Whole blood fatty acid analysis with micromethod in cystic fibrosis and pulmonary disease

ObjectivesTo assess fatty acid (FA) profiles in whole blood of 90 cystic fibrosis patients (CF) and 30 control subjects (C) and to correlate FA changes to the severity of respiratory disease.MethodsWhole blood FA were assessed by GC with a micromethod-based analysis.ResultsSaturated and monounsaturated FA are higher, whereas polyunsaturated FA are lower in CF versus C with reduction of total n-6 FA, 22:5n-3 and 22:6n-3 (DHA). The product of linoleic acid (LA) × DHA, proposed as a marker for the disease, is 30% lower in CF than in C. Correlations with the severity of the respiratory disease are present for different FA and for the LA × DHA product. There is a reduction of Δ5 desaturase activity in CF, greater in severe disease, suggesting a basic metabolic alteration.ConclusionsThe micromethod-based analysis of blood FA facilitates the assessment of the FA status while confirming alterations of FA profiles already reported in specific blood compartments of CF.     

Fatty acids in blood and intestine following docosahexaenoic acid supplementation in adults with cystic fibrosis.

The objective of this study was to investigate the effect of docosahexaenoic acid (DHA) supplementation on blood and intestinal DHA levels and lung function in mild/moderately affected adult CF patients with the DeltaF508 genotype. BACKGROUND: Cystic Fibrosis (CF) patients often present with plasma fatty acid levels indicating low levels of linoleic (18:2n-6) and docosahexaenoic (22:6n-3) acids and an increased level of arachidonic acid (20:4n-6). Improved dietary fat intake or reducing fat malabsorption with pancreatic enzymes has failed to normalize this biochemical deficiency of DHA. METHODS: Five CF patients, aged 18-43, received 70 mg of DHA/kg body weight/d for six weeks. At baseline and at six weeks a physical exam, lung function, 3-day dietary intake, duodenal mucosal biopsy and blood sample were assessed. The blood was analyzed for plasma vitamin A, D and E levels, liver function tests, clinical chemistry (CBC, differential and electrolytes). Plasma and red blood cell fatty acid levels were also analyzed. At three weeks, assessment included a physical exam, lung function test and fasting blood sample (vitamin levels, liver function and clinical chemistry only). RESULTS: Pre- and post-measurements were compared for the four subjects who completed the study. An increase in DHA content (% w/w) was observed in all phospholipid fractions of plasma, red blood cell and mucosal samples. No significant differences in vitamin levels, liver function or lung function were observed. CONCLUSIONS: The study proves the concept that an increase in tissue DHA levels in CF patients can be achieved by supplementing for six weeks with 70 mg/kg/d DHA.     

Effects of N-3 PUFAs supplementation on insulin resistance and inflammatory biomarkers in hemodialysis patients

AIMS/HYPOTHESIS: It was suggested that polyunsaturated n-3 fatty acids (n-3 PUFAs) could improve insulin sensitivity and have an anti-inflammatory effects in overall population. This study investigates a possible effect of n-3 PUFAs supplementation on the insulin sensitivity and some inflammatory markers; hence, patients with chronic renal failure (CRF) on maintenance hemodialysis (MHD) are presented with insulin resistance. METHODS: This study explored the ratio between red blood cells (RBC) phospholipid long chain fatty acids (LC FAs) and components of metabolic syndrome (MeS) in 35 patients (mean age 54.50 +/- 11.99 years) with CRF on MHD. Furthermore, the effects of omega-3 FA eight-week's supplementation (EPA+DHA, 2.4 g/d) on the MeS features and inflammatory markers TNF-alpha, IL 6, and hsCRP were examined. RESULTS: Supplementation increased EPA and DHA levels in RBCs (p = 0.009 for EPA and p = 0.002 for DHA). Total n-6 PUFAs: n-3 PUFAs ratio tended to be lower after supplementation (p = 0.31), but not significantly. Data revealed a significant decrease of saturated FAs (SFA) (p = 0.01) as well as total SFA: n-3 PUFAs ratio during the treatment (p = 0.04). The values of serum insulin and calculated IR index-IR HOMA were reduced after supplementation (p = 0.001 for both). There was a significant decrease in the levels of all inflammatory markers (p = 0.01 for TNF alpha, p = 0.001 for IL 6, p = 0.001 for hsCRP, and p = 0.01 for ferritin). In multivariate regression analysis, only the changes in n-6 PUFAs: n-3 PUFAs ratio independently contributed to 40% of the variance in IR HOMA. The impact of changes in PUFAs level in RBCs membrane phospholipid fatty acids on inflammation markers was also registered. The changes in n-6: n-3 PUFAs ratio independently contributed to 18% of the variance in TNF alpha. CONCLUSION: It was concluded that the EPA and DHA moderate dose administration in the patients with CRF on MHD had a beneficial effect on insulin resistance decrease. The anti-inflammatory effects of the supplemented PUFAs were also presented.     

The role of fish oil/omega-3 fatty acids in the treatment of IgA nephropathy

Beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFA) have been reported in recent epidemiologic studies and randomized clinical trials in a variety of cardiovascular and autoimmune diseases. Fish and marine oils are the most abundant and convenient sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the two major n-3 fatty acids that serve as substrates for cyclooxygenase and lipoxygenase pathways leading to less potent inflammatory mediators than those produced through the n-6 PUFA substrate, arachidonic acid. N-3 PUFA can also suppress inflammatory and/or immunologic responses through eicosanoid-independent mechanisms. Although the pathophysiology of IgA nephropathy is incompletely understood, it is likely that n-3 PUFA prevents renal disease progression by interfering with a number of effector pathways triggered by mesangial immune-complex deposition. In addition, potential targets of n-3 PUFA relevant to renal disease progression could be similar to those involved in preventing the development and progression of cardiovascular disease by lowering blood pressure, reducing serum lipid levels, decreasing vascular resistance, or preventing thrombosis. In IgA nephropathy, efficacy of n-3 PUFA contained in fish oil supplements has been tested with varying results. The largest randomized clinical trial performed by our collaborative group provided strong evidence that treatment for 2 years with a daily dose of 1.8 g of EPA and 1.2 g of DHA slowed the progression of renal disease in high-risk patients. These benefits persisted after 6.4 years of follow up. With safety, composition, and dosing convenience in mind, we can recommend two products that are available as pharmaceutical-grade fish-oil concentrates, Omacor (Pronova Biocare, Oslo, Norway) and Coromega (European Reference Botanical Laboratories, Carlsbad, CA).     

Combined effect of DHA and α-tocopherol supplementation during bull semen cryopreservation on sperm characteristics and fatty acid composition

The aim of this study was to investigate the effect of adding n-3 fatty acids (FA) and α-tocopherol (VE) to semen extender on freezing ability and FA composition of bull sperm. Semen was collected from 10 Iranian Holstein bulls and was pooled. In the first experiment, semen was divided into 12 groups including 4 levels of n-3 FA (0, 0.1, 1, 10 ng ml(-1) ) and 3 levels of VE (0, 0.1, 0.2 mmol). The treatment of 0.2 mmol VE and 10 ng ml(-1) n-3 FA had the best post-thawed sperm characteristics (P < 0.01). In the second experiment, lipid composition of the latest treatment and control (without FA and VE) was determined. Adding n-3 FA increased docosahexaenoic acid (DHA) percentage before freezing and after thawing. The ratio of n-3 to n-6 before freezing was higher (P < 0.05) in treated group than in control, and this ratio in the fresh sperm was greater than in the post-thawed sperm (P = 0.1). Results suggested that adding DHA accompanied with an antioxidant to an extender could improve cryosurvival of bull sperm via altering membrane lipid composition.     

Effects of N-3 PUFAs Supplementation on Insulin Resistance and Inflammatory Biomarkers in Hemodialysis Patients

Aims/Hypothesis. It was suggested that polyunsaturated n-3 fatty acids (n-3 PUFAs) could improve insulin sensitivity and have an anti-inflammatory effects in overall population. This study investigates a possible effect of n-3 PUFAs supplementation on the insulin sensitivity and some inflammatory markers; hence, patients with chronic renal failure (CRF) on maintenance hemodialysis (MHD) are presented with insulin resistance. Methods. This study explored the ratio between red blood cells (RBC) phospholipid long chain fatty acids (LC FAs) and components of metabolic syndrome (MeS) in 35 patients (mean age 54.50 ± 11.99 years) with CRF on MHD. Furthermore, the effects of omega-3 FA eight-week's supplementation (EPA+DHA, 2.4g/d) on the MeS features and inflammatory markers TNF-alpha, IL 6, and hsCRP were examined. Results. Supplementation increased EPA and DHA levels in RBCs (p = 0.009 for EPA and p = 0.002 for DHA). Total n-6 PUFAs: n-3 PUFAs ratio tended to be lower after supplementation (p = 0.31), but not significantly. Data revealed a significant decrease of saturated FAs (SFA) (p = 0.01) as well as total SFA: n-3 PUFAs ratio during the treatment (p = 0.04). The values of serum insulin and calculated IR index-IR HOMA were reduced after supplementation (p = 0.001 for both). There was a significant decrease in the levels of all inflammatory markers (p = 0.01 for TNF alpha, p = 0.001 for IL 6, p = 0.001 for hsCRP, and p = 0.01 for ferritin). In multivariate regression analysis, only the changes in n-6 PUFAs: n-3 PUFAs ratio independently contributed to 40% of the variance in IR HOMA. The impact of changes in PUFAs level in RBCs membrane phospholipid fatty acids on inflammation markers was also registered. The changes in n-6: n-3 PUFAs ratio independently contributed to 18% of the variance in TNF alpha. Conclusion. It was concluded that the EPA and DHA moderate dose administration in the patients with CRF on MHD had a beneficial effect on insulin resistance decrease. The anti-inflammatory effects of the supplemented PUFAs were also presented.     

Plasma and erythrocyte phospholipid fatty acids composition in Serbian hemodialyzed patients

Dyslipidemia is one of the possible risk factors for advanced atherosclerosis in patients with chronic renal failure. Abnormal phospholipid metabolism may play an important role in the progression of atherosclerosis in patients with renal failure. The aim of this study was to determine specific characteristics of plasma and erythrocyte phospholipid content and fatty acid composition in 37 patients with chronic renal failure on hemodialysis (HD). The results were compared with the characteristics of healthy subjects. Briefly, plasma triglyceride (p < 0.001), total cholesterol (p < 0.05), and total phospholipids (p < 0.01) levels were significantly higher and HDL-cholesterol level significantly lower (p < 0.01) in HD patients. Plasma phosphatidylcholine and phosphatidylethanolamine concentration were significantly higher (p < 0.001) in HD patients. The plasma phospholipid fatty acids composition indicated significantly (p < 0.01) higher level of oleic (18:1 n-9) and lower levels of eicopentaenoic (20:5 n-3 EPA) and docosahexaenoic (22:6 n-3 DHA) acids (p < 0.05). However, in HD patients, the relative concentration of plasma phospholipid n-6 polyunsaturated fatty acid (PUFA) was significantly lower (p < 0.05). The fatty acid composition of erythrocyte phospholipid in HD patients was modified with EPA and DHA levels significantly lowered (p < 0.05). Our results demonstrate an abnormal phospholipid metabolism and deficiency of n-3 PUFA in plasma and erythrocyte phospholipids in hemodialyzed patients.     

Role of polyunsaturated fatty acids in the inhibitory effect of human adipocytes on osteoblastic proliferation

As previously reported, the association of bone loss with an increase in bone marrow adipose volume may be related to the inhibition of human osteoblastic cell proliferation in the presence of human adipocytes. In the osteoblastic supernatant, fatty acid composition varied after coculture with mature adipocytes, with a marked increase in the proportion of docosahexaenoic acid (22:6 n-3; DHA) (+90 +/- 8%). This suggests that polyunsaturated fatty acids (PUFA) may contribute to the inhibitory effect of adipocytes on osteoblastic cell proliferation. The purpose of the present study was to evaluate the effects of two PUFA, DHA and arachidonic acid (20:4 n-6; AA), on the proliferation of primary human osteoblastic (hOB) cells and human osteosarcoma cell line, MG-63. The effects of cholesterol and oleic acid, a monounsaturated FA (18:1 n-9; OA), both being present in adipocyte lipidic vacuoles, were also investigated. At between 10 and 50 micromol/L, DHA and AA induced a significant dose-dependent decrease in hOB cell proliferation (p < 0.0001 and p < 0.006 for DHA and AA, respectively) when compared with control hOB cells exposed to the vehicle (bovine serum albumin). This inhibition reached -50% with 50 micromol/L of DHA or 20 micromol/L of AA. This effect was not related to cell apoptosis, as shown by terminal deoxynucleotidyltransferase-mediated dUTP-fluorescein nick end labeling (TUNEL) and Hoechst dye staining. In contrast, OA and cholesterol had no effect on hOB cell proliferation, even at a high concentration (200 micromol/L). Similar results were observed with regard to MG-63 cell proliferation. In addition, flow cytometric analysis showed that the number of hOB cells in the S phase of the cycle was twofold lower when treated with 50 micromol/L of DHA or AA. In vitro results indicate that mature adipocytes may contribute to age-related bone loss through the release of polyunsaturated fatty acids, which impair osteoblastic proliferation.     

Continual supplementation with n-3 fatty acids does not modify plasma lipid profile in spinal cord injury patients

STUDY DESIGN: A prospective study during a diet modification. OBJECTIVE: To observe the evolution of the plasma lipid profile in a group of spinal cord injury (SCI) patients given a supplement of a mixture of docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA). SETTING: Department of Physiological Sciences II, Medical School of the University of Barcelona and Guttmann Institut of Badalona, Barcelona, Spain. METHODS: A total of 19 adult males with SCI, 17 with paraplegia and two with tetraplegia, were given a daily supplement of 1.5 g of DHA and 0.75 g of EPA for 6 months. Determination of plasma values of DHA, EPA, total cholesterol, HDL-c, LDL-c, VLDL-c, triglycerides, and glucose was performed before supplementation and at 3 and 6 months of supplementation. RESULTS: A statistically significant increase in the plasma concentration of EPA (F=30.556, P<0.05) and DHA (F=106.6, P<0.05) was observed after 3 and 6 months of supplementation. However, there were no observable differences in the plasma concentration of total-cholesterol, HDL-c, LDL-c, VLDL-c, and triglycerides during the study. CONCLUSION: DHA-EPA supplementation for 6 months does not modify the glycemic and lipid plasmatic levels in SCI patients. Despite its absence of effect on the serum lipid profile, n-3 fatty acids may induce beneficial cardiovascular effects in this population.     

G2/M cell-cycle arrest and apoptosis by n-3 fatty acids in a pancreatic cancer model

BACKGROUND: n-3 fatty acids (n-3FA) have anti-inflammatory and anti-proliferative effects including modulation of pro-inflammatory cascade mediators and cytokine elaboration (i.e., TNF-alpha, IL-10 and PGE(2)) in many cell lines. However, mechanisms of anti-proliferative effects have not been clearly defined. MATERIALS AND METHODS: MIA PaCa-2 pancreatic cancer cells were treated either with n-3FA (treatment), media (control), or n-6FA (control) for all experiments. Cellular proliferation was evaluated with WST-1 reagent. Cells were stained with propidium iodide and analyzed by flow cytometry for cell-cycle arrest, which was further analyzed by cdc2 expression. Membrane and media lipid concentrations were analyzed by high-performance liquid chromatography. Apoptosis was evaluated by AnnexinV-FITC flow cytometry and reconfirmed by poly (ADP-ribose) polymerase (PARP) cleavage and B(cl)-2 expression. RESULTS: Propidium iodide flow cytometry of MIA PaCa-2 dosed with n-3FA showed a decrease in cells in G1 phase (11-17%) and an increase cells in G2 phase (7-13%) from controls. cdc2 expression was also decreased at 24 h compared to controls. Annexin-V staining of n-3FA-treated cells demonstrated time-dependent increased apoptosis and PARP cleavage was present only in the n-3FA treatment group. Phospho-B(cl)-2 was also decreased in the n-3FA-treated cells compared to controls. CONCLUSIONS: Co-incubation of MIA PaCa-2 cells with n-3FA results in both dose- and time-dependent cell-cycle arrest. Cells also progress to cell death via apoptosis. These data support the potential applicability for n-3FA as an antiproliferative and pro-apoptotic strategy.     

Oral fish oil supplementation raises blood omega-3 levels and lowers C-reactive protein in haemodialysis patients--a pilot study.

BACKGROUND: We previously reported that haemodialysis patients have suboptimal blood levels of the cardioprotective omega-3 polyunsaturated fatty acids (n-3 PUFA) eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. In the present pilot study, we tested the hypothesis that supplementing haemodialysis patients for 12 weeks with the American Heart Association (AHA)-recommended fish oil dose would be well tolerated and efficacious in boosting blood n-3 PUFA levels and improving cardiovascular risk biomarkers. METHODS: Twenty-seven subjects were randomized in a 2 : 1 ratio to either 1.3 g of EPA + DHA daily or placebo. RESULTS: At baseline, 83% of subjects consumed inadequate dietary fish and had the following erythrocyte n-3 PUFA levels (mean +/- SD,% weight)-EPA: 0.3 +/- 0.2, DHA: 2.9 +/- 2.0, and ratio of n-6/n-3 PUFA: 4.2 +/- 1.3. Supplementation induced large increases in mean blood EPA and DHA levels (% increase, P-value vs placebo group): erythrocyte-EPA: +400%, P = 0.0018, DHA: +205%, P < 0.0001; plasma-EPA: +275%, P = 0.0003, DHA: +69%, P = 0.0352. Levels in the placebo group remained relatively unchanged. The omega-3 index, a value correlating with the level of cardioprotection, increased significantly in the fish oil group. A reduction in mean C-reactive protein levels (-3.3 +/- 8.1 mg/l, P = 0.0282) and a trend towards lower triglyceride levels (-24 +/- 74 mg/dl, P = 0.0783) were also observed in the active vs placebo group. Minimal side effects were noted. CONCLUSIONS: Our preliminary observations that the AHA-recommended fish oil dose is well tolerated, efficacious and may improve surrogate markers of cardiovascular disease in haemodialysis patients paves the way for larger clinical trials to confirm a clinical benefit.     

Inhibition of Proliferation by Omega-3 Fatty Acids in Chemoresistant Pancreatic Cancer Cells

Background Pancreatic cancer-gemcitabine (GEM) chemoresistance has been demonstrated to be associated with enhanced NF-kB activation and antiapoptotic protein synthesis. The well-known capacity of omega-3 fatty acids (n-3 FAs) to inhibit NF-kB activation and promote cellular apoptosis has the potential to restore or facilitate gemcitabine chemosensitivity. Methods Four pancreatic cancer cell lines (MIA PaCa-2, BxPC-3, PANC-1, and L3.6), each with distinct basal NF-kB and differing GEM sensitivity profiles, were administered: 100 uM of (1) n-3FA, (2) n-6FA, (3) GEM, (4) n-3FA + GEM, or (5) n-6FA + GEM for 24 and 48 hours. Proliferation was assessed using the WST-1 assay. To define the mechanism(s) of altered proliferation, electron mobility shift assay for NF-kB activity, western blots of phoshoStat3, phosphoIκB, and poly(ADP-ribose) polymerase (PARP) cleavage were performed in the MIA PaCa-2 cell line. Results All cell lines demonstrated a time/dose-dependent inhibition of proliferation in response to n-3FA. For MIA PaCa-2 cells, n-3FA and n-3FA + GEM treatment resulted in reduction of I-kB phosphorylation and NF-kB activation when compared with n-6FA control. n-3FA and combination treatment also significantly decreased Stat3 phosphorylation, whereas GEM alone had no effect. n-3FAs and n-3FA + GEM groups demonstrated increased PARP cleavage, mirroring NF-kB activity and Stat3 phosphorylation. Conclusions n-3 FA treatment is specifically associated with inhibition of proliferation in these four pancreatic cell lines irrespective of varied gemcitabine resistance. An experimental paradigm to screen for potential contributory mechanism(s) in altered pancreatic cancer cellular proliferation was defined, and using this approach the co-administration of n-3 FA with GEM inhibited GEM-induced NF-kB activation and restored apoptosis in the MIA PaCa-2 cell-line. Supported by: NIDDK K08 DK DK60778 (Espat)     

n-3多不饱和脂肪酸对人结肠癌细胞增殖与凋亡的影响

目的探讨n-3多不饱和脂肪酸（n-3PUFA）对人结肠癌细胞HT．29的作用及其机制。方法应用MTT比色法、细胞的形态学观察（Hochest33258染色）、DNA凝胶电泳、流式细胞技术检测二十二碳六烯酸（DHA）对HT．29增殖和凋亡的影响：气相色谱分析的方法检测DHA对HT-29细胞n-3PUFA和n．6PUFA含量及n-6／n-3PUFA比例的影响。结果DHA在体外对HT．29有明显的增殖抑制作用,10、20、40和80mg儿DHA作用24h时的细胞增殖抑制率分别为16．8％、24．7％、50．0％和60．1％。40mg／LDHA作用24、48和72h的细胞增殖抑制率分别为50．0％、69．9％和77．0％：呈现明显的剂量和时间效应关系。荧光染色可观察到细胞核染色质浓集,核浓缩核碎裂．并出现典型的凋亡小体：DNA凝胶电泳呈现特征性的梯形条带（DNALadder）：流式细胞仪检测显示经DHA处理后HT-29DNA合成前期（G,期）细胞比例较对照组增加（72．1％比51．3％）,DNA合成期（S期）细胞比例明显减少（19．9％比38．9％）,细胞呈现明显的G,期阻滞;气相色谱分析显示．DHA可以降低HT-29细胞内n-6PUFA而提高n-3PUFA含量,降低n-6／n-3PUFA比率。结论n-3PUFA通过抑制细胞增殖和诱导细胞凋亡来阻遏结肠癌细胞的生长．这种作用的机制可能为降低了细胞的n-6／n-3PUFA的比例。     

Lipid mediated modification of rat heart allograft survival

The effect on allograft survival of intravenous fat emulsions that differed in the ratio of functionally important n-3 and n-6 fatty acids was studied in a heterotopic cardiac transplant model in rats. Twenty percent fat emulsions were administered by continuous infusion at a dosage of 9 g fat/kg body weight per day, starting immediately after transplantation and continuing until complete rejection. The n-6 and n-3 fatty acids represent 75%, 43%, 60%, and 59% of all fatty acids in safflower oil, fish oil, soybean oil, and a 1:1 mixture of safflower and fish oil, respectively. The n-6 fatty acids predominate in safflower oil (370/1) and soybean oil (6.5/1), while the n-3 fatty acids dominate in the fish oil (7.6/1). The 1:1 mixture of safflower and fish oil has the balanced composition (n-6/n-3=2.1/1) recommended by Kinsella and served as oil-treated controls. Continuous infusion of safflower oil, fish oil, and soybean oil prolonged graft survival time to 13.3, 12.3, and 10.4 days, respectively, compared to 6.8 days in the oil-treated controls (P<0.01 for all comparisons). Another control group infused with saline rejected the allografts after 7.8 days (P=NS compared to oil-treated controls; P<0.01 for all other comparisons). The data suggest that intravenous administration of polyunsaturated fat emulsions results in an immunosuppressive effect that seems to be dependent on the n-3/n-6 fatty acid ratio of the fat emulsion. The n-6 fatty acids turned out to be just as immunosuppressive as the n-3 fatty acids if each fatty acid family was applied as the main polyunsaturated fatty acid source. Soybean oil with a n-3/n-6 fatty acid ratio, coming closer to the ratio of the oil-treated controls, was significantly less immunosuppressive than safflower oil.     

Prostate tissue and leukocyte levels of n-3 polyunsaturated fatty acids in men with benign prostate hyperplasia or prostate cancer

OBJECTIVE: To compare the levels of n-3 polyunsaturated fatty acids (PUFAs) in leukocytes and prostate tissue in men with prostate cancer or benign prostatic hyperplasia (BPH), as dietary intake of n-3 PUFAs has been linked to the risk of prostate cancer; the prostate-specific antigen (PSA) level was also compared to prostate tissue levels of n-3 PUFAs. PATIENTS AND METHODS: Prostate tissue was obtained and leukocytes isolated from 20 men with prostate cancer and 35 with BPH. The n-3 PUFAs alpha-linolenic acid (ALA), eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA) were measured in prostate tissue and in peripheral blood leukocytes using gas chromatography. PSA levels were measured in all of the men. RESULTS: There was a strong positive correlation between EPA and DHA in leukocytes and in prostate tissue (EPA: r = 0.80, DHA: r = 0.53, both P < 0.001) in all the men, whereas there was no association between the content of ALA in leukocytes and in prostate tissue (r = -0.15). Men with BPH had similar levels of ALA in leukocytes and in prostate tissue, but men with prostate cancer had more ALA in prostate tissue than in leukocytes. The PSA level was significantly positively correlated with ALA level in prostate tissue (r = 0.42, P < 0.01) but there was no significant correlation between PSA level and EPA and DHA levels. There were no significant correlations between PSA level and n-3 PUFA levels in leukocytes. CONCLUSION: Dietary intake of the marine n-3 PUFAs reflected in EPA and DHA levels in leukocytes are also reflected in EPA and DHA levels in prostate tissue in men with and without prostate cancer. However, there is a discrepancy between the levels of ALA in leukocytes and in prostate tissue, with higher levels in men with prostate cancer. This is in accordance with the strong positive association between PSA and ALA levels in prostate tissue. This study therefore does not support the hypothesis that intake of marine n-3 PUFAs might protect against prostate cancer, but lends support to the deleterious role of ALA in the development of prostate cancer.     

Plasma and Erythrocyte Phospholipid Fatty Acids Composition in Serbian Hemodialyzed Patients

Dyslipidemia is one of the possible risk factors for advanced atherosclerosis in patients with chronic renal failure. Abnormal phospholipid metabolism may play an important role in the progression of atherosclerosis in patients with renal failure. The aim of this study was to determine specific characteristics of plasma and erythrocyte phospholipid content and fatty acid composition in 37 patients with chronic renal failure on hemodialysis (HD). The results were compared with the characteristics of healthy subjects. Briefly, plasma triglyceride (p < 0.001), total cholesterol (p < 0.05), and total phospholipids (p < 0.01) levels were significantly higher and HDL-cholesterol level significantly lower (p < 0.01) in HD patients. Plasma phosphatidylcholine and phosphatidylethanolamine concentration were significantly higher (p < 0.001) in HD patients. The plasma phospholipid fatty acids composition indicated significantly (p < 0.01) higher level of oleic (18:1 n-9) and lower levels of eicopentaenoic (20:5 n-3 EPA) and docosahexaenoic (22:6 n-3 DHA) acids (p < 0.05). However, in HD patients, the relative concentration of plasma phospholipid n-6 polyunsaturated fatty acid (PUFA) was significantly lower (p < 0.05). The fatty acid composition of erythrocyte phospholipid in HD patients was modified with EPA and DHA levels significantly lowered (p < 0.05). Our results demonstrate an abnormal phospholipid metabolism and deficiency of n‐3 PUFA in plasma and erythrocyte phospholipids in hemodialyzed patients.     

Dietary n-3 fatty acids decrease osteoclastogenesis and loss of bone mass in ovariectomized mice.

The mechanisms of action of dietary fish oil (FO) on osteoporosis are not fully understood. This study showed FO decreased bone loss in ovariectomized mice because of inhibition of osteoclastogenesis. This finding supports a beneficial effect of FO on the attenuation of osteoporosis. INTRODUCTION: Consumption of fish or n-3 fatty acids protects against cardiovascular and autoimmune disorders. Beneficial effects on bone mineral density have also been reported in rats and humans, but the precise mechanisms involved have not been described. METHODS: Sham and ovariectomized (OVX) mice were fed diets containing either 5% corn oil (CO) or 5% fish oil (FO). Bone mineral density was analyzed by DXA. The serum lipid profile was analyzed by gas chromatography. Receptor activator of NF-kappaB ligand (RANKL) expression and cytokine production in activated T-cells were analyzed by flow cytometry and ELISA, respectively. Osteoclasts were generated by culturing bone marrow (BM) cells with 1,25(OH)2D3. NF-kappaB activation in BM macrophages was measured by an electrophoretic mobility shift assay. RESULTS AND CONCLUSION: Plasma lipid C16:1n6, C20:5n3, and C22:6n3 were significantly increased and C20:4n6 and C18:2n6 decreased in FO-fed mice. Significantly increased bone mineral density loss (20% in distal left femur and 22.6% in lumbar vertebrae) was observed in OVX mice fed CO, whereas FO-fed mice showed only 10% and no change, respectively. Bone mineral density loss was correlated with increased RANKL expression in activated CD4+ T-cells from CO-fed OVX mice, but there was no change in FO-fed mice. Selected n-3 fatty acids (docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) added in vitro caused a significant decrease in TRACP activity and TRACP+ multinuclear cell formation from BM cells compared with selected n-6 fatty acids (linoleic acid [LA] and arachidonic acid [AA]). DHA and EPA also inhibited BM macrophage NF-kappaB activation induced by RANKL in vitro. TNF-alpha, interleukin (IL)-2, and interferon (IFN)-gamma concentrations from both sham and OVX FO-fed mice were decreased in the culture medium of splenocytes, and interleukin-6 was decreased in sham-operated FO-fed mice. In conclusion, inhibition of osteoclast generation and activation may be one of the mechanisms by which dietary n-3 fatty acids reduce bone loss in OVX mice.     

Effects of soybean oil emulsion and eicosapentaenoic acid on stress response and immune function after a severely stressful operation

OBJECTIVE: To investigate the effects of soybean oil emulsion and oral or enteral administration of eicosapentaenoic acid (EPA) on stress response, cytokine production, protein metabolism, and immune function after surgery for esophageal cancer. SUMMARY BACKGROUND DATA: It has been reported that safflower oil, rich in n-6 polyunsaturated fatty acid (n-6 PUFA), affects the survival rate of septic animals and decreases the immune function. It has also been reported that the administration of fish oil, in contrast, reduces these stress responses and stress-induced immunosuppression. In humans, the effects of soybean oil emulsion and the administration of EPA on stress response and immune function after surgery have not been established. METHODS: Patients who underwent esophagectomy with thoracotomy were divided into three groups. Seven patients were fed by total parenteral nutrition (TPN) with soybean oil emulsion, which accounted for 20% of total calories. Seven patients were given oral or enteral administration of 1.8 g/day EPA, in addition to TPN with soybean oil emulsion. Nine patients served as the control group; these patients received fat-free TPN. Serum interleukin-6 (IL-6), C-reactive protein, concanavalin A (con A)- or phytohemagglutinin (PHA)-stimulated lymphocyte proliferation, natural killer cell activity, and stress hormones were measured. RESULTS: The postoperative level of serum IL-6 was significantly higher in the group receiving soybean oil emulsion than in the fat-free group. Oral or enteral supplementation of EPA with soybean oil emulsion significantly reduced the level of serum IL-6 compared with the patients receiving soybean oil emulsion. Con A- or PHA-stimulated lymphocyte proliferation decreased significantly on postoperative day 7 in all groups of patients. The supplementation of EPA with soybean oil emulsion significantly improved the lymphocyte proliferation and natural killer cell activity on postoperative day 21 compared with the group receiving soybean oil emulsion. CONCLUSIONS: Soybean oil emulsion amplifies, and the supplementation of EPA reduces, the stress response and stress-induced immunosuppression.     

Marine n-3 PUFA protects hearts from I/R injury via restoration of mitochondrial function

Abstract

Objectives. Overwhelming evidence shows that dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) elicits protective effects on patients with cardiovascular disease. However, the detailed mechanisms underlying n-3 PUFA-mediated cardioprotection are unknown, and examined in the present study. Methods: We evaluated heart performances with Langendorff perfusion apparatus. Meanwhile, whole mitochondria were purified from non-perfused hearts for functional assessment, and lipid peroxidation level was measured as well. Results. Compared with control groups, hearts from n-3 PUFA-supplemented rats showed improved functional recovery and reduced tissue injury following ischemia/reperfusion (I/R). Furthermore, the mitochondrial function of PUFA-treated hearts was significantly enhanced, as demonstrated by biochemical analysis of respiratory chain activity. In addition, thiobarbituric acid-reactive substance or TBARS assay revealed that lipid peroxidation product, malondialdehyde or MDA, in the mitochondria was significantly reduced by PUFA treatment. Conclusion. Taken together, our data indicate that marine n-3 PUFA could improve cardiac performance after I/R injury by restoring mitochondrial respiratory activities and attenuating lipid peroxidation.