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1.
Antioxidant synergism of green tea polyphenols with alpha-tocopherol and L-ascorbic acid in SDS micelles 总被引:1,自引:0,他引:1
The synergistic antioxidant effect of polyphenols extracted from green tea, i.e. (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG) and gallic acid (GA), with alpha-tocopherol (vitamin E) and l-ascorbic acid (vitamin C) against the peroxidation of linoleic acid has been studied in sodium dodecyl sulfate (SDS) micelles. The peroxidation was initiated thermally by a water-soluble azo initiator 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH), and the reaction kinetics were studied by monitoring the formation of linoleic acid hydroperoxides and consumption of the antioxidants. It was found that the mixture of the green tea polyphenol, vitamin E and vitamin C could act synergistically to protect lipid peroxidation. Kinetic and mechanistic studies on the antioxidation process revealed that this antioxidant synergism was due to the regeneration of vitamin E by the green tea polyphenol and the regeneration of the latter by vitamin C. 相似文献
2.
In vitro lipid peroxidation initiated by NADPH/ADP/Fe3+ reveals an alteration of rat liver microsomal antioxidant factors at day D+4 after whole-body gamma irradiation (8Gy). This alteration is partly reversed by GSH, and more efficiently by Trolox C, a water-soluble analog of vitamin E. This reversion by Trolox C, together with the observed 50% decrease in vitamin E content in microsomes of irradiated rats as compared to those of control animals, indicate that Trolox C acts as a free-radical scavenger like and in place of vitamin E. The antioxidant action of Trolox C is not improved in the presence of GSH, which suggests that the former acts earlier than the latter on the autoxidative free-radical chain reactions. Neither GSH, nor Trolox C, nor both antioxidants totally inhibit in vitro lipid peroxidation, which appeals attention on the possible role of extra-microsomal antioxidant factors, especially cytosolic ones. 相似文献
3.
We assessed oxidative stress in three different clinical conditions: smoking, human immunodeficiency virus (HIV) infection, and inflammatory bowel disease, using breath alkane output and other lipid peroxidation parameters such as plasma lipid peroxides (LPO) and malondialdehyde (MDA). Antioxidant micronutrients such as selenium, vitamin E, C, beta-carotene and carotenoids were also measured. Lipid peroxidation was significantly higher and antioxidant vitamins significantly lower in smokers compared to nonsmokers. Beta-carotene or vitamin E supplementation significantly reduced lipid peroxidation in that population. However, vitamin C supplementation had no effect. In HIV-infected subjects, lipid peroxidation parameters were also elevated and antioxidant vitamins reduced compared to seronegative controls. Vitamin E and C supplementation resulted in a significant decrease in lipid peroxidation with a trend toward a reduction in viral load. In patients with inflammatory bowel disease, breath alkane output was also significantly elevated when compared to healthy controls. A trial with vitamin E and C is underway. In conclusion, breath alkane output, plasma LPO and MDA are elevated in certain clinical conditions such as smoking, HIV infection, and inflammatory bowel disease. This is associated with lower levels of antioxidant micronutrients. Supplementation with antioxidant vitamins significantly reduced these lipid peroxidation parameters. The results suggest that these measures are good markers for lipid peroxidation. 相似文献
4.
Marlene Lúcio Cláudia Nunes Diana Gaspar Helena Ferreira José L. F. C. Lima Salette Reis 《Food biophysics》2009,4(4):312-320
Peroxidation of lipids is of significant interest owing to the evidence that peroxyl radicals and products of lipid peroxidation
may be involved in the toxicity of compounds initiating a deteriorative reaction in the processing and storage of lipid-containing
foods. In view of the significance of the antioxidant role of the dietary compound vitamin E and its water-soluble analogue
Trolox in research of lipid-containing foods, it is desirable to determine more specifically how and where they operate its
antioxidant activity in lipid membranes. In this study, unilamellar liposomes of phosphatidylcholine were used as membrane
mimetic systems to estimate the antioxidant properties of vitamin E and Trolox and establish a relationship between their
interactions with the membrane and their consequent antioxidant activity. Lipid peroxidation was initiated by the peroxyl
radical (ROO•) in lipid and aqueous media by the thermal decomposition of azocompounds and was assessed by the fluorescence intensity decay
of the fluorescent probe diphenylhexatriene propionic acid. Results obtained showed that membrane lipoperoxidation is related
not only to the scavenging characteristics of the compounds studied but also to their ability to interact with the lipid bilayers,
and consequently liposomes provide additional information to that obtained currently from assays performed in aqueous buffer
media. 相似文献
5.
Dose-dependent modulation of systemic lipid peroxidation and activity of anti-oxidant enzymes by vitamin E in the rat 总被引:1,自引:0,他引:1
Hajiani M Golestani A Shariftabrizi A Rastegar R Payabvash S Salmasi AH Dehpour AR Pasalar P 《Redox report : communications in free radical research》2008,13(2):60-66
The objective of this work was to examine the time-dependent pro-oxidant versus antioxidant effect of various doses of vitamin E used commonly in experimental studies. Erythrocyte activity of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and plasma lipid peroxidation levels were investigated following biweekly intramuscular administration of 100, 300 and 600 mg/kg of vitamin E at a baseline time point, and additionally at 2, 4 and 6 weeks after initiating treatment. Vitamin E had an antioxidant effect when administered at low doses over short time periods, and increased the activity of antioxidant enzymes. At higher doses and over longer time periods, it increased the level of lipid peroxidation, and attenuated the activity of antioxidant enzymes. These results suggest that time-dependent variations in vitamin E effects should be considered in design and interpretation of experimental antioxidant studies, as well as during clinical trials. 相似文献
6.
Inhibition of lipid peroxidation by ubiquinol in submitochondrial particles in the absence of vitamin E 总被引:1,自引:0,他引:1
The relationship between the antioxidant effects of reduced coenzyme Q10 (ubiquinol, UQH2) and vitamin E (alpha-tocopherol) was investigated in beef heart submitochondrial particles in which lipid peroxidation was initiated by incubation with ascorbate + ADP-Fe3+. These effects were examined after extraction of coenzyme Q10 (UQ-10) and vitamin E from the particles and reincorporation of the same components alone or in combination. The results show that UQH2 efficiently inhibits lipid peroxidation even when vitamin E is absent. It is concluded that UQH2 can inhibit lipid peroxidation directly, without the mediation of vitamin E. 相似文献
7.
Caridad Rojas Susana Cadenas Mónica López-Torres Rosa Pérez-Campo Gustavo Barja 《Free radical biology & medicine》1996,21(7):907-915
Dietary treatment with three diets differing in vitamin E, Low E (15 mg of vitamin E/kg diet), Medium E (150 mg/kg), or High E (1,500 mg/kg), resulted in guinea pigs with low (but nondeficient), intermediate, or high heart a-tocopherol concentration. Neither the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and reductase, nor the nonenzymatic antioxidants, GSH, ascorbate, and uric acid were homeostatically depressed by increases in heart a-tocopherol. Protection from both enzymatic (NADPH dependent) and nonenzymatic (ascorbate-Fe2+) lipid peroxidation was strongly increased by vitamin E supplementation from Low to Medium E Whereas no additional gain was obtained from the Medium E to the High E group. The GSH/GSSG and GSH/total glutathione ratios increased as a function of the vitamin E dietary concentration closely resembling the shape of the dependence of heart a-tocopherol on dietary vitamin E. The results show the capacity of dietary vitamin E to increase the global antioxidant capacity of the heart and to improve the heart redox status in both the lipid and water-soluble compartments. This capacity occurred at levels six times higher than the minimum daily requirement of vitamin E, even in the presence of optimum dietary vitamin C concentrations and basal unstressed conditions. The need for vitamin E dietary supplementation seems specially important in this tissue due to the low constitutive levels of endogenous enzymatic and nonenzymatic antioxidants present of the mammalian heart in comparison with those of other internal organs. 相似文献
8.
《Redox report : communications in free radical research》2013,18(2):60-66
AbstractThe objective of this work was to examine the time-dependent pro-oxidant versus antioxidant effect of various doses of vitamin E used commonly in experimental studies. Erythrocyte activity of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and plasma lipid peroxidation levels were investigated following biweekly intramuscular administration of 100, 300 and 600 mg/kg of vitamin E at a baseline time point, and additionally at 2, 4 and 6 weeks after initiating treatment. Vitamin E had an antioxidant effect when administered at low doses over short time periods, and increased the activity of antioxidant enzymes. At higher doses and over longer time periods, it increased the level of lipid peroxidation, and attenuated the activity of antioxidant enzymes. These results suggest that time-dependent variations in vitamin E effects should be considered in design and interpretation of experimental antioxidant studies, as well as during clinical trials. 相似文献
9.
V E Kagan E A Serbinova A Safadi J D Catudioc L Packer 《Biochemical and biophysical research communications》1992,186(1):74-80
Microsomal NADPH-driven electron transport is known to initiate lipid peroxidation by activating oxygen in the presence of iron. This pro-oxidant effect can mask an antioxidant function of NADPH-driven electron transport in microsomes via vitamin E recycling from its phenoxyl radicals formed in the course of peroxidation. To test this hypothesis we studied the effects of NADPH on the endogenous vitamin E content and lipid peroxidation induced in liver microsomes by an oxidation system independent of iron: an azo-initiator of peroxyl radicals, 2,2'-azobis (2,4-dimethylvaleronitrile), (AMVN), in the presence of an iron chelator deferoxamine. We found that under conditions NADPH: (i) inhibited lipid peroxidation; (ii) this inhibitory effect was less pronounced in microsomes from vitamin E-deficient rats than in microsomes from normal rats; (iii) protected vitamin E from oxidative destruction; (iv) reduced chromanoxyl radicals of vitamin E homologue with a 6-carbon side-chain, chromanol-alpha-C-6. Thus NADPH-driven electron transport may function both to initiate and/or inhibit lipid peroxidation in microsomes depending on the availability of transition metal catalysts. 相似文献
10.
Data are presented in this paper on the effect of vitamin E on rats given a fish diet after whole-body gamma-irradiation. The content of lipid peroxidation products in rat plasma, brain and liver and also the content of vitamin E have been investigated. Irradiation increases lipid peroxidation in the studied tissues and decreases vitamin E content. This process is aggravated by the fish diet. Vitamin E given in addition to fish diet helps the organism to stabilize the antioxidant homeostasis at a qualitatively different level. 相似文献
11.
alpha-Tocopherol (vitamin E) is a lipophilic chain-breaking antioxidant which inhibits lipid peroxidation in isolated mitochondrial membranes and protects membranes from oxidative damage. The primary oxidation product of vitamin E is the tocopheroxyl radical. Reduction of the tocopheroxyl radical can occur by reactions with water-soluble anti-oxidants such as ascorbate or glutathione, resulting in the recycling of vitamin E. Physiological concentrations of vitamin E are too low to allow detection of tocopheroxyl radical by ESR. After dietary supplementation with vitamin E, a 10-20-fold increase in the rat liver mitochondrial membrane content of vitamin E was achieved and this allowed for direct detection of the tocopheroxyl radical by ESR, after treatment with an oxidizing system composed of lipoxygenase and arachidonic acid. By using submitochondrial particle membranes, it was shown that NADH, succinate, and reduced cytochrome c-linked oxidation reduce the tocopheroxyl radical, preventing both accumulation of the radical and vitamin E consumption. As the electron transport chain can reduce tocopheroxyl radical it may have an important physiological role in recycling vitamin E. 相似文献
12.
Reactive oxygen species (ROS) are implicated in both cartilage aging and the pathogenesis of osteoarthritis. We developed an in vitro model to study the role of chondrocyte-derived ROS in cartilage matrix protein degradation. Matrix proteins in cultured primary articular chondrocytes were labeled with [(3)H]proline, and the washed cell matrix was returned to a serum-free balanced salt solution. Exposure to hydrogen peroxide resulted in oxidative damage to the cell matrix as established by monitoring the release of labeled material into the medium. Calcium ionophore treatment of chondrocytes, in a dose-dependent manner, significantly enhanced the release of labeled matrix, suggesting a chondrocyte-dependent mechanism of matrix degradation. Antioxidant enzymes such as catalase or superoxide dismutase did not influence matrix release by the calcium ionophore-activated chondrocytes. However, vitamin E, at physiological concentrations, significantly diminished the release of labeled matrix by activated chondrocytes. The fact that vitamin E is a chain-breaking antioxidant indicates that the mechanism of matrix degradation and release is mediated by the lipid peroxidation process. Lipid peroxidation was measured in chondrocytes loaded with cis-parinaric acid. Both resting and activated cells showed constitutive and enhanced levels of lipid peroxidation activity, which were significantly reduced in the presence of vitamin E. In an immunoblot analysis, malondialdehyde and hydroxynonenal adducts were observed in chondrocyte-matrix extracts, and the amount of adducts increased with calcium ionophore treatment. Furthermore, vitamin E diminished aldehyde-protein adduct formation in activated extracts, which suggests that vitamin E has an antioxidant role in preventing protein oxidation. This study provides in vitro evidence linking chondrocyte lipid peroxidation to cartilage matrix protein (collagen) oxidation and degradation and suggests that vitamin E has a preventive role. These observations indicate that chondrocyte lipid peroxidation may have a role in the pathogenesis of cartilage aging and osteoarthritis. 相似文献
13.
Antioxidant effect of vitamin E and glutathione on lipid peroxidation in boar semen plasma 总被引:6,自引:0,他引:6
E. Brzezińska-Ślebodzińska A. B. Ślebodziński B. Pietras G. Wieczorek 《Biological trace element research》1995,47(1-3):69-74
The protective effect of vitamin E and reduced glutathione (GSH) against lipid peroxidation in boar semen plasma was studied.
The lipid peroxidation, measured by the test for thiobarbituric acid reactive substances (TBARS), doubled in the presence
of the lipid peroxidation Fe2+-sodium ascorbate-inducing system. The ascorbate-induced TBARS were inhibited by about 62% through the water-soluble vitamin
E analog (TROLOX) and about 57% by GSH. In the in vivo experiments, 7 wk of oraldl-α-tocopherol acetate (1000 IU/d/animal) administration caused a significant fall in the level of the semen plasma TBARS,
from 2.2±0.09 to 1.2±0.13 nmol MDA/mL. The semen plasma superoxide dismutase (SOD) and GSSG tended to increase with the time
of vitamin E administration, but the increment did not reach a significant level by the seventh week. The vitamin E supplementation
significantly increased the number of spermatozoa per 1 cm3 of ejaculate. The protective role of vitamin E and GSH with respect to boar semen against fatty acid peroxidation and a positive
influence of vitamin E supplementation on semen quality have been evidenced. 相似文献
14.
Antioxidant status and lipid peroxidation in hemodialysis patients undergoing erythropoietin and erythropoietin-vitamin E combined therapy. 总被引:3,自引:0,他引:3
In this study, plasma and red blood cell (RBC) antioxidant status and plasma lipid peroxidation were investigated in 46 hemodialysis patients. In addition, the effect of erythropoietin (EPO) and EPO-vitamin E combination therapy on plasma and RBC antioxidant status, and plasma lipid peroxidation were examined. There were 10 healthy subjects in the control group and 10 hemodialysis patients in the untreated group. The third group included 36 hemodialysis patients that were given EPO (100 U/kg) for 3 months, 3 times per week. The fourth group included 36 hemodialysis-patients from the EPO group that were given EPO at a 50% decreased dose + vitamin E (300 mg/day) for 3 months. MDA levels in the untreated group, the EPO group and the EPO + vitamin E groups were found to be higher than the control group (p < 0.001, in both). Furthermore, MDA levels in both of the treatment groups were lower when compared to the untreated group (p < 0.001, in both). Plasma vitamin E levels in the untreated, the EPO group and EPO + vitamin E groups were lower than the control group (p < 0. 001). In contrast, plasma vitamin E levels in the treatment groups were higher in comparison with the control group (p < 0.05). SOD activities in the untreated, the EPO group and the EPO + vitamin E groups were found to be lower than the control group (p < 0.001). SOD activities in the treatment groups were higher than the control group (p<0.001). The SOD activities in the EPO+vitamin E group increased when compared to the EPO group (p < 0.001). CAT activities in the untreated, the EPO group and the EPO + vitamin E groups were found to be lower than the control group (p < 0.001 in untreated and EPO groups, p <0.01 in EPO+ vitamin E group). CAT activities in EPO and EPO+ vitamin E groups were increased when compared to the untreated group (p < 0.01). In conclusion, our findings have shown that antioxidant status decreased and lipid peroxidation increased in hemodialysis patients. EPO has an antioxidant effect on the RBC and plasma antioxidant status, and plasma lipid peroxidation. These effects were moderately increased by the combination of vitamin E and EPO. 相似文献
15.
A diet high in cholesterol and deficient in vitamin E induces lipid peroxidation but does not enhance antioxidant enzyme expression in rat liver 总被引:1,自引:0,他引:1
Maggi-Capeyron MF Cases J Badia E Cristol JP Rouanet JM Besançon P Leger CL Descomps B 《The Journal of nutritional biochemistry》2002,13(5):296-301
Expression of antioxidant enzymes (AOE), an important mechanism in the protection against oxidative stress, could be modified by the redox status of the cells. The aim of this project was to evaluate the role of vitamin E deficiency in association with a high-cholesterol diet in the hepatic lipid peroxidation and the expression of AOE. Two groups of 6 male rats were fed with a high-cholesterol or a high-cholesterol vitamin E-deficient diet. All animals were sacrificed at 72 days of treatment. Liver lipid peroxidation index (Malondialdehyde; MDA) and hepatic AOE were evaluated. Total liver RNA was extracted, and the steady state messenger RNA (mRNA) levels of glutathion peroxydase, manganese superoxide dismutase, Cu/Zn superoxide dismutase and catalase were examined by northern blot. After 72 days on the diet, a significant increase in the lipid peroxidation index was observed in the vitamin E deficient group (MDA : 4.45 +/- 0.29 nmol/mg protein versus 3.65 +/- 0.1 nmol/mg protein in vitamin E normal group). Despite this oxidative stress, the activities and mRNA levels of liver AOE were not significantly different in the 2 groups. These preliminary results show that chronic vitamin E deficiency associated with high cholesterol diet is able to increase lipid peroxidation without modulation of AOE expression and activity in the liver. This suggests that beneficial effects of dietary vitamin E are due to a plasma antioxidant effect or a cell mediated action, rather than to a specific modulation of cellular enzymes. 相似文献
16.
Vitamin E remains the major lipid-soluble, chain-breaking antioxidant in human plasma even in individuals suffering severe vitamin E deficiency 总被引:5,自引:0,他引:5
K U Ingold A C Webb D Witter G W Burton T A Metcalfe D P Muller 《Archives of biochemistry and biophysics》1987,259(1):224-225
The chain-breaking (peroxyl radical-trapping) antioxidant activity of plasma obtained from several patients with a very severe vitamin E deficiency has been measured. The total chain-breaking antioxidant activity in lipid extracts has been shown to be approximately equal to the concentration of vitamin E. For whole plasma there is no significant difference in the concentrations of water-soluble, chain-breaking antioxidants between the E-deficient patients and healthy adults. It is concluded that even in cases of very severe vitamin E deficiency the requirement for this vitamin is not met by some other exogenous or endogenous antioxidant. 相似文献
17.
Vitamin E and oxidative stress 总被引:11,自引:0,他引:11
C K Chow 《Free radical biology & medicine》1991,11(2):215-232
Oxidative stress can result from or be enhanced by a large variety of conditions, including nutritional imbalance, exposure to chemical and physical agents in the environment, strenuous physical activities, injury, and hereditary disorders. While many enzymes and compounds are involved in protecting cells from the adverse effects of oxidative stress, vitamin E occupies an important and unique position in the overall antioxidant defense. The antioxidant function of vitamin E is closely related to the status of many dietary components. Vitamin E-depleted animals are generally more susceptible to the adverse effects of environmental agents than supplemented animals. Also, vitamin E supplementation is beneficial to certain groups of the population. However, supplementing vitamin E in experimental subjects maintained on a nutritionally adequate diet does not always provide additional protection. Differential metabolic responses in various organs and differences in experimental conditions often contribute in the discrepancies in the literature. The lack of clear evidence for the occurrence of lipid peroxidation or antioxidant function of vitamin E in vivo can be attributed partly to the presence of active pathways for metabolizing hydroperoxides, aldehydes, and other oxidation products. Specific and sensitive techniques for measuring lipid peroxidation products in biological systems are essential for understanding the role of free radical-induced lipid peroxidation in tissue damage and antioxidant function of vitamin E in vivo. 相似文献
18.
Protective antioxidant effect of vitamins C and E in streptozotocin induced diabetic rats 总被引:2,自引:0,他引:2
We have investigated the protective effect of vitamin C and E together supplementation on oxidative stress and antioxidant enzyme activities in the liver of streptozotocin-induced diabetic rats, unsupplemented diabetic and control rats. We also determined the levels of both the vitamins and oxidative stress in plasma. Vitamin supplementation in diabetic rats lowered plasma and liver lipid peroxidation, normalised plasma vitamin C levels and raised vitamin E above normal levels. In liver, the activity of glutathione peroxidase was raised significantly and that of glutathione-S-transferase was normalised by vitamin supplementation in diabetic rats. The levels of lipid peroxidation products in plasma and liver of vitamin-supplemented diabetic rats and activities of antioxidant enzymes in liver suggest that these vitamins reduce lipid peroxidation by quenching free radicals. 相似文献
19.
Synergistic interaction between vitamin E and the bile pigments bilirubin and biliverdin 总被引:4,自引:0,他引:4
The oxidation of soybean phosphatidylcholine (PC) liposomes initiated with a lipid-soluble azo compound within the liposomal membranes has been studied in the absence and presence of membrane-bound vitamin E and water-soluble bile pigments. In the absence of vitamin E, lipid peroxidation proceeded linearly and without delay. Low micromolar amounts of bilirubin ditaurine (BR-DT, a model compound of conjugated bilirubin) or biliverdin (BV) inhibited the oxidation of PC significantly and in a concentration-dependent way. In contrast, neither taurine, ascorbic acid nor reduced glutathione inhibited significantly under these conditions. Both bile pigments were consumed during their protective action. Vitamin E incorporated into the liposomal membranes suppressed the oxidation initially almost completely, thereby producing an induction period. In the combined presence of vitamin E and either of the two bile pigments at 10 microM each, this induction period was increased by at least 200%. In contrast, when 10 microM vitamin E was combined with an equimolar concentration of reduced glutathione, the induction period increased by only about 30%. BR-DT and BV both spared the consumption of vitamin E during the oxidation of PC liposomes. These results demonstrate that conjugated bilirubin and BV located in the aqueous phase can directly scavenge lipid radicals to some extent. Furthermore, both bile pigments can act synergistically with membrane-bound vitamin E to prevent lipid peroxidation initiated in the lipid phase, most likely through regeneration of the vitamin from its chromanoxyl radical. 相似文献
20.
Plasma obtained from fasted humans has been analysed for total radical-trapping antioxidant content by subjecting it to controlled peroxidation using the thermal decomposition of water-soluble azobis (2-amidinopropane hydrochloride) at 37 degrees C to produce peroxyl radicals at a known, steady rate. It is found that the total radical-trapping antioxidant content is rather similar for the 7 subjects that have been tested and, furthermore, it is 10-20-times larger than the effect attributable to vitamin E alone. Although it is shown that urate and ascorbate augment the contribution from vitamin E, their contributions (21-34 and 0-2%, respectively) still leave 57-73% of the total antioxidant content unaccounted for. Evidence is presented to show that this previously unrecognized large reserve of antioxidant capacity is attributable to the plasma proteins. 相似文献