RESUMO
BACKGROUND: Docosahexaenoic acid (DHA) is highly concentrated in the mammalian nervous and visual system. The fatty acid, which is required by the fetus and the newborn, is supplied by the mother from their tissue reservoirs. It has been suggested that mother's supplementation with DHA during pregnancy and even before pregnancy. Different sources of DHA are available for supplementation such as: single-cell algae triglycerides (TG), egg's yolk phospholipids (PL), DHA ethyl esther (EE), and sn-2 DHA monoacylglyceride (MG). We evaluated comparatively the effectiveness of these different DHA sources to produce tissue DHA accretion and to increase milk DHA content. METHODS: Female Wistar rats fed a diet which provided no DHA, were daily supplemented by 40 days before mating (BM) and during the pregnancy with either TG, PL, EE, or MG to an amount which provided 8 mg/kg b.w. of DHA. Samples of blood plasma, erythrocytes, hepatic and adipose tissue were obtained from rats at the BM condition and after the delivery (AD), and milk samples were also obtained from the gastric content of the pups nursed by the rats at day 3, 11 and 20 of suckling. Samples were processed to assess DHA and arachidonic acid (AA) content by gas-chromatography. RESULTS: TG, PL, EE, and MG supplementation produced a similar intestinal absorption of DHA as estimated from the plasma DHA at the BM condition. However, PL and MG supplementation produced a higher accretion of DHA into erythrocytes, hepatic, and adipose tissue than TG and EE supplementation at the BM condition. AA content was not modified by the different supplementing oils. A reduction of the DHA content of plasma, erythrocytes, hepatic and adipose tissue at the AD condition was observed, and a reduction of AA for the hepatic and adipose tissues was also observed, suggesting the importance of these tissues as DHA and AA reservoirs. Milk secretion from PL and MG supplemented rats showed a higher DHA content than secretion from TG- and EE-supplemented rats. CONCLUSIONS: We conclude that PL and MG supplementation provides higher tissue DHA accretion and higher milk DHA content than TG and EE supplementation. However, we were not able to visualize the comparative advantages derived from PL vs. MG supplementation.
Assuntos
Animais Lactentes/metabolismo , Ácidos Docosa-Hexaenoicos , Lactação/metabolismo , Leite/química , Tecido Adiposo/química , Tecido Adiposo/metabolismo , Animais , Animais Lactentes/sangue , Ácido Araquidônico/análise , Cromatografia Gasosa/métodos , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/química , Ácidos Docosa-Hexaenoicos/metabolismo , Membrana Eritrocítica/química , Membrana Eritrocítica/metabolismo , Feminino , Fígado/química , Fígado/metabolismo , Gravidez , Distribuição Aleatória , Ratos , Ratos Wistar , Distribuição TecidualRESUMO
BACKGROUND/AIMS: Docosahexaenoic acid (C22:6, DHA) is an omega-3 fatty acid required for the normal development of the mammalian nervous and visual system. DHA is provided by the mother during pregnancy and lactating period. Mother's DHA supplementation during pregnancy, and even before pregnancy, has been suggested. DHA can be provided by marine oils, egg's yolk phospholipids, single cell algae oils, the pure fatty acid, or by the ethyl ester derivative (DHA-EE). Another way to provide DHA can be by sn-2 docosahexaenyl monoacylglyceride (DHA-MG), obtained by the treatment of fish oil with stereospecific lipases. sn-2 Fatty acid monoacylglycerides can be more easily absorbed at the intestine than other fatty acid derivatives. METHODS: Female rats fed with a synthetic, which provided essentially no DHA, received a 40-day supplementation of either DHA-EE or DHA-MG. Plasma and erythrocyte fatty acid composition were assessed by gas chromatography at day 0 and 40 of supplementation. RESULTS: DHA-EE increased plasma and erythrocyte DHA by 15 and 11.9%, respectively, with no modification of arachidonic acid (AA) content. DHA-MG supplementation increased plasma and erythrocyte DHA by 24 and 23.8%, respectively, but reduced AA by 5.5 and 3%, respectively. CONCLUSIONS: We conclude that in the rat, DHA-MG supplementation allows a higher plasma and erythrocyte DHA content than DHA-EE with minor modification of AA content.
Assuntos
Gorduras Insaturadas na Dieta/administração & dosagem , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/sangue , Membrana Eritrocítica/química , Animais , Ácido Araquidônico/análise , Cromatografia Gasosa , Gorduras Insaturadas na Dieta/metabolismo , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/farmacocinética , Ácidos Graxos Insaturados/sangue , Feminino , Absorção Intestinal , Distribuição Aleatória , Ratos , Ratos WistarRESUMO
El ácido docosahexaenoico (DHA) es un ácido graso omega-3 de cadena larga derivado del ácido alfa-linolénico. El DHA, junto con el ácido araquidónico, es el ácido graso poliinsaturado que se encuentran en mayor concentración en el tejido nervioso. Se ha propuesto que el DHA tiene un importante rol en la formación y en la función del sistema nervioso, particularmente en el cerebro. Su mecanismo de acción aún no está totalmente dilucidado pero se propone que actuaría a nivel de las membranas celulares regulando sus funciones metabólicas y también a nivel de la expresión de genes relacionados con la función cerebral. Se ha correlacionado el contenido cerebral de DHA con la capacidad de aprendizaje y con el nivel de inteligencia de los recién nacidos y lactantes. Numerosos ensayos en animales de experimentación y en niños han demostrado la necesidad del ácido graso durante el desarrollo cerebral. El DHA, formado a partir de su precursor, proveniente de la dieta, o desde las reservas tisulares, es aportado por la madre al feto durante el período gestacional y a través de la leche durante la lactancia. Se ha sugerido la necesidad de suplementar a la madre con DHA durante el período gestacional, e incluso antes de este, para asegurar el adecuado aporte del ácido graso para el normal desarrollo del cerebro fetal. La suplementación se puede realizar a través de aceites con alto contenido de DHA, a partir de fosfolípidos, en la forma de etil esteres de DHA, o como monoglicéridos que contienen DHA como único ácido graso. En este trabajo se discute el rol del DHA en el desarrollo del sistema nervioso y en la funcionalidad del cerebro, y las evidencias que lo relacionan con una mayor capacidad de aprendizaje de las crías provenientes de madres previamente suplementadas con DHA. Además, se discute cual podría ser la mejor forma de suplementar con DHA la nutrición de la madre y del recién nacido a partir de los productos disponible para la suplementación.
Assuntos
Humanos , Feminino , Gravidez , Cérebro/crescimento & desenvolvimento , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos , AprendizagemRESUMO
Cholesterol is a molecule with an unsaturated bond; therefore, like polyunsaturated fatty acids, it is prone to oxidation. Cholesterol oxidation products (COPs) are found in many common foods and have been shown to be atherogenic, cytotoxic, mutagenic and possibly carcinogenic. Therefore, efforts to prevent or to avoid COPs formation during manufacture and/or processing of foods are of high priority. The effect of natural antioxidants on COPs formation has not been extensively studied. We assayed the effect of some widely applied natural antioxidants, such as tocopherol homologs (alpha-T, gamma-T, and delta-T) and rosemary extract, and of some natural products of newly developed as antioxidants, such as the flavonoids quercetin, catechin, morin, and rutin, and also of an alkaloid-derived product, boldine, to inhibit cholesterol oxidation of soybean oil, added of cholesterol, induced in the Rancimat test conditions (150 degrees C and air bubbling). Formation of six different COPs at the induction period and at the 100 microS conductivity value was monitored by gas chromatography. Under the experimental conditions gamma-T, quercetin, and rosemary extract prove effective to inhibit both soybean oil oxidation and COP formation. alpha-T, catechin, and morin are less efficient to prevent COP formation. delta-T, rutin and boldine are devoid of protective action against COP formation. gamma-T, quercetin and rosemary extract may inhibit COP formation from the nucleus and from the lateral chain of the cholesterol molecule.
Assuntos
Antioxidantes/farmacologia , Colesterol/química , Rosmarinus , Óleo de Soja/química , Flavonoides/farmacologia , Temperatura Alta , Humanos , Óleos Voláteis/farmacologia , Oxirredução/efeitos dos fármacos , Quercetina/farmacologia , Tocoferóis/farmacologiaRESUMO
BACKGROUND: Maternal omega-3 fatty acid supplementation has been suggested to provide docosahexaenoic acid (DHA) for the normal brain development during gestation. DHA can be given as such (preformed) or through the omega-3 precursor alpha-linolenic acid (LNA) which is transformed into DHA by elongation and desaturation reactions. Western diet provides low amounts of LNA and DHA; therefore, supplementation with these omega-3 fatty acids has been suggested for pregnant women. However, the bioequivalence of LNA ingestion to DHA supplementation has not been established. METHODS: Recently weaning female Wistar rats were fed a diet containing a small amount of LNA and no DHA. The animals were daily supplemented 40 days before mating, during pregnancy, and until delivery with 60 mg/kg of LNA or 6 mg/kg of DHA dissolved in coconut oil. Fatty acids were given as ethyl ester derivatives. Controls received coconut oil. The fatty acid composition of blood plasma, erythrocytes, liver, visceral adipose tissue, and brain segments (frontal cortex, hippocampus, and cerebellum) was analyzed. Brain segments obtained from 16- and 19-day-old fetuses and from 2- and 21-day-old rats were also analyzed for fatty acid composition. RESULTS: Supplementation with LNA and DHA induced a similar accretion of DHA in plasma, erythrocytes, liver, and brain segments of the mothers. The adipose tissue showed a higher DHA accretion after DHA-supplementation. The DHA accretion in frontal cortex, hippocampus, and cerebellum obtained from the fetuses and the newborn rats was similar when the mothers were supplemented with LNA and DHA. Our results show that under our experimental conditions a similar accretion of DHA in the different tissues of the mothers and in the brain segments of fetuses and newborn rats is obtained after LNA and DHA supplementation. CONCLUSION: LNA and DHA, at the amounts given in this study, show a similar bioequivalence for DHA accretion in different tissues of the mother and in brain segments of fetuses and newborn rats.
Assuntos
Animais Recém-Nascidos/metabolismo , Encéfalo/embriologia , Encéfalo/metabolismo , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido alfa-Linolênico/administração & dosagem , Administração Oral , Animais , Química Encefálica , Ácidos Docosa-Hexaenoicos/farmacocinética , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Desenvolvimento Embrionário e Fetal/fisiologia , Feminino , Gravidez , Distribuição Aleatória , Ratos , Ácido alfa-Linolênico/farmacocinéticaRESUMO
Cholesterol is a molecule with a double bond in its structure and is therefore susceptible to oxidation leading to the formation of oxysterols. These oxidation products are found in many commonly-consumed foods and are formed during their manufacture and/or processing. Concern about oxysterols consumption arises from the potential cytotoxic, mutagenic, atherogenic, and possibly carcinogenic effects of some oxysterols. Eggs and egg-derived products are the main dietary sources of oxysterols. Thermally-processed milk and milk-derived products are another source of oxysterols in our diet. Foods fried in vegetable/animal oil, such as meats and French-fried potatoes, are major sources of oxysterols in the Western diet. Efforts to prevent or to reduce cholesterol oxidation are directed to the use of antioxidants of either synthetic or natural origin. Antioxidants are not only able to inhibit triglyceride oxidation, some of them can also inhibit cholesterol oxidation. Among synthetic antioxidants 2,6-ditertiarybutyl-4-methylphenol (BHT), and tertiary butylhydroquinone (TBHQ) can efficiently inhibit the thermal-induced oxidation of cholesterol. Some natural antioxidants, such as alpha- and gamma-tocopherol, rosemary oleoresin extract, and the flavonoid quercetin, show strong inhibitory action against cholesterol oxidation.
Assuntos
Antioxidantes/administração & dosagem , Colesterol na Dieta , Colesterol/metabolismo , Temperatura Alta , Humanos , Oxirredução/efeitos dos fármacos , Esteróis/metabolismoRESUMO
By modifying the degree of hydrogenation of dietary fat, it is possible to modify the fatty acid composition and the biochemical activity of cellular tissues. The age can be another variable influencing these modifications. The effect of isocaloric diets containing oils with different degrees of hydrogenation: fish oil (FO, 0.3% TRANS), partially hydrogenated fish oil (PHFO, 29% TRANS), or highly hydrogenated fish oil (HHFO, 2.3% TRANS), in the fatty acid composition (CIS and TRANS isomers) of hepatic microsomes from young (70-day-old) and aged (18-month-old) rats, in the microsomal cytochrome P-450 (C-450) content, and in the aminopyrine N-demethylase (AND), aniline hydroxylase (AH), NADPH cytochrome P-450 reductase (NCR), UDP-glucuronyl transferase (UGT), and GSH-S transferase (GST) enzymatic activities were studied. Fatty acid composition and n-6/n-3 ratio of microsomal membranes was modified to a higher extent in young rats. C-450 content and AND activity were reduced when the degree of hydrogenation of dietary fat was increased in the young and the aged rats. AH activity was higher after the PHFO diet in the young rats only. NCR activity was reduced in the young animals when the hydrogenation of the fat was increased. However, in aged rats the enzyme exhibited a higher activity after the PHFO and HHFO diet. UGT and GST activities where not affected by the level of hydrogenation of the dietary fat in both the young and the aged rats. However, UGT activity was higher in the young rats, while GST activity was higher in the aged animals. We conclude that hydrogenation of dietary fat can modify the fatty acid composition of hepatic microsomes, young animals being more sensitive to these changes than aged animals. These effects were also reflected in the amount and/or the activity of some molecular components of the hepatic microsomal mixed-function oxidase enzyme system. Microsomal TRANS fatty acid composition is not affecting the activity of the enzymes, the age of the animals being the most important factor.
Assuntos
Envelhecimento/metabolismo , Ácidos Graxos/metabolismo , Óleos de Peixe/administração & dosagem , Microssomos Hepáticos/metabolismo , Análise de Variância , Animais , Ácidos Graxos/análise , Óleos de Peixe/química , Hidrogenação , Masculino , Microssomos Hepáticos/química , Microssomos Hepáticos/enzimologia , Ratos , Ratos WistarRESUMO
Cholesterol is a molecule with a double bond in its structure and is therefore susceptible to oxidation leading to the formation of oxysterols. These oxidation products are found in many commonly-consumed foods and are formed during their manufacture and/or processing. Concern about oxysterols consumption arises from the potential cytotoxic, mutagenic, atherogenic, and possibly carcinogenic effects of some oxysterols. Eggs and egg-derived products are the main dietary sources of oxysterols. Thermally-processed milk and milk-derived products are another source of oxysterols in our diet. Foods fried in vegetable/animal oil, such as meats and French-fried potatoes, are major sources of oxysterols in the Western diet. Efforts to prevent or to reduce cholesterol oxidation are directed to the use of antioxidants of either synthetic or natural origin. Antioxidants are not only able to inhibit triglyceride oxidation, some of them can also inhibit cholesterol oxidation. Among synthetic antioxidants 2,6-ditertiarybutyl-4-methylphenol (BHT), and tertiary butylhydroquinone (TBHQ) can efficiently inhibit the thermal-induced oxidation of cholesterol. Some natural antioxidants, such as alpha- and gamma-tocopherol, rosemary oleoresin extract, and the flavonoid quercetin, show strong inhibitory action against cholesterol oxidation.
Assuntos
Humanos , Antioxidantes , Colesterol , Colesterol na Dieta , Tecnologia de Alimentos , OxirreduçãoRESUMO
Docosahexanoic acid (C22:6, DHA) is a highly unsaturated omega-3 fatty acid that forms part of the central nervous and visual system structures. DHA is synthesized from its precursor, alfa-linolenic acid, that is also a omega-3 fatty acid and can be obtained from vegetable oils. Marine organisms, specially fish, are good nutritional sources of DHA and eicosapentanoic acid (EPA), another omega-3 fatty acid that has a role in vascular homeostasis. DHA increases membrane fluidity, improving neurogenesis, synaptogenesis and the activity of retinal photoreceptors. The fetus, specially during the last trimester of pregnancy, has high DHA requirements. It is provided by the mother, since fetal DHA synthesis is negligible in this stage of development. Breast feeding provides DHA to the child, but most replacement artificial formulas do not provide this fatty acid. At the present moment, many products for infant nutrition contain DHA
Assuntos
Humanos , Masculino , Adulto , Feminino , Gravidez , Recém-Nascido , Ácidos Docosa-Hexaenoicos , Desenvolvimento Fetal , Nutrição Materna , Nutrição do Lactente , /metabolismoAssuntos
Humanos , Fármacos Antiobesidade/farmacologia , Dieta Redutora , Exercício Físico , Obesidade/terapia , Terapia Cognitivo-Comportamental , Dieta com Restrição de Gorduras , Dieta Redutora/psicologia , Alimentos Formulados/estatística & dados numéricos , Comportamento Alimentar/psicologia , Metabolismo Energético/fisiologia , Obesidade , Psicoterapia , Tabela de Composição de Alimentos , Redução de PesoRESUMO
Las importantes propiedades fisiológicas y nutricionales descritas para los ácidos grasos poliinsaturados n-3 de origen marino han motivado la búsqueda de procedimientos que permitan obternerlos, preservarlos, con la finalidad de poder incorporarlos a productos de uso farmacológico o nutricional. La industria de harina de pescado provee importantes cantidades de aceites de pescado, sin embargo este aceite debe ser sometido a diferentes procedimientos de purificación para ser utilizado con fines alimenticios. Este trabajo describe el estatus actual de la investigación sobre los procedimientos aplicables para incorporar ácidos grasos poliinsaturados n-3 en nuestra alimentación. Se discute la factibilidad de aplicar técnicas de concentración química, procedimientos de transesterificación mediante enzimas estereospecíficas y la estabilización mediante sustancias naturales. Se plantea, además la posibilidad que algunas aves, como el pollo, alimentadas con una dieta rica en ácidos grasos n-3 pueden constituir un buen vehículo para que el hombre pueda adquirir estos ácidos grasos en forma sana, segura y nutricionalmente recomendable