Cynthia Barrera

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.

Vegetable oils rich in alpha linolenic acid increment hepatic n-3 LCPUFA, modulating the fatty acid metabolism and antioxidant response in rats

Alpha-linolenic acid (C18:3 n-3, ALA) is an essential fatty acid and the metabolic precursor of long-chain polyunsaturated fatty acids (LCPUFA) from the n-3 family with relevant physiological and metabolic roles: eicosapentaenoic acid (C20:5 n-3, EPA) and docosahexaenoic acid (C22:6 n-3, DHA). Western diet lacks of suitable intake of n-3 LCPUFA and there are recommendations to increase the dietary supply of such nutrients. Seed oils rich in ALA such as those from rosa mosqueta (Rosa rubiginosa), sacha inchi (Plukenetia volubis) and chia (Salvia hispanica) may constitute an alternative that merits research. This study evaluated hepatic and epididymal accretion and biosynthesis of n-3 LCPUFA, the activity and expression of Δ-5 and Δ-6 desaturase enzymes, the expression and DNA-binding activity of PPAR-α and SREBP-1c, oxidative stress parameters and the activity of antioxidative enzymes in rats fed sunflower oil (SFO, 1% ALA) as control group, canola oil (CO, 10% ALA), rosa mosqueta oil (RMO, 33% ALA), sacha inchi oil (SIO, 49% ALA) and chia oil (ChO, 64% ALA) as single lipid source. A larger supply of ALA increased the accretion of n-3 LCPUFA, the activity and expression of desaturases, the antioxidative status, the expression and DNA-binding of PPAR-α, the oxidation of fatty acids and the activity of antioxidant enzymes, whereas the expression and DNA-binding activity of SREBP-1c transcription factor and the biosynthetic activity of fatty acids declined. Results showed that oils rich in ALA such as SIO and ChO may trigger metabolic responses in rats such as those produced by n-3 PUFA.

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.

Polyunsaturated Fatty Acid Composition of Maternal Diet and Erythrocyte Phospholipid Status in Chilean Pregnant Women

Chilean diets are characterized by a low supply of n-3 polyunsaturated fatty acids (n-3 PUFA), which are critical nutrients during pregnancy and lactation, because of their role in brain and visual development. DHA is the most relevant n-3 PUFA in this period. We evaluated the dietary n-3 PUFA intake and erythrocyte phospholipids n-3 PUFA in Chilean pregnant women. Eighty healthy pregnant women (20–36 years old) in the 3rd–6th month of pregnancy were included in the study. Dietary assessment was done applying a food frequency questionnaire, and data were analyzed through the Food Processor SQL® software. Fatty acids of erythrocyte phospholipids were assessed by gas-liquid chromatography. Diet composition was high in saturated fat, low in mono- and PUFA, high in n-6 PUFA (linoleic acid) and low in n-3 PUFA (alpha-linolenic acid and DHA), with imbalance in the n-6/n-3 PUFA ratio. Similar results were observed for fatty acids from erythrocyte phospholipids. The sample of Chilean pregnant women showed high consumption of saturated fat and low consumption of n-3 PUFA, which is reflected in the low DHA content of erythrocyte phospholipids. Imbalance between n-6/n-3 PUFA could negatively affect fetal development. New strategies are necessary to improve n-3 PUFA intake throughout pregnancy and breast feeding periods. Furthermore, it is necessary to develop dietary interventions to improve the quality of consumed foods with particular emphasis on n-3 PUFA.

Anti-steatotic effects of an n-3 LCPUFA and extra virgin olive oil mixture in the liver of mice subjected to high-fat diet

Non-alcoholic fatty liver disease (NAFLD) is characterized by liver steatosis, oxidative stress, and drastic depletion of n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA), namely, eicosapentaenoic acid (C20:5 n-3, EPA) and docosahexaenoic acid (C22:6 n-3, DHA), which trigger lipolysis stimulation and lipogenesis inhibition. Extra virgin olive oil (EVOO) has important antioxidant effects. This study evaluated the anti-steatotic effects of n-3 LCPUFA plus EVOO in the liver of male C57BL/6J mice subjected to a control diet (CD) (10% fat, 20% protein, 70% carbohydrate) or high fat diet (HFD) (60% fat, 20% protein, 20% carbohydrate), without and with supplementation with n-3 LCPUFA (100 mg per kg per day) plus EVOO (100 mg per kg per day) for 12 weeks. HFD induced (i) liver steatosis (increased total fat, triacylglycerols, and free fatty acid total contents), (ii) higher fasting serum glucose and insulin levels and HOMA index, total cholesterol, triacylglycerols and TNF-α and IL-6, (iii) liver and plasma oxidative stress enhancement, (iv) depletion of the n-3 LCPUFA hepatic content, and (v) increment in lipogenic enzyme activity and reduction in lipolytic enzyme activity. These changes were either reduced (p < 0.05) or normalized to control the values in animals subjected to HFD supplemented with n-3 LCPUFA plus EVOO. In conclusion, n-3 LCPUFA plus EVOO intervention exerts anti-steatotic effects underlying antioxidant and anti-inflammatory responses, improved insulin sensitivity, and recovery of the lipolytic/lipogenic status of the liver altered by HFD, and supports the potential therapeutic use of n-3 LCPUFA plus EVOO supplementation in the treatment of human liver steatosis induced by nutritional factors or other etiologies.

Impact of anthropometric nutritional parameters on the university selection test in Chile: A multifactorial approach

OBJECTIVES Scholastic achievement (SA) is a multifactorial problem that depends on factors related to the child, the childs family, and the educational system. The aim of this study was to quantify the relative impact of significant variables at the beginning of high school during 2010 (first grade of high school [1 HSG]) on 2013 university selection test (Prueba de Seleccion Universitaria [PSU]) outcomes, both in language scholastic achievement (LSA) and mathematics scholastic achievement (MSA), when students graduated from high school (4 HSG). This was done at the time of university admission with a multicausal approach. The purpose was to confirm the hypothesis that the level of educational establishment SA, intellectual ability, sex, parental schooling levels, and head circumference for age Z-score at the onset of high school are the most relevant parameters associated with 2013 PSU outcomes, both in LSA and MSA. METHODS A representative, proportional, and stratified sample of 671 children of both sexes who enrolled in 1 HSG in 2010 (mean age: 14.8 ± 0.6 y) participated in the study. Nutritional, intellectual, brain developmental, cardiovascular risk, socio-to-economic, demographic, and educational variables were quantitated. SA was assessed at 4 HSG with the 2013 PSU tests. Data were analyzed with SAS software. RESULTS Educational establishment SA, intellectual ability, maternal schooling, and age Z-score were the most relevant parameters to explain LSA (R2 = 0.493; P < 0.0001) and MSA variance in addition to sex (male), but only in MSA (R2 = 0.600; P < 0.0001). CONCLUSIONS These findings confirm the hypothesis and can be useful to support nutritional, health, and educational planning.

Overnutrition and Scholastic Achievement: Is There a Relationship? An 8-Year Follow-Up Study

Objective: The aim of this study was to assess the association between overnutrition and scholastic achievement (SA). Methods: A representative and proportional sample of 477 children of the 5th elementary school grade of both genders was randomly chosen during 2010, in the Metropolitan Region of Chile. SA was measured through the 2009 Education Quality Measurement System (SIMCE) tests of language (LSA), mathematics (MSA) and understanding of the natural environment (UNESA). Current nutritional status was assessed through the body mass index Z-score (Z-BMI). Nutritional quality of diet, schedule exercise, socioeconomic status, family, and educational variables were also recorded. Four and 8 years later, SA was assessed through the 2013 SIMCE and the University Selection Test (2017 PSU), respectively. Results: Socioeconomic status, the number of repeated school years, and maternal schooling were strong predictors of 2009 SIMCE and the independent variables with the greatest explanatory power for LSA (Model R2 = 0.178; p < 0.00001) variances, besides of gender for MSA (Model R2 = 0.205; p< 0.00001) and UNESA (Model R2 = 0.272; p < 0.00001). Overnourished children did not have significantly lower 2009 and 2013 SIMCE and 2017 PSU outcomes. Conclusions: These results confirm that overnourished children did not achieve significantly lower SA.

The Impact of Maternal Diet during Pregnancy and Lactation on the Fatty Acid Composition of Erythrocytes and Breast Milk of Chilean Women

Maternal diet during pregnancy is relevant for fatty acid supply during fetal life and lactation. Arachidonic (AA) and docosahexaenoic (DHA) acids are also relevant for the normal growth and development of brain and visual system. AA and DHA provided by the mother to the fetus and infant are directly associated with maternal dietary intake and body stores. Our aim was to evaluate the impact of maternal diet, specially referring to the quality of fatty acid intake, in a sample of Chilean women during last stage of pregnancy and across the lactation period. Fifty healthy pregnant women (age range 20–33 years) were studied from the 6th month of pregnancy and followed until 6th month of lactation period. Diet characteristics were evaluated through food frequency questionnaires. Fatty acids composition of erythrocyte phospholipids and breast milk samples was assessed by gas-liquid chromatography. Overall, women had high saturated fatty acids intake with sufficient intake of mono- and polyunsaturated fatty acids (PUFA). Diet was high in n-6 PUFA and low in n-3 PUFA (mainly DHA), with imbalanced n-6/n-3 PUFA ratio. Erythrocytes and breast milk DHA concentration was significantly reduced during lactation compared to pregnancy, a pattern not observed for AA. We concluded that is necessary to increase the intake of n-3 PUFA during pregnancy and lactation by improving the quality of consumed foods with particular emphasis on its DHA content.

Molecular mechanisms related to the hepatoprotective effects of antioxidant-rich extra virgin olive oil supplementation in rats subjected to short-term iron administration

Abstract Enhanced iron levels in liver are associated with oxidative stress development and damage with increased fat accumulation. The aim of this work was to assess the hypothesis that antioxidant‐rich extra virgin olive oil (AR‐EVOO) counteracts iron‐rich diet (IRD)‐induced oxidative stress hindering hepatic steatosis. Male Wistar rats were fed and IRD (200 mg iron/kg diet) versus a control diet (CD; 50 mg iron/kg diet) with alternate AR‐EVOO supplementation (100 mg/day) for 21 days. IRD induced liver steatosis and oxidative stress (higher levels of protein oxidation and lipid peroxidation with glutathione depletion), mitochondrial dysfunction (decreased citrate synthase and complex I and II activities) and loss of polyunsaturated fatty acids (PUFAs), with a drastic enhancement in the sterol regulatory element‐binding protein‐1c (SREBP‐1c)/peroxisome proliferator‐activated receptor‐&agr; (PPAR‐&agr;) ratio upregulating the expression of lipogenic enzymes (acetyl‐CoA carboxylase, fatty acid (FA) synthase and stearoyl desaturase 2) and downregulating those involved in FA oxidation (carnitine palmitoyl transferase and acyl‐CoA oxidase) over values in the CD group. IRD also upregulated nuclear factor erythroid 2‐related factor 2 (Nrf2) and its target genes. AR‐EVOO supplementation alone did not modify the studied parameters, however, IRD combined with AR‐EVOO administration returned IRD‐induced changes to baseline levels of the CD group. It is concluded that IRD‐induced non‐alcoholic fatty liver disease (NAFLD) is prevented by AR‐EVOO supplementation, which might be related to the protective effects of its components such as hydroxytyrosol, oleic acid, tocopherols and/or PUFAs, thus representing a suitable anti‐steatotic strategy to avoid progression into more severe stages of the disease, underlying NAFLD associated with iron overloading pathologies or obesity. Graphical abstract Figure. No caption available. HighlightsIron (Fe) overload triggers liver oxidative stress and LCPUFA depletion.Low LCPUFAs decreases FA oxidation and upregulates lipogenesis inducing steatosis.Antioxidant‐rich extra virgin olive oil (AR‐EVOO) abrogates Fe‐induced hepatotoxicity.Steatosis prevention by AR‐EVOO may avoid progression into the inflammatory stage.