Saturated Fatty Acid-Induced Insulin Resistance Is Associated With Mitochondrial Dysfunction in Skeletal Muscle Cells

Increased plasma levels of free fatty acids (FFA) occur in states of insulin resistance such as obesity and type 2 diabetes mellitus. These high levels of plasma FFA are proposed to play an important role for the development of insulin resistance but the mechanisms involved are still unclear. This study investigated the effects of saturated and unsaturated FFA on insulin sensitivity in parallel with mitochondrial function. C2C12 myotubes were treated for 24 h with 0.1 mM of saturated (palmitic and stearic) and unsaturated (oleic, linoleic, eicosapentaenoic, and docosahexaenoic) FFA. After this period, basal and insulin-stimulated glucose metabolism and mitochondrial function were evaluated. Saturated palmitic and stearic acids decreased insulin-induced glycogen synthesis, glucose oxidation, and lactate production. Basal glucose oxidation was also reduced. Palmitic and stearic acids impaired mitochondrial function as demonstrated by decrease of both mitochondrial hyperpolarization and ATP generation. These FFA also decreased Akt activation by insulin. As opposed to saturated FFA, unsaturated FFA did not impair glucose metabolism and mitochondrial function. Primary cultures of rat skeletal muscle cells exhibited similar responses to saturated FFA as compared to C2C12 cells. These results show that in muscle cells saturated FFA-induced mitochondrial dysfunction associated with impaired insulin-induced glucose metabolism. J. Cell. Physiol. 222: 187-194, 2010. (C) 2009 Wiley-Liss, Inc.

Lipid, fatty acid, protein, amino acid and ash contents in four Brazilian red algae species

Four species of marine benthic algae (Laurencia filiformis, L. intricata, Gracilaria domingensis and G. birdiae) that belong to the phylum Rhodophyta were collected in Espirito Santo State, Brazil and investigated concerning their biochemical composition (fatty acid, total lipid, soluble proteins, amino acid and ash). The total content of lipid (% dry weight) ranged from 1.1% to 6.2%: fatty acid from 0.7% to 1.0%: soluble protein from 4.6% to 18.3%, amino acid from 6.7% to 11.3% and ash from 22.5% to 38.4%. judging from their composition, the four species of algae appear to be potential sources of dietary proteins, amino acids, lipids and essential fatty acids for humans and animals. (C) 2009 Elsevier Ltd. All rights reserved.

Total Trans Fatty Acid Analysis in Spreadable Cheese by Capillary Zone Electrophoresis

An alternative method for determination of total trans fatty acids expressed as elaidic acid by capillary zone electrophoresis (CZE) under indirect UV detection at 224 nm within an analysis time of 7.5 min was developed. The optimized running electrolyte includes 15.0 mmol L(-1) KH(2)PO(4)/Na(2)HPO(4) buffer (pH similar to 7.0), 4.0 mmol L(-1) SDBS, 8.0 mmol L(-1) Brij35, 45%v/v ACN, 8% methanol, and 1.5% v/v n-octanol. Baseline separation of the critical pair C18-9cis/C18:1-9t: with a resolution higher than 1.5 was achieved using C15:0 as the internal standard. The optimum capillary electrophoresis (CE) conditions for the background electrolyte were established with the aid of Raman spectroscopy and experiments of a 3(2) factorial design. After response factor (R(F)) calculations, the CE method was applied to total trans fatty acid (TTFA) analysis in a hydrogenated vegetable fat (HVF) sample, and compared with the American Oil Chemists` Society (AOCS) official method by gas chromatography (GC). The methods were compared with an independent sample t test, and no significant difference was found between CE and GC methods within the 95% confidence interval for six genuine replicates of TTFA analysis (p-value > 0.05). The CE method was applied to TTFA analysis in a spreadable cheese sample. Satisfactory results were obtained, indicating that the optimized methodology can be used for trans fatty acid determination for these samples.

Comparative study of the whisky aroma profile based on headspace solid phase microextraction using different fibre coatings

A dynamic headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to ion trap mass spectrometry (GC–ITMS) method was developed and applied for the qualitative determination of the volatile compounds present in commercial whisky samples which alcoholic content was previously adjusted to 13% (v/v). Headspace SPME experimental conditions, such as fibre coating, extraction temperature and extraction time, were optimized in order to improve the extraction process. Five different SPME fibres were used in this study, namely, poly(dimethylsiloxane)(PDMS),poly(acrylate)(PA),Carboxen-poly(dimethylsiloxane)(CAR/PDMS),Carbowax-divinylbenzene(CW/DVB)and Carboxen-poly(dimethylsiloxane)-divinylbenzene (CAR/PDMS/DVB). The best results were obtained using a 75 m CAR/PDMS fibre during headspace extraction at 40◦C with stirring at 750rpm for 60min, after saturating the samples with salt. The optimised methodology was then appliedtoinvestigatethevolatilecompositionprofileofthreeScotchwhiskysamples—BlackLabel,BallantinesandHighlandClan.Approximately seventy volatile compounds were identified in the these samples, pertaining at several chemical groups, mainly fatty acids ethyl esters, higher alcohols, fatty acids, carbonyl compounds, monoterpenols, C13 norisoprenoids and some volatile phenols. The ethyl esters form an essential group of aroma components in whisky, to which they confer a pleasant aroma, with “fruity” odours. Qualitatively, the isoamyl acetate, with “banana” aroma,wasthemostinteresting.Quantitatively,significantcomponentsareethylestersofcaprilic,capricandlauricacids.Thehighestconcentration of fatty acids, were observed for caprilic and capric acids. From the higher alcohols the fusel oils (3-methylbutan-1-ol and 2.phenyletanol) are the most important ones.

Analytical characterization of the aroma of Tinta Negra Mole red wine: Identification of the main odorants compounds

A method for the simultaneous determination of major and minor volatiles composition in different types (dry, medium dry, sweet and medium sweet) of a young Tinta Negra Mole (TNM) monovarietal red wine from 2003 harvest has been validated. Wine samples preparation includes a dichloromethane liquid–liquid extraction followed by concentration under a nitrogen atmosphere. The extracted fraction was analysed by gas chromatography–mass spectrometry and give quantitative information for more than 86 analytes whose concentration range from few μg l−1 to 259.1 mg l−1. The method enables high recovery of volatile compounds in wine good linearity with (r2) values higher than 0.980 and good sensitivity. The limits of detection range from 0.003 to 0.534 mg l−1 and limits of quantification from 0.009 to 1.170 mg l−1. The method allows satisfactory determination of more than 80 compounds in the TNM red wines. These wines are characterized by a high content of higher alcohols, ethyl esters, fatty acids and lactones. The levels of sulphur compounds in Tinta Negra Mole medium sweet wines are very low, but they have the highest concentration of carbonyl compounds. Quantitative analysis of the main odorants followed by the determination of aroma index allow us elucidate the aroma of these varieties. On the basis of their odour description and odour threshold, the most powerful odorants of Tinta Negra Mole wines were tentatively established.

Multivariate analysis for the classification and differentiation of Madeira wines according to main grape varieties

In order to differentiate and characterize Madeira wines according to main grape varieties, the volatile composition (higher alcohols, fatty acids, ethyl esters and carbonyl compounds) was determined for 36 monovarietal Madeira wine samples elaborated from Boal, Malvazia, Sercial and Verdelho white grape varieties. The study was carried out by headspace solid-phase microextraction technique (HS-SPME), in dynamic mode, coupled with gas chromatography–mass spectrometry (GC–MS). Corrected peak area data for 42 analytes from the above mentioned chemical groups was used for statistical purposes. Principal component analysis (PCA) was applied in order to determine the main sources of variability present in the data sets and to establish the relation between samples (objects) and volatile compounds (variables). The data obtained by GC–MS shows that the most important contributions to the differentiation of Boal wines are benzyl alcohol and (E)-hex-3-en-1-ol. Ethyl octadecanoate, (Z)-hex-3-en-1-ol and benzoic acid are the major contributions in Malvazia wines and 2-methylpropan-1-ol is associated to Sercial wines. Verdelho wines are most correlated with 5-(ethoxymethyl)-furfural, nonanone and cis-9-ethyldecenoate. A 96.4% of prediction ability was obtained by the application of stepwise linear discriminant analysis (SLDA) using the 19 variables that maximise the variance of the initial data set.

Development of a dynamic headspace solid-phase microextraction procedure coupled to GC–qMSD for evaluation the chemical profile in alcoholic beverages

In the present study, a simple and sensitive methodology based on dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography with quadrupole mass detection (GC–qMSD), was developed and optimized for the determination of volatile (VOCs) and semi-volatile (SVOCs) compounds from different alcoholic beverages: wine, beer and whisky. Key experimental factors influencing the equilibrium of the VOCs and SVOCs between the sample and the SPME fibre, as the type of fibre coating, extraction time and temperature, sample stirring and ionic strength, were optimized. The performance of five commercially available SPME fibres was evaluated and compared, namely polydimethylsiloxane (PDMS, 100 μm); polyacrylate (PA, 85 μm); polydimethylsiloxane/divinylbenzene (PDMS/DVB, 65 μm); carboxen™/polydimethylsiloxane (CAR/PDMS, 75 μm) and the divinylbenzene/carboxen on polydimethylsiloxane (DVB/CAR/PDMS, 50/30 μm) (StableFlex). An objective comparison among different alcoholic beverages has been established in terms of qualitative and semi-quantitative differences on volatile and semi-volatile compounds. These compounds belong to several chemical families, including higher alcohols, ethyl esters, fatty acids, higher alcohol acetates, isoamyl esters, carbonyl compounds, furanic compounds, terpenoids, C13-norisoprenoids and volatile phenols. The optimized extraction conditions and GC–qMSD, lead to the successful identification of 44 compounds in white wines, 64 in beers and 104 in whiskys. Some of these compounds were found in all of the examined beverage samples. The main components of the HS-SPME found in white wines were ethyl octanoate (46.9%), ethyl decanoate (30.3%), ethyl 9-decenoate (10.7%), ethyl hexanoate (3.1%), and isoamyl octanoate (2.7%). As for beers, the major compounds were isoamyl alcohol (11.5%), ethyl octanoate (9.1%), isoamyl acetate (8.2%), 2-ethyl-1-hexanol (5.9%), and octanoic acid (5.5%). Ethyl decanoate (58.0%), ethyl octanoate (15.1%), ethyl dodecanoate (13.9%) followed by 3-methyl-1-butanol (1.8%) and isoamyl acetate (1.4%) were found to be the major VOCs in whisky samples.

Comparison of prophylactic and therapeutic use of short-chain fatty acid enemas in diversion colitis: a study in Wistar rats

OBJECTIVES: To study the effect of short-chain fatty-acids on atrophy and inflammation of excluded colonic segments before and after the development of diversion colitis. INTRODUCTION: Diversion colitis is a chronic inflammatory process affecting the dysfunctional colon, possibly evolving with mucous and blood discharge. The most favored hypotheses to explain its development is short-chain fatty-acid deficiency in the colon lumen. METHODS: Wistar rats were submitted to colostomy with distal colon exclusion. Two control groups (A1 and B1) received rectally administered physiological saline, whereas two experimental groups (A2 and B2) received rectally administered short-chain fatty-acids. The A groups were prophylactically treated (5th to 40th days postoperatively), whereas the B groups were therapeutically treated (after post-operative day 40). The mucosal thickness of the excluded colon was measured histologically. The inflammatory reaction of the mucosal lamina propria and the lymphoid tissue response were quantified through established scores. RESULTS: There was a significant thickness recovery of the colonic mucosa in group B2 animals (p = 0.0001), which also exhibited a significant reduction in the number of eosinophilic polymorphonuclear cells in the lamina propria (p = 0.0126) and in the intestinal lumen (p = 0.0256). Group A2 showed no mucosal thickness recovery and significant increases in the numbers of lymphocytes (p = 0.0006) and eosinophilic polymorphonuclear cells in the lamina propria of the mucosa (p = 0.0022). CONCLUSION: Therapeutic use of short-chain fatty-acids significantly reduced eosinophilic polymorphonuclear cell numbers in the intestinal wall and in the colonic lumen; it also reversed the atrophy of the colonic mucosa. Prophylactic use did not impede the development of mucosal atrophy

Growth, fat content and fatty acid profile of South American catfish, surubim (Pseudoplatystoma fasciatum) juveniles fed live, commercial and formulated diets

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of different dietary lipid sources on the survival, growth, and fatty acid composition of South American catfish, Pseudoplatystoma fasciatum, Surubim, juveniles

The present study examines the effect of four semi-purified diets (casein-gelatin based) where the source of fatty acids was free (esterified) oleic acid and linoleic acid (LA) (LOA diet), linseed and olive oil (predominantly LA and linolenic acid) (LO diet), cod liver oil (rich in highly unsaturated fatty acids) (CLO diet), and soybean lecithin (phospholipids; mostly LA) (LE diet) on the growth of juvenile South American catfish (surubim, Pseudoplatystoma fasciatum, Pimelodidae) (0.98 +/- 0.04 g individual weight). Fish were fed at a restricted-readjusted feeding rate for 8 wk. At the end of the experiment, LE-diet-fed fish grew significantly larger than those of the other three groups (P < 0.05). Considerable cannibalism was observed in all the treatments. It is suggested that the quantitative growth performance may possibly change under other conditions, with less or no cannibalism. Survival did not differ significantly among the fish fed four different diets. Muscle and liver lipid contents did not vary among dietary treatments (P > 0.05), but whole-body lipid concentrations were affected by dietary treatments. Fish fed LE diet contained significantly lower lipid level than those fed three other diets (P < 0.05). Muscle and liver fatty acid profiles reflected dietary fatty acid composition. Arachidonic acid level was significantly higher in muscle and liver of fish fed LOA and LE diets than in those fed LO and CLO diets. The results suggest that the efficiency of elongation and desaturation of 18C fatty acids depends on the dietary lipid source, and South American catfish has considerable capacity to transform linoleate to arachidonate.

Milk fatty acid characterization and genetic parameter estimates for milk conjugated linoleic acid in buffaloes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação termoanalítica da eficiência de antioxidantes na estabilidade oxidativa do biodiesel de mamona

The biodiesel is defined as the mono-alkyl ester derived from long-chain fatty acids, from renewable sources such as vegetable oils or animal fat, whose use is associated with the replacement of fossil fuels in diesel engine cycle. The biodiesel is susceptible to oxidation when exposed to air and this process of oxidation affects the quality of fuel, mainly due to long periods of storage. Because of this, the oxidation stability has been the focus of numerous researches since it directly affects the producers, distributors and users of fuel. One of the possibilities to increase the resistance of biodiesel is the autoxidation treatment with inhibitors of oxidation. The antioxidants can be used as potential inhibitors of the effects of oxidation on the kinematic viscosity and the index of acidity of biodiesel, thereby increasing oxidative stability. This work aims to examine the efficiency of antioxidants, α-tocopherol and butylated hydroxy-toluene (BHT), added the biodiesel content of remembrance through Pressurized-Differential Scanning Calorimetry (P-DSC), Thermogravimetry (TG) and Petrology. The results showed that the use of antioxidant BHT, at the concentration of 2000ppm, increased resistance to oxidation of the biodiesel and oxidative induction time (OIT), which is a better result as antioxidant than the α-tocopherol. With the thermogravimetric analysis, it was observed that the biodiesel presented an initial decomposition temperature of lower tendency than that of oil, demonstrating to be more volatile, bearing great similarity to the diesel and being characterized as an alternative fuel. The rheological analysis indicated that each sample of biodiesel behaved as a Newtonian fluid

Fatty acid composition of mid-trimester amniotic fluid in women of different ethnicities

Objective: To determine whether the fatty acid composition of mid-trimester amniotic fluid differs by ethnicity and pregnancy outcome. Methods: Fatty acid composition was analyzed by gas chromatography in 198 women undergoing amniocentesis at 15-19 weeks gestation. Cytokine levels were determined by ELISA in a subgroup of 52 subjects. Results: The major fatty acids detected were palmitic acid (31.8%) and stearic acid (31.5%). The n-6 polyunsaturated fatty acids (PUFA), linoleic acid (LA, 18: 2) and arachidonic acid (AA, 20: 4), were 11.3%, while the n-3 PUFA fatty acids, alpha linolenic acid (ALA, 18: 3) and docosahexaenoic acid (DHA, 22: 6), were 3.8% of the total. Palmitic acid was a higher percentage in Asians (40.5%) and Whites (34.5%) than in Blacks (22.2%) and Hispanics (23.7%) (p <= 0.0012). Oleic acid (18:1 n-9) was a higher percentage in Blacks (12.2%) and Hispanics (12.1%) than in Whites (9.2%) or Asians (7.5%) (<= 0.0002). LA and AA were higher in Blacks (9.0%, 5.4%) and Hispanics (8.6%, 4.1%) than in Whites (6.1%, 3.7%) and Asians (5.5%, 2.9%) (p <= 0.0002). DHA did not differ among the ethnic groups or according to pregnancy outcome. A reduced palmitic acid percentage was identified in the six women with preeclampsia (p = 0.0233). Tumor necrosis factor-alpha levels were inversely proportional to the palmitic acid percentage (p = 0.0275) and positively associated with the percentages of stearic (18:0) (p = 0.0132) and oleic (p = 0.0290) acids. Conclusions: Amniotic fluid fatty acid composition differed among the ethnic groups and may influence inflammatory mediator production and susceptibility to preeclampsia.

Fatty acid profile of feedlot Brangus bullocks fed with monensin or polyclonal antibodies.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural insights for fatty acid binding in a Lys49-phospholipase A(2): crystal structure of myotoxin II from Bothrops molojeni complexed with stearic acid

The crystal structure of dimeric Lys49-phospholipase A2 myotoxin-II from Bothrops moojeni (MjTX-II) co-crystallized with stearic acid (C18H36O2) has been determined at a resolution of 1.8 angstrom. The electron density maps permitted the unambiguous inclusion of six stearic acid molecules in the refinement. Two stearic acid molecules could be located in the substrate-binding cleft of each monomer in positions, which favor the interaction of their carboxyl groups with active site residues. The way of binding of stearic acids to this Lys49-PLA(2)s is analogous to phospholipids and transition state analogues to catalytically active PLA(2)s. Two additional stearic acid molecules were located at the dimer interface region, defining a hitherto unidentified acyl-binding site on the protein surface. The strictly conserved Lys122 for Lys49-PLA(2)s may play a fundamental role for stabilization of legend-protein complex. The comparison of MjTX-II/satiric acid complex with other Lys-PLA(2)s structures whose putative fatty acids were located at their active site is also analysed. Molecular details of the stearic acid/protein interactions provide insights to binding in croup I/II PLA(2)s and to the possible interactions of Lys49-PLA(2)s with target membranes. (c) 2004 Elsevier SAS. All rights reserved.