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Tocopherol
Terms modified by Tocopherol Selected AbstractsTOCOTRIENOL OFFERS BETTER PROTECTION THAN TOCOPHEROL FROM FREE RADICAL-INDUCED DAMAGE OF RAT BONECLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2005NS Ahmad SUMMARY 1.,Free radicals generated by ferric nitrilotriacetate (FeNTA) can activate osteoclastic activity and this is associated with elevation of the bone resorbing cytokines interleukin (IL)-1 and IL-6. In the present study, we investigated the effects of 2 mg/kg FeNTA (2 mg iron/kg) on the levels of serum IL-1 and IL-6 with or without supplementation with a palm oil tocotrienol mixture or ,-tocopherol acetate in Wistar rats. 2.,The FeNTA was found to elevate levels of IL-1 and IL-6. Only the palm oil tocotrienol mixture at doses of 60 and 100 mg/kg was able to prevent FeNTA-induced increases in IL-1 (P < 0.01). Both the palm oil tocotrienol mixture and ,-tocopherol acetate, at doses of 30, 60 and 100 mg/kg, were able to reduce FeNTA-induced increases in IL-6 (P < 0.05). Therefore, the palm oil tocotrienol mixture was better than pure ,-tocopherol acetate in protecting bone against FeNTA (free radical)-induced elevation of bone-resorbing cytokines. 3.,Supplementation with the palm oil tocotrienol mixture or ,-tocopherol acetate at 100 mg/kg restored the reduction in serum osteocalcin levels due to ageing, as seen in the saline (control) group (P < 0.05). All doses of the palm oil tocotrienol mixture decreased urine deoxypyridinoline cross-link (DPD) significantly compared with the control group, whereas a trend for decreased urine DPD was only seen for doses of 60 mg/kg onwards of ,-tocopherol acetate (P < 0.05). 4.,Bone histomorphometric analyses have shown that FeNTA injections significantly lowered mean osteoblast number (P < 0.001) and the bone formation rate (P < 0.001), but raised osteoclast number (P < 0.05) and the ratio of eroded surface/bone surface (P < 0.001) compared with the saline (control) group. Supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent all these FeNTA-induced changes, but a similar dose of ,-tocopherol acetate was found to be effective only for mean osteoclast number. Injections of FeNTA were also shown to reduce trabecular bone volume (P < 0.001) and trabecular thickness (P < 0.05), whereas only supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent these FeNTA-induced changes. [source] PHENOLIC COMPOUNDS, TOCOPHEROLS AND OTHER MINOR COMPONENTS IN VIRGIN OLIVE OILS OF SOME TUNISIAN VARIETIESJOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2007D. KRICHENE ABSTRACT The phenols, ,-tocopherols, fatty acids and oxidative stability of six monovarietal virgin olive oils (VOOs) were determined. Fourteen phenolic compounds were detected and quantified by solid phase extraction and reversed phase-high performance liquid chromatography. Dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol, oleuropein and ligstroside aglycones were the main components in all samples. Pinoresinol was the most abundant component in lignan fraction. The total phenol content of these monovarietal oils varied from 66.82 mg/kg in "Neb Jmel" oil to 662.74 mg/kg in "El Hor" oil. A wide range of ,-tocopherol contents was also noticed; it varied from 141.94 mg/kg in "Semni" variety to 364.23 mg/kg in "Jdallou" variety. With regard to pigments, chlorophylls and carotenoids were found at variable concentrations: with median values of 11.33 and 3.10 mg/kg, respectively. Among the studied varieties, "Oueslati" and El Hor were characterized by the lowest levels of palmitic and linoleic acids and the highest values of oleic acid. [source] Effects of tocopherols and tocotrienols on the inhibition of autoxidation of conjugated linoleic acidEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2010Soon-Nam Ko Abstract The effect of eight vitamin E homologues, i.e. ,-, ,-, ,-, and ,-tocopherol and ,-, ,-, ,, and ,-tocotrienol, on the inhibition of autoxidation of conjugated linoleic acid (CLA) were investigated. The oxidation was carried out in the dark for 21 days at 50,°C and monitored by peroxide values (PV) and TBA values. The levels of the individual vitamin E homologues in CLA during storage were determined by HPLC. ,-Tocopherol exhibited the highest antioxidant activity among the homologues tested in this study when the antioxidant activities of the individual homologues in CLA were compared by PV. The order of antioxidant activity of eight homologues was ,-tocopherol,>,,-tocopherol,=,,-tocotrienol , ,-tocotrienol,>,,-tocopherol,=,,-tocotrienol,>,,-tocopherol,=,,-tocotrienol. The degradation rates of , -tocopherol and , -tocotrienol were faster than those of the other homologues, whereas ,-tocopherol had the highest stability in CLA during storage. All homologues exhibited an antioxidant activity by inhibiting the formation of secondary oxidation products. It appears that ,-tocotrienol and ,-tocotrienol have significantly higher antioxidant activities for secondary oxidation in CLA than ,-tocopherol and ,-tocopherol. Meanwhile, the other homologues, namely ,-tocopherol, ,-tocotrienol, ,-tocopherol, and ,-tocotrienol, exhibited similar antioxidant activity for secondary oxidation in CLA. [source] Serum antioxidant and cholesterol levels in patients with different types of cancerJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 6 2001Clifford Abiaka Abstract Serum antioxidant (urate, ,-tocopherol) activity and cholesterol concentration in 142 patients of Indian and Arab (Kuwaitis and other Arabs) origin with different types of cancer (breast, colon, stomach, thyroid, oral, rectal, pancreatic, and renal) were compared to 100 age- and sex-matched control subjects. Values were expressed as medians (interquartile range). Urate concentration was significantly decreased in male patients compared to male controls (P < 0.0001) and in female patients and female breast cancer cases compared to female controls; P < 0.0001 and P = 0.001, respectively. ,-Tocopherol concentration decreased significantly in total cancer, stomach, colon, rectal, and breast cancer cases than the controls; P < 0.0001, P < 0.0001, P < 0.0001, P = 0.012, and P = 0.022, respectively. Cholesterol concentration decreased significantly in stomach, oral, colon, and total cancer cases compared to the controls; P < 0.0001, P < 0.0001, P = 0.002, and P = 0.012, respectively. Among controls, females had significantly (P < 0.0001) lower concentrations of ,-tocopherol than males. Among patients, cholesterol, urate, and ,-tocopherol concentrations decreased significantly in smokers than in nonsmokers; P < 0.0001, P = 0.004, and P = 0.047, respectively. Generally, changes in ,-tocopherol/cholesterol ratios mimicked changes in ,-tocopherol concentration. Concentrations of all parameters decreased significantly in male patients compared to male controls. Age was positively associated with all three analytes with respect to the controls. ,-Tocopherol correlated with cholesterol in cancer patients (r = 0.367; P < 0.0001) and with urate in the controls (r = 0.342; P < 0.0001). The data suggest cancer-related diminished synthesis of cholesterol and, generally, a greater antioxidant burden for ,-tocopherol than urate in cancer-generated oxidative stress. The increased incidence of pancreatic cancer in Kuwaitis warrants further study. J. Clin. Lab. Anal. 15:324,330, 2001. © 2001 Wiley-Liss, Inc. [source] Amelioration of Cadmium-Induced Oxidative Stress, Impairment in Lipids and Plasma Lipoproteins by the Combined Treatment with Quercetin and ,-Tocopherol in RatsJOURNAL OF FOOD SCIENCE, Issue 7 2010S. Milton Prabu Abstract:, Cadmium (Cd) exposure results in numerous pathological consequences including oxidative stress and dyslipidemia. The present study was designed to investigate the efficacy of combined treatment with quercetin (QE) and ,-tocopherol (AT) against Cd-induced oxidative stress and alterations in lipids and lipoproteins in the plasma and liver of rats. Oral administration of Cd (5 mg/kg bw/d) for 4 wk has shown a significant (P < 0.05) increase in thiobarbituric acid reactive substances (TBARS), lipid hydro peroxides (LOOH), total cholesterol, low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), free fatty acids (FFA), phospholipids (PL), triglycerides (TGs), and the activity of hydroxyl-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase) in plasma with a significant (P > 0.05) reduction in the levels of reduced glutathione (GSH), high density lipoprotein cholesterol (HDL-C), and the activity of lecithin cholesterol acyl transferase (LCAT) in plasma. In addition, the levels of hepatic thiobarbituric acid reactive substances (TBARS), LOOH, conjugated dienes (CD), protein carbonyls (PC), and the activity of HMG-CoA reductase, levels of cholesterol, FFA, and TGs were significantly (P > 0.05) increased and the level of PL is significantly (P > 0.05) decreased along with the decreased activity of LCAT in the liver of Cd-treated rats. Oral supplementation with QE (50 mg/kg bw/d) and AT (50 mg/kg bw/d) for 4 wk in Cd intoxicated rats significantly (P > 0.05) has reduced the plasma levels of TBARS, LOOH, GSH, cholesterol, FFA, TGs, VLDL-C, LDL-C, and the activity of HMG-CoA and significantly (P > 0.05) has increased the activity of LCAT and the plasma levels of HDL-C. The oral supplementation also significantly (P > 0.05) has reduced the hepatic oxidative stress markers, cholesterol, TGs, FFA, and significantly (P > 0.05) has increased the LCAT activity and the PL in liver. Our results indicate that the combined treatment with QE and AT has normalized all the previously mentioned biochemical parameters in Cd-intoxicated rats than the individual treatments. The combined treatment has provided remarkable protection against Cd-induced oxidative stress and alterations in lipid metabolism and, thereby, reduced the Cd-mediated cardiovascular diseases. [source] Kinetic Study of the Quenching Reaction of Singlet Oxygen by Common Synthetic Antioxidants (tert -Butylhydroxyanisol, tert -di-Butylhydroxytoluene, and tert -Butylhydroquinone) as Compared with ,-TocopherolJOURNAL OF FOOD SCIENCE, Issue 5 2009Ji In Kim ABSTRACT:, Effects of synthetic phenolic antioxidants (BHA, BHT, and TBHQ) on the methylene blue (MB) sensitized photooxidation of linoleic acid as compared with that of ,-tocopherol have been studied. Their antioxidative mechanism was studied by both ESR spectroscopy in a 2,2,6,6-tetramethylpiperidone (TMPD)-methylene blue (MB) system and spectroscopic analysis of rubrene oxidation induced by a chemical source of singlet oxygen. Total singlet oxygen quenching rate constants (kox,Q+kq) were determined using a steady state kinetic equation. TBHQ showed the strongest protective activity against the MB sensitized photooxidation of linoleic acid, followed by BHA and BHT. TBHQ (1 × 10,3 M) exhibited 86.5% and 71.4% inhibition of peroxide and conjugated diene formations, respectively, in linoleic acid photooxidation after 60-min light illumination. The protective activity of TBHQ against the photosensitized oxidation of linoleic acid was almost comparable to that of ,-tocopherol. The data obtained from ESR and rubrene oxidation studies clearly showed the strong singlet oxygen quenching ability of TBHQ. The kox,Q+kq of BHA, BHT, and TBHQ were determined to be 3.37 × 107, 4.26 × 106, and 1.67 × 108 M,1 s,1, respectively. The kox,Q+kq of TBHQ was within the same order of magnitude of that of ,-tocopherol, a known efficient singlet oxygen quencher. There was a high negative correlation (r2,=,,0.991) between log (kox,Q+kq) and reported oxidation potentials for the synthetic antioxidants, indicating their charge-transfer mechanism for singlet oxygen quenching. This is the 1st report on the kinetic study on kox,Q+kq of TBHQ in methanol as compared with other commonly used commercial synthetic antioxidants and ,-tocopherol. [source] Antioxidative Activity and Safety of 50% Ethanolic Red Bean Extract (Phaseolus radiatus L. var. Aurea)JOURNAL OF FOOD SCIENCE, Issue 1 2003S.-T. Chou ABSTRACT: This study evaluated the antioxidative activities of 50% ethanolic extract from red bean (Phaseolus radiatus L. var. Aurea). The antioxidative activities, including ,,,-diphenyl-,-picryl-hydrazyl (DPPH) radicals scavenging effects, Fe2+ -chelating ability, and reducing power, were studied in vitro. The antioxidative activity was found to increase with the concentration of the extract to a certain extent and then level off as the concentration further increased. Compared with commercial antioxidants, the red bean extract showed less scavenging effect on the DPPH radical and less reducing power than ,-Tocopherol and BHT, but better Fe2+ -chelating ability. No mutagenic effect toward any tester strains was found in the 50% ethanolic extract of red bean. [source] Inhibition of Oxidative Flavor Changes in Meat by ,-Tocopherol in Combination with Sodium TripolyphosphateJOURNAL OF FOOD SCIENCE, Issue 4 2002S. Vara-ubol ABSTRACT The effects of ,-tocopherol at 0.03%, sodium tripolyphosphate (STP) at 0.3%, alone and in combination, and STP alone at 0.5% on hexanal and sensory attributes of refrigerated cooked ground turkey or pork, with and without salt (1% NaCl), were studied. For turkey, a combination of ,-tocopherol with 0.3% STP was nearly as effective as 0.5% STP. Turkey and meaty flavor of samples from these 2 treatments did not decline; hexanal content and staleness scores remained low throughout storage. Slick mouthfeel and metallic aftertaste were less for turkey with the antioxidant combination than with 0.5% STP. In pork, STP alone at 0.3% adequately prevented oxidative flavor changes. ,-Tocopherol, when used with STP, provided no additional effect. [source] Comparison of the lymphatic transport of a lipophilic drug from vehicles containing ,-tocopherol and/or triglycerides in ratsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2001P. B. Nielsen The applicability of ,-tocopherol as a lymphotropic carrier for a highly lipophilic drug has been evaluated. Transport to the intestinal lymph of the highly lipophilic model drug, Lu28,179, in rats after administration to the stomach in an ,-tocopherol emulsion was compared with lymphatic transport after administration of a sesame oil emulsion and an ,-tocopherol/sesame oil emulsion. Lymphatic transport of the triglycerides and of ,-tocopherol was determined. A conscious rat model was used, and the mesenteric lymph was collected. There was no significant difference between the cumulative masses of triglyceride from the two emulsions containing triglyceride 24 h after administration. Administration of an ,-tocopherol emulsion seemed to induce mobilization of endogenous triglyceride. The lymphatic transport of ,-tocopherol was less than 1 mg 24 h after administration of both emulsions containing ,-tocopherol. The absorption of Lu28,179 from the ,-tocopherol emulsion was very low, with a lymphatic recovery of 0.05%. When administered in an ,-tocopherol/sesame oil emulsion, the recovery of Lu28,179 increased sevenfold to 0.35%. However, after administration of Lu28,179 in a sesame oil emulsion, the lymphatic recovery increased a further 13-fold to 4.5%. In conclusion, the study showed that ,-tocopherol did not promote lymphatic absorption of Lu28,179 and thus was not a good lymphotropic carrier, as compared with sesame oil. ,-Tocopherol in combination with sesame oil was not a good lymphotropic carrier either. The non-absorbed ,-tocopherol fraction in the intestine might be able to prevent the absorption of Lu28,179. [source] Improvement of ,-tocopherols long-term efficiency by modeling its heterogeneous natural environment in polyethyleneJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2006Clara Strandberg Abstract The natural antioxidant vitamin E (,-tocopherol) is of interest to use in packaging applications to decrease the amount of toxic products migrating into food and drugs. We have earlier shown that the long-term efficiency of ,-tocopherol in polyethylene (PE) films is poor. ,-Tocopherol is located in the lipid phase of the cell in vivo and it has been revealed that it is more efficient in a polar substrate. PE is more hydrophobic and homogenous than the heterogeneous and hydrophilic lipid phase. Three different additive systems were investigated to model ,-tocopherols heterogeneous natural environment in PE. Two of these had carboxylic acid groups, EAA and polyTRIM/PAA core-shell particles (Core), and the third, oat starch, had no carboxylic acid groups. The materials were thermally aged and characterized by chemiluminescence (CL), FTIR, chromatography, and thermal analysis. The EAA system as well as the Core system improved the antioxidant properties of ,-tocopherol in PE, and the Core system had the best performance. We know that starch has stabilizing properties in PE, but it had no effect on the efficiency of ,-tocopherol. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1660,1666, 2006 [source] Inhibition of Alcohol-Associated Colonic Hyperregeneration by ,-Tocopherol in the RatALCOHOLISM, Issue 1 2003P. Vincon Background: Chronic alcohol consumption results in colorectal mucosal hyperregeneration, a condition associated with an increased risk for colorectal cancer. Possible mechanisms may involve the effects of acetaldehyde and/or free radicals generated during alcohol metabolism. Vitamin E is part of the antioxidative defense system, and its concentration is decreased or its metabolic utilization increased in various tissues after chronic alcohol consumption. We wondered whether ,-tocopherol supplementation may prevent ethanol-induced colorectal cell cycle behavior and whether these changes were related to alterations in protein synthesis. Methods: Five groups of male Wistar rats, each consisting of 14 animals, received liquid diets as follows: group 1, alcohol; group 2, alcohol +,-tocopherol; group 3, control (i.e., isocaloric glucose); group 4; control (i.e., isocaloric glucose) +,-tocopherol. Group 5 was fed a solid chow diet ad libitum. After 4 weeks of feeding, immunohistology was performed with anti-proliferating cell nuclear antigen (PCNA) or anti-BCL2 antibodies. Fractional (ks) and absolute (Vs) rates of protein synthesis and rates of protein synthesis relative to RNA (kRNA) and DNA (kDNA) were measured with a flooding dose of L-[4- 3H] phenylalanine with complementary analysis of protein and nucleic acid composition. Results: The PCNA index was increased significantly in the colon after ethanol administration compared with controls (ethanol, 10.3 ± 2.3 vs. control, 6.51 ± 1.6% PCNA positive cells, p < 0.05), although neither the protein, RNA, and DNA concentrations nor ks, kRNA, kDNA, and Vs were affected. This increase in PCNA index was significantly diminished by coadministration of ,-tocopherol (ethanol +, - tocopherol, 7.86 ± 1.71% PCNA positive cells, p < 0.05) without significant alterations in protein synthetic parameters. A similar result was obtained for the PCNA index in the rectal mucosa (ethanol, 14.6 ± 4.4 vs. control, 12.1 ± 4.2% PCNA positive cell), although this did not reach statistical significance. Neither ethanol nor , - tocopherol feeding had any significant effect on BCL-2 expression in the colorectal mucosa. As with the colon, protein synthetic parameters in the mucosa were not affected by alcohol feeding at 4 weeks. These effects on colonic cell turnover without corresponding changes in protein synthesis thus represent a specific localized phenomenon rather than a general increase in anabolic processes in the tissue and reaffirm the hyperregenerative properties of chronic alcohol consumption. Conclusions: Alcohol-associated hyperproliferation could be prevented, at least in part, by supplementation with ,-tocopherol. This may support the hypothesis that free radicals are involved in the pathogenesis of alcohol-associated colorectal hyperproliferation. [source] The antioxidant activity and stability of the phenolic fraction of green olives and extra virgin olive oilJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2001Turkan Keceli Abstract The antioxidant activity of phenolic extracts from olives and olive oil has been assessed by scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and by studying the effects on the stability of stripped olive oil in the absence and presence of ferric chloride. The olive extracts contained a much higher concentration (1940,5800,mg,kg,1) of phenolic components than the olive oil extract (180,mg,kg,1). Some olive extracts were more effective than the olive oil extract in scavenging DPPH radicals, but the three varieties of olives examined showed relatively large differences in both polyphenol concentration and antioxidant activity of extracts. ,-Tocopherol and extracts from both olives and olive oil were effective antioxidants in stripped olive oil at 60,°C. Ferric chloride reduced the stability of stripped olive oil, but the olive extract studied was significantly more effective as an antioxidant in the presence of the metal salt than the olive oil extract or ,-tocopherol. Ferric ions catalysed the oxidation of caffeic acid, oleuropein and phenolic components of the olive and olive oil extracts in aqueous solution (pH 5.4). The olive extract oxidised more rapidly than the olive oil extract in aqueous solution. © 2001 Society of Chemical Industry [source] Modulation of Monocyte-Macrophage Function with ,-Tocopherol: Implications for AtherosclerosisNUTRITION REVIEWS, Issue 1 2002Sridevi Devaraj PhD Cardiovascular disease is the leading cause of morbidity and mortality in the Western world. Monocyte-macrophages are crucial cells in atherogenesis. Several lines of evidence suggest that antioxidants, especially , -tocopherol, have beneficial effects with regard to cardiovascular disease. , -Tocopherol has beneficial effects on cell functions that are pivotal in atherogenesis. , -Tocopherol inhibits platelet aggregation and proinflammatory activity of monocytes. In vitro data also support an effect of , -tocopherol on smooth muscle cell proliferation and endothelial function. Finally, recent data support an effect of , -tocopherol on macrophage function. The mounting evidence from in vitro and in vivo studies provides a sound scientific basis for , -tocopherol supplementation. Further clinical trials are required, however, before a definitive recommendation can be made for primary and secondary prevention of heart disease. [source] Fluorescence Lifetimes Study of ,-Tocopherol and Biological Prenylquinols in Organic Solvents and Model MembranesPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2006Jerzy Kruk ABSTRACT We have found that for biological prenyllipids, such as plastoquinol-9, ,-tocopherol quinol, and ,-tocopherol, the shortest fluorescence lifetimes were found in aprotic solvents (hexane, ethyl acetate) whereas the longest lifetimes were those of ubiquinonol-10 in these solvents. For all the investigated prenyllipids, fluorescence lifetime in alcohols increased along with an increase in solvent viscosity. In a concentrated hexane solution, the lifetimes of prenylquinols considerably decreased. This contrasts with methanol solutions, which is probably due to the self-association of these compounds in aprotic solvents. We have also found a correlation of the Stokes shift of prenyllipids fluorescence with the orientation polarizability of the solvents. Based on data obtained in organic solvents, measurements of the fluorescence lifetimes of prenyllipids in liposomes allowed an estimation of the relative distance of their fluorescent rings from the liposome membrane surface, and was found to be the shortest for ,-tocopherol quinol in egg yolk phosphatidyl-choline liposomes, and increased in the following order: ,-tocopherol in dipalmitoyl phosphatidylcholine liposomes < ,-tocopherol < plastoquinol-9 < ubiquinol-10 in egg-yolk phosphatidylcholine liposomes. [source] Effect of , -Interferon and , -Tocopherol in Reversing Hepatic Cirrhosis in RatsANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2007T. C. Mathew Summary The aim of this study was to assess the effects of , -interferon and , -tocopherol (vitamin E), or a combination of both, in reversing hepatic fibrosis following the induction of cirrhosis using thioacetamide by histological and biochemical analysis. Fifty male Wistar rats were used in this study. The animals were divided equally into five groups. Animals in group I were used as controls. The remaining animals (groups II,V) were provided with 0.5 g/L of thioacetamide in order to induce liver cirrhosis. Group II animals were used as the cirrhotic control. Animals of groups III, IV and V were given , -interferon, , -tocopherol and interferon together with , -tocopherol, respectively, for 30 days. After 30 days the animals were killed and following gross morphological examination of the liver, the hepatic tissues were processed for histological analysis and the serum was used for liver function tests. Morphological analysis showed a decrease in the number of nodules on the surface of the liver in both interferon- as well as vitamin E-treated cirrhotic rats. Histopathological analysis showed that the abnormalities of the cirrhotic liver were partially reversed and liver function tests showed an overall improvement following treatment of animals of groups III, IV and V. Combination therapy using both interferon and , -tocopherol did not have any substantial effect on the rats compared with that when they were given separately. These findings suggest that , -interferon and , -tocopherol may have therapeutic value in reversing liver cirrhosis. [source] Low serum ,-tocopherol and selenium are associated with accelerated apoptosis in severe sepsisBIOFACTORS, Issue 2 2008Stefan U. Weber Abstract During sepsis, a severe systemic disorder, micronutrients often are decreased. Apoptosis is regarded as an important mechanism in the development of often significant immunosuppression in the course of the disease. This study aimed to investigate a -tocopherol and selenium in reference to apoptosis in patients with sepsis. 16 patients were enrolled as soon as they fulfilled the criteria of severe sepsis. 10 intensive care patients without sepsis and 11 healthy volunteers served as controls. a -Tocopherol, selenium and nucleosomes were measured in serum. Phosphatidylserine externalization and Bcl-2 expression were analyzed in T-cells by flow cytometry. Serum ,-tocopherol and selenium were decreased in severe sepsis but not in non-septic critically ill patients (p < 0.05). Conversely, markers of apoptosis were increased in sepsis but not in critically ill control patients: Nucleosomes were found to be elevated 3 fold in serum (p < 0.05) and phosphatidylserine was externalized on an expanded subpopulation of T-cells (p < 0.05) while Bcl-2 was expressed at lower levels (p < 0.05). The decrease of micronutrients correlated with markers of accelerated apoptosis. Accelerated apoptosis in sepsis is associated with low ,-tocopherol and selenium. The results support the investigation of micronutrient supplementation strategies in severe sepsis. [source] ,-Tocopherol counteracts ritonavir-induced proinflammatory cytokines expression in differentiated THP-1 cellsBIOFACTORS, Issue 3-4 2007Weimin Guo Abstract Treatment of HIV-infected individuals with HIV protease inhibitor (HPI) drugs has significantly increased their life span. However, one of the side effects of HPI drugs is the development of premature atherosclerosis, whose molecular pathogenesis remains unclear. Previously we have reported that ,-tocopherol (,-T) normalizes CD36 overexpression induced by ritonavir treatment and reduces oxLDL uptake in THP-1 cells. Since inflammation is a major player in the pathogenesis of atherosclerosis, we hypothesized that HPI drugs, such as ritonavir, increase proinflammatory cytokines synthesis and that ,-T supplementation counteracts this effect by suppressing proinflammatory cytokines levels. Here, we report that after differentiating THP-1 cells to macrophages, ritonavir treatment (10 ,g/mL) significantly increases expression of proinflammatory cytokines, IL-6, MCP-1 and IL-8, at both mRNA and protein levels. This ritonavir-induced effect is significantly suppressed by treatment of THP-1/macrophages with 50 ,M ,-T. We conclude that ritonavir can induce proinflammatory cytokines synthesis in THP-1/macrophages, which might be associated with the development of premature atherosclerosis in ritonavir-treated patients and that this effect is prevented by ,-T. [source] The accumulation of ,-Tocopherol and Retinol in the milk of water buffalo is correlated with the plasma levels of triiodothyronineBIOFACTORS, Issue 3-4 2003M. S. Spagnuolo Abstract Milk is the most important source of Retinol and ,-Tocopherol for calves. These antioxidants save the food quality and prevent lipid oxidation in the mammary gland and the calf growing tissues. In Bubalus bubalis, seasonal changes for the plasma levels of both antioxidants were not found. The levels of Retinol and ,-Tocopherol in the milk were 2 and 1.7 times higher in winter than in summer, respectively. These levels were correlated with the plasma level of triiodothyronine, and markedly increased in cows injected with triiodothyronine in summer. The cytosol from alveolar epithelial cells of mammary glands was incubated with ,-Tocopherol and 3H-Retinol and, after gel filtration chromatography, both antioxidants were found associated with proteins migrating as a single peak of 33 kD. The amount of ,-Tocopherol and Retinol binding proteins was 1.5 and 2.3 times higher in winter than in summer respectively. The Retinol binding proteins migrated as two bands (33 and 16 kD) by electrophoresis in denaturing and reducing conditions. Our data suggest that triiodothyronine enhances the transport of both liposoluble antioxidants through the blood-mammary barrier, and demonstrate that proteins of the mammary epithelial cells are involved in such a transport. [source] Levamisole induced apoptosis in cultured vascular endothelial cellsBRITISH JOURNAL OF PHARMACOLOGY, Issue 8 2000Michaela Artwohl To better understand the anticancer activity of Levamisole (LMS), which serves as an adjuvant in colon cancer therapy in combination with 5-Fluorouracil, this study analyses LMS' ability to induce apoptosis and growth arrest in cultured human micro- and macrovascular endothelial cells (ECs) and fibroblasts. Cells exposed (24 h) to Levamisole (range: 0.5,2 mmol l,1) alone or in combination with antioxidants (10 mmol l,1 glutathione or 5 mmol l,1 N-Acetylcysteine or 0.1 mmol l,1 Tocopherol) were evaluated for apoptosis (3H-thymidine assays, in situ staining), mRNA/protein expression (Northern/Western blot), and proliferation (3H-thymidine incorporation). Levamisole dose-dependently increased apoptosis in ECs to 230% (HUVECs-human umbilical vein ECs), 525% (adult human venous ECs) and 600% (human uterine microvascular ECs) but not in fibroblasts compared to control cells (set as 100%). Levamisole increased in ECs integrin-dependent matrix adhesion, inhibited proliferation (,70%), reduced expression of survival factors such as clusterin (,30%), endothelin-1 (,43%), bcl-2 (,34%), endothelial NO-synthase (,32%) and pRb (Retinoblastoma protein: ,89%), and increased that of growth arrest/death signals such as p21 (+73%) and bak (+50%). LMS (2 mmol l,1)-induced apoptosis was inhibited by glutathione (,50%) and N-Acetylcysteine (,36%), which also counteracted reduction by Levamisole of pRb expression, suggesting reactive oxygen species and pRb play a role in these processes. The ability of LMS to selectively induce apoptosis and growth arrest in endothelial cells potentially hints at vascular targeting to contribute to Levamisole's anticancer activity. British Journal of Pharmacology (2000) 131, 1577,1583; doi:10.1038/sj.bjp.0703660 [source] Tocopherols and tocotrienols in grape seeds from 14,cultivars grown in KoreaEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 12 2009Minjung Wie Abstract In this study, the tocopherol (T) and tocotrienol (T3) contents of grape seeds from 14 different varieties grown in Korea were analyzed using saponification extraction followed by normal-phase liquid chromatography. ,-T, ,-T, ,-T3, and ,-T3 were detected in all samples. The total concentration of tocopherol and tocotrienol was in the range of 4.8,9.9,mg/100,g seed (35.3,68.8,mg/100,g oil basis). The Muscat Bailey,A cultivar had the highest total tocopherol and tocotrienol contents, followed by Canner and Naples. ,-T3 ranged from 1.6 to 4.9,mg/100,g seed (11.2 to 53.81,mg/100,g oil basis) and was the main isomer, followed by ,-T3 in most of the samples. Analytical method validation parameters including accuracy and precision were determined. Overall recovery from grape seeds was close to 100%. [source] Singlet Oxygen Oxidation Rates of ,-, ,-, and ,-TocopherolsJOURNAL OF FOOD SCIENCE, Issue 8 2006H.J. Kim ABSTRACT:, The reaction rate constants of 5 × 10,4 M, 10 × 10,4 M, and 20 × 10,4 M ,-, ,-, and ,-tocopherols with singlet oxygen in methylene chloride containing 1 × 10,5 M chlorophyll under light at 25 °C for 60 min were studied. The oxidation of tocopherols determined by a spectrophotometric method showed that the losses of 20 × 10,4 M ,-, ,-, and ,-tocopherols after 60 min under light were 21%, 16%, and 9%, respectively. The degradation of ,-, ,-, and ,-tocopherols was undetectable in the absence of chlorophyll under light or in the presence of chlorophyll in dark. The losses of tocopherols under light were mainly due to singlet oxygen oxidation. The degradation rates of 20 × 10,4 M ,-, ,-, and ,-tocopherols were 6.6 ×10,6 M/min, 5.0 × 10,6 M/min, and 2.9 × 10,6 M/min, respectively. The reaction rates between ,-, ,-, or ,-tocopherol and singlet oxygen were 4.1 ×106/M s, 3.3 × 106/M s, and 1.4 × 106/M s, respectively. The singlet oxygen oxidation rate of ,-tocopherol was significantly lower than ,- or ,-tocopherol at ,= 0.05. As the electron density in the chromanol ring of tocopherol increased, the singlet oxygen oxidation was increased. [source] Oxidative Stability of Soybean and Sesame Oil Mixture during Frying of Flour DoughJOURNAL OF FOOD SCIENCE, Issue 7 2004J. Chung ABSTRACT: Effects of roasted sesame seed oil on the oxidative stability of soybean oil during frying of flour dough at 160 °C were studied by determining fatty acid composition and conjugated dienoic acid (CDA), p -anisidine (PA), and free fatty acid (FFA) values. Concentration of sesame oil in frying oil was 0%, 10%, 20%, or 30% (v/v). Tocopherols and lignan compounds in the frying oil were also determined by high-performance liquid chromatography. As the number of fryings performed by the oil increased, linolenic acid content in frying oil decreased, and the decreasing rate was lower in frying oil containing sesame oil than in the oil containing no sesame oil. CDA and FFA values of frying oil increased during frying and their relative values to the initial value were lower in frying oil containing sesame oil than in the oil containing no sesame oil. This indicates that the addition of sesame oil improved thermooxidative stability of frying oil, possibly due to the presence of lignan compounds in sesame oil. Tocopherols and lignan compounds in frying oil decreased during frying. As the amount of sesame oil in frying oil increased, degradation of tocopherols increased and lignan compounds degradation decreased. Tocopherols were suggested to protect lignan compounds in sesame oil from decomposition during frying. [source] Stability of Tocopherols and Retinyl Palmitate in Snack ExtrudatesJOURNAL OF FOOD SCIENCE, Issue 6 2001K. Suknark ABSTRACT: Fish- and peanut-containing half-products were obtained by extruding and drying tocopherol- and retinyl palmitate-fortified mixtures of tapioca starch and minced fish or partially defatted peanut flour (PDPF 60:40, wet basis). Half-products were puffed by deep-fat frying. Vitamins were determined simultaneously at each step of snack production using a direct solvent extraction method. Extrusion significantly reduced the content of tocopherols and retinyl palmitate in both products. Reduction of retinyl palmitate in fish and peanut extrudates during snack production was 48% and 27%, respectively. Final products contained more tocopherol than intermediates because of the high tocopherol content in the frying oil and its uptake. [source] Vitamin E inhibition of normal mammary epithelial cell growth is associated with a reduction in protein kinase C, activationCELL PROLIFERATION, Issue 6 2001P. W. Sylvester Tocopherols and tocotrienols represent the two subclasses within the vitamin E family of compounds. However, tocotrienols are significantly more potent than tocopherols in suppressing epidermal growth factor (EGF)-dependent normal mammary epithelial cell growth. EGF is a potent mitogen for normal mammary epithelial cells and an initial event in EGF-receptor mitogenic-signalling is protein kinase C (PKC) activation. Studies were conducted to determine if the antiproliferative effects of specific tocopherol and tocotrienol isoforms are associated with a reduction in EGF-receptor mitogenic signalling and/or PKC activation. Normal mammary epithelial cells isolated from midpregnant BALB/c mice were grown in primary culture, and maintained on serum-free media containing 10 ng/mL EGF as a mitogen, and treated with various doses (0,250 µm) of ,-, ,-, or ,-tocopherol or ,-, ,-, or ,-tocotrienol. Treatment with growth inhibitory doses of ,-tocopherol (100 µm), ,-tocotrienol (50 µm), or ,- or ,-tocotrienol (10 µm) did not affect EGF-receptor levels, EGF-induced EGF-receptor tyrosine kinase activity, or total intracellular levels of PKC,. However, these treatments were found to inhibit EGF-induced PKC, activation as determined by its translocation from the cytosolic to membrane fraction. Treatment with 250 µm,- or ,-tocopherol had no affect on EGF-receptor mitogenic signalling or cell growth. These findings demonstrate that the inhibitory effects of specific tocopherol and tocotrienol isoforms on EGF-dependent normal mammary epithelial cell mitogenesis occurs downstream from the EGF-receptor and appears to be mediated, at least in part, by a reduction in PKC, activation. [source] Alterations of plasma antioxidants and mitochondrial DNA mutation in hair follicles of smokersENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 3 2002Chin-San Liu Abstract The effects of long-term smoking on mitochondrial DNA (mtDNA) deletions in hair follicles were investigated in subjects with different antioxidant capacity. Twenty-two male smokers with a smoking index of greater than 5 pack-years and without any known systemic diseases were recruited for this study. Forty healthy nonsmoking males were included as controls. We found that the concentrations of ascorbate and ,-tocopherol and the activities of glutathione S -transferase (GST) and glutathione peroxidase in blood plasma were significantly decreased in smokers. The levels of glutathione and protein thiols in whole blood and the incidence of a 4,977 bp deletion of mtDNA (dmtDNA) in hair follicles were significantly increased in smokers. A significantly higher incidence of the 4,977 bp dmtDNA was found in smokers with plasma GST activity less than 5.66 U/l (OR = 7.2, P = 0.020). Using multiple covariate ANOVA and logistic regression, we found that age and low plasma GST activity were the only two risk factors for the 4,977 bp dmtDNA. These results suggest that smoking depletes antioxidants and causes mtDNA deletions and that plasma GST may play an important role in the preservation of the mitochondrial genome in tissue cells of smokers. Environ. Mol. Mutagen. 40:168,174, 2002. © 2002 Wiley-Liss, Inc. [source] The Effects of Ascorbic Acid on Penicillin-induced Epileptiform Activity in RatsEPILEPSIA, Issue 7 2007Mustafa Ayyildiz Summary:,Purpose: Epileptic seizure results from excessive discharge in a population of hyperexcitable neurons. A number of studies help to document the effects of active oxygen free radical scavengers such as ,-tocopherol or ascorbic acid (vitamin C). In the present study, we examined the effects of ascorbic acid, at the six different doses, on penicillin-induced epileptiform activity. Methods: A single microinjection of penicillin (2.5 ,l, 500 units, intracortically) into the left sensorimotor cortex induced epileptiform activity within 2,5 min, progressing to full seizure activity lasting ,3,5 h. In the first set of experiments, 30 min after penicillin injection, six different doses of ascorbic acid (25, 50, 100, 200, 400, or 800 mg/kg) were administered intraperitoneally (IP). The other group of animals received the effective dose of ascorbic acid (100 mg/kg, IP) for 7 days. Ascorbic acid administration was stopped 24 h before penicillin treatment. Another group of rats received the effective dose of ascorbic acid (100 mg/kg, IP) 30 min before penicillin treatment. In the second set of experiments, the lipid peroxidation (MDA) and reduced glutathione (GSH) levels of brain were measured in the control, control + ascorbic acid, penicillin, and penicillin + ascorbic acid groups. Results: Ascorbic acid, at the low dose (50, 100 mg/kg, 30 min after penicillin injection), decreased both the frequency and amplitude of penicillin-induced epileptiform activity in rats. Ascorbic acid, at intermediate doses (200, 400 mg/kg, 30 min after penicillin injection), decreased the frequency of epileptiform activity without changing the amplitude. Ascorbic acid, at the lowest dose (25 mg/kg) and highest dose (800 mg/kg) (30 min after penicillin injection), did not change either the frequency or amplitude of epileptiform activity. Ascorbic acid, at the low dose (100 mg/kg) was the most effective dose in changing the frequency and amplitude of penicillin-induced epileptiform activity. Pretreatment with ascorbic acid (100 mg/kg) 30 min before penicillin treatment caused a significant delay in the onset of penicillin-induced epileptiform activity. Pretreatment with ascorbic acid (100 mg/kg) for 7 days did not change the latency of epileptiform activity. The most effective dose of ascorbic acid (100 mg/kg) prevented both the decrease in GSH level and the increase in lipid peroxidation level (MDA) occurring after penicillin-induced epileptiform activity. Conclusions: These data indicate that ascorbic acid has neuroprotective activity against penicillin-induced epileptiform electrocorticogram activity. [source] Oral vitamin E supplementation on oxidative stress, vitamin and antioxidant status in intensely exercised horsesEQUINE VETERINARY JOURNAL, Issue S36 2006C. A. WILLIAMS Summary Reasons for performing study: Vitamin E is the most commonly supplemented antioxidant in horses; however, previous research is not conclusive as to the recommended level for exercising horses. Objective: To evaluate the effects of 3 levels of vitamin E supplementation on oxidative stress and vitamin/antioxidant status in intensely exercised horses to determine the optimal level of vitamin E supplementation. Methods: Twelve unfit Standardbreds were divided into 3 groups, supplemented orally with 0 (CON), 5000 (MOD), or 10,000 (HI) iu/day of DL-,-tocopheryl acetate. The 3 times 3 Latin square design consisted of three 4 week supplementation periods with 4 week wash out periods between. After each period, horses underwent a treadmill interval exercise test. Blood samples were collected and heart rate (HR) measured before, during and after exercise. Data were analysed using ANOVA with repeated measures in SAS. Results: The CON group had lower HR throughout the test compared to the MOD and HI groups (P<0.05). There was an increase in plasma retinol (RET), ,-carotene (BC), red blood cell total glutathione and glutathione peroxidase with exercise (P<0.05), but all groups returned to baseline after 24 h. Plasma ,-tocopherol (TOC) increased from baseline with exercise (P<0.0001) in all groups; treatment differences were observed at 24 h (P<0.05). The HI and CON groups had lower BC compared to the MOD group (P = 0.05). Conclusions: Horses supplemented with vitamin E, at nearly 10-times the 1989 NRC recommended level, did not experience lower oxidative stress compared to control horses. Additionally, lower plasma BC levels observed in the HI group, which may indicate that vitamin E has an inhibitory effect on BC metabolism. Potential relevance: Supplementation above control levels is not more beneficial to oxidative stress and antioxidant status in intensely exercising horses; indeed, levels 10 times in excess may be detrimental to BC and should be avoided. [source] Glutathione, vitamin E and oxidative stress in coronary artery disease: relevance of age and genderEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 4 2009V. Cavalca Abstract Background, Observational studies suggest that low levels of antioxidants are associated with high risk for coronary artery disease (CAD). We investigated whether the biomarkers of oxidative balance undergo the same modifications in all CAD patient groups, regardless of gender and age. Materials and methods, One hundred sixty-eight CAD patients and 107 healthy controls were assayed for plasma levels of reduced glutathione (GSH), ,- and ,-tocopherol (,- and ,-T) as endogenous antioxidants. A damage score (DS), representative of oxidative stress status, was calculated. ancova models were used to test the association between antioxidants, DS and CAD and its modulation by age and gender. Results, The DS was higher in CAD than in controls. GSH levels, were lower in CAD patients (mean ± SEM: 57·61 ± 1·87 ,mol 10 g,1 haemoglobin vs. 68·55 ± 2·23 in controls, P < 0·0006) in males and in older subjects. Levels of other antioxidants exhibited a complex pattern. Overall, no difference was found in ,- and ,-T contents between CAD and controls, but lower ,-T values were observed in CAD females. A significant interaction between CAD status and gender was observed (P = 0·003). Conclusions, Our study shows that the involvement of antioxidants in CAD is related to patients' characteristics. These findings may be relevant in planning antioxidant therapies. [source] D-2-Hydroxyglutaric acid inhibits creatine kinase activity from cardiac and skeletal muscle of young ratsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2003C. G. Da Silva Abstract Background, Tissue accumulation of high amounts of D-2-hydroxyglutaric acid (DGA) is the biochemical hallmark of the inherited neurometabolic disorder D-2-hydroxyglutaric aciduria (DHGA). Patients affected by this disease usually present hypotonia, muscular weakness, hypothrophy and cardiomyopathy, besides severe neurological findings. However, the underlying mechanisms of muscle injury in this disorder are virtually unknown. Materials and methods, In the present study we have evaluated the in vitro role of DGA, at concentrations ranging from 0·25 to 5·0 mm, on total, cytosolic and mitochondrial creatine kinase activities from skeletal and cardiac muscle of 30-day-old Wistar rats. We also tested the effects of various antioxidants on the effects elicited by DGA. Results, We first verified that total creatine kinase (CK) activity from homogenates was significantly inhibited by DGA (22,24% inhibition) in skeletal and cardiac muscle, and that this activity was approximately threefold higher in skeletal muscle than in cardiac muscle. We also observed that CK activities from mitochondrial (Mi-CK) and cytosolic (Cy-CK) preparations from skeletal muscle and cardiac muscle were also inhibited (12,35% inhibition) by DGA at concentrations as low as 0·25 mm, with the effect being more pronounced in cardiac muscle preparations. Finally, we verified that the DGA-inhibitory effect was fully prevented by preincubation of the homogenates with reduced glutathione and cysteine, suggesting that this effect is possibly mediated by modification of essential thiol groups of the enzyme. Furthermore, ,-tocopherol, melatonin and the inhibitor of nitric oxide synthase L-NAME were unable to prevent this effect, indicating that the most common reactive oxygen and nitrogen species were not involved in the inhibition of CK provoked by DGA. Conclusion, Considering the importance of creatine kinase activity for cellular energy homeostasis, our results suggest that inhibition of this enzyme by increased levels of DGA might be an important mechanism involved in the myopathy and cardiomyopathy of patients affected by DHGA. [source] ,-tocopherol improves impaired physiology of rat type II pneumocytes isolated from experimentally injured lungsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 11 2000B. Müller Background Oxidant stress delivered by nitrogen dioxide (NO2) inhalation impairs the function of extracellular surfactant as well as surfactant phospholipid metabolism in type II pneumocytes. Because protection against oxidant stress is important to normal lung function, the lung contains a variety of antioxidants, including vitamin E. Whether administration of this antioxidant during NO2 inhalation attenuates NO2 -induced alterations in phospholipid metabolism in type II pneumocytes has not been studied. Methods We exposed rats to identical NO2 body doses (720 p.p.m. x h) using continuous, intermittent, or repetitive protocols. During exposure periods, the animals received daily intramuscular injections of vitamin E (25 mg kg,1). We isolated type II pneumocytes from NO2 -exposed rats and evaluated them for cell yield and viability, as well as for synthesis and secretion of phosphatidylcholine (PC) as measures of surfactant metabolism. Results The yield of type II pneumocytes was significantly elevated from animals that had been exposed continuously to NO2 whereas in intermittently and repeatedly exposed rats, cell yield was similar to yield from control animals. Viability of the isolated cells was similar in controls and all NO2 exposure protocols. Vitamin E treatment of the NO2 -exposed rats neither changed cell yield nor cell viability. Phospholipid de novo synthesis, as estimated by choline incorporation into PC, was increased most after continuous NO2 inhalation whereas in the other conditions there was only a slight increase. Vitamin E administration further increased phospholipid synthesis; this difference reached statistical significance only in the case of intermittent NO2 exposure. Secretion of phosphatidylcholine from type II cells was only reduced after continuous NO2 inhalation and administration of the antioxidant reduced the impairment. Conclusion Because vitamin E appears to preserve the ability of type II pneumocytes isolated from NO2 -exposed rats to synthesize and secrete surfactant lipid, we conclude that administration of vitamin E may mitigate NO2 -induced lung injury. [source] | ||||||||||||||||||||||