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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To test whether the peripheral macrophage functions as early index of oxygen free radical release in association with the development of IgA nephropathy (IgAN), we studied female Lewis rats. IgAN was produced by treatment over 8 weeks with 0.1% bovine gamma globulin (BGG) in drinking water, followed by three daily intravenous injections of BGG, 1 mg/dose. Fifteen rats were divided randomly into three groups: control, IgAN, and IgAN fed vitamin E 100 IU/kg chow. At the end of the treatment period, rats were placed in individual metabolic cages for 24-h urine collections and then anesthetized with Inactin (100 mg/kg BW) for aspiration of peritoneal macrophages. The results (mean +/- SD) extended our previous data in male rats, confirming that the elevated proteinuria of IgAN (3.62 +/- 0.79 mg/day) was significantly reduced with vitamin E treatment (2.59 +/- 0.28 mg/day) in female rats (P < 0.002) More importantly, we indicated for the first time that oxygen free radicals production by peritoneal macrophages in IgAN was significantly reduced by vitamin E: 1.58 +/- 0.91 nmol/10(6) cells/15 min in the untreated group vs 3.28 +/- 0.54 nmol/10(6) cells/15 min in the vitamin E-treated group (P < 0.05).
Biochem Mol Med 1996 Apr
PMID:Rat macrophages in experimental IgA nephropathy. 873 94

"beta CATECHIN", a preparation containing green tea extract, ascorbic acid, sunflower seed extract, dunaliella carotene and natural vitamin E, has been designed as a model "universal antioxidant" that offers protection via its scavenging action on a wide range of free radicals, both water-soluble and fat-soluble. Reactive oxygen species like singlet oxygen, hydroxyl and superoxide radicals, are often generated in biological systems during photosensitized oxidation reactions. We report on the simultaneous effect of "beta CATECHIN" on active oxygen species generated during the photosensitized oxidation of riboflavin using 2,2,6,6-tetramethyl-4-piperidone (TMPD) as a "spin-trapping" agent. The intensities of the resulting stable nitroxide radical adduct, 2,2,6,6-tetramethyl-4-piperidone-1-oxyl (TEMPONE), were detected by electron spin resonance (ESR) spectroscopy. Results show simultaneous, nonspecific and complete scavenging action of reactive oxygen species generated in our in vitro model system by "beta CATECHIN". It is therefore suggested that "beta CATECHIN" could offer protection against free radical insult and in preventing cancer and other diseases that are mediated by reactive oxygen species.
Biochem Mol Biol Int 1996 May
PMID:Scavenging activity of "beta catechin" on reactive oxygen species generated by photosensitization of riboflavin. 873 38

Circulating lipid peroxide, antioxidant components and the activities of defense enzymes were estimated in uterine cervical carcinoma patients (before and after radiotherapy and radiotherapy combined chemotherapy) and compared with controls. Some of the antioxidant components such as glutathione, vitamin E and selenium are reduced in cervical cancer. The reduced levels of vitamin E and glutathione were normalized after treatment. Erythrocyte lipid peroxide (E-LPx) and erythrocyte membrane lipid peroxide (EM-LPx) levels were found to be increased in all the stages of uterine cervical carcinoma. The important antioxidant enzymes such as erythrocyte superoxide dismutase (E-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and glucose-6-phosphate dehydrogenase (G6PDH) were found to be decreased in uterine cervical carcinoma. These altered biochemical parameters were reversed to normal, of course with varied degree after different mode of therapy. Significant normalization was observed in Type II chemoradiotherapy.
Mol Cell Biochem 1996 May 10
PMID:Effect of radiotherapy and chemoradiotherapy on circulating antioxidant system of human uterine cervical carcinoma. 879 Dec 80

Rat testis mitochondria contain large amounts of both seleno-enzyme phospholipid hydroperoxide glutathione peroxidase (EC 1.11.1.12, PHGPx) and alpha-tocopherol. The scavenger role of vitamin E consists of transforming the lipoperoxyl radicals into lipid hydroperoxides, thus interrupting the peroxidative cascade. These hydroperoxides are in turn substrates of the PHGPx, which is considered one of the most important specific enzymes capable of protecting, in situ, the membranes from lipid peroxidation. A connection or synergism could, therefore, be envisaged between vitamin and enzyme opposing lipid damage in the mitochondria. Here we present data concerning the HPLC evaluation of vitamin E consumption in rat testis mitochondria and mitochondrial membranes, under different conditions of PHGPx activity, after Fe2+-induced lipid peroxidation. We have found that the enzyme activity, under the conditions tested, does not spare vitamin E from its peroxidation, therefore indicating that the postulated synergism between PHGPx and alpha-tocopherol can be excluded in rat testis mitochondria.
Biochem Mol Med 1996 Aug
PMID:Rat testis mitochondrial phospholipid hydroperoxide glutathione peroxidase does not protect endogenous vitamin E against Fe2+-induced (lipo)peroxidation. 881 43

The synthesis of vitamin C is substantially reduced in Osteogenic Disorder Shionogi (ODS) rats. Hepatocytes prepared from these rats contained approximately 12% of the wild-type content of this vitamin. In culture, the ascorbate content remained low in the absence of supplementation of the medium. Independent of their vitamin C status, cultured hepatocytes become depleted of vitamin E. Supplementation of the culture medium with 10C microM ascorbate and 1.2 microM alpha-tocopherol phosphate maintained the physiological content of both vitamins C and E in ODS hepatocytes. Thus, the antioxidant function of vitamins C and E could be evaluated in the presence of both or either vitamin or in the absence of both vitamins. Hepatocytes deficient in both vitamins were the most susceptible to lipid peroxidation (as measured by thiobarbituric acid) and to cell kllling within a 90-min exposure to 125-500 microM tert-butyl hydroperoxide (TBHP). Supplementation to achieve a physiological content of both vitamins C and E reduced the evidence of lipid peroxidation and abolished the cell killing. Supplementation with either vitamin alone resulted in an intermediate degree of both lipid peroxidation and cell killing. In ODS hepatocytes treated with TBHP, the decline in vitamin E preceded the decline in vitamin C. In ODS hepatocytes depleted of vitamin C, the loss of vitamin E after exposure to TBHP was greater than that in the presence of physiological levels of ascorbate. This greater loss of vitamin E in the face of a depletion of vitamin C was readily attributable to the increased peroxidation of lipids. Thus, the physiological level of vitamin C in cells does not seem to regenerate vitamin E. In contrast, the rate and extent of the depletion of vitamin C correlate with the degree of cell killing. These data document the antioxidant function of the physiological level of cellular vitamin C and relate this function to protection against peroxidative cell injury.
Mol Pharmacol 1996 Oct
PMID:The antioxidant function of the physiological content of vitamin C. 886 46

Several corneal complications have been reported in patients with long standing diabetes, but their exact pathogenesis is not well understood. It has been observed that the rate of epithelial wound healing in diabetic rats is delayed compared to those in normal animals. Here we present the effect of the free radial scavenger, Trolox, a water soluble vitamin E analogue, on epithelial wound healing in diabetic rat cornea. Three groups of rats were included: 1) normal, 2) diabetic, 3) diabetic + Trolox. After 3 months, rats were sacrificed and corneas removed. Standard 3 mm diameter corneal epithelial defects were made and residual epithelial defects were measured after 18 hours at 37 degrees C in a sterile cell culture incubator. Wound healing data measured in mm2 was used for statistical analysis. There were significantly larger (p < 0.05) epithelial defects in diabetic corneas as compared to control. Treatment with Trolox antioxidant in diabetic rats produced a significantly smaller (p < 0.05) epithelial defect than that of untreated diabetic rats. These studies suggest the involvement of free radicals in the delay of corneal epithelial wound healing in diabetes.
Res Commun Mol Pathol Pharmacol 1996 Jul
PMID:Acceleration of corneal wound healing in diabetic rats by the antioxidant trolox. 886 65

In the present report we demonstrate the in vitro effects of free radicals on an ecto-ATP diphosphohydrolase activity (apyrase, EC 3.6.1.5) from rat blood platelets. Rat blood platelets were exposed to an oxidant-generating system (H2O2/Fe2+/ascorbate) and the ATP diphosphohydrolase activity was inhibited. The enzyme inhibition was prevented by glutathione (GSH) and cysteine but not by trolox as a vitamin E analogue. The TBARS (thiobarbituric acid reactive substances) assay and the determination of sulphydryl groups indicate that the inhibition of the enzyme activity in resting platelets is not related to lipid peroxidation or to oxidation of sulphydryl residues. These results demonstrate the susceptibility of ATP diphosphohydrolase activity from platelets to free radicals and suggest that amino acid residues which are essential for the enzyme function are probably modified.
Biochem Mol Biol Int 1997 Jan
PMID:Free radical-induced inhibition of ATP diphosphohydrolase activity (EC 3.6.1.5) from rat blood platelets. 904 45

The purpose of the study was to investigate changes in serum ubiquinol/ubiquinone ratio with copper ion induced oxidative stress, and to assess the ubiquinol/ubiquinone ratio as marker of in vivo oxidative stress in patients with coronary artery disease (CAD). Plasma ubiquinol, ubiquinone, vitamin E (alpha-tocopherol) and total cholesterol (TC) concentrations were measured in 40 patients with angiographically confirmed coronary artery disease and 100 apparently healthy controls. The mean (SD) ubiquinol/ubiquinone ratio of 26.5 (7.5) of the CAD patients was significantly lower than the mean ratio of 30.2 (8.8) of the controls (p = 0.02). Our results indicate that the ubiquinol/ubiquinone ratio is a sensitive marker of oxidative stress and that an altered ubiquinol/ubiquinone ratio is the first sign of lipoprotein exposure to oxidative stress. The altered ratio in CAD patients cannot be explained by differences in plasma vitamin E levels. The vitamin E concentrations were in fact significantly higher in CAD patients, and did not appear to protect the ubiquinol from increased oxidation due to free radical reactions. These results may indicate that circulating lipoproteins of CAD patients are more exposed to, or are more susceptible to, free radical reactions compared with apparently healthy controls.
Res Commun Mol Pathol Pharmacol 1997 Jan
PMID:Ubiquinol/ubiquinone ratio as marker of oxidative stress in coronary artery disease. 905 45

Concentrations of vitamins A1 (retinol), A2 (3,4-didehydroretinol) and E (alpha-tocopherol) in the liver and blubber of ringed seals from Lake Saimaa (Phoca hispida saimensis), Lake Ladoga (P. h. ladogensis), the Baltic Sea (P. h. botnica) and Spitsbergen (P. h. hispida) were determined by high-performance liquid chromatography. The freshwater seals had much lower levels of vitamin A1 but higher levels of vitamin A2 than the marine seals. The concentrations of vitamin E in the livers of the subspecies studied were high compared with earlier reports of seals, but the ranges were large. The livers of the marine seals contained more vitamin E than the livers of the freshwater seals, but the levels in the blubber were uniform in all populations, except in old specimens from the Baltic. The differences between the freshwater and marine seals are suggested to be due mainly to diet. The ratios of A1 to A2 in the liver and blubber and in the fish diet were similar for the marine seals and for the freshwater seals (but differed in the marine and freshwater populations), which suggests no great differences in the absorption, transport and metabolism of the two analogues. Blubber was an important storage site for the vitamins studied, and age-dependent increases were detected, especially for vitamin E. In the 2-month to 2-year-old ringed seals of Lake Saimaa, however, the vitamin E concentration in the blubber was not affected by age.
Comp Biochem Physiol B Biochem Mol Biol 1997 Jan
PMID:Vitamins A1 (retinol), A2 (3,4-didehydroretinol) and E (alpha-tocopherol) in the liver and blubber of lacustrine and marine ringed seals (Phoca hispida sp.). 908 Jun 60

Proanthocyanidins, a group of polyphenolic bioflavonoids, have been reported to exhibit a wide range of biological, pharmacological and chemoprotective properties against oxygen free radicals. We have assessed the concentration-dependent oxygen free radical scavenging abilities of a grape seed proanthocyanidin extract (GSPE), vitamin C and vitamin E succinate (VES) as well as superoxide dismutase, catalase and mannitol against biochemically generated superoxide anion and hydroxyl radical using a chemiluminescence assay and cytochrome c reduction. A concentration-dependent inhibition was demonstrated by GSPE. At a 100 mg/l concentration, GSPE exhibited 78-81% inhibition of superoxide anion and hydroxyl radical. Under similar conditions, vitamin C inhibited these two oxygen free radicals by approximately 12-19%, while VES inhibited the two radicals by 36-44%. The combination of superoxide dismutase and catalase inhibited superoxide anion by approximately 83%, while mannitol resulted in an 87% inhibition of hydroxyl radical. The results demonstrate that GSPE is a more potent scavenger of oxygen free radicals as compared to vitamin C and VES.
Res Commun Mol Pathol Pharmacol 1997 Feb
PMID:Oxygen free radical scavenging abilities of vitamins C and E, and a grape seed proanthocyanidin extract in vitro. 909 Jul 54


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