ascorbic-acid and cobaltous-chloride

Vitamins are essential for sustaining daily activities and perform crucial roles in metabolism, such as preventing vascular events and delaying the development of diabetic nephropathy. The ultrasensitive assessment of thiamine in foods is required for food quality evaluation. A mini-platform utilizing two 3D sensors based on nanographene and gold nanoparticles paste modified with protoporphyrin IX and protoporphyrin IX cobalt chloride is proposed for the detection of thiamine in blueberry syrup, multivitamin tablets, water, and a biological sample (urine). Differential pulse voltammetry was utilized for the characterization and validation of the suggested sensors. The sensor modified with protoporphyrin IX has a detection limit of 3.0 × 10

Topics: Ascorbic Acid; Electrochemical Techniques; Electrodes; Gold; Limit of Detection; Metal Nanoparticles; Reproducibility of Results; Tablets; Thiamine; Water

The objective of the present work was to evaluate the toxic effects of cobalt chloride, a potent oxidative stress-inducing chemical, at 650 ppm in rats and the protective effect of quercetin and/or vitamin C against the cobalt chloride-induced toxicity. Thirty rats were randomly selected, and assigned to one of five groups: control, cobalt chloride, cobalt chloride + quercetin, cobalt chloride + vitamin C and cobalt chloride + quercetin + vitamin C. The exposure of rats to cobalt chloride led to a significant increase (p < 0.05) in malondialdehyde (MDA) and hydrogen peroxide (H

Topics: Animals; Ascorbic Acid; Cobalt; Gene Expression Regulation; Hypertension; Male; NF-kappa B; Oxidative Stress; Quercetin; Rats; Rats, Wistar

Intravenous application of high-dose ascorbate is used in complementary palliative medicine to treat cancer patients. Pharmacological doses of ascorbate in the mM range induce cytotoxicity in cancer cells mediated by reactive oxygen species (ROS), namely hydrogen peroxide and ascorbyl radicals. However, little is known about intrinsic or extrinsic factors modulating this ascorbate-mediated cytotoxicity. Under normoxia and hypoxia, ascorbate IC50 values were determined on the NCI60 cancer cells. The cell cycle, the influence of cobalt chloride-induced hypoxia-inducible factor-1α (HIF-1α) and the glucose transporter 1 (GLUT-1) expression (a pro-survival HIF-1α-downstream-target) were analysed after ascorbate exposure under normoxic and hypoxic conditions. The amount of ascorbyl radicals increased with rising serum concentrations. Hypoxia (0.1% O2 ) globally increased the IC50 of ascorbate in the 60 cancer cell lines from 4.5 ± 3.6 mM to 10.1 ± 5.9 mM (2.2-fold increase, P < 0.001, Mann-Whitney t-test), thus inducing cellular resistance towards ascorbate. This ascorbate resistance depended on HIF-1α-signalling, but did not correlate with cell line-specific expression of the ascorbate transporter GLUT-1. However, under normoxic and hypoxic conditions, ascorbate treatment at the individual IC50 reduced the expression of GLUT-1 in the cancer cells. Our data show a ROS-induced, HIF-1α- and O2 -dependent cytotoxicity of ascorbate on 60 different cancer cells. This suggests that for clinical application, cancer patients should additionally be oxygenized to increase the cytotoxic efficacy of ascorbate.

Topics: Ascorbic Acid; Cell Death; Cell Hypoxia; Cell Line, Tumor; Cell Proliferation; Cobalt; Culture Media; Dose-Response Relationship, Drug; G1 Phase; Glucose Transporter Type 1; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Inhibitory Concentration 50; Intracellular Space; Oxygen; Partial Pressure; Peroxides; Reactive Oxygen Species

Metal ions (Cr and Co) are released from metal orthopaedic implants in situ. We investigated tissue dissemination of Cr III, Cr VI and Co II ions in the body, and determined if administration of ascorbic acid (AA) affected their in vivo distribution using rats as a model system. Organs of rats treated with both Cr (VI) and Co (II) have higher metal ion levels when compared with control levels in the organs of rats without metal treatment. The reduced form of chromium, Cr III, is reported to be relatively impermeant to cell membranes in vitro, and in line with this, Cr III did not distribute into the organs of the rats after administration in vivo. Potent in vitro reduction of Cr (VI) to Cr III by AA was observed in this study. Prior intraperitoneal injection of AA lowered tissue uptake of both Cr VI and Co II, and increased faecal excretion, but not to a significant extent. AA may only be effective in increasing elimination of Cr VI at high concentrations when plasma reduction is saturated, and may be of limited therapeutic use in patients with orthopaedic implants.

Topics: Animals; Antioxidants; Ascorbic Acid; Chlorides; Chromium; Chromium Compounds; Cobalt; Drug Interactions; Humans; Male; Rats; Rats, Sprague-Dawley; Tissue Distribution

In animals, heme oxygenase (HO), a rate-limiting enzyme responsible for carbon monoxide (CO) production, was regarded as a protective system maintaining cellular homeostasis. It was also established that metal ions are powerful HO-inducing agents and cobalt chloride (CoCl(2)) was the first metal ion identified with an inducing property. Previous study suggests that CoCl(2) stimulates adventitious root formation in tomato and cucumber cuttings. In this test, we discover that both CoCl(2) and an inducer of HO-1, hemin, could lead to the promotion of lateral root development, as well as the induction of HO-1 protein expression, HO activity, or LeHO-1/2 transcripts, in lateral root initiation zone of tomato seedlings. The effect is specific for HO since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX) blocked the above actions of CoCl(2), and the inhibitory effect was reversed partially when 50% CO aqueous solution was added. However, the addition of ascorbic acid (AsA), a well-known antioxidant, exhibited no obvious effect on lateral root formation. Molecular evidence further showed that CoCl(2)-induced the up-regulation of target genes responsible for lateral root formation, including LeCDKA1, LeCYCA2;1, and LeCYCA3;1, was suppressed differentially by ZnPPIX. And these decreases were reversed further by the addition of CO. All together, these results suggest a novel role for HO in the CoCl(2)-induced tomato lateral root formation.

Topics: Ascorbic Acid; Blotting, Western; Cobalt; Heme Oxygenase (Decyclizing); Plant Proteins; Plant Roots; Reverse Transcriptase Polymerase Chain Reaction; Seedlings; Solanum lycopersicum

Prolyl-4-hydroxylation is necessary for proper structural assembly of collagens and oxygen-dependent protein stability of hypoxia-inducible transcription factors (HIFs). In vitro function of HIF prolyl-4-hydroxylase domain (PHD) enzymes requires oxygen and 2-oxoglutarate as cosubstrates with iron(II) and vitamin C serving as cofactors. Although vitamin C deficiency is known to cause the collagen-disassembly disease scurvy, it is unclear whether cellular oxygen sensing is similarly affected. Here, we report that vitamin C-deprived Gulo(-/-) knockout mice show normal HIF-dependent gene expression. The systemic response of Gulo(-/-) animals to inspiratory hypoxia, as measured by plasma erythropoietin levels, was similar to that of animals supplemented with vitamin C. Hypoxic HIF induction was also essentially normal under serum- and vitamin C-free cell-culture conditions, suggesting that vitamin C is not required for oxygen sensing in vivo. Glutathione was found to fully substitute for vitamin C requirement of all 3 PHD isoforms in vitro. Consistently, glutathione also reduced HIF-1α protein levels, transactivation activity, and endogenous target gene expression in cells exposed to CoCl(2). A Cys201Ser mutation in PHD2 increased basal hydroxylation rates and conferred resistance to oxidative damage in vitro, suggesting that this surface-accessible PHD2 cysteine residue is a target of antioxidative protection by vitamin C and glutathione.

Topics: Amino Acid Substitution; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Cell Hypoxia; Cell Line; Cobalt; Glutathione; HeLa Cells; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Hypoxia-Inducible Factor-Proline Dioxygenases; L-Gulonolactone Oxidase; Mice; Mice, Knockout; Mutagenesis, Site-Directed; Mutant Proteins; Oxygen; Procollagen-Proline Dioxygenase

The ability of ascorbic acid (Vitamin C) to modulate the genotoxic action of several mutagens was investigated in the wing spot test of Drosophila melanogaster. In this assay, 3-day-old transheterozygous larvae for the multiple wing hairs (mwh, 3-0.3) and flare (flr, 3-38.8) genes were treated with three reference mutagenic compounds, namely cobalt chloride (CoCl2), 4-nitroquinoline 1-oxide (4-NQO) and potassium dichromate (K2Cr2O7). The results obtained show that the three reference mutagens tested were clearly genotoxic in the Drosophila wing somatic mutation and recombination test (SMART). None of the three concentrations tested of ascorbic acid (25, 75 and 250mM) induced significant increases in the frequency of the mutant clones recorded. When co-treatment experiments with ascorbic acid were carried out, different results were found. Thus, ascorbic acid was effective in reducing the genotoxicity of K2Cr2O7 virtually to the control level; on the contrary, it did not show any antigenotoxic effect on the genotoxicity of 4-NQO. Finally, co-treatments with CoCl2 and ascorbic acid show a significant increase in the frequency of mutant clones over the values obtained with CoCl2 alone.

Topics: 4-Nitroquinoline-1-oxide; Animals; Animals, Genetically Modified; Antimutagenic Agents; Ascorbic Acid; Carcinogens; Cobalt; Coloring Agents; Drosophila melanogaster; Eye Color; Female; Genes, Insect; Larva; Male; Mutagenicity Tests; Mutation; Potassium Dichromate; Wings, Animal

1. Rat liver microsomal suspension containing NADPH and MgCl2 was incubated at 37 degrees C with naproxen, a non-steroidal anti-inflammatory drug. Thiobarbituric acid reactive substances (TBA-RS), high molecular weight protein aggregates and fluorescent substances were formed in the microsomal suspension. 2. Chemiluminescence was produced from the microsomal suspension. This chemiluminescence production was well correlated to the TBA-RS formation, indicating that the chemiluminescence production was closely associated with the lipid peroxidation. 3. The addition of SKF-525A to the microsomal suspension inhibited the production of TBA-RS, chemiluminescence and 6-demethylnaproxen (6-DMN), the oxidative product of naproxen. Further, the antioxidant, alpha-tocopherol and singlet oxygen quenchers like histidine, dimethylfuran and 1,4-diazabicyclo[2,2,2]octane strikingly inhibited the productions of chemiluminescence and TBA-RS. 4. Neither naproxen nor 6-DMN caused lipid peroxidation in the absence of NADPH. Thus, lipid peroxidation and chemiluminescence during the oxidation of naproxen in liver microsomes was suggested to be provoked by reactive oxygen species and an origin of chemiluminescence was shown to be singlet oxygen.

Topics: Animals; Antimutagenic Agents; Antioxidants; Ascorbic Acid; Cobalt; Electrophoresis, Polyacrylamide Gel; Ferrous Compounds; Histidine; Lipid Peroxidation; Luminescent Measurements; Magnesium Chloride; Male; Microsomes, Liver; Molecular Weight; NADP; Naproxen; Piperonyl Butoxide; Proadifen; Rats; Rats, Wistar; Reactive Oxygen Species; Thiobarbituric Acid Reactive Substances; Vitamin E

We employed an electron spin resonance (ESR)2 spectrometer and used a direct detection technique for determining free radicals in circulating blood in rats. We found that the simultaneous intravenous injection of CoCl2 (10-500 mM) and ascorbic acid (100 mM) led to the formation of ascorbic acid free radicals. The potential of the Co(II) salt for producing ascorbic acid radicals was found to be dose-dependent, and was 10-fold stronger than that of a Fe(III) salt. Low height signals of the ascorbic acid radical were also observed during the simultaneous injection of NiCl2 (500 mM) and ascorbic acid (100 mM). This study clearly demonstrated that the metal ions of iron family are promoters of free radicals in vivo. These results also provide evidence to support the speculation based predominantly on in vitro experiments, that the mechanism responsible for the toxicity produced by excessive intake of transitional metal ions may involve the formation of free radicals.

Topics: Animals; Ascorbic Acid; Cobalt; Electron Spin Resonance Spectroscopy; Free Radicals; Male; Nickel; Rats; Rats, Sprague-Dawley

Ascorbic acid has been shown to stimulate collagen synthesis in monolayer cultures of human dermal fibroblasts. In the present studies, we examined whether the presence of a collagen matrix influences this response of dermal fibroblasts to ascorbic acid. Fibroblasts and collagen were mixed and allowed to gel and contract for 6 days to form a matrix prior to determining the concentration and time dependence for ascorbic acid to affect collagen synthesis by fibroblasts within the matrix. Collagen synthesis was stimulated at levels at or above 10 microM ascorbic acid and was maximal after 2 days of treatment. This concentration and time dependence is similar to that of cells grown in monolayer cultures. The effects of transforming growth factor-beta (TGF-beta) and fibroblast growth factor (FGF) were also examined in this model. TGF-beta increased and FGF inhibited collagen synthesis in the gels, as has been shown for cells in monolayer cultures. The effects of potential inhibitors of lipid peroxidation induced by ascorbic acid were also examined in these matrices and compared to previous results obtained in monolayer cultures. Propyl gallate, cobalt chloride, alpha,alpha-dipyridyl, and alpha-tocopherol inhibited the ascorbic acid-mediated stimulation of collagen synthesis while mannitol had no effect. Natural retinoids inhibited total protein synthesis without the specific effect on collagen synthesis that was seen in monolayer cultures. These results indicate that ascorbic acid stimulates collagen synthesis in fibroblasts grown in a collagen matrix in a manner similar to that found in monolayer cultures. In contracting collagen gels, however, the magnitude of the effect is less and retinoids do not specifically inhibit collagen synthesis.

Topics: 2,2'-Dipyridyl; Ascorbic Acid; Cells, Cultured; Cobalt; Collagen; Dose-Response Relationship, Drug; Ethanol; Fibroblast Growth Factors; Fibroblasts; Gels; Growth Substances; Humans; Infant, Newborn; Kinetics; Lipid Peroxidation; Mannitol; Propyl Gallate; Skin; Time Factors; Transforming Growth Factor beta; Tretinoin; Vitamin A

The workers contacting with cobalt chloride for 10 years and more have been receiving 50 mg ascorbic acid for 30 days. DNA repair was analysed after this procedure in lymphocytes cultivated in vitro according to following criteria: reactivation and induced mutagenesis of vaccinia virus as well as formation of DNA breaks and their resynthesis upon treatment with cobalt chloride and 4-nitro-quinoline-1-oxide.

Topics: 4-Nitroquinoline-1-oxide; Ascorbic Acid; Cells, Cultured; Cobalt; DNA Damage; DNA Repair; Humans; Lymphocytes; Mutagens; Occupational Exposure; Vaccinia virus