Lipids, lipoproteins, and fatty acids during infantile marasmus in the Fès area of Morocco.

The lipid composition of plasma, including total HDL and LDL cholesterol, triglycerides, apo AI, apo B, and fatty acids was investigated in 29 malnourished Moroccan children in two groups: 12 children with mild PCM, and 17 with severe PCM. Normally nourished children from the same area (n = 15) served as controls. The severe malnourished children showed a significant reduction of apo AI, total and LDL cholesterol, and an increase in the levels of triglycerides. Furthermore, these children showed a decrease in the saturated fatty acids myristic and stearic acid, and a similar decrease in the essential fatty acid (EFA) metabolites, especially eicosatrienoic acid, arachidonic acid, and eicosapentaenoic acid, with an increase in the oleic and cisvaccenic monounsaturated fatty acids. In contrast, the PCM group showed only an increase of docosatetraenoic and docosapentaenoic, with an associated decrease in myristic acid and palmitic acid. On the other hand, the indexes of delta 9 desaturase and elongase n-3 and n-6 were increased, and this was found to be related to the severity of the malnutrition. These results suggest that the severity of malnutrition is associated with an increase of desaturation and elongation of PUFA, EFA deficiency and/or peroxidation.     

Renal function in rats with essential fatty acid deficiency

1. Renal function was studied in 50-, 70-, 90- and 200-day-old rats with essential fatty acid deficiency. The pharmacokinetics of tobramycin was investigated in 90-day-old essential fatty acid-deficient rats. 2. A higher glomerular filtration rate and a higher serum concentration of urea were seen in 50-day-old essential fatty acid-deficient rats compared with age-matched controls. Later, the glomerular filtration rate progressively deteriorated in parallel with a decline in effective renal plasma flow and with a concomittant rise in serum levels of urea and creatinine. The serum concentration of protein was lower in the rats with essential fatty acid deficiency and that of sodium was higher than in the control rats. The non-renal clearance of tobramycin was increased in the rats with essential fatty acid deficiency. 3. The early hyperfiltration in essential fatty acid-deficient rats with the subsequent fall in glomerular filtration rate, which was paralleled by a rise in serum levels of urea and creatinine, as well as the increased non-renal clearance of tobramycin, are in accordance with the clinical manifestations of cystic fibrosis. Rats with essential fatty acid deficiency might be a useful model with which to study the pathophysiological renal changes in cystic fibrosis related to the progressive essential fatty acid deficiency in this disease.     

肥胖儿童血清磷脂脂肪酸谱及其与血脂、脂肪肝的相关性分析

目的 探讨肥胖儿童血清磷脂脂肪酸谱与血脂、脂肪肝的相关性,指导饮食干预.方法 分别抽取肥胖儿童41例和健康儿童40例,采用气相色谱法测定血清磷脂脂肪酸谱,酶法测定血脂,比色法测定肝功能,B超检测脂肪肝,SPSS 13.0统计软件进行统计学处理,P<0.05确定为有显著性差异.结果 肥胖儿童血清磷脂脂肪酸谱与健康对照组相比有显著差异.肥胖儿童SFA、C16:0、C16:1、C18:0、C18:3 n-6、C18:3 n-3、C20:0、C20:2n-6、C20:3n-6、C22:1、C16:1/C16:0、C20:3n-6/C18:2n-6显著高于健康对照组;PUFA、n-6PUFA、PUFA/SFA、C14:0、C18:1 n-7、C18:2 n-6、C20:1、C20:4n-6、C20:4n-6/C20:3n-6显著低于健康对照组.肥胖儿童C14:1、C20:0与TG呈负相关,C14:1、C18:1n-7与TC呈负相关,C20:3n-6、C22:4n-6、C22:5n-6、C24:0与TC呈正相关;C14:1与ALT、AST呈负相关,C20:3n-6呈正相关;单因素Logistic回归分析显示WC、BMI、ALT、AST、SFA、C16:0与脂肪肝呈正相关;PUFA与脂肪肝呈负相关(P<0.05).结论 肥胖儿童血清磷脂脂肪酸谱与健康对照组相比有显著差异,其血清磷脂脂肪酸组成与脂代谢异常、脂肪肝密切相关.应重视儿童膳食脂肪酸摄人种类,增加膳食中PUFA尤其是n-3PUFA的摄人,减少SFA摄入,预防儿童肥胖及脂肪肝的发生.     

Essential fatty acid deficiency and neutrophil function: studies of lipid-free total parenteral nutrition in monkeys

Linoleic acid (18:2 omega 6), the obligate precursor of arachidonic acid (20:4 omega 6), is an essential nutrient for humans and other mammals. Because arachidonic acid release and metabolism are components of neutrophil activation by certain stimuli, we questioned whether neutrophils depleted of arachidonate as a result of essential fatty acid deficiency might be functionally impaired. We examined this possibility by producing essential fatty acid deficiency in monkeys with lipid-free total parenteral nutrition (TPN). Rhesus and African green monkeys were given calorically equal TPN for up to 23 days with and without a vegetable fat emulsion rich in linoleic acid. Fatty acids were analyzed in total lipid extracts of serum and isolated blood neutrophils by gas-liquid chromatography. Although fatty acids in the serum and neutrophils of monkeys given TPN with lipid did not change, linoleic acid levels decreased by at least 60% in serum and 50% in neutrophils from animals given TPN with no lipid. Moreover, arachidonate levels in neutrophil lipids decreased by at least 50% within 12 days of lipid-free TPN, and the abnormal fatty acid 20:3 omega 9 (characteristic of essential fatty acid deficiency) appeared and steadily increased with time. These biochemical signs of omega 6 fatty acid deficiency were associated with impaired neutrophil function in vitro. Both migration responses and superoxide generation stimulated by N-formyl-methionyl-leucyl-phenylalanine were significantly decreased by 12 days of lipid-free TPN, as was the capacity of activated cells to synthesize leukotriene B4. In contrast, functional responses of fatty acid-deficient neutrophils to leukotriene B4 and phorbol myristate acetate, which have little or no effect on arachidonate release or metabolism, were not significantly altered. These findings indicate that endogenous supplies of arachidonic acid and other essential omega 6 fatty acids influence the functional responsiveness of neutrophils. These studies also indicate that altered neutrophil function is a feature of essential fatty acid deficiency and that it may contribute to the increased risk of infection and decreased inflammatory responses observed in this condition.     

Long-chain polyunsaturated fatty acids in rat maternal milk, offspring brain and peripheral tissues in essential fatty acid deficiency.

Fatty acid status in humans is usually related to plasma or red blood cell fatty acid profiles. The aim of the study was to explore whether a maternal deficiency in dietary essential fatty acids would differentially affect lipid fractions in several tissues of the offspring, including brain. Female Wistar rats were fed an essential fatty acid-deficient diet during 3 months before mating. The fatty acid composition of different lipid fractions was examined in maternal milk, and in plasma, red blood cells, liver, adipose tissue, cerebral cortex and hippocampus of the offspring using thin layer and capillary column gas chromatography. Lipid fractions from most tissues of deprived offspring showed a common fatty acid profile characterized by elevated 20:3 omega9/20:4 omega6 ratio, and decreased docosahexaenoic acid and arachidonic acid. However, arachidonic acid was not affected in brain, even though 22:5 omega6 was increased in phospholipids of cerebral cortex and hippocampus. The present results demonstrate different degrees of resistance to essential fatty acid deficiency in lipid fractions and tissues. This suggests a priority distribution of arachidonic acid to preferential areas and shows that blood phospholipid fatty acids do not exactly reflect brain phospholipid status.     

Criteria for essential fatty acid deficiency in plasma as assessed by capillary column gas-liquid chromatography

To develop criteria for deficiency of essential fatty acids (EFA), we used capillary-column gas-liquid chromatography to determine fatty acids (percentage of total fatty acids) in plasma obtained in the fasting state from 56 reference subjects and from 10 patients with intestinal fat malabsorption and suspected EFA deficiency. Fatty acid evaluations (percentage of total fatty acids) that allowed for a clear distinction (P less than 0.01) between reference subjects and patients, based on values two standard deviations below or above the reference mean, included values for linoleic acid (18:2w6) below 27%, and values for palmitic acid (16:0), palmitoleic acid (16:1w7), oleic acid (18:1w9), vaccenic acid (18:1w7), and Mead acid (20:3w9) exceeding 21%, 2.6%, 23.3%, 2.1%, and 0.21%, respectively. Ratios of total EFA to total non-EFA of less than 0.60 and of Mead acid to arachidonic acid of greater than 0.025 also served to identify patients, and were not found in reference subjects. Significant inverse correlations between percentages of plasma EFA and plasma mono-unsaturated fatty acids were noted. Our reference-interval data can be used to assess normality of plasma EFA status.     

Desaturation and esterification of fatty acids in kidney cells from spontaneously hypertensive rats

In previous studies, several alterations in lipid metabolism have been related to hypertension, but the mechanisms explaining this relationship have not been elucidated. None of the previous works has focused on the lipid metabolism in kidney, which is a key organ in the overall regulation of blood pressure. The aim of the present work was to study the metabolism of polyunsaturated fatty acids, and the possible compositional changes in kidney from hypertensive rats. Radiolabelled linoleic acid (18:2,n-6) and dihomogammalinolenic acid (20:3, n-6) were incubated with isolated kidney cells from spontaneously hypertensive rats (SHR) or the parent normotensive strain (Wistar Kyoto, WKY). The rats were divided into groups of age 9 (young) and 17 (adult) weeks. Cellular uptake, desaturation, chain-elongation, oxidation and distribution into phospholipids and triacylglycerols were measured. Additionally, the lipid composition of kidney was characterized. With each of the labelled fatty acid substrates the uptake in cells from the SHR rats, compared to the WKY rats, was numerically lower in the young group and higher in the adult group. The incorporation of labelled fatty acids into phospholipids was increased and concomitantly decreased in triacylglycerols in cells from adult SHR rats. The delta6-desaturation, measured as the conversion of labelled 18:2(n-6) to 18:3(n-6) was between two and three times increased in cells from the adult rats compared to the young ones, while no difference was found in hypertensives compared to normotensives. Concomitantly, no difference in conversion of labelled 20:3(n-6) to 20:4(n-6) was observed in relation to blood pressure, but, different from delta6-desaturation, the delta5-desaturation was significantly decreased by age. Taken together, this study demonstrates for the first time desaturation of long-chain polyunsaturated fatty acids in isolated kidney cells in suspension and that, contrary to what has been observed in liver, the desaturase activity is unaffected by hypertension. Also different from what has been observed in liver, no blood-pressure-related changes in lipid composition of kidney were found.     

Structural requirements for activation of the 5-oxo-6E,8Z, 11Z,14Z-eicosatetraenoic acid (5-oxo-ETE) receptor: identification of a mead acid metabolite with potent agonist activity

The 5-lipoxygenase product 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-oxo-ETE) is a potent chemoattractant for neutrophils and eosinophils, and its actions are mediated by the oxoeicosanoid (OXE) receptor, a member of the G protein-coupled receptor family. To define the requirements for activation of the OXE receptor, we have synthesized a series of 5-oxo-6E,8Z-dienoic acids with chain lengths between 12 and 20 carbons, as well as a series of 20-carbon 5-oxo fatty acids, either fully saturated or containing between one and five double bonds. The effects of these compounds on neutrophils (calcium mobilization, CD11b expression, and cell migration) and eosinophils (actin polymerization) were compared with those of 5-oxo-ETE. The C12 and C14 analogs were without appreciable activity, whereas the C16 5-oxo-dienoic acid was a weak partial agonist. In contrast, the corresponding C18 analog (5-oxo-18:2) was nearly as potent as 5-oxo-ETE. Among the C20 analogs, the fully saturated compound had virtually no activity, whereas 5-oxo-6E-eicosenoic acid had only weak agonist activity. In contrast, 5-oxo-6E,8Z,11Z-eicosatrienoic acid (5-oxo-20:3) and its 8-trans isomer were approximately equipotent with 5-oxo-ETE in activating granulocytes. Because of the potent effects of 5-oxo-20:3, we investigated its formation from Mead acid (5Z,8Z,11Z-eicosatrienoic acid), which accumulates in dietary essential fatty acid deficiency, by neutrophils. The main Mead acid metabolite identified was 5-hydroxy-6,8,11-eicosatrienoic acid, followed by 5-oxo-20:3 and two 6-trans isomers of leukotriene B(3). We conclude that optimal activation of the OXE receptor is achieved with 5-oxo-ETE, 5-oxo-18:2, and 5-oxo-20:3, and that the latter compound could potentially be formed under conditions of essential fatty acid deficiency.     

Risk of secondary lymphedema in breast cancer survivors is related to serum phospholipid fatty acid desaturation

Purpose

Secondary lymphedema is a common irreversible side effect of breast cancer surgery. We investigated if risk of secondary lymphedema in breast cancer survivors was related to changes in serum phospholipid fatty acid composition.

Methods

Study subjects were voluntarily recruited into the following three groups: breast cancer survivors who had sentinel lymph node biopsy without lymphedema (SLNB), those who had auxillary lymph node dissection without lymphedema (ALND), and those who had ALND with lymphedema (ALND + LE). Body mass index (BMI), serum lipid profiles, bioimpedance data with single-frequency bioimpedance analysis (SFBIA), and serum phospholipid compositions were analyzed and compared among the groups.

Results

BMI, serum total cholesterol (total-C), and low-density lipoprotein cholesterol (LDL-C) and SFBIA ratios increased only in the ALND + LE. High polyunsaturated fatty acids (PUFAs) and high C20:4 to C18:2 n-6 PUFAs (arachidonic acid [AA]/linoleic acid [LA]) was detected in the ALND and ALND + LE groups compared to SLNB. The ALND + LE group showed increased activity indices for delta 6 desaturase (D6D) and D5D and increased ratio of AA to eicosapentaenoic acid (AA/EPA) compared to the ALND and SLNB groups. Correlation and regression analysis indicated that D6D, D5D, and AA/EPA were associated with SFBIA ratios.

Conclusion

We demonstrated that breast cancer survivors with lymphedema had elevated total PUFAs, fatty acid desaturase activity indices, and AA/EPA in serum phospholipids. Our findings suggested that desaturation extent of fatty acid composition might be related to the risk of secondary lymphedema in breast cancer survivors.

     

Plasma phospholipid fatty acid composition and estimated desaturase activity in heart failure patients with metabolic syndrome

Metabolic syndrome is one of the major factors to increase the incidence of heart failure. In our study, we compared plasma fatty acid compositions among heart failure patients with and without Metabolic syndrome. Fatty acid (FA) composition of plasma phospholipids was analyzed and the activities of desaturase were estimated as the ratio of substrate and product fatty acids in 85 stable heart failure patients. Fatty acid and estimated desaturase activities were further examined for their associations with Metabolic syndrome components. Heart failure patients with Metabolic syndrome showed significant changes in fatty acid composition in comparison to those without Metabolic syndrome, which had a decreased proportion of lauric acid (C12:0) and an increased proportion of dihomo-γ-linolenic acid (C20:3n-6). Also, estimated desaturase activities (D5D and D6D) were closely related to Metabolic syndrome condition among heart failure patients. The content of dihomo-γ-linolenic acid showed positive correlations with BMI, waist circumference, and plasma triglyceride levels. D6D were positively associated with plasma triglyceride levels, whereas D5D showed a negative correlation with plasma triglyceride levels and waist circumferences. The content of dihomo-γ-linolenic acid as well as estimated D6D and D5D were altered in heart failure patients with Metabolic syndrome.     

Adipose tissue fatty acid composition in humans with lipoprotein lipase deficiency.

BACKGROUND: Lipid stores in human adipose tissue are maintained primarily by incorporating lipid from circulating chylomicrons and very low density lipoproteins. Adipose tissue lipoprotein lipase (LPL) hydrolyzes triglyceride from these lipoprotein particles to facilitate their entry into adipocytes for storage. Subjects deficient in LPL still have normal adiposity, and this may result from increased adipocyte lipogenesis or from uptake of circulating lipid through alternate mechanisms. The objective of this study was to determine whether fatty acid composition of adipose tissue from LPL-deficient subjects reflects maintenance of lipid stores through increased lipogenesis or through alternate mechanisms of lipoprotein uptake. METHODS: Adipose tissue samples from LPL-deficient subjects who consume fat-restricted diets and normal subjects were analyzed for fatty acid composition by gas-liquid chromatography. RESULTS: Compared with that of normal subjects, adipose tissue from LPL-deficient subjects showed an increase in 16:1 and decreases in 18:0, 18:2, and 18:3 fatty acids, whereas other nonessential fatty acid levels were not statistically different. CONCLUSIONS: The reduction in essential fatty acids and increase in nonessential fatty acids in adipose tissue of those with LPL deficiency, taken together with recent data from animal studies, suggest that lipid stores in these subjects are maintained primarily through enhanced adipocyte lipogenesis.     

Serum fatty acids in postinfarction middle-aged men

There is a multitude of data showing that coronary heart disease is affected by the quality of dietary fat. The fatty acid composition of serum lipids has been shown to reflect that of the diet. It is likely that, after myocardial infarction, both the health-care professionals and the patients themselves pay more attention to dietary guidelines. In order to assess the correctness of this assumption, we compared the composition of serum fatty acids in 40 male subjects with a history of myocardial infarction (MI) with that of 40 age-matched controls, both from the FINRISK study. The percentage composition of fatty acids of total serum lipids was analysed by gas chromatography. In comparison with the control group, the MI group had higher body mass index (BMI), a higher prevalence of diabetes, higher level of serum triglycerides and a lower level of serum high-density lipoprotein (HDL) cholesterol, all indicators of the metabolic syndrome. The MI group had higher proportions of serum palmitic (16:0) and oleic acids (18:1), and a lower proportion of linoleic (18:2 n-6) acid than the control group. The metabolic syndrome is accompanied by an elevated level of serum insulin, which is known to enhance the synthesis of saturated and monounsaturated fatty acids, such as 16:0 and 18:1, and to stimulate the activity delta-6 desaturase, decreasing the concentration of linoleic acid. Our results suggest that the observed serum fatty acid composition in subjects with coronary heart disease is dependent on metabolic factors in addition to dietary fatty acid composition.     

C. elegans fat-1基因对SGC7901细胞的促凋亡作用

目的通过在人胃癌SGC7901细胞系上转入外源C.elegans fat-1基因观其对细胞增殖或对调亡的影响。方法构建携带有能够编码n-3多聚饱和脂肪酸脱氢酶的小秀丽隐杆线虫fat-1基因的重组质粒,转染人胃癌细胞SGC7901,检测n-6/n-3脂肪酸的比例,观察胃癌细胞的增殖和凋亡情况。结果转染成功后携带有fat-1基因的胃癌细胞,显示了对于n-3脂肪酸饱和酶的高表达。脂类分析表明,n-6PUFAs的比例大幅度降低,n-3PUFAs水平明显提高,n-6/n-3脂肪酸比例,从10.45下降到了0.79,尤其是花生四烯酸和二十碳戊烯酸的比率。相应地,在表达有fat-1基因的胃癌细胞中,来源于n-6PUFAs的类花生酸含量有显著减少。同时,fat-1基因的转移导致大量胃癌细胞的凋亡,抑制胃癌细胞的增殖。结论n-3脂肪酸去饱和酶的基因转移,能够有效调整人肿瘤细胞n-6/n-3脂肪酸的比例,起到抗癌作用,证明在癌症的预防和治疗中,n-6与n-3脂肪酸的比例扮演着一个重要的角色。     

Fatty acid composition of hepatic triglycerides in Reye's syndrome: implications for hepatic desaturase abnormalities.

Serum NEFA profiles in Reye's syndrome are reportedly unique with a disproportionate percent made up of polyunsaturated fatty acids some of which are not ordinarily found in the serum. This pattern is also reflected in the serum triglyceride composition as well. As the liver is probably the sole source of the serum triglyceride in Rye's syndrome because patients are vomiting or in coma, the fatty acid acid composition of the liver triglyceride was examined for insight regarding the lipid abnormalities in this disease. Palmitic acid (16:0) and the sum of all the saturated fatty acids in the liver triglycerides were significantly decreased whereas the sum of the monoenoic fatty acids and the products of delta 9 desaturase activity were increased in Reye's samples. When these data were compared to the fatty acid composition of the serum triglyceride from a separate cohort of Reye's and control subjects, certain inferences regarding hepatic delta 9, delta 6, delta 5, and delta 4 desaturase activities and the elongases can be drawn from the liver and serum triglyceride fatty acid profiles which are unique. Collectively, these data reflect considerable intrahepatic fatty acid desaturation and elongation activity and/or acyl transfer from lipid to lipid of various polyunsaturated fatty acids in Reye's syndrome.     

Chlorogenic acid from honeysuckle improves hepatic lipid dysregulation and modulates hepatic fatty acid composition in rats with chronic endotoxin infusion

Chlorogenic acid as a natural hydroxycinnamic acid has protective effect for liver. Endotoxin induced metabolic disorder, such as lipid dysregulation and hyperlipidemia. In this study, we investigated the effect of chlorogenic acid in rats with chronic endotoxin infusion. The Sprague-Dawley rats with lipid metabolic disorder (LD group) were intraperitoneally injected endotoxin. And the rats of chlorogenic acid-LD group were daily received chlorogenic acid by intragastric administration. In chlorogenic acid-LD group, the area of visceral adipocyte was decreased and liver injury was ameliorated, as compared to LD group. In chlorogenic acid-LD group, serum triglycerides, free fatty acids, hepatic triglycerides and cholesterol were decreased, the proportion of C20:1, C24:1 and C18:3n-6, Δ9-18 and Δ6-desaturase activity index in the liver were decreased, and the proportion of C18:3n-3 acid was increased, compared to the LD group. Moreover, levels of phosphorylated AMP-activated protein kinase, carnitine palmitoyltransferase-I, and fatty acid β-oxidation were increased in chlorogenic acid-LD group compared to LD rats, whereas levels of fatty acid synthase and acetyl-CoA carboxylase were decreased. These findings demonstrate that chlorogenic acid effectively improves hepatic lipid dysregulation in rats by regulating fatty acid metabolism enzymes, stimulating AMP-activated protein kinase activation, and modulating levels of hepatic fatty acids.     

Regulation of desaturase expression in HL60 cells

The expression of delta 5 desaturase (D5D), delta 6 desaturase (D6D) and delta 9 desaturase (D9D) was determined by RT-PCR in the human promyelocytic cell line HL60. During 72 h of culture with 10% FBS, D5D and D6D were upregulated 5 to 6-fold, whereas D9D approximately doubled. The addition of fatty acids (FAs) to the culture medium suppressed upregulation of all desaturases. N-3 and n-6 FA appeared to be more effective than n-9 or saturated FA. When FAs were added after 72 h, further upregulation during the next 24 h was suppressed for nearly all desaturases and FAs tested, except for D5D when oleic acid (OA) or stearic acid (SA) was added. In cells cultured with restricted amounts of FBS, desaturase expression increased with decreasing concentrations of FBS. Cellular FA content decreased by 60% in the neutral lipid fraction, whereas that of the phospholipid fraction decreased by 10% during 72 h of culture. The largest decrease occurred in the sum of n-3 and n-6 FA of the neutral lipid fraction, which was reduced by 83%, whereas the content of these FAs in the phospholipid fraction decreased by 32%. The results indicate that when the supply of FA to HL60 cells is limited, the intracellular content of n-3 and n-6 FA decreases and this leads to upregulation of the desaturases, particularly D5D and D6D. Since HL60 cells resemble human leukocytes, the results suggest that desaturase expression in leukocytes may be exploited as a biomarker for FA status.     

Effects of fish oil fatty acids on plasma lipids and lipoproteins and oxidant-antioxidant imbalance in healthy subjects

The purpose of this study was to investigate the effect of eicosapentaenoic and docosahexaenoic acids on plasma lipids and lipoproteins, lipid peroxidation and antioxidant status in healthy humans. A total of 19 healthy volunteers consumed 6 g/day Maxepa® fish oil for 3 weeks (1.8 g n-3 fatty acids/day). At baseline and at day 21, we evaluated plasma lipoproteins, plasma and low-density lipoprotein fatty acids, lipid peroxidation markers (malondialdehyde concentration, low-density lipoprotein peroxidation in vitro), and the content of a number of antioxidants (reduced and oxidized glutathione in whole blood, plasma and erythrocyte glutathione peroxidases, plasma vitamin E and beta carotene). Plasma concentrations of total cholesterol, triglycerides, phospholipids, low-density lipoprotein cholesterol and low-density lipoprotein size did not differ significantly after 3 weeks of supplementation. Adding the fish oil to the diet increased the concentration of n-3 very-long-chain polyunsaturated fatty acids and decreased the concentration of n-6 fatty acid and oleic acid in plasma and low-density lipoprotein. Eicosapentaenoic and docosahexaenoic acid supplementation caused elevated values of the high-density lipoprotein cholesterol due to an increment of the high-density lipoprotein 2 fraction and reduced low-density lipoprotein peroxidation rate in vitro. However, we observed an imbalance between oxidizable substrates and antioxidants with an increased lipid peroxidation, whereas the content of reduced glutathione and beta carotene decreased without any variation in vitamin E. Association of antioxidants with n-3 PUFA could prevent lipid peroxidation and enhance the antiatherogenic effects of n-3 polyunsaturated fatty acids.     

Effects of fish oil fatty acids on plasma lipids and lipoproteins and oxidant-antioxidant imbalance in healthy subjects.

The purpose of this study was to investigate the effect of eicosapentaenoic and docosahexaenoic acids on plasma lipids and lipoproteins, lipid peroxidation and antioxidant status in healthy humans. A total of 19 healthy volunteers consumed 6 g/day Maxepa fish oil for 3 weeks (1.8 g n-3 fatty acids/day). At baseline and at day 21, we evaluated plasma lipoproteins, plasma and low-density lipoprotein fatty acids, lipid peroxidation markers (malondialdehyde concentration, low-density lipoprotein peroxidation in vitro), and the content of a number of antioxidants (reduced and oxidized glutathione in whole blood, plasma and erythrocyte glutathione peroxidases, plasma vitamin E and beta carotene). Plasma concentrations of total cholesterol, triglycerides, phospholipids, low-density lipoprotein cholesterol and low-density lipoprotein size did not differ significantly after 3 weeks of supplementation. Adding the fish oil to the diet increased the concentration of n-3 very-long-chain polyunsaturated fatty acids and decreased the concentration of n-6 fatty acid and oleic acid in plasma and low-density lipoprotein. Eicosapentaenoic and docosahexaenoic acid supplementation caused elevated values of the high-density lipoprotein cholesterol due to an increment of the high-density lipoprotein 2 fraction and reduced low-density lipoprotein peroxidation rate in vitro. However, we observed an imbalance between oxidizable substrates and antioxidants with an increased lipid peroxidation, whereas the content of reduced glutathione and beta carotene decreased without any variation in vitamin E. Association of antioxidants with n-3 PUFA could prevent lipid peroxidation and enhance the antiatherogenic effects of n-3 polyunsaturated fatty acids.