OBJECTIVETo investigate the role of reactive oxygen species (ROS) and the effect of vitamin E on proliferation of vascular smooth muscle cells (VSMCs) induced by homocysteine.

METHODSDNA synthesis in the VSMCs cells was measured using [3H]-thymidine incorporation assay, and the cell number determined by trypan blue method. The level of ROS in the cells was determined using DCF-DA as the fluorescence probe.

RESULTSHomocysteine promoted VSMC DNA synthesis, proliferation, and ROS production. Cysteine resulted in increased ROS production in VSMCs, but had no significant effect on DNA synthesis and cell proliferation. Catalase significantly inhibited ROS production induced by homocysteine, but did not significantly inhibited homocysteine-mediated proliferation of VSMCs. While alpha-tocopherol and beta-tocopherol both suppressed increased ROS production induced by homocysteine in VSMCs, only alpha-tocopherol significantly inhibited homocysteine-mediated VSMC proliferation.

CONCLUSIONROS is not associated with VSMC proliferation, and vitamin E-induced suppression of VSMC proliferation is probably related to protein kinase C inhibition.

Animals ; Antioxidants ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Homocysteine ; pharmacology ; Muscle, Smooth ; cytology ; drug effects ; metabolism ; Muscle, Smooth, Vascular ; cytology ; drug effects ; metabolism ; Rats ; Reactive Oxygen Species ; metabolism ; Vitamin E ; pharmacology ; alpha-Tocopherol ; pharmacology ; beta-Tocopherol ; pharmacology

Alpha-tocopherol transfer protein (alpha-TTP) is a liver cytosolic transport protein that faciliates alpha-tocopherol (alpha-T) transfer into liver secreted plasma lipoproteins. Genetic defects in alpha-TTP, like dietary vitamin E deficiency, are associated with infertility, muscular weakness and neurological disorders. Both human and alpha-TTP deficient (alpha-TTP-/-) mice exhibit severe plasma and tissue vitamin E deficiency that can be attenuated by sufficient dietary alpha-T supplementations. In this review, we summarize the literature concerning studies utilizing the alpha-TTP-/- mice. Levels of vitamin E in the alpha-TTP-/- mice do not appear to be directly related to the amounts of dietary alpha-T or to the levels of alpha-TTP protein in tissues. The alpha-TTP-/- mice appear to present a good model for investigating the specific role of alpha-T in tissue vitamin E metabolism. Furthermore, alpha-TTP-/- mice appear to be useful to elucidate functions of alpha-TTP beyond its well recognized functions of transferring alpha-T from liver to plasma lipoprotein fractions.
alpha-Tocopherol* ; Animals ; Cytosol ; Humans ; Infertility ; Lipoproteins ; Liver ; Metabolism ; Mice ; Mice, Knockout* ; Muscle Weakness ; Nervous System Diseases ; Plasma ; Vitamin E ; Vitamin E Deficiency ; Vitamins

To investigate primary metabolites of alpha-tocopherol in human urine, the urine samples of five healthy volunteers after oral administration of 250 mg vitamin E once a day for seven days were collected within 0 -6 h in the seventh day. The samples were purified through C18 solid-phase extraction cartridge and analyzed by liquid chromatography-tandem mass spectrometry. alpha-Tocopheronic acid, 2,5,7, 8-tetramethyl-2-(2'-carboxyethyl) -6-suphate-chroman (alpha-CEHC-sulphate), gamma-tocopheronolactone, and 2, 5, 7, 8-tetramethyl-2-(4', 8', 12'-trimethyl-12'-carboxy dodecanyl) -6-suphate-chroman were found in urine of volunteers as four primary metabolites of alpha-tocopherol. The method has shown to be promising for alpha-tocopherol detection with many desirable properties including high sensitivity and selectivity, thus providing a reliable pathway for further study in metabolism of alpha-tocopherol.
Administration, Oral ; Antioxidants ; administration & dosage ; pharmacokinetics ; Chromatography, High Pressure Liquid ; methods ; Humans ; Spectrometry, Mass, Electrospray Ionization ; methods ; Vitamin E ; pharmacokinetics ; alpha-Tocopherol ; metabolism ; urine

This study examined the effects of dietary alpha-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight (350+/-12) g] were divided into three groups (E250, E500 and E1000) and reared in 9 cages. The fish were fed for 8 weeks with three diets containing different levels of dietary alpha-tocopheryl acetate (289, 553, 1 069 mg/kg). Over the experimental period, fish were fed to satiation and reached a final mean weight of (465+/-28) g without significant body weight difference and proximate composition difference. Fillet alpha-tocopherol was significantly (P<0.05) different between groups, reaching levels of 14.2, 22.1, 30.9 microg/mg fillet for groups E250, E500 and E1000, respectively. Total serum superoxide dismutase (SOD) activity increased significantly (P<0.05) in fish fed the diets high in alpha-tocopheryl acetate, but serum glutathione peroxidase (GPX) activity was unaffected. In storage on ice, fillets of fish fed the diets high in alpha-tocopheryl acetate exhibited significantly lower (P<0.05) levels of oxidation. These results suggested that increased dietary alpha-tocopheryl acetate could increase its flesh deposition, increase the activity of SOD and prevent lipid peroxidation of Sparus macrocephalus fillets in retail storage on ice.
Abattoirs ; Administration, Oral ; Animals ; Dietary Supplements ; Enzyme Activation ; drug effects ; Food Analysis ; Meat ; classification ; Oxidoreductases ; metabolism ; Tocopherols ; alpha-Tocopherol ; administration & dosage ; analogs & derivatives

Chronic alcoholism is considered a common cause of malnutrition. Especially, micronutrient deficiency may playa critical role in the incidence of alcoholic liver diseases. This study was conducted to investigate the effect of folate deficiency and ethanol consumption on cholesterol metabolism and the antioxidative system in rats. Plasma concentration of total cholesterol was increased by ethanol administration in folate-fed rats. HDL-cholesterol tended to be higher in the folate-fed group, but it was not significant. The plasma and hepatic levels of malondialdehyde were increased after chronic ethanol feeding, but dietary folate depressed the plasma malondialdehyde content of rats. Ethanol or folate feeding did not significantly change alcohol dehydrogenase activity. But folate feeding increased catalase activity in ethanol-fed rats. There was no significant change in superoxide dismutase activity among the experimental groups. Glutathione peroxidase activity tended to decrease by chronic ethanol feeding, but dietary folate did not affectthe glutathione peroxidase activity of chronic ethanol-fed rats. Glutathionine-S-transferase activity was not affected by ethanol feeding or folate deficiency. The plasma and hepatic levels of retinol decreased after chronic ethanol feeding. The hepatic level of retinol significantly decreased in ethanol-fed rats by folate deficiency. The plasma level of alpha-tocopherol tended to be low in the folate deficient group with ethanol feeding, but there was no difference among the experimental groups in the hepatic level of alpha-tocopherol. These results demonstrate that chronic ethanol consumption changes the plasma cholesterol metabolism and antioxidative system of rats, and optimal folate feeding in ethanol-fed rats exerts protective effects to some extent.
Alcohol Dehydrogenase ; Alcoholism ; alpha-Tocopherol ; Animals ; Catalase ; Cholesterol* ; Ethanol ; Folic Acid* ; Glutathione Peroxidase ; Incidence ; Liver Diseases, Alcoholic ; Malnutrition ; Malondialdehyde ; Metabolism ; Micronutrients ; Plasma* ; Rats* ; Superoxide Dismutase ; Vitamin A

The present study was designed to observe the effect of chronically ingested ethanol on the level of fatty acid ethyl esters (FAEEs), which is a non-oxidative metabolite of ethanol metabolism in tissues, and its correlation to the status of oxidative stress in rats. Forty male Sprague Dawley rats weighing 145 - 155 g were divided into 2 groups, Control and EtOH. All rats were fed Lieber-DeCarli liquid diet for 4 weeks by pair-feeding. An isocaloric maltose dextrin was added in replace of 50 g ethanol (36%kcal) in the control diet. Chronically ingested ethanol significantly increased the content of FAEEs in pancreas and liver, but not in brain. The level of 2-thiobarbituric acid reactive substances (TBARS) was significantly increased, but alpha-tocopherol level was significantly decreased in pancreas and liver. However, the levels of TBARS and alpha-tocopherol in brain were not significantly affected by ethanol ingestion. Therefore, chronically ingested ethanol might cause tissue damage by increasing the levels of FAEEs and TBARS and dissipating more alpha-tocopherol in tissues.
alpha-Tocopherol ; Animals ; Brain ; Control Groups ; Diet ; Eating* ; Esters* ; Ethanol* ; Humans ; Lipid Peroxidation* ; Liver ; Male ; Maltose ; Metabolism ; Oxidative Stress ; Pancreas ; Rats* ; Rats, Sprague-Dawley ; Thiobarbituric Acid Reactive Substances

OBJECTIVETo observe the influence of either alone or combined mixed-tocopherols combined with eicosapentaenoic acid (EPA) and &alpha;-Tocopherol use on oxidized LDL (oxLDL) induced 8-hydroxy-2'-deoxyguanosine (8-OHDG) and interleukin-6 (IL-6) secretion by human umbilical vein endothelial cells (HUVECs) and to explore the potential mechanism.

METHODCultured HUVECs in vitro were incubated with oxLDL, oxLDL + &alpha;-tocopherol, oxLDL + mixed-tocopherols, oxLDL + EPA, oxLDL + &alpha;-tocopherol + EPA, oxLDL + mixed-tocopherols + EPA for 24 hours, respectively. Secretion of 8-OHDG and IL-6 were detected by cell enzyme linked immunosorbent assay (ELISA). The expressions of superoxide dismutase (SOD), protein kinase C-δ (PKC-δ), phosphorylated PKC-δ (p-PKC-δ) were analyzed by Western blot.

RESULTS8-OHDG and IL-6 secretion of HUVECs was significantly increased significantly after incubated with oxLDL for 24 hours which could be significantly attenuated in the presence of tocopherols and EPA (alone or in combination, all P < 0.05) while the strongest inhibition effects were seen with combined use of mixed-tocopherols and EPA. Moreover, combination of mixed-tocopherols and EPA could also significantly increase SOD activity and decrease PKC activity (all P < 0.05). However, the protein expression of SOD and PKC-was similar among groups.

CONCLUSIONCombined mixed-tocopherols + EPA use enhanced the inhibiting effects on the secretion of 8-OHDG and IL-6 in oxLDL stimulated HUVECs which might be linked with increased SOD activity and reduced p-PKC activity.

Antioxidants ; Cells, Cultured ; Deoxyguanosine ; analogs & derivatives ; secretion ; Eicosapentaenoic Acid ; pharmacology ; Human Umbilical Vein Endothelial Cells ; drug effects ; metabolism ; Humans ; Interleukin-6 ; secretion ; Lipoproteins, LDL ; adverse effects ; Protein Kinase C ; metabolism ; Superoxide Dismutase ; metabolism ; alpha-Tocopherol ; pharmacology

Paclitaxel is one of the chemotheraputic drugs widely used for the treatment of nonsmall cell lung cancer (NSCLC) patients. Here, we tested the ability of alpha-tocopheryl succinate (TOS), another promising anticancer agent, to enhance the paclitaxel response in NSCLC cells. We found that sub-apoptotic doses of TOS greatly enhanced paclitaxel-induced growth suppression and apoptosis in the human H460 NSCLC cell lines. Our data revealed that this was accounted for primarily by an augmented cleavage of poly(ADP-ribose) polymerase (PARP) and enhanced activation of caspase-8. Pretreatment with z-VAD-FMK (a pan-caspase inhibitor) or z-IETD-FMK (a caspase-8 inhibitor) blocked TOS/paclitaxel cotreatment-induced PARP cleavage and apoptosis, suggesting that TOS potentiates the paclitaxel-induced apoptosis through enforced caspase 8 activation in H460 cells. Furthermore, the growth suppression effect of TOS/paclitaxel combination on human H460, A549 and H358 NSCLC cell lines were synergistic. Our observations indicate that combination of paclitaxel and TOS may offer a novel therapeutic strategy for improving paclitaxel drug efficacy in NSCLC patient therapy as well as for potentially lowering the toxic side effects of paclitaxel through reduced drug dosage.
Antineoplastic Agents/*pharmacology ; Apoptosis/*drug effects ; Carcinoma, Non-Small-Cell Lung/*drug therapy/metabolism/pathology ; Caspase 8/metabolism ; Cell Growth Processes/drug effects ; Cell Line, Tumor ; Drug Synergism ; Drug Therapy, Combination ; Humans ; Neoplastic Stem Cells ; Paclitaxel/pharmacology ; alpha-Tocopherol/*pharmacology

Cadmium is known to exert toxic effects on multiple organs, including the testes. To determine if alpha-tocopherol, an antioxidant, could protect testicular tissues and spermatogenesis from the toxic effects of cadmium, six-week old male Sprague-Dawley rats were randomized to receive cadmium at doses of 0 (control), 1, 2, 4 or 8 mg/kg by the intraperitoneal route (Group A) or alpha-tocopherol for 5 days before being challenged with cadmium (Group B) in an identical dose-dependent manner. When both groups received cadmium at 1 mg/kg, there were no changes in testicular histology relative to controls. When Group A received cadmium at 2 mg/kg, undifferentiated spermatids and dead Sertoli cells increased in the seminiferous tubules while interstitial cells decreased and inflammatory cells increased in the interstitial tissues. On flow cytometric analysis, the numbers of elongated spermatids (M1) and round spermatids (M2) decreased while 2c stage cells (M3, diploid) increased. In contrast, when Group B received cadmium at 2 mg/kg, the histological insults were reduced and the distribution of the germ cell population remained comparable to controls. However, alpha-tocopherol had no protective effects with higher cadmium doses of 4 and 8 mg/kg. These findings indicate that alpha-tocopherol treatment can protect testicular tissue and preserve spermatogenesis from the detrimental effects of cadmium but its effectiveness is dependent on the dose of cadmium exposed.
alpha-Tocopherol/*pharmacology ; Testis/*drug effects/pathology ; Spermatogenesis/*drug effects ; Rats, Sprague-Dawley ; Rats ; Male ; Inflammation ; Flow Cytometry ; Dose-Response Relationship, Drug ; Cadmium Poisoning/*pathology ; Cadmium/metabolism/*pharmacology ; Antioxidants/pharmacology ; Animals

BACKGROUND/AIMS: Ozone is an environmentally reactive oxidant, and pycnogenol is a mixture of flavonoid compounds extracted from pine tree bark that have antioxidant activity. We investigated the effects of pycnogenol on reactive nitrogen species, antioxidant responses, and airway responsiveness in BALB/c mice exposed to ozone. METHODS: Antioxidant levels were determined using high performance liquid chromatography with electrochemical detection. Nitric oxide (NO) metabolites in bronchoalveolar lavage (BAL) fluid from BALB/c mice in filtered air and 2 ppm ozone with pycnogenol pretreatment before ozone exposure (n = 6) were quantified colorimetrically using the Griess reaction. RESULTS: Uric acid and ascorbic acid concentrations were significantly higher in BAL fluid following pretreatment with pycnogenol, whereas gamma-tocopherol concentrations were higher in the ozone exposed group but were similar in the ozone and pycnogenol pretreatment groups. Retinol and gamma-tocopherol concentrations tended to increase in the ozone exposure group but were similar in the ozone and pycnogenol pretreatment groups following ozone exposure. Malonylaldehyde concentrations increased in the ozone exposure group but were similar in the ozone and pycnogenol plus ozone groups. The nitrite and total NO metabolite concentrations in BAL fluid, which parallel the in vivo generation of NO in the airways, were significantly greater in the ozone exposed group than the group exposed to filtered air, but decreased with pycnogenol pretreatment. CONCLUSIONS: Pycnogenol may increase levels of antioxidant enzymes and decrease levels of nitrogen species, suggesting that antioxidants minimize the effects of acute ozone exposure via a protective mechanism.
Animals ; Antioxidants/*pharmacology ; Ascorbic Acid/metabolism ; Bronchial Hyperreactivity/chemically induced/metabolism/*prevention & control ; Bronchoalveolar Lavage Fluid/chemistry ; Bronchoconstriction/drug effects ; Disease Models, Animal ; Female ; Flavonoids/*pharmacology ; Inhalation Exposure ; Lung/*drug effects/enzymology/physiopathology ; Malondialdehyde/metabolism ; Mice ; Mice, Inbred BALB C ; Nitric Oxide/metabolism ; Oxidative Stress/*drug effects ; *Ozone ; Uric Acid/metabolism ; Vitamin A/metabolism ; alpha-Tocopherol/metabolism