WorldWideScience
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Macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid  

International Nuclear Information System (INIS)

Graphical abstract: Ascorbic acid is used as an inhibitor to retard the oxidation rate of magnesium sulfite. It shows that the oxidation rate would decrease greatly with the rise of initial ascorbic acid concentration, which provides a useful reference for sulfite recovery in magnesia desulfurization. -- Highlights: • We studied the kinetics of magnesium sulfite oxidation inhibited by ascorbic acid. • The oxidation process was simulated by a three-phase model and proved by HPLC–MS. • We calculated the kinetic parameters of intrinsic oxidation of magnesium sulfite. -- Abstract: Magnesia flue gas desulfurization is a promising process for small to medium scale industrial coal-fired boilers in order to reduce sulfur dioxide emissions, in which oxidation control of magnesium sulfite is of great importance for the recycling of products. Effects of four inhibitors were compared by kinetic experiments indicating that ascorbic acid is the best additive, which retards the oxidation process of magnesium sulfite in trace presence. The macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid were studied. Effects of the factors, including ascorbic acid concentration, magnesium sulfite concentration, oxygen partial pressure, pH, and temperature, were investigated in a stirred reactor with bubbling. The results show that the reaction rate is ?0.55 order in ascorbic acid, 0.77 in oxygen partial pressure, and zero in magnesium sulfite concentration, respectively. The apparent activation energy is 88.0 kJ mol?1. Integrated with the kinetic model, it is concluded that the oxidation rate of magnesium sulfite inhibited by ascorbic acid is controlled by the intrinsic chemical reaction. The result provides a useful reference for sulfite recovery in magnesia desulfurization

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Macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: Ascorbic acid is used as an inhibitor to retard the oxidation rate of magnesium sulfite. It shows that the oxidation rate would decrease greatly with the rise of initial ascorbic acid concentration, which provides a useful reference for sulfite recovery in magnesia desulfurization. -- Highlights: • We studied the kinetics of magnesium sulfite oxidation inhibited by ascorbic acid. • The oxidation process was simulated by a three-phase model and proved by HPLC–MS. • We calculated the kinetic parameters of intrinsic oxidation of magnesium sulfite. -- Abstract: Magnesia flue gas desulfurization is a promising process for small to medium scale industrial coal-fired boilers in order to reduce sulfur dioxide emissions, in which oxidation control of magnesium sulfite is of great importance for the recycling of products. Effects of four inhibitors were compared by kinetic experiments indicating that ascorbic acid is the best additive, which retards the oxidation process of magnesium sulfite in trace presence. The macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid were studied. Effects of the factors, including ascorbic acid concentration, magnesium sulfite concentration, oxygen partial pressure, pH, and temperature, were investigated in a stirred reactor with bubbling. The results show that the reaction rate is ?0.55 order in ascorbic acid, 0.77 in oxygen partial pressure, and zero in magnesium sulfite concentration, respectively. The apparent activation energy is 88.0 kJ mol{sup ?1}. Integrated with the kinetic model, it is concluded that the oxidation rate of magnesium sulfite inhibited by ascorbic acid is controlled by the intrinsic chemical reaction. The result provides a useful reference for sulfite recovery in magnesia desulfurization.

Lidong, Wang, E-mail: wld@tsinghua.edu.cn [School of Environmental Science and Engineering, North China Electric Power University, Baoding 071003 (China); Department of Environmental Science and Engineering, Tsinghua University, Beijing 100054 (China); Yongliang, Ma, E-mail: liang@tsinghua.edu.cn [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100054 (China); Wendi, Zhang; Qiangwei, Li; Yi, Zhao [School of Environmental Science and Engineering, North China Electric Power University, Baoding 071003 (China); Zhanchao, Zhang [Jinan Environmental Monitoring Center, Jinan 250014 (China)

2013-08-15

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Macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid.  

Science.gov (United States)

Magnesia flue gas desulfurization is a promising process for small to medium scale industrial coal-fired boilers in order to reduce sulfur dioxide emissions, in which oxidation control of magnesium sulfite is of great importance for the recycling of products. Effects of four inhibitors were compared by kinetic experiments indicating that ascorbic acid is the best additive, which retards the oxidation process of magnesium sulfite in trace presence. The macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid were studied. Effects of the factors, including ascorbic acid concentration, magnesium sulfite concentration, oxygen partial pressure, pH, and temperature, were investigated in a stirred reactor with bubbling. The results show that the reaction rate is -0.55 order in ascorbic acid, 0.77 in oxygen partial pressure, and zero in magnesium sulfite concentration, respectively. The apparent activation energy is 88.0 kJ mol(-1). Integrated with the kinetic model, it is concluded that the oxidation rate of magnesium sulfite inhibited by ascorbic acid is controlled by the intrinsic chemical reaction. The result provides a useful reference for sulfite recovery in magnesia desulfurization. PMID:23692683

Lidong, Wang; Yongliang, Ma; Wendi, Zhang; Qiangwei, Li; Yi, Zhao; Zhanchao, Zhang

2013-08-15

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Dopamine requires ascorbic acid to be the prolactin release-inhibiting factor.  

Science.gov (United States)

A high concentration of dopamine (10(-6) mol/l) inhibited prolactin release for prolactin release for a longer period, indicating that the inability of dopamine to sustain an inhibitory action is likely caused by decreased sensitivity of the lactotrophs to dopamine. When 3 x 10(-7) mol/l dopamine was perifused, prolactin release was inhibited for only 15 min, and the rate of prolactin release was decreased to a nadir by addition of ascorbic acid (10(-4) mol/l) 15 min after the start of dopamine perifusion. Dopamine decreased density of dopamine D2 receptors, and ascorbic acid inhibited the receptor downregulation in GH4ZR7 cells. These results support our hypothesis that dopamine requires a supplementary agent to be the prolactin release-inhibiting factor and that the supplementary agent is ascorbic acid. PMID:9316450

Shin, S H; Si, F; Chang, A; Ross, G M

1997-09-01

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Ascorbic acid and melatonin reduce heat-induced performance inhibition and oxidative stress in Japanese quails.  

Science.gov (United States)

1. The effects of ascorbic acid (L-ascorbic acid) and melatonin supplementation on performance, carcase characteristics, malondialdehyde (MDA) as lipid peroxidation indicator, ascorbic acid, retinol, tocopherol and mineral status in the Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature were evaluated. 2. Two hundred and forty Japanese quails (10 d old) were randomly assigned to 8 treatment groups consisting of 10 replicates of three birds each. The birds were kept in a temperature-controlled room at 22 degrees C (Thermoneutral, TN groups) or 34 degrees C (for 8 h/d; 09:00 to 17:00 h; Heat stress, HS groups). Birds in both TN and HS were fed either a basal (control) diet or the basal diet supplemented with 250 mg of L-ascorbic acid/kg of diet (Ascorbic acid group), 40 mg of melatonin/kg of diet (Melatonin group) or both (Ascorbic acid + Melatonin group). 3. Supplementing heat-stressed quails with ascorbic acid and melatonin improved performance compared with the control group. Effects generally were greatest in quails supplemented with both ascorbic acid and melatonin. 4. Although supplementation did not consistently restore the concentrations of serum ascorbic acid, retinol and tocopherol to those of TN groups, these concentrations increased significantly with supplementation. Furthermore, serum and liver MDA and serum cholesterol and glucose concentrations were lower in the supplemented groups than in the heat-stressed controls. 5. Within each environment, excretion of Ca, P, Mg, Zn, Fe and Cr were lowest in the combination group and, in all cases, highest in the HS group. Interactions between diet and temperature were detected for live weight gain, cold carcase weight, MDA, ascorbic acid, tocopherol concentrations and excretion of zinc. 6. The results of the study indicate that ascorbic acid and melatonin supplementation attenuate the decline in performance and antioxidant and mineral status caused by heat stress and such supplementation may offer protection against heat-stress-related depression in performance of Japanese quails. PMID:15115209

Sahin, N; Onderci, M; Sahin, K; Gursu, M F; Smith, M O

2004-02-01

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Ascorbic acid inhibits replication and infectivity of avian RNA tumor virus.  

OpenAIRE

Ascorbic acid, at nontoxic concentrations, causes a substantial reduction in the ability of avian tumor viruses to replicate in both primary avian tendon cells and chicken embryo fibroblasts. The virus-infected cultures appear to be less transformed in the presence of ascorbic acid by the criteria of morphology, reduced glucose uptake, and increased collagen synthesis. The vitamin does not act by altering the susceptibility of the cells to initial infection and transformation, but instead app...

Bissell, M. J.; Hatie, C.; Farson, D. A.; Schwarz, R. I.; Soo, W. J.

1980-01-01

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Ascorbic acid transport into cultured pituitary cells  

International Nuclear Information System (INIS)

An amidating enzyme designated peptidyl-glycine ?-amidating monooxygenase (PAM) has been studied in a variety of tissues and is dependent on molecular oxygen and stimulated by copper and ascorbic acid. To continue investigating the relationship among cellular ascorbic acid concentrations, amidating ability, and PAM activity, the authors studied ascorbic acid transport in three cell preparations that contain PAM and produce amidated peptides: primary cultures of rat anterior and intermediate pituitary and mouse AtT-20 tumor cells. When incubated in 50 ?M [14C]ascorbic acid all three cell preparations concentrated ascorbic acid 20- to 40-fold, producing intracellular ascorbate concentrations of 1 to 2 mM, based on experimentally determined cell volumes. All three cell preparations displayed saturable ascorbic acid uptake with half-maximal initial rates occurring between 9 and 18 ?M ascorbate. Replacing NaCl in the uptake buffer with choline chloride significantly diminished ascorbate uptake in all three preparations. Ascorbic acid efflux from these cells was slow, displaying half-lives of 7 hours. Unlike systems that transport dehydroascorbic acid, the transport system for ascorbic acid in these cells was not inhibited by glucose. Thus, ascorbate is transported into pituitary cells by a sodium-dependent, active transport system

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Ascorbic acid inhibits replication and infectivity of avian RNA tumor virus  

Energy Technology Data Exchange (ETDEWEB)

Ascorbic acid, at nontoxic concentrations, causes a substantial reduction in the ability of avian tumor viruses to replicate in both primary avian tendon cells and chicken embryo fibroblasts. The virus-infected cultures appear to be less transformed in the presence of ascorbic acid by the criteria of morphology, reduced glucose uptake, and increased collagen synthesis. The vitamin does not act by altering the susceptibility of the cells to initial infection and transformation, but instead appears to interfere with the spread of infection through a reduction in virus replication and virus infectivity. The effect is reversible and requires the continuous presence of the vitamin in the culture medium.

BISSELL, MINA J; HATIE, CARROLL; FARSON, DEBORAH A.; SCHWARZ, RICHARD I.; SOO, WHAI-JEN

1980-04-01

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Ascorbic Acid Inhibits Replication and Infectivity of Avian RNA Tumor Virus  

Science.gov (United States)

Ascorbic acid, at nontoxic concentrations, causes a substantial reduction in the ability of avian tumor viruses to replicate in both primary avian tendon cells and chicken embryo fibroblasts. The virus-infected cultures appear to be less transformed in the presence of ascorbic acid by the criteria of morphology, reduced glucose uptake, and increased collagen synthesis. The vitamin does not act by altering the susceptibility of the cells to initial infection and transformation, but instead appears to interfere with the spread of infection through a reduction in virus replication and virus infectivity. The effect is reversible and requires the continuous presence of the vitamin in the culture medium.

Bissell, Mina J.; Hatie, Carroll; Farson, Deborah A.; Schwarz, Richard I.; Soo, Whai-Jen

1980-05-01

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Synergistic interaction between the probucol phenoxyl radical and ascorbic acid in inhibiting the oxidation of low density lipoprotein.  

Science.gov (United States)

Chain-breaking antioxidants such as butylated hydroxytoluene, alpha-tocopherol, and probucol have been shown to decrease markedly the oxidative modification of low density lipoprotein (LDL). Their mechanism of action appears to involve scavenging of LDL-lipid peroxyl radicals. The purpose of this study was to investigate the occurrence of radical reactions produced during oxidation of LDL and LDL-containing probucol initiated by lipoxygenase or copper. In addition, we have investigated the possibility of a synergistic interaction between ascorbate and probucol in inhibiting the oxidation of LDL. Incubation of LDL-containing probucol and lipoxygenase produced a composite electron spin resonance (ESR) spectrum due to the endogenous alpha-tocopheroxyl radical and probucol-derived phenoxyl radical. The spectral assignment was further verified by chemical oxidation of alpha-tocopherol and probucol. In the presence of ascorbic acid, these radicals in the LDL particle were reduced to their parent compounds with concomitant formation of the ascorbate radical. In both the peroxidation of linoleic acid and the copper-initiated peroxidation of LDL, the antioxidant activity of probucol was significantly increased by low (3-6 microM) concentrations of ascorbate. The probucol-dependent inhibition of LDL oxidation was enhanced in the presence of ascorbic acid. We conclude that the reaction between the phenoxyl radical of probucol and ascorbate results in a synergistic enhancement of the antioxidant capacity of these two compounds and speculate that such reactions could play a role in maintaining the antioxidant status of LDL during oxidative stress in vivo. PMID:1313022

Kalyanaraman, B; Darley-Usmar, V M; Wood, J; Joseph, J; Parthasarathy, S

1992-04-01

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Potential Application of Ascorbic Acid, Citric Acid and Oxalic Acid for Browning Inhibition in Fresh-Cut Fruits and Vegetables  

Directory of Open Access Journals (Sweden)

Full Text Available The market for fresh-cut fruits and vegetables has grown rapidly in recent decades as a result of their freshness, convenience, and human health benefits. However, fresh fruits and vegetables deteriorate very rapidly after processing, especially cut-surface browning resulting from wound-induced physiological and biochemical changes. The application of antibrowning agents is one of the most effective methods for controlling the enzymatic browning reaction in fresh-cut fruits and vegetables. This article reviews the use of nature identical antibrowning agents, which are generally recognized as safe (GRAS including ascorbic acid, citric acid and oxalic acid for preventing browning in fresh-cut fruits and vegetables. Factors affecting inhibitory efficiency of the antibrowning agents and synergistic effects of the mixtures in various fresh-cut fruits and vegetables are presented.

Weerayuth SUTTIRAK

2010-01-01

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The role of ascorbic acid in etomidate toxicity.  

Science.gov (United States)

Etomidate, a short-acting hypnotic used in anaesthesia, has been shown to block steroidogenesis in man. The free imidazole radical in etomidate binds to cytochrome P450. Serious side-effects of etomidate have only been observed in guinea-pigs and in man, both species relying for restoration of ascorbic acid pools upon resynthesis and upon the daily dietary intake of vitamin C. It has been shown that ascorbic acid and not ACTH can increase serum cortisol concentration during etomidate infusion. Ascorbic acid even restores the ACTH/cortisol ratio to pre-operative values. It is therefore suggested that etomidate blocks ascorbic acid metabolism. Resynthesis of ascorbic acid cannot occur because of the blockade of cytochrome P450. Depletion of the ascorbic acid pool would then cause inhibition of steroidogenesis. This is the case in man and probably also in the guinea-pig. All other species can synthesize their own ascorbic acid from alpha ketogluconic acid. PMID:3023074

Boidin, M P; Erdmann, W E; Faithfull, N S

1986-09-01

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Inhibition of stimulated ascorbic acid and luteinizing hormone-releasing hormone release by nitric oxide synthase or guanyl cyclase inhibitors.  

Science.gov (United States)

Ascorbic acid (AA), an antioxidant, is present in high concentrations in the hypothalamus. Previously, we have shown that AA inhibited stimulated release of luteinizing hormone-releasing hormone (LHRH) from medial basal hypothalami in vitro. We have also demonstrated that cell membrane depolarization by high [K(+)] media-induced AA release that is blocked by N(G)-mono-methyl-L-arginine, a competitive inhibitor of nitric oxide synthase (NOS), indicating that the release process is mediated by NO. The release of LHRH is also mediated by NO. We hypothesized that AA is a co-transmitter released with classical transmitters from synaptic vesicles that acts to reduce chemically the NO formed, thereby providing feed-forward inhibitory control over LHRH release. Because NO acts by activating guanylyl cyclase (GC) resulting in production of cGMP, in the present investigation we studied the effects of an NOS inhibitor LY 83583 and GC inhibitor, O.D.Q. to further characterize the role of NO in high [K(+)]-induced AA and LHRH release. Medial basal hypothalami were incubated in 0.5 ml of Krebs-Ringer Bicarbonate buffer or medium containing increased potassium [K(+) = 56 mM] for 1 hr or combinations of high [K(+)] + LY 83583 or O.D.Q. for 1 hr. AA and LHRH released into the incubation medium were measured by high-pressure liquid chromatography and radioimmunoassay, respectively. Cell membrane depolarization with high [K(+)] produced a significant increase in both AA and LHRH release. A combination of high [K(+)] + LY 83583 or high [K(+)] + O.D.Q. decreased basal AA and completely blocked high [K(+)]-induced AA and LHRH release. As in the case of high [K(+)], LHRH release induced by the excitatory amino acid N-methyl-D-aspartic acid (NMDA) was blocked by both the inhibitors. NMDA alone failed to alter AA release, but the combined presence of NMDA and the inhibitors totally blocked AA release. Because LY 83583 and O.D.Q. were shown to inhibit NOS and soluble GC, respectively, the data demonstrate that basal and high [K(+)]-induced AA and high [K(+)] and NMDA-stimulated LHRH release were mediated by NO by its activation of GC and consequent generation of cGMP. PMID:14709779

Karanth, Sharada; Yu, Wen H; Mastronardi, Claudio A; McCann, Samuel M

2004-01-01

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Diphenyl diselenide and ascorbic acid changes deposition of selenium and ascorbic acid in liver and brain of mice.  

Science.gov (United States)

Sodium selenite (Na2SeO3) is the selenium form used in the composition of dietary supplements, and diphenyl diselenide (PhSe)2 is an important intermediate in organic synthesis, which increases the risk of human exposure to this chemical in the workplace. These compounds have been reported to inhibit the cerebral and hepatic aminolevulinic acid dehydratase (ALA-D) in vitro, and now we show that ascorbic acid can reverse some alterations caused by in vivo selenium exposure, but not ALA-D inhibition. The effect of Na2SeO3 or (PhSe)2 and ascorbic acid on selenium distribution, total non-protein thiol, ascorbic acid content (liver and brain) and haemoglobin was also examined. Mice were exposed to 250 micromol/kg (PhSe)2, or 18.75 micromol/kg Na2SeO3 subcutaneously, and to ascorbic acid, twice a day, 1 mmol/kg intraperitonially, for 10 days. Hepatic ALA-D of mice treated with (PhSe)2 was inhibited about 58% and similar results were observed in the animals that received ascorbic acid supplementation (P0.10). Ascorbic acid treatment decreased significantly the hepatic and cerebral deposition of Se in (PhSe)2-exposed mice (P<0.01). Hepatic non-protein thiol content was not changed by treatment with (PhSe)2, ascorbic acid or (PhSe)2+ascorbic acid. Hepatic content of ascorbic acid was twice that in mice that received (PhSe)2, independent of ascorbic acid treatment (P<0.001). The results of this study suggest that vitamin C may have a protective role in organodiselenide intoxication. PMID:11245406

Jacques-Silva, M C; Nogueira, C W; Broch, L C; Flores, E M; Rocha, J B

2001-03-01

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Ascorbic Acid and Methylene Blue  

Science.gov (United States)

The WebWare molecules of the month for May are featured in several articles in this issue. "Arsenic: Not So Evil After All?" discusses the pharmaceutical uses of methylene blue and its development as the first synthetic drug used against a specific disease. The JCE Classroom Activity "Out of the Blue" and the article "Greening the Blue Bottle" feature methylene blue and ascorbic acid as two key ingredients in the formulation of the blue bottle. You can also see a colorful example of these two molecules in action on the cover. "Sailing on the 'C': A Vitamin Titration with a Twist" describes an experiment to determine the vitamin C (ascorbic acid) content of citrus fruits and challenges students, as eighteenth-century sea captains, to decide the best fruit to take on a long voyage.

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Dopamine receptors in rat brain regions. Optimal conditions for 3H-agonist binding, pH dependency and lack of inhibition by ascorbic acid.  

Science.gov (United States)

The binding of dopaminergic agonist and antagonist radioligands was investigated in rat brain regions. A 30-min preincubation of homogenates of caudate nucleus or mesolimbic brain regions at 37 degrees induced a several-fold increase in the stereospecific binding of [3H]-dopamine or [3H]apomorphine to the subsequently washed particulate fraction, whereas it induced a slight decrease in [3H]spiroperidol binding. Stereospecific 3H-agonist binding was not observed in brain regions devoid of dopaminergic innervation. Guanosyl nucleotides, EDTA or ethyleneglycol-bis-(beta-amino-ethyl ether) N,N'-tetraacetate (EGTA), included in the preincubation buffer, antagonized the stimulation of 3H-agonist binding. The stereospecific binding sites of 3H-agonists were saturable with equilibrium dissociation constants (Kd) of 1-2 nM. High-affinity binding was pH dependent, with different pH optima for each radioligand. Several dopamine receptor agonists and antagonists were potent inhibitors of stereospecific [3H]dopamine binding, whereas l-ascorbic acid was inactive at concentrations as high as 1.0 mM. The stereospecific binding of [3H]apomorphine or [3H]spiroperidol was also unaffected by ascorbic acid. The nonspecific (d-butaclamol-insensitive) portion of 3H-agonist binding was weakly inhibited by concentrations of ascorbic acid higher than 0.01 mM. This effect was also observed in the cerebellum and spinal cord, where none of the 3H-agonist binding was stereospecific. It is concluded that the portion of 3H-agonist or 3H-antagonist radioligand binding which is related to dopamine receptors is unaffected by ascorbic acid. PMID:7150335

Bacopoulos, N G

1982-10-01

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Ascorbic acid: effects on ricin intoxicated HeLa cells  

International Nuclear Information System (INIS)

A study of ricin was made to acertain if ascorbic acid had a specific effect on diphteria toxin or could it prevent the action of toxins from various sources with an activity different than that of diphteria. Ricin was isolated by suspending the defatted meal in double distilled water and adjusting to pH 3.8. The suspension was filtered, the precipitate collected and again dissolved in double distilled water. After saturation with ammonium sulfate, precipitate was collected by centrifugation. The concentration of ricin needed to inhibit at least 50% of the incorporation of (14C) alanine into trichloroacetic acid (TCA) precipitable material was determined. HeLa cells are protected by using ascorbic acid. Ascorbic acid or citric acid was added to the medium 30 min prior to the addition of toxic protein. The isolated ricin prevented the incorporation of (14C) alanine into TCA precipitate material in HeLa cells at levels of 11.5 to 0.00115 microgram of the toxin per ml of culture media. The addition of 100 microgram of ascorbic acid to the HeLa cell cultures 30 min prior to the addition of ricin completely prevented the inhibition of protein synthesis by ricin. Lesser amounts of ascorbic acid offered less protection. Although these data do not elucidate the mechanism of action of ascorbic acid, they show that in vitro ascorbic acid can prevent the action of this poisonous toxin. The data support the use of pharmacological doses of ascorbic acid in tharmacological doses of ascorbic acid in the treatment of various cases of poisoning. (Iwakiri, K.)

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Ascorbic acid modulates pathogenecity markers of Candida albicans  

Directory of Open Access Journals (Sweden)

Full Text Available Candida albicans is an opportunistic commensal of the human gastrointestinal tract and vaginalmucosa, causing opportunistic fungal infections in an immunocompromised patient. In the present study wehave investigated the effect of ascorbic acid on growth and its several pathogenicity markers. Turbidometricmeasurement for growth; proteinase assay, WST-1 cell cytotoxicity assay, colony count method andinverted microscopy were performed to check pathogenecity markers of C. albicans ATCC 10261 strain. 150mg/ml concentration of ascorbic acid arrests cell growth. It was observed that higher ascorbate level of 250mg/ml reduces proteinase secretion (an important mechanism suggestive of virulence in Candida exhibitedby mean precipitation zone value of 2.375 which is remarkably less than that of Control cells (value 4.125.At higher concentration of ascorbic acid increases cell cytotoxcity (79.71 percent inhibition at 150 mg/mland decreases percent viability under oxidative stress (98 percent reduction at 250 mg/ml concentration.Transition studies showed cessation of germ tube induction and hyphae formation at lower concentrations(15 mg onwards of ascorbic acid. Results indicate that higher ascorbic acid level somehow decreasespathogenic attribute of Candida albicans, while yeast to hyphal studies show an exception, were lowerconcentration was effective in inhibiting hyphae formation. Thus ascorbic acid exhibits its pro-oxidant naturein present in-vitro studies.

Ojha R.

2009-06-01

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Ascorbic acid improves the antioxidant activity of European grape juices by improving the juices' ability to inhibit lipid peroxidation of human LDL in vitro  

DEFF Research Database (Denmark)

Antioxidant activities of red and white European grape juices towards copper induced lipid oxidation of human low-density lipoproteins (LDL) were examined in vitro. LDL lipid peroxidation was assessed spectrophotometrically by monitoring the development of conjugated lipid hydroperoxides at 234 nm. Red grape juice concentrate inhibited lipid peroxidation of LDL by prolonging the lag phase by 2.7 times relative to a control when evaluated at a total phenolic concentration of 10 muM gallic acid equivalents (GAE). Both red grape juices tested blocked lipid peroxidation of LDL at 20 muM GAE. White grape juice exerted prooxidant activity at 5-20 muM GAE. The antioxidant activity, inhibition of lipid peroxidation of LDL in vitro, was correlated with the juices' levels of total phenols (r > 0.98, P 0.99, P 0.97 P 0.96, P <0.05) when the phenolic composition of each grape juices was analysed by HPLC. 5 M ascorbic acid alone did not exert antioxidant activity towards LDL, but combinations of 5 muM ascorbic acid with 5 muM GAE juice phenols eliminated the prooxidant activity of white grape juice, and significantly improved the antioxidant activities of red grape juices.

Landbo, Anne-Katrine Regel; Meyer, Anne Boye Strunge

2001-01-01

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21 CFR 172.315 - Nicotinamide-ascorbic acid complex.  

Science.gov (United States)

...2009-04-01 true Nicotinamide-ascorbic acid complex. 172.315 Section 172.315 Food and... § 172.315 Nicotinamide-ascorbic acid complex. Nicotinamide-ascorbic acid complex may be safely used in accordance with the...

2010-04-01

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Final report of the safety assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate as used in cosmetics.  

Science.gov (United States)

L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate function in cosmetic formulations primarily as antioxidants. Ascorbic Acid is commonly called Vitamin C. Ascorbic Acid is used as an antioxidant and pH adjuster in a large variety of cosmetic formulations, over 3/4 of which were hair dyes and colors at concentrations between 0.3% and 0.6%. For other uses, the reported concentrations were either very low (Calcium Ascorbate and Magnesium Ascorbate are described as antioxidants and skin conditioning agents--miscellaneous for use in cosmetics, but are not currently used. Sodium Ascorbyl Phosphate functions as an antioxidant in cosmetic products and is used at concentrations ranging from 0.01% to 3%. Magnesium Ascorbyl Phosphate functions as an antioxidant in cosmetics and was reported being used at concentrations from 0.001% to 3%. Sodium Ascorbate also functions as an antioxidant in cosmetics at concentrations from 0.0003% to 0.3%. Related ingredients (Ascorbyl Palmitate, Ascorbyl Dipalmitate, Ascorbyl Stearate, Erythorbic Acid, and Sodium Erythorbate) have been previously reviewed by the Cosmetic Ingredient Review (CIR) Expert Panel and found "to be safe for use as cosmetic ingredients in the present practices of good use." Ascorbic Acid is a generally recognized as safe (GRAS) substance for use as a chemical preservative in foods and as a nutrient and/or dietary supplement. Calcium Ascorbate and Sodium Ascorbate are listed as GRAS substances for use as chemical preservatives. L-Ascorbic Acid is readily and reversibly oxidized to L-dehydroascorbic acid and both forms exist in equilibrium in the body. Permeation rates of Ascorbic Acid through whole and stripped mouse skin were 3.43 +/- 0.74 microg/cm(2)/h and 33.2 +/- 5.2 microg/cm(2)/h. Acute oral and parenteral studies in mice, rats, rabbits, guinea pigs, dogs, and cats demonstrated little toxicity. Ascorbic Acid and Sodium Ascorbate acted as a nitrosation inhibitor in several food and cosmetic product studies. No compound-related clinical signs or gross or microscopic pathological effects were observed in either mice, rats, or guinea pigs in short-term studies. Male guinea pigs fed a control basal diet and given up to 250 mg Ascorbic Acid orally for 20 weeks had similar hemoglobin, blood glucose, serum iron, liver iron, and liver glycogen levels compared to control values. Male and female F344/N rats and B6C3F(1) mice were fed diets containing up to 100,000 ppm Ascorbic Acid for 13 weeks with little toxicity. Chronic Ascorbic Acid feeding studies showed toxic effects at dosages above 25 mg/kg body weight (bw) in rats and guinea pigs. Groups of male and female rats given daily doses up to 2000 mg/kg bw Ascorbic Acid for 2 years had no macro- or microscopically detectable toxic lesions. Mice given Ascorbic Acid subcutaneous and intravenous daily doses (500 to 1000 mg/kg bw) for 7 days had no changes in appetite, weight gain, and general behavior; and histological examination of various organs showed no changes. Ascorbic Acid was a photoprotectant when applied to mice and pig skin before exposure to ultraviolet (UV) radiation. The inhibition of UV-induced suppression of contact hypersensitivity was also noted. Magnesium Ascorbyl Phosphate administration immediately after exposure in hairless mice significantly delayed skin tumor formation and hyperplasia induced by chronic exposure to UV radiation. Pregnant mice and rats were given daily oral doses of Ascorbic Acid up to 1000 mg/kg bw with no indications of adult-toxic, teratogenic, or fetotoxic effects. Ascorbic Acid and Sodium Ascorbate were not genotoxic in several bacterial and mammalian test systems, consistent with the antioxidant properties of these chemicals. In the presence of certain enzyme systems or metal ions, evidence of genotoxicity was seen. The National Toxicology Program (NTP) conducted a 2-year oral carcinogenesis bioassay of Ascorbic Acid (25,000 and 50,000 ppm) in F344/N ra

Elmore, Amy R

2005-01-01

22

Inhibition of melatonin-induced ascorbic acid and LHRH release by a nitric oxide synthase and cyclic GMP inhibitor.  

Science.gov (United States)

Melatonin (MEL), the principle secretory product of the pineal gland, has been shown to function as an antioxidant and free-radical scavenger. We previously showed that the release of ascorbic acid (AA) and luteinizing hormone releasing hormone (LHRH) from medial basal hypothalamus (MBH) was mediated by nitric oxide (NO) that released cyclic guanosine 3'5'-mono-phosphate (cGMP). Therefore, it was of interest to evaluate the effect of MEL on AA and LHRH release and study the effect of a nitric oxide synthase (NOS) inhibitor, 6-anilino-5,8-quinoline-dione (LY 83583), and a guanylyl cyclase (GC) inhibitor, 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (O.D.Q.), on the release process. Because NO has been shown to activate soluble guanylyl cyclase that elicited an elevation of cGMP in target cells, in the current investigation LY 83583, O.D.Q., or N(G)-monomethyl-l-arginine (NMMA), a competitive inhibitor of NOS, were used to evaluate their effects on MEL-induced AA and LHRH release. Medial basal hypothalami were incubated in 0.5 ml of Krebs-Ringer bicarbonate (KRB) buffer for 1 hr. Subsequently, the tissues were incubated with graded concentrations of MEL (10(-8) to 10(-4) M), MEL + NMMA (3 x 10(-4) M), MEL + LY 83583 (10(-6) M), or MEL + O.D.Q. (10(-5) M) for 1 hr. Ascorbic acid and LHRH released into the medium were measured by high-performance liquid chromatography (HPLC) and radio-immunoassay (RIA), respectively. Melatonin (10(-6) and 10(-5) M) significantly stimulated both AA and LHRH release, but the lower and the highest concentrations were ineffective. A combination of MEL + NMMA completely blocked both AA and LHRH release, supporting a role for NO in the releasing action. Both LY 83583 and O.D.Q. significantly suppressed MEL-induced AA and LHRH release, emphasizing the role of NOS, GC, and cGMP in mediating the action of MEL. The data of these in vitro experiments support a role for MEL in the hypothalamic control of AA and LHRH release. PMID:15229359

Karanth, Sharada; Yu, Wen H; Mastronardi, Claudio A; McCann, Samuel M

2004-07-01

23

Regulation of collagen synthesis by ascorbic acid: characterization of the role of ascorbate-stimulated lipid peroxidation.  

Science.gov (United States)

Recently, we have described the ability of traditional lipid peroxidation inhibitors to inhibit ascorbate-stimulated collagen synthesis. In order to characterize further this effect, we have tested the ability of known and potential inhibitors of lipid peroxidation for their effects on ascorbate-stimulated collagen synthesis and lipid peroxidation. In our experiments, mannitol, a water soluble antioxidant, had no effect on ascorbate-induced collagen synthesis nor on lipid peroxidation. However, alpha-tocopherol, which is a lipophilic antioxidant, inhibited both effects of ascorbate. Superoxide dismutase, catalase, and their polyethylene glycol conjugate forms did not inhibit the ascorbate-stimulated collagen synthesis or lipid peroxidation. In addition, no effect was seen with the oxygen radical scavengers isopropanol, ethanol, or dimethyl sulfoxide. Two iron chelators, o-phenanthroline and alpha,alpha-dipyridyl, both inhibited ascorbate-induced lipid peroxidation and collagen synthesis, consistent with the previously described iron-dependence of lipid peroxidation by ascorbate. These results support a correlation between collagen synthesis and lipid peroxidation and provide a theory for the mechanism of ascorbic acid regulation of collagen synthesis. PMID:1898082

Geesin, J C; Hendricks, L J; Falkenstein, P A; Gordon, J S; Berg, R A

1991-10-01

24

Ascorbic acid modulation of calcium channels in pancreatic beta cells  

OpenAIRE

We have studied the effect of ascorbic acid on voltage-dependent calcium channels in pancreatic beta cells. Using the whole-cell and perforated-patch variants of the patch clamp technique to record calcium tail currents, we have shown that the slowly deactivating (SD) calcium channel, which is similar to the T-type channel in other cells, is inhibited in a voltage-dependent manner by ascorbic acid (AA). The other channels that carry inward current in beta cells, FD calcium channels and sodium...

1993-01-01

25

Ascorbic acid absorption in Crohn's disease. Studies using L-[carboxyl-14C]ascorbic acid  

International Nuclear Information System (INIS)

Total body pool and intestinal absorption of ascorbic acid were studied in 12 patients undergoing operation for Crohn's disease (six with fistulae and six without) and in six control patients undergoing operation for reasons other than Crohn's disease. L-[carboxyl-14C]Ascorbic acid, 0.19-0.40 megabecquerels (MBq), was given orally. After a period of equilibration, the labeled ascorbic acid was flushed out of the patient's body tissues using large doses of unlabeled ascorbic acid. Intestinal absorption of ascorbic acid, assessed from the total cumulative urinary 14C recovery, was found to be similar in patients with fistulizing Crohn's disease (73.9 +/- 8.45%), those without fistulas (72.8 +/- 11.53%), and in controls (80.3 +/- 8.11%). Total body pools of ascorbic acid, calculated using the plasma 14C decay curves, were similar in patients with Crohn's disease with fistulas (17.1 +/- 5.91 mg/kg), patients without fistulas (9.6 +/- 3.58 mg/kg), and in controls (13.3 +/- 4.28 mg/kg). The results indicate that ascorbic acid absorption is normal in patients with both fistulizing and nonfistulizing Crohn's disease. The results suggest that routine supplements of vitamin C are not necessary unless oral ascorbic acid intake is low

26

Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats  

DEFF Research Database (Denmark)

Several amidated biologically active peptides such as pancreastatin, thyrotropin-releasing hormone, pancreatic polypeptide and amylin are produced in endocrine pancreatic tissue which contains the enzyme necessary for their final processing, i.e. peptidylglycine alpha-amidating mono-oxygenase (EC 1.14.17.3). The enzyme needs ascorbic acid for activity as well as copper and molecular oxygen. The present work shows that pancreatic islet cells prepared from overnight cultures of isolated islets from 5-7-day-old rats accumulate 14C-labelled ascorbic acid by a Na(+)-dependent active transport mechanism which involves a saturable process (estimated Km 17.6 microM). Transport was inhibited by ouabain, phloridzin, cytochalasin B, amiloride and probenecid. Glucose inhibited or stimulated uptake, depending on the length of incubation time of the cells. The uptake of dehydroascorbic acid was linearly dependent on concentration. Dehydroascorbic acid was converted to ascorbic acid by an unknown mechanism after uptake. Theuptake of both ascorbic acid and dehydroascorbic acid was inhibited by tri-iodothyronine, and uptake of ascorbic acid, but not of dehydroascorbic acid, was inhibited by glucocorticoids. Isolated secretory granules contained a fairly low concentration of iron but a high concentration of copper.

Zhou, A; Farver, O

1991-01-01

27

Featured Molecules: Ascorbic Acid and Methylene Blue  

Science.gov (United States)

The WebWare molecules of the month for May are featured in several articles in this issue. "Arsenic: Not So Evil After All?" discusses the pharmaceutical uses of methylene blue and its development as the first synthetic drug used against a specific disease. The JCE Classroom Activity "Out of the Blue" and the article "Greening the Blue Bottle" feature methylene blue and ascorbic acid as two key ingredients in the formulation of the blue bottle. You can also see a colorful example of these two molecules in action on the cover. "Sailing on the 'C': A Vitamin Titration with a Twist" describes an experiment to determine the vitamin C (ascorbic acid) content of citrus fruits and challenges students, as eighteenth-century sea captains, to decide the best fruit to take on a long voyage. Fully manipulable (Chime) versions of these and other molecules are available at Only@JCE Online.

Coleman, William F.; Wildman, Randall J.

2003-05-01

28

Regulation of ascorbic acid synthesis in plants  

OpenAIRE

Ascorbic acid (AsA) is a major antioxidant and plays an important role in plant growth and development. There are two aspects to improve AsA content, including de novo synthesis and recycling from its oxidized form. However, the knowledge of regulatory mechanisms of AsA synthesis pathways and metabolism still remains limited. We have determined that AsA synthesis process was modulated on both transcriptional and post-transcriptional levels in Arabidopsis. GDP-mannose pyrophosphorylase (VTC1) ...

Wang, Juan; Zhang, Zhijin; Huang, Rongfeng

2013-01-01

29

Meloidogyne incognita and Tomato Response to Thiamine, Ascorbic Acid, L-arginine, and L-glutamic Acid  

OpenAIRE

The influence of solutions of ascorbic acid, thiamine, L-arginine, and L-gtutamic acid on egg hatch, juvenile survival, and development and reproduction of Meloidogyne incognita in susceptible and resistant tomatoes was studied. Maximum inhibition of egg hatch occurred at 2,000, 4,000, and 2,000 ppm for ascorbic acid, L-arginine, and L-glutamic acid, respectively. Larval survival was significantly reduced by concentrations of 2,000 ppm ascorbic acid and 1,000 ppm of L-arginine. Maximum inhibi...

Al-sayed, A. A.; Thomason, I. J.

1988-01-01

30

The influence of ascorbic acid on the oxygen consumption and the heat production by the cells of wheat seedling roots with their mitochondrial electron transport chain inhibited at complexes I and III  

International Nuclear Information System (INIS)

The influence of exogenous ascorbic acid (AsA) on oxidative phosphorylation was studied using wheat seedling roots. Treatment of them with AsA stimulated the rates of oxygen consumption and the heat production and caused a decrease of the respiratory coefficient. The increase in respiration was prevented by inhibitors of ascorbate oxidase, diethyldithiocarbamate (DEDTC), and of cytochrome oxidase, cyanide (KCN). Exogenous AsA sharply stimulated the rate of oxygen consumption of roots when complexes I and III of the mitochondrial electron transport chain were inhibited by rotenone and antimycin A, respectively, while the rates of heat production did not change significantly. It is concluded that AsA is a potent energy substrate, which can be used in conditions of failing I and III complexes in the mitochondrial electron transport chain

31

The influence of ascorbic acid on the oxygen consumption and the heat production by the cells of wheat seedling roots with their mitochondrial electron transport chain inhibited at complexes I and III  

Energy Technology Data Exchange (ETDEWEB)

The influence of exogenous ascorbic acid (AsA) on oxidative phosphorylation was studied using wheat seedling roots. Treatment of them with AsA stimulated the rates of oxygen consumption and the heat production and caused a decrease of the respiratory coefficient. The increase in respiration was prevented by inhibitors of ascorbate oxidase, diethyldithiocarbamate (DEDTC), and of cytochrome oxidase, cyanide (KCN). Exogenous AsA sharply stimulated the rate of oxygen consumption of roots when complexes I and III of the mitochondrial electron transport chain were inhibited by rotenone and antimycin A, respectively, while the rates of heat production did not change significantly. It is concluded that AsA is a potent energy substrate, which can be used in conditions of failing I and III complexes in the mitochondrial electron transport chain.

Gordon, L.K. [Kazan Institute of Biochemistry and Biophysics, Kazan Science Center of Russian Academy of Sciences, Kazan (Russian Federation); Rakhmatullina, D.F. [Kazan Institute of Biochemistry and Biophysics, Kazan Science Center of Russian Academy of Sciences, Kazan (Russian Federation); Ogorodnikova, T.I. [Kazan Institute of Biochemistry and Biophysics, Kazan Science Center of Russian Academy of Sciences, Kazan (Russian Federation); Alyabyev, A.J. [Kazan Institute of Biochemistry and Biophysics, Kazan Science Center of Russian Academy of Sciences, Kazan (Russian Federation)]. E-mail: alyabyev@mail.knc.ru; Minibayeva, F.V. [Kazan Institute of Biochemistry and Biophysics, Kazan Science Center of Russian Academy of Sciences, Kazan (Russian Federation); Loseva, N.L. [Kazan Institute of Biochemistry and Biophysics, Kazan Science Center of Russian Academy of Sciences, Kazan (Russian Federation); Mityashina, S.Y. [Kazan Institute of Biochemistry and Biophysics, Kazan Science Center of Russian Academy of Sciences, Kazan (Russian Federation)

2007-06-25

32

Evaluation of ascorbic acid in protecting labile folic acid derivatives.  

OpenAIRE

The use of ascorbic acid as a reducing agent to protect labile, reduced derivatives of folic acid has been evaluated by high-performance liquid chromatographic separations and Lactobacillus casei microbiological assay of eluate fractions. Upon heating for 10 min at 100 degrees C, solutions of tetrahydropteroylglutamic acid (H4PteGlu) in 2% sodium ascorbate gave rise to 5,10-methylene-H4PteGlu and 5-methyl-H4PteGlu. H2PteGlu acid gave rise to 5-methyl-H4PteGlu and PteGlu. 10-Formyl-H4PteGlu ga...

1983-01-01

33

Hepatoprotective Effect of Vitamin C (Ascorbic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Human and animal studies have shown that some drugs and chemical agents have potential hepatotoxic effects. The hepatotoxic effect of drugs and some chemical agents is reported to be associated with the generation of reactive oxygen species (ROS. These ROS are reported to be associated with lipid peroxidation in the liver. This mechanism has led to continuous evaluation of the hepatoprotective effect of antioxidants in humans and animals. Among the antioxidants been evaluated is vitamin C which is a water soluble antioxidant. Reports have linked vitamin C with hepatoprotective property in animals and humans. It synergistic hepatoprotective effect with other antioxidants was also reported. Due to these reports a comprehensive literature review on the hepatoprotective property of vitamin C in humans and animals was performed. It was observed that vitamin C exhibited a reputable hepatoprotective effect in humans and animals. Research showed that vitamin C inhibited hepatotoxicity induced by drugs, heavy metals, organophosphate insecticides and some chemical agents. Vitamin C was reported to normalized levels of serum alanine aminotransferase, aspartate aminotransferase, gamma glutamine, alkaline phosphatase, lactate dehydrogenase and malondialdehyde and serum bilirubin in intoxicated animals. It potentiates the activities of free radical scavengers, superoxide dimutase, and catalase glutathione peroxidase thereby preventing microsomal lipid peroxidation, liver fibrosis, liver necrosis and hepatic inflammation. In humans vitamin C was reported to be beneficial in non alcoholic steatohepatitis and in patients with fatty liver disease. Hepatoprotective property of vitamin C is attributed to it antioxidant property. Vitamin C (ascorbic acid which is a major water-soluble antioxidant is believed to decrease lipid peroxidation either directly or indirectly by regenerating vitamin E. Vitamin C is an important free radical scavenger in extracellular fluids, trapping radicals and protecting biomembranes from peroxide damage. Vitamin C effectively scavenges singlet oxygen, superoxide, hydroxyl, water soluble peroxyl radical and hypochlorous acid. It is also reported to be an excellent source of electrons and therefore can donate electrons to free radicals such as hydroxyl and super oxide radicals and quench their activity. Vitamin C is an essential co-factor involved in many biochemical functions and acts as an electron donor or reducing agent. In this review it is observe that vitamin C has hepatoprotective effect which increases when co administered with other agents precisely antioxidants.

Oputiri Deo

2013-01-01

34

Ascorbate inhibition of angiogenesis in aortic rings ex vivo and subcutaneous Matrigel plugs in vivo  

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Full Text Available Abstract Background Angiogenesis is critical to tumor growth and is therefore a potential target for cancer therapy. As many current inhibitors of angiogenesis exhibit host toxicity, natural alternatives are needed. At millimolar concentrations, ascorbate (vitamin C inhibits migration and tubule formation by mature endothelial cells and endothelial progenitors. In the present study, we examined the effects of ascorbate, at levels relevant during intravenous infusion therapy, on angiogenesis using an ex vivo an in vivo assay. Methods Two assays were used to evaluate effect of high-doses ascorbic acid on angiogenesis: ex vivo rat aortic ring explant assay in Matrigel matrices and in vivo Matrigel plug assay. In aortic rings, we quantified microvessel growth, branching and vessel regression under different treatment conditions. In murine angiogenesis assay, male C57 mice 6-8 weeks old were treated by high-dose ascorbic acid and the number of microvessels was analyzed by histological method. To characterize the population of cells that formed capillary network and microvessels, the sections were stained by CD34 and CD31 antibodies. Results Results show that sprouting of endothelial tubules from aortic rings was reduced in a concentration-dependent fashion by ascorbate: while controls roughly tripled sprout densities during the study, ascorbate (1 mg/mL, 5.5 mM actually reduced sprout density. In vivo, the ability of mice to vascularize subcutaneously implanted Matrigel plug was diminished if the mice were treated with 430 mg/kg vitamin C: numbers of vessels, and vessel densities, in plugs from treated mice were roughly 30% less than those in plugs from untreated mice. Conclusions We conclude that the inhibition of angiogenesis by ascorbate suggested in vitro is confirmed in vivo, and that angiogenesis inhibition may be one mechanism by which intravenous ascorbate therapy shows efficacy in animal experiments and clinical case studies.

Casciari Joseph J

2010-01-01

35

Ascorbic Acid in the Nutrition of Plant-Feeding Insects.  

Science.gov (United States)

Bollworms, Heliothis zea (Boddie), and salt-marsh caterpillars, Estigmene acrea (Drury) gradually decreased in ascorbic acid content as they matured, even in its presence. Cotton leafworms, Alabama argillacea (Hübner), also lost ascorbic acid, although a dietary need for the vitamin was not proved. Pink bollworms, Pectinophora gossypiella (Saunders), reared without the vitamin, increased in ascorbic acid content as they matured, an indication that the vitamin was synthesized by the insect. PMID:17836487

Vanderzant, E S; Richardson, C D

1963-05-31

36

Ascorbic acid-induced regression of amyloidosis in experimental animals.  

OpenAIRE

Ascorbic acid was found to accelerate amyloid degradation in an experimental animal model. Based on experiments in vitro which demonstrated the ability of ascorbic acid to restore the amyloid-degrading activity of amyloidotic human serum, the effect of orally administered ascorbic acid was tested in casein-induced murine amyloidosis. Histopathological examination of splenic tissue of mice killed at different times after the termination of the amyloidogenic stimulus showed a markedly decreased...

Ravid, M.; Chen, B.; Bernheim, J.; Kedar, I.

1985-01-01

37

21 CFR 862.1095 - Ascorbic acid test system.  

Science.gov (United States)

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1095 Ascorbic acid test system. (a)...

2010-04-01

38

Measuring the Amount of Ascorbic Acid in Cabbage  

Science.gov (United States)

Ascorbic acid may be easily extracted from plant tissue by grinding the tissue in a mortar and estle with 5% metaphosphoric acid. The amount of ascorbic acid present may be determined by titration with a reducible dye, dichlorophenol-indophenol (DCIP).

Carol Reiss (Cornell University;)

1993-01-01

39

Fate of the synergistic antioxidant system ascorbic acid, lecithin, and tocopherol in mayonnaise : Partition of ascorbic acid  

DEFF Research Database (Denmark)

The distribution of ascorbic acid between the lipid and aqueous phase was investigated in mayonnaises enriched with fish oil containing a synergistic antioxidant mixture of ascorbic acid, lecithin and gamma-tocopherol, i.e., the A/L/T system (Loliger and Saucy 1989). The ascorbic acid was found to be located in the aqueous phase indicating that the A/L/T system broke down in mayonnaises. Based on the hypothesis that synergistic antioxidant action between ascorbic acid, lecithin and tocopherol requires that the three components are in close assembly, the results offer an explanation as to why the A/L/T system does not function antioxidatively in mayonnaises.

Meyer, Anne S.; Jacobsen, Charlotte

1996-01-01

40

Ascorbic acid study in citrus juice: effect of preservative  

International Nuclear Information System (INIS)

This paper reports the effect of preservative on ascorbic acid extracted from freshly plucked oranges. Colorimetric method was used for the determination of ascorbic. Determination of some inorganic elements like sodium, potassium and lithium were also determined by flame photometry. The preservative was found to have a beneficial effect on the retention of ascorbic acid, particularly when used in high concentration. Metal content, particularly potassium did no alter significantly during preservation for duration of one month. (author)

41

Ascorbic acid monoglucoside as antioxidant and radioprotector  

International Nuclear Information System (INIS)

Ascorbic acid monoglucoside (AsAG), a glucoside derivative of ascorbic acid, has been examined for its antioxidant and radioprotective abilities. AsAG neutralized 1, 1 diphenyl -2-picryl-hydrazyl (DPPH), a stable free radical in a concentration dependent manner thus indicating its antioxidant ability. AsAG protected mice liver tissues in vitro from peroxidative damage in lipids (measured as TBARS) resulting from 25Gy ? irradiation. It also protected plasmid pBR322 DNA from gamma-radiation induced strand breaks as evidenced from studies on agarose gel electrophoresis of the plasmid DNA after radiation exposure. Oral administration of AsAG to mice prior to whole body gamma radiation exposure (4Gy) resulted in a reduction of radiation induced lipid peroxides in the liver tissue indicating in vivo radiation protection of membranes. Pulse radiolysis studies indicated that AsAG offered radioprotection by scavenging free radicals. The rate constants for the reactions OH and N3 radicals with AsAG were determined to be 6.4 x 109 dm3 mol-1 s-1 and 2.3 x 109 dm3 mol-1 s-1, respectively at pH 7. It was observed that AsAG radicals undergo conjugation as the pH of the solution is raised to 11 in the case of a one-electron oxidation reaction. As the OH· radical adds to the ring, the conjugation effect starts appearing at pH 10. (author)or)

42

Development of a new ascorbic acid sensor  

Directory of Open Access Journals (Sweden)

Full Text Available The SiO2/SnO2/Phosphate composite, SSF, was prepared by the sol-gel process. The redox dye methylene blue was immobilized on the SSF surface. This new material was utilized in the preparation of a modified carbon paste electrode (SSFAM and its electrochemical characteristics were studied by the cyclic voltammetry technique. The SSFAM sensor presented a formal potential of -90 mV vs SCE, excellent stability regarding the number of cycles and regarding the pH of electrolyte support solution ranging from 2.0 to 8.0. The SSFAM sensor was utilized for the determination of ascorbic acid (Vitamin C, utilizing the chronoamperometry technique, and presented a response time of 1.5 s, a linear response range between 2.0 x 10-4 and 3.0 x 10-3 mol L-1, with a detection limit of 7.8 x 10-6 mol L-1, considering a relation signal/noise = 3. The results obtained for real samples by the SSFAM sensor were compared with those from the standard method for determination of ascorbic acid by the 2,6-dichlorophenilindophenol. The comparison of the obtained results by the two methods demonstrated that the SSFAM sensor has great utilization potential.

Antonio Alberto da Silva Alfaya

2006-02-01

43

Ascorbic acid enables reversible dopamine receptor 3H-agonist binding  

International Nuclear Information System (INIS)

The effects of ascorbic acid on dopaminergic 3H-agonist receptor binding were studied in membrane homogenates of bovine anterior pituitary and caudate, and rat striatum. In all tissues virtually no stereospecific binding (defined using 1uM (+)butaclamol) of the 3H-agonists N-propylnorapomorphine (NPA), apomorphine, or dopamine could be demonstrated in the absence of ascorbic acid. Although levels of total 3H-agonist binding were three to five times greater in the absence than in the presence of 0.1% ascorbic acid, the increased binding was entirely non-stereospecific. Greater amounts of dopamine-inhibitable 3H-NPA binding could be demonstrated in the absence of 0.1% ascorbic acid, but this measure of ''specific binding'' was demonstrated not to represent dopamine receptor binding since several other catecholamines and catechol were equipotent with dopamine and more potent than the dopamine agonist (+/-)amino-6,7-dihydroxy-1,2,3,4-tetrahydronapthalene (ADTN) in inhibiting this binding. High levels of dopamine-displaceable 3H-agonist binding were detected in fresh and boiled homogenates of cerebellum, an area of brain which receives no dopaminergic innervation, further demonstrating the non-specific nature of 3H-agonist binding in the absence of ascorbic acid. These studies emphasize that under typical assay conditions ascorbic acid is required in order to demonstrate reversible and specific 3Hrate reversible and specific 3H-agonist binding to dopamine receptors

44

Dietary phenolic acids and ascorbic acid: Influence on acid-catalyzed nitrosative chemistry in the presence and absence of lipids.  

Science.gov (United States)

Acid-catalyzed nitrosation and production of potentially carcinogenic nitrosative species is focused at the gastroesophageal junction, where salivary nitrite, derived from dietary nitrate, encounters the gastric juice. Ascorbic acid provides protection by converting nitrosative species to nitric oxide (NO). However, NO may diffuse into adjacent lipid, where it reacts with O(2) to re-form nitrosative species and N-nitrosocompounds (NOC). In this way, ascorbic acid promotes acid nitrosation. Using a novel benchtop model representing the gastroesophageal junction, this study aimed to clarify the action of a range of water-soluble antioxidants on the nitrosative mechanisms in the presence or absence of lipids. Caffeic, ferulic, gallic, or chlorogenic and ascorbic acids were added individually to simulated gastric juice containing secondary amines, with or without lipid. NO and O(2) levels were monitored by electrochemical detection. NOC were measured in both aqueous and lipid phases by gas chromatography-tandem mass spectrometry. In the absence of lipids, all antioxidants tested inhibited nitrosation, ranging from 35.9 + or - 7.4% with gallic acid to 93 + or - 0.6% with ferulic acid. In the presence of lipids, the impact of each antioxidant on nitrosation was inversely correlated with the levels of NO they generated (R(2) = 0.95, p<0.01): gallic, chlorogenic, and ascorbic acid promoted nitrosation, whereas ferulic and caffeic acids markedly inhibited nitrosation. PMID:20026204

Combet, Emilie; El Mesmari, Aziza; Preston, Tom; Crozier, Alan; McColl, Kenneth E L

2010-03-15

45

Simultaneous Measurement of Dopamine and Ascorbic Acid at Cnt Electrode  

Science.gov (United States)

Electrochemical behaviors of dopamine and ascorbic acid have been studied at the carbon nanotube electrode using cyclic voltammetry. Electrocatalysis has been found for dopamine redox reactions at the carbon nanotube electrode in comparison with the glassy carbon electrode. A well-defined oxidative peak for ascorbic acid was observed at the carbon nanotube electrode with the peak potential negative shift versus the glassy carbon electrode. The important discover was that the carbon nanotube electrode can be used to detect low level of dopamine selectively with high sensitivity in the presence of a large excess of ascorbic acid in the acidic media and in the physiological pH buffer solution as well.

Hu, C. G.; Wang, W. L.; Feng, B.; Wang, H.

46

Regulation of collagen synthesis by ascorbic acid.  

OpenAIRE

After prolonged exposure to ascorbate, collagen synthesis in cultured human skin fibroblasts increased approximately 8-fold with no significant change in synthesis of noncollagen protein. This effect of ascorbate appears to be unrelated to its cofactor function in collagen hydroxylation. The collagenous protein secreted in the absence of added ascorbate was normal in hydroxylysine but was mildly deficient in hydroxyproline. In parallel experiments, lysine hydroxylase (peptidyllysine, 2-oxoglu...

Murad, S.; Grove, D.; Lindberg, K. A.; Reynolds, G.; Sivarajah, A.; Pinnell, S. R.

1981-01-01

47

THE EFFECT OF ASCORBIC ACID ON BLAST TRANSFORMATION OF LYMPHOCYTES  

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Full Text Available The impact of ascorbic acid on the intensity of blast transformation of lymphocytes induced by Con-A and LPS mytogens was considered. For the experiments the spleen lymphocytes C3H/HEJ mouse were used. The cells were explored to the impact of different ascorbic acid concentration, and the process of DNA synthesis was measured by frequent marking of 3H-TdR, which were incorporated into a newly sinthetisized DNA. The quantity of the incorporated 3H-TdR was measured by scintillation in the beta counter.The achieved results show that ascorbic acid exemplifies the stimulative influence on blast transformation lymphocyte in dose from 0,075 to 0,175 gamma/2,5x105 cells. With progressive increase of ascorbic acid dosage, the inhibitatory effect of ascorbic acid progressively increases. Ascorbic acid shows a stronger effect on T than on B lymphocytes. These results lead to a conclusion that ascorbic acid has an important effect on the intensity of stimulated lymphocyte activity by mitogen.

Zorica Anti?

2003-07-01

48

Effect of ascorbic acid on the properties of ammonia caramel colorant additives and acrylamide formation.  

Science.gov (United States)

Ammonia caramels are among the most widely used colorant additives in the food industry. They are commonly prepared through the Maillard reaction and caramelization of mixtures of reducing sugars with ammonia or ammonium salts. Antioxidants are known to inhibit acrylamide formation during the Maillard reaction, and they may affect the properties of the ammonia caramel products. Thus, the objective of this study was to investigate the effect of the antioxidant ascorbic acid on the properties of ammonia caramel. A mixture of glucose and ammonia was allowed to react at 120 °C for 60 min in the presence of ascorbic acid at final concentrations of 0 to 0.08 M. The ammonia caramels obtained from these reactions were all positively charged. As the concentration of ascorbic acid increased, the color intensity of the ammonia caramel showed a decreasing trend, while the intensity of the fluorescence and total amount of pyrazines in the volatiles showed a tendency to increase. The addition of ascorbic acid did not result in obvious changes in the UV-visible spectra of the ammonia caramels and the types of pyrazines in the volatiles were also unchanged. It is noteworthy that the addition of 0.02 to 0.08 M ascorbic acid did reduce the formation of the by-product acrylamide, a harmful substance in food. When the concentration of ascorbic acid added reached 0.04 M, the content of acrylamide in the ammonia caramel was 20.53 ?g/L, which was approximately 44% lower than that without ascorbic acid. As a result, ascorbic acid can be considered to improve the quality and safety of ammonia caramels. PMID:25204396

Chen, Hongxing; Gu, Zhengbiao

2014-09-01

49

Effect of Ascorbic Acid on Lipid Peroxidation Induced by Ceftazidime  

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Full Text Available Lipid peroxidation is the oxidative deterioration of polyunsaturated lipids which is a free radical related process and responsible for thedevelopment of many diseases and disorders like diabetes mellitus, hypertension, cancer etc. End products of lipid peroxidation aremalondialdehyde (MDA, 4-hydroxy-2-nonenal (4-HNE, etc. which are the ultimate mediator of toxicity. Antioxidants have the capability toinhibit lipid peroxidation. Keeping in mind this fact, the present in vitro study was carried out to evaluate lipid peroxidation induction potential of ceftazidime, a cephalosporin antibiotic and its suppression with ascorbic acid considering some laboratory markers of lipid peroxidation like MDA, 4-HNE and reduced glutathione (GSH. Goat liver was used as the lipid source. After treatment of the liver homogenate with drug and/or antioxidant the levels of 4-HNE, MDA and GSH were estimated in different samples at different hours of incubation. The results showed that the drug ceftazidime could significantly induce lipid peroxidation and the antioxidant ascorbic acid has the capability to inhibit ceftazidime-inducedlipid peroxidation.

Devbhuti P*,1

2011-01-01

50

Radiation protection by ascorbic acid in sodium alginate solutions  

Energy Technology Data Exchange (ETDEWEB)

Alginates are gelling hydrocolloids extracted from brown seaweed used widely in the nourishing and pharmaceutical industries. As alginic acid gellification retard food entrance in the stomach alginate is an additive used in diets. The objective of this work was to study the protective action of the ascorbic acid in alginate solutions against the action of {sup 60} Co gamma radiation. One % (w/v) solutions of alginate had been used and concentrations of ascorbic acid varied from 0 to 2.5% (w/v). The solutions were irradiated with doses up to 10 kGy. Viscosity/dose relationship and the p H of the solutions at 25 Centigrade were determined. Ascorbic acid behaved as an antioxidant against radiation oxidative shock in this model system of an irradiated viscous solution. Besides its radiation protective role on alginate solutions ascorbic acid promoted a viscosity increase in the range of concentrations employed. (Author)

Aliste, A.J.; Mastro, N.L. Del [Center of Radiation Technology, IPEN/CNEN/SP, University City, 05508-000 Sao Paulo (Brazil)]. E-mail: ajaliste@ipen.br

2004-07-01

51

Radiation protection by ascorbic acid in sodium alginate solutions  

International Nuclear Information System (INIS)

Alginates are gelling hydrocolloids extracted from brown seaweed used widely in the nourishing and pharmaceutical industries. As alginic acid gellification retard food entrance in the stomach alginate is an additive used in diets. The objective of this work was to study the protective action of the ascorbic acid in alginate solutions against the action of 60 Co gamma radiation. One % (w/v) solutions of alginate had been used and concentrations of ascorbic acid varied from 0 to 2.5% (w/v). The solutions were irradiated with doses up to 10 kGy. Viscosity/dose relationship and the p H of the solutions at 25 Centigrade were determined. Ascorbic acid behaved as an antioxidant against radiation oxidative shock in this model system of an irradiated viscous solution. Besides its radiation protective role on alginate solutions ascorbic acid promoted a viscosity increase in the range of concentrations employed. (Author)

52

Polarographic Methods for Determination of Ascorbic Acid in Pharmacetical Preparations  

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Full Text Available Ascorbic acid is determined polarographically present in various types of medicinal samples by internal standard addition method. Potassium hydrogen phthalate buffer (pH 4.0 containing 0.25% oxalic acid and 0.008 % gelatin solution used as supporting electrolytes and maxima suppressor. Presence of colouring matters does not interfere, and sample handling and solution preparation for analysis can be carried out sufficiently fast to prevent appreciable oxidation. Polarographic determination of ascorbic acid can be carried out even in presence of comparable amounts of other ingredients such as Vitamins A, B, C, D, and E. Results of estimation of ascorbic acid present in different multivitamin medicinal samples by internal standard addition method obtained are in good agreement with the quoted values. The method is precise as indicated by low values of standard deviation. Comparative study of ascorbic acid estimation by polarographic internal standard addition method with respect to their manufacturing company was also done

Swaroopa Rani N. Gupta

2014-04-01

53

Selective spectrophotometric determination of ascorbic acid in drugs and foods.  

Science.gov (United States)

A new analytical method was developed for the determination of ascorbic acid. The method is based on the reaction of ascorbic acid with 4-chloro-7-nitrobenzofurazane (NBD-Cl) in the presence of 0.2M sodium hydroxide, where a bluish green colour (lambda(max) 582 nm) is developed after dilution with 50% (v/v) aqueous acetone solution. Beer's law was obeyed in a concentration range of 5-20 microg ascorbic acid/ml with a good correlation coefficient (r = 0.9990). The method was found to be highly specific for the determination of ascorbic acid in the presence of dehydro-ascorbic acid, all other vitamins and minerals possibly present in multivitamin preparations, rutin, salicylamide, acetyl salicylic acid, paracetamol, caffeine, phenylephrine hydrochloride and dipyrone. Moreover, the proposed procedure was also successfully applied for the determination of ascorbic acid in some canned and fresh fruit juices, some vegetables and infant milk products without interference from coloured and other substances present in the plant extracts. PMID:18966266

Abdelmageed, O H; Khashaba, P Y; Askal, H F; Saleh, G A; Refaat, I H

1995-04-01

54

Regulation of ascorbic acid synthesis in plants.  

Science.gov (United States)

Ascorbic acid (AsA) is a major antioxidant and plays an important role in plant growth and development. There are two aspects to improve AsA content, including de novo synthesis and recycling from its oxidized form. However, the knowledge of regulatory mechanisms of AsA synthesis pathways and metabolism still remains limited. We have determined that AsA synthesis process was modulated on both transcriptional and post-transcriptional levels in Arabidopsis. GDP-mannose pyrophosphorylase (VTC1) is the initial AsA biosynthetic enzyme in L-galactose pathway, we previously showed that Arabidopsis ERF98 transcriptionally activates gene expression of VTC1 to improve AsA content and respond salt stress; recent discovery of the interaction between photomorphogenic factor COP9 signalosome (CSN) subunit CSN5B and VTC1 indicates that CSN5B promotes VTC1 degradation in the dark, which keeps the change of AsA content from day to night. This mini-review integrates previous reports and recent evidence to better understand the regulatory mechanisms involved in AsA synthesis. PMID:23603957

Wang, Juan; Zhang, Zhijin; Huang, Rongfeng

2013-06-01

55

Anti-angiogenic effect of high doses of ascorbic acid  

OpenAIRE

Abstract Pharmaceutical doses of ascorbic acid (AA, vitamin C, or its salts) have been reported to exert anticancer activity in vitro and in vivo. One proposed mechanism involves direct cytotoxicity mediated by accumulation of ascorbic acid radicals and hydrogen peroxide in the extracellular environment of tumor cells. However, therapeutic effects have been reported at concentrations insufficient to induce direct tumor cell death. We hypothesized that AA may exert ...

Ichim Thomas E; Mikirova Nina A; Riordan Neil H

2008-01-01

56

Ascorbate administration to normal and cholesterol-fed rats inhibits in vitro TBARS formation in serum and liver homogenates.  

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We have recently shown that ascorbate has a hypocholesterolemic and hypotriglyceridemic effect on rats fed a diet enriched with 1.5% cholesterol and 25% hydrogenated coconut oil (Nath diet). In this study we evaluated the effect of intraperitoneal ascorbate administration on susceptibility to lipoperoxidation either in rats fed standard or Nath diet. In normal rats ascorbate treatment decreased (pfatty acid profile. In rats fed Nath diet we observed a reduced susceptibility of serum to CU++-induced lipoperoxidation (36%), according with their low levels of serum unsaturated fatty acids (40% less than rats fed standard diet). In these animals ascorbate administration affects serum fatty acid profile leading to a decrease of S/U ratio from 1.6 to 1.2 without significantly modifying the susceptibility of serum to lipoperoxidation. Moreover, the production of spontaneous lipid peroxides in liver homogenates, measured as TBARS levels, was strongly inhibited by ascorbate (prats fed either standard or Nath diet. These data indicate that ascorbate administration exerts an antioxidant effect and that in hypercholesterolemic rats, in addition to a lipid lowering effect, ascorbate exerts a protective role against the peroxidative damage of lipids. PMID:8614261

Santillo, M; Mondola, P; Milone, A; Gioielli, A; Bifulco, M

1996-01-01

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Ascorbic acid as an oxygen-binding agent  

International Nuclear Information System (INIS)

Ascrobates should be used with caution in warm-water and hot-water heating systems because of the accumulation of their reaction products. Ascorbates, i.e., ascorbic acid in basic solutions seem nevertheless suitable as oxygen-binding agents for the protection of wet steam boiler components because their oxygen-binding capacity at room temperature is relative by high; their chemical reactions are better calculable than at system operating temperatures; and the basic, ascorbic preserving agent is readily biodegradable if previously neutralised as necessary. Their reactivity with iron oxide protective coatings requires further study. (EF)

58

Ascorbic acid: chemistry, biology and the treatment of cancer.  

Science.gov (United States)

Since the discovery of vitamin C, the number of its known biological functions is continually expanding. Both the names ascorbic acid and vitamin C reflect its antiscorbutic properties due to its role in the synthesis of collagen in connective tissues. Ascorbate acts as an electron-donor keeping iron in the ferrous state thereby maintaining the full activity of collagen hydroxylases; parallel reactions with a variety of dioxygenases affect the expression of a wide array of genes, for example via the HIF system, as well as via the epigenetic landscape of cells and tissues. In fact, all known physiological and biochemical functions of ascorbate are due to its action as an electron donor. The ability to donate one or two electrons makes AscH(-) an excellent reducing agent and antioxidant. Ascorbate readily undergoes pH-dependent autoxidation producing hydrogen peroxide (H(2)O(2)). In the presence of catalytic metals this oxidation is accelerated. In this review, we show that the chemical and biochemical nature of ascorbate contribute to its antioxidant as well as its prooxidant properties. Recent pharmacokinetic data indicate that intravenous (i.v.) administration of ascorbate bypasses the tight control of the gut producing highly elevated plasma levels; ascorbate at very high levels can act as prodrug to deliver a significant flux of H(2)O(2) to tumors. This new knowledge has rekindled interest and spurred new research into the clinical potential of pharmacological ascorbate. Knowledge and understanding of the mechanisms of action of pharmacological ascorbate bring a rationale to its use to treat disease especially the use of i.v. delivery of pharmacological ascorbate as an adjuvant in the treatment of cancer. PMID:22728050

Du, Juan; Cullen, Joseph J; Buettner, Garry R

2012-12-01

59

Effect of irradiation and cooking methods on ascorbic acid levels of four potato cultivars  

International Nuclear Information System (INIS)

The changes in reduced and total ascorbic acid (AA) contents in control and in tubers irradiated to 100 Gy gamma rays for sprout inhibition were studied by HPLC and iodophenol titrimetry methods in four potato cultivars as a function of storage at 15 degC and after cooking by different methods. Both reduced and total ascorbic acid levels decreased in control tubers during the first 3 months in storage recording respectively 22 to 35% and 26 to 45% losses depending on the cultivar. Irradiated tubers recorded additional losses of 5 to 10% and 6.5 to 13%, respectively in reduced and total ascorbic acid levels during the same period but remained in good marketable conditions. Cooking of tubers in boiling water showed maximum loss in vitamin C content, whereas pressure and microwave cooking recorded least losses. The magnitude of losses in reduced and total vitamin C during cooking was comparable in control and in irradiated tubers. (author)

60

Low brain ascorbic acid increases susceptibility to seizures in mouse models of decreased brain ascorbic acid transport and Alzheimer's disease.  

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Seizures are a known co-occurring symptom of Alzheimer's disease, and they can accelerate cognitive and neuropathological dysfunction. Sub-optimal vitamin C (ascorbic acid) deficiency, that is low levels that do not lead the sufferer to present with clinical signs of scurvy (e.g. lethargy, hemorrhage, hyperkeratosis), are easily obtainable with insufficient dietary intake, and may contribute to the oxidative stress environment of both Alzheimer's disease and epilepsy. The purpose of this study was to test whether mice that have diminished brain ascorbic acid in addition to carrying human Alzheimer's disease mutations in the amyloid precursor protein (APP) and presenilin 1 (PSEN1) genes, had altered electrical activity in the brain (electroencephalography; EEG), and were more susceptible to pharmacologically induced seizures. Brain ascorbic acid was decreased in APP/PSEN1 mice by crossing them with sodium vitamin C transporter 2 (SVCT2) heterozygous knockout mice. These mice have an approximately 30% decrease in brain ascorbic acid due to lower levels of SVCT2 that supplies the brain with ASC. SVCT2+/-APP/PSEN1 mice had decreased ascorbic acid and increased oxidative stress in brain, increased mortality, faster seizure onset latency following treatment with kainic acid (10mg/kg i.p.), and more ictal events following pentylenetetrazol (50mg/kg i.p.) treatment. Furthermore, we report the entirely novel phenomenon that ascorbic acid deficiency alone increased the severity of kainic acid- and pentylenetetrazol-induced seizures. These data suggest that avoiding ascorbic acid deficiency may be particularly important in populations at increased risk for epilepsy and seizures, such as Alzheimer's disease. PMID:25616451

Warner, Timothy A; Kang, Jing-Qiong; Kennard, John A; Harrison, Fiona E

2015-02-01

61

Mitochondria, Energy and Cancer: The Relationship with Ascorbic Acid  

OpenAIRE

Ascorbic Acid (AA) has been used in the prevention and treatment of cancer with reported effectiveness. Mitochondria may be one of the principal targets of ascorbate's cellular activity and it may play an important role in the development and progression of cancer. Mitochondria, besides generating adenosine triphosphate (ATP), has a role in apoptosis regulation and in the production of regulatory oxidative species that may be relevant in gene expression. At higher concentrations AA may increa...

Gonza?lez, Michael J.; Rosario-pe?rez, Glorivee; Guzma?n, Ange?lica M.; Miranda-massari, Jorge R.; Duconge, Jorge; Lavergne, Julio; Fernandez, Nadia; Ortiz, Norma; Quintero, Ana; Mikirova, Nina; Riordan, Neil H.; Ricart, Carlos M.

2010-01-01

62

Anti-angiogenic effect of high doses of ascorbic acid  

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Full Text Available Abstract Pharmaceutical doses of ascorbic acid (AA, vitamin C, or its salts have been reported to exert anticancer activity in vitro and in vivo. One proposed mechanism involves direct cytotoxicity mediated by accumulation of ascorbic acid radicals and hydrogen peroxide in the extracellular environment of tumor cells. However, therapeutic effects have been reported at concentrations insufficient to induce direct tumor cell death. We hypothesized that AA may exert anti-angiogenic effects. To test this, we expanded endothelial progenitor cells (EPCs from peripheral blood and assessed, whether or not high dose AA would inhibit EPC ability to migrate, change energy metabolism, and tube formation ability. We also evaluated the effects of high dose AA on angiogenic activities of HUVECs (human umbilical vein endothelial cells and HUAECs (human umbilical arterial endothelial cells. According to our data, concentrations of AA higher than 100 mg/dl suppressed capillary-like tube formation on Matrigel for all cells tested and the effect was more pronounced for progenitor cells in comparison with mature cells. Co-culture of differentiated endothelial cells with progenitor cells showed that there was incorporation of EPCs in vessels formed by HUVECs and HUAECs. Cell migration was assessed using an in vitro wound healing model. The results of these experiments showed an inverse correlation between AA concentrations relative to both cell migration and gap filling capacity. Suppression of NO (nitric oxide generation appeared to be one of the mechanisms by which AA mediated angiostatic effects. This study supports further investigation into non-cytotoxic antitumor activities of AA.

Ichim Thomas E

2008-09-01

63

Phytic Acid Inhibits Lipid Peroxidation In Vitro  

OpenAIRE

Phytic acid (PA) has been recognized as a potent antioxidant and inhibitor of iron-catalyzed hydroxyl radical formation under in vitro and in vivo conditions. Therefore, the aim of the present study was to investigate, with the use of HPLC/MS/MS, whether PA is capable of inhibiting linoleic acid autoxidation and Fe(II)/ascorbate-induced peroxidation, as well as Fe(II)/ascorbate-induced lipid peroxidation in human colonic epithelial cells. PA at 100??M and 500??M effectively inhibited th...

Alicja Zajdel; Adam Wilczok; Glarz, Ludmi Amp X. A. W. Amp X.; Ewicz, Zofia Dzier Amp X. C.

2013-01-01

64

Functional characterisation of the active ascorbic acid transport into cerebrospinal fluid using primary cultured choroid plexus cells.  

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Crossing the blood-CSF barrier is an important pathway for certain nutrients to enter the CNS. Cultured choroid plexus epithelial cells are a potent model system to study active transport properties of this tissue in vitro. In the present study this in vitro model was used to analyse ascorbic acid transport across the blood-CSF barrier that is supposedly mediated by the Na(+)-dependent transporter SVCT2. The expression of SVCT2 in the cultured cells was proven by RT-PCR. Active transport across the cell monolayer resulted in ascorbic acid enrichment at the CSF mimicking side. Ascorbic acid transport and uptake were decreased to 13 and 27%, respectively, in the presence of 200 microM phloretin. Inhibition of both transepithelial substrate transport (to 7.5%) and cytoplasmatic uptake (to 20%) was observed in Na(+)-free medium indicating that a basolaterally located and Na(+)-dependent transporter mediates ascorbic acid uptake. Substituting Cl(-) by either iodide or D-gluconate increased ascorbic acid uptake by factors of 3.7 or 2.5, respectively. Similar observations were made when Na(+)-dependent myo-inositol transport was analysed. Additionally, in presence of 100 microM bumetanide, an inhibitor of Na(+)-Cl(-)-cotransport, indirectly increased ascorbic acid and myo-inositol transport rates were observed showing that ascorbic acid-Na(+)-cotransport might balance low intracellular Na(+) concentration. PMID:14519531

Angelow, Susanne; Haselbach, Matthias; Galla, Hans-Joachim

2003-10-24

65

Enzymatic methods in food analysis: determination of ascorbic acid.  

Science.gov (United States)

The feasibility and expediency of enzymatic methods application in food analysis is demonstrated by the example of ascorbic acid (AsA) determination in foods. Enzymatic determination of ascorbic acid is based on its action as a second substrate of horseradish (HRP) and peanut (PNP) peroxidases in the reactions of o-dianisidine (OD) and 3,3',5,5'-tetramethylbenzidine (TMB) oxidation with hydrogen peroxide. The rates of the reactions are monitored spectrophotometrically by measuring the duration of the induction period on kinetic curves plotted in coordinates absorption-time. The proposed procedures are sensitive (c(L)=0.1 microM), simple, and rapid. The procedure using horseradish peroxidase and the reaction of TMB oxidation was used to determine ascorbic acid in fruit juices, milk and sour-milk products for babies' nutrition. PMID:17723515

Shekhovtsova, Tatyana N; Muginova, Svetlana V; Luchinina, Julia A; Galimova, Anna Z

2006-07-28

66

High dose of ascorbic acid induces cell death in mesothelioma cells.  

Science.gov (United States)

Malignant mesothelioma is an asbestos-related fatal disease with no effective cure. Recently, high dose of ascorbate in cancer treatment has been reexamined. We studied whether high dose of ascorbic acid induced cell death of four human mesothelioma cell lines. High dose of ascorbic acid induced cell death of all mesothelioma cell lines in a dose-dependent manner. We further clarified the cell killing mechanism that ascorbic acid induced reactive oxygen species and impaired mitochondrial membrane potential. In vivo experiment, intravenous administration of ascorbic acid significantly decreased the growth rate of mesothelioma tumor inoculated in mice. These data suggest that ascorbic acid may have benefits for patients with mesothelioma. PMID:20171954

Takemura, Yukitoshi; Satoh, Motohiko; Satoh, Kiyotoshi; Hamada, Hironobu; Sekido, Yoshitaka; Kubota, Shunichiro

2010-04-01

67

Effect of ascorbic acid supplementation on nitric oxide metabolites and systolic blood pressure in rats exposed to lead  

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Full Text Available Background: Extended exposure to low levels of lead causes high blood pressure in human and laboratory animals. The mechanism is not completely recognized, but it is relatively implicated with generation of free radicals, oxidant agents such as ROS, and decrease of available nitric oxide (NO. In this study, we have demonstrated the effect of ascorbic acid as an antioxidant on nitric oxide metabolites and systolic blood pressure in rats exposed to low levels of lead. Materials and Methods: The adult male Wistar rats weighing 200-250 g were divided into four groups: control, lead acetate (receiving 100 ppm lead acetate in drinking water, lead acetate plus ascorbic acid (receiving 100 ppm lead acetate and 1 g/l ascorbic acid in drinking water, and ascorbic acid (receiving 1 g/l ascorbic acid in drinking water groups. The animals were anesthetized with ketamin/xylazine (50 and 7 mg/kg, respectively, ip and systolic blood pressure was then measured from the tail of the animals by a sphygmomanometer. Nitric oxide levels in serum were measured indirectly by evaluation of its stable metabolites (total nitrite and nitrate (NOc. Results: After 8 and 12 weeks, systolic blood pressure in the lead acetate group was significantly elevated compared to the control group. Ascorbic acid supplementation could prevent the systolic blood pressure rise in the lead acetate plus ascorbic acid group and there was no significant difference relative to the control group. The serum NOc levels in lead acetate group significantly decreased in relation to the control group, but this reduction was not significantly different between the lead acetate plus ascorbic acid group and the control group. Conclusion: Results of this study suggest that ascorbic acid as an antioxidant prevents the lead induced hypertension. This effect may be mediated by inhibition of NOc oxidation and thereby increasing availability of NO.

Mohammad Amani

2010-01-01

68

A Chronoamperometric Screen Printed Carbon Biosensor Based on Alkaline Phosphatase Inhibition for W(IV) Determination in Water, Using 2-Phospho-l-Ascorbic Acid Trisodium Salt as a Substrate.  

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This paper presents a chronoamperometric method to determine tungsten in water using screen-printed carbon electrodes modified with gold nanoparticles and cross linked alkaline phosphatase immobilized in the working electrode. Enzymatic activity over 2-phospho-l-ascorbic acid trisodium salt, used as substrate, was affected by tungsten ions, which resulted in a decrease of chronoamperometric current, when a potential of 200 mV was applied on 10 mM of substrate in a Tris HCl buffer pH 8.00 and 0.36 M of KCl. Calibration curves for the electrochemical method validation, give a reproducibility of 5.2% (n = 3), a repeatability of 9.4% (n = 3) and a detection limit of 0.29 ± 0.01 µM. Enriched tap water, purified laboratory water and bottled drinking water, with a certified tungsten reference solution traceable to NIST, gave a recovery of 97.1%, 99.1% and 99.1% respectively (n = 4 in each case) and a dynamic range from 0.6 to 30 µM. This study was performed by means of a Lineweaver-Burk plot, showing a mixed kinetic inhibition. PMID:25621602

Alvarado-Gámez, Ana Lorena; Alonso-Lomillo, María Asunción; Domínguez-Renedo, Olga; Arcos-Martínez, María Julia

2015-01-01

69

A Chronoamperometric Screen Printed Carbon Biosensor Based on Alkaline Phosphatase Inhibition for W(IV Determination in Water, Using 2-Phospho-l-Ascorbic Acid Trisodium Salt as a Substrate  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a chronoamperometric method to determine tungsten in water using screen-printed carbon electrodes modified with gold nanoparticles and cross linked alkaline phosphatase immobilized in the working electrode. Enzymatic activity over 2-phospho-l-ascorbic acid trisodium salt, used as substrate, was affected by tungsten ions, which resulted in a decrease of chronoamperometric current, when a potential of 200 mV was applied on 10 mM of substrate in a Tris HCl buffer pH 8.00 and 0.36 M of KCl. Calibration curves for the electrochemical method validation, give a reproducibility of 5.2% (n = 3, a repeatability of 9.4% (n = 3 and a detection limit of 0.29 ± 0.01 µM. Enriched tap water, purified laboratory water and bottled drinking water, with a certified tungsten reference solution traceable to NIST, gave a recovery of 97.1%, 99.1% and 99.1% respectively (n = 4 in each case and a dynamic range from 0.6 to 30 µM. This study was performed by means of a Lineweaver–Burk plot, showing a mixed kinetic inhibition.

Ana Lorena Alvarado-Gámez

2015-01-01

70

Fast HPLC-ECD analysis of ascorbic acid, dehydroascorbic acid and uric acid.  

Science.gov (United States)

A robust and rapid high-pressure liquid chromatography-electrochemical detection (HPLC-ECD) method was developed and validated for the accurate determination of ascorbic acid (AA) and uric acid (UA), in human plasma. Dehydroascorbic acid (DHAA) was indirectly measured by subtracting native ascorbic acid from total ascorbic acid concentrations; the latter was obtained after chemical reduction. A stable electrochemical active internal standard (homogentisic acid) was added for the accurate quantification of the analytes. The analyses were performed on a reverse-phase column with traditional HPLC and ultra-HPLC (UHPLC). The UHPLC method showed increased sensitivity with detection limit of 0.05ng for both AA and UA, 2 times lower compared to conventional HPLC. UHPLC also reduced run times fourfold with less waste generation. Both assays showed good accuracy and precision, the intra- and inter-day CVs of AA and UA analysis are less than 7%. PMID:19250886

Li, Xingnan; Franke, Adrian A

2009-04-01

71

SOURCE, CHEMISTRY, METABOLISM, PHYSIOLOGICAL FUNCTION: ASCORBIC ACID WITH HUMAN HEALTH  

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Full Text Available Ascorbic acid commonly known as Vitamin C and it is water soluble vitamin having Antioxidant characteristics, abound in nature and highly labile.it is very important Vitamin for biosynthesis of collagen, carnitine and neurotransmitters. Some plants and animals synthesised this Vitamin but human, apes and some other are not able to synthesis this Vitamin due to lack of Gulonolactone oxidase enzyme. So, this Vitamin is supplemented by outer source like fruit, vegetable and synthetic pharmaceutical products. The current US recommended dietary allowances (RDA for Ascorbic acid is 100-120 mg/day. Ascorbic acid has many biochemical functions like Antioxidant, Anti-antherogenic, Anti-carcinogenic, immunodulator and its preventing cold. It’s also associated with reduction of incidence of cancer, immunity, blood pressure, drug metabolism and urinary hydroxyproline excretion, tissue regeneration. Mainly it shows effective result in gastric cancer. Ascorbic acid decreases the death risk. Now day, This Vitamin is used in nutraceutical in human biology and health.

Prashansa Sharma

2014-09-01

72

Methylene Blue-Ascorbic Acid: An Undergraduate Experiment in Kinetics.  

Science.gov (United States)

Describes a laboratory exercise involving methylene blue and L-ascorbic acid in a simple clock reaction technique to illustrate the basic concepts of chemical kinetics. If stock solutions are supplied and each type of experiment takes no more than half an hour, the entire investigation can be completed in three practical sessions of three hours…

Snehalatha, K. C.; And Others

1997-01-01

73

Mitochondria, Energy and Cancer: The Relationship with Ascorbic Acid.  

Science.gov (United States)

Ascorbic Acid (AA) has been used in the prevention and treatment of cancer with reported effectiveness. Mitochondria may be one of the principal targets of ascorbate's cellular activity and it may play an important role in the development and progression of cancer. Mitochondria, besides generating adenosine triphosphate (ATP), has a role in apoptosis regulation and in the production of regulatory oxidative species that may be relevant in gene expression. At higher concentrations AA may increase ATP production by increasing mitochondrial electron flux, also may induce apoptotic cell death in tumor cell lines, probably via its pro-oxidant action In contrast, at lower concentrations AA displays antioxidant properties that may prevent the activation of oxidant-induced apoptosis. These concentration dependent activities of ascorbate may explain in part the seemingly contradictory results that have been reported previously. PMID:23565030

González, Michael J; Rosario-Pérez, Glorivee; Guzmán, Angélica M; Miranda-Massari, Jorge R; Duconge, Jorge; Lavergne, Julio; Fernandez, Nadia; Ortiz, Norma; Quintero, Ana; Mikirova, Nina; Riordan, Neil H; Ricart, Carlos M

2010-01-01

74

Simultaneous determination of ascorbic acid and isoascorbic acid in food by high pressure liquid chromatography  

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Full Text Available Objective To establish a high pressure liquid chromatography (HPLC method for simultaneous determination of the contents of ascorbic acid and isoascorbic acid in food. Methods Ascorbic acid and isoascorbic acid were separated using a Venusil HILIC column (250 mm×4.6 mm, 5 ?m, 100 ?, taking acetonitrile-0.1% phosphoric acid solution (90?10, v/v as the mobile phase and extractant. Results The average recoveries of ascorbic acid and isoascorbic acid were 96.61% and 96.53%. And their minimum detectable concentration was 0.35 ?g/mL and 0.42 ?g/mL. Conclusion The method is accurate, sensitive and of precision, and can be used for the determination of ascorbic acid and isoascorbic acid in food.

LI Gang

2013-02-01

75

Effects of ascorbic acid and high oxygen modified atmosphere packaging during storage of fresh-cut eggplants.  

Science.gov (United States)

Ascorbic acid dip and high O2 modified atmosphere packaging were used to alleviate browning and quality loss of fresh-cut eggplants. Fresh-cut eggplants were dipped in water or 0.5% ascorbic acid solution for 2?min before being packed in polyethylene film bags filled with air or high O2. The physiochemical and sensorial attributes of cut eggplants were evaluated during 12 days for storage at 4?. Results demonstrated that high O2 modified atmosphere packaging and ascorbic acid dip improved the preservation of fresh-cut eggplants compared with the control. High O2 showed an ability to reduce the browning and inhibit polyphenol oxidase and peroxidase activities. Higher total phenolic content and lower malondialdehyde content were also observed in ascorbic acid treated samples during storage. Moreover, the combination of ascorbic acid and high O2 was more effective than single treatments. The surface color was protected by ascorbic acid and high O2 packaging, and higher sensory scores were observed after 12 days of storage. PMID:24522002

Li, Xihong; Jiang, Yuqian; Li, Weili; Tang, Yao; Yun, Juan

2014-03-01

76

Performance of structured lipids incorporating selected phenolic and ascorbic acids.  

Science.gov (United States)

Conditions applied during frying require antioxidant which is stable at these conditions and provides protection for frying oil and fried food. Novel structured lipids containing nutraceuticals and antioxidants were formed by enzymatic transesterification, exploring canola oil and naturally occurring antioxidants such as ascorbic and selected phenolic acids as substrates. Lipozyme RM IM lipase from Rhizomucor miehei was used as biocatalyst. Frying performance and oxidative stability of the final transesterification products were evaluated. The novel lipids showed significantly improved frying performance compared to canola oil. Oxidative stability assessment of the structured lipids showed significant improvement in resistance to oxidative deterioration compared to original canola oil. Interestingly, the presence of ascorbic acid in an acylglycerol structure protected ?-tocopherol against thermal degradation, which was not observed for the phenolic acids. Developed structured lipids containing nutraceuticals and antioxidants may directly affect nutritional properties of lipids also offering nutraceutical ingredients for food formulation. PMID:25466089

Gruczynska, Eliza; Przybylski, Roman; Aladedunye, Felix

2015-04-15

77

Comparative study of the quercetin, ascorbic acid, glutathione and superoxide dismutase for nitric oxide protecting effects in mouse gastric fundus.  

Science.gov (United States)

The aim of this work was to compare the preventing capacity of quercetin with Cu/Zn superoxide dismutase (Cu/Zn SOD), ascorbic acid and glutathione on nitric oxide (NO)-induced relaxation in mouse gastric fundus. Furthermore, the effects of the quercetin on the tissue level of total oxidant and antioxidant was investigated. Nitrergic stimulation (4Hz, 25V, 0.1 ms, 10s-train) and exogenous NO (10 ?M) induced relaxation. Pyrogallol (10 ?M), hydroquinone (100 ?M) and LY83583 (6-Anilino-quinolin-5,8-quinone, 5 ?M) inhibited nitrergic relaxations. The inhibition observed with pyrogallol, hydroquinone and LY83583 was prevented by quercetin (0.1 ?M). Also, ascorbic acid (500 ?M), glutathione (100 ?M) and Cu/Zn SOD (100 U/ml) prevented the inhibitory effect of superoxide anion generators on the relaxation to nitrergic stimulation and NO. Diethyldithiocarbamic acid (DETCA; 8mM) inhibited nitrergic relaxations. DETCA-induced inhibition on nitrergic stimulation and NO-induced relaxation was prevented by quercetin, ascorbic acid, glutathione or Cu/Zn SOD. DETCA plus pyrogallol, hydroquinone or LY83583 strengthened the inhibition on the relaxations. Also, pre-treatment with quercetin, ascorbic acid and glutathione prevented the inhibitory effect of DETCA plus LY-83583 on the relaxation to nitrergic stimulation and NO but Cu/Zn SOD did not prevent this inhibition. Also, quercetin increased tissue total antioxidant capacity and decreased tissue oxidant level and oxidative stress index in DETCA-treatment group. These results indicate that quercetin has antioxidant effect and protects NO from endogenous superoxide anion-driven inactivation and enhances its biological activity, suggesting that quercetin may scavenge superoxide anion in a Cu/Zn SOD, glutathione or ascorbic acid-inhibitable manner. PMID:23085029

Ertu?, Peyman U; Aydinoglu, Fatma; Goruroglu Ozturk, Ozlem; Singirik, Ergin; Ögülener, Nuran

2013-01-01

78

SOURCE, CHEMISTRY, METABOLISM, PHYSIOLOGICAL FUNCTION: ASCORBIC ACID WITH HUMAN HEALTH  

OpenAIRE

Ascorbic acid commonly known as Vitamin C and it is water soluble vitamin having Antioxidant characteristics, abound in nature and highly labile.it is very important Vitamin for biosynthesis of collagen, carnitine and neurotransmitters. Some plants and animals synthesised this Vitamin but human, apes and some other are not able to synthesis this Vitamin due to lack of Gulonolactone oxidase enzyme. So, this Vitamin is supplemented by outer source like fruit, vegetable and synthetic pharmaceuti...

Prashansa Sharma; Pramod Kumar Sharma; Vidya Bhushan Mishra; Akanksha Bhandari

2014-01-01

79

Spectroscopic investigation of the interaction between ?-cyclodextrin and ascorbic acid  

International Nuclear Information System (INIS)

Inclusion compound of vitamin C (ascorbic acid) with ?-cyclodextrin (?-CD), prepared by different methods (kneading, co-precipitation and freeze-drying) has been caracterized by several spectroscopic techniques (FTIR, 1H NMR, UV-Vis), powder X-ray diffraction and DSC technique. Based on the chemical shifts observed in the 1H-NMR and on FTIR spectra the tentative conclusion is that vitamin C probably enters the cyclodextrin torus forming the inclusion complex.

80

Uptake of ascorbic acid by freshly isolated cells and secretory granules from the intermediate lobe of ox hypophyses  

DEFF Research Database (Denmark)

Mechanically isolated cells from the intermediate lobe of ox hypophyses contained 40.6 +/- 3.7 nmol mg-1 protein (mean +/- SE, n = 5) of ascorbic acid. They accumulated radioactivity time dependently, on incubation with L-[14C]ascorbic acid in ionic medium dominated by NaCl. No definite saturation of uptake occurred when mechanically isolated cells were incubated with increasing ascorbic acid concentrations up to 0.6 mM. But if such cells were purified on a Percoll gradient, a clear saturation of uptake could be observed. Acetylsalicylic acid reduced the uptake markedly. When cells loaded with L-[14C]ascorbic acid were homogenized and placed on a Percoll gradient, the radioactivity was recovered in several subcellular fractions. Decrease of the Na+ concentration or presence of ouabain in the medium did not cause noticeable changes in uptake by non-purified cells, whereas uptake by purified cells was clearly sodium-dependent. Phloridzin inhibited uptake. Secretory granules from pars intermedia contained 40.0 +/- 3.8 nmol mg-1 protein of ascorbic acid (mean +/- SE, n = 3) and could accumulate L-[14C]ascorbic acid rapidly in a KCl-dominated medium. The uptake was not saturable with ascorbic acid concentration and was not influenced by the presence of I mM ATP + I mM Mg2+ in the medium. The concentration of copper and iron in isolated cells was comparable to that in isolated neurohypophysial nerve terminals, whereas the concentration of zinc was considerably higher in the pars intermedia cells. The concentration of Cu, Zn, Fe and Co in secretory granules from pars intermedia was higher than in secretory granules from neurohypophyses.

Zhou, A; Matsumoto, T

1990-01-01

81

AN EVALUATION OF ASCORBIC ACID AS A QUORUM SENSING ANALOGUE TO CONTROL GROWTH, SPORULATION, AND ENTEROTOXIN PRODUCTION IN CLOSTRIDIUM PERFRINGENS  

Science.gov (United States)

Inhibition of quorum sensing by enterotoxin-producing strains of Clostridium perfringens was investigated. Autoinducer-2 (AI-2) activity was measured in the presence and absence of ascorbic acid (vitamin C; concentrations ranging from 10 to 300 mM), an AI-2 analogue. Subsequent effects on AI-2 pro...

82

Determination of total L-Ascorbic Acid by high performance liquid chromatography in human plasma  

OpenAIRE

The total vitamin C content in human plasma is widely accepted as an indicator of the tissue status of vitamin C. A liquid chromatography method with ultraviolet detector (264 nm) for measuring ascorbic acid in human plasma was developed. A C18 reversed-phase column and cetrimide as an ion-pairing agent was employed. Ascorbic acid (AA) was measured after reducing L-dehydroascorbic acid to L-ascorbic acid with dithiothreitol. The stability of the ascorbic acid in plasma, metaphosphoric acid an...

Oveisi; Sadeghi N

2001-01-01

83

Nitric oxide mediates tightening of the endothelial barrier by ascorbic acid.  

Science.gov (United States)

Vitamin C, or ascorbic acid, decreases paracellular endothelial permeability in a process that requires rearrangement of the actin cytoskeleton. To define the proximal mechanism of this effect, we tested whether it might involve enhanced generation and/or sparing of nitric oxide (NO) by the vitamin. EA.hy926 endothelial cells cultured on semi-porous filter supports showed decreased endothelial barrier permeability to radiolabeled inulin in response to exogenous NO provided by the NO donor spermine NONOATE, as well as to activation of the downstream NO pathway by 8-bromo-cyclic GMP, a cell-penetrant cyclic GMP analog. Inhibition of endothelial nitric oxide synthase (eNOS) with N(?)-nitro-l-arginine methyl ester increased endothelial permeability, indicating a role constitutive NO generation by eNOS in maintaining the permeability barrier. Inhibition of guanylate cyclase by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one also increased endothelial permeability and blocked barrier tightening by spermine NONOATE. Loading cells with what are likely physiologic concentrations of ascorbate decreased endothelial permeability. This effect was blocked by inhibition of either eNOS or guanylate cyclase, suggesting that it involved generation of NO by eNOS and subsequent NO-dependent activation of guanylate cyclase. These results show that endothelial permeability barrier function depends on constitutive generation of NO and that ascorbate-dependent tightening of this barrier involves maintaining NO through the eNOS/guanylate cyclase pathway. PMID:21156160

May, James M; Qu, Zhi-Chao

2011-01-14

84

Direct Spectrophotometric Determination of L-ascorbic Acid in the Presence of Potassium Cyanide  

Directory of Open Access Journals (Sweden)

Full Text Available A simple and highly sensitive direct spectrophotometric method was developed for the determination of L-ascorbic acid. Potassium cyanide (9.21x10-5 mol dm-3 was used to stabilize ascorbic acid in aqueous medium. The molar absorptivity of the proposed method, which does not require an extraction procedure, was 1.38x104 dm3 mol-1 cm-1 at 264 nm. Beer’s law was obeyed in the concentration range of 0.26 – 12.0 ?g ascorbic acid cm-3. Th e relative standard deviation was 1.40 % for the determination of 8.0 ?g ascorbic acid cm-3 (n = 7. The substances commonly found in vitamin C products do not interfere with the determination of ascorbic acid. Other vitamins and organic acids interfere. The proposed procedure was successfully applied to the determination of ascorbic acid in pure form and vitamin C preparations.

Mirsad Salki?

2007-12-01

85

Antioxidant properties of ascorbic acid in bulk oils at different relative humidity.  

Science.gov (United States)

The effects of relative humidity (RH) on the antioxidant properties of ascorbic acid (10, 20, 42, and 84ppm) were investigated in stripped corn oils stored at 60°C. The degree of oxidation in oils was determined by analysing headspace oxygen content and conjugated dienoic acids. The oxidative stability of bulk oils without addition of ascorbic acid was significantly different depending on the RH. As the concentration of ascorbic acid increased from 10 to 84ppm, oxidative stability increased significantly irrespective of RH (p<0.05). Generally, oils containing ascorbic acid at low RH had higher oxidative stability after storage at 60°C than those at high RH. The antioxidant properties of ascorbic acid were greatly influenced by both the moisture content in the oil and the ascorbic acid concentration. PMID:25624237

Kim, Ji Young; Kim, Mi-Ja; Yi, Bora; Oh, Sumi; Lee, JaeHwan

2015-06-01

86

Effects of supplemental ascorbic acid on humeral immune response in broilers reared under heat-stress condition  

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Full Text Available An experiment was conducted to evaluate the efficacy of supplemental ascorbic acid (Vitamin C on the haemagglutination inhibition (HI and enzyme linked immune sorbent assay (ELISA antibody titer of the commercial broiler chicks vaccinated against Newcastle disease (ND virus, reared under heat stress condition. A total of 420, one day-old broiler chicks were randomly divided into 4 groups and kept under elevated summer temperature and treated with four levels of added ascorbic acid i.e., 0 (control group, 200, 400, 600 mg/kg in diets for 28 days, from 21 to 49 days of experimental period. HI antibody titer and ELISA antibody titer against ND virus were significantly (P<0.05 higher at 600 mg/kg Vitamin C in the diet than the others treatments. Apparently, adding ascorbic acid at 600 mg/kg in the diet could improve humoral immunity in broilers reared under heat stress.

Vahel J. A. Amedy,

2011-07-01

87

Simultaneous determination of ascorbic acid and acetylsalicylic acid in pharmaceutical formulations.  

Science.gov (United States)

A direct, simple, and practical first-derivative spectrophotometric method is described for simultaneous determination of ascorbic acid and acetylsalicylic acid. The effects of the solvent, excipients, and spectral variables on the analytical signal were investigated. The drugs were determined simultaneously with a 0.01 M methanolic hydrochloric acid solution as the solvent, and the signals were evaluated directly by using the zero-crossing method at 245.0 and 256.0 nm for acetylsalicylic acid and ascorbic acid, respectively. The method allows the simultaneous determinations of acetylsalicylic acid and ascorbic acid in the ranges of 6.6 x 10(-6) to 1.5 x 10(-4)M and 3.4 x 10(-6) to 2.0 x 10(-4)M, respectively, with standard deviation of determinations of these drugs in tablets. PMID:11234849

Toral, M I; Lara, N; Richter, P; Tassara, A; Tapia, A E; Rodriguez, C

2001-01-01

88

Degradation kinetic modelling of ascorbic acid and colour intensity in pasteurised blood orange juice during storage.  

Science.gov (United States)

The stability of ascorbic acid and colour intensity in pasteurised blood orange juice (Citrus sinensis [L.] Osbeck) during one month of storage was investigated at 4-37°C. The effects of ascorbic acid fortification (at 100, 200mgL(-1)) and deaeration, temperature/time storage on the kinetic behaviour were determined. Ascorbic acid was monitored by HPLC-DAD and colour intensity by spectrophotometric measurements. Degradation kinetics were best fitted by first-order reaction models for both ascorbic acid and colour intensity. Three models (Arrhenius, Eyring and Ball) were used to assess the temperature-dependent degradation. Following the Arrhenius model, activation energies were ranged from 51 to 135kJmol(-1) for ascorbic acid and from 49 to 99kJmol(-1) for colour intensity. The effect of storage temperature and deaeration are the most influent factors on kinetics degradation, while the fortification revealed no significant effect on ascorbic acid content and colour intensity. PMID:25466074

Remini, Hocine; Mertz, Christian; Belbahi, Amine; Achir, Nawel; Dornier, Manuel; Madani, Khodir

2015-04-15

89

Infrared spectra of ascorbic acid and its complexes with zinc(2) and vanadium(4)  

International Nuclear Information System (INIS)

The infrared spectra are studied of ascorbic acid and its complexes with zink(2) and vanadium(4) in the solid state and in aqueous solutions over a wide range of pH. The bands of the spectra of ascorbic acid (H2Asc), its dissociation products (HAsc- and Asc2-), and also complexes of ascorbic acid with zink(2) and vanadium(4) are correlated

90

A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex  

International Nuclear Information System (INIS)

A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 ?g ml-1. Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C

91

Enzyme-mimetic effects of gold@platinum nanorods on the antioxidant activity of ascorbic acid  

Science.gov (United States)

Au@Pt nanorods were prepared by growing platinum nanodots on gold nanorods. Using electron spin resonance (ESR), we determined that the mechanisms for oxidation of ascorbic acid (AA) by Au@Pt nanorods and ascorbic acid oxidase (AAO) were kinetically similar and yielded similar products. In addition we observed that Au@Pt nanorods were stable with respect to temperature and pH. Using UV-VIS spectroscopy, the apparent kinetics of enzyme-mimetic activity of Au@Pt nanorods were studied and compared with the activity of AAO. With the help of ESR, we found that Au@Pt nanorods did not scavenge hydroxyl radicals but inhibited the antioxidant ability of AA for scavenging hydroxyl radicals produced by photoirradiating solutions containing titanium dioxide and zinc oxide. Moreover, the Au@Pt nanorods reduced the ability of AA to scavenge DPPH radicals and superoxide radicals. These results demonstrate that Au@Pt nanorods can reduce the antioxidant activity of AA. Therefore, it is necessary to consider the effects of using Pt nanoparticles together with other reducing agents or antioxidants such as AA due to the oxidase-like property of Au@Pt nanorods.Au@Pt nanorods were prepared by growing platinum nanodots on gold nanorods. Using electron spin resonance (ESR), we determined that the mechanisms for oxidation of ascorbic acid (AA) by Au@Pt nanorods and ascorbic acid oxidase (AAO) were kinetically similar and yielded similar products. In addition we observed that Au@Pt nanorods were stable with respect to temperature and pH. Using UV-VIS spectroscopy, the apparent kinetics of enzyme-mimetic activity of Au@Pt nanorods were studied and compared with the activity of AAO. With the help of ESR, we found that Au@Pt nanorods did not scavenge hydroxyl radicals but inhibited the antioxidant ability of AA for scavenging hydroxyl radicals produced by photoirradiating solutions containing titanium dioxide and zinc oxide. Moreover, the Au@Pt nanorods reduced the ability of AA to scavenge DPPH radicals and superoxide radicals. These results demonstrate that Au@Pt nanorods can reduce the antioxidant activity of AA. Therefore, it is necessary to consider the effects of using Pt nanoparticles together with other reducing agents or antioxidants such as AA due to the oxidase-like property of Au@Pt nanorods. Electronic supplementary information (ESI) available: Ascorbic acid oxidase activity of Pt NPs and the effects of Au@Pt nanorods on hydroxyl radicals generated from the Fenton reactions and TiO2 exposed to UV radiation. See DOI: 10.1039/c2nr33072e

Zhou, Yu-Ting; He, Weiwei; Wamer, Wayne G.; Hu, Xiaona; Wu, Xiaochun; Lo, Y. Martin; Yin, Jun-Jie

2013-01-01

92

The methanol method for the quantification of ascorbic acid and dehydroascorbic acid in biological samples.  

Science.gov (United States)

We present a fast to perform spectrophotometric method for the quantification of ascorbic acid and its oxidized form dehydroascorbic acid in biological samples. The assay detects a chromophore formed during the reaction of dehydroascorbic acid with methanol in phosphate/citrate buffer. This reaction can also be employed for the determination of ascorbate (vitamin C) in the presence of ascorbate oxidase. The major advantage of the developed protocol for the determination of both forms of vitamin C is a simple spectrophotometrical single end point determination. It is demonstrated that the methanol method is an improvement compared with a commercially available test kit for the determination of vitamin C. Using the methanol method, a dose-dependent increase in intracellular ascorbic acid was determined upon incubation of L-929 cells and RAW 264.7 macrophages with increasing concentrations of extracellular ascorbate. In blood serum, vitamin C was determined at concentrations between 46 and 97 microM. Supplementation with different amounts of ascorbate showed satisfying recovery. In L-929 cells, even unphysiologically high amounts of reactive nitrogen species were unable to completely oxidize intracellular vitamin C. PMID:15026207

Badrakhan, Curd-David; Petrat, Frank; Holzhauser, Maren; Fuchs, Anke; Lomonosova, Elena E; de Groot, Herbert; Kirsch, Michael

2004-03-31

93

EVALUATION OF ASCORBIC ACID LEVELS IN WAR WOUNDED PATIENTS  

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Full Text Available This investigation determined that vitamin C intake of C.W. was higher than O.P. , S. C. and C. Statistically, there was a significant difference between C.W. and C. Blood ascorbic acid levels of O.P. and S.C. were lower than C.W. and C. , a significant difference was observed. Urinary vitamin C in all groups was lower than controls and this indicates that even though vitamin C intake was high, the demand for vitamin C was increased.

A. Keshavarz Dehno

1988-08-01

94

Efficiency of ascorbic acid and ?-rays to ameliorate the quality of ready-to-eat baked bolti fish fillets  

International Nuclear Information System (INIS)

Ascorbic acid (vitamin C) is a reducing agent, inhibits oxidative reactions developed in cold-storage Bolti (Tilapia nilotica) fish. It is the most popular fish repasts in Egypt. To determine the influence of ascorbic acid on cooking (roasting) and irradiated fish fillets to extend their storage-time in refrigerators, 3 patches of fish fillets were prepared; control (0 kGy), ascorbic acid plus 2.5 kGy and ascorbic acid plus 4 kGy and were tested for bacteriological examination, chemical analysis and sensory evaluation at 0, 1, 2 and 3 weeks of cold storage at 5±1 degree C. The bacteriological examinations were total aerobic plate counts, psychotropic bacterial counts, Enterobacteriaceae counts, total mould and yeast counts and microbial pathogens counts (Salmonella and Vibrio species). The chemical analyses were thiobarbituric acid reactive substances (TBARS), inosine 5-monophosphate (IMP) concentration, hypoxanthine (HX) concentration, ph figure, total volatile nitrogen (TVN) and total trimethylamine nitrogen (TMA-N). The sensory evaluation was (texture and odour factors) of the cold-storage Bolti fish fillets samples. The results revealed that aerobically packed fish fillets samples treated with ascorbic acid plus 4 kGy after cooking had satisfied bacteriological, chemical and organoleptical trails. Conclusion: using of baking, irradiation combined with natural antioxidant nd refrigeration could reduce the energy requirements for freezing and costs for the marketins for freezing and costs for the marketing of ready- to-eat fish repasts. Recommendation: combination effects of ?-irradiation plus ascorbic acid in processing fish fillets help to preserve its quality. The possible strategies for improving fish fillets quality and acceptability are discussed

95

Carbonate interlayered hydrotalcites-enhanced peroxynitrous acid chemiluminescence for high selectivity sensing of ascorbic acid.  

Science.gov (United States)

In this study, Mg-Al-carbonate layered double hydroxides (denoted as Mg-Al-CO(3) LDHs) were found to catalyze the chemiluminescence (CL) emission from peroxynitrous acid (ONOOH). The enhanced CL signals resulted from the concentration of peroxynitrite (ONOO(-)) onto the LDHs surface by electrostatic attraction, meaning that ONOO(-) can interact with the intercalated carbonate easily and effectively. Moreover, ascorbic acid can react with ONOO(-), or its decomposition products (e.g., ?OH and ?NO(2)), resulting in a decrease in the CL intensity from the Mg-Al-CO(3) LDHs-catalyzed ONOOH reaction. Based on these findings, a sensitive, selective and rapid CL method was developed for the determination of ascorbic acid using Mg-Al-CO(3) LDHs-catalyzed ONOOH as a novel CL system. The CL intensity was proportional to the concentration of ascorbic acid in the range from 5.0 to 5000 nM. The detection limit (S/N = 3) was 0.5 nM and the relative standard deviation (RSD) for nine repeated measurements of 0.1 ?M ascorbic acid was 2.6%. This method has been successfully applied to determine ascorbic acid in commercial liquid fruit juices with recoveries of 97-107%. This work is not only of importance for a better understanding of the unique properties of LDHs-catalyzed CL but also of great potential for extensive applications in many fields, such as luminescence devices, bioanalysis, and labeling probes. PMID:22382556

Wang, Zhihua; Teng, Xu; Lu, Chao

2012-04-21

96

Peroxydisulfate Oxidation of L-Ascorbic Acid for Its Direct Spectrophotometric Determination in Dietary Supplements  

Science.gov (United States)

A selective and accurate direct spectrophotometric method was developed for the determination of L-as cor bic acid in dietary supplements. Background correction was based on the oxidation of L-ascorbic acid by potassi um peroxydisulfate in an acidic medium. The molar absorptivity of the proposed method was 1.41 · 104 l/(mol · cm) at 265 nm. The method response was linear up to an L-ascorbic acid concentration of 12.00 ?g/ml. The detection limit was 0.11 ?g/ml, and the relative standard deviation was 0.9 % (n = 7) for 8.00 ?g/ml L-ascorbic acid. Other compounds commonly found in the dietary supplements did not interfere with the detection of L-ascorbic acid. The proposed procedure was successfully applied to the determination of L-ascorbic acid in these supplements, and the results obtained agreed with those obtained by iodine titration.

Salki?, M.; Selimovi?, A.; Pašali?, H.; Keran, H.

2014-03-01

97

Improvement of bioavailability for iron from vegetarian meals by ascorbic acid  

International Nuclear Information System (INIS)

There are two kinds of iron in the diet with respect to the mechanism of absorption, heme-iron which is present as haemoglobin or myoglobin in meat and blood products, and, non-heme iron which is the main source of dietary iron. The bioavailability of the non-heme food iron is much lower than heme-iron. Vegetarian diets contain only non-heme iron. Iron intake from vegetarian meals are generally satisfied with the requirements, however, the bioavailabilities for non-heme iron is determined not only by iron content byt also the balance between different dietary factors enhancing and inhibiting iron absorption. The main enhancing factor in vegetarian meals is ascorbic acid in fruits and vegetables, inhibitors are phytate in cereals and grains, and tannins in some spices and vegetables. It has been reported that iron deficiency is one of the common micronutrient problems associated with unplanned vegetarian diets. In the present study the absorption of non-heme iron was measured from 2 vegetarian meals containing considerable amounts of phytate and tannin. The extrinsic tay method (59Fe/ 55Fe) was used to labelled the non-heme iron. The mean percentage absorption of non-heme iron from both meals was slightly different due to differences in their dietary contents. Their initial percentages iron absorption were apparent low (3.5% and 4.1%), however, the absorption progressively increased with increase in the level of ascorbic acid, 2-3 times with 100 mg and 4-5 times with 200 mg of ascorbic acid. The average amount of iron absorbed per 2000 kcal increased from 0.37 mg to 0.86 mg and 1.45 mg with the addition of 100 mg and 200 mg ascorbic acid respectively (p < 0.001). Considering the limited caloric intakes and the iron content in the meals, the amount of iron absorbed from vegetarian meals without ascorbic acid was not able to meet certain requirements for children, adolescents and menstruating women. The minimal requirement for dietary iron needed to be absorbed is 0.49 mg for 50% of 1-2 year children and more than 1 mg for girls and menstruating women. The vegetarian meals as compared with ordinary mixed meals can provided most of the nutrients in the amounts close to or above the recommended intaked according to the Recommended Daily Allowances (RDA). However, the amounts of iron absorbed from these meals are quite precarious and fail to meet the requirements for the important target groups. It is suggested that, vegetarian diets can assure nutrient adequacy and promote health when they are planned and chosen in the line with scientific nutrition principles

98

The Oxidation of Ascorbic Acid by Hexacyanoferrate(III) Ion in Acidic Aqueous Media.  

Science.gov (United States)

Describes a kinetic and mechanistic investigation of ascorbic acid by a substitution-inert complex in acidic medium suitable for the undergraduate level. Discusses obtaining the second order rate constant for the rate determining step at a given temperature and comparison with the value predicted on the basis of the Marcus cross-relation. (CW)

Martins, Luis J. A.; da Costa, J. Barbosa

1988-01-01

99

Ischemia/reperfusion alters uric acid and ascorbic acid levels in liver.  

Science.gov (United States)

Tissue damage in ischemia/reperfusion injury may be mediated by oxidative stress caused by reactive oxidant species. Since such reactive species are difficult to measure directly, changes in antioxidant concentrations are often used as an indication of oxidative stress. In this study, microdialysis membranes were inserted into the livers of anesthetized rats to determine the effects of ischemia/reperfusion on the extra-cellular concentrations of two antioxidants, uric acid and ascorbic acid. Total hepatic ischemia was induced for 30 min by clamping the portal triad and was followed by 60 min of reperfusion. Uric acid and ascorbic acid concentrations were measured in microdialysis perfusates by high-performance liquid chromatography with electrochemical detection. Initial uric acid and ascorbic acid concentrations were high after insertion of membranes into the liver and decreased rapidly within 90 min (P acid concentrations increased over 300% after ischemia and by 600% during the first 30 min of reperfusion (n = 8; P Ascorbic acid concentrations were 60% higher than controls after ischemia and 90% higher during the first 30 min of reperfusion (n = 8; P < 0.05). Alterations in concentrations of these redox-active molecules may be associated with oxidative stress in liver extracellular fluid during ischemia/reperfusion. PMID:8806465

Layton, M E; Wood, J G; Yan, Z Y; Forster, J

1996-07-15

100

Effects of Household Storage on Ascorbic Acid Content of Some Selected Nigerian Vegetables  

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Full Text Available Effects of household preservation were assessed in five vegetables commonly consumed in major tribes of Nigeria; Hibiscus esculentus, Corchorus olitorus, Lycopersicum esculentum, Talinum triangulare and Amaranthus caudatus. The selected vegetables were purchased from local markets without knowing their maturity age and time of harvest. The wholesomeness of the vegetables was based on physical examination of their texture and colour. The vegetables were divided into two portions. In the first portion, moisture and ascorbic acid were estimated. This served as the control. The second portion was sundried and their moisture and ascorbic acid compositions determined as well. Both moisture and ascorbic acid content of the vegetables were determined using standard methods. Sun-drying decreased ascorbic acid values between 68.1 and 86.7%. Moisture losses due to sun-drying ranged between 80.1 and 96.6%. The highest moisture and ascorbic acid losses were those of Talinum triangulare while Lycopersicum esculentum and Hibiscus esculentus had the least losses of moisture and ascorbic acid, respectively. Sundrying adversely affected ascorbic acid in these vegetables. Nutrition education is therefore necessary to minimize loss of ascorbic acid in vegetables due to household storage methods.

I.C. Obizoba

2013-01-01

101

Retention of ascorbic acid in fortified orange juice powers during storage  

Directory of Open Access Journals (Sweden)

Full Text Available Both Coorg and Sathgudi orange juice powders are good carriers for added ascorbic acid during prolonged storage at ordinary temperatures. There is not much difference between nitrogen and air packs as regards retention of ascorbic acid during storage. Nitrogen pack, however, helps to keep the power in a better free-flowing condition.

G. S. Siddappa

2014-05-01

102

Glutathione deficiency increases hepatic ascorbic acid synthesis in adult mice.  

OpenAIRE

Glutathione deficiency, induced in adult mice by administering buthionine sulfoximine (an inhibitor of glutathione synthesis), led to a rapid and substantial increase in ascorbate in the liver. This effect was apparent 2-4 hr after giving the inhibitor; subsequently, the level of ascorbate decreased and that of dehydroascorbate increased markedly, supporting the conclusion that glutathione functions physiologically to keep ascorbate in its reduced form. In kidney and lung also, ascorbate leve...

Ma?rtensson, J.; Meister, A.

1992-01-01

103

Ascorbic acid metabolism during bilberry (Vaccinium myrtillus L.) fruit development.  

Science.gov (United States)

Bilberry (Vaccinium myrtillus L.) possesses a high antioxidant capacity in berries due to the presence of anthocyanins and ascorbic acid (AsA). Accumulation of AsA and the expression of the genes encoding the enzymes of the main AsA biosynthetic route and of the ascorbate-glutathione cycle, as well as the activities of the enzymes involved in AsA oxidation and recycling were investigated for the first time during the development and ripening of bilberry fruit. The results showed that the AsA level remained relatively stable during fruit maturation. The expression of the genes encoding the key enzymes in the AsA main biosynthetic route showed consistent trends with each other as well as with AsA levels, especially during the first stages of fruit ripening. The expression of genes and activities of the enzyme involved in the AsA oxidation and recycling route showed more prominent developmental stage-dependent changes during the ripening process. Different patterns of activity were found among the studied enzymes and the results were, for some enzymes, in accordance with AsA levels. In fully ripe berries, both AsA content and gene expression were significantly higher in skin than in pulp. PMID:22608079

Cocetta, Giacomo; Karppinen, Katja; Suokas, Marko; Hohtola, Anja; Häggman, Hely; Spinardi, Anna; Mignani, Ilaria; Jaakola, Laura

2012-07-15

104

Antidepressant-like effect of ascorbic acid is associated with the modulation of mammalian target of rapamycin pathway.  

Science.gov (United States)

The present study investigated the involvement of the PI3K, GSK-3?, heme oxygenase-1 (HO-1) and mTOR in the antidepressant-like effect of ascorbic acid in the tail suspension test (TST). Male Swiss mice were pretreated with ascorbic acid (1 mg/kg, p.o.) or vehicle and 45 min after, LY294002 (10 ?g/site, i.c.v., reversible PI3K inhibitor), rapamycin (0.2 nmol/site, i.c.v., selective mTOR inhibitor), zinc protoporphyrin (ZnPP - 10 ng/site, i.c.v., HO-1 inhibitor) or vehicle was administered. We also investigated the synergistic effect of ascorbic acid (0.1 mg/kg, p.o., sub-effective dose in the TST) with lithium chloride (10 mg/kg, p.o., non-selective GSK-3? inhibitor), AR-A014418 (0.01 ?g/site, i.c.v., selective GSK-3? inhibitor) or cobalt protoporphyrin (CoPP - 0.01 ?g/site, i.c.v., HO-1 inducer) in the TST. The antidepressant-like effect of ascorbic acid (1 mg/kg, p.o.) was prevented by the treatment of mice with LY294002, rapamycin or ZnPP. In addition, sub-effective doses of lithium chloride, AR-A014418 or CoPP, combined with a sub-effective dose of ascorbic acid produced a synergistic antidepressant-like effect. We also demonstrated that 1 h after its administration, ascorbic acid increased the phosphorylation of p70S6K and the immunocontent of PSD-95 in the hippocampus of mice. These results indicate that the antidepressant-like effect of ascorbic acid in the TST might be dependent on the activation of PI3K and mTOR, inhibition of GSK-3? as well as induction of HO-1, reinforcing the notion that these are important targets for antidepressant activity and contributing to better elucidate the mechanisms underlying the antidepressant-like effect of ascorbic acid. PMID:24209999

Moretti, Morgana; Budni, Josiane; Freitas, Andiara Espíndola; Rosa, Priscila Batista; Rodrigues, Ana Lúcia S

2014-01-01

105

Flow injection spectrophotometric determination of ascorbic acid using iron(III)-bathophenanthroliine disulfonic acid disodium salt  

International Nuclear Information System (INIS)

A single step straightforward, indirect flow injection spectrophotometric determination of ascorbic acid is proposed. The solution of iron (III) and bathophenanthroline disulfonic acid salt in 1 0/sup -4/M HCl media is used as an oxidative reagent. Reagent is reduced to tris-bathophenanthroline disulfonic acid-iron (II) chelate, by the ascorbic acid at room temperature. Spectrophotometric monitoring of absorbance signal of tris chelate at 535 nm is directly related to the concentration of ascorbic acid. The effect of various parameters e.g. pH, flow rate, sample volume, reaction coil length, etc. on the analytical signal were examined and optimized. Under optimized parameters such as sample volume (100mL), flow rate- (2.2 ml/min), reagent concentration (2 x 10/sup -4/ M ammonium iron(III) sulfate + 2 x 10/sup-4/ M bathophenonthroline disulfonic disodium salt.), pH (4.0), reaction coil length (50 cm) and wave length (535 nm), ascorbic acid can be determined in the range of 1-10 /ml (R=0.9924) with sample throughput of 80 samples per hour. Single channel flow injection analysis (FIA) manifold raises the sample throughput as compared to other existing procedures. The validity of the proposed method is tested by analyzing citrus fruits using present and the standard addition method. Results of the two methods are in good agreement.(author)

106

Effect of Dietary Ascorbic Acid on Performance of Broiler Chickens Exposed to Different Lighting Regime  

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Full Text Available A 2 x 2 factorial experiment was conducted to determine the performance of 400 Anak broiler chicks exposed to two lighting regimes viz. 12 h light:12 h darkness and 24 h light:0 h darkness and fed diets containing two levels of ascorbic acid (0 and 250 mg AA/kg of feed. Each treatment was replicated four times with 25 birds per replicate. Results showed that at the starter phase of growth, chicks on continuous lighting regime recorded significantly (p0.05 effect on weight gain but addition of ascorbic acid in the diet significantly (p0.05 between continuous and limited lighting on feed: gain ratio. However, chicks with ascorbic in their diet recorded significantly (p<0.05 better feed: gain ratio than those without ascorbic acid. Inclusion of ascorbic acid in the diet significantly (p<0.05 reduced feed cost per kilogram weight gain. Ascorbic acid inclusion significantly (p<0.05 increased femur weight but not femur ash and tibia length. Continuous lighting and inclusion of ascorbic acid from diets increased incidence of leg abnormality significantly. Inclusion of ascorbic acid significantly (p<0.05 reduced the severity of leg abnormality. In conclusion continuous lighting and ascorbic acid in the diet may improve weight gain, feed: gain ratio, reduced feed cost per kilogram weight gain and reduction in the severity of leg abnormality. It may be recommended that under continuous lighting, inclusion of ascorbic acid in the diet may be recommended for balanced growth of the chicks.

A.I. Okwori

2010-01-01

107

Amperometric biosensor for ascorbic acid / Biossensor amperométrico para ácido ascórbico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Desenvolveu-se um biossensor para ácido L-ascórbico empregando ascorbato oxidase. A enzima foi extraída do mesocarpo de pepino com solução tampão fosfato 0,05 mol L-1, pH 5,8 contendo NaCl 0,5 mol L-1. Após diálise versus solução tampão fosfato 0,05 mol L-1, pH 5,8 a enzima foi imobilizada em rede d [...] e nylon através de ligação covalente com glutaraldeído. A membrana foi acoplada em eletrodo de O2 e a reação monitorada pelo consumo de oxigênio a -600 mV em análise em fluxo (solução tampão fosfato 0,05 mol L-1, pH 5,8 como carregador e vazão 0,5 mL min-1). A curva analítica apresentou-se linear entre 1,2x10-4 a 1,0x10-3 mol L-1. O tempo de vida do biossensor foi de 500 análises. Amostras de medicamentos foram analisadas com a metodologia proposta e os resultados comparados com os obtidos com HPLC. Abstract in english A L-ascorbic acid biosensor based on ascorbate oxidase has been developed. The enzyme was extracted from the mesocarp of cucumber (Cucumis sativus) by using 0.05 mol L-1 phosphate buffer, pH 5.8 containing 0.5 mol L-1 NaCl. After the dialysis versus phosphate buffer 0.05 mol L-1 pH 5.8, the enzyme w [...] as immobilized onto nylon net through glutaraldehyde covalent bond. The membrane was coupled to an O2 electrode and the yielding reaction monitored by oxygen depletion at -600 mV using flow injection analysis optimized to 0.1 mol L-1 phosphate buffer pH 5.8, as the carrier solution and flow-rate of 0.5 mL min-1. The ascorbic acid calibration curve was linear from 1.2x10-4 to 1.0x10-3 mol L-1. The evaluation of biosensor lifetime leads to 500 injections. Commercial pharmaceutical samples were analyzed with the proposed method and the results were compared with those obtained by high-performance liquid chromatography (HPLC).

I. N., Tomita; A., Manzoli; F. L., Fertonani; H., Yamanaka.

108

Assessing the survival of mrc-5 and a549 cell lines upon exposure to ascorbic Acid and sodium ascorbate - biomed 2011.  

Science.gov (United States)

Lung cancer is among the highly prevalent and deadly cancers in the United States and worldwide. Cells that are cancerous exhibit higher rates of glycolysis as compared to normal cells. In an attempt to exploit this uniquely enhanced glucose-dependent ATP generation phenomenon, the authors hypothesize that exposure of cancer cells to normal organic metabolites that are capable of inhibiting glycolysis would have a negative impact on survival by altering growth and viability characteristics vastly through decline in ATP build up essentially leading to collapse in energy supply; normal lung cells will not demonstrate such changes. The human lung fibroblast cell line MRC-5 and the cancerous human lung alveolar epithelial cell line A549 were utilized in this study as in vitro models of normal and cancerous lung cell lines respectively. Using standard methods, both cell lines were maintained in culture and exposed to ascorbic acid and sodium ascorbate reagents at concentration levels ranging from 31.3-2,000 µg/ml. Cell survival measurements using MTT andT4 Cellometric assays monitored with phase-contrast photo-imaging were carried out in quadruplicates. Results indicate that exposure characteristics to these metabolites followed concentration-dependent cell mortality/survival curves by the cancerous versus normal cell lines respectively. Ascorbic acid and sodium ascorbate showed statistically significant (pcancerous A549 cell line in comparison to unexposed controls as well as to effects measured with the normal lung MRC-5 cell line; this is highly indicative of a promising therapeutic potential. PMID:21525621

Farah, Ibrahim O; Lewis, Veshell L; Ayensu, Wellington K; Mahmud, Ousman

2011-01-01

109

Determination of total L-Ascorbic Acid by high performance liquid chromatography in human plasma  

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Full Text Available The total vitamin C content in human plasma is widely accepted as an indicator of the tissue status of vitamin C. A liquid chromatography method with ultraviolet detector (264 nm for measuring ascorbic acid in human plasma was developed. A C18 reversed-phase column and cetrimide as an ion-pairing agent was employed. Ascorbic acid (AA was measured after reducing L-dehydroascorbic acid to L-ascorbic acid with dithiothreitol. The stability of the ascorbic acid in plasma, metaphosphoric acid and trichloroacetic acid was also evaluated. The analytical parameters, including linearity (1-60 µg/ml, accuracy (98.98%, repeatability (2.8% and reproducibility (7.2%, showed that the method is reliable for measuring the total vitamin C content in plasma.

Oveisi MR

2001-07-01

110

Ascorbate enhances u.v.-mutagenesis in E. coli but inhibits it in Chinese hamster cells  

International Nuclear Information System (INIS)

Ascorbic acid (vitamin C) causes an increase in the mutation frequency of u.v.-irradiated Escherichia coli WP2. The enhancement occurs at all u.v. fluences, and is dependent upon the ascorbate concentration in the medium. A maximum effect (approx. 8- to 13-fold) is seen at 100-150 ?g/ml, although some enhancement can be seen even at 10 ?g/ml. The comutagenic effect of ascorbate with u.v. in E. coli is dependent upon peptone, a constituent of nutrient broth. The enhancement of u.v.-mutagenesis by ascorbate is absent in strains WP2sub(s) (uvrA) amd WP6 (polA), suggesting that ascorbate affects the repair of pyrimidine dimers. The opposite results are observed for u.v.-mutagenesis in Chinese hamster V79 cells. The presence of ascorbate (50 ?g/ml) during u.v. irradiation does not enhance the u.v. effect, but rather decreases it approx. 30%. These results are discussed with regard to differences in the mechanism of u.v.-mutagenesis and DNA repair in bacterial and mammalian cells. (author)

111

Ascorbate enhances u.v.-mutagenesis in E. coli but inhibits it in Chinese hamster cells  

International Nuclear Information System (INIS)

Ascorbic acid (vitamin C) causes an increase in the mutation frequency of u.v.-irradiated Escherichia coli WP2. The enhancement occurs at all u.v. fluences, and is dependent upon the ascorbate concentration in the medium. A maximum effect (approximately 8- to 13-fold) is seen at 100-150 micrograms/ml, although some enhancement can be seen even at 10 micrograms/ml. The comutagenic effect of ascorbate with u.v. in E. coli is dependent upon peptone, a constituent of nutrient broth. The enhancement of u.v.-mutagenesis by ascorbate is absent in strains WP2s (uvrA) and WP6 (polA), suggesting that ascorbate affects the repair of pyrimidine dimers. The opposite results are observed for u.v.-mutagenesis in Chinese hamster V79 cells. The presence of ascorbate (50 micrograms/ml) during u.v. irradiation does not enhance the u.v. effect, but rather decreases it approximately 30%. These results are discussed with regard to differences in the mechanism of u.v.-mutagenesis and DNA repair in bacterial and mammalian cells

112

Antioxidants in sickle cell disease: the in vitro effects of ascorbic acid.  

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The authors examined the ability of antioxidants to prevent in vitro oxidant damage to the sickle red blood cell (RBC). One millimolar ascorbic acid and alpha-mercaptopropionylglycine significantly (p less than 0.005) protected against RBC Heinz body formation during incubation with acetylphenylhydrazine, while cysteine, cysteamine, and methionine did not. The effect of ascorbic acid was concentration dependent with concentrations as low as 0.1 mM having significant antioxidant effects. Ascorbic acid protected the RBC against hydrogen peroxide induced hemolysis as well (p less than 0.05). Ascorbic acid had a significant stimulatory effect on the rate of glucose oxidation by the pentose phosphate shunt (PPS), especially in the sickle RBC. Ascorbic acid did not protect the RBC from a patient with chronic hemolytic anemia due to G6PDTorrance from Heinz body formation, suggesting that an intact PPS is necessary for ascorbic acid to express its antioxidant properties. These data suggest that clinical trials should be undertaken to examine the efficacy of ascorbic acid in the treatment of SCD. PMID:3521279

Lachant, N A; Tanaka, K R

1986-07-01

113

Effects of ascorbic acid and antioxidants on color, lipid oxidation and volatiles of irradiated ground beef  

Science.gov (United States)

Beef loins with 3 different aging times after slaughter were ground, added with none, 0.1% ascorbic acid, 0.01% sesamol+0.01% ?-tocopherol, or 0.1% ascorbic acid+0.01% sesamol+0.01% tocopherol. The meats were packaged in oxygen-permeable bags, irradiated at 2.5 kGy, and color, oxidation-reduction potential (ORP), lipid oxidation and volatile profiles were determined. Irradiation decreased the redness of ground beef, and visible color of beef changed from a bright red to a green/brown depending on the age of meat. Addition of ascorbic acid prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. The ground beef added with ascorbic acid had lower ORP than control, and the low ORP of meat helped maintaining the heme pigments in reduced form. During aerobic storage, S-volatiles disappeared while volatile aldehydes significantly increased in irradiated beef. Addition of ascorbic acid at 0.1% or sesamol+?-tocopherol at each 0.01% level to ground beef prior to irradiation were effective in reducing lipid oxidation and S-volatiles. As storage time increased, however, the antioxidant effect of sesamol+tocopherol in irradiated ground beef was superior to that of ascorbic acid.

Ahn, D. U.; Nam, K. C.

2004-09-01

114

Effects of ascorbic acid and antioxidants on color, lipid oxidation and volatiles of irradiated ground beef  

Energy Technology Data Exchange (ETDEWEB)

Beef loins with 3 different aging times after slaughter were ground, added with none, 0.1% ascorbic acid, 0.01% sesamol+0.01% {alpha}-tocopherol, or 0.1% ascorbic acid+0.01% sesamol+0.01% tocopherol. The meats were packaged in oxygen-permeable bags, irradiated at 2.5 kGy, and color, oxidation-reduction potential (ORP), lipid oxidation and volatile profiles were determined. Irradiation decreased the redness of ground beef, and visible color of beef changed from a bright red to a green/brown depending on the age of meat. Addition of ascorbic acid prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. The ground beef added with ascorbic acid had lower ORP than control, and the low ORP of meat helped maintaining the heme pigments in reduced form. During aerobic storage, S-volatiles disappeared while volatile aldehydes significantly increased in irradiated beef. Addition of ascorbic acid at 0.1% or sesamol+{alpha}-tocopherol at each 0.01% level to ground beef prior to irradiation were effective in reducing lipid oxidation and S-volatiles. As storage time increased, however, the antioxidant effect of sesamol+tocopherol in irradiated ground beef was superior to that of ascorbic acid.

Ahn, D.U. E-mail: duahn@iastate.edu; Nam, K.C

2004-10-01

115

Effects of ascorbic acid and antioxidants on color, lipid oxidation and volatiles of irradiated ground beef  

International Nuclear Information System (INIS)

Beef loins with 3 different aging times after slaughter were ground, added with none, 0.1% ascorbic acid, 0.01% sesamol+0.01% ?-tocopherol, or 0.1% ascorbic acid+0.01% sesamol+0.01% tocopherol. The meats were packaged in oxygen-permeable bags, irradiated at 2.5 kGy, and color, oxidation-reduction potential (ORP), lipid oxidation and volatile profiles were determined. Irradiation decreased the redness of ground beef, and visible color of beef changed from a bright red to a green/brown depending on the age of meat. Addition of ascorbic acid prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. The ground beef added with ascorbic acid had lower ORP than control, and the low ORP of meat helped maintaining the heme pigments in reduced form. During aerobic storage, S-volatiles disappeared while volatile aldehydes significantly increased in irradiated beef. Addition of ascorbic acid at 0.1% or sesamol+?-tocopherol at each 0.01% level to ground beef prior to irradiation were effective in reducing lipid oxidation and S-volatiles. As storage time increased, however, the antioxidant effect of sesamol+tocopherol in irradiated ground beef was superior to that of ascorbic acid

116

21 CFR 862.1095 - Ascorbic acid test system.  

Science.gov (United States)

...CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1095 Ascorbic... (b) Classification. Class I (general controls). The device is exempt...

2010-04-01

117

Ascorbic acid antagonizes nicotine-induced place preference and behavioral sensitization in female mice  

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Full Text Available Introduction: The influence of ascorbic acid on the nicotine-induced conditioned place preference (CPP and behavioral sensitization was investigated in the present study. Methods: In a pilot study, place conditioning and locomotor activity were investigated after nicotine (0.25, 0.5, 0.75, 1, 1.5 and 2 mg/kg or ascorbic acid (1, 10, 100 and 1000 mg/kg administration. Different doses of ascorbic acid in conditioning days or on the test days were used. Behavioral sensitization was induced in animals by daily intraperitoneal administration of nicotine (0.25 mg/kg for seven cosecutive days followed by one day interval. On 9th day, locomotor activity was induced by ineffective dose of nicotine (0.1 mg/kg. Ascorbic acid was injected 20 min before each injection of nicotine (acquisition of sensitization or acutely 20 min before a challenge nicotine injection (expression of sensitization. Results: The results showed that intraperitoneal nicotine (1 mg/kg administration can induce place preference whereas acute administration of the drug induces catalepsy. Administration of ascorbic acid did not induce place preference nor place aversion and also did not change the locomotor activity. Locomotor sensitization in mice was produced by intraperitoneal injection of nicotine (0.25 mg/kg for 7 consecutive days. On the 9th day of experiments, activity of the mice was recorded after challenge with nicotine (0.1 mg/kg, i.p.. The senisitization was better achived when the ineffective dose of nicotine (0.1 mg/kg was applied. Administration with ascorbic acid reduced both the acquisition and expression of nicotine-induced CPP. It was shown that ascorbic acid attenuated the acquisition of nicotine sensitization in a dose-independent manner but the expression of nicotineinduced sensitization was not affected by ascorbic acid. Conclusion: We conclude that ascorbic acid may interfere with nicotine-induced place preference and behavioral sensitization.

Ali Akbar Aliabadi

2006-04-01

118

Reductive dissolution of magnetite by ascorbic acid in presence of chelating agents  

International Nuclear Information System (INIS)

The kinetics of the dissolution of magnetite (Fe3O4) by ascorbic acid alone and ascorbic acid in presence of different chelating agents have been studied at different acid concentrations and chelating agent concentrations and as a function of pH. The overall rate of reaction is dependent on the instantaneous surface area of the magnetite particles and the probable reaction mechanism involves electron transfer from ascorbate anion to protonated and or chelated ?FeIII sites on the surface of the magnetite particles. (author). 7 refs., 5 figs

119

Study of Ascorbic Acid as Iron(III) Reducing Agent for Spectrophotometric Iron Speciation  

OpenAIRE

The study of ascorbic acid as a reducing agent for iron(III) has been investigated in order to obtain an alternative carcinogenic reducing agent, hydroxylamine, used in spectrophotometric standard method based on the formation of a red-orange complex of Fe(II)-o-phenanthroline. The study was optimised with regards to ascorbic acid concentration as well as pH solution. The results showed that ascorbic acid showed maximum capacity as reducing agent of iron(III) under concentration of 4...

Antesar Elmagirbi; Hermin Sulistyarti; Atikah Atikah

2012-01-01

120

Ascorbic Acid Determination in Commercial Fruit Juice Samples by Cyclic Voltammetry  

OpenAIRE

A method was developed for assessing ascorbic acid concentration in commercial fruit juice by cyclic voltammetry. The anodic oxidation peak for ascorbic acid occurs at about 490 mV on a Pt disc working electrode (versus SCE). The influence of the potential sweep speed on the peak height was studied. The obtained calibration graph shows a linear dependence between peak height and ascorbic acid concentration in the domain (0.1–10 mmol·L?1). The equation of the calibration graph was y = 6.3...

Slawomir Kalinowski; Aurelia Magdalena Pisoschi; Andrei Florin Danet

2008-01-01

121

Novel Postharvest Treatment Reduces Ascorbic Acid Losses in Mango (Mangifera indica L. Var. Kent  

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Full Text Available Problem statement: Mango is a tropical fruit that ripens very quickly; for this reason, there has been a continuous effort to develop postharvest technologies to extend its shelf life and quality. Among them, 1-Methylcyclopropene (1-MCP is widely used because it inhibits the action of ethylene receptors. Approach: Changes in physicochemical parameters, bioactive compounds and cell wall degrading activities were evaluated during storage and ripening of fresh whole mangoes treated with 1-MCP (750 nL L-1. Mature-green mangoes, cultivar Kent, untreated or treated with 1-MCP were evaluated for external quality, phytochemicals, Polygalacturonase (PG and Pectin Methylesterase (PME enzymatic activities during storage at 20°C for 2 weeks. Results: Concentration of ascorbic acid decreased during fruit ripening but 1-MCP-treated mangoes had reduced losses. Polygalacturonase and pectin methylesterase activities were reduced in the treated fruits as compared to untreated mangoes. Small changes in ?-carotene were observed between treated and untreated fruits. Conclusion: 1-MCP affected the ripening process in Kent mango, reducing losses of ascorbic acid, this treatment is justified since it helps to maintain mangos nutritional value during its shelf life.

Maria A. Islas-Osuna

2010-01-01

122

Radiolytical oxidation of ascorbic acid in aqueous solutions  

International Nuclear Information System (INIS)

Complete text of publication follows. Ascorbic acid, AsA (vitamin c), has been widely studied as an antioxidant or as an initiator of some technological processes, for example polymerization or nanoparticles formation. AsA can be easily oxidized to ascorbyl radical, in the first stage, and to dehydroascorbic acid, DHA, in the second stage. It has been found that several different ascorbyl radicals are formed during AsA oxidation but the main radical exists as the anion with the unpaired electron delocalized on a highly conjugated tricarbonyl system. Absorption spectrum of ascorbyl radical shows two bands with maxima at 300 and 360 nm, however only that at 360 nm is proportional to the dose and thus this wavelength was chosen for observations. We studied the oxidation of AsA by the following oxidizing radicals generated by the pulse radiolysis method ·OH, (SCN)2-·, Cl2-·, N3· and NO2·. The observed dependence of the yield and the formation rate of the AsA radical on the reduction potential of the oxidizing radical is discussed. The results obtained in water are compared with those obtained with AsA enclosed in the water pools of reverse micelles formed by AOT in n-heptane or by Igepal CO-520 in c-hexane. Somewhat surprising observation of different ascorbyl radical in pulse irradiated reverse micelles containing DHA is also commented.ted.

123

Low temperature storage affects the ascorbic acid metabolism of cherry tomato fruits.  

Science.gov (United States)

Tomato fruits are an important source of l-Ascorbic acid, which is an essential compound of human diet. The effect of the widespread practice of cold storing (5-10 °C) tomato fruits was monitored to determine its impact on the concentration and redox status of l-Ascorbic acid. Total l-Ascorbic acid levels were well maintained in both attached fruits and cold treated fruits, while in other treatments its levels were considerably reduced. However, low temperature storage conditions enhanced the expression of most genes coding for enzymes involved in l-Ascorbic acid biosynthesis and redox reactions. The findings suggest that the transcriptional up-regulation under chilling stress conditions of most genes coding for l-Ascorbic acid biosynthetic genes galactono-1,4-lactone dehydrogenase, GDP-d-mannose 3,5-epimerase but also for the isoenzymes of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase enzyme, glutathione reductase that are strongly correlated to the l-Ascorbic redox status. Moreover, fruits stored at 10 °C exhibited higher levels of transcript accumulation of MDHAR2, DHAR1, DHAR2, GR1 and GR2 genes, pointing to a better ability to manage chilling stress in comparison to fruits stored at 5 °C. PMID:25282013

Tsaniklidis, Georgios; Delis, Costas; Nikoloudakis, Nikolaos; Katinakis, Panagiotis; Aivalakis, Georgios

2014-11-01

124

Study of Ascorbic Acid as Iron(III Reducing Agent for Spectrophotometric Iron Speciation  

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Full Text Available The study of ascorbic acid as a reducing agent for iron(III has been investigated in order to obtain an alternative carcinogenic reducing agent, hydroxylamine, used in spectrophotometric standard method based on the formation of a red-orange complex of Fe(II-o-phenanthroline. The study was optimised with regards to ascorbic acid concentration as well as pH solution. The results showed that ascorbic acid showed maximum capacity as reducing agent of iron(III under concentration of 4.46.10-4 M and pH solution of 1-4.Under these conditions, ascorbic acid reduced iron(III proportionally and performed similarly to that of hydroxylamine.  The method gave result to linear calibration over the range of 0.2-2 mg/L withhigh accuracy of 97 % and relative standard deviation of less than 2 %. This method was successfully applied to assay iron speciation in water samples.

Antesar Elmagirbi

2012-10-01

125

Photodynamic properties of a bispyrrolecarboxamide-modified hypocrellin B: the role of affinity and ascorbic acid.  

Science.gov (United States)

The photodynamic properties of a new hypocrellin B (HB) derivative bearing a bispyrrolecarboxamide pendant (HB-Net) were investigated in detail. EPR experiments revealed that the generation ability of reactive oxygen species (ROS) of HB-Net is inferior to that of HB. DNA melting temperature measurements and ethidium bromide (EB) displacement assay illustrated the affinity of HB-Net toward dsDNA as the result of the bispyrrolecarboxamide unit, which is structurally related to the well-known minor groove binder netropsin. The radical generation abilities of HB and HB-Net can be enhanced by ascorbic acid via the photoinduced electron transfer from ascorbic acid to the photosensitizer, however, only the DNA photodamage capability of HB-Net can be improved significantly by ascorbic acid due to the stronger affinity of HB-Net to DNA. Consequently, the combination of HB-Net and ascorbic acid may lead to efficient DNA photodamage even in anaerobic conditions. PMID:18646820

Liu, Yanyan; Zhou, Qianxiong; Zeng, Zhanghua; Qiao, Rui; Wang, Xuesong; Zhang, Baowen

2008-08-14

126

Enthalpic characteristics of interactions occurring between an ascorbic acid and some saccharides in aqueous solutions  

International Nuclear Information System (INIS)

The enthalpies of solution of mono- and disaccharides were measured in water and aqueous ascorbic acid solutions at 298.15 K using a calorimeter of solution. Enthalpies of transfer of saccharides from water to aqueous ascorbic acid solutions were derived, and enthalpic coefficients of pair interaction hxy were calculated according to MacMillan-Mayer theory. Interactions of ascorbic acid with D-fructose and sucrose are energetically favorable and characterized by negative hxy coefficients while hxy for the interactions occurring between ascorbic acid and ?-D glucose, D-galactose and maltose are positive. The obtained results are interpreted in terms of the influence of structure and solvation of solutes on the thermodynamic parameters of their interaction in solutions

127

Effects of ascorbic acid on sperm motility, viability, acrosome reaction and DNA integrity in teratozoospermic samples  

Science.gov (United States)

Background: Oxidative stress in teratozoospermic semen samples caused poor assisted reproductive techniques (ART) outcomes. Among antioxidants, ascorbic acid is a naturally occurring free radical scavenger and as such its presence assists various other mechanisms in decreasing numerous disruptive free radical processes. Objective: The main goal of this study was to evaluate potential protective effects of ascorbic acid supplementation during in vitro culture of teratozoospermic specimens. Materials and Methods: Teratozoospermic semen samples that collected from 15 volunteers were processed, centrifuged and incubated at 37oC until sperm swimmed-up. Supernatant was divided into four groups and incubated at 37oC for one hour under different experimental conditions: Control, 10 µm A23187, 600µm ascorbic acid and 10 µm A23187+600 µm ascorbic acid. After incubation sperm motility, viability, acrosome reaction, DNA damage and malondialdehyde levels were evaluated. Results: Our results indicated that after one hour incubation, ascorbic acid significantly reduced malondialdehyde level in ascorbic acid group (1.4±0.11 nmol/ml) compared to control group (1.58±0.13 nmol/ml) (p<0.001). At the end of incubation, progressive motility and viability in ascorbic acid group (64.5±8.8% and 80.3±6.4%, respectively) were significantly (p<0.05 and p<0.001, respectively) higher than the control group (54.5±6.8% and 70.9±7.3%, respectively). A23187 significantly (p<0.0001) increased acrosome reaction in A23187 group (37.3±5.6%) compared to control group (8.5±3.2%) and this effect of A23187 attenuated by ascorbic acid in ascorbic acid+A23187 group (17.2±4.4%). DNA fragmentation in ascorbic acid group (20±4.1%) was significantly (p<0.001) lower than controls (28.9±4.6%). Conclusion: In vitro ascorbic acid supplementation during teratozoospermic semen processing for ART could protect teratozoospermic specimens against oxidative stress, and it could improve ART outcome. PMID:24799867

Fanaei, Hamed; Khayat, Samira; Halvaei, Iman; Ramezani, Vahid; Azizi, Yaser; Kasaeian, Amir; Mardaneh, Jalal; Parvizi, Mohammad Reza; Akrami, Maryam

2014-01-01

128

Preventive activity of ascorbic acid on lead acetate induced cerebellar damaged in adult Wistar rats  

OpenAIRE

Among the environmental contaminants, lead is one of the most hazardous to living matter. In mammals, the main target is the central nervous system, particularly in the young. Ascorbic acid is an antioxidant which is a substance that may protect your cells against the effects of free radicals. This study investigated Experiment the protective effect of ascorbic acid on the cerebellum of adult Wistar rats following oral administration of different doses of Lead acetate. Thirty adult Wistar rat...

Sunday Abraham Musa; Iliyasu Musa Omoniye; Wilson Oliver Hamman; Augustine Oseloka Ibegbu; Uduak Emmanuel Umana

2012-01-01

129

Effects of Ascorbic Acid and Mono- and Diglycerides on Taftoon Bread Quality  

OpenAIRE

The quality of Iranian breads has intensively decreased during recent years due to socio-economic factors and poor quality of flour. The purpose of this study is to investigate the effects of mono- and diglycerides and ascorbic acid as improvers on Iranian bread (Taftoon) quality. Three wheat type flours (Ghods, Mahdavi and Roshan wheat varieties produced in Isfahan region) were used. The effects of ascorbic acid at three levels (20, 40 and 60 ppm flour basis) and esters of mono- and diglycer...

Shahedi, M.; Abdollahzadeh, A.

2001-01-01

130

Natural origin of ascorbic acid: validation by 13C-NMR and GC-C-IRMS  

OpenAIRE

A new method for the extraction and purification of ascorbic acid from two tropical fruits (acerola and camu-camu) is presented. 13C nuclear magnetic resonance and isotopic ratio mass spectroscopy (13C/12C) were used to recognize ascorbic acid coming from either natural or industrial sources. A quantitative 13C NMR procedure was optimized to calculate isotopic relative abundances on each molecular site; data were treated by a multivariate method. Samples were also analysed by I...

Cravotto, Giancarlo; Vincenti, Marco; Gobetto, Roberto; Albertino, Andrea; Barge, Alessandro

2009-01-01

131

Determination of l-Ascorbic Acid in Tomato by Capillary Electrophoresis  

OpenAIRE

In an undergraduate bioanalytical instrumental lab, students use capillary electrophoresis to quantify L-ascorbic acid (vitamin C) in food samples. The students are tasked to prepare standards, to obtain the calibration curves, and to determine the quantity of L-ascorbic acid in tomato samples (Lycopersicon fruit). A discussion about the function of each component of a capillary electrophoresis instrument, the effect of experimental variables, and the use of different calibrati...

Tortajada Genaro, Luis Antonio

2012-01-01

132

Low-volume plus ascorbic acid vs high-volume plus simethicone bowel preparation before colonoscopy  

OpenAIRE

AIM: To investigate the effectiveness of low-volume plus ascorbic acid [polyethylene glycol plus ascorbic acid (PEG + Asc)] and high-volume plus simethicone [polyethylene glycol plus simethicone (PEG + Sim)] bowel preparations. METHODS: A total of one hundred and forty-four outpatients (76 males), aged from 20 to 84 years (median age 59.5 years), who attended our Department, were divided into two groups, age and sex matched, and underwent colonoscopy. Two questionnaires, one for patients repo...

Stefano Pontone; Rita Angelini; Monica Standoli; Gregorio Patrizi; Franco Culasso; Paolo Pontone; Adriano Redler

2011-01-01

133

Association between the plasma proteome and serum ascorbic acid concentrations in humans.  

Science.gov (United States)

Vitamin C has been associated with a reduced risk of chronic diseases, but the biological pathways regulated by vitamin C are not all known. The objective was to use a proteomics approach to identify plasma proteins associated with circulating levels of ascorbic acid. Men and women (n=1022) 20-29 years of age from the Toronto Nutrigenomics and Health Study completed a general health and lifestyle questionnaire and a 196-item food frequency questionnaire and provided a fasting blood sample. Circulating ascorbic acid was analyzed by high-performance liquid chromatography, and a mass-spectrometry-based multiple reaction monitoring method was used to measure 54 proteins abundant in plasma that are involved in numerous physiologic pathways. Mean protein concentrations were compared across tertiles of serum ascorbic acid using analysis of covariance adjusted for sex, ethnocultural group, season of blood draw, hormonal contraceptive use among women, waist circumference and tertiles of plasma ?-tocopherol. A Bonferroni significance level of Pinversely associated with levels of ascorbic acid. The inverse association between ascorbic acid and vitamin D binding protein was highest in those with higher levels of serum 25-hydroxyvitamin D. In conclusion, several plasma proteins from various physiologic pathways are significantly associated with circulating levels of ascorbic acid. These findings suggest that vitamin C may have novel physiological effects. PMID:22841398

Da Costa, Laura A; García-Bailo, Bibiana; Borchers, Christoph H; Badawi, Alaa; El-Sohemy, Ahmed

2013-05-01

134

Application of titanium oxide nanotube films containing gold nanoparticles for the electroanalytical determination of ascorbic acid  

Energy Technology Data Exchange (ETDEWEB)

Au/TiO{sub 2}/Ti electrodes have been prepared by galvanic deposition of gold particles on TiO{sub 2} nanotube substrates. Titanium oxide nanotubes are fabricated by anodizing titanium foil in a Dimethyl Sulfoxide electrolyte containing fluoride. The scanning electron microscopy results indicated that gold particles are homogeneously deposited on the surface of TiO{sub 2} nanotubes. The TiO{sub 2} layers consist of individual tubes of about 40-80 nm diameters. The electro-catalytic behavior of Au/TiO{sub 2}/Ti and flat gold electrodes for the ascorbic acid electro-oxidation was studied by cyclic voltammetry. The results showed that the flat gold electrode is not suitable for the oxidation of ascorbic acid. However, the Au/TiO{sub 2}/Ti electrodes are shown to possess catalytic activity toward the oxidation reaction. Catalytic oxidation peak current showed a linear dependence on the ascorbic acid concentration and a linear calibration curve is obtained in the concentration range of 1-5 mM of ascorbic acid. Also, determination of ascorbic acid in real samples was evaluated. The obtained results were found to be satisfactory. Finally the effects of interference on the detection of ascorbic acid were investigated.

Hosseini, Mir Ghasem, E-mail: mg-hosseini@tabrizu.ac.ir; Faraji, Masoud; Momeni, Mohamad Mohsen

2011-03-31

135

Application of titanium oxide nanotube films containing gold nanoparticles for the electroanalytical determination of ascorbic acid  

International Nuclear Information System (INIS)

Au/TiO2/Ti electrodes have been prepared by galvanic deposition of gold particles on TiO2 nanotube substrates. Titanium oxide nanotubes are fabricated by anodizing titanium foil in a Dimethyl Sulfoxide electrolyte containing fluoride. The scanning electron microscopy results indicated that gold particles are homogeneously deposited on the surface of TiO2 nanotubes. The TiO2 layers consist of individual tubes of about 40-80 nm diameters. The electro-catalytic behavior of Au/TiO2/Ti and flat gold electrodes for the ascorbic acid electro-oxidation was studied by cyclic voltammetry. The results showed that the flat gold electrode is not suitable for the oxidation of ascorbic acid. However, the Au/TiO2/Ti electrodes are shown to possess catalytic activity toward the oxidation reaction. Catalytic oxidation peak current showed a linear dependence on the ascorbic acid concentration and a linear calibration curve is obtained in the concentration range of 1-5 mM of ascorbic acid. Also, determination of ascorbic acid in real samples was evaluated. The obtained results were found to be satisfactory. Finally the effects of interference on the detection of ascorbic acid were investigated.

136

Effects of ascorbic acid on some physiological changes of pepino (Solanum muricatum Ait.) under chilling stress.  

Science.gov (United States)

In this study, the changes caused by chilling stress on some physiological parameters of pepino (Solanum muricatum Ait.) plant and the effects of ascorbic acid (100 mM) applied exogenously on these changes were examined. For this purpose, the photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophylls and carotenoids), ascorbic acid, total phenolic compounds, malondialdehyde and proline contents in leaves of pepino taken on 5th and 10th days were determined. As a result of chilling stress, it was found that while the photosynthetic pigments and proline contents decreased in pepino leaves, the ascorbic acid, total phenolic compounds and malondialdehyde contents increased. In plants which were subjected to pre-treatment of ascorbic acid on the 10th day of stress, ascorbic acid and proline contents increased while a decrease was observed in malondialdehyde content, compared to stress group without pre-treated. This study may be important for explaining resistance induced by treatment of exogenous ascorbic acid in pepino exposed to chilling stress. PMID:25194734

Sivaci, Aysel; Kaya, A; Duman, Sevcan

2014-09-01

137

Serum ascorbic acid concentration in patients with acute Falciparum malaria infection: possible significance  

Directory of Open Access Journals (Sweden)

Full Text Available Falciparum malaria infection is associated with significant destruction of erythrocytes. This leads to the release of toxic metabolic products, including oxidant compounds.We measured the serum concentration of the antioxidant, ascorbic acid, in 129 patients presenting with acute falciparum malaria infection and in 65 healthy individuals. None of the study subjects administered any form of ascorbic acid supplementation within one week prior to participation in this study. The mean serum ascorbate concentration in infected adult males (n = 49, age range 18-50 years was found to be 2.02 ± 0.20 mg/dL, and it was 2.03 ± 0.24 mg/dL in infected adult females (n = 56, age range 18-50 years. These values were significantly greater than the serum ascorbate levels (1.54 ± 0.10 mg/dL in healthy adult males (n = 28 and females (n = 28 (p < 0.05. In children (age range 3 to 5 years, the serum ascorbate concentration was significantly lower (1.95 ± 0.20 mg/dL during infection (n = 25 than in their healthy counterparts (2.9 ± 0.24 mg/dL, n = 9 (p < 0.05. It is evident therefore that ascorbic acid plays a significant role in the pathogenesis of acute falciparum malaria in adults. Infected children also need to be given supplemental doses of ascorbate in view of the weakness of their immune system.

Garba Ibrahim Hassan

2004-10-01

138

Radiation degradation of ascorbic acid, EDTA and citric acid in aqueous solutions  

International Nuclear Information System (INIS)

Gamma radiolysis of ascorbic acid (AA), EDTA and citric acid (CA) in aqueous solutions indicated that AA and EDTA are more sensitive to radiation than CA. In individual solutions, G(-AA) and G(-EDTA) were determined to be ? 4.4 each whereas G(-CA) was ? 2.2. In irradiated AA solutions, dehydroascorbic acid was the major product with G-value of 4.2. In a mixture, while AA and EDTA underwent radiolytic decomposition, CA was protected. (author). 3 refs., 3 figs

139

Effects of Ascorbic Acid, Phytic Acid and Tannic Acid on Iron Bioavailability from Reconstituted Ferritin Measured by an In Vitro Digestion/Caco-2 Cell Model  

Science.gov (United States)

The effects of ascorbic acid, phytate and tannic acid on Fe bioavailability from Fe supplied as ferritin was compared to FeSO4 using an in vitro digestion/Caco-2 cell model. Horse spleen ferritin (HSF) was chemically reconstituted into a plant-type ferritin (P-HSF). In the presence of ascorbic acid...

140

Effects of Ascorbic Acid, Phytic Acid and Tannic Acid on Ferritin-Iron Bioavailability as Determined Using an In Vitro Digestion/Caco-2 Cell Model  

Science.gov (United States)

The effects of ascorbic acid, phytate and tannic acid on Fe bioavailability from Fe supplied as ferritin was compared to FeSO4 using an in vitro digestion/Caco-2 cell model. Horse spleen ferritin (HSF) was chemically reconstituted into a plant-type ferritin (P-HSF). In the presence of ascorbic acid...

141

Regulation of L-ascorbic acid content in strawberry fruits.  

Science.gov (United States)

Plants have several L-ascorbic acid (AsA) biosynthetic pathways, but the contribution of each one to the synthesis of AsA varyies between different species, organs, and developmental stages. Strawberry (Fragaria×ananassa) fruits are rich in AsA. The pathway that uses D-galacturonate as the initial substrate is functional in ripe fruits, but the contribution of other pathways to AsA biosynthesis has not been studied. The transcription of genes encoding biosynthetic enzymes such as D-galacturonate reductase (FaGalUR) and myo-inositol oxygenase (FaMIOX), and the AsA recycling enzyme monodehydroascorbate reductase (FaMDHAR) were positively correlated with the increase in AsA during fruit ripening. Fruit storage for 72 h in a cold room reduced the AsA content by 30%. Under an ozone atmosphere, this reduction was 15%. Ozone treatment increased the expression of the FaGalUR, FaMIOX, and L-galactose-1-phosphate phosphatase (FaGIPP) genes, and transcription of the L-galactono-1,4-lactone dehydrogenase (FaGLDH) and FAMDHAR genes was higher in the ozone-stored than in the air-stored fruits. Analysis of AsA content in a segregating population from two strawberry cultivars showed high variability, which did not correlate with the transcription of any of the genes studied. Study of GalUR protein in diverse cultivars of strawberry and different Fragaria species showed that a correlation between GalUR and AsA content was apparent in most cases, but it was not general. Three alleles were identified in strawberry, but any sequence effect on the AsA variability was eliminated by analysis of the allele-specific expression. Taken together, these results indicate that FaGalUR shares the control of AsA levels with other enzymes and regulatory elements in strawberry fruit. PMID:21561953

Cruz-Rus, Eduardo; Amaya, Iraida; Sánchez-Sevilla, José F; Botella, Miguel A; Valpuesta, Victoriano

2011-08-01

142

Intravenous ascorbic acid to prevent and treat cancer-associated sepsis?  

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Full Text Available Abstract The history of ascorbic acid (AA and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS and multi organ failure (MOF, has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once these patients develop septic symptoms, a further decrease in ascorbic acid levels occurs. Given the known role of ascorbate in: a maintaining endothelial and suppression of inflammatory markers; b protection from sepsis in animal models; and c direct antineoplastic effects, we propose the use of ascorbate as an adjuvant to existing modalities in the treatment and prevention of cancer-associated sepsis.

Bogin Vladimir

2011-03-01

143

Intravenous ascorbic acid to prevent and treat cancer-associated sepsis?  

Science.gov (United States)

The history of ascorbic acid (AA) and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS) and multi organ failure (MOF), has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once these patients develop septic symptoms, a further decrease in ascorbic acid levels occurs. Given the known role of ascorbate in: a) maintaining endothelial and suppression of inflammatory markers; b) protection from sepsis in animal models; and c) direct antineoplastic effects, we propose the use of ascorbate as an adjuvant to existing modalities in the treatment and prevention of cancer-associated sepsis. PMID:21375761

Ichim, Thomas E; Minev, Boris; Braciak, Todd; Luna, Brandon; Hunninghake, Ron; Mikirova, Nina A; Jackson, James A; Gonzalez, Michael J; Miranda-Massari, Jorge R; Alexandrescu, Doru T; Dasanu, Constantin A; Bogin, Vladimir; Ancans, Janis; Stevens, R Brian; Markosian, Boris; Koropatnick, James; Chen, Chien-Shing; Riordan, Neil H

2011-01-01

144

Antioxidant Effects of Aqueous Extract of Sweet Potato and Ascorbic Acid on Paracetamol Induced Damage  

Directory of Open Access Journals (Sweden)

Full Text Available The antioxidant effects of aqueous extract of sweet potato (Ipomoea batata and ascorbic acid on paracetamol induced damage in liver and kidney were investigated in female rats by monitoring the enzymatic and non-enzymatic antioxidant profiles as well as lipid peroxidation and serum enzymes activities. The rats were given freshly prepared aqueous extract of sweet potato (100 mg kg-1 body weight or ascorbic acid (100 mg kg-1 body weight orally for 4 weeks. These rats were also given paracetamol (4 g kg-1 body weight orally for 2 days at the last week of treatment. Another group of rats were either given extract (100 mg kg-1 body weight. daily, orally, for 4 weeks or ascorbic acid (100 mg kg-1 body weight. daily, orally, for 4 weeks or paracetamol (4 g kg-1 body weight for 2 days or distilled water. The results show that the level of lipid peroxides in the liver and kidney and serum enzymes GOT and GPT activities were significantly decreased in extract and ascorbic acid pretreated rats when compared to control (p<0.05. Paracetamol however significantly increase the level of these parameters when compared to control. Liver and kidney Superoxide Dismutase (SOD and Catalase activities significantly increase in extract and ascorbic acid pretreated rats compared to control. Paracetamol significantly reduced the activities of these enzymes in liver but the reduction in SOD activity was not significant in the kidney when compared to control. There were significant increase in reduced Glutathione (GSH in both organs in ascorbic acid pretreated rat but the increase were not significant in extract pretreated rats. Paracetamol significantly decrease GSH level in the liver when compared to control. The study revealed that sweet potato extract and ascorbic acid have a potential to prevent oxidative damage induced by acute dose of paracetamol in both the liver and the kidney.

A.O. Lawal

2006-01-01

145

Effect of Storage Time on Ascorbic Acid Content of Some Selected `Made in Nigeria` Fruit Preserves  

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Full Text Available The vitamin C content of many "Made in Nigeria" fruit products is not known for sure, since Nutrition Labeling is usually absent. Furthermore the change in the concentration with increasing shelf-life is not certain. Ascorbic acid (vitamin C content of sixteen different fruit preserves made in Nigeria was assessed, on the day of production and after different lengths of storage time ranging from 3 to 8 months. Six fruit juices, six fruit squashes and four marmalades/jams were analyzed for ascorbic acid contents using the 2,6 dichlorophenol indophenol visual titration method. Ascorbic acid content varied with the type of fruit preserve, grapefruit juice having the highest (42.0mg/100g, while pineapple juice had the lowest (10.3mg/100g on the first day of manufacture/production. Other juices had values ranging from 20.0mg/100g to 41.5mg/100g sample. There was minimal loss in ascorbic acid content with time. Fruit squashes generally had higher ascorbic acid content than the juices. Mango had the highest (62.0mg/100g, while pineapple squash had the lowest (18.1mg/100g on the first day of production/manufacture. The percentage loss in ascorbic acid content of squashes was lower than that found in similar fruit juices. Other fruit preserves also had values ranging from 13.1mg/100g to 50mg/100g. Ascorbic acid loss was more than 10% in marmalades and jams after storage for 12 months at ambient room temperature. While processing of fruits reduce post-harvest loss and provides nutrients from these fruits, it will be beneficial to apply nutrition labels to the containers and also print `best before` date conspicuously. Nutrition education is necessary to increase market demand and monitoring to ensure quality. The effect of ambient conditions should be considered in manufacture procedures.

SANUSI Rasaki A.

2008-01-01

146

Effect of eradication of Helicobacter pylori on gastric juice ascorbic acid concentrations.  

OpenAIRE

Ascorbic acid, the reduced form of vitamin C, may protect against gastric cancer and is secreted by the normal stomach. Secretion is impaired in Helicobacter pylori (H pylori) associated chronic gastritis. This study examined if eradication of H pylori improves gastric juice ascorbate values. Fasting gastric juice and plasma samples were collected at endoscopy from patients participating in trials of H pylori eradication for duodenal ulcer disease and intestinal metaplasia before and up to 15...

Sobala, G. M.; Schorah, C. J.; Shires, S.; Lynch, D. A.; Gallacher, B.; Dixon, M. F.; Axon, A. T.

1993-01-01

147

Intravenous ascorbic acid protocol for cancer patients: scientific rationale, pharmacology, and clinical experience  

OpenAIRE

ABSTRACTBackground: Ascorbic acid (vitamin C, ascorbate) has been shown to protect cells against various types of oxidant injury at physiologically relevant concentrations. Vitamin C has been suggested as having both a preventative and therapeutic role in a number of pathologies when administered at much higher-than-recommended dietary allowance levels. This article reviews the scientific rational for intravenous vitamin C as a potential treatment for cancer. Many mechanisms of action for asc...

Na, Mikirova; Jj, Casciari; Re, Hunninghake; Nh, Riordan

2013-01-01

148

Tear ascorbic acid levels and the total antioxidant status in contact lens wearers: A pilot study  

OpenAIRE

Aims: The tear ascorbate owing to its high concentration, functions as an effective antioxidant against the oxidative damage of cornea. Contact lens wearers (CLW) are prone to oxidative stress due to the lens-induced hypoxic conditions. A pilot study was done to compare the tear ascorbic acid level and the total antioxidant capacity give as in normal and CLW. Materials and Methods: In this study 21 CLW (Mean age 23 ± 3 years ; M-2, F-19), who were dail...

Venkata Sai; Narayanasamy Angayarkanni; Srinivasan Vidhya; Iyer Geetha; Sivaramakrishnan Ramakrishnan; Subramanian Madhumathi; Mahadevan Rajeshwari

2009-01-01

149

A study of the peroxidation of fatty acid micelles promoted by ionizing radiation, hydrogen peroxide and ascorbate  

International Nuclear Information System (INIS)

The kinetics of peroxidation of fatty acid micelles promoted by ionizing radiation, hydrogen peroxide and ascorbate were compared. At the dose-rate range of ionizing radiation studied, the higher the dose-rate, the greater the total dose required to produce the same effect. With ascorbate, the rate of lipid peroxidation was dependent on the concentration of the promoter only up to 1 x 10-4M, beyond which a decreasing rate of peroxidation induction was observed. Higher concentration of ascorbate also suppressed the promoting effect of ionizing radiation. Formate, a hydroxyl radical scavenger, inhibited the peroxidation process promoted by these three agents. Caesium was found to be slightly inhibitory. EDTA and deoxycholate were also inhibitory, which may be attributed to iron-chelating and micelle-disrupting capacity, respectively. Addition of iron (Fe2+ or Fe3+) to EDTA-chelated fatty acid micelles re-initiated the peroxidation process. The ease of fatty acid oxidation at pH 7.5 was arochidonic (20:4)>linolenic (18:3)>linoleic (18:2). This order was reversed at pH 11.5. Similarities in the kinetics of peroxidation obtained suggest that certain biological sequelae encountered in cells treated with these seemingly dissimilar agents might arise through some common mechanism(s). (author)

150

Ascorbic acid treatment reduces the radiation-induced delay in the skin excision wound of Swiss mice  

International Nuclear Information System (INIS)

Effect of ascorbic acid was studied on the radiation induced changes in wound contraction, collagen synthesis. Wound histology, glutathione, glutathione peroxidase, superoxide dismutase and lipid peroxidation in mice exposed to 10, 16, and 20 Gy of fractionated gamma radiation. The animals were administered daily with double distilled water or ascorbic acid before exposure to 2 Gy/da fractionated irradiation. Ascorbic acid pretreatment resulted in a significant elevation in the activities of both the enzymes and glutathione in the irradiated mouse skin

151

Killing of Bacillus subtilis Spores by a Modified Fenton Reagent Containing CuCl2 and Ascorbic Acid  

OpenAIRE

Bacillus subtilis spores were killed by CuCl2-ascorbic acid, chloride ions were essential for killing of spores, and spores with defective coats were killed more rapidly. CuCl2-ascorbic acid did not damage spore DNA, and spores killed by this reagent initiated germination. However, spores killed by CuCl2-ascorbic acid may have damage to their inner membrane.

Shapiro, Michael P.; Setlow, Barbara; Setlow, Peter

2004-01-01

152

Ascorbic acid and total vitamin C concentrations in plasma, gastric juice, and gastrointestinal mucosa: effects of gastritis and oral supplementation.  

OpenAIRE

Epidemiological evidence suggests that high dietary ascorbic acid reduces gastric cancer risk. It may do this by either reducing N-nitroso compound formation in gastric juice, or by scavenging reactive oxygen species in gastric mucosa. The aim of this study was to discover if potential ascorbic acid protection might be increased by supplementation. Thirty two patients were supplemented with ascorbic acid, 500 mg twice daily for two weeks. Gastric juice, plasma, and upper gastrointestinal biop...

Waring, A. J.; Drake, I. M.; Schorah, C. J.; White, K. L.; Lynch, D. A.; Axon, A. T.; Dixon, M. F.

1996-01-01

153

The Effect of ascorbic acid injection into lateral ventricle on spatial learning and memory on adult male rats  

OpenAIRE

Introduction: Ascorbic acid (AA) acts as an antioxidant in the Central nervous system (CNS) of the mammalians. It is released from the some nerve ending together with neurotransmitters. The results have shown that Ascorbic acid could affect learning as well as memory. In this study, we examined the effect of ICV injection of ascorbic acid on learning and memory by Morris water maze. Method: In the present study, 42 adult male rats weighing 250-300 g were used. then cannula implanted bilateral...

mehdi abbasnejad; Sima Nasri; Habib Nazem; Mehri Bahaaddini

2008-01-01

154

Use of Experimental Design for Calibration and Validation of Ascorbic Acid and Citric Acid Mixtures  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish El objetivo general de este trabajo ha sido el desarrollo y aplicación de metodologías analíticas basadas en la combinación de medidas espectroscópicas de UV con métodos quimiométricos de diseño de experimentos para establecer la matriz de calibración y posterior análisis de los resultados obtenidos [...] . Los analitos seleccionados para este estudio han sido el ácido cítrico y el ácido tartárico. El ácido cítrico es un ácido orgánico tricarboxílico presente en la mayoría de las frutas, principalmente en cítricos como el limón y la naranja. El ácido ascórbico (vitamina C) es un ácido orgánico con propiedades antioxidantes, importante para el sistema inmunológico y para prevenir enfermedades. Abstract in english The general objective of present work has been the development and application of analytical methodologies based on the combination of UV spectra with chemometrics methods of experimental design for establishing the matrix of calibration and later analysis of the obtained results. The analytes selec [...] ted for this study have been citric acid and ascorbic acid. The citric acid is a tri-carboxylic organic acid that is present in most of the fruits, mainly in citrus like the lemon and the orange. Ascorbic acid (vitamin C) is an organic acid with antioxidant properties; their importance for the human immune system and for the prevention of various diseases is a matter of common knowledge.

Fuensanta, Sánchez Rojas; Catalina, Bosch Ojeda; Antonio Jesús, Ruiz Sánchez; María, Espinosa Bosch.

2008-12-01

155

Effect of ascorbic, isoascorbic and dehydroascorbic acids on the growth and survival of Campylobacter jejuni.  

Science.gov (United States)

Ascorbic acid (AsA), added to nutrient broth at a concentration of 5 mmol/l, was bactericidal towards Campylobacter jejuni grown at 42 degrees C in a micro-aerobic atmosphere. Specific enzymes, radical scavengers, metal chelators and reducing agents were tested as possible antagonists to the cytotoxicity of AsA. The addition of catalase or of the metal chelators ceruloplasmin or Desferal did not prevent the cytotoxic effect of AsA. The addition of the hydroxyl radical scavengers mannitol, formate, histidine or DMSO also failed to counteract the toxicity of AsA. On the other hand, thiourea or cysteamine and the reducing agents cysteine or dithionite significantly increased the recovery of C. jejuni in the presence of AsA. Although the possibility of the involvement of hydroxyl radicals in AsA cytotoxicity cannot be ruled out, it appears that the toxic effect of AsA is due mostly to the formation of products of oxidation of AsA and particularly to dehydroascorbic acid (DHA). Dehydroascorbic acid was also bactericidal to C. jejuni at a concentration of 5 mmol/l. Of all the compounds tested, only cysteamine was effective in preventing (partially) the toxic effect of DHA. The growth of C. jejuni was not inhibited by the addition of 5 mmol/l of isoascorbic acid or sodium isoascorbate. PMID:3781941

Juven, B J; Kanner, J

1986-10-01

156

Determination of L-Ascorbic Acid in Pharmaceutical Preparations Using Direct Ultraviolet Spectrophotometry  

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Full Text Available A new, selective and accurate direct ultraviolet spectrophotometric method was developed for the determination of L-ascorbic acid in pharmaceuticals. The oxidation of L-ascorbic acid by iodate in an acidic medium was used as a means of correcting for background absorption. The molar absorptivity of the proposed method was found to be 8.71x103 dm3 mol-1 cm-1 at 250 nm. Beer’s law was obeyed in the concentration range of 0.46 – 16.00 ?g cm-3 for L-ascorbic acid. The relative standard deviation was 0.67 % for a concentration of 8.00 ?g cm-3 of ascorbic acid (n = 7. The ingredients commonly found in vitamin C and multivitamin products did not interfere. The proposed procedure was successfully applied to assays of L-ascorbic acid in pharmaceutical preparations. The results obtained with the proposed method showed good agreement with those given by the titrimetric method using iodine.

Mirsad Salki?

2009-12-01

157

The comparison of techniques and methods for L-ascorbic acid determination in the fruits  

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Full Text Available Vitamin C is an essential vitamin for human nutrition; with the L-ascorbic acid (AA being the active form of vitamin C. Hence, determination of the L-ascorbic acid in the natural and processed foods is very important. In the past, plenty of methods based on the reversible redox reaction of AA oxidation/DHA reduction were developed. Because of L-ascorbic acid instability in aqueous solutions, it is useful to analyze various types of extraction. The aim of this study is to compare three different methods and three different extractants for the L-ascorbic acid determination. Fruits (kiwi, lemon, orange, and grapefruit were purchased from a local market. The L-ascorbic acid in these four samples was determined by the three different methods: the AOAC, the HPLC method with three different types of extractions, and the colorimetric method using ascorbate-oxidase. For the HPLC measurements, one part of the fruits was extracted with distilled water, the second with potassium hydrogen phosphate, and the third with 3% meta-phosphoric acid (MPA in 8% acetic acid. The HPLC measurements of each sample were repeated three times, the AOAC titration was repeated five times, and in the calorimetric method three measurements were performed. The results were statistically evaluated related to sample basis. Statistical analysis shows that there is a significant difference between the results for all three methods of extraction for all samples, except for the grapefruit sample where no significant difference was observed between the results obtained after the buffer extraction (E2 and the metaphosphoric acid in acetic acid extraction (E3. Discriminative analysis for the HPLC determinations proves that there is a clear difference and defined border between the samples in relation to the methods of extraction during the HPLC determination.

Cvetkovi? Biljana R.

2012-01-01

158

Luminescence quenching of porous silicon nanoparticles in presence of ascorbic acid  

Energy Technology Data Exchange (ETDEWEB)

In this work, the effect of ascorbic acid on luminescence of porous silicon nanoparticles is studied. Porous nanoparticles with a multi-sized distribution are produced from a porous silicon free standing film and filtered through a 450 nm membrane. The highly luminescent and water-soluble nanoparticles are dispersed in deionized water. The stability of photoluminescence signal and the dimensions of porous silicon nanoparticles are characterized before adding ascorbic acid into the porous nanoparticles solution. The increasing of photoluminescence, before stabilization, has been correlated to oxidation of nanoparticles in water, evaluated by the technique of Attenuated Total Reflection. Once the nanoparticle photoluminescence signal is stabilized, ascorbic acid is loaded into the solution and its presence and real absorption onto the porous silicon nanoparticles are evaluated from their emission quenching. The quenching of photoluminescence is studied with different concentrations of ascorbic acid by Stern-Volmer plot for confirming the quenching law. This study shows that luminescence quenching of porous nanoparticles could be used for determining the presence of ascorbic acid in a solution. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

La Ferrara, Vera; Fiorentino, Giuseppe; Rametta, Gabriella; Di Francia, Girolamo [ENEA Research Centre, Portici (Italy)

2012-04-15

159

Ascorbic acid protects against restraint stress-induced memory deficits in wistar rats  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english OBJECTIVE: Chronic stress has been shown to cause oxidative damage in the central nervous system. Although stress-induced impairments in learning and memory have been studied extensively, very few studies have investigated possible ways to prevent their ill effects. The present work was designed to [...] study the protective effects of ascorbic acid in memory loss induced by chronic restraint stress. METHODS: Adult male Wistar rats were designated into the following groups: (i) Normal control, (ii) Ascorbic acid treatment, (iii) Vehicle control, (iv) Restraint stress, (v) Restraint stress + vehicle, and (vi) Restraint stress + ascorbic acid treatment. At the end of 21 days, animals of all groups were subjected to memory tests using Morris water maze and passive avoidance apparatus. Then, the results obtained were compared between the experimental groups. RESULTS: Rats exposed to restraint stress alone and those pretreated with vehicle solution before restrained stress showed deficits in learning and impaired memory retention in the memory tests when compared to animals in other experimental groups. Animals pretreated with ascorbic acid before restraining showed significant improvement in memory retention in the same memory tests. CONCLUSIONS: Results of this study suggest the possibility of using ascorbic acid as a dietary supplement to prevent stress-induced memory impairments.

Raju Suresh, Kumar; Sareesh Naduvil, Narayanan; Satheesha, Nayak.

1211-12-01

160

Ascorbic acid protects against colistin sulfate-induced neurotoxicity in PC12 cells.  

Science.gov (United States)

This study aimed to examine the protective effect of ascorbic acid against colistin-induced neurotoxicity mediated by oxidative stress, a potential mechanism. An in vitro neurotoxicity model was established with PC12 cells exposed to 125?µg/mL colistin sulfate for 24 h. PC12 cells were treated with colistin (125 µg/mL) in the absence and presence of ascorbic acid (0.1, 1.0 and 10 µM/mL) for 24 h. Both 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) assay were carried out to evaluate cell viability. The levels of intracellular reactive oxygen species (ROS), superoxide dismutase (SOD) and glutathione (GSH) levels were assessed. Moreover, we tested the level of DNA fragmentation, the release of cytochrome-c and the expressions of caspase-9 and -3 mRNA. The results showed that 1 and 10 µM/mL ascorbic acid significantly increased the cell viability and the levels of SOD and GSH (both pcolistin-treated PC12 cells, compared with the colistin model group. These results suggest that ascorbic acid could reduce colistin sulfate-induced neurotoxicity through the resistance of oxidative stress and the prevention of apoptosis mediated via mitochondria pathway. They also highlight the potential of coadministering ascorbic acid to widen the therapeutic dose of colistin. PMID:23692127

Liu, Yang; Dai, Chongshan; Gao, Ruixia; Li, Jichang

2013-10-01

161

Electrochemical oxidation of ascorbic acid mediated by carbon nano tubes/ Li+/ carbon paste modified solid electrode  

International Nuclear Information System (INIS)

Multi-walled carbon nano tube (MWCNT) was used to modify BPPG electrode because of its unique structure and extraordinary properties. MWCNT modified electrode exhibited obvious enhancing and electro catalyzing effects to the oxidation of ascorbic acid using cyclic voltammetry technique. MWCNT was bonded on BPPG electrode surface using carbon paste with ratio of 30 % (w/ W) carbon paste (binder): 70 % (w/ w) MWCNT. This method of modification has lowered the capacitance background current and enabled lower detection limit of ascorbic acid concentration. The electrical conductivity property of MWCNT modified electrode was further improved with the intercalation with lithium ion and resulted in current enhancement of 2 times on the oxidation current of ascorbic acid. Parameters of pH and temperature showed significant relation to the sensitivity of MWCNT modified electrode. Under the optimized parameters, the calibration curve constructed was linear up from 50 ?M to 5 mM with sensitivity of 34.5 mA M-1. The practical application of MWCNT modified electrode was demonstrated with Vitamin C pill and orange juice. Good reproducibility and recovery of ascorbic acid concentration showed the feasibility of MWCNT modified electrode to be used in the detection of ascorbic acid in aqueous solution. This also proposed MWCNT modified BPPG electrode possessed advantages such as low detection limit, high stability, low cost and simplicity in fabrication. (author)licity in fabrication. (author)

162

Effect of Ascorbic Acid and Cysteine Hydrochloride on Growth of Bifidobacterium bifidum  

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Full Text Available The effects of ascorbic acid and L-Cysteine Hydrochloride (Cys-HCl on growth of Bifidobacterium bifidum BB01 and BB03 were studied by using MRS broth as the control, the concentrations of ascorbic acid and Cys-HCl were both of 0.4, 0.6, 0.8, 1.0 and 1.2g/L. The result showed as follows: ascorbic acid 0.8g/L or Cys-HCl 0.6g/L on growth of B. bifidum BB01 and ascorbic acid 0.4g/L and Cys-HCl 0.4g/L on growth of B. bifidum BB03 had significant influence (p<0.05, respectively. The OD600 of B. bifidum BB01 and B. bifidum BB03 reached 1.32, 1.32, 1.347 and 1.296 at optimal concentration of ascorbic acid and Cys-HCl mentioned above, while the control only reached 1.121 and 1.213 respectively.

Guowei Shu

2013-06-01

163

Self-powered biosensor for ascorbic acid with a Prussian blue electrochromic display.  

Science.gov (United States)

We report on the development of a nanocarbon based anode for sensing of ascorbic acid (AA). The oxidation of AA on this anode occurs at a quite low overpotential which enables the anode to be connected to a biocathode to form an ascorbic acid/O2 biofuel cell that functions as a self-powered biosensor. In conjunction with a Prussian blue electrochromic display the anode can also work as a truly self-powered sensor. The oxidation of ascorbic acid at the anode leads to a reduction of the Prussian blue in the display. The reduced form of Prussian blue, called Prussian white, is transparent. The rate of change from blue to colourless is dependent on the concentration of ascorbic acid. The display can easily be regenerated by connecting it to the biocathode which returns the Prussian blue to its oxidized form. In this way we have created the first self-powered electrochromic sensor that gives quantitative information about the analyte concentration. This is demonstrated by measuring the concentration of ascorbic acid in orange juice. The reported quantitative read-out electrochromic display can serve as a template for the creation of cheap, miniturizable sensors for other relevant analytes. PMID:24321882

Zloczewska, Adrianna; Celebanska, Anna; Szot, Katarzyna; Tomaszewska, Dorota; Opallo, Marcin; Jönsson-Niedziolka, Martin

2014-04-15

164

Arsenic-induced toxicity and the protective role of ascorbic acid in mouse testis  

International Nuclear Information System (INIS)

Oxidative stress has been suggested to be a major cause of male reproductive failure. Here, we investigated whether arsenic, which impairs male reproductive functions in rodent models, acts by inducing oxidative stress. Male 8-week-old ICR mice were given drinking water containing 20 or 40 mg/l sodium arsenite with or without 0.75 or 1.5 g/l of the antioxidant ascorbic acid for 5 weeks. The arsenic-treated mice showed decreased epididymidal sperm counts and testicular weights compared to untreated mice. These effects were reversed in mice that were co-treated with ascorbic acid. Similarly, arsenic treatment lowered the activities of testicular 3?-hydroxysteroid dehydrogenase (HSD) and 17?-HSD, which play important roles in steroidogenesis, and this was reversed by co-treatment with ascorbic acid. The testicles of arsenic-treated mice had decreased glutathione (GSH) levels (which correlate inversely with the degree of cellular oxidative stress) and elevated levels of protein carbonyl (a marker of oxidative damage to tissue proteins). Ascorbic acid co-treatment reversed both of these effects. Thus, ascorbic acid blocks both the adverse effects of arsenic on male reproductive functions and the arsenic-induced testicular oxidative changes. These observations support the notion that arsenic impairs male reproductive function by inducing oxidative stress

165

Light avoidance reduces ascorbic acid accumulation in the peel of Citrus fruit.  

Science.gov (United States)

Citrus fruits are highly consumed worldwide and represent one of the most important sources of ascorbic acid (AsA). However, information about the molecular mechanisms regulating AsA accumulation in Citrus fruit and the effects of environmental factors is scarce. In this study we have investigated the effect of fruit shading on AsA content and the expression of AsA biosynthetic, degrading and recycling genes in fruits of different Citrus species. Immature-green fruits were covered at the end of the cell enlargement phase and AsA concentration in the flavedo declined and remained at low levels as compared with light-exposed fruits. Fruit shading marginally altered the expression of genes from the l-galactose pathway and this effect was variable in the four Citrus species. However, specific isoforms (GalUR8 or GalUR12) from the l-galacturonic acid pathway were significantly repressed paralleling the reduction in AsA concentration. No significant effect of shading was detected in transcription of genes of the myo-inositol and l-gulose pathways as well as recycling and degradation. Collectively, results indicate that light avoidance inhibited accumulation of AsA in the flavedo of Citrus fruits and suggest that the l-galacturonic acid pathway has a relevant contribution to AsA content in this tissue. PMID:25575999

Lado, Joanna; Alós, Enriqueta; Rodrigo, María Jesús; Zacarías, Lorenzo

2015-02-01

166

Effect of Ascorbic Acid and Acetylsalicylic Acid Supplementation on Performance of Broiler Chicks Exposed to Heat Stress  

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Full Text Available A total of 100, day-old broiler chickens were randomly divided into 5 groups and kept under elevated temperature (34-36oC to see the effect of ascorbic acid and acetylsalicylic acid (Sb-Asper-C, a commercial product on the feed conversion ratio (FCR, immune status and ratio of weight of bursa, thymus and spleen to body weight. Heat stress increased the FCR but decreased the immune response and ratio of bursa, thymus and spleen to body weight of the birds. Ascorbic acid and acetylsalicylic acid supplementation during heat stress had beneficial effects on FCR, immune status and ratio of weight of bursa, thymus and spleen to body weight of the birds. Grossly, bursa thymus and spleen of heat stressed birds were atrophied but ascorbic acid and acetylsalicylic acid supplemented birds were not atrophied, No specific histopathological changes were observed in all groups.

Shamoon Naseem

2005-01-01

167

EFFECTS OF ASCORBIC ACID AND ACETYLSALICYLIC ACID SUPPLEMENTATION ON THE PERFORMANCE OF BROILER CHICKS EXPOSED TO HEAT STRESS  

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Full Text Available A total of 100, day-old broiler chicks were randomly divided into 5 equal groups and kept under elevated temperature (93-97oF to see the effect of ascorbic acid and acetylsalicylic acid on the feed conversion ratio (FCR, immune status and ratio of weight of bursa, thymus and spleen to body weight. Heat stress increased the FCR but decreased the immune response and ratio of bursa, thymus and spleen to body weight of the birds. Ascorbic acid and acetylsalicylic acid supplementation during heat stress had beneficial effects on FCR, immune status and ratio of bursa, thymus and spleen to body weight. Grossly, bursa, thymus and spleen of heat stressed birds were atrophied but in ascorbic acid and acetylsalicylic acid supplemented birds these organs were not atrophied. No specific histopathological changes were observed in all groups.

B. Anwar, S. A. Khan, A. Aslam, A. Maqbool1 and K. A. Khan

2004-07-01

168

Redox Regulation of Calcium Signaling in Cancer Cells by Ascorbic Acid Involving the Mitochondrial Electron Transport Chain  

OpenAIRE

Previously, we have reported that ascorbic acid regulates calcium signaling in human larynx carcinoma HEp-2 cells. To evaluate the precise mechanism of Ca2+ release by ascorbic acid, the effects of specific inhibitors of the electron transport chain components on mitochondrial reactive oxygen species (ROS) production and Ca2+ mobilization in HEp-2 cells were investigated. It was revealed that the mitochondrial complex III inhibitor (antimycin A) amplifies ascorbate-induced Ca2+ release from i...

Martinovich, Grigory G.; Golubeva, Elena N.; Martinovich, Irina V.; Cherenkevich, Sergey N.

2012-01-01

169

Crystal structures, circular dichroism spectra and absolute configurations of some ?-ascorbic acid derivatives  

Science.gov (United States)

Chiral 2,3-O,O-dibenzyl ethers of L-ascorbic acid with 4-(5,6-epoxy)- (4) and 6-O-tosyl- (8) functional groups were studied by X-ray crystallography and circular dichroism (CD) spectroscopy. The stereostructure of 2,3-O,O-dibenzyl-5,6-isopropylidene-L-ascorbic acid (6) and 8 was determined by X-ray crystal structure analysis. Comparison of the CD-spectra of 4 and 8 with the CD-spectra of their synthetic precursors (2-3, 5-7) and L-ascorbic acid (1) itself, as well as crystal structures of 6 and 8 permitted to deduce the absolute configuration of 4. Thus, the chiral atoms C-4 and C-5 in 4 have R and S configurations, which is consistent with the configuration of 1.

Wittine, Karlo; Gazivoda, Tatjana; Markuš, Marko; Mrvoš-Sermek, Draginja; Hergold-Brundi?, Antonija; Cetina, Mario; Žiher, Dinko; Gabelica, Vesna; Mintas, Mladen; Rai?-Mali?, Silvana

2004-01-01

170

Electro-oxidation of ascorbic acid catalyzed on cobalt hydroxide-modified glassy carbon electrode  

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Full Text Available The electrochemical behavior of ascorbic acid on a cobalt hydroxide modified glassy carbon (CHM–GC electrode in alkaline solution was investigated. The process of the involved oxidation and its kinetics were established using the cyclic voltammetry, chronoamperometry techniques, as well as by steady state polarization measurements. The results revealed that cobalt hydroxide promotes the rate of oxidation by increasing the peak current; hence ascorbic acid is oxidized at lower potentials, which is thermodynamically more favorable. The cyclic voltammograms and chronoamperometry indicate a catalytic EC mechanism is operative with the electrogeneration of Co(IV as the electrochemical process. Also, the process is diffusion-controlled and the current–time responses follow Cottrellian behavior. This result was confirmed by steady state measurements. The rate constants of the catalytic oxidation of ascorbic acid and the electron-transfer coefficient are reported.

GHASEM KARIM-NEZHAD

2009-05-01

171

EFFECTS OF ASCORBIC ACID AND ACETYLSALICYLIC ACID SUPPLEMENTATION ON THE PERFORMANCE OF BROILER CHICKS EXPOSED TO HEAT STRESS  

OpenAIRE

A total of 100, day-old broiler chicks were randomly divided into 5 equal groups and kept under elevated temperature (93-97oF) to see the effect of ascorbic acid and acetylsalicylic acid on the feed conversion ratio (FCR), immune status and ratio of weight of bursa, thymus and spleen to body weight. Heat stress increased the FCR but decreased the immune response and ratio of bursa, thymus and spleen to body weight of the birds. Ascorbic acid and acetylsalicylic acid supplementation during hea...

B Anwar, S. A. Khan

2004-01-01

172

Preventive activity of ascorbic acid on lead acetate induced cerebellar damaged in adult Wistar rats  

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Full Text Available Among the environmental contaminants, lead is one of the most hazardous to living matter. In mammals, the main target is the central nervous system, particularly in the young. Ascorbic acid is an antioxidant which is a substance that may protect your cells against the effects of free radicals. This study investigated Experiment the protective effect of ascorbic acid on the cerebellum of adult Wistar rats following oral administration of different doses of Lead acetate. Thirty adult Wistar rats of average weight of 215g were used in this study. The animals were divided into five (5 groups of six animals per group and were administered different doses of lead acetate (60mg/kg bwt of 1/10th LD50 and 30mg/kg bwt of 1/20th of LD50 and ascorbic acid (4.3mg/kg bwt orally over a period of three (3 weeks.Group 1 (control was administered distilled water and Group 2 and 3 were administered 30mg/kg and 60mg/kg of Lead acetate respectively while Group 4 and 5 were given co-administration of 30mg/kg of Lead acetate 4.3mg/kg of ascorbic acid and 60gm/kg of Lead acetate 4.3mg/kg of ascorbic acid respectively. Histopathologically, Lead acetate induced cellular damage in the cerebellum of adult Wistar rats and it was also observed that ascorbic acid prevents or minimize lead-induced cellular damage in the cerebellum of adult Wistar rats.

Sunday Abraham Musa

2012-12-01

173

Effects of Ascorbic Acid and Mono- and Diglycerides on Taftoon Bread Quality  

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Full Text Available The quality of Iranian breads has intensively decreased during recent years due to socio-economic factors and poor quality of flour. The purpose of this study is to investigate the effects of mono- and diglycerides and ascorbic acid as improvers on Iranian bread (Taftoon quality. Three wheat type flours (Ghods, Mahdavi and Roshan wheat varieties produced in Isfahan region were used. The effects of ascorbic acid at three levels (20, 40 and 60 ppm flour basis and esters of mono- and diglycerides at three levels (0.5, 1.0 and 1.5 percent on the dough baking and bread quality were measured. The Taftoon bread was baked in a semi-traditional oven. Loaves of bread were scored after baking and also on the first and second days of storage at room temperature. Analysis of variances indicated that ascorbic acid and mono- and diglycerides have significant effects on the improvement of the rheological properties of dough. However, ascorbic acid had higher effects than mono- and diglycerides. The results of the tests showed that dough resistance to mixing and tensile stress increased with addition of the improvers. Both improvers used in this experiment have an anti-stabling effect on bread. However, the ascorbic acid effect is much less than that of mono- and diglyceride. The low concentration of 0.5 percent of mono- and diglyceride and 60 ppm of ascorbic acid with flours of moderate protein contents (10-11% resulted in good quality Taftoon bread with good organoleptic and tearing qualities after two days.

M. Shahedi

2001-10-01

174

Effect of air pollution and other factors on ascorbic acid content of blueberries and lingonberries  

Energy Technology Data Exchange (ETDEWEB)

Blueberries (Vaccinium myrtillus L.) and lingonberries (Vaccinium vitis-idaea L.) were collected on rural and urban forest sites in Finland during the yield periods 1983 and 1984. A major part of the berry material was frozen immediately and analyzed after a shorter or longer storage period. The aim of the study was to simulate the normal use of forest berries and to study the effects of site pollution and other factors on the ascorbic acid content of berries. The ascorbic acid content of blueberries varied from 2.7 mg/100 g frozen berries to 9.9 mg/100 g in 1983 and from 5.0 mg/100 g to 10.9 mg/100 g in 1984. The corresponding values for lingonberries were 5.5 to 13.0 mg in 1983 and 7.3 to 14.1 mg in 1984. The lowest values of the ascorbic acid content of blueberries were obtained for longstored, urban, southern Finnish samples. The corresponding lowest values of lingonberries were obtained for berry samples picked later from industrial sites. The urban and industrial sites, compared to nearby rural ones, had relative mean values for the ascorbic acid content varying from 74% to 112% in blueberries and from 89% to 109% in lingonberries. In urban blue berry sites, the berries generally had a somewhat lower ascorbic acid content during both of the yield periods. Significantly lower values of the ascorbic acid content of blueberries were measured on the urban site in 1984 compared with the rural site during the whole yield period. In blueberries, the effect of freezing was to cause a clear drop in the AA-content level from the fresh value, although after freezing the level remained quite constant.

Huttunen, S.; Karhu, M.

1986-01-01

175

Inhibition of cell proliferation and migration by oxidative stress from ascorbate-driven juglone redox cycling in human bladder-derived T24 cells  

International Nuclear Information System (INIS)

Highlights: ? The cytotoxicity of juglone is markedly increased by ascorbate. ? T24 cell death by oxidative stress is necrosis-like. ? Redox cycling by juglone/ascorbate inhibits cell proliferation. ? Cellular migration is impaired by juglone/ascorbate. -- Abstract: The effects of juglone on T24 cells were assessed in the presence and absence of ascorbate. The EC50 value for juglone at 24 h decreased from 28.5 ?M to 6.3 ?M in the presence of ascorbate. In juglone-treated cells, ascorbate increased ROS formation (4-fold) and depleted GSH (65%). N-acetylcysteine or catalase restricted the juglone/ascorbate-mediated effects, highlighting the role of oxidative stress in juglone cytotoxicity. Juglone alone or associated with ascorbate did not cause caspase-3 activation or PARP cleavage, suggesting necrosis-like cell death. DNA damage and the mild ER stress caused by juglone were both enhanced by ascorbate. In cells treated with juglone (1–5 ?M), a concentration-dependent decrease in cell proliferation was observed. Ascorbate did not impair cell proliferation but its association with juglone led to a clonogenic death state. The motility of ascorbate-treated cells was not affected. Juglone slightly restricted motility, but cells lost their ability to migrate most noticeably when treated with juglone plus ascorbate. We postulate that juglone kills cells by a necrosis-like mechanism inhibiting cell proliferation and the motility of T24 cells. These effects are enhanced in the presence of ascorbate.

176

Visible light-induced oxidation of ascorbic acid and formation of hydrogen peroxide  

International Nuclear Information System (INIS)

Photosensitized oxidation of ascorbic acid and the formation of hydrogen peroxide using tris(2,2'-bipyridine)ruthenium(II), Ru(bpy)32+, proceed simultaneously in oxygen containing an aqueous solution of ascorbic acid with the illumination of visible light. The mechanism of the reaction has been suggested from the rate dependence on the solute concentrations and from quenching experiments. The charge separation could be achieved as the result of scavenging Ru(bpy)33+, which is formed by the reaction of the lowest excited state species of Ru(bpy)32+ with O2. (author)

177

Water disinfection with the hydrogen peroxide-ascorbic acid-copper (II) system.  

OpenAIRE

Treatment of secondary effluents with hydrogen peroxide (10 mg/liter)-ascorbic acid (10 mg/liter)-Cu2+ (0.5 mg/liter) for 60 min resulted in around 99% reduction of the initial plate count. Hydrogen peroxide could be replaced by other peroxygen compounds; ascorbic acid could be replaced by other reducing agents, of which sodium sulfite and ethanol were the most effective. Cu2+, however, could not be replaced by other metal ions without loss of bactericidal efficiency of the ternary combinatio...

Ragab-depre, N. J.

1982-01-01

178

Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea  

OpenAIRE

In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT+S), with ascorbic acid (GT+AA) and with sucrose and ascorbic acid (GT+S+AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P<0.05) enhanced in GT+S+AA formulations...

Peters, Catrina M.; Green, Rodney J.; Janle, Elsa M.; Ferruzzi, Mario G.

2010-01-01

179

The Effect of Ascorbic Acid on Cadmium Exposure in the Gills of Puntius altus  

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Full Text Available The effects of cadmium and ascorbic acid on the gills of Red-tailed tinfoil barb (Puntius altus were compared using light and scanning electron microscopic study for the period 24, 48, 72 and 96 h. The main alterations in the cadmium treated group were edema, filament cell proliferation, lamellar cell hyperplasia, lamellar fusion, epithelial lifting and aneurysm. These changes occurred predominantly in the 96 h treatment. In the combination of cadmium and ascorbic acid treated group, they showed similar alterations as those observed in the cadmium treated alone group but they were less severe.

Piya Kosai

2007-01-01

180

Kinetics of ascorbic acid loss during hot water blanching of fluted pumpkin (Telfairia occidentalis) leaves  

OpenAIRE

The kinetics of thermal degradation of ascorbic acid in fluted pumpkin leaves were investigated from 60 to 90°C (pH 5.0 to 6.5). Ascorbic acid degradation was modeled as a first order rate reaction with the rate constants increasing with increase in pH of the medium. The pH and temperature dependence of the rates of destruction gave highly significant correlations when analyzed by the thermal resistance and activated complex reaction rate methods. Activation energy (Ea) ranged from 41.2 to 1...

Ariahu, Charles C.; Abashi, Diana K.; Chinma, Chiemela Enyinnaya

2011-01-01

181

Study on NO2 absorption by ascorbic acid and various chemicals*  

OpenAIRE

Study on NO2 absorption aimed at seeking a better NO2 absorption chemical at pH 4.5~7.0 for application to existing wet flue gas desulfurization (FGD). The results from the double-stirred reactor indicated that ascorbic acid has very high absorption rate at this pH range. The rate constant of ascorbic acid reaction with NO2 (0~1000×10?6 mol/mol) is about 3.54×106 mol/(L·s) at pH 5.4~6.5 at 55 °C.

Li, Wei; Wu, Cheng-zhi; Fang, He-liang; Shi, Yao; Lei, Le-cheng

2006-01-01

182

Intravenous ascorbic acid protocol for cancer patients: scientific rationale, pharmacology, and clinical experience  

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Full Text Available ABSTRACTBackground: Ascorbic acid (vitamin C, ascorbate has been shown to protect cells against various types of oxidant injury at physiologically relevant concentrations. Vitamin C has been suggested as having both a preventative and therapeutic role in a number of pathologies when administered at much higher-than-recommended dietary allowance levels. This article reviews the scientific rational for intravenous vitamin C as a potential treatment for cancer. Many mechanisms of action for ascorbate efficacy against cancer have been proposed over the years. Cancer patients are often deficient in vitamin C, and require large doses to replenish depleted stores. It has been demonstrated in vitro and in animal studies that vitamin C is preferentially toxic to tumor cells at millimolar concentrations; moreover, pharmacokinetic data suggest that these concentrations are clinically achievable when ascorbate is administered intravenously. Data suggests that ascorbate may serve as a biological response modifier, affecting inflammation and angiogenesis as well as improving immune function parameters. While Phase II clinical trials using ascorbate in cancer therapy are under way, vitamin C is not subject to the regulations that synthetic drugs are and therefore has been used clinically for decades to treat cancer patients. This clinical experience suggests the therapy is safe, and may be effective in some instances. Attached to this article is the Riordan IVC Protocol, which details an intravenous vitamin C protocol that can be safely administered to cancer patients.Keywords: Cancer, inflammation, C-reactive protein, inflammatory cytokines, high-dose vitamin C

Mikirova NA

2013-08-01

183

Tear ascorbic acid levels and the total antioxidant status in contact lens wearers: A pilot study  

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Full Text Available Aims: The tear ascorbate owing to its high concentration, functions as an effective antioxidant against the oxidative damage of cornea. Contact lens wearers (CLW are prone to oxidative stress due to the lens-induced hypoxic conditions. A pilot study was done to compare the tear ascorbic acid level and the total antioxidant capacity give as in normal and CLW. Materials and Methods: In this study 21 CLW (Mean age 23 ± 3 years ; M-2, F-19, who were daily wear users, with duration of wear not more than four years, along with age-matched 28 controls (Mean age 28 ± 3 ; M-15, F-13 were recruited in the study for collection of reflex tears using Schirmer?s strip. Ascorbic acid in tears was determined using high-performance liquid chromatography (HPLC, total antioxidant capacity (TAC and total protein assay by spectrophotometric analysis. Results: CLW showed no significant change in the tear ascorbic acid levels (0.4 ± 0.26 mM compared to the control subjects (0.61 ± 0.59 mM. The amount of ascorbic acid in tears did not correlate with the TAC or the total protein of the tears. The mean TAC in CLW was 0.69 ± 0.16 mM, with a total protein of 1.35 ± 0.46?mg/ml while in controls it was 0.7 ± 0.18 mM and 1.21 ± 0.47 mg/ml respectively . Conclusions: Soft contact lens wear did not show any significant change in tear ascorbic acid, TAC and total protein levels compared to controls.

Venkata Sai

2009-01-01

184

Gold Electrodes Modified with Self-Assembled Monolayers for Measuring L-Ascorbic Acid: An Undergraduate Analytical Chemistry Laboratory Experiment  

Science.gov (United States)

This article describes an undergraduate electrochemistry laboratory experiment in which the students measure the L-ascorbic acid content of a real sample. Gold electrodes modified with self-assembled monolayers (SAMs) of thioctic acid and cysteamine are prepared to study the effects of surface modification on the electrode reaction of L-ascorbic

Ito, Takashi; Perera, D. M. Neluni T.; Nagasaka, Shinobu

2008-01-01

185

Comparison of oxalate formation from ascorbic and glyoxyl acids in detached glandular heads of tobacco trichomes  

International Nuclear Information System (INIS)

Ca-oxalate crystal containing cells from detached glandular heads of trichomes from Nicotiana tabacum, TI 1068, are capable of converting [1-14C] ascorbic acid (AA) and [1-14C] glyoxylic acid (GA) to oxalate. AA was found to be a better precursor for oxalate formation than GA. In detached glandular heads, 3.6x more label was converted to oxalate from AA than from GA, in the epidermis the factor was 3x while that with petiole tissue was 7x. Oxalate formation from AA, in detached glandular heads, was only partially inhibited in the dark and in the presence of metabolic inhibitors, suggesting that a nonenzymatic component might be involved. Oxalate formation from GA increased in the presence of metabolic inhibitors. During treatment of detached glandular heads with 2 mM Ca-acetate for 2 days, oxalate formation from AA was stimulated 3 fold, while the presence of 2mM Ca-acetate had no effect on the oxalate formation from GA. These results suggest that Ca2+ stimulates the formation of Ca-oxalate crystals in glandular head cells, and that AA can serve as a precursor for oxalate production

186

Selective Detection of Dopamine in the Presence of Ascorbic Acid at Poly (m-Aminobenzene Sulfonic Acid  

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Full Text Available Poly (m-aminobenzene sulfonic acid, m-ABSA films were electrochemically prepared by cyclic voltammetry (CV in 0.1 mol L–1 KCl solution. The dopamine (DA selectivity of polymeric electrodes prepared at the different thicknesses was examined in the presence of ascorbic acid (AA. The results showed that the modified electrode showed an excellent electrocatalytical effect towards oxidation of dopamine (DA and ascorbic acid (AA. Electrostatic interaction between the negatively charged poly(m-ABSA film and either cationic DA species or anionic AA species favorably contributed to the redox response of DA and AA. Moreover, the regular and repetitive responses for dopamine were obtained even in the presence of the some interfering substances such as ascorbic acid, NaCl, NaClO4, Na2SO4 ,NaNO3 and KCl.

Gamze Erdo?du

2011-09-01

187

The Effect of Oral Ascorbic Acid Pretreatment on Feeding Changes Following Injection in Nucleus Accumbens Shell in Adult Male Rats  

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Full Text Available Background: Ascorbic acid (AA is not synthesized in the brain but it is actively transported through blood-brain barrier by SVCT2 cotransporter and it is stored in high concentrations with heterogeneous distribution in areas such as nucleus accumbens shell (AcbSh in the mammalian brain. Previous studies have shown that Ascorbic acid injection into AcbSh decreases feeding; therefore, in the present study we evaluated the effects of oral Ascorbic acid pretreatment on changes in feeding upon its injection in AcbSh in adult male rats.Methods: Sixty-three adult male rats (220-280 g were divided into five treatment and five pretreatment groups. The treatment groups included the control (intact group, sham-operated Ascorbic acid group that received normal saline as vehicle, and three other groups that received different doses of ascorbic acid (10, 50 and 250 µg/rat by injection into AcbSh for four days. The pretreatment groups received Ascorbic acid (100 mg/kg for 15 days via gastric gavage before receiving the aforementioned doses in treatment groups into intra nucleus AcbSh. Feeding measurement was repeated every 12 hours by automatic metabolic cage.Results: The results indicated that all injected doses of Ascorbic acid (10, 50 and 250 µg/rat into nucleus accumbens shell decrease food intake (P<0.05 in rats and oral Ascorbic acid pretreatment had no effects in this regard.Conclusion: Our findings show that ascorbic acid is an effective factor in feeding regulation. Oral pretreatment seems to have no influence on the central effects of ascorbic acid in the nucleus accumbens shell.

Badreh F

2012-02-01

188

Simultaneous determination of ascorbic acid, uric acid and neurotransmitters with a carbon ceramic electrode prepared by sol-gel technique.  

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A sol-gel carbon composite electrode (CCE) has been prepared by mixing a sol-gel precursor (e.g. methyltrimethoxysilane) and carbon powder without adding any electron transfer mediator or specific reagents. It was demonstrated that this sensor can be used for simultaneous determination ascorbic acid, neurotransmitters (dopamine and adrenaline) and uric acid. Direct electrochemical oxidation of ascorbic acid, uric acid and catecholamines at a carbon composite electrode was investigated. The experimental results were compared with other common carbon based electrodes, specifically, boron doped diamond, glassy carbon, graphite and carbon paste electrodes. It was found that the CCE shows a significantly higher of reversibility for dopamine. In addition, in comparison to the other electrodes used, for CCE the oxidation peaks of uric acid, ascorbic acid and catecholamines in cyclic and square wave voltammetry were well resolved at the low positive potential with good sensitivity. The advantages of this sensor were high sensitivity, inherent stability and simplicity and ability for simultaneous determination of uric acid, catecholamines and ascorbic acid without using any chromatography or separation systems. The analytical performance of this sensor has been evaluated for detection of biological molecules in urine and serum as real samples. PMID:18970846

Salimi, Abdollah; Mamkhezri, Hussein; Hallaj, Rahman

2006-11-15

189

Kinetics and mechanism of reduction of iron (III) kojic acid complex by ascorbic acid  

International Nuclear Information System (INIS)

Kinetics of reduction of iron (III) kojic acid complex by ascorbic acid has been carried out using photodiode array spectrophotometer over the ranges: 4.0<=pH<=5.5 and 5.0<=T<=25.0 degree C at ionic strength 0.2 M under pseudo-first order conditions by stopped-flow technique. Rate of the reaction was found to be pH dependent. The redox reaction followed the saturation kinetics. The rate law is deduced as follows: Rate = (k/sub 3/k/sub eq(H/sup +/)(HAsc/sup -/)(Fe(KA)/sub 3/) / (HKA) + K/sub eq/(H/sup +/)(HAsc/sup -/) The activation parameters of this reaction were determined. A mechanism consistent with this rate law has been proposed. (author)

190

Distribution of ascorbate-2-sulfate and distribution, half-life and turnover rates of [1-14C]ascorbic acid in rainbow trout  

International Nuclear Information System (INIS)

Rainbow trout (250 g) were maintained at 15 degrees C for 3 months on a low ascorbic acid diet, given [1-14C]ascorbic acid by gavage, then fed the NAS/NRC requirement 12 times per week. Total urine, fecal water and branchial water were collected daily from five fish placed in metabolism chambers for four successive 5-day periods. Tissue samples were analyzed for 14C, ascorbic acid (C1) and ascorbate-2-sulfate (C2). Excretion analysis indicated t1/2 . 42 days. After 20 days, the feeding schedule was changed to 3 times per week. Fish fed 14C were sampled after 1, 2, 3 and 4 months. The half-life in each organ except brain was inversely proportional to the dietary level of ascorbate. Concentrations of C1 and C2 in the various tissues reflected dietary intake of vitamin C. Total C (CT . C1 + C2) levels were maintained in the liver even with the low vitamin C diet. Estimates of body pool for C1 are 27-29 mg/kg. At the higher ascorbate intake CT was 92-114 mg/kg, but decreased by 34% at the lower feeding rate to 51-62 mg/kg. Data indicate that there are two or more body pools that include a store of C2, which is readily interconverted in metabolizing tissues to and from C1. Since air and water stable C2 is antiscorbutic for fish, it is the preferred form of ascorbate for fish feeds

191

Impact of Exogenous Ascorbic Acid on Antioxidant Activity and Some Physiological Traits of Common Bean Subjected to Salinity Stress  

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Full Text Available The role of ascorbic acid as a key molecule antioxidant involves in biotic and abiotic stress has already been well described. Recent study indicates that it also participates in the detoxification of generated reactive oxygen species due to abiotic stresses. Thus, In order to study effects of salt stress and ascorbic acid on antioxidant enzyme activity, chlorophyll content, lipid peroxidation and abscisic acid accumulation of bean an experiment was conducted. The exogenous application of ascorbic acid in nutrition solution of bean plants indicated that later is involve in reduction of antioxidant enzyme activity and increase of resistance to salt stress. We observed that antioxidant enzyme activity increased due to salt stress and ascorbic acid via eliminating of reactive oxygen species decreased activities. Moreover, abscisic acid and lipid peroxidation were affected of salt stress. Increase of ascorbic acid concentration at 100 mM NaCl treatment prevented of lipid peroxidation and decreased generation of malondialdehyde as final product of peroxidation of membrane lipids. However, at high level of salinity, ascorbic acid did not significant effect on reduction of lipid peroxidation. Whereas, chlorophyll content decreased by reactive oxygen species. Ascorbic acid increased chlorophyll content at all of stressed and non-stressed treatments. Abscisic acid assay showed that, accumulation of this hormone increased under salt stress treatments and raise of ascorbic acid concentration in nutrition solution of stressed plants prevented of abscisic acid accumulation. Our data provide strong support to the hypothesis that exogenous of ascorbic acid reduces the harmful effects of salinity and increases resistance to salinity in bean plant.

Ramin SALEH JOUNEGHANI

2009-11-01

192

Factors that affect leaf extracellular ascorbic acid content and redox status  

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Leaf ascorbic acid content and redox status were compared in ozone-tolerant (Provider) and ozone-sensitive (S156) genotypes of snap bean (Phaseolus vulgaris L.). Plants were grown in pots for 24 days under charcoal-filtered air (CF) conditions in open-top field chambers and then maintained as CF controls (29 nmol mol{sup 1} ozone) or exposed to elevated ozone (71 nmol mol{sup 1} ozone). Following a 10-day treatment, mature leaves of the same age were harvested early in the morning (06:00-08:00 h) or in the afternoon (13:00-15:00 h) for analysis of ascorbic acid (AA) and dehydroascorbic acid (DHA). Vacuum infiltration methods were used to separate leaf AA into apoplast and symplast fractions. The total ascorbate content [AA + DHA] of leaf tissue averaged 28% higher in Provider relative to S156, and Provider exhibited a greater capacity to maintain [AA + DHA] content under ozone stress. Apoplast [AA + DHA] content was 2-fold higher in tolerant Provider (360 nmol g{sup 1} FW maximum) relative to sensitive S156 (160 nmol g1 FW maximum) regardless of sampling period or treatment, supporting the hypothesis that extracellular AA is a factor in ozone tolerance. Apoplast [AA + DHA] levels were significantly higher in the afternoon than early morning for both genotypes, evidence for short-term regulation of extracellular ascorbate content. Total leaf ascorbate was primarily reduced with AA/[AA + DHA] ratios of 0.81-0.90. In contrast, apoplast AA/[AA + DHA] ratios were 0.01-0.60 and depended on genotype and ozone treatment. Provider exhibited a greater capacity to maintain extracellular AA/[AA + DHA] ratios under ozone stress, suggesting that ozone tolerance is associated with apoplast ascorbate redox status. (au)

Burkey, K.O.; Fiscus, E.L. [North Carolina State Univ., United States dept. og Agriculture-Agricultural Research Service and Dept. of Crop Science, Raleigh, NC (United States); Eason, G. [North Carolina, State Univ., United States Dept. of Plant Pathology, Raleigh, NC (United States)

2003-01-01

193

INFLUENCES OF THIAMINE AND/OR ASCORBIC ACID ON LEAD INTOXICATION  

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Full Text Available The effects of thiamine, ascorbic acid ami their combination an workers who are continuously exposal to lead has been investigated. In this study 60 persons in a Battery industry was selected and divided into four equal groups. Group I received placebo, group II thiamine (300 mg, group III ascorbic acid (250 mg anil group IV thiamine (300 mg plus ascorbic acid (250 mg three times a day (Orally. At beginning of the study and after one month of above drug regimen; blood, urine and a questionnaire about their clinical signs were examined. 'there were no significant differences between blood anil urine lead level in all groups after treatment. Zinc protoporphyrin (zpp level showed a significant reduction in ascorbic acid treated group (group III as compared to pretreatment. Clinical manifestation improved in the group that received both vitamins (group IV. However, from a clinical stand point, it appears the usage of these vitamins may have a beneficial effects in lead occupational exposure.

M. Ghazi-Khansari

1996-07-01

194

Effect of L-ascorbic Acid on Nili Ravi Buffalo Oocytes During in vitro Maturation  

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Full Text Available The present study was conducted to investigate the effect of L-ascorbic acid (AsA on Nile Ravi buffalo oocytes. Cumulus Enclosed Oocytes (CEOs and Cumulus Denuded Oocytes (CDOs were cultured for 24 h in TCM-199 supplemented with Recombinant Human Follicular Stimulating Hormone (RhFSH, 0.4% Bovine Serum Albumin (BSA, oestradiol and Gentamycin. Nili Ravi buffalo oocytes with or free from cumulus cells were exposed to 250 ?M AsA. Meiotic maturation, degeneration of oocytes was assessed at different maturation time (0, 12, 24 h. CDOs treated with L-ascorbic acid resumed meiosis and oocytes were significantly (p<0.05 increased to MII stage. Where as CDOs matured in control medium with out L-ascorbic acid supplementation did not show any significant increase in MII oocytes proportion as the maturation time was extended to 24 h (p<0.05. In present study it was observed that cumulus cells are involved in protection against degeneration as CEOs treated in control medium the degenerated oocytes high significantly (p<0.05 decreased to 7.40% as compared to CDOs in which 21.4% oocytes were found to be degenerated. These results indicate that exposure to L-ascorbic acid promote the development of the Nili Ravi buffalo CDOs and cumulus cells are involved in protection against degeneration of oocytes.

Ikram Ullah

2006-01-01

195

A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex  

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A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 {mu}g ml{sup -1}. Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C. [Italiano] Si propone un rapido e semplice metodo spettrofotometrico per la determinazione dell`acido ascorbico. L`acido ascorbico riduce il ferro(III) a ferro(II) che forma con la dimetilgliossima, in presenza di piridina, un complesso colorato in rosso. L`assorbanza della soluzione risultante e` misurata a 514 nm e si ottiene una relazione lineare tra assorbanza e concentrazione dell`acido ascorbico fino a 14 {mu}g ml{sup -1}. Si sono condotti studi sugli interferenti usualmente associati all`acido ascorbico ed e` stata valutata l`applicabilita` del metodo all`analisi di preparati farmaceutici di vitamina C.

Arya, S. P.; Mahajan, M. [Haryana, Kurukshetra Univ. (India). Dept. of Chemistry

1998-05-01

196

PLASMID DNA DAMAGE CAUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN  

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Plasmid DNA damage caused by methylated arsenicals, ascorbic acid and human liver ferritin. Arsenic causes cancer in human skin, urinary bladder, lung, liver and kidney and is a significant world-wide public health problem. Although the metabolism of inorganic arsenic is ...

197

A green method for the synthesis of Copper Nanoparticles using L-ascorbic acid  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Chemical Reduction technique was employed to prepared highly stable and dispersed Copper nanoparticles using L-Ascorbic Acid (Vitamin C) as reducing as well as capping agent. In this technique, cupric chloride was used as precursor. The effects of different molar ratios of L-Ascorbic Acid on the con [...] centration and size of copper nanoparticles were studied. The Copper nanoparticles were characterized by X-Ray Diffraction, Atomic Absorption Spectrometry, and Fourier Transform Infrared Spectrometry. The results show that with the increase in the molar ratio of L-ascorbic acid the concentration of Copper nanoparticles were also increased. The average particles size of copper nanoparticle was found in the range of 50-60 nm. The product was kept in ambient conditions for three month but no sedimentation or separation was observed. The use of ascorbic acid makes the process a non-toxic, cost effective and environmental friendly green method.

Asim, Umer; Shahid, Naveed; Naveed, Ramzan; Muhammad Shahid, Rafique; Muhammad, Imran.

2014-09-01

198

Effect of preservation method and storage condition on ascorbic acid loss in beverages  

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Full Text Available Global market is flooded with vitamin-enriched foods, mainly beverages. Major vitamins for enriching beverages are the antioxidant vitamins A, C and E. Ascorbic acid is readily oxidized and lost during storage of the beverages, at rates depending on the conditions of storage. This fact is of great importance for the consumer who must know how to store beverages and when to consume them in order to get the maximum benefit of added vitamin C. The objective of this paper was to determine the amount of ascorbic acid lost in beverages applying different preservation methods and storage condition. Beverage was made in laboratory conditions with synthetic L-ascorbic acid added according to the national legislations. After 30 days of storage at 4-8oC ascorbic acid overall loss was from 81.01% to 90.27% in thermally pasteurized samples and from 97.83 % to almost complete loss in samples preserved with sodium benzoate.

Jokanovi? Marija R.

2009-01-01

199

Effects of ascorbic acid on sperm motility, viability, acrosome reaction and DNA integrity in teratozoospermic samples  

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Background: Oxidative stress in teratozoospermic semen samples caused poor assisted reproductive techniques (ART) outcomes. Among antioxidants, ascorbic acid is a naturally occurring free radical scavenger and as such its presence assists various other mechanisms in decreasing numerous disruptive free radical processes.

Fanaei, Hamed; Khayat, Samira; Halvaei, Iman; Ramezani, Vahid; Azizi, Yaser; Kasaeian, Amir; Mardaneh, Jalal; Parvizi, Mohammad Reza; Akrami, Maryam

2014-01-01

200

CAPSAICIN AND ASCORBIC ACID VARIABILITY IN CHILLI AND PAPRIKA CULTIVARS AS REVEALED BY HPLC ANALYSIS  

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Full Text Available Capsaicin and ascorbic acid contents of seven Indian peppers varieties/accessions from Capsicum annuum (CA 97, CCH, K1, KTPL19, Arka Abhir and Bayadagi Kaddi and C. frutescens (CF1 species were determined using High Performance Liquid Chromatography (HPLC. Based on their pungency value, all the chilli accession/varieties (CA 97, CCH, K1, and CF 1 were classified as highly pungent peppers. The accession CF1 showed the highest concentration of capsaicin (445mg 100g -1 DW with corresponding pungency value of 71,200 SHUs and Arka Abhir variety showed the lowest capsaicin concentration (29mg 100g -1 DW with 4,672 SHUs of pungency value. Similarly, Bayadaggi kaddi variety showed the highest ascorbic acid content (189 mg/100 FW and the accession CA 97 showed the lowest ascorbic acid contents (55.3 mg/100 FW. The variability in capsaicin and ascorbic acid content presented in the pepper germplasm can be exploited for breeding cultivars with improved nutritional qualities. Moreover, CF1and Bayadagi kaddi can be used as a potential source for capsaicin and vitamin C, respectively.

Samuel Tilahun

2013-08-01

201

CAPSAICIN AND ASCORBIC ACID VARIABILITY IN CHILLI AND PAPRIKA CULTIVARS AS REVEALED BY HPLC ANALYSIS  

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Full Text Available Capsaicin and ascorbic acid contents of seven Indian peppers varieties/accessions from Capsicum annuum (CA 97, CCH, K1, KTPL19, Arka Abhir and Bayadagi Kaddi and C. frutescens (CF1 species were determined using High Performance Liquid Chromatography (HPLC. Based on their pungency value, all the chilli accession/varieties (CA 97, CCH, K1, and CF 1 were classified as highly pungent peppers. The accession CF1 showed the highest concentration of capsaicin (445mg 100g -1 DW with corresponding pungency value of 71,200 SHUs and Arka Abhir variety showed the lowest capsaicin concentration (29mg 100g -1 DW with 4,672 SHUs of pungency value. Similarly, Bayadaggi kaddi variety showed the highest ascorbic acid content (189 mg/100 FW and the accession CA 97 showed the lowest ascorbic acid contents (55.3 mg/100 FW. The variability in capsaicin and ascorbic acid content presented in the pepper germplasm can be exploited for breeding cultivars with improved nutritional qualities. Moreover, CF1and Bayadagi kaddi can be used as a potential source for capsaicin and vitamin C, respectively.

Samuel Tilahun

2013-10-01

202

Combined metoprolol and ascorbic acid treatment prevents intrinsic damage to the heart during diabetic cardiomyopathy.  

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Metabolic disturbances and oxidative stress have been highlighted as potential causative factors for the development of diabetic cardiomyopathy. The ?-blocker metoprolol is known to improve function in the diabetic rat heart and ameliorates the sequelae associated with oxidative stress, without lowering oxidative stress. The antioxidant ascorbic acid is known to improve function in the diabetic rat heart. We tested whether a combination of ascorbic acid and metoprolol treatment would improve function further than each drug individually. Control and streptozotocin-induced diabetic Wistar rats were treated with metoprolol (15 mg·(kg body mass)(-1)·day(-1), via an osmotic pump) and (or) ascorbic acid (1000 mg·(kg body mass)(-1)·day(-1), via their drinking water). To study the effect of treatment on the development of dysfunction, we examined time points before (5 weeks diabetic) and after (7 weeks diabetic) development of overt systolic dysfunction. Echocardiography and working-heart-perfusion were used to assess cardiac function. Blood and tissue samples were collected to assess the severity of disease and oxidative stress. While both drugs improved function, only ascorbic acid had effects on oxidative damage. Combination treatment had a more pronounced improvement in function. Our ?-blocker + antioxidant treatment strategy focused on oxidative stress, not diabetes specifically; therefore, it may prove useful in other diseases where oxidative stress contributes to the pathology. PMID:25229873

Saran, Varun; Sharma, Vijay; Wambolt, Richard; Yuen, Violet G; Allard, Michael; McNeill, John Hugh

2014-10-01

203

Capparidaceous Medicinal Plants of North-West Rajasthan: Good Sources of Ascorbic Acid  

OpenAIRE

Ascorbic acid contents of roots, shoots and fruits of three selected medicinal plants like Capparis decidua,Cleome gynandra and Cleome viscosa of family Capparidaceae have been analysed. Maximum ascorbicacid contents were found in the fruits of Capparis decidua (108.12mg/100g.d.w.) while, minimum in theroots of Cleome viscosa (62.25mg/100g.d.w).

Kapoor And Raksha Mishra, B. B. S.

2013-01-01

204

Ascorbic acid as a new reductant in the thiocyanate method for the spectrophotometric determination of rhenium  

International Nuclear Information System (INIS)

A spectrophotometric determination of rhenium is based on its reduction with ascorbic acid in the presence of thiocyanate. The orange-yellow complex is extracted into isoamyl alcohol and the absorbance measured at 430 nm. Various foreign ions do not interfere. Molar absorptivity and Sandell's sensitivity are 31162.79 l/mol/cm and 0.0059 ?g/cm2, respectively. (orig.)

205

Structure of ascorbic acid and its biological function: V. Transport of ascorbate and isoascorbate across artificial membranes as studied by the spin label technique.  

Science.gov (United States)

It could be shown by the reduction of the spin label (1,14) located within DPPC vesicles, that Na-ascorbate and K-isoascorbate can permeate membranes. At physiologic pH value, these two compounds exist as electroneutral radicals with a cyclic side chain structure. Ascorbic acid and isoascorbic acid, on the contrary, can hardly permeate such an artificial membrane. Since the radical will cause lipid peroxidation, it must be modified prior to permeation. This can be done by GSH which changes the radical state but maintains the electroneutral bicyclic configuration. PMID:6670356

Lohmann, W; Winzenburg, J

1983-01-01

206

Relevance of DNA repair pathways on ascorbic acid effects on Echerichia Coli K-12 cells  

International Nuclear Information System (INIS)

Inactivation kinetics were performed with repair proficient and deficient Escherichia coli K-12 cells treated with oxidized solutions of ascorbic acid. The repair pathways controlled by the recA and uvrA gene products are essential for cell survival to the treatment. However, SOS chromotest result indicates that the SOS functions are only induced at high and toxic concentrations of the drug. Moreover, single strand breaks in DNA from treated cells are detected, demonstrating genome damage promoted by oxidized solutions of ascorbate. (M.A.C.)

207

In vitro effect of ascorbic acid on infectivity of herpesviruses and paramyxoviruses.  

OpenAIRE

Suspensions of herpes simplex virus types 1 and 2, cytomegalovirus, and parainfluenzavirus type 2 were inactivated within 24 h when treated at 37 degrees C with 1 mg (5.05 mM) of copper-catalyzed sodium ascorbate per ml. The infectivity titer of respiratory syncytial virus was reduced substantially after 24 h but required 48 h for inactivation. Under these conditions, inactivation of these viruses was also successfully achieved with 5.68 mM catalyzed ascorbic acid. Copper (Cu2+), when added w...

White, L. A.; Freeman, C. Y.; Forrester, B. D.; Chappell, W. A.

1986-01-01

208

Gender difference following high cholesterol diet induced renal injury and the protective role of rutin and ascorbic acid combination in Wistar albino rats  

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Full Text Available Abstract Background An increased interest is given to the impact of high fat diet on health worldwide. Abnormalities in lipid metabolism induced by high cholesterol diet (HCD were reported to exacerbate renal diseases via oxidative stress pathways. Rutin and ascorbic acid showed a protective role against oxidative stress-mediated diseases. Furthermore, both lipid metabolism and tissue response to oxidative stress damage was found to vary according to animal gender. Thus, the objective of this work was to examine possible gender-related differences and the possible protective effects of rutin and ascorbic acid supplementation on high cholesterol diet induced nephrotoxicity. Methods 96 young male and female Wistar albino rats were used. HCD supplemented animals were treated with rutin alone or in combination with ascorbic acid for 6 weeks. Creatinine plasma level was estimated. Furthermore, kidney levels of nucleic acids, total protein, malondialdehyde (MDA, reduced glutathione (GSH, total cholesterol, and triglycerides were determined. Finally, kidney tissues were used for histopathological examination. Results HCD supplementation decreased kidney level of nucleic acids, which was more prominent in female animals. Both vitamin combination significantly attenuated HCD induced decrease in nucleic acids. Moreover, kidney level of MDA was significantly altered by HCD in both genders, which was inhibited by rutin and ascorbic acid alone or in combination in male groups and by both vitamins in female groups. There was a reduction in kidney level of GSH by HCD, especially in male groups, which was attenuated by rutin and ascorbic acid combination. Kidney levels of total cholesterol and triglycerides were significantly increased by HCD supplementation in both genders. Coadministration with rutin and/or ascorbic acid protected from such increase, which was more obvious in both vitamins combination. Histopathological investigation supported vitamins protective effect, which was more prominent in male vitamins combination group. Conclusions HCD-induced renal injury in female was higher than in male animals, suggesting a better anti-oxidative stress defense response in male's kidney. Moreover, the antioxidant and reno-protective effects of rutin and ascorbic acid were augmented following their combination.

Al-Rejaie Salim

2012-03-01

209

An Attempt at Alleviating Heat Stress Infertility in Male Broiler Breeder Chickens with Dietary Ascorbic Acid  

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Full Text Available Previous research regarding the effect of heat stress on broiler breeders is very limited. The objective of the present study was to determine the amount of ascorbic acid in the broiler breeders` diet that will improve reproductive performance of males that are exposed to continuous heat stress. One hundred forty-four Ross males (18 weeks old were divided equally among six temperature controlled rooms. Three rooms were used for heat treatment and three rooms served as controls (21°C. The temperature in the heat treatment rooms was increased in two four-week phases followed by a final three week recovery phase with the temperatures for each period being 29 (mild stress, 32 (severe stress, and 21°C, respectively. The roosters in each room were equally divided among four dietary treatments consisting of 0, 250, 500, and 1000 ppm of ascorbic acid. Heat stress significantl/y decreased sperm quality index, sperm viability, and fertility. The percentage of dead sperm rose significantly during both the mild and severe heat phases and dropped immediately upon initiation of the recovery phase. Sperm motility decreased linearly with increasing ambient temperature but rebounded upon the removal of heat stress. The rate of fertilization was decreased as a result of heat stress. Dietary ascorbic acid did not improve any of the semen characteristics of control or heat stressed birds. Administration of 500 and 1000 ppm of dietary ascorbic acid resulted in a depression of fertility over each day postinsemination when the males were heat stressed. In conclusion, dietary ascorbic acid at the levels used in the present study did not improve the reproductive performance of broiler breeder males under normal or heat stress conditions.

C.D. McDaniel

2004-01-01

210

Comparison of radioprotective effects of caffeine and ascorbic acid in male mice  

Energy Technology Data Exchange (ETDEWEB)

The oxygen effect in radiation biology is well known. Since oxygen enhances radiation-induced biological damage, antioxidants should be radioprotectors. Ascorbic acid (vitamin C) or caffeine is an essential component in the diet of humans and a small range of other mammals. Radioprotective effects of vitamin C have been demonstrated in certain cells and animals, which would result from scavenging free radicals. Caffeine is the main psychoactive ingredient of coffee, tea, even coke with a high frequency of concurrent use in humans. Caffeine has been recently reported as a scavenger of hydroxyl radical in millimolar levels and a potently radioprotector in a chronically exposed rodent. This study investigates functional radioprotection of caffeine and ascorbic acid against gamma irradiation in male mice. Eight-week-old male C57BL/6N mice were irradiated with 6.5 Gy. A caffeine treated group was administered with 80 mg/kg body weight by i.p injection, a single exposure 1 hour before irradiation. Ascorbic acid was administered 330 mg/liter in drinking water through all the experimental period. The remaining mice were kept as sham controls. After collecting a serum from the experimental mice 6 hr after irradiation, qualitative analysis of testosterone was performed by means of radioimmunoassay (RIA). For histological investigation, testes were removed 1 week after irradiation and fixed in NBF. Fixed testes were processed for paraffin sections and stained by H-E. The circulating testosterone significantly decreased in all irradiated groups. The harmful effect of radiation on the body and organ weight and the appearance of semiferous tubules were significantly improved in the caffeine - or ascorbic acid-treated group. In conclusion, caffeine and ascorbic acid protected spermatogenesis from impairment against gamma radiation, acting as a radioprotector.

Kim, Jin Kyu; Kim, Ji Hyang; Lee, Byoung Hun [KAERI, Taejon (Korea, Republic of); Yoon, Yong Dal [Hanyang Univ., Seoul (Korea, Republic of)

2003-04-01

211

Comparison of radioprotective effects of caffeine and ascorbic acid in male mice  

International Nuclear Information System (INIS)

The oxygen effect in radiation biology is well known. Since oxygen enhances radiation-induced biological damage, antioxidants should be radioprotectors. Ascorbic acid (vitamin C) or caffeine is an essential component in the diet of humans and a small range of other mammals. Radioprotective effects of vitamin C have been demonstrated in certain cells and animals, which would result from scavenging free radicals. Caffeine is the main psychoactive ingredient of coffee, tea, even coke with a high frequency of concurrent use in humans. Caffeine has been recently reported as a scavenger of hydroxyl radical in millimolar levels and a potently radioprotector in a chronically exposed rodent. This study investigates functional radioprotection of caffeine and ascorbic acid against gamma irradiation in male mice. Eight-week-old male C57BL/6N mice were irradiated with 6.5 Gy. A caffeine treated group was administered with 80 mg/kg body weight by i.p injection, a single exposure 1 hour before irradiation. Ascorbic acid was administered 330 mg/liter in drinking water through all the experimental period. The remaining mice were kept as sham controls. After collecting a serum from the experimental mice 6 hr after irradiation, qualitative analysis of testosterone was performed by means of radioimmunoassay (RIA). For histological investigation, testes were removed 1 week after irradiation and fixed in NBF. Fixed testes were processed for paraffin sections and stained by H-E. The circulan sections and stained by H-E. The circulating testosterone significantly decreased in all irradiated groups. The harmful effect of radiation on the body and organ weight and the appearance of semiferous tubules were significantly improved in the caffeine - or ascorbic acid-treated group. In conclusion, caffeine and ascorbic acid protected spermatogenesis from impairment against gamma radiation, acting as a radioprotector

212

Response of Gamma Irradiated Mungbean Seeds to Salinity and Ascorbic Acid Treatments  

International Nuclear Information System (INIS)

Dry seeds of mungbean (Vigna radiata L.) were irradiated with different doses of gamma rays (0-250 Gy) and germinated under laboratory conditions in 100 mM of sodium chloride or 10 mM ascorbic acid or mixture of both. The growth parameters of the two weeks old seedlings were recorded. Photosynthetic pigments, total carbohydrates, crud protein and amino acids contents were also determined. Gamma radiation (50-100 Gy) increased total chlorophylls and carotenoid pigments. The highest dose of irradiation (250 Gy) reduced these contents. Saline condition decreased total chlorophyll and carotenoid contents of seedlings resulted from irradiated seeds than controls. Addition of ascorbic acid to irradiated mungbean seeds in presence of NaCl overcame partially the inhibitory effect of NaCl on chlorophyll and carotenoid contents of seedlings. The pattern of changes in amino acids content was more or less similar to that of photosynthetic pigments

213

Pharmacologic ascorbic acid concentrations selectively kill cancer cells: Action as a pro-drug to deliver hydrogen peroxide to tissues  

OpenAIRE

Human pharmacokinetics data indicate that i.v. ascorbic acid (ascorbate) in pharmacologic concentrations could have an unanticipated role in cancer treatment. Our goals here were to test whether ascorbate killed cancer cells selectively, and if so, to determine mechanisms, using clinically relevant conditions. Cell death in 10 cancer and 4 normal cell types was measured by using 1-h exposures. Normal cells were unaffected by 20 mM ascorbate, whereas 5 cancer lines had EC50 values of <4 mM, a ...

Chen, Qi; Espey, Michael Graham; Krishna, Murali C.; Mitchell, James B.; Corpe, Christopher P.; Buettner, Garry R.; Shacter, Emily; Levine, Mark

2005-01-01

214

Effect of L-ascorbic acid on nickel-induced alterations in serum lipid profiles and liver histopathology in rats.  

Science.gov (United States)

Nickel exposure greatly depletes intracellular ascorbate and alters ascorbate-cholesterol metabolism. We studied the effect of the simultaneous oral treatment with L-ascorbic acid (50 mg/100 g body weight (BW) and nickel sulfate (2.0 mg/100 g BW, i.p) on nickelinduced changes in serum lipid profiles and liver histopathology. Nickel-treated rats showed a significant increase in serum low-density lipoprotein-cholesterol, total cholesterol, triglycerides, and a significant decrease in serum high-density lipoprotein-cholesterol. In the liver, nickel sulfate caused a loss of normal architecture, fatty changes, extensive vacuolization in hepatocytes, eccentric nuclei, and Kupffer cell hypertrophy. Simultaneous administration of L-ascorbic acid with nickel sulfate improved both the lipid profile and liver impairments when compared with rats receiving nickel sulfate only. The results indicate that L-ascorbic acid is beneficial in preventing nickel-induced lipid alterations and hepatocellular damage. PMID:16639878

Das, Kusal K; Gupta, Amrita Das; Dhundasi, Salim A; Patil, Ashok M; Das, Swastika N; Ambekar, Jeevan G

2006-01-01

215

Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears  

OpenAIRE

Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a ?-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, beta...

Leonardo Martinez-Cardenas; Carmen Valadez-Vega; Nelly Cruz-Cansino; Raquel Cariño-Cortés; Juan Diego García-Paredes; Eduardo Madrigal-Santillán; María Teresa Sumaya-Martínez; Sandra Cruz-Jaime; Ernesto Alanís-García

2011-01-01

216

Vitamin C (ascorbic acid) induced hydroxyl radical formation in copper contaminated household drinking water: role of bicarbonate concentration.  

Science.gov (United States)

We have previously shown that Vitamin C (ascorbic acid) can trigger hydroxyl radical formation in copper contaminated household drinking water. We report here that the capacity of ascorbic acid to catalyze hydroxyl radical generation in the drinking water samples is strongly dependent on the bicarbonate concentration (buffer capacity and pH) of the samples. We found that at least 50 mg/l bicarbonate was required in the water samples to maintain the pH over 5.0 after ascorbic acid addition. At this pH, that is higher than the pKa1 4.25 of ascorbic acid, a hydroxyl radical generating redox cycling reaction involving the mono-anion of vitamin C and copper could take place. The ascorbic acid induced hydroxyl radical generating reaction could easily be mimicked in Milli-Q water by supplementing the water with copper and bicarbonate. Our results demonstrate that ascorbic acid can induce a pH dependent hydroxyl radical generating reaction in copper contaminated household tap water that is buffered with bicarbonate. The impact of consuming ascorbic acid together with copper and bicarbonate containing drinking water on human health is discussed. PMID:14567450

Jansson, Patric J; Asplund, Klara U M; Mäkelä, Johanna C; Lindqvist, Christer; Nordström, Tommy

2003-08-01

217

The Effect of ascorbic acid injection into lateral ventricle on spatial learning and memory on adult male rats  

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Full Text Available Introduction: Ascorbic acid (AA acts as an antioxidant in the Central nervous system (CNS of the mammalians. It is released from the some nerve ending together with neurotransmitters. The results have shown that Ascorbic acid could affect learning as well as memory. In this study, we examined the effect of ICV injection of ascorbic acid on learning and memory by Morris water maze. Method: In the present study, 42 adult male rats weighing 250-300 g were used. then cannula implanted bilaterally in LV (AP=-0.8, LA=±1.5, DV=3.4.After recovery period, the animals were divided into 6 groups including; control group(no injected, 4 groups as experimental groups (received different doses of ascorbic acid 25, 50, 100, 150 mg/kg, 5th group as Sham-operated group (received normal saline as vehicle. Injection period has taken five consecutive days. 30 min after each injection they were trained in Morris Water Maze (MWM. Spatial learning and memory parameters recorded and then were analyzed. Results: These results showed that ICV injection of ascorbic acid decreased learning and spatial memory in rats. Ascorbic acid (100 mg/kg significantly decreased learning and spatial memory. Conclusion: It can be concluded that ascorbic acid decreased learning and spatial memory, directly or indirectly through interference to the neurotransmitters effects.

mehdi abbasnejad

2008-11-01

218

Catalytic therapy of cancer by ascorbic acid involves redox cycling of exogenous/endogenous copper ions and generation of reactive oxygen species.  

Science.gov (United States)

Catalytic therapy is a cancer treatment modality based on the generation of reactive oxygen species (ROS) through administration of ascorbate/medicinal herbal extracts and copper. It is known that antioxidants such as ascorbate also exhibit prooxidant activity in the presence of transition metals such as copper. Based on our work and that in the literature, in this review we propose a mechanism for the cytotoxic action of ascorbate against cancer cells. It involves redox cycling of exogenous/endogenous copper ions and the consequent generation of ROS leading to oxidative DNA breakage. Using human peripheral lymphocytes and the Comet assay, we have shown that ascorbic acid is able to cause oxidative breakage in cellular DNA. Such DNA degradation is inhibited by neocuproine (a Cu(I) sequestering agent) and scavengers of ROS indicating that the cellular DNA breakage involves the generation of Cu(I) and formation of ROS. Similar results are also obtained with plant polyphenol antioxidants that are important constituents of medicinal herbal extracts. Copper is an essential component of chromatin and can take part in redox reactions. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and ascorbate/plant polyphenols to generate ROS. In this review we cite evidence to indicate that in catalytic therapy cytotoxic action against cancer cells involves redox cycling of exogenous/endogenous copper ions. PMID:20714144

Hadi, S M; Ullah, M F; Shamim, U; Bhatt, S H; Azmi, A S

2010-01-01

219

The study of molecular interactions of ascorbic acid and sodium ascorbate with water at temperatures (278.15, 288.15 and 298.15) K  

International Nuclear Information System (INIS)

Highlights: • Density, speed of sound, viscosity and refractive index of important vitamins are reported. • Molecular interactions of ascorbic acid and sodium ascorbate in water have been studied. • V?0 and B-coefficient of solutes studied show the presence of strong solute–solvent interaction. • These interactions strengthened at higher temperatures. • Ascorbic acid and sodium ascorbate act as a water structure destroyer (Chaotropes). -- Abstract: The article reports experimental values of density (?), speed of sound (u), viscosity (?) and refractive index (nD) for the binary systems, (L-ascorbic acid + water) and (sodium ascorbate + water) over the concentration range (0.01 to 0.75) mol · kg?1 at temperatures (T = 278.15, 288.15 and 298.15) K. From these experimental results, apparent molar volume (V?) of solute, isentropic compressibility of solution (?S), apparent molar isentropic compressibility (??) of solute and relative viscosity of solution (?r) have been calculated. The limiting apparent molar volume (V?0) of solute, limiting apparent molar isentropic compressibility (??0), limiting apparent molar expansivity (E?0) of solute, coefficient of thermal expansion (??) and hydration number (nH) of water soluble vitamins have been obtained. The experimental values of relative viscosity were used to calculate Falkenhagen coefficient A and Jones–Dole coefficient B. The transition state theory has been used to calculate the Gibbs free energy of activation of viscous flow per mole of solvent (??10numbersign) and per mole of solute (??20numbersign). The related activation parameters like ?S20numbersign and ?H20numbersign have also been calculated. From the results obtained, a discussion was carried out in terms of interactions and structure factor (in the framework of “structure-making” and “structure-breaking” solutes) in these binary mixtures

220

Serum ascorbic acid concentration in patients with acute Falciparum malaria infection: possible significance  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Falciparum malaria infection is associated with significant destruction of erythrocytes. This leads to the release of toxic metabolic products, including oxidant compounds.We measured the serum concentration of the antioxidant, ascorbic acid, in 129 patients presenting with acute falciparum malaria [...] infection and in 65 healthy individuals. None of the study subjects administered any form of ascorbic acid supplementation within one week prior to participation in this study. The mean serum ascorbate concentration in infected adult males (n = 49, age range 18-50 years) was found to be 2.02 ± 0.20 mg/dL, and it was 2.03 ± 0.24 mg/dL in infected adult females (n = 56, age range 18-50 years). These values were significantly greater than the serum ascorbate levels (1.54 ± 0.10 mg/dL) in healthy adult males (n = 28) and females (n = 28) (p

Garba Ibrahim, Hassan; Ubom, Gregory; Haruna, Maryam.

2004-10-01

221

Ascorbic Acid and ?-Tocopherol Minimize Salt-Induced Wheat Leaf Senescence  

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Full Text Available BackgroundLeaf senescence is an oxidative process, and most of the catabolic events involved in senescence are propagated irreversibly once initiated. ResultsSalinity hastened the senescence of wheat flag leaves, decreased the concentrations of chlorophyll, total carotenoids, ascorbic acid, total phenol, calcium, potassium, magnesium, K+/Na+ ratio and soluble proteins, as well as the activities of catalase and peroxidase. Conversely, salinity increased sodium, chloride, and the chlorophylla:b ratio, as well as membrane permeability, hydrogen peroxide, and malondialdehyde synthesis. Both antioxidants application reduced the hydrogen peroxide accumulation, lipid peroxidation, membrane permeability, sodium and chloride content over control plants. The antioxidants enzyme activities were significantly increased by antioxidant spray. Enhanced accumulation of ascorbate, phenol, carotenoids, calcium, potassium and magnesium was seen in antioxidants-sprayed plants compared with control plants at 65 days after sowing. Under moderate and sever salinity levels application of both antioxidants alleviated the harmful effects of salinity on leaf senescence related parameter. The higher levels of antioxidants and low level of H2O2 in flag leaf may be the prerequisite for delayed leaf senescence in antioxidants-sprayed plants. ConclusionsIt can be concluded that ascorbic acid-sprayed plants can postpone the leaf senescence by peroxide/phenolic/ascorbate system which is involved in scavenging the ROS produced during leaf senescence.

Farouk S.

2011-09-01

222

Factors affecting plasma Contents of thiamine and Ascorbic acid in Camels (Camelus dromedarius)  

OpenAIRE

The study was designed to investigate the effect of age, breed, sex, and breeding season on thiamine and ascorbic acid status (AA) in camels (Camelus dromedarius). A total of 375 camels were sampled over a one-year field survey in Butana area, Central Sudan. No effect of sex on thiamine and ascorbic acid levels was observed. The breeding male and female camels showed higher status of plasma thiamine and lower ascorbic acid as compared to non-breeding camels. Thiamine plasma contents showed va...

Mohamed, H. E.

2006-01-01

223

The spectrophotometric method for the determination of vanadium and ascorbic acid by means of eriochrome cyanine R and lauryldimethylbenzylammonium bromide  

International Nuclear Information System (INIS)

The spectrophotometric method determination of the microgram amounts of vanadium and ascorbic acid with Eriochrome Cyanine R (ECR) and cationic surfactant: lauryldimethylbenzylammonium bromide (ST) is described. The complex between vanadium(IV), ECR and ST is formed in the pH 5.0 ± 0.2. The molar absorptivity is 8.4 x 104. The influence of other ions has been studied. The reaction vanadium(IV) with ECR and ST was applied to determination of ascorbic acid. The molar absorptivity is 1.37 x 105. The method was used to determination of ascorbic acid in Rutinoscorbin preparation. (author). 12 refs, 2 tabs, 1 fig

224

Effect of combination treatment of gamma irradiation and ascorbic acid on physicochemical and microbial quality of minimally processed eggplant (Solanum melongena L.)  

Science.gov (United States)

Gamma irradiation alone and in combination with ascorbic acid was tested for preventing the surface browning and maintaining the quality attributes of minimally processed eggplant. Eggplant samples after preparation were subjected to treatment of gamma irradiation in the dose range of 0.25-1.0 kGy and to combination treatments of ascorbic acid dip at a concentration of 2.0% w/v and gamma irradiation (dose range 0.5-2.0 kGy) followed by storage at 3±1 °C, RH 80%. Studies revealed inverse correlation (r=-0.93) between the polyphenol oxidase (PPO) activity, browning index and the treatments of ascorbic acid and gamma irradiation. Combinatory treatment of 2.0% w/v ascorbic acid and 1.0 kGy gamma irradiation proved to be significantly (p?0.05) effective in inhibiting the PPO activity, preventing the surface browning and maintaining the creamy white color and other quality attributes of minimally processed eggplant up to 6 days of refrigerated storage. Sensory evaluation revealed that control and 0.25 kGy irradiated samples were unacceptable only after 3 days of storage. Samples irradiated at 0.5 kGy and 0.75 kGy were unacceptable after 6 days of storage. Microbial analysis revealed that radiation processing of minimally processed eggplant at 1.0 kGy with and without ascorbic acid resulted in around 1 and 1.5 log reduction in yeast and mold count as well as bacterial count just after treatment and 6 days of storage therefore, enhances the microbial safety.

Hussain, Peerzada R.; Omeera, A.; Suradkar, Prashant P.; Dar, Mohd A.

2014-10-01

225

Effects of ascorbic acid on cell mediated, humoral immune response and pathophysiology of  

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Full Text Available The purpose of this study was to conduct an experiment related to the effects of chronic heat stress on total white blood cell changes, pathophysiology of leukocyte and effects of ascorbic acid on lymphocytes, lympholytic cells and humoral immunity of New-castle disease of broilers under chronic heat stress. Randomized complete block was the design. One hundred-forty-four chickens were maintained at 33+1 oC environmental temperature and on four levels of added ascorbic acid i.e. 0 (control group, 200, 400 and 800 mg/kg in dietsfor 21 days. On days 1, 3, 7, 14 and 21 of the experimental period, total white blood cells count, lympholytic cell and HI titer for Newcastle disease were determined. On day 21, histopathology of lung, liver, kidney, heart and bursa of fabricius of randomly selected broilers (n=36; 3 birds per experimental unit were studied. Total white blood cells (TWBC of the birds were significantly increased on day 3 (P<0.05 and were higheston days 7 and 14 then significantly decreased on days 21 (P<0.05. Monocytes were significantly increased on day 3 (P<0.05. Lymphocytes were significantly increased on day 7, and were highest on day 14 (P<0.05. On day 21, the value of lymphocyte was significantly lower than on days 7 and 14 (P<0.05, respectively. Lympholytic cells were significantly increased on day 3 and 7 (P<0.05, respectively, but on day 21, lympholyticcells were significantly decreased to lower value than on day 7 (P<0.05. Heterophils were significantly increased on day 3 and 7 and then decreased on day 14 (P<0.05. Tissue injury and hemorrhage in broilers under chronic heat stress caused leukocytosis, heterophilia, lympholysis and monocytosis. The size of lobules within the bursa of fabricius in broilers receiving ascorbic acid at 800 mg/kg in the diet were larger than inbirds that received added ascorbic acid at 400, 200 and 0 mg/kg in their diets, respectively. Lymphocytes and lympholytic cells were not significantly different among the ascorbic acid treatment groups. Besides, HI titers of Newcastle disease at 800 mg/kg in the diet were significantly higher than the others (P<0.05. Apparently, adding ascorbic acid at 800 mg/kg in the diet could improve humoral immunity in broilers under heat stress.

Suchint Simaraks

2003-05-01

226

Study of radio-protective effects of ascorbic acid in rates  

International Nuclear Information System (INIS)

The aim of this study was to evaluate the potential radio-protective effects of different ascorbic acid concentrations (vitamin C) in rats before whole body irradiation with total dose of 7 Gy (60Co source) using two different dose rates of 1 and 0.55 Gy.min-1 by increasing percent of surviving. In the first group (1 Gy/m); rats were administered four different concentrations of ascorbic acid (7.5, 12.5, 100, 200 mg/kg b wt ) in drinking water for 30 days before irradiation starting from the ablactation which considered as day 0. Whereas, in the second group (0.55 Gy/m); rats were administered six different concentrations of ascorbic acid (1, 5, 7.5, 12.5, 100, 200 mg/kg b wt) before irradiation with total dose 7 Gy (60Co source). The results have showed that the ascorbic acid enhance the 30-day survival of irradiated rats in 1 and 0.55 Gy/m groups, compared to the control group. The mean cumulated probability of survival of rats (1 Gy/m group) was 66%± 6 (Mean± S.E), 69%± 5, 52%± 9 and 51%± 9 in groups of rats which administered 7.5, 12.5, 100, 200 mg/kg, respectively, versus 41%± 9 in control group for 14 days. While, it was 90%± 2, 90%± 2, 88%± 2, 94%± 1, 84%± 3 and 78%± 3 in groups of rats which administered 1, 5, 7.5, 12.5, 100, 200 mg/kg respectively, versus 52%± 6 in control group for 30 days. Our data, also, indicated that all ascorbic acid concentrations in both groups had significant reduction in mortality and increasing percent of surviving compared to the control groups. We conclude that all ascorbic acid concentrations which used in both groups (1 and 0.55 Gy/m), had radioprotective effects in rats when administrated before irradiations, and this role was more effective against lower dose rate of radiation exposure. (author)

227

Vitamin A inhibits lipoperoxidation ascorbate-Fe++ dependent of rat kidney microsomes and mitochondria.  

Science.gov (United States)

In the present study it was investigated if Vitamin A supplementation could protect rat kidney microsomes and mitochondria from in vitro lipoperoxidation. After incubation of rat kidney microsomes and mitochondria in an ascorbate-Fe+2 system, at 37 degrees C during 60 min, it was observed that the total cpm/mg protein originated from light emission (chemiluminescence) was lower in those organelles obtained from the control group when compared with the vitamin A supplemented group. The fatty acid composition of microsomes and mitochondria from control group was profoundly modified when subjected to non-enzymatic lipoperoxidation with a considerable decrease of arachidonic acid, C20:4 (n-6) and docosapentaenoic acid, C22:5 (n-3) in mitochondria and docosahexaenoic acid C22:6 (n-3) in microsomes. As a consequence the peroxidizability index, a parameter based on the maximal rate of oxidation of specific fatty acids was higher in the supplemented animals than in those used as control. These results indicate that Vitamin A may act as antioxidant protecting rat kidney microsomes and mitochondria from deleterious effect. PMID:8979260

Piergiacomi, V A; Palacios, A; Catalá, A

1996-12-20

228

Effect of Acridine and Ascorbic Acid on Rhizobia of Legume Trees  

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Full Text Available The present study aimed to induce a great variation exists among Rhizobium spp. that nodulate Leucaena leucocephala and Sesbania sesban, through the treatment with acridine and ascorbic acid and selection of strains for efficiency of the symbiotic association appears possible. Bacteria were isolated from nodules of both hosts growing in Egyptian soil, subcultured, and verified to be rhizobia. The isolates varied significantly in their resistance to antibiotics and NaCl, their growth on different carbohydrate sources, and their effect on the pH of culture media. Most isolates showed intermediate antibiotic resistance, the capacity to use numerous carbohydrates, and a neutral to acid pH response. The mean generation times of these isolates ranged from 4.813 to 6.437 and 4.600 to 6.523 for Sesbania sesban and Leucaena leucocephala, respectively. Both acridine orange and ascorbic acid appeared genotoxic hazards effect on all rhizobial strains examined here. They demonstrated a dose-response for decreasing cell survival at the levels that are not excessively toxic to the bacteria. The standard assay with pre-incubation was quite toxic to the bacteria than plate incorporation test. Acridine orange and ascorbic acid shows an increase in the number of auxotrophic mutants over the spontaneous value this is evidence for their mutagenicity caused by DNA damage. The biochemical mutants obtained in this study were identified using nine plates of minimal medium each was supplemented with different combinations of four growth factors. From the results reported here, it can be concluded that acridine mutagenesis is due to an enhancement of mismatch repair. In addition, ascorbic acid may be mutagenic and cytotoxic through the generation of hydrogen peroxide.

El-Adl

2001-01-01

229

Mutagenicity of Acridine and Ascorbic Acid in Rhizobia of Legume Trees  

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Full Text Available The present study aimed to induce a great variation existing among Rhizobium spp. that nodulate Leucaena leucocephala and Sesbania sesban, through the treatment with acridine and ascorbic acid and selection of isolates for efficiency in the symbiotic association. Bacteria were isolated from nodules of both hosts growing in Egyptian soil, subcultured, and verified to be rhizobia. The isolates varied significantly in their resistance to antibiotics and NaCl, their growth on different carbohydrates, and their effect on the pH of culture media. Most isolates showed intermediate antibiotic resistance, the capacity to use numerous carbohydrates, and a neutral to acid pH response. The mean generation time of these isolates ranged from 4.813 to 6.437 and 4.600 to 6.523 for Sesbania sesban and Leucaena leucocephala, respectively. Both acridine orange and ascorbic acid had genotoxic hazards on all rhizobial strains examined here. They demonstrated a dose-response for decreasing cell survival at the levels that are not excessively toxic to bacteria. The standard assay with pre-incubation was quite toxic to the bacteria than plate incorporation test. Acridine orange and ascorbic acid shows an increase in number of auxotrophic mutants over the spontaneous value which is evidence for their mutagenicity caused by DNA damage. The biochemical mutants obtained in this study were identified using nine plates of minimal medium, each supplemented with different combinations of four growth factors. From the results reported here, it can be concluded that acridine mutagenesis is due to an enhancement of mismatch repair. In addition, ascorbic acid may be mutagenic and cytotoxic through the generation of hydrogen peroxide.

M.A. Nassef

2002-01-01

230

SO/sub 2/-induced enzymatic changes and ascorbic acid oxidation in Oryza sativa  

Energy Technology Data Exchange (ETDEWEB)

Field grown rice (Oryza sativa L.) plants exposed separately to 0.25 or 0.55 ppm SO/sub 2/ for 1.5 hr daily for 40 days, showed significant decrease of catalase (p<0.001) and increase of peroxidase (p<0.001) activities as well as decreases of protein (p<0.001) and ascorbic acid (p<0.001) contents associated with leaf lesions, which were proportional to SO/sub 2/-dose. Catalase and peroxidase activity levels showed an inverse relationship. It is hypothesized from the molecular structure of both enzymes and from the in vitro relationship between catalase and peroxidase activity that the tetrameric molecules of catalase in vivo might disintegrate into monomeric units with peroxidase activity, which in turn oxidize ascorbic acid and may reduce tolerance of plants to SO/sub 2/.

Nandi, P.K.; Agrawal, M.; Rao, D.N.

1984-01-01

231

Kinetics of ascorbic acid loss during hot water blanching of fluted pumpkin (Telfairia occidentalis) leaves.  

Science.gov (United States)

The kinetics of thermal degradation of ascorbic acid in fluted pumpkin leaves were investigated from 60 to 90°C (pH 5.0 to 6.5). Ascorbic acid degradation was modeled as a first order rate reaction with the rate constants increasing with increase in pH of the medium. The pH and temperature dependence of the rates of destruction gave highly significant correlations when analyzed by the thermal resistance and activated complex reaction rate methods. Activation energy (Ea) ranged from 41.2 to 18.2 kJ/mol while D-values ranged from 103.3 to 22.4 min. The changes in activation energy affected Ko values which ranged from 5.98?×?10(4) to 41.7 min(-1). PMID:23572770

Ariahu, Charles C; Abashi, Diana K; Chinma, Chiemela Enyinnaya

2011-08-01

232

Influence of osmotic dehydration on ascorbic acid loss in pickled dry peppers (Capsicum chinense)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The objective of this work was (1) to develop a dehydrated pepper with 45% humidity, determining the drying curves for pepper, with and without osmotic pre-treatment and (2) to evaluate the influence of both drying and osmotic treatment on the content ascorbic acid (vitamin C) in fresh pepper and pe [...] pper with 45% humidity. The experiments were carried out using the peppers cut in half, with and without osmotic pre-treatment, followed by drying in an oven at 70 ºC. The results showed that the osmotic pretreatment did not influence the retention of ascorbic acid during the drying of pepper. The sensory analysis regarding the color, flavor, and texture attributes revealed that there was no difference in the acceptability.

Tissiane Mayara da, Silva; Eliana Janet Sanjinez, Argandoña; Grasiele Scaramal, Madrona; Izabel Cristina Freitas, Moraes; Charles Windson Isidoro, Haminiuk; Ivanise Guilherme, Branco.

2012-10-01

233

IMPACT OF EXTRACELLULAR CALCIUM ALONG WITH ASCORBIC ACID ON CELLULAR REACTIVATION AND INSULIN SECRETION IN DIABETIC MIN6 CELLS  

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Full Text Available Diabetes is not a single disease but characterized by a group of syndromes. Oxidative stress and defects in insulin secretory pathway are the major problems associated with type 2 diabetes. Extracellular Ca2+ influx is the major trigger which stimulates insulin secretion in pancreatic β cells. In this study we combined the most common antioxidant ascorbic acid with extracellular calcium to observe their cooperative effect on diabetic MIN6 cells. Our results demonstrated firstly the major role of ascorbic acid individually as well as with calcium in cell viability as compared to individual calcium supplementation. Secondly, the combined concentration of ascorbic acid and calcium leads to maximum increase in insulin level in dose dependent manner upto 5mM ascorbic acid and decrease beyond this concentration.

Archana Tiwari

2012-01-01

234

Role of ascorbic acid in human seminal plasma against the oxidative damage to the sperms  

OpenAIRE

This study evaluated the extent of oxidative stress by measuring malondialdehyde and ascorbic acid in the seminal plasma of human subjects with different fertility potential. Semen samples from 148 subjects were evaluated (48 normozoospermics, 34 oligoasthenoteratozoospermics, 34 asthenoteratozoospermics and 32 azoospermics). malondialdehyde level was found to be significantly higher in the abnormal groups (oligoasthenoterato and asthenoterato-zoospermics) than normozoospermics (P < 0.01). Ne...

Das, Piyali; Choudhari, A. R.; Dhawan, A.; Singh, Ramji

2009-01-01

235

Iron-rich drinking water and ascorbic acid supplementation improved hemolytic anemia in experimental Wistar rats.  

Science.gov (United States)

Anemia is a frequent problem in both the primary and secondary health care programs. In contrast, most areas of northeast India are vulnerable to iron toxicity. In the present study, we documented the effect of administration of iron rich water on hemolytic anemia in a Wistar rats' animal model. Hemolytic anemia was induced by phenyl hydrazine through intraperitoneal route and diagnosed by the lowering of blood hemoglobin. After inducing the hemolytic anemia, 24 Wistar rats (n?=?6 in four groups) were randomly assigned to 1?mg/l, 5?mg/l, and 10?mg/l ferric oxide iron along with 1?mg/ml ascorbic acid administered through drinking water; a control group was treated with iron-free water. The hematological and biochemical parameters, iron levels in liver, spleen, and kidney were estimated after 30?d of treatment. In the group treated with 5?mg/l iron and ascorbic acid, a significant increase of serum iron and ferritin, and a decrease of TIBC (total iron binding capacity) were observed without changes in other biochemical parameters and histopathological findings. However, in the group treated with 10?mg/l iron and ascorbic acid, hematological changes with significantly higher values for white blood cell count, serum glutamic phospho transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, glucose, splenic, and liver iron content, indicate potential toxicity at this supplementation level. Data suggest that the optimum concentration of iron (5?mg/l) and ascorbic acid solution may improve anemic conditions and may be therapeutically beneficial in the treatment of iron deficiency anemia without any negative impact, while 10?mg/l in drinking water seems to be the threshold for the initiation of toxicity. PMID:24896300

Chaturvedi, Richa; Chattopadhyay, Pronobesh; Banerjee, Saumen; Bhattacharjee, Chira R; Raul, Prasanta; Borah, Kusum; Singh, Lokendra; Veer, Vijay

2014-11-01

236

Intravenous ascorbic acid to prevent and treat cancer-associated sepsis?  

OpenAIRE

Abstract The history of ascorbic acid (AA) and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS) and multi organ failure (MOF), has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once th...

Bogin Vladimir; Ancans Janis; Dasanu Constantin A; Alexandrescu Doru T; Miranda-Massari Jorge R; Gonzalez Michael J; Jackson James A; Mikirova Nina A; Hunninghake Ron; Luna Brandon; Braciak Todd; Minev Boris; Ichim Thomas E; Brian, Stevens R.; Markosian Boris

2011-01-01

237

Amelioration of High Cholesterol Diet Caused Lipids Accumulation in Hepatic Cells by Rutin and Ascorbic Acid  

OpenAIRE

Non Alcoholic Fatty Liver Disease (NAFLD) has become a very common metabolic disorder. It refers to a group of conditions where excess fats are deposited in hepatic cells. Several approaches have been considered for the management of NAFLD including dietary changes, which were reported to suppress hepatic lipids accumulation in previous studies. The present study was designed to investigate the possible synergistic effects of Rutin (RT) and Ascorbic Acid (AA) against lipids accumulation in he...

Aleisa, Abdulaziz M.

2013-01-01

238

Ascorbic Acid Content in Extractive Aqueous Solutions of Rosa canina L. Fruits  

OpenAIRE

The main goal of the hereby study is two folded: first, to mark out the most adequate methods of preparing the watery solution extracts (infusions, decoctions) in order to obtain a high content of ascorbic acid, and second, to identify the most suitable method for determining this vitamin in aqueous solution extracts made out of medicinal herbs. In this experiment six groups were assembled containing 20 fruit samples each. The samples were analyzed one week, one and a half month and three mon...

Veturia-Ileana Nueleanu,; Maria Mihoc; Cernea Mihai

2008-01-01

239

CAPSAICIN AND ASCORBIC ACID VARIABILITY IN CHILLI AND PAPRIKA CULTIVARS AS REVEALED BY HPLC ANALYSIS  

OpenAIRE

Capsaicin and ascorbic acid contents of seven Indian peppers varieties/accessions from Capsicum annuum (CA 97, CCH, K1, KTPL19, Arka Abhir and Bayadagi Kaddi) and C. frutescens (CF1) species were determined using High Performance Liquid Chromatography (HPLC). Based on their pungency value, all the chilli accession/varieties (CA 97, CCH, K1, and CF 1) were classified as highly pungent peppers. The accession CF1 showed the highest concentration of capsaicin (445mg 100g -1...

Samuel Tilahun; Pandiyan Paramaguru; Kandhasamy Rajamani

2013-01-01

240

Capparidaceous Medicinal Plants of North-West Rajasthan: Good Sources of Ascorbic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Ascorbic acid contents of roots, shoots and fruits of three selected medicinal plants like Capparis decidua,Cleome gynandra and Cleome viscosa of family Capparidaceae have been analysed. Maximum ascorbicacid contents were found in the fruits of Capparis decidua (108.12mg/100g.d.w. while, minimum in theroots of Cleome viscosa (62.25mg/100g.d.w.

B.B.S. Kapoor* and Raksha Mishra

2013-06-01

241

Reductive release of Fe(III) from bovine lactoferrin by ascorbic acid  

International Nuclear Information System (INIS)

The kinetics of the reduction of Fe/sup 3+/ from bovine diferric Lactoferrin (Fe/sub 2/Lf) and monoferric C-terminal (Fe/sub C/-Lf) and N-terminal (Lf-Fe/sub N/) sites is investigated at ph 6.1 and 3.5 under pseudo first-order conditions using ascorbic acid (AA) as a biological reducing agent and 1, 10-Ortho phenanthroline (O-phen) as Fe/sup 2+/ chelator. Pseudo first-order rate constants as a function of ascorbic acid concentration are measured. Second order rate constants (k2) for Fe/sub 2/Lf, Lf-Fe/sub N/, Fe/sub C/-Lf at ph 6.1 and 27 deg. C are 0.1527 M/sup -1/.min/sup -1/, 0.0381 M/sup -1/.min-1, 0.1381 M/sup -1/.min/sup -1/, respectively. While, at ph 3.5 and 27 deg. C these values are 0.1915 M/sup -1/.min-1, 0.1116 M/sup -1/.min/sup -1/, 0.4434 M/sup -/.min/sup -1/, respectively. A linear dependence of k/sub obs/ on ascorbic acid concentration is suggestive of simple pseudo first-order pathway for reduction of iron under the conditions applied for all the three forms of protein. Moreover, the results show that the C-terminal site is more labile toward reduction by ascorbic acid than the N-terminal site. (author)

242

Killing of Bacillus Spores by Aqueous Dissolved Oxygen, Ascorbic Acid, and Copper Ions  

OpenAIRE

An approach to decontamination of biological endospores is discussed. Specifically, the performance of an aqueous modified Fenton reagent is examined. A modified Fenton reagent formulation of cupric chloride, ascorbic acid, and sodium chloride is shown to be an effective sporicide under aerobic conditions. The traditional Fenton reaction involves the conversion of hydrogen peroxide to hydroxyl radical by aqueous ionic catalysts such as the transition metal ions. Our modified Fenton reaction i...

Cross, J. B.; Currier, R. P.; Torraco, D. J.; Vanderberg, L. A.; Wagner, G. L.; Gladen, P. D.

2003-01-01

243

Combined ?-tocopherol and ascorbic acid protects against smoke-induced lung squamous metaplasia in ferrets  

OpenAIRE

Many epidemiological studies show the benefit of fruits and vegetables on reducing risk of lung cancer, the leading cause of cancer death in the United States. Previously, we demonstrated that cigarette smoke exposure (SM)-induced lung lesions in ferrets were prevented by a combination of low dose of ?-carotene, ?-tocopherol (AT), and ascorbic acid (AA). However, the role of a combination of AT and AA alone in the protective effect on lung carcinogenesis remains to be examined. In the prese...

Kim, Yuri; Chongviriyaphan, Nalinee; Liu, Chun; Russell, Robert M.; Wang, Xiang-dong

2011-01-01

244

Spectroscopic investigation of the interaction between {beta}-cyclodextrin and ascorbic acid  

Energy Technology Data Exchange (ETDEWEB)

Inclusion compound of vitamin C (ascorbic acid) with {beta}-cyclodextrin ({beta}-CD), prepared by different methods (kneading, co-precipitation and freeze-drying) has been caracterized by several spectroscopic techniques (FTIR, {sup 1}H NMR, UV-Vis), powder X-ray diffraction and DSC technique. Based on the chemical shifts observed in the {sup 1}H-NMR and on FTIR spectra the tentative conclusion is that vitamin C probably enters the cyclodextrin torus forming the inclusion complex.

Bratu, Ioan; Kacso, Irina [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Muresan-Pop, Marieta [Babes-Bolyai University, Faculty of Physics, 1 Mihail Kogalniceanu 400084 Cluj-Napoca (Romania); Farcas, Sorin I, E-mail: ioan.bratu@itim-cj.r

2009-08-01

245

Nitric Oxide Mediates Tightening of the Endothelial Barrier by Ascorbic Acid  

OpenAIRE

Vitamin C, or ascorbic acid, decreases paracellular endothelial permeability in a process that requires rearrangement of the actin cytoskeleton. To define the proximal mechanism of this effect, we tested whether it might involve enhanced generation and/or sparing of nitric oxide (NO) by the vitamin. EA.hy926 endothelial cells cultured on semi-porous filter supports showed decreased endothelial barrier permeability to radiolabeled inulin in response to exogenous NO provided by the NO donor spe...

May, James M.; Qu, Zhi-chao

2010-01-01

246

Investigations into the relationship between the dopaminergic system and ascorbic acid in rat striatum  

OpenAIRE

Levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), ascorbic acid (AA) and dehydroascorbic acid (DHAA) were determined by HPLC in the striatum of male Wistar rats after single or repeated injections of apomorphine (1 mg/kg/day s.c.) and/or haloperidol (1 mg/kg/day i.p.), and 24 h after the last drug administration. Apomorphine significantly reduced the DOPAC/DA ratio and increased the DHAA/AA ratio; these ratio changes were significantly correlated (r = ?0.9969, P...

Desole, Maria Speranza; Miele, Maddalena; Enrico, Paolo; Esposito, Giovanni; Fresu, Luigia Grazia; Natale, Guglielmo; Miele, Egidio

1991-01-01

247

Effects of ascorbic acid and oxalic acid on uptake and translocation of zinc in maize (Zea Mays L.) using 65Zn radiotracer  

International Nuclear Information System (INIS)

This study was done to evaluate the effect of oxalic and ascorbic acids on 65Zn uptake and translocation in Maize plants through solution culture experiment so that the desired acid remains available in the roots zone

248

SIMULTANEOUS ELECTROCHEMICAL DETECTION OF DOPAMINE, ASCORBIC ACID AND URIC ACID USING COPPER-PHTHALOCYANINE FUNCTIONALIZED MWCNTS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Multiwalled carbon nanotububes functionalized with amino groups (MWCNT-NH2) and further modified with copper-phthalocyaninetetrasulphonate (4ß(SO3) CuPc) were used for preparing a hybrid electrode [MWCNT-NH2/4ß(SO3)CuPc/GC] using glassy carbon (GC) as a support. This hybrid electrode was tested for [...] the detection of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA) in a PBS buffer solution at pH 6.8. The presence of the macrocyclic increased the resolution of the oxidation signals of AA, DA and UA into three very well distinct oxidation peaks. This effect was enhanced when the complex is adsorbed on multiwalled carbon nanotubes. In addition, the hybrid films provide a simple method for selective detection of DA, AA and UA in biological samples. The calibration curves for DA were obtained over the range of 1x10-6-1x10-3M, obtaining a good selectivity and sensitivity.

MAMIE, SANCY; J, FRANCISCO SILVA; JORGE, PAVEZ; JOSÉ H, ZAGAL.

2117-21-01

249

Inhibition of cell proliferation and migration by oxidative stress from ascorbate-driven juglone redox cycling in human bladder-derived T24 cells  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer The cytotoxicity of juglone is markedly increased by ascorbate. Black-Right-Pointing-Pointer T24 cell death by oxidative stress is necrosis-like. Black-Right-Pointing-Pointer Redox cycling by juglone/ascorbate inhibits cell proliferation. Black-Right-Pointing-Pointer Cellular migration is impaired by juglone/ascorbate. -- Abstract: The effects of juglone on T24 cells were assessed in the presence and absence of ascorbate. The EC{sub 50} value for juglone at 24 h decreased from 28.5 {mu}M to 6.3 {mu}M in the presence of ascorbate. In juglone-treated cells, ascorbate increased ROS formation (4-fold) and depleted GSH (65%). N-acetylcysteine or catalase restricted the juglone/ascorbate-mediated effects, highlighting the role of oxidative stress in juglone cytotoxicity. Juglone alone or associated with ascorbate did not cause caspase-3 activation or PARP cleavage, suggesting necrosis-like cell death. DNA damage and the mild ER stress caused by juglone were both enhanced by ascorbate. In cells treated with juglone (1-5 {mu}M), a concentration-dependent decrease in cell proliferation was observed. Ascorbate did not impair cell proliferation but its association with juglone led to a clonogenic death state. The motility of ascorbate-treated cells was not affected. Juglone slightly restricted motility, but cells lost their ability to migrate most noticeably when treated with juglone plus ascorbate. We postulate that juglone kills cells by a necrosis-like mechanism inhibiting cell proliferation and the motility of T24 cells. These effects are enhanced in the presence of ascorbate.

Kviecinski, M.R., E-mail: mrkviecinski@hotmail.com [Laboratorio de Bioquimica Experimental, Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Pedrosa, R.C., E-mail: rozangelapedrosa@gmail.com [Laboratorio de Bioquimica Experimental, Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Felipe, K.B., E-mail: kakabettega@yahoo.com.br [Laboratorio de Bioquimica Experimental, Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Farias, M.S., E-mail: mirellesfarias@hotmail.com [Laboratorio de Bioquimica Experimental, Departamento de Bioquimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Glorieux, C., E-mail: christophe.glorieux@uclouvain.be [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Universite Catholique de Louvain, 73 Avenue E. Mounier, GTOX 7309, 1200 Brussels (Belgium); Valenzuela, M., E-mail: mavalenzuela@med.uchile.cl [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Universite Catholique de Louvain, 73 Avenue E. Mounier, GTOX 7309, 1200 Brussels (Belgium); Sid, B., E-mail: brice.sid@uclouvain.be [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Universite Catholique de Louvain, 73 Avenue E. Mounier, GTOX 7309, 1200 Brussels (Belgium); and others

2012-05-04

250

INFLUENCE OF ASCORBIC ACID ON SCLEROTIA PRODUCTION OF DESCENDANCE OF SOME CLAVICEPS PURPUREA HYBRID AND NON-HYBRID PARENTAL STRAINS  

OpenAIRE

This paper includes the experimental results regarding the effects of ascorbic acid, present in culture media, on the phenotypisation of “sclerotia/ha production” character. The behaviour of descendance of some monoparental and hybrid strains of Claviceps purpurea is analysed; the obtained data evidenced variations of strain bioproductivity, under the influence of ascorbic acid, variations which can be correlated with strain origin, alkaloid type etc.

Maria+Magdalena Zamfirache; Zenovia Olteanu; Stefania Surdu; Elena Truta

2006-01-01

251

INFLUENCE OF ASCORBIC ACID ON SCLEROTIA PRODUCTION OF DESCENDANCE OF SOME CLAVICEPS PURPUREA HYBRID AND NON-HYBRID PARENTAL STRAINS  

Directory of Open Access Journals (Sweden)

Full Text Available This paper includes the experimental results regarding the effects of ascorbic acid, present in culture media, on the phenotypisation of “sclerotia/ha production” character. The behaviour of descendance of some monoparental and hybrid strains of Claviceps purpurea is analysed; the obtained data evidenced variations of strain bioproductivity, under the influence of ascorbic acid, variations which can be correlated with strain origin, alkaloid type etc.

Maria+Magdalena Zamfirache

2006-08-01

252

The Protective Effects of Ethanolic Extract of Garlic and Ascorbic Acid on Cadmium-Induced Oxidative Stress  

OpenAIRE

The protective effects of ethanolic extract of garlic (Allium sativum) and ascorbic acid on cadmium-induced oxidative stress were investigated in the liver and kidney of male rats by monitoring the lipid peroxides profiles, enzymatic and non-enzymatic antioxidants activities. The rats were pretreated with ethanolic extract of garlic (100 mg kg-1 body weight) or ascorbic acid (100 mg kg-1 body weight) orally for 4 weeks. These rats were also given cadmium (4 g kg

Ogungbe, I. V.; Lawal, A. O.

2008-01-01

253

Differentiation of axon-related Schwann cells in vitro. I. Ascorbic acid regulates basal lamina assembly and myelin formation.  

Science.gov (United States)

Rat Schwann cells cultured with dorsal root ganglion neurons in a serum-free defined medium fail to ensheathe or myelinate axons or assemble basal laminae. Replacement of defined medium with medium that contains human placental serum (HPS) and chick embryo extract (EE) results in both basal lamina and myelin formation. In the present study, the individual effects of HPS and EE on basal lamina assembly and on myelin formation by Schwann cells cultured with neurons have been examined. Some batches of HPS were unable to promote myelin formation in the absence of EE, as assessed by quantitative evaluation of cultures stained with Sudan black; such HPS also failed to promote basal lamina assembly, as assessed by immunofluorescence using antibodies against laminin, type IV collagen, and heparan sulfate proteoglycan. The addition of EE or L-ascorbic acid with such HPS led to the formation of large quantities of myelin and to the assembly of basal laminae. Pretreatment of EE with ascorbic acid oxidase abolished the EE activity, whereas trypsin did not. Other batches of HPS were found to promote both basal lamina and myelin formation in the absence of either EE or ascorbic acid. Ascorbic acid oxidase treatment or dialysis of these batches of HPS abolished their ability to promote Schwann cell differentiation, whereas the subsequent addition of ascorbic acid restored that ability. Ascorbic acid in the absence of serum was relatively ineffective in promoting either basal lamina or myelin formation. Fetal bovine serum was as effective as HPS in allowing ascorbic acid (and several analogs but not other reducing agents) to manifest its ability to promote Schwann cell differentiation. We suggest that ascorbic acid promotes Schwann cell myelin formation by enabling the Schwann cell to assemble a basal lamina, which is required for complete differentiation. PMID:3624305

Eldridge, C F; Bunge, M B; Bunge, R P; Wood, P M

1987-08-01

254

Body pool and synthesis of ascorbic acid in adult sea lamprey (Petromyzon marinus): An agnathan fish with gulonolactone oxidase activity  

OpenAIRE

Although many vertebrates can synthesize ascorbic acid (vitamin C), it is still unclear from the evolutionary perspective when the ability to synthesize the vitamin first appeared in the animal kingdom and how frequently the trait has been lost. We report here ascorbic acid biosynthesis ability in sea lamprey (Petromyzon marinus) which represent the most ancient vertebrate lineage examined thus far for presence of gulonolactone oxidase, the enzyme catalyzing the terminal step in biosynthesis ...

Moreau, Re?gis; Dabrowski, Konrad

1998-01-01

255

Influence of trace elements on stabilization of aqueous solutions of ascorbic acid.  

Science.gov (United States)

Together with vitamin C, zinc, selenium, manganese, and magnesium play a vital role in the preservation of organs scheduled for transplantation. In the present study, it is shown that addition of 1 mg/l of these elements influences the stability of 0.3 mM ascorbic acid solutions. The solution's stability was estimated using an accelerated stability test. The concentration of vitamin C was measured using a validated spectrophotometric method, which uses the reduction of 2,6-dichlorophenoloindophenol by ascorbic acid. Elevated temperatures, the factor accelerating substances' decomposition reaction rate, were used in the tests. The research was conducted at two temperatures at intervals of 10 °C: 80?±?0.1 and 90?±?0.1 °C. It was stated that the studied substances' decomposition occurred in accordance with the equation for first-order reactions. The function of the logarithmic concentration (log%C) over time was revealed to be rectilinear. This dependence was used to determine the kinetics of decomposition reaction rate parameters. The stabilization of vitamin C solutions was measured as the time in which 10 % of the substance decomposed at 20 and 0 °C. Addition of Se(IV) or Mg(II) ions significantly increase the stability of ascorbic acid solution (?34 and ?16 %, respectively), but Zn(II) causes a significant decrease in stability by ?23 %. Addition of Mn(II) has no significant influence on vitamin C stability. PMID:23099563

Doli?ska, Barbara; Ostró?ka-Cie?lik, Aneta; Caban, Artur; Rimantas, Klimas; Leszczy?ska, Lucyna; Ryszka, Florian

2012-12-01

256

Comparative Study of Ascorbic Acid and Tocopherol Concentrations in Hydroponic- and Soil-Grown Lettuces  

Directory of Open Access Journals (Sweden)

Full Text Available Hydroponically-grown produce may be a way of helping to feed the world a variety of fruits and vegetables, regardless of soil quality, space availability or climate. The objective of this study was to determine whether hydroponicallygrown lettuce contains as much ascorbic acid and tocopherol as soil-grown lettuce. We analyzed four varieties of lettuce, including: Waldmann’s Dark Green, Red Lollo Antago, Red Romaine Annapolis, and Butterleaf. The tocopherol content of hydroponically-grown Waldmann’s Dark Green, Red Lollo Antago, and Red Romaine Annapolis was 229%, 497% and 492% higher, respectively, compared to their soil-grown counterpart. The ascorbic acid content of hydroponically-grown Waldmann’s Dark Green, Red Lollo Antago, and Red Romaine Annapolis was 93%, 171% and 216% higher, respectively, compared to their soil-grown counterparts. Hydroponically grown lettuce varieties are significantly higher in both ascorbic acid and tocopherol content than their soil-grown counterparts, and hydroponic gardening is a viable option for producing nutritious fruits and vegetables.

Drew N. Buchanan

2013-09-01

257

Decylglucoside-based microemulsions for cutaneous localization of lycopene and ascorbic acid.  

Science.gov (United States)

Cutaneous delivery of combinations of antioxidants offers the possibility of enhanced protection against UV-radiation. In this study, we investigated the potential of sugar-based microemulsions containing monoglycerides to promote simultaneous cutaneous delivery of lycopene and ascorbic acid, and increase tissue antioxidant activity. Lycopene and ascorbic acid were incorporated (0.04% and 0.2% (w/w), respectively) in decylglucoside-based microemulsions containing isopropyl myristate mixed with monocaprylin (ME-MC), monolaurin (ME-ML) or monoolein (ME-MO) as oil phase. The microemulsions increased lycopene delivery into porcine ear skin by 3.3- to 8-fold compared to a drug solution. The effect of microemulsions on ascorbic acid cutaneous delivery was more modest (1.5-3-fold), and associated with an approximately 2-fold increase in transdermal delivery. According to their penetration-enhancing ability, the microemulsions were ranked ME-MC>ME-MO>ME-ML. This superiority of ME-MC coincided with a stronger effect in decreasing skin electrical resistance. After 18 h of treatment, the viability of bioengineered skin treated with ME-MC was 2.2-times higher compared to Triton-X100 (moderate irritant), demonstrating that ME-MC is less cytotoxic. Skin treatment with ME-MC containing both antioxidants increased the tissue antioxidant activity by 10.2-fold, but no synergism between the antioxidants was observed. PMID:22692080

Pepe, Dominique; Phelps, Jessica; Lewis, Kevin; Dujack, Jared; Scarlett, Katrina; Jahan, Sumaya; Bonnier, Emilee; Milic-Pasetto, Tatjana; Hass, Martha A; Lopes, Luciana B

2012-09-15

258

IMPROVEMENT OF SALT TOLERANCE IN DURUM WHEAT BY ASCORBIC ACID APPLICATION  

Directory of Open Access Journals (Sweden)

Full Text Available The main objective of this study is to examine whether exogenously applied Ascorbic acid (AsA may enhance the salt tolerance in durum wheat (Triticum durum Desf. var. Waha. Two weeks old seedling, grown in plastic pots of 1kg, were subjected to salt stress by adding 25ml of NaCl (150mm, and treated or not with the addition of ascorbic acid (0.7 mM. Two weeks after salt stress, plants were harvested and the various measures were recorded.The effects of salt stress, in the presence and absence of vitamin C, on the leaf growth, leaf area (LA and some physiological and biochemical changes were investigated. It was established that the application of vitamin C mitigate to variable extent the adverse effect of salt stress on plant growth, may be due, in part, to increased leaf area, improved chlorophyll and carotenoid contents, enhanced proline accumulation and decreased H2O2 content.In conclusion, we can say that treatment with ascorbic acid improve salt tolerance in durum wheat through the enhancement of multiple processes.

Fercha Azzedine

2011-03-01

259

Radiation protective effects of cysteamine and glutathione on four nucleobases and ascorbic acid in aqueous solution  

International Nuclear Information System (INIS)

This paper shows the radiation protective effects of cysteamine and glutathione (reduced form) on the ?-systems of four nucleobases in aqueous solution. Thymine, cytosine, adenine, and guanine solutions containing cysteamine (or glutathione) in various concentrations were irradiated with gamma-rays from a 0.22 PBq Co-60 source. The residual concentration of each nucleobase after irradiation was measured by spectrophotometry and liquid chromatography. The ?-systems of cytosine and adenine were protected and repaired by adding about a 3-6 fold excess of cysteamine in relative to the cytosine and the adenine concentration. Each amino group, cytosine and adenine, plays an important role for the protection of their own ?-system from the radiation damage. The ?-system of thymine was protected from the radiation damage, but was not repaired by cysteamine. The protective effects of cysteamine on guanine were saturated with increasing the cysteamine concentration. Ascorbic acid solutions containing cysteamine were irradiated also. The radiation protective effect of cysteamine on ascorbic acid was small. A first approximation analysis was made on the radiation protective effects. The autooxidation of ascorbic acid in aqueous solution containing several kinds of antioxidants was measured and analyzed. (author)

260

Determination of Proximate Composition, Ascorbic Acid and Heavy Metal Content of African Walnut (Tetracarpidium conophorum  

Directory of Open Access Journals (Sweden)

Full Text Available The proximate composition, ascorbic acid and heavy metal content of (African walnut Tetracarpidium conophorum were evaluated using chemical analysis. The result of the proximate composition showed the following; moisture (48.70%, carbohydrate (53.20%, crude protein (35.22%, crude fat (6.21%, crude fiber (3.34% and ash (2.03%.It also contained 53.50mg/100ml of ascorbic acid. The heavy metal concentrations in the fruit is Fe (0.064ppm, Mn (0.012ppm, Cr (0.001ppm, Ni (0.005ppm while the concentrations of Hg, Pb and Cd were not detected. The results revealed that the T. conophorum is rich in ascorbic acid and carbohydrate with moderate valves of crude protein while the ash content was shown to be very low. This result shows that T. conophorum nut is not polluted with heavy metals since the concentrations of the heavy metals were all below WHO permissible limits. This nut is therefore shown to be safe for public consumption.

Edem

2009-01-01

261

Characterization of L-ascorbic acid single crystals grown from solution with different solvents  

Energy Technology Data Exchange (ETDEWEB)

Single crystals of L-ascorbic acid, popularly known as vitamin-C, were grown from solutions with different solvents and solvent combinations by low temperature solution growth methods. The suitability of different solvents and solvent combinations such as acetone, ethanol, methanol, isopropyl alcohol, water, water + acetone (1:1), water + ethanol (3:1), water + isopropyl alcohol (3:1) and isopropyl alcohol + methanol (1:1) for crystal growth of L-ascorbic acid was found out by assessing the solubility and crystallization behaviours. Solubility of L-ascorbic acid in selected solvents and solvent combinations in a range of temperatures was determined by gravimetric method. Solution prepared with water, water + acetone (1:1), water + ethanol (3:1) and water + isopropyl alcohol (3:1) were yielded crystals with tabular, columnar and prismatic habits and their morphologies were evaluated by goniometry. Grown single crystals were characterized with various instrumental techniques such as powder X-ray diffraction, Fourier infrared spectroscopy, optical transmittance study, differential scanning calorimetry and second harmonic generation studies. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Srinivasan, K.; Vanitha Devi, K. [Crystal Growth Laboratory, Department of Physics, School of Physical Sciences, Bharathiar University, Coimbatore-641 046, Tamil Nadu (India)

2010-09-15

262

Seasonal profiles of leaf ascorbic acid content and redox state in ozone-sensitive wildflowers  

Energy Technology Data Exchange (ETDEWEB)

Cutleaf coneflower (Rudbeckia laciniata L.), crown-beard (Verbesina occidentalis Walt.), and tall milkweed (Asclepias exaltata L.) are wildflower species native to Great Smoky Mountains National Park (U.S.A.). Natural populations of each species were analyzed for leaf ascorbic acid (AA) and dehydroascorbic acid (DHA) to assess the role of ascorbate in protecting the plants from ozone stress. Tall milkweed contained greater quantities of AA (7-10 {mu}mol g{sup -1} fresh weight) than crown-beard (2-4 {mu}mol g{sup -1} fresh weight) or cutleaf coneflower (0.5-2 {mu}mol g{sup -1} fresh weight). DHA was elevated in crown-beard and cutleaf coneflower relative to tall milkweed suggesting a diminished capacity for converting DHA into AA. Tall milkweed accumulated AA in the leaf apoplast (30-100 nmol g{sup -1} fresh weight) with individuals expressing ozone foliar injury symptoms late in the season having less apoplast AA. In contrast, AA was not present in the leaf apoplast of either crown-beard or cutleaf coneflower. Unidentified antioxidant compounds were present in the leaf apoplast of all three species. Overall, distinct differences in antioxidant metabolism were found in the wildflower species that corresponded with differences in ozone sensitivity. - Wildflower species exhibit differences in ascorbic acid content and redox status that affect ozone sensitivity.

Burkey, Kent O. [Plant Science Research Unit, USDA-ARS and North Carolina State University, 3127 Ligon Street, Raleigh, NC 27607 (United States)]. E-mail: koburkey@unity.ncsu.edu; Neufeld, Howard S. [Appalachian State University, Boone, NC (United States); Souza, Lara [Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN (United States); Chappelka, Arthur H. [Auburn University, Auburn, AL (United States); Davison, Alan W. [University of Newcastle, Newcastle, England (United Kingdom)

2006-10-15

263

Seasonal profiles of leaf ascorbic acid content and redox state in ozone-sensitive wildflowers  

International Nuclear Information System (INIS)

Cutleaf coneflower (Rudbeckia laciniata L.), crown-beard (Verbesina occidentalis Walt.), and tall milkweed (Asclepias exaltata L.) are wildflower species native to Great Smoky Mountains National Park (U.S.A.). Natural populations of each species were analyzed for leaf ascorbic acid (AA) and dehydroascorbic acid (DHA) to assess the role of ascorbate in protecting the plants from ozone stress. Tall milkweed contained greater quantities of AA (7-10 ?mol g-1 fresh weight) than crown-beard (2-4 ?mol g-1 fresh weight) or cutleaf coneflower (0.5-2 ?mol g-1 fresh weight). DHA was elevated in crown-beard and cutleaf coneflower relative to tall milkweed suggesting a diminished capacity for converting DHA into AA. Tall milkweed accumulated AA in the leaf apoplast (30-100 nmol g-1 fresh weight) with individuals expressing ozone foliar injury symptoms late in the season having less apoplast AA. In contrast, AA was not present in the leaf apoplast of either crown-beard or cutleaf coneflower. Unidentified antioxidant compounds were present in the leaf apoplast of all three species. Overall, distinct differences in antioxidant metabolism were found in the wildflower species that corresponded with differences in ozone sensitivity. - Wildflower species exhibit differences in ascorbic acid content and redox status that affect ozone sensitivity

264

Combined ?-tocopherol and ascorbic acid protects against smoke-induced lung squamous metaplasia in ferrets.  

Science.gov (United States)

Many epidemiological studies show the benefit of fruits and vegetables on reducing risk of lung cancer, the leading cause of cancer death in the United States. Previously, we demonstrated that cigarette smoke exposure (SM)-induced lung lesions in ferrets were prevented by a combination of low dose of ?-carotene, ?-tocopherol (AT), and ascorbic acid (AA). However, the role of a combination of AT and AA alone in the protective effect on lung carcinogenesis remains to be examined. In the present study, we investigated whether the combined AT (equivalent to ?100 mg/day in the human) and AA (equivalent to ?210 mg/day) supplementation prevents against SM (equivalent to 1.5 packs of cigarettes/day) induced lung squamous metaplasia in ferrets. Ferrets were treated for 6 weeks in the following three groups (9 ferrets/group): (i) Control (no SM, no AT+AA), (ii) SM alone, and (iii) SM+AT+AA. Results showed that SM significantly decreased concentrations of retinoic acid, AT, and reduced form of AA, not total AA, retinol and retinyl palmitate, in the lungs of ferrets. Combined AT+AA treatment partially restored the lowered concentrations of AT, reduced AA and retinoic acid in the lungs of SM-exposed ferrets to the levels in the control group. Furthermore, the combined AT+AA supplementation prevented SM-induced squamous metaplasia [0 positive/9 total ferrets (0%) vs. 5/8 (62%); p<0.05] and cyclin D1 expression (p<0.05) in the ferret lungs, in which both were positively correlated with expression of c-Jun expression. Although there were no significant differences in lung microsomal malondialdehyde (MDA) levels among the three groups, we found a positive correlation between MDA levels and cyclin D1, as well as c-Jun expressions in the lungs of ferrets. These data indicate that the combination of antioxidant AT+AA alone exerts protective effects against SM-induced lung lesions through inhibiting cyclin D1 expression and partially restoring retinoic acid levels to normal. PMID:21665318

Kim, Yuri; Chongviriyaphan, Nalinee; Liu, Chun; Russell, Robert M; Wang, Xiang-Dong

2012-01-01

265

Status of lipid peroxidation, glutathione, ascorbic acid, vitamin E and antioxidant enzymes in patients with osteoarthritis  

Directory of Open Access Journals (Sweden)

Full Text Available Background : The exact pro-oxidant and antioxidant status in osteoarthritis patients is still not clear. To add a new insight to the question, changes in the erythrocyte lipid peroxidation products (MDA, levels of glutathione (GSH, ascorbic acid and plasma vitamin E (nonenzymatic antioxidant parameters; and activities of antioxidant enzymes superoxide dismutase (SOD, glutathione peroxidase (GPX, catalase in erythrocytes and plasma glutathione - S - transferase (GST were measured in patients with osteoarthritis. Aim: This work was undertaken to assess oxidative stress and antioxidant status in patients with osteoarthritis. Settings and design: The study was conducted in 20 patients and compared to controls. Levels of erythrocyte MDA, GSH, ascorbic acid, plasma vitamin E; and activities of antioxidant enzymes were measured in patients with osteoarthritis. materials and Methods: Erythrocyte GSH was measured by the method of Beutler et al. Ascorbic acid levels were measured by the method of Tietz. Plasma vitamin E levels were measured by the method of Baker et al. MDA was determined as the measure of thio barbituric acid reactive substances (TBARS. SOD activity in the hemolysate was measured by the method of Misra and Fridovich. Activity of catalase was measured by the method of Beers and Sizer. GPX activity was measured as described by Paglia and Valentine in erythrocytes, and Plasma GST activity was measured as described by Warholm et al. These parameters were measured in 20 patients and compared to controls. Statistical analysis: Statistical analysis between group 1 (controls and group 2 (patients was performed by the student?s t - test using the stat -view package. Results: It was observed that there was a significant increase in erythrocyte MDA levels; SOD, GPX and plasma GST activities; and a significant decrease in erythrocyte GSH, ascorbic acid, plasma vitamin E levels and catalase activity in patients with osteoarthritis when compared to controls. Conclusions: The results of our study suggest higher oxygen-free radical production, evidenced by increased MDA and decreased GSH, ascorbic acid, vitamin E and catalase activity, support to the oxidative stress in osteoarthritis. The increased activities of antioxidant enzymes may be a compensatory regulation in response to increased oxidative stress.

Surapaneni Krishna

2007-01-01

266

L-Ascorbic acid metabolism during fruit development in an ascorbate-rich fruit crop chestnut rose (Rosa roxburghii Tratt).  

Science.gov (United States)

Chestnut rose (Rosa roxburghii Tratt) is a fruit crop that contains unusually high levels of l-ascorbic acid (AsA; ?1300 mg 100g(-1) FW). To explore the mechanisms underlying AsA metabolism, we investigated the distribution and abundance of AsA during fruit development. We also analyzed gene expression patterns, enzyme activities, and content of metabolites related to AsA biosynthesis and recycling. AsA first accumulated during late fruit development and continued to accumulate during ripening, with the highest accumulation rate near fruit maturity. The redox state of AsA in fruit was also enhanced during late fruit development, while leaf and other tissues had much lower levels of AsA and the redox state of AsA was lower. In mature fruit, AsA was mainly distributed in the cytoplasm of the mesocarp. Correlation analysis suggested that the gene expression patterns, enzyme activities, and related metabolite concentrations involved in the l-galactose pathway showed relatively high correlations with the accumulation rate of AsA. The gene expression pattern and activity of dehydroascorbate reductase (DHAR, EC 1.8.5.1) correlated strongly with AsA concentration, possibly indicating the crucial role of DHAR in the accumulation of high levels of AsA in chestnut rose fruit. Over expression of DHAR in Arabidopsis significantly increased the reduced AsA content and redox state. This was more effective than over expression of the l-galactose pathway gene GDP-d-mannose-3,5-epimerase (EC 5.1.3.18). These findings will enhance understanding of the molecular mechanisms regulating accumulation of AsA in chestnut rose. PMID:25019249

Huang, Ming; Xu, Qiang; Deng, Xiu-Xin

2014-09-01

267

Long-term culture of primary porcine mature hepatocytes in the medium supplemented with ascorbic acid 2-phosphate  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, the effect of ascorbic acid 2-phosphate (Asc2P was tested on porcine and rat mature hepatocytes in vitro. a. Asc2P increased the porcine, but not rat, albumin secretion and mRNA expression. The enhancing effect of Asc2P on porcine C/EBP alpha mRNA was observed in porcine mature hepatocytes. These data suggested that Asc2P played an important role in the regulation of porcine albumin mRNA level. b. The enhancing effect of Asc2P on ammonium metabolic activity was also observed in porcine, but not rat, mature hepatocytes. The porcine ornithine transcarbamylase (OTC and arginase mRNAs were augmented by Asc2P, indicating that Asc2P had a direct effect on the urea cycle. c. The porcine collagen type I and type III mRNA, but not type XII mRNA, were detected as well, sugessting that Asc2P did not have the effect on the non-parenchymal hepatocytes to induce collagen type I and III mRNA expression. d. Our RT-PCR analysis demonstrated that the porcine hepatocytes expressed the sodium-ascorbate co-transporters SVCT1 and SVCT2, however, the intensities of porcine sodium-ascorbate co-transporters SVCT1 and SVCT2 bands were not changed markedly. These findings indicated that the Asc2P had no effect on SVCT1 and SVCT2 mRNA expression. e. The enhancing effect of Asc2P on porcine albumin mRNA was inhibited by staurosporine, a portein kinase inhibitor. We conclude that the enhanced albumin mRNA by Asc2P might be due to activation of tyrosine protein kinase and/or PKC and the Asc2P enhanced porcine albumin mRNA mainly at the transcriptional step.

Noriko Sasaki

2010-11-01

268

Effect of Salicylic Acid and Ascorbic Acid on Germination Indexes and Enzyme Activity of Sorghum Seeds under Drought Stress  

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Full Text Available Seed priming methods have been used to increase germination characteristics under stress conditions. The effects of drought stress (0, -4, -8, -12 and -16 bar and salicylic acid 25 ppm at 15 °C for 15 h and ascorbic acid 25 ppm at 15 °C for 15 h on germination percentage, germination index, means time to germination, normal seedling percentage and enzyme activity were assessed in the laboratory for sorghum seeds (Sorghum bicolor L.. Results showed that the highest germination percentage (83.33%, normal seedling percentage (69.67%, germination index (25.29 and the minimum means time to germination (2.87 were attained from priming with salicylic acid in control conditions. Therefore, seed priming significantly (p? 0.01 increased germination characteristics as compared to the unprimed under drought stress. Also, priming increased catalase and ascorbate peroxidase as compared to the unprimed seeds.

Tabatabaei S. A.

2013-11-01

269

Enhancement of electrogenerated chemiluminescence of luminol by ascorbic acid at gold nanoparticle/graphene modified glassy carbon electrode  

Science.gov (United States)

Gold nanoparticle/graphene (GNP/GR) nanocomposite was one-pot synthesized from water soluble graphene and HAuCl4 by hydrothermal method and characterized by TEM, Raman spectroscopy, XRD, XPS, UV-vis spectroscopy, and electrochemical impedance spectroscopy (EIS). Electrogenerated chemiluminescence (ECL) of luminol was investigated at the GNP/GR modified glassy carbon electrode (GNP/GR/GCE) and the GNP modified glassy carbon electrode (GNP/GCE) in aqueous solution respectively. The results revealed that one strong anodic ECL peak could be observed at ?0.8 V at two modified electrodes compared with that at the bare electrode. The intensity of the anodic ECL at the GNP/GR/GCE is weaker than that at the GNP/GCE, which should be due to the synergic effect of the enhancing effect of gold nanoparticles and the inhibiting effect of graphene on anodic luminol ECL. One strong cathodic ECL peak located at ?-0.8 V could be observed at the GNP/GR/GCE but not at the GNP/GCE, which should be result from the adsorbed oxygen at the graphene film. In the presence of ascorbic acid, the anodic ECL at the GNP/GR/GCE was enhanced more than 8-times, which is more apparent than that at the GNP/GCE. Whereas, the cathodic ECL peak was seriously inhibited at the GNP/GR/GCE. The enhanced ECL intensity at the GNP/GR/GCE varied linearly with the logarithm of ascorbic acid concentration in the range of 1.0 × 10-8 to 1.0 × 10-6 mol L-1 with a detection limit of 1.0 × 10-9 mol L-1. The possible ECL mechanism was also discussed.

Dong, Yongping; Gao, Tingting; Zhou, Ying; Chu, Xiangfeng; Wang, Chengming

2015-01-01

270

Inhibition of microsomal chemiluminescence by cytosolic fractions containing fatty acid binding protein.  

Science.gov (United States)

Studies were carried out to determine the relationship between Fe(++)-ascorbate initiated chemiluminescence and lipid peroxidation in rat liver, lung, kidney and brain microsomes. In order to follow the time course of membrane lipid peroxidation, we measured simultaneously physical and biochemical changes. Thus we determined the fatty acid composition of microsomal membranes from those tissues after peroxidation with and without ascorbic acid. Fractionation of cytosolic proteins with ammonium sulfate 70% saturation yielded a soluble fraction (enriched in fatty acid binding protein) that inhibited ascorbate-Fe++ dependent lipid peroxidation. The inhibitory effect was concentration dependent and was not abolished by heating of the soluble fraction during 5 min at 100 degrees C. Preparations from kidney, lung, heart and brain showed similar effect on lipid peroxidation of liver microsomal membranes. It is especulated that retinyl esters bound to fatty acid binding protein may act as antioxidants against lipid peroxidation. PMID:8574775

Catala, A; Cerruti, A; Arcemis, C

1995-04-01

271

Further ivestigations into the relationship between the dopanminergic system ascorbic acid and uric acid in the rat striatum  

OpenAIRE

Levels of dopaminc (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), ascorbic acid (AA), dehydroascorbic acid (DHAA), and uric acid were determined in the rat striatum following single apomorphine (1 mg/kg), scopolamine (0.6 mg/kg), pilocarpine (4 mg/kg), or pilocarpine + scopolamine (4 and 0.6 mg/kg, respectively) injections. The decrease in DOPAC levels and in the DOPAC/DA ratio, induced by the pharmacological manipulation, was linearly correlated with the increase in DHAA levels (r = ?0...

Desole, Maria Speranza; Miele, Maddalena; Esposito, Giovanni; Enrico, Paolo; Fresu, Luigia Grazia; Natale, Guglielmo; Miele, Egidio

1991-01-01

272

Effects of morphine treatment and withdrawal on striatal and limbic monoaminergic activity and ascorbic acid oxidation in the rat  

OpenAIRE

Since ascorbic acid (AA) reportedly suppresses tolerance to and dependence on morphine in humans and rodents, levels of dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxytyramine (3-MT), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), AA, dehydroascorbic acid (DHAA), uric acid, xanthine, hypoxanthine, glutamate and ?-amino-butyric acid (GABA) were determined by high-pressure liquid chromatography (HPLC) in the striatum and in the limbi...

Desole, Maria Speranza; Esposito, Giovanni; Fresu, Luigia Grazia; Migheli, Rossana; Enrico, Paolo; Mura, Maria A.; Natale, Guglielmo; Miele, Egidio; Miele, Maddalena

1996-01-01

273

Industrialized cashew juices: variation of ascorbic acid and other physicochemical parameters Sucos de caju industrializados: variação no teor de ácido ascórbico e em outros parâmetros físico-químicos  

OpenAIRE

Commercial cashew apple juice is widely accepted in the Brazilian market. Cashew apple has high content of ascorbic acid, an important nutrient to human beings. Ascorbic acid content in food can be affected by processing and storage conditions. Commercial cashew apple juice samples, ready-to-drink and concentrated, were analyzed. The ascorbic acid content, total titratable acidity, total soluble solids, and pH of the juices were determined during storage at 4 °C after the containers were ope...

Christiane de Queiroz Pereira; Flávia Conde Lavinas; Maria Lúcia Mendes Lopes; Vera Lúcia Valente-Mesquita

2008-01-01

274

Comparison of ascorbic acid biosynthesis in different tissues of three non-heading Chinese cabbage cultivars.  

Science.gov (United States)

Ascorbic acid (L-AsA) is an important antioxidant in plants and humans. Vegetables are one of the main sources of ascorbic acid for humans. For instance, non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) is considered as one of the most important vegetables in south China. To elucidate the mechanism by which AsA accumulates, we systematically investigated the expression profiles of D-mannose/L-galactose pathway-related genes. We also investigated the recycling-related genes and AsA contents in different tissues of three non-heading Chinese cabbage cultivars, 'Suzhouqing', 'Wutacai' and 'Erqing' containing different amounts of AsA. Our results showed that six genes [D-mannose-6-phosphate isomerase 1 (PMI1), GDP-L-galactose phosphorylase 1 (GGP1), GGP2, GGP4, GDP-mannose-3', 5'-epimerase1 (GME1), and GME2] were expressed at high level and ascorbate oxidase (AAO) was expressed at low level. This expression pattern contributes, at least partially, to higher AsA accumulation in the leaves and petioles than in the roots. Eight genes (PMI1, GME, GGP, L-galactose-1-phosphate phosphatase, L-galactose dehydrogenase, L-galactono-1, 4-lactone dehydrogenase, monodehydroascorbate reductase 1, and glutathione reductase1) were also expressed at high level; AAO and ascorbate peroxidase (APX) were expressed at low level. This expression pattern may similarly contribute to higher AsA accumulation in 'Wutacai' and 'Suzhouqing' than in 'Erqing'. Therefore, the high expression levels of PMI, GME, and GGP and the low expression level of AAO contributed to the high AsA accumulation in non-heading Chinese cabbage. PMID:24157701

Ren, Jun; Chen, Zhongwen; Duan, Weike; Song, Xiaoming; Liu, Tongkun; Wang, Jianjun; Hou, Xilin; Li, Ying

2013-12-01

275

Redox regulation of calcium signaling in cancer cells by ascorbic Acid involving the mitochondrial electron transport chain.  

Science.gov (United States)

Previously, we have reported that ascorbic acid regulates calcium signaling in human larynx carcinoma HEp-2 cells. To evaluate the precise mechanism of Ca(2+) release by ascorbic acid, the effects of specific inhibitors of the electron transport chain components on mitochondrial reactive oxygen species (ROS) production and Ca(2+) mobilization in HEp-2 cells were investigated. It was revealed that the mitochondrial complex III inhibitor (antimycin A) amplifies ascorbate-induced Ca(2+) release from intracellular stores. The mitochondrial complex I inhibitor (rotenone) decreases Ca(2+) release from intracellular stores in HEp-2 cells caused by ascorbic acid and antimycin A. In the presence of rotenone, antimycin A stimulates ROS production by mitochondria. Ascorbate-induced Ca(2+) release in HEp-2 cells is shown to be unaffected by catalase. The results obtained suggest that Ca(2+) release in HEp-2 cells caused by ascorbic acid is associated with induced mitochondrial ROS production. The data obtained are in line with the concept of redox signaling that explains oxidant action by compartmentalization of ROS production and oxidant targets. PMID:23227042

Martinovich, Grigory G; Golubeva, Elena N; Martinovich, Irina V; Cherenkevich, Sergey N

2012-01-01

276

A novel nanocomposites sensor for epinephrine detection in the presence of uric acids and ascorbic acids  

Energy Technology Data Exchange (ETDEWEB)

Highlights: {center_dot} A novel PPy/AuNPs/SWCNTs nanomaterials biosensor was prepared to the selective determination of EP. {center_dot} The methods we employed to prepare PPy/AuNPs/SWCNTs nanomaterials are extremely simple. {center_dot} The PPy/AuNPs/SWCNTs nanocomposites biosensor we got from the results of experiments can totally eliminate the interference from AA and distinguish EP from UA. - Abstract: A novel nanocomposites film of conducting polymers including single-walled carbon nanotubes (SWCNTs), polypyrrole (PPy) and gold nanoparticles (AuNPs) modified electrode has been applied in voltammetric sensors to detect epinephrine (EP) sensitively when ascorbic acids (AA) and uric acids (UA) exist. The nanocomposites film of conducting polymers which show an excellent electrocatalystic activity for the oxidation of EP and UA was characterized by scanning electron microscopy (SEM) and electrochemical methods. The catalytic peak currents obtained from differential pulse voltammetry (DPV) increased linearly with increasing EP concentrations in the range of 4.0 x 10{sup -9}-1.0 x 10{sup -7} M with a detection limit of 2.0 x 10{sup -9} M (S/N = 3), respectively. The results showed that the nanocomposites of conducting polymers can selectively determine EP in the coexistence of a large amount of UA and AA. In addition, the sensor exhibited excellent sensitivity, selectivity and stability. The PPy/AuNPs/SWCNTs nanocomposites film can also be satisfactorily used for detecting EP in epinephrine hydrochloride injection when contain AA and UA, which also shows good recovery for determination of EP in some biological fluids.

Lu Xiaoquan, E-mail: luxq@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, LanZhou, 730070 (China); Li Yaya; Du Jie; Zhou Xibin; Xue Zhonghua; Liu Xiuhui; Wang Zhihua [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, LanZhou, 730070 (China)

2011-08-30

277

A novel nanocomposites sensor for epinephrine detection in the presence of uric acids and ascorbic acids  

International Nuclear Information System (INIS)

Highlights: · A novel PPy/AuNPs/SWCNTs nanomaterials biosensor was prepared to the selective determination of EP. · The methods we employed to prepare PPy/AuNPs/SWCNTs nanomaterials are extremely simple. · The PPy/AuNPs/SWCNTs nanocomposites biosensor we got from the results of experiments can totally eliminate the interference from AA and distinguish EP from UA. - Abstract: A novel nanocomposites film of conducting polymers including single-walled carbon nanotubes (SWCNTs), polypyrrole (PPy) and gold nanoparticles (AuNPs) modified electrode has been applied in voltammetric sensors to detect epinephrine (EP) sensitively when ascorbic acids (AA) and uric acids (UA) exist. The nanocomposites film of conducting polymers which show an excellent electrocatalystic activity for the oxidation of EP and UA was characterized by scanning electron microscopy (SEM) and electrochemical methods. The catalytic peak currents obtained from differential pulse voltammetry (DPV) increased linearly with increasing EP concentrations in the range of 4.0 x 10-9-1.0 x 10-7 M with a detection limit of 2.0 x 10-9 M (S/N = 3), respectively. The results showed that the nanocomposites of conducting polymers can selectively determine EP in the coexistence of a large amount of UA and AA. In addition, the sensor exhibited excellent sensitivity, selectivity and stability. The PPy/AuNPs/SWCNTs nanocomposites film can also be satisfactorily used for detecting EP in episfactorily used for detecting EP in epinephrine hydrochloride injection when contain AA and UA, which also shows good recovery for determination of EP in some biological fluids.

278

Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis  

International Nuclear Information System (INIS)

Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na3VO4) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na3VO4 was cytotoxic against T24 cells (EC50 = 5.8 ?M at 24 h), but in the presence of ascorbate (100 ?M) the EC50 fell to 3.3 ?M. Na3VO4 plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na3VO4 did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na3VO4 and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na3VO4 alone, or combined with ascorbate, increased catalase activity, but only Na3VO4 plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na3VO4 plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na3VO4. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na3VO4 in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment

279

Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis.  

Science.gov (United States)

Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na(3)VO(4)) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na(3)VO(4) was cytotoxic against T24 cells (EC(50)=5.8 ?M at 24 h), but in the presence of ascorbate (100 ?M) the EC(50) fell to 3.3 ?M. Na(3)VO(4) plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na(3)VO(4) did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na(3)VO(4) and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na(3)VO(4) alone, or combined with ascorbate, increased catalase activity, but only Na(3)VO(4) plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na(3)VO(4) plus ascorbate (2-3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na(3)VO(4). The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na(3)VO(4) in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment. PMID:23261463

Günther, Tânia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; da Silva, Fabiana Ourique; Bücker, Nádia Cristina Falcão; Pich, Claus Tröger; Ferreira, Eduardo Antonio; Wilhelm Filho, Danilo; Verrax, Julien; Calderon, Pedro Buc; Pedrosa, Rozangela Curi

2013-01-18

280

Effect of temperature variations during cooking and storage on ascorbic acid contents of vegetables: a comparative study  

International Nuclear Information System (INIS)

Summary: Vegetables are generally boiled for cooking or stored in refrigerators. This results in loss of their nutritional values. Ascorbic acid is one of the important nutrients for human health. In this study, Ascorbic acid (vitamin-C) content of various vegetables of Pakistan was determined, and effect of boiling and freezing were compared with natural Ascorbic acid contents by HPLC. The maximum concentration of Ascorbic acid was found in green chilli: i.e. 105 mg /100 g in fresh state; while in boiled and frozen state its concentration is comparatively less: i.e. 85 and 92 mg/100 g respectively. The other vegetables like: cabbage, to mato, turnip, potato, spinach, onion, garlic, green pea, green beans and cauliflower contained greater amount of Ascorbic acid in their fresh state i.e. 30, 20, 25.3, 20, 30, 24.3, 31, 28.5, 30, 42 mg/100 g as compared to frozen (23.4, 13, 23.6, 15, 23.4, 14.1,25, 26.5, 27.0, and 39 mg/100g respectively) and boiled state (11.6, 9.3, 22.5, 10.0, 20.3, 13.1, 23, 25.2 and 35 mg /100g respectively). The minimum amount of Ascorbic acid was found in boiled state of carrot and lettuce: i.e. 4.0 mg/100 g. These results showed that freezing or boiling of vegetables causes significant lo ss of available Ascorbic acid contents, especially boiling. (author)

281

Evaluation of gamma irradiation effects on carotenoids, ascorbic acid and sugar contents of buriti fruit (Mauritia flexuosa L.)  

International Nuclear Information System (INIS)

Buriti (Mauritia flexuosa L.), a typical fruit from the Northeast and Center-West Amazon of Brazil, is used in many regional dishes. It is considered an excellent source of carotenoids that are A vitamin precursors, showing a majority of beta-carotene. It also presents ascorbic acid and sugar contents. Many studies have indicated that the lack of A vitamin is the main cause of night blindness and xerophthalmia. Also, ascorbic acid deficiency may cause scorbutic disease. The use of food irradiation is growing and represents an economic benefit to agriculture through the reduction of post-harvesting losses while maintaining food nutritional quality. In this study, buriti in natura was treated with gamma irradiation with doses of 0.5 kGy and 1.0 kGy. The objective was to evaluate the irradiation effects on total carotenoids, ascorbic acid and sugars concentrations of buriti. The fruit was evaluated through the total carotenoids analysis, by spectrophotometry, and the carotenoids (alpha and beta-carotene and lutein), ascorbic acid and sugars were determined by high performance liquid chromatography (HPLC). The results showed that buriti is an excellent source of total carotenoids (44600 ?g/100 g). The irradiation of buriti with the dose of 0.5 kGy did not significantly change carotenoids and sugars contents. However, there was a reduction of ascorbic acid concentration with an increase of the dose, which may have been caused by irradiation or by intrinsic and extrinsic fradiation or by intrinsic and extrinsic factors that alter ascorbic acid stability in food, converting ascorbic to dehydroascorbic acid, while keeping the C vitamin active form. (author)

282

Adaptive alterations in the fatty acids composition under induced oxidative stress in heavy metal-tolerant filamentous fungus Paecilomyces marquandii cultured in ascorbic acid presence.  

Science.gov (United States)

The ability of the heavy metal-tolerant fungus Paecilomyces marquandii to modulate whole cells fatty acid composition and saturation in response to IC50 of Cd, Pb, Zn, Ni, and Cu was studied. Cadmium and nickel caused the most significant growth reduction. In the mycelia cultured with all tested metals, with the exception of nickel, a rise in the fatty acid unsaturation was noted. The fungus exposure to Pb, Cu, and Ni led to significantly higher lipid peroxidation. P. marquandii incubated in the presence of the tested metals responded with an increase in the level of linoleic acid and escalation of electrolyte leakage. The highest efflux of electrolytes was caused by lead. In these conditions, the fungus was able to bind up to 100 mg g(-1) of lead, whereas the content of the other metals in the mycelium was significantly lower and reached from 3.18 mg g(-1) (Cu) to 15.21 mg g(-1) (Zn). Additionally, it was shown that ascorbic acid at the concentration of 1 mM protected fungal growth and prevented the changes in the fatty acid composition and saturation but did not alleviate lipid peroxidation or affect the increased permeability of membranes after lead exposure. Pro-oxidant properties of ascorbic acid in the copper-stressed cells manifested strong growth inhibition and enhanced metal accumulation as a result of membrane damage. Toxic metals action caused cellular modulations, which might contributed to P. marquandii tolerance to the studied metals. Moreover, these changes can enhance metal removal from contaminated environment. PMID:23132407

S?aba, Miros?awa; Gajewska, Ewa; Bernat, Przemys?aw; Fornalska, Magdalena; D?ugo?ski, Jerzy

2013-05-01

283

Oral high dose ascorbic acid treatment for one year in young CMT1A patients: a randomised, double-blind, placebo-controlled phase II trial  

OpenAIRE

Abstract Background High dose oral ascorbic acid substantially improved myelination and locomotor function in a Charcot-Marie-Tooth type 1A mouse model. A phase II study was warranted to investigate whether high dose ascorbic acid also has such a substantial effect on myelination in Charcot-Marie-Tooth type 1A patients and whether this treatment is safe. Methods Patients below age 25 years were randomly assigned to receive placebo or ascorbic acid (one gram twic...

de Visser Marianne; Baas Frank; Vermeulen Marinus; de Haan Rob J; Verhamme Camiel; van Schaik Ivo N

2009-01-01

284

Ascorbic acid improves stability and pharmacokinetics of rifampicin in the presence of isoniazid.  

Science.gov (United States)

Bioavailability of rifampicin (RIF) from fixed dose combination (FDC) products remains problematic for effective control of tuberculosis (TB) owing to its degradation in the presence of isoniazid (INH) in the stomach acid environment. Ascorbic acid (ASC) is being added to the dissolution medium as well as the plasma sample as anti-oxidant to prevent degradation of RIF and also daily intake of ascorbic acid is recommended to control TB infection. However the role of ASC on the interaction between dissolution stability and in vivo bioavailability of RIF in the presence of INH has not been explored and therefore examined in the present study. RIF and its degradation product 3-FRSV were measured by dual wavelength spectroscopy. ASC significantly reduced RIF degradation or formation of 3-FRSV in the presence of INH (p<0.001) in the dissolution medium (pH 1.2) and showed increase in Cmax, AUC0-24, AUC0-? and t1/2 of RIF (p<0.001) as compared to that without ASC in rabbits. The study demonstrates that co-administration of ASC with RIF-INH combination can protect RIF from degradation in the acid environment and improve its bioavailability with effective control of TB. PMID:25151231

Rajaram, Subashini; Vemuri, Venkata Deepthi; Natham, Rajendran

2014-11-01

285

effect of ascorbic acid and/or sodium chloride on irradiated mungbean seeds  

International Nuclear Information System (INIS)

dry seeds of mungbean (Vigna radiata L.) were irradiated with different doses of gamma rays (0, 50, 100, 250 Gy) dose rate was 1.33 Gy/sec and germinated under laboratory conditions (28 degree C±2 degree C) in 100 mM of sodium chloride or 10 mM ascorbic acid or mixture of both in equal amounts . a group of irradiated and unirradiated seeds were moistened with tap water and considered as control. the growth parameters of two weeks old seedling were recorded. photosynthetic pigments, total carbohydrates, crud protein and amino acids contents were also determined. gamma radiation (50-100 Gy)increased total chlorophylls and carotenoid pigments while the highest dose of irradiation (250 Gy) reduced these contents. saline condition decreased total chlorophyll and carotenoid contents of seedlings resulted from irradiated seeds than control. adding of ascorbic acid to irradiated mungbean seeds in presence of NaCl overcame partially the inhibitory effect of NaCl on chlorophyll and carotenoid contents of seedlings. the pattern of changes in amino acids content was more or less similar to that of photosynthetic pigments.

286

The Effect of Ascorbic Acid Treatment on Viability and Vigor Maize (Zea mays L. Seedling under Drought Stress  

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Full Text Available This study was conducted in the laboratory and the field to examine the effects of ascorbic acid treatment on germination and seedling growth under drought stress. The laboratory works consisted of two experiments and were designed to determine the critical osmotic potential of maize and to determine the optimum ascorbic acid concentration. The field study was designed to examine the effects of soaking seed in ascorbic acid on seedling growth under drought stress. Drought condition was simulated by PEG-6000 and regulation of water treatment. During the first experiment, interactions of both osmotic potential and varieties were significant at all variables. Germination percentage and speed of germination were significantly decreased by increasing of osmotic potential. The second experiment showed that interactions of both factors were significant at all variables except vigor index, the length of shoot, primary, and seminal root. The results showed that the ascorbic acid treatment improved the germination percentage, the speed of germination and the vigor index compared with the control, besides the increase in length of shoot, primary and seminal root and number of seminal root. However, the best result was showed by 55 mM ascobic acid. The result of field experiment showed that interactions were not always significant and 55 mM ascorbic acid treatment increased the seedling height, the number of leaves and leaf area but it had no effect on the water deficit and the root length.

HAMIDAH HAMAMA

2010-09-01

287

Protective role of L-ascorbic acid, N-acetylcysteine and apocynin on neomycin-induced hair cell loss in Zebrafish.  

Science.gov (United States)

Hair cells are highly sensitive to environmental insults and other therapeutic drugs. The adverse effects of drugs such as aminoglycosides can cause hair cell death and lead to hearing loss and imbalance. The objective of the present study was to evaluate the protective activity of L-ascorbic acid, N-acetylcysteine (NAC) and apocynin on neomycin-induced hair cell damage in zebrafish (Danio rerio) larvae at 5 days post fertilization (dpf). Results showed that the loss of hair cells within the neuromasts of the lateral lines after neomycin exposure was evidenced by a significantly lower number of neuromasts labeled with fluorescent dye FM1-43FX observed under a microscope. Co-administration with L-ascorbic acid, NAC and apocynin protected neomycin-induced hair cell loss within the neuromasts. Moreover, these three compounds reduced the production of reactive oxygen species (ROS) in neuromasts exposed to neomycin, indicating that their antioxidant action is involved. In contrast, the neuromasts were labeled with specific fluorescent dye Texas-red conjugated with neomycin to detect neomycin uptake. Interestingly, the uptake of neomycin into hair cells was not influenced by these three antioxidant compounds. These data imply that prevention of hair cell damage against neomycin by L-ascorbic acid, NAC and apocynin might be associated with inhibition of excessive ROS production, but not related to modulating neomycin uptake. Our findings conclude that L-ascorbic acid, NAC and apocynin could be used as therapeutic drugs to protect aminoglycoside-induced listening impairment after further confirmatory studies. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25092119

Wu, Chia-Yen; Lee, Han-Jung; Liu, Chi-Fang; Korivi, Mallikarjuna; Chen, Hwei-Hsien; Chan, Ming-Huan

2015-03-01

288

Biological Significance of Ascorbic Acid (Vitamin C in Human Health - A Review  

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Full Text Available The recognition of vitamin C (Ascorbic acid is associated with history of an unrelenting search for the cause of the ancient hemorrhagic disease scurvy. Isolated in 1928, vitamin C is essential for the development and maintenance of connective tissues. It plays an important role in bone formation, wound healing and the maintenance of healthy gums. Vitamin C plays an important role in a number of metabolic functions including the activation of the B vitamin, folic acid, the conversion of cholesterol to bile acids and the conversion of the amino acid, tryptophan, to the neurotransmitter, serotonin. It is an antioxidant that protects body from free radicals` damages. It is used as therapeutic agent in many diseases and disorders. Vitamin C protects the immune system, reduces the severity of allergic reactions and helps fight off infections.

Khalid Iqbal

2004-01-01

289

Protective Effect of Ascorbic Acid on Molecular Behavior Changes of Hemoglobin Induced by Magnetic Field  

Science.gov (United States)

With the use of electricity and industrialization of societies, humans are commonly exposed to static magnetic field induced by electric currents. The putative mechanisms by which Static Magnetic Field (SMF) may affect biological systems is that of increasing free radical life span in organisms. To test this hypothesis, we investigate the effect of ascorbic acid (Vitamin C) treatment on the changes in the molecular behavior of hemoglobin as a result of exposure of the animals to magnetic field in the occupation levels. By measuring the relative permittivity, dielectric loss, relaxation time, conductivity, radius and diffusion coefficient of aqueous solutions of hemoglobin. These measurements were calculated in the frequency range of (100 Hz-100 kHz) to give more information about molecular behavior. Twenty four male albino rats were equally divided into four groups 1, 2, 3 and 4. Animals of group 1, were used as control, animals of group 2, were exposed to (0.2T) magnetic field and that of group 3, 4, were treated with Ascorbic Acid by two doses group 3 (20 mg kg-1 body weight), group 4 (50 mg kg-1 body weight) orally half hour before exposure to magnetic field. The sub chronic exposure expanded (1 h day-1) for 30 consecutive days. The results indicated that exposure of animals to magnetic field resulted in changes in the molecular behavior of hemoglobin molecule while treatment with ascorbic acid afforded comparatively more significant amelioration in these molecular changes, via decreasing the radical pair interaction of magnetic field with biological molecules.

Hassan, Nahed S.; Abou Aiad, T. H. M.

290

Ascorbic acid suppresses endotoxemia and NF-?B signaling cascade in alcoholic liver fibrosis in guinea pigs: A mechanistic approach  

International Nuclear Information System (INIS)

Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-?B activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4 g/kg b.wt for 90 days. After 90 days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250 mg/kg b.wt) and AA (250 mg/kg b.wt) supplemented groups and maintained for 30 days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKK? and the protein expressions of phospho-I?B?, NF-?B, TNF-?, TGF-?1 and IL-6 were also altered in ethanol group. The expressions of fibrosis markers ?-SMA, ?1 (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-?B activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKK?, which decreased the activation of NF-?B and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis. - Highlights: • Alcohol increases intestinal bacterial overgrowth and permeability of endotoxin. • Endotoxin mediated inflammation plays a major role in alcoholic liver fibrosis. • Ascorbic acid reduces endotoxemia, NF-?B activation and proinflammatory cytokines. • AA's action is by inhibition of SIBO, IKK? and alteration of intestinal permeability. • This might have led to suppression of HSCs activation and liver fibrosis

291

Ascorbic acid suppresses endotoxemia and NF-?B signaling cascade in alcoholic liver fibrosis in guinea pigs: A mechanistic approach  

Energy Technology Data Exchange (ETDEWEB)

Alcohol consumption increases the small intestinal bacterial overgrowth (SIBO) and intestinal permeability of endotoxin. The endotoxin mediated inflammatory signaling plays a major role in alcoholic liver fibrosis. We evaluated the effect of ascorbic acid (AA), silymarin and alcohol abstention on the alcohol induced endotoxemia and NF-?B activation cascade pathway in guinea pigs (Cavia porcellus). Guinea pigs were administered ethanol at a daily dose of 4 g/kg b.wt for 90 days. After 90 days, ethanol administration was stopped. The ethanol treated animals were divided into abstention, silymarin (250 mg/kg b.wt) and AA (250 mg/kg b.wt) supplemented groups and maintained for 30 days. The SIBO, intestinal permeability and endotoxin were significantly increased in the ethanol group. The mRNA expressions of intestinal proteins claudin, occludin and zona occludens-1 were significantly decreased in ethanol group. The mRNA levels of inflammatory receptors, activity of IKK? and the protein expressions of phospho-I?B?, NF-?B, TNF-?, TGF-?{sub 1} and IL-6 were also altered in ethanol group. The expressions of fibrosis markers ?-SMA, ?{sub 1} (I) collagen and sirius red staining in the liver revealed the induction of fibrosis. But the supplementation of AA could induce greater reduction of ethanol induced SIBO, intestinal barrier defects, NF-?B activation and liver fibrosis than silymarin. The possible mechanism may be the inhibitory effect of AA on SIBO, intestinal barrier defect and IKK?, which decreased the activation of NF-?B and synthesis of cytokines. This might have led to suppression of HSCs activation and liver fibrosis. - Highlights: • Alcohol increases intestinal bacterial overgrowth and permeability of endotoxin. • Endotoxin mediated inflammation plays a major role in alcoholic liver fibrosis. • Ascorbic acid reduces endotoxemia, NF-?B activation and proinflammatory cytokines. • AA's action is by inhibition of SIBO, IKK? and alteration of intestinal permeability. • This might have led to suppression of HSCs activation and liver fibrosis.

Abhilash, P.A.; Harikrishnan, R.; Indira, M., E-mail: indiramadambath@gmail.com

2014-01-15

292

Influence of Trace Elements on Stabilization of Aqueous Solutions of Ascorbic Acid  

OpenAIRE

Together with vitamin C, zinc, selenium, manganese, and magnesium play a vital role in the preservation of organs scheduled for transplantation. In the present study, it is shown that addition of 1 mg/l of these elements influences the stability of 0.3 mM ascorbic acid solutions. The solution’s stability was estimated using an accelerated stability test. The concentration of vitamin C was measured using a validated spectrophotometric method, which uses the reduction of 2,6-dichlorophenolo...

Dolin?ska, Barbara; Ostro?z?ka-cies?lik, Aneta; Caban, Artur; Rimantas, Klimas; Leszczyn?ska, Lucyna; Ryszka, Florian

2012-01-01

293

Silver Colloid Synthesis in Linear and Branched Anionic Polymer Matrices by Using Ascorbic Acid as Reductant  

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Full Text Available Silver colloids were synthesized in linear and branched anionic polymer matrices at different pH reducing by ascorbic acid. The template role of the host polymers in anionic form was studied at pH = 7 and pH = 12. Linear Polyacrylamide and star-like copolymers Dextran-graft-Polyacrylamide after alkaline hydrolysis were used as matrices. Silver colloids were studied by UV-Vis spectrophotometry just after synthesis and in 3 months. It is shown that branched polymer matrices are more efficient in comparison with linear one for in situ silver nanoparticle synthesis. The pH value affects the process of formation was investigated.

Korychenska O.

2013-09-01

294

Influence of osmotic dehydration on ascorbic acid loss in pickled dry peppers (Capsicum chinense)  

OpenAIRE

The objective of this work was (1) to develop a dehydrated pepper with 45% humidity, determining the drying curves for pepper, with and without osmotic pre-treatment and (2) to evaluate the influence of both drying and osmotic treatment on the content ascorbic acid (vitamin C) in fresh pepper and pepper with 45% humidity. The experiments were carried out using the peppers cut in half, with and without osmotic pre-treatment, followed by drying in an oven at 70 ºC. The results showed that the ...

Tissiane Mayara da Silva; Eliana Janet Sanjinez Argandoña; Grasiele Scaramal Madrona; Izabel Cristina Freitas Moraes; Charles Windson Isidoro Haminiuk; Ivanise Guilherme Branco

2012-01-01

295

Electrocatalysis and Determination of Ascorbic Acid Through Graphite Paste Electrode Modified With Iron Nitroprusside  

OpenAIRE

Iron nitroprusside, Fe(II)NP was incorporated into a carbon paste electrode and the electrochemical studies were performed by cyclic voltammetry. The cyclic voltammogram of the modified electrode, Fe(II)NP showed two redox couples ( E½ox)1 = 0.24 and (E½ox)2 = 0.85 V vs. SCE attributed to Fe(II)/Fe(III) and Fe(II)(CN)5NO / Fe(III)(CN)5NO, respectively. The redox couple at (E½ox)1 = 0.24 V presents an electrocatalytic response for ascorbic acid. The modified paste electrode exhibits a decre...

Do Carmo, Devaney R.; Da Silva, Ricardo M.; Stradiotto, Nelson R.

2004-01-01

296

SCREEN-PRINTED ELECTRODE MODIFIED WITH SILVER HEXACY ANOFERRATE-NAFION® FOR ASCORBIC ACID DETERMINATION  

OpenAIRE

A flow injection system using a new and/or re-used graphite screen-printed electrode modified with silver hexacyanoferrate and a Nafion® polymer layer (AgHCF/GSPE) was employed for the determination of ascorbic acid in orange juice and drugs samples. Both modified electrodes showed an initial sensitivity of 0.015 A.cm²?.M¹?, with a linear response over the range from 50 to 300 mg L¹ , relative standard deviations smaller than 2%, detection and quantification limits of c.a. 5.0...

Mattos, I. L.; Padilla, F.; Zagal, J. H.; Falcao, E. H. L.; Segura, R.

2011-01-01

297

Ascorbic Acid and BSA Protein in Solution and Films: Interaction and Surface Morphological Structure  

OpenAIRE

This paper reports on the study of the interactions between ascorbic acid (AA) and bovine serum albumin (BSA) in aqueous solution as well as in films (BSA/AA films) prepared by the layer-by-layer technique. Regarding to solution studies, a hyperchromism (in the range of ultraviolet) was found as a function of AA concentration, which suggested the formation of aggregates from AA and BSA. Binding constant, K, determined for aggregates from BSA and AA was found to be about 102?M?1, which ind...

Souza, Nara C.; Silva, Josmary R.; Trescher, Tarquin F.; Pedro, Graciela C.; Gorza, Filipe D. S.; Almeida, Adriele A.; Godinho, Odin G. C.; Maciel, Rafael R. G.

2013-01-01

298

Exogenous application of ascorbic acid alleviates chilling injury in apricot (Prunus armeniaca L. cv. Shahroudi) flowers  

OpenAIRE

One of the most important limiting factors in spread of apricot in Iran is late spring frost, which damages flower bud and decrease total yield of crop. It has been found that ascorbic acid (AA) plays a beneficial role during plant response to chilling and freezing stresses. To evaluate the effects of AA on alleviating of cold stress, the flower buds of Prunus armeniaca L. cv. Shahroudi were sprayed at pink cluster stage with AS at 4 levels (0, 100, 200 and 300 mg. L-1) and were then exposed ...

Hassan Bayat; Morteza Alirezaie Noghondar; Hossein Neamati; Ahmad Nezami

2013-01-01

299

Effect of Storage Time on Ascorbic Acid Content of Some Selected `Made in Nigeria` Fruit Preserves  

OpenAIRE

The vitamin C content of many "Made in Nigeria" fruit products is not known for sure, since Nutrition Labeling is usually absent. Furthermore the change in the concentration with increasing shelf-life is not certain. Ascorbic acid (vitamin C) content of sixteen different fruit preserves made in Nigeria was assessed, on the day of production and after different lengths of storage time ranging from 3 to 8 months. Six fruit juices, six fruit squashes and four marmalades/jams were analyzed for as...

Sanusi, Rasaki A.; Nwozoh, Sarah; Ogunro, Yetunde

2008-01-01

300

Ascorbic acid induces furanocoumarin production in organ cultures of Glehnia littoralis.  

Science.gov (United States)

Exogenously supplied ascorbic acid (AsA) strongly induced furanocoumarin production in leaf and root cultures of GLEHNIA LITTORALIS, but not in cell suspension cultures, after 24 h of treatment. The dose dependency showed that both organ tissues responded well to AsA supplied at concentrations of 10 - 40 mM. For induction of furanocoumarin production, roots required contact with AsA for at least 6 h and productivity markedly increased after 8 h of treatment. This is the first report of the induction of furanocoumarin biosynthesis by AsA alone and of the detection of furanocoumarin biosynthesis in a root culture system. PMID:18671199

Ishikawa, Aya; Kobayashi, Nobuyuki; Kitamura, Yoshie

2008-10-01

301

Photometric starch-iodine determination in plant materials as influenced by ascorbic acid. Critical remarks  

OpenAIRE

Following the work of Sharma et al. (1990) on the interference of ascorbic acid (AA) with starch-iodine reaction, the present authors repeated it, giving a proper explanation of the influence of AA in this reaction. AA oxidizes iodine-iodide (I-KI) reagent which makes impossible to form the blue complex with starch. Three measures are suggested to overcome the interference of AA: 1) to titrate starch solution with I-KI reagent and thus work out an I-KI amount for development of blue coloratio...

Bogus?aw Samotus; El?bieta Doerre; Adam ?widerski; Andrzej ?cigalski

1994-01-01

302

Voltammetric Oxidation of Ascorbic Acid Mediated by Multi-Walled Carbon Nanotubes/Titanium Dioxide Composite Modified Glassy Carbon Electrode  

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Full Text Available A MWCNT/TiO2 composite was modified onto glassy carbon electrode and fabricated by mechanical attachment, then applied to detection of ascorbic acid using cyclic voltammetry. Electrode responses were obtained for the oxidation of 0.5 mM ascorbic acid at the glassy carbon electrode modified with MWCNT, TiO2, MWCNT/TiO2 composite and an unmodified glassy carbon electrode. A well-defined and highly resolved oxidation peak of ascorbic acid at the MWCNT/TiO2/GCE with current enhancement and peak potential shift toward the origin being observed, this indicates evidence of electrocatalytic process. In comparison with other electrodes, the observed current enhancements at the MWCNT/TiO2/GCE were 1.3 folds higher than those obtained by MWCNT/GCE and 1.5 folds by a bare glassy carbon electrode. The response peak current revealed a good linear relationship of up to 2.5 mM ascorbic acid with correlation coefficient of 0.998. A good detection limit of 4.0 ?M was found using MWCNT/TiO2/GCE. Other usual parameters such as effect of pH, scan rate, temperature, supporting electrolyte and concentration of ascorbic acid were studied.

P. Ganchimeg

2011-01-01

303

Modelling the effects of transglutaminase and L-ascorbic acid on substandard quality wheat flour by response surface methodology  

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Full Text Available In recent decade, there have been observed extreme variations in climatic conditions which in combination with inadequate agro techniques lead to decreased quality of mercantile wheat, actally flour. The application of improvers can optimise the quality of substandard wheat flour. This paper focuses to systematic analysis of individual and interaction effects of ascorbic acid and transglutaminase as dough strengthening improvers. The effects were investigated using the Response Surface Methodology. Transglutaminase had much higher linear effect on the rheological and fermentative properties of dough from substandard flour than L-ascorbic acid. Both transglutaminase and L-ascorbic acid additions had a significant linear effect on the increase of bread specific volume. Effects of transglutaminase and ascorbic acid are dependent on the applied concentrations and it is necessary to determine the optimal concentration in order to achieve the maximum quality of the dough and bread. Optimal levels of tested improvers were determined using appropriate statistical techniques which applied the desirability function. It was found that the combination of 30 mg/kg of transglutaminase and 75.8 mg/kg of L-ascorbic acid achieved positive synergistic effect on rheological and fermentative wheat dough properties, as well on textural properties and specific volume of bread made from substandard quality flour.

Šimurina Olivera D.

2014-01-01

304

Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears  

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Full Text Available Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a ?-carotene-linoleic acid emulsion, and iron (II chelation, the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II-dependent hydroxyl radicals (OH•, in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05 and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05 to the concentration of total phenolic compounds (R2 = 0.90 and ascorbic acid (R2 = 0.86. All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•.

Leonardo Martinez-Cardenas

2011-09-01

305

Betalain, Acid ascorbic, phenolic contents and antioxidant properties of purple, red, yellow and white cactus pears.  

Science.gov (United States)

Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a ?-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R(2) = 0.90) and ascorbic acid (R(2) = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•. PMID:22072899

Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

2011-01-01

306

Ascorbic acid deficiency decreases the renal level of kidney fatty acid-binding protein by lowering the alpha2u-globulin gene expression in liver in scurvy-prone ODS rats.  

Science.gov (United States)

The evidence for the role of ascorbic acid in gene expression or protein synthesis in vivo is limited. To investigate this role of ascorbic acid, we surveyed proteins whose tissue levels are changed by ascorbic acid deficiency by using ODS rats with a hereditary defect in ascorbic acid biosynthesis. Male ODS rats (7 wk old, body weight approximately 130 g) were fed a basal diet containing ascorbic acid (300 mg/kg diet) or an ascorbic acid-free diet for 14 d. Ascorbic acid deficiency decreased a renal protein with an apparent molecular mass of 17 kDa. The amino-terminal amino acid sequence of 16 residues of this 17-kDa protein was identical to a kidney fatty acid-binding protein known to be generated by proteolytic degradation of alpha2u-globulin, a major urinary protein of adult male rats. alpha2u-Globulin is synthesized in liver, secreted into blood and excreted into urine, but partially reabsorbed by renal proximal tubules. It exists in kidney in a proteolytically modified form. Ascorbic acid deficiency lowered the renal level of kidney fatty acid-binding protein to 53% (P ascorbic acid-deficient rats was significantly lower (30%) than that of the control rats. These results suggest that in male ODS rats, ascorbic acid deficiency decreases the renal level of kidney fatty acid-binding protein by lowering alpha2u-globulin gene expression in liver. PMID:9349844

Ikeda, S; Takasu, M; Matsuda, T; Kakinuma, A; Horio, F

1997-11-01

307

Efficient voltammetric discrimination of free bilirubin from uric acid and ascorbic acid by a CVD nanographite-based microelectrode.  

Science.gov (United States)

We report a novel electrochemical sensor based on nanographite grown on platinum microelectrodes for the determination of bilirubin in the presence of normal concentrations of albumin. The albumin is a protein with an intrinsic ability to bind the bilirubin therefore reducing the concentration of the free electroactive metabolite in human fluids. In addition, the proposed device permits the discrimination of free bilirubin from two interferents, uric acid and ascorbic acid, by the separation of their oxidation peaks in voltammetry. Preliminary measurements in human serum prove that the proposed nanostructured platform can be used to detect bilirubin. PMID:25159430

Taurino, Irene; Van Hoof, Viviane; Magrez, Arnaud; Forró, László; De Micheli, Giovanni; Carrara, Sandro

2014-12-01

308

Role of cellular antioxidants (glutathione and ascorbic acid) in the growth and development of wild carrot suspension cultures  

International Nuclear Information System (INIS)

Determinations of endogenous glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AA) and dehydroascorbic acid (DHA) in proliferating and developing wild carrot cultures showed that lower levels of GSH and AA were associated with developing cultures. The GSSG and DHA levels did not account for the changes in the levels of antioxidants between proliferating and developing cultures. Studies were designed to test an observed auxin (2,4-Dichlorophenoxyacetic acid, 2,4-D)-antioxidant association. Two fractions (embryo and less developed) were obtained by screening developed cultures which were previously grown in the presence of 14C-2, 4-D. The embryo fraction had a lower concentration of 14C than the less developed fraction, supporting the association, since the two fractions showed this relationship with respect to GSH and AA concentrations. Determinations of GSH and AA levels of cells grown in various concentrations of 2,4-D showed the association, decreases in the 2,4-D concentration correlated with decreases in the GSH and AA concentrations. The existence of a respiratory pathway involving GSSG reductase, DHA reductase, and AA oxidase was investigated to test whether inhibition of AA oxidase by 2,4-D could explain the auxin-antioxidant association; however, AA oxidase activity was not detected

309

Effects of ascorbic acid supplementation on male reproductive system during exposure to hypoxia  

Science.gov (United States)

Two groups of male rats were exposed to simulated altitudes of 6060 m and 7576 m for 6 h/day for 7 days (intermittent exposure). In two additional groups of animals exposed to the same altitude, 100 mg of ascorbic acid (AA) was fed daily for 5 days prior to the exposure period and also during the exposure period. Rats that did not receive AA showed loss of body weight and weight of reproductive organs after exposure. Sex organs showed atrophy on histological examination and there was a deterioration in spermatozoal quality. There was an increase in alkaline and acid phosphatase, and decrease in protein, sialic acid and glyceryl phosphorylcholine content in various reproductive tissues after exposure. All the above changes in histology and biochemical composition could be partially prevented by AA supplementation. AA supplementation can therefore protect the male reproductive system from deleterious effects of hypoxia. The probable mechanism of action of AA is discussed.

Havazhagan, G.; Riar, S. S.; Kain, A. K.; Bardhan, Jaya; Thomas, Pauline

1989-09-01

310

Determination of Vitamin C (Ascorbic Acid Using High Performance Liquid Chromatography Coupled with Electrochemical Detection  

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Full Text Available Vitamin C (ascorbic acid, ascorbate, AA is a water soluble organic compound that participates in many biological processes. The main aim of this paper was to utilize two electrochemical detectors (amperometric – Coulouchem III and coulometric – CoulArray coupled with flow injection analysis for the detection of ascorbic acid. Primarily, we optimized the experimental conditions. The optimized conditions were as follows: detector potential 100 mV, temperature 25 °C, mobile phase 0.09% TFA:ACN, 3:97 (v/v and flow rate 0.13 mL·min-1. The tangents of the calibration curves were 0.3788 for the coulometric method and 0.0136 for the amperometric one. The tangent of the calibration curve measured by the coulometric detector was almost 30 times higher than the tangent measured by the amperometric detector. Consequently, we coupled a CoulArray electrochemical detector with high performance liquid chromatography and estimated the detection limit for AA as 90 nM (450 fmol per 5 μL injection. The method was used for the determination of vitamin C in a pharmaceutical preparations (98 ± 2 mg per tablet, in oranges (Citrus aurantium (varied from 30 to 56 mg/100 g fresh weight, in apples (Malus sp. (varied from 11 to 19 mg/100 g fresh weight, and in human blood serum (varied from 38 to 78 μM. The recoveries were also determined.

Ondrej Zitka

2008-11-01

311

Rheological Characteristics of Gluten after Modified by DATEM, Ascorbic Acid, Urea and DTT Using Creep-Recovery Test  

OpenAIRE

The effects of diacetyl tartaric acid ester of monoglycerides (DATEM), ascorbic acid (AA), urea, and dithiothreitol (DTT) on viscoelastic properties of commercial hard red winter wheat gluten were investigated. A constant shear stress of 40 Pa was applied to gluten during creep-recovery test. Experimental creep-recovery compliance responses were fitted into a Burgers model with four elements accounting fo...

Pavalee Chompoorat; Amogh Ambardekar; Steven Mulvaney; Patricia Rayas-Duarte

2013-01-01

312

Sol-gel process for preparing YBa2Cu4O8 precursors from Y, Ba, and Cu acidic acetates/ammonia/ascorbic acid systems  

International Nuclear Information System (INIS)

Sols were prepared by addition of ammonia to acidic acetate solutions of Y3+, Ba2+, and Cu2+. Ascorbic acid was added to a part of the sol. The resultant sols were gelled to a shard, a film, or microspheres by evaporation at 60 C or by extraction of water from drops of emulsion suspended in 2-ethylhexanol-1. Addition of ethanol to the sols facilitated the formation of gel films, fabricated by a dipping technique, on glass or silver substrates. At 100 C, gels that were formed in the presence of ascorbic acid were perfectly amorphous, in contrast to the crystalline acetate gels. Conversion of the amorphous ascorbate gels to final products was easier than for the acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings

313

The effect of 2,4-dichlorophenol on lipid peroxidation in tissues of guinea pigs with different ascorbic acid intake.  

Science.gov (United States)

Chlorinated phenols are widely used in the manufacture of biocides and wood preservatives. 2,4-dichlorophenol administered perorally 3 times a week at a dose of 40 mg in 0.2 ml of olive oil per kg of body weight to guinea pigs increased lipid peroxidation in liver and adrenals after 2 weeks of treatment. A high intake of ascorbic acid (50 mg/animal/day) significantly decreased lipid peroxidation in the liver of 2, 4-dichlorophenol treated guinea pigs in comparison to guinea pigs with low ascorbic acid intake (2 mg/animal/day). 2,4-dichlorophenol accumulation was also decreased in the liver of animals with high ascorbic acid intake. Increased daily intake of vitamin C to persons involved in production and use of chlorophenoxy herbicides is recommended. PMID:8908852

Clerhata, D; Kováciková, Z; Veningerová, M; Lukácsová, M; Ginter, E

1996-01-01

314

A novel method for the determination of ascorbic acid and antioxidant capacity in Opuntia ficus indica using in vivo microdialysis.  

Science.gov (United States)

A simple and rapid method was developed for in vivo simultaneous determination of ascorbic-acid and antioxidant capacity in microdialysates from cladodes of Opuntia ficus-indica (L.) Miller. The method is verified in water-stressed plants, as compared with a well-watered test controls. The microdialysis probe construction and insertion procedure was specifically developed to minimise the tissue trauma of the plant and to obtain optimal dialysis performance. Microdialysis was performed using a flow rate of 3 ?L/min and the samples were analysed by HPLC coupled to electrochemical detection of ascorbic-acid and DPPH-determined antioxidant capacity. Our data indicate exponential decay of the concentrations of the analysed compounds as a function of microdialysis sampling time. Water-stressed Opuntia show decreased ascorbic acid levels and increased the others antioxidants. PMID:24206696

Pretti, L; Bazzu, G; Serra, P A; Nieddu, G

2014-03-15

315

The ameliorative effect of ascorbic acid and Ginkgo biloba on learning and memory deficits associated with fluoride exposure.  

Science.gov (United States)

Chronic exposure to fluoride causes dental and skeletal fluorosis. Fluoride exposure is also detrimental to soft tissues and organs. The present study aimed at evaluation of the effect of Ginkgo biloba and ascorbic acid on learning and memory deficits caused by fluoride exposure. Male Wistar rats were divided into five groups (n=6). Group 1 control. Groups 2 to 5 received 100 ppm of sodium fluoride over 30 days. Groups 3, 4 and 5 were further treated for 15 days receiving respectively 1% gum acacia solution, 100 mg/kg body weight ascorbic acid, and 100mg/kg body weight Ginkgo biloba extract. After 45 days, all animals were subjected to behavioural tests. The results showed that fluoride affected learning and memory. Fluoride causes oxidative stress and neurodegeneration, thereby affecting learning and memory. Ascorbic acid and Ginkgo biloba were found to augment the reversal of learning and memory deficits caused by fluoride ingestion. PMID:24678261

Raghu, Jetti; Raghuveer, Vasudeva C; Rao, Mallikarjuna C; Somayaji, Nagabhooshana S; Babu, Prakash B

2013-12-01

316

Effect of ascorbic acid on reduced glutathione level in arsenic-loaded isolated liver tissues of rat  

Directory of Open Access Journals (Sweden)

Full Text Available Isolated liver tissues of rat were loaded with trivalent arsenic and were exposed in presence and absence of ascorbic acid. The amount of reduced glutathione (GSH in normal liver tissue was 52.0 ? 0.2 ?g/g protein. Addition of arsenic to the tissues reduced the amount of GSH to 11.5 ? 0.3 ?g/g protein. But when the arsenic loaded liver tissues were incubated with ascorbic acid at the concentration of 20 ?g/ml, the amount of GSH was 14.2 ? 0.1 ?g/g protein. There was 22.6% increase of GSH level which was statistically significant (p<0.001 when compared with arsenic alone. This study suggests that ascorbic acid increased the GSH level in arsenic-treated rat's liver.

Beauty Saha

2006-12-01

317

Antioxidant capacity and contents of phenols, ascorbic acid, ?-carotene and lycopene in lettuce  

Directory of Open Access Journals (Sweden)

Full Text Available The antioxidant activity of three lettuce varieties (Lactuca sativa L. Emerald, Vera and Neva, cultivated in two kinds of protected spaces, a glasshouse and a plastic greenhouse, under controlled conditions, was determined. The content of antioxidant compounds: total phenols, flavonoids, L-ascorbic acid, ß-carotene and lycopene, were determined in ethanolic extracts of the lettuce with spectrophotometric methods. The largest content of total phenols (78.98 ± 0.67 mg GAE/g of dry extract was found in ethanolic extract of the lettuce variety Neva cultivated in a plastic greenhouse, whereas the largest content of flavonoids (35.45 ± 0.95 mg RU/g of dry extract was displayed in the lettuce Emerald cultivated in a glasshouse. It was observed that the lettuce cultivated in the glasshouse contained a somewhat higher content of L-ascorbic acid than the lettuce same variety from plastic greenhouse. The content of lycopene in the examined lettuce is negligible, and the content of ß-carotene is low. On the other hand, the high content of phenolic components causes favourable antioxidant properties found in all varieties of examined lettuce. [Projekat Ministarstva nauke Republike Srbije, br. TR 31059: A new concept in breeding vegetable cultivars and hybrids designed for sustainable growing systems using biotechnological methods

Zdravkovi? Jasmina M.

2014-01-01

318

Iodine application increased ascorbic acid content and modified the vascular tissue in opuntia ficus-indica  

International Nuclear Information System (INIS)

The objective of this study was to discern the effect of applying both iodide and iodate to Opuntia ficus indica irrigation. The effect of iodate (KIO/sub 3/, 10-4 M) and iodide (KI, 10-4 M) on plant growth, yield and morphology was studied. Experiments were carried in three samples under tunnel conditions. In the last sampling, iodine species (KIO/sub 3/, KI) caused a negative effect in biomass. The amount of ascorbic acid, however, was increased over 51% in both iodine treatments. Phosphorus (0.26%), iron (50 ppm), and magnesium (1402 ppm) increases were also observed with iodate treatment in the first sampling, and increases in potassium (46.8 ppm) were apparent in the second. Iodide treatment increased the amounts of copper (1.02 ppm) and manganese (32.80 ppm) in the first sampling. Iodate treatment modified the number of xylem vessels and increased both the mucilage area and amount of druses. In general this study shows that iodate increases the amount of ascorbic acid and the morphology of the vascular tissue. (author)

319

Ascorbic Acid Content in Extractive Aqueous Solutions of Rosa canina L. Fruits  

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Full Text Available The main goal of the hereby study is two folded: first, to mark out the most adequate methods of preparing the watery solution extracts (infusions, decoctions in order to obtain a high content of ascorbic acid, and second, to identify the most suitable method for determining this vitamin in aqueous solution extracts made out of medicinal herbs. In this experiment six groups were assembled containing 20 fruit samples each. The samples were analyzed one week, one and a half month and three months, respectively, after gathering. Fruit drying was accomplished either in open air, at room temperature, or artificially, for three days, in 15 minutes intervals at 95°C (in the exicator, followed again by room temperature drying. Preparation of each group was different: it comprised either pickling in cold water for 10 hours, followed by sinking in cold water, boiling and then cooling, or sinking the fruits in boiling water followed by cooling, or sinking the fruits in boiling water followed by boiling the solution for five or 10 minutes, or, finally, by infusion and decoction method. The results obtained through the Tillmans method revealed a high level of ascorbic acid when the fruits were immersed into boiling water (100°C and boiled in open fire (11.02 ± 1.51 mg % for five minutes or when they were introduced in boiling water and kept covered in the boiling basin for 30 minutes (12.26 ± 0.55mg %.

Veturia-Ileana Nueleanu

2008-03-01

320

Investigating Ascorbic Acid Effect in Prevention of CIN in Diabetic Patients  

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Full Text Available Introduction: Contrast induced nephropathy (CIN is one the complications resulting from coronary catheterization and is regarded as one of the reasons of acute kidney failure. Therefore, this study aimed to investigate the effect of ascorbic acid in the prevention of CIN in Yazd in 2012. Methods: This study involves a double blind clinical trial in which 90 Diabetic patients with coronary catheterization have attended. The patients were divided randomly into two groups: control group and treatment group. Demographic and clinical data were collected by a questionnaire. Treatment group received vitamin C (2 grams 2 hours before the intervention and the control groups were given 2 grams of the Placebo. The GFR (Glomerular filtration rate, BUN (Blood Urea Nitrogen, and Cr (Creatinin were measured and compared after 2-3 days. Results: The CIN in treatment group was about 3 patients (7.7% and was 7 (16.7% in the control group. Thus, no significant difference was observed; though, there was a significant difference between Cr and GFR before and after the treatment in vitamin C group (PV= 0.006, PV=0.001, but these differences were not significant in the placebo group.(PV=0.661, PV=0.747. Moreover, considering the participants’ age, sex and their primary function of kidney, a significant difference had not appeared due to the incidence of CIN between the two groups. Conclusion: Our study did not show Ascorbic Acid effects in prevention of CIN in Diabetic patients.

Nough

2013-06-01

321

Hepato-protective effect of ascorbic acid on oxidative stress in mic exposed to cypermethrin  

International Nuclear Information System (INIS)

To evaluate protective effect of ascorbic acid on liver parameters in mice exposed to Cypermethrin. Study Design:Laboratory based randomized control trial. Place and Duration of Study: Research was conducted in Army Medical College's biochemistry and molecular biology department in association with department of pathology, Army Medical College, Rawalpindi and National Institute of Health, Islamabad, Pakistan from 19 May 2013 to 17 June 2013. Material and Methods: Thirty albino mice of Balb/C strain weighing 40-45g were randomly divided into three groups. Each group comprised 10 mice. Control group A which received normal diet. Cypermethrin experimental group B received cypermethrin with normal diet experimental group C which received cypermethrin and vitamin C with normal diet. This process continued for 28 days. After this duration serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST) values were determined. Results: Serum ALT and AST levels were significantly increased in group B as compared to group A (p< .001). ALT levels of group A and group C were insignificant (p= 0.473). AST levels of group A and C were significantly different (p< 0.01). Conclusion: Ascorbic acid can protect liver from Cypermethrininduced oxidative stress in mice. (author)

322

Effect of morphine on striatal dopamine metabolism and ascorbic and uric acid release in freely moving rats  

OpenAIRE

Recent ex vivo findings have shown that morphine increases dopamine (DA) and xanthine oxidative metabolism and ascorbic acid (AA) oxidation in the rat striatum. In the present study, we evaluated the effects of subcutaneous daily morphine (20 mg/kg) administration on DA, dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), AA and uric acid in the striatum of freely moving rats using microdialysis. Dialysates were assayed by high performance liquid chromatography with electrochemical d...

Enrico, Paolo; Esposito, Giovanni; Mura, Maria A.; Fresu, Luigia Grazia; Natale, Guglielmo; Miele, Egidio; Desole, Maria Speranza; Miele, Maddalena

1997-01-01

323

Corrosion behaviours of AISI 304 stainless steel and Inconel-600 in EDTA/citric acid/ascorbic acid base decontamination solution  

International Nuclear Information System (INIS)

Corrosion behaviours of AISI 304 stainless steel (SS) and Inconel-600 in dilute EDTA/citric acid/ascorbic acid solution of pH = 2.8 have been studied at 95 .deg. C with electrochemical polarization, weight loss measurement and metallographic observation. Polarization curves on AISI 304 SS were very similar to those on Inconel-600 in all solutions except a slightly higher passive current density on Inconel-600. Anodic polarization curves on AISI 304 SS and Inconel-600 in EDTA/citric acid mixture were also similar to those in EDTA solution. A passive region was found over the range of potential from-300 mV to 400 mV in EDTA solution as well as in EDTA/citric acid mixture. The passive current density in EDTA solution and in EDTA/citric acid mixture dose not depend on both kinds and concentration of chemicals in the experimental range. In case of EDTA/ascorbic acid mixture, the anodic current density was exactly the same with that in EDTA/citric acid mixture at potential below 100 mV. The higher anodic current density in EDTA/ascorbic acid mixture than in EDTA/citric acid mixture, however, was observed at potential above 100 mV. The metal oxidation current density calculated from weight loss at 400 mV in EDTA/ascorbic acid mixture was almost equal to that in EDTA/citric acid mixture. And anodic oxidation of chemicals on Pt increased with a sequence of citric acid, EDTA and ascorbic acid. So the higher anodic current in EDTA/ascorbic acid mixture than in EDTA/citric acid mic acid mixture than in EDTA/citric acid mixture was due to ascorbic acid oxidation. Those results indicated that EDTA, citric acid and ascorbic acid have no influence on corrosion behaviours of AISI 304 SS and Inconel-600 in the passive region. In all solutions passive current density was about 3 ? 5 ? A/cm2, and corrosion current density was about 1 ? 5 ? A. No pitting and intergranular corrosion were observed over the range of potential from 300 mV to 400 mV

324

Effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in mice exposed to cocaine  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: To investigate the effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in experimental animals exposed to cocaine. Materials and Methods: Mice were used in this study and were divided randomly into different groups of six animals each. They were either treated with intraperitoneal injection of saline or cocaine hydrochloride or an oral feeding of oil of Ocimum sanctum, ascorbic acid or verapamil, or both (ascorbic acid and verapamil, and were evaluated for a respiratory burst of macrophages, superoxide and nitric oxide (NO production, estimation of TNF-a in the serum and supernatant of cultured macrophages, estimation of lipid peroxidation (malondialdehyde- MDA in the serum, and superoxide dismutase activity in the erythrocytes. Results: Unstimulated respiratory burst as well as superoxide production was enhanced on treatment with cocaine and all the three drugs were found to attenuate this enhancement. The bactericidal capacity of macrophages decreased significantly on chronic cocaine exposure, as it was associated with decreased respiratory burst and superoxide production. There was a significant decrease in NO production by macrophages on chronic cocaine exposure and all the test drugs were found to restore nitrite formation to a normal level. There was an increase in the malonylodialdehyde (MDA level and decrease in the superoxide dismutase level on chronic cocaine exposure, and all the three drugs effectively decreased the MDA level and increased superoxide dismutase level. There was an increase in serum TNF-? on chronic cocaine exposure, which was decreased significantly by ascorbic acid and verapamil. Conclusion: O. sanctum, ascorbic acid, and verapamil were equally effective in improving the macrophage function and reducing oxidative stress. These findings suggested that O. sanctum, ascorbic acid, and verapamil attenuated acute and chronic cocaine-mediated effects.

Bhattacharya S

2009-01-01

325

Ascorbate supplementation inhibits growth and metastasis of B16FO melanoma and 4T1 breast cancer cells in vitamin C-deficient mice  

OpenAIRE

Degradation of the extracellular matrix (ECM) plays a critical role in the formation of tumors and metastasis and has been found to correlate with the aggressiveness of tumor growth and invasiveness of cancer. Ascorbic acid, which is known to be essential for the structural integrity of the intercellular matrix, is not produced by humans and must be obtained from the diet. Cancer patients have been shown to have very low reserves of ascorbic acid. Our main objective was to determine the effec...

Cha, John; Roomi, M. Waheed; Ivanov, Vadim; Kalinovsky, Tatiana; Niedzwiecki, Aleksandra; Rath, Matthias

2013-01-01

326

DNA-decorated nanoparticles as nanosensors for rapid detection of ascorbic acid.  

Science.gov (United States)

We designed an assay for rapid detection of ascorbic acid (AA) with a DNAzyme cleaving its DNA substrate in the presence of Cu(2+) and AA. The sensor consists of two DNA strands that form a complex between each other. The 5'-end of the DNAzyme binds the substrate DNA via Watson-Crick bonding and the 3'-end binds through formation of a DNA-triplex via Hoogsteen hydrogen bonding. The substrate DNA was prepared by two different methods. In the first case the nucleic acid was modified with fluorescein/dabcyl FRET pair across the cleavage site. In the second case the nucleic acid modified with fluorescein was immobilised on gold nanoparticles. DNAzyme contains a loop forming a complex with Cu(2+) ions. The oxidation of ascorbic acid (AA) with oxygen yields hydrogen peroxide. The latter interacts with Cu(2+) to give hydroxyl radicals. They break substrate DNA in close vicinity to the copper/DNA complex to separate fluorescein from gold nanoparticles leading to the increase in fluorescence intensity. Use of substrate DNA modified with the fluorescein/dabcyl couple allowed to measure AA concentration within 3 min with the detection limit of 2.5 ?M. Employment of gold nanoparticles decorated with fluorescein-modified DNA allowed to improve the detection limit of AA quantification by two orders of magnitude due to enhanced cleavage of DNA catalysed by Au clusters. Fructose, sucrose, glucose, urea, and citric acid did not interfere with our assay even at concentration of 1mM. Good selectivity allowed us to apply our rapid and sensitive assays to detection of AA in vitamin C tablets, urine and orange juice. PMID:22317836

Malashikhina, Natalia; Pavlov, Valeri

2012-03-15

327

Determination of Ascorbic Acid Content of Some Fruit Juices and Wine by Voltammetry Performed at Pt and Carbon Paste Electrodes  

OpenAIRE

A method was developed for assessing ascorbic acid concentration in fruit juices and wine by differential pulse voltammetry. The oxidation peak for ascorbic acid occurs at about 530 mV (versus SCE) on a Pt strip working electrode and at about 470 mV on a carbon paste working electrode. The influence of the operational parameters like the pulse amplitude and the pulse period on the analytical signal was investigated. The obtained calibration graph shows a linear dependence between the peak hei...

Aurel Pisoschi; Aurelia Magdalena Pisoschi; Aneta Pop; Gheorghe Petre Negulescu

2011-01-01

328

Determination of Proximate Composition, Ascorbic Acid and Heavy Metal Content of African Walnut (Tetracarpidium conophorum)  

OpenAIRE

The proximate composition, ascorbic acid and heavy metal content of (African walnut) Tetracarpidium conophorum were evaluated using chemical analysis. The result of the proximate composition showed the following; moisture (48.70%), carbohydrate (53.20%), crude protein (35.22%), crude fat (6.21%), crude fiber (3.34%) and ash (2.03%).It also contained 53.50mg/100ml of ascorbic acid. The heavy metal concentrations in the fruit is Fe (0.064ppm), Mn (0.012ppm), Cr (0.001ppm), Ni (0.00...

Edem; Dosunmu, Christopher A.; Miranda I.; Bassey Francesca I.

2009-01-01

329

Effect of pre and post treatment of ascorbic acid on wheat and maize seeds exposed to gamma radiation  

International Nuclear Information System (INIS)

Seeds treated with and grown in the presence of ascorbic acid (AA) showed reduction in germination, seedling height and chlorophyll content. The LD50 of AA was found to be 0.7 M and 10 M for wheat and maize, respectively. Pre-irradiation treatment of the seeds with ascorbic acid showed relatively increased germination, seedling height and chlorophyll content compared to that of AA treatment after irradiation. The protection rendered by the pre-treatment of AA may be due to AA acting as a free radical scavenger and thus protecting seeds from radiation induced damages. (author)

330

Estimation of Thiamin and Ascorbic Acid Contents in Fresh and Dried Hibiscus sabdarriffa (Roselle) and Lactuca sativa (Tettuce)  

OpenAIRE

The utilization of locally available vegetables is limited due to lack of information and knowledgeon their nutritive values. The thiamin and ascorbic acid content of both fresh and dried leaves of Hibiscussahdarriffa and Lactuca sativa was investigated. The result revealed that the thiamin content of dried and freshHibiscus sabdarrjffa was 0.00194mg/g and 0.75mg/g respectively. The thiamin content of dried and freshLactuca sativa were 0.00139mg/g and 15.08mg/g respectively. The ascorbic acid...

Sarkiyayi, S.

2010-01-01

331

Expression profiling of ascorbic acid-related genes during tomato fruit development and ripening and in response to stress conditions  

DEFF Research Database (Denmark)

L-Ascorbate (the reduced form of vitamin C) participates in diverse biological processes including pathogen defence mechanisms, and the modulation of plant growth and morphology, and also acts as an enzyme cofactor and redox status indicator. One of its chief biological functions is as an antioxidant. L-Ascorbate intake has been implicated in the prevention/alleviation of varied human ailments and diseases including cancer. To study the regulation of accumulation of this important nutraceutical in fruit, the expression of 24 tomato (Solanum lycopersicon) genes involved in the biosynthesis, oxidation, and recycling of L-ascorbate during the development and ripening of fruit have been characterized. Taken together with L-ascorbate abundance data, the results show distinct changes in the expression profiles for these genes, implicating them in nodal regulatory roles during the process of L-ascorbate accumulation in tomato fruit. The expression of these genes was further studied in the context of abiotic and post-harvest stress, including the effects of heat, cold, wounding, oxygen supply, and ethylene. Important aspects of the hypoxic and post-anoxic response in tomato fruit are discussed. The data suggest that L-galactose-1-phosphate phosphatase could play an important role in regulating ascorbic acid accumulation during tomato fruit development and ripening.

Ioannidi, Eugenia; Kalamaki, Mary S.

2009-01-01

332

Biomarkers of lead exposure in petrol station attendants and auto-mechanics in Abeokuta, Nigeria: effect of 2-week ascorbic acid supplementation.  

Science.gov (United States)

In order to study the ameliorative effects of ascorbic acid in chronic lead poisoning, petrol station attendants and auto-mechanics in Abeokuta, Nigeria, who have been shown to be occupationally exposed to lead and university students (serving as control), were supplemented daily with 500mg ascorbic acid for 2 weeks. Blood and urine samples were collected from the subjects before and after ascorbic acid regimen and analysed for lead and biochemical effects associated with lead toxicity. The 2-week ascorbic acid supplementation resulted in a significant (P lead in the occupationally exposed subjects. The reduction in blood lead amounted to 57% in male petrol station attendants, 50% in female petrol station attendants and 44% in the auto-mechanics. Urinary excretion of lead increased remarkably in the occupationally exposed subjects (P lead also responded positively to the ascorbic acid regimen. Plasma and urine aminolevulinic acid (ALA) were reduced significantly (P lead poisoning. PMID:21782728

Onunkwor, B; Dosumu, O; Odukoya, O O; Arowolo, T; Ademuyiwa, O

2004-07-01

333

Boric acid and boronic acids inhibition of pigeonpea urease.  

Science.gov (United States)

Urease from the seeds of pigeonpea was competitively inhibited by boric acid, butylboronic acid, phenylboronic acid, and 4-bromophenylboronic acid; 4-bromophenylboronic acid being the strongest inhibitor, followed by boric acid > butylboronic acid > phenylboronic acid, respectively. Urease inhibition by boric acid is maximal at acidic pH (5.0) and minimal at alkaline pH (10.0), i.e., the trigonal planar B(OH)3 form is a more effective inhibitor than the tetrahedral B(OH)4 -anionic form. Similarly, the anionic form of phenylboronic acid was least inhibiting in nature. PMID:17059182

Reddy, K Ravi Charan; Kayastha, Arvind M

2006-08-01

334

Fabrication of solid lipid microcapsules containing ascorbic acid using a microfluidic technique.  

Science.gov (United States)

The importance of ascorbic acid (AA) in the human diet has motivated food researchers to develop AA-fortified food products. However, this compound is very unstable. The aim of this work was to produce solid lipid microcapsules (SLMs) loaded with AA using microfluidic technology. The morphology of the SLMs was analysed by optical, scanning electron and confocal microscopy. We determined the encapsulation efficiency, particle size and stability of the encapsulated material. Two different means of enhancing the encapsulation efficiency and stability of AA were demonstrated: a pore blocking method and a micromolecule-chelating agent within the core. The results indicated the enormous potential of the designed vehicle to prevent AA degradation in a food product; additionally, this vehicle could mask the acidic taste of AA. PMID:24444936

Comunian, Talita A; Abbaspourrad, Alireza; Favaro-Trindade, Carmen S; Weitz, David A

2014-01-01

335

The use of L-ascorbic acid in speciation of arsenic compounds in drinking water  

Directory of Open Access Journals (Sweden)

Full Text Available Arsenic speciation, besides total arsenic content determination, is very important in analysis of water, foodstuffs, and environmental samples, because of varying degrees of toxicity of different species. For such purpose hydride generation atomic absorption spectrometry can be used based on the generation of certain types of hydride, depending on the pH value and pretreatment in different reaction media. In this study, we have investigated the effect of L-ascorbic acid as the reaction medium as well as the pre-reducing agent in speciation of arsenic by hydride generation-atomic absorption spectrometry in order to determine monomethyl arsonic acid (MMA in the presence of inorganic forms of arsenic.

Marjanovi? Nikola J.

2009-01-01

336

Functionalization of conducting polymer with novel Co(II) complex: Electroanalysis of ascorbic acid  

Energy Technology Data Exchange (ETDEWEB)

We report for the first time the functionalization of a conducting polymer with a metal complex in order to develop a new type of catalytic material exhibiting better electronic communication through their delocalized {pi} electrons. The Co(II) complex having hydroxyl group as functional moiety is chemically coupled with carboxyl group of polyanthranilic acid which itself is a self doped conducting polymer. The covalent linkage between Co(II) and -OH group is confirmed using UV-vis, FT-IR and NMR spectroscopic techniques. The Co(II) complex functionalized polymer does exhibit excellent redox behavior and stability with mixed properties of Co(II) complex and {pi}-conjugated polymer. The material possesses potential benefits in sensors/biosensor applications and it is demonstrated for the electroanalysis of ascorbic acid at a level of nano molar concentration.

Mohan, Swati [School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Varanasi 221005 (India); Prakash, Rajiv, E-mail: rajivprakash12@yahoo.com [School of Materials Science and Technology, Institute of Technology, Banaras Hindu University, Varanasi 221005 (India)

2010-06-15

337

Functionalization of conducting polymer with novel Co(II) complex: Electroanalysis of ascorbic acid  

International Nuclear Information System (INIS)

We report for the first time the functionalization of a conducting polymer with a metal complex in order to develop a new type of catalytic material exhibiting better electronic communication through their delocalized ? electrons. The Co(II) complex having hydroxyl group as functional moiety is chemically coupled with carboxyl group of polyanthranilic acid which itself is a self doped conducting polymer. The covalent linkage between Co(II) and -OH group is confirmed using UV-vis, FT-IR and NMR spectroscopic techniques. The Co(II) complex functionalized polymer does exhibit excellent redox behavior and stability with mixed properties of Co(II) complex and ?-conjugated polymer. The material possesses potential benefits in sensors/biosensor applications and it is demonstrated for the electroanalysis of ascorbic acid at a level of nano molar concentration.

338

Modified gold electrodes based on thiocytosine/guanine-gold nanoparticles for uric and ascorbic acid determination  

International Nuclear Information System (INIS)

The present paper describes the preparation of new modified surfaces for electrodes based on guanine/thiocytosine and gold nanoparticles. The gold nanoparticles were analyzed by UV–vis spectroscopy and transmission electron microscopy (TEM) and it was found that they have diameters between 30 and 40 nm. The layers were characterized by specular reflectance infrared spectroscopy (FTIR-RAS) and by atomic force microscopy (AFM). The thickness of layers was found to be approximately 30 nm for TC layers and 300 nm for GU layers. Every layer was characterized as electrochemical sensor (by cyclic voltammetry) both for uric acid and ascorbic acid determinations, separately and in their mixture. The modified sensors have good calibration functions with good sensitivity (between 1.145 and 1.406 mA cm?2/decade), reproducibility (thiocytosine (AuTC) and goldguanine (AuGU) layers

339

The metabolism of L-[6-14C] ascorbic acid in detached grape leaves  

International Nuclear Information System (INIS)

Grape leaves (Vitis labrusca L.) that are removed from the position opposite the flower cluster either 28 or 14 days before anthesis cleave L-ascorbic acid (AA) at the C4-C5 bond into a C4 and, presumably, a C2 fragment. Leaves taken from this position 14 days after anthesis fail to cleave AA. The C4 fragment is utilized for L(+)-tartaric acid (TA) biosynthesis while the C2 fragment is recycled into hexose and products of the hexose metabolism. When ( 6-14C ) AA is the source of the label, the sucrose-drived glucose from labeled leaves has a distribution of 14C in the carbon skeleton as follows: C1, 35%; C2, 14%; C3, 4%; C(4 + 5), 13% and C6, 34%. The effect of inhibitors of the glycolate pathway on ( 6-14C ) AA metabolism is examined. (author)

340

L-ascorbic acid quenching of singlet delta molecular oxygen in aqueous media: generalized antioxidant property of vitamin C  

International Nuclear Information System (INIS)

L-ascorbic acid quenches singlet (1?/sub g/) molecular oxygen in aqueous media (pH 6.8 for [1H]H2O and pD 7.2 for (2H)D2O) as measured directly by monitoring (0,0) 1?/sub g/ ? 3?/sub g/- emission at 1.28 micron. Singlet oxygen was generated at room temperature in the solutions via photosensitization of sodium chrysene sulfonate; this sulfonated polycyclic hydrocarbon was synthesized to provide a water soluble chromophore inert to usual dye-ascorbate photobleaching. A marked isotope effect is found; k/sub Q//sup H2O/ is 3.3 times faster than k/sub Q//sup D2O/, suggesting ascorbic acid is chemically quenching singlet oxygen

341

On the mechanism of d-amphetamine-induced changes in glutamate, ascorbic acid and uric acid release in the striatum of freely moving rats  

OpenAIRE

1 The effects of systemic, intrastriatal or intranigral administration of d-amphetamine on glutamate, aspartate, ascorbic acid (AA), uric acid, dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in dialysates from the striatum of freely-moving rats were evaluated using microdialysis. 2 d-Amphetamine (2 mg kg?1) given subcutaneously (s.c.) increased DA, AA and uric acid and decreased DOPAC+HV...

Miele, Maddalena; Mura, Maria A.; Enrico, Paolo; Esposito, Giovanni; Serra, Pier Andrea; Migheli, Rossana; Zangani, Danilo; Miele, Egidio

2000-01-01

342

Mechanism of degradation and discoloration reaction of L-ascorbic acid  

International Nuclear Information System (INIS)

The mechanisms of decomposition and coloration reaction of L-ascorbic acid are reviewed. At the initial stage of the decomposition, it can be classified roughly into oxidative and non-oxidative processes of decomposition. ASA forms furfural by being heated and decomposed in strong acid. The mechanism of the production of furfural at varying pH in acidic region was discussed. Furfural was produced through the enol form of 3-deoxy-L-pentosulose(3DP). 3DP seemed to be produced by two different routes: the one route consists of successive reactions from ASA through lactone ring-opening, dehydration, decarboxylation, to 3DP, and the other consists of reactions from the 3-keto form of ASA, through lactone ring-opening, decarboxylation, and dehydration, to the enol form of 3DP. ASA is easily reduced and decomposed through dehydro-ASA(DHA) by the presence of an oxidizing agent. The decomposition of DHA is discussed in cases of the systems of DHA alone, DHA and ?-aminoacid, and DHA and amine. DHA was decomposed by the same reaction scheme as the decomposition of ASA and yielded 2-furoic acid. In the presence of an amino acid, DHA was decomposed by the Strecker decomposition, and yielded a red compound and a radical. In the presence of an amine, the discoloration reaction seemed to take place through radical reaction mechanism. The coloration reaction of ASA occurs in an acidic medium, and is accelerated by the oxidative process of decomposition. (Nishino, S.)mposition. (Nishino, S.)

343

Effects of ozone on apoplast/cytoplasm partitioning of ascorbic acid in snap bean  

Energy Technology Data Exchange (ETDEWEB)

Apoplast/cytoplasm partitioning of ascorbic acid (AA) was examined in four genotypes of snap bean (Phaseolus vulgaris L.) known to differ in ozone sensitivity. Plants were grown in pots under field conditions using open-top chambers to establish charcoal-filtered (CF) air (36 nmol mol{sup -1} ozone) or elevated ozone (77 nmol mol{sup -1} ozone) treatments, AA in fully expanded leaves of 36-day-old plants was separated into apoplast and cytoplasm fractions by vacuum infiltration methods using glucose 6-phosphate as a marker for cytoplasm contamination, Apoplast ascorbate levels ranged from 30 to 150 nmol g{sup -1} fresh weight. Ozone-sensitive genotypes partitioned 1-2% of total AA into the apoplast under CF conditions and up to 7% following a 7-day ozone exposure. In contrast, an ozone-tolerant genotype partitioned 3-4% of total leaf AA into the leaf apoplast in both CF and ozone-treated plants. The results suggest that genetic background and ozone stress are factors that affect AA levels in the extracellular space. For all genotypes, the fraction of AA in the oxidized form was higher in the apoplast compared to the cytoplasm, indicative of a more oxidizing environment within the cell wall. (au)

Burkey, K.O. [North Carolina State Univ., Dept. of Crop Science and Botany, Raleigh, NC (United States)

1999-07-01

344

Serum Angiotensin Converting Enzyme Activity, Total Antioxidants and Ascorbic Acid in Iranian Patients with Coronary Artery Disease  

Directory of Open Access Journals (Sweden)

Full Text Available Angiotensin-Converting Enzyme (ACE is a dipeptidyl carboxypeptidase (EC: 3.4.15.1 that catalyzes the conversion of angiotensin I to the potent vasoconstrictor angiotensin II. Angiotesin II is responsible for an increase in blood pressure and maintenance of hypertension through the stimulation of oxidative stress. The relationship between Coronary Artery Disease (CAD, Angiotensin-Converting Enzyme (ACE activity, ascorbic acid and serum antioxidant status in patients with coronary artery disease. A group of 65 patients with angiographically defined Coronary Artery Disease (CAD and 60 normal control subjects were examined. The activity of Angiotensin-Converting Enzyme (ACE was determined by the reversed-phase High Performance Liquid Chromatography (HPLC to separate and quantify Hippuryl-Histidyl-Leucin (HHL and Hippuric Acid (HA. Ferric Reducing Ability of Plasma (FRAP Assay as a measure of antioxidant power was used. Serum ascorbic acid concentration was determined photometrically. The results demonstrated significant differences in ACE activity, antioxidant and ascorbic acid between CAD cases and normal controls. Increased levels of ACE activity in serum have been related to coronary artery disease. Serum ascorbic acid concentration (25.6±3.8 mg dL-1 and total antioxidant capacity (475.5±18.51 ?M L-1 were significantly (p<0.05 decreased in CAD patients compared with controls.

F. Ghazi

2009-01-01

345

Cortical ablation and drug-induced changes in striatal ascorbic acid oxidation and behavior in the rat  

OpenAIRE

Rats whose frontoparietal cortex had been bilaterally ablated were allowed 21 days for recovery and then treated with apomorphine (APO), 1 mg/kg SC or scopolamine (SCOP), 0.6 mg/kg SC. Soon after a behavioral test, dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), ascorbic acid (AA), and dehydroascorbic acid (DHAA) levels were determined by HPLC/EC in striatal synaptosomes (left side) and whole striatum (right side). SCOP behavioural effects were attenuated by cortical ablation, while th...

Miele, Maddalena; Enrico, Paolo; Esposito, Giovanni; Fresu, Luigia Grazia; Migheli, Rossana; Natale, Guglielmo; Desole, Maria Speranza

1995-01-01

346

Fabrication and characterisation of high performance polypyrrole modified microarray sensor for ascorbic acid determination  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: -- Highlights: •Gold microelectrode array (Au/MEA) with electrode of 12 ?m diameter was fabricated by photolithography technique. •Subsequently, polypyrrole (Ppy) modified gold microarrays sensor (Ppy/Au/MEA) was prepared. •Ppy/Au/MEA used for ascorbic acid determination in the presence of different neurotransmitters. •The micro array exhibited wide linear range, very high sensitivity and very low LOD than the earlier reports. •It was used successfully to test ascorbic acid in different types real samples. -- Abstract: In this study, gold microelectrode array (Au/MEA) with electrode of 12 ?m diameter was fabricated by photolithography technique. Subsequently, polypyrrole (Ppy) modified gold microarrays sensor (Ppy/Au/MEA) was prepared by cyclic voltammetry technique. The deposition potential range and number of cycles were optimised in order to get optimum thickness of Ppy film. Scanning Electron Microscope and Atomic Force Microscope investigations reveal that Ppy coating formed at 3 cycles is porous with thickness of 1.5 ?m which exhibiting high catalytic current for ascorbic acid (AA) in square wave technique (SWV). In contrast to earlier sensors designs, these Ppy/Au/MEA sensors exhibits lower detection limit (LOD) of 10 nm towards AA at physiological conditions. It also exhibits enhanced sensitivity (2.5 mA cm{sup ?2} mM{sup ?1}) and long range of linear detection limit from 10 nm to 2.8 mM. In the same way, polypyrrole modified macro Au (Ppy/Au/MA) biosensor was also fabricated and its electro catalytic property towards AA was compared with that of Ppy/Au/MEA. The Ppy/Au/MA exhibits sensitivity of only 0.27 mA cm{sup ?2} mM{sup ?1}, LOD of 5 ?M and linear range of 10 ?M to 2.2 mM. Hence, our investigations indicate that the Ppy/Au/MEA could serve as highly sensitive sensor for AA than any of the earlier designs. So, the Ppy/Au/MEA electrode was utilised for determination AA in a wide variety of real samples.

Samseya, J. [Alagappa University, Karaikudi, Tamil Nadu (India); Srinivasan, R., E-mail: sivarunjan@gmail.com [Central Electro Chemical Research Insititute, Karaikudi, Tamil Nadu (India); Chang, Yu-Tsern; Tsao, Cheng-Wen [Department of Cosmetic Applications, Taoyuan Innovation Institute of Technology, Taiwan (China); Vasantha, V.S. [Madurai Kamaraj University, Madurai, Tamil Nadu (India)

2013-09-02

347

Fabrication and characterisation of high performance polypyrrole modified microarray sensor for ascorbic acid determination  

International Nuclear Information System (INIS)

Graphical abstract: -- Highlights: •Gold microelectrode array (Au/MEA) with electrode of 12 ?m diameter was fabricated by photolithography technique. •Subsequently, polypyrrole (Ppy) modified gold microarrays sensor (Ppy/Au/MEA) was prepared. •Ppy/Au/MEA used for ascorbic acid determination in the presence of different neurotransmitters. •The micro array exhibited wide linear range, very high sensitivity and very low LOD than the earlier reports. •It was used successfully to test ascorbic acid in different types real samples. -- Abstract: In this study, gold microelectrode array (Au/MEA) with electrode of 12 ?m diameter was fabricated by photolithography technique. Subsequently, polypyrrole (Ppy) modified gold microarrays sensor (Ppy/Au/MEA) was prepared by cyclic voltammetry technique. The deposition potential range and number of cycles were optimised in order to get optimum thickness of Ppy film. Scanning Electron Microscope and Atomic Force Microscope investigations reveal that Ppy coating formed at 3 cycles is porous with thickness of 1.5 ?m which exhibiting high catalytic current for ascorbic acid (AA) in square wave technique (SWV). In contrast to earlier sensors designs, these Ppy/Au/MEA sensors exhibits lower detection limit (LOD) of 10 nm towards AA at physiological conditions. It also exhibits enhanced sensitivity (2.5 mA cm?2 mM?1) and long range of linear detection limit from 10 nm to 2.8 mM. In the same way, polypyrrole modified macro Au (Ppy/Au/MA) biosensor was also fabricated and its electro catalytic property towards AA was compared with that of Ppy/Au/MEA. The Ppy/Au/MA exhibits sensitivity of only 0.27 mA cm?2 mM?1, LOD of 5 ?M and linear range of 10 ?M to 2.2 mM. Hence, our investigations indicate that the Ppy/Au/MEA could serve as highly sensitive sensor for AA than any of the earlier designs. So, the Ppy/Au/MEA electrode was utilised for determination AA in a wide variety of real samples

348

Dietary ascorbic acid and subsequent change in body weight and waist circumference : associations may depend on genetic predisposition to obesity--a prospective study of three independent cohorts  

DEFF Research Database (Denmark)

BACKGROUND: Cross-sectional data suggests that a low level of plasma ascorbic acid positively associates with both Body Mass Index (BMI) and Waist Circumference (WC). This leads to questions about a possible relationship between dietary intake of ascorbic acid and subsequent changes in anthropometry, and whether such associations may depend on genetic predisposition to obesity. Hence, we examined whether dietary ascorbic acid, possibly in interaction with the genetic predisposition to a high BMI, WC or waist-hip ratio adjusted for BMI (WHR), associates with subsequent annual changes in weight (?BW) and waist circumference (?WC). METHODS: A total of 7,569 participants' from MONICA, the Diet Cancer and Health study and the INTER99 study were included in the study. We combined 50 obesity associated single nucleotide polymorphisms (SNPs) in four genetic scores: a score of all SNPs and a score for each of the traits (BMI, WC and WHR) with which the SNPs associate. Linear regression was used to examine the association between ascorbic acid intake and ?BW or ?WC. SNP-score?×?ascorbic acid interactions were examined by adding product terms to the models. RESULTS: We found no significant associations between dietary ascorbic acid and ?BW or ?WC. Regarding SNP-score?×?ascorbic acid interactions, each additional risk allele of the 14 WHR associated SNPs associated with a ?WC of 0.039?cm/year (P?=?0.02, 95% CI: 0.005 to 0.073) per 100?mg/day higher ascorbic acid intake. However, the association to ?WC only remained borderline significant after adjustment for ?BW. CONCLUSION: In general, our study does not support an association between dietary ascorbic acid and ?BW or ?WC, but a diet with a high content of ascorbic acid may be weakly associated to higher WC gain among people who are genetically predisposed to a high WHR. However, given the quite limited association any public health relevance is questionable.

Larsen, Sofus C; Angquist, Lars

2014-01-01

349

Multifunctional PLGA particles containing poly(l-glutamic acid)-capped silver nanoparticles and ascorbic acid with simultaneous antioxidative and prolonged antimicrobial activity.  

Science.gov (United States)

A water-soluble antioxidant (ascorbic acid, vitamin C) was encapsulated together with poly(l-glutamic acid)-capped silver nanoparticles (AgNpPGA) within a poly(lactide-co-glycolide) (PLGA) polymeric matrix and their synergistic effects were studied. The PLGA/AgNpPGA/ascorbic acid particles synthesized by a physicochemical method with solvent/non-solvent systems are spherical, have a mean diameter of 775 nm and a narrow size distribution with a polydispersity index of 0.158. The encapsulation efficiency of AgNpPGA/ascorbic acid within PLGA was determined to be >90%. The entire amount of encapsulated ascorbic acid was released in 68 days, and the entire amount of AgNpPGAs was released in 87 days of degradation. The influence of PLGA/AgNpPGA/ascorbic acid on cell viability, generation of reactive oxygen species (ROS) in HepG2 cells, as well as antimicrobial activity against seven different pathogens was investigated. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay indicated good biocompatibility of these PLGA/AgNpPGA/ascorbic acid particles. We measured the kinetics of ROS formation in HepG2 cells by a DCFH-DA assay, and found that PLGA/AgNpPGA/ascorbic acid caused a significant decrease in DCF fluorescence intensity, which was 2-fold lower than that in control cells after a 5h exposure. This indicates that the PLGA/AgNpPGA/ascorbic acid microspheres either act as scavengers of intracellular ROS and/or reduce their formation. Also, the results of antimicrobial activity of PLGA/AgNpPGA/ascorbic acid obtained by the broth microdilution method showed superior and extended activity of these particles. The samples were characterized using Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, zeta potential and particle size analysis. This paper presents a new approach to the treatment of infection that at the same time offers a very pronounced antioxidant effect. PMID:23988864

Stevanovi?, Magdalena; Bra?ko, Ines; Milenkovi?, Marina; Filipovi?, Nenad; Nuni?, Jana; Filipi?, Metka; Uskokovi?, Dragan P

2014-01-01

350

A sensor of a polyoxometalate and Au–Pd alloy for simultaneously detection of dopamine and ascorbic acid  

International Nuclear Information System (INIS)

A composite film based on K8P2W16V2O62·18H2O decorated by Au–Pd nanoparticles was prepared by the layer-by-layer self-assembly method. This composite film exhibits enhanced electrocatalytic performance, repeatability and long-term stability for the simultaneous determination of dopamine and ascorbic acid at biological pH (pH 7.0). The proposed electrochemical sensing film for simultaneous detecting dopamine and ascorbic acid shows rather low detection limit of 8.3 × 10?7 and 4.3 × 10?7 M and a linear response range from 2.1 × 10?6 to 2.06 × 10?3 M and 1.2 × 10?6 to 1.61 × 10?3 M, as well as no interference from the common interfering species at an applied potential. -- Abstract: A novel composite film based on Dawson-type phosphovanadotungstate K8P2W16V2O62·18H2O (P2W16V2) decorated by Au–Pd alloy nanoparticles (Au–Pd) was fabricated on quartz, silicon and ITO using the layer-by-layer self-assembly method. The composite film was characterized by UV–vis spectroscopy, X-ray photoelectron spectra, atomic force microscopy, Scanning electronic microscope, cyclic voltammetry and differential pulse voltammetry. The composite film can be employed for sensitive and simultaneous determination of dopamine and ascorbic acid at biological pH (pH 7.0). Linear analytical curves were obtained in the ranges from 2.1 × 10?6 to 2.06 × 10?3 M and 1.2 × 10?6 to 1.61 × 10?3 M for dopamine and ascorbic acid by DPV methods, respectively. The low detection limit for dopamine and ascorbic acid were 8.3 × 10?7 and 4.3 × 10?7 M, as well as no interference was observed from the common interfering species such as glucose, uric acid, L-cysteine, CH3OH, CH3CH2OH and H2O2. The composite film was used for dopamine and ascorbic acid determinations in real samples with satisfactory results. With high sensitivity and selectivity, the proposed electrochemical sensor would provide a simple method for simultaneous determination of dopamine and ascorbic acid in practical applications

351

Bound sugars in hepatic glycoproteins from male rats during dietary citrus bioflavonoid and/or ascorbic acid supplementation.  

Science.gov (United States)

The purpose of these experiments was to determine whether quantitative changes take place in the attached sugars of hepatic (postmitochondrial) glycoproteins isolated from rats fed a diet supplemented with citrus bioflavonoids (an equal mixture of rutin, naringin, and hesperidin) (B) and/or ascorbic acid (C) for 40 days and 90 days. Statistically significant increases in body weights (P acid-soluble glycoprotein fraction, statistically significant decreases were seen in bound hexoses and fucose (P acid-insoluble glycoprotein fraction, statistically significant changes were seen in bound hexoses and fucose (P acid-soluble glycoprotein fraction that is accentuated even further by combined CB supplementation. This decrease is more probable after 40 days than it is after 90 days of dietary supplementation. An adaptive phenomenon is suggested for maintaining the intracellular environment during periods of dietary citrus bioflavonoid and/or ascorbic acid supplementation. PMID:16379564

Wood, Nelson

2005-01-01

352

Phenols and ascorbic acid in black currants (Ribes nigrum L.): variation due to genotype, location, and year.  

Science.gov (United States)

Black currant berries contain many biochemical compounds with proven or potential human health benefits. We studied the content of total and single polyphenols, ascorbic acid, soluble sugars, and titratable acidity for two advanced selections and three cultivars of black currant at two distant locations in Sweden (south: 56°06'N; north: 65°21'N) over a 3 year period. Regression analyses revealed the effect of genotype to be considerably larger than that of location and year. However, significant effects of location, year, and interactions were also revealed. A principal component analysis nevertheless separated the genotypes. The content of ascorbic acid, total phenols, total anthocyanins, and soluble sugars was highest in berries from the south, whereas the content of phenolic acids and titratable acidity was highest in berries from the north. The results show that selection of cultivars and production sites are important for cultivation of high-quality black currant raw material for health-promoting products. PMID:24011264

Vagiri, Michael; Ekholm, Anders; Öberg, Elisabeth; Johansson, Eva; Andersson, Staffan C; Rumpunen, Kimmo

2013-10-01

353

ASCORBIC ACID, PROVITAMIN A, AND MINERAL COMPOSITION OF BANANA (MUSA SP.) AND PAPAYA (CARICA PAPAYA) CULTIVARS GROWN IN HAWAII.  

Science.gov (United States)

Banana (Musa sp.) and papaya (Carica papaya) cultivars were harvested from different locations throughout Hawaii and analyzed for vitamin C (ascorbic acid), provitamin A ( ß-carotene, alpha-carotene, ß-cryptoxanthin), and mineral composition. Dwarf Brazilian ('apple') bananas had almost three times ...

354

Preparation of polypyrrole/ferrocyanide films modified carbon paste electrode and its application on the electrocatalytic determination of ascorbic acid  

Energy Technology Data Exchange (ETDEWEB)

Functionalized polypyrrole film were prepared by incorporation of (Fe(CN){sub 6}){sup 4-} as doping anion, during the electropolymerization of pyrrole onto a carbon paste electrode (CPE) in aqueous solution by using potentiostatic method. The electrochemical behavior of the (Fe(CN){sub 6}){sup 3-}/(Fe(CN){sub 6}){sup 4-} redox couple in polypyrrole was studied by cyclic voltammetry and double step potential chronoamperometry methods. In this study, an obvious surface redox reaction was observed and dependence of this reaction on the solution pH was illustrated. The electrocatalytic ability of polypyrrole/ferrocyanide films modified carbon paste electrode (Ppy/FCNMCPEs) was demonstrated by oxidation of ascorbic acid. It has been found that under optimum condition (pH 7.00), the oxidation of ascorbic acid at the surface of such electrode occurs at a potential about 540 mV less positive than unmodified carbon paste electrode. The kinetic parameters such as electron transfer coefficient, {alpha} and catalytic reaction rate constant, k{sub h}', were also determined by using various electrochemical approaches. The catalytic oxidation peak current showed a linear dependent on the ascorbic acid concentration and a linear calibration curve was obtained in the range of 4.5x10{sup -4} to 9.62x10{sup -3} M of ascorbic acid with a correlation coefficient of 0.9999. The detection limit (2{sigma}) was determined as 5.82x10{sup -5} M.

Raoof, Jahan-Bakhsh; Ojani, Reza; Rashid-Nadimi, Sahar

2004-01-15

355

A GREEN CHEMISTRY APPROACH TO PREPARATION OF CORE (FE OR CU)-SHELL (NOBLE METALS) NANOCOMPOSITES USING AQUEOUS ASCORBIC ACID  

Science.gov (United States)

A greener method to fabricate novel core (Fe or Cu)-shell (noble metals) nanocomposites of transition metals such as Fe and Cu and noble metals such as Au, Pt, Pd, and Ag using aqueous ascorbic acid is described. Transition metal salts such as Cu and Fe were reduced using ascor...

356

A self-seeding synthesis of Ag microrods of tuned aspect ratio: ascorbic acid plays a key role  

Science.gov (United States)

Control of the shape and size of nanoparticles is crucial for using them as labels or as building blocks in nanotechnology. In fact, silver has so far been considered as having the widest variety of different morphologies at the nano-scale and micro-scale levels. To make progress in these criteria, in our paper we have synthesized highly reproducible silver (Ag) microrods of controlled aspect ratios through a rapid self-seeding method. The Ag nano seeds are formed via the reduction of Ag ions in hot ethylene glycol by ascorbic acid, and the subsequent growth of microrods is controlled by further deposition of Ag atoms in the presence of poly(vinylpyrrolidone). Moreover, ascorbic acid is exclusively responsible for the rod morphology, as we describe here in detail. A very low concentration of ascorbic acid forms very few Ag microrods along with a majority of Ag colloidal particles, while random overgrowth on the surfaces is observed for higher concentrations. The critical reaction condition has been found in that the aspect ratio of the Ag microrods can be systematically tuned between 4 and 90. Also, the method in which ascorbic acid is added to the reaction medium plays a key role in controlling the aspect ratio of the Ag microrods. The non-monotonic dependence of the length and the diameter of the Ag microrods has been described by an empirical equation. The function can be interpreted by means of concentration-dependent competition between the adsorption of ligands and metal deposition.

Visaveliya, Nikunjkumar; Köhler, J. Michael

2013-08-01

357

Preparation of polypyrrole/ferrocyanide films modified carbon paste electrode and its application on the electrocatalytic determination of ascorbic acid  

International Nuclear Information System (INIS)

Functionalized polypyrrole film were prepared by incorporation of (Fe(CN)6)4- as doping anion, during the electropolymerization of pyrrole onto a carbon paste electrode (CPE) in aqueous solution by using potentiostatic method. The electrochemical behavior of the (Fe(CN)6)3-/(Fe(CN)6)4- redox couple in polypyrrole was studied by cyclic voltammetry and double step potential chronoamperometry methods. In this study, an obvious surface redox reaction was observed and dependence of this reaction on the solution pH was illustrated. The electrocatalytic ability of polypyrrole/ferrocyanide films modified carbon paste electrode (Ppy/FCNMCPEs) was demonstrated by oxidation of ascorbic acid. It has been found that under optimum condition (pH 7.00), the oxidation of ascorbic acid at the surface of such electrode occurs at a potential about 540 mV less positive than unmodified carbon paste electrode. The kinetic parameters such as electron transfer coefficient, ? and catalytic reaction rate constant, kh', were also determined by using various electrochemical approaches. The catalytic oxidation peak current showed a linear dependent on the ascorbic acid concentration and a linear calibration curve was obtained in the range of 4.5x10-4 to 9.62x10-3 M of ascorbic acid with a correlation coefficient of 0.9999. The detection limit (2?) was determined as 5.82x10-5 Mned as 5.82x10-5 M

358

Effects of Ascorbic Acid on Egg Production and Egg Shell Quality in Laying Hens Drinking Saline Water  

Directory of Open Access Journals (Sweden)

Full Text Available An experiment was conducted to study the effects of different water source, saline water (Tap water +2 g L-1 Na and tape water with a diet that supplemented by three level of Ascorbic Acid (0, 1.5 and 3 g kg-1 of diet on laying hen`s performance and egg shell quality. This trail was carried out on 108 commercial laying hens (Hy-Line 32 weeks old for 12 weeks. All of the data were subjected to Two- way analysis of variance test. The result showed that egg production (%, egg weight (g, egg mass (g/h/day, feed conversion ratio, feed consumptions didn`t effected by saline water but using saline water increased the percentage of eggs with damaged shells (p<0.01. Also the effect of different level of Ascorbic acid on egg production (%, egg weight (g, egg mass (g/h/day, feed conversion ratio were not significant, but feed consumption reduced by using ascorbic acid (p<0.05. Egg shell thickness (mm, egg shell weight (%, egg shell weight (mg/cm2, egg specific gravity, egg shell calcium (% and egg shell phosphorous (% didn`t affected by saline water and different level of Ascorbic acid.

J. Mirabdollbaghi

2006-01-01

359

Determination of ascorbic acid levels in food samples by using an ionic liquid-carbon nanotube composite electrode.  

Science.gov (United States)

A novel carbon composite electrode consisted of ionic liquid n-octylpyridinum hexafluorophosphate (OPFP) and single-walled carbon nanotube (SWCNT) was fabricated and investigated. This electrode combined the advantages of ionic liquid and SWCNT together with the "bulk" composite electrode. Compared with other composite electrodes using graphite or paraffin oil, the ionic liquid-SWCNT (IL-SWCNT) composite electrode exhibited remarkable increase in the electron transfer rate for electroactive compound and significant decrease in the overpotential for ascorbic acid oxidation reaction. Based on the greatly enhanced electrocatalytic activity for the oxidation of ascorbic acid, a wide linear detection range from 3.0 ?M to 4.2 mM with a low detection limit of 1.0 ?M was obtained. Furthermore, the IL-SWCNT electrode was applied to determine ascorbic acid levels in real food samples. Experimental results showed that the proposed electrode could be used as an effective and sensitive sensor for direct detection of ascorbic acid. PMID:22868100

Ping, Jianfeng; Wang, Yixian; Wu, Jian; Ying, Yibin; Ji, Feng

2012-11-15

360

Anti-obesity effects of chitosan and psyllium husk with L-ascorbic acid in guinea pigs.  

Science.gov (United States)

The aim of this study was to investigate whether L-Ascorbic acid would facilitate the anti-obesity effects of chitosan and psyllium husk in vivo. The study was carried out with male Hartley guinea pigs for 5 weeks. The results show that chitosan itself did not influence body weight gain and food efficiency ratio (FER). However, the addition of L-Ascorbic acid to chitosan decreased these parameters; the body weight gain and FER in the chitosan-2 group (high-fat diet group with 5 % chitosan containing 0.5 % L-Ascorbic acid) was significantly (p psyllium husk did not differ from psyllium husk alone in terms of changes in weight gain, plasma lipid levels, and fat pad weight. We found that the addition of L-Ascorbic acid to chitosan influenced the reduction in body weight gain and FER, and the increase in total fecal weight and fecal fat excretion in guinea pigs fed a high-fat diet. PMID:23065836

Jun, Sung Chul; Jung, Eun Young; Hong, Yang Hee; Park, Yooheon; Kang, Duk ho; Chang, Un Jae; Suh, Hyung Joo

2012-04-01

361

EFFECTS OF DEPLETION OF ASCORBIC ACID OR NONPROTEIN SULFYDRYLS ON THE ACUTE INHALATION TOXICITY OF NITROGEN DIOXIDE, OZONE, AND PHOSGENE  

Science.gov (United States)

The effect of depleting lung ascorbic acid (AH2) and nonprotein sulfhydryls (NPSH) on the acute inhalation toxicity of nitrogen dioxide (N02), ozone (03), and phosgene (C0Cl2) was investigated in guinea pigs. he increase in bronchoalveolar lavage (BAL) fluid protein (an indicator...

362

Ascorbic acid-functionalized Ag NPs as a probe for colorimetric sensing of glutathione  

Science.gov (United States)

In this work, we report the use of ascorbic acid-capped silver nanoparticles (AA-Ag NPs) as a probe for selective colorimetric detection of glutathione (GSH) in aqueous solution. This detection system was based on the GSH-induced aggregation of AA-Ag NPs, resulting in drastic changes in the absorption spectra and color of the AA-Ag NPs system. The GSH-induced AA-Ag NPs aggregation was confirmed by UV-visible spectrometry, dynamic light scattering (DLS) and transmission electron microscopic (TEM) techniques. Under optimal conditions, this method exhibited good linearity over the concentration ranges from 5.0 to 50 µM, with the limit of detection 2.4 × 10-7 M. This method was successfully applied to detect GSH in the presence of other biomolecules, which confirms that this probe can be used for the detection of GSH in real samples.

D'souza, Stephanie L.; Pati, Ranjan; Kailasa, Suresh Kumar

2014-10-01

363

Cadmium sulfide photocatalysed reduction of malachite green by ascorbic acid and EDTA as reductants  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Foi efetuada a fotoredução do verde de malaquita na presença de CdS como fotocatalizador e ácido ascorbico/EDTA como redutores. Foram estudados os efeitos de diferentes parâmetros como pH, concentração de verde de malaquita, redutores, quantidade de semicondutor e intensidade de luz, na velocidade d [...] a reação fotocatalítica. Levando em conta os dados obtidos propomos um de mecanismo.para a fotoredução do verde de malaquita. Abstract in english The photoreduction of malachite green in presence of CdS as photocatalyst and ascorbic acid/EDTA as reductants has been carried out. The effect of different parameters like pH, concentration of malachite green, reductants, amount of semiconductor and light intensity on the rate of photocatalytic rea [...] ction has been studied. On the basis of observed data, a tentative mechanism for the photoreduction of malachite green has been proposed.

Shilpa, Kothari; Anil, Kumar; Ritu, Vyas; Rakshit, Ameta; Pinki B., Punjabi.

1821-18-01

364

Photometric starch-iodine determination in plant materials as influenced by ascorbic acid. Critical remarks  

Directory of Open Access Journals (Sweden)

Full Text Available Following the work of Sharma et al. (1990 on the interference of ascorbic acid (AA with starch-iodine reaction, the present authors repeated it, giving a proper explanation of the influence of AA in this reaction. AA oxidizes iodine-iodide (I-KI reagent which makes impossible to form the blue complex with starch. Three measures are suggested to overcome the interference of AA: 1 to titrate starch solution with I-KI reagent and thus work out an I-KI amount for development of blue coloration, 2 to remove from plant material AA (and other reducing soluble substances by washing the material with cold water or ethanol, and 3 starch solution could be treated with alkali (pH about 9, which destroys AA in 15 minutes. After acidifying the solution and adding I-KI reagent the blue complex can be determined.

Bogus?aw Samotus

1994-03-01

365

Preparation and characterization of ascorbic acid loaded solid lipid nanoparticles and investigation of their apoptotic effects.  

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In this paper, ascorbic acid (Vitamin C, AA) known as an antioxidant was successfully incorporated in solid lipid nanoparticles (SLNs) by hot homogenization and efficient delivery of AA to cancer cells. The obtained SLN formulations were characterized by Nano Zetasizer ZS and HPLC with the particle size being less than 250nm. AA-SLNs exhibited sustained release and high entrapment efficiency. According to MTT test results, AA-SLNs showed high cytotoxic activity compared to the free AA against H-Ras 5RP7 cells without damaging NIH/3T3 control cells. These results were supported by the Annexin V-PI and caspase-3 assay. Furthermore, as compared to the AA, AA-SLNs exhibited more efficient cellular uptake, accumulated in the cytoplasm and induced apoptosis which was observed by confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM). Thus, the results of this study suggest that SLNs can be a potential nanocarrier system for AA. PMID:24985762

Güney, Gamze; Kutlu, H Mehtap; Genç, Lütfi

2014-09-01

366

An adult case of cerebral malakoplakia successfully cured by treatment with antibiotics, bethanechol and ascorbic acid.  

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Cerebral malakoplakia is a very rare chronic inflammatory disease. We herein report the case of a 49-year-old female who presented with a slowly progressive speech disturbance and right hemiparesis. Computed tomography and magnetic resonance imaging showed irregular enhanced mass lesions with numerous scattered areas of calcification in the left insula, thalamus and basal ganglia. Histopathologically, the biopsy specimen showed basophilic laminated inclusion bodies and intracellular and extracellular calculospherules, usually with a typical targetoid appearance (Michaelis-Gutmann bodies). Treatment with antibiotics, bethanechol and ascorbic acid improved her symptoms in association with a decrease in the abnormal calcification and enhancement. The cerebral malakoplakia mimicked a brain tumor in terms of the patient's clinical course and neuroradiological image findings; however, it was successfully cured with medical treatment. This case provides evidence that the pathogenesis of cerebral malakoplakia is deeply tied to bacterial infection and that medical treatment is effective in cases of this disease. PMID:24863007

Fudaba, Hirotaka; Ooba, Hiroshi; Abe, Tatsuya; Kamida, Tohru; Wakabayashi, Yukihiro; Nagatomi, Hirofumi; Fujiki, Minoru

2014-07-15

367

Polyoxometalate-Graphene Nanocomposite Modified Electrode for Electrocatalytic Detection of Ascorbic Acid  

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Phosphomolybdate functionalized graphene nanocomposite (PMo12-GS) has been successfully formed on a glassy carbon electrode (GCE) for the detection of ascorbic acid (AA). The obtained PMo12-GS modified GCE, was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy and compared with GCE, GS modified GCE, and PMo12 modified GCE. It shows an increased current and a decrease in over-potential of ~210 mV. The amperometric signals are linearly proportional to the AA concentration in a wide concentration range from 1×10?6 M to 8×10?3 M, with a detection limit of 0.5×10?6 M. The PMo12-GS modified electrode was employed for the determination of the AA level in vitamin C tablets, with recoveries between 96.3 and 100.8?%.

Zhang, Weiying; Du, Dan; Gunaratne, Kalupathirannehelage Don D.; Colby, Robert J.; Lin, Yuehe; Laskin, Julia

2014-01-15

368

Cross-linked potato starch-based blend films using ascorbic acid as a plasticizer.  

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The main objects of this study were to prepare the cross-linked potato starch/polyvinyl alcohol blend films with ascorbic acid (AsA) added as a plasticizer with and without heat curing and to examine their mechanical properties, elongation at break, degree of swelling, solubility, water vapor absorption, thermal properties, optical properties, and biodegradability. The specific surface area, pore volume, and topography of the films with and without heat curing were also investigated via nitrogen adsorption and desorption isotherms and atomic force microscopy analysis. The results indicate that the cured films possess mechanical, thermal, and optical properties enhanced compared to those of noncured films. The mechanical and water barrier properties of the AsA-added film were also found to be superior to those of other films with polyol plasticizers (glycerol and xylitol). The biodegradability test revealed that the prepared films are degraded by ~35-80% after 165 days. PMID:23909738

Yoon, Soon-Do

2014-02-26

369

Simultaneous determination of ascorbic acid, pyridoxine hydrochloride, and tyrosine by derivative UV spectrophotometry.  

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A new UV spectrophotometric method for resolving a three-component drug mixture of ascorbic acid (I), pyridoxine hydrochloride (II), and tyrosine (III), on the basis of the first-derivative UV spectra and zero-crossing technique, is described. Beer's law was obeyed in the concentration range of 7.0-15.0, 0.25-1.0, and 8.0-40.0 micrograms/ml for I, II, and III, respectively. Lower limits of detection at the 95% confidence level were 2.88, 0.69, and 5.43 micrograms/ml, respectively. The advantages of the proposed method (speed, easy sample preparation, and lower cost per analysis) also include its application to the content uniformity and dissolution test of a three-component mixture of drugs. PMID:9876517

Surmeian, M

1998-07-01

370

Simultaneous spectrophotometric determination of rutin, quercetin and ascorbic acid in drugs using a Kalman Filter approach.  

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A UV-spectrophotometric analysis of severely overlapped spectra yielded by anti-capillary fragility pharmaceutical materials, viz. rutin, quercetin and ascorbic acid, in authentic mixtures and in tablets or soft elastic capsules was proposed. The method was based on Kalman Filter calibration of either orthogonal experimental design, i.e. standard solutions containing only one component at a time, or non-orthogonal experimental design, i.e. standard solutions containing more than one component. This calibration was followed by quantitative determinations of two- and three-component mixtures in synthetic mixtures or in oral dosages within the concentration range 2-10 microg ml(-1). A statistical analysis of the results was reported. PMID:10704037

Hassan, H N; Barsoum, B N; Habib, I H

1999-06-01

371

Sensitive and reliable ascorbic acid sensing by lanthanum oxide/reduced graphene oxide nanocomposite.  

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A simple strategy for the detection and estimation of ascorbic acid (AA), using lanthanum oxide-reduced graphene oxide nanocomposite (LO/RGO) on indium tin oxide (ITO) substrate, is reported. LO/RGO displays high catalytic activity toward the oxidation of AA, and the synergism between lanthanum oxide and reduced graphene oxide was attributed to the successful and efficient detection. Detection mechanism and sensing efficacy of LO/RGO nanocomposite are investigated by electrochemical techniques. Chronoamperometric results under optimal conditions show a linear response range from 14 to 100 ?M for AA detection. Commercially available vitamin C tablets were also analyzed using the proposed LO/RGO sensor, and the remarkable recovery percentage (97.64-99.7) shows the potential application in AA detection. PMID:24879601

Mogha, Navin Kumar; Sahu, Vikrant; Sharma, Meenakshi; Sharma, Raj Kishore; Masram, Dhanraj T

2014-10-01

372

Uptake of dehydroascorbic acid and ascorbic acid to isolated nerve terminals and secretory granules from ox neurohypophyses  

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When uptake of L-[14C]ascorbic acid ([14C]AA) to various organs in guinea-pigs was studied after intracardiac injection, the adenohypophysis, pars intermedia, and the neurohypophysis had an uptake per milligramme protein which was about half of the uptake to the adrenals. Adrenal uptake was 20 +/- 2.8 pmol mg-1 protein microCi-1 injected. The uptake to the different parts of the hypophysis was considerably higher than the uptake to pancreas, liver, kidney, spleen and other organs. When isolated nerve endings (neurosecretosomes) from ox neurohypophyses were incubated with a medium containing labelled dehydroascorbic acid ([14C]DHA), the uptake was much slower than when the medium contained labelled ascorbic acid. The uptake of [14C]DHA showed a linear dependence on concentration, and was not influenced by addition of Mg2+ and ATP. Addition of Mg2+ + ATP, omission of Ca2+ and Mg2+ or exchange of Na+ in the medium with K+ had no effect on the uptake of ascorbic acid. When isolated secretory granules from ox neurohypophyses were incubated with a medium containing [14C]DHA, uptake was considerably faster than the uptake when they were incubated in a medium containing [14C]AA. The uptake of dehydroascorbic acid was linear with the concentration in the medium and was not changed by addition of Mg2+ ATP. Addition of 10 mM NH4Cl or exchange of 120 mM K+ in the incubation medium with Na+ did not change the uptake of dehydroascorbic acid. The contents of copper, zinc, iron and cobalt were determined in isolated nerve endings (A) and membranes (B) as well as in lysate (C) from isolated neurosecretory granules. The results (in nmol mg-1 protein) were for Cu: (A): 0.25 +/- 0.01 (SEM), (B): 0.67 +/- 0.16, (C): 0.22 +/- 0.06; for Zn: (A): 0.53 +/- 0.13, (B): 6.97 +/- 0.75, (C): 1.8 +/- 0.53; and for Fe: (A): 15.6 +/- 1.9, (B): 6.92 +/- 0.32, (C): 3.15 +/- 0.43. In all preparations the cobalt content was below the detection limit (less than 5 pmol mg-1 protein).

Thorn, N A; Nielsen, F S

1986-01-01

373

Ionic high-osmolar contrast medium causes oxidant stress in kidney tissue: partial protective role of ascorbic acid.  

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It has been known that contrast medium may cause contrast-induced nephropathy in risk groups. This study sought to establish possible effects of ionic high-osmolar contrast medium administration with or without antecedent cisplatin treatment on oxidant/antioxidant status in rat kidney tissues, as well as to investigate a possible protective role of antioxidant ascorbic acid in this regard. Thirty-five female, 14-week-old Wistar-albino rats were used in this study. They were divided into five groups of seven rats (sham, contrast, contrast + ascorbic acid, contrast + cisplatin, and contrast + cisplatin + ascorbic acid). Ascorbic acid was given in a dose of 250 mg/kg/day orally throughout the study period, and cisplatin (10 mg/kg) as a single i.v. dose on the fourth day. Ionic high-osmolar contrast medium (3 gr/kg iodine as a single dose) was administered by i.v. route on the fifth day. After the animals were sacrificed on the sixth day, their kidney tissues were removed surgically to be used in the analyses. Malondialdehyde (MDA) level and activities of antioxidant (superoxide dismutase [SOD], glutathione peroxidase [GSH-Px] and catalase [CAT]) and oxidant (xanthine oxidase [XO]) enzymes were measured in these samples. Serum urea and creatinine levels were measured to evaluate kidney functions. Histopathological investigation of the tissues was also performed. It was observed that contrast medium administration caused increases in MDA levels in the kidney tissues, either alone or together with antecedent cisplatin treatment. However, ascorbic acid prevented the increases in MDA levels in the kidney tissues. Histopathological findings revealed that ionic high-osmolar contrast medium administration alone led to mild acute structural damage, but contrast medium administration together with antecedent cisplatin usage caused severe tubular necrosis. Ascorbic acid supplementation prevented these changes, to a great extent. The results suggest that ionic high-osmolar contrast medium administration, either alone or together with antecedent cisplatin treatment, leads to accelerated oxidative reactions in rat kidney tissues, and ascorbic acid protects in part the kidney tissues against this oxidant stress. PMID:18569939

Cetin, Meltem; Devrim, Erdinç; Serin Kiliçoglu, Sibel; Ergüder, Imge B; Namuslu, Mehmet; Cetin, Recep; Durak, Ilker

2008-01-01

374

Pharmacological ascorbate induces cytotoxicity in prostate cancer cells through ATP depletion and induction of autophagy.  

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Recent studies have revealed the scientific basis for the use of intravenous (i.v.) vitamin C or ascorbic acid (ascorbate) in treating cancers, and raised the possibility of using i.v. ascorbate as a prooxidant anticancer therapy. Through the production of H2O2, pharmacologic ascorbate can induce some cancer cell death in vitro and inhibit a number of types of tumor growth in animal models. However, the mechanism of cell death triggered by ascorbate is not well understood. In this study, we investigated the cytotoxicity of pharmacological concentrations of ascorbate to human prostate cancer cells and the mechanisms involved. The results showed that ascorbate in the millimolar range induced cytotoxicity in five of the six tested prostate cancer cell lines. The IC50 values in the sensitive prostate cancer cells ranged from 1.9 to 3.5 mmol/l, concentrations clinically achievable with i.v. ascorbate use. All tested androgen-independent cells were sensitive to ascorbate treatment. The ascorbate-insensitive cell line LaPC4 is hormonally dependent. Whereas the reasons for sensitivity/resistance to ascorbate treatment need to be investigated further, cell death in sensitive cells was dependent on H2O2. Ascorbate treatment depleted ATP and induced autophagy in sensitive prostate cancer cells, resulting in cell death. Taken together with previous studies, high-dose ascorbate has the potential to be a novel treatment option to hormone-refractory prostate cancer. PMID:22205155

Chen, Ping; Yu, Jun; Chalmers, Brain; Drisko, Jeanne; Yang, Jun; Li, Benyi; Chen, Qi

2012-04-01

375

Novel composite material polyoxovanadate@MIL-101(Cr): a highly efficient electrocatalyst for ascorbic acid oxidation.  

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A novel hybrid composite material, PMo10V2@MIL-101 was prepared by the encapsulation of the tetra-butylammonium (TBA) salt of the vanadium-substituted phosphomolybdate [PMo10V2O40](5-) (PMo10V2) into the porous metal-organic framework (MOF) MIL-101(Cr). The materials characterization by powder X-ray diffraction, Fourier transform infrared spectra and scanning electron microscopy confirmed the preparation of the composite material without disruption of the MOF porous structure. Pyrolytic graphite electrodes modified with the original components (MIL-101(Cr), PMo10V2), and the composite material PMo10V2@MIL-101 were prepared and their electrochemical responses were studied by cyclic voltammetry. Surface confined redox processes were observed for all the immobilized materials. MIL-101(Cr) showed one-electron reduction process due to chromium centers (Cr(III) ? Cr(II)), while PMo10V2 presented five reduction processes: the peak at more positive potentials is attributed to two superimposed 1-electron vanadium reduction processes (V(V) ? V(IV)) and the other four peaks to Mo-centred two-electron reduction processes (Mo(VI) ? Mo(V)). The electrochemical behavior of the composite material PMo10V2@MIL-101 showed both MIL-101(Cr) and PMo10V2 redox features, although with the splitting of the two vanadium processes and the shift of the Mo- and Cr- centered processes to more negative potentials. Finally, PMo10V2@MIL-101 modified electrode showed outstanding enhanced vanadium-based electrocatalytic properties towards ascorbic acid oxidation, in comparison with the free PMo10V2, as a result of its immobilization into the porous structure of the MOF. Furthermore, PMo10V2@MIL-101 modified electrode showed successful simultaneous detection of ascorbic acid and dopamine. PMID:24308331

Fernandes, Diana M; Barbosa, André D S; Pires, João; Balula, Salete S; Cunha-Silva, Luís; Freire, Cristina

2013-12-26

376

Ascorbic acid, alpha-tocopherol, and oregano supplements reduce stress-induced deterioration of chicken meat quality.  

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In order to ameliorate a negative effect of stress on meat quality characteristics, chickens were fed a diet supplemented with a combination of ascorbic acid (1,000 ppm) and alpha-tocopherol (200 ppm) or oregano (3%), which has a high content of antioxidants. Chickens were slaughtered by cervical dislocation in the stable (no stress) or after transport and electrical stunning at the slaughter plant (stress). Activities of antioxidative enzymes (catalase, superoxide dismutase, and glutathion peroxidase) in pectoralis major (PM), iliotibialis (IL), and liver were unaffected by supplementation. However, erythrocyte stability, which is a more complex model system for determining oxidative status, increased with ascorbic acid-alpha-tocopherol supplementation and tended to increase after oregano supplementation. In nonstressed birds, this improved antioxidative status was reflected in decreased TBA-reactive substances (TBARS) in PM and liver of ascorbic acid-alpha-tocopherol-supplemented chickens and likewise in liver from oregano-supplemented chickens compared to that of nonstressed control birds. However, postmortem temperature, pH, and water-holding capacity were not affected by supplementation. Drip loss from oregano-supplemented chickens showed increased protein oxidation in specific bands, but this did not relate to water-holding capacity or antioxidative status. When exposed to stress, the concentration of TBARS in the control animals increased in PM and IL. Ascorbic acid-alpha-tocopherol supplementation protected IL, and oregano supplementation protected PM from stress-induced increases in TBARS. This differential effect between muscles may indicate differences in protection mechanisms. In conclusion, ascorbic acid-alpha-tocopherol and oregano supplements to chickens protect against stress-induced increase in TBARS, in different muscles. PMID:12943308

Young, J F; Stagsted, J; Jensen, S K; Karlsson, A H; Henckel, P

2003-08-01

377

Protective role of ascorbic acid isolated from Cissus quadrangularis on NSAID induced toxicity through immunomodulating response and growth factors expression.  

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The present study investigate the effect of ascorbic acid, the major bioactive component isolated from Cissus quadrangularis extract (CAA) on inflammatory cytokines and growth factors in non-steroidal anti-inflammatory drug (NSAID) induced gastric ulcer. Analysis of serum cytokine profile using enzymelinked immunosorbent assay (ELISA) showed a drastic increase in interleukin (IL)-1beta, IL-6, tumour necrosis factor-alpha (TNF)-alpha, interferon-gamma (IFN-gamma) and decrease in IL-10, Il-4 and prostaglandin E2 (PGE2) levels in NSAID (aspirin) treated rats. The reduction of growth factors such as transforming growth factor-alpha (TGF)-alpha and vascular endothelial cell growth factor (VEGF) by aspirin was determined by immunohistochemistry method. Administration of CAA produced significant protection against aspirin induced gastric toxicity by showing significant increase in PGE2, TGF-alpha, VEGF expression and accompanied by a significant inhibition of nitric oxide and regulating the levels of cytokines in rats. These findings suggest that CAA prevents gastric ulcer formation due to its immunomodulatory effect, antioxidant activity along with the ability to modulate PG synthesis and up-regulation of the growth factors. PMID:18773975

Jainu, Mallika; Mohan, Kunju Vijai

2008-12-20

378

Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis  

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Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na{sub 3}VO{sub 4}) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na{sub 3}VO{sub 4} was cytotoxic against T24 cells (EC{sub 50} = 5.8 ?M at 24 h), but in the presence of ascorbate (100 ?M) the EC{sub 50} fell to 3.3 ?M. Na{sub 3}VO{sub 4} plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na{sub 3}VO{sub 4} did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na{sub 3}VO{sub 4} and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na{sub 3}VO{sub 4} alone, or combined with ascorbate, increased catalase activity, but only Na{sub 3}VO{sub 4} plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na{sub 3}VO{sub 4} plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na{sub 3}VO{sub 4}. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na{sub 3}VO{sub 4} in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.

Günther, T-hat nia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; Ourique da Silva, Fabiana; Bücker, Nádia Cristina Falcão [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Pich, Claus Tröger [Campus de Araranguá, Universidade Federal de Santa Catarina, Araranguá (Brazil); Ferreira, Eduardo Antonio [Universidade de Brasília, Faculdade de Ceilândia, DF (Brazil); Filho, Danilo Wilhelm [Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Verrax, Julien; Calderon, Pedro Buc [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels (Belgium); Pedrosa, Rozangela Curi, E-mail: rozangelapedrosa@gmail.com [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil)

2013-01-18

379

A biosensor based on zucchini (Cucurbita pepo L.) homogenate as a biorecognition layer for ascorbic acid determination.  

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An amperometric biosensor based on zucchini (Cucurbita pepo) tissue homogenate is presented. The zucchini tissue homogenate was crosslinked with gelatine using glutaraldehyde and fixed on a pretreated teflon membrane. The zucchini tissue contained the enzyme ascorbate oxidase and this enzyme catalyzed the oxidation of ascorbic acid in the presence of dissolved oxygen. The principle of the measurements was based on the determination of the decrease in the dissolved oxygen level. Determinations were carried out by standard curves, which were obtained by the measurement of the decrease in the oxygen level related to ascorbic acid concentration. Optimization and characterization studies of the biosensor were carried out in detail. First of all, the amounts of zucchini tissue homogenate, gelatin, and glutaraldehyde percentage were optimized. Experimental parameters such as buffer system, pH, buffer concentration, and temperature were also optimized carefully. Thermal stability, storage stability, and repeatability of the biosensor were investigated. A linear response was observed from 5x10(-6) M to 1.2x10(-3) M ascorbic acid. Finally, the results of some plant and drug samples analyzed with the presented biosensor compared with the spectrophotometric method (Tillman reagent) used as a reference. PMID:20384439

Sezgintürk, Mustafa Kemal; Koca, Halit Bu?ra; Ozben, Yavuz Selim; Dinçkaya, Erhan

2010-08-01

380

Ascorbate and dehydroascorbic acid as reliable biomarkers of oxidative stress : analytical reproducibility and long-term stability of plasma samples subjected to acidic deproteinization  

DEFF Research Database (Denmark)

Lack of post-sampling stability of ascorbate and dehydroascorbic acid and failure to block their in vivo equilibrium have lowered their value as biomarkers of oxidative stress and limited the ability to further investigate their possible role in disease prevention. In the present paper, the analytical reproducibility was tested by repeated analysis of plasma aliquots from one individual over four years. The plasma was subjected to acidic deproteinization with an equal volume of 10% meta-phosphoric acid containing 2 mM EDTA and analyzed for ascorbate and dehydroascorbic acid by high-performance liquid chromatography with coulometric detection. In a parallel experiment, stability of human plasma samples treated as above and stored at -80°C for five years was tested in a cohort of 131 individuals. No degradation or shift in the equilibrium between ascorbate and dehydroascorbic acid was observed in either of the experiments. In conclusion, ascorbate and dehydroascorbic acid can be adequately preserved in plasma stored at -80°C following acidic deproteinization with meta-phosphoric acid containing 2 mM EDTA.

Lykkesfeldt, Jens

2007-01-01

381

Influence of ascorbic acid on in vivo amidation of alpha-melanocyte stimulating hormone in guinea pig pituitary  

DEFF Research Database (Denmark)

The effect of ascorbic acid depletion on the amidation of alphamelanocyte stimulating hormone (alpha MSH) was studied in vivo in guinea pig pituitary. After four weeks, the concentration of ascorbic acid was 1.20 +/- 0.11 mumol/g tissue (mean +/- SD) in the pituitary and 0.34 +/- 0.07 mumol/g tissue in the cerebral cortex from the depleted animals versus 7.58 +/- 0.08 and 1.51 +/- 0.32 mumol/g tissue, respectively, in the control animals. In the pituitaries from the animals depleted of ascorbate (N = 4), the relative amount of alpha MSH was reduced to approximately half the values obtained in the control group (from 66.5 +/- 4.6% of total ACTH-related peptides to 31.1 +/- 12.2% (P less than 0.0025]. A concomitant increase (from 5.9 +/- 3.1% to 19.4 +/- 4.3% (P less than 0.004] in ACTH (1-14) (the glycine-extended precursor of alpha MSH) immunoreactivity and a smaller increase in ACTH (1-39) immunoreactivity was observed in the depleted guinea pigs. Gel chromatography and reversed-phase high-performance luquid chromatography showed that the alpha MSH and ACTH (1-14) immunoreactivity was of low molecular weight and partly mono- or diacetylated. Depletion of ascorbic acid had no influence on the degree of acetylation of alpha MSH and ACTH (1-14). It is concluded that depletion of ascorbic acid reduces the in vivo amidation of ACTH (1-14) in the guinea pig pituitary.

Fenger, M; Hilsted, L

1988-01-01

382

All-solid-state potentiometric sensors for ascorbic acid by using a screen-printed compatible solid contact  

International Nuclear Information System (INIS)

The development of all-solid-state potentiometric ion selective electrodes for monitoring of ascorbic acid, by using a screen-printed compatible solid contact is described. The applied methodology is based on the use of PVC membrane modified with some firstly-tested ionophores (triphenyltin(IV)chloride, triphenyltin(IV)hydroxide and palmitoyl-L-ascorbic acid) and a novel one synthesized in our laboratory (dibutyltin(IV) diascorbate). Synthesis protocol and some preliminary identification studies are given. A conductive graphite-based polymer thick film ink was used as an internal solid contact between the graphite electrode and the PVC membrane. The presence and the nature of the solid contact (plain or doped with lanthanum 2,6-dichlorophenolindophenol (DCPI)) seem to enhance the analytical performance of the electrodes in terms of sensitivity, dynamic range, and response time. The analytical performance of the constructed electrodes was evaluated with potentiometry, constant-current chronopotentiometry and electrochemical impedance spectroscopy (EIS). The interference effect of various compounds was also tested. The potential response of the optimized Ph3SnCl-based electrode was linear against ascorbic acid concentration range 0.005-5.0 mM. The applicability of the proposed sensors in real samples was also tested. The detection limit was 0.002 mM ascorbic acid (50 mM phosphate, pH 5 in 50 mM KCl). The slope of the electrodes was super-Nernstian and pH depeelectrodes was super-Nernstian and pH dependent, indicating a mechanism involving a combination of charge transfer and ion exchange processes. Fabrication of screen-printed ascorbate ISEs has also been demonstrated

383

Amelioration of High Cholesterol Diet Caused Lipids Accumulation in Hepatic Cells by Rutin and Ascorbic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Non Alcoholic Fatty Liver Disease (NAFLD has become a very common metabolic disorder. It refers to a group of conditions where excess fats are deposited in hepatic cells. Several approaches have been considered for the management of NAFLD including dietary changes, which were reported to suppress hepatic lipids accumulation in previous studies. The present study was designed to investigate the possible synergistic effects of Rutin (RT and Ascorbic Acid (AA against lipids accumulation in hepatic cells of male Wistar albino rats. Thirty animals received freshly prepared experimental High Cholesterol Diets (HCD with or without RT and/or AA for 6 consecutive weeks. In hepatic tissues nucleic acids, total protein, Total Cholesterol (TC and Triglycerides (TG concentrations were measured. Histopathological changes were also observed. In hepatic cells, nucleic acids and total protein levels were significantly reduced in HCD alone fed group, quite the reverse, TC and TG levels increased. RT and/or AA supplementation along with HCD showed antilipidemic effects in hepatic cells while compared to only HCD group. Histopathological assessment of the liver sections revealed moderate degree of hepatotoxicity following HCD feedings and mild degree of hepatoxocity when combining either RT or AA with HCD, while HCD+RT+AA group had no such changes. The present data demonstrated that the degree of HCD induced hepatotoxicity is in positive correlation with hepatic lipids accumulations. Both RT and AA could reduce this toxicity through their antilipidaemic properties, which may be augmented by their combined intake.

Abdulaziz M. Aleisa

2013-04-01

384

Study on the Ascorbic Acid Content of rose Hip fruit Depending on Stationary Conditions  

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Full Text Available The dog rose area includes southern and central Europe, reaching southern Scandinavia; it is also found in Asia Minor, Central Asia and North Africa. In our country, Rosa canina is the most widespread of the many species of Rosa, common in all areas. The components of the station, known also as the „stationary factors” affect differently the plant life and their chemical composition. Cynosbati fructus is the false fruit of Rosa canina L. (Rosaceae, known in Romanian as rose hip. The rose hip contain as active ingredients 500-1000 % vitamin C, 600-10000 mg% carotenoids, pectin, dextrin, vitamins B2, E, PP, flavone, sugars, organic acids, tannins, volatile oil, vanillin, triterpenoid saponosides, beta-sitosterol, fat (lecithin, glycerides of fatty acids in seeds, minerals (potassium, calcium, magnesium, iron. Vitamin C (ascorbic acid plays an important role in human body. The greatest amount is found in plants which reached maturity. It is concentrated in the rose hip flesh. Solutions easily destroyit in the presence of UV, of copper, silver, iron and oxidative enzymes traces. Vitamin C participates actively in all processes of oxidoreductions of the living cell. Its lack in food causes the disease called scurvy which manifests itself by inflammated and bleeding gums, tooth loss. Rose hip fruits are known as medicines since prehistoric times.

Sorina Ropciuc

2011-10-01

385

Effect of naloxone on morphine-induced changes in striatal dopamine metabolism and glutamate, ascorbic acid and uric acid release in freely moving rats  

OpenAIRE

Recent findings have shown that systemic morphine increases extracellular dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), ascorbic acid (AA) and uric acid concentrations in the striatum of freely moving rats. The morphine-induced increase in DA oxidative metabolism is highly correlated with that of xanthine. In the present study, we evaluated the effects of subcutaneous (s.c.) naloxone (1 mg/kg) on morphine-induced changes in DA, DOPAC, HVA, 5-hydroxyindoleacetic a...

Enrico, Paolo; Mura, Maria A.; Esposito, Giovanni; Serra, Pier Andrea; Migheli, Rossana; Natale, Guglielmo; Desole, Maria Speranza; Miele, Maddalena; Miele, Egidio

1998-01-01

386

Inhibition of liver microsomal lipid peroxidation by 13-cis-retinoic acid.  

Science.gov (United States)

The effects of 13-cis-retinoic acid on iron/ascorbate-dependent lipid peroxidation were investigated with rat liver microsomes. 13-cis-retinoic acid effectively inhibited malondialdehyde generation and molecular oxygen consumption associated with lipid peroxidation. Under the conditions employed, inhibition was complete at concentrations as low as 25 microM and the IC50 was 10 microM. Evidence for concomitant retinoid oxidation by microsomal unsaturated fatty acid-derived peroxyl radicals was demonstrated by detection of several retinoid-derived metabolites, including 5,8-oxy-13-cis-retinoic acid, generated during lipid peroxidation. The data indicate that 13-cis-retinoic acid inhibits lipid peroxidation by scavenging lipid peroxyl radicals with its conjugated polyene system. Its antioxidant properties may contribute to the pharmacological activities of this and related retinoids. PMID:2253899

Samokyszyn, V M; Marnett, L J

1990-01-01

387

Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)  

International Nuclear Information System (INIS)

An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 ± 4 cm and weight of 86 ± 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl2.H2O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl2.H2O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposedntrol group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to reduce tissue accumulation of Cd and associated oxidative stress in freshwater catfish.

388

Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)  

Energy Technology Data Exchange (ETDEWEB)

An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 {+-} 4 cm and weight of 86 {+-} 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl{sub 2}.H{sub 2}O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl{sub 2}.H{sub 2}O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to reduce tissue accumulation of Cd and associated oxidative stress in freshwater catfish.

Kumar, Puneet, E-mail: puneetbiochem@gmail.com [Aquatic Biotechnology and Fish Pathology Laboratory, Department of Animal Science, M.J.P. Rohilkhand University, Bareilly-243 006 (India); Prasad, Y. [Aquatic Biotechnology and Fish Pathology Laboratory, Department of Animal Science, M.J.P. Rohilkhand University, Bareilly-243 006 (India); Patra, A.K. [West Bengal University of Animal and Fishery Sciences, Kolkata-700037 (India); Ranjan, R.; Swarup, D.; Patra, R.C. [Division of Medicine, Indian Veterinary Research Institute, Izatnagar-243122 (India); Pal, Satya [Env. Eng. Lab., Deptt. of Civil Engineering, I.I.T., Roorkee-247667 (India)

2009-09-01

389

Evaluation of the Effects of Intravenous Ascorbic Acid on Correction of Anemia in Renal Failure Patients Undergoing Hemodialysis  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: Hemodialysis patients often develop resistance to recombinant human erythropoietin due to functional Iron Deficiency. In these patients iron therapy can be hazardous leading to hemosiderosis. Recent studies have suggested that intravenous ascorbic acid may be able to improve this hyporeponsiveness. The aim of this study was to evaluate the effect of intravenous ascorbic acid on functional iron deficiency and whether it results in better correction of anemia or not. Methods: Forty hemodialysis patients with serum ferritin >300ug/l, hemoglobin less than 10 gm/dl, and transferrin saturation less than 20% were selected. The reticulocyte index and KT/V was also calculated. Patients were later administered 500 mg intravenous ascorbic acid three times a week for three months. At the end of study, serum ferritin, transferrin saturation, hemoglobin, reticulocyte index and KT/V were rechecked and compared with the base line values by before and after method. Results: Serum ferritin decreased significantly (median base line ferritin 480.45 ug/dl as compared to final ferritin level of 363.78 (P=0.0001, whereas there was a significant rise in hemoglobin concentration (median baseline hemoglobin 8.92 gm/dl compared to 9.88gm/dl (P=0.0001. Transferrin saturation was also significantly raised (median baseline transferrin saturation 17.35% as compared to final level of 25.12% (P= 0.0001. KT/V before and after treatment with ascorbic acid had no significant change (P =0.396. Finally, the rate of decrease in serum ferritin and increase in hemoglobin according to age and duration of dialysis was studied. The effect of ascorbic acid was found to be significantly greater in older patients and those with longer duration of dialysis (P <0.05; but there was no significant relationship between transferrin saturation increase and age or duration of dialysis. Conclusion: Intravenous ascorbic acid may partially correct functional iron deficiency, although anemia is not totally corrected.

AA Shojaie

2006-04-01

390

Effects of genotype, latitude, and weather conditions on the composition of sugars, sugar alcohols, fruit acids, and ascorbic acid in sea buckthorn (Hippophaë rhamnoides ssp. mongolica) berry juice.  

Science.gov (United States)

Sea buckthorn berries (Hippophaë rhamnoides ssp. mongolica) of nine varieties were collected from three growth locations in five inconsecutive years (n = 152) to study the compositional differences of sugars, sugar alcohols, fruit acids, and ascorbic acid in berries of different genotypes. Fructose and glucose (major sugars) were highest in Chuiskaya and Vitaminaya among the varieties studied, respectively. Malic acid and quinic acid (major acids) were highest in Pertsik and Vitaminaya, respectively. Ascorbic acid was highest in Oranzhevaya and lowest in Vitaminaya. Berry samples of nine varieties collected from two growth locations in five years (n = 124) were combined to study the effects of latitude and weather conditions on the composition of H. rhamnoides ssp. mongolica. Sea buckthorn berries grown at lower latitude had higher levels of total sugar and sugar/acid ratio and a lower level of total acid and were supposed to have better sensory properties than those grown at higher latitude. Glucose, quinic acid, and ascorbic acid were hardly influenced by weather conditions. The other components showed various correlations with temperature, radiation, precipitation, and humidity variables. In addition, fructose, sucrose, and myo-inositol correlated positively with each other and showed negative correlation with malic acid on the basis of all the samples studied (n = 152). PMID:22397621

Zheng, Jie; Yang, Baoru; Trépanier, Martin; Kallio, Heikki

2012-03-28

391

Sensitive and selective trypsin detection using redox cycling in the presence of L-ascorbic acid.  

Science.gov (United States)

We report a simple, sensitive, and selective electrochemical method for trypsin detection that can cover a wide range of concentrations. The method is based on the proteolytic generation of an electroactive species (P) by trypsin followed by a signal-amplified electrochemical measurement of P using electrochemical-chemical (EC) or electrochemical-chemical-chemical (ECC) redox cycling. The detection is performed using bare indium-tin oxide (ITO) electrodes without washing steps. P is generated by the cleavage of an amide bond between P and oligopeptide (Gly-Pro-Arg) at the C-terminal of Gly-Pro-Arg-P. Four trypsin products including 4-amino-1-naphthol (AN) and their trypsin substrates are investigated to obtain a high signal-to-background ratio in ECC redox cycling. AN and its trypsin substrate produce the highest signal-to-background ratio. The detection limits obtained with ECC redox cycling involving AN (approximately 1 ng mL(-1) and 100 ng mL(-1) with an incubation period of 2 h and 30 min, respectively) in Tris buffer (pH 8.0) are lower than those obtained with EC redox cycling involving AN (approximately 5 ng mL(-1) and 200 ng mL(-1) with an incubation period of 2 h and 30 min, respectively). In trypsin detection using ECC redox cycling, the interference effects of electroactive species such as l-ascorbic acid and uric acid are not significant. PMID:24955437

Park, Seonhwa; Yang, Haesik

2014-08-21

392

Ascorbic acid and citric flavonoids for broilers under heat stress: effects on performance and meat quality  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The aim of this study was to evaluate the effects of increasing doses of ascorbic acid (AA) and citric flavonoids (quercetin and rutin) on the performance and meat quality characteristics of broilers submitted to cyclic heat stress. Four-hundred one-day-old female Ross 308 were housed in 40 battery [...] cages a in temperature controlled room. Treatments consisted of 0, 250, 500, and 1000 g/ton on of AA + citric flavonoids. Birds were fed ad libitum until 32 day of age. Beginning on day 14 post-hatch until the end of the experiment, in order to simulate cyclic heat stress, the temperature inside the room was increased to 32°C for 5 hours, and decreased until reaching the comfort temperature corresponding to the age of the animals. Birds were slaughtered at 33 days of age, and carcass and commercial cuts yields were determined. Thighs and boneless breast samples were collected and frozen for subsequent analyses of pH, cooking loss, shear force, color, and Thiobarbituric Acid Reactive Substances (TBARS). Significant differences (p

JEM, Peña; SL, Vieira; J, López; RN, Reis; R, Barros; FVF, Furtado; PX, Silva.

2008-06-01

393

Thermal-driven attachment of gold nanoparticles prepared with ascorbic acid onto indium tin oxide surfaces  

International Nuclear Information System (INIS)

Thermal-driven attachment of gold nanoparticles (AuNPs), of which size was less than 50 nm, onto the surfaces of indium tin oxide (ITO) is reported as a new phenomenon. This was permitted by preparing AuNPs via the reduction of hydrogen tetrachloroaurate (HAuCl4) with ascorbic acid (AA). While the AuNPs prepared via the AA reduction sparsely attached on the surface of ITO even at room temperature, a heat-up treatment at ca. 75 °C caused denser attachment of AuNPs on ITO surfaces. The attached density and the homogeneity after the thermal treatment were better than those of AuNP/ITO prepared using 3-aminopropyl-trimethoxysilane linker molecules. The denser attachment was observed similarly both by the immersion of ITO samples after the preparations of AuNPs by AA and by the in situ preparation of AuNPs with AA together with ITO samples. Thus, it is considered that the thermal-driven attachment of AuNPs would occur after the formation of AuNPs in the aqueous solutions, not via the growth of AuNPs on ITO surfaces. The preparation of AuNPs with AA would be a key for the thermal-driven attachment because the same attachments were not observed for AuNPs prepared with citrate ions or commercially available tannic acid-capped AuNPs.

394

Thermal-driven attachment of gold nanoparticles prepared with ascorbic acid onto indium tin oxide surfaces  

Energy Technology Data Exchange (ETDEWEB)

Thermal-driven attachment of gold nanoparticles (AuNPs), of which size was less than 50 nm, onto the surfaces of indium tin oxide (ITO) is reported as a new phenomenon. This was permitted by preparing AuNPs via the reduction of hydrogen tetrachloroaurate (HAuCl{sub 4}) with ascorbic acid (AA). While the AuNPs prepared via the AA reduction sparsely attached on the surface of ITO even at room temperature, a heat-up treatment at ca. 75 Degree-Sign C caused denser attachment of AuNPs on ITO surfaces. The attached density and the homogeneity after the thermal treatment were better than those of AuNP/ITO prepared using 3-aminopropyl-trimethoxysilane linker molecules. The denser attachment was observed similarly both by the immersion of ITO samples after the preparations of AuNPs by AA and by the in situ preparation of AuNPs with AA together with ITO samples. Thus, it is considered that the thermal-driven attachment of AuNPs would occur after the formation of AuNPs in the aqueous solutions, not via the growth of AuNPs on ITO surfaces. The preparation of AuNPs with AA would be a key for the thermal-driven attachment because the same attachments were not observed for AuNPs prepared with citrate ions or commercially available tannic acid-capped AuNPs.

Aziz, Md. Abdul; Oyama, Munetaka, E-mail: oyama.munetaka.4m@kyoto-u.ac.jp [Kyoto University, Department of Material Chemistry, Graduate School of Engineering (Japan)

2013-05-15