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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  

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

2013-08-15

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Ascorbic Acid  

Science.gov (United States)

Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

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Ascorbic acid-dependent GLUT3 inhibition is a critical step for switching neuronal metabolism.  

Science.gov (United States)

Intracellular ascorbic acid is able to modulate neuronal glucose utilization between resting and activity periods. We have previously demonstrated that intracellular ascorbic acid inhibits deoxyglucose transport in primary cultures of cortical and hippocampal neurons and in HEK293 cells. The same effect was not seen in astrocytes. Since this observation was valid only for cells expressing glucose transporter 3 (GLUT3), we evaluated the importance of this transporter on the inhibitory effect of ascorbic acid on glucose transport. Intracellular ascorbic acid was able to inhibit (3)H-deoxyglucose transport only in astrocytes expressing GLUT3-EGFP. In C6 glioma cells and primary cultures of cortical neurons, which natively express GLUT3, the same inhibitory effect on (3)H-deoxyglucose transport and fluorescent hexose 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG) was observed. Finally, knocking down the native expression of GLUT3 in primary cultured neurons and C6 cells using shRNA was sufficient to abolish the ascorbic acid-dependent inhibitory effect on uptake of glucose analogs. Uptake assays using real-time confocal microscopy demonstrated that ascorbic acid effect abrogation on 2-NBDG uptake in cultured neurons. Therefore, ascorbic acid would seem to function as a metabolic switch inhibiting glucose transport in neurons under glutamatergic synaptic activity through direct or indirect inhibition of GLUT3. PMID:21321936

Beltrán, Felipe A; Acuña, Aníbal I; Miró, María Paz; Angulo, Constanza; Concha, Ilona I; Castro, Maite A

2011-12-01

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Studies on rancidity inhibition in frozen horse mackerel (Trachurus trachurus) by citric and ascorbic acids  

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This study is aimed to investigate the effect of aqueous solutions of citric acid (CA) and ascorbic acid (AA) on the lipid stability of horse mackerel (Trachurus trachurus) fillets and whole fish during frozen storage (up to 6 and 9 months, respectively) by means of a soaking pretreatment. Best oxidation inhibition results on fish fillets were obtained when employing a 0.5% CA solution. Lower (p <0.05) peroxide (month?3), thiobarbituric acid-reactive substance (months?1 and 3) and fluores...

Aubourg, Santiago P.; Pe?rez-alonso, Francisco; Gallardo, Jose? Manuel

2004-01-01

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Polyhydroxybenzoates inhibit ascorbic acid activation of mitochondrial glycerol-3-phosphate dehydrogenase: implications for glucose metabolism and insulin secretion.  

Science.gov (United States)

Glycerol-3-phosphate dehydrogenase from pig brain mitochondria was stimulated 2.2-fold by the addition of 50 microm l-ascorbic acid. Enzyme activity, dependent upon the presence of l-ascorbic acid, was inhibited by lauryl gallate, propyl gallate, protocatechuic acid ethyl ester, and salicylhydroxamic acid. Homogeneous pig brain mitochondrial glycerol-3-phosphate dehydrogenase was activated by either 150 microm L-ascorbic acid (56%) or 300 microm iron (Fe(2+) or Fe(3+) (62%)) and 2.6-fold by the addition of both L-ascorbic acid and iron. The addition of L-ascorbic acid and iron resulted in a significant increase of k(cat) from 21.1 to 64.1 s(-1), without significantly increasing the K(m) of L-glycerol-3-phosphate (10.0-14.5 mm). The activation of pure glycerol-3-phosphate dehydrogenase by either L-ascorbic acid or iron or its combination could be totally inhibited by 200 microm propyl gallate. The metabolism of [5-(3)H]glucose and the glucose-stimulated insulin secretion from rat insulinoma cells, INS-1, were effectively inhibited by 500 microm or 1 mm propyl gallate and to a lesser extent by 5 mm aminooxyacetate, a potent malate-aspartate shuttle inhibitor. The combined data support the conclusion that l-ascorbic acid is a physiological activator of mitochondrial glycerol-3-phosphate dehydrogenase, that the enzyme is potently inhibited by agents that specifically inhibit certain classes of di-iron metalloenzymes, and that the enzyme is chiefly responsible for the proximal signal events in INS-1 cell glucose-stimulated insulin release. PMID:11060297

Wells, W W; Xu, D P; Washburn, M P; Cirrito, H K; Olson, L K

2001-01-26

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Ascorbic acid supplementation enhances recovery from ethanol induced inhibition of Leydig cell steroidogenesis than abstention in male guinea pigs.  

Science.gov (United States)

The impact of ascorbic acid supplementation against ethanol induced Leydig cell toxicity was studied in guinea pigs. Male guinea pigs were exposed to ethanol (4g/kgb.wt.) for 90 days. After 90 days, ethanol administration was completely stopped and animals in the ethanol group were divided into abstention group and ascorbic acid supplemented group (25mg/100gb.wt.) and those in control group were maintained as control and control+ascorbic acid group. Ethanol administration reduced the serum testosterone and LH (luteinising hormone) levels and elevated estradiol levels. Cholesterol levels in Leydig cell were increased whereas the mRNA and protein expressions of StAR (steroidogenic acute regulatory) protein, cytochrome P450scc (cytochrome p450side chain cleavage enzyme), 3?-HSD (3?-hydroxysteroid dehydrogenase), 17?-HSD (17?-hydroxysteroid dehydrogenase) and LH receptor were drastically reduced. Administration of ascorbic acid resulted in alteration of all these parameters indicating enhanced recovery from ethanol induced inhibition of Leydig cell steroidogenesis. Although abstention could also reduce the inhibition of steroidogenesis, this was lesser in comparison with ascorbic acid supplemented group. PMID:24333212

Radhakrishnakartha, Harikrishnan; Appu, Abhilash Puthuvelvippel; Indira, Madambath

2014-01-15

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Ascorbic acid inhibits development of tolerance and dependence to opiates in mice: Possible glutamatergic or dopaminergic modulation  

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Full Text Available In a recent study, it has been demonstrated that ascorbic acid possessed antidopaminergic activity and modulate the glutamatergic neurotransmission in mice. With this background, the present study was undertaken to study the effect of ascorbic acid on the development of tolerance and dependence to opiate and its mechanism of action. Male Swiss mice weighing 20-25 g were used in the present study. Mice were made physically dependent on opioid by the chronic administration of morphine (10 mg/kg, twice a day, for 9 days intraperitoneally. Ascorbic acid, haloperidol (dopamine antagonist or MK 801 (NMDA receptor antagonist was administered daily for 9 d before challenging the animals with morphine. The development of tolerance was assessed by noting the tail-flick latency on day 1, 3, 9 and 10. On the 10 th day after the measurement of tail-flick latency, animals were challenged with naloxone (2 mg/kg., i.p. and incidence of escape jumps were recorded by placing the animals in 45 cm high plexiglass container. Ascorbic acid (400-1600 mg/kg dose dependently inhibited development of tolerance and dependence to morphine as noted from tail-flick latency. When given along with MK 801 (0.01 mg/kg., i.p or haloperidol (0.1 mg/kg i.p., ascorbic acid (800 mg/kg., i.p. potentiated the response of MK 801 or haloperidol. In conclusion, it is hypothesized that inhibition of development of tolerance and dependence to morphine by ascorbic acid appears to have two components, namely dopaminergic and glutamatergic.

Kulkarni S

2008-01-01

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Metalloporphyrin synergizes with ascorbic acid to inhibit cancer cell growth through fenton chemistry.  

Science.gov (United States)

Ascorbic acid (AA) has been reported to inhibit tumor cell growth through the generation of extracellular hydrogen peroxide (H(2)O(2)). However, the clinical utility of AA has been limited by relatively low potency and in vivo efficacy. This study reports that the metalloporphyrin, Mn(III) tetrakis(N-methylpyridinium-2-yl)porphyrin(5+) (MnTMPyP), has a potent synergistic cytotoxic effect when combined with AA in a variety of cancer cell lines. In the presence of MnTMPyP, the concentration of AA required to inhibit cancer cell growth was markedly reduced. In vitro (cell-free) experiments demonstrated that AA alone enhanced the Fenton reaction that produces cytotoxic hydroxyl radical (HO(*)); however, this reaction was limited by the low rate by which AA generates H(2)O(2) (Fenton reaction substrate) from O(2). MnTMPyP catalyzed H(2)O(2) generation through the AA-facilitated Mn(II III)TMPyP redox cycle and thereby markedly potentiated the Fenton reaction. Accordingly, MnTMPyP and AA resulted in increased cellular levels of H(2)O(2) and HO(*) in cancer cells, which mediate the synergistic cytotoxicity of this combined treatment. This effect was inhibited by cellular enzymes that metabolize H(2)O(2), such as catalase and glutathione peroxidase, suggesting that selective killing of cancer cells deficient in such enzymes can be achieved in vivo. PMID:20735206

Tian, Junqiang; Peehl, Donna M; Knox, Susan J

2010-08-01

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Inhibition of radiation induced apoptosis in escherichia coli and bacillus subtilis by ascorbic acid and zinc sulphate  

International Nuclear Information System (INIS)

Programmed cell death or apoptosis a process of physiological cell death, was expressed as DNA fragmentation. The process was carried out in two isolates of bacteria bacillus subtilis and escherichia coli by exposure to dose of gamma-radiation equal to their D10 value. Post irradiation treatment of these bacteria with ascorbic acid at concentrations 400, 500 and 600 mg/ml or zinc sulfate at conentrations 10, 20 and 50 mg/ml at different times showed that these compounds inhibit radiation induced apoptosis in both species. It had been investigated that DNA fragmentation appears to be an essential step in apoptosis after radiation injury and that a strong potentiation of this inhibitory effect was obtained with ascorbic acid and zinc sulfate

2002-07-01

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

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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.

Supranee MANURAKCHINAKORN

2010-01-01

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Ascorbic acid and reactive oxygen species are involved in the inhibition of seed germination by abscisic acid in rice seeds  

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The antagonism between abscisic acid (ABA) and gibberellin (GA) plays a key role in controlling seed germination, but the mechanism of antagonism during this process is not known. The possible links among ABA, reactive oxygen species (ROS), ascorbic acid (ASC), and GA during rice seed germination were investigated. Unlike in non-seed tissues where ROS production is increased by ABA, ABA reduced ROS production in imbibed rice seeds, especially in the embryo region. Such reduced ROS also led to...

Ye, Nenghui; Zhu, Guohui; Liu, Yinggao; Zhang, Aying; Li, Yingxuan; Liu, Rui; Shi, Lu; Jia, Liguo; Zhang, Jianhua

2012-01-01

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High dose concentration administration of ascorbic acid inhibits tumor growth in BALB/C mice implanted with sarcoma 180 cancer cells via the restriction of angiogenesis  

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Full Text Available Abstract To test the carcinostatic effects of ascorbic acid, we challenged the mice of seven experimental groups with 1.7 × 10-4 mol high dose concentration ascorbic acid after intraperitoneal administrating them with sarcoma S-180 cells. The survival rate was increased by 20% in the group that received high dose concentration ascorbic acid, compared to the control. The highest survival rate was observed in the group in which 1.7 × 10-4 mol ascorbic acid had been continuously injected before and after the induction of cancer cells, rather than just after the induction of cancer cells. The expression of three angiogenesis-related genes was inhibited by 0.3 times in bFGF, 7 times in VEGF and 4 times in MMP2 of the groups with higher survival rates. Biopsy Results, gene expression studies, and wound healing analysis in vivo and in vitro suggested that the carcinostatic effect induced by high dose concentration ascorbic acid occurred through inhibition of angiogenesis.

Lee Hye

2009-08-01

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The ascorbic acid paradox.  

Science.gov (United States)

Ascorbic acid (AA) is a common culture medium and dietary supplement. While AA is most commonly known for its antioxidant properties, it is also known to function as a pro-oxidant under select conditions. However, the complexity and often unknown composition of biological culture systems makes prediction of AA behaviour in supplemented cultures challenging. The frequent observation of outcomes inconsistent with antioxidant behaviour suggests that AA may be playing a pro-oxidant role more often than appreciated. In this work we explored the intracellular and extracellular impact of AA supplementation on KG1a myeloid leukaemia cells over a 24-h culture period following the addition of the AA supplement. At 24h we found that supplementation of AA up to 250?M resulted in intracellular antioxidant behaviour. However, when these same cultures were evaluated at 2 or 4h we observed pro-oxidant activity at the higher AA concentrations indicating that the outcome was very much time and dose dependent. In contrast, pro-oxidant activity was never observed in the extracellular medium. Paradoxically, and to our knowledge not previously reported, we observed that intracellular pro-oxidant activity and extracellular antioxidant activity could occur simultaneously. These results indicate that the precise activity of AA supplementation varies as a function of dose, time and cellular location. Further, these results demonstrate how in the absence of careful culture characterization the true impact of AA on cultures could be underappreciated. PMID:20732307

Osiecki, Michael; Ghanavi, Parisa; Atkinson, Kerry; Nielsen, Lars K; Doran, Michael R

2010-10-01

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Inhibition of UVA-mediated melanogenesis by ascorbic acid through modulation of antioxidant defense and nitric oxide system.  

Science.gov (United States)

Ascorbic acid (AA) has been well known as a skin whitening agent, although attempts have been made to evaluate its protective role against ultraviolet (UV)-induced skin hyperpigmentation or increased melanin production. While melanogenesis is a defense mechanism of the skin against UV irradiation, melanin overproduction may also contribute to melanoma initiation. UVA might play a role in melanogenesis through promoting oxidative stress, which occurs as the result of increased formation of oxidants and/or reactive nitrogen species (RNS) including nitric oxide (NO). Therefore, we investigated the antimelanogenic effect of AA (7.5-120 ?M) in association with its inhibitory effect on UVA-induced oxidant formation, NO production through endothelial and inducible NO synthases (eNOS and iNOS) activation and impairment of antioxidant defense using G361 human melanoma cells. Our study demonstrated a comparable ability of AA with that of kojic acid, a well-known tyrosinase inhibitor in inhibiting mushroom tyrosinase. Melanin content was reduced by AA, but neither tyrosinase activity nor mRNA levels were reduced by AA at non-cytotoxic concentrations in UVA-irradiated G361 cells. AA was shown to inhibit UVA-mediated catalase (CAT) inactivation, glutathione (GSH) depletion, oxidant formation and NO production through suppression of eNOS and iNOS mRNA. We report herein that AA can protect against UVA-dependent melanogenesis possibly through the improvement of antioxidant defense capacity and inhibition of NO production through down-regulation of eNOS and iNOS mRNA. PMID:21656367

Panich, Uraiwan; Tangsupa-a-nan, Vanida; Onkoksoong, Tasanee; Kongtaphan, Kamolratana; Kasetsinsombat, Kanda; Akarasereenont, Pravit; Wongkajornsilp, Adisak

2011-05-01

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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 (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

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Ascorbic acid specific utilization by some yeasts.  

Science.gov (United States)

One hundred and eighty strains of yeasts belonging to 17 genus and 53 species were screened for their ability to grow on ascorbic acid and iso-ascorbic acid as the sole carbon source. Most of the tested strains (157) were unable to grow on either compound. Strains of seven species of the genus Cryptococcus, of two Candida species, of Filobasidiella neoformans, Trichosporon cutaneum, Lipomyces starkeyi, Hansenula capsulata, and one strain of Aureobasidium pullulans were able to grow on ascorbic as well as on iso-ascorbic acid. Conversely, four strains of Aureobasidium pullulans, Candida blankii, and Cryptococcus dimennae could use only ascorbic acid for growth. PMID:3779527

Costamagna, L; Rosi, I; Garuccio, I; Arrigoni, O

1986-09-01

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Ascorbic acid modulates pathogenecity markers of Candida albicans  

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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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Evaluation of the Health Aspects of Ascorbic Acid, Sodium Ascorbate, Calcium Ascorbate, Erythorbic Acid, Sodium Erythorbate, and Ascorbyl Palmitate as Food Ingredients.  

Science.gov (United States)

The report, by a group of qualified scientists designated the Select Committee of GRAS Substances (SCOGS), provides an independent evaluation of the safety of ascorbic acid, sodium ascorbate, calcium ascorbate, erythorbic acid, sodium erythorbate, and asc...

1979-01-01

 
 
 
 
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Ascorbic acid modulation of calcium channels in pancreatic beta cells  

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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

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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

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An investigation of rancidity inhibition during frozen storage of Wels catfish (Silurus glanis) fillets by previous ascorbic and citric acid treatment  

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The effect of preliminary ascorbic and citric acid (AA and CA, respectively) soaking treatments on the rancidity development in Wels catfish (Silurus glanis) fillets during further frozen storage (?18 °C; up to 6 months) was studied. Rancidity development was measured by biochemical quality indices (formation of free fatty acids, peroxides and secondary oxidation products) and compared with sensory analysis (appearance, rancid odour and consistency) and general chemical analyses (pH, expre...

Pourashouri, Parastoo; Shabanpour, Bahareh; Aubourg, Santiago P.; Rohi, Javad Daghigh; Shabani, Ali

2009-01-01

24

Transfer of ascorbic acid across the vascular endothelium: mechanism and self-regulation  

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To determine how ascorbic acid moves from the bloodstream into tissues, we assessed transfer of the vitamin across the barrier generated by EA.hy926 endothelial cells when these were cultured on semipermeable filter supports. Ascorbate transfer from the luminal to the abluminal compartment was time dependent, inhibited by anion channel blockers and by activation of protein kinase A, but was increased by thrombin. Ascorbate transfer occurred by a paracellular route, since it did not correlate ...

2009-01-01

25

Transglucosylation of ascorbic acid to ascorbic acid 2-glucoside by a recombinant sucrose phosphorylase from Bifidobacterium longum.  

Science.gov (United States)

A novel transglycosylation reaction from sucrose to L-ascorbic acid by a recombinant sucrose phosphorylase from Bifidobacterium longum was used to produce a stable L-ascorbic acid derivative. The major product was detected by HPLC, and confirmed to be 2-O-alpha-D-glucopyranosyl-L-ascorbic acid by LC-MS/MS analysis. PMID:17216298

Kwon, Taeyeon; Kim, Cheong Tae; Lee, Jong-Hoon

2007-04-01

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Titrimetric determination of ascorbic acid using chloranil.  

Science.gov (United States)

Ascorbic acid is oxidized and quantitatively titrated with chloranil (2,3,5,6-tetrachloro-1,4-benzoquinone) in the presence of hexamethylenetetramine in acetone-water; the end point is determined visually by the appearance of a golden yellow color. Colored solutions are assayed by setting the initial absorbance at 451 nm to zero or the minimum, titrating with chloranil solution, and measuring absorbance after each increment of titrant. A plot of the volume of chloranil added against the absorbance gives a straight line with the volume intercept as the end point. Interference by the thiol group of cysteine, glutathione, etc., is avoided by masking with acrylamide; interference by iron(II) is masked with ammonium thiocyanate and sodium potassium tartrate. Hydrogen sulfite and thiourea (which do not interfere) are added as antioxidants during extraction of ascorbic acid from drugs and fruits. PMID:6725194

Verma, K K; Jain, A; Rawat, R

1984-01-01

27

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  

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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

28

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

2007-06-25

29

Supplementation of Ascorbic Acid in Weanling Horses Following Prolonged Transportation  

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Full Text Available Though horses synthesize ascorbic acid in their liver in amounts that meet their needs under normal circumstances, prolonged stress results in low plasma concentrations due to enhanced utilization and renal excretion and can reduce immune function. It was hypothesized that plasma ascorbic acid could be maintained in weanling horses by oral supplementation following prolonged transportation. Weanlings were supplemented with no ascorbic acid (Tx 0: n = 4, 5 grams ascorbic acid twice daily for 5 days (Tx 1: n = 4 or for 10 days (Tx 2: n = 4 following >50 hours of transportation. Supplementation caused slight (P < 0.2 increases in plasma ascorbic acid concentrations. Both supplemented groups had decreased (P < 0.05 plasma concentrations for 1 to 3 weeks following cessation of supplementation, possibly due to increased renal excretion or suppressed hepatic synthesis. Supplementation of ascorbic acid following prolonged stress will increase plasma concentrations, but prolonged supplementation should be avoided.

Michelle Stives

2012-04-01

30

PDMS-based gold electrode for sensing ascorbic acid.  

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Electrode with optical shapes is appreciated in microfluidics. In this article, we reported a flexible poly(dimethylsiloxane) (PDMS)-based gold electrode for ascorbic acid detection. Gold nanoparticles were chemically deposited on PDMS and the composite film was applied as working electrode. The electrode could undergo deformation and display good response performance without damage. This biosensor could give quick response to ascorbic acid (AA) (ascorbic acid content in vitamin C tablets and the results were consistent with traditional iodometric method. PMID:21807485

Xu, Qin; Bi, Lianhua; Zheng, Huxiang; Fan, Dahe; Wang, Wei

2011-11-01

31

Ascorbic Acid in the Nutrition of Plant-Feeding Insects.  

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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

32

Hepatoprotective Effect of Vitamin C (Ascorbic Acid  

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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

33

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

34

Pharmacokinetic study of ascorbic acid in sheep.  

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Four groups of sheep (5/group) were used in the experiment. Group 1 sheep were given 1 g of ascorbic acid (AA) intravenously (i.v.), group 2 were given 3 g i.v., group 3 were given 1 g intramuscularly (i.m.) and group 4 received 3 g i.m. Blood was collected for 7 h after i.v. administration and for 48 h following i.m. administration. Plasma was analyzed for AA using HPLC techniques. After i.v. administration the rate of elimination was greater at the high dose than the low (0.8560 vs 0.5231 h...

Black, W. D.; Hidiroglou, M.

1996-01-01

35

Measuring the Amount of Ascorbic Acid in Cabbage  

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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

36

P66Shc-rac1 pathway-mediated ROS production and cell migration is downregulated by ascorbic acid.  

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The oxidative role(s) of p66Shc protein has been increasingly expanded over the last decade. However, its relation with the most potent antioxidant molecule, i.e. ascorbic acid has never been studied. We have previously shown that p66Shc mediates rac1 activation, reactive oxygen species (ROS) production and cell death. Here we studied the effect of ascorbic acid on the pathway involving p66Shc and rac1. Our results indicate a decrease in the expression of p66Shc in a dose- and time-dependent manner. We studied the effect of ascorbic acid on rac1 expression and its activity. Ascorbic acid has no effect on total rac1 expression; however, rac1 activation was inhibited in a dose-dependent manner. Results suggest that the decrease in rac1 activity is mediated through ascorbic acid-modulated p66Shc expression. The decrease in rac1 activity was evident in cells transfected with the p66shc mutant (proline motif mutant, at residues P47 to P50). Our studies indicate that p66Shc-mediated ROS upregulation is significantly decreased in the presence of ascorbic acid. Cell migration experiments point towards the inhibition of p66Shc-rac1-mediated migration in the presence of ascorbic acid. Finally, results are suggestive that ascorbic acid-mediated decrease in Shc expression occurs through an increased Shc ubiquitination. Overall, the study brings out the novel role of ascorbic acid in antioxidant signal transduction. PMID:23461363

Kirmani, Deeba; Bhat, Hina F; Bashir, Muneesa; Zargar, Mohammad A; Khanday, Firdous A

2013-04-01

37

Ascorbic acid biosensor using ascorbate oxidase immobilized on alkylamine glass beads.  

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A biosensor for ascorbic acid based on enzyme kinetics of ascorbate oxidase (E.C.1.10.3.3) was developed. The enzyme was extracted from Cucurbita maxima, or jerimun and immobilized by covalent bounding, using glutaradehyde as a bifunctional agent, on alkylamine glass beads, with and without enzyme active site protection. A low-cost, home-made oxygen electrode was applied as a transducer. The system has sensitivity from 62.5 up to 500 microM of ascorbic acid with satisfactory operation for more than 2 mo. PMID:1416950

Marques, E T; Lima Filho, J L

1992-01-01

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Effects of cytochalasin B on the uptake of ascorbic acid and glucose by 3T3 fibroblasts: Mechanism of impaired ascorbate transport in diabetes  

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Hyperglycemia and/or hypoinsulinemia have been found to inhibit L-ascorbic acid cellular transport. The resultant decrease in intracellular ascorbic acid may de-inhibit aryl sulfatase B and increase degradation of sulfated glycosaminoglycans (sGAG). This could lead to a degeneration of the extracellular matrix and result in increased intimal permeability, the initiating event in atherosclerosis. The present studies show that the glucose transport inhibitor cytochalasin B blocked the uptake of 3H-2-deoxy-D-glucose by mouse 3T3 fibroblasts. Cytochalasin B also blocked the uptake of 14C-L-ascorbic acid. The results of these studies further support the hypothesis that glucose and ascorbate share a common transport system. This may have important implications concerning the vascular pathology associated with diabetes mellitus

1990-01-01

39

Cytogenetic and biochemical effects induced by the treatment with ascorbic acid and citric acid on Picea abies (L. Karst.  

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Full Text Available This paper present the influence of ascorbic acid and citric acid upon the mitotic division, and to the activity of some antioxidant enzymes to Picea abies (L. Karst. The treatment was made through the germination of seeds in ascorbic acid and citric acid. We observed the stimulator or inhibitor effect of ascorbic acid and citric acid to the mitotic index and estimated the aberrations appearance. Comparative the control, the mitotic index increased at 0.1 % concentration ascorbic acid and decreased at 0.25 % and 0.5 % concentration of the same substance. The citric acid induced a decrease in the dynamics of mitotic index comparative the control. Also, we observed an increase of aberrations appearance to the treatment with citric acid. We established the activity of catalase, peroxidase and superoxide dismutase and the influence of ascorbic acid and citric acid to the activity of these antioxidant enzymes. After statistical interpretation emerged that these substances (except 0.25 % ascorbic acid induced an inhibition of catalase activity and a stimulation of peroxidase and superoxide dismutase activity.

Vlad Artenie

2008-05-01

40

Ascorbic acid absorption in Crohn's disease. Studies using L-(carboxyl-/sup 14/C)ascorbic acid  

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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-/sup 14/C)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 /sup 14/C 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 /sup 14/C 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.

Pettit, S.H.; Shaffer, J.L.; Johns, C.W.; Bennett, R.J.; Irving, M.H.

1989-04-01

 
 
 
 
41

Additional antilipoperoxidant activities of alpha-tocopherol and ascorbic acid on membrane-like systems are potentiated by rutin.  

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The effects of alpha-tocopherol, ascorbic acid and rutin on peroxidative processes were studied in xanthine-xanthine oxidase system, linoleic acid ufasomes and human erythrocyte membranes. In these three systems, tested compounds scavenge superoxide anion radicals or inhibit lipid peroxidation in a concentration-dependent manner, and it was shown that rutin was the most potent radical scavenger, followed by ascorbic acid and alpha-tocopherol. An important antilipoperoxidant activity was observed when these compounds were tested in combination, demonstrating that a dose-dependent interaction occurs. Water-soluble (rutin and ascorbic acid) as well as lipid-soluble (tocopherol) antioxidants are involved in the protection of polyunsaturated fatty acids constituting the ufasome or erythrocyte ghosts. When these compounds are used in combination, an additive effect is observed with alpha-tocopherol and ascorbic acid or rutin, while a supra-additive effect (synergism) is noted with ascorbic acid and rutin. Results obtained with the triple combination alpha-tocopherol-ascorbic acid-rutin show that an increase in superoxide radical scavenging activities or in lipid peroxidation inhibition is possible after the addition of a third antioxidant, as compared with the protective effects produced by the double combination of these compounds. This interaction takes place not only in homogeneous aqueous solutions, but also in ufasome or erythrocyte ghost preparations. It is suggested that ascorbic acid and rutin interacts with tocopherol at the surface of or the interface with the membrane, and that rutin simultaneously interacts with ascorbic acid. PMID:1652140

Nègre-Salvayre, A; Affany, A; Hariton, C; Salvayre, R

1991-01-01

42

Ascorbic acid contents of Pakistani fruits and vegetables.  

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Fresh fruits and vegetables are good sources of vitamin C which is known for its antioxidant and immune-enhancing effects. The objective of this study was to determine ascorbic acid (vitamin C) contents of regularly consumed fruits and vegetables available in Pakistani markets. Most commonly used fresh fruits and vegetables were homogenized in 5% trichloroacetic acid, and ascorbic acid contents in the extracts were determined using a spectrophotometric method. Banana, custard apple, orange, lemon, guava and papaya were found to be very rich in ascorbic acid. Among vegetables, capsicum (green sweet pepper), cauliflower, bittergourd, roundgourd, beetroot, spinach, cabbage and radish contained high concentrations of ascorbic acid. Chikoo, grapes, pear, apricot, peach, carrot, cucumber, lettuce and "kakri" were found to be poor sources of ascorbic acid. Several Pakistani fruits and vegetables (pear, melon, onion, sweet green pepper, spinach, cucumber) had ascorbic acid values similar to those reported by US Department of Agriculture in these fruits and vegetables in USA. However, wide differences in vitamin C contents were also observed in certain other fruits and vegetables from these two countries. This indicates that regional varieties of fruits and vegetables could vary in their ascorbic acid contents. Since subclinical deficiency of vitamin C appears to be quite common in developing countries like Pakistan, there is a need to develop awareness among masses to consume fresh fruits and vegetables with high contents of vitamin C. PMID:17105704

Iqbal, M Perwaiz; Kazim, Syed Faraz; Mehboobali, Naseema

2006-10-01

43

Synthesis of New L-Ascorbic Ferulic Acid Hybrids  

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Full Text Available A feasibility and chemical study of the coupling conditions of L-ascorbic acidwith ferulic acid derivatives are described on the basis of the known synergistic effects ofmixtures of various antioxidants. Novel L-ascorbic ferulic hybrids linked at the C-3hydroxyl group were prepared with the aim to protect the alcohol function and the enediolsystem.

Sylvain Rault

2007-11-01

44

Synthesis of New L-Ascorbic Ferulic Acid Hybrids  

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A feasibility and chemical study of the coupling conditions of L-ascorbic acidwith ferulic acid derivatives are described on the basis of the known synergistic effects ofmixtures of various antioxidants. Novel L-ascorbic ferulic hybrids linked at the C-3hydroxyl group were prepared with the aim to protect the alcohol function and the enediolsystem.

2007-01-01

45

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

46

THE EFFECTS OF ASCORBIC ACID ON MEMBRANE TRANSPORT OF GLUCOSE  

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Full Text Available In this study we compared the effects of ascorbic acid on the glucose levels in the plasma.At the beginning of the experiment the level of ascorbic acid and the level of glycemia were determined twelve hours after the last meal. In the following seven days each of the examined women was given, beside the usual nourishment, 1000 mg ascorbic acid (two times a day of 500 mg with breakfast and lunch. The level of ascorbic acid and glycemia was determined on the eight day of the experiment, twenty-four hours after the last taken dosage of ascorbic acid. The achived results of oral glucose ‡ tolerance test (OGTT at the begining and in the end of the test were shown in a table and on a diagram.The intake of ascorbic acid in the dosage of 1000 mg/a day for seven days, intensifies the level of glycemia during OGTT.This hyperglycemia is probaly the consequence of receptor obstruction in cellular membrane by ascorbic acid.

Voja Pavlovic

2004-07-01

47

THE EFFECTS OF ASCORBIC ACID ON MEMBRANE TRANSPORT OF GLUCOSE  

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Full Text Available The level of glycemia and ascorbic acid was tested of oral glucose-tolerance test (OGTT. This test was done on thirty healthy normoglycemic adult women, between 18 and 30 years of age, who showed no clinical signs of endocrine disturbances.At the beginning of the experiment the level of ascorbic acid and the level of glycemia were determined twelve hours after the last meal. In the following seven days eash of the examined women was given, beside the usual nourishment, 1.000 mg ascorbic acid (two times a day of 500 mg with breakfast and lunch. The level of ascorbic acid the last taken dosage of ascorbic acid. The achieved results of OGTT at the beginning and in the end of the test showed the ascorbic acid in the dosage of 1.000 mg/per day for seven days intensified the level glycemia during OGTT.This hyperglycemy is probably the consequence of the receptor obstruction in cellular membrane by ascorbic acid.

Zoran Pavlovic

2004-01-01

48

Ascorbic Acid Contents in Chili Peppers (Capsicum L.)  

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The genus Capsicum commonly known as chili pepper is a major spice crop and is almost cosmopolitan in distribution. The nutritive value of chili pepper is largely determined by ascorbic acid content. The fruits at five ripening stages viz., (M1, M2, M3, M4 and M5) from seventeen cultivars of Capsicum annuum L and one cultivar of Capsicum frutescens L were analyzed for ascorbic acid content. Among eighteen genotypes the C. annuum var. IC: 119262(CA2) showed higher ascorbic acid content (mg/100...

2009-01-01

49

Collagen synthesis in human skin fibroblasts is stimulated by a stable form of ascorbate, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid.  

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We evaluated the effect of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) on collagen synthesis in cultured human skin fibroblasts and on proliferation of fibroblasts. At concentrations of 0.1-0.5 mmol/L, AA-2G effectively stimulated collagen synthesis with an effectiveness comparable to that of L-ascorbic acid. On the other hand, 6-O-alpha-D-glucopyranosyl-L-ascorbic acid showed a weak effect. The stimulation of collagen synthesis by AA-2G was attenuated by the addition of a collagen synthesis inhibitor, L-azetidine 2-carboxylic acid, in a dose-dependent manner. In addition, AA-2G-induced stimulation of collagen synthesis could be completely inhibited by the addition of castanospermine, an inhibitor of neutral alpha-glucosidase. Relatively high alpha-glucosidase activity, which would contribute to release of ascorbic acid from AA-2G, could be detected in the lysate of cultured fibroblasts. The stimulatory activity of AA-2G on collagen synthesis was observed after 5 d in culture, whereas L-ascorbic acid tended to lose its stimulatory activity. Continuous supplementation of AA-2G (0.25 mmol/L) to culture medium for 24 d enhanced the cell growth four times that of the control. These results indicate that AA-2G is gradually cleaved by the cellular alpha-glucosidase to release L-ascorbic acid, which adequately stimulates collagen synthesis and proliferation of human skin fibroblasts. PMID:1552361

Yamamoto, I; Muto, N; Murakami, K; Akiyama, J

1992-04-01

50

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 "6"0 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)

2004-07-11

51

MYOCARDIAL INFARCTION WITH ITS RELATION TO ASCORBIC ACID  

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Full Text Available The present study includes a total 66 patients with acute myocardial infarction and 66 age group and sex matched healthy controls. 53 (80.3% were males and 13 (19.7% were females. Mean age in patients was 51.76±11.1 and maximum patients were in the age group 40-60 years (75.76%. Mean plasma ascorbic acid in patients (0.37±0.064 mg/dL was lower than controls (0.58±0.16 mg/dL. 50 (75.76% patients had plasma ascorbic acid ?0.4mg/dL as compared to 5 (7.58% controls. Low plasma ascorbic acid (?0.4 mg/dL, hypercholesterolemia (?200 mg/dL, increased triglycerides (?150 mg/dL, decreased HDL (0.40 mg/dL. A total of 8 patients died within one week in hospital, among them 7 had plasma ascorbic acid ?0.04 mg/dL and 1 had plasma ascorbic acid >0.4 mg/dL. At one week 23 patients had plasma ?0.04 mg/dL and 35 had >0.4 mg/dL. A total of 7 patients died in 2nd and 3rd week, among them 5 had plasma ascorbic ?0.40 mg/dL and 2 had plasma ascorbic acid >0.40 mg/dL. At 3 weeks, 8 patients had plasma ascorbic acid ?0.40 mg/dL and 40 had >0.40 mg/dL. A total of 4 patients died and among them 3 had plasma ascorbic ?0.40 mg/dL and 1 had plasma ascorbic acid >0.04 mg/dL. The association was significant (p<0.01 with a relative risk of 15.2 and attributable risk of 93.42% indicating mortality was significantly associated in patients in whom plasma ascorbic acid remained persistently low i.e. ?0.40 mg/dL. The mean plasma ascorbic acid was 0.37±0.06 mg/dL, 0.44±0.08 mg/dL, and 0.50±0.09 mg/dL on admission, at one week and after 3 weeks respectively.

Chaitanyakumar S

2013-02-01

52

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

53

Habitual diet and ascorbic acid status in Sudanese camels.  

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There is suggestive evidence that a low status of ascorbic acid in camels enhances their risk for infectious diseases. This study was carried out to find clues as to the role of diet in affecting ascorbic acid status. In a crossover trial with feeding periods of 3 weeks each, six camels (Camelus dromedarius) were fed either a composite of their habitual diet or alfalfa. The simulated habitual diet contained grass (hummra), Acacia mellifera and Blepharis persica. The habitual diet significantly lowered ascorbic acid concentrations in plasma and leukocytes. It is concluded that camels kept on natural desert vegetation may not have optimal disease resistance due to a diet-induced low ascorbic acid status. PMID:23345066

Mohamed, Hasablerasoul E; Alhaidary, Ahmed; Beynen, Anton Christian

2013-03-01

54

Anti-angiogenic effect of high doses of ascorbic acid  

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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...

Mikirova, Nina A.; Ichim, Thomas E.; Riordan, Neil H.

2008-01-01

55

Identification of ascorbic acid-deficient Arabidopsis thaliana mutants.  

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Vitamin C (l-ascorbic acid) is a potent antioxidant and cellular reductant present at millimolar concentrations in plants. This small molecule has roles in the reduction of prosthetic metal ions, cell wall expansion, cell division, and in the detoxification of reactive oxygen generated by photosynthesis and adverse environmental conditions. However, unlike in animals, the biosynthesis of ascorbic acid (AsA) in plants is only beginning to be unraveled. The previously described AsA-deficient Ar...

Conklin, P. L.; Saracco, S. A.; Norris, S. R.; Last, R. L.

2000-01-01

56

An In Vitro Study on Effect of Lactic Acid and Ascorbic Acid on Etoposide-Induced Lipid Peroxidation  

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Full Text Available Lipid peroxidation, a free radical mediated process is involved in several injurious consequences like cardiomyopathy, neurodegenerative diseases, etc. Reactive oxygen species (ROS is involved as a mediator of free radical related damage. Antioxidants have the capability to scavenge free radicals and protect tissues from ROS. Keeping in mind this fact the present in vitro study was carried out to evaluate the lipid peroxidation induction potential of etoposide, an antimalarial and its suppression with ascorbic acid and lactic acid using malondialdehyde (MDA as laboratory marker. Liver homogenate was treated with drug as well as antioxidant and incubated for definite time period and MDA content was estimated in different samples. Result showed that etoposide could significantly induce lipid peroxidation and ascorbic acid and lactic acid could significantly inhibit etoposide-induced lipid peroxidation. It was further found from the study that antioxidant potential of lactic acid is more than that of ascorbic acid.

Pritesh Devbhuti*

2013-01-01

57

Phytic Acid Inhibits Lipid Peroxidation In Vitro  

Science.gov (United States)

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 the decay of linoleic acid, both in the absence and presence of Fe(II)/ascorbate. The observed inhibitory effect of PA on Fe(II)/ascorbate-induced lipid peroxidation was lower (10–20%) compared to that of autoxidation. PA did not change linoleic acid hydroperoxides concentration levels after 24 hours of Fe(II)/ascorbate-induced peroxidation. In the absence of Fe(II)/ascorbate, PA at 100??M and 500??M significantly suppressed decomposition of linoleic acid hydroperoxides. Moreover, PA at the tested nontoxic concentrations (100??M and 500??M) significantly decreased 4-hydroxyalkenal levels in Caco-2 cells which structurally and functionally resemble the small intestinal epithelium. It is concluded that PA inhibits linoleic acid oxidation and reduces the formation of 4-hydroxyalkenals. Acting as an antioxidant it may help to prevent intestinal diseases induced by oxygen radicals and lipid peroxidation products.

Weglarz, Ludmila; Dzierzewicz, Zofia

2013-01-01

58

Possible role of ascorbic acid in the oxidative damage induced by inhaled crystalline silica particles  

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The selective interaction of ascorbic acid with crystalline silica (quartz) has been studied by measuring the ascorbic acid consumption (by means of UV/vis and IR spectroscopy) and the release of silicon when quartz particles or amorphous silica (Aerosil 50) is incubated in ascorbic acid solution. At a physiological ascorbic acid concentration, quartz, and not amorphous silica, reacts, suggesting the formation of a 1:1 silicon-ascorbate complex, while at higher concentrations, the reacting am...

Coluccia, Salvatore; Fenoglio, Ivana; Fubini, Bice; Martra, Gianmario

2000-01-01

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)

1998-01-01

60

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

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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., ...

2011-01-01

 
 
 
 
61

Ascorbic Acid Contents in Chili Peppers (Capsicum L.  

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Full Text Available The genus Capsicum commonly known as chili pepper is a major spice crop and is almost cosmopolitan in distribution. The nutritive value of chili pepper is largely determined by ascorbic acid content. The fruits at five ripening stages viz., (M1, M2, M3, M4 and M5 from seventeen cultivars of Capsicum annuum L and one cultivar of Capsicum frutescens L were analyzed for ascorbic acid content. Among eighteen genotypes the C. annuum var. IC: 119262(CA2 showed higher ascorbic acid content (mg/100g FW i.e., 208.0?0.68 (M1, 231.0?0.66 (M2, 280.0?0.31 (M3, 253.0?0.34 (M4 and 173.7?0.27 (M5. The study revealed that the gradual increase in ascorbic acid content from green to red and subsequently declined in the lateral stages (red partially dried and red fully dried fruits. The variability of ascorbic acid content in the genotypes suggests that these selected genotypes may be use full as parents in hybridization programs to produce fruits with good nutritional values.

Owk ANIEL KUMAR

2009-12-01

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

Study of Plasma Ascorbic Acid Levels in Wheezing Children  

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Full Text Available Background: Reactive Oxygen species induced bronchial abnormalities may have important consequences in asthma, the main symptom being wheezing specially in children. Vitamin C is an important antioxidant known to quench the reactive oxygen species. A beneficial effect of fresh fruit consumption on lung function has been observed in several studies. Plasma levels Vitamin C was determined in relation to wheezing symptoms in cross sectional study. Methods: In a cross sectional blood samples of 50 patients attending pediatrics OPD, having wheezing and shortness of breath were analyzed for plasma Ascorbic acid level and compared with healthy controls of same age and sex. Results: The total number of 50 wheezing children were in the age group of 2 to 12 years with similar age matched controls. It was observed that the plasma ascorbic acid concentration in the wheezing children (0.43 – 0.12 mg/dl was significantly decreased as compared to the normal controls ( 0.75 – 0.18 mg/dl P< 0.001. The highly significant low levels of plasma ascorbic acid level in wheezing children was irrespective of sex and severity of symptoms. However the ascorbic acid levels were at the lower side in female and with severe symptoms. Conclusions: Plasma Ascorbic acid levels were significantly, decreased in the process of scavenging the reactive oxygen species. Ascorbic acid directly neutralizes free radical and protects the bronchial tissue from oxidative injury, so it can be concluded that the consumption of fruit rich in vitamin C may reduce wheezing symptoms in children.

Nagdeote AN,

2011-01-01

64

Vacuolar deposition of ascorbate-derived oxalic acid in barley  

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L-(1-/sup 14/C)Ascorbic acid was supplied to detached barley seedlings to determine the subcellular location of oxalic acid, one of its metabolic products. Intact vacuoles isolated from protoplasts of labeled leaves contained (/sup 14/C)oxalic acid which accounted for about 70% of the intraprotoplast soluble oxalic acid. Tracer-labeled oxalate accounted for 36 and 72% of the /sup 14/C associated with leaf vacuoles of seedlings labeled for 22 and 96 hours, respectively.

Wagner, G.J.

1981-03-01

65

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

66

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

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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.

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

2011-01-01

67

Variation in ascorbic acid and oxalate levels in the fruit of Actinidia chinensis tissues and genotypes.  

Science.gov (United States)

Ascorbic acid and total oxalate were measured in fruit from six genotypes of Actinidia chinensis. Ascorbic acid was separated from oxalate in fruit extracts by HPLC and quantified from absorbance at 245 nm, whereas oxalate was measured enzymatically in the HPLC eluate. Levels of whole fruit mean ascorbic acid in the different genotypes ranged from 98 to 163 mg/100 g of fresh weight (FW), whereas mean oxalate varied between 18 and 45 mg/100 g of FW. Ascorbic acid was highest in the inner and outer pericarp, whereas oxalate was concentrated in the skin, inner pericarp, and seed. Essentially no ascorbic acid was found in the seed. Each tissue clustered separately when the tissue ascorbic acid and oxalate data were normalized to the whole fruit level of ascorbic acid and oxalate in that genotype and plotted against each other, suggesting that oxalate is not a sink for excess ascorbic acid but that oxalate formation is regulated. PMID:15769175

Rassam, Maysoon; Laing, William

2005-03-23

68

Bioavailability of a series of novel acylated ascorbic acid derivatives, 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids, as an ascorbic acid supplement in rats and guinea pigs.  

Science.gov (United States)

The bioavailability of a series of novel acylated ascorbic acid derivatives, 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G), as an ascorbic acid (AA) supplement was investigated in rats and guinea pigs. Oral administration of 6-Acyl-AA-2G to rats resulted in an increase in the plasma AA level. However, the intact form was not detectable in the plasma by high-performance liquid chromatography, indicating its hydrolysis through the process of absorption. After an intravenous injection to rats of 6-Octa-AA-2G as a representative derivative, the intact form rapidly disappeared from the plasma, being followed by a prolonged and marked elevation of the plasma AA level. Various tissue homogenates from guinea pigs were examined for their releasing activity of AA, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and 6-O-acyl-AA from 6-Acyl-AA-2G. High activity was observed in the small intestine. These hydrolytic activities to AA and 6-O-acyl-AA were completely inhibited by castanospermine, an alpha-glucosidase inhibitor, and AA-2G was observed as the only resulting hydrolysate, suggesting the participation of alpha-glucosidase and esterase in the in vivo hydrolysis of 6-Acyl-AA-2G. 6-Octa-AA-2G was found to exhibit an obvious therapeutic effect in scorbutic guinea pigs from its repeated oral administration. These results indicate that 6-Acyl-AA-2G is a readily available source of AA activity in vivo, and may be useful as an effective pharmacological agent and as a promising food additive. PMID:12353620

Tai, Akihiro; Fujinami, Yoshihito; Matsumoto, Kyoko; Kawasaki, Daisuke; Yamamoto, Itaru

2002-08-01

69

ANTIOXIDANT AND PRO-OXIDANT EFFECT OF ASCORBIC ACID  

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Full Text Available Free radicals attack proteins, lipids, enzymes and DNA causing pathological changes in organism. There are many mechanisms that organism uses to fight against free radicals. Ascorbic acid is one of the strongest reducers and eliminators of free radicals. It reduces stable oxygenic, azoth and thyol radicals and acts as a primary defense against water radicals in blood. When radicals are dissolved in water suspensions of erythrocytes and low density lipoproteins (LDL, ascorbic acid catches and eliminates free radicals before they arrive to the membrane and LDL molecules. Even though ascorbic acid is not capable of eliminating free radicals out of fluid medium, it acts as synergist to alpha-tocopherol in lipid section, contributes to the lessening of lipid tocoperoxil radicals, and above all, regenerates alpha-tocopherol. Ascorbic acid may act as pro-oxidant under in vitro conditions in the presence of metals; however, this effect is probably not important under in vivo conditions where metal ions, being sequestered, become second reducers.

Goran Rankovic

2005-01-01

70

Amperometric biosensor for ascorbic acid Biossensor amperométrico para ácido ascórbico  

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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 was 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 injecti...

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

2005-01-01

71

Ascorbic acid estimation in aqueous humour of normal cataractous and aphakic eyes  

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Full Text Available Ascorbic acid has received a great deal of attention in lens metabolism. A good number of workers have estimated aqueous humour and serum ascorbic acid values in animals and human beings. But the question whether the concentration of ascorbic acid in aqueous humour varies in normal, cataractous and aphakic patients is still disputed.

Khurrum M

1988-01-01

72

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

73

Toxicity of nickel and silver to Nostoc muscorum: interaction with ascorbic acid, glutathione, and sulfur-containing amino acids  

Energy Technology Data Exchange (ETDEWEB)

Exposure of Nostoc muscorum to different concentrations of Ni and Ag brought about reduction in growth, carbon fixation, heterocyst production, and nitrogenase activity and increase in the loss of ions (K+, Na+). In an attempt to ameliorate the toxicity of test metals by ascorbic acid, glutathione, and sulfur-containing amino acids (L-cysteine and L-methionine), it was found that the level of protection by ascorbic acid and glutathione was more for Ag than Ni. However, metal-induced inhibition of growth and carbon fixation was equally ameliorated by methionine. But the level of protection by cysteine was quite different, i.e., 27% for Ni and 22% for Ag. Protection of metal toxicity in N. muscorum by amino acids lends further support to self-detoxifying ability of cyanobacteria because they are known to synthesize all essential amino acids.

Rai, L.C.; Raizada, M.

1987-08-01

74

Antioxidant properties of 2-O-beta-D-glucopyranosyl-L-ascorbic acid.  

Science.gov (United States)

The antioxidant activity of a provitamin C agent, 2-O-beta-D-glucopyranosyl-L-ascorbic acid (AA-2betaG), was compared to that of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and ascorbic acid (AA) using four in vitro methods, 1,1-diphenyl-picrylhydrazyl (DPPH) radical-scavenging assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(*+))-scavenging assay, oxygen radical absorbance capacity (ORAC) assay, and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced erythrocyte hemolysis inhibition assay. AA-2betaG slowly and continuously scavenged DPPH radicals and ABTS(*+) in roughly the same reaction profiles as AA-2G, whereas AA quenched these radicals immediately. In the ORAC assay and the hemolysis inhibition assay, AA-2betaG showed similar overall activities to AA-2G and to AA, although the reactivity of AA-2betaG against the peroxyl radical generated in both assays was lower than that of AA-2G and AA. These data indicate that AA-2betaG had roughly the same radical-scavenging properties as AA-2G, and a comprehensive in vitro antioxidant activity of AA-2betaG appeared to be comparable not only to that of AA-2G but also to that of AA. PMID:18540110

Takebayashi, Jun; Yagi, Yasuyuki; Ishii, Rie; Abe, Shigeki; Yamada, Kazuhiko; Tai, Akihiro

2008-06-01

75

Ascorbic Acid Distribution in Three Introgression Lines of Tomato  

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Full Text Available Total ascorbic acid (total-AsA content and percentage of reduced ascorbic acid on total-AsA (AsA% were investigated and discussed in fruits, leaves, petiole, stem and roots of the Solanum lycopersicum cv M82 and S. pennellii introgression lines IL7-3, IL10-1 and IL12-4. In fruits total-AsA content showed to be different according to genotype analysed. Higher total-AsA accumulations was observed for IL7-3 and IL12-4 followed by M82 and IL10-1. Total-AsA was generally higher in leaves than in petioles, stems and roots of all genotypes. In roots higher total-AsA concentration and lower AsA% was generally observed in introgression lines than M82, in particular for IL7-3.

Maria Minutolo

2010-08-01

76

Induction of Monozygotic Twinning by Ascorbic Acid in Tobacco  

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Embryo development in plants initiates following the transverse division of a zygote into an apical, proembryo cell and a basal cell that gives rise to the suspensor. Although mutants affected in embryo development through changes in cell division have been described, little is known about the control of the first zygotic division that gives rise to the proembryo. Ascorbic acid (Asc) promotes cell division by inducing G1 to S progression but its role in embryo development has not been examine...

Chen, Zhong; Gallie, Daniel R.

2012-01-01

77

Amino acid peroxyl radicals. Formation and reaction with ascorbate  

International Nuclear Information System (INIS)

Complete text of publication follows. Proteins are significant targets for partly reduced oxygen species in vivo. This results in random formation of radicals on the amino acid residues (AA·) of the protein, which in turn, in the presence of oxygen, can yield the corresponding peroxyl radicals (AAOO·). Both radical types can cause further biological damage. We studied the N-acetylamide derivatives of the amino acids glycine, alanine and proline as models of these residues in proteins. We generated the amino acid radicals specifically by reaction with hydroxyl radicals produced in solutions irradiated with 2 MeV electrons in the presence of N2O. In the absence of oxygen the amino acid radicals decayed with rate constants in the narrow range (0.9-1.3) x 109 M-1s-1, while in the presence of oxygen they were converted very rapidly to the corresponding peroxyl radicals with rate constants that vary between 6.3 x 108 and 5.5 x 109 M-1s-1, depending on the amino acid. The corresponding N-acetylated amino acids were also studied and showed similar behaviour but with slightly smaller rate constants. Antioxidants are able to repair tyrosyl and tryptophanyl radicals in various proteins in vitro. For ascorbate, the principal endogenous biological antioxidant, we have measured rate constants in the range 105-108 M-1s-1. The peroxyl radicals of all amino acids studied here were reduced by oxidizing ascorbate to the ascorbyl radical. The reaction was followed at 360 nm, where ascorbyl radical has an absorption coefficient of 3300 M-1cm-1, and the derived rate constants were all close to 107 M-1s-1. However, the spontaneous decay of peroxyl radicals is also fast and competes with the reaction with ascorbate. It is to be stressed that reaction of AAOO· and ascorbate gives rise to hydroperoxides (AAOOH) that are also reactive molecules. Our study suggests that reaction with protein radicals may be responsible for the ascorbate loss reported in organisms exposed to oxidative stress.

2009-09-02

78

Modelling and analysis of a direct ascorbic acid fuel cell  

Energy Technology Data Exchange (ETDEWEB)

L-Ascorbic acid (AA), also known as vitamin C, is an environmentally-benign and biologically-friendly compound that can be used as an alternative fuel for direct oxidation fuel cells. While direct ascorbic acid fuel cells (DAAFCs) have been studied experimentally, modelling and simulation of these devices have been overlooked. In this work, we develop a mathematical model to describe a DAAFC and validate it with experimental data. The model is formulated by integrating the mass and charge balances, and model parameters are estimated by best-fitting to experimental data of current-voltage curves. By comparing the transient voltage curves predicted by dynamic simulation and experiments, the model is further validated. Various parameters that affect the power generation are studied by simulation. The cathodic reaction is found to be the most significant determinant of power generation, followed by fuel feed concentration and the mass-transfer coefficient of ascorbic acid. These studies also reveal that the power density steadily increases with respect to the fuel feed concentration. The results may guide future development and operation of a more efficient DAAFC. (author)

Zeng, Yingzhi; Wu, Ping [Institute of High Performance Computing, 1 Science Park Road, 01-01, The Capricorn, Singapore 117528 (Singapore); Fujiwara, Naoko; Yamazaki, Shin-ichi; Tanimoto, Kazumi [Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31, Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

2008-10-15

79

Enhancing effect of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid, a stable ascorbic acid derivative, on collagen synthesis.  

Science.gov (United States)

The objective of the present study was to compare 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) with ascorbic acid (AA) and ascorbic acid 2-phosphate (AA-2P) concerning the promotion of collagen production in human skin fibroblasts. Though AA-2G was still observed to be promoting collagen synthesis at the same level on the 8th day of the culture, collagen synthesis was seen to decrease on the fifth day of culturing with AA and AA-2P. This sustained collagen synthesis-promoting action is considered to be a major feature of the novel vitamin C derivative, AA-2G by conducting an experiment in which an alpha-glucosidase inhibitor was present, it was shown that AA-2G exerts its collagen synthesis-promoting action after being decomposed to AA by alpha-glucosidase. Further, we observed that for AA-2G, even on the 8th day of the culture, the amount of AA in the fibroblasts was virtually unchanged from the beginning of the experiment, whereas, in the case of adding AA and AA-2P, virtually no AA was detectable in the culture medium on the fifth day. These findings suggests that AA-2G is decomposed to AA by alpha-glucosidase in the cells. This AA promotes collagen synthesis, which is prolonged through AA-2G's sustained decomposition. PMID:9703245

Kumano, Y; Sakamoto, T; Egawa, M; Tanaka, M; Yamamoto, I

1998-07-01

80

Cytotoxicity of ascorbate, lipoic acid, and other antioxidants in hollow fibre in vitro tumours  

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Vitamin C (ascorbate) is toxic to tumour cells, and has been suggested as an adjuvant cancer treatment. Our goal was to determine if ascorbate, in combination with other antioxidants, could kill cells in the SW620 hollow fibre in vitro solid tumour model at clinically achievable concentrations. Ascorbate anti-cancer efficacy, alone or in combination with lipoic acid, vitamin K 3, phenyl ascorbate, or doxorubicin, was assessed using annexin V staining and standard survival assays. 2-day treatm...

2001-01-01

 
 
 
 
81

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

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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

82

Both HDL3 and HDL2 exert a powerful anti-oxidative and protective effect against acceleration of oxidative modification of LDL by ascorbic acid.  

Science.gov (United States)

The objective of the present study was to establish whether high-density lipoprotein 3 (HDL3) or high-density lipoprotein 2 (HDL2) might show an anti-oxidative effect on the acceleration of the oxidative modification of low-density lipoprotein (LDL) by ascorbic acid from measurement of the agarose gel electrophoretic mobility of LDL. LDL was incubated without adding transitional-metal ions for 48 or 96 h in phosphate-buffered saline (PBS) alone, with ascorbic acid (20 microg/mL), or with both ascorbic acid (20 microg/mL) and HDL3 (200 microg protein/mL). The LDL autoxidation occurred in PBS alone. Although ascorbic acid significantly suppressed oxidative modification of LDL after incubation for 48 h, the opposite was true after 96 h. However, since the anti-oxidative ability of HDL2 shows a weaker tendency than that of HDL3, both HDL3 and HDL2 significantly inhibited this acceleration of oxidative modification of LDL by ascorbic acid as assessed by electrophoretic mobility. If there is an augmented oxidative modification of LDL due to ascorbic acid in vivo, HDL3 or HDL2 may thus have an important role in inhibiting this ascorbic acid-accelerated oxidation of LDL. PMID:16022192

Sakuma, Nagahiko; Saeki, Tomoaki; Yajima, Kazuhiro; Hibino, Takeshi; Yoshida, Takayuki; Mizuno, Hiromi; Mukai, Seiji; Sakata, Seiichiro; Kunimatsu, Mitoshi; Kimura, Genjiro

2005-04-01

83

Carbon tetrachloride-induced alterations in hepatic glutathione and ascorbic acid contents in mice fed a diet containing ascorbate esters.  

Science.gov (United States)

The effects of L-ascorbyl stearate and L-ascorbyl palmitate on carbon tetrachloride-induced alterations in glutathione and ascorbic acid content in mouse livers were investigated. Powdered food containing 1% ascorbate ester was given to mice for 3 days before and 1 day after a single injection of CCl4 (0.1 ml/kg, i.p.). Biochemical parameters were determined 1 day after the CCl4 administration. The ascorbate esters markedly attenuated CCl4-induced alterations such as reductions in ascorbate content and hepatic glutathione S-transferase (GST) activity, and increases in glutathione and calcium content and serum GST activity. The CCl4-induced rise in thiobarbituric acid-reactive substances, an index of lipid peroxidation, was not affected by ascorbate feeding. These findings suggest that exogenous ascorbate, in addition to endogenous glutathione, is available to maintain the intracellular milieu in a reduced state, and that this system operates more effectively in aqueous compartments than in membrane lipid bilayers. PMID:8135659

Nakagawa, K

1993-01-01

84

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

85

Ascorbic acid extends replicative life span of human embryonic fibroblast by reducing DNA and mitochondrial damages  

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Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid (at 200 µM) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered SA-?-gal positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Asc...

2007-01-01

86

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

1977-06-01

87

Ascorbic acid status in third trimester of pregnancy, at delivery and in cord blood  

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Ascorbic acid levels in 30 subjects in their third trimester of pregnancy were estimated. Their haematological parameters (packed cell volume, haemoglobin and mean cell haemoglobin concentration) were also determined. The values were compared with that of 30 non-pregnant women (control group). The ascorbic acid status of newly born babies using cord blood were determined along with that of their mothers at delivery. The ascorbic acid level of 0.92±0.37 mg/dl was reported in third trimester. ...

Awoyelu, C. O.; Agharanya, J. C.; Oguntibeju, O. O.

2004-01-01

88

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

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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/sup -4/M, 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 (Fe/sup 2 +/ or Fe/sup 3 +/) to EDTA-chelated fatty acid micelles re-initiated the peroxidation process. The ease of fatty acid oxidation at pH 7.5 was arachidonic (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).

Yau, T.M.; Mencl, J. (Case Western Reserve Univ., Cleveland, OH (USA). Div. of Radiation Biology)

1981-07-01

89

Effect of Dietary Ascorbic Acid on Performance and Immune Response of Heat Stressed Broiler Chicks  

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Full Text Available A total of 112, day-old broiler chicks were reared under summer temperature of the Sudan (35-45°C to study the effect of supplementation of ascorbic acid on the feed intake, Feed Conversion Ratio (FCR, weight gain, immune status and ratio of weight of bursa, thymus and spleen to body weight. Four level of ascorbic acid 0 (control, 150 (low level, 350 (moderate level and 550 (high level mg/kg were used from day 14-42 day. Birds fed low and moderate levels of ascorbic acid (150, 350 mg/kg show high feed intake compared to those fed high level (550 mg/kg, which resulted in improvement in body weight and feed conversion ratio of the moderate and low levels. Dressing percentage was not affected by different level of ascorbic acid. Total white blood cells were reduced as the level of ascorbic acid was increased. Lymphocytes increased in birds fed moderate or high levels of ascorbic acid. Heterophils were decreased in the group fed the moderate level and high levels of ascorbic acid. Monocytes decreased in the groups fed the high level, However, basophils and esinophils were not affected by the different levels of ascorbic acid. The mean weight of lymphoid organs or the ratio of lymphoid organs to body weight was not affected by the different treatments. Antibody titer against Newcastle virus was increased in birds fed diets supplemented with different levels of ascorbic acid.

Hind A.A. Elagib

2012-01-01

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

1998-01-01

91

Regulation of L-ascorbic acid content in strawberry fruits  

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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-galacturo...

Cruz-rus, Eduardo; Amaya, Iraida; Sa?nchez-sevilla, Jose? F.; Botella, Miguel A.; Valpuesta, Victoriano

2011-01-01

92

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

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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,...

2010-01-01

93

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

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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 Ã?...

Zbynek Gazdik; Ondrej Zitka; Jitka Petrlova; Vojtech Adam; Josef Zehnalek; Ales Horna; Vojtech Reznicek; Miroslava Beklova; Rene Kizek

2008-01-01

94

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

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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

95

Differential Regulation of the Ascorbic Acid Transporter SVCT2 during Development and in Response to Ascorbic Acid Depletion  

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The sodium-dependent vitamin C transporter-2 (SVCT2) is the only ascorbic acid (ASC) transporter significantly expressed in brain. It is required for life and critical during brain development to supply adequate levels of ASC. To assess SVCT2 function in the developing brain, we studied time-dependent SVCT2 mRNA and protein expression in mouse brain, using liver as a comparison tissue because it is the site of ASC synthesis. We found that SVCT2 expression followed an inverse relationship with...

Meredith, M. Elizabeth; Harrison, Fiona E.; May, James M.

2011-01-01

96

Synergic interaction between ascorbic acid and antibiotics against Pseudomonas aeruginosa  

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Full Text Available Studies were carried out on in vitro combination of ascorbic acid (AA with six antibiotics against 12 multi-resistant Pseudomonas aeruginosa isolates. Synergic activity was detected with AA chloramphenicol, kanamycin, streptomycin and tetracycline. Indifference was observed to any antibiotics and antagonism only for chloramphenicol. Results indicated that multiresistant P. aeruginosa was affected by combination of AA and antibiotics. Future research on ascorbic acid-antimicrobial interactions may find new methods to control strains of multiresistant P. aeruginosa.Investigou-se in vitro o efeito da combinação do ácido ascórbico (AA com seis antibióticos frente a 12 isolados multirresistentes de Pseudomonas aeruginosa. As concentrações inibitórias mínimas (CIM foram determinadas pelo método de diluição em caldo. Foi estudado o efeito do AA nas CIM pelo cálculo das concentrações inibitórias fracionais (CIF. Para quase todas as combinações AA-antibiótico foi detectado efeito sinérgico, exceto para ampicilina e tobramicina. Indiferença foi observada na interação com todos os antibióticos, porém antagonismo foi somente observado para cloranfenicol. Os resultados deste estudo indicam que o sinergismo contra P. aeruginosa resistentes pode ocorrer entre AA e cloranfenicol, canamicina, estreptomicina e tetraciclina, ainda que as linhagens sejam resistentes aos antibióticos individualmente. Além disso, estes resultados encorajam futuros trabalhos in vivo a respeito da interação AA-antimicrobianos na incessante busca de novas alternativas para o controle de linhagens multirresistentes de P.aeruginosa.

Luciana Cursino

2005-05-01

97

Glutathione deficiency increases hepatic ascorbic acid synthesis in adult mice.  

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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...

1992-01-01

98

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

1996-12-01

99

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

100

[Use of HPLC for identification and quantitative determination of ascorbic acid in kiwi fruit].  

Science.gov (United States)

The content of ascorbic acid in kiwi fruits (Actinidia chinensis Planch) of various cultivars was determined by high-performance liquid chromatography (HPLC). The minimal content (mg/g) of ascorbic acid was found in fruits of the cultivar Gaivard: 5.44 in juice, 1.14 in the skin, and 4.20 in the pulp. PMID:11357433

Kvesitatdze, G I; Kalandiia, A G; Papunidze, S G; Vanidze, M R

2001-01-01

 
 
 
 
101

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

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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

102

Antioxidant activity of the aqueous extracts of spicy food additives--evaluation and comparison with ascorbic acid in in-vitro systems.  

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The antioxidant activity of the aqueous extracts of five umbelliferous fruits--caraway (Carum carvi), coriander (Coriandrum sativum), cumin (Cuminum cyminum), dill (Anethum graveolens) and fennel (Foeniculum vulgare)--were investigated in comparison with the known antioxidant ascorbic acid in in vitro studies. The amount of aqueous extract of these five umbelliferous fruits and ascorbic acid needed for 50% scavenging of superoxide radicals was found to be 105 microg (caraway), 370 microg (coriander), 220 microg (cumin), 190 microg (dill), 205 microg (fennel) and 260 microg (ascorbic acid). The amount needed for 50% inhibition of lipid peroxide was 2100 microg (caraway), 4500 microg (coriander), 4300 microg (cumin), 3100 microg (dill), 4600 microg (fennel) and 5000 microg (ascorbic acid). The quantity needed for 50% inhibition of hydroxyl radicals was 1150 microg (caraway), 1250 microg (coriander), 470 microg (cumin), 575 microg (dill), 700 microg (fennel) and 4500 microg (ascorbic acid). The daily use of the above fruits in various forms is very common in India and the present study revealed strong antioxidant activity of their extracts that was superior to known antioxidant ascorbic acid and indicate their intake may be beneficial as food additives. PMID:15364640

Satyanarayana, S; Sushruta, K; Sarma, G S; Srinivas, N; Subba Raju, G V

2004-01-01

103

Salivary ascorbic acid levels in betel quid chewers: A biochemical study  

Science.gov (United States)

Background: Quid chewing practice has been a part of our tradition since centuries with little known evidence of oral cancer. However, recent trends show a rise in occurrence of oral cancer often associated with tobacco and arecanut usage. Ascorbic acid is an important salivary antioxidant. Betel leaf which is used in quid is known to contain ascorbic acid. Aim: The aim of our study was to assess the salivary levels of ascorbic acid in traditional quid chewers so as to determine whether the betel leaf has protective antioxidant action. Materials and Methods: Salivary ascorbic acid levels of 60 subjects were estimated using the Dinitrophenyl hydrazine method. Results: The results revealed that quid chewers who used betel leaf had higher salivary ascorbic acid content compared to nonbetel leaf quid chewers. This could possibly be due to the protective antioxidants in the betel leaf.

Shetty, Shishir R.; Babu, Subhas; Kumari, Suchetha; Prasad, Rajendra; Bhat, Supriya; Fazil, K. A.

2013-01-01

104

Influence of thiamine and ascorbic acid supplementation on the antidotal efficacy of thiol chelators in experimental lead intoxication  

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The influence of the administration of thiamine (vitamin B/sub 1/), ascorbic acid (vitamin C) or their combination on the efficacy of two thiol metal chelators, viz. ..cap alpha..-mercapto-..beta..-(2-furyl) acrylic acid (MFA) and 2,3-dimer-captosuccinic acid (DMS), in counteracting lead (Pb) toxicity was investigated in rats. Ascorbic acid or its combination with thiamine enhanced the urinary elimination of Pb, reduced the hepatic and renal burden of Pb, and reversed the Pb-induced inhibition of the activity of blood delta-aminolevulinic acid dehydratase (delta-ALA-D). All these effects were more evident in DMS- than in MFA-treated rats. The combination of MFA and DMS treatments further improved the performance of the animals in enhancing urinary Pb excretion and in reducing Pb hepatic levels.

Dhawan, M.; Kachru, D.N.; Tandon, S.K.

1988-10-01

105

Effects of ascorbic acid on impaired vascular reactivity in aortas isolated from age-matched hypertensive and diabetic rats.  

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Impaired vascular reactivity is a hallmark of several cardiovascular diseases that include hypertension and diabetes. This study compared the changes in vascular reactivity in age-matched experimental hypertension and diabetes, and, subsequently, tested whether these changes could be affected directly by ascorbic acid (10 microM). Endothelium-derived nitric oxide (NO) modulation of ascorbic acid effects was also investigated. All the experiments were performed in the presence of a cyclooxygenase inhibitor, indomethacin (10 microM). Results showed that the endothelium-dependent and -independent relaxations induced by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively, were blunted to a similar extent in isolated aortic rings from age-matched spontaneously hypertensive (SHR) (R(max): ACh = 72.83+/-1.86%, SNP = 96.6+/-1.90%) and diabetic (Rmax: ACh = 64.09+/-5.14%, SNP = 95.84+/-1.41%) rats compared with aortic rings of normal rats (Rmax: ACh = 89%, SNP = 104.0+/-1.0%). The alpha1-receptor-mediated contractions induced by phenylephrine (PE) were augmented in diabetic (Cmax = 148.8+/-9.0%) rat aortic rings compared to both normal (Cmax = 127+/-6.9%) and SHR (Cmax = 118+/-4.5%) aortic rings. Ascorbic acid pretreatment was without any significant effects on the vascular responses to ACh, SNP and PE in aortic rings from normal rats. Ascorbic acid significantly improved ACh-induced relaxations in SHR (Rmax = 89.09+/-2.82%) aortic rings to a level similar to that observed in normal aortic rings, but this enhancement in ACh-induced relaxations was only partial in diabetic aortic rings. Ascorbic acid lacked any effects on SNP-induced relaxations in both SHR and diabetic aortic rings. Ascorbic acid markedly attenuated contractions induced by PE in aortic rings from both SHR (Cmax = 92.9+/-6.68%) and diabetic (Cmax = 116.9+/-9.4%) rats. Additionally, following inhibition of nitric oxide synthesis with l-NAME, ascorbic acid attenuated PE-induced contractions in all aortic ring types studied. These results suggest that (1) vascular hyper-responsiveness to alpha(1)-receptor agonists in diabetic arteries is independent of endothelial nitric oxide dysfunction; (2) ascorbic acid directly modulates contractile responses of hypertensive and diabetic rat aortas, likely through mechanisms in part independent of preservation of endothelium-derived nitric oxide. PMID:16807125

Ajay, Machha; Mustafa, Mohd Rais

2006-08-01

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

Comparative analysis of ascorbic acid in human milk and infant formula using varied milk delivery systems  

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Full Text Available Abstract Background The expression of human milk for later use is on the rise. Bottle systems are used to deliver the expressed milk. Research has shown that storage of both human milk and artificial baby milk, or infant formula, leads to a loss of ascorbic acid (commonly called Vitamin C. As milk is removed from the bottle during feeding and replaced by ambient air, it is unknown if loss of ascorbic acid occurs during the course of a feeding. The purpose of this study is to investigate the effect of the milk delivery system on levels of ascorbic acid in human milk and infant formula. The objectives are to 1 determine changes in ascorbic acid concentration during a 20 minute "feed," 2 determine if there is a difference in ascorbic acid concentration between delivery systems, and 3 evaluate if any differences are of clinical importance. Methods Commonly available bottles were used for comparison of bottle delivery systems. Mature human milk was standardized to 42 mg/L of ascorbic acid. Infant formula with iron and infant formula with docosahexanoic acid were used for the formula samples. Each sample was analyzed for ascorbic acid concentration at baseline (0, 5, 10, 15, and 20 minutes. Each collection of samples was completed in triplicate. Samples were analyzed for ascorbic acid using normal-phase high performance liquid chromatography. Results Ascorbic acid concentration declined in all bottle systems during testing, Differences between the bottle systems were noted. Ascorbic acid concentrations declined to less than 40% of recommended daily intake for infants in 4 of the bottles systems at the 20 minute sampling. Conclusion The bottle systems used in this study had measurable decreases in the mean concentration of ascorbic acid. More research is needed to determine if the observed decreases are related to lower plasma ascorbic acid concentration in infants exclusively bottle fed. The decrease of ascorbic acid concentration observed in both human milk and infant formula using varied milk delivery systems may be of clinical importance. For infants who rely solely on bottle feeds there may be increased risk of deficiency. Bottle shape, size, and venting should be considered.

Dickton Darby

2008-08-01

108

CITOGENETICS EFFECTS INDUCED BY THE ASCORBIC ACID TREATMENT OF LARIX DECIDUA MILL. SSP. CARPATICA AND PICEA ABIES (L. KARST  

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Full Text Available The paper present the influence of ascorbic acid upon the mitotic division of Larix decidua Mill ssp. carpatica and Picea abies (L. Karst. The treatment is applied of two variants, germinated seed in ascorbic acid (variantAand germinated seeds in disttilate water, than treated with ascorbic acid in 3 concentrations (variant B.

Ion Bara

2006-08-01

109

An efficient synthesis of tetramic acid derivatives with extended conjugation from L-Ascorbic Acid  

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Full Text Available Abstract Background Tetramic acids with polyenyl substituents are an important class of compounds in medicinal chemistry. Both solid and solution phase syntheses of such molecules have been reported recently. Thiolactomycin, a clinical candidate for treatment of tuberculosis has led to further explorations in this class. We have recently developed an efficient synthesis of tetramic acids derivatives from L- ascorbic acid. In continuation of this work, we have synthesised dienyl tetramic acid derivatives. Results 5,6-O-Isopropylidene-ascorbic acid on reaction with DBU led to the formation of tetronolactonyl allyl alcohol, which on oxidation with pyridinium chlorochromate gave the respective tetranolactonyl allylic aldehydes. Wittig olefination followed by reaction of the resulting tetranolactonyl dienyl esters with different amines resulted in the respective 5-hydroxy lactams. Subsequent dehydration of the hydroxy lactams with p-toluene sulphonic acid afforded the dienyl tetramic acid derivatives. All reactions were performed at ambient temperature and the yields are good. Conclusion An efficient and practical method for the synthesis of dienyl tetramic acid derivatives from inexpensive and easily accessible ascorbic acid has been developed. The compounds bear structural similarities to the tetramic acid based polyenic antibiotics and thus this method offers a new and short route for the synthesis of tetramic acid derivatives of biological significance.

Bisht Surendra S

2006-12-01

110

Tomato fruit ascorbic acid content is linked with monodehydroascorbate reductase activity and tolerance to chilling stress.  

Science.gov (United States)

Quantitative trait loci (QTL) mapping is a step towards the identification of factors regulating traits such as fruit ascorbic acid content. A previously identified QTL controlling variations in tomato fruit ascorbic acid has been fine mapped and reveals that the QTL has a polygenic and epistatic architecture. A monodehydroascorbate reductase (MDHAR) allele is a candidate for a proportion of the increase in fruit ascorbic acid content. The MDHAR enzyme is active in different stages of fruit ripening, shows increased activity in the introgression lines containing the wild-type (Solanum pennellii) allele, and responds to chilling injury in tomato along with the reduced/oxidized ascorbate ratio. Low temperature storage of different tomato introgression lines with all or part of the QTL for ascorbic acid and with or without the wild MDHAR allele shows that enzyme activity explains 84% of the variation in the reduced ascorbic acid levels of tomato fruit following storage at 4 degrees C, compared with 38% at harvest under non-stress conditions. A role is indicated for MDHAR in the maintenance of ascorbate levels in fruit under stress conditions. Furthermore, an increased fruit MDHAR activity and a lower oxidation level of the fruit ascorbate pool are correlated with decreased loss of firmness because of chilling injury. PMID:18433441

Stevens, R; Page, D; Gouble, B; Garchery, C; Zamir, D; Causse, M

2008-08-01

111

Effects of ascorbic acid and ?-carotene on HepG2 human hepatocellular carcinoma cell line.  

Science.gov (United States)

Recent studies have demonstrated that vegetable rich diets have protective effects on the occurrence and prognosis of various cancers. In addition to dietary intakes, ascorbic acid and ?-carotene are also taken as supplements. The aim of this study was to assess effects of ascorbic acid, ?-carotene and their combinations on human hepatocellular carcinoma cell line HepG2. Ascorbic acid and ?-carotene were applied to cells as plasma peak concentrations (70 and 8 ?M, respectively) and their half concentrations (35 and 4 ?M, respectively) for 24 and 48 h. Genotoxic and cytotoxic effects of ascorbic acid and ?-carotene were evaluated by alkali single cell gel electrophoresis (SCGE), acridine orange/ethidium bromide staining patterns of cells (apoptosis and necrosis) and lipid peroxidation (thiobarbituric acid reactive substances, TBARS). Results of the SCGE demonstrated that both ascorbic acid and ?-carotene caused DNA damage on HepG2 which were also concordant to increased apoptosis and necrosis of cells. Increased TBARS values also demonstrated increased lipid peroxidation in these cells. Results of the present study demonstrates that when dietary intakes of ascorbic acid and ?-carotene and their relevant achievable plasma level concentrations were considered, both ascorbic acid and ?-carotene induce genotoxic and cytotoxic damage on HepG2 together with increased oxidative damage in contrast to their protective effect on healthy cells. This may be correlated to oxidative status and balance of ROS in hepatocellular carcinoma cells. PMID:21116852

Yurtcu, Erkan; Iseri, Ozlem Darcansoy; Sahin, Feride I

2011-10-01

112

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

113

Intramolecular acyl migration and enzymatic hydrolysis of a novel monoacylated ascorbic acid derivative, 6-O-dodecanoyl-2-O-alpha-d-glucopyranosyl-L-ascorbic acid.  

Science.gov (United States)

A stable ascorbic acid derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), exhibits vitamin C activity in vitro and in vivo after enzymatic hydrolysis to ascorbic acid. AA-2G has been approved by the Japanese Government as a quasi-drug principal ingredient in skin care and as a food additive. In order to achieve efficient action as an ascorbic acid source, a pro-vitamin C agent, on a variety of cells or tissues, we have synthesized a series of monoacyl AA-2G derivatives. Our previous studies indicate that a series of the derivatives is a readily available source of AA activity in vitro and in vivo, and suggested that intramolecular acyl migration of the derivatives might have occurred in a neutral aqueous solution. In this study, intramolecular acyl migration and enzymatic hydrolysis of a monoacyl AA-2G derivative, 6-O-dodecanoyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acid (6-sDode-AA-2G), were investigated. 6-sDode-AA-2G underwent an intramolecular acyl migration to yield ca. 10% of an isomer in neutral aqueous solutions, and the acyl-migrated isomer was isolated and characterized as 5-O-dodecanoyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acid (5-sDode-AA-2G). In some tissue homogenates from guinea pigs as well as in neutral aqueous solutions, 6-sDode-AA-2G underwent partial acyl migration to give 5-sDode-AA-2G. 6-sDode-AA-2G and the resulting 5-sDode-AA-2G were predominantly hydrolyzed with esterase to AA-2G and then with alpha-glucosidase to ascorbic acid in the tissue homogenates. The results will provide a further basis for its use as an ingredient in skin care, as an effective pharmacological agent and as a promising food additive. PMID:20638286

Tai, Akihiro; Mori, Tasuku; Urushihara, Masaya; Ito, Hideyuki; Kawasaki, Daisuke; Yamamoto, Itaru

2010-08-15

114

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)

1986-01-01

115

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

1986-01-01

116

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

117

INFLUENCES OF THIAMINE AND/OR ASCORBIC ACID ON LEAD INTOXICATION  

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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 questi...

1996-01-01

118

Ascorbic Acid Determination in Commercial Fruit Juice Samples by Cyclic Voltammetry  

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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...

Pisoschi, Aurelia Magdalena; Danet, Andrei Florin; Kalinowski, Slawomir

2008-01-01

119

Effect of L-ascorbic acid on the bioretention of 169Yb  

International Nuclear Information System (INIS)

Studies with L-ascorbic acid as biological complexing agent were performed to investigate its influence on the uptake and retention of the radionuclide of ytterbium in animals. The results indicate that the retention of 169Yb in the investigated organs of mice is affected when 169YbCl3 is administered simultaneously with L-ascorbic acid. L-ascorbic acid has little or no effect on the 169Yb excretion when it is injected prior or succeeding to the administration of 169YbCl3. (author) 7 refs.; 3 tabs

1989-02-01

120

Ascorbic acid and striatal transport of [3H]1-methyl-4-phenylpyridine (MPP+) and [3H]dopamine  

International Nuclear Information System (INIS)

The inhibition of uptake of [3H]dopamine and [3H]1-methyl-4-phenylpyridine (MPP+) was examined in mouse striatal synaptosomal preparations. Kinetic analysis indicated that ascorbic acid is a noncompetitive inhibitor of [3H]MPP+ uptake. No inhibition of [3H]dopamine uptake is observed. The dopamine uptake blockers, GBR-12909, cocaine, and mazindol strongly inhibit (IC50 3H]dopamine and [3H]MPP+ transport. Nicotine, its metabolites, and other tobacco alkaloids are weak inhibitors except 4-phenylpyridine and lobeline, which are moderate inhibitors of both [3H]dopamine and [3H]MPP+ uptake. These similarities in potencies are in agreement with the suggestion that [3H]MPP+ and [3H] are transported by the same carrier. The differences observed in the alteration of dopaminergic transport and mazindol binding by ascorbic acid suggest that ascorbic acid's effects on [3H]MPP+ transport are related to translocation and/or dissociation processes occurring subsequent to the initial binding event

1988-01-01

 
 
 
 
121

Ascorbic acid synthesis and metabolism in maize are subject to complex and genotype-dependent feedback regulation during endosperm development.  

Science.gov (United States)

L-ascorbic acid (vitamin C) is an antioxidant and electron donor whose metabolism in plants is under strict feedback control. The factors that influence L-ascorbic acid accumulation in staple crops are only partially understood. One way to gain insight into the regulation of L-ascorbic acid metabolism is to investigate the endogenous pathways in various genetic backgrounds and characterize their interactions with transgenes encoding relevant enzymes. In an initial step, we investigated the developmental profile of L-ascorbic acid accumulation in the endosperm of three diverse maize genotypes and a transgenic line expressing rice dehydroascorbate reductase, which enhances L-ascorbic acid recycling. We determined the transcript levels of all the key genes in the L-ascorbic acid metabolic pathways as well as the specific levels of ascorbic acid and dehydroascorbate. L-ascorbic acid levels were high 20 days after pollination and declined thereafter. We found significant genotype-dependent variations in the transcript levels of some genes, with particular complexity in the ascorbic acid recycling pathway. Our data will help to elucidate the complex mechanisms underlying the regulation of L-ascorbic acid metabolism in plants, particularly the impact of genetic background on the strict regulation of ascorbic acid metabolism in endosperm cells. PMID:23744785

Sanahuja, Georgina; Farré, Gemma; Bassie, Ludovic; Zhu, Changfu; Christou, Paul; Capell, Teresa

2013-10-01

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.

2009-09-02

123

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

124

Pre-sowing application of ascorbic acid and salicylic acid to seed of pumpkin and seedling response to salt  

International Nuclear Information System (INIS)

The effects of seed soaking with salicylic acid or ascorbic acid on pumpkin seedlings growth under saline (10 dS m/sup -1/) conditions were investigated. Seedlings fresh weight, protein contents, protease and nitrate reductase activities were significantly affected by 15 and 30 mg L/sup -1/ salicylic acid and 30 mg L/sup -1/ ascorbic acid priming treatments, under both normal and saline conditions. Priming reduced the severity of the salt stress, the amelioration was better due to 30 mg L/sup -1/ ascorbic acid or 30 mg L/sup -1/ salicylic acid treatments as these treatments showed best results on seedling growth, fresh and dry matter production under non-saline and saline environments. Application of seed priming with ascorbic acid and salicylic acid in pumpkin ameliorate the adverse effects of salt stress. (author)

2011-12-01

125

Kinetics of Ascorbic Acid Degradation in Un-Pasteurized Iranian Lemon Juice During Regular Storage Conditions  

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Full Text Available The aim of this research was to determine shelf life stability of un-pasteurized lemon juice filled in clear or dark green glass bottles. Presence of light, time and temperature affect the ascorbic acid retention in citrus juices. Bottles were stored at room temperature (27 ± 3 °C and in the refrigerator (3 ± 1 °C. Total soluble solids, total titrable acidity and pH value were measured every three weeks and analysis was carried out on ascorbic acid content by means of titration method in the presence of 2,6-dichlorophenol indophenol. The study was carried out for 12 weeks after which slight changes in color, taste and apparent texture in some samples were observed and ascorbic acid content reduced by 50%. Soluble solids content, pH value and total acidity were 5.5 ° Brix, 2.73 and 5 g/100 mL, respectively which appeared not to be significantly influenced by storage time or conditions. Ascorbic acid content initially at 38.50 mg/100 mL was sharply reduced to about 22 mg/100 mL within the first three weeks of storage. The final ascorbic acid content of all samples was about 15 mg/100 mL. The deteriorative reaction of ascorbic acid in the juice at all conditions followed a first-order kinetic model with activation energy of 137 cal mol-1.

Abbasi

2008-01-01

126

In situ intestinal absorption of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid in guinea pigs.  

Science.gov (United States)

The intestinal absorption efficacy of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), which has been recently synthesized and characterized as a stable ascorbate (AsA), was determined in guinea pigs by the perfusion technique. Perfusion of AA-2G in isotonic phosphate buffer to the small intestine resulted in a decrease of AA-2G accompanied by an increase of AsA in the perfusate. The results showed that intact AA-2G was not detected in the plasma of the portal vein of guinea pigs at 2 h after perfusion. The disappearance of AA-2G from perfusate was completely inhibited by the addition of castanospermine, a specific alpha-glucosidase inhibitor, or by carbohydrates such as maltose. These results indicate that ascorbic acid released from AA-2G by alpha-glucosidase on the brush border membrane is effectively taken up across the intestinal ascorbate transport channels, into a serosal site, whereas AA-2G permeation was poor via the passive transport system. PMID:7562119

Wakamiya, H; Suzuki, E; Yamamoto, I; Akiba, M; Arakawa, N

1995-04-01

127

Ascorbic acid (AA) metabolism in protection against radiation damage  

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The possibility is considered that AA protects tissues against radiation damage by scavenging free radicals that result from radiolysis of water. A physiologic buffer (pH 6.7) was incubated with /sup 14/C-AA and 1 mM thiourea (to slow spontaneous oxidation of AA). Aliquots were assayed by HPLC and scintillation spectrometry to identify the /sup 14/C-label. Samples exposed to Cobalt-60 radiation had a half time of AA decay of < 3 minutes compared with nonirradiated samples (t/sub 1/2/ > 30 minutes) indicating that AA scavenges radiation-induced free radicals and forms the ascorbate free radical (AFR). Pairs of /sup 14/C-AFR disproportionate, with the net effect of /sup 14/C-dehydroascorbic acid formation from /sup 14/C-AA. Having established that AFR result from ionizing radiation in an aqueous solution, the possibility was evaluated that a tissue factor reduces AFR. Cortical tissue from the kidneys of male rats was minced, homogenized in buffer and centrifuged at 8000 xg. The supernatant was found to slow the rate of radiation-induced AA degradation by > 90% when incubated at 23/sup 0/C in the presence of 15 ..mu..M /sup 14/C-AA. Samples of supernatant maintained at 100/sup 0/C for 10 minutes or precipitated with 5% PCA did not prevent radiation-induced AA degradation. AA may have a specific role in scavenging free radicals generated by ionizing radiation and thereby protect body tissues.

Rose, R.C.; Koch, M.J.

1986-03-05

128

Ascorbic acid (AA) metabolism in protection against radiation damage  

International Nuclear Information System (INIS)

The possibility is considered that AA protects tissues against radiation damage by scavenging free radicals that result from radiolysis of water. A physiologic buffer (pH 6.7) was incubated with "1"4C-AA and 1 mM thiourea (to slow spontaneous oxidation of AA). Aliquots were assayed by HPLC and scintillation spectrometry to identify the "1"4C-label. Samples exposed to Cobalt-60 radiation had a half time of AA decay of 30 minutes) indicating that AA scavenges radiation-induced free radicals and forms the ascorbate free radical (AFR). Pairs of "1"4C-AFR disproportionate, with the net effect of "1"4C-dehydroascorbic acid formation from "1"4C-AA. Having established that AFR result from ionizing radiation in an aqueous solution, the possibility was evaluated that a tissue factor reduces AFR. Cortical tissue from the kidneys of male rats was minced, homogenized in buffer and centrifuged at 8000 xg. The supernatant was found to slow the rate of radiation-induced AA degradation by > 90% when incubated at 23"0C in the presence of 15 ?M "1"4C-AA. Samples of supernatant maintained at 100"0C for 10 minutes or precipitated with 5% PCA did not prevent radiation-induced AA degradation. AA may have a specific role in scavenging free radicals generated by ionizing radiation and thereby protect body tissues

1986-03-05

129

Molecularly imprinted polyaniline film for ascorbic acid detection.  

Science.gov (United States)

Molecularly imprinted polyaniline (PANI) film (? 100 nm thick) has been electrochemically fabricated onto indium-tin-oxide (ITO) coated glass plate using ascorbic acid (AA) as template molecule. Fourier transform infra-red spectroscopy, scanning electron microscopy, cyclic voltammetry and differential pulse voltammetry (DPV) studies indicate the presence of AA in PANI matrix, which also acts as a dopant for PANI. Further, the AA selective molecularly imprinted PANI electrode (AA-MI-PANI/ITO) has been developed via over-oxidation of AA doped PANI electrode which leads to the removal of AA moieties from PANI film. The response studies using DPV technique have revealed that this molecularly imprinted AA-MI-PANI/ITO electrode can detect AA in the range of 0.05-0.4 mM with detection limit of 0.018 mM and sensitivity of 1.2 × 10(-5) AmM(-1). Interestingly, this AA-MI-PANI/ITO electrode shows excellent reusability, selectivity and stability. PMID:21584880

Roy, Abani Kumar; Nisha, V S; Dhand, Chetna; Malhotra, Bansi D

2011-01-01

130

Effects of ascorbic acid on stress and disease in chickens.  

Science.gov (United States)

White leghorn chickens were given feed containing 100 mg of ascorbic acid (AA)/kg. One day later, treated chickens and a similar group of unmedicated control chickens were chilled for 1 hour at 6 C, exposed to an unusual sound, fasted, or subjected to rough handling. Heterophil:lymphocyte (H:L) ratios were determined one day later. The AA-treated birds had significantly lower H:L ratios than untreated controls. Chickens that received a diet containing AA had lower H:L ratios than controls (0.86 vs. 1.65) following administration of adrenocorticotropic hormone. Chickens fed a diet containing AA showed increased resistance to a combined Newcastle disease virus-Mycoplasma gallisepticum infection and to a secondary Escherichia coli infection, as well as to a primary E. coli challenge infection. The effects of AA and an antibacterial drug (furaltadone) were additive. In all experiments, the optimum dose of AA was 100 mg/kg of feed. There was a negative correlation between AA level in the diet and feed efficiency. PMID:1417599

Gross, W B

1992-01-01

131

Inhibition of human breast carcinoma cell proliferation by ascorbate and copper.  

Science.gov (United States)

We tested the effect of different concentrations of ascorbic acid (AA), 50, 100, 250 mg/500 mg/dL) with copper sulfate (CS), 10 mg/dL) on human breast carcinoma (MDA-MB231) cell proliferation in vitro. Cell proliferation was measured using a colori-metric assay (Cell proliferation kit II (XTT), Boehringer, NJ). The results of the mean absorbance of the tissue culture at different AA concentrations and a constant CS concentration were as follow: 0.82 +/- 0.03 (control, mean +/- SE), 0.64 +/- 0.02 (CS above); 0.48 +/- 0.03 (50 mg/dL) AA), 0.21 +/- 0.02 (100 mg/dL), 0.08 +/- 0.01 (250 mg/dL) AA, 0.60 +/- 0.05 (500 mg/dL). These results show that a combination of AA and CS inhibits human breast carcinoma cell proliferation in vitro. This cell proliferation inhibitory effect is directly proportional to the AA concentration with the exception of the 500 mg/dL AA dose. This chemotherapeutic effect was optimally enhanced when AA was added at a concentration of 250 mg/dL. The AA concentrations of 500 mg/dL had a biphasic effect on tumor cell proliferation probably due to back and forth redox reactions between AA and dehydroascorbic acid in a closed system. This study provides preliminary evidence that AA and SC can be used as biological response modifiers (BRM) for tumor growth inhibition. PMID:12013676

González, Michael J; Mora, Edna M; Miranda-Massari, Jorge R; Matta, Jaime; Riordan, Hugh D; Riordan, Neil H

2002-03-01

132

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

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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

Ascorbic acid mediates acetylcholine receptor increase induced by brain extract on myogenic cells.  

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Extracts of fetal calf brain cause a 3- to 5-fold increase in acetylcholine receptors (AcChoR) on cultured myogenic L5 cells. Purification of the substance causing the major portion of this receptor increase has been completed. Ultraviolet spectral characteristics, nuclear magnetic resonance, mass spectra, and AcChoR induction by the active factor are the same as those of commercially available ascorbic acid. The biological activity of ascorbic acid is not mimicked by reducing agents with or ...

1985-01-01

134

Evaluation of mineral elements and ascorbic acid contents in fruits of some wild plants.  

Science.gov (United States)

The fruits of some wild plants were examined for their contents of mineral elements and ascorbic acid. High levels of ascorbic acid were found in fruits of Sclerocarya birrea (403.3 mg/100 g) and Adansonia digitata (337 mg/100 g). In nine of the fruits examined, the mineral contents (Ca, P) were comparable with average values found in common fruits. The iron contents were however 2-5 times higher than the values for common fruits. PMID:1852726

Eromosele, I C; Eromosele, C O; Kuzhkuzha, D M

1991-04-01

135

Cell proliferation of the ileum intestinal mucosa of diabetic rats treated with ascorbic acid  

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The objective of this work was to evaluate the effect of the ascorbic acid supplementation on the cellular proliferation on the ileum mucosa of diabetic rats. Fifteen 90-days rats were divided in the groups: control, diabetic and diabetic supplemented with ascorbic acid (DA). Two hours prior the sacrifice, they were injected with Vincristin. Semi-seriate histological cuts stained with HE were accomplished. About 2500 crypt cells from the intestinal mucosa were counted in order to obtain the m...

Jacqueline Nelisis Zanoni; Renata Virginia Fernandes Pereira

2008-01-01

136

Ascorbic acid for homogenous redox buffering in electrospray ionization-mass spectrometry.  

Science.gov (United States)

Electrospray ionization (ESI) involves the dispersion of a liquid containing analytes of interest into a fine aerosol by applying a high potential difference to the sample solution with respect to a counter electrode. Thus, from the electrochemical point of view, the ESI source represents a two-electrode controlled-current electrochemical flow cell. The electroactive compounds part of the solvent sprayed may be altered by occurring electrolysis (oxidation in positive ion mode and reduction in negative ion mode). These reactions can be troublesome in the context of unknown identification and quantification. In the search for a simple, inexpensive, and efficient way to suppress electrochemical oxidation in positive ESI, the usability of ascorbic acid, hydroquinone, and glutathione for homogenous redox buffering was tested. Performance of the antioxidants was assessed by analyzing pharmaceutical compounds covering a broad range of functional groups prone to oxidation. Different emitter setups were applied for continuous infusion, flow injection, and liquid chromatography/mass spectrometry experiments. Best performance was obtained with ascorbic acid. In comparison to hydroquinone and glutathione, ascorbic acid offered superior antioxidant activity, a relatively inert oxidation product, and hardly any negative effect on the ionization efficiency of analytes. Furthermore, ascorbic acid suppressed the formation of sodiated forms and was able to induce charge state reduction. Only in the very special case of analyzing a compound isobaric to ascorbic acid, interference with the low-abundant [ascorbic acid+H](+) signal may become a point of attention. PMID:22772139

Plattner, Sabine; Erb, Robert; Chervet, Jean-Pierre; Oberacher, Herbert

2012-09-01

137

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

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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

Catalytic oxidation of ascorbic acid by some ferrocene derivative mediators at the glassy carbon electrode. Application to the voltammetric resolution of ascorbic acid and dopamine in the same sample.  

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Direct-current cyclic voltammetry is used to investigate the suitability of some ferrocene derivatives such as ferrocenecarboxylic acid, ferroceneacetic acid and ferrocenemethanol as mediators for ascorbic acid oxidation in aqueous solutions with low pH. The ascorbic acid coupled catalytically to three ferrocene derivatives exhibiting homogeneous second-order rate constants k(s), in the range 7.36 x 10(5) - 1.23 x 10(7). The catalytic oxidation peak current was linearly dependent on the ascorbic acid concentration and the linearity range obtained in the presence of ferrocenecarboxilic acid, having the largest second-order rate constant, was 5 x 10(-5) - 1.5 x 10(-3) M. The catalytic effect of the ferrocene derivatives on the electrochemical oxidation of ascorbic acid reduced the oxidation potential of ascorbic acid, resulting in the separation of the overlapping voltammograms of ascorbic acid and dopamine at the glassy carbon electrode in a mixture. This allowed the determination of ascorbic acid in the presence of dopamine. The calibration graph obtained by linear sweep voltammetry for ascorbic acid in the presence of dopamine of fixed concentration is linear in the range 5 x 10(-5) - 1.5 x 10(-3) M. In a similar manner, dopamine is determined in the presence of a high concentration of ascorbic acid, up to 100 times that of dopamine, using ferroceneacetic acid as the most suitable mediator for this purpose. PMID:18966422

Pournaghi-Azar, M H; Ojani, R

1995-12-01

139

Ascorbic Acid and Salicylic Acid Mitigate NaCl Stress in Caralluma tuberculata Calli.  

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Plants exposed to salt stress undergo biochemical and morphological changes even at cellular level. Such changes also include activation of antioxidant enzymes to scavenge reactive oxygen species, while morphological changes are determined as deformation of membranes and organelles. Present investigation substantiates this phenomenon for Caralluma tuberculata calli when exposed to NaCl stress at different concentrations. Elevated levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) in NaCl-stressed calli dwindled upon application of non-enzymatic antioxidants; ascorbic acid (AA) and salicylic acid (SA). Many fold increased enzymes concentrations trimmed down even below as present in the control calli. Electron microscopic images accentuated several cellular changes upon NaCl stress such as plasmolysed plasma membrane, disruption of nuclear membrane, increased numbers of nucleoli, alteration in shape and lamellar membrane system in plastid, and increased number of plastoglobuli. The cells retrieved their normal structure upon exposure to non-enzymatic antioxidants. The results of the present experiments conclude that NaCl aggravate oxidative molecules that eventually alleviate antioxidant enzymatic system. Furthermore, the salt stress knocked down by applying ascorbic acid and salicylic acid manifested by normal enzyme level and restoration of cellular structure. PMID:24744157

Rehman, Riaz Ur; Zia, Muhammad; Abbasi, Bilal Haider; Lu, Gang; Chaudhary, Muhammad Fayyaz

2014-06-01

140

Ascorbic acid and 4-hexylresorcinol effects on pear PPO and PPO catalyzed browning reaction.  

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The effects of ascorbic acid (AA) and 4-hexylresorcinol (4-HR) on pear polyphenoloxidase (PPO) activity and stability have been investigated in vitro. AA does not interact directly with PPO but prevents browning by reducing oxidized substrates. The 4-HR exerts a dual role on PPO. If no substrates are present, it interacts preferably with the deoxy form of PPO inactivating it. If substrates and 4-HR are both present they compete for the catalytic site. The 4-HR behaves then as a canonical enzyme inhibitor, binding to the met form of PPO. Simultaneous addition of 4-HR and AA has synergistic inhibition or inactivatory effects depending on the presence or the absence of PPO substrates. PMID:17995596

Arias, E; González, J; Oria, R; Lopez-Buesa, P

2007-10-01

 
 
 
 
141

A Comparative Study of Influence of Ascorbic Acid and Other Organic Acid on Corrosion of Mild Steel Using Mössbauer Spectroscopy  

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In present investigation a systematic study of role of Ascorbic Acid and other organic acids like Salicylic Acid, Acetyl Salicylic Acid and Maleic Acid, of different strength, on corrosion of Mild Steel in corrosive media brackish water is carried out. It is observed that the Ascorbic Acid of concentration 0.05M and higher in corrosive media brackish water effectively influences the formation of usual corrosion species and also retards the rate of rust formation while for other organic acid it is observed that these acids are not able to suppress the formation of usual corrosion product

Dhoot, Kashyap

2012-06-01

142

Ascorbic acid, catalase and chlorpromazine reduce cryopreservation-induced damages to crossbred bull spermatozoa.  

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The present study evaluated the effectiveness of ascorbic acid, catalase, chlorpromazine and their combinations in reducing the cryodamages to crossbred bull (Bos taurus x Bos indicus) spermatozoa. A total of 32 ejaculates (eight each from four bulls) were diluted in Tris-citric acid-fructose-egg yolk-glycerol extender. Each ejaculate was split into six parts (five treatment and one control). Treatment groups included 10 mm ascorbic acid, 0.1 mm chlorpromazine, 200 IU/ml catalase, 10 mm ascorbic acid + 0.1 mm chlorpromazine or 200 IU/ml catalase + 0.1 mm chlorpromazine in the extender. Fluorescent probes (Fluorescein isothiocyanate--Pisum sativum agglutinin + Propidium iodide) were used for the assessment of spermatozoa viability and acrosomal status. The proportion of acrosome intact live (AIL), acrosome intact dead, acrosome reacted live and acrosome reacted dead sperm was assessed in fresh, equilibrated and frozen-thawed semen. The functional status of the sperm was assessed using hypo-osmotic sperm swelling test (HOSST). Activities of acrosin and hyaluronidase enzyme were also determined. Lipid peroxidation level was assayed based on the melonaldehyde (MDA) production. In cryopreserved semen, the values of AIL spermatozoa, HOSST response, hyaluronidase and acrosin activity were reduced by 53%, 47%, 34% and 54%, respectively from their initial values in fresh semen. However, MDA level was threefold higher in the frozen-thawed sperm compared with fresh sperm. Significant (p < 0.05) improvement in motility, viability, HOSST response, retention of hyaluonidase and acrosin and reduction in MDA was recorded in ascorbic acid, catalase, ascorbic acid + chlorpromazine and catalase + chlorpromazine incorporated groups. The percentage of AIL sperm was significantly (p < 0.05) higher in ascorbic acid, catalase and ascorbic acid + chlorpromazine incorporated groups compared with the control. Chlorpromazine alone did not improve the post-thaw semen quality but when combined with either ascorbic acid or catalase, improvement in semen quality was noticed. It was inferred that incorporation of ascorbic acid, catalase and ascorbic acid + chlorpromazine in semen extender improved the post-thaw semen quality in crossbred bulls. PMID:19032433

Paudel, K P; Kumar, S; Meur, S K; Kumaresan, A

2010-04-01

143

Expression of ascorbic acid oxidase in zucchini squash (Cucurbita pepo L. )  

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The expression of ascorbic acid oxidase was studied in zuchini squash (Cucurbita pepo L.), one of the most abundant natural sources of the enzyme. In the developing fruit, specific activity of ascorbic acid oxidase was highest between 4 and 6 days after anthesis. Protein and mRNA levels followed the same trend as enzyme activity. Highest growth rate of the fruit occurred before 6 days after anthesis. Within a given fruit, ascorbic acid oxidase activity was higher in young leaves, and very low in old leaves. Within a given leaf, enzyme activity was highest in the fast-growing region (approximately the lower third of the blade), and lowest in the central placental region. In leaf tissue, ascorbic acid oxidase activity was higher in young leaves, and very low in old leaves. Within a given leaf, enzyme activity was highest in the fast-growing region (approximately the lower third of the blade), and lowest in the slow-growing region (near leaf apex). High expression of ascorbic acid oxidase at a stage when rapid growth is occurring (in both fruits and leaves), and localization of the enzyme in the fruit epidermis, where cells are under greatest tension during rapid growth in girth, suggest that ascorbic acid oxidase might be involved in reorganization of the cell wall to allow for expansion. Based on the known chemistry of dehydroascorbic acid, the end product of the ascorbic acid oxidase-catalyzed reaction, the authors have proposed several hypotheses to explain how dehydroascorbic acid might cause cell wall loosening.

Lin, Liangshiou; Varner, J.E. (Washington Univ., St. Louis, MO (United States))

1991-05-01

144

Synthesis and characterization of a series of novel monoacylated ascorbic acid derivatives, 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids, as skin antioxidants.  

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A series of novel monoacylated vitamin C derivatives were chemically synthesized with a stable ascorbate derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), and acid anhydrides in pyridine. Their solubility in organic phase, thermal stability, radical scavenging activity, and in vitro skin permeability was evaluated. These monoacylated derivatives were identified as 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G) by UV spectra, elemental analyses, and nuclear magnetic resonance spectroscopy. The reactions afforded 6-Acyl-AA-2G in high yields (30-60%). 6-Acyl-AA-2G exhibited satisfactory stability in neutral solution comparable to that of a typical stable derivative, AA-2G, and also showed the radical scavenging activity. The lipid solubility of 6-Acyl-AA-2G was increased with increasing length of their acyl group. Increased skin permeability was superior to those of AA-2G and ascorbic acid (AsA). 6-Acyl-AA-2G that is susceptible to enzymatic hydrolysis by tissue esterase and/or alpha-glucosidase produces AA-2G and AsA, which is in the skin tissues. Thus, these findings indicate that the novel vitamin C derivatives presented here, 6-Acyl-AA-2G, may be effective antioxidants in skin care and medicinal use. PMID:11784150

Yamamoto, Itaru; Tai, Akihiro; Fujinami, Yoshihito; Sasaki, Kenji; Okazaki, Shino

2002-01-17

145

Synthesis of L-ascorbic acid in the phloem  

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Full Text Available Abstract Background Although plants are the main source of vitamin C in the human diet, we still have a limited understanding of how plants synthesise L-ascorbic acid (AsA and what regulates its concentration in different plant tissues. In particular, the enormous variability in the vitamin C content of storage organs from different plants remains unexplained. Possible sources of AsA in plant storage organs include in situ synthesis and long-distance transport of AsA synthesised in other tissues via the phloem. In this paper we examine a third possibility, that of synthesis within the phloem. Results We provide evidence for the presence of AsA in the phloem sap of a wide range of crop species using aphid stylectomy and histochemical approaches. The activity of almost all the enzymes of the primary AsA biosynthetic pathway were detected in phloem-rich vascular exudates from Cucurbita pepo fruits and AsA biosynthesis was demonstrated in isolated phloem strands from Apium graveolens petioles incubated with a range of precursors (D-glucose, D-mannose, L-galactose and L-galactono-1,4-lactone. Phloem uptake of D-[U-14C]mannose and L-[1-14C]galactose (intermediates of the AsA biosynthetic pathway as well as L-[1-14C]AsA and L-[1-14C]DHA, was observed in Nicotiana benthamiana leaf discs. Conclusions We present the novel finding that active AsA biosynthesis occurs in the phloem. This process must now be considered in the context of mechanisms implicated in whole plant AsA distribution. This work should provoke studies aimed at elucidation of the in vivo substrates for phloem AsA biosynthesis and its contribution to AsA accumulation in plant storage organs.

Haupt Sophie

2003-11-01

146

Ascorbic Acid Determination in Commercial Fruit Juice Samples by Cyclic Voltammetry  

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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 = 6.391x + 0.1903 (where y represents the value of intensity measured for the anodic peak height, expressed as ?A and x the analyte concentration, as mmol·L?1, r2 = 0.9995, r.s.d. = 1.14%, n = 10, Cascorbic acid = 2 mmol·L?1). The developed method was applied to ascorbic acid assessment in fruit juice. The ascorbic acid content determined ranged from 0.83 to 1.67 mmol·L?1 for orange juice, from 0.58 to 1.93 mmol·L?1 for lemon juice, and from 0.46 to 1.84 mmol·L?1 for grapefruit juice. Different ascorbic acid concentrations (from standard solutions) were added to the analysed samples, the degree of recovery being comprised between 94.35% and 104%. Ascorbic acid determination results obtained by cyclic voltammetry were compared with those obtained by the volumetric method with dichlorophenol indophenol. The results obtained by the two methods were in good agreement.

Pisoschi, Aurelia Magdalena; Danet, Andrei Florin; Kalinowski, Slawomir

2008-01-01

147

Ascorbic acid, calcium, phosphorus and magnesium intake variations: effects on calcium, phosphorus and magnesium utilization by human adults  

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The objective of the study was to determine the effects of feeding two levels of ascorbic acid, calcium, phosphorus, magnesium and ascorbic acid on the apparent utilization of calcium, phosphorus and magnesium by healthy, human adult subjects. During 4 randomly-arranged experimental periods of 7 days each, a laboratory-controlled diet alone or with supplements of ascorbic acid, dicalcium phosphate or magnesium oxide was fed to the 18 subjects. Results indicated that ascorbic acid supplementation tended to reduce urinary phosphorus loss and to slightly increase fecal phosphorus loss so that overall phosphorus balances became more positive. Conversely, under these conditions, urinary calcium losses were little affected but fecal calcium losses were increased resulting in an overall decrease in calcium balance with ascorbic acid supplementation. Ascorbic acid supplementation resulted in decreased urine and fecal losses of magnesium and more positive magnesium balances. Magnesium supplementation resulted in more positive calcium and phosphorus balances as did calcium phosphate supplementation on magnesium balance.

Kies, C.; Brennan, M.A.; Parks, S.K.; Stauffer, D.J.; Wang, H.Y.; Young, S.F.; Fox, H.M.

1986-03-01

148

Quantitative estimation of ascorbic acid by HPTLC in different varieties of amla  

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Medicinal plants provide good remedies for human diseases and play a vital role in our day-to-day lifes. Phyllanthus emblica Linn family- Euphorbiaceae, commonly known as amla, is an important household fruit. The anti-ascorbic agent Vitamin C is a very effective antioxidant constituent present in amla. It is considered to be the richest source of Vitamin C. The determination of ascorbic acid in this fruit was done by thin layer chromatography (TLC) and qualitative test. Thus, it was...

2009-01-01

149

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

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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

150

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

151

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

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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

152

Comparison between radioimmunoanalysis and Mancini methods for a case of ascorbic acid radioprotection on rats contaminated with tritiated water  

International Nuclear Information System (INIS)

The recovery of humoral immune response has been comparatively studied by a radioimmunoanalysis (RIA) method and by Mancini single immuno radial diffusion method in an experiment consisting in chronic contamination with low doses of tritiated water (HTO) and oral administration of high doses of ascorbic acid on rats as radioprotector. The radioprotective effect of ascorbic acid was found to be dependent both on the radiation dose and the amount of ascorbic acid administered. (author). 11 refs., 1 tab

1995-10-10

153

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

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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 i...

Salari S; Abbasnejad M; Badreh F; Esmaeili Mahani S

2012-01-01

154

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

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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

155

Effect of the ascorbic acid treatment on the NADHd-positive myenteric neurons of diabetic rats proximal colon  

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The aim of this work was to study the effect of the ascorbic acid on the myenteric neurons of diabetic rats proximal colon. Fifteen rats (90 days old) were divided into three groups: control, untreated diabetic and treated diabetic with ascorbic acid (DA). After 120 days of daily treatment with ascorbic acid, the intestinal segments were submitted to the NADH-diaphorase (NADHd) histochemistry technique to expose the myenteric neurons. The group DA showed a higher neuronal density (33.4 %) whe...

Jacqueline Nelisis Zanoni; Renata Virginia Fernandes Pereira; Priscila de Freitas

2007-01-01

156

Monitoring on the Presence of Ascorbic Acid in Not Prepacked Fresh Meat Preparations by a Validated HPLC Method  

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Ascorbic acid is a commonly-used food additive permitted in prepacked fresh meat preparations. Consequently, the addition of this antioxidant is subject to a specific packaging authorization. In this survey 180 samples of not prepacked fresh meat preparations have been analyzed in order to evaluate the diffusion of not authorized ascorbic acid additions. The ascorbic acid has been determined by a high performance liquid chromatography with diode array detection method, validated according to ...

Marco Iammarino; Aurelia Di Taranto

2012-01-01

157

Chemical Characterization and Evolution of Ascorbic Acid Concentration During Dehydration of Rosehip (Rosa eglanteria) Fruits  

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Rose hip fruits possess a high ascorbic acid content, which may partially degrade during dehydration in heated air. In this study, the chemical composition of the fruits was determined in order to study degradation of ascorbic acid as a function of drying temperature. The results indicated that, in effect, the content of this nutrient is reduced. The degradation mechanisms differed according to the drying temperature but the final ascorbic acid content was almost independent from such operati...

Pirone, Beatriz N.; Ochoa, Monica R.; Kesseler, Alicia G.; Antonio De Michelis

2007-01-01

158

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 (Fe"2"+ or Fe"3"+) 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)

1981-01-01

159

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

160

Effect of ascorbic acid on cadmium toxicity in the young coturnix  

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This study was designed to evaluate the effects of supplements of individual dietary components in altering the toxicity of dietary cadmium. Day-old coturnix (Japanese quail) were fed 75 mg Cd/kg of an adequate purified diet for 2- or 4-week periods. Cadmium produced moderate growth retardation, severe anemia, decreased ash content of the tibia, and deviations from the normal concentrations of zinc, iron, cadmium, copper, and calcium in one or more of the cells or tissues assayed (erythrocyte, liver, kidney, and tibia). Dietary supplements of zinc, iron(III), copper, and L-cysteine-HCl and injected ascorbic acid produced slight to moderate protection against cadmium-induced anemia, whereas iron(II), ascorbic acid, and D-isoascorbic acid had marked effects in preventing the anemia, growth retardation, poor bone mineralization, and perturbations in elemental concentrations of tissues. Chromium, cobalt, selenium, nickel, molybdenum, and pteroylglutamic acid had no effects. Cadmium did not affect the total ascorbate content of the liver. Removal of dietary ethoxyquin did not affect the toxicity of cadmium or the protective effects of ascorbic acid. Initiation of ascorbic acid feeding at 2 weeks was beneficial to birds fed cadmium throughout the 4-week experiment. Under the conditions of these experiments cadmium produced a functional iron deficiency and less clear-cut affects on zinc function. It appears that a primary effect of cadmium was to prevent absorption of dietary iron. 33 references, 6 tables.

Fox, M.R.S.; Fry, B.E. Jr.; Harland, B.F.; Schertel, M.E.; Weeks, C.E.

1971-01-01

 
 
 
 
161

Simultaneous detection of ascorbic acid, uric acid and homovanillic acid at copper modified electrode  

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The copper was deposited on glassy carbon (GC) and indium tin oxide (ITO) electrodes by electrochemical method. The copper structures on electrode were characterized by atomic force microscope, X-ray diffractometeric pattern and differential pulse voltammetric studies. Optimal conditions for uniform growth of copper structures on the electrode were established. Voltammetric sensor was fabricated using the copper deposited GC electrode for the simultaneous detection and determination of uric acid (UA) and homovanillic acid (HVA) in the presence of excess concentrations of ascorbic acid (AA). The voltammetric signals due to AA and UA oxidation were well separated with a potential difference of 400 mV and AA did not interfere with the measurement of UA and HVA at the GC/Cu electrode. Linear calibration curves were obtained in the concentration range 1-40 {mu}M for AA and 20-50 {mu}M for UA at physiological pH and a detection limit of 10 nM of UA in the presence of 10-fold excess concentrations of AA was achieved. The simultaneous detection of submicromolar concentrations of AA, UA and HVA was achieved at the GC/Cu electrode. The practical utility of the present GC/Cu modified electrode was demonstrated by measuring the AA content in Vitamin C tablet, UA content in human urine and blood serum samples with satisfactory results.

Selvaraju, T. [Centre for Photoelectrochemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625021 (India); Ramaraj, R. [Centre for Photoelectrochemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625021 (India)]. E-mail: ramarajr@yahoo.com

2007-02-15

162

Voltammetric Sensing of Uric Acid and Ascorbic Acid with Poly (p-toluene sulfonic acid) Modified Electrode  

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Glassy carbon electrode (GCE) is modified with electropolymerized films of p-toluene sulfonic acid (pTSA). This polymer (pTSA) modified electrode is used to electrochemically detect uric acid (UA) in the presence of ascorbic acid (AA) and shows an excellent electrocatalyticl effect on the oxidation of UA and AA by cyclic voltammetry (CV). In differential pulse voltammetric measurements (DPV), the polymer (pTSA) modified electrode could separate the oxidation peak potentials of UA and AA prese...

2006-01-01

163

High-dose ascorbic acid decreases detoxification of cyanide derived from amygdalin (laetrile): studies in guinea pigs.  

Science.gov (United States)

Cysteine, a sulphur-containing amino acid, is required to metabolize ascorbic acid (as ascorbate sulphate) and detoxify cyanide (to thiocyanate). In guinea pigs, conjoint use of laetrile (a cyanogenic glycoside) and ascorbic acid (in large doses) decreases the detoxification of cyanide derived from laetrile through diminishing the availability of cysteine, but not impairing hepatic rhodanese activity, which is involved in the detoxification of cyanide to thiocyanate. These results agree with the symptoms of a sublethal dose of KCN toxicity manifested by the animals. The studies, therefore, indicate that individuals taking megadoses of ascorbic acid concurrently with laetrile may be subject to self-poisoning. PMID:6661693

Basu, T K

1983-11-01

164

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

165

Irradiation effects on ascorbic acid contents of potato tubers grown on different fertilizer regimes  

International Nuclear Information System (INIS)

Russet burbank potatoes were grown under 0.0, 181.8 and 363.6 kg/ha nitrogen, irradiated with 0, 0.05, 0.1 and 0.2 kGy of gamma rays (Co-60 source) and stored for three months at 10 deg. C. Nitrogen, irradiation and temperature significantly affected on loss of ascorbic acid content during storage period. Low nitrogen stressed tubers suffered loss of ascorbic acid content during storage as high as 21.6%. Loss of ascorbic acid decreased from 21.6 to 14.5% with increased level of nitrogen (363.6 kg/ha). Low irradiation dosages of 0.05 and 0.1 kGy reduced ascorbic acid loss (10.74 and 15.40% respectively) but 0.2 kGy increased the loss to 25.63%. Irradiation further increased loss of ascorbic acid content as storage temperature is increased. Higher storage temperature resulted in 21.60% of compared to low storage which caused only 12.90% loss. (author)

1992-01-01

166

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

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Full Text Available 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

2009-01-01

167

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

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Full Text Available Iron nitroprusside, Fe(IINP was incorporated into a carbon paste electrode and the electrochemical studies were performed by cyclic voltammetry. The cyclic voltammogram of the modified electrode, Fe(IINP showed two redox couples ( E½ox1 = 0.24 and (E½ox2 = 0.85 V vs. SCE attributed to Fe(II/Fe(III and Fe(II(CN5NO / Fe(III(CN5NO, respectively. The redox couple at (E½ox1 = 0.24 V presents an electrocatalytic response for ascorbic acid. The modified paste electrode exhibits a decrease of 180 mV in the ascorbic acid oxidation. The modified graphite paste electrode gives a linear range from 1.0 × 10-3 to 2.6 × 10-2 mol L-1 of ascorbic acid with a detection limit of 1.4 × 10-3 (±1.2% mol L-1 (n =3. The electrocatalytic oxidation of ascorbic acid compounds by the mediator has been used for the determination of ascorbic acid in a commercially pharmaceutical available product.

Devaney R. do Carmo

2004-01-01

168

Protective Effect Of Ascorbic Acid On Cisplatin Genotoxicity In Male Mice Bone Marrow Cells  

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Full Text Available Cisplatin (cis-diamminedichloroplatinum II is an effective antitumor agent with a wide spectrum of activity against varies solid tumors, but it has serious side effects on nontumour cells. Cisplatin produces intra- and interstrand DNA cross-linking effects and chromosomal aberrations in mammalian cells. Vitamin C (ascorbic acid is an antioxidant that can scavenge free radicals and protect cellular macromolecules, including DNA, from oxidative damage induced by different agents. Pretreatment administration of ascorbic acid on cisplatin induced chromosome aberrations has been determined in bone marrow cells of Swiss albino mice. Results showed that cisplatin (7.5 & 10mg/kg bwIP injection to male mice induced significant increase in the frequencies of chromosomal aberrations. The results of pre-treatment with ascorbic acid (66mg/kg bw showed a significant decrease in the number of chromosomal aberrations induced with cisplatin tested doses. Ascorbic acid did not exhibit any clastogenic effect in male mice bone marrow cells. We concluded that ascorbic acid has a protective role against the genotoxicity induced by antitumor drug cisplatin.

Nada, H.A. Al- Twaty

2005-03-01

169

Oxidation in fish oil enriched mayonnaise : Ascorbic acid and low pH increase oxidative deterioration  

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The effect of ascorbic acid (0-4000 ppm) and pH (3.8-6.2) on oxidation and levels of iron and copper in various fractions of mayonnaise enriched with 16% fish oil was investigated. Ascorbic acid induced release of iron from the assumed oil- water interface into the aqueous phase at all pH levels, but this effect of ascorbic acid was strongest at low pH (pH 3.8- 4.2). Ascorbic acid generally promoted formation of volatile oxidation compounds and reduced the peroxide value in mayonnaises. Peroxide values and total volatiles generally increased with decreasing pH values, suggesting that low pH promoted oxidation. It is proposed that iron bridges between the egg yolk proteins low-density lipoproteins, lipovitellin, and phosvitin at the oil-water interface are broken at low pH values, whereby iron ions become accessible as oxidation initiators. In the presence of ascorbic acid, oxidation is further enhanced due to the reduction of Fe3+ to Fe2+ that rapidly catalyzes lipid oxidation via lipid hydroperoxide decomposition at the oil-water interface in mayonnaise

Jacobsen, Charlotte; Timm Heinrich, Maike

2001-01-01

170

Preparation and Characterization of Poly(D,L-Lactide-co-Glycolide Nanoparticles Containing Ascorbic Acid  

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Full Text Available This paper is covering new, simplistic method of obtaining the system for controlled delivery of the ascorbic acid. Copolymer poly (D,L-lactide-co-glycolide (DLPLG nanoparticles are produced using physical method with solvent/nonsolvent systems where obtained solutions were centrifuged. The encapsulation of the ascorbic acid in the polymer matrix is performed by homogenization of water and organic phases. Particles of the DLPLG with the different content of ascorbic acid have different morphological characteristics, that is, variable degree of uniformity, agglomeration, sizes, and spherical shaping. Mean sizes of nanoparticles, which contain DLPLG/ascorbic acid in the ratio 85/150%, were between 130 to 200 nm depending on which stereological parameters are considered (maximal diameters Dmax, feret X, or feret Y. By introducing up to 15% of ascorbic acid, the spherical shape, size, and uniformity of DLPLG particles are preserved. The samples were characterized by infrared spectroscopy, scanning electron microscopy, stereological analysis, and ultraviolet spectroscopy.

Magdalena M. Stevanovi?

2007-09-01

171

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

172

Binding of ascorbic acid and ?-tocopherol to bovine serum albumin: a comparative study.  

Science.gov (United States)

Binding of ascorbic acid (water-soluble antioxidant) and ?-tocopherol (lipid-soluble antioxidant) to bovine serum albumin (BSA) has been studied using isothermal titration calorimetry (ITC), in combination with fluorescence spectroscopy, UV-vis absorption spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. Thermodynamic investigations reveal that ascorbic acid/?-tocopherol binding to BSA is driven by favorable enthalpy and unfavorable entropy, and the major driving forces are hydrogen bonding and van der Waals forces. For ascorbic acid, the interaction is characterized by a high number of binding sites, which suggests that binding occurs by a surface adsorption mechanism that leads to coating of the protein surface. For ?-tocopherol, one molecule of ?-tocopherol combines with one molecule of BSA and no more ?-tocopherol binding to BSA occurs at concentration ranges used in this study. Fluorescence experiments suggest that ascorbic acid has predominantly a "sphere of action" quenching mechanism, whereas, for ?-tocopherol, the quenching mechanism is "static quenching" and due to the formation of a ground state complex. Additionally, as shown by the UV-vis absorption, synchronous fluorescence spectroscopy, and FT-IR, ascorbic acid and ?-tocopherol may induce conformational and microenvironmental changes of BSA. PMID:24310979

Li, Xiangrong; Wang, Gongke; Chen, Dejun; Lu, Yan

2014-02-01

173

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: English Abstract in english 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 decrease of 180 mV in the ascorbic acid oxidation. The modified graphite paste electrode gives a linear range from 1.0 × 10-3 to 2.6 × 10-2 mol L-1 of ascorbic acid with a detection limit of 1.4 × 10-3 (±1.2%) mol L-1 (n =3). The electrocatalytic oxidation of ascorbic acid compounds by the mediator has been used for the determination of ascorbic acid in a commercially pharmaceutical available product.

Devaney R. do, Carmo; Ricardo M. da, Silva; Nelson R., Stradiotto.

174

Mitochondrial ascorbic acid transport is mediated by a low-affinity form of the sodium-coupled ascorbic acid transporter-2.  

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Despite the fundamental importance of the redox metabolism of mitochondria under normal and pathological conditions, our knowledge regarding the transport of vitamin C across mitochondrial membranes remains far from complete. We report here that human HEK-293 cells express a mitochondrial low-affinity ascorbic acid transporter that molecularly corresponds to SVCT2, a member of the sodium-coupled ascorbic acid transporter family 2. The transporter SVCT1 is absent from HEK-293 cells. Confocal colocalization experiments with anti-SVCT2 and anti-organelle protein markers revealed that most of the SVCT2 immunoreactivity was associated with mitochondria, with minor colocalization at the endoplasmic reticulum and very low immunoreactivity at the plasma membrane. Immunoblotting of proteins extracted from highly purified mitochondrial fractions confirmed that SVCT2 protein was associated with mitochondria, and transport analysis revealed a sigmoidal ascorbic acid concentration curve with an apparent ascorbic acid transport Km of 0.6mM. Use of SVCT2 siRNA for silencing SVCT2 expression produced a major decrease in mitochondrial SVCT2 immunoreactivity, and immunoblotting revealed decreased SVCT2 protein expression by approximately 75%. Most importantly, the decreased protein expression was accompanied by a concomitant decrease in the mitochondrial ascorbic acid transport rate. Further studies using HEK-293 cells overexpressing SVCT2 at the plasma membrane revealed that the altered kinetic properties of mitochondrial SVCT2 are due to the ionic intracellular microenvironment (low in sodium and high in potassium), with potassium acting as a concentration-dependent inhibitor of SVCT2. We discarded the participation of two glucose transporters previously described as mitochondrial dehydroascorbic acid transporters; GLUT1 is absent from mitochondria and GLUT10 is not expressed in HEK-293 cells. Overall, our data indicate that intracellular SVCT2 is localized in mitochondria, is sensitive to an intracellular microenvironment low in sodium and high in potassium, and functions as a low-affinity ascorbic acid transporter. We propose that the mitochondrial localization of SVCT2 is a property shared across cells, tissues, and species. PMID:24594434

Muñoz-Montesino, Carola; Roa, Francisco J; Peña, Eduardo; González, Mauricio; Sotomayor, Kirsty; Inostroza, Eveling; Muñoz, Carolina A; González, Iván; Maldonado, Mafalda; Soliz, Carlos; Reyes, Alejandro M; Vera, Juan Carlos; Rivas, Coralia I

2014-05-01

175

Effects of low-dose irradiation on the free amino acid, glucose and ascorbic acid contents of potato  

International Nuclear Information System (INIS)

Free amino acid, glucose and ascorbic acid contents of potato with doses of 0.05, 0.1 and 0.15 kGy have been investigated immediately after irradiation. Aspartic acid and glutamic acid decreased about 50 % at a dose of 0.15 kGy. An increase in the glucose content has been observed with increase in radiation doses. A decrease of approximately 20, 36 and 43 % in ascorbic acid was observed in 0.05, 0.10 and 0.15 kGy irradiated potatoes than that of the unirradiated one. (author)

1988-01-01

176

The Use of Ascorbate as an Oxidation Inhibitor in Prebiotic Amino Acid Synthesis: A Cautionary Note  

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It is generally thought that the terrestrial atmosphere at the time of the origin of life was CO2-rich and that organic compounds such as amino acids would not have been efficiently formed abiotically under such conditions. It has been pointed out, however, that the previously reported low yields of amino acids may have been partially due to oxidation by nitrite/nitrate during acid hydrolysis. Specifically, the yield of amino acids was found to have increased significantly (by a factor of several hundred) after acid hydrolysis with ascorbic acid as an oxidation inhibitor. However, it has not been shown that CO2 was the carbon source for the formation of the amino acids detected after acid hydrolysis with ascorbic acid. We therefore reinvestigated the prebiotic synthesis of amino acids in a CO2-rich atmosphere using an isotope labeling experiment. Herein, we report that ascorbic acid does not behave as an appropriate oxidation inhibitor, because it contributes amino acid contaminants as a consequence of its reactions with the nitrogen containing species and formic acid produced during the spark discharge experiment. Thus, amino acids are not efficiently formed from a CO2-rich atmosphere under the conditions studied.

Kuwahara, Hideharu; Eto, Midori; Kawamoto, Yukinori; Kurihara, Hironari; Kaneko, Takeo; Obayashi, Yumiko; Kobayashi, Kensei

2012-12-01

177

In Vitro Effect of a-Tocopherol, Ascorbic Acid and Lycopene on Low Density Lipoprotein Glycation  

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Full Text Available Nonenzymatic glycation of low density lipoprotein (LDL is a reaction of glucose and other reducing sugars with apolipoprotein B100 (apo-B100 lysine residues. In diabetes, this reaction is greatly accelerated and is important in the pathogenesis of diabetic complications. The objective of this study was to investigate in vitro effects of ?-tocopherol, ascorbic acid and lycopene on LDL glycation. LDL was isolated from EDTA-plasma by ultracentrifugation using a single step discontinuous gradient. LDL and glucose were incubated without and with different concentrations of lycopene, ascorbic acid and ?-tocopherol. LDL glycation were estimated by sodium periodate assay. Based on this study results, ?-tocopherol, ascorbic acid and lycopene decrease LDL glycation in a dose dependent manner. The electrophoretic mobility of glycated LDL decreased in presence these nutrients. These effects may be due to antioxidant properties of these nutrients and may have a role in ameliorating atherosclerotic risk of patients with diabetes mellitus.

Mohammad Ali Ghaffari

2007-01-01

178

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

179

Modulatory Effects of Ascorbic Acid and ?-tocopherol on Arsenic Induced Micronuclei Formation  

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Full Text Available Arsenic is a well known human carcinogen and has many other toxic effects. Sodium arsenite, a compound of arsenic, capable of inducing genotoxic effects through oxidative stress, is evaluated for its genotoxic effect by the formation of micronuclei in the polychromatic erythrocytes in the bone marrow cells of Wistar rats. Further, the modulatory effects of antioxidants like ascorbic acid and ?-tocopherol on arsenic intoxicated rats is investigated. Therefore, the present study was designed to determine whether the oral supplementation of ?-tocopherol (400 mg kg-1 body weight and ascorbic acid (200 mg kg-1 b.wt. to arsenic-intoxicated rats (100 ppm in drinking water for 30 days, modulates the genotoxicity caused by arsenic through the formation of micronuclei (p<0.05. The findings suggest that co-treatment of ascorbic acid and ?-tocopherol to arsenic-exposed rats protects the antioxidant system and modulates arsenic induced micronuclei formation.

R. Suresh

2010-01-01

180

Studies on the stability of 3H-dopamine in neostriatal membrane preparations: effects of ascorbic acid  

International Nuclear Information System (INIS)

The rate of 3H-dopamine decomposition was determined in buffers and in neostriatal membrane preparations that are commonly used in binding experiments. The rate of decomposition of 3H-dopamine was inhibited considerably by the membrane preparation and by ascorbic acid. Under conditions in which the binding of 3H-dopamine is routinely measured in neostriatal membrane preparations, there was almost no 3H-dopamine decomposition. The data would seem to suggest that the routine addition of very high concentrations of antioxidants is unnecessary when 3H-dopamine binding is being determined

1983-02-21

 
 
 
 
181

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

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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

182

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

183

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

184

Effects of Ascorbic Acid and FSH on the Maturation of Mice's Oocytes and Follicles  

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Full Text Available Introduction: Progress in laboratory culture conditions for in vitro oocyte maturation has led to development of the treatment of human and animal infertility. In this study we investigated the effects of FSH and ascorbic acid on the in vitro maturation of mouse's follicles and enclosed oocytes. Methods: For experiment, intact pre-antral follicles were isolated from the ovaries of 6 week-old female mice and cultured in TCM-199 medium. Special quantities of FSH and ascorbic acid were added to the culture medium (containing 25-30 follicles during separate experiments: 5, 20, 40, 60, 100, 140, 180 and 220 IU/L of FSH and 20, 40, 80, 240, 300 and 400 nmol/mL of ascorbic acid. Follicles were cultured for 6 days in an incubator at 37 °C, 92% humidity and 5% air CO2. Our study was semi-experimental. The entire statistical analysis was carried out by SPSS (version 14.0 for Windows using one way ANOVA. Post Hoc tests were used for the multiple comparisons at 95% confidence interval. P values < 0.05 were considered statistically significant. Results: At FSH concentration of 100 IU/L increase in follicle diameter (190µm, survival rate (91%, germinal vesicle breakdown (GVBD (81% and oocyte maturation rates (61% was observed (p ?0.05. Ascorbic acid increased survival rate (42%, p<0.001 but didn’t affect diameter, GVBD and oocyte maturation rates. Conclusion: Ascorbic acid and FSH-containing medium showed a marked increase in all parameters except for follicle diameter. FSH and ascorbic acid increase the maturation rate of follicles and enclosed oocytes but if they are supplied in a combination, this growth rate can be significantly increased

Barzegari Firouzabadi

2011-11-01

185

Studies on the fortification of cane sugar with iron and ascorbic acid.  

Science.gov (United States)

1. The feasibility of improving iron nutrition by fortifying cane sugar with Fe and ascorbic acid was studied. 2. It was found to be possible to add a number of Fe salts together with ascorbic acid to sugar without affecting its appearance or storage properties. 3. The absorption of Fe from fortified sugar eaten with maize-meal porridge or made into jam or biscuits was measured in ninety-four volunteer multiparous Indian women using the 59-Fe erythrocyte utlization method. 4. The absorption of Fe from sugar fortified with ascorbic acid and ferrous sulphate and eaten with maize-meal porridge was increased about twofold in the ratio, ascorbic acid:Fe was 10:1 by weight. If the ratio was increased to 20:2, Fe absorption was increased a further threefold. 5. Sugar fortified with soluble Fe salts, including FeSO4.7H2O, discoloured both tea and coffee; sugar fortified with ferric orthophosphate did not have this effect. 6. Fe from FePO4.H2O was poorly absorbed when added with sugar to maize-meal porridge, and also when added with adequate quantities of ascorbic acid. This form of Fe was absorbed much less well than was the intrinsic Fe present in the maize. 7. When sugar fortified with FePO4.H2O and ascorbic acid was added to maize-meal porridge before cooling or was made into jam there was a several-fold increase in the amount of Fe absorbed. PMID:1148151

Disler, P B; Lynch, S R; Charlton, R W; Bothwell, T H; Walker, R B; Mayet, F

1975-07-01

186

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 P<.0009 was applied, and analyses were adjusted for multiple comparisons using the Tukey-Kramer procedure. Levels of complement C9, ceruloplasmin, alpha-1-anti-trypsin, angiotensinogen, complement C3, vitamin D binding protein and plasminogen were inversely 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

187

Degradation of ascorbic acid and potassium sorbate by different Lactobacillus species isolated from packed green olives.  

Science.gov (United States)

The aim of this research was to ascertain the lactic acid bacteria responsible for the degradation of ascorbic acid and/or potassium sorbate, isolated from packed green olives where these additives had diminished. A total of 14 isolates were recovered from samples of different green olive containers. According to partial sequencing of the 16S rRNA coding gene, Lactobacillus parafarraginis, Lactobacillus rapi, Lactobacillus pentosus, Lactobacillus paracollinoides, and Pediococcus ethanolidurans were identified. With the exception of L. pentosus and L. paracollinoides, the other species had not been mentioned in table olives before this study. Only three of the 14 isolates metabolized ascorbic acid in MRS broth, and the products from ascorbic acid in modified MRS broth without carbon sources were acetic and lactic acids. Except for the two L. rapi and the two P. ethanolidurans strains, the remaining 10 isolates depleted potassium sorbate added into MRS broth to some extent. The product generated by three of these strains was confirmed to be trans-4-hexenoic acid. The degradation of ascorbate or sorbate by lactic acid bacteria should be taken into account when these additives are used in food products where this group of bacteria may be present. PMID:23498172

Montaño, Alfredo; Sánchez, Antonio Higinio; Casado, Francisco Javier; Beato, Víctor Manuel; de Castro, Antonio

2013-05-01

188

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

189

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.

2012-05-04

190

6-Deoxy-6-["1"8F]fluoro-L-ascorbic acid. Tissue biodistribution in ascorbic acid-deficiency and RG-C6 glioma bearing rats  

International Nuclear Information System (INIS)

A comparative study in Wistar normal rats and ODS rats unable to synthesize ascorbic acid showed that the radioactivity distribution in tissues after i. v. injection of 6-deoxy-6-["1"8F]fluoro-L-ascorbic acid ("1"8F-DFA) was not significantly influenced by the vitamin C status of the animal. Biodistribution studies in Wistar male rats implanted with RG-C6 glioma intracerebrally demonstrated that "1"8F-DFA had low tumor localization (0.17% dose/g at 30 min and 0.16% dose/g at 60 min) with very little specific distribution compared with non-target brain tissues. These results indicate that the use of "1"8F-DFA may not be a candidate for imaging brain tumor by PET. (author)

1995-02-01

191

Effect of natural antibrowning agents on color and related enzymes in fresh-cut Fuji apples as an alternative to the use of ascorbic acid.  

Science.gov (United States)

Polyphenoloxidase (PPO) and peroxidase (POD) were evaluated in fresh-cut Fuji apple slices and the effeet of the individual or combined use of ascorbic acid, 4-hexylresorcinol, N-acetylcysteine, and glutathione on their respective activities was determined. Additionally, color changes during storage at 4 degrees C were measured throughout 14 d of storage. PPO activity increased with storage time and was inhibited by the individual use of N-acetylcysteine and glutathione. POD activity in the apple slices was effectively inhibited by the combined use of ascorbic acid with any of the other antibrowning agents. On the other hand, an individual treatment with 1% N-acetylcysteine helped in maintaining the color of fresh-cut apples during 14 d of storage, whereas the use of ascorbic acid was not enough to prevent color deterioration of the apple slices from the 1st day of storage. The results obtained corroborated the effectiveness of other natural antibrowning agents over the traditional use of ascorbic acid in the control of the enzymatic browning in the fresh-cut fruit industry. PMID:19241570

Rojas-Graü, M A; Soliva-Fortuny, R; Niartín-Belloso, O

2008-08-01

192

Plasma ascorbic acid levels in senile cataract patients and in normal individuals: a comparative study  

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Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Dietary antioxidant vitamins, in particular vitamin C, can play a role in preventing the onset or progression of age-related visual impairment. The aim of this study was to determine the plasma ascorbic acid levels in normal individuals and in senile cataract patients."n"nMethods: The test group included fifty cataract patients, while the control group members were selected among medical staff and patients' companions after age matching with test group. The use questionnaire contained age, sex and location of residency (Urban or Rural. Five milliliter of drawn blood centrifuged and plasma ascorbic acid level was measured by spectrophotometry. Statistical analysis of plasma ascorbic acid concentrations were done using paired t-test. "n"nResults: The mean plasma ascorbic acid level intest group and incotral group was 0.96±0.08 and 1.12±0.15mg/dl respectively. Plasma ascorbic acid level in test group was significantly lower than control group (p<0.0001. Aging was associated with a reduction in plasma ascorbic acid level in male while it showed no significant alteration in females. Rural and the female gender showed higher plasma ascorbic acid level."n"nConclusions: This study revealed plasma ascorbic acid level in patients with senile cataract was lower than normal individuals. Antioxidant vitamins, in particular vitamin C, found in Mediterranean fruits and vegetables could be probably used in the prevention of cataracts, which is a major health service burden in many countries.

Derkhshandeh J

2009-11-01

193

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

194

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)_3"2"+, 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)_3"3"+, which is formed by the reaction of the lowest excited state species of Ru(bpy)_3"2"+ with O_2. (author)

1981-01-01

195

Modulating Effect of Ascorbic Acid on Transport-Induced Immunosuppression in Goats  

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The effect of 12?h road transportation on some basic blood cells and the modulating role of ascorbic acid were investigated in 40 adult Red Sokoto goats during the hot dry season. The animals were divided into two groups, GI (experimental; n = 20) and GII (control; n = 20). Group 1 was administered with ascorbic acid (AA) per os at a dosage rate of 100?mg/kg body weight, while GII was given 10?mL of sterile water per goat. Forty minutes after the administration and loading, the goats we...

Ndazo Salka Minka; Joseph Olusegun Ayo

2011-01-01

196

Electrooxidation of ascorbic acid on polyaniline and its implications to fuel cells  

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L-Ascorbic acid (AA) has been shown to undergo oxidation on polyaniline(PANI) without a platinum in-group catalyst. A direct ascorbic acid fuel cell (DAAFC) has been assembled by employing an anode coated with PANI catalyst. From the experimental studies using cyclic voltammetry,amperometry and IR spectroscopy, it has been concluded that PANI facilitates the oxidation of AA. It has been possible to achieve a maximum power density of 4.3 mW $cm^{-2}$ at a load current density of 15 mA $cm^{-2}...

2005-01-01

197

Nitrate Detoxification of drinking water by ascorbic acid in growing rabbits.  

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This work was carried out to study the capacity of ascorbic acid for detoxification of drinking water nitrate in growing New Zealand White rabbits. Forty growing female rabbits were assigned to five groups (8 rabbits/group). The control animals (group 1) drank tap water without nitrate addition, those of group 2 drank water with 729 mg/l nitrate, while rabbits of groups 3, 4 and 5 drank water with the same nitrate level plus 100, 200 and 400 mg/l ascorbic acid respectively for seven weeks. Th...

Shehata, S. A.

2005-01-01

198

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

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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...

2011-01-01

199

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

200

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

1987-08-01

 
 
 
 
201

Fabrication of multiwalled carbon nanotubes/polyaniline modified Au electrode for ascorbic acid determination.  

Science.gov (United States)

An ascorbate oxidase (AsOx) (E.C.1.10.3.3) purified from Lagenaria siceraria fruit was immobilized covalently onto a carboxylated multiwalled carbon nanotubes and polyaniline (c-MWCNT/PANI) layer electrochemically deposited on the surface of an Au electrode. The diffusion coefficient of ascorbic acid was determined as 3.05 × 10(-4) cm(2) s(-1). The behavior of different electrolytes on electro-deposition was also studied. An ascorbate biosensor was fabricated using a AsOx/c-MWCNT/PANI/Au electrode as a working electrode, Ag/AgCl (3 M/saturated KCl) as standard and Pt wire as an auxiliary electrode connected through a potentiostat. Linear range, response time and detection limit were 2-206 ?M, 2 s and 0.9 ?M respectively. The biosensor showed optimum response at pH 5.8 and in a broader temperature range (30-45 °C), when polarized at +0.6 V. The biosensor was employed for determination of ascorbic acid level in sera, fruit juices and vitamin C tablets. The sensor was evaluated with 91% recovery of added ascorbic acid in sera and 6.5% and 11.4% within and between batch coefficients of variation respectively for five serum samples. There was a good correlation (r = 0.98) between fruit juice ascorbic acid values by the standard 2,6-dichlorophenolindophenol (DCPIP) method and the present method. The enzyme electrode was used 200 times over a period of two months, when stored at 4 °C. The biosensor has advantages over earlier enzyme sensors in that it has no leakage of enzyme, due to the covalent coupling of enzyme with the support, lower response time, wider working range, higher storage stability and no interference by serum substances. PMID:21416096

Chauhan, Nidhi; Narang, Jagriti; Pundir, C S

2011-05-01

202

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

203

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

1984-01-01

204

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

205

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

206

Effect of ascorbic acid on food preference and consumption in captive capybaras (Hydrochoerus hydrochaeris  

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Full Text Available The aim of this work was to study the short and long term influences of ascorbic acid on Hydrochoerus hydrochaeris, if supplemented in their food. No differences regarding food intake were observed in the absence of vitamin C. On a daily basis, animals accustomed to food containing ascorbic acid prefered to continue eating the same food. Food preference in capybaras did not seem to depend on ascorbic acid availability; however, when accustomed to vitamin C, capybaras might recognize and select ascorbic acid in subsequent food. Mechanisms allowing capybaras to "evaluate" the nutritional quality of their food are discussed, as well as the adaptive value of this behavior in free ranging populations.O ácido ascórbico é um nutriente essencial para as capivaras (Hydrochoerus hydrochaeris. No presente trabalho foi avaliado o efeito do ácido ascórbico sobre o consume e as preferências alimentares a curto e longo prazo, assim como a influencia da escolha sobre a sintomatologia da carência de vitamina C na dieta. Não foram observadas diferencias no consumo de alimento na ausência deste nutriente. Considerando as preferências a longo prazo (24h, os animais acostumados a consumir vitamina C continuavam consumindo preferencialmente o alimento suplementado. As preferências alimentares em capivaras não parecem depender da disponibilidade de ácido ascórbico; no entanto, quando acostumados à vitamina C, estes animais podem reconhecer e selecionar o ácido ascórbico na alimentação subseqüente. São discutidos os mecanismos que permitem as capivaras "avaliar" a qualidade nutricional do alimento, assim como o valor adaptativo destes comportamentos em populações silvestres.

Martín Roberto Alvarez

2009-06-01

207

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

208

Exogenous application of ascorbic acid stimulates growth and photosynthesis of wheat (Triticum aestivum L. under drought  

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Full Text Available Drought causes considerable reduction in plant growth. A hydroponic experiment was conducted to appraise the potential role of exogenously applied ascorbic acid in alleviating the effect of drought on wheat. Two contrasting wheat genotypes, a drought tolerant cultivar Chakwal-86 and a drought sensitive strain 6544-6 were used in the study. Drought was induced by dissolving 20% Polyethylene glycol (PEG8000 in the nutrient solution producing -0.6MPa osmotic stress. Drought caused a significant decrease in chlorophyll pigments and net photosynthesis resulting in growth reduction of both wheat genotypes. However, this decrease was more severe in the genotype 6544-6 compared to Chakwal-86. Ascorbic acid (AsA was applied through rooting medium, as a foliar spray and seed soaking treatment. Ascorbic acid treated seedlings of both genotypes maintained higher chlorophyll contents, net photosynthesis and growth compared to the non-treated plants. Of the three different modes of ascorbic acid application, rooting medium was more effective in alleviating the adversities of drought in wheat. `

Samina Malik and Muhammad Ashraf

2012-05-01

209

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

210

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

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Full Text Available 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 variation with respect to age. The thiamine plasma levels for neonate, yearling, and adult were 59.94.4, 70.58.9 and 88.96.7 g/L, respectively. The corresponding figures for AA were 6.21.0, 4.90.9, and 4.50.8 mg/L, respectively. The Arabi showed higher ascorbic acid (5.91.0 than Anafi (4.20.9 mg/L. However, no significant breed variation for thiamine status was indicated.

Mohamed, H. E.

2006-01-01

211

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

212

ECOPHYSIOLOGICAL INFLUENCE ON ASCORBIC ACID AND GLUTHATION CONTENT IN SPRING BARLEY SEED ?????????????????? ??????? ?? ?????????? ????????????????? ?????????????? ? ????? ??????? ??????? ??????  

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Full Text Available The content of ascorbic acid (AA and glutathione (GSH in spring barley seed of four varieties depends upon hydro-temperature environment (HTE in different way. The genotype and HTE have equal input on AA content (35 and 34,8 %, and GSH content depends mainly upon “genotype-HTE” interaction (67,6 %.

Kovaljeva O. N.

2011-06-01

213

Ascorbic acid reduces accumulation of (/sup 3/H)spiperone in mouse striatum in vivo  

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(/sup 3/H)Spiperone was administered to mice. In agreement with other published reports, 2 hr later the accumulation of tritium was three to four times greater in the corpus striatum than in the cerebellum. Ascorbic acid (100, 1000, 2000 mg/kg, ip, 30 min) reduced the 2-hr accumulation in the corpus striatum 16, 42, and 63%, respectively, with only the highest does producing any significant reduction in the cerebellum. The effect was still evident in striatum 18 hr after a single dose of 1000 mg/kg. Striatal minces taken from mice treated 1 or 2 hr earlier with ascorbic acid showed no reduction in (/sup 3/H)spiperone binding. However, preincubation of striatal minces for 2 hr with ascorbic acid (10/sup -3/ M) produced an 82% reduction in specific binding while not having any effect on nonspecific binding. While it cannot be certain that the reduction of striatal (/sup 3/H) spiperone concentrations after ascorbic acid in vivo was not a result of some nonspecific alteration in the pharmacokinetics of (/sup 3/H)spiperone, the in vitro observation strongly suggests that it resulted from an alteration of binding characteristics at the receptor level.

Dorris, R.L.

1987-10-01

214

Ascorbic Acid Retention in Shredded Iceberg Lettuce as Affected by Minimal Processing  

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The effects of slicing method, packaging atmosphere and storage temperature were determined on total ascorbic acid (TAA) content of modified atmosphere packaged shredded lettuce. TAA was extracted from the lettuce samples and levels were monitored using either titration with 2,6-dichlorophenolindophenol solution or an assay kit. Slicing affected (p manual slicing > machine slicing. Flushing with 100% nitrogen increased retention (~5%...

1998-01-01

215

Alpha-tocopherol and Ascorbic Acid Combinations Influence the Maturation of Sheep Oocytes  

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Full Text Available The goal of this research was to establish whether supplementation with combinations of ?-tocopherol and ascorbic acid could improve the maturation and expansion of sheep cumulus-oocyte complexes. Sheep oocytes were cultured for 24 hours at 37°C in 5.4% CO2 atmosphere in M199 containing 20 ?M ?-tocopherol+750 ?M ascorbic acid or 5 ?M ?-tocopherol+250 ?M ascorbic acid. Afterwards, cumulus oophorus expansion was assessed and oocytes were denuded. The presence of the first polar body was assessed by fluorescent staining with Hoechst 33258. Differences between treatments were analyzed by the analysis of variance and interpreted using the LSD test. Supplementation with the combination of 20 ?M ?-tocopherol+750 ?M ascorbic acid resulted in significantly greater (p<0.05 percentages of COCs that were scored as 3. However, the number of COCs scored at 4 decreased. The same dynamic could be seen when oocytes were checked for the presence of the first polar body. Percentages decreased with the increase in antioxidant concentration. This indicates that although antioxidants, in these particular concentrations have been proven to have a positive influence on swine oocyte maturation the same cannot be said for ovine female gametes.

Ileana Miclea

2012-05-01

216

Enhancing Lipid Stability in Irradiated Beef Mince by Oleoresins and/ or Ascorbic Acid during Chilling Storage  

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Lipid Oxidation, fatty acids profile and sensory properties of irradiated beef mince (2.5 kGy) treated with oleoresins (rosemary or ginger), ascorbic acid, or combination of ascorbic acid and oleoresins were investigated during 30 days of chilled storage. Thiobarbituric acid reactive substances (TBARS) as an indication of lipid oxidation, of irradiated control samples were significantly higher than those of non irradiated control and samples treated with rosemary and ginger oleoresins. By GC-MS analysis, it was found that the relative percentage of total saturated fatty acids (TSFA) increased in all treatments. However, the highest increase was recorded in irradiated control samples compared to non irradiated control samples. Beef mince samples treated with oleoresins (rosemary or ginger) had the best scores for discoloration and off odour. Thus, the addition of oleoresins (rosemary or ginger) to beef mince before irradiation could be an easily applied method to minimize oxidative degradation of irradiated meat

2008-01-01

217

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.)

1985-01-01

218

Antioxidative activity of citric and ascorbic acids and their preventive effect on lipid oxidation in frozen persian sturgeon fillets  

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Persian sturgeon (Acipenser persicus) fillets were soaked in Citric acid, Ascorbic acid and combination of Citric and Ascorbic acid solutions and then were stored at frozen conditions (-18 °C) up to 6 months. During storage, some general chemical analysis such as free fatty acids, primary and secondary oxidation products and sensory analysis were measured in order to study rancidity development. Results showed that antioxidant treatments had lower (P<0.05) lipid oxidation development in comp...

Rostamzad, H.; Shabanpour, B.; Kashaninejad, M.; Shabani, A.

2011-01-01

219

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

220

Norepinephrine-modified glassy carbon electrode for the simultaneous determination of ascorbic acid and uric acid  

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The oxidation of norepinephrine (NE) on a preactivated glassy carbon electrode leads to the formation of a deposited layer of about 4.2 x 10{sup -10} mol cm{sup -2} at the surface of the electrode. The electron transfer rate constant, k {sub s}, and charge transfer coefficient, {alpha}, for electron transfer between the electrode and immobilized NE film were calculated as 44 s{sup -1} and 0.46, respectively. The NE-modified glassy carbon electrode exhibited good electrocatalytic properties towards ascorbic acid (AA) oxidation in phosphate buffer (pH 7.0) with an overpotential of about 475 mV lower than that of the bare electrode. The electrocatalytic response was evaluated by cyclic voltammetry, chronoamperometry, amperometry and rotating disk voltammetry. The overall number of electrons involved in the catalytic oxidation of AA and the number of electrons involved in the rate-determining step are 2 and 1, respectively. The rate constant for the catalytic oxidation of AA was evaluated by RDE voltammetry and an average value of k {sub h} was found to be 8.42 x 10{sup 3} M{sup -1} s{sup -1}. Amperometric determination of AA in stirred solution exhibits a linear range of 2.0-1300.0 {mu}M (correlation coefficient 0.9999) and a detection limit of 0.076 {mu}M. The precision of amperometry was found to be 1.9% for replicate determination of a 49.0 {mu}M solution of AA (n = 6). In differential pulse voltammetric measurements, the NE-modified glassy carbon electrode can separate the AA and uric acid (UA) signals. Ascorbic acid oxidizes at more negative potential than UA. Also, the simultaneous determination of UA and AA is achieved at the NE-modified electrode.

Zare, H.R. [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)]. E-mail: hrzare@yazduni.ac.ir; Memarzadeh, F. [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of); Ardakani, M. Mazloum [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of); Namazian, M. [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of); Golabi, S.M. [Electroanalytical Chemistry Laboratory, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

2005-05-30

 
 
 
 
221

Norepinephrine-modified glassy carbon electrode for the simultaneous determination of ascorbic acid and uric acid  

International Nuclear Information System (INIS)

The oxidation of norepinephrine (NE) on a preactivated glassy carbon electrode leads to the formation of a deposited layer of about 4.2 x 10-10 mol cm-2 at the surface of the electrode. The electron transfer rate constant, k s, and charge transfer coefficient, ?, for electron transfer between the electrode and immobilized NE film were calculated as 44 s-1 and 0.46, respectively. The NE-modified glassy carbon electrode exhibited good electrocatalytic properties towards ascorbic acid (AA) oxidation in phosphate buffer (pH 7.0) with an overpotential of about 475 mV lower than that of the bare electrode. The electrocatalytic response was evaluated by cyclic voltammetry, chronoamperometry, amperometry and rotating disk voltammetry. The overall number of electrons involved in the catalytic oxidation of AA and the number of electrons involved in the rate-determining step are 2 and 1, respectively. The rate constant for the catalytic oxidation of AA was evaluated by RDE voltammetry and an average value of k h was found to be 8.42 x 103 M-1 s-1. Amperometric determination of AA in stirred solution exhibits a linear range of 2.0-1300.0 ?M (correlation coefficient 0.9999) and a detection limit of 0.076 ?M. The precision of amperometry was found to be 1.9% for replicate determination of a 49.0 ?M solution of AA (n = 6). In differential pulse voltammetric measurements, the NE-modified glassy carbon electrode can separate the AA and uric acid (UA) signals. Ascorbic acid oxidizes at more negative potential than UA. Also, the simultaneous determination of UA and AA is achieved at the NE-modified electrode

2005-05-30

222

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

2006-01-01

223

Ascorbic acid synergistically potentiates phloxine b-induced photocytotoxicity in human acute promyelocytic leukemia cells.  

Science.gov (United States)

Ascorbic acid (AsA) is known as an antioxidant but concomitantly possesses a pro-oxidant property. Because the impact of AsA on photodynamic therapy response is unclear, we investigated the effect of AsA on photocytotoxicity induced by phloxine B in human acute promyelocytic leukemia HL-60 cells. AsA synergistically enhanced phloxine B-induced photocytotoxic effects, including inhibition of cell proliferation, DNA ladder formation, and caspase-3 activation, whereas AsA itself showed no photocytotoxicity. AsA also enhanced the consumption of the reduced glutathione level compared with the cells treated with phloxine B alone under the light condition. Combination of AsA with phloxine B under the light condition enhanced the phosphorylation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase (MAPK). These effects were completely cancelled by catalase. These results suggest that AsA synergistically enhances phloxine B-induced photocytotoxicity, possibly through the extracellular oxidative stress-dependent MAPK pathway activation. PMID:24488945

Qi, Hang; Wu, Qian; Abe, Naomi; Saiki, Shunya; Zhu, Beiwei; Murata, Yoshiyuki; Nakamura, Yoshimasa

2014-04-01

224

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

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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 chol...

Khalid Iqbal; Alam Khan; Muzaffar Ali Khan Khattak, M.

2004-01-01

225

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

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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...

Sumaya-marti?nez, Mari?a Teresa; Cruz-jaime, Sandra; Madrigal-santilla?n, Eduardo; Garci?a-paredes, Juan Diego; Carin?o-corte?s, Raquel; Cruz-cansino, Nelly; Valadez-vega, Carmen; Martinez-cardenas, Leonardo; Alani?s-garci?a, Ernesto

2011-01-01

226

Kinetics of reduction of molybdate with ascorbic acid in the presence of germanate-ion  

International Nuclear Information System (INIS)

Three-stage reaction of molybdate reduction with ascorbic acid has been studied in the presence of germanate-ion. Kinetics of the first stage involving the formation of germanium-molybdic acid and of germanium molybdic blue has been investigated. The measurements have been conducted at 25 deg C and pH=1.7. The dependence of the reaction rate on the concentration of the reacting agents is considered. The kinetic equation for this stage has been derived

1977-06-01

227

Ascorbic Acid Contents From Some Exotic Tree Species Growing in Rajasthan Desert  

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Full Text Available Ascorbic acid contents of stems, leaves and fruits from four selected exotic tree species like Colophospermummopane, Holoptelea integrifolia, Kigelia pinnata and Putranjiva roxburghii have been analysed. Maximumascorbic acid contents were found in the fruits of Colophospermum mopane (42.10mg/100g.d.w. while, minimumin the stems of Kigelia plnnata (22.15mg/100g.d.w.

B.B.S. Kapoor* and Shelja Pandita

2013-09-01

228

Ascorbate metabolism and the developmental demand for tartaric and oxalic acids in ripening grape berries  

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Abstract Background Fresh fruits are well accepted as a good source of the dietary antioxidant ascorbic acid (Asc, Vitamin C). However, fruits such as grapes do not accumulate exceptionally high quantities of Asc. Grapes, unlike most other cultivated fruits do however use Asc as a precursor for the synthesis of both oxalic (OA) and tartaric acids (TA). TA is a commercially important product in the wine industry and due to its acidifying effect on crushed juice it can influenc...

2009-01-01

229

A Combination of Pre- and Post-Exposure Ascorbic Acid Rescues Mice from Radiation-Induced Lethal Gastrointestinal Damage  

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Full Text Available The development of an effective therapy for radiation-induced gastrointestinal damage is important, because it is currently a major complication of treatment and there are few effective therapies available. Although we have recently demonstrated that pretreatment with ascorbic acid attenuates lethal gastrointestinal damage in irradiated mice, more than half of mice eventually died, thus indicating that better approach was needed. We then investigated a more effective therapy for radiation-induced gastrointestinal damage. Mice receiving abdominal radiation at 13 Gy were orally administered ascorbic acid (250 mg/kg/day for three days before radiation (pretreatment, one shot of engulfment (250 mg/kg at 8 h before radiation, or were administered the agent for seven days after radiation (post-treatment. None of the control mice survived the abdominal radiation at 13 Gy due to severe gastrointestinal damage (without bone marrow damage. Neither pretreatment with ascorbic acid (20% survival, engulfment (20%, nor post-treatment (0% was effective in irradiated mice. However, combination therapy using ascorbic acid, including pretreatment, engulfment and post-treatment, rescued all of the mice from lethal abdominal radiation, and was accompanied by remarkable improvements in the gastrointestinal damage (100% survival. Omitting post-treatment from the combination therapy with ascorbic acid markedly reduced the mouse survival (20% survival, suggesting the importance of post-treatment with ascorbic acid. Combination therapy with ascorbic acid may be a potent therapeutic tool for radiation-induced gastrointestinal damage.

Yukihiro Takahashi

2013-09-01

230

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

231

Ascorbic Acid Offsets the Inhibitory Effect of Bioactive Dietary Polyphenolic Compounds on Transepithelial Iron Transport in Caco-2 Intestinal Cells12  

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We previously reported that (-)-epigallocatechin-3-gallate (EGCG) and grape seed extract (GSE) at high concentration nearly blocked intestinal iron transport across the enterocyte. In this study, we aimed to determine whether small amounts of EGCG, GSE, and green tea extract (GT) are capable of inhibiting iron absorption, to examine if ascorbic acid counteracts the inhibitory action of polyphenols on iron absorption, and to explore the mechanisms of polyphenol-mediated apical iron uptake and ...

2011-01-01

232

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

2013-12-01

233

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.

234

ISOLATION AND SEQUENCING OF A GENOMIC DNA ENCODING FOR ASCORBATE OXIDASE, A KEY ENZYME INVOLVED IN THE BIODEGRADATION OF ASCORBIC ACID IN MELON  

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A melon genomic library was used to isolate and characterize a clone of genomic DNA coding for ascorbate oxidase (AO) which is considered a key enzyme in the biodegradation of ascorbic acid (AA). The screening of genomic library was performed by using two probes: AO-PCR product and ?E/CMAO3. Seven clones of recombinant phage, with positive signal, were isolated. The extracted DNA was digested with EcoRI, Sal I and Bam HI and the combinations among these restriction enzymes. Four clones of AO...

2002-01-01

235

Changes in Ascorbic Acid Content, Antioxidant Capacity and Sensory Quality of Fresh-cut Mangosteens During Storage  

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Fresh-cut mangosteens, stored in modified atmosphere packaging (MAP; 5% O2 + 9% CO2), in vacuum packaging (VAC) and in air (AIR) were examined for ascorbic acid content, antioxidant capacity and sensory quality during 14 days of storage at 4oC. After 4 days-storage, fresh-cut fruits with MAP resulted in better retention of ascorbic acid and antioxidant capacity than those stored in AIR throughout the storage. Furthermore, there were no significant differences in ascorbic acid contents between...

Manurakchinakorn, Supranee; Intavong, Pattama; Yuennan, Pilapa; Tonwattana, Salisa; Pankong, Amonrat

2004-01-01

236

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

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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

237

Protease-catalyzed monoacylation of 2-O-alpha-D-Glucopyranosyl-L-ascorbic acid in pyridine.  

Science.gov (United States)

2-O-alpha-D-Glucopyranosyl-6-O-octanoyl-L-ascorbic acid was enzymatically synthesized from 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and vinyl octanoate with a protease from Bacillus subtilis in pyridine. Furthermore, with various linear saturated fatty acid vinylesters as acyl donors, AA-2G was also converted to their corresponding 6-O-acyl AA-2G in the same manner. The reactivities of transacylation decreased with increasing length of the acyl groups. Thus, short chain acyl groups were transferred to AA-2G by this protease more efficiently than were long chain acyl groups. This enzymatic method is recommended for the synthesis of 6-Acyl-AA-2G with short or medium length chain acyl groups. PMID:11515578

Tai, A; Okazaki, S; Tsubosaka, N; Yamamoto, I

2001-08-01

238

Stability of carotenoids, phenolic compounds, ascorbic acid and antioxidant capacity of tomatoes during thermal processing.  

Science.gov (United States)

In the present investigation we ascertained the stability of lycopene, beta-carotene, ascorbic acid, polyphenolic compounds and total antioxidant capacity (AC) during the process of concentrating tomatoes into two tomato pastes (10 and 15 degrees Brix). Thermal processing increased the content of lycopene, total phenolic compounds, total flavonoids, and the individual phenolic compounds quercetin, rutin, chlorogenic and cafeic acids, whereas it decreased the other analysed compounds. However, lycopene in the 15 degrees Brix-tomato paste decreased due to the extension of thermal processing, which led to degradation. The AC of aqueous and organic extracts was measured and different AC values were observed depending on the antioxidant profile of the extract and assay used (TEAC and FRAP). AC expressed in dry matter decreased as result of ascorbic acid losses. Overall, thermal processing enhanced the nutritional value of tomatoes, mainly by increasing the lycopene and phenolic antioxidants, but the extension of treatment must be controlled to prevent lycopene degradation. PMID:21425720

Jacob, K; Garcia-Alonso, F J; Ros, G; Periago, M J

2010-06-01

239

The electrochemical synthesis of polyaniline/polysulfone composite films and electrocatalytic activity for ascorbic acid oxidation  

Energy Technology Data Exchange (ETDEWEB)

Polyaniline (PANI)/polysulfone (PSF) composite films with asymmetric porous structure were successfully prepared by electropolymerization. The back face (in contact with the electrode) of the freestanding composite film is green while the outer face is white. The chemical component and the morphology of the surfaces were characterized by FTIR spectra and scanning electron microscopy, respectively. It was shown that replicate films gave reproducible voltammetry in 0.5 M H{sub 2}SO{sub 4}. The influence of the electrolyte and the acidic concentration on the redox peak currents of polyaniline were investigated in detail. The composite film electrode showed good electrocatalytic activity for ascorbic acid, which the anodic overpotential was evidently reduced compared with that obtained at bare Pt electrode. The diffusion coefficient of ascorbic acid was 1.38 x 10{sup -6} cm{sup 2} s{sup -1}.

Hu Zhongai [Key Laboratory of Polymer, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China)]. E-mail: Zhongai@nwnu.edu.cn; Shang Xiuli [Key Laboratory of Polymer, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Yang Yuying [Key Laboratory of Polymer, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Kong Chao [Key Laboratory of Polymer, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Wu Hongying [Key Laboratory of Polymer, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China)

2006-04-10

240

The application of conducting polymer nanoparticle electrodes to the sensing of ascorbic acid.  

Science.gov (United States)

An ascorbic acid sensor was fabricated via the drop-casting of dodecylbenzene sulphonic acid (DBSA)-doped polyaniline nanoparticles onto a screen-printed carbon-paste electrode. The modified electrode was characterised with respect to the numbers of drop cast layers, optimum potential and operating pH. The sensor was found to be optimal at neutral pH and at 0V vs. Ag/AgCl. Under these conditions, the sensor showed good selectivity and sensitivity in that it did not respond to a range of common interferents such as dopamine, acetaminophen, uric acid and citric acid, but was capable of the detection of ascorbic acid at a sensitivity of 0.76 microA mM(-1) or 10.75 microA mM(-1) cm(-2) across a range from 0.5 to 8mM (r2=0.996, n=6), and a limit of detection of 8.3 microM (S/N=3). The sensor was compared to a range of other conducting polymer-based ascorbate sensors and found to be comparable or superior in terms of analytical performance. PMID:18243871

Ambrosi, Adriano; Morrin, Aoife; Smyth, Malcolm R; Killard, Anthony J

2008-02-18

 
 
 
 
241

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

Directory of Open Access Journals (Sweden)

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

242

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)

2011-01-01

243

Routine sample preparation and HPLC analysis for ascorbic acid (vitamin C) determination in wheat plants and Arabidopsis leaf tissues.  

Science.gov (United States)

Plants have developed various mechanisms to protect themselves against oxidative stress. One of the most important non-enzymatic antioxidants is ascorbic acid. There is thus a need for a rapid, sensitive method for the analysis of the reduced and oxidised forms of ascorbic acid in crop plants. In this paper a simple, economic, selective, precise and stable HPLC method is presented for the detection of ascorbate in plant tissue. The sensitivity, the short retention time and the simple isocratic elution mean that the method is suitable for the routine quantification of ascorbate in a high daily sample number. The method has been found to be better than previously reported methods, because of the use of an economical, readily available mobile phase, UV detection and the lack of complicated extraction procedures. The method has been tested on Arabidopsis plants with different ascorbate levels and on wheat plants during Cd stress. PMID:24873913

Szalai, Gabriella; Janda, T; Pál, Magda

2014-06-01

244

Free radical mechanisms for the oxidation of substituted ascorbates. A pulse radiolysis study of L-ascorbic acid-2-sulfate  

International Nuclear Information System (INIS)

The oxidations of L-ascorbate 2-sulfate by Br2- and OH radicals generated in aqueous solutions (pH 4.5 to 9.5) were studied by pulse radiolysis. The (2-SO4A).- radical, generated in an electron transfer reaction between Br2- and the parent compound, loses sulfate (tau approx. 500 ?sec) to give ascorbate free radical (A.-) with a G(A.-) = 2.0. The oxidation of L-ascorbate 2sulfate by OH radicals is complex, yielding both (2-SO4A)- and OH radical adducts. Some of these transients subsequently yield A.-. HPLC studies corroborate the overall mechanism postulated for the oxidation of L-ascorbate 2-sulfate by OH radicals

1983-01-01

245

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

246

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

247

Determination of uric acid in the presence of ascorbic acid with hexacyanoferrate lanthanum film modified electrode  

Energy Technology Data Exchange (ETDEWEB)

A glassy carbon electrode modified with LaHCF was constructed and was characterized by cyclic voltammetry (CV) and electrochemical impedance spectrum (EIS). The resulting LaHCF modified glassy carbon electrode had a good catalytic character on uric acid (UA) and was used to detect uric acid and ascorbic acid (AA) simultaneously. This modified electrode exhibits potent and persistent electron-mediating behavior followed by well-separated oxidation peaks towards UA and AA with activation overpotential. For UA and AA in mixture, one can well separate from the other with a potential large enough to allow the determination of one in presence of the other. The DPV peak currents obtained increased linearly on the UA in the range of 2.0 x 10{sup -7} to 1.0 x 10{sup -4} mol/L with the detection limit (signal-to-noise ratio was 3) for UA 1.0 x 10{sup -7} mol/L. The proposed method showed excellent selectivity and stability, and the determination of UA and AA simultaneously in urine was satisfactory.

Wang Guangfeng; Meng Jian; Liu Hongying; Jiao Shoufeng; Zhang Wei; Chen Daolei [College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Anhui Key Laboratory of Chemo-Biosensing, Wuhu 241000 (China); Fang Bin [College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Anhui Key Laboratory of Chemo-Biosensing, Wuhu 241000 (China)], E-mail: wangyusandra@yahoo.com.cn

2008-02-15

248

Solubilities of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid in water  

International Nuclear Information System (INIS)

The solubility in water of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid was determined in the 278.15 K to 343.15 K temperature range. The solubility of these compounds served to permit the evaluation of the apparent molar enthalpies of solution

2008-05-01

249

Solubilities of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid in water  

Energy Technology Data Exchange (ETDEWEB)

The solubility in water of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid was determined in the 278.15 K to 343.15 K temperature range. The solubility of these compounds served to permit the evaluation of the apparent molar enthalpies of solution.

Mishelevich, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel); Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel)], E-mail: apelblat@bgu.ac.il

2008-05-15

250

The crystal structure and physicochemical properties of L-ascorbic acid 2-glucoside.  

Science.gov (United States)

The stable L-ascorbic acid glucoside produced by the action of the cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) from Bacillus stearothermophilus was crystallized from an aqueous solution. Determination of the molecular structure by single crystal X-ray analysis showed the compound to be 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G). The crystals are orthorhombic, space group P2(1)2(1)2(1), with unit-cell dimensions a = 11.929 A, b = 24.351 A, and c = 4.864 A. The D-glucopyranose residue has the 4C1 conformation. These conclusions are in good agreement with those based on the 13C-NMR spectrum. The general physicochemical properties of crystalline AA-2G are reported. PMID:1423355

Mandai, T; Yoneyama, M; Sakai, S; Muto, N; Yamamoto, I

1992-08-01

251

A Flexible Ascorbic Acid Fuel Cell with a Microchannel Fabricated using MEMS Techniques  

Science.gov (United States)

We fabricated a miniature ascorbic acid fuel cells equipped with a microchannel for the circulation of ascorbic acid (AA) solution using micro electronic mechanical system techniques. The fuel cell was fabricated on a flexible polyimide substrate, and its porous carbon-coated aluminium (Al) electrodes of 2.8 mm in width and 11 mm in length were formed using photolithography and screen-printing techniques. The porous carbon was deposited by screen-printing of carbon-black ink on the Al electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the cathode surface. The microchannel with a depth of 200 ?m was fabricated using a hot-embossing technique. A maximum power of 0.60 ?W at 0.58 V that corresponds to a power density of 1.83 ?W/cm2 was realized by introducing a 200 mM concentrated AA solution at room temperature.

Mogi, Hiroshi; Fukushi, Yudai; Koide, Syohei; Sano, Ryohei; Sasaki, Tsubasa; Nishioka, Yasushiro

2013-12-01

252

Efficacy of Ascorbic Acid Reducing Waterborne Copper Toxicity in Butterfish (Poronotus triacanthus  

Directory of Open Access Journals (Sweden)

Full Text Available This study was investigated the effects of copper (Cu and Ascorbic Acid (AA on butterfish (Poronotus triacanthus, using the micronucleus (MN and Nuclear Abnormality (NA tests for the period of 7, 14 and 21 days. NA shapes in erythrocytes were scored into blebbed nuclei (BL, lobed nuclei (LB, notched nuclei (NT and binuclei (BN. It was observed that, fish showed significant sensitivity to the different treatments. In general, the highest value of both MN and NA cells were significantly increased in the Cu treated group followed by the combination of Cu and AA treated group. These values revealed the highest number after 21 days treatment in all cases. The frequencies of each NA shape in erythrocytes of all treatments were observed in the following NT> LB> BN> BL. Present results demonstrated the efficacy of ascorbic acid in reducing genotoxicity in fish induced by waterborne copper.

Wannee Jiraungkoorskul

2007-01-01

253

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

254

Stability studies of ascorbic acid 2-glucoside in cosmetic lotion using surface response methodology.  

Science.gov (United States)

Ascorbic acid 2-glucoside (AA-2G) has been widely used in cream and lotion types of cosmetic products. Thus, the degradation of AA-2G caused by the temperature change and pH variation was very critical for determining the bio-functionality of cosmetics. Response surface methodology (RSM) was introduced to study the influence of temperature and pH on the stability of AA-2G. The optimal condition of retaining AA-2G with the highest stability was determined to be 55.3°C and pH 6.4. The antioxidative activities of AA-2G including DPPH and ABTS free radical scavenging activities, metal chelating activity, and reducing ability were also determined. AA-2G was a good ascorbic acid derivative which could be used in cosmetic products as an active ingredient. PMID:23416010

Huang, Wen-Ying; Lee, Pei-Chi; Huang, Ling-Kuei; Lu, Li-Ping; Liao, Wayne C

2013-03-15

255

Changes in Ascorbic Acid Content, Antioxidant Capacity and Sensory Quality of Fresh-cut Mangosteens During Storage  

Directory of Open Access Journals (Sweden)

Full Text Available Fresh-cut mangosteens, stored in modified atmosphere packaging (MAP; 5% O2 + 9% CO2, in vacuum packaging (VAC and in air (AIR were examined for ascorbic acid content, antioxidant capacity and sensory quality during 14 days of storage at 4oC. After 4 days-storage, fresh-cut fruits with MAP resulted in better retention of ascorbic acid and antioxidant capacity than those stored in AIR throughout the storage. Furthermore, there were no significant differences in ascorbic acid contents between fruits stored in MAP and VAC, as well as antioxidant capacities, during the remaining period of storage. Fresh-cut fruits with MAP treatment obtained the highest sensory scores, compared with other treatments, throughout the entire period of storage. Fresh-cut mangosteens stored in MAP resulted in the best overall retention of ascorbic acid, antioxidant capacity and sensory quality.

Salisa TONWATTANA

2004-06-01

256

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

Directory of Open Access Journals (Sweden)

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

257

Retention of ascorbic acid in pickles--effect of different spices and salt (an in vitro study).  

Science.gov (United States)

Effect of spices, different concentration of sodium chloride and other salts on retention of ascorbic acid during storage period (21 days in case of spices and eight days for salts) was studied. The retention of ascorbic acid with the addition of 24% NaCl was 55%, followed by 37% with red chillies, fenugreek, turmeric; 32% with the addition of pepper, sugar and 26% with mustard and asafoetida. When all the spices and salt were added together, the retention was much higher (73%) than those with individual spices. Sodium chloride over a wide range of concentrations was found to have higher retention of ascorbic acid. The retention being 80%, when stored with 24.0% sodium chloride solution for eight days. Sulfates of sodium, potassium, magnesium and manganese or chlorides of magnesium or manganese did not have a significant effect on the retention of ascorbic acid. The retention with potassium chloride was close to that observed with sodium chloride. PMID:8121472

Surekha, S; Begum, K

1993-01-01

258

Effect of ascorbic acid on food preference and consumption in captive capybaras (Hydrochoerus hydrochaeris)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O ácido ascórbico é um nutriente essencial para as capivaras (Hydrochoerus hydrochaeris). No presente trabalho foi avaliado o efeito do ácido ascórbico sobre o consume e as preferências alimentares a curto e longo prazo, assim como a influencia da escolha sobre a sintomatologia da carência de vitami [...] na C na dieta. Não foram observadas diferencias no consumo de alimento na ausência deste nutriente. Considerando as preferências a longo prazo (24h), os animais acostumados a consumir vitamina C continuavam consumindo preferencialmente o alimento suplementado. As preferências alimentares em capivaras não parecem depender da disponibilidade de ácido ascórbico; no entanto, quando acostumados à vitamina C, estes animais podem reconhecer e selecionar o ácido ascórbico na alimentação subseqüente. São discutidos os mecanismos que permitem as capivaras "avaliar" a qualidade nutricional do alimento, assim como o valor adaptativo destes comportamentos em populações silvestres. Abstract in english The aim of this work was to study the short and long term influences of ascorbic acid on Hydrochoerus hydrochaeris, if supplemented in their food. No differences regarding food intake were observed in the absence of vitamin C. On a daily basis, animals accustomed to food containing ascorbic acid pre [...] fered to continue eating the same food. Food preference in capybaras did not seem to depend on ascorbic acid availability; however, when accustomed to vitamin C, capybaras might recognize and select ascorbic acid in subsequent food. Mechanisms allowing capybaras to "evaluate" the nutritional quality of their food are discussed, as well as the adaptive value of this behavior in free ranging populations.

Martín Roberto, Alvarez; Fernando Osvaldo, Kravetz.

259

Long-distance transport of L-ascorbic acid in potato  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Following on from recent advances in plant AsA biosynthesis there is increasing interest in elucidating the factors contributing to the L-ascorbic acid (AsA) content of edible crops. One main objective is to establish whether in sink organs such as fruits and tubers, AsA is synthesised in situ from imported photoassimilates or synthesised in source tissues and translocated via the phloem. In the current work we test the hypothesis...

Tedone Luigi; Hancock Robert D; Alberino Salvatore; Haupt Sophie; Viola Roberto

2004-01-01

260

Synthesis of L-ascorbic acid in the phloem  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Although plants are the main source of vitamin C in the human diet, we still have a limited understanding of how plants synthesise L-ascorbic acid (AsA) and what regulates its concentration in different plant tissues. In particular, the enormous variability in the vitamin C content of storage organs from different plants remains unexplained. Possible sources of AsA in plant storage organs include in situ synthesis and long-distanc...

Hancock Robert D; McRae Diane; Haupt Sophie; Viola Roberto

2003-01-01

 
 
 
 
261

Regulation of fruit ascorbic acid concentrations during ripening in high and low vitamin C tomato cultivars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background To gain insight into the regulation of fruit ascorbic acid (AsA) pool in tomatoes, a combination of metabolite analyses, non-labelled and radiolabelled substrate feeding experiments, enzyme activity measurements and gene expression studies were carried out in fruits of the ‘low-’ and ‘high-AsA’ tomato cultivars ‘Ailsa Craig’ and ‘Santorini’ respectively. Results The two cultivars exhibited different profiles of total AsA (totA...

2012-01-01

262

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Surapaneni Krishna; Venkataramana G

2007-01-01

263

Efficacy of Ascorbic Acid Reducing Waterborne Copper Toxicity in Butterfish (Poronotus triacanthus)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study was investigated the effects of copper (Cu) and Ascorbic Acid (AA) on butterfish (Poronotus triacanthus), using the micronucleus (MN) and Nuclear Abnormality (NA) tests for the period of 7, 14 and 21 days. NA shapes in erythrocytes were scored into blebbed nuclei (BL), lobed nuclei (LB), notched nuclei (NT) and binuclei (BN). It was observed that, fish showed significant sensitivity to the different treatments. In general, the highest value of both MN and NA cells were signi...

Wannee Jiraungkoorskul; Somphong Sahaphong

2007-01-01

264

L-ascorbic acid producing yeasts learn from plants how to recycle it  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Microorganisms employed in industrial fermentation processes are often subjected to a variety of stresses that negatively affect growth, production and productivity. Therefore, stress robustness is an important property for their application. Reactive Oxygen Species (ROS) accumulation is a common denominator to a lot of these stress factors. Ascorbic acid (L-AA) acts as ROS scavenger, thus potentially protecting cells from harmful oxidative products. We have previously reported the developmen...

Fossati, Tiziana; Solinas, Nicola; Porro, Danilo; Branduardi, Paola

2011-01-01

265

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)

2011-02-01

266

Study of pharmacokinetic interaction of ascorbic acid and phenytoin in rats  

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Background and purpose of the study: There is great interest for researchers and therapists to study the interactions of phenytoin with other drugs or foods because of its enzyme inducing effects, saturable biodisposition and specific physicochemical properties. There are reports indicating that ascorbic acid (ASC) affects interacting properties of phenytoin. By considering pharmacokinetic aspects, the present study was carried out to evaluate the effect of ASC on single and multiple dose kin...

Minaiyan M.; Ghafghazi T; Majdzadeh-Ardakani M.

2008-01-01

267

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

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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

268

Ascorbic Acid Ameliorates Toxic Effects of Chlopyrifos on Testicular Functions of Albino Rats  

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Chlorpirifos (CPF) is a widely used organophosphate insecticide for both agricultural and domestic purposes with attendant human exposures. Many authors have documented the toxic effects of CPF on the central nervous system. This study was designed to study the effect of CPF and the influence of coadministration of ascorbic acid (AA) on the testicular functions of albino rats. Twenty five 2 months old male albino wistar rats were divided into 5 groups of 5 rats each (Group A-E). A (control) r...

2011-01-01

269

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

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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...

2003-01-01

270

Electrocatalytic Oxidation Properties of Ascorbic Acid at Poly(3, 4-ethylenedioxythiophene) Films Studied by Electrochemical-Surface Plasmon Resonance Spectroscopy  

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In this report, we demonstrate electrocatalytic oxidation properties of ascorbic acid at poly(3, 4-ethylenedioxythiophene) (PEDOT) thin films in view of their potential application for bio-sensing devices. PEDOT thin films were deposited on gold thin films by electropolymerization of EDOT monomer in acetonitrile solvent. In-situ electrochemical-surface plasmon resonance spectroscopy (EC-SPR) was used to detect both electrochemical and optical signals upon an injection of ascorbic acid.

Baba, Akira; Sano, Yohsuke; Ohdaira, Yasuo; Shinbo, Kazunari; Kato, Keizo; Kaneko, Futao

271

Ascorbic Acid Levels in Hepatitis and Non-Hepatitis Subjects in University of Calabar Teaching Hospital (UCTH), Calabar  

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The ascorbic acid levels of thirty (30) hepatitis (sero-positive) subjects who presented themselves as donors at the serology unit of the Department of Hematology and blood transfusion, University of Calabar Teaching Hospital (UCTH), Calabar, Nigeria were assessed alongside thirty (30) non-hepatitis (Sero-negative) subjects as controls. Using the 2, 4 dinitrophenyl hydrazine (spectrophotometric method), the mean ascorbic acid level for the control subjects was 1.05 ? 0.45mg/dl while ...

Etim, Afiong A.; Etukudo, Maisie H.

2006-01-01

272

Nonresponsiveness of serum high-density lipoprotein-cholesterol to high dose ascorbic acid administration in normal men.  

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In a prospective, single-blind, 12-wk study, serum lipids were measured serially in nine normal male volunteers before and during oral administration of megadose ascorbic acid (1 g vitamin C/day). Study results revealed no significant effect of vitamin therapy on serum cholesterol, high-density lipoprotein-cholesterol, triglycerides, or calculated low-density lipoprotein-cholesterol. Megadose ascorbic acid therapy is not effective in elevating serum high-density lipoprotein-cholesterol in normal adult men. PMID:7293936

Johnson, G E; Obenshain, S S

1981-10-01

273

Antitumoral activity of L-ascorbic acid-poly- D,L-(lactide-co-glycolide) nanoparticles containing violacein  

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It has been demonstrated that tumoral cells have a higher uptake of ascorbic acid compared to normal cells. This differential characteristic can be used as a way to improve the specificity of antitumoral compounds if combined with polymeric drug delivery systems. The aim of this study was to prepare, characterize and evaluate the antitumoral activity of poly- D,L-(lactide-co-glycolide) 50:50 loading the antitumoral compound violacein and capped with L-ascorbic acid. Nanoparticles were prepare...

Martins, Dorival; Frungillo, Lucas; Anazzetti, Maristela C.; Melo, Patri?cia S.; Dura?n, Nelson

2010-01-01

274

PVA Stabilized Gold Nanoparticles Using Ascorbic Acid as A Reducing Agent  

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The stabilization of AuNPs by Poly-vinyl Alcohol (PVA) with ascorbic acid as a reducing agent has been investigated here. PVA and ascorbic acid are bio-compatible and water soluble compounds, thus the approach is green. We study the extent of stabilization provided by PVA under differing initial pH conditions and at different ascorbic acid (AA) to gold chloride (AuCl3) molar ratios. It is found that if the molar ratio AA:AuCl3 is below 3 then PVA is effective as an stabilizer otherwise not. Furthermore, an improvement in stabilization is observed when initial pH value of reaction mixture is adjusted to be above 7 and TEM imaging shows fairly monodisperse and medium sized AuNPs (52+/-9 nm) at pH- 11. A decrease in width of plasmon peak and disappearance of secondary surge near 750 nm with time in time dependent UV-Vis absorption spectra shows that in presence of PVA, the nucleation is not according to standard LaMer nucleation model but particles are formed via a complex intermediary.

Tyagi, Himanshu; Kushwaha, Ajay; Kumar, Anshuman; Aslam, M.

2011-07-01

275

THE INFLUENCE OF ASCORBIC ACID ON DEVELOPMENT OF ADENOCARCINOMA MAMMAE IN MICES  

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Full Text Available The influence of great dosage of ascorbic acid during the experimental induction of adenocarcinoma mammae was experimented. For the experiments the female of CBA/H mice were used. The animals were divided into two groups: the control (K and experimental (I, II, III group. The mice of the control group were given 0.5 ml physiological solution, and the mice of experimental subgroup I were given 10, and of the subgroup II were given 100, and of subgroup III were given 1.000 mg of ascorbic acid/d. In the beginning of experiment all animals of both control and experimental group were given 5x10 6 of live cells of adenocarcinoma mammae. During and in the end of the experiment the changes in the body weight, weigth of adenocarcinoma mammae, and weigth o spleen was examined. The achieved results exemplify that the aplication of high doses of ascorbic acid, in the case of CBA/H mice, decreased the weight of mice, decreased the weight of adenocacinoma mammae, decreased the mass and celularity of spleen, and decreased stimulates the number of leucocytes.

Zoran Pavlovi?

2004-07-01

276

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

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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

277

IMPROVEMENT OF SALT TOLERANCE IN DURUM WHEAT BY ASCORBIC ACID APPLICATION  

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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

278

Radioprotection potential of the ascorbic acid on the carrageenan used as food additive  

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Carrageenans are a group of natural carbohydrates that are present in the structure of certain varieties of red algae (Rhodophyceae). They are used in emulsions, for syneresis control and to grow up, to promote adhesiveness and dispersion. In the industry of foods they can be used for instance, as thickness and gelling agents, alone or together with other additives. The processing of foods by radiation is increasing considerably, because the efficiency of the process in the industrial decontamination of products. The objective of this work was to study the action of the ascorbic acid as potential radioprotector of the carrageenan against 60 Co gamma radiation effects, using the viscosity as parameter. Samples of commercial carrageenan dissolved at 1,0% were irradiated in the presence or not of ascorbic acid, with doses of 0.0 kGy; 1.0 kGy; 2.5 kGy; 5.0 kGy and 10.0 kGy. After the irradiation the relationships viscosity/dose were established for the temperature of 60 deg C. For the dose of 10.0 kGy a better protecting effect of the ascorbic acid on the carrageenan was seen. The implications of the use of this antioxidant is discussed as a form of minimizing the effect of the radiation in irradiated foods. (author)

2002-08-11

279

Voltammetric Behavior and Amperometric Determination of Ascorbic Acid at Cadmium Pentacyanonitrosylferrate Film Modified GC Electrode  

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Full Text Available The present work, describes electrochemical preparation of a novel cadmium pentacyanonitrosylferrate (CdPCNF film as a Prussian Blue analogous on the glassy carbon (GC electrode from a solution of 5 mM CdCl2 and 5 mM Na2[Fe(CN5NO]. The effect of experimental conditions such as pH and composition of electrodeposition solution on the peak current of the modified electrode and its stability were investigated. In the optimized conditions a controllable and repeatable value of CdPCNF film was obtained. The modified GC electrode showed a reversible cyclic voltammograms due to the redox reaction of Fe(III / Fe(II in the film. The CdPCNF film showed a good electrocatalytic activity toward the oxidation of ascorbic acid. The mean value of rate constant k and the diffusion coefficient of ascorbic acid in the solution D, were found to be 3.6 ´ 102 M-1 s-1, and 4.4 ´ 10-6 cm2 s-1 respectively. A calibration graph was obtained over concentration of 5 – 50 µM. The limit of detection was found to be 2.52 µM by hydrodynamic amperometry. This technique was used to the selective determination of ascorbic acid in the pharmaceutical preparations and fruit juices.

H. Razmi and M. Harasi

2008-01-01

280

Cell proliferation of the ileum intestinal mucosa of diabetic rats treated with ascorbic acid  

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Full Text Available The objective of this work was to evaluate the effect of the ascorbic acid supplementation on the cellular proliferation on the ileum mucosa of diabetic rats. Fifteen 90-days rats were divided in the groups: control, diabetic and diabetic supplemented with ascorbic acid (DA. Two hours prior the sacrifice, they were injected with Vincristin. Semi-seriate histological cuts stained with HE were accomplished. About 2500 crypt cells from the intestinal mucosa were counted in order to obtain the metaphasic indexes. The height and depth of 30 villi and 30 crypts were measured for each animal, respectively. The metaphasic indexes showed no significant changes when we compared the three groups: 20.2 ± 0.7 (control, 18 ± 1.9 (diabetic and 17 ± 1.4 (DA (p > 0.05. The values obtained from the crypts measurement were 221.2 ± 8.5 (control, 225.3 ± 9.5 (diabetic and 222 ± 34 (DA. The villi of the control, diabetic and DA animals presented the following results: 301.7 ± 25.33, 304.8 ± 25.63 and 322.1 ± 45.77 respectively. The morphometric data were not different statistically (p > 0.05. Summing up, the present work showed that there was no alteration in the cellular proliferation of the ileum of diabetic-induced rats supplemented with ascorbic acid.

Jacqueline Nelisis Zanoni

2008-08-01

 
 
 
 
281

Cell proliferation of the ileum intestinal mucosa of diabetic rats treated with ascorbic acid  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in english The objective of this work was to evaluate the effect of the ascorbic acid supplementation on the cellular proliferation on the ileum mucosa of diabetic rats. Fifteen 90-days rats were divided in the groups: control, diabetic and diabetic supplemented with ascorbic acid (DA). Two hours prior the sac [...] rifice, they were injected with Vincristin. Semi-seriate histological cuts stained with HE were accomplished. About 2500 crypt cells from the intestinal mucosa were counted in order to obtain the metaphasic indexes. The height and depth of 30 villi and 30 crypts were measured for each animal, respectively. The metaphasic indexes showed no significant changes when we compared the three groups: 20.2 ± 0.7 (control), 18 ± 1.9 (diabetic) and 17 ± 1.4 (DA) (p > 0.05). The values obtained from the crypts measurement were 221.2 ± 8.5 (control), 225.3 ± 9.5 (diabetic) and 222 ± 34 (DA). The villi of the control, diabetic and DA animals presented the following results: 301.7 ± 25.33, 304.8 ± 25.63 and 322.1 ± 45.77 respectively. The morphometric data were not different statistically (p > 0.05). Summing up, the present work showed that there was no alteration in the cellular proliferation of the ileum of diabetic-induced rats supplemented with ascorbic acid.

Jacqueline, Nelisis Zanoni; Renata Virginia, Fernandes Pereira.

282

Influence of refrigeration length and of sugar addition on ascorbic acid content in some natural juices  

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Full Text Available Following some studies concerning the main factors influencing the concentration of vitamins within food raw materials, especially ascorbic acid, this work tries to evidence the influence of the refrigeration temperature and of the sucrose addition on content of this vitamin in three types of natural juice. The biological material was represented by orange, strawberry and kivi natural juices, obtained from these fruits by means a crushing out process. For each type of juice there were made up samples without addition and samples with 5% and 10% sucrose addition. The ascorbic acid determination was carried out from fresh juice as well as from juice kept in refrigerator, at certain time intervals (24, 48, 96 ?i 168 hours. The storage of these juices under refrigeration conditions has determined percentage reductions of vit. C content of these ones. Thus, after 168 hours of storage, in the three types of analysed juices the highest loss of vitamin have been registrated in samples without sucrose addition, and the least ones in samples with 10% addition. The comparison of vitamin C values in the three analysed juices, subjected 168 hours to refrigeration process, has evidenced that the highest loss of ascorbic acid have been in orange juice, and the least one in kiwi juice. Keywords: vitamin C, sucrose, orange, strawberry, kiwi

Liviu Fartaies

2009-06-01

283

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

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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

284

Validation of ascorbic acid tablets of national production by igh-performance liquid chromatography method  

International Nuclear Information System (INIS)

We validate an analytical method by high-performance liquid chromatography to determine ascorbic acid proportion in vitamin C tablets, which was designed as an alternative method to quality control and to follow-up of active principle chemical stability, since official techniques to quality control of ascorbic acid in tablets are not selective with degradation products. Method was modified according to that reported in USP 28, 2005 for analysis of injectable product. We used a RP-18 column of 250 x 4.6 mm 5 ?m with a UV detector to 245 nm. Its validation was necessary for both objectives, considering parameters required for methods of I and II categories. This method was enough linear, exact, and precise in the rank of 100-300 ?g/mL. Also, it was selective with remaining components of matrix and with the possible degradation products achieved in stressing conditions. Detection and quantification limits were estimated. When method was validated it was applied to ascorbic acid quantification in two batches of expired tablets and we detected a marked influence of container in active degradation principle after 12 months at room temperature. (Author)

2009-01-01

285

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.

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

286

Antagonism between abscisic acid and gibberellins is partially mediated by ascorbic acid during seed germination in rice  

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The antagonism between abscisic acid (ABA) and gibberellin (GA) plays a key role in controlling seed germination,1,2 but the mechanism of antagonism during this process is not known. In the associated study,3 we investigated the relationship among ABA, reactive oxygen species (ROS), ascorbic acid (ASC) and GA during rice seed germination. ROS production is reduced by ABA, which hence results in decreasing ASC accumulation during imbibition. GA accumulation was also suppressed by a reduced ROS...

Ye, Nenghui; Zhang, Jianhua

2012-01-01

287

Effect of previous ascorbic acid treatment on the fatty acid profile of cobia (Rachycentron canadum) fillets during frozen storage  

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[EN] The present research focuses on the nutritional value of the lipid retention associated with frozen cobia (Rachycentron canadum). The effect of a previous soaking in an aqueous ascorbic acid (AA) solution on the fatty acid profile of fish fillets during a further frozen storage period (–18 °C) was investigated. Two different AA concentrations were tested (0.25% and 0.50%) and compared to control conditions. As a result of the frozen storage period (up to 6 months), marked decreases...

Taheri, S.; Motallebi, A. A.; Fazlara, A.; Aftabsavar, Y.; Aubourg, Santiago P.

2012-01-01

288

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

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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

289

Monitoring on the Presence of Ascorbic Acid in Not Prepacked Fresh Meat Preparations by a Validated HPLC Method  

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Full Text Available Ascorbic acid is a commonly-used food additive permitted in prepacked fresh meat preparations. Consequently, the addition of this antioxidant is subject to a specific packaging authorization. In this survey 180 samples of not prepacked fresh meat preparations have been analyzed in order to evaluate the diffusion of not authorized ascorbic acid additions. The ascorbic acid has been determined by a high performance liquid chromatography with diode array detection method, validated according to the European Legislation. Quantifiable concentrations of ascorbic acid (> LOQ = 20.1 mg · kg-1 were registered in 33 samples confirming a wide diffusion of not authorized additions. Moreover, low concentrations not attributable to a additives additions were detected in 14 samples. Ascorbic acid sources (tomato were declared on the label of these samples. Considering that the addition of this food additive is generally considered safe, these low concentrations registered may be useful for the determination of an allowable limit for the ascorbic acid in not prepacked fresh meat preparations.

Marco Iammarino

2012-04-01

290

Influence of antioxidant (L- ascorbic acid on tolbutamide induced hypoglycaemia/antihyperglycaemia in normal and diabetic rats  

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Full Text Available Abstract Background Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycaemia. Increased oxidative stress and decreased antioxidant levels are the leading cause of diabetes and diabetic complications. So it is felt that supplementation of antioxidants may be useful in controlling the glucose levels and to postpone the occurrence of diabetic complications. The objective of our study is to find the influence of antioxidant supplementation (L-ascorbic acid on tolbutamide activity in normal and diabetic rats. Methods L- ascorbic acid/tolbutamide/L-ascorbic acid + tolbutamide were administered orally to 3 different groups of albino rats of either sex in normal and diabetic condition. Blood samples were collected from retro-orbital puncture at different time intervals and were analyzed for blood glucose by GOD-POD method. Diabetes was induced by alloxan 100 mg/kg body weight administered by I.P route. Results L-ascorbic acid/ tolbutamide produced hypoglycaemic activity in a dose dependant manner in normal and diabetic condition. In the presence of L-ascorbic acid, tolbuatmide produced early onset of action and maintained for longer period compared to tolbutamide matching control. Conclusion Supplementation of antioxidants like L-ascorbic acid was found to improve tolbutamide response in normal and diabetic rats.

Vardhan Vishnu A

2005-03-01

291

Effects of ascorbic acid and sugars on solubility, thermal, and mechanical properties of egg white protein gels.  

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The effects of reducing sugars (fructose, glucose, ribose, and arabinose), sucrose, and ascorbic acid were studied on thermo-mechanical properties and crosslinking of egg white proteins (EWP) through Maillard reaction. Sugars (0%, 1%, 5%, and 10%) and ascorbic acid (0%, 0.25%, 0.5%, and 2.5%) were added to EWP solutions. Thermal denaturation and crosslinking of EWP were characterized by differential scanning calorimetry (DSC). Mechanical properties (failure strength, failure strain and Young's modulus) of modified and unmodified EWP gels were evaluated by texture analyzer. Ascorbic acid decreased thermal denaturation temperature of EWP, but the reducing sugars increased the denaturation temperature. DSC thermograms of EWP showed that ascorbic acid exhibited an exothermic transition (?110 °C) which was attributed to Maillard crosslinking of the protein. The reduction in pH (from 7.21 to ?6) and protein solubility of egg white protein gel (from ?70% to ?10%) provides further evidence of the formation of Maillard cross-linking. Reactive sugars (ribose and arabinose) increased the mechanical properties of EWP gels, whereas ascorbic acid decreased the mechanical properties. Generally, the effect of ascorbic acid was more pronounced than that of various reducing sugars on the thermal and mechanical properties of egg white proteins. PMID:24099933

Mohammadi Nafchi, Abdorreza; Tabatabaei, Ramin H; Pashania, Bita; Rajabi, Hadiseh Z; Karim, A A

2013-11-01

292

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

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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

293

Maintenance of cold-preserved porcine hepatocyte function with UW solution and ascorbic acid-2 glucoside.  

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Normal human hepatocytes are an ideal source of liver-targeted cell therapies, such as hepatocyte transplantation and bioartificial livers, but availability of human donor livers for liver cell isolation is severely limited. To effectively utilize scarce donor organs for cell therapies, it is of extreme importance to establish an efficient isolation technique and an effective cold preservation solution for transportation of isolated cells. A lateral segment of the liver was surgically resected from pigs weighing 10 kg and a four-step collagenase and dispase digestion was conducted. Isolated hepatocytes were subjected to 8-h cold storage on ice. The following preservation solutions were tested: 1) University of Wisconsin (UW) solution, 2) UW with 100 microg/ml of ascorbic acid-2 glucoside (AA2G), 3) 100% fetal bovine serum (FBS), and 4) Dulbecco's modified Eagle's medium (DMEM) supplemented with 100% FBS. The mean viability of porcine hepatocytes was 95.5 +/- 2.5% when isolated in three independent experiments. Viability, plating efficiency, membrane stability, and ammonia metabolic capacity of cold-preserved hepatocytes were significantly better maintained by the use of UW solution. When AA2G (100 microg/ml) was combined with UW solution, such parameters were further improved. It was explained by inhibition of caspase-3 activation and retention of ATP at high levels of hepatocytes preserved with UW solution containing AA2G. The present work demonstrates that a combination of UW solution with AA2G (100 microg/ml) would be a useful cold preservation means for the development of cell therapies. PMID:14579928

Takesue, Michihiko; Maruyama, Masanobu; Shibata, Norikuni; Kunieda, Takemi; Okitsu, Teru; Sakaguchi, Masakiyo; Totsugawa, Toshinori; Kosaka, Yoshikazu; Arata, Akira; Ikeda, Hideaki; Matsuoka, Junji; Oyama, Toshie; Kodama, Makoto; Ohmoto, Kenji; Yamamoto, Shinichiro; Kurabayashi, Yuzuru; Yamamoto, Itaru; Tanaka, Noriaki; Kobayashi, Naoya

2003-01-01

294

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

295

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 epinephrine hydrochloride injection when contain AA and UA, which also shows good recovery for determination of EP in some biological fluids.

2011-08-30

296

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

297

Implications for degenerative disorders: Antioxidative activity, total phenols, flavonoids, ascorbic acid, ?-carotene and ?-tocopherol in Aloe vera  

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In order to demonstrate whether the known biological effects of Aloe vera (L.) Burm. fil. could correlate with the antioxidant activity of the plant, the antioxidant activity of the aqueous leaf extract was investigated. The present study demonstrated that the aqueous extract from A. vera leaves contained naturally occuring antioxidant components, including total phenols, flavonoids, ascorbic acid, ?-carotene and ?-tocopherol. The extract exhibited inhibitory capacity against Fe3+/ascorbic ...

Ozsoy, Nurten; Candoken, Eda; Akev, Nuriye

2009-01-01

298

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)

2013-02-01

299

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 factors that alter ascorbic acid stability in food, converting ascorbic to dehydroascorbic acid, while keeping the C vitamin active form. (author)

2009-01-01

300

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

2013-01-18

 
 
 
 
301

Modulation of Cholesterol and Copper Residue Levels in Muscles and Blood Serum of Finishing Broiler Chickens Fed Copper and Ascorbic Acid Supplements  

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Full Text Available To study the effect of Copper (Cu and ascorbic acid supplements on modulation of cholesterol and copper residue content of chicken muscles and blood serum, two hundred and forty finishing Anak broiler chickens of mixed sexes were randomly allotted to four dietary treatment groups with four replication of fifteen birds each. The feeding period was 5 weeks. The response to copper and ascorbic acid were such that dietary supplementation with 250 ppm Cu alone resulted in 30 and 19% reduction in pectoralis major and biceps femoris muscles cholesterol respectively. Supplementation with 250 ppm Cu + 100 ppm Ascorbic acid resulted in 29 and 12% reduction in muscles cholesterol while inclusion of 100 ppm ascorbic acid alone brought about 4 and 10% reduction in the two muscles respectively. Serum cholesterol reduced by 28% and the addition 100 ppm ascorbic acid reduced this to 26%. Ascorbic acid (100 ppm exerted 12% reduction in serum cholesterol. Ascorbic lowered the hypocholesterolemic potency of copper by about 1-7%. Combination of 100 ppm ascorbic and 250 ppm Cu slowed down rate of weight gain by 11% when compared with 250 ppm Cu alone as supplement, Supplementation with 100 ppm ascorbic alone improved carcass yield by 4% compared to 250 ppm Cu. Metalloprotein enzyme (AST and ALP activities were significantly increased with supplementation. Cu residue was more in biceps femoris than pectoralis major muscle. Above 30% reduction in Cu residue was noticed with addition of ascorbic acid.

A.O. Oso

2011-01-01

302

Iron absorption from a breakfast cereal: effects of EDTA compounds and ascorbic acid.  

Science.gov (United States)

Sodium iron ethylenediaminetetracetic acid (NaFeEDTA) has been recommended for food fortification programmes to improve iron status but its performance in commercial products has not been evaluated. The effect of EDTA on iron absorption from fortified cornflakes, given as part of a typical Western breakfast, was determined in a double-blind randomised study with 20 non-anaemic female volunteers, using experimentally prepared iron compounds, enriched with 58Fe, and faecal monitoring. Five meals were compared: hydrogen reduced iron, hydrogen reduced iron plus Na2EDTA (molar ratio EDTA:Fe 1:2), hydrogen reduced iron plus NaFe(III)EDTA at two different molar ratios (EDTA:total Fe 1:3 and 1:2), and hydrogen reduced iron plus 15 mg ascorbic acid (ascorbic acid:Fe 1.3:1). The iron and EDTA compounds were accurately weighed into gelatine capsules and taken with unfortified cornflakes, semi-skimmed milk and tea on two consecutive days; the iron dose per meal was 3.75 mg. Iron absorption from all five test meals was measured in each volunteer with a minimum wash-out period of 2 weeks between tests. Geometric mean iron absorption (%) from the 5 tests was 14.1, 17.6, 20.6, 24.4 and 17.5 respectively (equivalent to 0.5-0.9 mg absorbed iron). There was a significantly higher iron absorption from the mixture of reduced iron and NaFe(III)EDTA (EDTA:Fe 1:2) than from reduced iron alone (p = 0.014). It is not known whether the higher absorption was from reduced iron or NaFeEDTA or both. Absorption was not increased significantly with NaFe(III)EDTA (EDTA:Fe 1:3), Na2EDTA (EDTA:Fe 1:2) or ascorbic acid (15 mg). PMID:11339108

Fairweather-Tait, S J; Wortley, G M; Teucher, B; Dainty, J

2001-03-01

303

Exposure to ?-Tocopherol, Lutein or Ascorbic Acid improve Cumulus Expansion, Viability and Maturation of Swine Oocytes  

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Full Text Available Protection of the fatty acid and lipid components of oocytes that render them susceptible to free radical or other oxidative injury may prevent the damage currently associated with culture. The goal of this study was to establish the influence of several ?-tocopherol, lutein and ascorbic acid concentrations on swine oocyte maturation, viability and the function of cumulus cells in order to improve culture media. Pig oocytes were cultured for 45 hours at 37°C in 5% CO2 atmosphere; in M199 containing several ?-tocopherol (5, 10, 20, 40, 80 ?M, lutein (2.5, 4, 5, 8, 10 ?M or ascorbic acid (50, 150, 250, 500, 750 ?M concentrations and cumulus expansion was assessed. Afterwards oocytes were coloured using FDA, PI and Hoechst 33258. The differences between treatments were analyzed by the analysis of variance and interpreted using the Newman-Keuls method. When cultured in ?-tocopherol supplemented medium the number of expanded COCs to be scored as 3 was significantly greater (p<0.05 for the 5 and 40 ?M concentrations. The addition of 8 ?M lutein to the maturation medium lead to a significant (p<0.05 increase in the number of COCs that were scored at 4. For both ?-tocopherol and lutein additions the numbers of oocytes stained by FDA, as well as those stained by Hoechst were greater than the control without being statistically significant. When cultured in 150 and 500 ?M ascorbic acid the percentages of COCs scored at 4 were significantly lower (p<0.05 than the control. Also, significantly (p<0.05 fewer oocytes were stained with FDA when matured in 500 ?M. Differences between the control and the several concentrations were significant (p<0.05 for 150 and 750 ?M and distinctly significant (p<0.01 for 250 ?M.

Ileana Miclea

2010-05-01

304

Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress  

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Abstract Background Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS) involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100?mmol/L). The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated...

Klingelhoeffer Christoph; Kämmerer Ulrike; Koospal Monika; Mühling Bettina; Schneider Manuela; Kapp Michaela; Kübler Alexander; Germer Christoph-Thomas; Otto Christoph

2012-01-01

305

Ascorbic acid and pectin in different sizes and parts of citric fruits Ácido ascórbico e pectina em diferentes partes de frutas cítricas de vários tamanhos  

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Citric fruits - in natura, as frozen pulp or even as juice - are one of the most important Brazilian exportation products. They are a source of ascorbic acid - a potent antioxidant, and pectin, which is used in the food industry and is an important dietary fiber. This project aims to quantify ascorbic acid and pectin contents in citric fruits, commercial oranges and tangerines, comparing them in sizes and varieties. Ascorbic acid amount was measured in juice comparing sizes, varieties and sto...

Larissa Akemi Ywassaki; Solange Guidolin Canniatti-Brazaca

2011-01-01

306

In vitro and in vivo prolonged biological activities of novel vitamin C derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), in cosmetic fields.  

Science.gov (United States)

The biological activity of the novel vitamin C derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), was evaluated in vitro and in vivo. The percutaneous absorption of AA-2G was determined in five Japanese males. The excretion of ascorbic acid (AA) in the subjects administered AA-2G was sustained for a longer period than in the subjects administered ascorbic acid 2-phosphate (AA-2P), which is a conventional vitamin C derivative. An analysis of the distribution of AA in the skin showed that small black specks assumed to be AA were observed in the epidermis even 3 d after applying AA-2G. The melanin synthesis in B16 melanoma cells was inhibited more by AA-2G than by AA-2P, and AA-2G also prevented more UV-induced damage of human skin keratinocytes and fibroblasts than AA-2P did. From these in vivo and in vitro results, it is supposed that the conversion of AA-2G to AA is sustained for a long time compared with that of AA-2P, and that AA-2G is an effective and available compound having vitamin C activity in human subjects. PMID:9742456

Kumano, Y; Sakamoto, T; Egawa, M; Iwai, I; Tanaka, M; Yamamoto, I

1998-06-01

307

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

308

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.

2010-05-01

309

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

310

The role of ascorbic acid on collagen structure and levels of serum interleukin-6 and tumour necrosis factor-alpha in experimental lathyrism.  

Science.gov (United States)

Lathyrism is characterized by defective collagen synthesis due to inhibition of lysyl oxidase, an enzyme essential for interfibrillar cross-linking. The lathyritic agent beta-aminoproprionitrile (beta-APN) is considered an appropriate agent for studying connective tissue metabolism. We investigated the effects of ascorbic acid on collagen structure and serum cytokine levels in experimentally induced lathyrism. Forty Wistar rats weighing 200-300 g were used in the study: three test groups of 10 rats each (groups 2, 3 and 4) and 10 rats used as a control group (group 1). Experimental lathyrism was induced with daily subcutaneous injections of beta-APN in the test groups for 40 days. On the 40th day, skin biopsies were taken from the control group (group 1) and group 2, to evaluate the effect of beta-APN on dermal collagen. After the 40th day, 10 rats received ascorbic acid 100 mg/kg intraperitoneally daily for 15 days (group 3) and 10 rats (group 4) received no medication and served as a control for group 3. On the 55th day, skin biopsies were taken from groups 3 and 4. Serum concentrations of interleukin-6 and tumour necrosis factor-alpha were assessed in each group by enzyme-linked immunosorbent assay. Ultrastructural examination of the skin biopsies in group 1 revealed normal-appearing epidermal and dermal structures. Group 2 showed disorganization of the epidermis and collagen structure, and vacuolization of the endoplasmic reticulum in fibroblasts. In group 3, ultrastructural examination revealed significant improvement in the structure of dermal collagen after administration of ascorbic acid, whereas the changes in group 4 were unremarkable. Ascorbic acid administration significantly decreased the concentrations of serum cytokines in group 3 compared with group 2 (P lathyrism. PMID:14987276

Senturk, N; Keles, G C; Kaymaz, F F; Yildiz, L; Acikgoz, G; Turanli, A Y

2004-03-01

311

Controlling Temperature and Water Loss to Maintain Ascorbic Acid Levels in Strawberries During Postharvest Handling  

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Chandler’, ‘Oso Grande’ and ‘Sweet Charlie’ strawberries were stored for 8 days at 1 or 10°C, or 4 days at 20°C, either unwrapped or wrapped in PVC film to retard were conducted during the 1 water loss. Total ascorbic acid (AA) content was expressed on a dry weight basis to correct for water loss differences between treatments. Loss of AA was low and did not differ between wrapped treatments at 1 and 10°C, but was much greater at 20°C. Wrapping reduced AA loss by 5-fold at 1 and...

Nunes, M. C. N.; Brecht, J. K.; Morais, A. M. M. B.; Sargent, S. A.

1998-01-01

312

Ascorbic acid and citric flavonoids for broilers under heat stress: effects on performance and meat quality  

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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-hat...

Jem, Pen?a; Sl, Vieira; Lo?pez, J.; Rn, Reis; Barros, R.; Fvf, Furtado; Px, Silva

2008-01-01

313

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

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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...

1994-01-01

314

Stimulation of hepatocyte growth factor production by ascorbic acid and its stable 2-glucoside.  

Science.gov (United States)

Hepatocyte growth factor (HGF), a cytokine which is generally produced by mesenchymal cells, has mitogenic, motogenic and morphogenic activities in epithelial cells and it also has tumor-suppressing activities. Induction of HGF production may be involved in organ regeneration, wound healing and embryogenesis. We examined the effects of ascorbic acid (AsA), which stimulates the proliferation of fibroblasts, and its stable derivative, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), on HGF production by human skin fibroblasts. Basal HGF secretion was significantly stimulated by more than 0.1 mM AsA or AA-2G. Both vitamins synergistically enhanced HGF secretion stimulated by growth factors such as epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF), cholera toxin and other inducers. Induction by EGF or bFGF was most markedly potentiated by the vitamins. HGF production by the KG-1 human leukemia cell line was also augmented by AsA or AA-2G. Another stable AsA derivative, ascorbic acid 2-phosphate (AA-2P) effectively promoted basal and EGF-induced HGF secretion by the fibroblasts, but ascorbic acid 2-sulfate (AA-2S) was much less effective. Intracellular AsA levels increased after the addition of AA-2G and AA-2P as well as AsA, but not after AA-2S. The effect of AA-2G was completely abrogated by the simultaneous addition of castanospermine, an alpha-glucosidase inhibitor, suggesting that the active form of AA-2G is AsA. Constitutive and EGF-induced HGF gene expression was also up-regulated after adding AsA or AA-2G to the cells. These results indicated that AsA acts alone or in synergy with several inducers to stimulate the production and gene expression of HGF in human skin fibroblasts and that the stable AsA derivative AA-2G is as effective as AsA in promoting HGF production. PMID:10984304

Wu, Y L; Gohda, E; Iwao, M; Matsunaga, T; Nagao, T; Takebe, T; Yamamoto, I

1998-10-01

315

The action of the couple ascorbic acid--Cu(II) on NAD(+)-coenzymatic function.  

Science.gov (United States)

The coenzymatic capacity of NAD+ decreases by exposing it to the action of ascorbic acid--Cu(II) system, a generator of free radicals. The participation of the radicals in degrading NAD+ depends on the nature of the buffer, incubation medium pH, temperature, incubation time. Thiourea, IK, GSH, cysteine, mannitol, albumine reduce to different extents the noxious action of the radicals. The decrease of the coenzymatic function of NAD+ is caused by the break of esther and anhydride links, evidenced by releasing th cian-sensitive compounds--nicotinamide riboside and nicotinamide ribonucleotide. Also the presence of ortophosphate was demonstrated. PMID:1823402

Filip, M; P?duraru, I

1991-01-01

316

Genetic evidence for the role of GDP-mannose in plant ascorbic acid (vitamin C) biosynthesis  

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Vitamin C (l-ascorbic acid; AsA) acts as a potent antioxidant and cellular reductant in plants and animals. AsA has long been known to have many critical physiological roles in plants, yet its biosynthesis is only currently being defined. A pathway for AsA biosynthesis that features GDP-mannose and l-galactose has recently been proposed for plants. We have isolated a collection of AsA-deficient mutants of Arabidopsis thaliana that are valuable tools for testing of an AsA biosynthetic pathway....

Conklin, Patricia L.; Norris, Susan R.; Wheeler, Glen L.; Williams, Elizabeth H.; Smirnoff, Nicholas; Last, Robert L.

1999-01-01

317

Excitability scores of goats administered ascorbic acid and transported during hot-dry conditions  

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In this study, we investigated the effect of ascorbic acid (AA) administration on goat excitability due to transportation. Ten goats administered AA (p.o.) at 100 mg/kg of body weight before transportation served as the experimental group, and seven goats administered only 10ml/kg of sterile water (p.o.) served as controls. Excitability scores were recorded for each goat; when weighed, before, immediately after, and 3 h after 8 h of transportation. A score of one to four was allocated to each...

Ayo, J. O.; Minka, N. S.; Mamman, M.

2006-01-01

318

Ascorbic Acid and the Brain: Rationale for the Use against Cognitive Decline  

Science.gov (United States)

This review is focused upon the role of ascorbic acid (AA, vitamin C) in the promotion of healthy brain aging. Particular attention is attributed to the biochemistry and neuronal metabolism interface, transport across tissues, animal models that are useful for this area of research, and the human studies that implicate AA in the continuum between normal cognitive aging and age-related cognitive decline up to Alzheimer’s disease. Vascular risk factors and comorbidity relationships with cognitive decline and AA are discussed to facilitate strategies for advancing AA research in the area of brain health and neurodegeneration.

Harrison, Fiona E.; Bowman, Gene L.; Polidori, Maria Cristina

2014-01-01

319

Influence of heating conditions and ascorbic acid concentration over furan formation in starchy model systems  

DEFF Research Database (Denmark)

Furan, a potential carcinogen, can be formed in foods processed at high temperatures such as coffee, baby foods, bread and snacks. Although there is still no clarity about the risks associated with the current intake levels of dietary furan, to limit the furan occurrence in foods may be considered as a challenge in the prevention of human diseases as cancer. Considering that heat processed starchy products are characterized by their high worldwide consumption, we decided to dig into the mechanisms that would define their final content of furan. The present study explored the effect of heating conditions (frying and baking) and ascorbic acid concentration over furan occurrence in a starchy model system. Two different formulations of wheat flour dough (WF: wheat flour and WF-AA: wheat flour and ascorbic acid) were prepared with a 40 % of moisture (wb). Then, dough were cut in circle chips (40 mm of diameter ; 2.3 mm of thickness) which were fried and baked at 170°C and 200°C for 5, 7 and 9 minutes. Furan contents of heat processed products were quantified by GC-MS. WF fried products contained higher furan levels than baked ones for all different processing times (e.g. 97 % higher furan in 5 minutes fried chips). For the case of WF-AA chips baking produced more furan compared to the frying (e.g. 58 % higher furan in 7 minutes baked chips). For all process conditions ascorbic acid addition produced an increase in furan levels (̴17%-58% in frying and ̴74-98 % in baking). As for Maillard reactions in general, for all samples, an increase in furan level was observed when the moisture content decreased. Additionally, in fried products furan level was directly proportional to their oil uptake. We conclude that for the present model conditions, ascorbic acid improves the furan generation, having a stronger effect in baked products. We also propose that while lipid oxidation has been considered as one of main furan generation routes, for this particular case, it should not have a greater influence over furan formation; since frying experiments were realized with commercial sunflower oil with added antioxidant. Finally, considering that furan is an unpolar compound, for fried product the oil uptake may be responsible for the higher furan retention.

Mariotti, Salomé; Granby, Kit

320

Stability in fish feed and bioavailability to rainbow trout of two ascorbic acid forms  

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The stability in warm pelleted fish feed and the bioavailability to rainbow trout of crystalline ascorbic acid (AA) and a synthetic polymer-coated AA product (PCAA) were compared. The AA loss during pelleting was 29% for crystalline AA and 19% for PCAA. After 6 weeks at room temperature 73% of PCAA was still retained whereas less than 10% of crystalline AA was left. Rainbow trout were deprived of AA for 8 weeks, and then supplemented with AA from crystalline AA and PCAA, respectively. At the ...

Skelbaek, T.; Andersen, Niels Gerner; Winning, M.; Westergaard, S.

2011-01-01

 
 
 
 
321

Simultaneous Chronoamperometric Sensing of Ascorbic Acid and Acetaminophen at a Boron-Doped Diamond Electrode  

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Cyclic voltammetry (CV) and chronoamperometry (CA) have been used to sense and determine simultaneously L-ascorbic acid (AA) and acetaminophen (AC) at a boron-doped diamond electrode (BDDE) in a Britton-Robinson buffer solution. The calibration plots of anodic current peak versus concentration obtained from CV and CA data for both investigated compounds in single and di-component solutions over the concentration range 0.01 mM – 0.1 mM proved to be linear, with very good correlati...

2008-01-01

322

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

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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

323

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

324

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

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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 i...

2013-01-01

325

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

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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

326

Ascorbic Acid and the Brain: Rationale for the Use against Cognitive Decline  

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Full Text Available This review is focused upon the role of ascorbic acid (AA, vitamin C in the promotion of healthy brain aging. Particular attention is attributed to the biochemistry and neuronal metabolism interface, transport across tissues, animal models that are useful for this area of research, and the human studies that implicate AA in the continuum between normal cognitive aging and age-related cognitive decline up to Alzheimer’s disease. Vascular risk factors and comorbidity relationships with cognitive decline and AA are discussed to facilitate strategies for advancing AA research in the area of brain health and neurodegeneration.

Fiona E. Harrison

2014-04-01

327

Protective Effects of Extract from Dates (Phoenix Dactylifera L. and Ascorbic Acid on Thioacetamide-Induced Hepatotoxicity in Rats  

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Full Text Available The ameliorative activity of aqueous extract of the flesh of dates (Phoenix dactylifera L. and ascorbic acid on thioacetamide-induced hepatotoxicity was studied in rats. Sixty male rats were divided into six equal groups of 10. Two groups were controls, one treated with thioacetamide and one with only distilled water. Two groups received extract of flesh Phoenix dactylifera and intraperitoneal (IP thioacetamide (400 mg/kg either before or after administration of flesh extract. Two groups received ascorbic acid and intraperitoneal (IP thioacetamide (400 mg/kg b.wt. either before or after administration of ascorbic acid. Liver damage was assessed by estimation of plasma concentration of bilirubin and enzymes activities of aspartate aminotransferase (AST, alanine aminotransferase ( ALT, lactate dehydrogenase (LDH, ? glutamyl transferase and alkaline phosphatase and serum alpha fetoprotein and serum total testosterone. Treatment with aqueous extract of date flesh or by ascorbic acid significantly reduced thioacetamide-induced elevation in plasma bilirubin concentration and enzymes. This study suggests that thioacetamide-induced liver damage in rats can be ameliorated by administration of extract of date flesh and ascorbic acid.

Mohamed Bastway Ahmed

2008-01-01

328

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

329

Electrochemical Preparation of a Molecularly Imprinted Polypyrrole-modified Pencil Graphite Electrode for Determination of Ascorbic Acid  

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Full Text Available A molecularly imprinted polymer (MIP polypyrrole (PPy-based film was fabricated for the determination of ascorbic acid. The film was prepared by incorporation of a template molecule (ascorbic acid during the electropolymerization of pyrrole onto a pencil graphite electrode (PGE in aqueous solution using a cyclic voltammetry method. The performance of the imprinted and non-imprinted (NIP films was evaluated by differential pulse voltammetry (DPV. The effect of pH, monomer and template concentrations, electropolymerization cycles and interferents on the performance of the MIP electrode was investigated and optimized. The molecularly imprinted film exhibited a high selectivity and sensitivity toward ascorbic acid. The DPV peak current showed a linear dependence on the ascorbic acid concentration and a linear calibration curve was obtained in the range of 0.25 to 7.0 mM of ascorbic acid with a correlation coefficient of 0.9946. The detection limit (3σ was determined as 7.4x10-5 M (S/N=3. The molecularly-imprinted polypyrrole-modified pencil graphite electrode showed a stable and reproducible response, without any influence of interferents commonly existing in pharmaceutical samples. The proposed method is simple and quick. The PPy electrodes have a low response time, good mechanical stability and are disposable simple to construct.

Yücel Sahin

2008-09-01

330

Protective roles of ascorbic acid in oxidative stress induced by depletion of superoxide dismutase in vertebrate cells.  

Science.gov (United States)

Superoxide dismutases (SODs) are antioxidant proteins that convert superoxide to hydrogen peroxide. In vertebrate cells, SOD1 is mainly present in the cytoplasm, with small levels also found in the nucleus and mitochondrial intermembrane space, and SOD2 is present in the mitochondrial matrix. Previously, the authors conditionally disrupted the SOD1 or SOD2 gene in DT40 cells and found that depletion of SOD1 caused lethality, while depletion of SOD2 led to growth retardation. The observations from previous work showed that the lethality observed in SOD1-depleted cells was completely rescued by ascorbic acid. Ascorbic acid is a water-soluble antioxidant present in biological fluids; however, the exact target for its antioxidant effects is not known. In this study, the authors demonstrated that ascorbic acid offset growth defects observed in SOD2-depleted cells and also lowered mitochondrial superoxide to physiological levels in both SOD1- or SOD2-depleted cells. Moreover, depletion of SOD1 or SOD2 resulted in the accumulation of intracellular oxidative stress, and this increased oxidative stress was reduced by ascorbic acid. Taken together, this study suggests that ascorbic acid can be applied as a nontoxic antioxidant that mimics the functions of cytoplasmic and mitochondrial SODs. PMID:23016763

Tamari, Yuki; Nawata, Hisakatsu; Inoue, Eri; Yoshimura, Akari; Yoshii, Hanako; Kashino, Genro; Seki, Masayuki; Enomoto, Takemi; Watanabe, Masami; Tano, Keizo

2013-01-01

331

Nonenzymatic amperometric sensor for ascorbic acid based on hollow gold/ruthenium nanoshells.  

Science.gov (United States)

We report a new nonenzymatic amperometric detection of ascorbic acid (AA) using a glassy carbon (GC) disk electrode modified with hollow gold/ruthenium (hAu-Ru) nanoshells, which exhibited decent sensing characteristics. The hAu-Ru nanoshells were prepared by the incorporation of Ru on hollow gold (hAu) nanoshells from Co nanoparticle templates, which enabled AA selectivity against glucose without aid of enzyme or membrane. The structure and electrocatalytic activities of the hAu-Ru catalysts were characterized by spectroscopic and electrochemical techniques. The hAu-Ru loaded on GC electrode (hAu-Ru/GC) showed sensitivity of 426 ?A mM(-1) cm(-2) (normalized to the GC disk area) for the linear dynamic range of <5 ?M to 2 mM AA at physiological pH. The response time and detection limit were 1.6 s and 2.2 ?M, respectively. Furthermore, the hAu-Ru/GC electrode displayed remarkable selectivity for ascorbic acid over all potential biological interferents, including glucose, uric acid (UA), dopamine (DA), 4-acetamidophenol (AP), and nicotinamide adenine dinucleotide (NADH), which could be especially good for biological sensing. PMID:24636416

Jo, Ara; Kang, Minkyung; Cha, Areum; Jang, Hye Su; Shim, Jun Ho; Lee, Nam-Suk; Kim, Myung Hwa; Lee, Youngmi; Lee, Chongmok

2014-03-28

332

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

333

Effects of ascorbic acid enrichment by immersion of rainbow trout (Oncorhynchus mykiss, Walbaum 1792) eggs and embryos  

Science.gov (United States)

This study was conducted to examine the effects of different forms and concentrations of ascorbic acid (vitamin C), and different enrichment times (24 and 48 h post ovulation) on egg, embryo and alevin ascorbate concentrations and survival of rainbow trout (enrichment was at the ova stage). In experiments 1 and 2, fertilized eggs were immersed in water containing ascorbate at 0 (control), 100, 1000 mg L-1 l-ascorbic acid (AA) and 2000 mg L -1 l-ascorbyl monophosphate (AP). In experiment 3, 0 (control), 500 and 1000 mg L-1 AA neutralized (N) with NaOH, 1000 mg L-1 AA non-neutralized (NN), 1000 and 2000 mg L-1 AP immersions were used. The mean total ascorbic acid (TAA) and dehydroascorbic acid (DHA) concentrations were measured before fertilization, at 3 and 24 h after fertilization, at the eyed stage, and in hatched alevins. We observed significant differences in TAA concentration at different immersion levels at 3 and 24 h after fertilization. Survival decreased significantly depending on the level of vitamin C, pH of the solutions and immersion time. We suggest that when broodstock rainbow trout do not have enough vitamin C in their ovaries, immersion of eggs in 1000 mg L-1 of neutralized AA may be useful. ?? 2006 Blackwell Publishing Ltd.

Falahatkar, B.; Dabrowski, K.; Arslan, M.; Rinchard, J.

2006-01-01

334

Influence of poly(ethylene glycol)-alpha-cyclodextrin complexes on stabilization and transdermal permeation of ascorbic acid.  

Science.gov (United States)

The present study was conducted to investigate the effect of poly(ethylene glycol)-alpha-cyclodextrin (alpha-CD) complexes on stabilization and cutaneous permeation of ascorbic acid from specially prepared transdermal patches. Poly(ethylene glycol) citrate (6-armPEG) and its inclusion complex with alpha-CD were prepared and used for preparation of the transdermal patches. Duro-Tak 87-2979 was taken as an adhesive matrix in combination with ascorbic acid. A diffusion cell with an artificial membrane was used to evaluate the absorption of ascorbic acid from the patches. The influence of drug release of alpha-CD and two types of its PEG complexes (as the novel permeation enhancers) was tested. The 6-armPEG-alpha-CD complex consisting of a PEG-citric acid ester at a concentration of 0.08-0.1% (w/v) is a suitable stabilizer for ascorbic acid during UV assay. The release studies showed that the type of enhancer is important in diffusion of the drug across membrane. Furthermore, the diffusion of ascorbic acid was considerably enhanced in the presence of 6-armPEG-alpha-CD complex. Inclusion complexes of 6-armPEG with alpha-CD at a concentration of 0.08-0.1% (w/v) is a suitable stabilizer for UV method of assay. The present data suggest that 6-armPEG-alpha-CD complex is also useful in enhancing the release of ascorbic acid from the acrylic type pressure sensitive adhesives. PMID:16739182

Davaran, Soodabeh; Hanaee, Jalal; Rashidi, Mohammad R; Valiolah, Fatemeh; Hashemi, Mahdi

2006-09-01

335

Effect of Food Supplementation by N and Ascorbic Acid on Larval Mortality of Silkworm (Bombyx mori L.  

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Full Text Available The study was carried out to determine the effect of 0.2 % N in combination with different doses of ascorbic acid (0.025, 0.075, 0.100, 0.125 and 0.150% on larval growth and silk production of silk worm larvae (Bombyx mori L.. The larvae were fed on mulberry leaves treated with given doses of nitrogen and ascorbic acid throughout the larval period. It was observed that all the growth parameter were influenced by food supplementation. The larvae which were offered mulberry leaves treated with 0.2% N + 0.150% ascorbic acid showed lower mean values of body weight, body length, food consumption, coefficient of utilization and cocoon shell ratio but higher mortality rate.

Humayun Javed

2002-01-01

336

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

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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

337

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

338

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

1995-09-18

339

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

Energy Technology Data Exchange (ETDEWEB)

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 /sup 14/C-2, 4-D. The embryo fraction had a lower concentration of /sup 14/C 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.

Earnshaw, B.A.

1986-01-01

340

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

1986-01-01

 
 
 
 
341

Colorimetric determination of thiram based on formation of gold nanoparticles using ascorbic acid.  

Science.gov (United States)

A novel optical method for the determination of thiram has been developed using surface plasmon resonance peak of gold nanoparticles (AuNPs). The stable and dispersed AuNPs were directly synthesized by reduction of HAuCl4 with ascorbic acid in micellar media according to a simple approach. The presence of thiram during formation of AuNPs results in the decrease of the intensity of plasmon resonance peak. The variation in the plasmon absorbance allows the colorimetric determination of thiram. The effect of different variables such as pH, ascorbic acid and CTAB concentrations was studied and optimized. The proposed method is capable of determining thiram over a range of 2.0×10(-7)-1.0×10(-5) mol L(-1) with a limit of detection 1.7×10(-7) mol L(-1). The relative standard deviation of the method was <3.7%. The method was successfully applied to the determination of thiram in water and plant seed samples. PMID:23597883

Rastegarzadeh, S; Abdali, Sh

2013-01-30

342

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

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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

343

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

344

An isocratic HPLC method for the simultaneous determination of novel stable lipophilic ascorbic acid derivatives and their metabolites.  

Science.gov (United States)

2-O-alpha-D-glucopyranosyl-6-O-hexadecanoyl-L-ascorbic acid (6-sPalm-AA-2G), a novel stable lipophilic ascorbic acid derivative, was hydrolyzed to 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), ascorbyl 6-palmitate (6-sPalm-AA) and ascorbic acid (AA) with alpha-glucosidase and lipase. An HPLC method for the simultaneous determination of AA, AA-2G, 6-sPalm-AA and 6-sPalm-AA-2G was developed using a cyanopropyl column with an isocratic solution of methanol-phosphate buffer (pH 2.1) (65:35, v/v) containing 20mg/l of dithiothreitol at a detection wavelength of 240 nm. The calibration curves were found to be linear in the range of 10-200 microM. Linear regression analysis of the data demonstrated the efficacy of the method in terms of precision and accuracy. This method was satisfactorily applied to the determination of 6-sPalm-AA-2G and its three metabolites in a 6-sPalm-AA-2G solution treated with purified enzymes or a small intestine post-mitochondrial supernatant and to the separation of novel stable lipophilic AA derivatives other than 6-sPalm-AA-2G and their metabolites. AA, AA-2G and other well-known stable AA derivatives, ascorbic acid 2-phosphate and ascorbic acid 2-sulfate, were also separated under the same conditions. The results show that the procedure is rapid and simple and that it can be employed for in vitro metabolic analysis of various AA derivatives. PMID:16822727

Tai, Akihiro; Takebayashi, Jun; Ueno, Ayako; Gohda, Eiichi; Yamamoto, Itaru

2006-08-01

345

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

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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

346

Ascorbate recycling in human neutrophils: Induction by?bacteria  

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Ascorbate (vitamin C) recycling occurs when extracellular ascorbate is oxidized, transported as dehydroascorbic acid, and reduced intracellularly to ascorbate. We investigated microorganism induction of ascorbate recycling in human neutrophils and in microorganisms themselves. Ascorbate recycling was determined by measuring intracellular ascorbate accumulation. Ascorbate recycling in neutrophils was induced by both Gram-positive and Gram-negative pathogenic bacteria, and the fungal pathogen C...

1997-01-01

347

Ozone affects ascorbate and glutathione biosynthesis as well as amino acid contents in three Euramerican poplar genotypes.  

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Ozone is an air pollutant that causes oxidative stress by generation of reactive oxygen species (ROS) within the leaf. The capacity to detoxify ROS and repair ROS-induced damage may contribute to ozone tolerance. Ascorbate and glutathione are known to be key players in detoxification. Ozone effects on their biosynthesis and on amino acid metabolism were investigated in three Euramerican poplar genotypes (Populus deltoides Bartr.?×?Populus nigra L.) differing in ozone sensitivity. Total ascorbate and glutathione contents were increased in response to ozone in all genotypes, with the most resistant genotype (Carpaccio) showing an increase of up to 70%. Reduced ascorbate (ASA) concentration at least doubled in the two most resistant genotypes (Carpaccio and Cima), whereas the most sensitive genotype (Robusta) seemed unable to regenerate ASA from oxidized ascorbate (DHA), leading to an increase of 80% of the oxidized form. Increased ascorbate (ASA?+?DHA) content correlated with the increase in gene expression in its biosynthetic pathway, especially the putative gene of GDP-l-galactose phosphorylase VTC2. Increased cysteine availability combined with increased expression of ?-glutamylcysteine synthetase (GSH1) and glutathione synthetase (GSH2) genes allows higher glutathione biosynthesis in response to ozone, particularly in Carpaccio. In addition, ozone caused a remobilization of amino acids with a decreased pool of total amino acids and an increase of Cys and putrescine, especially in Carpaccio. In addition, the expression of genes encoding threonine aldolase was strongly induced only in the most tolerant genotype, Carpaccio. Reduced ascorbate levels could partly explain the sensitivity to ozone for Robusta but not for Cima. Reduced ascorbate level alone is not sufficient to account for ozone tolerance in poplar, and it is necessary to consider several other factors including glutathione content. PMID:24682617

Dumont, Jennifer; Keski-Saari, Sarita; Keinänen, Markku; Cohen, David; Ningre, Nathalie; Kontunen-Soppela, Sari; Baldet, Pierre; Gibon, Yves; Dizengremel, Pierre; Vaultier, Marie-Noëlle; Jolivet, Yves; Oksanen, Elina; Le Thiec, Didier

2014-03-01

348

Voltammetric Sensing of Uric Acid and Ascorbic Acid with Poly (p-toluene sulfonic acid Modified Electrode  

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Full Text Available Glassy carbon electrode (GCE is modified with electropolymerized films of p-toluene sulfonic acid (pTSA. This polymer (pTSA modified electrode is used to electrochemically detect uric acid (UA in the presence of ascorbic acid (AA and shows an excellent electrocatalyticl effect on the oxidation of UA and AA by cyclic voltammetry (CV. In differential pulse voltammetric measurements (DPV, the polymer (pTSA modified electrode could separate the oxidation peak potentials of UA and AA present in the same solution by about 300 mV though the bare electrode gave a single broad response. A successful elimination of the fouling effect by the oxidized product of AA on the response of UA has been achieved at the polymer (pTSA modified electrode. The detection limit of UA in the presence of AA at millimolar level was 5.0 × 10-7 M. The modified electrode exhibits the stable and sensitive response to UA.

Liang Wang, Pengfei Huang, Junyue Bai, Hongjing Wang, Xiaowei Wu, Yuqing Zhao

2006-10-01

349

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

350

Stimulation of collagen production in vitro by ascorbic acid released from explants of migrating avian neural crest.  

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Embryonic neuronal tissues contain a collagen-stimulating factor, shown to enhance the hydroxylation and secretion of proline-containing macromolecules by cultured muscle cells. Here we report on a similar activity found during avian embryonic development in explants of migrating mesencephalic neural crest. The degree of proline hydroxylation of proteins secreted into the medium was stimulated 2.5-6-fold in neural crest-muscle and neural crest-somite cocultures, as compared with control cultures devoid of crest explants. No such stimulation occurred when cocultures were treated with the enzyme ascorbate oxidase (EC 1.10.3.3), suggesting that the active factor in neural crest explants was ascorbic acid or an ascorbate-like molecule. Further characterization of this molecule was performed in crest explants and other embryonic tissues by using HPLC with amperometric detection: this study revealed that migrating cephalic neural crest contains 1.5 micrograms ascorbic acid per mg protein. Our results suggest that ascorbic acid and/or related molecule(s) could act during development of the nervous system as a trigger for collagen production and subsequent assembly of an extracellular matrix. PMID:2830031

Kalcheim, C; Leviel, V

1988-01-01

351

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

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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...

2013-01-01

352

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

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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

353

Effects of the ascorbic acid supplementation on NADH-diaphorase myenteric neurons in the duodenum of diabetic rats  

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We assessed the ascorbic acid (AA) supplementation on the myenteric neurons in the duodenum of rats. Fifteen rats with 90 days of age were divided into three groups: control (C), diabetics (D) and ascorbic acid treated diabetics (DA). After 120 days of daily treatment with AA, the duodenum was submitted to the NADH-diaphorase (NADH-d) histochemical technique, which allowed us to evaluate the neuronal density in an area of 8.96 mm² for each duodenum, and also to measure the cellular profile a...

Marli Aparecida Dos Santos Pereira; Maria Claúdia Bagatin; Jacqueline Nelisis Zanoni

2006-01-01

354

Efeito do ácido ascórbico em massa de pão na presença do ácido tânico = Effect of ascorbic acid in bread dough in the presence of tannic acid  

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Full Text Available Pães de farinha de trigo com adição do agente oxidante ácido ascórbico foram elaborados, tentando-se encontrar a concentração de ácido tânico que melhor retivesse o ácido ascórbico, sem afetar significativamente as características reológicas e os principaisatributos sensoriais do pão. Os pães foram elaborados com a formulação de pão-padrão. Na primeira etapa, determinou-se a concentração de ácido ascórbico que melhor proporcionasse estabilidade à massa de pão-padrão (300 ppm. Na etapa seguinte, foramutilizadas na formulação da massa-padrão três concentrações diferentes de ácido tânico: 0,10; 0,20 e 0,30%, com a finalidade de se verificar a concentração que melhor retivesse o ácido ascórbico. Os pães foram elaborados com a formulação-padrão. Após o resfriamentodos pães, foi avaliada a retenção de ácido ascórbico, presente no pão de acordo com a concentração previamente determinada. Os resultados indicaram que o pão elaborado com a massa de pão-padrão (300 ppm de ácido ascórbico apresentou concentração de ácido ascórbico de 41,50 mg 100 g-1 de pão.Wheat flour breads with the addition of oxidizing agent ascorbic acid were elaborated trying to find the concentrations of tannic acid that best retained the ascorbic acid without significantly affecting the rheologic characteristics and main sensorial attributes of bread. Inthe first stage, the concentration of ascorbic acid that best provided stability to the dough (300 ppm was determined. In the following stage, three different concentrations of tannic acid were used: 0.10, 0.20 and 0.30%, with the purpose of verifying the ascorbic acid retention in the dough. The breads were elaborated with the standard formulation. After the elaboration of the breads, the ascorbic acid retention was evaluated in the previously determined concentration. The results showed that the bread elaborated with standard dough (300 ppm of ascorbic acid, presented ascorbic acid concentration of 41.50 mg 100 g-1 of bread.

Ana Leticia Gomes Saraiva

2010-07-01

355

The metabolism of L-[6-"1"4C] 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 C_4 and, presumably, a C_2 fragment. Leaves taken from this position 14 days after anthesis fail to cleave AA. The C_4 fragment is utilized for L(+)-tartaric acid (TA) biosynthesis while the C_2 fragment is recycled into hexose and products of the hexose metabolism. When ( 6-"1"4C ) AA is the source of the label, the sucrose-drived glucose from labeled leaves has a distribution of "1"4C 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-"1"4C ) AA metabolism is examined. (author)

1979-01-01

356

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.

2010-06-15

357

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

2014-06-01

358

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

2013-01-15

359

Lipoic acid and ascorbic acid affect plasma free amino acids selectively in the teleost fish pacu (Piaractus mesopotamicus).  

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Most studies on the antioxidants, lipoic acid (LA) and ascorbic acid (AA), focused on species that, unlike teleost fish, are not scurvy-prone, and are able to synthesize AA. The antioxidant properties of LA may make it useful in aquaculture nutrition, but several effects must first be investigated, and we address here plasma free amino acids (FAA). In mammals, LA and AA in high doses were claimed to alter plasma FAA profile; to our knowledge, however, no data are available in fish. We therefore studied the effects of dietary LA and AA on plasma FAA in the South American teleost fish pacu, which is being used increasingly in aquaculture. LA treatment decreased concentrations of 18 of 23 individual FAA; specifically, dispensable and total FAA were significantly affected. Ornithine was elevated (+26%) in LA-treated fish and significantly decreased ratios of plasma [Arg]/[Orn] and other individual [FAA]/[Orn] were observed. LA and AA both affected sulfur FAA concentrations. Plasma cystine levels were significantly increased in the LA-supplemented groups. AA had little effect on most amino acids, and no interaction with LA was detected. AA supplementation did, however, significantly lower taurine (-42%) and cystathionine (-31%) levels in plasma. No effect on the branched chain:aromatic amino acid ratios was observed. The data indicate that at the dietary level studied, LA and AA independently affect selected plasma FAA in pacu, and suggest that any use of LA in particular as a dietary supplement should take into account an altered plasma FAA profile. PMID:15514254

Terjesen, Bendik F; Park, Kwan; Tesser, Marcelo B; Portella, Maria C; Zhang, Yongfang; Dabrowski, Konrad

2004-11-01

360

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

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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

 
 
 
 
361

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

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Full Text Available 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 height and ascorbic acid concentration within the range 0.31-20 mM with a Pt working electrode, and within the range 0.07-20 mM with a carbon paste working electrode. The equation of the calibration graph was y = 21.839x + 35.726, r2 = 0.9940, when a Pt strip electrode was used (where y represents the value of the current intensity measured for the peak height, expressed as µA and x the analyte concentration, as mM. R.S.D. = 2.09%, n = 10, Cascorbic acid = 2.5 mM. The equation of the calibration graph was y = 3.4429x + 5.7334, r2 = 0.9971, when a carbon paste electrode was used (where y represents the value of intensity measured for the peak height, expressed as µA and x the analyte concentration, as mM. R.S.D. = 2.35%, n = 10, Cascorbic acid = 2.5 mM. The developed method was applied to ascorbic acid assessment in fruit juices and wine. The ascorbic acid content determined ranged between 6.83 mg/100 mL juice for soft drinks (Fanta Madness and 54.74 mg/100 mL for citrus (lemon juices obtained by squeezing fruit. Different ascorbic acid concentrations (from standard solutions were added to the analysed samples, the degree of recovery being comprised between 94.74 and 104.97%. The results of ascorbic acid assessment by differential pulse voltammetry were compared with those obtained by cyclic voltammetry. The results obtained by the two methods were in good agreement.

Aurel Pisoschi

2011-02-01

362

Anti-atherogenic effects of a mixture of ascorbic acid, lysine, proline, arginine, cysteine, and green tea phenolics in human aortic smooth muscle cells.  

Science.gov (United States)

Certain drastic behavioral modifications by arterial wall smooth muscle cells (SMC) have been considered key steps in the formation of atherosclerotic lesions: massive migration of SMC from the media to the intima layer of the vessel, dedifferentiation of SMC to proliferating phenotype, and increased secretion of inflammatory cytokines as a response to inflammatory stimuli. We investigated the anti-atherogenic effects of naturally occurring compounds (ascorbic acid, green tea extract, lysine, proline, arginine, and N-acetyl cysteine) using the model of cultured aortic SMC. Cell growth was measured by DNA synthesis, cell invasiveness was measured through Matrigel, matrix metalloproteinase-2 (MMP-2) secretion was measured by zymography, and SMC secretion of monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) was measured by immunochemistry. Fetal bovine serum-stimulated SMC growth was inhibited by the nutrient mixture (NM) with 85% inhibition at 100 microg/mL. A corresponding concentration of epigallocatechin gallate (EGCG; 15 microM), the most active tea phenolic, produced a significant effect but one lower than NM. NM inhibited aortic SMC Matrigel invasion in a dose-dependent manner and significantly decreased MMP-2 expression. Stimulation of SMC with tumor necrosis factor-alpha significantly increased production and secretion of such mediators of inflammation as IL-6 and MCP-1; addition of 100 microg/mL NM inhibited secretion of MCP-1 and IL-6 by 65% and 47%, respectively. These data suggest that the NM of ascorbic acid, tea phenolics, and selected amino acids has potential in blocking the development of atherosclerotic lesions by inhibiting atherogenic responses of vascular SMC to pathologic stimuli and warrants in vivo studies. PMID:17414225

Ivanov, Vadim; Roomi, M Waheed; Kalinovsky, T; Niedzwiecki, Aleksandra; Rath, Matthias

2007-03-01

363

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

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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

364

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  

Science.gov (United States)

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.

2014-01-01

365

Ácido L-ascórbico: reações de complexação e de óxido-redução com alguns íons metálicos de transição L-ascorbic acid: complexation and redox reactions with some transition metal ions  

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The strong reducing action of L-ascorbic acid (Vitamin C) are of fundamental interest in biochemical and related process. The oxidation of ascorbic acid by molecular oxygen and others oxidants are of fundamental importance, involving the intervention of transition metal ions as catalysts and the formation transition metal complexes of ascorbic acid as intermediates. The present article is intended to cover some aspects of the reactions of ascorbic acid and rel...

1998-01-01

366

Ácido L-ascórbico: reações de complexação e de óxido-redução com alguns íons metálicos de transição L-ascorbic acid: complexation and redox reactions with some transition metal ions  

Directory of Open Access Journals (Sweden)

Full Text Available The strong reducing action of L-ascorbic acid (Vitamin C are of fundamental interest in biochemical and related process. The oxidation of ascorbic acid by molecular oxygen and others oxidants are of fundamental importance, involving the intervention of transition metal ions as catalysts and the formation transition metal complexes of ascorbic acid as intermediates. The present article is intended to cover some aspects of the reactions of ascorbic acid and related compounds involving some transition metal ions.

Adalgiza Fornaro

1998-10-01

367

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

2013-12-15

368

Quantificação dos isômeros ácido L-ascórbico e ácido D-iso-ascórbico em geleias de frutas por cromatografia líquida de alta eficiência Quantification of L-ascorbic acid and D-iso-ascorbic acid in jellies fruit by high performance liquid chromatography  

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Full Text Available Ascorbic acid has important nutritional characteristics such as high antioxidant potential, preventing diverse damage and diseases in the tissues and the process of aging. Different isomeric forms of the ascorbic acid can be found in nature and each one have different potential antioxidant and different activity pro-vitamin C. This work examined a method to detect and quantify the isomers L-ascorbic acid (LAA and D-iso-ascorbic acid (DIAA in jelly fruit. The method showed acceptable selectivity, linearity, repeatability and recovery. DIAA was not found in the analyzed samples, but LAA was found up to 605 mg in 100 g of sample.

Raquel Grando de Oliveira

2012-01-01

369

Proteomic analysis of tumor tissue in CT-26 implanted BALB/C mouse after treatment with ascorbic acid.  

Science.gov (United States)

Tumor establishment and penetration consists of a series of complex processes involving multiple changes in gene expression and protein modification. Proteome changes of tumor tissue were investigated after intraperitoneal administration of a high concentration of ascorbic acid in BALB/C mice implanted with CT-26 cancer cells using two-dimensional gel electrophoresis and mass spectrometry. Eighteen protein spots were identified whose expression was different between control and ascorbic acid treatment groups. In particular, eukaryotic translation initiation factor 3 subunit 1, nucleophosmin, latexin, actin-related protein 2/3 complex subunit 5, M2-type pyruvate kinase, vimentin, tumor protein translationally-controlled 1, RAS oncogene family Ran, plastin 3 precursor, ATPase, Rho GDT dissociation inhibitor ?, and proteasome activator subunit 2 expression were quantitatively up-regulated. The increase in the level of these proteins was accompanied by an increase in mRNA level. The cytoskeleton protein actin, vimentin, and tumor protein translationally-controlled 1 showed quantitative expression profile differences. A change in actin cytoskeleton distribution, functionally relevant to the proteome result, was observed after treatment with ascorbic acid. These results suggest a previously undefined role of ascorbic acid in the regulation of cytoskeleton remodeling in tumor tissues. PMID:22139585

Lee, Jihye; Lee, Gunsup; Park, Jin Hee; Lee, Sukchan; Yeom, Chang-Hwan; Na, Byungjo; Park, Seyeon

2012-03-01

370

The Effect of Ascorbic Acid on the Substantivity of Tetraclean in Sodium Hypochlorite-Treated Bovine Dentin  

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Full Text Available Objective: The purpose of this study was to assess the in vitro effect of ascorbic acid on the antibacterial substantivity of Tetraclean in bovine root dentin pretreated with sodium hypochlorite (NaOCl.Materials and Methods: Eighty dentin tubes prepared from bovine incisor teeth were infected with Enterococcus faecalis for 14 days. The specimens were divided into five groups as follows: Tetraclean; 5.25% NaOCl/Tetraclean; 5.25% NaOCl/ascorbic acid/Tetraclean; infected dentin tubes (positive control; and sterile dentin tubes (negative control. At experimental times of 0, 7, 14, 21 and 28 days, dentin chips were removed from the canals by sequential sterile low-speed round burs with increasing diameters of 025, 027, 029, 031 and 033 ISO sizes, respectively. After culturing, the number of colony-forming units (CFU was counted.Results: In all experimental groups, the number of CFU was minimum in the first cultures and the results obtained were significantly different at any time period (p 0.05.Conclusion: Ascorbic acid prevents the decrease of residual antibacterial activity of Tetraclean in dentin samples pretreated with NaOCl.Keywords: Ascorbic Acid; Enterococcus Faecalis; Pretreatment; Sodium Hypochlorite; Substantivity; Tetraclean

Z. Mohammadi

2012-01-01

371

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 M

2004-01-15

372

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

373

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

374

Effect of ascorbic acid on long-term cold exposure induced changes in thyroid activity in sprague dawley rats  

International Nuclear Information System (INIS)

Objective: To determine the effect of ascorbic acid supplementation on long-term cold exposure induced changes in thyroid activity in Sprague-Dawley rats. Study Design: Experimental study. Place and Duration of Study: Physiology Department of Islamic International Medical College, Rawalpindi, National Institute of Health, Islamabad and Railway Hospital, Rawalpindi, from January to December 2009. Methodology: Ninety Sprague-Dawley rats were randomly divided into three groups of control, cold exposed and cold exposed along with ascorbic acid supplementation. After one month, their thyroid levels were analyzed by using chemiluminescent immunometric Assay on Siemens Immulite 2000 Analyzer. Results: After 4 weeks of cold exposure to experimental animals, the thyroid activity was raised significantly in the cold exposed group as compared to the control group (p-value for T3 difference = 0.004, T4 difference = 0.002 and TSH difference < 0.001). Supplementation with ascorbic acid in the third group normalized the thyroid hormone activity with p-value for difference in levels of T3 being 0.6661, T4 = 0.027 and TSH = 0.0028. Conclusion: Ascorbic acid prevented the cold induced changes in thyroid hormone levels in rodents. (author)

2013-09-01

375

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

376

Highly efficient differentiation of embryonic stem cells into adipocytes by ascorbic acid.  

Science.gov (United States)

Adipocyte differentiation and function have become the major research targets due to the increasing interest in obesity and related metabolic conditions. Although, late stages of adipogenesis have been extensively studied, the early phases remain poorly understood. Here we present that supplementing ascorbic acid (AsA) to the adipogenic differentiation cocktail enables the robust and efficient differentiation of mouse embryonic stem cells (mESCs) to mature adip