Relative bioavailability and pharmacokinetics of two oral formulations of docosahexaenoic acid/eicosapentaenoic acid after multiple-dose administration in healthy volunteers

The polyunsaturated fatty acid docosahexaenoic affects mitochondrial function in prostate cancer cells

BACKGROUND

Prostate cancer (PCa) shows a rewired metabolism featuring increased fatty acid uptake and synthesis via de novo lipogenesis, both sharply related to mitochondrial physiology. The docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid (PUFA) that exerts its antitumoral properties via different mechanisms, but its specific action on mitochondria in PCa is not clear. Therefore, we investigated whether the DHA modulates mitochondrial function in PCa cell lines.

METHODS

Here, we evaluated mitochondrial function of non-malignant PNT1A and the castration-resistant (CRPC) prostate 22Rv1 and PC3 cell lines in response to DHA incubation. For this purpose, we used Seahorse extracellular flux assay to assess mitochondria function, [14C]-glucose to evaluate its oxidation as well as its contribution to fatty acid synthesis, 1H-NMR for metabolite profile determination, MitoSOX for superoxide anion production, JC-1 for mitochondrial membrane polarization, mass spectrometry for determination of phosphatidylglycerol levels and composition, staining with MitoTracker dye to assess mitochondrial morphology under super-resolution in addition to Transmission Electron Microscopy, In-Cell ELISA for COX-I and SDH-A protein expression and flow cytometry (Annexin V and 7-AAD) for cell death estimation.

RESULTS

In all cell lines DHA decreased basal respiratory activity, ATP production, and the spare capacity in mitochondria. Also, the omega-3 induced mitochondrial hyperpolarization, ROS overproduction and changes in membrane phosphatidylglycerol composition. In PNT1A, DHA led to mitochondrial fragmentation and it increased glycolysis while in cancer cells it stimulated glucose oxidation, but decreased de novo lipogenesis specifically in 22Rv1, indicating a metabolic shift. In all cell lines, DHA modulated several metabolites related to energy metabolism and it was incorporated in phosphatidylglycerol, a precursor of cardiolipin, increasing the unsaturation index in the mitochondrial membrane. Accordingly, DHA triggered cell death mainly in PNT1A and 22Rv1.

CONCLUSION

In conclusion, mitochondrial metabolism is significantly affected by the PUFA supplementation to the point that cells are not able to proliferate or survive under DHA-enriched condition. Moreover, combination of DHA supplementation with inhibition of metabolism-related pathways, such as de novo lipogenesis, may be synergistic in castration-resistant prostate cancer.

Omega-3 world map: 2024 update

In 2016, the first worldwide n3 PUFA status map was published using the Omega-3 Index (O3I) as standard biomarker. The O3I is defined as the percentage of EPA + DHA in red blood cell (RBC) membrane FAs. The purpose of the present study was to update the 2016 map with new data. In order to be included, studies had to report O3I and/or blood EPA + DHA levels in metrics convertible into an estimated O3I, in samples drawn after 1999. To convert the non-RBC-based EPA + DHA metrics into RBC we used newly developed equations. Baseline data from clinical trials and observational studies were acceptable. A literature search identified 328 studies meeting inclusion criteria encompassing 342,864 subjects from 48 countries/regions. Weighted mean country O3I levels were categorized into very low ≤4%, low >4-6%, moderate >6-8%, and desirable >8%. We found that the O3I in most countries was low to very low. Notable differences between the current and 2016 map were 1) USA, Canada, Italy, Turkey, UK, Ireland and Greece (moving from the very low to low category); 2) France, Spain and New Zealand (low to moderate); and 3) Finland and Iceland (moderate to desirable). Countries such as Iran, Egypt, and India exhibited particularly poor O3I levels.

Esterified derivatives of DHA and EPA increase bortezomib cytotoxicity in human multiple myeloma cells

BACKGROUND & AIMS

Although the proteasome inhibitor bortezomib has greatly improved the clinical outcome of patients with multiple myeloma (MM), acquired drug resistance remains the greatest obstacle on the road of treating MM. We previously showed that omega-3 polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) with the chemotherapeutic agent bortezomib can overcome its chemoresistance in MM cells. However, most DHA/EPA are esterified shortly after oral administration, which may affect its bioactivity. This study was to evaluate the cytotoxicity of ethyl ester-DHA/EPA in human MM cells. The mechanisms relevant for the cytotoxicity of these esterified-fatty acids were further investigated.

METHODS

Human MM cell lines L363, OPM2, U266 were treated with ethyl ester-DHA/EPA with or without bortezomib. The percentage of dead cells and intracellular reactive oxygen species (ROS) levels were analyzed by flow cytometry.

RESULTS

Ethyl ester-DHA and -EPA were much more potent than DHA/EPA to induce cytotoxicity in MM cells, even in DHA/EPA-resistant MM cells. Pretreating MM cells with esterified-DHA/EPA before bortezomib potently increased its chemosensitivity. Additionally, intracellular ROS levels were upregulated in MM cells after treatment with ethyl ester-DHA/EPA, which reflected the enhanced oxidative stress in treated cells.

CONCLUSIONS

This study provides evidence that ethyl ester-DHA/EPA in combination with bortezomib may improve the overall efficacy in MM cells, similar to DHA/EPA, relieving the concern that esterification of DHA/EPA may affect its bioactivity and further supporting the potential clinical use of fatty acids DHA/EPA for combating drug resistance during MM therapy.

Omega-3 fatty acids decrease CRYAB, production of oncogenic prostaglandin E2 and suppress tumor growth in medulloblastoma

AIMS

Medulloblastoma (MB) is one of the most common malignant central nervous system tumors of childhood. Despite intensive treatments that often leads to severe neurological sequelae, the risk for resistant relapses remains significant. In this study we have evaluated the effects of the ω3-long chain polyunsaturated fatty acids (ω3-LCPUFA) docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on MB cell lines and in a MB xenograft model.

MAIN METHODS

Effects of ω3-LCPUFA treatment of MB cells were assessed using the following: WST-1 assay, cell death probes, clonogenic assay, ELISA and western blot. MB cells were implanted into nude mice and the mice were randomized to DHA, or a combination of DHA and EPA treatment, or to control group. Treatment effects in tumor tissues were evaluated with: LC-MS/MS, RNA-sequencing and immunohistochemistry, and tumors, erythrocytes and brain tissues were analyzed with gas chromatography.

KEY FINDINGS

ω3-LCPUFA decreased prostaglandin E2 (PGE₂) secretion from MB cells, and impaired MB cell viability and colony forming ability and increased apoptosis in a dose-dependent manner. DHA reduced tumor growth in vivo, and both PGE₂ and prostacyclin were significantly decreased in tumor tissue from treated mice compared to control animals. All ω3-LCPUFA and dihomo-γ-linolenic acid increased in tumors from treated mice. RNA-sequencing revealed 10 downregulated genes in common among ω3-LCPUFA treated tumors. CRYAB was the most significantly altered gene and the downregulation was confirmed by immunohistochemistry.

SIGNIFICANCE

Our findings suggest that addition of DHA and EPA to the standard MB treatment regimen might be a novel approach to target inflammation in the tumor microenvironment.

Applications of choline-based ionic liquids in drug delivery

Ionic liquids (ILs) usually refer to kinds of salts with melting point below 100 °C and are composed of definite anions and cations. In recent years, in addition to the field of material engineering, the applications of ILs have been extended to biomedical application. As a solubilizer, skin penetration enhancer, antibacterial agent, and macromolecular stabilizer of poorly soluble active pharmaceutical ingredients, ILs have attracted great attention in the field of pharmaceutical research. Among them, choline-based ILs are very popular in the field of drug delivery due to their biocompatibility, biodegradability, low toxicity or non-toxicity and other characteristics. This article mainly reviews the applications of choline-based ILs formed by choline and organic acid and choline-based ionic liquids-pharmaceutical active ingredients in transdermal delivery, topical delivery and oral delivery.

The efficacy of bortezomib in human multiple myeloma cells is enhanced by combination with omega-3 fatty acids DHA and EPA: Timing is essential

BACKGROUND & AIMS

Although bortezomib as one of the first line medicines that has greatly improved the overall survival of patients with multiple myeloma (MM), undesired drug resistance is frequently observed. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have been shown to be able to enhance the efficacy of chemotherapeutic drugs in many cancer types. The aim of the present study was to further evaluate the anticancer activity of DHA and EPA in relation to bortezomib chemosensitivity in human MM cells. The potential involvement of NF-κB signaling pathway was studied.

METHODS

MM cells were treated with DHA/EPA with or without bortezomib. Cell viability was estimated by WST-1 assay. Apoptotic cells were determined through flow cytometry using annexin V and propidium iodide (PI) staining. Protein expression and phosphorylation was investigated by western blotting.

RESULTS

Cell type dependent anticancer potential of DHA and EPA was observed in the cell viability assay. DHA and EPA induced apoptosis in L363, OPM2, MM.1S and U266 cell lines through both mitochondrial and death receptor pathways. Treating MM cells with DHA and EPA significantly downregulated IκBα and upregulated phosphorylation of p65, indicating that they triggered NF-κB activation in MM cells. Treating cells with DHA or EPA prior to bortezomib enhanced the induced cell death. However, concomitant use of bortezomib in combination with either of DHA or EPA decreased the cell death induced by bortezomib, indicating that timing of coincubation is important for the effects on chemosensitivity.

CONCLUSIONS

The present study provides novel evidence for the anticancer effects of DHA and EPA, and highlights their rational utilization in combination with bortezomib to achieve improved therapeutic outcome for MM.

Synergistic platelet inhibition between Omega-3 and acetylsalicylic acid dose titration; an observational study

BACKGROUND

Omega-3 and acetylsalicylic acid (ASA) are two widely used "over-the-counter" drugs. Previous research has shown multiple electrode aggregometry (MEA) can detect ASA and varying Omega-3 platelet inhibiting effects. Synergistic platelet inhibiting effects of ASA and Omega-3 have been found using other methods than MEA. The aim of this study was to investigate the antiplatelet effects of Omega-3, and ASA synergism with MEA.

METHODS

Ten healthy male volunteers ingested Omega-3 (1260 mg/day) for 5 days. MEA was used to analyse platelet function before and after Omega-3 intake. Aggregation was initiated using three different agonists and measured as area under the curve (AUC): adenosine diphosphate (ADP), thrombin receptor activating peptide (TRAP) and arachidonic acid (ASPI). Two concentrations of ASA were dose titrated ex vivo to 2 out of 3 ASPI test cells in order to measure synergism between Omega-3 and ASA.

RESULTS

Following 5 days Omega-3 intake, ADP, TRAP and ASPI AUC did not change significantly. In vitro ASA before Omega-3 intake, reduced ASPI AUC < 30 U, indicating a strong platelet inhibiting effect. Below this AUC level, the 5 days Omega-3 intake increased ASPI-AUC with the ex vivo added low dose ASA (P = 0.02) and high dose ASA (P = 0.04).

CONCLUSIONS

No synergism between ASA and Omega-3 was found using the MEA ASPI test. The surprising increase in ASPI-AUC following Omega-3 intake and ex vivo ASA suggest that there are methodological issuses with the MEA ASPI test.

TRIAL REGISTRATION

Trial registration ISRCTN78027929 . Registered 19 May 2015.

Oral ionic liquid for the treatment of diet-induced obesity

More than 70% of American adults are overweight or obese, a precondition leading to chronic diseases, including diabetes and hypertension. Among other factors, diets with high fat and carbohydrate content have been implicated in obesity. In this study, we hypothesize that the choline and geranate (CAGE) ionic liquid can reduce body weight by decreasing fat absorption through the intestine. In vitro studies performed using docosahexaenoic acid (DHA), a model fat molecule, show that CAGE forms particles 2 to 4 μm in diameter in the presence of fat molecules. Ex vivo permeation studies in rat intestine showed that formation of such large particles reduces intestinal fat absorption. In vivo, CAGE reduces DHA absorption by 60% to 70% compared with controls. DHA administered with CAGE was retained in the intestine even after 6 h. Rats fed with a high-fat diet (HFD) and 10 μL of daily oral CAGE exhibited 12% less body weight gain compared with rats fed with an HFD without CAGE for 30 d. Rats that were given CAGE also ate less food than the control groups. Serum biochemistry and histology results indicated that CAGE was well tolerated by the rats. Collectively, our data support the hypothesis that CAGE interacts with fat molecules to prevent their absorption through intestinal tissue and potentially providing a feeling of satiety. We conclude that CAGE offers an effective means to control body weight and a promising tool to tackle the obesity epidemic.

EPA and DHA have selective toxicity for PBMCs from multiple myeloma patients in a partly caspase-dependent manner

Poly-unsaturated fatty acids (PUFAs) have been shown to have cytotoxic effects in both solid and non-solid tumors. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are among the most studied PUFAs. The aim of the present study was to evaluate the cytotoxic effects of these two fatty acids (FAs) in the peripheral blood mononuclear cells (PBMCs) obtained from untreated patients (new cases) with confirmed symptomatic multiple myeloma (MM). Our results showed that EPA at the concentration of 100 μM and DHA at 50 and 100 μM induce potent apoptotic effects in the PBMCs of MM patients (P < 0.05) as evidenced by Annexin V and propidium iodide (PI) staining, while they have little or no effects on the PBMCs isolated from healthy donors (P > 0.05). The observed effects were concentration- and time-dependent and 72 h treatment with DHA at a concentration of 100 μM had the strongest effect (P < 0.01). CD138 + cells isolated from MM patients showed great sensitivity to EPA/DHA. EPA- and DHA-induced apoptosis was significantly inhibited by the pan-caspase inhibitor (Z-VAD-FMK), indicating that cell death was at least partly dependent on caspase activation. The results of the present study showed that EPA and DHA have selective toxicities for malignant human plasma cells from MM patients, but not for mononuclear cells of healthy donors. These results warrant further studies with larger study populations to investigate the usefulness of PUFAs as a promising adjunctive therapy in the treatment of MM.

Effect of Oral Docosahexaenoic Acid (DHA) Supplementation on DHA Levels and Omega-3 Index in Red Blood Cell Membranes of Breast Cancer Patients

Rationale: Docosahexaenoic acid (DHA) in cell membrane may influence breast cancer (BC) patients' prognosis, affecting tumor cells sensitivity to chemo- and radio-therapy and likely modulating inflammation. The possibility of identifying BC patients presenting with low DHA levels and/or low ability of DHA incorporation into cell membrane might help to treat this condition.

Methods: We enrolled BC patients and healthy controls, recording their seafood dietary intake. DHA in form of algal oil was administered for 10 consecutive days (2 g/day). Blood samples were collected at baseline (T0) and after 10 days of supplementation (T1) to assess DHA, omega-3 index, as the sum of DHA + eicosapentaenoic acid (EPA), in red blood cells (RBC) membranes and plasma tumor necrosis factor-alpha and interleukin-6 levels. Pre- and post-treatment fatty acid profiles were obtained by gas-chromatography. Parametric and non-parametric tests were performed, as appropriate, and P-value < 0.05 was considered statistically significant.

Results: Forty-three women were studied, divided into 4 groups: 11 patients with BRCA1/2 gene mutation (M group), 12 patients with familiar positive history for BC (F group), 10 patients with sporadic BC (S group), and 10 healthy controls (C group). DHA and omega-3 index increased from T0 to T1 in the 3 groups of BC patients and in controls (P < 0.001). No difference was found in DHA incorporation between each group of BC patients and between patients and controls, except for M group, which incorporated higher DHA levels with respect to controls (β = 0.42; P = 0.03). No association was documented between cytokines levels and DHA and omega-3 index at baseline and after DHA supplementation. Independent of the presence of BC, women considered as “good seafood consumers” showed at baseline DHA and omega-3 index higher with respect to “low seafood consumers” (P = 0.04; P = 0.007, respectively). After supplementation, the increase in DHA levels was greater in “low seafood consumers” with respect to “good seafood consumers” (P < 0.0001).

Conclusion: DHA supplementation was associated with increased DHA levels and omega-3 index in RBC membranes of BC cancer patients, independent of the type of BC presentation, and in controls. BRCA1/2 mutation, as well as low seafood consuming habits in both BC patients and healthy controls, seem to be associated with greater ability of DHA incorporation. Larger samples of BC patients are necessary to confirm our observation.

Anti-inflammatory effects of docosahexaenoic acid: Implications for its cancer chemopreventive potential

The implication of inflammatory tissue damage in pathophysiology of human cancer as well as some metabolic disorders has been under intense investigation. Numerous studies have identified a series of critical signaling molecules involved in cellular responses to inflammatory stimuli. These include nuclear factor κB, peroxisome proliferator-activated receptor γ, nuclear factor erythroid 2 p45-related factor 2 and sterol regulatory element-binding protein 1. The proper regulation of these transcription factors mediating pro- and anti-inflammatory signaling hence provides an important strategy for the chemoprevention of inflammation-associated cancer. There is compelling evidence supporting that dietary supplementation with fish oil-derived ω-3 polyunsaturated fatty acids including docosahexaenoic acid (DHA) ameliorates symptomatic inflammation associated with cancer as well as other divergent human disorders. Acute or physiologic inflammation is an essential body's first line of defence to microbial infection and tissue injuries, but it must be properly completed by a process termed 'resolution'. Failure of resolution mechanisms can result in persistence of inflammation, leading to chronic inflammatory conditions and related malignancies. The phagocytic engulfment of apoptotic neutrophils and clearance of their potentially histotoxic contents by macrophages, called efferocytosis is an essential component in resolving inflammation. Of note, DHA is a precursor of endogenous proresolving lipid mediators which regulate the leukocyte trafficking and recruitment and thereby facilitate efferocytosis. Therefore, DHA and its metabolites may have a preventive potential in the management of human cancer which arises as a consequence of impaired resolution of inflammation as well as chronic inflammation.

Global survey of the omega-3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid in the blood stream of healthy adults

Studies reporting blood levels of the omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were systematically identified in order to create a global map identifying countries and regions with different blood levels. Included studies were those of healthy adults, published in 1980 or later. A total of 298 studies met all inclusion criteria. Studies reported fatty acids in various blood fractions including plasma total lipids (33%), plasma phospholipid (32%), erythrocytes (32%) and whole blood (3.0%). Fatty acid data from each blood fraction were converted to relative weight percentages (wt.%) and then assigned to one of four discrete ranges (high, moderate, low, very low) corresponding to wt.% EPA+DHA in erythrocyte equivalents. Regions with high EPA+DHA blood levels (>8%) included the Sea of Japan, Scandinavia, and areas with indigenous populations or populations not fully adapted to Westernized food habits. Very low blood levels (≤4%) were observed in North America, Central and South America, Europe, the Middle East, Southeast Asia, and Africa. The present review reveals considerable variability in blood levels of EPA+DHA and the very low to low range of blood EPA+DHA for most of the world may increase global risk for chronic disease.

Enhanced anti-inflammatory effects of DHA and quercetin in lipopolysaccharide-induced RAW264.7 macrophages by inhibiting NF-κB and MAPK activation

The aim of the present study was to investigate the anti-inflammatory effects of docosahexaenoic acid (DHA) + quercetin (QE) used in combination. DHA and QE are natural compounds derived from various foods and have been demonstrated to exert anti‑inflammatory effects The protein mRNA expression involved in the nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signalling pathway was analyzed by western blot analysis and reverse transcription-polymerase chain reaction methods respectively, other cytokines were detected by an enzyme‑linked immunosorbent assay kit. The results of the present study demonstrated that combined treatment of lipopolysaccharide (LPS)‑stimulated RAW264.7 cells with DHA + QE decreased the levels of pro‑inflammatory mediators to a greater extent than QE or DHA alone. Additionally, DHA + QE synergistically suppressed nitric oxide, prostaglandin E2 and cyclooxygenase-2 levels. Molecular‑level studies indicated that the DHA + QE combination can significantly inhibit the mRNA expression of NF‑κB subunits p50 and p65, extracellular signal‑regulated kinase (ERK) 1/2 and c‑JUN N‑terminal kinase (JNK) 1/2, which suggests that the NF‑κB signalling pathway is involved in the synergistic effects observed. Furthermore, western blot analysis demonstrated that DHA + QE synergistically inhibit the phosphorylation of p50, p65, ERK1/2 and JNK1/2. This finding indicates that the enhanced anti‑inflammatory effects of the combined compounds are achieved by suppressing NF‑κB and MAPK signalling in LPS‑stimulated RAW264.7 cells. The results of the present study suggest that DHA and QE in combination may be utilized as potent anti‑inflammatory compounds, with potential preventative or palliative effects on obesity, atherosclerosis and cardiovascular diseases.

The free fractions of circulating docosahexaenoic acid and eicosapentenoic acid as optimal end-point of measure in bioavailability studies on n-3 fatty acids

The high complexity of n-3 fatty acids absorption process, along with the huge amount of endogenous fraction, makes bioavailability studies with these agents very challenging and deserving special consideration. In this paper we report the results of a bioequivalence study between a new formulation of EPA+DHA ethyl esters developed by IBSA Institut Biochimique and reference medicinal product present on the Italian market. Bioequivalence was demonstrated according to the criteria established by the EMA Guideline on the Investigation of Bioequivalence. We found that the free fractions represent a better and more sensitive end-point for bioequivalence investigations on n-3 fatty acids, since: (i) the overall and intra-subject variability of PK parameters was markedly lower compared to the same variability calculated on the total DHA and EPA fractions; (ii) the absorption process was completed within 4h, and the whole PK profile could be drawn within 12-15 h from drug administration.

Fatty acids from edible sea hares: anti-inflammatory capacity in LPS-stimulated RAW 264.7 cells involves iNOS modulation

The inclusion of marine organisms in the diet is gaining importance due to their richness in health beneficial nutrients.

Astaxanthin and omega-3 fatty acids individually and in combination protect against oxidative stress via the Nrf2-ARE pathway

Oxidative stress is a major driver of many diseases, including cancer. The induction of Nrf2-ARE-mediated antioxidant enzymes provides a cellular defense against oxidative stress. Astaxanthin (AST), a red dietary carotenoid, possesses potent antioxidant activity, and inhibits oxidative damages. Polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are important nutritional essentials and potent antioxidants found in fish oil. In the present study, we investigated whether AST in combination with low concentrations of DHA or EPA has a synergistic antioxidant effect in a HepG2-C8-ARE-luciferase cell line system. Using free radical scavenging DPPH assay, AST was more potent DPPH radical scavenger than DHA and EPA. MTS assay revealed that AST was non-toxic up to 100μM compared with more toxic DHA and EPA. The three compounds alone and in combination elevated cellular GSH levels, increased the total antioxidant activity, induced mRNA expression of Nrf2 and Nrf2 downstream target genes NQO1, HO-1, and GSTM2. Lower concentrations of AST show synergistic effects when combined with DHA or EPA. In summary, our study shows synergistic antioxidant effects of AST and PUFAs at low concentrations. The Nrf2/ARE pathway plays an important role in the antioxidative effects induced by AST, DHA, and EPA.

Docosahexaenoic acid (DHA)-induced heme oxygenase-1 attenuates cytotoxic effects of DHA in vascular smooth muscle cells

OBJECTIVE

Docosahexaenoic acid (DHA), a member of n-3 polyunsaturated fatty acids (n-3 PUFA) is a potent regulator of molecular events implicated in cardiovascular health. In a previous study we found that Ca(2+)-dependent oxidative stress is the central and initial event responsible for induction of unfolded protein response (UPR), cell cycle arrest and apoptosis in DHA treated primary human smooth muscle cells isolated from small pulmonary artery (hPASMC). In the present study we examined the impact of heme oxygenase (HO)-1, induced by DHA, on DHA-induced oxidative stress, UPR, cell proliferation and apoptosis in hPASMC.

METHODS & RESULTS

DHA led to a time- and concentration-dependent increase in HO-1 mRNA and protein levels in hPASMC. The DHA-induced HO-1 upregulation could be attenuated by preincubation of cells with a strong antioxidant Tempol or by siRNA-mediated depletion of nuclear factor erythroid 2-related factor-2 (Nrf2). In DHA-treated hPASMC, depletion of HO-1 by siRNA-mediated silencing resulted in increased levels of reactive oxygen species (ROS) and increased duration of UPR, the latter revealed by monitoring of spliced X-box binding protein 1 (XBP-1) variant. Moreover, HO-1 silencing augmented apoptosis in DHA-treated hPASMC as found by increased numbers of cleaved caspase-3-positive cells. HO-1 silencing did not affect proliferation of hPASMC exposed to DHA.

CONCLUSION

Our results indicate that DHA-induced, ROS-dependent upregulation of HO-1 attenuates oxidative stress, UPR and apoptosis in DHA-treated hPASMC.

The multifaceted effects of omega-3 polyunsaturated Fatty acids on the hallmarks of cancer

Omega-3 polyunsaturated fatty acids, in particular eicosapentaenoic acid, and docosahexaenoic acid have been shown to have multiple beneficial antitumour actions that affect the essential alterations that dictate malignant growth. In this review we explore the putative mechanisms of action of omega-3 polyunsaturated fatty acid in cancer protection in relation to self-sufficiency in growth signals, insensitivity to growth-inhibitory signals, apoptosis, limitless replicative potential, sustained angiogenesis, and tissue invasion, and how these will hopefully translate from bench to bedside.

Inhibition of matrix metalloproteinase-9 expression by docosahexaenoic acid mediated by heme oxygenase 1 in 12-O-tetradecanoylphorbol-13-acetate-induced MCF-7 human breast cancer cells

Matrix metalloproteinase-9 (MMP-9) plays a crucial role in tumor metastasis. Previous studies showed that polyunsaturated fatty acids exhibit an anti-cancer effect in various human carcinoma cells, but the effect of docosahexaenoic acid (DHA) and linoleic acid (LA) on metastasis of breast cancer cells is not fully clarified. We studied the anti-metastasis potential of DHA and LA in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MCF-7 cells. We found that TPA (100 ng/ml) induced MMP-9 enzyme activity both dose- and time-dependently, and 200 μM DHA and LA significantly inhibited MMP-9 mRNA and protein expression, enzyme activity, cell migration, and invasion. Treatment with PD98059 (10 μM), wortmannin (10 μM), and GF109203X (0.5 μM) decreased TPA-induced MMP-9 protein expression and enzyme activity. TPA-induced activation of ERK1, Akt, and PKCδ was attenuated by DHA, whereas LA attenuated only ERK1 activation. GF109203X also suppressed ERK1 activation. EMSA showed that DHA, LA, PD98059, and wortmannin decreased TPA-induced NF-κB and AP-1 DNA-binding activity. Furthermore, DHA rather than LA dose-dependently increased HO-1 expression. HO-1 siRNA alleviated the inhibition by DHA of TPA-induced MMP-9 protein expression and enzyme activity in MCF-7 cells, and HO-1 knockdown reversed the DHA inhibition of cell migration. These results suggest that DHA and LA have both similar and divergent signaling pathways in the suppression of TPA-induced MCF-7 metastasis.

Treatment for tobacco smoking: a new alternative?

Smoking is a very common addiction and is associated with several kinds of diseases including different forms of cancer. Nicotine is the only substance present in cigarettes that can cause dependence. There are pharmacological treatments available to smoking cessation, but all of them are associated with side effects and low efficacy. Therefore, the development of new strategies and treatments is necessary. A possibility is the supplementation with polyunsaturated fatty acids (PUFAs) of the omega 3 series. It is known that low concentration of omega 3 can affect the dopaminergic neurotransmission, resulting in hypofunctioning of the mesocortical system. This system controls the mesolimbic system, associated in rewarding and dependence mechanisms. New perspectives of treatment focus on the reestablishment of the omega 3 levels, having as a result the normalization of the dopaminergic system and the reduction of the negative symptoms of withdrawal.

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

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

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

WHAT THIS STUDY ADDS

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Docosahexaenoic acid-induced unfolded protein response, cell cycle arrest, and apoptosis in vascular smooth muscle cells are triggered by Ca²⁺-dependent induction of oxidative stress

Proliferation of vascular smooth muscle cells is a characteristic of pathological vascular remodeling and represents a significant therapeutic challenge in several cardiovascular diseases. Docosahexaenoic acid (DHA), a member of the n-3 polyunsaturated fatty acids, was shown to inhibit proliferation of numerous cell types, implicating several different mechanisms. In this study we examined the molecular events underlying the inhibitory effects of DHA on proliferation of primary human smooth muscle cells isolated from small pulmonary artery (hPASMCs). DHA concentration-dependently inhibited hPASMC proliferation, induced G1 cell cycle arrest, and decreased cyclin D1 protein expression. DHA activated the unfolded protein response (UPR), evidenced by increased mRNA expression of HSPA5, increased phosphorylation of eukaryotic initiation factor 2α, and splicing of X-box binding protein 1. DHA altered cellular lipid composition and led to increased reactive oxygen species (ROS) production. DHA-induced ROS were dependent on both intracellular Ca(2+) release and entry of extracellular Ca(2+). Overall cellular ROS and mitochondrial ROS were decreased by RU360, a specific inhibitor of mitochondrial Ca(2+) uptake. DHA-induced mitochondrial dysfunction was evidenced by decreased mitochondrial membrane potential and decreased cellular ATP content. DHA triggered apoptosis as found by increased numbers of cleaved caspase-3- and TUNEL-positive cells. The free radical scavenger Tempol counteracted DHA-induced ROS, cell cycle arrest, induction of UPR, and apoptosis. We conclude that Ca(2+)-dependent oxidative stress is the central and initial event responsible for induction of UPR, cell cycle arrest, and apoptosis in DHA-treated hPASMCs.

Omega-3 docosahexaenoic acid and procyanidins inhibit cyclo-oxygenase activity and attenuate NF-κB activation through a p105/p50 regulatory mechanism in macrophage inflammation

The inflammatory response has been implicated in the pathogenesis of many chronic diseases. Along these lines, the modulation of inflammation by consuming bioactive food compounds, such as ω-3 fatty acids or procyanidins, is a powerful tool to promote good health. In the present study, the administration of DHA (docosahexaenoic acid) and B1, B2 and C1 procyanidins, alone or in combination, prevented the inflammatory response induced by the LPS (lipopolysaccharide) endotoxin in human macrophages and brought them to the homoeostatic state. DHA and B1 were strong and selective negative regulators of cyclo-oxygenase 1 activity, with IC50 values of 13.5 μM and 8.0 μM respectively. Additionally, B2 and C1 were selective inhibitors of pro-inflammatory cyclo-oxygenase 2 activity, with IC50 values of 9.7 μM and 3.3 μM respectively. Moreover, DHA and procyanidins prevented the activation of the NF-κB (nuclear factor κB) cascade at both early and late stages with shared mechanisms. These included inhibiting IκBα (inhibitor of NF-κB α) phosphorylation, inducing the cytoplasmic retention of pro-inflammatory NF-κB proteins through p105 (NF-κB1) overexpression, favouring the nuclear translocation of the p50-p50 transcriptional repressor homodimer instead of the p50-p65 pro-inflammatory heterodimer, inhibiting binding of NF-κB DNA to κB sites and, finally, decreasing the release of NF-κB-regulated cytokines and prostaglandins. In conclusion, DHA and procyanidins are strong and selective inhibitors of cyclo-oxygenase activity and NF-κB activation through a p105/p50-dependent regulatory mechanism.

An approach for quantitatively balancing methylmercury risk and omega-3 benefit in fish consumption advisories

BACKGROUND

Nearly all fish consumption advisories for methylmercury (MeHg) are based only on risk. There is a need to also address benefits, especially those from polyunsaturated fatty acids (PUFAs), in neurodevelopmental function and cardiovascular health. However, because MeHg and PUFA generally act on these same end points, disentangling risk and benefit is challenging.

OBJECTIVES

We propose an approach for balancing risk and benefit that is based on the use of statistically dissociated measures of risk and benefit.

DISCUSSION

Because of mutual coexposure of MeHg and PUFAs in population-based studies and their opposite effect on many of the same end points, MeHg risk and PUFA benefit are tightly linked statistically, which results in mutual (negative) confounding. Thus, neither MeHg risk nor PUFA benefit can be accurately quantified without taking the other into account. A statistical approach that generates unconfounded risk and benefit coefficients for each end point can permit their subsequent recombination to describe the overall risk-benefit profile of each species of fish or fish diet. However, it appears that some end points may be adversely affected by MeHg without experiencing counterbalancing benefit from PUFAs. Such end points may drive consumption advisories and may preclude balancing of risk and benefit on the basis of other end points.

CONCLUSIONS

Our thinking about fish consumption advisories now recognizes the need to balance risk and benefit. However, although statistical analysis of the appropriate data can eliminate mutual confounding, care is required to address the most sensitive end points that may be sensitive to risk and not benefit.

A synergistic antiproliferation effect of curcumin and docosahexaenoic acid in SK-BR-3 breast cancer cells: unique signaling not explained by the effects of either compound alone

Background

Breast cancer is a collection of diseases in which molecular phenotypes can act as both indicators and mediators of therapeutic strategy. Therefore, candidate therapeutics must be assessed in the context of multiple cell lines with known molecular phenotypes. Docosahexaenoic acid (DHA) and curcumin (CCM) are dietary compounds known to antagonize breast cancer cell proliferation. We report that these compounds in combination exert a variable antiproliferative effect across multiple breast cell lines, which is synergistic in SK-BR-3 cells and triggers cell signaling events not predicted by the activity of either compound alone.

Methods

Dose response curves for CCM and DHA were generated for five breast cell lines. Effects of the DHA+ CCM combination on cell proliferation were evaluated using varying concentrations, at a fixed ratio, of CCM and DHA based on their individual ED₅₀. Detection of synergy was performed using nonlinear regression of a sigmoid dose response model and Combination Index approaches. Cell molecular network responses were investigated through whole genome microarray analysis of transcript level changes. Gene expression results were validated by RT-PCR, and western blot analysis was performed for potential signaling mediators. Cellular curcumin uptake, with and without DHA, was analyzed via flow cytometry and HPLC.

Results

CCM+DHA had an antiproliferative effect in SK-BR-3, MDA-MB-231, MDA-MB-361, MCF7 and MCF10AT cells. The effect was synergistic for SK-BR-3 (ER^- PR^- Her2⁺) relative to the two compounds individually. A whole genome microarray approach was used to investigate changes in gene expression for the synergistic effects of CCM+DHA in SK-BR-3 cells lines. CCM+DHA triggered transcript-level responses, in disease-relevant functional categories, that were largely non-overlapping with changes caused by CCM or DHA individually. Genes involved in cell cycle arrest, apoptosis, inhibition of metastasis, and cell adhesion were upregulated, whereas genes involved in cancer development and progression, metastasis, and cell cycle progression were downregulated. Cellular pools of PPARγ and phospho-p53 were increased by CCM+DHA relative to either compound alone. DHA enhanced cellular uptake of CCM in SK-BR-3 cells without significantly enhancing CCM uptake in other cell lines.

Conclusions

The combination of DHA and CCM is potentially a dietary supplemental treatment for some breast cancers, likely dependent upon molecular phenotype. DHA enhancement of cellular curcumin uptake is one potential mechanism for observed synergy in SK-BR-3 cells; however, transcriptomic data show that the antiproliferation synergy accompanies many signaling events unique to the combined presence of the two compounds.

Role of Nrf2 in suppressing LPS-induced inflammation in mouse peritoneal macrophages by polyunsaturated fatty acids docosahexaenoic acid and eicosapentaenoic acid

This study is to investigate the role of Nrf2 in suppressing LPS-mediated inflammation in ex vivo macrophages by polyunsaturated fatty acids (PUFA) docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Primary peritoneal macrophages from Nrf2 wild-type (+/+; WT) and Nrf2 knockout (-/-; KO) mice were treated with lipopolysaccharides (LPS) in the presence or absence of DHA or EPA. Quantitative real-time PCR (qPCR) analyses showed that LPS potently induced cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in the macrophages collected from Nrf2 (+/+) wild-type mice. DHA and EPA inhibited LPS-induced COX-2, iNOS, IL-1β, IL-6, or TNF-α, but increased hemeoxygenase (HO-1) expression. DHA was found to be more potent than EPA in inhibiting COX-2, iNOS, IL-1β, IL-6, and TNF-α mRNA expression. DHA and EPA were also found to induce HO-1 and Nrf2 mRNA with a different dose-response. LPS induced COX-2, iNOS, IL-1β, IL-6, and TNF-α in the macrophages collected from Nrf2 (-/-) mice as well, however, DHA and EPA suppression of COX-2, iNOS, IL-1β, IL-6, and TNF-α was attenuated as compared to that in Nrf2 (+/+) macrophages. Taken together, using Western blotting, ELISA and qPCR approaches coupled with Nrf2 (-/-) mice, our study clearly shows for the first time that DHA/EPA would induce Nrf2 signaling pathway and that Nrf2 plays a role in DHA/EPA suppression of LPS-induced inflammation.

Role of lysophosphatidic acid acyltransferase 3 for the supply of highly polyunsaturated fatty acids in TM4 Sertoli cells

Sertoli cells supply germ cells with nutrients, including highly polyunsaturated fatty acids (hPUFAs), which are essential for testicular function. We have previously reported high expression of lysophosphatidic acid acyltransferase (LPAAT)3 in mature mouse testis and suggested an arachidonoyl-transferase activity to LPA. To investigate the role of LPAAT3 in the storage and release of PUFAs, TM4 Sertoli cells were stably transfected with LPAAT3-small hairpin (sh)RNA. Arachidonoyl-, eicosapentaenoyl-, and docosapentaenoyl-containing phosphatidylcholine (PC) and linoleoyl-containing phosphatidylethanolamine (PE), phosphatidylserine (PS), and phosphatidylglycerol were significantly decreased as determined by liquid chromatography coupled to electrospray ionization mass spectrometry. Expression of murine LPAAT3 in Chinese hamster ovary (CHO)-K1 cells had essentially an opposite effect. The level of polyunsaturated PC correlated with cellular levels of free docosapentaenoic acid and eicosapentaenoic acid in TM4 and CHO-K1 cells, respectively. Activity assays using microsomal preparations as a source of LPAAT3 revealed an excessive PA synthesis from LPA acceptors for docosahexaenoyl-, arachidonoyl- and less pronounced for linoleoyl-CoA. We propose that the efficient incorporation of hPUFAs into PA-the precursor of several phospholipids, including PC-and the selective increase of the polyunsaturated PC pool in TM4 Sertoli cells might be required for the controlled release of hPUFAs and their supply to germ cells.

Omega-3 fatty acids in cancer, the protectors of good and the killers of evil?

Omega-3 fatty acids have been implicated in cancer prevention and treatment. Conventional chemotherapeutics are considered "double-edged swords", as they kill the cancer cells but also strike the healthy cells causing severe morbidity and sometimes also mortality. Could omega-3 fatty acids in this setting work as a "sword and shield" instead, by being cytotoxic to cancer cells, but at the same time protect healthy cells from these deleterious effects? In addition, may our current diet with decreased omega-3/omega-6 ratio contribute to the increased cancer incidence, and could an omega-3 enriched diet be used as a preventive measure against cancer? Here, we seek answers to these questions by reviewing the effects of omega-3 fatty acids, particularly DHA, on various cancers with emphasis on a cancer of neural origin, neuroblastoma. Results from preventive and therapeutic animal as well as human studies together with mechanisms behind the observed toxicity are summarized.

Synergistic anti-inflammatory effects of low doses of curcumin in combination with polyunsaturated fatty acids: docosahexaenoic acid or eicosapentaenoic acid

Inflammatory response plays an important role not only in the normal physiology but also in the pathology such as cancers. As chronic inflammations are associated with malignancies, it is important to prevent inflammation-mediated neoplastic formation, promotion and/or progression. One possible intervention will be using cancer chemopreventive agents such as curcumin (CUR), a potent anti-inflammatory and anti-oxidative stress compound. Polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) are potent anti-inflammatory agents by decreasing the production of inflammatory eicosanoids, cytokines, and reactive oxygen species (ROS). The present study aims at examining whether CUR with DHA or EPA would have synergistic anti-inflammatory effects in RAW 264.7 cells. Non-toxic concentrations of single and combination of the compounds were investigated at 6, 12 and 24h. The nitric oxide (NO) suppression effects were most prominent at 24h. All the combinations of CUR and DHA or EPA with lower concentrations of CUR 5 microM and 25 microM of DHA or EPA were found to have synergistic effects in suppressing LPS-stimulated NO and endogenous NO levels. Importantly, very low doses of CUR 2.5 microM and DHA or EPA of 0.78 microM could synergistically suppress the LPS-induced prostaglandin E(2) (PGE(2)). The combinations were also found to suppress iNOS, COX-2, 5-lipoxygenase (5-LOX) and cPLA(2) but induce HO-1. Taken together, the present study clearly shows the synergistic anti-inflammatory as well as anti-oxidative stress effects of CUR and PUFA.