Suppression of high-fat diet-induced obesity-associated liver mitochondrial dysfunction by docosahexaenoic acid and hydroxytyrosol co-administration.

OBJECTIVE: Obesity-induced by high-fat diet (HFD) is associated with liver steatosis, oxidative stress and mitochondrial dysfunction, which can be eluded by the co-administration of the lipid metabolism modulator docosahexaenoic acid (DHA) and the antioxidant hydroxytyrosol (HT). METHODS: C57BL/6J mice fed a HFD were orally administered either with vehicle, DHA, HT or DHA+HT for 12 weeks. We measured parameters related to insulin resistance, serum lipid levels, liver fatty acid (FA) content and steatosis score, concomitantly with those associated with mitochondrial energy functions modulated by the transcriptional coactivator PGC-1a. RESULTS: HFD induced insulin resistance, liver steatosis with n-3 FA depletion, and loss of mitochondrial respiratory functions with diminished NAD+/NADH ratio and ATP levels compared with CD, with the parallel decrease in the expression of the components of the PGC-1α cascade, namely, PPAR-α, FGF21 and AMPK, effects that were not observed in mice subjected to DHA and HT co-administration. CONCLUSIONS: Data presented indicate that the combination of DHA and HT prevents the development of liver steatosis and the associated mitochondrial dysfunction induced by HFD, thus strengthening the significance of this protocol as a therapeutic strategy avoiding disease evolution into more irreversible forms characterised by the absence of adequate pharmacological therapy in human obesity.

Docosahexaenoic acid and hydroxytyrosol co-administration fully prevents liver steatosis and related parameters in mice subjected to high-fat diet: A molecular approach.

Attenuation of high-fat diet (HFD)-induced liver steatosis is accomplished by different nutritional interventions. Considering that the n-3 PUFA docosahexaenoic acid (DHA) modulates lipid metabolism and the antioxidant hydroxytyrosol (HT) diminishes oxidative stress underlying fatty liver, it is hypothesized that HFD-induced steatosis is suppressed by DHA and HT co-administration. Male C57BL/6J mice were fed a control diet (CD; 10% fat, 20% protein, 70% carbohydrates) or a HFD (60% fat, 20% protein, 20% carbohydrates) for 12 weeks, without and with supplementation of DHA (50 mg/kg/day), HT (5 mg/kg/day) or both. The combined DHA + HT protocol fully prevented liver steatosis and the concomitant pro-inflammatory state induced by HFD, with suppression of lipogenic and oxidative stress signaling, recovery of fatty acid oxidation capacity and enhancement in resolvin availability affording higher inflammation resolution capability. Abrogation of HFD-induced hepatic steatosis by DHA and HT co-administration represents a crucial therapeutic strategy eluding disease progression into stages lacking efficacious handling at present time.

Efectos neuroprotectores del ácido araquidónico y del ácido docosahexaenoico en las etapas extremas de la vida: Una visión integradora / Neuroprotective effects of arachidonic and docosahexaenoic acid in the extreme stages of life: An integrative view

RESUMEN El estudio focalizado en dilucidar el rol neuroprotector del ARA y del DHA a lo largo del ciclo vital ha cobrado cada vez más interés puesto que se continúan descubriendo mecanismos mediante los cuales estos ácidos grasos poliinsaturados de cadena larga (AGPICL) modulan el metabolismo. Tanto el ARA como el DHA se encuentran depositados en los lípidos de las membranas de las células que forman la materia gris y representan aproximadamente el 25% del contenido total de ácidos grasos cerebrales. El ARA y el DHA tienen efectos sobre el crecimiento y la diferenciación neuronal a través de la modulación de las propiedades físicas de la membrana, de la transducción de señales asociada a proteínas G y la modulación de la expresión génica, adquiriendo un rol relevante en la neuro-génesis y el desarrollo cerebral. Además, se les atribuye un rol neuroprotector en patologías neurodegenerativas como la enfermedad de Alzheimer y la enfermedad de Parkinson, pudiendo disminuir la disfunción mitocondrial, la neuro-inflamación y el estrés oxidativo, expresiones características de estas patologías. La presente revisión analiza y discute acerca del rol del ARA y del DHA en la neuro-protección y en la neurodegeneración a través de una visión integradora.

ABSTRACT The study focused on elucidating the neuro-protective effects of ARA and DHA throughout the life cycle has become of increasingly interest since the continue discovering of mechanisms by which these long-chain polyunsaturated fatty acids (LCPUFA) modulate the metabolism. Both ARA and DHA are deposited into the membrane lipids of the cells that form the gray matter of the brain and represent approximately 25% of the total content of cerebral fatty acids. ARA and DHA have effects on the growth and neuronal differentiation through the modulation of the physical properties of the membrane, the signal transduction associated to G proteins and by the modulation of gene expression, acquiring a relevant role in neurogenesis and brain development. In addition, it is attributed to these fatty acids a neuro-protective role in neurodegenerative pathologies such as Alzheimer's disease and Parkinson's disease by decreasing the mitochondrial dysfunction, neuroinflammation and oxidative stress, characteristic of these pathologies. This review analyzes and discusses the role of ARA and DHA in neuro-protection and neuro-degeneration through an integrative vision.

Modification of Docosahexaenoic Acid Composition of Milk from Nursing Women Who Received Alpha Linolenic Acid from Chia Oil during Gestation and Nursing.

α-Linolenic acid (ALA) is the precursor of docosahexaenoic acid (DHA) in humans, which is fundamental for brain and visual function. Western diet provides low ALA and DHA, which is reflected in low DHA in maternal milk. Chia oil extracted from chia (Salvia hispanica L.), a plant native to some Latin American countries, is high in ALA (up to 60%) and thereby is an alternative to provide ALA with the aim to reduce DHA deficits. We evaluated the modification of the fatty acid profile of milk obtained from Chilean mothers who received chia oil during gestation and nursing. Forty healthy pregnant women (22-35 years old) tabulated for food consumption, were randomly separated into two groups: a control group with normal feeding (n = 21) and a chia group (n = 19), which received 16 mL chia oil daily from the third trimester of pregnancy until the first six months of nursing. The fatty acid profile of erythrocyte phospholipids, measured at six months of pregnancy, at time of delivery and at six months of nursing, and the fatty acid profile of the milk collected during the first six months of nursing were assessed by gas-chromatography. The chia group, compared to the control group, showed (i) a significant increase in ALA ingestion and a significant reduction of linoleic acid (LA) ingestion, no showing modification of arachidonic acid (AA), eicosapentaenoic acid (EPA) and DHA; (ii) a significant increase of erythrocyte ALA and EPA and a reduction of LA. AA and DHA were not modified; (iii) a increased milk content of ALA during the six months of nursing, whereas LA showed a decrease. AA and EPA were not modified, however DHA increased only during the first three months of nursing. Consumption of chia oil during the last trimester of pregnancy and the first three months of nursing transiently increases the milk content of DHA.

Reduction in the desaturation capacity of the liver in mice subjected to high fat diet: Relation to LCPUFA depletion in liver and extrahepatic tissues.

α-Linolenic (ALA) and linoleic (LA) acids are precursors of long chain polyunsaturated fatty acids (LCPUFAs), FAs with important biochemical and physiological functions. In this process, desaturation reactions catalyzed by Δ5- and Δ6-desaturase play a major role, enzymes that are subjected to hormonal and dietary regulation. The aim of this study was to assess the influence of a high fat diet (HFD) on activity of liver Δ5 and Δ6 desaturases, in relation to LCPUFA composition in liver and extrahepatic tissues. Male C57BL/6J mice received control diet (CD) (10% fat, 20% protein and 70% carbohydrate) or high fat diet (HFD) (60% fat, 20% protein, and 20% carbohydrate) for 12 weeks. After this time, blood and liver samples were taken for metabolic, morphologic, inflammatory, oxidative stress and desaturase activity assessment, besides FA phospholipid analysis in erythrocytes, heart, adipose tissue and brain. HFD significantly increased hepatic total fat, triacylglycerides and free FA content with macrovesicular steatosis and oxidative stress enhancement, concomitantly with higher fasting serum glucose and insulin levels, HOMA, and serum cholesterol, triacylglycerols, TNF-α, and IL-6. Diminution in liver Δ5- and Δ6-desaturase activities and LCPUFA depletion were induced by HFD, the later finding being also observed in extrahepatic tissues. In conclusion, HFD-induced reduction in the bioavailability of liver LCPUFA is associated with defective desaturation of ALA and LA, with Δ5- and Δ6-desaturase activities being correlated with insulin resistance development. Data analyzed point to the liver as a major organ responsible for extrahepatic LCPUFA homeostasis, which is markedly deranged by HFD.