Browsing by Autor "Julio Sanhueza"

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Alpha linolenic acid (ALA) from Rosa canina, sacha inchi and chia oils may increase ALA accretion and its conversion into n-3 LCPUFA in diverse tissues of the rat
(Royal Society of Chemistry, 2014) Rodrigo Valenzuela B; Cynthia Barrera; Marcela González-Astorga; Julio Sanhueza; Alfonso Valenzuela B
Alpha-linolenic acid (ALA) is an essential n-3 PUFA; its n-3 LCPUFA derivatives EPA and DHA, which have diverse beneficial effects, are scarce in the human diet. In recent years nontraditional vegetable oils rich in ALA (up to 45%) have been developed as new alternatives to increase ALA consumption. This work evaluated the accretion of ALA, EPA and DHA into the phospholipids extracted from erythrocytes, liver, kidney, small intestine, heart, quadriceps and the brain in rats fed sunflower (SFO), canola (CO), Rosa canina (RCO), sacha inchi (Plukenetia volubilis, SIO) and chia (Salvia hispánica, ChO) oils. Five experimental groups (n = 12 per group) were fed for 21 days with SFO (1% ALA), CO (10% ALA), RCO (33% ALA), SIO (49% ALA), and ChO (64% ALA). SIO and ChO allowed higher ALA accretion in all tissues, except the brain, and a reduction in the content of arachidonic acid in all tissues except the brain. EPA was increased in erythrocytes, liver, kidney, small intestine, heart and quadriceps, but not in the brain. DHA was increased in the liver, small intestine and brain tissues. Our results demonstrate that ALA, when provided in significant amounts, can be converted into n-3 LCPUFA, mostly DHA in the liver and brain. It is suggested that oils rich in ALA, such as SIO and ChO, are good sources for obtaining higher tissue levels of ALA, also allowing its selective conversion into n-3 LCPUFA in some tissues of the rat.
Cholesterol metabolism: increasingly complex
(Spanish National Research Council, 2012) Julio Sanhueza; Rodrigo Valenzuela; A. Valenzuela
Cholesterol is an important molecule; it is necessary for the biosynthesis of steroidal hormones, bile salts and to maintain the stability of biological membranes in animal cells. However, its excess is negative and is responsible for the development of many diseases involving the heart and brain, or in the generation of some types of cancer. For these reasons, the cellular cholesterol levels must be finely regulated and therefore, an infinite number of mechanisms participate in this regulation, which undertake the organism as a whole. These mechanisms should begin to operate efficiently from the intake of cholesterol from the diet, its incorporation into the enterocyte, where are involved carriers such as ABC and NCP1 transporters, PDZ structural motif, to name a few. It is also necessary an adequate regulation of circulating cholesterol and once inside the body, there should be a perfect harmony between the addition of cholesterol to various tissues, its metabolic use, the mechanisms of its tissue deposition, and the synthesis of this lipid. From this perspective, this review offers a general view of the molecular mechanisms that allow the regulation of extra and intracellular cholesterol levels.
Effect of Supplementation with Docosahexaenoic Acid Ethyl Ester and sn-2 Docosahexaenyl Monoacylglyceride on Plasma and Erythrocyte Fatty Acids in Rats
(Karger Publishers, 2005) Alfonso Valenzuela; Viviana Valenzuela; Julio Sanhueza; Susana Nieto
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.
Supplementing female rats with DHA-lysophosphatidylcholine increases docosahexaenoic acid and acetylcholine contents in the brain and improves the memory and learning capabilities of the pups.
(Spanish National Research Council, 2009) A. Valenzuela; Susana Nieto; Julio Sanhueza; N. Morgado; I. Rojas; P. Zañartu
Docosahexaenoic acid (DHA) is supplied to the foetus and newborn through the mother from their own reserves and their diet. No consensus about the best form to supplement DHA has been established. We propose that DHAcontaining lysophosphatidylcholine (DHA-LPC), obtained from DHA-rich eggs may be a suitable form of DHA and choline (the precursor of acetylcholine) supplementation. We evaluated the effectiveness of DHA-LPC to increase DHA and acetylcholine concentration in the brain of pups born from female rats supplemented with DHA-LPC before and during pregnancy. We also evaluated the effect of DHA supplementation on learning and memory capabilities of pups through the Skinner test for operant conditioning. Female Wistar rats received 40-day supplementation of DHA-LPC (8 mg DHA/kg b.w/daily.), before and during pregnancy. After delivery, plasma, erythrocyte, liver, and adipose tissue DHA and plasma choline were analyzed. Brains from 60 day-old pups separated into frontal cortex, cerebellum, striatum, hippocampus, and occipital cortex, were assessed for DHA, acetylcholine, and acetylcholine transferase (CAT) activity. Pups were subjected to the Skinner box test. DHA-LPC supplementation produces higher choline and liver DHA contents in the mother’s plasma and increases the pups’ DHA and acetylcholine in the cerebellum and hippocampus. CAT was not modified by supplementation. The Skinner test shows that pups born from DHA-LPC supplemented mothers exhibit better scores of learning and memory than the controls. Conclusion: DHA-LPC may be an adequate form for DHA supplementation during the perinatal period.