Reproductive long-term effects, endocrine response and fatty acid profile of rabbit does fed diets supplemented with n-3 fatty acids

The effect of a diet enriched with polyunsaturated n -3 fatty acids (PUFA) on endocrine, reproductive, and productive responses of rabbit females and the litters has been studied. Nulliparous does ( n = 125) were fed ad libitum from rearing to second weaning two diets supplemented with different fat sources: 7.5 g/kg lard for the control diet (group C; n = 63) or 15 g/kg of a commercial supplement containing a 50% ether extract and 35% of total fatty acids (FAs) as PUFA n -3 (Group P; n = 62). Dietary treatments did not affect apparent digestibility coefficients of nutrients, or reproductive variables of does including milk pro- duction, mortality and average daily gain of kits over two lactations. However, on Day 5 and 7 post-induction of ovulation, progesterone of Group P tended to increase to a greater extent than in does of Group C. Total PUFAs, n -6 and n -3 and eicosapentanoic (EPA) contents were greater in adipose tissues of does in Group P than in Group C. Docosapentaenoic acid (DPA), EPA, and docosahexaenoic acid (DHA) concentrations were greater in peri-ovarian than in scapular fat with abdominal fat being intermediate in concentration. In PUFA sup- plemented does, kit mortality at the second parturition tended to be less than in control does. Also, kits born to does of the PUFA-supplemented group weighed more and were of greater length than from does of control group. In conclusion, effectiveness of dietary intervention on reproductive and performance response is greater in the second parity, which suggests an accumulative long-term beneficial effect of n -3 FA supplementation in reproductive rabbit does

Polyunsaturated fatty acid oxidation in Alzheimer’s disease.

Alzheimer’s disease is a neurodegenerative disorder which has been characterised with genetic (apolipoproteins), protein (ß-amyloid and tau) and lipid oxidation/metabolism alterations in its pathogenesis. In conjunction with the Dementia Research Group, Bristol University, investigation into genetic, protein and lipid oxidation in Alzheimer’s disease was conducted. A large sample cohort using the double-blind criteria, along with various clinical and chemical data sets were used to improve the statistical analysis and therefore the strength of this particular study. Bristol University completed genetic and protein analysis with lipid oxidation assays performed at Aston University. Lipid oxidation is a complex process that creates various biomarkers, from transient intermediates, to short carbon chain products and cyclic ring structures. Quantification of these products was performed on lipid extracts of donated clinical diseased and non-diseased frontal and temporal brain regions, from the Brain Bank within Frenchay Hospital. The initial unoxidised fatty acids, first transient oxidation intermediates the conjugated dienes and lipid hydroperoxides, the endpoint aldehyde biomarkers and finally the cyclic isoprostanes and neuroprostanes were determined to investigate lipid oxidation in Alzheimer’s. Antioxidant levels were also investigated to observe the effect of oxidation on the defence pathways. Assays utilised in this analysis included; fatty acid composition by GC-FID, conjugated diene levels by HPLC-UV and UV-spec, lipid hydroperoxide levels by FOX, aldehyde content by TBARs, antioxidant status by TEAC and finally isoprostane and neuroprostane quantification using a newly developed EI-MS method. This method involved the SIM of specific ions from F-ring isoprostane and neuroprostane fragmentation, which enabled EI-MS to be used for their quantification. Analyses demonstrated that there was no significant difference between control and Alzheimer samples across all the oxidation biomarkers for both brain regions. Antioxidants were the only marker that showed a clear variance; with Alzheimer samples having higher levels than the age matched controls. This unique finding is supported with the observed lower levels of lipid oxidation biomarkers in Alzheimer brain region samples. The increased antioxidant levels indicate protection against oxidation which may be a host response to counteract the oxidative pathways, but this requires further investigation. In terms of lipid oxidation, no definitive markers or target site for therapeutic intervention have been revealed. This study concludes that dietary supplementation of omega-3 fatty acids or antioxidants would most likely be ineffective against Alzheimer disease, although it may support improvement in other areas of general health.

Polyunsaturated fatty acid requirements of murine colon adenocarcinomas

The polyunsaturated fatty acid (PUFA) requirements of three transplantable murine colon adenocarcinomas, the MAC13, MAC16 and MAC26, were evaluated in vitro and in vivo. When serum concentrations became growth limiting in vitro, proliferation of the MAC13 and MAC26 cell lines was stimulated by linoleic acid (LA) at 18μM and arachidonic acid (AA) at 16 or 33μM respectively. This was not demonstrated by the MAC16 cell line. MAC13 and MAC26 cells were found to be biochemically fatty acid deficient as measured by the formation of Mead acid (20:3 n-9), but the MAC16 cells were not. In vivo the growth of the MAC26 tumour was stimulated by daily oral administration of LA between 0.4-2.0g/kg. There was a threshold value of 0.4g/kg for the stimulation of MAC26 tumour growth, above which there was no further increase in tumour growth, and below which no increase in tumour growth was observed. This increased tumour growth was due to the stimulation of tumour cell proliferation in all areas of the tumour, with no effect on the cell loss factor. The growth of the MAC13, MAC16, and MAC26 cell lines in vitro were more effectively inhibited by lipoxygenase (LO) inhibitors than the cyclooxygenase inhibitor indomethacin. The specific 5-LO inhibitor Zileuton and the leukotriene D4 antagonist L-660,711 were less effective inhibitors of MAC cell growth in vitro than the less specific LO inhibitors BWA4C, BWB70C and CV6504. Studies of the hyroxyeicosatetraenoic acids (HETEs) produced from exogenous AA in these cells, suggested that a balance of eicosanoids produced from 5-LO, 12-LO and 15-LO pathways was required for cell proliferation. In vivo BWA4C, BWB70C and CV6504 demonstrated antitumour action against the MAC26 tumour between 20-50mg/kg/day. CV6504 also inhibited the growth of the MAC 13 tumour in vivo with an optimal effect between 5-10mg/kg/day. The antitumour action against the MAC16 tumour was also accompanied by a reduction in the tumour-induced host body weight loss at 10-25mg/kg/day. The antitumour action of CV6504 in all three tumour models was partially reversed by daily oral administration of 1.0g/kg LA. Studies of the AA metabolism in tumour homogenates suggested that this profound antitumour action, against what are generally chemoresistant tumours, was due to inhibition of eicosanoid production through LO pathways. As a result of these studies, CV6504 has been proposed for stage I./II. clinical trials against pancreatic cancer by the Cancer Research Campaign. This will be the first LO inhibitor entering the clinic as a therapeutic agent.

Deleterious Effects of Lard-enriched Diet on Tissues Fatty Acids Composition and Hypothalamic Insulin Actions

Altered tissue fatty acid (FA) composition may affect mechanisms involved in the control of energy homeostasis, including central insulin actions. In rats fed either standard chow or a lard-enriched chow (high in saturated/low in polyunsaturated FA, HS-LP) for eight weeks, we examined the FA composition of blood, hypothalamus, liver, and retroperitoneal, epididymal and mesenteric adipose tissues. Insulin-induced hypophagia and hypothalamic signaling were evaluated after intracerebroventricular insulin injection. HS-LP feeding increased saturated FA content in adipose tissues and serum while it decreased polyunsaturated FA content of adipose tissues, serum, and liver. Hypothalamic C20:5n-3 and C20:3n-6 contents increased while monounsaturated FA content decreased. HS-LP rats showed hyperglycemia, impaired insulin-induced hypophagia and hypothalamic insulin signaling. The results showed that, upon HS-LP feeding, peripheral tissues underwent potentially deleterious alterations in their FA composition, whist the hypothalamus was relatively preserved. However, hypothalamic insulin signaling and hypophagia were drastically impaired. These findings suggest that impairment of hypothalamic insulin actions by HS-LP feeding was not related to tissue FA composition.

Formation and Fragmentation of Unsaturated Fatty Acid M-2H+Na (-) Ions: Stabilized Carbanions for Charge-Directed Fragmentation

Fatty acids are long-chain carboxylic acids that readily produce \[M - H](-) ions upon negative ion electrospray ionization (ESI) and cationic complexes with alkali, alkaline earth, and transition metals in positive ion ESI. In contrast, only one anionic monomeric fatty acid-metal ion complex has been reported in the literature, namely \[M - 2H + (FeCl)-Cl-II](-). In this manuscript, we present two methods to form anionic unsaturated fatty acid-sodium ion complexes (i.e., \[M - 2H + Na](-)). We find that these ions may be generated efficiently by two distinct methods: (1) negative ion ESI of a methanolic solution containing the fatty acid and sodium fluoride forming an \[M - H + NaF](-) ion. Subsequent collision-induced dissociation (CID) results in the desired \[M - 2H + Na](-) ion via the neutral loss of HF. (2) Direct formation of the \[M - 2H + Na](-) ion by negative ion ESI of a methanolic solution containing the fatty acid and sodium hydroxide or bicarbonate. In addition to deprotonation of the carboxylic acid moiety, formation of \[M - 2H + Na](-) ions requires the removal of a proton from the fatty acid acyl chain. We propose that this deprotonation occurs at the bis-allylic position(s) of polyunsaturated fatty acids resulting in the formation of a resonance-stabilized carbanion. This proposal is supported by ab initio calculations, which reveal that removal of a proton from the bis-allylic position, followed by neutral loss of HX (where X = F- and -OH), is the lowest energy dissociation pathway.

Mass spectrometric study of the dissociation of Group XI metal complexes with fatty acids and glycerolipids : Ag2H+ and Cu2H+ ion formation in the presence of a double bond

Results of mass spectrometric studies are reported for the collisional dissociation of Group XI (Cu, Ag, Au) metal ion complexes with fatty acids (palmitic, oleic, linoleic and a-linolenic) and glycerolipids. Remarkably, the formation of M2H+ ions (M = Cu, Ag) is observed as a dissociation product of the ion complexes containing more than one metal cation and only if the lipid in the complex contains a double bond. Ag2H+ is formed as the main dissociation channel for all three of the fatty acids containing double bonds that were investigated while Cu2H+ is formed with one of the fatty acids and, although abundant, is not the dominant dissociation channel. Also. Cu(I) and Ag(I) ion complexes were observed with glycerolipids (including triacylglycerols and glycerophospholipids) containing either saturated or unsaturated fatty acid substituents. Interestingly. Ag2H+ ion is formed in a major fragmentation channel with the lipids that are able to form the complex with two metal cations (triacylglycerols and glycerophosphoglycerols), while lipids containing a fixed positive charge (glycerophospocholines) complex only with a single metal cation. The formation of Ag2H+ ion is a significant dissociation channel from the complex ion Ag-2(L-H)(+) where L = Glycerophospholipid (GP) (18:1/18:1). Cu(I) also forms complexes of two metal cations with glycerophospholipids but these do not produce Cu2H+ upon dissociation. Rather organic fragments, not containing Cu(I), are formed, perhaps due to different interactions of these metal cations with lipids resulting from the much smaller ionic radius of Cu(I) compared to Ag(I) (C).

Investigation of the effects of the fatty acid profile on fuel properties using a Multi-Criteria Decision Analysis

The structural features of fatty acids in biodiesel, including degree of unsaturation, percentage of saturated fatty acids and average chain length, influence important fuel properties such as cetane number, iodine value, density, kinematic viscosity, higher heating value and oxidation stability. The composition of fatty acid esters within the fuel should therefore be in the correct ratio to ensure fuel properties are within international biodiesel standards such as ASTM 6751 or EN 14214. This study scrutinises the influence of fatty acid composition and individual fatty acids on fuel properties. Fuel properties were estimated based on published equations, and measured according to standard procedure ASTM D6751 and EN 14214 to confirm the influences of the fatty acid profile. Based on fatty acid profile-derived calculations, the cetane number of the microalgal biodiesel was estimated to be 11.6, but measured 46.5, which emphasises the uncertainty of the method used for cetane number calculation. Multi-criteria decision analysis (MCDA), PROMETHEE-GAIA, was used to determine the influence of individual fatty acids on fuel properties in the GAIA plane. Polyunsaturated fatty acids increased the iodine value and had a negative influence on cetane number. Kinematic viscosity was negatively influenced by some long chain polyunsaturated fatty acids such as C20:5 and C22:6 and some of the more common saturated fatty acids C14:0 and C18:0. The positive impact of average chain length on higher heating value was also confirmed in the GAIA plane

A soluble preparation from developing groundnut seeds (Arachis hypogaea) catalyzes de novo synthesis of long chain fatty acids

A 100,000 x g supernatant fraction prepared from developing groundnut seeds (30-35 days after flowering) catalyzed the synthesis of fatty acids from [l-14C]acetate at a rate of 120nmoles of acetate incorporated per hr per gram fresh weight of tissue. 90% of this incorporated label was associated with fatty acids. The major fatty acids formed were stearic- (77%) and palmitic acids (14%) with 4% of oleic acid. The fatty acid synthetase activity was stable when stored at 0-4 degrees C for at least fifteen days. It is concluded from these results that acetyl-coA carboxylase and all the enzymes of fatty acid synthetase from developing groundnut seeds are soluble.

Frictional response of fatty acids on steel

Self-assembled monolayers of fatty acids were formed on stainless steel by room-temperature solution deposition. The acids are covalently bound to the Surface as carboxylate in a bidentate manner. To explore the effect Of Saturation in the carbon backbone on friction in sliding tribology, we Study the response of saturated stearic acid (SA) and unsaturated linoleic acid (LA) as self-assembled monolayers using lateral force microscopy and nanotribometry and when the molecules are dispersed in hexadecane, using pin-on-disc tribometry. Over a very wide range (10 MPa-2.5 GPa) of contact pressures it is consistently demonstrated that the unsaturated linoleic acid molecules yield friction which is significantly lower than that of the saturated stearic acid. it is argued, using density functional theory predictions and XPS of slid track, that when the molecular backbone of unsaturated fatty acids are tilted and pressed strongly by a probe, in tribological contact, the high charge density of the double bond region of the backbone allows coupling with the steel Substrate. The interaction yields a low friction carboxylate soap film on the substrate. The saturated fatty acid does not show this effect.

Fatty acids, fibre, carotenoids and tocopherols in relation to glucose metabolism in subjects at high risk for type 2 diabetes : a cross-sectional analysis

Fatty acids, fibre, carotenoids and tocopherols in relation to glucose metabolism in subjects at high risk for type 2 diabetes a cross-sectional analysis Type 2 diabetes (T2D) is a heterogeneous disorder of carbohydrate, lipid and protein metabolism, resulting from genetics, environmental influences and interactions between these. The disease is characterized by insulin resistance, β-cell dysfunction, hepatic glucose overproduction and disordered fat mobilization and storage. The literature on associations between dietary factors and glucose metabolism is inconsistent. One factor behind the discrepant results may be genetic heterogeneity of study populations. Data on nutrient-gene interactions in relation to glucose metabolism are scarce. Thus, investigating high-risk populations and exploring nutrient-gene interactions are essential for improving the understanding of T2D aetiology. Ideally, this information could help to develop prevention programmes that take into account the genetic predisposition to the disease. In this study, associations between measures of glucose metabolism predicting T2D and fatty acids, antioxidative nutrients and fibre were examined in a high-risk population, i.e., in non-diabetic relatives of affected patients. Interactions between the PPARG Pro12Ala polymorphism and fatty acids on glucose metabolism were taken into consideration. This common polymorphism plays an important role in the regulation of glucose metabolism. The inverse associations observed between dietary fibre and insulin resistance are consistent with the prevailing recommendations urging increased intake of fibre to prevent T2D. Beneficial associations observed between the intake of carotenoids and glucose levels stress that a high consumption of vegetables, fruits and berries rich in carotenoids might also play a role in the prevention of T2D. Whether tocopherols have an independent association with glucose metabolism remains questionable. Observed interactions between fatty acids and glucose metabolism suggest that a high intake of palmitic acid is associated with high fasting glucose levels mainly in female Ala allele carriers. Furthermore, the PPARG Pro12Ala polymorphism may modify the metabolic response to dietary marine fat. The beneficial associations of high intake of marine n 3 fatty acids with insulin resistance and glucose levels may be restricted to carriers of the Ala allele. The findings pertain to subjects with a family history of T2D, and the cross-sectional nature of the study precludes inferences about causality. Results nevertheless show that associations of dietary factors with glucose metabolism may be modulated by the genetic makeup of an individual. Additional research is warranted to elucidate the role of probably numerous nutrient-gene interactions, some of which may be sex-specific, in the aetiology of T2D.

Solubilities of palmitic and stearic fatty acids in supercritical carbon dioxide

The solubilities of two fatty acids, namely hexadecanoic acid (palmitic acid) and octadecanoic acid (stearic acid) in supercritical carbon dioxide (SCCO2), were determined at T = (328 and 338) K from 12.8 MPa to 22.6 MPa. Three models, namely a thermodynamic model based on the Peng-Robinson equation of state with Kwak and Mansoori mixing rules, a model based on dilute solution theory proposed by Mendez-Santiago and Teja and a new reformulated Chrastil equation model, were used to correlate the solubilities. In all the models, the correlation constants are temperature independent. All the models successfully correlated the experimental results for the solubilities of hexadecanoic acid within 3%.

Evidence for the inability of the intestinal mitochondria of the silkworm, Bombyx mori L.to oxidize fatty acids

Conditions for the preparation of mitochondria from silkworm intestines have been standardized. The inability of mitochondria to oxidize fatty acids has been demonstrated. Evidence for the absence of an inhibitor in the mitochondria has been obtained.