Polyunsaturated fatty acids (PUFA) and eicosanoids in human health and pathologies

Formation of dopamine adducts derived from brain polyunsaturated fatty acids: mechanism for Parkinson disease

Oxidative stress appears to be directly involved in the pathogenesis of the neurodegeneration of dopaminergic systems in Parkinson disease. In this study, we formed four dopamine modification adducts derived from docosahexaenoic acid (C22:6/omega-3) and arachidonic acid (C18:4/omega-6), which are known as the major polyunsaturated fatty acids in the brain. Upon incubation of dopamine with fatty acid hydroperoxides and an in vivo experiment using rat brain tissue, all four dopamine adducts were detected. Furthermore, hexanoyl dopamine (HED), an arachidonic acid-derived adduct, caused severe cytotoxicity in human dopaminergic neuroblastoma SH-SY5Y cells, whereas the other adducts were only slightly affected. The HED-induced cell death was found to include apoptosis, which also seems to be mediated by reactive oxygen species generation and mitochondrial abnormality. Additionally, the experiments using monoamine transporter inhibitor and mouse embryonic fibroblast NIH-3T3 cells that lack the monoamine transporter indicate that the HED-induced cytotoxicity might specially occur in the neuronal cells. These data suggest that the formation of the docosahexaenoic acid- and arachidonic acid-derived dopamine adducts in vitro and in vivo, and HED, the arachidonic acid-derived dopamine modification adduct, which caused selective cytotoxicity of neuronal cells, may indicate a novel mechanism responsible for the pathogenesis in Parkinson disease.

Influence of processing on quality parameters of strawberries

To determine the effects of different processing steps, such as enzymatic treatment of the mash and pasteurization, on selected quality parameters, strawberries were processed to juices and purees. To identify the processing steps causing the highest losses, samples were taken after each step, and ascorbic acid, total phenols, anthocyanins, and antioxidant capacity were analyzed. To assess the antioxidant capacity, three different methods were applied: the trolox equivalent antioxidant capacity (TEAC), the ferric reducing antioxidant power (FRAP), and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, showing correlation coefficients of 0.889 to 0.948. The antioxidant capacity decreased with processing steps except heat treatment, which partly caused an increase due to the formation of antioxidant active products. The content of ascorbic acid, in comparison to that in the frozen strawberries, decreased significantly during the processing of the fruit to puree by 77%. In the pressed cloudy juices, the loss of ascorbic acid was 37%. The decline of phenolic compounds, measured as total polyphenols and anthocyanins, was smaller (between 30-40%). Pressing and pasteurization were the most critical steps for the decrease of these compounds. The enzymatic treatment of the mash within 90 min supported the release of secondary plant metabolites, while ascorbic acid is reduced up to 20%.

Maternal di-(2-ethylhexyl)-phthalate exposure influences essential fatty acid homeostasis in rat placenta

Maintaining essential fatty acid (EFA) homeostasis during pregnancy is critical for fetal development. As the organ that controls the maternal-to-fetal supply of nutrients, the placenta plays a significant role in guiding EFA transfer to the fetus. Many EFA homeostasis proteins are regulated by peroxisome proliferator-activated receptors (PPARs). The metabolites of di-(2-ethylhexyl)-phthalate (DEHP), a ubiquitous environmental contaminant, might influence EFA homeostasis via trans-activation of PPARs with subsequent downstream effects on EFA transporters and enzymes. To investigate DEHP's effect on placental/fetal EFA homeostasis, female Sprague-Dawley rats were orally gavaged with either vehicle or DEHP at 750 or 1500 mg/kg/day from gestational day (GD) 0 to GD 19. Changes in the expression of several EFA homeostasis regulating proteins were determined in the junctional (JXN) and labyrinthine (LAB) zones of the placenta, including PPAR isoforms (alpha, beta and gamma), fatty acid translocase (FAT/CD36), fatty acid transport protein 1 (FATP1), plasma membrane fatty acid binding protein (FABPpm), heart cytoplasmic fatty acid binding protein (HFABP), cytochrome P450 (CYP) 4A1, and cyclooxygenase (COX)-1 and -2. Additionally, effects of DEHP maternal exposure on the placental transfer and fetal distribution of representative EFAs, arachidonic acid (AA) and docosahexaenoic acid (DHA), and the placental production of prostaglandins (PGs) were investigated. Expression of PPARalpha, PPARgamma, FAT/CD36, FATP1, HFABP and CYP4A1 was up-regulated in JXN and/or LAB while COX-2 was down-regulated in JXN. PPARbeta, FABPpm, and COX-1 demonstrated variable expression. Reduced directional maternal-to-fetal placental transfer and altered fetal distribution of AA and DHA were observed in concordance with a decreased total placental PG production. These results correlate with previous in vitro data, suggesting that DEHP could influence placental EFA homeostasis with potential downstream effects in the developing fetus.

Neurological benefits of omega-3 fatty acids

The central nervous system is highly enriched in long-chain polyunsaturated fatty acid (PUFA) of the omega-6 and omega-3 series. The presence of these fatty acids as structural components of neuronal membranes influences cellular function both directly, through effects on membrane properties, and also by acting as a precursor pool for lipid-derived messengers. An adequate intake of omega-3 PUFA is essential for optimal visual function and neural development. Furthermore, there is increasing evidence that increased intake of the long-chain omega-3 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may confer benefits in a variety of psychiatric and neurological disorders, and in particular neurodegenerative conditions. However, the mechanisms underlying these beneficial effects are still poorly understood. Recent evidence also indicates that in addition to the positive effects seen in chronic neurodegenerative conditions, omega-3 PUFA may also have significant neuroprotective potential in acute neurological injury. Thus, these compounds offer an intriguing prospect as potentially new therapeutic approaches in both chronic and acute conditions. The purpose of this article is to review the current evidence of the neurological benefits of omega-3 PUFA, looking specifically at neurodegenerative conditions and acute neurological injury.

Fatty acid profile of sunshine bass: I. Profile change is affected by initial composition and differs among tissues

Fatty acid (FA) composition of fillet tissue can be tailored by transitioning fish from alternative lipid-based, low long-chain polyunsaturated fatty acid (LC-PUFA) grow-out feeds to high LC-PUFA "finishing" feeds. To address whether grow-out feed composition influences the responsiveness of fillet tissue to finishing, sunshine bass (SB, Morone chrysops x M. saxatilis) were reared to a submarketable size on grow-out feeds containing fish oil (FO) or a 50:50 blend of FO and coconut (CO), grapeseed (GO), linseed (LO), or poultry (PO) oil. For the final 8 weeks of the trial, fish were either maintained on assigned grow-out feeds or finished with the 100% FO feed. Production performance was unaffected by dietary lipid source, but fillet FA profile generally conformed to nutritional history. Regardless of grow-out regimen, finishing had a significant restorative effect on fillet FA composition; however, complete restoration of control levels of 20:5n-3, 22:6n-3, total LC-PUFA and n-3:n-6 FA ratio was achieved only among fish fed the CO-based grow-out feed. Saturated fatty acids (SFA) appear to be preferential catabolic substrates, whereas medium-chain and long-chain PUFA are selectively deposited in tissues. Provision of SFA in grow-out feeds appears to optimize selective FA metabolism and restoration of beneficial fillet FA profile during finishing.

Ácido linoléico conjugado e perfil de ácidos graxos no músculo e na capa de gordura de novilhos bubalinos alimentados com diferentes fontes de lipídios

Avaliaram-se o teor de ácido linoléico conjugado (CLA) e o perfil de ácidos graxos no músculo e na capa de gordura de novilhos bubalinos alimentados com diferentes fontes de lipídios. Utilizaram-se 12 animais castrados, da raça Murrah, com peso vivo de 306±8kg, submetidos aos tratamentos sem lipídeo adicional, grão de soja e óleo de soja, confinados durante 84 dias. Após o abate a carcaça foi resfriada a 5ºC, durante 24 horas. Foi feita secção entre a nona e a 11ª costelas da meia carcaça direita, de onde se separou músculo e capa de gordura, analisadas as concentrações de CLA e de ácidos graxos, por cromatografia gasosa. O fornecimento de óleo de soja resultou em maior concentração de CLA no músculo e na capa de gordura, e a adição de óleo de soja menores concentrações de ácidos graxos saturados, principalmente os ácidos mirístico e palmítico. Os animais que receberam a dieta com grão de soja integral também apresentaram menor teor de CLA e redução nas concentrações de mirístico e palmítico. Esses efeitos foram observados somente na capa de gordura e em menor intensidade.

Maternal supply of omega-3 polyunsaturated fatty acids alter mechanisms involved in oocyte and early embryo development in the mouse

Despite the well-known benefits of omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation on human health, relatively little is known about the effect of n-3 PUFA intake on fertility. More specifically, the aim of this study was to determine how oocyte and preimplantation embryo development might be influenced by n-3 PUFA supply and to understand the possible mechanisms underlying these effects. Adult female mice were fed a control diet or a diet relatively high in the long-chain n-3 PUFAs for 4 wk, and ovulated oocytes or zygotes were collected after gonadotropin stimulation. Oocytes were examined for mitochondrial parameters (active mitochondrial distribution, mitochondrial calcium and membrane potential) and oxidative stress, and embryo developmental ability was assessed at the blastocyst stage following 1) in vitro fertilization (IVF) or 2) culture of in vivo-derived zygotes. This study demonstrated that exposure of the oocyte during maturation in the ovary to an environment high in n-3 PUFA resulted in altered mitochondrial distribution and calcium levels and increased production of reactive oxygen species. Despite normal fertilization and development in vitro following IVF, the exposure of oocytes to an environment high in n-3 PUFA during in vivo fertilization adversely affected the morphological appearance of the embryo and decreased developmental ability to the blastocyst stage. This study suggests that high maternal dietary n-3 PUFA exposure periconception reduces normal embryo development in the mouse and is associated with perturbed mitochondrial metabolism, raising questions regarding supplementation with n-3 PUFAs during this period of time.

Activation of peroxisome proliferator-activated receptor alpha by dietary fish oil attenuates steatosis, but does not prevent experimental steatohepatitis because of hepatic lipoperoxide accumulation

BACKGROUND AND AIM

Non-alcoholic fatty liver disease is the result of an imbalance in hepatic lipid partitioning that favors fatty acid synthesis and storage over fatty acid oxidation and triglyceride secretion. The progressive, inflammatory disorder of steatohepatitis can be prevented or reversed by correcting this lipid imbalance by activating peroxisome proliferator-activated receptor (PPAR) alpha, a transcription factor which regulates fatty acid oxidation. n-3 polyunsaturated fatty acids (PUFA), such as those found in fish oil (FO), are naturally occurring PPARalpha ligands which also suppress lipid synthesis.

METHODS

We tested the role of dietary activation of PPARalpha by feeding mice a n-3 PUFA-enriched FO diet in the methionine and choline deficient (MCD) model of steatohepatitis. Results were compared with mice fed the corresponding diet supplemented with monounsaturated fatty acids as olive oil (OO).

RESULTS

As expected, FO feeding led to robust hepatic PPARalpha activation in control mice, and decreased expression of genes involved with fatty acid synthesis. Such lipolytic gene expression profile was also clearly evident in FO MCD-fed mice, and was associated with reduced hepatic lipid accumulation in comparison with mice fed OO MCD diet. FO feeding in control mice also caused marked hepatic accumulation of lipoperoxides compared with OO and chow-fed mice. This was further exacerbated in FO MCD-fed animals, which developed steatohepatitis characterized by mild steatosis and moderate inflammation in comparison with OO MCD-fed mice; such inflammatory recruitment was not related to NF-kappaB activation or enhanced cyclooxygenase-2 activity.

CONCLUSIONS

Feeding an n-3 PUFA-enriched diet activated PPARalpha and suppressed hepatic de novo lipogenesis, but failed to prevent development of steatohepatitis in the presence of methionine and choline deficiency. Instead, the very high levels of hepatic lipoperoxides may have abrogated the protection that would otherwise be conferred by PPARalpha activation, and could also be responsible for lipotoxic hepatocellular injury and inflammatory recruitment.

Modulation of angiogenesis by omega-3 polyunsaturated fatty acids is mediated by cyclooxygenases

The potential role of dietary fats in cancer is attracting considerable interest within the community. Both epidemiologic and experimental findings suggest that omega-3 polyunsaturated fatty acids (omega-3 PUFAs), which are almost absent from typical Western diets, exert protective effects against cancer progression, although the precise mechanism of this suppression remains unknown. One of the potential targets for omega-3 PUFAs in cancer suppression is angiogenesis, a process of new blood vessel formation within rapidly growing tumors. Here, we demonstrate that omega-6 PUFAs stimulate and omega-3 PUFAs inhibit major proangiogenic processes in human endothelial cells, including the induction of angiopoietin-2 (Ang2) and matrix metalloprotease-9, endothelial invasion, and tube formation, that are usually activated by the major omega-6 PUFA arachidonic acid. The cyclooxygenase (COX)-mediated conversion of PUFAs to prostanoid derivatives participated in modulation of the expression of Ang2. Thus, the omega-6 PUFA-derived prostaglandin E2 augmented, whereas the omega-3 PUFA-derived prostaglandin E3 suppressed the induction of Ang2 by growth factors. Our findings are consistent with the suggestion that PUFAs undergo biotransformation by COX-2 to lipid mediators that modulate tumor angiogenesis, which provides new insight into the beneficial effects of omega-3 PUFAs.

Modification of fillet composition and evidence of differential fatty acid turnover in sunshine bass Morone chrysops x M. saxatilis following change in dietary lipid source

Marine oil-based finishing diets have been used to restore fillet FA profile in several "medium-fat" fleshed aquaculture species, and a simple dilution model describing FA turnover has been established to predict and tailor final fillet composition. We evaluated finishing diet efficacy and suitability of the dilution model to describe patterns of FA change in a lean-fleshed model, sunshine bass. Two practical diets (45% crude protein, 15% crude lipid) were formulated, respectively containing corn oil (CO) or menhaden oil (MO) as the primary lipid sources. Sunshine bass (age 1 [approximately 14 mo], 347 +/- 8.6 g, mean individual weight +/- SEM) were stocked in a recirculating system and fed the diets according to different feeding regimens during the final 28 wk of the production cycle. Control groups were fed the CO or the MO feeds exclusively; whereas, the remaining treatment groups were transitioned from the CO diet to the MO diet at 4-, 8-, or 12-wk intervals. Upon completion of the feeding trial, fish were harvested, and production performance and fillet composition were assessed. Replacing MO with CO as the primary lipid source in sunshine bass diets yielded fillets with distinctly different FA profiles; however, finishing with a MO-based diet offered significant compensation for CO-associated reductions in fillet long-chain highly unsaturated FA (LC-HUFA). Although complete restoration was not observed, we achieved significant augmentation of endogenous n-3 FA within 4 wk of feeding the MO diet, and observed a significant increase in LC-HUFA and a beneficial shift in n-3:n-6 FA ratio after 8 weeks. Simple dilution accurately predicted tissue composition for most FA; however, deviations from the model were noted, suggesting selective retention of n-3, PUFA, and LC-HUFA and preferential catabolism of saturates. We conclude marine oil-based finishing diets can rapidly augment beneficial FA levels in sunshine bass fillets; however, simple dilution models do not fully describe selective FA metabolism observed for this lean-fleshed fish.

Effect of Chia oil (Salvia Hispanica) rich in omega-3 fatty acids on the eicosanoid release, apoptosis and T-lymphocyte tumor infiltration in a murine mammary gland adenocarcinoma

We investigated the effects of certain dietary polyunsaturated fatty acids (PUFAs) and related eicosanoids on the growth and metastasis formation of a murine mammary gland adenocarcinoma. Salvia hispanica (ChO) and Carthamus tinctorius (SaO) vegetable oil sources of omega-3 and -6 PUFAs and a commercial diet as control (CO), were used. We analysed fatty acids of neoplastic cells (NC) membranes by GLC; the eicosanoids 12- HETE and 12-HHT (LOX and COX metabolites) by HPLC and apoptosis and T-lymphocyte infiltration by flow cytometry and microscopy. NC from ChO groups showed lower levels of arachidonic acid and of both eicosanoids compared to SaO and CO (p<0.05). The ChO diet decreased the tumor weight and metastasis number (p<0.05). Apoptosis and T-lymphocyte infiltration were higher and mitosis decreased with respect to the other diets (p<0.05). Present data showed that ChO, an ancient and almost unknown source of omega-3, inhibits growth and metastasis in this tumor model.

Tissue n-3 and n-6 fatty acids and risk for coronary heart disease events

BACKGROUND

Tissue proportions of long chain n-6 [especially arachidonic acid (AA)] and n-3 fatty acids [FA; eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) acids], or some ratio of these may be markers of risk for coronary heart disease (CHD). The purpose of this paper is to evaluate the published associations between risk for CHD events and tissue n-3 and n-6 FA composition.

METHODS

Case-control or prospective cohort data sets examining the risk for CHD endpoints as a function of tissue FA composition were identified. Effect sizes were computed for case versus control comparisons using standard meta-analytic methods.

RESULTS

Twenty-five studies were included, 18 examining the FA composition of phospholipid-rich and 7 of triglyceride-rich samples. DHA, with or without EPA, was significantly lower in cases than controls in all studies combined, in those with fatal endpoints, in those with prospective designs, and in both tissue types. The only setting where increased AA was associated with case status was in adipose tissue. The AA/EPA ratio in phospholipid-rich samples did not distinguish cases from controls. Lower linoleic acid content was associated with increased risk for non-fatal events.

CONCLUSIONS

The long-chain n-3 FA, especially DHA, were consistently and significantly reduced in patients experiencing CHD events. These findings add further support to the view that long-chain n-3 FA are cardioprotective.

Genetic and epigenetic regulation of the human prostacyclin synthase promoter in lung cancer cell lines

The importance of the arachidonic acid pathway has been established in colon and lung cancers, as well as in inflammatory diseases. In these diseases, prostacyclin I(2) (PGI2) and prostaglandin E(2) (PGE2) are thought to have antagonistic activities, with PGI2 exerting anti-inflammatory and antiproliferative activities, whereas PGE2 is proinflammatory and antiapoptotic. In human lung cancer, prostacyclin synthase (PGIS) and PGI2 are down-regulated, whereas PGE2 synthase (PGES) and PGE2 are up-regulated. Murine carcinogenesis models of human lung cancer reciprocate the relationship between PGIS and PGES expression. PGIS-overexpressing transgenic mice are protected from carcinogen- and tobacco smoke-induced lung tumor formation, suggesting that PGI2 may play a role in chemoprevention. We investigated several potential mechanisms for the down-regulation of PGIS in human lung cancer. Using transcription reporter assays, we show that single nucleotide polymorphisms in the PGIS promoter can affect transcriptional activity. In addition, PGIS expression in several human lung cancer cell lines is silenced by CpG methylation, and we have mapped these sites across the variable number of tandem repeats (VNTR) sequence in the promoter, as well as CpGs within exon 1 and the first intron. Finally, using fluorescence in situ hybridization, we show that human lung cancer cell lines and lung cancer tissues do not have a loss of the PGIS genomic region but multiple copies. These results show that an individual's PGIS promoter haplotype can play an important role in the predisposition for lung cancer and CpG methylation provides an epigenetic mechanism for the down-regulated PGIS expression.

The effects of fish oil supplementation on rumen metabolism and the biohydrogenation of unsaturated fatty acids in beef steers given diets containing sunflower oil

Duodenally and ruminally fistulated steers were offered grass silage and one of three concentrates at a ratio of 60: 40 (forage: concentrate on a dry-matter basis) : F0, F1 or F4 at 14 g/kg live weight. The concentrates were designed to be iso-lipid and to provide the same amount of sunflower oil but increasing amounts of fish oil : 0, 1 and 4 g per 100 g, respectively. Ruminal characteristics were measured along with fatty acid intakes and duodenal flows to determine the effect of fish oil on : ruminal pH, ammonia-N concentration, volatile fatty acid (VFA) concentration and polyunsaturated fatty acid (PUFA) metabolism. Fish oil had no significant effect on ruminal pH, ammonia-N concentration or the molar proportions of the major VFA, although total VFA concentration was significantly reduced at the highest level of fish oil inclusion. Fish oil significantly increased the flow of long chain PUFA, total conjugated linoleic acid and vaccenic acid to the duodenum and decreased the flow of stearic acid. Biohydrogenation, as determined by the net loss of fatty acid between the mouth and duodenum, of oleic and linolenic acid was not affected by fish oil inclusion and averaged 0·64 and 0·92, respectively. There was a small increase in the biohydrogenation of linoleic acid with increasing fish oil from 0·89 to 0·92 (P< 0·01) on F0 and F4, respectively. Biohydrogenation of the long chain PUFA C20 : 5(n-3) and C22 : 6(n-3) increased from 0·49 and 0·74 to 0·79 and 0·86 (P< 0·01), respectively when fish oil in the concentrate increased from 1 to 4 g per 100 g. The net effect of fish oil on lipid metabolism appears to inhibit the transition of vaccenic acid to stearic acid in the rumen resulting in a build up of this intermediate in the biohydrogenation pathway of C18 PUFA.

Altered lipid parameters in hepatic subcellular membrane fractions induced by fumonisin B1

Alteration of lipid constituents of cellular membranes has been proposed as a possible mechanism for cancer promotion by fumonisin B(1 )(FB(1)). To further investigate this hypothesis a dietary dosage which initiates and promotes liver cancer (250 mg FB(1)/kg) was fed to male Fischer rats for 21 days and the lipid composition of plasma, microsomal, mitochondrial and nuclear subcellular fractions determined. The effect of FB(1) on the cholesterol, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), as well as sphingomyelin (SM) and the phospholipids-associated fatty acid (FA) profiles, were unique for each subcellular membrane fraction. PE was significantly increased in the microsomal, mitochondrial and plasma membrane fractions, whereas cholesterol was increased in both the microsomal and nuclear fraction. In addition SM was decreased and increased in the mitochondrial and nuclear fractions, respectively. The decreased PC/PE and polyunsaturated/saturated (P/S) FA ratio in the different membrane fractions suggest a more rigid membrane structure. The decreased levels in polyunsaturated fatty acids in PC together with a pronounced increase in C18:1omega9 and C18:2omega6 were indicative of an impaired delta-6 desaturase. The increased omega6/omega3 ratio and decreased C20:4omega6 PC/PE ratio due to an increase in C20:4omega6 in PE relatively to PC in the different subcellular fractions suggests a shift towards prostanoid synthesis of the E2 series. Changes in the PE and C20:4omega6 parameters in the plasma membrane could alter key growth regulatory and/or other cell receptors in lipid rafts known to be altered by FB(1). An interactive role between C20:4omega6 and ceramide in the mitochondria, is suggested to regulate the balance between proliferation and apoptosis in altered initiated hepatocytes resulting in their selective outgrowth during cancer promotion effected by FB(1).

Dietary omega-3 fatty acids for women

This review details the specific needs of women for omega-3 fatty acids, including alpha linoleic acid (ALA) and the very long chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega-3 fatty acid (dietary or in capsules) ensures that a woman's adipose tissue contains a reserve of these fatty acids for the developing fetus and the breast-fed newborn infant. This ensures the optimal cerebral and cognitive development of the infant. The presence of large quantities of EPA and DHA in the diet slightly lengthens pregnancy, and improves its quality. Human milk contains both ALA and DHA, unlike that of other mammals. Conditions such as diabetes can alter the fatty acid profile of mother's milk, while certain diets, like those of vegetarians, vegans, or even macrobiotic diets, can have the same effect, if they do not include seafood. ALA, DHA and EPA, are important for preventing ischemic cardiovascular disease in women of all ages. Omega-3 fatty acids can help to prevent the development of certain cancers, particularly those of the breast and colon, and possibly of the uterus and the skin, and are likely to reduce the risk of postpartum depression, manic-depressive psychosis, dementias (Alzheimer's disease and others), hypertension, toxemia, diabetes and, to a certain extend, age-related macular degeneration. Omega-3 fatty acids could play a positive role in the prevention of menstrual syndrome and postmenopausal hot flushes. The normal western diet contains little ALA (less than 50% of the RDA). The only adequate sources are rapeseed oil (canola), walnuts and so-called "omega-3" eggs (similar to wild-type or Cretan eggs). The amounts of EPA and DHA in the diet vary greatly from person to person. The only good sources are fish and seafood, together with "omega-3" eggs.

In vivo anti-inflammatory and anti-nociceptive activities of Cheilanthes farinosa

In Ethiopia inflammatory skin diseases are among the most common health problems treated with traditional remedies which mainly comprise medicinal plants. In the present work, the anti-inflammatory and anti-nociceptive activities of Cheilanthes farinosa (Forsk.) Kaulf (Adianthaceae), a fern used in many parts of Ethiopia to treat inflammatory skin disorders, were studied using in vivo models of inflammation and pain. The results of the study showed that the fronds Cheilanthes farinosa possess strong anti-inflammatory and anti-nociceptive properties. It was further demonstrated that the active ingredients of the fern reside mainly in the methanol fraction from which three compounds viz. the flavonol glycoside rutin, and the natural cinnamic acids, caffeic acid and its quinic acid derivative chlorogenic acid have been isolated. The methanol extract was also shown to potentiate the anti-inflammatory activity of acetyl salicylic acid. At the tested concentrations, the methanol extract displayed a better anti-nociceptive activity than that of ASA in both the early and late phases of formalin induced nociception in mice. However, the activity of the extract was more pronounced in the late phase, which is commonly associated with inflammatory pain. Evaluation of the pharmacological properties of the compounds isolated from the active fractions pointed out that chlorogenic acid possesses strong anti-inflammatory and anti-nociceptive activities while caffeic acid and rutin were inactive. Moreover, on molar basis chlorogenic acid was proved to be superior in its anti-inflammatory action to acetyl salicylic acid. It was therefore concluded that chlorogenic acid contributes, in full or in part, to the anti-inflammatory and anti-nociceptive activities of Cheilanthes farinosa. Both the methanolic extract and pure chlorogenic acid failed to display anti-nociceptive activity when tested by the tail-flick test indicating that the plant is not a centrally acting analgesic but instead exerts its analgesic activity by way of its antinflammtory action.

Effects of high-sugar ryegrass silage and mixtures with red clover silage on ruminant digestion. 2. Lipids1

The experiment investigated the digestion of lipids from different forage silages in beef steers. Six Hereford x Friesian steers prepared with rumen and duodenal cannulas were given ad libitum access to a high-sugar grass silage, control grass silage, red clover silage, or mixtures of the red clover and each of the grass silages (50:50, DM basis). The experiment was conducted as an incomplete 5 x 5 Latin square, with an additional randomly repeated sequence. Total fatty acid and C18:3n-3 concentrations were greater (P < 0.05) for the high-sugar grass silage than the control grass silage or the red clover silage. Dry matter and total fatty acid intake were less (P < 0.05) for steers fed the control grass silage than for steers fed the other diets. Duodenal flow of C18:3n-3 was greater (P < 0.05), and flows of C18:0 and total C18:1 trans were less (P < 0.05), for the red clover silage compared with the 2 grass silage diets, with the mixtures intermediate. These results were supported by a reduction (P < 0.05) in biohydrogenation of C18:3n-3 for the red clover silage, with the mixtures again being intermediate. Flows of total branched- and odd-chain fatty acids were greater (P < 0.05) for the high-sugar grass silage diet, possibly as a result of greater microbial flow, because these fatty acids are associated with bacterial lipid. Duodenal flows of the chlorophyll metabolite, phytanic acid, were greater (P < 0.05) for animals fed the high-sugar grass silage treatments compared with the other treatments. These results confirm the potential for modifying the fatty acid composition of ruminant products by feeding red clover silage.

Tissue omega-6/omega-3 fatty acid ratio and risk for coronary artery disease

A ratio that estimates tissue proportions of omega-6 fatty acids (linoleic acid and/or arachidonic acid [AA]) and omega-3 fatty acids (eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA], and/or alpha-linolenic acid) has been proposed as a biomarker of risk for coronary artery disease (CAD). Use of an omega-6/omega-3 fatty acid ratio instead of either fatty acid class alone is based on theoretical reasons and has not been validated. The relationship between risk for CAD events and tissue omega-3 and omega-6 fatty acid composition was evaluated by pooling data from case-control or prospective cohort studies that examined the risk for CAD end points as a function of tissue fatty acid composition. Thirteen studies were included, 11 case-control and 2 prospective cohort studies, and case-control differences in computed averages of several fatty acids and fatty acid ratios were compared. The largest and most consistent difference was for the sum of EPA + DHA (-11% in cases, p = 0.002). Proportions of EPA, DHA, and AA were about 8% lower in cases, but none of these differences was significant. Total omega-3 and omega-6 fatty acids were lower by 7% and 4%, respectively, in cases versus controls, but only the total omega-3 fatty acid difference was significant. The AA/EPA ratio was nonsignificantly lower by 10% in cases. Fatty acid ratios generally failed to distinguish cases from controls, and any discriminatory power they had derived from the omega-3 fatty acid component. Tissue EPA + DHA appears to be the best fatty acid metric for evaluating for CAD risk.

Microsomal prostaglandin E synthase-1 regulates human glioma cell growth via prostaglandin E2–dependent activation of type II protein kinase A

Dysregulation of enzymes involved in prostaglandin biosynthesis plays a critical role in influencing the biological behavior and clinical outcome of several tumors. In human gliomas, overexpression of cyclooxygenase-2 has been linked to increased aggressiveness and poor prognosis. In contrast, the role of prostaglandin E synthase in influencing the biological behavior of human gliomas has not been established. We report that constitutive expression of the microsomal prostaglandin E synthase-1 (mPGES-1) is associated with increased prostaglandin E(2) (PGE(2)) production and stimulation of growth in the human astroglioma cell line U87-MG compared with human primary astrocytes. Consistently, pharmacologic and genetic inhibition of mPGES-1 activity and expression blocked the release of PGE(2) from U87-MG cells and decreased their proliferation. Conversely, exogenous PGE(2) partially overcame the antiproliferative effects of mPGES-1 inhibition and stimulated U87-MG cell proliferation in the absence of mPGES-1 inhibitors. The EP2/EP4 subtype PGE(2) receptors, which are linked to stimulation of adenylate cyclase, were expressed in U87-MG cells to a greater extent than in human astrocytes. PGE(2) increased cyclic AMP levels and stimulated protein kinase A (PKA) activity in U87-MG cells. Treatment with a selective type II PKA inhibitor decreased PGE(2)-induced U87-MG cell proliferation, whereas a selective type I PKA inhibitor had no effect. Taken together, these results are consistent with the hypothesis that mPGES-1 plays a critical role in promoting astroglioma cell growth via PGE(2)-dependent activation of type II PKA.

Arachidonic acid preserves hippocampal neuron membrane fluidity in senescent rats

Previous studies indicate that long-term dietary supplementation with arachidonic acid (AA) in 20-month-old rats (OA) effectively restores performance in a memory task and the induction of long-term potentiation in the hippocampus to the level of young control animals (YC). The present study examined protein mobility using the live cell imaging technique "Fluorescent Recovery After Photobleaching (FRAP)" in YC, old control (OC) and OA neurons in hippocampal slice preparations. Three measures; mobile fraction (M(f)), diffusion constant (D) and time constant (tau), were estimated among YC, OC and OA. Each of these parameters was significantly different between OC and YC, suggesting that membrane fluidity is lower in OC than in YC. In contrast, D and tau were comparable in OA and YC, indicating that hippocampal neuronal membranes supplemented with AA were more fluid than those in OC, whereas the fraction of diffusible protein in the bleached region remained smaller than in YC. Long-term administration of AA to senescent rats might help to preserve membrane fluidity and maintain hippocampal plasticity.

Syntheses and evaluation of novel fatty acid-second-generation taxoid conjugates as promising anticancer agents

Polyunsaturated fatty acids such as docosahexaenoic acid (DHA), linolenic acid, and linoleic acid were linked to the C-2' position of the second-generation taxoids that could overcome MDR caused by overexpressed ABC transporters. The new conjugates, tested in vivo, exhibited strong activity against drug-resistant colon cancer and drug-sensitive ovarian cancer xenografts in mice. Two of the new conjugates, DHA-SB-T-1214 and DHA-SB-T-1213, were found to achieve the total regression of drug-resistant and drug-sensitive tumors, respectively, in the animal models with substantially reduced systemic toxicity.

Recent advances in tumor-targeting anticancer drug conjugates

Traditional cancer chemotherapy relies on the premise that rapidly proliferating cancer cells are more likely to be a killed by cytotoxic agent. In reality, however, cytotoxic agents have very little or no specificity, which leads to systemic toxicity, causing severe undesirable side effects. Therefore, various drug delivery protocols and systems have been explored in the last three decades. Tumor cells overexpress many receptors and biomarkers, which can be used as targets to deliver cytotoxic agents into tumors. In general, a tumor-targeting drug delivery system consists of a tumor recognition moiety and a cytotoxic warhead connected directly or through a suitable linker to form a conjugate. The conjugate, which can be regarded as 'prodrug', should be systemically non-toxic. This means that the linker must be stable in circulation. Upon internalization into the cancer cell the conjugate should be readily cleaved to regenerate the active cytotoxic agent. Tumor-targeting conjugates bearing cytotoxic agents can be classified into several groups based on the type of cancer recognition moieties. This review describes recent advances in tumor-targeting drug conjugates including monoclonal antibodies, polyunsaturated fatty acids, folic acid, hyaluronic acid, and oligopeptides as tumor-targeting moieties.

Ratio of n6 to n-3 Fatty Acids in the Diet Affects Tumor Growth and Cachexia in Walker 256 Tumor-Bearing Rats

In this study we investigate the impact of the dietary ratio of n-6 to n-3 fatty acids (FAs) from postweaning until adult age upon tumor growth, lipid peroxidation in tumor tissue, and metabolic indicators of cancer cachexia in Walker 256 tumor-bearing rats. Weanling male Wistar rats received a normal low-fat (40 g/kg diet) chow diet or high-fat diets (300 g/kg) that included fish oil (FO) or sunflower oil or blends of FO and sunflower oil to yield n-6 to n-3 FA ratios of approximately 6:1, 30:1, and 60:1 ad libitum. After 8 wk, half of each group was inoculated with 1 ml of 2 x 10(7) Walker 256 cells. At the 14th day after tumor inoculation, the animals were killed, and tumors and blood were removed. The different diets did not modify the blood parameters in the absence of tumor bearing, except the high-FO diet, which decreased serum cholesterol and triacylglycerol concentrations. Tumor weight in chow-fed rats was 19 g, and these rats displayed cancer cachexia, characterized by hypoglycemia, hyperlacticidemia, hypertriacylglycerolemia, loss of body weight, and food intake reduction. Tumor weight in FO-fed rats was 7.7 g, and these animals gained body weight (14.6 g) and maintained blood metabolic parameters similar to non-tumor-bearing animals. Tumor weight in rats fed the diet with an n-6 to n-3 FA ratio of 6:1 was similar to tumor-bearing, chow-fed rats, but they gained 2 g in the body weight and blood metabolic parameters were similar to those in non-tumor-bearing rats. However, a further increase in the n-6 FA content of the diet did not change the cachectic state associated with tumor bearing. In this experimental model, a dietary n-6 to n-3 FA ratio of 6:1 was able to increase food intake and body weight, restore the biochemical blood parameters of cachexia, and prevent the development of cancer cachexia.

Dietary modulation of fatty acid profiles and oxidative status of rat hepatocyte nodules: effect of different n-6/n-3 fatty acid ratios

Male Fischer rats were fed the AIN 76A diet containing varying n-6/n-3 FA ratios using sunflower oil (SFO), soybean oil (SOY), and SFO supplemented with EPA-50 and GLA-80 (GLA) as fat sources. Hepatocyte nodules, induced using diethylnitrosamine followed by 2-acetylaminofluorene/partial hepatectomy promotion, were harvested, with surrounding and respective dietary control tissues, 3 mon after partial hepatectomy. The altered growth pattern of hepatocyte nodules in rats fed SFO is associated with a distinct lipid pattern entailing an increased concentration of PE, resulting in increased levels of 20:4n-6. In addition, there is an accumulation of 18:1 n-9 and 18:2n-6 and a decrease in the end products of the n-3 metabolic pathway in PC, suggesting a dysfunctional delta-6-desaturase enzyme. The hepatocyte nodules of the SFO-fed rats exhibited a significantly reduced lipid peroxidation level that was associated with an increase in the glutathione (GSH) concentration. The low n-6/n-3 FA ratio diets significantly decreased 20:4n-6 in PC and PE phospholipid fractions with a concomitant increase in 20:5n-3, 22:5n-3, and 22:6n-3. The resultant changes in the 20:4/20:5 FA ratio and the 20:3n-6 FA level in the case of the GLA diet suggest a reduction of prostaglandin synthesis of the 2-series. The GLA diet also counteracted the increased level of 20:4n-6 in PE by equalizing the nodule/surrounding ratio. The low n-6/n-3 ratio diets significantly increased lipid peroxidation levels in hepatocyte nodules, mimicking the level in the surrounding and control tissue while GSH was decreased. An increase in n-3 FA levels and oxidative status resulted in a reduction in the number of glutathione-S-transferase positive foci in the liver of the GLA-fed rats. Modulation of cancer development with low n-6/n-3 ratio diets containing specific dietary FA could be a promising tool in cancer intervention in the liver.

Expression of PPAR, RXR isoforms and fatty acid transporting proteins in the rat and human gastrointestinal tracts

Dietary fatty acid (FA) absorption across the gastrointestinal (GI) tract is of critical importance for sustenance, however, excessive FA absorption has also been linked to metabolic syndrome and associated disorders. The expression of isoforms that regulate the dietary FA absorption are not as well characterized in the GI tract as they are elsewhere. Peroxisome proliferator-activated receptors (PPARalpha, beta, and gamma) and 9-cis-retinoic acid receptors (RXRalpha, beta, and gamma) are nuclear hormone transcription factors that control FA homeostasis, in part through the regulation of expression of membrane-bound FA transporting proteins. The present study was designed to elucidate the expression of PPAR and RXR isoforms and FA transporting proteins (FABPpm and FAT/CD36) in the rat and human GI tracts using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemical staining. The results revealed rat GI expression of all the PPAR and RXR isoforms, FABPpm and FAT/CD36. PPARalpha, PPARbeta, PPARgamma, RXRalpha, FABPpm, and FAT/CD36 isoforms exhibited ubiquitous expression in human GI tract, whereas RXRbeta was not detected. RXRgamma was observed in a majority of the human GI samples. These results provide a physiological foundation for rational drug design and drug delivery for the mitigation of metabolic syndrome and associated disorders to normalize intestinal FA absorption.

Content and composition of fatty acids in normal and inflamed gingival tissues

The balance of essential fatty acid is important for good health and normal development. Essential fatty acids (EFA) are the precursors of prostaglandins (PGs), thromboxanes and leukotrienes (LT). The aim of this clinical study was to determine the total fatty acid level of polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), saturated fatty acids (SFA) and each fatty acids level of inflamed and normal gingival tissues. Twenty-seven subjects were included the present study. Nineteen samples of inflamed human gingival tissue (nine of fibrous hyperplasia (FH), ten of peripheral giant cell granuloma (PGCG) and eight samples of normal human gingival tissue were analyzed. The characteristics of inflammation were assessed histologically. Variance analyses were performed to assess the differences among tissues. The total cellular fatty acid profiles of the tissues in inflamed human gingival tissue and in eight samples of normal human gingival tissue were determined by gas chromatography using Sherlock microbial identification system (MIS) software (Microbial ID, Newark, DE, USA) with a database of FAME profiles for eukary. PUFAs, MUFAs, and SFAs were quantified by Sherlock microbial identification system (MIS) or database gas chromatography (DGC). There were statistically significant differences between the concentrations in inflamed (FH, PGCG) and healthy gingival tissues for PUFA and MUFA (P<0.001, P<0,011, respectively). There were statistically significant differences among the concentrations in FH, PGCG, and healthy gingival tissues for SFA (P<0.0001). Arachidonic acid, docosahexaenoic acid, linoleic acid were increased in inflamed tissue. The results of this study showed that unsaturated fatty acids (PUFA and MUFA) significantly increased in inflamed gingival tissues.

Long-chain (n-3) fatty acid intake and risk of cancers of the breast and the prostate: recent epidemiological studies, biological mechanisms, and directions for future research

The association between dietary (n-3) fatty acids and hormone-responsive cancers continues to attract considerable attention in epidemiological, clinical, and experimental studies. We previously reviewed the epidemiological literature on the association between hormone-responsive cancers and the long-chain fatty acids eicosapentaenoic acid and docosahexaenoic acid. We concluded that the compelling evidence from ecological studies, animal models, and mechanistic experiments in vitro was not supported clearly by the available epidemiological data. To various degrees, epidemiological studies published more recently attempted to address some of the methodological limitations plaguing earlier studies by using validated questionnaires, examining specific fatty acids and their interrelationships, and adjusting estimates for a wider range of potentially confounding factors than in previous studies. In this review, our aim was to update the previous review with the results of recent epidemiological studies and to discuss possible biological mechanisms and directions for future research.

Translational regulation of gene expression by omega-3 fatty acids

The incidence of some cancers shows dramatic variations around the world that cannot be explained by ethnic or racial differences. Observational studies point to a negative correlation between consumption of fish and incidence of breast and prostate cancer. In vitro and animal model studies indicate that (omega-3) PUFAs present at high concentrations in marine animals inhibit proliferation of cancer cells and growth of tumors. However, how these fatty acids inhibit cell proliferation and tumor growth is a matter of considerable debate. In this review we summarize our recent work indicating that Ca(++) depletion mediated phosphorylation of the alpha subunit of eIF2 and subsequent inhibition of translation initiation account for the anti-cancer activity of (omega-3) PUFAs.

The role of carotenoids in the prevention of human pathologies

Reactive oxygen species (ROS) and oxidative damage to biomolecules have been postulated to be involved in the causation and progression of several chronic diseases, including cancer and cardiovascular diseases, the two major causes of morbidity and mortality in Western world. Consequently dietary antioxidants, which inactivate ROS and provide protection from oxidative damage are being considered as important preventive strategic molecules. Carotenoids have been implicated as important dietary nutrients having antioxidant potential, being involved in the scavenging of two of the ROS, singlet molecular oxygen (1O2) and peroxyl radicals generated in the process of lipid peroxidation. Carotenoids are lipophilic molecules which tend to accumulate in lipophilic compartments like membranes or lipoproteins. Chronic ethanol consumption significantly increases hydrogen peroxide and decreases mitochondrial glutathione (GSH) in cells overexpressing CYP2E1. The depletion of mitochondrial GSH and the rise of hydrogen peroxide are responsible for the ethanol-induced apoptosis. Increased intake of lycopene, a major carotenoid in tomatoes, consumed as the all-trans-isomer attenuates alcohol induced apoptosis in 2E1 cells and reduces risk of prostate, lung and digestive cancers. Cancer-preventive activities of carotenoids have been associated as well as with their antioxidant properties and the induction and stimulation of intercellular communication via gap junctions which play a role in the regulation of cell growth, differentiation and apoptosis. Gap junctional communication between cells which may be a basis for protection against cancer development is independent of the antioxidant property.

Anti-HCV activities of selective polyunsaturated fatty acids

HCV infection can lead to chronic infectious hepatitis disease with serious sequelae. Interferon-alpha, or its PEGylated form, plus ribavirin is the only treatment option to combat HCV. Alternative and more effective therapy is needed due to the severe side effects and unsatisfactory curing rate of the current therapy. In this study, we found that several polyunsaturated fatty acids (PUFAs) including arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) are able to exert anti-HCV activities using an HCV subgenomic RNA replicon system. The EC(50) (50% effective concentration to inhibit HCV replication) of AA was 4microM that falls in the range of physiologically relevant concentration. At 100microM, alpha-linolenic acid, gamma-linolenic, and linoleic acid only reduced HCV RNA levels slightly and saturated fatty acids including oleic acid, myristic acid, palmitic acid, and steric acid had no inhibitory activities toward HCV replication. When AA was combined with IFN-alpha, strong synergistic anti-HCV effect was observed as revealed by an isobologram analysis. It will be important to determine whether PUFAs can provide synergistic antiviral effects when given as food supplements during IFN-based anti-HCV therapy. Further elucidation of the exact anti-HCV mechanism caused by AA, DHA, and EPA may lead to the development of agents with potent activity against HCV or related viruses.