Phospholipid Fatty Acid Composition Research Articles

GC-MS Analysis of Some Bioactive Constituents from the Marine Sponge Spongosorites halichondriodes

Sponges have proved to be a rich source of sterols with unusual structural features 1, 2. They are also a rich source of structurally unusual and interesting fatty acids and steryl esters. To analyze and extract phylogenetic information from chemical characters, the 3-hydroxysterol composition of Halichondria lutea, H. magniconulosa, Topsentia ophiraphidites, and Petromica ciocalyptoides (family Halichondriidae) were studied. Three out of four Halichondriidae species were related by a unique sterol property. The diversity of sterols found in the studied species of Halichondrida confirms the usual pattern in Porifera 3. A close relationship between Topsentia and Petromica has already been drawn from morphology 4 and from similarity in secondary metabolite composition 5. In contrast, the two studied species of Halichondria came out separately in the analysis, not sharing a sterol synapomorphy, further evidencing the fact that this genus has been mainly defined by primitive characters 4, 6 and that it is polyphyletic 7. It is of special interest that, although some sponge species provide the greatest structural diversity of membrane sterols in comparison with any other animals, many of the studied sponges have sterol compositions resembling those of animals belonging to other taxa. In another study, D. australiensis contained 7 -, 5 -, 5,7 -, 5,7,9 (11)-sterols, and cholest-7-ene-3-ol was shown to be a main sterol. The free sterols from A. mauritiana proved to be stanols and 7 -series compounds. Haliclona sp. contained 5 -sterols with cholesterol as a main constituent. C. major and D. aceratus contained 5 -sterols, and clionasterol was a main sterol. T. labirintica was shown to contain 3-hydroxymethyl-A-nor-sterols. 8. The Caribbean sponge Neofibularia nolitangere showed comparable amounts of 24-methylene-4-methyl-5-cholest-8-ene-3-ol, which is very unusual among sponge sterols, and lesser quantities of two new polyoxygenated sterols, (24S)-24-ethyl-5-cholest-8-ene-5,6,7-triol and (24S)-24-ethyl-5-cholest-8(14)-ene-5,6,7triol 9. In our search for active compounds in Spongosorites halichondriodes, a marine sponge of class Demospongiae and family Halichondriidae, we have found that polyhydroxy steryl esters and cholesterol are predominant in this species. Spongosorites sp. is in almost all instances found in association with Vermetid molluscs and possesses potent bioactive compounds. Interestingly, it has also been observed that organisms that are conspicuously colored and live in habitats with limited or no ambient light often possess interesting secondary metabolites (Dercitus sp. and Spongosorites sp.) Seven monoindole derivatives were isolated from the MeOH extract of the marine sponge Spongosorites sp. by bioactivity-guided fractionation 10. Also, four bis (indole) alkaloids of the topsentin class, including two new brominated compounds, have been isolated from the sponge Spongosorites genitrix collected from Jaeju Island, Korea 11. These compounds also exhibited moderate cytotoxicity against cancer cell lines at concentrations between 1.1 and > 20 g/mL 12. Spongosorites halichondriodes has been studied and investigated for its antibacterial and antifungal activity. It has shown prominent antimicrobial activity in all the extracts along with cytotoxic activity in ethyl acetate extract. In the current work, the data collected from the GC-MS of the butanol extract was analyzed, and spectral matches were searched by comparing the parent ion fragmentation pattern m/z with the Mass Bank Database, Japan using Quick peak Search. The separation chromatogram of the crude extract of butanol and ethyl acetate showed the presence of similar peaks; butanol was selected for MS because of major peaks. Identification of Compounds by GC-MS. The fatty acid composition of phospholipids from marine sponges of the Colombian Caribbean Sea of the order Halichondrida (Halichondria magniconulosa, Halichondria lutea, Petromica ciocalyptoides, Axinyssa ambrosia, Didiscus oxeata, and Dragmaxia undata) has already been studied. Structure elucidation was accomplished by means of gas chromatography retention parameters and GC-MS of eight new fatty acids and their methyl esters and N-acylpyrrolidide derivatives (i.e., 5-methyl-6-octadecenoic, 16-methyl-11-heptadecenoic, 8-methyl-4-tetracosenoic,

Impact of Super Absorbent Polymer and Plants on Microbial Community and Petroleum Hydrocarbon Degradation in Contaminated Soil

A greenhouse pot test, in which wheat, cabbage, spinach were cultivated separately in petroleum contaminated soil with and without super absorbent polymer (SAP), was conducted to evaluated the effect of plants and SAP on soil microbiological properties. phospholipid fatty acids (PLFAs) profiles were analyzed to reveal the microbial communities. As a measure of the functional activity of soil microbial community, the ratio of degraded to total petroleum hydrocarbon (TPH) in soil was estimated. The results indicated that SAP had an important effect on the soil microbial community and its degrading TPH activities. First, the principal component analysis (PCA) of the PLFA signatures revealed marked changes between soil with SAP and without SAP. In addition, the total amount and the profile of PLFA were significantly different between the untreated and SAP-amended soils. Using PLFA patterns as a biomarker, it was found that gram-positive bacteria (G+) were more sensitive to SAP than gram-negative bacteria (G-), and the biomass of G+ was higher in soil with SAP than in that without SAP. Second, the crop could stimulate the growth of soil microorganisms; however, the differences depended clearly on the crop species. The G+ and G- biomass was increased in cabbage, spinach soil containing SAP, but was decreased in wheat soils. The population of fungi was increased in cabbage and spinach soils containing SAP, but was decreased in wheat soil with SAP. The population of actinomycetes was decreased in all soils with SAP. Third, the ratio of degraded to TPH was slightly increased in soil with SAP treatment, but a significant change depended on the crop species. In total, 12 different PLFAs were identified, including saturated, monounsaturated, branched, and polyunsaturated species. There was a clear difference in the PLFAs composition between soils with and without SAP.

Dietary Linoleic Acid and α-Linolenic Acid Differentially Affect Renal Oxylipins and Phospholipid Fatty Acids in Diet-Induced Obese Rats

Analysis of oxylipins derived from fatty acids may provide insight into the biological effects of dietary lipids beyond their effects on tissue fatty acid profiles. We have previously observed that diets with higher amounts of α-linolenic acid (ALA; 18:3n3) are associated with reduced obesity-related glomerulopathy (ORG). Therefore, to examine the renal oxylipin profile, the effects of dietary linoleic acid (LA; 18:2n6) and ALA on oxylipins and renal phospholipid fatty acid composition, and the relationship between oxylipins and ORG, diet-induced obese rats displaying ORG were fed 8 different diets for 8 wk as follows (oil/oil = combination of two oils) [shown as ALA/LA (in g) per 100 g oil]: canola/flax (20/18), canola (8/18), soy (9/53), high-oleic canola/canola (5/16), high-oleic canola (2/15), lard/soy (1/8), and safflower (0.2/73). Targeted lipidomic analysis by HPLC–tandem mass spectrometry revealed that LA and ALA oxylipins comprised 60% of the total renal oxylipin profile examined. Of the >60 oxylipins screened, only those derived either directly or indirectly from ALA were associated with less glomerulomegaly, indicative of reduced ORG progression. Both the amount and ratio of dietary LA and ALA influenced renal polyunsaturated fatty acids (PUFAs); in contrast, only fatty acid amount altered oxylipins derived from these fatty acids, but there was no apparent competition by LA or ALA on their formation. Dietary LA incorporation into renal phospholipids was higher than for ALA, but ALA oxylipin:ALA ratios were higher than the analogous LA ratios for select lipoxygenase reactions. This indicates that the effect of dietary ALA on renal oxylipins exceeded what was reflected in renal PUFA composition. In conclusion, dietary LA and ALA have differential effects on renal oxylipins and PUFAs, and ALA-derived oxylipins are associated with renoprotection in this model of ORG.

Prenatal Ethanol Exposure Increases Brain Cholesterol Content in Adult Rats

Fetal alcohol syndrome is the most severe expression of the fetal alcohol spectrum disorders (FASD). Although alterations in fetal and neonate brain fatty acid composition and cholesterol content are known to occur in animal models of FASD, the persistence of these alterations into adulthood is unknown. To address this question, we determined the effect of prenatal ethanol exposure on individual phospholipid class fatty acid composition, individual phospholipid class mass, and cholesterol mass in brains from 25-week-old rats that were exposed to ethanol during gestation beginning at gestational day 2. While total phospholipid mass was unaffected, phosphatidylinositol and cardiolipin mass was decreased 14 and 43%, respectively. Exposure to prenatal ethanol modestly altered brain phospholipid fatty acid composition, and the most consistent change was a significant 1.1-fold increase in total polyunsaturated fatty acids (PUFA), in the n-3/n-6 ratio, and in the 22:6n-3 content in ethanolamine glycerophospholipids and in phosphatidylserine. In contrast, prenatal ethanol consumption significantly increased brain cholesterol mass 1.4-fold and the phospholipid to cholesterol ratio was significantly increased 1.3-fold. These results indicate that brain cholesterol mass was significantly increased in adult rats exposed prenatally to ethanol, but changes in phospholipid mass and phospholipid fatty acid composition were extremely limited. Importantly, suppression of postnatal ethanol consumption was not sufficient to reverse the large increase in cholesterol observed in the adult rats.

Profiling of soil fatty acids using comprehensive two-dimensional gas chromatography with mass spectrometry detection

Profiling of phospholipid fatty acids (PLFA) represents a challenging goal for distinguishing the diversity of microbial communities and biomass in the complex and heterogeneous soil ecosystem. Comprehensive two-dimensional gas chromatography (GC×GC) coupled with simultaneous flame ionisation and mass spectrometry detection was applied as a culture-independent method for PLFA profiling of microbial classification in forest soil. A number of column sets were evaluated for the GC×GC separation of fatty acid methyl esters (FAME). Due to better isomeric separation and compound patterns on the 2D contour plot, an apolar–polar column combination was selected for soil microbial PLFA characterisation. A comprehensive view of PLFA composition with carbon chain length varying from 12 to 20 was observed in forest soil samples, with the commonly reported bacterial FAME of iso-/anteiso-, methyl-branched-, cyclopropyl-, and hydroxyl-substituted FA identified by their mass spectral and retention time according to authentic standards. Notably, some uncommon oxygenated FAME were found in high abundance and were further characterised by GC×GC coupled with high resolution mass spectrometry. This tentatively revealed geometric pairs of methyl 9,10-epoxyoctadecanoate isomers.

Alteration of plasma phospholipid fatty acid profile in patients with septic shock

In septic shock patients, alterations of plasma phospholipid fatty acid profile have never been described. The purpose of this monocentric, non-interventional, observational prospective study was to describe this fatty acid profile in the early phase of septic shock in intensive care unit. Thirty-seven adult patients with septic shock were included after the first day of stay in intensive care unit, before any form of artificial nutritional support. Plasma phospholipid fatty acid composition was determined by gas chromatography. All biological data from patients with septic shock were compared with laboratory reference values. Patients presented hypocholesterolemia and hypertriglyceridemia. They had low concentrations of phospholipid fatty acids specifically n-6 and n-3 polyunsaturated fatty acids (PUFAs) with a high n-6/n-3 ratio. Plasma phospholipid PUFA concentrations were strongly correlated with cholesterolemia. PUFAs/SFAs (saturated fatty acids) and PUFAs/MUFAs (monounsaturated fatty acids) ratios were low because of low percentage of n-6 and n-3 PUFAs and high percentage of SFAs and MUFAs. Low levels of plasma long chain PUFAs (≥20 carbons) were significantly associated with mortality at 28th day. In conclusion, plasma phospholipid FA profile of septic patients is very characteristic, close to that of acute respiratory distress syndrome and mortality is associated with long chain PUFA decrease. This profile could be explained by numerous non-exclusive physio-pathological processes 1) an activation of hepatic de novo lipogenesis that could contribute to hepatic steatosis, 2) an elevated adipose tissue lipolysis, 3) an increased free radical attack of FA by oxidative stress, 4) an over-production of inflammatory lipid mediators.

Impact of Humics and Plants on Microbial Community and Petroleum Hydrocarbon Degradation in Contaminated Soil

A greenhouse pot experiment, in which 3 different crops (wheat, cabbage, spinach) were cultivated in soil with and without humics (HS), was conducted to evaluate the effect of HS on soil microbiological properties. Phospholipid fatty acid (PLFA) profiles were analyzed to reveal the microbial community structure. As a measure of the functional activity of soil microbial community, the ratio of degraded to total petroleum hydrocarbon in soil was estimated. The results indicated that HS had an important effect on the soil microbial community and its functional activities. First, the principal component analysis (PCA) of the PLFA signatures revealed marked changes between soil with HS and without HS. In addition, the total amount and the profile of PLFA were significantly different between the untreated and HS-amended soils. Using PLFA patterns as a biomarker, it was found that gram-positive bacteria (G+) were more sensitive to HS than gram-negative bacteria (G-), and the biomass of G+ was higher in soil with HS than in that without HS. Second, the crop could stimulate the growth of soil microorganisms; however, the differences depended clearly on the crop species. The G+ and G- biomass was increased in spinach soil containing HS, but was decreased in wheat and cabbage soils. The population of fungi was increased in wheat and spinach soils containing HS, but was decreased in cabbage soil. The population of actinomycetes was increased in cabbage soil, but was decreased in wheat and spinach soils containing HS. Third, the ratio of degraded to total petroleum hydrocarbon was also affected by the HS treatment. It was slightly increased in soil with HS treatment, but a significant change depended on the crop species. In general, fatty acids ranged from C13 to C19. In total, 25 different PLFAs were identified, including saturated (SAT), monounsaturated (MUFA), branched (BR), and polyunsaturated (PUFA) species. There was a clear difference in the PLFA composition between soils with and without HS.

Streptozotocin‐Induced Diabetes Partially Attenuates the Effects of a High‐Fat Diet on Liver and Brain Fatty Acid Composition in Mice

The current study addresses the effects of a high-fat diet on liver and brain fatty acid compositions and the interaction of that diet with diabetes in a type 1 mouse model. Adult, male, normal and streptozotocin-induced diabetic C57BL/6 mice were fed standard (14%kcal from fat) or high-fat (54%kcal from fat, hydrogenated vegetable shortening and corn oil) diets for 8weeks. Liver and whole brain total phospholipid fatty acid compositions were then determined by TLC/GC. In the liver of non-diabetic mice, the high-fat diet increased the percentages of 18:1n-9, 20:4n-6, and 22:5n-6 and decreased 18:2n-6 and 22:6n-3. Diabetes increased 16:0 in liver, and decreased 18:1n-7 and 20:4n-6. The effects of the high-fat diet on liver phospholipids in diabetic mice were similar to those in non-diabetic mice, or were of smaller magnitude. In the brain, the high-fat diet increased 18:0 and 20:4n-6 of non-diabetic, but not diabetic mice. Brain 22:5n-6 acid was increased by the high-fat diet in both non-diabetic and diabetic mice, but this increase was smaller in diabetic mice. Diabetes alone did not alter the percentage of any individual fatty acid in brain. This indicates that the effects of a high-fat diet on liver and brain phospholipid fatty acid compositions are partially attenuated by concomitant hyperglycemia with hypoinsulinemia.

Lipid Composition Analysis of Milk Fats from Different Mammalian Species: Potential for Use as Human Milk Fat Substitutes

The lipid compositions of commercial milks from cow, buffalo, donkey, sheep, and camel were compared with that of human milk fat (HMF) based on total and sn-2 fatty acid, triacylglycerol (TAG), phospholipid, and phospholipid fatty acid compositions and melting and crystallization profiles, and their degrees of similarity were digitized and differentiated by an evaluation model. The results showed that these milk fats had high degrees of similarity to HMF in total fatty acid composition. However, the degrees of similarity in other chemical aspects were low, indicating that these milk fats did not meet the requirements of human milk fat substitutes (HMFSs). However, an economically feasible solution to make these milks useful as raw materials for infant formula production could be to modify these fats, and a possible method is blending of polyunsaturated fatty acids (PUFA) and 1,3-dioleoyl-2-palmitoylglycerol (OPO) enriched fats and minor lipids based on the corresponding chemical compositions of HMF.

Turnover of “new” and “old” carbon in soil microbial biomass

The contributions of “new” carbon coming from plants with the C4-type of photosynthesis (maize) and “old” carbon from soil organic matter (SOM) formed under C3 vegetation as carbon sources for microorganisms was determined. Soil samples were taken from the plots of field experiments on Chernozem and Phaeozem. The values of δ13C were determined in evolved CO2, SOM, total microbial biomass (Cmic), and phospholipid fatty acids (PLFA), assuming that the PLFA markers for certain taxonomic groups of microorganisms enriched in C4 carbon indicated a more significant role of these microorganisms in the transformation of root exudates and plant residues. Carbon pools were arranged in the following order by the degree of their enrichment with “new” C: SOM < Cmic < CO2. Consequently, the “new” carbon proved to be a more preferable substrate for microbial growth than the “old” one. The share of C4 in the markers varied from 18 to 60% (on average 38%) in Phaeozem and from 15 to 40% in Chernozem (on average 28%). The groups of microorganisms in Phaeozem were arranged in the following order by the degree of their enrichment with “new” carbon: protozoa < saprotrophic fungi < actinomycetes < gram-positive bacteria < gramnegative bacteria < mycorrhizal fungi. In Chernozem, the contribution of C4 to the carbon composition of PLFA did not differ significantly for various groups of microorganisms. The C4 content within the PLFA markers of fungi and gram-negative bacteria did not demonstrate any crucial contribution of these groups of organisms to the transformation of “new” C. The long-term C3–C4 transition probably results in formation of a broad range of carbon pools similar in their C4 content but different in resistance to mineralization; therefore, gram-positive bacteria could assimilate C4 from resistant C pools. The low content of “new” carbon in the PLFA markers of fungi may be explained by a considerable portion of dormant forms.

Fatty Acid Profile of Cardiac Muscle Phospholipid and Triacylglycerol in MDX Mice and C57BL/10ScSnJ Controls

The mdx mouse is a model for Duchenne muscular dystrophy (DMD), a debilitating disease affecting striated muscle. It is established that the fatty acid (FA) composition of skeletal muscle phospholipid (PL) is altered in mdx mice, but it is not known if cardiac muscle is similarly affected by dystrophin-deficiency. We tested FA profiles in PL and triacylglycerol (TAG) in cardiac muscle of 12-week old mdx and control (con) mice. Of 22 different FA, similar to our previous finding for skeletal muscle, the most abundant FA in heart PL were palmitic, stearic, cis-vaccenic, linoleic, and docosahexaenoic acid, while for TAG the most abundant FA were palmitic, oleic, cis-vaccenic, and linoleic acid. In comparing mdx and con, no significant group differences were detected for any FA in PL or TAG. Thus, unlike skeletal muscle, FA composition in cardiac muscle PL is not different between mdx and con at the age studied. The results can be understood in the context of tissue-specific disease severity in mdx mice, as pathology is quite modest in cardiac compared with skeletal muscle.

Ambient temperature and nutritional stress influence fatty acid composition of structural and fuel lipids in Japanese quail (Coturnix japonica) tissues

In birds, fatty acids (FA) serve as the primary metabolic fuel during exercise and fasting, and their composition affects metabolic rate and thus energy requirements. To ascertain the relationship between FAs and metabolic rate, a distinction should be made between structural and fuel lipids. Indeed, increased unsaturation of structural lipid FAs brings about increased cell metabolism, and changes in the FA composition of fuel lipids affects metabolic rate through selective mobilization and increasing availability of specific FAs. We examined the effects of acclimation to a low ambient temperature (Ta: 12.7±3.0°C) and nutritional status (fed or unfed) on the FA composition of four tissues in Japanese quail, Coturnix japonica. Differentiating between neutral (triglycerides) and polar (phospholipids) lipids, we tested the hypothesis that both acclimation to low Ta and nutritional status modify FA composition of triglycerides and phospholipids. We found that both factors affect FA composition of triglycerides, but not the composition of phospholipids. We also found changes in liver triacylglyceride FA composition in the low-Ta acclimated quail, namely, the two FAs that differed, oleic acid (18:1) and arachidonic acid (20:4), were associated with thermoregulation. In addition, the FAs that changed with nutritional status were all reported to be involved in regulation of glucose metabolism, and thus we suggest that they also play a role in the response to fasting.

Changes in the phospholipid fatty acid composition of the lipid droplet during the differentiation of 3T3-L1 adipocytes

Lipid droplets (LDs) are independent organelles in adipocytes that are composed of a lipid ester core surrounded by a phospholipid monolayer. The fatty acid composition of the phospholipid monolayer should determine the metabolism and dynamics of LDs. In this study, we examined the fatty acid composition of phospholipid monolayer in LDs during the differentiation of 3T3-L1 adipocytes. The levels of saturated fatty acids (SFAs), such as 16:0 and 18:0, in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of LDs decreased during differentiation. In contrast, the levels of monounsaturated fatty acids (MUFAs) such as 16:1n-7 and 18:1n-9 in PC and PE of LDs and the level of polyunsaturated fatty acids (PUFAs) such as 20:3n-6, 20:4n-6 and 22:6n-3 in PE of LDs increased during differentiation. These results suggest that the phospholipid monolayer in mature LDs is more fluid than that in nascent LDs. The fatty acid compositions of the LD monolayer were different from those of the microsome bilayer in the early stage of differentiation, but similar to those of the microsome bilayer in the late stage of differentiation. These data provide evidence that biophysical properties of the phospholipid monolayer in LDs change during adipocyte differentiation.

Pre- and early-postnatal nutrition modify gene and protein expressions of muscle energy metabolism markers and phospholipid Fatty Acid composition in a muscle type specific manner in sheep.

We previously reported that undernutrition in late fetal life reduced whole-body insulin sensitivity in adult sheep, irrespective of dietary exposure in early postnatal life. Skeletal muscle may play an important role in control of insulin action. We therefore studied a range of putative key muscle determinants of insulin signalling in two types of skeletal muscles (longissimus dorsi (LD) and biceps femoris (BF)) and in the cardiac muscle (ventriculus sinister cordis (VSC)) of sheep from the same experiment. Twin-bearing ewes were fed either 100% (NORM) or 50% (LOW) of their energy and protein requirements during the last trimester of gestation. From day-3 postpartum to 6-months of age (around puberty), twin offspring received a high-carbohydrate-high-fat (HCHF) or a moderate-conventional (CONV) diet, whereafter all males were slaughtered. Females were subsequently raised on a moderate diet and slaughtered at 2-years of age (young adults). The only long-term consequences of fetal undernutrition observed in adult offspring were lower expressions of the insulin responsive glucose transporter 4 (GLUT4) protein and peroxisome proliferator-activated receptor gamma, coactivator 1α (PGC1α) mRNA in BF, but increased PGC1α expression in VSC. Interestingly, the HCHF diet in early postnatal life was associated with somewhat paradoxically increased expressions in LD of a range of genes (but not proteins) related to glucose uptake, insulin signalling and fatty acid oxidation. Except for fatty acid oxidation genes, these changes persisted into adulthood. No persistent expression changes were observed in BF and VSC. The HCHF diet increased phospholipid ratios of n-6/n-3 polyunsaturated fatty acids in all muscles, even in adults fed identical diets for 1½ years. In conclusion, early postnatal, but not late gestation, nutrition had long-term consequences for a number of determinants of insulin action and metabolism in LD. Tissues other than muscle may account for reduced whole body insulin sensitivity in adult LOW sheep.

Vegetarian diet-induced increase in linoleic acid in serum phospholipids is associated with improved insulin sensitivity in subjects with type 2 diabetes

BACKGROUND AND AIMS:Fatty acids are important cellular constituents that may affect many metabolic processes relevant for the development of diabetes and its complications. We showed previously that vegetarian diet leads to greater increase in metabolic clearance rate of glucose (MCR) than conventional hypocaloric diet. The aim of this secondary analysis was to explore the role of changes in fatty acid composition of serum phospholipids in diet- and exercise-induced changes in MCR in subjects with type 2 diabetes (T2D).METHODS:Subjects with T2D (n=74) were randomly assigned into a vegetarian group (VG, n=37) following vegetarian diet or a control group (CG, n=37) following a conventional diet. Both diets were calorie restricted (−500 kcal day–1). Participants were examined at baseline, 12 weeks of diet intervention and 24 weeks (subsequent 12 weeks of diet were combined with aerobic exercise). The fatty acid composition of serum phospholipids was measured by gas liquid chromatography. MCR was measured by hyperinsulinemic isoglycemic clamp. Visceral fat (VF) was measured by magnetic resonance imaging.RESULTS:Linoleic acid (LA; 18:2n6) increased in VG (P=0.04), whereas it decreased in CG (P=0.04) in response to dietary interventions. It did not change significantly after the addition of exercise in either group (group × time P<0.001). In VG, changes in 18:2n6 correlated positively with changes in MCR (r=+0.22; P=0.04) and negatively with changes in VF (r=−0.43; P=0.01). After adjustment for changes in body mass index, the association between 18:2n6 and MCR was no longer significant. The addition of exercise resulted in greater changes of phospholipid fatty acids composition in VG than in CG.CONCLUSION:We demonstrated that the insulin-sensitizing effect of a vegetarian diet might be related to the increased proportion of LA in serum phospholipids.

Phospholipid classes and fatty acid composition of ewe’s and goat’s milk

The content, distribution of individual species, and the fatty acid composition of phospholipids (PL) from ewe’s and goat’s milk were analyzed. The binding of enterotoxigenic and uropathogenic Escherichia coli strains to PL and the inhibition of bacterial hemagglutination by PL were addressed using high performance thin-layer chromatography-overlay assays and microtiter plates, respectively. Ovine and caprine milk contained more PL than bovine milk but less than human milk. The profile of individual PL was similar, including sphingomyelin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol in both ovine and caprine milk. Regarding the fatty acid composition, a high content of long-chain fatty acids (more than C16) and unsaturated fatty acids, with C18:1 as the most abundant was found in ovine and caprine milk PL. Ovine milk has longer and less saturated fatty acids while caprine milk has shorter and more saturated ones. Neither the adhesion of any bacterial strains assayed to the individual PL from ovine or caprine milk nor the inhibition of bacterial hemagglutination by PL were observed. These are important constituents of the milk fat globule membrane, but it seems that they do not play a role in the defence of new-borns against bacteria if the results obtained are taken into account.

Hypolipidemic and antioxidant effects of buckwheat leaf and flower mixture in hyperlipidemic rats

As a source of biologically active compounds, buckwheat has beneficial effects in nutrition due to its high content of flavonoids, particularly rutin. Aim of our study was to examine effects of buckwheat on plasma lipid status and phospholipids fatty acids composition, histological and parameters of oxidative stress in Wistar rats fed a high-fat diet. This study showed that buckwheat leaf and flower (BLF) mixture supplementation significantly reduce weight gain, plasma lipid concentrations and atherogenic index in rats fed a high-fat diet. Treatment of the high-fat group of animals with buckwheat significantly increased percentage of n-6 fatty acids as well as eicosapentaenoic acid (EPA) and decreased percentage of saturated fatty acids (SFA) and oleic acid. Buckwheat antioxidant effects diminished negative influence of high-fat diet in hyperlipidemic rats, while pathohistological analysis of liver confirmed changes after high-fat consumption. Our results showed hypolipidemic, antiatherogenic and antioxidative features of buckwheat leaf and flower mixture, and these parts of the plant with the highest rutin content could be beneficial in prevention and curing of hyperlipidemia.

Membrane Phospholipid Fatty Acid Composition Regulates Cardiac SERCA Activity in a Hibernator, the Syrian Hamster (Mesocricetus auratus)

Polyunsaturated fatty acids (PUFA) have strong effects on hibernation and daily torpor. Increased dietary uptake of PUFA of the n-6 class, particularly of Linoleic acid (LA, C18:2 n-6) lengthens torpor bout duration and enables animals to reach lower body temperatures (Tb) and metabolic rates. As previously hypothesized, this well-known influence of PUFA may be mediated via effects of the membrane fatty acid composition on sarcoplasmic reticulum (SR) Ca2+−ATPase 2a (SERCA) in the heart of hibernators. We tested the hypotheses that high proportions of n-6 PUFA in general, or specifically high proportions of LA (C18:2 n-6) in SR phospholipids (PL) should be associated with increased cardiac SERCA activity, and should allow animals to reach lower minimum Tb in torpor. We measured activity of SERCA from hearts of hibernating and non-hibernating Syrian hamsters (Mesocricetus auratus) in vitro at 35°C. Further, we determined the PL fatty acid composition of the SR membrane of these hearts. We found that SERCA activity strongly increased as the proportion of LA in SR PL increased but was negatively affected by the content of Docosahexaenoic acid (DHA; C22:6 n-3). SR PL from hibernating hamsters were characterized by high proportions of LA and low proportions of DHA. As a result, SERCA activity was significantly higher during entrance into torpor and in torpor compared to inter-bout arousal. Also, animals with increased SERCA activity reached lower Tb during torpor. Interestingly, a subgroup of hamsters which never entered torpor but remained euthermic throughout winter displayed a phenotype similar to animals in summer. This was characterized by lower proportions of LA and increased proportions of DHA in SR membranes, which is apparently incompatible with torpor. We conclude that the PUFA composition of SR membranes affects cardiac function via modulating SERCA activity, and hence determines the minimum Tb tolerated by hibernators.

Altered heart and kidney phospholipid fatty acid composition are associated with cardiac hypertrophy in hypertensive rats

ObjectiveWe examined the association of cardiac hypertrophy or fibrosis with the phospholipid fatty acid (FA) composition of heart and kidney in hypertensive rats. Design and methodsEight-week-old spontaneously hypertensive rats (SHRs) (n=8) and Wistar Kyoto rats (WKYs, n=8) as a normotensive control, were fed ad libitum for 6weeks with regular AIN-76 diet. Phospholipid FA compositions in the left ventricle and kidney were measured and histological analyses were performed. ResultsCompared with WKYs, SHRs had lower proportions of γ-linolenic acid, α-linolenic acid, eicosadienoic acid, eicosatrienoic acid, dihomo-γ-linoleic acid, docosadienoic acid and nervonic acid in heart, and stearic acid (SA), γ-linolenic acid, and eicosapentaenoic acid (EPA) in kidney. After adjusting for food intake, SHRs still maintained higher proportions of SA, and total saturated FAs in the heart and a lower proportion of eicosapentaenoic acid in the kidney. Additionally, compared with WKYs, SHRs showed larger cardiomyocyte diameters in the left ventricles, indicating cardiac hypertrophy and interstitial fibrosis. Cardiomyocyte diameters also positively correlated with cardiac SA (r=0.550, p<0.05) and negatively with kidney EPA (r=−0.575, p<0.05). ConclusionTissue FA compositions were associated with cardiac hypertrophy in a hypertensive setting, implicating the pathogenic role of tissue FAs in hypertension and related complications.

Effect of functional feeds on fatty acid and eicosanoid metabolism in liver and head kidney of Atlantic salmon (Salmo salar L.) with experimentally induced Heart and Skeletal Muscle Inflammation

Heart and Skeletal Muscle Inflammation (HSMI) is an emerging viral disease caused by a novel Atlantic salmon reovirus (ASRV) affecting farmed fish. Primary symptoms associated with HSMI include myocardial and skeletal muscle necrosis indicating a severe inflammatory process. Recently, we applied the concept of clinical nutrition to moderate the long-term inflammatory process associated with HSMI in salmon subjected to experimental ASRV challenge. The use of functional feeds with lower lipid (hence energy) content reduced the inflammatory response to ASRV infection and the severity of associated heart lesions. The aim of the present study was to elucidate possible mechanisms underpinning the observed effects of the functional feeds, focussing on eicosanoid and fatty acid metabolism in liver and head kidney. Here we show that liver was also a site for histopathological lesions in HSMI showing steatosis reflecting impaired lipid metabolism. This study is also the first to evaluate the expression of a suite of key genes involved in pathways relating diet and membrane phospholipid fatty acid compositions, and the inflammatory response after ASRV infection. The expression of hepatic Δ6 and Δ5 desaturases was higher in fish fed the functional feeds, potentially increasing their capacity for endogenous production and availability of anti-inflammatory EPA. Effects on mobilization of lipids and changes in the LC-PUFA composition of membrane phospholipids, along with significant changes in the expression of the genes related to eicosanoid pathways, showed the important role of the head kidney in inflammatory diseases caused by viral infections. The results from the present study suggest that clinical nutrition through functional feeding could be an effective complementary therapy for emerging salmon viral diseases associated with long-term inflammation.