共查询到10条相似文献,搜索用时 109 毫秒
1.
D. Kromhout 《Lipids》1999,34(1):S27-S31
Oxidized low density lipoproteins (LDL) play a major role in the development of atherosclerosis. Saturated fatty acids, especially fatty acids with 12–16 carbon atoms, are the most important determinants of the LDL cholesterol level. The LDL lipoprotein fraction can be oxidized by, e.g., smoking. Oxidative damage of LDL lipoproteins can be prevented by nutritive, e.g., vitamin E, and nonnutritive antioxidants, e.g., flavonoids. It can therefore be hypothesized that fatty acids and antioxidants are important determinants of coronary heart disease (CHD). There is a large body of evidence from prospective studies that LDL cholesterol-lowering is associated with a lower CHD risk. The evidence for a protective effect of antioxidants on CHD risk is much weaker and is most promising for vitamin E and flavonoids. The Seven Countries Study showed that at the population level saturated fat, cigarette smoking, and flavonoids are important determinants of long-term CHD mortality. These results suggest that a diet low in saturated fat and rich in antioxidants in combination with no smoking is associated with low CHD risk. 相似文献
2.
Hideki Shige Toshitsugu Ishikawa Michio Suzukawa Masato Nishiwaki Takeshi Yamashita Kei Nakajima Toshimitsu Ito Kenji Higashi Makoto Ayaori Atsushi Yonemura Paul Nestel Haruo Nakamura 《Lipids》1998,33(12):1169-1175
The effects of vitamin E on cholesteryl ester (CE) metabolism in 1774 cells were examined. Pretreatment of 1774 cells with
vitamin E at concentrations above 50 μM significantly decreased acetylated low density lipoprotein (LDL)-induced incorporation
of [14C]oleate into CF in cells in a dose-dependent manner. This was partly due to vitamin E Also significantly inhibiting the uptake
of [3H]CE-labeled acetylated LDL by 1774 cells. A trend existed toward suppression of acyl-CoA:cholesterol acyltransferase (ACAT)
activity in the cell lysate at high vitamin E concentration, but there was no effect on hydrolysis of CE. These data indicate
that vitamin E reduces the uptake of modified LDL and suppresses ACAT activity, resulting in less cholesterol esterification
in macrophages; a novel mechanism underlying the antiatherogenic properties of vitamin E. 相似文献
3.
Roberta Masella Claudio Giovannini Rosaria Varì Roberta Di Benedetto Ettore Coni Roberto Volpe Nadia Fraone Antonello Bucci 《Lipids》2001,36(11):1195-1202
The aim of this study was to assess the effects of the dietary intake of extra virgin olive oil on the oxidative susceptibility
of low density lipoproteins (LDL) isolated from the plasma of hyperlipidemic patients. Ten patients with combined hyperlipidemia
(mean plasma cholesterol 281 mg/dL, triglycerides 283 mg/dL) consumed a low-fat, low-cholesterol diet, with olive oil (20
g/d) as the only added fat, with no drug or vitamin supplementation for 6 wk. Then they were asked to replace the olive oil
they usually consumed with extra virgin olive oil for 4 wk. LDL were isolated at the beginning, and after the 4 wk of dietary
treatment. LDL susceptibility to CuSO4-mediated oxidation was evaluated by measuring the extent of lipid peroxidation. We also determined fatty acid composition
and vitamin E in plasma and LDL and plasma phenolic content. Extra virgin olive oil intake did not affect fatty acid composition
of LDL but significantly reduced the copper-induced formation of LDL hydroperoxides and lipoperoxidation end products as well
as the depletion of LDL linoleic and arachidonic acid. A significant increase in the lag phase of conjugated diene formation
was observed after dietary treatment. These differences are statistically correlated with the increase in plasma phenolic
content observed at the end of the treatment with extra virgin olive oil; they are not correlated with LDL fatty acid composition
or vitamin E content, which both remained unmodified after the added fat change. This report suggests that the daily intake
of extra virgin olive oil in hyperlipidemic patients could reduce the susceptibility of LDL to oxidation, not only because
of its high monounsaturated fatty acid content but probably also because of the antioxidative activity of its phenolic compounds. 相似文献
4.
In 24 healthy pregnant women, parameters related to the oxidative stability of low density lipoproteins (LDL) were determined
at three times during pregnancy and shortly after delivery. The fatty acid composition of plasma phospholipids (PL) and the
plasma concentrations of vitamin E, vitamin A, and β-carotene were assessed in the same samples. Total triglyceride (TG),
total cholesterol, LDL-cholesterol, and high density lipoprotein (HDL)-cholesterol concentrations were also determined. The
length of the lag phase of isolated LDL challenged with Cu2+ ions significantly increased with the progression of pregnancy. The oxidation rate and the amount of conjugated dienes formed
increased and reached a maximum at 29–37 wk of pregnancy. Total TG, cholesterol, and LDL-cholesterol reached a maximum in
the third trimester of pregnancy. β-Carotene remained stable, vitamin A decreased, and vitamin E significantly increased throughout
pregnancy. Vitamin E plasma concentration correlated positively with the length of the lag phase. The increased levels of
vitamin E could contribute to the higher resistance of LDL toward oxidation with progressing gestation, measured by the prolonged
lag phase. Furthermore, vitamin E plasma levels correlated positively with TG concentration but not with LDL-cholesterol.
The level of polyunsaturated fatty acids in PL decreased with the progression of pregnancy. No correlation was found between
the fatty acid composition of plasma PL, nor with the cholesterol concentration, and the parameters studied related to the
oxidative stability of LDL. The major finding of this study is the increased oxidative resistance of LDL with progressing
gestation. 相似文献
5.
Cuevas AM Guasch V Castillo O Irribarra V Mizon C San Martin A Strobel P Perez D Germain AM Leighton F 《Lipids》2000,35(2):143-148
Endothelial dysfunction is associated with atherogenesis and oxidative stress in humans. In rat and rabbit blood vessels,
wine polyphenol antioxidants induce vascular relaxationin vitro through the NO-cGMP pathway. To assess the effect of a regular high-fat diet (HFD) and moderate red wine consumption on endothelial
function (EF), a study was performed in healthy male volunteers. EF was measured as flow-mediated dilatation of the brachial
artery, employing high-resolution ultrasound after an overnight fast. Other clinical and biochemical parameters related to
EF were also measured. Six volunteers received a control diet, rich in fruits and vegetables (27% calories as fat) and five
volunteers received an HFD (39.5% calories as fat). Measurements were done twice on each volunteer: after a period of 30 d
with diet plus 240 mL of red wine/d, and after a period of 30 d with diet, without wine. In the absence of wine, there is
a reduction of EF with HFD when compared to the control diet (P=0.014). This loss of EF is not seen when both diets are supplemented with wine for 30 d (P=0.001). Plasma levels ofn−3 fatty acids (R
2=0.232,P=0.023) and lycopene (R
2=0.223,P=0.020) show a positive correlation with individual EF measurements, but they do not account for the significant differences
observed among dietary groups or after wine supplementation. These results help elucidate the deleterious effect of a high-fat
diet and the protective role of wine, n−3 fatty acids and dietary antioxidants in cardiovascular disease. 相似文献
6.
Effects of dietary phenolic compounds on tocopherol, cholesterol, and fatty acids in rats 总被引:5,自引:0,他引:5
The effects of the phenolic compounds butylated hydroxytoluene (BHT), sesamin (S), curcumin (CU), and ferulic acid (FA) on
plasma, liver, and lung concentrations of α- and γ-tocopherols (T), on plasma and liver cholesterol, and on the fatty acid
composition of liver lipids were studied in male Sprague-Dawley rats. Test compounds were given to rats ad libitum for 4 wk at 4 g/kg diet, in a diet low but adequate in vitamin E (36 mg/kg of γ-T and 25 mg/kg of α-T) and containing 2 g/kg
of cholesterol. BHT significantly reduced feed intake (P<0.05) and body weight and increased feed conversion ratio; S and BHT caused a significant enlargement of the liver (P<0.001), whereas CU and FA did not affect any of these parameters. The amount of liver lipids was significantly lowered by
BHT (P<0.01) while the other substances reduced liver lipid concentrations but not significantly. Regarding effects on tocopherol
levels, (i) feeding of BHT resulted in a significant elevation (P<0.001) of α-T in plasma, liver, and lung, while γ-T values remained unchanged; (ii) rats provided with the S diet had substantially
higher γ-T levels (P<0.001) in plasma, liver, and lung, whereas α-T levels were not affected; (iii) administration of CU raised the concentration
of α-T in the lung (P<0.01) but did not affect the plasma or liver values of any of the tocopherols; and (iv) FA had no effect on the levels of
either homolog in the plasma, liver, or lung. The level of an unknown substance in the liver was significantly reduced by
dietary BHT (P<0.001). BHT was the only compound that tended to increase total cholesterol (TC) in plasma, due to an elevation of cholesterol
in the very low density lipoprotein + low density lipoprotein (VLDL+LDL) fraction. S and FA tended to lower plasma total and
VLDL+LDL cholesterol concentrations, but the effect for CU was statistically significant (P<0.05). FA increased plasma high density lipoprotein cholesterol while the other compounds reduced it numerially, but not
significantly. BHT, CU, and S reduced cholesterol levels in the liver TC (P<0.001) and percentages of TC in liver lipids (P<0.05). With regard to the fatty acid composition of liver lipids, S increased the n-6/n-3 and the 18∶3/20∶5 polyunsaturated
fatty acids (PUFA) ratios, and BHT lowered total monounsaturated fatty acids and increased total PUFA (n−6+n−3). The effects
of CU and FA on fatty acids were not highly significant. These results suggest some in vivo interactions between these phenolic compounds and tocopherols that may increase the bioavailability of vitamin E and decrease
cholesterol in rats. 相似文献
7.
This experiment was designed to evaluate the effects of dietary red wine phenolic compounds (WP) and cholesterol on lipid
oxidation and transport in rats. For 5 wk, weanling rats were fed polyunsaturated fat diets (n−6/n−3=6.4) supplemented or
not supplemented with either 3 g/kg diet of cholesterol, 5 g/kg diet of WP, or both. The concentrations of triacylglycerols
(TAG, P<0.01) and cholesterol (P<0.0002) were reduced in fasting plasma of rats fed cholesterol despite the cholesterol enrichment of very low density lipoprotein
+ low density lipoprotein (VLDL+LDL). The response was due to the much lower plasma concentration of high density lipoprotein
(HDL) (−35%, P<0.0001). In contrast, TAG and cholesteryl ester (CE) accumulated in liver (+120 and +450%, respectively, P<0.0001). However, the cholesterol content of liver microsomes was not affected. Dietary cholesterol altered the distribution
of fatty acids mainly by reducing the ratio of arachidonic acid to linoleic acid (P<0.0001) in plasma VLDL+LDL (−35%) and HDL (−42%) and in liver TAG (−42%), CE (−78%), and phospholipids (−28%). Dietary WP
had little or no effect on these variables. On the other hand, dietary cholesterol lowered the α-tocopherol concentration
in VLDL+LDL (−40%, P<0.003) and in microsomes (−60%, P<0.0001). In contrast, dietary WP increased the concentration in microsomes (+21%, P<0.0001), but had no effect on the concentration in VLDL+LDL. Cholesterol feeding decreased (P<0.006) whereas WP feeding increased (P<0.0001) the resistance of VLDL+LDL to copper-induced oxidation. The production of conjugated dienes after 25 h of oxidation
ranged between 650 (WP without cholesterol) and 2,560 (cholesterol without WP) μmol/g VLDL+LDL protein. These findings show
that dietary WP were absorbed at sufficient levels to contribute to the protection of polyunsaturated fatty acids in plasma
and membranes. They could also reduce the consumption of α-tocopherol and endogenous antioxidants. The responses suggest that,
in humans, these substances may be beneficial by reducing the deleterious effects of a dietary overload of cholesterol. 相似文献
8.
Increasing evidence exists that oxidative modification of low density lipoprotein (LDL) plays an important role in the pathogenesis of atherosclerosis. Lipid peroxidation processes degrade polyunsaturated fatty acids of the LDL-lipids to hydroperoxyacids and further breakdown products, which themselves modify the apolipoprotein B. These oxidized LDL-particles are taken up via the scavenger receptor of tissue-macrophages in an uncontrolled manner and lead to the formation of lipid laden foam cells, which are present in fatty streaks. Oxidized LDL (oxLDL) is detectable in atherosclerotic plagues immunochemically. Autoantibodies against oxLDL are detectable in serum and their titers correlate with the progression of atherosclerosis. The oxidation resistance of LDL is in part dependent of its antioxidant content (vitamin E, carotenoids, ubiquinol-10). Oral supplementation of vitamin E increases significantly the oxidation resistance of LDL while β-carotene supplementation seems to increase the oxidation resistance only of certain individuals. A clinical trial has demonstrated an inverse correlation of severity of myocardial infarction and oxidation resistance of LDL. 相似文献
9.
Plasma kinetic behavior in hyperlipidemic subjects of a lipidic microemulsion that binds to low density lipoprotein receptors 总被引:2,自引:2,他引:2
Raul C. Maranhão Ivete A. Roland Odaly Toffoletto José Antonio Ramires Romélia P. Gonçalves Carlos H. Mesquita Fulvio Pileggi 《Lipids》1997,32(6):627-633
It was previously reported that a protein-free microemulsion (LDE) with structure roughly resembling that of the lipid portion
of low density lipoprotein (LDL) was presumably taken up by LDL receptors when injected into the bloodstream. In contact with
plasma, LDE acquires apolipoproteins (apo) including apo E that would be the ligand for receptor binding. Currently, apo were
associated to LDE by incubation with high density lipoprotein (HDL). LDE-apo uptake by mononuclear cells showed a saturation
kinetics, with an apparent K
m of 13.1 ng protein/mL. LDE-apo is able to displace LDL uptake by mononuclear cells with a K
i of 11.5 ng protein/mL. LDE without apo is, however, unable to displace LDL. The uptake of 14C-HDL is not dislocated by increasing amounts of LDE-apo, indicating that HDL and LDE-apo do not bind to the same receptor
sites. In human hyperlipidemias, LDE labeled with 14C-cholesteryl ester behaved kinetically as expected for native LDL. LDE plasma disappearance curve obtained from eight hypercholesterolemic
patients was markedly slower than that from 10 control normolipidemic subjects [fractional clearance rate (FCR)=0.02±0.01
and 0.12±0.04 h−1, respectively; P<0.0001]. On the other hand, in four severely hypertriglyceridemic patients, LDE FCR was not significantly different from
the controls (0.07±0.03 h−1). These results suggest that LDE can be a useful device to study lipoprotein metabolism. 相似文献
10.
Fernández-Pachón MS Villaño D Troncoso AM García-Parrilla MC 《Archivos latinoamericanos de nutrición》2006,56(2):110-122
The aim of this paper is to evaluate the significance of these methods, as well as to correlate the antioxidant activity of wines with their phenolic profile, both in qualitative and quantitative terms. Red wines show higher antioxidant capacities than white ones and the magnitude of these differences depends on the method used. The antioxidant activity of wine can not be mainly ascribed to a particular phenolic compound, instead it is explained by the global interaction of all of them. To evaluate the influence of red wine consumption in the human organism, plasma antioxidant capacity has been frequently used as biomarker, and studies have shown that it increases after wine ingestion. We can conclude that it is necessary to use a battery of methods that provide different and complementary information to properly interpret the results. Phenolic compounds undergo metabolic transformations in the organism which modify their activities. In vivo assays do consider these changes. From the studies performed up to date we can conclude that acute ingestion of wine directly acts on plasma antioxidant capacity due to phenolic compounds and indirectly influences by means of changes on plasmatic concentration of endogenous antioxidants. 相似文献