Decrease In Polyunsaturated Fatty Acids Research Articles

Improvement of safflower oil quality for biodiesel production by integrated application of PGPR under reduced amount of NP fertilizers

Safflower is an important industrial oil seed and bioenergy crop in semi-arid subtropical regions due to its potential to grow on marginal land and having good percentage of seed oil contents which is an important parameter for biofuel production. However, it is an ignored crop in Pakistan. In order to improve the crop productivity and reduce the use of agrochemicals for sustainable biodiesel feedstock production, an experiment was conducted for two years to improve the fatty acid composition and oil quality of Carthamus tinctorius L. (safflower) by the inoculation of Azospirillum and Azotobacter alone as well as in combined application with nitrogen and phosphate (NP) fertilizers on cultivars Thori and Saif-32 under field conditions. Separation and quantification of fatty acids were done on precise comprehensive two-dimensional gas chromatography (GC×GC). The results showed that fatty acid profile specifically monounsaturated fatty acids i-e oleic acid (C18:1) was significantly improved by Azospirillum supplemented with the quarter dose of NP fertilizers (SPQ) with concomitant decrease in polyunsaturated fatty acids by the respective treatment. Oil quality attributes such as acid value, saponification number, iodine value, refractive index and free fatty acid contents were reduced by the application of Azotobacter and Azospirillum in combination with half and quarter doses of NP fertilizers treatments (BTH, SPH, BTQ and SPQ). The reduction in these variables is positively linked with improved biodiesel yield and quality. It can be concluded that application of Azospirillum and Azotobacter not only reduced the use of NP fertilizers up to 50%–75% but also improved the oil quality in order to obtain environment friendly, sustainable and green fuel.

Integrated transcriptomics and metabolomics reveal signatures of lipid metabolism dysregulation in HepaRG liver cells exposed to PCB 126

Chemical pollutant exposure is a risk factor contributing to the growing epidemic of non-alcoholic fatty liver disease (NAFLD) affecting human populations that consume a western diet. Although it is recognized that intoxication by chemical pollutants can lead to NAFLD, there is limited information available regarding the mechanism by which typical environmental levels of exposure can contribute to the onset of this disease. Here, we describe the alterations in gene expression profiles and metabolite levels in the human HepaRG liver cell line, a validated model for cellular steatosis, exposed to the polychlorinated biphenyl (PCB) 126, one of the most potent chemical pollutants that can induce NAFLD. Sparse partial least squares classification of the molecular profiles revealed that exposure to PCB 126 provoked a decrease in polyunsaturated fatty acids as well as an increase in sphingolipid levels, concomitant with a decrease in the activity of genes involved in lipid metabolism. This was associated with an increased oxidative stress reflected by marked disturbances in taurine metabolism. A gene ontology analysis showed hallmarks of an activation of the AhR receptor by dioxin-like compounds. These changes in metabolome and transcriptome profiles were observed even at the lowest concentration (100 pM) of PCB 126 tested. A decrease in docosatrienoate levels was the most sensitive biomarker. Overall, our integrated multi-omics analysis provides mechanistic insight into how this class of chemical pollutant can cause NAFLD. Our study lays the foundation for the development of molecular signatures of toxic effects of chemicals causing fatty liver diseases to move away from a chemical risk assessment based on in vivo animal experiments.

Extremely low frequency electromagnetic field exposure and restraint stress induce changes on the brain lipid profile of Wistar rats

BackgroundExposure to electromagnetic fields can affect human health, damaging tissues and cell homeostasis. Stress modulates neuronal responses and composition of brain lipids. The aim of this study was to evaluate the effects of chronic extremely low frequency electromagnetic field (ELF-EMF) exposure, restraint stress (RS) or both (RS + ELF-EMF) on lipid profile and lipid peroxidation in Wistar rat brain.MethodsTwenty-four young male Wistar rats were allocated into four groups: control, RS, ELF-EMF exposure, and RS + ELF-EMF for 21 days. After treatment, rats were euthanized, the blood was obtained for quantitate plasma corticosterone concentration and their brains were dissected in cortex, cerebellum and subcortical structures for cholesterol, triacylglycerols, total free fatty acids, and thiobarbituric acid reactive substances (TBARS) analysis. In addition, fatty acid methyl esters (FAMEs) were identified by gas chromatography.ResultsIncreased values of plasma corticosterone were found in RS and ELF-EMF exposed groups (p < 0.05), this effect was higher in RS + ELF-EMF group (p < 0.05, vs. control group). Chronic ELF-EMF exposure increased total lipids in cerebellum, and total cholesterol in cortex, but decreased polar lipids in cortex. In subcortical structures, increased concentrations of non-esterified fatty acids were observed in RS + ELF-EMF group. FAMEs analysis revealed a decrease of polyunsaturated fatty acids of cerebellum and increases of subcortical structures in the ELF-EMF exposed rats. TBARS concentration in lipids was increased in all treated groups compared to control group, particularly in cortex and cerebellum regions.ConclusionsThese findings suggest that chronic exposure to ELF-EMF is similar to physiological stress, and induce changes on brain lipid profile.

INDICES OF FATTY ACIDS SPECTRUM OF LIPIDS IN THE BLOOD SERUM OF STERLET OF DIFFERENT AGE

As the only sturgeon living in freshwater, sterlet is important for breeding in industrial fish farms, where lately cases of early mortality of this species have been detected. Hence, in order to preserve the species, it is important to study the parameters of fatty acid (FA) composition of lipid fractions of the blood serum of sterlet. Here we present changes of fatty acid composition in different lipid fractions of the blood serum of sterlets of different age (namely two-, three- and nine-year-old) with the masses 0.3–0.4, 0.5–0.6 and 5–6 kgfor the age-groups of fish, respectively. Fatty acid (FA) composition was determined using gas-chromatography on HRGC 5300 (Italy) in Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine (NASU). Fatty acid composition of starlet blood serum is presented by saturated and unsaturated high-molecular weight carboxylic acids, mostly palmic, stearic, oleic and linoleic. In the phospholipids fraction, there was a moderate increase in saturated and monounsaturated fatty acids and a slight decrease in polyunsaturated fatty acids depending on the age of fish. As for free fatty acids, there was a drop in the saturated ones depending on the starlet age. Among the free fatty acids of sterlet blood serum, we identified 28 acids, of them 39 %, 35 % and 30 % were saturated in 2-, 3-year-old and mature fish, respectively. Monounsaturated FA content was 14 %, 23 % and 23 % in 2-, 3-year-old and adult sterlet fish, and polyunsaturated FA content –46 %, 41 % and 36 %, respectively. The data can be used for the theoretical verification of correcting supplementary feed and premixes.

Lactic acid fermentation enriches the profile of biogenic compounds and enhances the functional features of common purslane (Portulaca oleracea L.)

This study aimed to explore common purslane (Portulaca oleracea L.) as potential raw substrate to develop novel functional preparations through lactic acid fermentation. Different lactic acid bacteria were used as single starter. P. oleracea fermented with Lactobacillus kunkeii B7 and Lactobacillus plantarum POM1 resulted in decreased levels (ca. 30%) of oxalic acid, which is commonly recognized as an anti-nutritional compound. Lactobacillus brevis POM4 enhanced by ca. 400% the concentration of γ-amino butyric acid, a non-protein amino acid with various physiological functions. Fermentation of P. oleracea led to a marked increase of α-linalool, a monoterpene compounds with various pharmacological properties. Bioconversion of oleraceins by L. kunkeii B7 is likely responsible for the increased antioxidant activity. The decrease of polyunsaturated fatty acids potentially underlined the synthesis of various derivatives with potential health or nutritional effects. Hence lactic acid fermentation of P. oleracea is a powerful tool to achieve standardized functional foods.

Thymol as natural antioxidant additive for poultry feed: oxidative stability improvement

Antioxidant are regularly included in poultry feed as protection from deterioration during storage. Recently the interest for the use of natural phytochemicals in animal diets has been increased. Thymol (THY) has been proven to be an effective antioxidant for extending broiler meat quality during storage with similar action to the widely used butylated hydroxytoluene (BHT). This study evaluates whether THY can also have a protective effect on the feed mash by assessing its antioxidant potential and related changes in fatty acid (FA) balance. Feed mash was assigned to 1 of 4 treatments, control (CON, no additive), vehicle (VEH, ethanol 96%), BHT (400 mg BHT /kg feed) and THY (400 mg THY /kg feed). Three replicates of each treatment were taken after 0, 30, and 60 d of storage at room temperature (23 ± 3°C) and relative humidity (40 ± 5%). Peroxide value (PV), titratable acidity (TA) and FA relative composition were determined. As expected, there were no treatment effects on those variables at 0 d of storage. However, higher PV values were detected in the CON and VEH groups after 30 and 60 d of storage in comparison to the THY and BHT treated samples (CON = VEH > THY = BHT). While a slight increase was also observed in TA through storage time, no particular treatment effects were detected. Relative FA composition changed with storage time only in the CON and VEH group which had a decrease in polyunsaturated fatty acids and an increase in saturated FA. No changes were detected in the Thy and BHT treated feeds. The results suggest a similar THY and BHT protective effect on feed mash lipid oxidation. Thus, THY could be considered as a useful natural alternative to help sustain quality of poultry feed.

Eicosapentaenoic acid protects cardiomyoblasts from lipotoxicity in an autophagy-dependent manner.

The cardiovascular health benefits of eicosapentaenoic acid (EPA) have been demonstrated previously; however, the exact mechanism underlying them remains unclear. Our previous study found that lipotoxicity induced cardiomyocyte apoptosis via the inhibition of autophagy. Accordingly, in this study, we investigated whether EPA attenuated lipotoxicity-induced cardiomyocyte apoptosis through autophagy regulation. The role of EPA in mitochondrial dynamics was analyzed as well. To explore how EPA protected against lipotoxicity-induced myocardial injury, cardiomyoblast (H9C2) cells were left untreated or were treated with 400μM palmitic acid (PAM) and/or 80μM EPA for 24h. Excessive PAM treatment induced apoptosis. EPA reduced this PAM-induced apoptosis; however, EPA was unable to ameliorate the effects of PAM when autophagy was blocked by 3-methyladenine and bafilomycin A1. PAM blocked the autophagic flux, thus causing the accumulation of autophagosomes and acid vacuoles, whereas EPA restored the autophagic flux. PAM caused a decrease in polyunsaturated fatty acid (PUFA) content and an increase in saturated fatty acid content in the mitochondrial membrane, while EPA was incorporated in the mitochondrial membrane and caused a significant increase in the PUFA content. PAM also decreased the mitochondrial membrane potential, whereas EPA enhanced it. Finally, PAM elevated the expressions of autophagy-related proteins (LC3I, LC3II, p62) and mitochondrial fission protein (Drp1), whereas EPA inhibited their elevation under PAM treatment. EPA reduces lipotoxicity-induced cardiomyoblast apoptosis through its effects on autophagy.

Abstract 2495: The metabolic secretome of cachexia inducing pancreatic ductal adenocarcinoma

Abstract Cachexia is an underexplored and yet devastating consequence of cancer that is the cause of 20% of all cancer related deaths1. Cachexia inducing tumors cause a ‘wasting away’ of the body. The condition is associated with poor treatment outcome2, fatigue, and extremely poor quality of life2,3. Because of the multi-factorial characteristics of this condition, it has been difficult to understand the mechanisms driving the impact of the tumor on body organs and the sequence of events that leads to this lethal condition. Here we have used 1H MRS to characterize the metabolic profile of tumor interstitial fluid (TIF) obtained from noncachexia (Panc1) and cachexia inducing (Pa04C) tumors to further understand the impact of the deranged metabolism of cachexia-inducing tumors on the tumor metabolic secretome. The human pancreatic cancer cell line, Panc1, was obtained from ATCC. The human pancreatic cancer cell line, Pa04C, was provided by Dr. Maitra4. Six to 8 week old male SCID mice were inoculated in both the right and left flank with cancer cells (5×106, Panc1 N=2, Pa04C N=2). We created a collection chamber to collect TIF. The chamber was implanted together with small tumor pieces harvested from the subcutaneous flank tumors, into the subcutaneous flank space of SCID mice (Panc1 N=8 and Pa04C N=6) until the tumor encompassed the chamber (4-5 weeks). The tumor was then removed and the tumor tissue and TIF were collected. To obtain control TIF, an empty chamber was implanted in the subcutaneous flank space of healthy mice. Dual phase solvent extraction was performed on tumor tissue. The water phase was separated, freeze dried, reconstituted in D2O PBS for spectral acquisition. All 1H MR spectra were acquired on an Avance III 750 MHz (17.6T) Bruker NMR spectrometer equipped with a 5 mm broad band inverse (BBI) probe. Spectral acquisition, processing and quantification were performed using TOPSPIN 2.1 software. Notable differences between Pa04C compared to Panc1 TIF or normal interstitial fluid were a significant decrease of polyunsaturated fatty acids (PUFA) and lipids, and formate, pyruvate, glutamine, and glucose. Lactate, glutamate, succinate, glycine and acetone significantly increased in Pa04C TIF compared to Panc1 TIF or normal interstitial fluid. These differences in TIF cannot be explained solely by the differences in the tumor metabolic profile. Our data provide new insights into changes in the metabolic secretome with induction of cachexia that may shed new light on the cachexia cascade, and identify metabolic strategies to reverse the syndrome.

N-3 Polyunsaturated Fatty Acids Decrease the Protein Expression of Soluble Epoxide Hydrolase via Oxidative Stress-Induced P38 Kinase in Rat Endothelial Cells.

N-3 polyunsaturated fatty acids (PUFAs) improve endothelial function. The arachidonic acid-derived metabolites (epoxyeicosatrienoic acids (EETs)) are part of the endothelial hyperpolarization factor and are vasodilators independent of nitric oxide. However, little is known regarding the regulation of EET concentration by docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in blood vessels. Sprague-Dawley rats were fed either a control or fish oil diet for 3 weeks. Compared with the control, the fish oil diet improved acetylcholine-induced vasodilation and reduced the protein expression of soluble epoxide hydrolase (sEH), a key EET metabolic enzyme, in aortic strips. Both DHA and EPA suppressed sEH protein expression in rat aorta endothelial cells (RAECs). Furthermore, the concentration of 4-hydroxy hexenal (4-HHE), a lipid peroxidation product of n-3 PUFAs, increased in n-3 PUFA-treated RAECs. In addition, 4-HHE treatment suppressed sEH expression in RAECs, suggesting that 4-HHE (derived from n-3 PUFAs) is involved in this phenomenon. The suppression of sEH was attenuated by the p38 kinase inhibitor (SB203580) and by treatment with the antioxidant N-acetyl-L-cysteine. In conclusion, sEH expression decreased after n-3 PUFAs treatment, potentially through oxidative stress and p38 kinase. Mild oxidative stress induced by n-3 PUFAs may contribute to their cardio-protective effect.

The Effect of Membrane Polyunsaturated Fatty Acids on Receptor Partitioning to Ordered Domains

Numerous G protein-coupled receptors (GPCRs) contain cholesterol binding sites, and are therefore assumed to partition into cholesterol-rich ordered membrane domains to function properly. Neurotransmitter receptors - many of which are GPCRs and located mainly in the nervous system - are responsible for regulating our behavior and mood, and their compromised signaling often results in neurodegenerative diseases. Interestingly, many such diseases are associated with a decrease in polyunsaturated fatty acid (PUFA) levels in the brain.The PUFAs, usually paired with a saturated lipid tail in hybrid lipids, are known to favorably interact with receptors. This might - in addition to modulating the activation of individual receptors - also affect larger scale GPCR organization, including their partitioning between ordered and disordered membrane domains. However, such effects are very tedious to be studied experimentally, and therefore the determinants of membrane protein partitioning remain currently elusive.Here, using multi-scale computer simulations and free energy calculations, we show that the association of the adenosine A2A receptor, a prototypical GPCR, with the PUFA tail of a hybrid lipid drastically affects its partitioning. The strong PUFA-receptor interaction results in the formation of a well defined lipid corona, whose outer shell is consists of the saturated tails of a hybrid lipid. This cushion softens the membrane perturbation caused by the rough receptor surface and hence makes it more compatible with ordered membrane domains. Interestingly, this favorable solvation by PUFAs seems to be characteristic only for membrane proteins consisting of helical bundles.Our results reveal an unexpected connection between PUFAs and disease: A decrease in the brain PUFA levels might affect GPCR partitioning, thereby compromising their function and perhaps eventually leading to disease. This finding, together with our previous study revealing the role of PUFAs on GPCR oligomerization, highlights the complex interplay of brain membrane lipid composition and neurotransmitter receptor function.

Oil Quality Control of Culinary Oils Subjected to Deep-Fat Frying Based on NMR and EPR Spectroscopy

The culinary oils, sunflower and olive, and the oil from the cultivated cardoon (Cynara cardunculus L.) were submitted to deep-fat frying during 36 h. The heterospectroscopy analysis by nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) allowed to control oil quality through the monitor of (1) the percentage of fatty acid types (increase of saturated and decrease of polyunsaturated fatty acids), (2) the new compounds formed (aldehydes and peroxides), and (3) the oil oxidative stability during the deep-fat frying. The aldehyde content was much higher in sunflower and cynara oils than in olive; however, the epoxides increased more in this oil. Oxidative stability measured by EPR was correlated (p < 0.05) with the aldehyde formation measured by NMR. The multivariate analysis of the NMR data allowed classifying the oils depending on (a) the oxidation degree (PC1) and (b) the fatty acid composition (PC2). Moreover, the favorable behavior of cynara oil suggests the potential use as frying edible oil.

The Deletion of GPR40/FFAR1 Signaling Damages Maternal Care and Emotional Function in Female Mice.

The free fatty acid receptor 1 (GPR40/FFAR1) is activated by polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acids (DHA). This receptor has been the focus of many studies regarding physiological functions of the central nervous system. PUFAs are essential for neuronal development and maintenance of neuronal function; thus, the decrease of PUFAs in the brain is closely related to the induction of psychiatric diseases associated with emotional disorder, such as anxiety, depression, and schizophrenia. However, details of the mechanisms remain unclear. In this study, we investigated changes of maternal and/or emotional behavior caused by a deficiency of GPR40/FFAR1 signaling. GPR40/FFAR1 deficient (FFAR1-/-) female mice exhibited impaired maternal care such as retrieving behaviors and an increased rate of neglect and infanticide when compared to wild type (WT) female mice. Furthermore, FFAR1-/- female mice showed increased time spent in the open arms in an elevated plus maze test, reduction of locomotor activity and social interaction behavior, and decreased sucrose intake, when compared to WT female mice. In conclusion, these findings suggest that PUFAs-GPR40/FFAR1 signaling might function, at least in part, as a regulatory factor of emotional and maternal behavior in mice.

A (too) bright future? Arctic diatoms under radiation stress

Decreasing Arctic sea ice cover and increasing stratification of ocean surface waters make the exposure of pelagic microalgae to high irradiances more likely. Apart from light being a necessary prerequisite for photosynthesis, rapidly changing and/or high irradiances are potentially detrimental. An in situ study was performed in the high Arctic (79°N) to determine the effect of high irradiances in general, and ultraviolet radiation (UVR, 280–400 nm) in particular, on cell concentrations, fatty acid composition, and photoprotective pigments of three diatom species isolated from seawater around Svalbard. Unialgal cultures were exposed in situ at 0.5- and 8 m-depth. After 40 h, cell concentrations of Synedropsis hyperborea and Thalassiosira sp., were lower at 0.5 than at 8 m, and the content of the photoprotective xanthophyll-cycle pigment diatoxanthin in all species (S. hyperborea, Thalassiosira sp., Porosira glacialis) was higher in the 0.5 m exposure compared to 8 m. In S. hyperborea, growth was additionally inhibited by UVR at 0.5-m depth. In situ radiation conditions led, furthermore, to a significant decrease in polyunsaturated fatty acids (PUFAs) in all three species, but UVR had no additional effect. Hence, we conclude that natural radiation conditions close to the surface could reduce growth and PUFA concentrations, but the effects are species specific. The diatoms’ potential to acclimate to these conditions over time has to be evaluated.

Influence of Storage Conditions on the Stability of Phospholipids-Rich Krill (Euphausia superba) Oil

The influences of storage temperature (−20C, 4C, room temperature and 40C), light and oxygen on stability of a phospholipids-rich krill oil (PRKO) with storage time up to 8 weeks were evaluated. The acid value and free fatty acid content were constant when PRKO was stored at −20C, 4C and room temperature. The two values remained stable for 3 weeks, and then increased slowly when PRKO was stored at 40C. The peroxide value of PRKO stored at all conditions was constant during the 8-week storage. However, the thiobarbituric reactive substance of sample stored at most conditions showed a firstly increased and then decreased pattern. Meanwhile, after 8-week storage, the fatty acid composition of PRKO changed slightly, with a decrease in polyunsaturated fatty acids and an increase in saturated fatty acids. Furthermore, astaxanthin content of PRKO decreased when the sample was stored at 40C. Practical Applications These years, krill oil (KO) has captured increasing consumer interest and market share as an alternative source of omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA). Especially, most of the n-3 LC-PUFA in KO is incorporated into phospholipids (PL). Some studies showed that n-3 LC-PUFA in PL form had higher bioavailability than those in ethyl esters (EE) form and triglycerides (TG) form, giving a basis for developing a new type of commercial krill product using krill PL. The present study prepared a PL-rich KO (PRKO) through a supercritical carbon dioxide coupled to ethanol extraction procedure. The influences of storage temperature (−20C, 4C, room temperature and 40C), light and oxygen on stability of the PRKO with storage time up to 8 weeks were evaluated. Results of this research revealed that the PRKO had very good storage stability, which provides information for determining the storage conditions of krill PL.

Effect of transport length on in vivo oxidative status and breast meat characteristics in outdoor-reared chicken genotypes

The aim of the study was to evaluate the effect of transport length on in vivo oxidative status and breast meat characteristics in two chicken genotypes reared under free range conditions. A total of 200 male chicks, 100 from fast-growing (Ross 308) and 100 from medium-growing (Naked Neck) strain were used. Fifty-six of these, 28 for genotype, before slaughtering, were randomly allocated to 2 pre-slaughter conditions: absence (0 h) or 4 h of transport. The transport length significantly affected the in vivo oxidative status of broiler greatly reducing the α and δ-tocopherol, retinol and lutein + zeaxanthin content of plasma, and increased the oxidative stress (thiobarbituric acid reactive substances, TBARS) in both strains. Concerning meat quality, the pH (0, 2 and 24 h post-mortem) of breast muscles of chickens transported for 4 h, showed higher values, and respect to strains, Naked Neck had lower values. The pH values were negatively correlated with the lightness (2–24 h) and the shear force of meat. The transport length significantly affected the fatty acid profile of breast muscle, with a decrease in polyunsaturated fatty acids and an increase in TBARS value. Even the antioxidants content of breast was reduced by chicken transport (α-tocotrienol, α-, δ-tocopherol and lutein + zeaxanthin), especially in Naked Neck birds. In conclusion, the results indicate that transport for 4 h prior to slaughter, negatively affect the meat quality of poultry. Slow-growing chickens seem more sensible to stress transport due to the higher kinetic behaviour of these strains.

Changes in Sediment Fatty Acid Composition during Passage through the Gut of Deposit Feeding Holothurians: Holothuria atra (Jaeger, 1883) and Holothuria leucospilota (Brandt, 1835).

Sea cucumbers Holothuria atra and Holothuria leucospilota play an important role in the bioturbation of sediment in coral reef and rocky intertidal ecosystems. This study investigated changes in sediment fatty acid (FA) composition during gut passage in H. atra and H. leucospilota. The FA composition did not differ significantly between species. Comparison of FA composition in ambient sediment (AS), foregut (FG), midgut (MG), hindgut (HG), and faecal pellets (FPs) indicated that marked changes in FA composition occurred during passage through the gut of H. atra and H. leucospilota. Saturated fatty acids (SAFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and branched fatty acids (BrFAs) were significantly higher in FG than in AS, suggesting that both species selectively ingested nutrient rich particles. Significant reduction of SAFAs, MUFAs, PUFAs, and BrFAs occurred in MD and HD, with complete elimination of most PUFAs in FPs. A decrease in PUFAs 20:5ω3, 18:4ω3, 22:5ω3, 22:6ω3, 18:2ω6, 18:3ω3, 18:3ω6, odd-numbered BrFAs, and MUFA 18:1ω7 indicated that algal detritus and bacteria were important part of diet. These results have implications for the fate of specific dietary FAs, especially ω3 and ω6, and the contribution holothurian FPs make to the FA composition of coral reef and rocky intertidal ecosystems.

Fatty acid composition and biogenic amines in acidified and fermented fish silage: a comparison study

ABSTRACTIn the presented study, ensiling of discard fish by acidification or fermentation was evaluated. Klunzinger’s ponyfish which is a discard fish was used for the production of fish silage by acidification (3% formic acid for Method FA; 1.5% formic and 1.5% sulphuric acid for Method FASA) and fermentation (Lactobacillus plantarum for Method LP and Streptococcus thermophilus for Method ST). The chemical, microbiological and nutritional properties of the differently preserved fish silages were estimated during a storage period of 60 d at ambient temperature. Compared to the raw material, a slight increase in saturated fatty acids and a slight decrease in polyunsaturated fatty acids were observed in all silages. At the end of the storage period, the aerobic bacteria counts after applying Methods FA, FASA, LP and ST amounted to 2.35, 2.39, 5.77 and 5.43 log cfu/g, respectively. The analysis of thiobarbituric acid revealed that acidification of silages accelerated the lipid oxidation. Nine biogenic amines were found in raw fish and different silages. The initial histamine concentration in raw fish was 0.17 mg/100 g and in all silages it remained at low levels during the storage period. The initial tyramine content was found to be 1.56 mg/100 g in raw fish and increased significantly in all silages. The increase of the tyramine content in fermented silages was considerably higher than in acidified silages (23–48 mg/100 g and 5–10 mg/100 g, respectively). It can be concluded that acidified or fermented fish silage should be considered as potential feed component for animals because of its high nutritional value and appropriate microbiological and chemical quality.

Effect of culture conditions on growth, fatty acid composition and DHA/EPA ratio of Phaeodactylum tricornutum

The effect of growth phase and environmental factors on growth, fatty acid composition and DHA/EPA ratio of Phaeodactylum tricornutum Bohlin was studied. Microalgae were grown in laboratory batch cultures in f/2 medium. Cultures were grown at different salinities (15, 20, 28, and 35ppt), nitrogen (N) concentrations (1.24, 12.35, 24.70 and 49.40mgL−1), light intensities (50, 100 and 150μmolm−2s−1; 14:10h light:dark cycle) and temperatures (15, 20 and 25°C), and sampled at different points of the respective growth phases (inoculums, early-linear, middle-linear and late-linear phases). Samples were analyzed for biomass weight, fatty acid composition and total fatty acid content (TFAC). The main fatty acids in all culture conditions were C14:0 (5.25%–6.04%), C16:0 (13.96%–14.78%), C16:1n-7 (19.09%–35.73%), C18:1n-9 (5.56%–9.01%) and eicosapentaenoic acid (EPA, 22.81%–30.72%). The percentage of polyunsaturated fatty acids (PUFAs) was reduced while that of monounsaturated fatty acid acids (MUFAs) and TFACs increased with culture time. Salinity had no serious effect on fatty acid composition, however, a significant decline of TFAC was observed at the lowest salinity (p<0.05). Significant (p<0.05) increases of the relative contents of SFAs and MUFAs and a decrease of PUFAs were observed under N-limitation condition. The percentage of docosahexaenoic acid (DHA) was significantly enhanced with increasing light intensity (p<0.05), while that of DHA, EPA and PUFA decreased significantly with increasing temperature (p<0.05). DHA/EPA ratio tended to rise initially and fall later with increasing growth time, and reached the highest level with the lowest salinity, and the lowest temperature and initial N concentration, revealing a possible cell response to the stress brought from the unfavorable conditions. In conclusion, this study demonstrates the variation of growth, fatty acid composition and DHA/EPA ratio with growth phase and environmental factors in P. tricornutum, benefiting the production of PUFA-rich microalgae, with a DHA/EPA ratio optimal for aquaculture live food. Statement of relevanceWe conducted detailed analysis on the effect of the culture conditions on growth, fatty acid composition and DHA/EPA ratio in Phaeodactylum tricornutum, a widely used microalga for aquaculture feedstuff in China. We found that the environmental stress conditions increased DHA/EPA ratio. The research will benefit the production of PUFA-rich and DHA/EPA-ratio-optimal microalgae for aquaculture feedstuff.

N-3 polyunsaturated fatty acids decrease levels of doxorubicin-induced reactive oxygen species in cardiomyocytes -- involvement of uncoupling protein UCP2

BackgroundUse of the chemotherapeutic drug doxorubicin (DOX) is associated with serious cardiotoxicity, as it increases levels of reactive oxygen species (ROS). N-3 polyunsaturated fatty acid dietary supplements can be of benefit to patients undergoing cancer therapy. The aims of this study were to determine whether DOX-induced cardiotoxicity is related to mitochondrial uncoupling proteins and whether eicosapentaenoic acid (EPA, C20:5 n-3) or docosahexaenoic acid (DHA, C22:6 n-3) affects DOX-induced cardiomyocyte toxicity.ResultsTreatment of H9C2 cells with DOX resulted in decreased cell viability and UCP2 expression. Treatment with 100 μM EPA or 50 μM DHA for 24 h resulted in a maximal mitochondria concentration of these fatty acids and increased UCP2 expression. Pretreatment with 100 μM EPA or 50 μM DHA prevented the DOX-induced decrease in UCP2 mRNA and protein levels, but these effects were not seen with EPA or DHA and DOX cotreatment. In addition, the DOX-induced increase in ROS production and subsequent mitochondrial membrane potential change (∆ψ) were significantly attenuated by pretreatment with EPA or DHA.ConclusionEPA or DHA pre-treatment inhibits the DOX-induced decrease in UCP2 expression, increase in ROS production, and subsequent mitochondrial membrane potential change that contribute to the cardiotoxicity of DOX.Electronic supplementary materialThe online version of this article (doi:10.1186/s12929-014-0101-3) contains supplementary material, which is available to authorized users.

Combined effect of temperature and bleaching herbicides on photosynthesis, pigment and fatty acid composition of Chlamydomonas reinhardtii

Norflurazon (Nf) and fluridone (Fd) are phytoene desaturase inhibitor herbicides that are widely used for the control of grasses and invasive aquatic weeds, respectively. These herbicides enter aquatic environments where they can negatively affect non-target plant species (e.g. algae). Their toxicity towards algae may be modified by abiotic factors such as light intensity, temperature, pH and nutrients. Investigating the effect of low temperature on the toxicity of Nf and Fd is particularly important because both temperature and herbicides affect some of the same physiological process (e.g. carotenoid biosynthesis). Here we demonstrate that Nf reduced photosynthesis in the green alga Chlamydomonas reinhardtii more strongly at 15 than at 25ºC, while Fd showed stronger effects at 25 than at 15ºC. Neither herbicide significantly inhibited photosynthesis at 8ºC. Although the overall pigment content decreased with lower temperature, there was an increase in photo-protective carotenoids relative to chlorophylls at both 15 and 8ºC in the absence of herbicides. Moreover, most of the measured pigments decreased markedly in the presence of Nf and Fd at 15 and 25ºC, including β-carotene which fell to below detection limits. The fatty acid composition was modified by temperature and the level of unsaturation noticeably increased at 15 compared with 25ºC. At 8ºC, however, despite a 2.4 times decrease in fatty acid content, the unsaturation level was similar to 25ºC acclimated cells. Monounsaturated fatty acids increased concomitant with a decrease in polyunsaturated fatty acid in the 2.5 µM Nf treatment at 25ºC. Differences in the effect of Nf and Fd on photosynthesis at 15 and 25ºC can be attributed to the marked decrease in carotenoids, which play an important role in photoprotection. At 8ºC, the apparent lack of inhibitory effects compared with control cultures could be due to enhanced photoprotection and/or decreased uptake of herbicides by the alga.