[Effect of phenolic compounds of virgin olive oil on LDL oxidation resistance].
OBJECTIVE
Several epidemiological and experimental studies have associated the intake of antioxidants, which are abundant in the Mediterranean diet, with a low incidence of cardiovascular disease. One possible mechanism of this action is the oxidative protection in low density lipoproteins (LDL). The aim of our study was to compare the antioxidative activity of diverse phenolic compounds present in virgin olive oil on these lipoproteins.


METHODS
LDL was isolated from blood plasma of healthy volunteers by sequential ultracentrifugation. This was followed by oxidation with CuC12 in the presence of different concentrations of phenolic compounds and virgin olive oil extract. Production of conjugated dienes was determined by the continuous monitoring of increased absorbency at 234 nm as an indicator of LDL oxidation.


RESULTS
Virgin olive oil extract prolonged the latency phase and significantly lowered the progression rate (p < 0.05) at low concentrations (2 g/ml). This antioxidative effect was also observed with low concentrations (2 M) of caffeic acid and oleuropein (p < 0.05). However, it was necessary to increase the concentration of flavone up to 50 times to observe a similar effect (p < 0.05).


CONCLUSIONS
Both virgin olive oil extract enriched in phenolic compounds and phenolic compounds present in olive oil (caffeic acid and oleuropein) are potent antioxidants at very low concentrations. Thus, the beneficial effects of a Mediterranean diet may be partly due to the protective action of these compounds.
Moreno
Juan Antonio
JA
Unidad de Lípidos y Arteriosclerosis. Hospital Universitario Reina Sofía. Córdoba. España.
López-Miranda
José
J
Gómez
Purificación
P
Benkhalti
Fatiha
F
El Boustani
Es-Saddik
ES
Pérez-Jiménez
Francisco
F
D000975:Antioxidants / Q000494:pharmacology*; D002109:Caffeic Acids / Q000494:pharmacology; D038441:Diet, Mediterranean; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology; D047309:Flavones; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D057888:Iridoid Glucosides; D039823:Iridoids; D015227:Lipid Peroxidation / Q000502:physiology*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D000069463:Olive Oil; D010084:Oxidation-Reduction; D010636:Phenols / Q000494:pharmacology*; D010938:Plant Oils / Q000494:pharmacology*; D011714:Pyrans / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D000975:Antioxidants; D002109:Caffeic Acids; D004042:Dietary Fats, Unsaturated; D047309:Flavones; D005419:Flavonoids; D057888:Iridoid Glucosides; D039823:Iridoids; D008077:Lipoproteins, LDL; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D011714:Pyrans; D014665:Vasodilator Agents; C002769:oleuropein; C043562:flavone; C040048:caffeic acid