RESUMEN
Abstract Introduction: Professional and recreational athletes make daily use of nutritional supplements to improve physical performance. Polyunsaturated fatty acids (PUFAs) have been used in this sense. N-3 PUFA, particularly eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are involved in important physiological functions and the benefits of supplementation are demonstrated in several types of users. Shark liver oil (SLO) is a natural source of n-3 PUFA. Objective: To evaluate the effect of supplementation with SLO on contractility of skeletal muscles with different metabolic characteristics, soleus and extensor digitorum longus (EDL) from rats submitted to eight weeks of interval training of progressive intensity on a motorized treadmill. In the supplemented group, animals were supplemented with SLO (1 g/kg) five times a week for eight weeks. Method: Contractile parameters as maximum isometric twitch force (Tmax), maximum speed of force development (+dF/dt), maximum speed of force decrease (-dF/dt), maximum tetanic force (Fmax) and resistance to fatigue were analyzed in isolated muscle. Results: Compared to the control group, EDL muscles from the supplemented group reduced Tmax at the first (10.82 ± 0.89 vs 14.30 ± 0.67 mN/mm2. p < 0.01) and second minutes of experimentation (9.85 ± 0.63 vs 13.12 ± 0.70 mN/mm2. p < 0.01). However, it increased resistance to fatigue (22.80 ± 0.97 vs 18.60 ± 0.51 seconds. p = 0.005). Conclusion: No difference was observed in the soleus muscle.
Resumo Introdução: Atletas profissionais e recreativos utilizam suplementos nutricionais diariamente para melhorar a performance física. Os ácidos graxos poliinsaturados (PUFA) têm sido usados nesse sentido. Os n-3 PUFA, particularmente os ácidos eicosapentaenoicos (EPA) e docosaexaenoico (DHA), são relacionados com importantes funções fisiológicas e os benefícios da suplementação são demonstrados em diversas populações. O óleo de fígado de tubarão (OFT) é fonte natural de n-3 PUFA. Objetivo: Avaliar o efeito da suplementação com OFT na contratilidade de músculos esqueléticos com diferentes características metabólicas, sóleo e extensor longo de dedos (EDL) de ratos submetidos a oito semanas de treinamento intervalado de intensidade progressiva em esteira motorizada. No grupo suplementado, os animais foram suplementados com OFT (1 g/kg) cinco vezes por semana por oito semanas. Método: Parâmetros contráteis como produção de força isométrica máxima (Tmax), velocidade máxima de contração (+dF/dt), velocidade máxima de relaxamento (-dF/dt), força tetânica máxima (Fmax) e resistência à fadiga foram analisados em músculos isolados. Resultados: Comparados ao grupo controle, os músculos EDL dos animais do grupo suplementado reduziram Tmax no primeiro (10.82 ± 0.89 vs 14.30 ± 0.67 mN/mm2. p < 0.01) e no segundo minutos de experimentação (9.85 ± 0.63 vs 13.12 ± 0.70 mN/mm2. p < 0.01), entretanto, aumentaram a resistência à fadiga (22.80 ± 0.97 vs 18.60 ± 0.51 segundos. p = 0.005). Conclusão: Nenhuma diferença foi observada no músculo sóleo.
Resumen Introducción: Los atletas profesionales y recreativos utilizan suplementos nutricionales diariamente para mejorar el rendimiento físico. Los ácidos grasos poliinsaturados (PUFA) se han utilizado en este sentido. Los n-3 PUFA, particularmente los ácidos eicosapentaenoicos (EPA) y el docosaexáenoico (DHA), se relacionan con importantes funciones fisiológicas y los beneficios de la suplementación se demuestran en diversas poblaciones. El aceite de hígado de tiburón (AHT) es fuente natural de n-3 PUFA. Objetivo: Evaluar el efecto de la suplementación con AHT en la contractilidad de músculos esqueléticos con diferentes características metabólicas, sololeo y extensor largo de dedos (EDL) de ratas sometidas a ocho semanas de entrenamiento intervalado de intensidad progresiva en estera motorizada. En el grupo suplementario, los animales fueron suplementados con AHT (1 g/kg) cinco veces por semana durante ocho semanas. Método: Parámetros contráctiles como producción de fuerza isométrica máxima (Tmax), velocidad máxima de contracción (+dF/dt), velocidad máxima de relajación (-dF/dt), fuerza tetánica máxima (Fmax) y resistencia a la fatiga se analizaron en músculos aislados. Resultados: En comparación con el grupo control, los músculos EDL de los animales del grupo suplementado redujeron Tmax en el primer (10.82 ± 0.89 vs 14.30 ± 0.67 mN/mm2. p < 0.01) y en el segundo minuto de experimentación (9.85 ± 0.63 vs 13.12 ± 0.70 mN/mm2. p < 0.01), sin embargo, aumentaron la resistencia a la fatiga (22.80 ± 0.97 vs 18.60 ± 0.51 segundos. p = 0.005). Conclusión: No se observó ninguna diferencia en el músculo sóleo.
Asunto(s)
Animales , Ratas , Tiburones/fisiología , Aceites de Pescado , Ácidos Grasos Omega-3/fisiología , Músculo Esquelético , Suplementos Dietéticos , Rendimiento Atlético , AtletasRESUMEN
BACKGROUND: Although several studies have reported an association between mental disorders and serum levels of brain-derived neurotrophic factor (BDNF), this association is still poorly understood. The study of factors associated with both BDNF levels and mental disorders, such as n-3 polyunsaturated fatty acids (n-3 PUFAs), may help to elucidate the mechanisms mediating the relationship between the two variables. Therefore, the present study aimed to evaluate whether the intake n-3 PUFAs correlates with serum levels of BDNF. FINDINGS: This study involved 137 adolescents drawn from a community sample, including a group with high levels of anxiety, assessed using the Screen for Children and Anxiety Related Emotional Disorders. Blood samples were collected and serum BDNF levels were measured. n-3 PUFAs were estimated using a food frequency questionnaire for adolescents. Correlations were performed to assess the association between n-3 PUFAs intake and BDNF levels. Effects of potential confounders (total fat consumption, age, gender and anxiety) were examined using linear regression models. There was a direct correlation between n-3 PUFAs consumption and serum BDNF levels, which remained significant even after accounting for potential confounders. CONCLUSIONS: We were able to detect a correlation between n-3 PUFAs intake and peripheral BDNF levels. Our study was limited by its small sample size, and our external validity may be restricted by the oversampling of anxious adolescents. Our findings may help determine the nature of the association between mental disorders and serum levels of BDNF. However, more studies are needed to elucidate the possible mechanisms by which n-3 PUFAs intake affects BDNF levels, and how this may lead to an increased vulnerability to psychiatric disorders.
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Ansiedad/sangre , Factor Neurotrófico Derivado del Encéfalo/sangre , Ácidos Grasos Omega-3/fisiología , Adolescente , Niño , Dieta , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: Our previous study demonstrated that essential fatty acid (EFA) dietary restriction over two generations induced midbrain dopaminergic cell loss and oxidative stress in the substantia nigra (SN) but not in the striatum of young rats. In the present study we hypothesized that omega-3 deficiency until adulthood would reduce striatum's resilience, increase nitric oxide (NO) levels and the number of BDNF-expressing neurons, both potential mechanisms involved in SN neurodegeneration. METHODS: Second generation rats were raised from gestation on control or EFA-restricted diets until young or adulthood. Lipoperoxidation, NO content, total superoxide dismutase (t-SOD) and catalase enzymatic activities were assessed in the SN and striatum. The number of tyrosine hydroxylase (TH)- and BDNF-expressing neurons was analyzed in the SN. RESULTS: Increased NO levels were observed in the striatum of both young and adult EFA-deficient animals but not in the SN, despite a similar omega-3 depletion (~65%) in these regions. Increased lipoperoxidation and decreased catalase activity were found in both regions, while lower tSOD activity was observed only in the striatum. Fewer TH- (~40%) and BDNF-positive cells (~20%) were detected at the SN compared to the control. CONCLUSION: The present findings demonstrate a differential effect of omega-3 deficiency on NO production in the rat's nigrostriatal system. Prolonging omega-3 depletion until adulthood impaired striatum's anti-oxidant resources and BDNF distribution in the SN, worsening dopaminergic cell degeneration. GENERAL SIGNIFICANCE: Omega-3 deficiency can reduce the nigrostriatal system's ability to maintain homeostasis under oxidative conditions, which may enhance the risk of Parkinson's disease.
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Factor Neurotrófico Derivado del Encéfalo/fisiología , Ácidos Grasos Omega-3/fisiología , Óxido Nítrico/biosíntesis , Enfermedad de Parkinson/etiología , Sustancia Negra/fisiología , Animales , Factor Neurotrófico Derivado del Encéfalo/análisis , Catalasa/metabolismo , Femenino , Peroxidación de Lípido , Masculino , Estrés Oxidativo , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo , Tirosina 3-Monooxigenasa/análisisRESUMEN
The transient receptor potential channels family (TRP channels) is a relatively new group of cation channels that modulate a large range of physiological mechanisms. In the nervous system, the functions of TRP channels have been associated with thermosensation, pain transduction, neurotransmitter release, and redox signaling, among others. However, they have also been extensively correlated with the pathogenesis of several innate and acquired diseases. On the other hand, the omega-3 polyunsaturated fatty acids (n-3 fatty acids) have also been associated with several processes that seem to counterbalance or to contribute to the function of several TRPs. In this short review, we discuss some of the remarkable new findings in this field. We also review the possible roles played by n-3 fatty acids in cell signaling that can both control or be controlled by TRP channels in neurodegenerative processes, as well as both the direct and indirect actions of n-3 fatty acids on TRP channels.
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Ácidos Grasos Omega-3/fisiología , Enfermedades Neurodegenerativas/metabolismo , Estrés Oxidativo/fisiología , Canales de Potencial de Receptor Transitorio/fisiología , Animales , Calcio/metabolismo , Muerte Celular/fisiología , Humanos , Espacio Intracelular/fisiología , Transducción de Señal/fisiologíaRESUMEN
Essential omega-3 polyunsaturated fatty acids (omega3) are crucial to brain development and function, being relevant for behavioral performance. In the present study we examined the influence of dietary omega3 in the development of the glutamatergic system and on behavior parameters in rats. Female rats received isocaloric diets, either with omega3 (omega3 group) or a omega3 deficient diet (D group). In ontogeny experiments of their litters, hippocampal immunocontent of ionotropic NMDA and AMPA glutamatergic receptors subunits (NR2 A\B and GluR1, respectively) and the alpha isoform of the calcium-calmodulin protein kinase type II (alphaCaMKII) were evaluated. Additionally, hippocampal [(3)H]glutamate binding and uptake were assessed. Behavioral performance was evaluated when the litters were adult (60 days old), through the open-field, plus-maze, inhibitory avoidance and flinch-jump tasks. The D group showed decreased immunocontent of all proteins analyzed at 02 days of life (P2) in comparison with the omega3 group, although the difference disappeared at 21 days of life (except for alphaCaMKII, which content normalized at 60 days old). The same pattern was found for [(3)H]glutamate binding, whereas [(3)H]glutamate uptake was not affected. The D group also showed memory deficits in the inhibitory avoidance, increased in the exploratory pattern in open-field, and anxiety-like behavior in plus-maze. Taken together, our results suggest that dietary omega3 content is relevant for glutamatergic system development and for behavioral performance in adulthood. The putative correlation among the neurochemical and behavioral alterations caused by dietary omega3 deficiency is discussed.
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Conducta Animal/fisiología , Ácidos Grasos Omega-3/administración & dosificación , Ácidos Grasos Insaturados/deficiencia , Ácido Glutámico/fisiología , Sinapsis/fisiología , Animales , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/análisis , Ácidos Grasos Omega-3/fisiología , Femenino , Ácido Glutámico/metabolismo , Hipocampo/química , Hipocampo/metabolismo , Lactancia , Masculino , Embarazo , Efectos Tardíos de la Exposición Prenatal , Ratas , Ratas Wistar , Receptores AMPA/análisis , Receptores de N-Metil-D-Aspartato/análisis , Sinaptosomas/química , TritioRESUMEN
The role of omega-3 polyunsaturated fatty acids (3PUFAs) on brain function is increasingly demonstrated. Here, the effect of dietary deprivation of essential 3PUFAs on some parameters related to neuroprotection was investigated. Rats were fed with two different diets: omega-3 diet and omega-3-deprived diet. To assess the influence of 3PUFAs on brain responses to ischemic insult, hippocampal slices were subjected to an oxygen and glucose deprivation (OGD) model of in vitro ischemia. The omega-3-deprived group showed higher cell damage and stronger decrease in the [(3)H]glutamate uptake after OGD. Moreover, omega-3 deprivation influenced antiapoptotic cell response after OGD, affecting GSK-3beta and ERK1/2, but not Akt, phosphorylation. Taken together, these results suggest that 3PUFAs are important for cell protection after ischemia and also seem to play an important role in the activation of antiapoptotic signaling pathways.
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Muerte Celular , Grasas Insaturadas en la Dieta/administración & dosificación , Ácidos Grasos Omega-3/administración & dosificación , Hipocampo/fisiopatología , Hipoxia-Isquemia Encefálica/fisiopatología , Fármacos Neuroprotectores/administración & dosificación , Daño por Reperfusión/prevención & control , Animales , Hipoxia de la Célula , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Ácidos Grasos Esenciales/deficiencia , Ácidos Grasos Omega-3/fisiología , Femenino , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Hipocampo/metabolismo , Hipoxia-Isquemia Encefálica/metabolismo , Técnicas In Vitro , Masculino , Fosforilación , Procesamiento Proteico-Postraduccional , Ratas , Ratas Wistar , Daño por Reperfusión/metabolismo , Transducción de SeñalRESUMEN
Essential polyunsaturated fatty acids (PUFAs), linoleic acid n6 (LA) and linolenic acid (ALA) n3 obtained from the diet are precursors of the long-chain polyunsaturated fatty acids (Lc-PUFAs) arachidonic acid (AA) and docosahexaenoic acid (DHA) respectively. Consumption of PUFAs is related with a better neurological and cognitive development in newborns. It has been demonstrated that consumption of n-6 and n-3 PUFAs decreases blood triglycerides by increasing fatty acid oxidation through activation of PPARalpha or by reducing the activation of SREBP-1 inhibiting lipogenesis. Dietary PUFAs activate PPARalpha and PPARgamma increasing lipid oxidation, and decreasing insulin resistance leading in a reduction of hepatic steatosis. Beneficial effects of PUFAs have been observed in humans and in animals models of diabetes, obesity, cancer, and cardiovascular diseases. It is important to promote the consumption of PUFAs. Main food sources of PUFAs n-6 are corn, soy and safflower oil, and for PUFAs n-3 are fish, soy, canola oil and, flaxseed. Finally FAO/WHO recommends an optimal daily intake of n6/n3 of 5-10:1.
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Ácidos Grasos Insaturados/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Ácidos Araquidónicos/metabolismo , Proteínas Potenciadoras de Unión a CCAAT/fisiología , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/prevención & control , Proteínas de Unión al ADN/fisiología , Dermatitis Atópica/tratamiento farmacológico , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/prevención & control , Grasas de la Dieta/farmacología , Grasas de la Dieta/uso terapéutico , Desarrollo Embrionario/efectos de los fármacos , Desarrollo Embrionario/fisiología , Ácidos Grasos/metabolismo , Ácidos Grasos Omega-3/farmacología , Ácidos Grasos Omega-3/fisiología , Ácidos Grasos Omega-3/uso terapéutico , Ácidos Grasos Omega-6/farmacología , Ácidos Grasos Omega-6/fisiología , Ácidos Grasos Omega-6/uso terapéutico , Ácidos Grasos Insaturados/farmacocinética , Ácidos Grasos Insaturados/farmacología , Ácidos Grasos Insaturados/uso terapéutico , Hígado Graso/tratamiento farmacológico , Femenino , Crecimiento/efectos de los fármacos , Crecimiento/fisiología , Humanos , Hipertrigliceridemia/tratamiento farmacológico , Recién Nacido , Resistencia a la Insulina , Peroxidación de Lípido/efectos de los fármacos , Masculino , Ratones , Persona de Mediana Edad , Neoplasias/tratamiento farmacológico , Neoplasias/prevención & control , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/prevención & control , Obesidad/tratamiento farmacológico , Obesidad/prevención & control , PPAR alfa/agonistas , PPAR gamma/agonistas , Aceites de Plantas/farmacología , Aceites de Plantas/uso terapéutico , Embarazo , RatasRESUMEN
OBJECTIVE: To assess the effects of n-3 polyunsaturated phospholipid acyl chains on the initial steps in G-protein-coupled signaling. STUDY DESIGN: Isolated components of the visual signal transduction system, rhodopsin, G protein (G(t)), and phosphodiesterase (PDE), were reconstituted in membranes containing various levels of n-3 polyunsaturated phospholipid acyl chains. In addition, rod outer segment disk membranes containing these components were purified from rats raised on n-3-deficient and n-3-adequate diets. The conformation change of rhodopsin, coupling of rhodopsin to G(t), and PDE activity were each measured separately. RESULTS: The ability of rhodopsin to form the active metarhodopsin II conformation and bind G(t) were both compromised in membranes with reduced levels of n-3 polyunsaturated acyl chains. The activity of PDE, directly related to the integrated cellular response, was reduced in all membranes lacking or deficient in n-3 polyunsaturated acyl chains. PDE activity in membranes containing 22:5n-6 PC was 50% lower than in membranes containing either 22:6n-3 PC or 22:5n-3 PC. CONCLUSIONS: The earliest events in G-protein-coupled signaling; receptor conformation change, receptor-G-protein binding, and PDE activity are reduced in membranes lacking n-3 polyunsaturated acyl chains. Efficient and rapid propagation of G-protein-coupled signaling requires polyunsaturated n-3 phospholipid acyl chains.
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Ácidos Grasos Omega-3/fisiología , Receptores Acoplados a Proteínas G/fisiología , Rodopsina/análogos & derivados , Rodopsina/fisiología , Transducción de Señal/fisiología , Humanos , Conformación Molecular , Retina/fisiología , Segmento Externo de la Célula en Bastón/fisiología , Relación Estructura-ActividadRESUMEN
This review addresses the potential role of omega-3 fatty acids in mood disorders, from the biochemical rationale for their use to the growing body of data supporting their clinical efficacy.