Maternal plasma VEGF, sVEGF-R1, and PlGF concentrations in preeclamptic and normotensive pregnant Zimbabwean women

Vascular endothelial growth factor (VEGF), a disulphide-linked homodimeric glycoprotein that is selectively mitogenic for endothelial cells, plays an important role in vasculogenesis and angiogenesis. Preeclampsia, a relatively common complication of pregnancy that is characterized by diffuse endothelial dysfunction possibly secondary to impaired trophoblast invasion of the spiral arteries during implantation, has recently been associated with alterations in maternal serum/plasma concentrations of VEGF, and other related growth factors and their receptors. We examined the relationship of maternal plasma VEGF, sVEGF-R1 and PlGF levels to the risk of preeclampsia among women delivering at Harare Maternity Hospital, Zimbabwe. 131 pregnant women with preeclampsia and 175 controls were included in a case-control study. Maternal plasma concentrations of each biomarker were measured using enzymatic methods. We used logistic regression to calculate odds ratios (OR) and 95 % confidence intervals (CI). Preeclampsia risk was inversely related with quartiles of plasma VEGF (OR: 1.0, 1.0, 0.7, and 0.5, with the lowest quartile as reference; p for trend=0.06). We noted a strong positive association between preeclampsia risk and sVEGF-R1 concentrations (OR: 1.0, 6.5, 9.7, 31.6, with the first quartile as the referent group; p for trend<0.001). After adjusting for confounders, we noted that women with sVEGF-R1 concentrations in the highest quartile (>or=496 pg/ml), as compared with those in the lowest quartile (<62 pg/ml) had a 31.6-fold increased risk of preeclampsia (OR=31.6, 95 % CI 7.7-128.9). There was no clear evidence of a linear relation in risk of preeclampsia with PlGF concentrations. In conclusion, plasma VEGF, sVEGF-R1 and PlGF concentrations (measured at delivery) were altered among Zimbabwean women with preeclampsia as compared with normotensive women. Our results are consistent with some, though not all, previous reports. Prospective studies are needed to: 1) identify modifiable determinants of maternal plasma concentrations VEGF, sVEGF-R1, and PlGF; and 2) evaluate the temporal relationship between observed alterations of these biological markers in preeclamptic pregnancies.     

The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases

Several sources of information suggest that human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids (EFA) of approximately 1 whereas in Western diets the ratio is 15/1-16.7/1. Western diets are deficient in omega-3 fatty acids, and have excessive amounts of omega-6 fatty acids compared with the diet on which human beings evolved and their genetic patterns were established. Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today's Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio), exert suppressive effects. In the secondary prevention of cardiovascular disease, a ratio of 4/1 was associated with a 70% decrease in total mortality. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. A ratio of 2-3/1 suppressed inflammation in patients with rheumatoid arthritis, and a ratio of 5/1 had a beneficial effect on patients with asthma, whereas a ratio of 10/1 had adverse consequences. These studies indicate that the optimal ratio may vary with the disease under consideration. This is consistent with the fact that chronic diseases are multigenic and multifactorial. Therefore, it is quite possible that the therapeutic dose of omega-3 fatty acids will depend on the degree of severity of disease resulting from the genetic predisposition. A lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies, as well as in the developing countries.     

Leukocyte selenium, zinc, and copper concentrations in preeclamptic and normotensive pregnant women

Preeclampsia is an important cause of maternal and perinatal mortality worldwide. The etiology of this relatively common medical complication of pregnancy, however, remains unknown. We studied the relationship between maternal leukocyte selenium, zinc, and copper concentrations and the risk of preeclampsia in a large hospital-based case-control study. One hundred seventy-one women with proteinuric pregnancy-induced hypertension (with or without seizures) comprised the case group. Controls were 184 normotensive pregnant women. Leukocytes were separated from blood samples collected during the patients’ postpartum labor and delivery admission. Leukocyte concentrations for the three cations were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Concentrations for each cation were reported as micrograms per gram of total protein. Women with preeclampsia had significantly higher median leukocyte selenium concentrations than normotensive controls (3.23 vs 2.80 μg/g total protein, p<0.0001). Median leukocyte zinc concentrations were 31% higher in preeclamptics as compared with controls (179.15 vs 136.44 μg/g total protein, p<0.0001). Although median leukocyte copper concentrations were slightly higher for cases than controls, this difference did not reach statistical significance (17.72 vs 17.00 μg/g total protein, p=0.468). There was evidence of a linear increase in risk of preeclampsia with increasing concentrations of selenium and zinc. The relative risk for preeclampsia was 3.38 (adjusted odds ratio [OR]=3.38, 95% confidence interval [CI]=1.53–7.54) among women in the highest quartile of the control selenium distribution compared with women in the lowest quartile. The corresponding relative risk and 95% CI for preeclampsia was 5.30 (2.45–11.44) for women in the highest quartile of the control zinc distribution compared with women in the lowest quartile. There was no clear pattern of a linear trend in risk with increasing concentration of leukocyte copper concentrations (adjusted for linear trend in risk =0.299). Our results are consistent with some previous reports. Prospective studies are needed to determine whether observed alterations in selenium and zinc concentrations precede preeclampsia or whether the differences may be attributed to preeclampsia-related alterations in maternal and fetal-placental trace metal metabolism.     

Evolutionary aspects of omega-3 fatty acids in the food supply

Information from archaeological findings and studies from modern day hunter-gatherers suggest that the Paleolithic diet is the diet we evolved on and for which our genetic profile was programmed. The Paleolithic diet is characterized by lower fat and lower saturated fat intake than Western diets; a balanced intake of omega-6 and omega-3 essential fatty acids; small amounts of trans fatty acids, contributing less than 2% of dietary energy; more green leafy vegetables and fruits providing higher levels of vitamin E and vitamin C and other antioxidants than today's diet and higher amounts of calcium and potassium but lower sodium intake. Studies on the traditional Greek diet (diet of Crete) indicate an omega-6/omega-3 ratio of about 1/1. The importance of a balanced ratio of omega-6:omega-3, a lower saturated fatty acid and lower total fat intake (30-33%), along with higher intakes of fruits and vegetables leading to increases in vitamin E and C, was tested in the Lyon Heart study. The Lyon study, based on a modified diet of Crete, confirmed the importance of omega-3 fatty acids from marine and terrestrial sources, and vitamin E and vitamin C, in the secondary prevention of coronary heart disease, and cancer mortality.     

Plasma Elaidic Acid Level as Biomarker of Industrial Trans Fatty Acids and Risk of Weight Change: Report from the EPIC Study

BackgroundFew epidemiological studies have examined the association between dietary trans fatty acids and weight gain, and the evidence remains inconsistent. The main objective of the study was to investigate the prospective association between biomarker of industrial trans fatty acids and change in weight within the large study European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.MethodsBaseline plasma fatty acid concentrations were determined in a representative EPIC sample from the 23 participating EPIC centers. A total of 1,945 individuals were followed for a median of 4.9 years to monitor weight change. The association between elaidic acid level and percent change of weight was investigated using a multinomial logistic regression model, adjusted by length of follow-up, age, energy, alcohol, smoking status, physical activity, and region.ResultsIn women, doubling elaidic acid was associated with a decreased risk of weight loss (odds ratio (OR) = 0.69, 95% confidence interval (CI) = 0.55-0.88, p = 0.002) and a trend was observed with an increased risk of weight gain during the 5-year follow-up (OR = 1.23, 95% CI = 0.97-1.56, p = 0.082) (p-trend<.0001). In men, a trend was observed for doubling elaidic acid level and risk of weight loss (OR = 0.82, 95% CI = 0.66-1.01, p = 0.062) while no significant association was found with risk of weight gain during the 5-year follow-up (OR = 1.08, 95% CI = 0.88-1.33, p = 0.454). No association was found for saturated and cis-monounsaturated fatty acids.ConclusionsThese data suggest that a high intake of industrial trans fatty acids may decrease the risk of weight loss, particularly in women. Prevention of obesity should consider limiting the consumption of highly processed foods, the main source of industrially-produced trans fatty acids.     

Tolerability of omega-3 fatty acid supplements in perinatal women

BACKGROUND: Benefits of omega-3 fatty acids in perinatal women are well documented, although fish intake has declined among perinatal women. OBJECTIVE: To determine the tolerability of omega-3 fatty acid supplementation in perinatal women. DESIGN: Pregnant and postpartum women with major depressive disorder (MDD) entered an 8-week double-blind, placebo-controlled trial of omega-3 fatty acids. Four capsules provided 1.84 g/day of eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA), or matching placebo (corn oil with 1% fish oil to maintain blind). Tolerability was assessed by clinician interview biweekly. RESULTS: Fifty-nine women enrolled. Thirteen (22%) reported mainly transient side effects including dizziness, diarrhea, nausea, burping, heartburn/reflux, difficulty swallowing capsules, unpleasant breath/bad taste or feeling tired. The most common were unpleasant breath/bad taste and heartburn/reflux. Six reporting side effects received omega-3 fatty acids; seven received placebo. Neither pregnant nor postpartum women discontinued due to intolerability. CONCLUSIONS: Omega-3 fatty acid supplements were well tolerated by perinatal women.     

Association of the FADS2 gene with omega-6 and omega-3 PUFA Concentration in the egg yolk of Japanese quail

This study focused on the association of polymorphisms of the FADS2 gene with fatty acid profiles in egg yolk of eight Japanese quail lines selected for high and low omega-6:omega-3 PUFA ratio (h2 = 0.36-0.38). For the identification of polymorphisms within the FADS2 gene 1350 bp of cDNA sequence were obtained encoding 404 amino acids. Five synonymous SNPs were found by comparative sequencing of animals of the high and low lines. These SNPs were genotyped by single base extension on 160 Japanese quail. The association analysis, comprising analysis of variance and family based association test (FBAT), revealed significant effects of SNP3 and SNP4 genotypes on the egg yolk fatty acid profiles, especially the omega-6 and omega-3 PUFAs (P < 0.05). No effects of the other SNPs were found - indicating that these are not in linkage disequilibrium with the causal polymorphism. The results of this study promote FADS2 as a functional candidate gene for traits related to omega-6 and omega-3 PUFA concentration in the egg yolk.     

Association between Ω3 and Ω6 fatty acid intakes and serum inflammatory markers in COPD

Dietary intake of polyunsaturated fatty acids, including omega-3 and omega-6, could modulate chronic obstructive pulmonary disease (COPD) persistent inflammation. We aimed to assess the relationship between dietary intake of omega-3 and omega-6 fatty acids and serum inflammatory markers in COPD. A total of 250 clinically stable COPD patients were included. Dietary data of the last 2 years were assessed using a validated food frequency questionnaire (122 items), which provided levels of three omega-3 fatty acids: docosahexaenoic acid, eicosapentaenoic acid and α-linolenic acid (ALA); and two omega-6 fatty acids: linoleic acid and arachidonic acid (AA). Inflammatory markers [C-reactive protein (CRP), interleukin (IL)-6, IL-8 and tumor necrosis factor alpha (TNFα)] were measured in serum. Fatty acids and inflammatory markers were dichotomised according to their median values, and their association was assessed using multivariate logistic regression. Higher intake of ALA (an anti-inflammatory omega-3 fatty acid) was associated with lower TNFα concentrations [adjusted odds ratio (OR)=0.46; P=.049]. Higher AA intake (a proinflammatory omega-6 fatty acid) was related to higher IL-6 (OR=1.96; P=.034) and CRP (OR=1.95; P=.039) concentrations. Therefore, this study provides the first evidence of an association between dietary intake of omega-3 and omega-6 fatty acids and serum inflammatory markers in COPD patients.     

Cardiovascular disease and long-chain omega-3 fatty acids

PURPOSE OF REVIEW: Of all known dietary factors, long-chain omega-3 fatty acids may be the most protective against death from coronary heart disease. New evidence has confirmed and refined the cardioprotective role of these fatty acids. RECENT FINDINGS: Omega-3 fatty acid supplementation reduces the risk of sudden cardiac death and death from any cause within 4 months in post-myocardial infarction patients. Evidence continues to accrue for benefits in the primary prevention of coronary heart disease and stroke, and an anti-arrhythmogenic mechanism is emerging as the most likely explanation. SUMMARY: Current evidence suggests that individuals with coronary artery disease may reduce their risk of sudden cardiac death by increasing their intake of long-chain omega-3 fatty acids by approximately 1 g per day.     

Beyond blood lipids: phytosterols,statins and omega-3 polyunsaturated fatty acid therapy for hyperlipidemia

Phytosterols and omega-3 fatty acids are natural compounds with potential cardiovascular benefits. Phytosterols inhibit cholesterol absorption, thereby reducing total- and LDL cholesterol. A number of clinical trials have established that the consumption of 1.5–2.0 g/day of phytosterols can result in a 10–15% reduction in LDL cholesterol in as short as a 3-week period in hyperlipidemic populations. Added benefits of phytosterol consumption have been demonstrated in people who are already on lipid-lowering medications (statin drugs). On the other hand, omega-3 fatty acid supplementation has been associated with significant hypotriglyceridemic effects with concurrent modifications of other risk factors associated with cardiovascular disease, including platelet function and pro-inflammatory mediators. Recent studies have provided evidence that the combination of phytosterols and omega-3 fatty acids may reduce cardiovascular risk in a complementary and synergistic way. This article reviews the health benefits of phytosterols and omega-3 fatty acids, alone or in combination with statins, for the treatment/management of hyperlipidemia, with particular emphasis on the mechanisms involved.     

Protein kinase inhibition by omega-3 fatty acids

Recent data suggest that omega-3 fatty acids may be effective in epilepsy, cardiovascular disorders, arthritis, and as mood stabilizers for bipolar disorder; however, the mechanism of action of these compounds is unknown. Based on earlier studies implicating omega-3 fatty acids as inhibitors of protein kinase C activity in intact cells, we hypothesized that omega-3 fatty acids may act through direct inhibition of second messenger-regulated kinases and sought to determine whether the omega-3 double bond might uniquely confer pharmacologic efficacy and potency for fatty acids of this type. In our studies we observed that omega-3 fatty acids inhibited the in vitro activities of cAMP-dependent protein kinase, protein kinase C, Ca(2+)/calmodulin-dependent protein kinase II, and the mitogen-activated protein kinase (MAPK). Our results with a series of long-chain fatty acid structural homologs suggest an important role for the omega-3 double bond in conferring inhibitory efficacy. To assess whether omega-3 fatty acids were capable of inhibiting protein kinases in living neurons, we evaluated their effect on signal transduction pathways in the hippocampus. We found that omega-3 fatty acids could prevent serotonin receptor-induced MAPK activation in hippocampal slice preparations. In addition, we evaluated the effect of omega-3 fatty acids on hippocampal long-term potentiation, a form of synaptic plasticity known to be dependent on protein kinase activation. We observed that omega-3 fatty acids blocked long-term potentiation induction without inhibiting basal synaptic transmission. Overall, our results from both in vitro and live cell preparations suggest that inhibition of second messenger-regulated protein kinases is one locus of action of omega-3 fatty acids.     

Fatty Acid Profiling of Commercially Important Raw and Boiled Seer Fish <Emphasis Type="Italic">Scomberomorus commerson</Emphasis> (Lacepede, 1800) (Scombridae,Teleostei, Pisces)

The present study aims to determine the fatty acid profiling of commercially important fresh and boiled Scomberomorus commerson. Fatty acids in fresh and boiled fish were separated and quantitatively determined by gas chromatography–mass spectrophotometer using standard methods. The findings revealed that the predominant fatty acids in fresh S. commerson were octadecanoic acid methyl ester, octanoic acid, 1,2-benzenedicarboxylic acid and 3-cyclopentylpropionic acid representing respectively 45.91, 5.69, 6.75 and 8.65% of total fatty acids. Boiled S. commerson showed predominant changes in their fatty acid profiles. In the omega-3 and omega-6 families the dominant fatty acids were doconexent, 3-cyclopentylpropionic acid, octadeconoic acid methyl ester and Hexadecane representing respectively 3.87, 12.08, 44.26 and 3.11% of total fatty acids. After boiling, some fatty acids present in fresh fish are damaged and formed new fatty acids which belonged to ω-3 polyunsaturated fatty acids (PUFA). Boiling increased the concentration of PUFAs from 73.25 to 80.37% of total fatty acids and also formed new fatty acids.     

Gender-specific associations of marine n-3 fatty acids and fish consumption with 10-year incidence of stroke

Background

There is some evidence that the association of fish and marine fatty acids with stroke risk differs between men and women. We investigated the gender-specific associations of habitual intake of the marine fatty acids eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) and fish on incident stroke in a population-based study in the Netherlands.

Methods

We prospectively followed 20,069 men and women, aged 20–65 years, without cardiovascular diseases at baseline. Habitual diet was assessed with a validated 178-item food frequency questionnaire. Incidence of stroke was assessed through linkage with mortality and morbidity registers. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (95%CI).

Results

During 8–13 years of follow-up, 221 strokes occurred. In women, an inverse dose-response relation (P-trend = 0.02) was observed between EPA-DHA intake and incident stroke, with an HR of 0.49 (95% CI: 0.27–0.91) in the top quartile of EPA-DHA (median 225 mg/d) as compared to the bottom quartile (median 36 mg/d). In men, the HR (95%CI) for the top quartile of EPA-DHA intake was 0.87 (0.51–1.48) (P-trend = 0.36). Similar results were observed for fish consumption and stroke incidence.

Conclusion

A higher EPA-DHA and fish intake is related to a lower stroke risk in women, while for men an inverse association could not be demonstrated.     

Synthesis of structured lipid with balanced omega-3: Omega-6 ratio by lipase-catalyzed acidolysis reaction: Optimization of reaction using response surface methodology

The present study deals with the production of structured lipid containing omega-3 and omega-6 fatty acids in the ratio of 1:1 by incorporating omega-3 fatty acids (α-linolenic acid) from linseed oil into groundnut oil using lipase (Lipozyme IM from Rhizomucor miehei) catalyzed acidolysis reaction in hexane. The reaction conditions were optimized by response surface methodology with a four-variable five-level central composite rotatable experimental design. The influence of four independent parameters, namely ratio of fatty acid concentrate from linseed to groundnut oil (0.66–1.98, w/w), reaction temperature (30–60 °C), enzyme concentration (1–5%) and reaction time (2–54 h) on omega-3 fatty acids incorporation into groundnut oil were optimized. Optimal conditions for the structured lipid containing omega-3 to omega-6 fatty acids in the ratio of 1:1 were determined to be; enzyme concentration 3.75% (w/w), temperature 37.5 °C, incubation time 30.81 h and ratio of free fatty acid concentrate from linseed oil to groundnut oil 1.16 (w/w).     

Modulation of native T-type calcium channels by omega-3 fatty acids

Low voltage-activated, rapidly inactivating T-type Ca(2+) channels are found in a variety of cells where they regulate electrical activity and Ca(2+) entry. In whole-cell patch clamp recordings from bovine adrenal zona fasciculata cells, cis-polyunsaturated omega-3 fatty acids including docosahexaenoic acid (DHA), eicosapentaenoic acid, and alpha-linolenic acid inhibited T-type Ca(2+) current (I(T-Ca)) with IC(50)s of 2.4, 6.1, and 14.4microM, respectively. Inhibition of I(T-Ca) by DHA was partially use-dependent. In the absence of stimulation, DHA (5microM) inhibited I(T-Ca) by 59.7+/-8.1% (n=5). When voltage steps to -10mV were applied at 12s intervals, block increased to 80.5+/-7.2%. Inhibition of I(T-Ca) by DHA was accompanied by a shift of -11.7mV in the voltage dependence of steady-state inactivation, and a smaller -3.3mV shift in the voltage dependence of activation. omega-3 fatty acids also selectively altered the gating kinetics of T-type Ca(2+) channels. DHA accelerated T channel recovery from inactivation by approximately 3-fold, but did not affect the kinetics of T channel activation or deactivation. Arachidonic acid, an omega-6 polyunsaturated fatty acid, also inhibited T-type Ca(2+) current at micromolar concentrations, while the trans polyunsaturated fatty acid linolelaidic acid was ineffective. These results identify cis polyunsaturated fatty acids as relatively potent, new T-type Ca(2+) channel antagonists. omega-3 fatty acids are essential dietary components that have been shown to possess remarkable neuroprotective and cardioprotective properties that are likely mediated through suppression of electrical activity and associated Ca(2+) entry. Inhibition of T-type Ca(2+) channels in neurons and cardiac myocytes could contribute significantly to their protective actions.     

Body Mass Index,Smoking and Hypertensive Disorders during Pregnancy: A Population Based Case-Control Study

While obesity is an indicated risk factor for hypertensive disorders of pregnancy, smoking during pregnancy has been shown to be inversely associated with the development of preeclampsia and gestational hypertension. The purpose of this study was to investigate the combined effects of high body mass index and smoking on hypertensive disorders during pregnancy. This was a case-control study based on national registers, nested within all pregnancies in Iceland 1989–2004, resulting in birth at the Landspitali University Hospital. Cases (n = 500) were matched 1:2 with women without a hypertensive diagnosis who gave birth in the same year. Body mass index (kg/m²) was based on height and weight at 10–15 weeks of pregnancy. We used logistic regression models to calculate odds ratios and corresponding 95% confidence intervals as measures of association, adjusting for potential confounders and tested for additive and multiplicative interactions of body mass index and smoking. Women’s body mass index during early pregnancy was positively associated with each hypertensive outcome. Compared with normal weight women, the multivariable adjusted odds ratio for any hypertensive disorder was 1.8 (95% confidence interval, 1.3–2.3) for overweight women and 3.1 (95% confidence interval, 2.2–4.3) for obese women. The odds ratio for any hypertensive disorder with obesity was 3.9 (95% confidence interval 1.8–8.6) among smokers and 3.0 (95% confidence interval 2.1–4.3) among non-smokers. The effect estimates for hypertensive disorders with high body mass index appeared more pronounced among smokers than non-smokers, although the observed difference was not statistically significant. Our findings may help elucidate the complicated interplay of these lifestyle-related factors with the hypertensive disorders during pregnancy.     

Substrate specificity, regioselectivity and cryptoregiochemistry of plant and animal omega-3 fatty acid desaturases

In order to define the substrate requirements, regiochemistry and cryptoregiochemistry of the omega-3 fatty acid desaturases involved in polyunsaturated fatty acid formation, the genes Fad3 and fat-1 from Brassica napus and the nematode Caenorhabditis elegans respectively were expressed in baker's yeast (Saccharomyces cerevisiae). Various fatty acids, including deuterium-labelled thia-fatty acids, were supplied to growing cultures of transformed yeast. The results from GC-MS analysis of the desaturated products indicate that both the plant and animal desaturases act on unsaturated substrates of 16-20 carbons with a preference for omega-6-unsaturated fatty acids. The regioselectivities of both enzymes were confirmed to be that of omega-3 desaturases. The primary deuterium kinetic isotope effects at C-15 and C-16 of a C(18) fatty acid analogue were measured via competitive incubation experiments. Whereas k(H)/k(D) at the omega-3 position was shown to be large, essentially no kinetic isotope effect at the omega-2 position was observed for the plant or the nematode enzymes. These results indicate that omega-3 desaturation is initiated by an energetically difficult C-H bond cleavage at the carbon closer to the carboxyl terminus. These results will be discussed in the context of a general model relating the structure and function of membrane-bound fatty acid desaturases featuring different regioselectivities.     

Effect of saturated, omega-3 and omega-6 polyunsaturated fatty acids on myocardial infarction

Dietary fatty acids have cholesterol lowering, antiatherogenic, and antiarrhythmic properties that decrease the risk of myocardial infarction (MI). This study was designed to study the effects of various oils rich in either polyunsaturated (omega-3 or omega-6) fatty acids (PUFA) or saturated fatty acids (SFA) on the severity of experimentally induced MI. Male albino Sprague-Dawley rats (100-150 g; n = 20) were fed diets enriched with fish oil (omega-3 PUFA), peanut oil (omega-6 PUFA), or coconut oil (SFA) for 60 days. Experimental MI was induced with isoproterenol. Mortality rates; serum enzymes aspartate amino transferase; alanine amino transferase; creatine phosphokinase (CPK); lipid profiles in serum, myocardium, and aorta; peroxide levels in heart and aorta; activities of catalase and superoxide dismutase; and levels of glutathione were measured. The results demonstrated that mortality rate, CPK levels, myocardial lipid peroxides, and glutathione levels were decreased in the omega-3 PUFA treated group. Maximum increase in parameters indicative of myocardial damage was seen in the coconut oil group. These findings suggest that dietary omega-3 PUFA offers maximum protection in experimentally induced MI in comparison to omega-6 PUFA and SFA enriched diets. SFA was found to have the least protective effect.     

Delay of preterm delivery in sheep by omega-3 long-chain polyunsaturates

A positive correlation has been shown between dietary intake of long-chain omega-3 fatty acids in late pregnancy and gestation length in pregnant women and experimental animals. To determine whether omega-3 fatty acids have an effect on preterm labor in sheep, a fish oil concentrate emulsion was continuously infused to six pregnant ewes from 124 days gestational age. At 125 days, betamethasone was administered to the fetus to produce preterm labor. Both the onset of labor and the time of delivery were delayed by the fish oil emulsion. Two of the omega-3-infused ewes reverted from contractions to nonlabor, an effect never previously observed for experimental glucocorticoid-induced preterm labor in sheep. Maternal plasma estradiol and maternal and fetal prostaglandin E2 rose in control ewes but not in those infused with omega-3 fatty acid. The ability of omega-3 fatty acids to delay premature delivery in sheep indicates their possible use as tocolytics in humans. Premature labor is the major cause of neonatal death and long-term disability, and these studies present information that may lead to a novel therapeutic regimen for the prevention of preterm delivery in human pregnancy.     

The synthesis and accumulation of stearidonic acid in transgenic plants: a novel source of 'heart-healthy' omega-3 fatty acids

Dietary omega-3 polyunsaturated fatty acids have a proven role in reducing the risk of cardiovascular disease and precursor disease states such as metabolic syndrome. Although most studies have focussed on the predominant omega-3 fatty acids found in fish oils (eicosapentaenoic acid and docosahexaenoic acid), recent evidence suggests similar health benefits from their common precursor, stearidonic acid. Stearidonic acid is a Δ6-unsaturated C18 omega-3 fatty acid present in a few plant species (mainly the Boraginaceae and Primulaceae ) reflecting the general absence of Δ6-desaturation from higher plants. Using a Δ6-desaturase from Primula vialii , we generated transgenic Arabidopsis and linseed lines accumulating stearidonic acid in their seed lipids. Significantly, the P. vialii Δ6-desaturase specifically only utilises α-linolenic acid as a substrate, resulting in the accumulation of stearidonic acid but not omega-6 γ-linolenic acid. Detailed lipid analysis revealed the accumulation of stearidonic acid in neutral lipids such as triacylglycerol but an absence from the acyl-CoA pool. In the case of linseed, the achieved levels of stearidonic acid (13.4% of triacylglycerols) are very similar to those found in the sole natural commercial plant source ( Echium spp.) or transgenic soybean oil. However, both those latter oils contain γ-linolenic acid, which is not normally present in fish oils and considered undesirable for heart-healthy applications. By contrast, the stearidonic acid-enriched linseed oil is essentially devoid of this fatty acid. Moreover, the overall omega-3/omega-6 ratio for this modified linseed oil is also significantly higher. Thus, this nutritionally enhanced linseed oil may have superior health-beneficial properties.