Reversed-Phase Medium-Pressure Liquid Chromatography Purification of Omega-3 Fatty Acid Ethyl Esters Using AQ-C18.

Omega-3 fatty acids are in high demand due to their efficacy in treating hypertriglyceridemia and preventing cardiovascular diseases. However, the growth of the industry is hampered by low purity and insufficient productivity. This study aims to develop an efficient RP-MPLC purification method for omega-3 fatty acid ethyl esters with high purity and capacity. The results indicate that the AQ-C18 featuring polar end-capped silanol groups outperformed C18 and others in retention time and impurity separation. By injecting pure fish oil esters with a volume equivalent to a 1.25% bed volume on an AQ-C18 MPLC column using a binary isocratic methanol-water (90:10, v:v) mobile phase at 30 mL/min, optimal omega-3 fatty acid ethyl esters were obtained, with the notable purity of 90.34% and a recovery rate of 74.30%. The total content of EPA and DHA produced increased from 67.91% to 85.27%, meeting the acceptance criteria of no less than 84% set by the 2020 edition of the Pharmacopoeia of the People's Republic of China. In contrast, RP-MPLC significantly enhanced the production efficiency per unit output compared to RP-HPLC. This study demonstrates a pioneering approach to producing omega-3 fatty acid ethyl esters with high purity and of greater quantity using AQ-C18 RP-MPLC, showing this method's significant potential for use in industrial-scale manufacturing.

Simultaneous Treatment of Long-chain Monounsaturated Fatty Acid and n-3 Polyunsaturated Fatty Acid Decreases Lipid and Cholesterol Levels in HepG2 Cell.

The n-3 type polyunsaturated fatty acids (n-3PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), from fish oil exhibit health benefits such as triacylglycerol- and cholesterol-lowering effects. Some pelagic fishes contain long-chain monounsaturated fatty acids (LC-MUFAs) such as eicosenoic acid (C20:1), which exert health-promoting effects. However, no study has evaluated beneficial effects of n-3PUFA and LC-MUFA combination. Here, we investigated effects of simultaneous treatment with n-3PUFA (EPA and DHA) and LC-MUFA (cis-5-C20:1 and cis-7-C20:1) and found that n-3PUFA and LC-MUFA combination significantly decreased lipid accumulation and reduced total cholesterol in HepG2 cells. Cholesterol level was significantly lower in DHA + cis-7-C20:1 group than in DHA + EPA group. These results suggest the importance of LC-MUFA as a functional molecule in fish oil.

N-Docosahexaenoylethanolamine Attenuates Neuroinflammation and Improves Hippocampal Neurogenesis in Rats with Sciatic Nerve Chronic Constriction Injury.

Chronic neuropathic pain is a condition that causes both sensory disturbances and a variety of functional disorders, indicating the involvement of various brain structures in pain pathogenesis. One of the factors underlying chronic neuropathic pain is neuroinflammation, which is accompanied by microglial activation and pro-inflammatory factor release. N-docosahexaenoylethanolamine (DHEA, synaptamide) is an endocannabinoid-like metabolite synthesized endogenously from docosahexaenoic acid. Synaptamide exhibits anti-inflammatory activity and improves neurite outgrowth, neurogenesis, and synaptogenesis within the hippocampus. This study aims to evaluate the effects of synaptamide obtained by the chemical modification of DHA, extracted from the Far Eastern raw material Berryteuthis magister on neuroinflammatory response and hippocampal neurogenesis changes during neuropathic pain. The study of microglial protein and cytokine concentrations was performed using immunohistochemistry and ELISA. The brain lipid analysis was performed using the liquid chromatography-mass spectrometry technique. Behavioral experiments showed that synaptamide prevented neuropathic pain-associated sensory and behavioral changes, such as thermal allodynia, impaired locomotor activity, working and long-term memory, and increased anxiety. Synaptamide attenuated microglial activation, release of proinflammatory cytokines, and decrease in hippocampal neurogenesis. Lipid analysis revealed changes in the brain N-acylethanolamines composition and plasmalogen concentration after synaptamide administration. In conclusion, we show here that synaptamide may have potential for use in preventing or treating neuropathic cognitive pain and emotional effects.

Health Beneficial Food Emulsifier Produced from Fishery Byproducts.

The bioavailability of DHA-bound phospholipids, especially the DHA-bound lysophospholipid (DHA-LPL) could be considered the most effective DHA chemical forms for DHA accretion in the brain. Such a DHA-LPL should also have very high emulsifying stability performance based on its analogy with conventional soy LPL. Therefore, in this study, we describe two fishery byproducts, rich in DHA-bound phospholipids, to derive DHA-LPL via sn-1 positional specific lipase partial hydrolysis of the phospholipids. Through this reaction, the DHA composition increased to 43.8 % from 29.1 % in the salmon head phospholipid-derived DHA-LPL, and to 84.0 % from 47.4 % in the squid meal phospholipid-derived DHA-LPL. In fact, these obtained DHA-LPLs exhibited far higher emulsifying stability than the conventional food emulsifiers in the market. For example, the prepared high-purity squid meal phospholipid-derived LPL sustained an emulsion form for a week even under 80°C. Thus, food emulsifiers produced from fishery byproducts are considered to exhibit very high values of both in a sense of outstandingly high health benefits and sustaining emulsions even under very high temperatures.

Separation of eicosapentaenoic acid and docosahexaenoic acid by three-zone simulated moving bed chromatography.

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential fatty acids for human body, which are widely used in the field of healthy food and medicine. Meanwhile, there are some differences in their physiological functions, such as "scavenger for blood vessel" of EPA and "brain protector" of DHA. In order to make full use of EPA and DHA, it is necessary to prepare their high-purity component. In this paper, EPA and DHA were separated and purified by three-zone simulated moving bed (SMB) chromatography with C18 used as stationary phase and ethanol-water as mobile phase. For the single column experiment, a separation unit of SMB, the effects of the ratio of ethanol to water, pH value and temperature on the separation were investigated. The equilibrium dispersion (ED) model was used to obtain the adsorption parameters of EPA and DHA by inverse method and genetic algorithm, and the accuracy of the adsorption parameters was verified by fitting the overloaded elution curves under different conditions. Based on the acquired nonlinear adsorption isotherms the complete separation region was found according to triangle theory. The effects of sample concentration, flow ratios of adsorption zone and rectification zone, and column distribution mode of SMB on the separation were investigated. Under the optimized SMB conditions, the experimental result was that without regard to the other components, the chromatographic purity and recovery values of EPA and DHA exceeded 99% with the productivity of 4.15 g/L/h, and the solvent consumption of 1.11 L/g.

The formation, stability of DHA/EPA nanoemulsion prepared by emulsion phase inversion method and its application in apple juice.

This study prepared edible docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) nanoemulsion using EPI (emulsion phase inversion) method. The method for preparing DHA and EPA nanoemulsions is safe, convenient, low in energy consumption and can be used for food production. Factors affecting particle size and stability during preparation were investigated. Based on the optimal particle size combination, stability studies including particle size and residual rates of DHA and EPA at different temperature, pH and metal ions. The results showed that the nanoemulsion had good stability at low temperature storage, near neutral pH and in the absence of transition metal ions such as Fe3+, Cu2+, Al3+. The experiment initially studied the effect of nanoemulsion on apple juice beverage on the basic properties of juice itself. It was feasible in practical application of edible nanoemulsion.

Novel RvD6 stereoisomer induces corneal nerve regeneration and wound healing post-injury by modulating trigeminal transcriptomic signature.

The high-density corneal innervation plays a pivotal role in sustaining the integrity of the ocular surface. We have previously demonstrated that pigment epithelium-derived factor (PEDF) plus docosahexaenoic acid (DHA) promotes corneal nerve regeneration; here, we report the mechanism involved and the discovery of a stereospecific Resolvin D6-isomer (RvD6si) that drives the process. RvD6si promotes corneal wound healing and functional recovery by restoring corneal innervation after injury. RvD6si applied to the eye surface elicits a specific transcriptome signature in the trigeminal ganglion (TG) that includes Rictor, the rapamycin-insensitive complex-2 of mTOR (mTORC2), and genes involved in axon growth, whereas genes related to neuropathic pain are decreased. As a result, attenuation of ocular neuropathic pain and dry eye will take place. Thus, RvD6si opens up new therapeutic avenues for pathologies that affect corneal innervation.

Novel Vibrio spp. Strains Producing Omega-3 Fatty Acids Isolated from Coastal Seawater.

Omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs), such as eicosapentaenoic acid (EPA) (20:5n-3) and docosahexaenoic acid (DHA) (22:6n-3), are considered essential for human health. Microorganisms are the primary producers of omega-3 fatty acids in marine ecosystems, representing a sustainable source of these lipids, as an alternative to the fish industry. Some marine bacteria can produce LC-PUFAs de novo via the Polyunsaturated Fatty Acid (Pfa) synthase/ Polyketide Synthase (PKS) pathway, which does not require desaturation and elongation of saturated fatty acids. Cultivation-independent surveys have revealed that the diversity of microorganisms harboring a molecular marker of the pfa gene cluster (i.e., pfaA-KS domain) is high and their potential distribution in marine systems is widespread, from surface seawater to sediments. However, the isolation of PUFA producers from marine waters has been typically restricted to deep or cold environments. Here, we report a phenotypic and genotypic screening for the identification of omega-3 fatty acid producers in free-living bacterial strains isolated from 5, 500, and 1000 m deep coastal seawater from the Bay of Biscay (Spain). We further measured EPA production in pelagic Vibrio sp. strains collected at the three different depths. Vibrio sp. EPA-producers and non-producers were simultaneously isolated from the same water samples and shared a high percentage of identity in their 16S rRNA genes, supporting the view that the pfa gene cluster can be horizontally transferred. Within a cluster of EPA-producers, we found intraspecific variation in the levels of EPA synthesis for isolates harboring different genetic variants of the pfaA-KS domain. The maximum production of EPA was found in a Vibrio sp. strain isolated from a 1000 m depth (average 4.29% ± 1.07 of total fatty acids at 10 °C, without any optimization of culturing conditions).

Co-production of DHA and squalene by thraustochytrid from forest biomass.

Omega-3 fatty acids, and specifically docosahexaenoic acid (DHA), are important and essential nutrients for human health. Thraustochytrids are recognised as commercial strains for nutraceuticals production, they are group of marine oleaginous microorganisms capable of co-synthesis of DHA and other valuable carotenoids in their cellular compartment. The present study sought to optimize DHA and squalene production by the thraustochytrid Schizochytrium limacinum SR21. The highest biomass yield (0.46 g/gsubstrate) and lipid productivity (0.239 g/gsubstrate) were observed with 60 g/L of glucose, following cultivation in a bioreactor, with the DHA content to be 67.76% w/wtotal lipids. To reduce costs, cheaper feedstocks and simultaneous production of various value-added products for pharmaceutical or energy use should be attempted. To this end, we replaced pure glucose with organosolv-pretreated spruce hydrolysate and assessed the simultaneous production of DHA and squalene from S. limacinum SR21. After the 72 h of cultivation period in bioreactor, the maximum DHA content was observed to 66.72% w/wtotal lipids that was corresponded to 10.15 g/L of DHA concentration. While the highest DHA productivity was 3.38 ± 0.27 g/L/d and squalene reached a total of 933.72 ± 6.53 mg/L (16.34 ± 1.81 mg/gCDW). In summary, we show that the co-production of DHA and squalene makes S. limacinum SR21 appropriate strain for commercial-scale production of nutraceuticals.

A biphasic system based on guanidinium ionic liquid: Preparative separation of eicosapentaenoic acid ethyl ester and docosahexaenoic acid ethyl ester by countercurrent chromatography.

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are high nutritional components. Evidence for unique effects of them is increasing. Further understanding of their independent biological functions urgently needs more efficient separation techniques. Nowadays, most of the commercially available fish oil products are the mixture of eicosapentaenoic acid ethyl ester (EPAEE) and docosahexaenoic acid ethyl ester (DHAEE). It will be convenient to directly separate esterified EPA and DHA without saponification pretreatment. However, it is of great challenge to separate EPAEE and DHAEE because of their extremely fat-soluble nature and the equivalent chain length rule. In this research, the suitability of green guanidinium ionic liquid (IL) in countercurrent chromatography (CCC) solvent system for the separation of them was evaluated for the first time. Compared with imidazolium IL and phosphonium IL, guanidinium IL based non-aqueous biphasic system showed more outstanding separation performance. The separation mechanism was elucidated in depth through quantum mechanical calculations. It was found that guanidinium IL acted a crucial role in the CCC separation, which resulted in difference of partition behavior of EPAEE and DHAEE via different hydrogen-bonding affinity. EPAEE and DHAEE were successfully separated by solvent system (n-heptane/methanol/propylguanidinium chloride ([C3Gun]Cl, 1:1:5%, v/v/m)) with high purity (>95%) in one step, which was not achieved beforehand. Moreover, an easy recycling procedure of IL had also been devised, which significantly reduced waste generated. It opens up a new way for reasonable design water-free two-phase solvent system for efficient separation of very non-polar lipid compounds.

Selective Extraction of ω-3 Fatty Acids from Nannochloropsis sp. Using Supercritical CO2 Extraction.

In this article, microalgae Nannochloropsis sp. was used for fatty acid (FA) extraction, using a supercritical fluid-carbon dioxide (SF-CO2) extraction method. This study investigated the influence of different pre-treatment conditions by varying the grinding speed (200-600 rpm), pre-treatment time (2.5-10 min), and mixing ratio of diatomaceous earth (DE) and Nannochloropsis sp. biomass (0.5-2.0 DE/biomass) on FAs extraction. In addition, the effect of different operating conditions, such as pressure (100-550 bar), temperature (50-75 °C), and CO2 flow rate (7.24 and 14.48 g/min) on eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) recovery, was analyzed. Experimental data evidenced that, keeping constant the extraction conditions, the pre-treatment step enhanced the FAs extraction yield up to 3.4 fold, thereby the maximum extracted amount of FAs (61.19 mg/g) was attained with the pre-treatment with a ratio of DE/biomass of 1 at 600 rpm for 5 min. Moreover, by increasing both SF-CO2 pressure and temperature, the selectivity towards EPA was enhanced, while intermediate pressure and lower pressure promoted DHA recovery. The highest amount of extracted EPA, i.e., 5.69 mg/g, corresponding to 15.59%, was obtained at 75 °C and 550 bar with a CO2 flow rate of 14.48 g/min, while the maximum amount of extracted DHA, i.e., ~0.12 mg/g, equal to 79.63%, was registered at 50 °C and 400 bar with a CO2 flow rate of 14.48 g/min. Moreover, the increased CO2 flow rate from 7.24 to 14.48 g/min enhanced both EPA and DHA recovery.

Separation of high-purity eicosapentaenoic acid and docosahexaenoic acid from fish oil by pH-zone-refining countercurrent chromatography.

The evidence for unique effects of eicosapentaenoic acid and docosahexaenoic acid is growing. Further understanding and exploration of their independent effects in the nutraceutical and pharmaceutical industry is calling for the more efficient separation techniques to overcome the equivalent chain length rule of fatty acids. In this study, free eicosapentaenoic and docosahexaenoic acid were successfully separated by pH-zone-refining countercurrent chromatography for the first time. The different solvent systems and the influence of retainer and eluter concentration on the separation efficiency were investigated. A two-phase solvent system composed of n-heptane/methanol/water (100:55:45, v/v) was selected with 50 mM of trifluoroacetic acid as retainer in the organic phase and 40 mM of ammonium hydroxide as an eluter in the aqueous phase for the separation of 500 mg of free fatty acids from a refined fish oil sample. 79.6 mg of eicosapentaenoic acid and 328.3 mg docosahexaenoic acid were obtained with the purities of 95.5 and 96.9% respectively determined by gas chromatography with mass spectrometry after methyl esterification. The scale-up separation of 1 g of samples from both refined and crude fish oil after urea complexation were also achieved successfully with a markedly increased concentration 150 mM of retainer, producing satisfactory yields and purities of targets.

Production of Lipids and Proteome Variation in a Chilean Thraustochytrium striatum Strain Cultured under Different Growth Conditions.

Total lipids and docosahexaenoic acid (DHA) production by a Chilean isolated thraustochytrid were evaluated under different growth conditions in shake flasks. The analyzed strain was identified as Thraustochytrium striatum according to an 18S rRNA gene sequence analysis. The strain (T. striatum AL16) showed negligible growth in media prepared with artificial seawater at concentrations lower than 50% v/v and pH lower than 5. Maltose and starch were better carbon sources for growth than glucose. DHA content of the biomass grown with maltose (60 g L-1) was doubled by increasing the agitation rate from 150 to 250 rpm. The DHA (0.8-6%) and eicosapentaenoic acid (0.2-21%) content in the total lipids varied depending on culture conditions and culture age. Lipid and DHA concentration increased (up to 5 g L-1 and 66 mg L-1, respectively) by regularly feeding the culture with a concentrated starch solution. Carotenoid accumulation was detected in cells grown with maltose or starch. Contrasting conditions of starch and glucose cultures were selected for comparative proteomics. Total protein extracts were separated by two-dimensional gel electrophoresis; 25 spots were identified using ESI-MS/MS. A protein database (143,006 entries) for proteomic interrogation was generated using de novo assembling of Thraustochytrium sp. LLF1b - MMETSP0199_2 transcriptome; 18 proteins differentially expressed were identified. Three ATP synthases were differentially accumulated in cultures with glucose, whereas malate dehydrogenase was more abundant in cells cultured with starch.

N-docosahexaenoylethanolamine detected in human breast milk.

PURPOSE: Measure concentrations of the neurogenic, pro-neurogenic, pro-synaptogenic and anti-inflammatory mediator N-docosahexaenoylethanolamine (synaptamide) in relation to its precursor docosahexaenoic acid (DHA) in breast milk. DESIGN AND METHODS: Postpartum women were recruited prior to discharge. We supplemented half the subjects with omega-3 fatty acids. Breast milk samples were collected at 1, 4 and 8 weeks. Synaptamide and DHA concentrations were determined by liquidchromatography/tandem mass spectrometry (LC-MS/MS) and gas chromatography, respectively. RESULTS: Synaptamide was detected in all breast milk samples. The concentration ranged from 44 to 257 fmol/mL. Omega-3 fatty acid supplementation did not affect DHA or synaptamide concentration in breast milk due to a high-DHA-containing diet self-selected by control mothers. Nevertheless, synaptamide levels significantly correlated with DHA concentration in breast milk (r = 0.624, P < 0.001). CONCLUSION: This is the first demonstration of detectable concentrations of synaptamide in human breast milk. Although the attempt to raise the milk DHA content by omega-3 fatty acid supplementation was not successful in the current study, the positive correlation observed between synaptamide and DHA concentration suggests that synaptamide levels in human milk can be raised by proper omega-3 fatty acid supplementation that is known to increase DHA.

[Separation of eicosapentaenoic acid ethyl ester and docosahexaenoic acid ethyl ester by simulated moving bed chromatography].

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are important ω -3 polyunsaturated fatty acids. Their physiological effects on humans are not exactly the same; therefore, the production of products with high-purity EPA or DHA monomers is significant. In this work, EPA ethyl ester (EPA-EE) and DHA ethyl ester (DHA-EE) were first separated using HPLC with poly(styrene-co-divinylbenzene) (PS/DVB) as the stationary phase. The effects of the mobile phase, PS/DVB particle diameter, and column temperature were systematically evaluated. The results showed that methanol is a suitable mobile phase, having a resolution of 2.75. By comparing resolutions, a PS/DVB particle diameter of 10 µ m was chosen; however, when the pressure drop of PS/DVB is considered, PS/DVB with a particle diameter of 20 µ m is more favorable for large-scale preparations. A column temperature of 40℃ was found to be the most feasible for maintaining efficient separation. Second, eight semi-preparative columns (150 mm×10 mm) of PS/DVB polymer were prepared for the simulated moving bed (SMB) chromatography; the homogeneity of these columns was perfect, with a relative total column porosity error of less than 1%. Finally, an EPA-EE and DHA-EE mixture was separated using the SMB chromatography, and the contents of the extract and the raffinate were determined using GC-FID. The effects of the flow rate of Zone Ⅱ and Zone Ⅲ, the flow rate of the feed, and the feed concentration were investigated. Under optimal conditions, EPA-EE and DHA-EE with favorable purities of 91.6% and 93.6%, respectively, were achievable. The recovery of the EPA-EE was 97.0% and the recovery of the DHA-EE was 91.6%. The productivity and solvent requirements were 5.97 g/(L\5h) and 1.52 L/g, respectively. Therefore, SMB chromatography is an attractive technology for the production of high-value products.

Effect of spray-drying with organic solvents on the encapsulation, release and stability of fish oil.

Fish-oil (FO) was encapsulated with hydroxypropylcelullose (HPC) by conventional spray-drying with water (FO-water) and solvent spray-drying with ethanol (FO-EtOH), methanol (FO-MeOH) and acetone (FO-Acet) in order to study the effect of the solvent on the encapsulation efficiency (EE), microparticle properties and stability of FO during storage at 40 °C. Results showed that FO-Acet presented the highest EE of FO (92.0%), followed by FO-EtOH (80.4%), FO-MeOH (75.0%) and FO-water (71.1%). A decrease of the dielectric constant increased the EE of FO, promoting triglyceride-polymer interactions instead of oil-in-water emulsion retention. FO release profile in aqueous model was similar for all FO-microparticles, releasing only the surface FO, according to Higuchi model. Oxidative stability of FO significantly improved by spray-drying with MeOH, both in surface and encapsulated oil fractions. In conclusion, encapsulation of FO by solvent spray-drying can be proposed as an alternative technology for encapsulation of hydrophobic molecules.

Secreted Phospholipase A2 Specificity on Natural Membrane Phospholipids.

The secreted phospholipase A2 (sPLA2) family contains 10 catalytically active isoforms. Current in vitro biochemical studies have shown that individual sPLA2s have distinct substrate selectivity in terms of the polar head groups or sn-2 fatty acids of their substrate phospholipids. Importantly, transgenic or knockout mice for distinct sPLA2s display nonoverlapping phenotypes, arguing that they do act on different phospholipid substrates and mobilize unique lipid metabolites in vivo. In an effort to comprehensively understand lipid metabolism driven by individual sPLA2s under pathophysiological conditions, we took advantages of mass spectrometric lipidomics technology to monitor the spatiotemporal changes in phospholipids (substrates) and products (fatty acids, lysophospholipids, and their metabolites) in tissues or cells of sPLA2-transgenic or knockout mice. The in vivo lipidomic data were compared with the in vitro activity of recombinant sPLA2s toward phospholipid mixtures extracted from the target tissues, cells, or extracellular membrane components on which sPLA2s may intrinsically act. These approaches reveal that the overall tendency in in vitro assays using natural membranes is recapitulated in several in vivo systems, often with even more selective patterns of hydrolysis. In this chapter, we will summarize current understanding of the in vivo substrate specificity of sPLA2s toward natural membrane phospholipids.

The Association of Fatty Acid Levels and Gleason Grade among Men Undergoing Radical Prostatectomy.

BACKGROUND: Epidemiological data suggest that omega-6 (ω-6) fatty acids (FAs) may be associated with cancer incidence and/or cancer mortality, whereas ω-3 FAs are potentially protective. We examined the association of the ratio of ω-6 to ω-3 FA (ω-6:ω-3) and individual FA components with pathological results among men with prostate cancer (PCa) undergoing radical prostatectomy. METHODS: Sixty-nine men were included in the study. Components of ω-6 (linoleic acid (LA), arachidonic acid (AA), and dihomo-γ-linolenic acid (DGLA)) and ω-3 (docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)) were analyzed by liquid chromatography/mass selective detector separation. Logistic regression analysis was performed to determine association of FA with pathological high grade (Gleason ≥4+3) disease. RESULTS: The were 35 men with low grade disease (Gleason ≤3+4) and 34 men with high grade disease. Men with low grade disease were significantly younger (58y vs 61y, p = 0.012) and had lower D'Amico clinical classification (p = 0.001) compared to men with high grade disease. There was no significant association of ω-6:ω-3 with high grade disease (OR 0.93, p = 0.78), however overall ω-6, ω-3, and individual components of ω-6 and ω-3 FAs except EPA were significantly associated with high grade disease (ω-6: OR 3.37, 95% CI: 1.27,8.98; LA: OR 3.33, 95% CI:1.24,8.94; AA: OR 2.93, 95% CI:1.24,6.94; DGLA: OR 3.21, 95% CI:1.28,8.04; ω-3: OR 3.47, 95% CI:1.22,9.83; DHA: OR 3.13, 95% CI:1.26,7.74). ω-6 and ω-3 FA components were highly correlated (Spearman ρ = 0.77). CONCLUSION: Higher levels of individual components of ω-6 and ω-3FAs may be associated with higher-grade PCa. IMPACT: Studies into the causative factors/pathways regarding FAs and prostate carcinogenesis may prove a potential association with PCa aggressiveness.

Canola engineered with a microalgal polyketide synthase-like system produces oil enriched in docosahexaenoic acid.

Dietary omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs), docosahexaenoic acid (DHA, C22:6) and eicosapentaenoic acid (EPA, C20:5) are usually derived from marine fish. Although production of both EPA and DHA has been engineered into land plants, including Arabidopsis, Camelina sativa and Brassica juncea, neither has been produced in commercially relevant amounts in a widely grown crop. We report expression of a microalgal polyketide synthase-like PUFA synthase system, comprising three multidomain polypeptides and an accessory enzyme, in canola (Brassica napus) seeds. This transgenic enzyme system is expressed in the cytoplasm, and synthesizes DHA and EPA de novo from malonyl-CoA without substantially altering plastidial fatty acid production. Furthermore, there is no significant impact of DHA and EPA production on seed yield in either the greenhouse or the field. Canola oil processed from field-grown grain contains 3.7% DHA and 0.7% EPA, and can provide more than 600 mg of omega-3 LC-PUFAs in a 14 g serving.

Heterotrophic Production of Omega-3 Long-Chain Polyunsaturated Fatty Acids by Trophically Converted Marine Diatom Phaeodactylum tricornutum.

We have created via metabolic engineering a heterotrophic strain of Phaeodactylum tricornutum that accumulates enhanced levels of the high value omega-3 long chain polyunsaturated fatty acid (LC-PUFAs) docosahexaenoic acid (DHA). This was achieved by generation of transgenic strains in which the Δ5-elongase from Ostreococcus tauri was co-expressed with a glucose transporter from the moss Physcomitrella patens. This double transformant has the capacity to grow in the dark in liquid medium supplemented with glucose and accumulate substantial levels of omega-3 LC-PUFAs. The effects of glucose concentrations on growth and LC-PUFA production of wild type and transformed strains cultivated in the light and dark were studied. The highest omega-3 LC-PUFAs accumulation was observed in cultures grown under mixotrophic conditions in the presence of 1% glucose (up to 32.2% of total fatty acids, TFA). Both DHA and EPA are detected at high levels in the neutral lipids of transgenic cells grown under phototrophic conditions, averaging 36.5% and 23.6% of TFA, respectively. This study demonstrates the potential for P. tricornutum to be developed as a viable commercial strain for both EPA and DHA production under mixo- and heterotrophic conditions.