SUNFLOWER OIL RESEARCH
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Decreased aortic early atherosclerosis and associated risk
factors in hypercholesterolemic hamsters fed a high- or mid-oleic acid oil compared to a high-linoleic acid oil. |
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J Nutr Biochem
2004 Sep;15(9):540-7 (ISSN: 0955-2863) |
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Nicolosi RJ; Woolfrey
B; Wilson TA; Scollin P; Handelman
G; Fisher R |
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Currently, diets higher in polyunsaturated fat are believed to
lower blood cholesterol concentrations, and thus reduce atherosclerosis,
greater than diets containing high amounts of saturated or possibly even
monounsaturated fat. The present study was designed to investigate the effect
of diets containing mid- or high-linoleic oil
versus the typical high-linoleic sunflower oil
on LDL oxidation and the development of early atherosclerosis in a hypercholesterolemic hamster model. Animals were fed a hypercholesterolemic diet containing 10% mid-oleic sunflower
oil, high-oleic olive oil, or high-linoleic
sunflower oil (wt/wt) plus 0.4% cholesterol (wt/wt) for 10
weeks. After 10 weeks of dietary treatment, only the animals fed the
mid-oleic sunflower oil had significant reductions in plasma
LDL-C levels (-17%) compared to the high-linoleic sunflower
oil group. The high-oleic olive oil-fed hamsters had
significantly higher plasma triglyceride levels (+41%) compared to the high-linoleic sunflower oil-fed hamsters. The tocopherol levels in plasma LDL were significantly higher
in hamsters fed the mid-oleic sunflower oil (+77%) compared to
hamsters fed either the high-linoleic sunflower
or high-oleic olive oil. Measurements of LDL oxidation parameters,
indicated that hamsters fed the mid-oleic sunflower oil and
high-oleic olive oil diets had significantly longer lag phase (+66%
and +145%, respectively) and significantly lower propagation rates (-26% and
-44%, respectively) and conjugated dienes formed
(-17% and -25%, respectively) compared to the hamsters fed the high-linoleic sunflower oil. Relative to the
high-linoleic sunflower oil, aortic
cholesterol ester was reduced by -14% and -34% in the mid-oleic sunflower
oil and high-oleic olive oil groups, respectively, with the
latter reaching statistical significance. Although there were no significant
associations between plasma lipids and lipoprotein cholesterol with aortic
total cholesterol and cholesterol esters for any of the groups, the lag phase
of conjugated diene formation was inversely
associated with both aortic total and esterified
cholesterol in the high-oleic olive oil-fed hamsters (r = -0.69, P
< 0.05). The present study suggests that mid-oleic sunflower oil
reduces risk factors such as lipoprotein cholesterol and oxidative stress
associated with early atherosclerosis greater than the typical high-linoleic sunflower oil in hypercholesterolemic hamsters. The high-oleic olive oil
not only significantly reduced oxidative stress but also reduced aortic
cholesterol ester, a hallmark of early aortic atherosclerosis greater than
the typical high-linoleic sunflower oil. |
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Antioxidants and total peroxyl
radical-trapping ability of olive and seed oils. |
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J Agric Food Chem 2001
Dec;49(12):6026-32 (ISSN: 0021-8561) |
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Cabrini L; Barzanti
V; Cipollone M; Fiorentini
D; Grossi G; Tolomelli B;
Zambonin L; Landi L |
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The presence of the oxidized and reduced forms of ubiquinones Q(9) and Q(10) was determined in commercial
extra virgin olive and seed oils, where the amounts of alpha-
and gamma-tocopherols and beta-carotene were also quantitated. Very high concentrations of ubiquinones were found in soybean and corn oils.
Furthermore, the total antioxidant capability of each oil was
evaluated by measuring total radical-trapping antioxidant parameters (TRAP)
in tert-butyl alcohol and using egg lecithin as the
oxidizable substrate. These values decreased in the
order sunflower > corn > peanut > olive; the highest TRAP,
which was found in sunflower oil, was related to the very high
amount of alpha-tocopherol. Olive oil,
because of the low content of alpha-tocopherol,
exhibited a TRAP value approximately one-third that of sunflower oil.
TRAP values of corn and soybean oils, in which low amounts of alpha-tocopherol but very high contents of gamma-tocopherol and reduced ubiquinones
were present, were intermediate. gamma-Tocopherol
exhibited a poor ability of trapping peroxyl
radicals in tert-butyl alcohol. This behavior was
probably due to the effects of the solvent on the rate of hydrogen
abstraction from this phenol. |
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