Values Of Polyunsaturated Fatty Acids Research Articles

Fatty acid composition of lamb meat as affected by production system, weaning and sex

Fatty acid composition in intramuscular fat of Longissimus dorsi (LD) of 32 Jezersko-Solčava lambs was measured in two kinds of production system (grazing on mountain pasture and fattening in stable with hay and cereals ad libitum) and two kinds of weaning system (suckling and weaned) and interaction between them. The effect of sex was also determined. Pasture and stable lambs were slaughtered at average live weight 34 kg. Suckling lambs were slaughtered at 125 days of age (30 kg of live weight) and weaned lambs were slaughtered at 165 days (38 kg of live weight). Lambs on pasture displayed lower percentage of palmitic (C16:0) and oleic (C18:1n-9) and higher percentage of linoleic (C18:2n-6), α-linolenic (C18:3n-3), arachidonic (C20:4n-6) and eicosapentaenoic (C20:5n-3) fatty acids. Pasture lambs had lower percentage of SFA (saturated fatty acids) and MUFA (monounsaturated fatty acids), higher percentage of PUFA (polyunsaturated fatty acids) and especially relatively high percentage of C18:3n-3 (3.3%) in intramuscular fat. Pasture lambs also had higher percentage of n-6 PUFA (15.06%), even 1.5 times higher than stable lambs (9.34%) and consecutively higher n-6/n-3 PUFA ratio (2.1 vs. 1.6). Above all weaning affected MUFA and PUFA. Intramuscular fat of suckling lambs contained less MUFA (34.84% vs. 38.35%) and more PUFA (21.89% vs. 17.08%) as well as higher n-6/n-3 ratio than weaned lambs (1.9 vs. 1.7). The interaction between production system and weaning was statistically significant only for α-linolenic acid, with the highest proportion in LD fat of weaned lambs grazing on pasture (3.48%) and the lowest proportion of weaned lambs fatten in stable (2.71%). Males had lower values of MUFA and higher values of PUFA, n-6 PUFA and n-3 PUFA. The n-6/n-3 PUFA ratio was the same in both sexes (1.8).

Seasonal changes in the proximate chemical compositions and fatty acids of chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus) from the north eastern Mediterranean Sea

SummaryThe effects of seasonal variations on the proximate chemical compositions and fatty acid profiles of chub mackerel (Scomber japonicus) and horse mackerel (Trachurus trachurus) captured in the north‐eastern Mediterranean Sea were investigated. Protein fluctuations were observed in two species for all seasons. The lipid content of both species was lower in winter than in autumn and spring. In all seasons, the major fatty acids in both species were observed to be palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1 ω9), eicosapentaenoic acid (20:5 ω3) and docosahexaenoic acid (20:6 ω3). Chub mackerel and horse mackerel exhibited seasonal fluctuations in their fatty acid contents. The fatty acid profile of the two species had a higher degree of unsaturation during winter. The levels of EPA in chub mackerel in winter, spring and autumn were 5.96%, 4.86% and 4.33%, respectively, while those of DHA were 24.94%, 18.75% and 17.12%, respectively. The levels of EPA in horse mackerel in winter, spring and autumn were 5.42%, 5.03% and 4.86%, respectively, while those of DHA were 14.96%, 13.31% and 11.10%, respectively. The PUFA (polyunsaturated fatty acids) values and ω3/ω6 ratios in the two species were highest in winter. The results indicate that chub mackerel and horse mackerel captured in the north‐eastern Mediterranean Sea, which are among the most important fish in Turkey and of international commercial value, are a good source of nutrition for human consumption in terms of their proximate chemical composition and fatty acids.

The Fatty Acid Composition of Red Blood Cells in Mildly Demented Dogs and of Commercially Available Dog Foods in Japan

In order to investigate the relationship between the fatty acid composition of the dogs' tissue and dementia, we compared the fatty acid composition of red blood cells (RBCs) between 15 mildly demented dogs and 15 normal controls (≥10 years old). In the mildly demented dogs polyunsaturated fatty acids (PUFA) were significantly decreased and the ratios of arachidonic acid to total PUFA (AA⁄PUFA) were signiflcantly increased compared with normal dogs. AA⁄PUFA ratios had a significant correlation with dementia scores of 30 dogs (r=0.48). Dog food analysis showed that the average n-6 fatty acids⁄n-3 fatty acids ratios, a parameter influencing AA⁄PUFA ratios in tissues, were very high in pellet-type dog foods (n=20, the ratios=12). In conclusion, high AA⁄PUFA values in RBCs might be a risk factor of mild dementia in dogs. It seems not prudent to provide AA supplements to mildly demented dogs.

Fatty acids, cholesterol and protein content of nutria ( Myocastor coypus) meat from an intensive production system in Uruguay

This study describes the total lipids, protein and fatty acids in the meat, liver, brain and adipose tissue of five male and five female nutria ( Myocastor coypus). The animals were reared on a specialized farm in Uruguay. Total lipid content was between 1.41% and 1.84% in males and females. Total cholesterol content was between 70.1 mg and 72.7 mg/100 g of wet tissue. The protein content was between 19.56% and 22.34% in males and females. No significant differences ( P > 0.05) were detected between males and females for total lipid, cholesterol or protein. Total, saturated, monounsaturated and polyunsaturated fatty acid values were higher ( P < 0.001) in female than in male thigh muscle. Pectoral muscle had more ( P < 0.05) saturated and monounsaturated fatty acids in females than in males. Subcutaneous adipose tissue from females had the highest ( P < 0.01) total, saturated and monounsaturated but not polyunsaturated fatty acids while abdominal adipose tissue from males had more polyunsaturated fatty.

Moderate fish-oil supplementation reverses low-platelet, long-chain n−3 polyunsaturated fatty acid status and reduces plasma triacylglycerol concentrations in British Indo-Asians

The mechanisms involved in the increased mortality from coronary artery disease in British Indo-Asians are not well understood. This study aimed to investigate whether British Indo-Asian Sikhs have higher plasma triacylglycerol concentrations, lower platelet phospholipid levels, and lower dietary intakes of long-chain n-3 polyunsaturated fatty acids (PUFAs) than do age- and weight-matched Europeans and whether moderate dietary fish-oil intake can reverse these differences. A randomized, double-blind, placebo-controlled, parallel, fish-oil intervention study was performed. After a 2-wk run-in period, 44 Europeans and 40 Indo-Asian Sikhs were randomly assigned to receive either 4.0 g fish oil [1.5 g eicosapentaenoic acid (EPA) and 1.0 g docosahexaenoic acid (DHA)] or 4.0 g olive oil (control) daily for 12 wk. At baseline, the Indo-Asians had significantly higher plasma triacylglycerol, small dense LDL, apolipoprotein B, and dietary and platelet phospholipid n-6 PUFA values and significantly lower long-chain n-3 PUFAs (EPA and DHA) than did the Europeans. A significant decrease in plasma triacylglycerol, plasma apolipoprotein B-48, and platelet phospholipid arachidonic acid concentrations and a significant increase in plasma HDL concentrations and platelet phospholipid EPA and DHA levels were observed after fish-oil supplementation. No significant effect of ethnicity on the responses to fish-oil supplementation was observed. Moderate fish-oil supplementation contributes to a reversal of lipid abnormalities and low n-3 PUFA levels in Indo-Asians and should be considered as an important, yet simple, dietary manipulation to reduce CAD risk in Indo-Asians with an atherogenic lipoprotein phenotype.

Variations in the lipid profile of patients with chronic renal failure, treated with folic acid.

Dyslipidemia and increases in plasma homocysteine usually occur at end-stage renal disease; both are recognized as risk factors for atherosclerosis. Folate administration reduces homocysteine concentration. In this study we determined the effect of a high dose of folic acid (40 mg intravenous injection three times a week) on plasma and red blood cell lipid profiles in twelve chronic renal failure patients on regular hemodialysis. Fasting blood samples were taken at the beginning of the study (baseline) and after 21, 42, and 64 days of treatment. Folic acid supplementation decreased plasma homocysteine. Plasma triglyceride levels decreased whereas polyunsaturated fatty acid values increased after 21 days; then they returned to baseline levels at the end of treatment. Total cholesterol and low-density lipoprotein (LDL) cholesterol were higher than those of the baseline during all the study, whereas high-density lipoprotein (HDL) cholesterol was reduced. In erythrocyte membranes, folic acid therapy enhanced cholesterol/phospholipid ratios and the fluorescence anisotropy of diphenyl-hexatriene. We conclude that large doses of folic acid produce a favorable effect, reducing plasma homocysteine levels and protecting patients from atherosclerosis. However, as this therapy induces significant alterations in both plasma and erythrocyte membrane lipid profiles, plasma lipid values should be controlled throughout the treatment of patients with renal failure.

Polyunsaturated fatty acids induce ischemic and epileptic tolerance

The findings reported in this work show that pretreatment with polyunsaturated fatty acids, particularly linolenic acid, present in vegetable oils, can provide a potent tolerance against neurodegeneration in two models of neuronal death-generating treatments such as kainic acid injection and global ischemia. Rats were injected i.v. with 500 nmol/kg of linolenic acid as long as 3 days prior to 6 min global ischemia or received an injection of linolenic acid as long as 3 days prior to a dose of 7.5 mg/kg kainic acid. Neuronal degeneration, assessed by analysis of neuronal density on Cresyl Violet-stained hippocampal sections, was significantly reduced in linolenic acid-treated rats (94–85% of cell survival in the ischemic model and 99–79% of cell survival in the epileptic model in respective CA1 and CA3 subfields). The neuroprotection observed following the injection of linolenic acid 3 days prior to induction of a severe ischemic or epileptic challenge was associated with the induction of the neuroprotective HSP70 heat shock protein within the time window of protection. The injection of 500 nmol/kg of linolenic acid induced a maximal HSP70 expression of 387% at 72 h. In contrast, the overexpression of one well-known protein inducer of neuronal cell death, Bax, which is induced by both ischemic and kainic acid-induced epileptic insults, was prevented by linolenic acid in the 3-day window of protection. These results strengthen the idea of an interesting potential therapeutical value of polyunsaturated fatty acids in neuronal protection.

Polyunsaturated fatty acids are potent neuroprotectors.

Results reported in this work suggest a potential therapeutic value of polyunsaturated fatty acids for cerebral pathologies as previously proposed by others for cardiac diseases. We show that the polyunsaturated fatty acid linolenic acid prevents neuronal death in an animal model of transient global ischemia even when administered after the insult. Linolenic acid also protects animals treated with kainate against seizures and hippocampal lesions. The same effects have been observed in an in vitro model of seizure-like activity using glutamatergic neurons and they have been shown to be associated with blockade of glutamatergic transmission by low concentrations of distinct polyunsaturated fatty acids. Our data suggest that the opening of background K(+) channels, like TREK-1 and TRAAK, which are activated by arachidonic acid and other polyunsaturated fatty acids such as docosahexaenoic acid and linolenic acid, is a significant factor in this neuroprotective effect. These channels are abundant in the brain where they are located both pre- and post-synaptically, and are insensitive to saturated fatty acids, which offer no neuroprotection.

Relationship between red blood cell antioxidant enzymatic system status and lipoperoxidation during the acute phase of malaria

Objective: To investigate the relationship between oxidative stress and aggrevation of the disease in patients with malaria. Methods and Results: In the present study lipoperoxidation was demonstrated during the acute phase of malaria by a significant decrease in polyunsaturated fatty acids (PUFA). The lowest values of PUFA were obtained for C20:4 and C22:6, which were the main targets of reactive oxygen species (ROS) when parasitemia was higher than 1%. Similarly, plasma vitamins E and A were significantly reduced during the acute phase of malaria owing to their consumption in part as antioxidants. However, evaluation of the antioxidant enzymatic system in red blood cells of malaria patients indicated no significant difference from controls. Only superoxide dismutase activity tended to decrease when parasitemia increased. Conclusion: The results suggest that superoxide radicals are the main ROS produced during the acute phase of malaria, and that rejuvenation of RBC during hemolysis involving increased enzyme activities interacts to protect RBC from excessive superoxide radical production.

Kinetic parameters of lysophospholipid acyltransferase systems in diet-induced modifications of platelet phospholipid acyl chains.

Competitive effectiveness and relative Km values of polyunsaturated fatty acids were determined in the acyl-CoA : lysophospholipid acyltransferase systems in platelet membranes. Some CoA esters of fatty acids such as 18 : 2n-6 (linoleic), 18 : 3n-3(α-linolenic), 18 : 3n-6, 20 : 3n-6 (dihomo-γ-linolenic) and 20 : 5n-3 (eicosapentaenoic) were found in vitro to be relatively good competitive inhibitors of arachidonate (20 : 4n-6) incorporation into phosphatidylcholine, while in the acylation of lysophosphatidylinositol, 18 : 2n-6, 20 : 2n-6, 20 : 3n-6, 20 : 5n-3 and 22 : 4n-6 were relatively good inhibitors. When vegetable oil-supplemented diets rich in 18 : 2n-6 or 18 : 3n-3 were fed to rats, these fatty acids were converted to highly unsaturated fatty acids such as 20 : 4n-6 and 20 : 5n-3, and were esterified to phospholipids in platelets. The kinetic parameters determined in vitro were useful in predicting grossly the relative abundance of eicosanoid precursors (20 : 4n-6 and 20 : 5n-3), but not that of 18-carbon polyunsaturated fatty acids. It was found that arachidonate was conserved but n-3 fatty acids were excluded relatively more strictly in phosphatidylinositol than in phosphatidylcholine in platelets of rats on diets containing different proportions of 18 : 2n-6 and 18 : 3n-3.

Formation of conjugated diene and triene products in lipoxygenase oxidation of C18, C20, C22 PUFAs

AbstractThe determination of conjugated diene formation revealed that the mol % conversions of allcis‐6,9,12‐octadecatrienoic acid [γ‐linolenic, 18:3(n‐6)], allcis‐5,8,11,14‐eicosatetraenoic acid [arachidonic, 20:4(n‐6)], allcis‐5,8,11,14,17‐eicosapentaenoic acid [20:5(n‐3)], and allcis‐4,7,10,13,16,19‐docosahexaenoic acid [22:6(n‐3)] into conjugated diene products by soybean lipoxygenase‐1 at pH 9.0 were 84, 86, 60 and 40% of that of allcis‐9,12‐octadecadienoic acid [linoleic, 18:2(n‐6)], respectively. On the other hand, the conversions of allcis‐9,12,15‐octadecatrienoic acid [α‐linolenic, 18:3(n‐3)], allcis‐5,9,12‐octadecatrienoic acid (c5,c9,c12‐18:3), andtrans‐5,cis‐9,cis‐12‐octadecatrienoic acid (t5,c9,c12‐18:3) were equal to that of 18:2(n‐6). The lowering of the conjugated diene formation in the oxidation of 18:3(n‐6), 20:4(n‐6), 20:5(n‐3), and 22:6(n‐3) by the lipoxygenase was thought to be caused by the further oxidation of conjugated diene monohydroperoxides to yield conjugated triene products. For this reason, the conventional lipoxygenase method gave erroneous values forcis,cis‐methylene interrupted polyunsaturated fatty acids (PUFA) in oils containing a large amount of 20:5(n‐3) and 22:6(n‐3) such as fish oils. However, by changing the pH of reaction mixtures from 9.0 to 11.0, the secondary oxidation of conjugated diene monohydroperoxides was completely inhibited, and the PUFA values in fish oils obtained by this improved method were in good agreement with those obtained by a GLC method.

Lipid changes in the plasma lipoproteins of baboons given an atherogenic diet part 2. Changes in the phospholipid classes of total plasma and of α- and β-lipoproteins

The phospholipid classes of total plasma and of α- and β-lipoproteins, in baboons given control and atherogenic diets, have been studied using the techniques of electrochromatography (ECG), thin-layer chromatography (TLC) and gas-liquid chromatography (GLC). In animals given an atherogenic diet, a 70 % increase in plasma phospholipids (mg/ 100 ml) could be attributed to rises in all phospholipids in the β-lipoproteins but chiefly phosphatidyl choline (PC). Phospholipids in the a-lipoproteins were not appreciably affected. Arachidonic acid (mg/100 ml) was increased 2-fold in plasma phosphatidyl ethanolamine (PE) and 3-fold in plasma phosphatidyl choline (PC). However, the increase of arachidonic acid was most pronounced in the β-lipoproteins. The percentage value of polyunsaturated fatty acids and of unsaturated fatty acids remained constant at 35 and at 50% in PE and PC, respectively. It is concluded that the rise in PC in the β-lipoproteins is in response to the increased cholesterol transported in this fraction. There was no evidence to support the hypothesis that a raised cholesterol/phospholipid ratio is an index of athero geneity. The unexpected large increase in arachidonic acid which replaced linoleic acid in PE and PC was probably derived from its relatively large concentration in the atherogenic diet. For animals on the same diet the percentage fatty acid composition of α-PC and β-PC were similar, and likewise for α-PE and β-PE. This suggests that the phospholipids in each of the lipoproteins arise from the same body pool.