteins involved in cell-cell signaling, including monoaminergic receptors and transporters. 2) The n-3:n-6 LC-PUFA balance profoundly influences inflammation. Generally, metabolic products of n-6 LC-PUFAs (eicosanoids) are pro-inflammatory, while those of n-3 LC-PUFAs (docosanoids) participate in the resolution of inflammation. Additionally, n-3 LC-PUFAs suppress microglial activation and the ensuing proinflammatory cascade. 3) N-3 LC-PUFAs in the inner mitochondrial membrane affect oxidative stress, suppressing production of and scavenging reactive oxygen species (ROS), with neuroprotective benefits. Until now, this wealth of knowledge about LC-PUFA biomechanisms has not been adequately tapped to develop translational studies of LC-PUFA clinical effects in humans. Future studies integrating neurobiological mechanisms with clinical outcomes may suggest ways to identify depressed individuals most likely to respond to n-3 LC-PUFA supplementation, and mechanistic research may generate new treatment strategies.

Fish Oil Derivatives in Hypertriglyceridemia: Mechanism and Cardiovascular Prevention: What Do Studies Say?

Hypertriglyceridemia is a type of dyslipidemia characterized by high triglyceride levels in the blood and increases the risk of cardiovascular disease. Conventional management includes antilipidemic medications such as statins, lowering LDL and triglyceride levels as well as raising HDL levels. However, the treatment may be stratified using omega-3 fatty acid supplements such as eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA), aka fish oil derivatives. Studies have shown that fish oil supplements reduce the risk of cardiovascular diseases; however, the underlying mechanism and the extent of reduction in CVD need more clarification. Our paper aims to review the clinical trials and observational studies in the current literature, investigating the use of fish oil and its benefits on the cardiovascular system as well as the proposed underlying mechanism.

Biotechnological production of omega-3 fatty acids: current status and future perspectives

Omega-3 fatty acids, including alpha-linolenic acids (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), have shown major health benefits, but the human body's inability to synthesize them has led to the necessity of dietary intake of the products. The omega-3 fatty acid market has grown significantly, with a global market from an estimated USD 2.10 billion in 2020 to a predicted nearly USD 3.61 billion in 2028. However, obtaining a sufficient supply of high-quality and stable omega-3 fatty acids can be challenging. Currently, fish oil serves as the primary source of omega-3 fatty acids in the market, but it has several drawbacks, including high cost, inconsistent product quality, and major uncertainties in its sustainability and ecological impact. Other significant sources of omega-3 fatty acids include plants and microalgae fermentation, but they face similar challenges in reducing manufacturing costs and improving product quality and sustainability. With the advances in synthetic biology, biotechnological production of omega-3 fatty acids via engineered microbial cell factories still offers the best solution to provide a more stable, sustainable, and affordable source of omega-3 fatty acids by overcoming the major issues associated with conventional sources. This review summarizes the current status, key challenges, and future perspectives for the biotechnological production of major omega-3 fatty acids.

Higher docosahexaenoic acid levels lower the protective impact of eicosapentaenoic acid on long-term major cardiovascular events

Introduction

Long-chain omega-3 polyunsaturated fatty acids (OM3 PUFA) are commonly used for cardiovascular disease prevention. High-dose eicosapentaenoic acid (EPA) is reported to reduce major adverse cardiovascular events (MACE); however, a combined EPA and docosahexaenoic acid (DHA) supplementation has not been proven to do so. This study aimed to evaluate the potential interaction between EPA and DHA levels on long-term MACE.

Methods

We studied a cohort of 987 randomly selected subjects enrolled in the INSPIRE biobank registry who underwent coronary angiography. We used rapid throughput liquid chromatography-mass spectrometry to quantify the EPA and DHA plasma levels and examined their impact unadjusted, adjusted for one another, and fully adjusted for comorbidities, EPA + DHA, and the EPA/DHA ratio on long-term (10-year) MACE (all-cause death, myocardial infarction, stroke, heart failure hospitalization).

Results

The average subject age was 61.5 ± 12.2 years, 57% were male, 41% were obese, 42% had severe coronary artery disease (CAD), and 311 (31.5%) had a MACE. The 10-year MACE unadjusted hazard ratio (HR) for the highest (fourth) vs. lowest (first) quartile (Q) of EPA was HR = 0.48 (95% CI: 0.35, 0.67). The adjustment for DHA changed the HR to 0.30 (CI: 0.19, 0.49), and an additional adjustment for baseline differences changed the HR to 0.36 (CI: 0.22, 0.58). Conversely, unadjusted DHA did not significantly predict MACE, but adjustment for EPA resulted in a 1.81-fold higher risk of MACE (CI: 1.14, 2.90) for Q4 vs. Q1. However, after the adjustment for baseline differences, the risk of MACE was not significant for DHA (HR = 1.37; CI: 0.85, 2.20). An EPA/DHA ratio ≥1 resulted in a lower rate of 10-year MACE outcomes (27% vs. 37%, adjusted p-value = 0.013).

Conclusions

Higher levels of EPA, but not DHA, are associated with a lower risk of MACE. When combined with EPA, higher DHA blunts the benefit of EPA and is associated with a higher risk of MACE in the presence of low EPA. These findings can help explain the discrepant results of EPA-only and EPA/DHA mixed clinical supplementation trials.

The Anti-Aggregative Potential of Resolvin E1 on Human Platelets

Resolvin E1 is a metabolite of eicosapentaenoic acid (EPA) which is one of the omega-3 polyunsaturated fatty acids (omega-3 PUFAs). The antiplatelet properties of omega-3 PUFAs are well known, but the effect of resolvin E1 on platelets via the collagen receptors is extremely poorly reported. We investigated the effect of resolvin E1 on collagen-induced platelet aggregation, activation, and reactivity, and also platelet membrane fluidity. The ultimate and statistically significant results showed that resolvin E1 may inhibit platelet reactivity due to the reduction of collagen-induced platelet aggregation in platelet-rich plasma and isolated platelets, but not in whole blood. Also, resolvin E1 significantly reduced P-selectin exposure on collagen-stimulated platelets. Moreover, we demonstrated that resolvin E1 can maintain platelet membrane structure (without increasing membrane fluidity). The association between platelet reactivity and membrane fluidity, including resolvin E1 and collagen receptors requires further research. However, the goal of this study was to shed light on the molecular mechanisms behind the anti-aggregative effects of resolvin E1 on platelets, which are still not fully clarified. We also indicate an innovative research direction focused on further analysis and then use of omega-3 PUFAs metabolites as antiplatelet compounds for future applications in the treatment and prevention of cardiovascular diseases.

Eicosapentaenoic acid (EPA) reduces pulmonary endothelial dysfunction and inflammation due to changes in protein expression during exposure to particulate matter air pollution

AIMS

Inhalation of air pollution small particle matter (PM) is a leading cause of cardiovascular (CV) disease. Exposure to PMs causes endothelial cell (EC) dysfunction as evidenced by nitric oxide (NO) synthase uncoupling, vasoconstriction and inflammation. Eicosapentaenoic acid (EPA) has been shown to mitigate PM-induced adverse cardiac changes in patients receiving omega-3 fatty acid supplementation. We set out to determine the pro-inflammatory effects of multiple PMs (urban and fine) on pulmonary EC NO bioavailability and protein expression, and whether EPA restores EC function under these conditions.

METHODS AND RESULTS

We pretreated pulmonary ECs with EPA and then exposed them to urban or fine air pollution PMs. LC/MS-based proteomic analysis to assess relative expression levels. Expression of adhesion molecules was measured by immunochemistry. The ratio of NO to peroxynitrite (ONOO-) release, an indication of eNOS coupling, was measured using porphyrinic nanosensors following calcium stimulation. Urban/fine PMs also modulated 9/12 and 13/36 proteins, respectively, linked to platelet and neutrophil degranulation pathways and caused > 50% (p < 0.001) decrease in the stimulated NO/ONOO- release ratio. EPA treatment altered expression of proteins involved in these inflammatory pathways, including a decrease in peroxiredoxin-5 and an increase in superoxide dismutase-1. EPA also increased expression of heme oxygenase-1 (HMOX1), a cytoprotective protein, by 2.1-fold (p = 0.024). EPA reduced elevations in sICAM-1 levels by 22% (p < 0.01) and improved the NO/ONOO- release ratio by > 35% (p < 0.05).

CONCLUSION

These cellular changes may contribute to anti-inflammatory, cytoprotective and lipid changes associated with EPA treatment during air pollution exposure.

Omega-3 Fatty Acids in Arterial Hypertension: Is There Any Good News?

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs), including alpha-linolenic acid (ALA) and its derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are "essential" fatty acids mainly obtained from diet sources comprising plant oils, marine blue fish, and commercially available fish oil supplements. Many epidemiological and retrospective studies suggested that ω-3 PUFA consumption decreases the risk of cardiovascular disease, but results of early intervention trials have not consistently confirmed this effect. In recent years, some large-scale randomized controlled trials have shed new light on the potential role of ω-3 PUFAs, particularly high-dose EPA-only formulations, in cardiovascular prevention, making them an attractive tool for the treatment of "residual" cardiovascular risk. ω-3 PUFAs' beneficial effects on cardiovascular outcomes go far beyond the reduction in triglyceride levels and are thought to be mediated by their broadly documented "pleiotropic" actions, most of which are directed to vascular protection. A considerable number of clinical studies and meta-analyses suggest the beneficial effects of ω-3 PUFAs in the regulation of blood pressure in hypertensive and normotensive subjects. These effects occur mostly through regulation of the vascular tone that could be mediated by both endothelium-dependent and independent mechanisms. In this narrative review, we summarize the results of both experimental and clinical studies that evaluated the effect of ω-3 PUFAs on blood pressure, highlighting the mechanisms of their action on the vascular system and their possible impact on hypertension, hypertension-related vascular damage, and, ultimately, cardiovascular outcomes.

Natural Products as a Potential Source of Promising Therapeutics for COVID-19 and Viral Diseases

Background

A global pandemic has recently been observed due to the new coronavirus disease, caused by SARS-CoV-2. Since there are currently no antiviral medicines to combat the highly contagious and lethal COVID-19 infection, identifying natural sources that can either be viricidal or boost the immune system and aid in the fight against the disease can be an essential therapeutic support.

Methods

This review was conducted based on published papers related to the herbal therapy of COVID-19 by search on databases including PubMed and Scopus with herbal, COVID-19, SARS-CoV-2, and therapy keywords.

Results

To combat this condition, people may benefit from the therapeutic properties of medicinal plants, such as increasing their immune system or providing an antiviral impact. As a result, SARS-CoV-2 infection death rates can be reduced. Various traditional medicinal plants and their bioactive components, such as COVID-19, are summarized in this article to assist in gathering and debating techniques for combating microbial diseases in general and boosting our immune system in particular.

Conclusion

The immune system benefits from natural products and many of these play a role in activating antibody creation, maturation of immune cells, and stimulation of innate and adaptive immune responses. The lack of particular antivirals for SARS-CoV-2 means that apitherapy might be a viable option for reducing the hazards associated with COVID-19 in the absence of specific antivirals.

Eicosapentaenoic acid vs. docosahexaenoic acid for the prevention of cardiovascular disease

PURPOSE OF REVIEW

Populations with greater fatty fish intake have lower risk of coronary heart disease. However, trials testing omega-3 fatty acids (FA) on cardiovascular outcomes have yielded inconsistent results. In this review, we summarize the major cardiovascular trials examining omega-3 FA supplementation, and compare differences with eicosapentaenoic acid (EPA) alone vs. docosahexaenoic acid (DHA) combined with EPA.

RECENT FINDINGS

The JELIS and REDUCE-IT trials both demonstrated significant reduction in cardiovascular events with high dose EPA in the form of icosapent ethyl (IPE), with a similar trend seen in the RESPECT-EPA trial. In contrast, the ASCEND, VITAL, STRENGTH, and OMEMI trials examining EPA+DPA combinations failed to demonstrate benefit. Beyond the difference in omega-3 FA formulations (IPE vs. omega-3 carboxylic acid), other differences between REDUCE-IT and STRENGTH include the achieved EPA levels, differing properties that EPA and DHA have on membrane stabilization, and the comparator oils tested in the trials.

SUMMARY

The totality of evidence suggests EPA alone, administered in a highly-purified, high-dose form, improves cardiovascular outcomes among patients with elevated triglycerides at high cardiovascular risk, but EPA and DHA together does not. Current guidelines endorse the use of IPE in statin-treated patients at high cardiovascular risk who have triglycerides >135 mg/dl.

Differential Behavior of Eicosapentaenoic and Docosahexaenoic Acids on the Organization, Dynamics, and Fusion of Homogeneous and Heterogeneous Membranes

Membrane fusion is a common course in innumerable biological processes that helps in the survival of eukaryotes. Enveloped viruses utilize this process to enter the host cells. Generally, the membrane lipid compositions play an important role in membrane fusion by modulating the membrane's physical properties and the behavior of membrane proteins in the cellular milieu. In this work, we have demonstrated the role of polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, on the organization, dynamics, and fusion of homogeneous and heterogeneous membranes. We have exploited arrays of steady-state and time-resolved fluorescence spectroscopic methods and polyethylene glycol-induced membrane fusion assay to elucidate the behavior of EPA and DHA on dioleoyl phosphatidylcholine (DOPC)/cholesterol (CH) homogeneous and DOPC/sphingomyelin/CH heterogeneous membranes. Our results suggest that EPA and DHA display differential effects on two different membranes. The effects of PUFAs in homogeneous membranes are majorly attributed to their flexible chain dynamics, whereas the ability of PUFA-induced cholesterol transfer from the l_o to the l_d phase rules their behavior in heterogeneous membranes. Overall, our results provide detailed information on the effect of PUFAs on homogeneous and heterogeneous membranes.

Eicosapentaenoic and Docosahexaenoic Acid Supplementation Increases HDL Content in n-3 Fatty Acids and Improves Endothelial Function in Hypertriglyceridemic Patients

High-density lipoproteins (HDLs) are known to enhance vascular function through different mechanisms, including the delivery of functional lipids to endothelial cells. Therefore, we hypothesized that omega-3 (n-3) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content of HDLs would improve the beneficial vascular effects of these lipoproteins. To explore this hypothesis, we performed a placebo-controlled crossover clinical trial in 18 hypertriglyceridemic patients without clinical symptoms of coronary heart disease who received highly purified EPA 460 mg and DHA 380 mg, twice a day for 5 weeks or placebo. After 5 weeks of treatment, patients followed a 4-week washout period before crossover. HDLs were isolated using sequential ultracentrifugation for characterization and determination of fatty acid content. Our results showed that n-3 supplementation induced a significant decrease in body mass index, waist circumference as well as triglycerides and HDL-triglyceride plasma concentrations, whilst HDL-cholesterol and HDL-phospholipids significantly increased. On the other hand, HDL, EPA, and DHA content increased by 131% and 62%, respectively, whereas 3 omega-6 fatty acids significantly decreased in HDL structures. In addition, the EPA-to-arachidonic acid (AA) ratio increased more than twice within HDLs suggesting an improvement in their anti-inflammatory properties. All HDL-fatty acid modifications did not affect the size distribution or the stability of these lipoproteins and were concomitant with a significant increase in endothelial function assessed using a flow-mediated dilatation test (FMD) after n-3 supplementation. However, endothelial function was not improved in vitro using a model of rat aortic rings co-incubated with HDLs before or after treatment with n-3. These results suggest a beneficial effect of n-3 on endothelial function through a mechanism independent of HDL composition. In conclusion, we demonstrated that EPA and DHA supplementation for 5 weeks improved vascular function in hypertriglyceridemic patients, and induced enrichment of HDLs with EPA and DHA to the detriment of some n-6 fatty acids. The significant increase in the EPA-to-AA ratio in HDLs is indicative of a more anti-inflammatory profile of these lipoproteins.

Adherence to the Mediterranean Diet Association with Serum Levels of Nitric Oxide, Prostacyclin, and Thromboxane B2 among Prinzmetal Angina Patients and Healthy Persons

This study aimed to assess the association between adherence to the Mediterranean diet with serum Nitric oxide, Prostacyclin, and Thromboxane B₂ among Prinzmetal angina patients and healthy persons. This case-control study was conducted among 100 Prinzmetal angina patients and 100 healthy persons referred to the Ardabil Imam Khomeini hospital between 2021 and 2022. Blood samples were obtained from all study participants for measurement of serum Nitric oxide, Prostacyclin, and Thromboxane B₂. To calculate adherence to the Mediterranean diet, the ten-item screener was used. The serum Nitric oxide in patients who adhered more to the Mediterranean diet was higher than patients with less adherence (coeff. = 0.41 p = 0.04). The serum Prostacyclin level in patients with greater adherence to the Mediterranean diet was 0.34 units higher than patients with less adherence (coeff. = 0.34 p = 0.02). The level of serum Thromboxane B₂ had a negative association with adherence to the Mediterranean diet (coeff. = -0.48 p = 0.04). The amount of consumption of olive oil, fruits, vegetables, and legumes in healthy people was more than Prinzmetal angina patients. In Prinzmetal angina patients, more adherence to the Mediterranean diet can decrease the serum Thromboxane B₂ and increase the serum Nitric oxide and Prostacyclin.

Cost-Effectiveness of Icosapent Ethyl (IPE) for the Reduction of the Risk of Ischemic Cardiovascular Events in Canada

Background

Despite the use of statins, many patients with cardiovascular disease (CVD) have persistent residual risk. In a large Phase III trial (REDUCE-IT), icosapent ethyl (IPE) was shown to reduce the first occurrence of the primary composite endpoint of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or hospitalization for unstable angina.

Methods

We conducted a cost-utility analysis comparing IPE to placebo in statin-treated patients with elevated triglycerides, from a publicly funded, Canadian healthcare payer perspective, using a time-dependent Markov transition model over a 20-year time horizon. We obtained efficacy and safety data from REDUCE-IT, and costs and utilities from provincial formularies and databases, manufacturer sources, and Canadian literature sources.

Results

In the probabilistic base-case analysis, IPE was associated with an incremental cost of $12,523 and an estimated 0.29 more quality-adjusted life years (QALYs), corresponding to an incremental cost-effectiveness ratio (ICER) of $42,797/QALY gained. At a willingness-to-pay of $50,000 and $100,000/QALY gained, there is a probability of 70.4% and 98.8%, respectively, that IPE is a cost-effective strategy over placebo. The deterministic model yielded similar results. In the deterministic sensitivity analyses, the ICER varied between $31,823-$70,427/QALY gained. Scenario analyses revealed that extending the timeframe of the model to a lifetime horizon resulted in an ICER of $32,925/QALY gained.

Conclusion

IPE represents an important new treatment for the reduction of ischemic CV events in statin-treated patients with elevated triglycerides. Based on the clinical trial evidence, we found that IPE could be a cost-effective strategy for treating these patients in Canada.

Role of Omega-3 Fatty Acids in Cardiovascular Disease: the Debate Continues

PURPOSE OF REVIEW

The omega-3 fatty acids (n3-FAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have recently undergone testing for their ability to reduce residual cardiovascular (CV) risk among statin-treated subjects. The outcome trials have yielded highly inconsistent results, perhaps attributable to variations in dosage, formulation, and composition. In particular, CV trials using icosapent ethyl (IPE), a highly purified ethyl ester of EPA, reproducibly reduced CV events and progression of atherosclerosis compared with mixed EPA/DHA treatments. This review summarizes the mechanistic evidence for differences among n3-FAs on the development and manifestations of atherothrombotic disease.

RECENT FINDINGS

Large randomized clinical trials with n3-FAs have produced discordant outcomes despite similar patient profiles, doses, and triglyceride (TG)-lowering effects. A large, randomized trial with IPE, a prescription EPA only formulation, showed robust reduction in CV events in statin treated patients in a manner proportional to achieved blood EPA concentrations. Multiple trials using mixed EPA/DHA formulations have not shown such benefits, despite similar TG lowering. These inconsistencies have inspired investigations into mechanistic differences among n3-FAs, as EPA and DHA have distinct membrane interactions, metabolic products, effects on cholesterol efflux, antioxidant properties, and tissue distribution. EPA maintains normal membrane cholesterol distribution, enhances endothelial function, and in combination with statins improves features implicated in plaque stability and reduces lipid content of plaques. Insights into reductions in residual CV risk have emerged from clinical trials using different formulations of n3-FAs. Among high-risk patients on contemporary care, mixed n3-FA formulations showed no reduction in CV events. The distinct benefits of IPE in multiple trials may arise from pleiotropic actions that correlate with on-treatment EPA levels beyond TG-lowering. These effects include altered platelet function, inflammation, cholesterol distribution, and endothelial dysfunction. Elucidating such mechanisms of vascular protection for EPA may lead to new interventions for atherosclerosis, a disease that continues to expand worldwide.

Potential Mechanisms by Which Hydroxyeicosapentaenoic Acids Regulate Glucose Homeostasis in Obesity

Dysregulation of glucose metabolism in response to diet-induced obesity contributes toward numerous complications, such as insulin resistance and hepatic steatosis. Therefore, there is a need to develop effective strategies to improve glucose homeostasis. In this review, we first discuss emerging evidence from epidemiological studies and rodent experiments that increased consumption of EPA (either as oily fish, or dietary/pharmacological supplements) may have a role in preventing impairments in insulin and glucose homeostasis. We then review the current evidence on how EPA-derived metabolites known as hydroxyeicosapentaenoic acids (HEPEs) may be a major mode of action by which EPA exerts its beneficial effects on glucose and lipid metabolism. Notably, cell culture and rodent studies show that HEPEs prevent fat accumulation in metabolic tissues through peroxisome proliferator activated receptor (PPAR)-mediated mechanisms. In addition, activation of the resolvin E1 pathway, either by administration of EPA in the diet or via intraperitoneal administration of resolvin E1, improves hyperglycemia, hyperinsulinemia, and liver steatosis through multiple mechanisms. These mechanisms include shifting immune cell phenotypes toward resolution of inflammation and preventing dysbiosis of the gut microbiome. Finally, we present the next steps for this line of research that will drive future precision randomized clinical trials with EPA and its downstream metabolites. These include dissecting the variables that drive heterogeneity in the response to EPA, such as the baseline microbiome profile and fatty acid status, circadian rhythm, genetic variation, sex, and age. In addition, there is a critical need to further investigate mechanisms of action for HEPEs and to establish the concentration of HEPEs in differing tissues, particularly in response to consumption of oily fish and EPA-enriched supplements.

Association of omega-3 and omega-6 fatty acid intake with leukocyte telomere length in US males

BACKGROUND

Omega-3 (n-3) and omega-6 (n-6) fatty acids may contribute to oxidative stress and inflammation, which are related to telomere shortening. Evidence supporting an association between intake of n-3 or n-6 fatty acids and leukocyte telomere length (LTL) in males has been limited.

OBJECTIVES

We conducted a cross-sectional study to examine the associations of total or individual n-3 or total n-6 fatty acid intake with LTL in US males.

METHODS

We included 2,494 US males with LTL measurement from 4 nested case-control studies within the Health Professionals Follow-Up Study. Individuals with previous histories of cancers, diabetes, and cardiovascular diseases at or before blood collection were excluded. Blood collection was performed between 1993 and 1995, and relevant information including n-3 and n-6 intake was collected in 1994 by questionnaire. The LTL was log-transformed and Z scores of the LTL were calculated for statistical analyses by standardizing the LTL in comparison with the mean within each selected nested case-control study.

RESULTS

We found that consumption of DHA (22:6n-3) was positively associated with LTL. In the multivariable-adjusted model, compared with individuals who had the lowest intake of DHA (i.e., first quartile group), the percentage differences (95% CIs) of LTL were -3.7 (-13.7, 7.5), 7.0 (-4.3, 19.7), and 8.2 (-3.5, 21.3) for individuals in the second, third, and fourth quartiles of consumption, respectively (P-trend = 0.0498). We did not find significant associations between total n-3 or total n-6 fatty acid intakes and LTL. In addition, we found that males who consumed canned tuna had longer LTL than those who did not; in the multivariable-adjusted model, the percentage difference of LTL was 10.5 (95% CI: 1.3, 20.4) (P = 0.02).

CONCLUSIONS

Our results suggest that higher intakes of DHA and canned tuna consumption are associated with longer LTL.

Cholesterol crystals and atherosclerotic plaque instability: Therapeutic potential of Eicosapentaenoic acid

Atherosclerotic plaques associated with acute coronary syndromes (ACS), i.e. culprit lesions, frequently feature a ruptured fibrous cap with thrombotic complications. On imaging, these plaques exhibit a low attenuation, lipid-rich, necrotic core containing cholesterol crystals and are inherently unstable. Indeed, cholesterol crystals are causally associated with plaque vulnerability in vivo; their formation results from spontaneous self-assembly of cholesterol molecules. Cholesterol homeostasis is a central determinant of the physicochemical conditions leading to crystal formation, which are favored by elevated membrane free cholesterol content in plaque endothelial cells, smooth muscle cells, monocyte-derived macrophages, and foam cells, and equally by lipid oxidation. Emerging evidence from imaging trials in patients with coronary heart disease has highlighted the impact of intervention involving the omega-3 fatty acid, eicosapentaenoic acid (EPA), on vulnerable, low attenuation atherosclerotic plaques. Thus, EPA decreased features associated with unstable plaque by increasing fibrous cap thickness in statin-treated patients, by reducing lipid volume and equally attenuating intraplaque inflammation. Importantly, atherosclerotic plaques rapidly incorporate EPA; indeed, a high content of EPA in plaque tissue is associated with decreased plaque inflammation and increased stability. These findings are entirely consistent with the major reduction seen in cardiovascular events in the REDUCE-IT trial, in which high dose EPA was administered as its esterified precursor, icosapent ethyl (IPE); moreover, clinical benefit was proportional to circulating EPA levels. Eicosapentaenoic acid is efficiently incorporated into phospholipids, where it modulates cholesterol-enriched domains in cell membranes through physicochemical lipid interactions and changes in rates of lipid oxidation. Indeed, biophysical analyses indicate that EPA exists in an extended conformation in membranes, thereby enhancing normal cholesterol distribution while reducing propagation of free radicals. Such effects mitigate cholesterol aggregation and crystal formation. In addition to its favorable effect on cholesterol domain structure, EPA/IPE exerts pleiotropic actions, including antithrombotic, antiplatelet, anti-inflammatory, and proresolving effects, whose plaque-stabilizing potential cannot be excluded. Docosahexaenoic acid is distinguished from EPA by a higher degree of unsaturation and longer carbon chain length; DHA is thus predisposed to changes in its conformation with ensuing increase in membrane lipid fluidity and promotion of cholesterol aggregation into discrete domains. Such distinct molecular effects between EPA and DHA are pronounced under conditions of high cellular cholesterol content and oxidative stress. This review will focus on the formation and role of cholesterol monohydrate crystals in destabilizing atherosclerotic plaques, and on the potential of EPA as a therapeutic agent to attenuate the formation of deleterious cholesterol membrane domains and of cholesterol crystals. Such a therapeutic approach may translate to enhanced plaque stability and ultimately to reduction in cardiovascular risk.

Association between the ratio of serum eicosapentaenoic acid to arachidonic acid and risk of coronary artery disease in young Chinese patients

OBJECTIVE

Long-chain (LC) omega-3 PUFAs, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may play an anti-inflammatory effect and decrease the risk of coronary artery disease (CAD). In contrast, omega-6 PUFA, mainly arachidonic acid (AA), has pro-inflammatory and pro-aggregatory effects, which may increase the risk of CAD. This study evaluated the associations between EPA, DHA, AA, and their ratios (EPA/AA and DHA/AA) with the risk of CAD in young Chinese patients.

METHODS

A total of 182 young patients with CAD and 143 age-matched controls were included. Traditional cardiovascular risk factors were recorded. Serum EPA, DHA and AA were measured by ultra-performance liquid chromatography-mass spectrometry.

RESULTS

The level of AA was significantly higher, while the level of EPA was lower in the CAD group than that in the control group. There was no significant difference in DHA level in the two groups. Both the ratios of EPA/AA and DHA/AA were lower in the CAD group than that in the control. Multivariate logistic regression analysis showed that higher serum AA level was associated with the increased risk of CAD, while EPA was a protective factor for CAD. There was no significant association between DHA level and the risk of CAD. Although both higher ratios of EPA/AA [per tertile increment, adjusted odds ratios (ORs) (OR) 0.356, 95% confidence intervals (CI) 0.247-0.513] and DHA/AA (adjusted OR = 0.465, 95%CI = 0.332-0.653) were associated with a lower risk of CAD in young patients. Receiver operating characteristic (ROC) curve analysis showed that compared with AA, the diagnostic value was increased in EPA/AA, but not in DHA/AA.

CONCLUSION

EPA, but not DHA may play a protective role in CAD, while AA may be associated with the increased risk of CAD in young Chinese patients. The ratio of EPA/AA can increase the predictive value for diagnosing CAD than EPA or AA alone.

Review of recent clinical trials and their impact on the treatment of hypercholesterolemia

PURPOSE OF REVIEW

Cardiovascular disease is the leading cause of death in the United States with incidence expected to increase in the coming decades. Recent years have produced a variety of new and novel therapeutics aimed at reducing the global burden of cardiovascular disease. This review highlights these recent advancements.

RECENT FINDINGS

In addition to more rigorous therapeutic thresholds for traditional LDL lowering agents such as statins, recent studies have developed new pathways of lipid lowering for both typical cardiovascular disease and complex, genetic lipid disorders. This includes inhibition of the cholesterol synthesis enzyme ATP citrate lyase with bempedoic acid, prevention of PCSK9 mRNA translation with inclisiran, inhibition of the lipoprotein lipase inhibitor angiopoetin like 3 protein with evinacumab and the use of anti-sense oligonucleotides to lower lipoprotein(a) levels. Icosapent ethyl, while remaining a topic of debate and controversy, demonstrates efficacy in cardiovascular risk reduction when all available data are examined. Lastly fibrate therapy continues to produce negative results in terms of cardiovascular disease reduction.

SUMMARY

Recent years have yielded breadth and depth to cardiovascular treatments. This expanded armamentarium will allow for more effective and more consistent treatment and prevention of cardiovascular disease.

The Importance of the Plasma Membrane in Atherogenesis

Atherosclerotic cardiovascular diseases are an important medical problem due to their high prevalence, impact on quality of life and prognosis. The pathogenesis of atherosclerosis is an urgent medical and social problem, the solution of which may improve the quality of diagnosis and treatment of patients. Atherosclerosis is a complex chain of events, which proceeds over many years and in which many cells in the bloodstream and the vascular wall are involved. A growing body of evidence suggests that there are complex, closely linked molecular mechanisms that occur in the plasma membranes of cells involved in atherogenesis. Lipid transport, innate immune system receptor function, and hemodynamic regulation are linked to plasma membranes and their biophysical properties. A better understanding of these interrelationships will improve diagnostic quality and treatment efficacy.

Clinical significance of polyunsaturated fatty acids in the prevention of cardiovascular diseases

Cardiovascular diseases are one of the most important problems of modern medicine. They are associated with a large number of health care visits, hospitalizations and mortality. Prevention of atherosclerosis is one of the most effective strategies and should start as early as possible. Correction of lipid metabolism disorders is associated with definite clinical successes, both in primary prevention and in the prevention of complications of many cardiovascular diseases. A growing body of evidence suggests a multifaceted role for polyunsaturated fatty acids. They demonstrate a variety of functions in inflammation, both participating directly in a number of cellular processes and acting as a precursor for subsequent biosynthesis of lipid mediators. Extensive clinical data also support the importance of polyunsaturated fatty acids, but all questions have not been answered to date, indicating the need for further research.

Genetic- and diet-induced ω-3 fatty acid enrichment enhances TRPV4-mediated vasodilation in mice

TRPV4 channel activation in endothelial cells leads to vasodilation, while impairment of TRPV4 activity is implicated in vascular dysfunction. Strategies that increase TRPV4 activity could enhance vasodilation and ameliorate vascular disorders. Here, we show that supplementation with eicosapentaenoic acid (EPA), an ω-3 polyunsaturated fatty acid known to have beneficial cardiovascular effects, increases TRPV4 activity in human endothelial cells of various vascular beds. Mice carrying the C. elegans FAT-1 enzyme, which converts ω-6 to ω-3 polyunsaturated fatty acids, display higher EPA content and increased TRPV4-mediated vasodilation in mesenteric arteries. Likewise, mice fed an EPA-enriched diet exhibit enhanced and prolonged TRPV4-dependent vasodilation in an endothelial cell-specific manner. We also show that EPA supplementation reduces TRPV4 desensitization, which contributes to the prolonged vasodilation. Neutralization of positive charges in the TRPV4 N terminus impairs the effect of EPA on channel desensitization. These findings highlight the beneficial effects of manipulating fatty acid content to enhance TRPV4-mediated vasodilation.

Killing the Culprit: Pharmacological Solutions to Get Rid of Cholesterol Crystals

Cholesterol crystals (CCs) play a key role in the pathophysiology of cardiovascular diseases (CVD) via triggering inflammation, plaque formation and subsequently plaque rupture. Although statins can stabilize plaques via calcification and alteration of the lipid composition within plaques, there is still a high residual risk of CVD events among statins users. Several studies have tried to blunt the detrimental effects of cholesterol crystals by pharmacological interventions. Cyclodexterins (CDs) and other nanoformulations, including polymers of CDs and liposomes, have the ability to dissolve CCs in vitro and in vivo. CDs were the first in their class that entered clinical trials and showed promising results, though their ototoxicity outweighed their benefits. Moreover, small molecules with structural similarity to cholesterol may also perturb cholesterol-cholesterol interactions and prevent from expansion of 2D crystalline domains to large 3D CCs. The results from ethyl eicosapentaenoic acid and ursodeoxycholic acid were encouraging and worth further consideration. In this review, the significance of CCs in pathogenesis of CVD is discussed and pharmacological agents with the ability to dissolve CCs or prevent from CCs formation are introduced.

Associations of Dietary Fats with All-Cause Mortality and Cardiovascular Disease Mortality among Patients with Cardiometabolic Disease

Previous studies have shown distinct associations between specific dietary fats and mortality. However, evidence on specific dietary fats and mortality among patients with cardiometabolic disease (CMD) remains unclear. The aim of this study was to estimate the association between consumption of specific fatty acids and survival of patients with CMD and examine whether cardiometabolic biomarkers can mediate the above effects. The study included 8537 participants with CMD, from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 1999–2014. Cox proportional hazards regression, restricted cubic spline regression, and isocaloric substitution models were used to estimate the associations of dietary fats with all-cause mortality and cardiovascular disease (CVD) mortality among participants with CMD. Mediation analysis was performed to assess the potential mediating roles of cardiometabolic biomarkers. During a median follow-up of 10.3 years (0–27.1 years), 3506 all-cause deaths and 882 CVD deaths occurred. The hazard ratios (HRs) of all-cause mortality among patients with CMD were 0.85 (95% confidence interval (CI), 95% CI, 0.73–0.99; p trend = 0.03) for ω-6 polyunsaturated fatty acids (ω-6 PUFA), 0.86 (95% CI, 0.75–1.00; p trend = 0.05) for linoleic acid (LA), and 0.86 (95% CI, 0.75–0.98; p trend = 0.03) for docosapentaenoic acid (DPA). Isocalorically replacing energy from SFA with PUFA and LA were associated with 8% and 4% lower all-cause mortality respectively. The HRs of CVD mortality among CMD patients comparing extreme tertiles of specific dietary fats were 0.60 (95% CI, 0.48–0.75; p trend = 0.002) for eicosapentaenoic acid (EPA), and 0.64 (95% CI, 0.48–0.85; p trend = 0.002) for DPA and above effects were mediated by levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL), and high density lipoprotein cholesterol (HDL). Restricted cubic splines showed significant negative nonlinear associations between above specific dietary fats and mortality. These results suggest that intakes of ω-6 PUFA, LA, and DPA or replacing SFA with PUFA or LA might be associated with lower all-cause mortality for patients with CMD. Consumption of EPA and DPA could potentially reduce cardiovascular death for patients with CMD, and their effects might be regulated by cardiometabolic biomarkers indirectly. More precise and representative studies are further needed to validate our findings.

A biological rationale for the disparate effects of omega-3 fatty acids on cardiovascular disease outcomes

The omega-3 fatty acids (n3-FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) rapidly incorporate into cell membranes where they modulate signal transduction pathways, lipid raft formation, and cholesterol distribution. Membrane n3-FAs also form specialized pro-resolving mediators and other intracellular oxylipins that modulate inflammatory pathways, including T-cell differentiation and gene expression. Cardiovascular (CV) trials have shown that EPA, administered as icosapent ethyl (IPE), reduces composite CV events, along with plaque volume, in statin-treated, high-risk patients. Mixed EPA/DHA regimens have not shown these benefits, perhaps as the result of differences in formulation, dosage, or potential counter-regulatory actions of DHA. Indeed, EPA and DHA have distinct, tissue-specific effects on membrane structural organization and cell function. This review summarizes: (1) results of clinical outcome and imaging trials using n3-FA formulations; (2) membrane interactions of n3-FAs; (3) effects of n3-FAs on membrane oxidative stress and cholesterol crystalline domain formation during hyperglycemia; (4) n3-FA effects on endothelial function; (5) role of n3-FA-generated metabolites in inflammation; and (6) ongoing and future clinical investigations exploring treatment targets for n3-FAs, including COVID-19.

Omega-3-fatty acids: Do they prevent cardiovascular disease?

Despite cardiovascular disease (CVD) reductions with high-intensity statins, there remains residual risk among patients with metabolic disorders. Alongside low-density lipoproteins (LDL-C), elevated triglycerides (TG) are associated with incident CVD events. Omega-3 fatty acids (n3-FAs), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), lower TG levels, but their ability to reduce CV risk has been highly inconsistent. Trials using icosapent ethyl (IPE), a purified EPA ethyl ester, produced reductions in CVD events and atherosclerotic plaque regression compared with mixed EPA/DHA formulations despite similar TG-reductions. The separate effects of EPA and DHA on tissue distribution, oxidative stress, inflammation, membrane structure and endothelial function may contribute to these discordant outcomes. Additional mechanistic trials will provide further insights into the role of n3-FAs in reducing CVD risk beyond TG lowering.