共查询到20条相似文献,搜索用时 15 毫秒
1.
Mustafa Cemek Mehmet Emin Büyükokuroğlu Ömer Hazman Muhsin Konuk Sait Bulut Yavuz Osman Birdane 《Biological trace element research》2011,142(1):55-66
The therapeutic effects of melatonin or vitamin E plus Se (vE + Se) on the restrain of the heroin withdrawal-induced oxidative
stress were studied. For this, rats were divided into ten groups. The rats were injected by fixed or variable doses of heroin
for 16 consecutive days, and naloxone was given 1 h after the last heroin injection. One hour after naloxone administration,
some groups were treated with melatonin or vE + Se. After 1 h this, blood samples were taken, and the levels of malondialdehyde
(MDA) and reduced glutathione (GSH) in whole blood, ascorbic acid, α-tocopherol, retinol, β-carotene, nitrite, nitrate, and
ceruloplasmin levels in the serum were measured. Our findings showed that, naloxone administration precipitated the heroin
withdrawal. This also increased the level of MDA and decreased the levels of GSH in blood. Melatonin or vE + Se administration
prevented the rise in MDA levels and increased the GSH levels. On the other hand, there were some significant differences
between α-tocopherol, retinol, β-carotene, nitrite, nitrate, and ceruloplasmin levels of experimental groups. Results of present
study showed that heroin withdrawal increased the lipid peroxidation and depressed endogenous antioxidative systems. Additionally,
melatonin or vE + Se administrations prevented lipid peroxidation and augmented endogenous antioxidant defense systems. 相似文献
2.
Amelioration of lead and mercury effects on germination and rice seedling growth by antioxidants 总被引:4,自引:0,他引:4
Germination of two rice (Oryza sativa L.) cultivars (Ratna and IR 36) in the presence of 10 μM PbCl2 and 10 μM HgCl2 decreased
germination percentage, germination index, shoot/root length, tolerance index and dry mass of shoots and roots. Mercury was
more toxic than lead. Reduced glutathione (GSH), cysteine (Cys), ascorbic acid, and α-tocopherol alleviated the adverse effects
of these metals on plants in the order GSH > Cys > ascorbic acid > α-tocopherol. The effects were more pronounced in tolerant
cultivar IR 36 than in the relatively susceptible cultivar Ratna.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
Background
The status of α-tocopherol (vit E) and selenium (Se) has been shown to influence disease resistance in pigs, and may be important for the health of weanling pigs. 相似文献4.
Impact of ultraviolet-B (UV-B) and Cd, applied individually and in combination, measured in terms of oxygen-evolution, chlorophyll
(Chl) and protein contents, lipid peroxidation, and enzymatic and non-enzymatic antioxidants of Anabaena doliolum, revealed a greater oxidative damage induced by UV-B than by Cd. While superoxide dismutase (SOD) showed a greater stimulation
by UV-B than Cd, the activities of catalase (CAT) and glutathione reductase (GR) declined after UV-B treatment. Cd treatment,
however, enhanced the activities of ascorbate peroxidase (APX) and GR. CAT activity increased at low but decreased at high
dose of Cd. Increase in carotenoid (Car) content in UV-B treated cells suggested a shielding effect of Car against UV-B stress.
A 15-and 10-fold rise in α-tocopherol (α-TOC) content at high dose of Cd and/or UV-B offered testimony to the antioxidant
role of α-TOC. 相似文献
5.
Tocopherols, with antioxidant properties, are synthesized by photosynthetic organisms and play important roles in human and animal nutrition. In soybean, γ-tocopherol, the biosynthetic precursor to α-tocopherol, is the predominant form found in the seed, whereas α-tocopherol is the most bioactive component. This suggests that the final step of the α-tocopherol biosynthetic pathway catalyzed by γ-tocopherol methyltransferase (γ-TMT) is limiting in soybean seed. Soybean oil is the major edible vegetable oil consumed, so manipulating the tocopherol biosynthetic pathway in soybean seed to convert tocopherols into more active α-tocopherol form could have significant health benefits. In order to increase the soybean seed α-tocopherol content, the γ-TMT gene isolated from Perilla frutescens was overexpressed in soybean using a seed-specific promoter. One transgenic plant was recovered and the progeny was analyzed for two generations. Our results demonstrated that the seed-specific expression of the P. frutescens γ-TMT gene resulted in a 10.4-fold increase in the α-tocopherol content and a 14.9-fold increase in the β-tocopherol content in T2 seed. Given the relative contributions of different tocopherols to vitamin E activity, the activity in T2 seed was calculated to be 4.8-fold higher than in wild-type seed. In addition, the data obtained on lipid peroxidation indicates that α-tocopherol may have a role in preventing oxidative damage to lipid components during seed storage and seed germination. The increase in the α-tocopherol content in the soybean seed could have a potential to significantly increase the dietary intake of vitamin E. 相似文献
6.
It has been established that the effect of lecithin on the oxidation of methyl oleate depends on the rate of the free radical
initiation: lecithin does not affect the reaction rate at high rates of radical initiation (the initiated oxidation) and accelerates
the oxidation at low rates (autooxidation), causing the reduction of the induction period. The inhibitory action of mixtures
of lecithin and the natural antioxidant α-tocopherol depends on the concentrations of both α-tocopherol and lecithin at different
rates of oxidation. The inhibitory efficiency of mixtures with low concentrations of α-tocopherol is close to additive. Increasing
the initial concentration of α-tocopherol in mixtures causes a gain in the synergistic effect. The synergistic effect depends
extremally on lecithin concentration at high concentrations of α-tocopherol. The mechanism of the synergistic effect for the
mixtures of α-tocopherol and lecithin is discussed. 相似文献
7.
Byoung-Kyu Lee Sun-Lim Kim Kyung-Hwan Kim Seung-Hee Yu Sang-Chul Lee Zhanyuan Zhang Myung-Sik Kim Hyang-Mi Park Jang-Yong Lee 《Plant Cell, Tissue and Organ Culture》2008,92(1):47-54
Increasing vitamin E activity in economically important oil crops such as perilla will enhance the nutritional value of these
crops. Perilla (Perilla frutescens Britt) represents an important oil crop in Asian countries, including Korea. Using Agrobacterium-mediated transformation, we have engineered perilla with the γ-tocopherol methyltransferase (γ-TMT) gene under the control
of seed-specific vicillin promoter. Molecular characterization including PCR, Southern and Northern blots confirmed that the
γ-TMT transgene was successfully inherited to and expressed in the progeny plants. The γ -TMT transgene was specifically expressed
in immature seeds of transgenic plants, leading to efficient conversion of γ-tocopherol to α-tocopherol and dramatic increase
in seed α-tocopherol content, as detected by high performance liquid chromatography analysis. We also showed that such a high
α-tocopherol content phenotype was transmitted to the progeny plants. In addition, there was no significant change in fatty
acid composition in transgenic seeds as compared with untransformed control Yeupsil cultivar, suggesting the lack of interplay
between the fatty acid and tocopherol biosynthesis pathways. This was the first report on over expression of the γ-TMT gene
in transgenic perilla displaying desirable high α-tocopherol content phenotype. Since α-tocopherol has the highest vitamin
E activity, the transgenic perilla with high α-tocopherol content in seeds developed in this study will benefit both human
and animal health. 相似文献
8.
9.
Natural vitamin E includes four tocopherols and four tocotrienols. RRR-α-tocopherol is the most abundant form in nature and has the highest biological activity. Although vitamin E is the main lipid-soluble antioxidant in the body, not all its properties can be assigned to this action. As antioxidant, vitamin E acts in cell membranes where prevents the propagation of free radical reactions, although it has been also shown to have pro-oxidant activity. Non-radical oxidation products are formed by the reaction between α-tocopheryl radical and other free radicals, which are conjugated to glucuronic acid and excreted through the bile or urine. Vitamin E is transported in plasma lipoproteins. After its intestinal absorption vitamin E is packaged into chylomicrons, which along the lymphatic pathway are secreted into the systemic circulation. By the action of lipoprotein lipase (LPL), part of the tocopherols transported in chylomicrons are taken up by extrahepatic tissues, and the remnant chylomicrons transport the remaining tocopherols to the liver. Here, by the action of the “α-tocopherol transfer protein”, a major proportion of α-tocopherol is incorporated into nascent very low density lipoproteins (VLDL), whereas the excess of α-tocopherol plus the other forms of vitamin E are excreted in bile. Once secreted into the circulation, VLDL are converted into IDL and LDL by the action of LPL, and the excess of surface components, including α-tocopherol, are transferred to HDL. Besides the LPL action, the delivery of α-tocopherol to tissues takes place by the uptake of lipoproteins by different tissues throughout their corresponding receptors. Although we have already a substantial information on the action, effects and metabolism of vitamin E, there are still several questions open. The most intriguing is its interaction with other antioxidants that may explain how foods containing small amounts of vitamin E provide greater benefits than larger doses of vitamin E alone. 相似文献
10.
Tae Kyung Hyun Kundan Kumar Kudupudi Prabhakara Rao Alok Krishna Sinha Thomas Roitsch 《Plant biotechnology reports》2011,5(1):19-25
Tocopherols belong to the plant-derived poly phenolic compounds known for antioxidant functions in plants and animals. Activation
of mitogen-activated protein kinases (MAPK) is a common reaction of plant cells in defense-related signal transduction pathways.
We report a novel non-antioxidant function of α-tocopherol in higher plants linking the physiological role of tocopherol with
stress signalling pathways. Pre-incubation of a low concentration of 50 μM α-tocopherol negatively interferes with MAPK activation
in elicitor-treated tobacco BY2 suspension culture cells and wounded tobacco leaves, whereas pre-incubated BY2 cells with
α-tocopherol phosphate did not show the inhibitory effect on stimuli-induced MAPK activation. The decreased MAPK activity
was neither due to a direct inhibitory effect of α-tocopherol nor due to the induction of an inhibitory or inactivating activity
directly affecting MAPK activity. The data support that the target of α-tocopherol negatively regulates an upstream component
of the signaling pathways that leads to stress dependent MAPK activation. 相似文献
11.
Effects of hydrodynamic stress, dissolved oxygen (DO) concentration and carbon sources on heterotrophic α-tocopherol production
by Euglena gracilis were investigated. In a jar fermentor without baffle plates, increasing the agitation speed up to 500
rpm had no significant effect on cell growth and α-tocopherol production. However, in a jar fermentor equipped with baffle
plates, both the cell growth and α-tocopherol production were highly suppressed at 500 rpm. At high hydrodynamic stress, the
cells secreted nucleic acid-related substances to the culture broth and the shape of the cells shifted from elongated toward
spherical. High DO concentration had adverse effects on both cell growth and α-tocopherol production, the optimum DO concentration
being below 0.8 ppm. In comparison with glucose, the growth rate was lower but the α-tocopherol content of the cells was almost
four times higher when ethanol was used as the organic carbon source. In a fed-batch culture with ethanol, a very high cell
concentration of 39.5 g L-1 was obtained with α-tocopherol content of 1200 μg g-cell-1. This α-tocopherol content is very close to the values reported for photoautotrophic and photoheterotrophic cultures. A very
high α-tocopherol productivity of 102 μg L-1 h-1 was obtained, indicating that heterotrophic cultivation of E. gracilis has a very high potential as a substitute for the
current method of extraction from vegetable oils.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
12.
Effect of physical restraint on oxidative stress in mice fed a selenium and vitamin E deficient diet
Physical restraint has been associated with increased oxidative damage to lipid, protein, and DNA. The purpose of this experiment
was to determine whether physical restraint would further exacerbate oxidative stress in mice fed a selenium (Se) and vitamin
E (VE) deficient diet. Three-week-old mice were fed a Torula yeast diet containing adequate or deficient Se and VE. Menhaden
oil was added to the deficient diet to impose an additional oxidative stress. After 4 wk feeding, half the mice in each group
were restrained for 5 d in well-ventilated conical tubes for 8 h daily. Mice fed the Se and VE deficient diets had increased
liver thiobarbituric acid-reactive substance (TBARS) levels and decreased liver glutathione peroxidase (GPX1) activity and
α-tocopherol levels. Plasma corticosterone levels were elevated in restrained mice fed the deficient diet compared to unrestrained
mice fed the adequate diet. Restraint had no effect on liver TBARS or α-tocopherol levels. Liver GPX1 activity, however, was
lower in restrained mice fed the adequate diet. In addition, liver superoxide dismutase (SOD) activity was lower in the restrained
mice fed the adequate or deficient diet. Thus, under our conditions, Se and VE deficient diet, but not restraint, increased
lipid peroxidation in mice. Restraint, however, decreased antioxidant protection in mice due to decreased activities of GPX1
and SOD enzymes. 相似文献
13.
Tomoya Fujita James C. Ogbonna Hideo Tanaka Hideki Aoyagi 《Journal of applied phycology》2009,21(2):185-191
The effects of reactive oxygen species (ROS) on α-tocopherol production in mitochondria and chloroplasts of Euglena gracilis were investigated. Addition of an organic carbon source to the medium resulted in increased mitochondrial activity, intracellular
O2
- concentration and α-tocopherol productivity in E. gracilis W14ZUL (a chloroplast deficient mutant). α-Tocopherol productivity of the wild-type strain (with both mitochondria and chloroplast)
was higher than that of the W14ZUL strain. In the case of the wild strain, the O2
− generated in chloroplasts was efficiently scavenged by the α-tocopherol synthesized inside the chloroplast. In photoheterotrophic
culture (with an organic carbon source), there was a positive correlation between α-tocopherol production and O2
− generation. Addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (an inhibitor of photosynthesis) resulted in increased O2
− generation and α-tocopherol productivity. These results indicate that the ROS generated in mitochondria and chloroplasts
play important roles in α-tocopherol production by E. gracilis. The presence of chloroplasts and generation of intracellular ROS are important for efficient production of α-tocopherol. 相似文献
14.
There are many studies about iron-induced neuronal hyperactivity and oxidative stress. Some reports also showed that iron
levels rise in the brain in some neurodegenerative diseases such as Parkinson’s (PD) and Alzheimer’s disease (AD). It has
been suggested that excessive iron level increases oxidative stress and causes neuronal death. Tocopherols act as a free radical
scavenger when phenoxylic head group encounters a free radical. We have aimed to identify the effect of α-tocopherol (Vitamin
E) on iron-induced neurotoxicity. For this reason, rats were divided into three groups as control, iron, and iron + α-tocopherol
groups. Iron chloride (200 mM in 2.5 μl volume) was injected into brain ventricle of iron and iron + α-tocopherol group rats.
Same volume of saline (2.5 μl) was given to the rats belonging to control group. Rats of iron + α-tocopherol group received
intraperitoneally (i.p.) α-tocopherol (100 mg/kg/day) for 10 days. After 10 days, rats were perfused intracardially under
deep urethane anesthesia. Removed brains were processed using standard histological techniques. The numbers of neurons in
hippocampus and substantia nigra of all rats were estimated by stereological techniques. Results of present study show that
α-tocopherol decreased hippocampal and nigral neuron loss from 51.7 to 12.1% and 41.6 to 17.8%, respectively. Findings of
the present study suggest that α-tocopherol may have neuroprotective effects against iron-induced hippocampal and nigral neurotoxicity
and it may have a therapeutic significance for neurodegenerative diseases involved iron. 相似文献
15.
Selenium as an anti-oxidant and pro-oxidant in ryegrass 总被引:12,自引:1,他引:12
Selenium is an essential element for antioxidation reactions in human and animals. In order to study its biological role in
higher plants, ryegrass (Lolium perenne) was cultivated in a soil without Se or amended with increasing dosages of H2SeO4 (0.1, 1.0, 10.0 and 30.0 mg Se kg−1). Ryegrass was harvested twice and the yields were analyzed for antioxidative systems and growth parameters. Selenium exerted
dual effects: At low concentrations it acted as an antioxidant, inhibiting lipid peroxidation, whereas at higher concentrations,
it was a pro-oxidant, enhancing the accumulation of lipid peroxidation products. The antioxidative effect was associated with
an increase in glutathione peroxidase (GSH-Px) activity, but not with superoxide dismutase (SOD) and αα-tocopherol, which
was the only tocopherol detected. In the second yield, the diminished lipid peroxidation due to a proper Se addition coincided
with promoted plant growth. The oxidative stress found at the Se addition level ≥ 10 mg kg−1 resulted in drastic yield losses. This result indicates that the toxicity of Se can be attributed, in addition to metabolic
disturbances, to its pro-oxidative effects. Neither the growth-promoting nor the toxic effect of Se could be explained by
the changes in the total chlorophyll concentration.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
Peter Surai Inna Kostjuk Graham Wishart Allan Macpherson Brian Speake Raymond Noble Igor Ionov Evgeny Kutz 《Biological trace element research》1998,64(1-3):119-132
The phospholipids of avian spermatozoa are characterized by high proportions of arachidonic (20:4n-6) and docosatetraenoic
(22:4n-6) fatty acids and are therefore sensitive to lipid peroxidation. α-Tocopherol and glutathione peroxidase [GSH-Px]
are believed to be the primary components of the antioxidant system of the spermatozoa. The present study evaluates the effect
of vitamin E and vitamin E plus Se supplementation of the cockerel diet on GSH-Px activity, vitamin E accumulation, and lipid
peroxidation in the spermatozoa, testes, and liver. At the beginning of the experiment 75 Rhode Island Red cockerels were
divided into five groups, kept in individual cages, and fed a wheat-barley-based ration balanced in all nutrients. Supplements
fed to the different groups were as follows: vitamin E, 0, 20, 200, 20, and 200 mg/kg to groups 1–5, respectively, with groups
4 and 5 also receiving 0. 3 mg Se/kg. The vitamin E supplementation produced increased levels of α-tocopherol in semen, testes,
and liver. The inclusion of the Se into the cock diet had a significant (P < 0.01) stimulating effect on GSH-Px activity in
seminal plasma, spermatozoa, testes, and liver. The increased vitamin E concentration in the spermatozoa was associated with
a reduction in their susceptibility to lipid peroxidation. Similarly, the increased GSH-Px activity provided enhanced protection
against lipid peroxidation. 相似文献
17.
Liu ZQ 《Cell biochemistry and biophysics》2006,44(2):233-239
Vitamin E involves a group of tocopherols and tocotrienols, in which α-tocopherol with the highest biological activity plays
a more efficient role in advanced lesions with aged oxidized tissues. However, the results of the present study reveal that
a large amount of endogenous α-tocopherol in human low-density lipoprotein (LDL) in the absence of any other antioxidants
may initiate additional free radical propagation under low concentration of free radical initiator (i.e., 2,2′-azobis(2-amidinopropane
hydrochloride) [AAPH], a water-soluble free radical source) to peroxide polyunsaturated fatty acids in LDL in the manner of
α-tocopherol-mediated peroxidation (TMP). Whether the addition of high concentration of exogenous α-tocopherol to human erythrocytes
under low concentration of AAPH can also drive TMP is the concern in this research work. Moreover, the hemolysis extent of
human erythrocytes peroxidized by AAPH is followed easily by the determination of the hemoglobin outside the erythrocytes.
A series of observations on various concentrations of AAPH-induced hemolysis in the presence of various concentrations of
exogenous α-tocopherol demonstrates that the high concentration of exogenous α-tocopherol, coupled with low concentration
of AAPH, can initiate TMP in the free-radical-induced peroxidation of human erythrocytes system as well. This result provides
direct evidence to support TMP theory and expands its application into in vitro erythrocytes system. 相似文献
18.
Nutrient content of tropical edible seaweeds, Eucheuma cottonii, Caulerpa lentillifera and Sargassum polycystum 总被引:2,自引:0,他引:2
Patricia Matanjun Suhaila Mohamed Noordin M. Mustapha Kharidah Muhammad 《Journal of applied phycology》2009,21(1):75-80
The proximate composition, vitamin C, α-tocopherol, dietary fibers, minerals, fatty acid and amino acid profiles of three
tropical edible seaweeds, Eucheuma cottonii (Rhodophyta), Caulerpa lentillifera (Chlorophyta) and Sargassum polycystum (Phaeophyta) were studied. The seaweeds were high in ash (37.15–46.19%) and dietary fibers (25.05–39.67%) and low in lipid
content (0.29–1.11%) on dry weight (DW) basis. These seaweeds contained 12.01–15.53% macro-minerals (Na, K, Ca and Mg) and
7.53–71.53 mg.100 g−1 trace minerals (Fe, Zn, Cu, Se and I). The crude protein content of E. cottonii (9.76% DW) and C. lentillifera (10.41% DW) were higher than that of S. polycystum (5.4% DW), and protein chemical scores are between 20 and 67%. The PUFA content of E. cottonii was 51.55%, C. lentillifera 16.76% and S. polycystum 20.34%. Eicosapentaenoic acid (EPA), accounted for 24.98% of all fatty acids in E. cottonii. These seaweeds have significant vitamin C (∼35 mg.100 g−1) and α-tocopherol (5.85–11.29 mg.100 g−1) contents. 相似文献
19.
To investigate the possible effects of α-tocopherol on erythrocyte membrane adenosine triphosphatases against radiation damage
in oral cancer patients. Adenosine triphosphatase activities were analysed in oral cancer patients before and after radiotherapy
(at a dosage of 6000 cGY in five fractions per week for a period of six weeks) and after supplemented with α-tocopherol (400
IU per day for entire period of radiotherapy). The membrane bound enzymes such as Na+/K+-ATPase, Ca2+-ATPase, Mg2+-ATPase and some trace elements were altered in oral cancer patients before and after radiotherapy. Supplemented with α-tocopherol
modulates the erythrocyte membrane which is damaged by radiotherapy which suggests that α-tocopherol protects the erythrocyte
membrane from radiation damage in oral cancer patients. 相似文献
20.
Kerstin Müller Rainer Altenkamp Jens Raila Daniel Schmidt Robert Dietrich Andrea Hurtienne Michael Wink Oliver Krone Leo Brunnberg Florian J. Schweigert 《European Journal of Wildlife Research》2011,57(5):1043-1049
In this study, we investigated the α-tocopherol plasma concentrations in healthy free-ranging nestlings of the white-tailed
sea eagle (Haliaeetus albicilla) (n = 32), osprey (Pandion haliaetus) (n = 39), northern goshawk (Accipiter gentilis) (n = 25), common buzzard (Buteo buteo) (n = 31), and honey buzzard (Pernis apivorus) (n = 18) as well as of free-ranging adults of the white-tailed sea eagle (n = 10), osprey (n = 31), and northern goshawk (n = 45). α-Tocopherol plasma concentrations were determined by reverse-phase high-performance liquid chromatography. α-Tocopherol
plasma concentrations in nestlings of osprey, white-tailed sea eagle, and northern goshawk did not differ significantly amongst
the species, but the common buzzard and honey buzzard nestlings had significantly lower α-tocopherol plasma concentrations
than nestlings of the other species (both P < 0.001). Adult male ospreys and white-tailed sea eagles had significantly higher α-tocopherol concentrations compared to
adult females (both P < 0.005). Adult ospreys and northern goshawks had significantly higher α-tocopherol plasma concentrations compared to their
nestlings (both P < 0.001). In adult female northern goshawks, plasma concentrations of α-tocopherol increased significantly before egg laying
(P < 0.001). These results demonstrate α-tocopherol plasma concentrations in birds of prey to be species specific and influenced
by age and reproductive status. 相似文献