This diploma thesis deals with the issue of fatty acids containing distribution, metabolism, physiological properties and effects on health. In the experimental part there is detail descripiton of the experiment, where the amount of dietary fatty acids in the liver and visceral fat in rats was determined. Rats were divided into five groups, each of that was fed with mixture with 8% oil addition (palm oil, fish oil, safflower oil and Schizochytrium extract). The last group was fed with the mixture without any oil addition. The results of the experiment point to a high SFA content in feed with 8% fish oil addition. Although fish oil contains a significant amount of n-3 PUFA, high deposition of SFA could have negative effects on plasma lipid and lipoprotein levels. The most suitable oil is Schizochytrium microalga extract, which has a positive effect on EPA and DHA deposition, but does not contain significant amount of SFA, MUFA and PUFA n 6. Regarding the ratio of PUFA n-6/n-3, fish oil appears to be the second most suitable. The least suitable PUFA n-6/n-3 ratio is observed in safflower and palm oil.

The aim of this study was to determine whether there is an influence of the active components of the fish oil, in particular polyunsaturated fatty acids n3 (PUFA n3) on expression of selected proteins which modulate the inflammatory response in model organisms pig. In the n3 PUFA is to assume that over signaling pathway PPARgamma, NFkappaB, increase adiponectin production, inhibit the production of proinflammatory cytokines, increase antiinflammatory cytokines production, thereby suppressing the inflammatory response in the body. This hypothesis was tested on 32 pigs, which were divided into two groups of 16 pieces in each group. The first experimental group was fed the basic feed mixture enriched with 2.5% fish oil (F) and the second control group was fed the basic feed with 2.5% palm oil (P). Last day of fattening pigs were 8 F and 8 P pigs intravenously application lipopolysaccharide (LPS) to induce an inflammatory response, the rest of group left without LPS stimulation, followed by intramuscular application of anesthetics and defeat. By Western blot was measured protein expression PPARgamma and NFkappaB in selected tissues, by ELISA concentration of adiponectin in plasma and by multiplex analysis plasma levels of cytokines. The results indicate that PPARgamma concentration in the F adipocytes after LPS stimulation tended to increase by 21% in comparison with P control stimulation with LPS, but the result was not statistically significant (P> 0.05; P = 0.11). Further, the F pigs stimulation with LPS as compared with intact F counterparts trend toward increased plasma levels of adiponectin by 18%, which was likely a reflection of the tendency to higher values in adipocytes by 18% (P> 0.05, p = 0.12), result was not statistically significant. Plasma adiponectin took on the same values of 21.1 ng x mL-1 in experimental and control groups (P> 0.05). Elevation (P <0.05) of NFkappaB in fatty tissue F pigs after LPS stimulation. In addition, the plasma level of anti-inflammatory IL4 and IL10 interleukins, as well as the proinflammatory cytokine TNFalfa, was increased (P <0.05) in the F group of pigs stimulated with LPS. The results of the present experiment are thus ambiguous. The hypothesis of the effect of fish oil or n3 PUFA to suppress the inflammatory response cannot this experiment conclusively confirmed.

Aquatic habitats are closely linked to surrounding terrestrial environments via reciprocal subsidies. Much of the research on these subsidies has been focused on streams, while subsidies across aquatic-terrestrial boundaries of other aquatic systems, like temporary ponds, have received little attention. Temporary ponds are seasonally inundated aquatic habitats and patterns of energy transport across transient aquatic-terrestrial boundaries are not well understood. To address the lack of information regarding these cross-habitat subsidies, I quantified: 1) leaf litter inputs, 2) amphibian egg inputs, 3) terrestrial insect inputs, 4) amphibian metamorph emergence, and 5) aquatic insect emergence for eight temporary ponds. Terrestrial insect inputs to ponds represented substantial high-quality subsidies to ponds that are generally unaccounted for in similar studies. While larger ponds produced greater total fluxes to terrestrial habitats, smaller ponds were often more productive per unit area. Therefore, a mosaic of small ponds may produce greater or equivalent subsidies and may be of greater value to terrestrial food webs than a single large pond. Resource subsidies of energy and nutrients can be transported via physical forces or biotic processes, such as animal migration or emigration. I quantified net nutrient fluxes associated with amphibian migrations across aquatic-terrestrial boundaries of eight temporary ponds in Illinois. I measured carbon (C), nitrogen (N), and phosphorus (P) subsidies from forests to ponds, in the form of eggs, and the reciprocal subsidies from ponds to forests via juvenile emigration. Juvenile emergence biomass did not resemble egg biomass, as not all species bred successfully in each pond, resulting in variability in the magnitude of nutrient fluxes both across ponds and species. The forest was not always the recipient system of net nutrient fluxes. Hydroperiod, trophic interactions, and species composition explained some dynamics of N and P subsidies. Most studies have focused on the magnitude of cross-boundary fluxes, but the impact of a subsidy is mediated by the size of the flux as well as the quality and relative abundance of similar resources in the recipient habitat. Long-chain polyunsaturated fatty acids (LC-PUFAs) are necessary for proper physiological function, are unevenly distributed across the landscape, and animals differ greatly in their ability to synthesize them de novo. This creates the potential for limitation and increases their possible importance as a subsidy. I examined LC-PUFA tissue concentration and export in eight species of emerging amphibian metamorphs across eight temporary ponds in a wetland complex. I found that tissue concentrations and export of LC-PUFAs varied across species, but were generally within the ranges of several freshwater fish and aquatic insects. Anurans exported higher amounts of LC-PUFAs than salamanders, largely due to the higher emergence biomass of anurans. Further, I explored fatty acid profiles and immune function of wolf spiders in wetland and upland habitats. Wetland spiders had higher tissue levels of aquatic-derived LC-PUFAs and elevated immune function compared to upland spiders. These patterns suggest aquatically derived nutrients, such as LC-PUFAs, may benefit organisms exploiting freshwater habitats.

Mammary cancer is one of the leading causes of death in both the human and companion animal population. There are many histological and pathophysiological similarities between human and feline mammary cancer, therefore investigating the molecular pathways of disease progression in one species may provide useful information for both. The EGFR/MAPK signal transduction pathway is upregulated in many human breast tumors, and both EGFR and MAPK have been implicated as independent prognostic indicators for decreased survival times in human breast cancer patients. We report here that active MAPK levels can be detected in both peripheral white blood cells (WBC) and mammary adipose tissue in cats. Adipose tissue levels of active MAPK were similar to those observed in peripheral WBC, suggesting that WBC MAPK might serve as a useful biomarker in the diagnosis or follow-up treatment of disease. PUFA have been reported to influence breast cancer risk in humans, and may modulate the EGFR/MAPK pathway through a variety of mechanisms. Dietary PUFA n-6-to-n-3 ratio in cats was reflected in mammary adipose tissue and resulted in altered active MAPK levels in both adipose tissue and peripheral white blood cells, suggesting that PUFA may have similar effects on the feline and human MAPK pathway. In human breast tumor cell line studies, rather than having opposing effects, as was hypothesized, it was demonstrated that n-6 and n-3 PUFA exerted similar effects on EGFR+ breast tumor cell proliferation and activity of the EGFR/MAPK pathway. Slightly more than twice the concentration of n-3 PUFA was needed to elicit the same response as n-6 in cells. These results indicate n-6 and n-3 PUFA can modulate proliferation of EGFR+ tumor cells similarly and may be exerting their effects, in part, through the EGFR/MAPK pathway. Decreasing total PUFA intake, while increasing the n-3-to-n-6 PUFA ratio, may be practical as preventative or adjuvant therapy for breast cancer. / Ph. D.

La picoalgue verte marine Ostreococcus tauri est un eucaryote minimal développé en système modèle et qui a servi de ressource de gènes en biologie des lipides. Des informations détaillées sur ces caractéristiques lipidiques étaient cependant manquantes. Lors de ma thèse j’ai caractérisé le glycérolipidome d’O. tauri et ai cherché à déterminer quelles sont les cibles enzymatiques responsables de la dynamique des acides gras (FA) et de la régulation du métabolisme lipidique en réponse à des modifications de l’environnement (carences nutritives et refroidissement). O. tauri présente des caractéristiques uniques de composition en lipides et en FA mixtes entre les algues vertes et les Chromalveolates, et a été validé comme espèce modèle pour la classe des Mamiellophyceae. L’acide docosahexaénoïque (DHA) est confiné dans les lipides présumés extraplastidiaux : le phosphatidyldimethylpropanethiol (PDPT) et le bétaïne-lipide diacylglyceryl-hydroxymethyl-trimethyl-β-alanine (DGTA), tous deux marqueurs lipidiques des Chromalveolates. Les lipides plastidiaux de type procaryotique sont caractérisés par une prépondérance de FA polyinsaturés (PUFA) en C18 n-3, le 18:5 n-3 étant restreint aux galactolipides. Le 16:4 n-3, PUFA typique des galactolipides des microalgues vertes, est également un composant majoritaire des lipides extraplastidiaux chez O. tauri. Les triacylglycérols (TAG) présentent tout le panel d’acides gras d’O. tauri et leurs combinaisons moléculaires indiquent une origine plastidiale majoritaire. La carence azote provoque une forte accumulation de TAG, notamment des espèces présentant des combinaisons sn-1/sn-2 en 18:X/16:X et s'accompagne d'un transfert de carbone du phosphatidylglycérol (PG) et du monogalactosyldiacylglycérol (MGDG) aux TAG ce qui indique une contribution croissante de la voie plastidiale à la synthèse des TAG. Des expériences préliminaires de RT-qPCR sur des gènes du métabolisme des TAG révèlent une forte activation transcriptionnelle de certaines diacylglycérol acyltransférases (DAGT). Les carences nutritives répriment sévèrement l’activité Δ6 désaturase, générant une inversion du ratio 18:3/18:4 dans les lipides plastidiaux qui se répercute dans les TAG. La régulation fine et dynamique de ce ratio suggère un rôle important du 18:3 et du 18:4 dans les membranes plastidiales. Le refroidissement engendre une augmentation spécifique du 18:5 des galactolipides. La recherche active de la désaturase responsable de ce phénotype par une approche d'expression de gènes candidats en systèmes homologue et hétérologues (S. cerevisiae, N. Benthamiana) a conduit à l’indentification de deux Δ6 désaturases plastidiales jamais caractérisées dans d'autres systèmes. Celles-ci possèdent des spécificités non redondantes et originales entre elles et par rapport à l'acyl-CoA-Δ6 d'O. tauri. / The marine green picoalga Ostreococcus tauri is a minimal eukaryote implemented as model system that has been used as gene resource for lipid biology. Detailed information about its lipidic features was however missing. During my PhD, I characterized O. tauri glycerolipidome and associated dynamics under environmental stresses such as nutrient starvations and chilling and investigated transcriptional variations of putative target enzymes responsible for these changes. O. tauri which could be validated as model for related species of the class Mamiellophyceae, was found to display unique lipidic features related to both green and Chromalveolates microalgae. Docosahexaenoic acid (DHA) is confined to presumed extraplastidial lipids i.e. phosphatidyldimethylpropanethiol (PDPT) and the betaine lipid diacylglyceryl-hydroxymethyl-trimethyl-β-alanine (DGTA); all of these compounds are hallmarks of Chromalveolates. Plastidial lipids found to be of prokaryotic type are characterized by the overwhelming presence of C18 n-3 polyunsaturated FA (PUFA), 18:5 n-3 being restricted to galactolipids. C16:4 n-3, an FA typical of green microalgae galactolipids, also was a major component of O. tauri extraplastidial lipids. Triacylglycerols (TAGs) display the complete panel of FAs, and their molecular combinations designate a major plastidial origin of DAG precursors. Nitrate starvation greatly increases TAG content, in particular 18:X/16:X (sn-1/sn-2) combinations, and was associated with the transfer of carbon from phosphatidylglycerol (PG) and monogalactosyldiacylglycerol (MGDG) to TAG indicating an increased contribution of the plastidial pathway to the TAG synthesis. Preliminary RT-qPCR experiments on TAG metabolism genes revealed an important transcriptional activation of some diacylglycerol acyltransferases (DGAT). Nutrient starvations severely repress Δ6 desaturase activity and result in the inversion of the 18:3/18:4 ratio in plastidial lipids that was feedback into TAG. The fine-tuning and dynamic regulation of the 18:3/18:4 ratio suggests an important physiological role of these FAs in photosynthetic membranes. Chilling generates an increase of 18:5 in galactolipids. The active quest for the desaturases responsible for this phenotype was achieved by expressing candidate genes in homologuous and heterologous (S. cerevisiae, N. Benthamiana) systems and led to the identification of two yet uncharacterized plastidial Δ6 desaturases. These desaturases display original and non-redundant specificity between each other and with the previously characterized in O. tauri Δ6 acyl-CoA desaturase.

The aim of this thesis was to investigate the effects of dietary fatty acids on body composition and ectopic fat in humans, with emphasis on the role of the omega-6 polyunsaturated fatty acid (PUFA) linoleic acid (18:2n-6) and the saturated fatty acid (SFA) palmitic acid (16:0). The overall hypothesis was that linoleic acid would be beneficial compared with palmitic acid during overfeeding, as previously indicated in animals. Papers I, II and IV were double-blinded, randomized interventions in which different dietary fats were provided to participants and Paper III was a cross-sectional study in a community-based cohort (PIVUS) in which serum fatty acid composition was assessed as a biomarker of dietary fat intake. In Paper I, overfeeding with sunflower oil (n-6 PUFA) for 7 weeks caused less accumulation of liver fat, visceral fat and total body fat (as assessed by MRI) compared with palm oil (SFA) in young and lean subjects despite similar weight gain among groups. Instead, sunflower oil caused a larger accumulation of lean tissue. In Paper II, plasma from Paper I was analyzed with NMR-based metabolomics, aiming to identify metabolites differentially affected by the two dietary treatments. Acetate decreased by PUFA and increased by SFA whereas lactate increased by PUFA and decreased by SFA. In Paper III, the proportion of linoleic acid in serum was inversely associated with contents of visceral-, subcutaneous- and total body adipose tissue whereas the proportion of palmitic acid was directly associated with visceral- and total body adipose tissue in 70-year old men and women. In Paper IV, overfeeding with sunflower oil for 8 weeks caused less accumulation of liver fat compared with palm oil also in overweight and obese subjects. SFA increased visceral fat in men only. Accumulation of lean tissue was similar between groups. In conclusion, SFA (palmitic acid) from palm oil promotes marked liver fat accumulation in both normal-weight and overweight/obese subjects during overeating, whereas n-6 PUFA (linoleic acid) from sunflower oil prevents such liver fat accumulation. Diverging effects of SFA and PUFA on visceral adipose tissue and lean tissue may only be applicable in some groups and/or circumstances. These results imply that negative effects associated with weight gain (e.g. fatty liver) may be partly counteracted by the type fat in the diet, overall supporting a beneficial role of diets higher in unsaturated fat compared with saturated fat for preventing liver fat accumulation.

Un statut pauvre en Acides Gras Poly-Insaturés ω3 (AGPI ω3), favorisé par une alimentation occidentale comportant un faible ratio en ω3/ω6, semble contribuer au déclin cognitif chez les personnes âgées, mais les mécanismes cellulaires impactés sont encore mal connus. Nous avons donc étudié l’influence du statut en ω3 sur l’évolution de la neurotransmission glutamatergique et des fonctions astrocytaires au cours du vieillissement dans l’hippocampe de rats. Ces processus sont impliqués dans la formation de la mémoire et leurs dérégulations participent aux dommages cérébraux conduisant au déclin cognitif. Nous avons comparé 6 groupes de rats agés de 6 et 22 mois nourris avec un régime déficient en ω3, équilibré en ω3/ω6 ou supplémenté en ω3 (huile de poisson) : Jeunes équilibrés (JEq), déficients (JDef) ou supplémentés (JSup) et Agés équilibrés (AEq), déficients (ADef) ou supplémentés (ASup). Nous avons évalué l’efficacité synaptique et la plasticité (enregistrements électrophysiologiques), les fonctions astrocytaires (capture de glutamate et expression de la GFAP), les marqueurs neuronaux (transporteurs et récepteurs du glutamate), les capacités cognitives (Openfield et Labyrinthe de Barnes) et analysé la composition lipidique cérébrale. Les manipulations nutritionnelles d’apport en ω3 modifient efficacement l’incorporation de l’acide docosahexaénoïque (DHA, principale ω3 des membranes cellulaires) dans le cerveau (-50% deficient vs équilibré, +10% supplementé vs équilibré). Le vieillissement induit une diminution de 35% de l’efficacité synaptique en raison d’une baisse de la libération de glutamate pré-synatique, et une diminution de 30% de la capture de glutamate associé à une astrogliose conséquente (+100% GFAP). La déficience en ω3 acentue les effets du vieillissement (rats ADef vs AEq: -35% efficacité synaptique, -15% capture de glutamate, +30% GFAP). Al’inverse, la supplémentation en ω3 améliore l’efficacité synaptique (rats ASup vs AEq +25%) et semble inhiber l’astrogliose chez le rat âgé (ASup vs JEq : pas de modification de la GFAP). Les tests comportementaux montrent que le vieillissement a des effets plus marqués chez les déficients en ω3 et au contraire atténués chez les supplémentés. Nos résultats révèlent des altérations de la synapse glutamatergique de l’hippocampe au cours du vieillissement aggravées par la déficience en ω3 et atténuées par la supplémentation en ω3. Afin d’évaluer l’influence du statut en ω3 sur l’activation astrocytaire, des modèles in vitro d’astrocytes « âgés » et « activés » par des cytokines inflammatoires dont l’augmentation à bas bruit est caractéristique du vieillissement cérébral, ont été développés. / A poor ω3 polyunsaturated fatty acids (ω3 PUFA) status, favored by the low ω3/ω6 ratio in western diets, seems to contribute to cognitive decline in the elderly, but mechanistic evidence is lacking. We therefore explored the impact of ω3 status on the evolution of glutamatergic transmission and astrocytic functions in the hippocampus during ageing in rats. These processes are involved in memory formation and their dysregulation participates to the age-related brain damage leading to cognitive decline. We have compared 6 groups of rats aged 6 to 22 months fed ω3-deficient, ω3/ω6-balanced, or ω3 (fish oil) supplemented diets: Young ω3 Balanced (YB), Deficient (YD) or Supplemented (YS), and Old ω3 Balanced (OB), Deficient (OD) or Supplemented (OS) rats. We have evaluated synaptic efficacy and plasticity (electrophysiological recording), astroglial regulations (glutamate uptake and GFAP expression), neuronal markers (glutamate transporters and receptors), cognitive abilities (Barnes maze and Openfield) and analyzed brain fatty acids composition. Dietary modulation of ω3 intakes efficiently modified the incorporation of docosahexaenoic acid (DHA, the main ω3 in cell membranes) in brain (-50% deficient vs balanced, +10% supplemented vs balanced). Ageing induced a 35% reduction of synaptic efficacy due to decreased pre-synaptic glutamate release, and a 30% decrease in the astroglial glutamate uptake associated to a marked astrogliosis (+100% GFAP). ω3 deficiency further decreased these hallmarks of ageing (OD vs OB rats: -35% synaptic efficacy, -15% glutamate uptake, +30% GFAP). On the opposite, ω3 supplementation increased synaptic efficacy (+25% OS vs OD) and seems to abolish astrogliosis (OS vs YS : no change in GFAP). Behavioural tests showed some increased effects of age in deficient rats and attenuated effects in supplemented ones. Our results characterize some specific age-related alterations of the glutamatergic synapse in the hippocampus that are aggravated by a dietary deficit in ω3 and attenuated by ω3 supplementation. In order to explore ω3 status on astrocytic activation, in vitro models of “old” astrocytes and “activated” by inflammatory cytokines which characterize the low-grade inflammation in brain aging, have been developed.

Significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the hypothesis that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells which are deficient in polyunsaturated fatty acids (PUFAs), and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50% reduction of the postmetamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha lead to irreversible effects for postmetamorphic animals, and is related to inferior competitive abilities.

En els últims anys, s’ha estudiat com els agents antiinflamatoris presents en els aliments poden modular la inflamació relacionada amb diverses malalties. Les procianidines presents en fruites i vegetals i els àcids grassos poliinsaturats (PUFAs) presents en peix i els olis derivats d’ells són compostos que tenen diferents propietats antiinflamatòries en front de diverses malalties com l’obesitat, la diabetis i malalties cardiovasculars. L’objectiu del nostre estudi va ser investigar diferents aspectes i mecanismes relacionats amb l’eficàcia d’un extracte de procianidines de pinyol de raïm (GSPE) en front de l’estat inflamatori crònic en rates Zucker fa/fa genèticament obeses, i d’un estat inflamatori agut activat per la injecció de lipopolisacàrids (LPS) en rates Wistar. Una dosi moderada de 35 mg/kg per dia de GSPE durant 10 setmanes va produir efectes antiinflamatoris sobre l’expressió gènica en teixit adipós mesentèric en les rates Zucker fa/fa. Tot i així, no es van trobar efectes significatius en la inflamació sistèmica. A més, el GSPE va tenir efectes antiinflamatoris a nivell sistèmic i en l’expressió gènica quan es va administrar durant 15 dies previs a la inducció de la inflamació per LPS en rates Wistar. La dosi alta nutricional de 75 mg/kg per dia i la dosi alta farmacològica de 200 mg/kg per dia de GSPE van ser les més efectives en prevenir aquesta inflamació. Per altra banda, diferents molècules bioactives com els flavonoides resveratrol (RES), epigal•locatequina gal•lat, i les procianidines dimèriques B1-B4, i els PUFAs EPA i DHA van ser administrats en combinació per analitzar els efectes antiinflamatoris sinèrgics, additius o antagònics en macròfags estimulats amb LPS. Les combinacions de B3 més EPA i RES més EPA van mostrar efectes antiinflamatoris sinèrgics disminuint els nivells d’òxid nítric, els nivells d’expressió de gens proinflamatoris i relacionats amb l’estrès oxidatiu, i modulant la fosforilació de diferents proteïnes involucrades en l’activació de les vies proinflamatòries senyalitzadores de l’NF-κB i de l’AP-1. / The study of how anti-inflammatory agents found in food can mediate in various diseases in which inflammation is involved has become relevant in recent years. Procyanidins present in fruits and vegetables and polyunsaturated fatty acids (PUFAs) present in fish and fish oils are compounds that have anti-inflammatory properties against several diseases such as obesity, diabetes and cardiovascular disease. The goal of this study was to investigate some aspects and mechanisms related to the reported efficacy of grape seed procyanidin extract (GSPE) against the inflammatory state in the genetically obese Zucker fa/fa rat model with low-chronic inflammation and a model of acute inflammation triggered by the injection of lipopolysaccharide (LPS) into Wistar rats. A moderate dose of 35 mg/kg*day of GSPE for 10 weeks had anti-inflammatory effects at the gene expression level in mesenteric adipose tissue in Zucker fa/fa rats. However, no significant effects on systemic inflammation were found. In contrast, GSPE had anti-inflammatory effects at the systemic and gene expression levels when administered for 15 days prior to LPS-induced inflammation in Wistar rats. The moderate-high dose of 75 mg/kg*day and the high dose of 200 mg/kg*day of GSPE were the most effective doses in preventing acute inflammation. In addition, several pure bioactive flavonoids such as resveratrol (RES), epigallocatechin gallate, B1-B4 dimeric procyanidins, and PUFAs such as EPA and DHA were administered in various combinations to assess any potential synergistic, additive or antagonistic anti-inflammatory effects that may exist between these flavonoids and PUFAs in LPS-stimulated murine macrophages. Importantly, the combinations of B3 plus EPA and RES plus EPA had strong synergistic anti-inflammatory effects manifested by a decrease in nitric oxide levels, a decrease in the expression of proinflammatory and oxidative stress-related genes and the modulation of the phosphorylation status of various proteins involved in the activation of the NF-κB and AP-1 proinflammatory pathways. / En los últimos años, se ha estudiado como los agentes antinflamatorios presentes en los alimentos pueden modular la inflamación relacionada con diversas enfermedades. Las procianidinas presentes en frutas y vegetales y los ácidos grasos polinsaturados (PUFAs) presentes en el pescado y los aceites derivados de ellos son compuestos que tienen diferentes propiedades antinflamatorias frente a varias enfermedades como la obesidad, la diabetes y enfermedades cardiovasculares. El objetivo de nuestro estudio fue investigar diferentes aspectos y mecanismos relacionados con la eficacia de un extracto de procianidinas de pepita de uva (GSPE) frente al estado inflamatorio crónico en ratas Zucker fa/fa genéticamente obesas, y de un estado inflamatorio agudo activado por la inyección de lipopolisacáridos (LPS) en ratas Wistar. Una dosis moderada de 35 mg/kg por día de GSPE durante 10 semanas produjo efectos antinflamatorios sobre la expresión génica en tejido adiposo mesentérico en las ratas Zucker fa/fa. Aún así, no se encontraron efectos significativos en la inflamación sistémica. Además, el GSPE tuvo efectos antinflamatorios a nivel sistémico y en la expresión génica cuando fue administrado durante 15 días previos a la inducción de la inflamación por LPS en ratas Wistar. La dosis alta nutricional de 75 mg/kg por día y la dosis alta farmacológica de 200 mg/kg por día de GSPE fueron las más efectivas en prevenir esta inflamación. Por otro lado, diferentes moléculas bioactivas como los flavonoides resveratrol (RES), epigalocatequina galada, y las procianidinas diméricas B1-B4, y los PUFAs EPA y DHA fueron administrados en combinación para analizar los efectos antinflamatorios sinérgicos, aditivos o antagónicos en macrófagos estimulados con LPS. Las combinaciones de B3 más EPA y RES más EPA mostraron efectos antinflamatorios sinérgicos disminuyendo los niveles de óxido nítrico, los niveles de expresión de genes proinflamatorios y relacionados con el estrés oxidativo, y modulando la fosforilación de diferentes proteínas involucradas en la activación de las vías proinflamatorias señalizadoras del NF-κB y del AP-1.

The molecular mechanisms of putative anti-inflammatory nutrients, i.e., fish oil, curcumin and limonin, were investgated with respect to CD4+ T cell function. Initially, using a DO11.10 mouse model which exhibits a transgenic T cell receptor specific to OVA 323-339 peptide, we demonstrated that dietary fish oil suppresses antigen-specific Th1 clonal expansion in vivo. Following immunization, the accumulation of adoptively transferred transgenic cells in wild type recipient mouse lymph nodes was suppressed. In addition, cell division analysis by carboxyfluorescein succinimidyl ester (CFSE) revealed that both total cell number in lymph nodes as well as cell division were decreased by fish oil. Since n-3 polyunsaturated fatty acids (PUFA), active long chain fatty acids in fish oil, elicit favorable effects on a variety of cell types, e.g., anti-tumor effect on colonocytes, amelioration of coronary heart disease and anti-inflammatory effects involving T cells, B cells, dendritic cells and macrophages, we postulated that a fundamental mechanism of action may explain the multiple effects observed. In a series of experiments described herein, we demonstrated that n-3 PUFA alters the formation/location of membrane subdomains, referenced to as lipid rafts. Specifically, lipid raft formation at the immunological synapse (IS) in CD4+ T cells was suppressed following membrane enrichment with n-3 PUFA. The alteration of lipid rafts down-regulated the localization of select signaling proteins, including F-actin, PKC and PLC-1, and phosphorylation of PLC-1 at the IS. Consequently, CD4+ T cell proliferation was suppressed as assessed by CFSE analysis and radioactive thymidine incorporation. Phytochemicals have been used for chemopreventive and chemotherapeutic purposes. We examined the putative anti-inflammatory effects of curcumin (1%) and limonin (0.02%) with respect to CD4+ T cell function. Dietary curcumin and limonin suppressed NF-B activation in CD4+ T cells. In addition, CD4+ T cell proliferation was modulated by 2% curcumin. We further investigated the combined therapeutic potential of phytochemicals and fish oil, containing n-3 PUFA. Interestingly, fish oil and limonin together significantly (P<0.05) suppressed T cell proliferation, whereas feeding either fish oil or limonin alone showed little effect. In summary, our data indicated that dietary fish oil alters proximal signaling of T cells by perturbing lipid raft formation. Curcumin and limoin are capable of suppressing NF-B in T cells, thereby exhibiting a synergistic effect when combined with fish oil. Further studies are required to elucidate the relationship of dietary dose of active compoments with respect to mechanism of actions.