Effects Of Eicosapentaenoic Acid Research Articles

Eicosapentaenoic acid activates the P62/KEAP1/NRF2 pathway for the prevention of diabetes-associated cognitive dysfunction.

Diabetes-associated cognitive dysfunction (DCD) is a severe complication of diabetes mellitus (DM), threatening the life quality of the diabetic population. However, there is still a lack of effective approaches for its intervention. Eicosapentaenoic acid (EPA) is an omega-3 polyunsaturated fatty acid that was not previously investigated for its effect on DCD. In this study, EPA was found to improve DCD in a mouse model of type 2 DM (T2DM) induced by streptozotocin and a high-fat diet, exhibiting profound protective effects on cognitive dysfunction, neuronal loss, and cerebral oxidative stress and inflammation. While EPA did not attenuate advanced glycation end product-induced neuron injury, we hypothesized that EPA might protect neurons by regulating microglia polarization, the effect of which was confirmed by the co-culture of neurons and lipopolysaccharide-stimulated microglia. RNA sequencing identified nuclear factor-erythroid-2-related factor 2 (NRF2) antioxidant signaling as a major target of EPA in microglia. Mechanistically, EPA increased sequestosome-1 (SQSTM1 or P62) levels that might structurally inhibit Kelch-like ECH associated protein 1 (KEAP1), leading to nuclear translocation of NRF2. P62 and NRF2 predominantly mediated EPA's effect since the knockdown of P62 or NRF2 abolished EPA's protective effect on microglial oxidative stress and inflammation and sequential neuron injuries. Moreover, the regulation of P62/KEPA1/NRF2 axes by EPA was confirmed in the hippocampi of diabetic mice. The present work presents EPA as an effective nutritional approach and microglial P62/KEAP1/NRF2 as molecular targets for the intervention of DCD.

Mechanisms Mediating the Anti‐inflammatory Effects of Eicosapentaenoic Acid in the APPswePS1dE9 Alzheimer's Mouse Model

AbstractBackgroundAlzheimer’s disease (AD) is a progressive, neurodegenerative disorder characterized by amyloid‐beta (Aβ) plaques, which may be exacerbated by obesity. We previously reported anti‐obesity and anti‐inflammatory effects of eicosapentaenoic acid (EPA), in diet‐induced obese mice. Therefore, the objective of this research is to determine whether EPA also protects against AD‐associated Aβ deposition.MethodMale and female AD mouse model APPswePS1E9 transgenic (TG) and non‐TG wild type littermates (WT) were fed with low fat (LF), high fat (HF), or HF supplemented with 36g/kg EPA (EPA) for 8 months. Mice were metabolically phenotyped during the intervention and blood and tissues were collected at the end of the study. Cortex RNA was isolated, and changes in genes related to AD, obesity, and inflammation were measured. Data were analyzed by 3‐way ANOVA using GraphPad Prism.ResultHF groups weighed significantly more than LF groups (p < 0.001), but other groups were comparable regardless of diet or genotype but overall, males weighed more than females. TG mice had higher serum Aβ‐40 levels than WT mice (p= 0.004), paralleled with higher cortex human APP mRNA levels in TG mice (p = 0.0204). Compared to HF, EPA decreased serum Aβ‐40 in WT male mice (p = 0.0182) as well as APP gene expression in the cortex of male and female TG mice (p = 0.0168 and 0.0030). Moreover, TG mice expressed higher level of MCP1 and IL1β (p = 0.0158 and 0.0142, respectively) mRNA levels compared to WT. Females in both genotypes expressed higher level of MCP1, IL1β and NLRP3 than males (p = 0.0025, 0.0038, and < 0.0001 respectively). In addition, EPA exhibited anti‐inflammatory effects in both sexes of TG mice as indicated by downregulation of mRNAs levels for MCP1 (p = 0.0226 and 0.0108) NLRP3 (p = 0.0205 and < 0.0001) and for IL1β in TG females only (p= 0.0344).ConclusionOur data indicate protective effects of EPA in AD, in part, by reducing Aβ deposition, possibly through inflammatory/neuroinflammatory mechanisms. Given the popularity of fish oil supplements, our findings merit further investigation to dissect mechanisms of fish oil effects especially in AD patients with obesity.

Abstract 11150: The Effect of Eicosapentaenoic Acid and Docosahexaenoic Acid on Neutrophil/Lymphocyte Ratio, a Marker of Inflammation, in Subjects With Coronary Artery Disease: Results of a Randomized Trial

Background: The neutrophil/lymphocyte (N/L) ratio increases with the systemic inflammatory response due to an increase in neutrophils and decrease in lymphocytes with systemic inflammation. An elevated N/L ratio has been associated with an increased risk of cardiovascular disease (CVD), cancer and mortality. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) decrease levels of high sensitivity C-reactive protein (hs-CRP), the gold standard inflammatory marker, when levels of hs-CRP are elevated. Randomized trials have also reported a decrease in CVD events with EPA. The mechanism for this benefit is unclear. Objective: To examine the effect of high-dose EPA and DHA supplementation on inflammation as measured by the N/L ratio in the setting of low levels of hs-CRP. Methods: A total of 242 subjects with stable coronary artery disease on statin treatment were randomized to 3.36 g EPA+DHA daily or none. N/L ratio and the monocyte to lymphocyte (M/L) ratio were measured at baseline and 1 year. Results: Mean (SD) age was 63.1 years (7.7); mean (SD) LDL-C: 77.8 mg/dL (27.3); median [IQR] TG: 117.5 mg/dL [81.3,166.8] and median [IQR] hs-CRP: 0.75 mg/L [0.40,2.5]. Those on EPA+DHA had a 2.2% reduction in N/L ratio (P=0.014) at 1 year compared to those not on EPA+DHA who had a 12.2% increase (Figure) (between group P= 0.007). There was a trend toward benefit with the M/L ratio (P=0.078). Conclusion: High-dose EPA+DHA decreases systemic inflammation as reflected in the N/L ratio even with low hs-CRP levels. This is a new finding which suggests that under conditions of generally low levels of inflammation in terms of hs-CRP levels, the N/L ratio may be a more sensitive measure of underlying inflammation than hs-CRP and should be considered as an additional marker in future studies of omega-3 fatty acids. If a decrease in inflammation by N/L ratio were accompanied by a clinical decrease in CVD events, this would assist in determining a plausible mechanism of action.

Abstract 13889: Effect of Eicosapentaenoic and Docosahexaenoic Acid Supplementation on Noncalcified Coronary Plaque and Coronary Artery Calcium Score in Subjects With Coronary Artery Disease According to Hypertension Status

Introduction: Higher amounts of noncalcified plaque and higher coronary artery calcium (CAC) scores are associated with increased cardiovascular events and mortality. The effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on noncalcified coronary plaque and more advanced calcified plaque as measured by the CAC score according to hypertensive (HTN) status is unknown. Methods: A total of 242 subjects with coronary artery disease (CAD) on statin were randomized to 3.36 g of EPA+DHA or none (control) for 30 months. Coronary plaque composition and CAC scores were measured with computed tomographic coronary angiography at baseline and 30-month follow-up. Results: Mean (SD) age was 63.1 years (7.7); mean (SD) LDL-C: 77.8 mg/dL (27.3) and median [IQR] triglyceride (TG): 117.5 mg/dL [81.3,166.8]. Despite a significantly higher CAC score at baseline in HTN subjects, both HTN and normotensive (NTN) subjects had similar CAC progression over 30 months with no difference between EPA+DHA and control groups (Figure B). NTN subjects on EPA+DHA had a 20.7% reduction in TG level and 36.6% lower neutrophil count, a marker of inflammation, and lack of progression of noncalcified plaque compared to control who had progression (median % change: -7.6 vs 13.2 mm 3 /mm, P=0.008) (Figure A). In contrast, HTN subjects on EPA+DHA and control had progression of noncalcified coronary plaque with no significant difference between the two groups (Figure A) Conclusions: EPA+DHA prevented progression of noncalcified plaque in NTN subjects but not HTN subjects with no effect on more advanced plaque which has calcified in the setting of low LDL-C and TG levels. The benefit of EPA+DHA in CAD patients on statin therapy appears limited to noncalcified coronary plaque in NTN subjects. Whether this benefit is related to more favorable effects on inflammation based on blood pressure status should be examined further.

Eicosapentaenoic acid loaded silica nanoemulsion attenuates hepatic inflammation through the enhancement of cell membrane components

BackgroundLiver inflammation is a multistep process that is linked with cell membrane fatty acids composition. The effectiveness of eicosapentaenoic acid (EPA) undergoes an irreversible change during processing due to their unsaturated nature; so the formation of nanocarrier for EPA is crucial for improving EPA’s bioavailability and pharmacological properties.ObjectiveIn this study we aimed to evaluate the efficiency of EPA alone or loaded silica nanoemulsion on the management of hepatic inflammation induced by diethyl nitrosamine (DEN) through the enhancement of the cell membrane structure and functions.MethodsThe new formula of EPA was prepared to modify the properties of EPA. Forty-eight male Wistar albino rats were classified into: control, EPA, EPA loaded silica nanoemulsion (EPA–NE), DEN induced hepatic inflammation; DEN induced hepatic inflammation treated with EPA or EPA –NE groups. Plasma tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), liver hydroxyproline (Hyp) content, and liver oxidant and anti-oxidants were estimated. Urinary 8- hydroxyguanozine (8- OHdG) and erythrocyte membrane fatty acids fractions were estimated by High-performance liquid chromatography (HPLC). Also, histopathology studies were done to verify our hypothesis.ResultsIt was appeared that administration of EPA, in particular EPA loaded silica nanoemulsion, ameliorated the inflammatory response, increased the activity of the anti-oxidants, reduced levels of oxidants, and improved cell membrane structure compared to hepatic inflammation induced by DEN group. Histopathological examination confirmed these results.ConclusionEPA and notably EPA loaded silica nanoemulsion strongly recommended as a promising supplement in the management of hepatic inflammation.

8-Hydroxyeicosapentaenoic Acid Reduces Adipogenesis and Inflammation in 3T3-L1 Adipocytes

ObjectivesObesity is a complex disease and a chronic low-grade inflammatory state, which contributes to metabolic dysfunctions. Eicosapentaenoic acid (EPA), an n-3 fatty acid in fish oil, exerts anti-obesity and anti-inflammatory effects. Our previous study indicated that EPA lowered fat mass in obese female mice, potentially through increased biosynthesis of 8-hydroxyeicosapentaenoic acid (HEPE), an EPA-derived metabolite. Therefore, the objective of this study was to elucidate mechanisms underlying 8-HEPE effects on adipogenesis and inflammation using cultured 3T3-L1 cells. We hypothesized that 8-HEPE is more effective than EPA in reducing lipid accumulation and inflammatory genes in vitro. MethodsMurine 3T3-L1 adipocytes were cultured and differentiated with 5μM EPA, 18-HEPE, 8-HEPE, or control. Differentiated adipocytes were fixed and stained with Oil-Red-O solution and lipid content measured spectrophotometrically. To determine anti-inflammatory effects, 3T3-L1 pre- and differentiated cells were treated as above with or without lipopolysaccharide (LPS). Medium and cells were collected to measure interleukin-6 (IL-6) levels and genes involved in adipogenesis and inflammation. Results were analyzed by one-way ANOVA followed by a Tukey post-hoc test (GraphPad Prism).Results3T3-L1 cells differentiated with 8-HEPE had lower lipid content than control (p < 0.01). Consistently, 8-HEPE treated cells expressed a lower level of fatty acid synthesis gene, like acetyl-CoA carboxylase and fatty acid synthase than control (p = 0.059 and p = 0.042). And 8-HEPE exhibited promising anti-inflammatory effects by downregulating the IL-6 cytokine level in both LPS stimulated pre- and differentiated 3T3-L1 cells (p < 0.05). LPS-stimulated differentiated cells treated with 8-HEPE expressed a lower level of the inflammatory gene, IL-6 (p = 0.017), and a trend toward a higher level of the anti-inflammatory gene, arginase 1 (p = 0.067), than LPS control.ConclusionsOur findings indicate that the 8-HEPE has potent antiadipogenic and anti-inflammatory effects in vitro, and merit further investigations in vivo to determine whether EPA's effects are mediated by its downstream metabolite 8-HEPE. Our findings further demonstrate the importance of studying the role of EPA-derived metabolites in obesity and inflammation.Funding SourcesNone.

Eicosapentaenoic acid mitigates palmitic acid-induced heat shock response, inflammation and repair processes in fish intestine

Understanding the metabolic effects of fatty acids on fish intestine is critical to the substitution of fish oil with vegetable oils in aquaculture. In this study, the effects of eicosapentaenoic acid (EPA) and palmitic acid (PA) on fish intestine were evaluated in vitro and in vivo. As the first step for in vitro study, an intestinal cell line (SPIF) was established from silver pomfret (Pampus argenteus). Thereafter, the effects of EPA and PA on cell viability, prostaglandin E2 (PGE2) production, and the expression of genes related to heat shock response, inflammation, extracellular matrix (ECM) formation and degradation were examined in SPIF cells. Finally, these metabolic effects of EPA and PA on the intestine were examined in zebrafish (Danio rerio) larvae. Results showed that all tested fatty acids (PA, oleic acid, linoleic acid, α-linolenic acid, arachidonic acid, and docosahexaenoic acid) except EPA reduced SPIF viability to distinct degrees at the same concentrations. PA decreased SPIF viability accompanied by an increase in PGE2 level. Meanwhile, PA increased the expression of genes related to heat shock response (grp78, grp94, hsp70, and hsp90) and inflammation (nf-κb, il-1β, and cox2). Furthermore, PA reduced the expression of collagen type I (col1a1a and col1a1b) and extracellular matrix (ECM) degradation-related gene mmp2, while up-regulating timp2 mRNA expression. In vivo, PA also increased hsp70, il-1β, and cox2 mRNA levels and limited the expression of collagen type I in the larval zebrafish intestine. Interestingly, the combination of EPA and PA partially recovered the PA-induced changes in cell viability, PGE2 production, and mRNA expression in vitro and in vivo. These results suggest that PA may result in heat shock and inflammatory responses, as well as alter ECM formation and degradation in fish intestine, while EPA could at least partially mitigate these negative effects caused by PA.

Effect of Eicosapentaenoic Acid on sFlt-1 and HIF-1α Expression Under Induced Hypoxia Conditions in Trophoblast Tumor Cell Line (JEG-3)

Background: Previous studies have shown the altered levels of long-chain polyunsaturated fatty acids (LCPUFAs) in pathological hypoxic conditions. Elevated soluble fms-like tyrosine kinase-1 (sFlt-1) expression in hypoxia plays an important role in the pathogenesis of placental as preeclampsia. Objectives: The eicosapentaenoic acid (EPA; 20:5, n-3) as LCPUFAs (omega-3) might attenuate sFlt-1 and hypoxia-inducible factor-1α (HIF-1α) expressions and secretions. Methods: JEG-3 cells were incubated with dimethyloxalylglycine (DMOG) and EPA. The SFlt-1 gene expression was determined using a real-time polymerase chain reaction. The protein secretion of sFlt-1 and HIF-1α were analyzed using Western blot. Results: The incubation of JEG-3 cells with DMOG significantly elevated messenger ribonucleic acid (mRNA) expression and protein secretion of sFlt-1 (P &lt; 0.05); nevertheless, EPA decreased mRNA expression and protein secretion of sFlt-1 (P &lt; 0.05). Moreover, EPA inhibited the effect of DMOG on sFlt-1 (P = 0.0361) gene expression and protein secretion and HIF-1α (P = 0.0241) protein secretion. Conclusions: The sFlt-1 expression decreased by n-3 fatty acids in trophoblast tumor cell line under induced hypoxia conditions. It seems that changes in sFlt-1 expression are mediated by the transcription factor HIF-1α.

Effect of Eicosapentaenoic Acid/ Docosahexaenoic Acid on Coronary High-Intensity Plaques Detected Using Non-Contrast T1-Weighted Imaging: A Randomized&amp;nbsp;Trial

Effect of Eicosapentaenoic Acid/ Docosahexaenoic Acid on Coronary High-Intensity Plaques Detected Using Non-Contrast T1-Weighted Imaging: A Randomized&amp;nbsp;Trial

Effects of eicosapentaenoic acid on serum levels of selenoprotein P and organ-specific insulin sensitivity in humans with dyslipidemia and type 2 diabetes.

ABSTRACTAimSelenoprotein P (SeP, encoded by SELENOP in humans) is a hepatokine that causes insulin resistance in the liver and skeletal muscle. It was found that polyunsaturated fatty acid eicosapentaenoic acid (EPA) downregulates Selenop expression by inactivating SREBP‐1c. The present study aimed to examine the effect of EPA for 12 weeks on circulating SeP levels and insulin sensitivity in humans with type 2 diabetes.MethodsA total of 20 participants with dyslipidemia and type 2 diabetes were randomly assigned to an EPA (900 mg, twice daily) group and a control group. The primary endpoint was a change in serum SeP levels. Organ‐specific insulin sensitivity in the liver (HGP and %HGP), skeletal muscle (Rd), and adipose tissue (FFA and %FFA) were assessed using a hyperinsulinemic‐euglycemic clamp study with stable isotope‐labeled glucose infusion.ResultsSerum SeP levels were not changed in either group at the end of the study. In the EPA group, the changes in SeP levels were positively correlated with the change in serum EPA levels (r = 0.709, P = 0.022). Treatment with EPA significantly enhanced %FFA but not %HGP and Rd. The change in serum EPA levels was significantly positively correlated with the change in %HGP, and negatively correlated with changes in Rd.ConclusionsThe change in serum EPA levels was positively correlated with serum SeP levels, hepatic insulin sensitivity, and negatively with skeletal muscle insulin sensitivity in humans with type 2 diabetes. The EPA‐induced enhancement of hepatic insulin sensitivity might be associated with a mechanism independent of serum SeP levels.

Effect of Eicosapentaenoic Acid Supplementation on Murine Preadipocytes 3T3-L1 Cells Activated with Lipopolysaccharide and/or Tumor Necrosis Factor-α.

The beneficial effect of n-3 fatty acids can be related to anti-inflammatory properties. The aim of the study was to analyzed the effect of eicosapentaenoic acid (EPA) on 3T3-L1 cells (murine embryonic fibroblasts‒preadipocytes) activated with inflammatory factors (IF). Cells were incubated with 50 µmol of EPA for 48 h, and then activated with lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α). The level of cycloxygenase-2 (Prostaglandin-Endoperoxide Synthase 2, PTGS2, COX-2), cytosolic prostaglandin synthase E2 (cPGES), fatty acid binding protein 4 (FABP4), toll-like receptor 4 (TLR4), glucose receptor type 4 (GLUT-4), and cannabinoid receptor 2 (CB2) was determined using Western blot analysis. The phospholipase A2 (Pla2g4a), and prostaglandin-Endoperoxide Synthase 2 (Ptgs2) gene expression was analyzed by real-time qPCR. After EPA and IF activation, a significant decrease in the COX-2, cPGES, and TRL4 protein levels was observed. Incubation of cells with EPA and IF resulted in a decrease in Ptgs2 and an increase in the Pla2g4a gene. A significant increase in the CB2 protein was observed in adipocytes co-treated with EPA and IF. The results indicated an anti-inflammatory properties of EPA. Interestingly, the activation of the GLUT4 receptor by EPA suggests an unique role of this FA in the regulation of the adipocyte metabolism and prevention of insulin resistance.

Differential and shared effects of eicosapentaenoic acid and docosahexaenoic acid on serum metabolome in subjects with chronic inflammation

The omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) affect cell function and metabolism, but the differential effects of EPA and DHA are not known. In a randomized, controlled, double-blind, crossover study, we assessed the effects of 10-week supplementation with EPA-only and DHA-only (3 g/d), relative to a 4-week lead-in phase of high oleic acid sunflower oil (3 g/day, defined as baseline), on fasting serum metabolites in 21 subjects (9 men and 12 post-menopausal women) with chronic inflammation and some characteristics of metabolic syndrome. Relative to baseline, EPA significantly lowered the tricarboxylic acid (TCA) cycle intermediates fumarate and α-ketoglutarate and increased glucuronate, UDP-glucuronate, and non-esterified DHA. DHA significantly lowered the TCA cycle intermediates pyruvate, citrate, isocitrate, fumarate, α-ketoglutarate, and malate, and increased succinate and glucuronate. Pathway analysis showed that both EPA and DHA significantly affected the TCA cycle, the interconversion of pentose and glucuronate, and alanine, and aspartate and glutamate pathways (FDR < 0.05) and that DHA had a significantly greater effect on the TCA cycle than EPA. Our results indicate that EPA and DHA exhibit both common and differential effects on cell metabolism in subjects with chronic inflammation and some key aspects of metabolic syndrome.

Abstract 13314: Effect of Eicosapentaenoic Acid and Docosahexaenoic Acid on Epicardial Fat Volume; Results From a Randomized Controlled Trial

Introduction: Epicardial adipose tissue is an ectopic fat depot that may be associated with coronary artery atherosclerosis. Reduction in weight has been associated with a reduction in epicardial fat volume in several studies. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are known to lower triglyceride level. Whether the reduction in triglyceride level is associated with a reduction in epicardial fat volume is unknown. Hypothesis: We hypothesize that EPA and DHA reduce triglyceride levels and possibly can cause regression of epicardial fat volume after 30 months of therapy. Methods: A total of 139 patients with stable coronary artery disease on statins were randomized to EPA and DHA versus none for 30 months. Epicardial fat volume was measured with coronary computed tomographic angiography at baseline and 30 months. Change in epicardial fat volume was calculated. Results: No difference in baseline characteristics was observed (Table). At 30-month follow-up, those on EPA and DHA had a significant 6.7% reduction in triglyceride level compared to a 12.6% increase in controls (p=0.02). However, there was no difference in percent change in epicardial fat volume between control and EPA/DHA groups at 30 months (-3.1% [-16.7, 4.9] vs. -5.0% [-13.1,7.3], p-value=0.80, respectively). There was no significant change in body mass index in either group at 30-month follow-up. Conclusions: EPA and DHA led to a significant reduction of triglyceride level; however, there was no corresponding significant reduction in epicardial fat volume. This finding suggests that lowering triglyceride level does not affect epicardial fat volume.

Abstract 15019: Differential Effects of Omega-3 Fatty Acid Combinations on the Inhibition of Oxidation Of Human Low-density Lipoproteins in vitro

Background: Omega-3 fatty acids (O3FAs) reduce levels of triglyceride but may also have additional atheroprotective benefits. Randomized trials have suggested potential clinical outcome differences among O3FAs formulations. Oxidative modification of low-density lipoproteins (LDL) contributes to endothelial dysfunction, inflammation, and other aspects of atherogenesis. Individual O3FAs have been shown to inhibit LDL oxidation to varying degrees, but the antioxidant effects of combining O3FAs is unknown. Objective: To compare the dose- and time-dependent antioxidant effects of eicosapentaenoic acid (EPA, 20:5) alone and in combination with either docosapentaenoic acid (DPA, 22:5) or docosahexaenoic acid (DHA, 22:6) in human LDL in vitro . Methods: Human LDL was isolated from healthy subjects and adjusted to a final ApoB concentration of 100 μg/mL in physiologic buffer (PBS) before being incubated with O3FAs at 37°C. The EPA levels in the combinations were fixed at either 2.0, 3.0, or 4.5 μM, while the DPA or DHA levels were set at 0, 0.5, 1.0, and 2.0 μM. Oxidation was initiated by copper sulfate (10 μM) and measured over time by formation of malondialdehyde (MDA), a lipid oxidation product. Results: When combined with EPA, both DPA and DHA increased inhibition of oxidation in a dose- and time-dependent manner, with DPA showing a greater effect and more prolonged inhibition. At high levels of EPA (4.5 μM), DPA showed significantly greater antioxidant activity than equimolar DHA; these differences were more apparent with time. After 8 hours, adding 1.0 μM DPA reduced MDA formation by 61% versus vehicle (3.10 ± 0.42 vs. 7.98 ± 0.56, p &lt;0.001), while adding 1.0 μM DHA only reduced MDA formation by 20% (6.40 ± 1.23, p &lt;0.05). When 2 μM DPA or DHA were added, after 10 hours only DPA still had a significant degree of inhibition versus vehicle (37%; 6.65 ± 0.95 vs. 8.21 ± 0.53, p &lt;0.05). Similar trends were observed in combinations containing 2.0 and 3.0 μM EPA. Conclusion: Adding DPA or DHA to EPA provide dose-dependent incremental antioxidant effects, with DPA providing a larger degree and a longer duration of inhibition. These observations highlight potential differences among O3FAs (and their combinations) in novel mechanisms of atheroprotection.

Abstract 16402: Epa and Dha Suppressed Myocardial Infarction-induced Systolic Dysfunction by Inhibiting P300 Hat Activity

Introduction: p300, an intrinsic histone acetyltransferase (HAT), has a crucial role in the pathological cardiac hypertrophy and the development of heart failure in vivo . Although many studies have shown a cardioprotective effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), omega-3 fatty acids, little is known about the effects of these acids on cardiac hypertrophy. Aim: This study investigated whether EPA and DHA inhibited the development of heart failure in rats with myocardial infarction (MI). Methods and Results: To investigate the effects on cardiomyocyte hypertrophy in cultured cardiomyocytes, neonatal rat cultured cardiomyocytes were stimulated with phenylephrine (PE). EPA or DHA significantly inhibited PE-induced cardiomyocyte hypertrophy. EPA and DHA repressed to the same extent PE-induced acetylation of histone H3 in cultured cardiomyocytes. An in vitro HAT assay was performed to determine the direct inhibition of p300-HAT activity. The results revealed that EPA and DHA significantly inhibited p300-HAT activity. To assess whether EPA and DHA suppress p300-HAT activity directly in cultured cardiomyocytes, p300 was overexpressed in cultured cardiomyocytes. Treatment with EPA or DHA inhibited the overexpression of p300-induced cardiomyocyte hypertrophy in cultured cardiomyocytes. MI-operated rats (FS &lt; 40%) were randomly assigned to 3 groups: vehicle, EPA (1 g/kg) and DHA (1 g/kg). One week after MI operation, oral administrations were repeated for 6 weeks. Echocardiographic analysis demonstrated that EPA and DHA significantly improved MI-induced cardiac dysfunction. In addition, Masson's trichrome staining showed that EPA and DHA inhibit MI-induced fibrosis response in MI rats. EPA and DHA repressed MI-induced hypertrophic response gene transcriptions such as ANF and BNP with RT-PCR. Western blotting demonstrated that inhibited MI-induced H3K9 acetylation in rats . Conclusion: EPA and DHA suppressed hypertrophic responses to the same extent, through the direct inhibition of p300-HAT activity and repressed MI-induced development of heart failure.

Abstract 335: Distinct Effects of Eicosapentaenoic Acid and Docosahexaenoic Acid Linked Phospholipids on Membrane Structure

In REDUCE-IT, prescription eicosapentaenoic acid (EPA), an omega-3 fatty acid (O3FA), significantly reduced ischemic events in patients with diabetes or cardiovascular disease. Treatments containing docosahexaenoic acid (DHA) have not shown similar benefits in other trials. EPA and DHA differentially influence lipid oxidation, signal transduction, fluidity, and cholesterol domain formation, potentially due to distinct membrane interactions. Small angle x-ray diffraction approaches compared the separate and combined effects of 1-palmitoyl-2-eicosapentaenoyl-sn-glycero-3-phosphocholine (PL-EPA) and 1-palmitoyl-2-docosahexaenoic-sn-glycero-3-phosphocholine (PL-DHA) at a 1:20 ratio in membranes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (PL-OA) and cholesterol (C) at a 0.3:1 C:PL ratio. As a control, we also evaluated membranes consisting of PL-OA and C only. Electron density profiles (electrons/Å 3 vs Å) generated from the diffraction data served to determine membrane structure, including its width or d -space, at 1 Å resolution (Fig. 1A). Addition of PL-EPA increased membrane hydrocarbon core electron density over a broad area ± 0-10 Å from the membrane center, indicating an energetically favorable extended membrane orientation for EPA, stabilized by van der Waals interactions (Fig. 1B). By contrast, PL-DHA increased electron density in the phospholipid head group region concomitant with disordering in the hydrocarbon core ± 0-9 Å (Fig. 1C). Addition of the PL-O3FAs did not alter the overall membrane width (57 ± 1 Å). The combination of PL-EPA with PL-DHA highly attenuated their separate effects on the hydrocarbon core and headgroup (Fig. 1D). The contrasting EPA and DHA effects on membrane structure signify distinct molecular orientations that may contribute to observed differences in biological activity.

Effects of Eicosapentaenoic Acid on Arterial Calcification.

Arterial calcification is a hallmark of advanced atherosclerosis and predicts cardiovascular events. However, there is no clinically accepted therapy that prevents progression of arterial calcification. HMG-CoA reductase inhibitors, statins, lower low-density lipoprotein-cholesterol and reduce cardiovascular events, but coronary artery calcification is actually promoted by statins. The addition of eicosapentaenoic acid (EPA) to statins further reduced cardiovascular events in clinical trials, JELIS and REDUCE-IT. Additionally, we found that EPA significantly suppressed arterial calcification in vitro and in vivo via suppression of inflammatory responses, oxidative stress and Wnt signaling. However, so far there is a lack of evidence showing the effect of EPA on arterial calcification in a clinical situation. We reviewed the molecular mechanisms of the inhibitory effect of EPA on arterial calcification and the results of some clinical trials.

Contribution of Pyk2 pathway and reactive oxygen species (ROS) to the anti-cancer effects of eicosapentaenoic acid (EPA) in PC3 prostate cancer cells

Backgroundn-3 polyunsaturated fatty acids (n-3 PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are thought to exert protective effects in cardiovascular diseases. In addition, n-3 PUFAs have demonstrated anti-cancer effects in vitro and in vivo.ObjectiveWe investigated the anti-cancer effects and mechanism of action of EPA on PC3 prostate cancer cells in vitro.MethodsPC3 cells were treated with various concentrations of EPA, and cell survival and the abilities of migration and invasion were evaluated. The time course of the growth inhibitory effect of EPA on PC3 cells was also assessed. The mechanism underlying the anti-cancer effects of EPA was investigated by human phosphokinase and human apoptosis antibody arrays, and confirmed by western blot analysis. We also examined the contribution of reactive oxygen species (ROS) to the effects of EPA using the ROS inhibitor N-acetyl cysteine.ResultsEPA decreased the survival of PC3 cells in a dose-dependent manner within 3 h of application, with an effective concentration of 500 μmol/L. EPA inhibited proline-rich tyrosine kinase (Pyk)2 and extracellular signal-regulated kinase 1/2 phosphorylation as determined by western blotting and the antibody arrays. The growth of PC3 cells was inhibited by EPA, which was dependent on ROS induction, while EPA inhibited Pyk2 phosphorylation independent of ROS production.ConclusionsInhibition of Pyk2 phosphorylation and ROS production contribute to the anticancer effects of EPA on PC3 cells.

Effects of eicosapentaenoic acid and docosahexaenoic acid versus α-linolenic acid supplementation on cardiometabolic risk factors: a meta-analysis of randomized controlled trials.

Previous randomized controlled trials (RCTs) made direct comparisons between EPA/DHA versus ALA on improving cardiovascular risk factors and have reached inconsistent findings. The aim of this meta-analysis was to compare the effects of EPA/DHA vs. ALA supplementation on cardiometabolic disturbances. Databases including MEDLINE, Embase, PubMed and Cochrane Trials were searched until December 2019. The pooled effects (weighted mean difference, WMD) of outcomes with moderate and high heterogeneity were calculated with a random-effects model, while low heterogeneity was calculated with a fixed-effect model. Fourteen RCTs with 1137 participants who met the eligibility criteria were pooled. Compared with participants supplemented with ALA, those who received EPA/DHA supplementation experienced a greater reduction in triglycerides (TG) (WMD -0.191 mmol l-1; 95% CI -0.249, -0.133) but a greater increase in high-density lipoprotein (HDL) (WMD 0.033 mmol l-1; 95% CI 0.004, 0.062), low-density lipoprotein (LDL) (WMD 0.130 mmol l-1; 95% CI 0.006, 0.253) and total cholesterol (TC) (WMD 0.179 mmol l-1; 95% CI 0.006, 0.352). In subgroup analyses, the WMD for TG was much lower in trials with participants >40 years old (-0.246 mmol l-1; 95% CI -0.325, -0.167). When DHA and EPA were separately administered, modest increases in HDL were observed in trials that used DHA as a supplement (0.161 mmol l-1; 95% CI 0.017, 0.304), but not in trials using EPA (0.040 mmol l-1; 95% CI -0.132, 0.212). In conclusion, dietary EPA/DHA supplementation improved the TG and HDL status but increased LDL levels in comparison with ALA.

Adipokines secretion in feline primary adipose tissue culture in response to dietary fatty acids

BackgroundObesity in cats has been associated with alterations in adipokines including: adiponectin, interleukin-6 (IL6), and tumor necrosis factor-α (TNFα). Omega-3 polyunsaturated fatty acids have multiple beneficial effects on obesity-associated disorders, and therefore may alleviate these alterations. This study aimed to determine the effects of body condition, fat depot, troglitazone, and different fatty acids on secretion of adiponectin, IL6 and TNFα from adipose tissue of healthy cats. Subcutaneous and visceral adipose tissue samples were collected from 18 healthy intact female cats, and body condition score (Range 3–7/9) was determined. Concentrations of adiponectin were measured in mature adipocytes cultures and concentrations of IL6 and TNFα were measured in stromovascular cells cultures following treatment with control medium, troglitazone at 10 μM, eicosapentaenoic acid, arachidonic acid, or palmitic acid, at 25, 50, or 100 μM.ResultsStromovascular cells of visceral origin secreted higher concentrations of IL6 than corresponding cells of subcutaneous origin (P = 0.003). Arachidonic acid treatment at 25, 50, and 100 μM increased IL6 secretion in subcutaneous (P = 0.045, P = 0.002, and P < 0.001, respectively) and visceral (P = 0.034, P = 0.001, and P < 0.001, respectively) stromovascular cells. Eicosapentaenoic acid treatment increased TNFα secretion in subcutaneous stromovascular cells at 25, 50, and 100 μM (P = 0.002, P = 0.001, and P = 0.015, respectively) and in visceral stromovascular cells at 50 μM (P < 0.001). No significant effect on medium adiponectin concentration was observed following troglitazone treatment (P = 0.4) or fatty acids treatments at 25 (P = 0.2), 50 (P = 0.8), or 100 (P = 0.7) μM. Body condition score did not have significant effects on medium concentrations of adiponectin (P = 0.4), IL6 (P = 0.1), or TNFα (P = 0.8).ConclusionsThis study demonstrated higher basal secretion of IL6 from visceral compared to subcutaneous adipose tissue, a stimulatory effect of arachidonic acid on secretion of IL6 and a stimulatory effect of eicosapentaenoic acid on TNFα from feline adipose tissue.