Early antihypertensive treatment and ischemia-induced acute kidney injury.

Acute kidney injury (AKI) frequently complicates major surgery and can be associated with hypertension and progress to chronic kidney disease, but reports on blood pressure normalization in AKI are conflicting. In the present study, we investigated the effects of an angiotensin-converting enzyme inhibitor, enalapril, and a soluble epoxide hydrolase inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl)urea (TPPU), on renal inflammation, fibrosis, and glomerulosclerosis in a mouse model of ischemia-reperfusion injury (IRI)-induced AKI. Male CD1 mice underwent unilateral IRI for 35 min. Blood pressure was measured by tail cuff, and mesangial matrix expansion was quantified on methenamine silver-stained sections. Renal perfusion was assessed by functional MRI in vehicle- and TPPU-treated mice. Immunohistochemistry was performed to study the severity of AKI and inflammation. Leukocyte subsets were analyzed by flow cytometry, and proinflammatory cytokines were analyzed by quantitative PCR. Plasma and tissue levels of TPPU and lipid mediators were analyzed by liquid chromatography mass spectrometry. IRI resulted in a blood pressure increase of 20 mmHg in the vehicle-treated group. TPPU and enalapril normalized blood pressure and reduced mesangial matrix expansion. However, inflammation and progressive renal fibrosis were severe in all groups. TPPU further reduced renal perfusion on days 1 and 14. In conclusion, early antihypertensive treatment worsened renal outcome after AKI by further reducing renal perfusion despite reduced glomerulosclerosis.

Characterization of changes in plasma and tissue oxylipin levels in LPS and CLP induced murine sepsis.

OBJECTIVE: The present study aimed to comprehensively investigate the changes in oxylipins during murine sepsis induced by lipopolysaccharide (LPS) or cecal ligation and puncture (CLP). METHODS: Twenty-four hours after induction of sepsis in male C57BL/6 mice by LPS or CLP, plasma and liver, lung, kidney and heart tissues were sampled. Oxylipin levels in plasma and tissue were quantified by means of LC-MS. Moreover, clinical chemistry parameters were determined in plasma and interleukin levels (MCP-1 and IL-6) were determined in kidney and liver. RESULTS: Elevation of liver function plasma parameters at 24 h revealed that both models were successful in the induction of sepsis. LPS induced sepsis resulted in a dramatic increase of plasma PGE2 (2,100% change in comparison to control) and other cyclooxygenase metabolites, whereas this effect was less pronounced in CLP induced sepsis (97% increase of PGE2). Plasma epoxy-fatty acids (FAs) and hydroxy-FAs and most of the dihydroxy-FAs were elevated in both models of sepsis. Changes of tissue oxylipin concentrations were organ dependent. Only few changes were detected in the lung and liver tissue, epoxy-FAs were elevated in the kidney. In the heart tissue a trend towards lower levels of hydroxy-FAs and epoxy-FAs was observed. CONCLUSION: Both murine models of sepsis are characterized by changes of oxylipins formed in all branches of the arachidonic acid (AA) cascade. The more pronounced effects in the LPS model make this model more suitable for the investigation of the AA cascade and its pharmacological modulation in sepsis.

Impact of dextran sulphate sodium-induced colitis on the intestinal transport of the colon carcinogen PhIP.

Colorectal cancer is one of the most frequent cancers in Western countries. Chronic intestinal diseases such as Crohn's disease and ulcerative colitis, in which the intestinal barrier is massively disturbed, significantly raise the risk of developing a colorectal tumour. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a genotoxic heterocyclic aromatic amine that is formed after strongly heating fish and meat. In this study, the hypothesis that PhIP uptake in the gut is increased during chronic colitis was tested. Chronic colitis was induced by oral administration of dextran sulphate sodium (DSS) to Fischer 344 rats. The transport of PhIP in eight different rat intestinal segments was examined in Ussing chambers. The tissues were incubated with 10 µM PhIP for 90 min, and the concentration of PhIP was determined in the mucosal and serosal compartments of the Ussing chambers as well as in the clamped tissues by LC-MS. Although chronic colitis was clearly induced in the rats, no differences in the intestinal transport of PhIP were observed between control and DSS-treated animals. The hypothesis that in the course of chronic colitis more PhIP is taken up by the intestinal epithelium, thereby increasing the risk of developing colorectal cancer, could not be confirmed in the present report.

Effect of acute and chronic DSS induced colitis on plasma eicosanoid and oxylipin levels in the rat.

Eicosanoids and oxylipins are potent lipid mediators involved in the regulation of inflammation. In order to evaluate their role and suitability as biomarkers in colitis, we analyzed their systemic levels in the acute and chronic phase of dextran sulfate sodium (DSS) induced colitis. Male Fischer 344 rats were treated in three cycles with 4% DSS in the drinking water (4 days followed by 10 days recovery) and blood was drawn 3 days prior to the first DSS treatment and on days 4, 11, 32 and 39. Histopathological evaluation of the colon tissue after 42 days showed that the animals developed a mild to severe chronic colitis. Consistently, prostaglandin levels were massively (twofold) elevated in the colonic tissue. LC-MS based targeted metabolomics was used to determine plasma oxylipin levels at the different time points. In the acute phase of inflammation directly after DSS treatment, epoxy-fatty acid (FA), dihydroxy-FA and hydroxy-FA plasma concentrations were uniformly elevated. With each treatment cycle the increase in these oxylipin levels was more pronounced. Our data suggest that in the acute phase of colitis release of polyunsaturated FAs from membranes in the inflamed tissue is reflected by a uniform increase of oylipins formed in different branches of the arachidonic acid cascade. However, during the recovery phases the systemic oxylipin pattern is not or only moderately altered and does not allow to evaluate the onset of chronic inflammation in the colon.

Oral treatment of rodents with soluble epoxide hydrolase inhibitor 1-(1-propanoylpiperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl]urea (TPPU): Resulting drug levels and modulation of oxylipin pattern.

Epoxides from polyunsaturated fatty acids (PUFAs) are potent lipid mediators. In vivo stabilization of these epoxides by blockade of the soluble epoxide hydrolase (sEH) leads to anti-inflammatory, analgesic and normotensive effects. Therefore, sEH inhibitors (sEHi) are a promising new class of drugs. Herein, we characterized pharmacokinetic (PK) and pharmacodynamic properties of a commercially available potent sEHi 1-(1-propanoylpiperidin-4-yl)-3-[4-(trifluoromethoxy)phenyl]urea (TPPU). Cell culture studies suggest its high absorption and metabolic stability. Following administration in drinking water to rats (0.2, 1, and 5mg TPPU/L with 0.2% PEG400), TPPU's blood concentration increased dose dependently within the treatment period to reach an almost steady state after 8 days. TPPU was found in all the tissues tested. The linoleic epoxide/diol ratios in most tissues were dose dependently increased, indicating significant sEH inhibition. Overall, administration of TPPU with the drinking water led to systemic distribution as well as high drug levels and thus makes chronic sEH inhibition studies possible.

Targeted metabolomics of the arachidonic acid cascade: current state and challenges of LC-MS analysis of oxylipins.

Quantification of eicosanoids and oxylipins derived from other polyunsaturated fatty acids in biological samples is crucial for a better understanding of the biology of these lipid mediators. Moreover, a robust and reliable quantification is necessary to monitor the effects of pharmaceutical intervention and diet on the arachidonic acid (AA) cascade, one of today's most relevant drug targets. Low (sub-nanomolar) concentrations and a large number of structurally similar analytes, including regioisomers, require high chromatographic resolution and selective and sensitive mass spectrometry analysis. Currently, reversed-phase liquid chromatography in combination with detection on sensitive triple-quadrupole instruments, operating in selected reaction monitoring mode, is the main method of quantitative oxylipin analysis. A lack of standardized sample collection, handling, and preparation procedures, degradation of the analytes during sample preparation, and purity and availability of standards (internal standards) are the major problems of targeted metabolomics approaches for the AA cascade. Major challenges for instrumental analytical methods are the detection of esterified oxylipins, and separation and individual detection of oxylipin isomers. Solving these problems would help to further knowledge of the biology of lipid mediators, and is an important task for bio-analytical research.

Comparison of sample preparation methods for the quantitative analysis of eicosanoids and other oxylipins in plasma by means of LC-MS/MS.

Oxylipins are potent lipid mediators. For the evaluation of their biological roles, several LC-MS based methods have been developed. While these methods are similar, the described sample preparation procedures for the extraction of oxylipins differ considerably. In order to deduce the most appropriate method for the analysis of non-esterified oxylipins in human plasma, we evaluated the performance of seven established sample preparation procedures. Six commonly used solid phase extraction (SPE) and one liquid-liquid extraction (LLE) protocol were compared based on the recovery of 13 added internal standards, extraction efficacy of oxylipins from plasma and reduction of ion-suppressing matrix. Dramatic differences in the performance in all three parameters were found. LLE with ethyl acetate was overall not a sufficient sample preparation strategy. The protocols using Oasis- and StrataX-material insufficiently removed interfering matrix compounds. Extraction efficacy of oxylipins on anion-exchanging BondElut cartridges was low, while removal of matrix was nearly perfect. None of the protocols led to a high extraction efficacy of analytes while removing all interfering matrix components. However, SPE on a C18-material with removal of matrix by water and n-hexane prior elution with methyl formate showed the best performance for the analysis of a broad spectrum of oxylipins in plasma.

The influence of chronic L-carnitine supplementation on the formation of preneoplastic and atherosclerotic lesions in the colon and aorta of male F344 rats.

L-Carnitine, a key component of fatty acid oxidation, is nowadays being extensively used as a nutritional supplement with allegedly "fat burning" and performance-enhancing properties, although to date there are no conclusive data supporting these claims. Furthermore, there is an inverse relationship between exogenous supplementation and bioavailability, i.e., fairly high oral doses are not fully absorbed and thus a significant amount of carnitine remains in the gut. Human and rat enterobacteria can degrade unabsorbed L-carnitine to trimethylamine or trimethylamine-N-oxide, which, under certain conditions, may be transformed to the known carcinogen N-nitrosodimethylamine. Recent findings indicate that trimethylamine-N-oxide might also be involved in the development of atherosclerotic lesions. We therefore investigated whether a 1-year administration of different L-carnitine concentrations (0, 1, 2 and 5 g/l) via drinking water leads to an increased incidence of preneoplastic lesions (so-called aberrant crypt foci) in the colon of Fischer 344 rats as well as to the appearance of atherosclerotic lesions in the aorta of these animals. No significant difference between the test groups regarding the formation of lesions in the colon and aorta of the rats was observed, suggesting that, under the given experimental conditions, L-carnitine up to a concentration of 5 g/l in the drinking water does not have adverse effects on the gastrointestinal and vascular system of Fischer 344 rats.

Investigation of the effects of soluble fibers on the absorption of resveratrol and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PHIP) in the Caco-2 cellular model of intestinal absorption.

Soluble fibers are known to modulate intestinal absorption of non-polar compounds in the small intestine. Little is known about the modulation of absorption of more polar compounds. In the present study, we applied the Caco-2-transwell-system in order to investigate the modulation of intestinal bioavailability by soluble fibers. The system was tested using pectin and carrageenan as model soluble fibers at a concentration of 0.1% (w/v), which did not compromise the integrity of the cell monolayer. Modulation of absorption was evaluated for the heterocyclic amine aromatic 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PHIP) and the polyphenol resveratrol. Neither pectin nor carrageenan reduced the high flux of PHIP, apparent permeability coefficient (Papp) of 16 × 10(-6) cm s(-1). The low Papp of resveratrol was reduced by both soluble fibers, particularly by pectin. These results suggest that the low bioavailability of polyphenols could be further reduced by soluble fibers. Because of their co-occurrence in several fruits, these findings warrant further research.

Increase of EPA-derived hydroxy, epoxy and dihydroxy fatty acid levels in human plasma after a single dose of long-chain omega-3 PUFA.

INTRODUCTION: Several supplementation studies with long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA) describe an increase of EPA-derived hydroxy, epoxy and dihydroxy fatty acids in blood, while changes in levels of other LC n-3 and n-6 PUFA-derived oxylipins were minor. In order to investigate the kinetics of changes in oxylipin levels in response to LC n-3 PUFA ingestion, we conducted a single dose treatment study with healthy subjects. SUBJECTS AND METHODS: In the present kinetic study, we compared patterns of hydroxy, epoxy and dihydroxy fatty acids in plasma of 6 healthy men before and after 6, 8, 24, and 48h of fish oil (1008mg EPA and 672mg DHA) ingestion. Levels of EPA- as well as other LC PUFA-derived hydroxy, epoxy and dihydroxy fatty acids were analyzed in plasma by LC-MS. Additionally, levels of these oxylipins were compared with their parent PUFA levels in plasma phospholipids. RESULTS: All EPA-derived oxylipin levels were significantly increased 6h after LC n-3 PUFA ingestion and gradually drop thereafter reaching the baseline levels about 48h after treatment. The relative increase in EPA plasma phospholipid levels highly correlated with the increase of plasma EPA-derived oxylipin levels at different time points. In contrast, plasma levels of arachidonic acid- and DHA-derived oxylipins as well as parent PUFA levels in plasma phospholipids were hardly changed. DISCUSSION AND CONCLUSIONS: Our findings demonstrate that a single dose of LC n-3 PUFAs can rapidly induce a shift in the EPA oxylipin profile of healthy subjects within a few hours. Taking the high biological activity of the EPA-derived epoxy fatty acids into account, even short-term treatment with LC n-3 PUFAs may cause systemic effects, which warrant further investigation.

Trans-Hydroxy, Trans-Epoxy, and Erythro-dihydroxy Fatty Acids Increase during Deep-Frying.

Deep-frying of food is a common cooking technique causing thermal oxidation of fatty acids (FA). Here, we investigated for the first time the formation of hydroxy-, epoxy- and dihydroxy-FA derived from oleic, linoleic (LA), and α-linolenic acid (ALA) during frying. Potato chips were fried in high-oleic sunflower oil for 4 × 5 cycles on 2 days, and the oil was comprehensively analyzed by liquid chromatography-tandem mass spectrometry. During frying, the E,Z-9- and E,Z-13-hydroperoxy-LA and -ALA concentrations decrease while their corresponding hydroxy-FA remain constant. The concentrations of both E,E-9-/13-hydroperoxy-LA and E,E-9-/13-hydroxy-LA increase with the frying cycles, which is also found for the concentration of trans-epoxy-FA. The increase in trans-epoxy-FA is more pronounced than that of the corresponding cis-epoxy-FA, exceeding their concentrations on the second day of frying. This selective change in the cis-/trans-epoxy-FA ratio is also observed for their hydrolysis products: concentrations of erythro-dihydroxy-FA, derived from trans-epoxy-FA, increase during frying stronger than threo-dihydroxy-FA derived from cis-epoxy-FA. Based on these data, we suggest that the ratio of E,E-/E,Z-hydroxy-FA, in combination with the cis-/trans-epoxy-FA ratio, as well as the threo-/erythro-dihydroxy-FA ratio are promising new parameters to evaluate the heating of edible oils and to characterize the status of frying oils.

Beyond Autoxidation and Lipoxygenases: Fatty Acid Oxidation Products in Plant Oils.

For decades, research on oxidation of linoleic acid (LA, C18:2 n6) and α-linolenic acid (ALA, C18:3 n3) in plant oils has focused on autoxidatively formed and lipoxygenase-derived 9-hydro(pero)xy- and 13-hydro(pero)xy-LA and -ALA. Here, using a non-targeted approach, we show that other hydroxy fatty acids are more abundant in plant oils. Liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry analyses unveiled highly abundant peaks in flaxseed and rapeseed oils. Using authentic reference standards, seven of the peaks were identified as 9-, 10-, 12-, 13-, and 15-HODE as well as 9- and 13-HOTrE. Additionally, six peaks were characterized based on the retention time, the exact mass of the [M-H]- ion, and its fragment ions as 16-OH-C18:3, 18-OH-C18:3, three isomers of 12-OH-C18:2, and one of 15-OH-C18:2. 16-OH-C18:3 and 18-OH-C18:3 were tentatively identified as 16-OH-ALA and 18-OH-ALA, respectively, based on autoxidation and terminal hydroxylation of ALA using CYP4F2. Investigation of formation pathways suggests that fatty acid desaturase 3 is involved in the formation of the 12-OH-C18:2 isomers, 15-HODE, and its isomer. The dominantly occurring 12-OH-C18:2 isomer was identified as 12R,S-OH-9Z,15Z-octadecadienoic acid (densipolic acid) based on a synthetic standard. The characterized oxylipins occurred in cold-pressed flaxseed and rapeseed oils at concentrations of up to 0.1 g/100 g and thus about sixfold higher than the well-known 9-hydro(pero)xy- and 13-hydro(pero)xy-LA and -ALA. Concentrations in sunflower oil were lower but increased when oil was pressed from preheated seeds. Overall, this study provides fundamental new information about the occurrence of oxidized fatty acids in plant oils, having the potential to characterize their quality and authenticity.

Characterization of the Oxylipin Pattern and Other Fatty Acid Oxidation Products in Freshly Pressed and Stored Plant Oils.

Enzymatic and nonenzymatic oxidation of linoleic (LA) and α-linolenic acid (ALA) during pressing and storage of plant oils leads to a variety of oxylipins. We pressed oils from flaxseeds, rapeseeds, and sunflower seeds and analyzed the oxylipin pattern in freshly pressed oils. 9-/13-Hydro(pero)xy-LA/-ALA occurred in high concentration resulting probably from lipoxygenase-catalyzed reactions as well as autoxidation and photooxidation. However, in flaxseed and rapeseed oil, the highest concentrations were found for the terminal epoxy-ALA (15(16)-EpODE) and the hardly known 15-hydroxy-LA (15-HODE, 80 mg/100 g in flaxseed oil). Oils were stored for 6 months and the peroxide value (PV) as well as oxylipin and secondary volatile aldehyde concentrations were determined. While lipid peroxidation in flaxseed oil was surprisingly low, the oxylipin concentration and PV massively increased in rapeseed oil dependent on oxygen availability. Oxylipin concentrations correlated well with the PV, while secondary volatile aldehydes did not reflect the changes of oxylipins and PVs. The comprehensive analysis of hydroxy-, epoxy-, and dihydroxy-LA/-ALA reveals new and unique insights into the composition of plant oils and ongoing oxidation processes.

The potential of wild olive leaves (Olea europaea L. subsp. oleaster) addition as a functional additive in olive oil production: the effects on bioactive and nutraceutical compounds using LC-ESI-QTOF/MS.

This study aims to investigate the influence of traditional maceration upon the enrichment of olive oil with oleaster leaves. The phenolic and tocopherolic compositions of control olive oil and enriched olive oils were determined. The influence of these oil preparation procedures on oil quality indicators was also investigated through spectrophotometric indices and fatty acid profiles. The total contents of bioactive compounds and pigments improved in oils obtained by maceration of fresh wild olive leaves, and were in statistically significant correlation with leaves proportions additions. The obtained results revealed that 15 phenolic compounds belonging to different phenolic types were characterized and quantified by an effective HPLC-DAD-ESI-MS/MS method. In all expected olive oils, the oleuropein aglycon (3,4-DHPEA-EA), and ligstroside aglycon (p-HPEAEA) derivatives were the most abundant compounds. Similarly, to phenolic compounds, tocopherols strongly increased with leaves addition during maceration process. The data obtained from this study suggested that the addition of olive leaf to oils allowed more functional olive oils with higher antioxidant contents. Thus, Extra Virgin Olive Oil (EVOO) extracted with 10% of olive leaves presented the highest amount of phenolic and tocopherol compounds.

Development of Chemometric Models Based on a LC-qToF-MS Approach to Verify the Geographic Origin of Virgin Olive Oil.

In the presented study a non-targeted approach using high-performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-qToF-MS) combined with chemometric techniques was used to build a statistical model to verify the geographic origin of virgin olive oils. The sample preparation by means of liquid/liquid extraction of polar compounds was optimized regarding the number of multiple extractions, application of ultrasonic treatment and temperature during concentration of the analytes. The presented workflow for data processing aimed to identify the most predictive features and was applied to a set of 95 olive oils from Spain, Italy, Portugal and Greece. Different strategies for data reduction and multivariate analysis were compared. Stepwise variable selection showed for both applied multivariate models-linear discriminant analysis (LDA) and logit regression (LR)-to be the most suitable variable selection strategy. The 10-fold cross validation of the LDA showed a classification rate of 83.1% for the test set. For the LR models the prediction accuracy of the test set was even higher with values of 90.4% (Portugal), 86.2% (Italy), 93.8% (Greece) and 88.3% (Spain). Moreover, the reduction of features allows an easier following up strategy for identification of the unknowns and defining marker substances.

Profile of Volatile Aroma-Active Compounds of Cactus Seed Oil (Opuntia ficus-indica) from Different Locations in Morocco and Their Fate during Seed Roasting.

Volatile compounds from oils extracted from cactus seeds (Opuntia ficus-indica) of five regions of Morocco were analyzed by dynamic headspace-GC/MS. Aroma active compounds were characterized by olfactometry. A total of 18 compounds was detected with hexanal, 2-methyl propanal, acetaldehyde, acetic acid, acetoin and 2,3-butanedione as most abundant. Olfactometric analysis showed that those compounds are aroma active; therefore, cactus seed oil flavor can be attributed to those compounds. Moreover, the effect of roasting of cactus seeds on the composition of volatile compounds in the oil was investigated. Especially the concentration of compounds known as products from the Maillard reaction increased significantly with roasting time such as furfural, furan, 3-methyl furan, 2-butanone, thiophene, 2, 3- dithiabutane, methyl pyrazine, 2-methyl pyrimidine, 2-metoxy phenol, dimethyl trisulfide and 5-methyl furfural.

Characterization of Phenolic Compounds Extracted from Cold Pressed Cactus (Opuntia ficus-indica L.) Seed Oil and the Effect of Roasting on Their Composition.

Phenolic compounds extracted from cactus seed oil were identified for the first time by HPLC-ESI-qToF-MS and subsequently quantified by HPLC-DAD. A total of 7 compounds were identified, vanillin, syringaldehyde, and ferulaldehyde were found to be the most abundant ones. The effect of geographical origin and roasting process of cactus seeds was evaluated. Differences between different locations were not found, however the roasting process had a significant effect on the amount of phenolic compounds. The amount of syringaldehyde, p-coumaric acid, p-coumaric acid ethyl ester, and ferulaldehyde increased during the roasting process. Nevertheless, the concentration of vanillin was not influenced by roasting. It was demonstrated that the increase of those compounds was due to the thermal degradation of lignin from the seeds during the roasting process of seeds.

Impact of food polyphenols on oxylipin biosynthesis in human neutrophils.

The intake of food polyphenols is associated with beneficial impacts on health. Besides anti-oxidative effects, anti-inflammatory properties have been suggested as molecular modes of action, which may result from modulations of the arachidonic acid (AA) cascade. Here, we investigated the effects of a library of food polyphenols on 5-lipoxygenase (5-LOX) activity in a cell-free assay, and in human neutrophils. Resveratrol, its dimer (ε-viniferin), and its imine analogue (IRA) potently blocked the 5-LOX-mediated LT formation in neutrophils with IC50 values in low µM-range. Among the tested flavonoids only the isoflavone genistein showed potent 5-LOX inhibition in neutrophils (IC50 = 0.4 ±â€¯0.1 µM), however was ineffective on isolated 5-LOX. We exclude an interference with the 5-LOX-activating protein (FLAP) in HEK_5-LOX/±FLAP cells and suggest global effects on intact immune cells. Using LC-MS based targeted oxylipin metabolomics, we analyzed the effects of 5-LOX-inhibiting polyphenols on all branches of the AA cascade in Ca2+-ionophore-challenged neutrophils. While ε-viniferin causes a clear substrate shunt towards the remaining AA cascade enzymes (15-LOX, cyclooxygenase - COX-1/2, cytochrome P450), resveratrol inhibited the COX-1/2 pathway and showed a weak attenuation of 12/15-LOX activity. IRA had no impact on 15-LOX activity, but elevated the formation of COX-derived prostaglandins, having no inhibitory effects on COX-1/2. Overall, we show that food polyphenols have the ability to block 5-LOX activity and the oxylipin pattern is modulated with a remarkable compound/structural specificity. Taken the importance of polyphenols for a healthy diet and their concentration in food supplements into account, this finding justifies further investigation.

Activation of Lipid Mediator Formation Due to Lipoprotein Apheresis.

Lipoprotein apheresis reliably reduces low-density lipoprotein (LDL) cholesterol in patients with atherosclerotic disease and therapy-refractory hypercholesterolemia or elevated lipoprotein (a) (Lp(a)). Besides lowering lipoproteins and triglycerides, apheresis also decreases levels of essential omega-6 and omega-3 polyunsaturated fatty acids (n-6 and n-3 PUFAs) in blood plasma. In contrast, heparin-induced extracorporeal low-density lipoprotein precipitation (HELP) lipid apheresis might increase the formation of potentially pro-inflammatory and pro-thrombotic lipid mediators derived from n-6 and n-3 PUFAs. The study presented here analyzed lipid mediator profiles in the plasma of patients with hyperlipidemia treated by one of three different apheresis methods, either HELP, direct absorption (DA), or membrane filtration (MDF), in a direct pre- and post-apheresis comparison. Using gas chromatography and liquid chromatography tandem mass spectrometry (LC-MS/MS) we were able to analyze fatty acid composition and the formation of lipid mediators called oxylipins. Our data illustrate-particularly in HELP-treated patients-significant decreases of essential omega-6 and omega-3 polyunsaturated fatty acids in blood plasma but significant increases of PUFA-derived lipoxygenase-, as well as cyclooxygenase- and cytochrome P450-derived lipid mediators. Given that n-3 PUFAs in particular are presumed to be cardioprotective and n-3 PUFA-derived lipid mediators might limit inflammatory reactions, these data indicate that n-3 PUFA supplementation in the context of lipid apheresis treatment might have additional benefits through apheresis-triggered protective n-3 PUFA-derived lipid mediators.

Fatty acid composition of free-living and parasitic stages of the bovine lungworm Dictyocaulus viviparus.

The development of parasitic nematodes proceeds via multiple stages, often implicating the necessity to adapt to different environments. Especially the transition from free-living to parasitic stages is accompanied by a significant change in the environmental conditions. To shed light on possible adaptations to these transitions, the fatty acid composition of different developmental stages of the bovine lungworm Dictyocaulus viviparus was investigated. Fatty acids of D. viviparus eggs, the free-living first, second and third larval stage (L1-L3) as well as the parasitic preadult stage and adult male and female worms residing in the lungs of infected hosts were quantified by gas chromatography after transesterification to their fatty acid methyl esters. The fatty acid content and diversity were higher in parasitic stages compared to those of free-living larvae. The most prevalent fatty acids in both parasitic and free-living stages were stearic (C18:0), palmitic (C16:0), palmitoleic (C16:1) and caprylic acid (C8:0). A variety of (poly-)unsaturated FAs was found in the parasitic stages and in the eggs, which was similar to the variety of FAs found in bovine surfactant. This finding indicates that parasitic stages of D. viviparus take up FAs from their environment. While eggs contained the highest concentration of fatty acids, a decrease was observed from eggs to L1 and further from L2 to L3. The lowest concentration was found in 38-days-old L3, which suggests that FAs serve as an energy reserve for the free-living, non-feeding larval stages. The free-living larvae contained mainly saturated fatty acids and only traces of unsaturated fatty acids, which is in contrast to the phospholipid saturation hypothesis of cold tolerance. Instead, a trade-off between desiccation stress and temperature adaptation may favour a higher amount of saturated FAs in the free-living larval stages. Further studies explicitly examining the FA composition of the different classes of lipids are necessary to better describe the adaptative responses of the FA metabolism to different environmental conditions.