production of selected secondary metabolites in transformed ...

INFLUENCE OF POLYUNSATURATED FATTY ACIDS INTAKE
ON LIPID METABOLISM IN PATIENTS WITH HYPERLIPIDAEMIA
Simona Macuchová
Mentor: Doc. RNDr. Ivana Márová, CSc.
Brno University of Technology, Faculty of Chemistry, Department of Food Technology
and Biotechnology, Purkyňova 118, 612 00, Brno, email: macuchova@fch.vutbr.cz
INTRODUCION
Cardiovascular diseases are the main cause of mortality in most of industrialized countries.
Risk factors include smoking, diabetes, obesity, high level of blood cholesterol, a diet high in
fats, and having a personal or family history of heart disease. Cerebrovascular disease,
peripheral vascular disease, high blood pressure, and kidney disease involving dialysis are
disorders that may also be associated with atherosclerosis (1).
Atherosclerosis is characterized by deposition of cholesterol rich plaques in the
endothelium. This observation stimulated research on the metabolism of cholesterol and
revealed that cholesterol is transported in esterified form to cells by the low density
lipoprotein (LDL). LDL is recognized by an endothelial cell receptor and introduced into the
cell by endocytosis. There the esters are cleaved. The resulting free cholesterol is transferred
to the cell walls. The process is strictly regulated. In atherosclerotic patients LDL is altered by
oxidation. This altered LDL is taken up in unlimited amounts by macrophages. Dead
macrophages filled with cholesterol esters are finally deposited in arteries (1).
The fact that LDL is rendered toxic by oxidation raises the question which constituents of
LDL are prone to undergo oxidation. LDL consists of a core of cholesterol esters which is
surrounded by a phospholipid membrane in which the protein is inbedded. The latter is
required to recognize the LDL cell receptor.
Polyunsaturated fatty acids (PUFAs) esterified to cholesterol or present as phospholipids
represent the most oxygen sensitive compounds of all these LDL constituents.
Dietary polyunsaturated fatty acids (PUFA) have effects on diverse physiological
processes impacting normal health and chronic diseases, such as the regulation of plasma lipid
levels, cardiovascular and immune function, insulin action, and neural development and
visual function (1).
Ingestion of PUFA would lead to their distribution to virtually every cell in the body with
effects on membrane composition and function, eicosanoid synthesis, and signaling as well as
the regulation of gene expression.
Cell specific lipid metabolism, as well as the expression of fatty acid-regulated
transcription factors likely play an important role in determining how cells respond to changes
in PUFA composition.
Chemically, PUFA belong to the class of simple lipids, as are fatty acids with two or more
double bonds in cis position. There are two main families of PUFA: n-3 and n-6. These fatty
acids family are not convertible and have very different biochemical roles.
Dietary n-3 PUFA have several beneficial properties:
- act favorably on blood characteristics by reducing platelet aggregation and blood
viscosity;
Sborník soutěže Studentské tvůrčí činnosti Student 2006 a doktorské soutěže O cenu děkana 2005 a 2006
Sekce DSP 2006, strana 210