Prostaglandins, Leukotrienes and Essential Fatty Acids

Editorial Board

2010-07-01

The association of fatty acid deficiency symptoms (FADS) with actual essential fatty acid status in cheek cells

A. Kirby, A. Woodward, S. Jackson, Y. Wang, M.A. Crawford — 2010-04-01

Abstract: Seven clinical symptoms have been utilised in several studies as a means of potentially identifying children with a deficiency in essential polyunsaturated fatty acids (PUFAs). The purpose of this study was to investigate whether there was any correlation between parental reports of the frequency of these seven ‘fatty acid deficiency symptoms’ (FADS) with actual levels of fatty acids in buccal cell samples of 450 children aged 8–10 years old. Additionally, the relationship between FADS and cognitive test performance, ratings of attention and behaviour and other somatic complaints were explored.The severity of reported FADS was not related to the levels of omega-6 or omega-3 in buccal cell samples. There was a relationship between parental reports of child behaviour and reported FADS; with high FADS being related to higher ratings of behaviour problems. Using FADS as a marker of PUFA deficiency may not be appropriate especially when assessing typically developing children.

Human milk fatty acids from lactating mothers of preterm infants: A study revealing wide intra- and inter-individual variation

L.G. Smithers, M. Markrides, R.A. Gibson — 2010-04-23

Abstract: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important nutrients in the preterm diet and fixed ratios have been proposed for formula. We evaluated the intra- and inter-individual variation in milk fatty acids from mothers of preterm infants involved in a randomised trial of tuna oil or placebo supplementation. Milk samples were collected every 2 weeks while infants were hospitalised and fatty acids analysed by capillary gas chromatography. DHA was higher in milk of supplemented mothers than control (% total fatty acids, mean±SD, treatment 0.9±0.4, control 0.3±0.1, p<0.0005) and ranged between 0.3–2.5% and 0.1–1.1%, respectively. AA did not differ between groups and ranged between 0.2–0.9% and 0.3–0.9%, respectively. Control mothers milk had wider AA:DHA ratio than treatment mothers (0.4–3.2 versus 0.2–2.1). Due to the wide variation in milk AA and DHA, statements recommending infant formula based on a fixed AA:DHA ratio should be re-examined.

CysLT1-R expression following allergen provocation in asthma and allergic rhinitis

2010-05-12

Abstract: Cysteinyl leukotrienes (CysLTs) contribute to allergic and inflammatory diseases through CysLT1-R. We aimed to assess CysLT1-R mRNA expression in induced sputum of rhinitics with or without asthma before and following allergen challenges. Both groups underwent nasal and “low dose” lung allergen challenges. Asthmatics also underwent “standard” lung challenge. Sputum was obtained before and at different time-points following the challenges for CysLT1-R, 5-lipoxygenase (5-LO), and eotaxin mRNA assessments. At baseline, there was no difference in mediator levels between groups. An increase in CysLT1-R mRNA (p=0.04) and a trend towards an increase in 5-LO and eotaxin (p=0.06 for both) at 24h post-nasal challenge were observed. Following “low dose” lung allergen challenge, there was a trend towards an increase in CysLT1-R (p=0.07). In conclusion, CysLT1-R gene expression changes can be detected in sputum following allergen challenges. No difference was observed between groups, suggesting that changes in CysLT1-R expression occur whether or not the subject has concurrent asthma.

Uptake of dihomo-γ-linolenic acid by murine macrophages increases series-1 prostaglandin release following lipopolysaccharide treatment

2010-03-29

Abstract: Administration of dihomo-γ-linolenic acid is useful for atopic dermatitis and atherosclerosis in mice; however, the metabolites of dihomo-γ-linolenic acid have been little studied. We employed a method which enabled simultaneous analysis of nine prostaglandins using liquid chromatography–tandem mass spectrometry, and determined the concentrations of prostaglandins in the supernatants of cultures of mouse peritoneal macrophages stimulated with lipopolysaccharide after pre-incubation with dihomo-γ-linolenic acid, arachidonic acid, or eicosapentaenoic acid. Accumulated prostaglandin concentrations from mouse macrophages with dihomo-γ-linolenic acid uptake increased in a dihomo-γ-linolenic acid concentration-dependent fashion. These increases were mainly due to prostaglandin D1 and prostaglandin E1. The order of accumulated prostaglandin concentrations was dihomo-γ-linolenic acid>arachidonic acid>eicosapentaenoic acid in supernatants with the same concentration of polyunsaturated fatty acid. Since mouse macrophages can clearly produce series-1 prostaglandins, they must be formed in vivo. These findings suggest that the effects of dihomo-γ-linolenic acid on diseases may be due to series-1 prostaglandins.

Fish consumption, not fatty acid status, is related to quality of life in a healthy population

O.J.G. Schiepers, R.H.M. de Groot, J. Jolles, M.P.J. van Boxtel — 2010-03-08

Abstract: Depressive symptoms in the community have a considerable impact on quality of life. Although long-chain polyunsaturated fatty acids (LCPUFA) have frequently been implicated in depressed mood, their relationship with quality of life has scarcely been investigated.This study examined the cross-sectional associations between fish consumption and plasma phospholipid LCPUFA status on the one hand, and quality of life, as measured by the Short Form 36 questionnaire, on the other in a population-based sample. The mental health component of quality of life was not associated with LCPUFA status or fish consumption. Fish consumption showed a positive association with physical well-being, which remained significant after correction for LCPUFA status, suggesting that the relationship between fish consumption and physical well-being is independent of the LCPUFA content of fish. These findings indicate that fish consumption may serve as a proxy for a healthy lifestyle or a favorable nutritional status, which is reflected in better quality of life.

Polyunsaturated docosahexaenoic acid suppresses oxidative stress induced endothelial cell calcium influx by altering lipid composition in membrane caveolar rafts

Sheng Ye, Li Tan, Jian Ma, Qian Shi, Jieshou Li — 2010-03-08

Abstract: Objective: To determine whether DHA suppresses oxidative stress induced endothelial cell calcium influx by altering lipid composition and TRPC1 distribution in membrane rafts.Methods: Endothelial cells (EC) were pretreated with DHA or stearic acid, then incubated for another 3h with media containing H2O2. Membrane lipid rafts were isolated using the discontinuous sucrose density gradient ultracentrifugation method. Intracellular calcium was detected with laser scanning confocal microscope. TRPC1 protein in membrane fractions was detected by immunoblotting. Membrane fatty acids compositions were analyzed by gas chromatography; raft cholesterol level was assayed by an Amplex Red Cholesterol Assay kit, and DAG concentration was quantified by a DAG kinase assay.Results: DHA significantly reduced oxidative stress induced calcium influx; pretreated with DHA the n-3 PUFAs were significantly increased in raft fractions, as well as saturated myristic acid, palmitic acid content of membrane rafts in EC; while the stearic acid, monounsaturated oleic acid and cis-oleic acid were decreased. Incubation with DHA also significantly reduced the amount of SM and cholesterol levels in the raft. Interestingly, we fractioned plasma membrane subcellular compartments and discovered that certain amounts of TRPC1 existed in detergent-resistant plasma membrane fractions of EC. After DHA treatment, TRPC1 was partly displaced from lipid raft to detergent-soluble membrane fractions.Conclusions: DHA significantly reduces oxidative stress induced endothelial calcium influx, this effect might be associated with, at least in part, altered raft lipid environment, and suppresses TRPC1-mediated calcium signaling pathway by partially displacing TRPC1 from membrane caveolar lipid rafts.

Elevated plasma fibrinogen caused by inadequate α-linolenic acid intake can be reduced by replacing fat with canola-type rapeseed oil

2010-03-08

Abstract: The effects of canola-type rapeseed oil (RSO) on serum lipids, plasma fibrinogen, lipid oxidation and fatty acids were studied in three groups of subjects, two of which had not been consuming fish in their habitual diets. Forty-two volunteers (35 women, 7 men, 16–62 years) replaced fat with RSO for 6 weeks in a parallel design. The average cholesterol and fibrinogen concentrations were 5.0mmol/l and 2.6g/l, respectively. The intake of α-linolenic acid (α-LLA) was doubled. Efficient competitive inhibition by α-LLA was seen as a decrease in long-chain (LC) n-6 PUFA at 3 weeks. Elevated fibrinogen (2.6–3.9g/l) decreased by 0.95g/l at 6 weeks. Docosahexaenoic acid (22:6n-3) in plasma phospholipids increased at low fibrinogen levels only. The associations and changes in plasma C18 and LC PUFA followed the competitive and metabolic principles of the body, and especially in the case of n-3 PUFA according to the recycling pathway.

Antisecretory, antioxidative and antiapoptotic effects of montelukast on pyloric ligation and water immersion stress induced peptic ulcer in rat

Arunachalam Muthuraman, Shailja Sood — 2010-02-15

Abstract: In the present study, we tried to explore the mechanism of montelukast as an antiulcerogenic agent in pyloric ligation (PL) and water immersion stress (WIS) induced peptic ulcer. The ameliorative effects of montelukast (5, 10, and 20mg/kg, p.o.) on gastric volume and total acidity were studied in PL model. We have investigated the alteration in the ulcerative index, thiobarbituric acid reactive substances, reduced glutathione, activity of myeloperoxidase, and total calcium level in both models. Estimation of DNA fragmentation by gel electrophoresis was also performed. Medium and higher doses of montelukast showed significant (p<0.05) ameliorative potential on all the above parameters as compared with omeprazole treated group. DNA fragmentation pattern clearly indicated the antiapoptotic effect of montelukast in preventing mucosal erosion in both models. Hence, the gastroprotective effect of montelukast may be attributed to its antisecretory, antioxidative along with its antiapoptotic effect.