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Sample records for intravenous ascorbic acid

  1. Oxalic acid excretion after intravenous ascorbic acid administration

    Science.gov (United States)

    Robitaille, Line; Mamer, Orval A.; Miller, Wilson H.; Levine, Mark; Assouline, Sarit; Melnychuk, David; Rousseau, Caroline; Hoffer, L. John

    2012-01-01

    Ascorbic acid is frequently administered intravenously by alternative health practitioners and, occasionally, by mainstream physicians. Intravenous administration can greatly increase the amount of ascorbic acid that reaches the circulation, potentially increasing the risk of oxalate crystallization in the urinary space. To investigate this possibility, we developed gas chromatography mass spectrometry methodology and sampling and storage procedures for oxalic acid analysis without interference from ascorbic acid and measured urinary oxalic acid excretion in people administered intravenous ascorbic acid in doses ranging from 0.2 to 1.5 g/kg body weight. In vitro oxidation of ascorbic acid to oxalic acid did not occur when urine samples were brought immediately to pH less than 2 and stored at –30°C within 6 hours. Even very high ascorbic acid concentrations did not interfere with the analysis when oxalic acid extraction was carried out at pH 1. As measured during and over the 6 hours after ascorbic acid infusions, urinary oxalic acid excretion increased with increasing doses, reaching approximately 80 mg at a dose of approximately 100 g. We conclude that, when studied using correct procedures for sample handling, storage, and analysis, less than 0.5% of a very large intravenous dose of ascorbic acid is recovered as urinary oxalic acid in people with normal renal function. PMID:19154961

  2. Phase I safety trial of intravenous ascorbic acid in patients with severe sepsis

    Science.gov (United States)

    2014-01-01

    Background Parenterally administered ascorbic acid modulates sepsis-induced inflammation and coagulation in experimental animal models. The objective of this randomized, double-blind, placebo-controlled, phase I trial was to determine the safety of intravenously infused ascorbic acid in patients with severe sepsis. Methods Twenty-four patients with severe sepsis in the medical intensive care unit were randomized 1:1:1 to receive intravenous infusions every six hours for four days of ascorbic acid: Lo-AscA (50 mg/kg/24 h, n = 8), or Hi-AscA (200 mg/kg/24 h, n = 8), or Placebo (5% dextrose/water, n = 8). The primary end points were ascorbic acid safety and tolerability, assessed as treatment-related adverse-event frequency and severity. Patients were monitored for worsened arterial hypotension, tachycardia, hypernatremia, and nausea or vomiting. In addition Sequential Organ Failure Assessment (SOFA) scores and plasma levels of ascorbic acid, C-reactive protein, procalcitonin, and thrombomodulin were monitored. Results Mean plasma ascorbic acid levels at entry for the entire cohort were 17.9 ± 2.4 μM (normal range 50-70 μM). Ascorbic acid infusion rapidly and significantly increased plasma ascorbic acid levels. No adverse safety events were observed in ascorbic acid-infused patients. Patients receiving ascorbic acid exhibited prompt reductions in SOFA scores while placebo patients exhibited no such reduction. Ascorbic acid significantly reduced the proinflammatory biomarkers C-reactive protein and procalcitonin. Unlike placebo patients, thrombomodulin in ascorbic acid infused patients exhibited no significant rise, suggesting attenuation of vascular endothelial injury. Conclusions Intravenous ascorbic acid infusion was safe and well tolerated in this study and may positively impact the extent of multiple organ failure and biomarkers of inflammation and endothelial injury. Trial registration ClinicalTrials.gov identifier NCT01434121. PMID

  3. 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 ...

  4. Evaluation of the Effects of Intravenous Ascorbic Acid on Correction of Anemia in Renal Failure Patients Undergoing Hemodialysis

    Directory of Open Access Journals (Sweden)

    AA Shojaie

    2006-04-01

    Full Text Available Introduction: Hemodialysis patients often develop resistance to recombinant human erythropoietin due to functional Iron Deficiency. In these patients iron therapy can be hazardous leading to hemosiderosis. Recent studies have suggested that intravenous ascorbic acid may be able to improve this hyporeponsiveness. The aim of this study was to evaluate the effect of intravenous ascorbic acid on functional iron deficiency and whether it results in better correction of anemia or not. Methods: Forty hemodialysis patients with serum ferritin >300ug/l, hemoglobin less than 10 gm/dl, and transferrin saturation less than 20% were selected. The reticulocyte index and KT/V was also calculated. Patients were later administered 500 mg intravenous ascorbic acid three times a week for three months. At the end of study, serum ferritin, transferrin saturation, hemoglobin, reticulocyte index and KT/V were rechecked and compared with the base line values by before and after method. Results: Serum ferritin decreased significantly (median base line ferritin 480.45 ug/dl as compared to final ferritin level of 363.78 (P=0.0001, whereas there was a significant rise in hemoglobin concentration (median baseline hemoglobin 8.92 gm/dl compared to 9.88gm/dl (P=0.0001. Transferrin saturation was also significantly raised (median baseline transferrin saturation 17.35% as compared to final level of 25.12% (P= 0.0001. KT/V before and after treatment with ascorbic acid had no significant change (P =0.396. Finally, the rate of decrease in serum ferritin and increase in hemoglobin according to age and duration of dialysis was studied. The effect of ascorbic acid was found to be significantly greater in older patients and those with longer duration of dialysis (P <0.05; but there was no significant relationship between transferrin saturation increase and age or duration of dialysis. Conclusion: Intravenous ascorbic acid may partially correct functional iron deficiency, although

  5. Ascorbic acid in bronchial asthma

    African Journals Online (AJOL)

    1983-04-23

    Apr 23, 1983 ... by comparing the pre-ascorbic acid results with those obtained 21/2 hours after the intravenous ... (ASO), C-reactive protein and antibodies to certain respiratory viruses. These investigations were ..... vitamin.6 However, other investigators were unable to detect any protective effects of ascorbic acid on the ...

  6. 21 CFR 582.5013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ascorbic acid. 582.5013 Section 582.5013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5013 Ascorbic acid. (a) Product. Ascorbic acid. 1 Amino acids listed in this subpart may be...

  7. 21 CFR 582.3013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ascorbic acid. 582.3013 Section 582.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as...

  8. 21 CFR 182.8013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ascorbic acid. 182.8013 Section 182.8013 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as safe when used in...

  9. Ascorbic acid transport into cultured pituitary cells

    International Nuclear Information System (INIS)

    Cullen, E.I.; May, V.; Eipper, R.A.

    1986-01-01

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

  10. 21 CFR 182.3013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ascorbic acid. 182.3013 Section 182.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as safe...

  11. Alleviation of ascorbic acid-induced gastric high acidity by calcium ascorbate in vitro and in vivo

    OpenAIRE

    Lee, Joon-Kyung; Jung, Sang-Hyuk; Lee, Sang-Eun; Han, Joo-Hui; Jo, Eunji; Park, Hyun-Soo; Heo, Kyung-Sun; Kim, Deasun; Park, Jeong-Sook; Myung, Chang-Seon

    2017-01-01

    Ascorbic acid is one of the most well-known nutritional supplement and antioxidant found in fruits and vegetables. Calcium ascorbate has been developed to mitigate the gastric irritation caused by the acidity of ascorbic acid. The aim of this study was to compare calcium ascorbate and ascorbic acid, focusing on their antioxidant activity and effects on gastric juice pH, total acid output, and pepsin secretion in an in vivo rat model, as well as pharmacokinetic parameters. Calcium ascorbate an...

  12. Fate of the synergistic antioxidant system ascorbic acid, lecithin, and tocopherol in mayonnaise: Partion of ascorbic acid

    DEFF Research Database (Denmark)

    Meyer, Anne Merete Boye; Jacobsen, Charlotte Munch

    1996-01-01

    Meyer, A. S. & C. Jacobsen, 1996. Fate of the synergistic antioxidant system ascorbic acid, lecithin, and tocopherol in mayonnaise: Partion of ascorbic acid, J. Food Lipids, 3, 139-147.......Meyer, A. S. & C. Jacobsen, 1996. Fate of the synergistic antioxidant system ascorbic acid, lecithin, and tocopherol in mayonnaise: Partion of ascorbic acid, J. Food Lipids, 3, 139-147....

  13. Alleviation of ascorbic acid-induced gastric high acidity by calcium ascorbate in vitro and in vivo

    Science.gov (United States)

    Lee, Joon-Kyung; Jung, Sang-Hyuk; Lee, Sang-Eun; Han, Joo-Hui; Jo, Eunji; Park, Hyun-Soo; Heo, Kyung-Sun; Kim, Deasun

    2018-01-01

    Ascorbic acid is one of the most well-known nutritional supplement and antioxidant found in fruits and vegetables. Calcium ascorbate has been developed to mitigate the gastric irritation caused by the acidity of ascorbic acid. The aim of this study was to compare calcium ascorbate and ascorbic acid, focusing on their antioxidant activity and effects on gastric juice pH, total acid output, and pepsin secretion in an in vivo rat model, as well as pharmacokinetic parameters. Calcium ascorbate and ascorbic acid had similar antioxidant activity. However, the gastric fluid pH was increased by calcium ascorbate, whereas total acid output was increased by ascorbic acid. In the rat pylorus ligation-induced ulcer model, calcium ascorbate increased the gastric fluid pH without changing the total acid output. Administration of calcium ascorbate to rats given a single oral dose of 100 mg/kg as ascorbic acid resulted in higher plasma concentrations than that from ascorbic acid alone. The area under the curve (AUC) values of calcium ascorbate were 1.5-fold higher than those of ascorbic acid, and the Cmax value of calcium ascorbate (91.0 ng/ml) was higher than that of ascorbic acid (74.8 ng/ml). However, their Tmax values were similar. Thus, although calcium ascorbate showed equivalent antioxidant activity to ascorbic acid, it could attenuate the gastric high acidity caused by ascorbic acid, making it suitable for consideration of use to improve the side effects of ascorbic acid. Furthermore, calcium ascorbate could be an appropriate antioxidant substrate, with increased oral bioavailability, for patients with gastrointestinal disorders. PMID:29302210

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

    International Nuclear Information System (INIS)

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

    1989-01-01

    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- 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 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 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

  15. Spectrophotometric determination of copper with ascorbic acid

    International Nuclear Information System (INIS)

    Majeed, A.; Mustafa, M.M.; Asma, R.N.; Sareecha, N.

    1996-01-01

    Copper has been determined spectrophotometrically by using ascorbic acid as a chromagenic reagent. The complex formed in basic medium is measured for its absorbance at 340 n.m. Interference for 23 cations and 9 anions has also been checked. Effect of pH, time, temperature, ammonia, reagent concentration and interferents has been report. (author)

  16. Plasma Ascorbic Acid Concentration and some Haematological ...

    African Journals Online (AJOL)

    Aim: To determine the plasma ascorbic acid concentration, haematocrit, reticulocyte count and blood cell morphology in homozygous sickle cell disease in Enugu metropolis. Materals and Methods: Forty known sickle cell anaemia patients (HbSS) and ten non-sicklers (HbAA) were used as tests and controls respectively.

  17. Oxygen dependency of one-electron reactions generating ascorbate radicals and hydrogen peroxide from ascorbic acid.

    Science.gov (United States)

    Boatright, William L

    2016-04-01

    The effect of oxygen on the two separate one-electron reactions involved in the oxidation of ascorbic acid was investigated. The rate of ascorbate radical (Asc(-)) formation (and stability) was strongly dependent on the presence of oxygen. A product of ascorbic acid oxidation was measurable levels of hydrogen peroxide, as high as 32.5 μM from 100 μM ascorbic acid. Evidence for a feedback mechanism where hydrogen peroxide generated during the oxidation of ascorbic acid accelerates further oxidation of ascorbic acid is also presented. The second one-electron oxidation reaction of ascorbic acid leading to the disappearance of Asc(-) was also strongly inhibited in samples flushed with argon. In the range of 0.05-1.2 mM ascorbic acid, maximum levels of measurable hydrogen peroxide were achieved with an initial concentration of 0.2 mM ascorbic acid. Hydrogen peroxide generation was greatly diminished at ascorbic acid levels of 0.8 mM or above. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Ascorbic Acid and Beta-Carotene Alleviate Oxidative Effect of ...

    African Journals Online (AJOL)

    Ascorbic Acid and Beta-Carotene Alleviate Oxidative Effect of London King Size® Cigarette Smoke on Tissue Lipids. ... Malondialdehyde production in the tissues was reduced by ascorbic acid and or beta-carotene given daily to the rats. It is implied that ascorbic acid or ... http://dx.doi.org/10.4314/njhbs.v2i1.11451.

  19. 21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nicotinamide-ascorbic acid complex. 172.315 Section... HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.315 Nicotinamide-ascorbic acid complex. Nicotinamide-ascorbic acid complex may be safely used in accordance with the following prescribed conditions...

  20. Iodometric determination of the ascorbic acid (Vitamin c) content of ...

    African Journals Online (AJOL)

    The ascorbic acid content of seven different fruits –grapefruit, lime, orange, tangerine, banana, pawpaw and pineapple was determined by iodine titration, in order to know which fruit would best supply the ascorbic acid need for the body. Results showed that tangerine had the highest value of ascorbic acid, ...

  1. Higher transcription levels in ascorbic acid biosynthetic and recycling genes were associated with higher ascorbic acid accumulation in blueberry.

    Science.gov (United States)

    Liu, Fenghong; Wang, Lei; Gu, Liang; Zhao, Wei; Su, Hongyan; Cheng, Xianhao

    2015-12-01

    In our preliminary study, the ripe fruits of two highbush blueberry (Vaccinium corymbosum L.) cultivars, cv 'Berkeley' and cv 'Bluecrop', were found to contain different levels of ascorbic acid. However, factors responsible for these differences are still unknown. In the present study, ascorbic acid content in fruits was compared with expression profiles of ascorbic acid biosynthetic and recycling genes between 'Bluecrop' and 'Berkeley' cultivars. The results indicated that the l-galactose pathway was the predominant route of ascorbic acid biosynthesis in blueberry fruits. Moreover, higher expression levels of the ascorbic acid biosynthetic genes GME, GGP, and GLDH, as well as the recycling genes MDHAR and DHAR, were associated with higher ascorbic acid content in 'Bluecrop' compared with 'Berkeley', which indicated that a higher efficiency ascorbic acid biosynthesis and regeneration was likely to be responsible for the higher ascorbic acid accumulation in 'Bluecrop'. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Occurrence of L-Ascorbic Acid in Euglena gracilis z

    OpenAIRE

    SHIGEOKA, Shigeru; NAKANO, Yoshihisa; KITAOKA, Shozaburo

    1980-01-01

    Euglena gracilis synthesizes L-ascorbic acid. The content of total L-ascorbic acid in the cells grown photoautotrophically for 9 days in the stationary phase was 4.01 μmole/10^9 cells, corresponding to 4.25 mg per g dry weight. The oxidized form, dehydro-L-ascorbic acid was about 20% of total L-ascorbic acid. Illumination influenced the acid content markedly. From the present data, formation and physiological roles of L-ascorbic acid seem to be strongly affected by illumination.

  3. Ascorbic acid protects against the nephrotoxicity and apoptosis caused by colistin and affects its pharmacokinetics

    Science.gov (United States)

    Yousef, Jumana M.; Chen, Gong; Hill, Prue A.; Nation, Roger L.; Li, Jian

    2012-01-01

    Objectives The use of colistin in the treatment of life-threatening Gram-negative infections is associated with a high rate of nephrotoxicity that is dose limiting. This study aimed to examine the nephroprotective effect of ascorbic acid against colistin-induced nephrotoxicity. Methods Rats were treated intravenously twice daily with saline, colistin (cumulative dose of 36.5 mg/kg), a combination of ascorbic acid (50 or 200 mg/kg) and colistin, or ascorbic acid (200 mg/kg) over 7 days. Colistin-induced apoptosis was examined in rats over 5 days and in vitro using rat renal proximal tubular cells NRK-52E over 24 h with and without ascorbic acid. The effect of co-administered ascorbic acid on colistin pharmacokinetics was investigated. Results The 24 h urinary excretion of N-acetyl-β-d-glucosaminidase, a sensitive marker for tubular damage, was significantly lower (P ascorbic acid 200 mg/kg group. Significant histological abnormalities (P ascorbic acid, which decreased the apoptotic effect in a concentration-dependent manner. Ascorbic acid (200 mg/kg) altered colistin pharmacokinetics, as the total body clearance decreased from 3.78 ± 0.36 mL/min/kg (colistin group) to 2.46 ± 0.57 mL/min/kg (P = 0.0024). Conclusions This is the first study demonstrating the protective effect of ascorbic acid against colistin-induced nephrotoxicity and tubular apoptosis. Co-administration of ascorbic acid has the potential to increase the therapeutic index of colistin. PMID:22127588

  4. ASCORBIC ACID RETENTION IN CANNED LIME JUICE ...

    African Journals Online (AJOL)

    Des calculs de régression linéaires, 300 metabisulfite de sodium de ppm résulté dans l'étagère-vie plus longue de 49 semaines pendant que les échantillons de contrôle ont eu l'étagère-vie plus courte de 22 semaines. LE MOTS PRINCIPAL: Ascorbic la stabilité acide; aurantifolia d'Agrume; le jus de chaux, metabisulfite ...

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

    DEFF Research Database (Denmark)

    Meyer, A.S.; Jacobsen, Charlotte Munch

    1996-01-01

    The distribution of ascorbic acid between the lipid and aqueous phase was investigated in mayonnaises enriched with fish oil containing a synergistic antioxidant mixture of ascorbic acid, lecithin and gamma-tocopherol, i.e., the A/L/T system (Loliger and Saucy 1989). The ascorbic acid was found...... to be located in the aqueous phase indicating that the A/L/T system broke down in mayonnaises. Based on the hypothesis that synergistic antioxidant action between ascorbic acid, lecithin and tocopherol requires that the three components are in close assembly, the results offer an explanation as to why the A...

  6. Selective response of dopamine in the presence of ascorbic acid ...

    African Journals Online (AJOL)

    Selective response of dopamine in the presence of ascorbic acid and uric acid at gold nanoparticles and multi-walled carbon nanotubes grafted with ethylene diamine tetraacetic acid modified electrode.

  7. Ascorbic acid in bronchial asthma | Anderson | South African ...

    African Journals Online (AJOL)

    Sixteen White children with bronchial asthma were divided into two groups; one received standard antiasthma chemoprophylaxis (SAC) and the other SAC supplemented with 1 g ascorbic acid (Redoxon) given as a single daily dose for a 6-month period. In 10 patients the effects of ascorbic acid on exerciseinduced ...

  8. Enhancement of salt tolerance in sugarcane by ascorbic acid ...

    African Journals Online (AJOL)

    Ascorbic acid is a non-enzymatic antioxidant which plays an important role in the activation of biological defense mechanisms. The effect of 24 h ascorbic acid (0.5 mM) pretreatment was observed on subsequent growth and development of callus cultures as well as in vitro-grown plants of Saccharum sp. hybrid (cvs.

  9. Oral Metformin-Ascorbic Acid Co-Administration Ameliorates Alcohol ...

    African Journals Online (AJOL)

    Oral Metformin-Ascorbic Acid Co-Administration Ameliorates Alcohol-Induced Hepatotoxicity In Rats. ... Nigerian Quarterly Journal of Hospital Medicine ... the present in vivo animal study was to determine whether metformin-ascorbic acid co-administration also prevents alcoholic hepatotoxicity in chronic alcohol exposure.

  10. Lipid peroxidation and ascorbic acid levels in Nigeria children with ...

    African Journals Online (AJOL)

    This study was undertaken to establish data on the roles of lipid peroxidation and ascorbic acid in the pathology of malaria in Nigeria children. We measured the levels of malondialdehyde (MDA), a marker of lipid peroxidation and ascorbic acid in the plasma of 406 parasitaemic and 212 non-parasitaemic Nigerian children.

  11. APPLICATION OF ASCORBIC ACID 2-PHOSPHATE AS A NEW ...

    African Journals Online (AJOL)

    An electrochemical assay of the enzyme alkaline phosphatase (ALP) using ascorbic acid 2-phosphate (AAP) as a new voltammetric substrate has been described in this paper. In the alkaline buffer solution the ALP enzymatic hydrolysis product of AAP was ascorbic acid (AA), which was an electro-active substance and had ...

  12. Modelling of thermal degradation kinetics of ascorbic acid in ...

    African Journals Online (AJOL)

    Ascorbic acid (vitamin C) loss in thermally treated pawpaw and potato was modelled mathematically. Isothermal experiments in the temperature range of 50 -80 oC for the drying of pawpaw and 60 -100 oC for the blanch-drying of potato were utilized to determine the kinetics of ascorbic acid loss in both fruit and vegetable.

  13. Erythrocyte osmotic fragility of pigs administered ascorbic acid and ...

    African Journals Online (AJOL)

    The experiment was carried out with the aim of investigating the effect of an antioxidant ascorbic acid on erythrocyte osmotic fragility of pigs transported by road for 4 h during the harmattan season. 16 pigs administered with ascorbic acid at the dose of 250 mg/kg per os and individually served as experimental animals and ...

  14. Modelling of Thermal Degradation Kinetics of Ascorbic Acid in ...

    African Journals Online (AJOL)

    Ascorbic acid (vitamin C) loss in thermally treated pawpaw and potato was modelled mathematically. Isothermal experiments in the temperature range of 50 -80 oC for the drying of pawpaw and 60 -100 oC for the blanch-drying of potato were utilized to determine the kinetics of ascorbic acid loss in both fruit and vegetable.

  15. Erythrocyte osmotic fragility of pigs administered ascorbic acid and ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... tron carrier. It can give up 2 electrons, and it is converted to dehydro-L-ascorbic acid (Rice, 2000; Sahin et al.,. 2001). It has been established that ascorbic acid amelio- rates heat stress and the adverse effects of stressful environmental conditions (Tauler et al., 2003; Adenkola and Ayo, 2006; Ayo et al., ...

  16. Effect of ascorbic acid supplementation level to diets of indigenous ...

    African Journals Online (AJOL)

    All the birds were offered the same grower feed and fresh water ad libitum. Indigenous Venda hens supplemented with ascorbic acid produced chicks with improved (P<0.05) feed intake, feed conversion ratio, growth rate and live weight at 7 weeks of age. However, ascorbic acid supplementation to the diets of indigenous ...

  17. Effects of Ascorbic Acid on Reproductive Functions of Male Wistar ...

    African Journals Online (AJOL)

    Plasma levels of FSH, LH and testosterone were significantly reduced in nicotine exposed rats when compared with the control (p<0.05), both FSH and LH plasma levels were significantly increased in rats exposed to ascorbic acid (p<0.05) relative to the control, while ascorbic acid also increased the level of these hormone ...

  18. Allosteric modulation of retinal GABA receptors by ascorbic acid

    Science.gov (United States)

    Calero, Cecilia I.; Vickers, Evan; Moraga Cid, Gustavo; Aguayo, Luis G.; von Gersdorff, Henrique; Calvo, Daniel J.

    2011-01-01

    Summary Ionotropic γ-aminobutyric acid receptors (GABAA and GABAC) belong to the cys-loop receptor family of ligand-gated ion channels. GABAC receptors are highly expressed in the retina, mainly localized at the axon terminals of bipolar cells. Ascorbic acid, an endogenous redox agent, modulates the function of diverse proteins, and basal levels of ascorbic acid in the retina are very high. However, the effect of ascorbic acid on retinal GABA receptors has not been studied. Here we show that the function of GABAC and GABAA receptors is regulated by ascorbic acid. Patch-clamp recordings from bipolar cell terminals in goldfish retinal slices revealed that GABAC receptor-mediated currents activated by tonic background levels of extracellular GABA, and GABAC currents elicited by local GABA puffs, are both significantly enhanced by ascorbic acid. In addition, a significant rundown of GABA-puff evoked currents was observed in the absence of ascorbic acid. GABA-evoked Cl- currents mediated by homomeric ρ1 GABAC receptors expressed in Xenopus laevis oocytes were also potentiated by ascorbic acid in a concentration-dependent, stereospecific, reversible, and voltage-independent manner. Studies involving the chemical modification of sulfhydryl groups showed that the two cys-loop cysteines and histidine 141, all located in the ρ1 subunit extracellular domain, each play a key role in the modulation of GABAC receptors by ascorbic acid. Additionally, we show that retinal GABAA IPSCs and heterologously expressed GABAA receptor currents are similarly augmented by ascorbic acid. Our results suggest that ascorbic acid may act as an endogenous agent capable of potentiating GABAergic neurotransmission in the CNS. PMID:21715633

  19. Characterization of ascorbic acid uptake by isolated rat kidney cells

    Energy Technology Data Exchange (ETDEWEB)

    Bowers-Komro, D.M.; McCormick, D.B. (Emory Univ. School of Medicine, Atlanta, GA (USA))

    1991-01-01

    Isolated kidney cells accumulated L(1-14C)ascorbic acid in a time-dependent manner and reached a steady state after 15 min at 37 degrees C. Initial velocity for uptake was over 300 pmol/mg protein per min when cells were separated from the bathing solution using a density gradient established during centrifugation. The uptake process was saturable with an apparent concentration at half maximal uptake of 36 mumols/L. Ascorbate uptake was reduced by metabolic inhibitors and was temperature dependent. Although ascorbic acid is an acid anion at pH 7.4, uptake did not appear to be inhibited by other acid anions such as p-aminohippurate and probenecid; however, involvement of the ion gradient established by Na+, H(+)-adenosine triphosphatase could not be confirmed. Replacing the sodium ion with other monovalent ions reduced the accumulation of ascorbate significantly. Isoascorbic and dehydroascorbic acids inhibited ascorbate uptake (34 and 13 mmol/L, respectively), whereas high concentrations of glucose showed some stimulation. These findings indicated that ascorbic acid is reabsorbed by the kidney in a sodium-dependent active transport process that is not common to other acid anions and has some specificity for the ascorbic acid structure.

  20. Ascorbic acid contents of Pakistani fruits and vegetables.

    Science.gov (United States)

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

    2006-10-01

    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.

  1. Response of Adult Cockerels to Different Sources of Ascorbic acid ...

    African Journals Online (AJOL)

    A study was conducted to determine the response of Adult cockerels to three sources of ascorbic acid (AA). The sources of ascorbate (vitamin C) tested were industrial, medical and from natural (baobab pulp) in a completely randomized design. Weekly feed intake, feed:gain and weight gain were affected (P<0.05) by the ...

  2. Synthesis of New L-Ascorbic Ferulic Acid Hybrids

    Directory of Open Access Journals (Sweden)

    Sylvain Rault

    2007-11-01

    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.

  3. Radiation protection by ascorbic acid in sodium alginate solutions

    International Nuclear Information System (INIS)

    Aliste, A.J.; Mastro, N.L. Del

    2004-01-01

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

  4. Radiation protection by ascorbic acid in sodium alginate solutions

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  5. Combined effect of sodium valproate and ascorbic acid on ...

    African Journals Online (AJOL)

    conventional antiepileptic drug) and ascorbic acid (potent antioxidant) in pentylenetetrazole (PTZ) induced seizures. Thirty mice were divided into six groups of five each (n=5). Group 1 served as control and administered normal saline 1ml/kg, ...

  6. Toxic effect of chalkones and antitoxic role of ascorbic acid

    OpenAIRE

    Khan, A.M.; Ali, S.M.

    1980-01-01

    One of the chalkones synthesised in the author's laboratory was selected to determine its toxicity to fish, Lepidocephalicthys thermalis at different concentrations and time periods. Ascorbic acid contents were determined and it was found to be antitoxic.

  7. Ascorbic acid is a key participant during the interactions between ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 36; Issue 1. Ascorbic acid is a key participant during the interactions between chloroplasts and mitochondria to optimize photosynthesis and protect against photoinhibition. Saikrishna Talla Khateef Riazunnisa Lolla Padmavathi Pidakala Rajsheel Agepati S Raghavendra.

  8. Ascorbic acid: Nonradioactive extracellular space marker in canine heart

    International Nuclear Information System (INIS)

    Reil, G.H.; Frombach, R.; Kownatzki, R.; Quante, W.; Lichtlen, P.R.

    1987-01-01

    The distribution pattern of ascorbic acid and L-[ 14 C]ascorbic acid in myocardial tissue was compared with those of the classical radioactive extracellular space markers [ 3 H]-inulin, [ 3 H]sucrose, and Na 82 Br. A new polarographic techniques was developed for analogue registration of ascorbic acid concentration in coronary venous blood. The kinetic data of the markers were studied in an open-chest canine heart preparation during a constant tracer infusion of up to 9 min. Distribution volumes were calculated based on the mean transit time method of Zierler. The distribution volume of ascorbic acid as well as of L-[ 14 C]ascorbic acid in myocardial tissue agreed closely with those of [ 3 H]inulin and [ 3 H]sucrose as well as 82 Br. The obtained kinetic data confirmed that ascorbic acid exhibits the physicochemical properties of an extracellular space marker, though this compound was shown to leak slowly into myocardial cells. Favorable attributes of this indicator are its low molecular weight, high diffusibility in interstitial fluid, low binding affinity to macromolecules, and high transcapillary as well as low transplasmalemmal penetration rate. Therefore, this nonradioactive marker can be applied in a safe and simple fashion, and without untoward side effects in experimental animals as well as in patients

  9. Ascorbic acid deficiency in patients with lichen planus.

    Science.gov (United States)

    Nicolae, Ilinca; Mitran, Cristina Iulia; Mitran, Madalina Irina; Ene, Corina Daniela; Tampa, Mircea; Georgescu, Simona Roxana

    2017-01-01

    Recent studies have highlighted the role of oxidative stress in the pathogenesis of lichen planus (LP). In the present study, the interest of the authors is focused on the investigation of ascorbic acid status in patients with LP and identification of parameters that might influence the level of this vitamin. We analyzed the level of urinary ascorbic acid (reflectometric method) in 77 patients with LP (cutaneous LP (CLP)-49 cases; oral LP (OLP)-28 cases) and 50 control subjects. The evaluation of all participants included clinical examination and laboratory and imaging tests. Compared to the control group (19.82 mg/dl) the level of ascorbic acid was significantly lower both in patients with CLP (8.47 mg/dl, p = 0.001) and in those with OLP (8.04 mg/dl, p = 0.001). In patients with LP it was found that the deficiency of ascorbic acid increases with age (r = -0.318, p = 0.032). The urinary concentrations of ascorbic acid were significantly lower in patients with LP associated with infections compared to patients with LP without infections. The urinary ascorbic acid level may be a useful parameter in identifying patients with LP who are at risk of developing viral or bacterial infections.

  10. Ascorbic acid concentrations in aqueous humor after systemic vitamin C supplementation in patients with cataract: pilot study.

    Science.gov (United States)

    Hah, Young-Sool; Chung, Hye Jin; Sontakke, Sneha B; Chung, In-Young; Ju, Sunmi; Seo, Seong-Wook; Yoo, Ji-Myong; Kim, Seong-Jae

    2017-07-11

    To measure ascorbic acid concentration in aqueous humor of patients with cataract after oral or intravenous vitamin C supplementation. Forty-two eyes of 42 patients with senile cataract who underwent uncomplicated cataract surgery were enrolled. Patients (n = 14 each) were administered oral vitamin C (2 g), intravenous vitamin C (20 g) or no treatment (control group) on the day before surgery. Samples of aqueous humor (0.1 cm 3 ) were obtained by anterior chamber aspiration at the beginning of surgery and stored at -80 °C. Ascorbic acid concentration in aqueous humor was measured by high-pressure liquid chromatography. The mean age at surgery was 62.5 years, with no difference among the three groups. The mean ± standard deviation concentrations of ascorbic acid in aqueous humor in the control and oral and intravenous vitamin C groups were 1347 ± 331 μmol/L, 1859 ± 408 μmol/L and 2387 ± 445 μmol/L, respectively. Ascorbic acid concentration was significantly lower in the control than in the oral (P humor is increased by systemic vitamin C supplementation, with intravenous administration being more effective than oral administration.

  11. Ascorbate and dehydroascorbic acid as reliable biomarkers of oxidative stress

    DEFF Research Database (Denmark)

    Lykkesfeldt, Jens

    2007-01-01

    , the analytical reproducibility was tested by repeated analysis of plasma aliquots from one individual over four years. The plasma was subjected to acidic deproteinization with an equal volume of 10% meta-phosphoric acid containing 2 mM EDTA and analyzed for ascorbate and dehydroascorbic acid by high...

  12. ESR Study on Irradiated Ascorbic Acid Single Crystal

    International Nuclear Information System (INIS)

    Tuner, H.; Korkmaz, M.

    2007-01-01

    Food irradiation is a 'cold' process for preserving food and has been established as a safe and effective method of food processing and preservation after more than five decades of research and development. The small temperature increase, absence of residue and effectiveness of treatment of pre-packed food are the main advantages. In food industry, ascorbic acid and its derivatives are frequently used as antioxidant agents. However, irradiation is expected to produces changes in the molecules of food components and of course in the molecules of the agents added as preservation agents such as ascorbic acid. These changes in the molecular structures could cause decreases in the antioxidant actions of these agents. Therefore, the radiation resistance of these agents must be known to determine the amount of radiation dose to be delivered. Electron spin resonance (ESR) is one of the leading methods for identification of intermediates produced after irradiation. ESR spectrum of irradiated solid powder of ascorbic acid is fairly complex and determinations of involved radical species are difficult. In the present work, single crystals of ascorbic acid irradiated by gamma radiation are used to determine molecular structures of radiation induced radicalic species and four radicalic species related in pair with P21 crystal symmetry are found to be responsible from experimental ESR spectrum of gamma irradiated single crystal of ascorbic acid

  13. Green reduction of graphene oxide by ascorbic acid

    Science.gov (United States)

    Khosroshahi, Zahra; Kharaziha, Mahshid; Karimzadeh, Fathallah; Allafchian, Alireza

    2018-01-01

    Graphene, a single layer of sp2-hybridized carbon atoms in a hexagonal (two-dimensional honey-comb) lattice, has attracted strong scientific and technological interest due to its novel and excellent optical, chemical, electrical, mechanical and thermal properties. The solution-processable chemical reduction of Graphene oxide (GO is considered as the most favorable method regarding mass production of graphene. Generally, the reduction of GO is carried out by chemical approaches using different reductants such as hydrazine and sodium borohydride. These components are corrosive, combustible and highly toxic which may be dangerous for personnel health and the environment. Hence, these reducing agents are not promising choice for reducing of graphene oxide (GO). As a consequence, it is necessary for further development and optimization of eco-friendly, natural reducing agent for clean and effective reduction of GO. Ascorbic acid, an eco-friendly and natural reducing agents, having a mild reductive ability and nontoxic property. So, the aim of this research was to green synthesis of GO with ascorbic acid. For this purpose, the required amount of NaOH and ascorbic acid were added to GO solution (0.5 mg/ml) and were heated at 95 °C for 1 hour. According to the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and electrochemical results, GO were reduced with ascorbic acid like hydrazine with better electrochemical properties and ascorbic acid is an ideal substitute for hydrazine in the reduction of graphene oxide process.

  14. Macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid.

    Science.gov (United States)

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

    2013-08-15

    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. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Plasma Ascorbic Acid and Non-Enzymatic Antioxidants Level in ...

    African Journals Online (AJOL)

    Free radicals have been implicated in the pathology of several diseases including cataract. Ascorbic acid functions as the major chain breaking antioxidant vitamin in the aqueous phase. Bilirubin, albumin and uric acid are regarded as natural antioxidants. There are conflicting reports on plasma concentrations of these ...

  16. Plasma Concentration of Ascorbic Acid and Some Hematological ...

    African Journals Online (AJOL)

    hanumantp

    acid, which is a vital antioxidant, and blood cell production or morphology may be affected. Objective: To investigate the ... not adversely affect plasma ascorbic acid concentration and hematological parameters in adult humans. The study, however .... peroxidase/H202 halide system in vitro and in vivo. Am J Clin. Nutr 1995 ...

  17. ascorbic acid retention in canned lime juice preserved with sulfur ...

    African Journals Online (AJOL)

    ASCORBIC ACID RETENTION IN CANNED LIME JUICE. PRESERVED WITH SULFUR DIOXIDE AND BENZOIC ACID. Francis M Malhooko“ and Elizabeth N Kiniiya'. ABSTRACT. The effects of two levels each of sodium metabisulfite and sodium benzoate on the shelf-life of canned lime juice stored at ambient temperature ...

  18. Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

    Science.gov (United States)

    Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

    2002-12-06

    Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

  19. RelB Expression Determines the Differential Effects of Ascorbic Acid in Normal and Cancer Cells.

    Science.gov (United States)

    Wei, Xiaowei; Xu, Yong; Xu, Fang Fang; Chaiswing, Luksana; Schnell, David; Noel, Teresa; Wang, Chi; Chen, Jinfei; St Clair, Daret K; St Clair, William H

    2017-03-15

    Cancer cells typically experience higher oxidative stress than normal cells, such that elevating pro-oxidant levels can trigger cancer cell death. Although pre-exposure to mild oxidative agents will sensitize cancer cells to radiation, this pre-exposure may also activate the adaptive stress defense system in normal cells. Ascorbic acid is a prototype redox modulator that when infused intravenously appears to kill cancers without injury to normal tissues; however, the mechanisms involved remain elusive. In this study, we show how ascorbic acid kills cancer cells and sensitizes prostate cancer to radiation therapy while also conferring protection upon normal prostate epithelial cells against radiation-induced injury. We found that the NF-κB transcription factor RelB is a pivotal determinant in the differential radiosensitization effects of ascorbic acid in prostate cancer cells and normal prostate epithelial cells. Mechanistically, high reactive oxygen species concentrations suppress RelB in cancer cells. RelB suppression decreases expression of the sirtuin SIRT3 and the powerful antioxidant MnSOD, which in turn increases oxidative and metabolic stresses in prostate cancer cells. In contrast, ascorbic acid enhances RelB expression in normal cells, improving antioxidant and metabolic defenses against radiation injury. In addition to showing how RelB mediates the differential effects of ascorbic acid on cancer and normal tissue radiosensitivities, our work also provides a proof of concept for the existence of redox modulators that can improve the efficacy of radiotherapy while protecting against normal tissue injury in cancer settings. Cancer Res; 77(6); 1345-56. ©2017 AACR . ©2017 American Association for Cancer Research.

  20. Localization of ascorbic acid, ascorbic acid oxidase, and glutathione in roots of Cucurbita maxima L.

    Science.gov (United States)

    Liso, Rosalia; De Tullio, Mario C; Ciraci, Samantha; Balestrini, Raffaella; La Rocca, Nicoletta; Bruno, Leonardo; Chiappetta, Adriana; Bitonti, Maria Beatrice; Bonfante, Paola; Arrigoni, Oreste

    2004-12-01

    To understand the function of ascorbic acid (ASC) in root development, the distribution of ASC, ASC oxidase, and glutathione (GSH) were investigated in cells and tissues of the root apex of Cucubita maxima. ASC was regularly distributed in the cytosol of almost all root cells, with the exception of quiescent centre (QC) cells. ASC also occurred at the surface of the nuclear membrane and correspondingly in the nucleoli. No ASC could be observed in vacuoles. ASC oxidase was detected by immunolocalization mainly in cell walls and vacuoles. This enzyme was particularly abundant in the QC and in differentiating vascular tissues and was absent in lateral root primordia. Administration of the ASC precursor L-galactono-gamma-lactone markedly increased ASC content in all root cells, including the QC. Root treatment with the ASC oxidized product, dehydroascorbic acid (DHA), also increased ASC content, but caused ASC accumulation only in peripheral tissues, where DHA was apparently reduced at the expense of GSH. The different pattern of distribution of ASC in different tissues and cell compartments reflects its possible role in cell metabolism and root morphogenesis.

  1. Iron (II) ions induced oxidation of ascorbic acid and glucose.

    Science.gov (United States)

    Mlakar, A; Batna, A; Dudda, A; Spiteller, G

    1996-12-01

    Lipid peroxidation (LPO) of polyunsaturated fatty acids (PUFAs) is suspected to be involved in the generation of chronic diseases. A model reaction for LPO is the air oxidation of PUFAs initiated by Fe2+ and ascorbic acid. In the course of such model reactions glycolaldehyde (GLA) was detected as main aldehydic product. Since it is difficult to explain the generat on of GLA by oxidation of PUFAs, it was suspected that GLA might be derived by oxidation of ascorbic acid. This assumption was verified by treatment of ascorbic acid with Fe2+. Produced aldehydic compounds were trapped by addition of pentafluorobenzylhydroxylamine hydrochloride (PFBHA-HCl), trimethylsilylated and finally identified by gas chromatography/mass spectronetry (GC/MS). Oxidation of ascorbic acid with O2 in presence of iron ions produced not only glycolaldehyde (GLA), but also glyceraldehyde (GA), dihydroxyacetone (DA) and formaldehyde. Glyoxal (GO) and malondialdehyde (MDA) were detected as trace compounds. The yield of the aldehydic compounds was increased by addition of lipid hydroperoxides (LOOH) or H2O2. The buffer influenced the reaction considerably: Iron ions react with Tris buffer by producing dihydroxyacetone (DA). Since ascorbic acid is present in biological systems and Fe2+ ions are obviously generated by cell damaging processes, the production of GLA and other aldehydic components might add to the damaging effects of LPO. Glucose suffers also oxidation to short-chain aldehydic compounds in aqueous solution, but this reaction requires addition of equimolar amounts of Fe2+ together with equimolar amounts of H2O2 or 13-hydroperoxy -9-cis-11-trans-octadecadienoic acid (13-HPODE). Therefore this reaction, also influenced by the buffer system, seems to be not of biological relevance.

  2. Ameliorative effects of ascorbic acid on rectal temperature ...

    African Journals Online (AJOL)

    This experiment was performed with the aim of investigating the effects of ascorbic acid (AA) on stress due to road transportation of rabbits. Nine rabbits administered AA served as the treated animals, while seven others given sterile water were used as the controls. All the rabbits were transported by road for 2 h under ...

  3. Total phenols, flavonoids, anthocyanins, ascorbic acid contents and ...

    African Journals Online (AJOL)

    mmpa

    2014-03-05

    Mar 5, 2014 ... The antioxidant capability, total phenol, total flavonoid, anthocyanins, ascorbic acid contents, and reducing power contents of polar and non-polar extracts for flower and leaves in two stages of growth for Rhamnus kurdica Boiss in flowering were evaluated in this work. The polar extraction of flower of R.

  4. Ascorbic acid is a key participant during the interactions between ...

    Indian Academy of Sciences (India)

    While acknowledging the importance of the COX pathway, we hypothesize that AsA and the. AOX pathway may complement each other to protect photosynthesis against photoinhibition. [Talla S, Riazunnisa K, Padmavathi L, Sunil B, Rajsheel P and Raghavendra AS 2011 Ascorbic acid is a key participant during the ...

  5. Effects of Ascorbic Acid on Reproductive Functions of Male Wistar ...

    African Journals Online (AJOL)

    ABSTRACT. Nicotine is a pharmacologically active and addictive alkaloid component of the cigarette smoke, and its effects on male reproductive system and fertility are well documented. Influence of ascorbic acid on reproductive functions of male wistar rats exposed to nicotine was examined in this study. Thirty-two adult ...

  6. Plasma Concentration of Ascorbic Acid and Some Hematological ...

    African Journals Online (AJOL)

    Background: Tobacco snuffing, like cigarette smoking, is known to be a common habit among the adults of Igbo communities in Nigeria. In view of the various pharmacological actions of nicotine and other additive constituents of tobacco snuff, there is growing concern that ascorbic acid, which is a vital antioxidant, and blood ...

  7. 21 CFR 862.1095 - Ascorbic acid test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ascorbic acid test system. 862.1095 Section 862.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

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

    Science.gov (United States)

    Snehalatha, K. C.; And Others

    1997-01-01

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

  9. Silver nanoparticles prepared in presence of ascorbic acid and ...

    Indian Academy of Sciences (India)

    In this paper, we reported a simple and low-cost procedure to synthesize silver nanoparticles (AgNPs) by using ascorbic acid as reducing agent and gelatin as stabilizer. The synthesized AgNPs were characterized by various means such as transmission electron microscope (TEM), powder X-ray diffraction (XRD) and ...

  10. Modulatory Role of Ascorbic Acid on Behavioural Responses of Pigs ...

    African Journals Online (AJOL)

    Experiments were performed on adult local pigs with the aim of investigating the modulatory role of ascorbic acid (AA) on their behavioural responses to 4-h, road transportation during the harmattan season. Sixteen adult pigs administered with AA at the dose of 250 mg/kg dissolve in sterile water served as experimental ...

  11. Stability Studies of a Mixture of Paracetamol and Ascorbic Acid ...

    African Journals Online (AJOL)

    Purpose: To determine the effect of the temperature of water used for the preparation of paracetamol and ascorbic acid mixture on its stability, as well as to assess the influence of humidity on the stability of single components and their mixtures. Methods: The stability of the mixtures in aqueous medium was evaluated with ...

  12. Formulation and Evaluation of Ascorbic acid Tablets by Direct ...

    African Journals Online (AJOL)

    PURPOSE: To evaluate the tableting properties of microcrystalline starch (MCS) used as a direct compression excipient in the formulation of ascorbic acid tablets and to compare with the properties of tablets produced using microcrystalline cellulose (MCC). METHODS: MCS was obtained by partial hydrolysis of cassava ( ...

  13. Effect of ascorbic and folic acids supplementation on oxidative ...

    African Journals Online (AJOL)

    An experiment was conducted on the effect of supplementation of ascorbic and folic acids on the oxidative hormones, enzymatic antioxidants, haematological and biochemical properties of layers exposed to increased heat load. A total of 72 Isa Brown laying hens at 31 weeks of age were randomly divided into four groups ...

  14. Effects of calcium gluconate and ascorbic acid on controlling shoot ...

    African Journals Online (AJOL)

    In vitro shoot necrosis is a quite widespread disorder affecting raspberry micropropagation. This study was conducted to investigate effects of calcium gluconate and ascorbic acid on shoot necrosis and dieback of raspberry shoots during micropropagation. Nodal segments of primocane-fruiting raspberry cultivars 'Allgold', ...

  15. Influence of enzymes and ascorbic acid on dough rheology and ...

    African Journals Online (AJOL)

    The combined action of ascorbic acid and two commercial enzymatic complexes containing amylase and xylanase/amylase was analyzed to determine their effects on dough rheology and bread quality. Seven bread formulations containing different concentrations of these improvers were used in the analysis.

  16. Ascorbic acid for the healing of skin wounds in rats

    Directory of Open Access Journals (Sweden)

    CC. Lima

    Full Text Available BACKGROUND: Healing is a complex process that involves cellular and biochemical events. Several medicines have been used in order to shorten healing time and avoid aesthetic damage. OBJECTIVE: to verify the topical effect of ascorbic acid for the healing of rats' skin wounds through the number of macrophages, new vessels and fibroblast verifications in the experimental period; and analyse the thickness and the collagen fibre organization in the injured tissue. METHODS: Male Rattus norvegicus weighing 270 ± 30 g were used. After thionembutal anesthesia, 15 mm transversal incisions were made in the animals' cervical backs. They were divided into two groups: Control Group (CG, n = 12 - skin wound cleaned with water and soap daily; Treated Group (TG, n = 12 - skin wound cleaned daily and treated with ascorbic acid cream (10%. Samples of skin were collected on the 3rd, 7th and 14th days. The sections were stained with hematoxylin-eosin and picrosirius red for morphologic analysis. The images were obtained and analysed by a Digital Analyser System. RESULTS: The ascorbic acid acted on every stage of the healing process. It reduced the number of macrophages, increased the proliferation of fibroblasts and new vessels, and stimulated the synthesis of thicker and more organized collagen fibres in the wounds when compared to CG. CONCLUSION: Ascorbic acid was shown to have anti-inflammatory and healing effects, guaranteeing a suiTable environment and conditions for faster skin repair.

  17. application of ascorbic acid 2-phosphate as a new voltammetric

    African Journals Online (AJOL)

    a

    ALP activity. The hydrolysis product, ascorbic acid (AA) is electroactive and could be detected by differential pulse voltammetry (DPV) at +380 mV, which could be used for the determination of ALP concentration. ..... The results show that AAP can be used as the suitable substrate for the routine ALP assay with satisfactory ...

  18. Ascorbic acid and microbiological analyses of extra - Cotyledonous ...

    African Journals Online (AJOL)

    Extra - cotyledonous deposits of Pride of Barbados, whenever collected, Should be consumed immediately or stored appropriately in pods for as long as 7 days at - 21°C for the preservation of the ascorbic acid (vitamin C) content and to avert the health hazard of contamination by pathogenic bacteria and fungi.

  19. Seasonal Variation in Serum Ascorbic Acid and Serum Lipid ...

    African Journals Online (AJOL)

    determine the serum ascorbic acid and serum lipid composition of the baboons under natural environmental conditions. We consider these data important as they .... way analysis of covariance" was computed on serum cholesterol, using cubic regression on body mass. Since 5 variables were under consideration, IO signi-.

  20. Silver nanoparticles prepared in presence of ascorbic acid and ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. In this paper, we reported a simple and low-cost procedure to synthesize silver nanoparticles. (AgNPs) by using ascorbic acid as reducing agent and gelatin as stabilizer. The synthesized AgNPs were characterized by various means such as transmission electron microscope (TEM), powder X-ray diffraction.

  1. The biochemical, physiological and therapeutic roles of ascorbic acid

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... It is a strong reducing agent involved in reduction reaction and it is structurally related to glucose. ..... trial to evaluate the impact of ascorbic acid status on fat oxidation during sub-maximal exercise in a study .... Effects of vitamins A, E, C and P on intensity of blood coagulation in experimental animals. Bull.

  2. ANTIOXIDANT AND PRO-OXIDANT EFFECT OF ASCORBIC ACID

    Directory of Open Access Journals (Sweden)

    Goran Rankovic

    2005-01-01

    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.

  3. Modulatory Effects of Ascorbic Acid on Spermatoxicity of Artesunate ...

    African Journals Online (AJOL)

    This study examined the effects of short-term use of oral artesunate on testicular function in rats. Artesunate is an atermisinin derivative, now widely used to treat malaria. We also studied the modulatory effects of ascorbic acid (vitamin C) on any toxicity that might occur. We compared sperm parameters, serum testosterone, ...

  4. Ascorbic acid promotes a TGFβ1-induced myofibroblast phenotype switch

    NARCIS (Netherlands)

    Piersma, Bram; Wouters, Olaf Y; de Rond, Saskia; Boersema, Miriam; Gjaltema, Rutger A F; Bank, Ruud A

    2017-01-01

    l-Ascorbic acid (AA), generally known as vitamin C, is a crucial cofactor for a variety of enzymes, including prolyl-3-hydroxylase (P3H), prolyl-4-hydroxylase (P4H), and lysyl hydroxylase (LH)-mediated collagen maturation. Here, we investigated whether AA has additional functions in the regulation

  5. Effect of dietary supplementation with ascorbic acid in coccidial ...

    African Journals Online (AJOL)

    The effect of dietary supplementation with ascorbic acid on broiler chicken challenged with coccidial oocysts was studied. The percentage mortality was significant (P<0.05) for all the treatments. The adrenal weight, caecal length and width for all the treatments were significantly (P<0.05) different. Caecum length was ...

  6. Urinary ascorbic acid and serum concentrations of circulating ...

    African Journals Online (AJOL)

    The aim of the present study was to determine the presence or absence of ascorbic acid in urine and serum levels of circulating immune complexes (CIC) and albumin in HIV infected subjects. A total of 90 participants (30 Symptomatic HIV infected subjects on antiretroviral therapy (ART), 30 Symptomatic HIV infected ...

  7. Changes in plasma lipid peroxide and ascorbic acid levels in ...

    African Journals Online (AJOL)

    Design and method: This study was conducted on the relationship between plasma lipid peroxides, ascorbic acid levels and diabetes mellitus. Forty two diabetic patients (24 males and 18 females) age grouped between 40 - 60 years were studied in the diabetic clinic of Federal Medical Centre Owerri. Controls were ...

  8. An Inquiry into the Effect of Heating on Ascorbic Acid

    Science.gov (United States)

    Yip, Din Yan

    2009-01-01

    Investigations that study the effect of heating on ascorbic acid are commonly performed in schools, but the conclusions obtained are quite variable and controversial. Some results indicate that heating may destroy vitamin C, but others suggest that heating may have no effect. This article reports an attempt to resolve this confusion through a…

  9. Effect of supplemental Ascorbic acid and disturbance stress on the ...

    African Journals Online (AJOL)

    The study was conducted with four hundred day-old Anak broilers to determine the effects of dietary Ascorbic acid (AA) and disturbance (D) dress on the performance of broiler chickens in a tropical environment. There were four treatments consisting of two levels of disturbance (ID) and (4D) and two levels of dietary AA (0 ...

  10. Morphological characters and ascorbic acid content of an elite ...

    African Journals Online (AJOL)

    Moisture stress can be deleterious to physicochemical properties of crop species to a varying degree. The influence of moisture stress on the ascorbic acid content in the leaf and morphological characters of an elite genotype of Corchorus olitorius were tested in a glasshouse experiment. The experiment was arranged in a ...

  11. ASCORBIC ACID IS DECREASED IN INDUCED SPUTUM OF MILD ASTHMATICS

    Science.gov (United States)

    Asthma is primarily an airways inflammatory disease, and the bronchial airways have been shown to be particularly susceptible to oxidant-induced tissue damage. The antioxidant ascorbic acid (AA) plays an essential role in defending against oxidant attack in the airways. Decreased...

  12. Ameliorative effects of ascorbic acid on rectal temperature ...

    African Journals Online (AJOL)

    Jane

    2011-08-29

    Aug 29, 2011 ... This experiment was performed with the aim of investigating the effects of ascorbic acid (AA) on stress due to road transportation ... evaluate the role of AA on rectal temperature (RT), behavioural and liveweight ... (Electron thermometer, COCET, China) for about 1 to 2 min into the rectum of each rabbit until ...

  13. Protective Effect of Oral Ascorbic Acid (Vitamin C) on ...

    African Journals Online (AJOL)

    Rev Olaleye

    Protective Effect of Oral Ascorbic Acid (Vitamin C) on. Acetaminophen-Induced Renal Injury in Rats a,*Adeneye A. A. and bOlagunju, J. O. Departments of aPharmacology, bMedical Biochemistry,. Lagos State University College of Medicine, Ikeja, Lagos State, Nigeria. ABSTRACT: The incidence of acetaminophen-induced ...

  14. Formulation and Evaluation of Ascorbic acid Tablets by Direct ...

    African Journals Online (AJOL)

    Formulation and Evaluation of Ascorbic acid Tablets by Direct Compression using Microcrystalline Starch as a Direct Compression Excipient. ... Abstract. PURPOSE: To evaluate the tableting properties of microcrystalline starch (MCS) used as a direct ... RESULTS: Mechanical properties of tablets formulated with MCS were

  15. Protective effect of oral ascorbic acid (vitamin c) against ...

    African Journals Online (AJOL)

    The incidence of acetaminophen-induced hepatotoxicity is reported to be on the increase, with limited therapeutic or chemoprophylactic options. In the present in vivo study, single daily oral doses (100 – 500 mg/kg) of ascorbic acid (ASC) were investigated for their protective effects against acetaminophen (APAP)-induced ...

  16. The biochemical, physiological and therapeutic roles of ascorbic acid

    African Journals Online (AJOL)

    Ascorbic acid is an important micronutrient necessary for a significant number of metabolic reactions in humans and other primates. It is a strong reducing agent involved in reduction reaction and it is structurally related to glucose. Experimental and epidemiological studies have documented the biochemical, physiological ...

  17. modelling of thermal degradation kinetics of ascorbic acid

    African Journals Online (AJOL)

    Administrator

    nutritional importance of antioxidants in foods such as ascorbic acid (vitamin C) has found increased interest due to their possible role in the prevention of human diseases such as cancer, atherosclerosis and immune depression (Byres and Perry, 1992). The status of vitamins during processing is receiving more attention. A.

  18. Determination of ascorbic acid content of some tropical fruits by ...

    African Journals Online (AJOL)

    The ascorbic acid content of three common juicy tropical fruits, orange, water melon and cashew, were determined using iodometric titration method under three temperature regimes (refrigerated, room temperature, and heated to about 80 oC), representing the range of temperatures the fruits may be exposed to during ...

  19. Apparent increase of vitamin C (ascorbic acid) levels in potato ...

    African Journals Online (AJOL)

    Vitamin C (Ascorbic acid) levels in Irish potato (Solanum tuberosum) tubers purchased from shops and open markets in Cardiff, U.K. were determined in the raw, boiled and fried (chips) pieces by 2,6, Dichlorophenolindophenol dye (DCP) method in the laboratory. The chips were prepared in sunflower oil, corn oil and ...

  20. Mixed metal complexes of isoniazid and ascorbic acid: chelation ...

    African Journals Online (AJOL)

    Novel mixed complexes of isoniazid and ascorbic acid have been synthesized and characterized using infrared, electronic absorption data, elemental analysis, molar conductivity, melting point, thin layer chromatography and solubility. The metal ions involved in the complex formation are Cu2+, Zn2+ and Cd2+. The melting ...

  1. Kinetics of Ascorbic acid degradation in asceptically packaged ...

    African Journals Online (AJOL)

    The recent ban on importation of fruit juices into Nigeria led to increase in production of locally - made orange juice. Degradation kinetics of ascorbic acid at refrigeration (70C ± 20C) and ambient temperature (280C ± 20C) were evaluated by the application of zero-order reaction kinetic. Results showed satisfactory ...

  2. Ameliorative effect of ascorbic acid on mercury chloride‑induced ...

    African Journals Online (AJOL)

    Introduction: Mercury is a highly toxic metal that exerts its adverse effects on the health of humans and animals through air, soil, water and food. Aim: The present study was aimed at the evaluation of the effects of ascorbic acid on mercury chloride-induced changes on the histomorphology of the spleen of adult Wistar Rats.

  3. Influence of enzymes and ascorbic acid on dough rheology and ...

    African Journals Online (AJOL)

    The breads were also characterized in general aspect - especially shelf-life - based on the presence of fungi. The dough rheology results showed that the formulation developed in the presence of 0.01% xylanase/amylase and 200 ppm of ascorbic acid was more efficient. Improved shelf-life was obtained from the ...

  4. Exogenous ascorbic acid increases resistance to salt of Silybum ...

    African Journals Online (AJOL)

    However, irrigation with salt water enhanced carotenoids and antioxidant enzyme activities. The detrimental effects of salt water were ameliorated by application of 100 ppm ascorbic acid (vitamin C). The inductive role of vitamin was associated with the improvement of seed germination, growth, plant water status, ...

  5. Effect of Combined Intake of Garcinia Kola and Ascorbic Acid on ...

    African Journals Online (AJOL)

    open-angle glaucoma or ocular hypertension. Middle East African Journal .... monkey and guinea pig), occurring as both ascorbic acid and .... Data Analysis. Results. Egbeahie et al. JNOA.2018;20(1): 20 - 29. Ascorbic acid only or Garcinia kola plus Ascorbic acid) belonging to the par cipant's group was then administered ...

  6. Ascorbic Acid Induces Necrosis in Human Laryngeal Squamous Cell Carcinoma via ROS, PKC, and Calcium Signaling.

    Science.gov (United States)

    Baek, Min-Woo; Cho, Heui-Seung; Kim, Sun-Hun; Kim, Won-Jae; Jung, Ji-Yeon

    2017-02-01

    Ascorbic acid induces apoptosis, autophagy, and necrotic cell death in cancer cells. We investigated the mechanisms by which ascorbic acid induces death in laryngeal squamous cell carcinoma Hep2 cells. Ascorbic acid markedly reduced cell viability and induced death without caspase activation and an increase in cytochrome c. Hep2 cells exposed to ascorbic acid exhibited membrane rupture and swelling, the morphological characteristics of necrotic cell death. The generation of reactive oxygen species (ROS) was increased in Hep2 cells treated with ascorbic acid, and pretreatment with N-acetylcysteine blocked ascorbic acid-induced cell death. Ascorbic acid also stimulated protein kinase C (PKC) signaling, especially PKC α/β activation, and subsequently increased cytosolic calcium levels. However, ascorbic acid-induced necrotic cell death was inhibited by Ro-31-8425 (PKC inhibitor) and BAPTA-AM (cytosolic calcium-selective chelator). ROS scavenger NAC inhibited PKC activation induced by ascorbic acid and Ro-31-8425 suppressed the level of cytosolic calcium increased by ascorbic acid, indicating that ROS is represented as an upstream signal of PKC pathway and PKC activation leads to the release of calcium into the cytosol, which ultimately regulates the induction of necrosis in ascorbic acid-treated Hep2 cells. These data demonstrate that ascorbic acid induces necrotic cell death through ROS generation, PKC activation, and cytosolic calcium signaling in Hep2 cells. J. Cell. Physiol. 232: 417-425, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  7. Response of antioxidant system of tomato to water deficit stress and its interaction with ascorbic acid

    Directory of Open Access Journals (Sweden)

    Fatemeh Daneshmand

    2014-03-01

    Full Text Available Environmental stresses including water deficit stress may produce oxidants such as reactive oxygen species that damage the membrane structure in plants. Among the antioxidants, ascorbic acid has a critical role in the cell and scavenges reactive oxygen species. In this research, effects of ascorbic acid at two levels (0 and 10 mM and water deficit stress based on 3 levels of field capacity (100, 60 and 30% were studied in tomato plants. Both levels of stress increased lipid peroxidation, reduced the amount of ascorbic acid and glutathione and increased the activity of enzymes superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, guaiacol peroxidase and reduced the growth parameters. Ascorbic acid treatment, reduced lipid peroxidation, increased ascorbic acid and glutathione levels and decreased the activity of superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase and guaiacol peroxidase and positive effects of ascorbic acid treatment appeared to improve the plant growth parameters.

  8. Influence of Dietary Ascorbic Acid on the Immune Responses of Juvenile Korean Rockfish Sebastes schlegelii.

    Science.gov (United States)

    Kim, Jun-Hwan; Kang, Ju-Chan

    2015-09-01

    Juvenile Korean Rockfish Sebastes schlegelii (length, 13.6 ± 1.4 cm [mean ± SD]; weight, 53.6 ± 4.2 g) were fed twice daily with diets containing varying levels of ascorbic acid (0, 50, 100, 200, and 400 mg/kg) for 4 weeks. Significant increases in daily weight and length occurred in fish fed more than 50 mg/kg ascorbic acid. The lysozyme activity of fish fed diets containing ascorbic acid was considerably increased in rockfish plasma at 400 mg/kg ascorbic acid and in kidney at over 50 mg/kg ascorbic acid. Total plasma immunoglobulin M (IgM) levels were markedly elevated in fish fed 400 mg/kg ascorbic acid. The results suggest that dietary ascorbic acid supplementation in juvenile rockfish can induce a significant increase in growth and in immunological features such as lysozyme activity and plasma IgM levels.

  9. Elimination of ascorbic acid after high-dose infusion in prostate cancer patients

    DEFF Research Database (Denmark)

    Nielsen, Torben Kjær; Højgaard, Martin; Andersen, Jon Thor Trærup

    2015-01-01

    Treatment with high-dose intravenous (IV) ascorbic acid (AA) is used in complementary and alternative medicine for various conditions including cancer. Cytotoxicity to cancer cell lines has been observed with millimolar concentrations of AA. Little is known about the pharmacokinetics of high dose...... infusion stop in prostate cancer patients with normal kidney function. We propose a regimen with a bolus loading followed by a maintenance infusion based on the calculated clearance.......Treatment with high-dose intravenous (IV) ascorbic acid (AA) is used in complementary and alternative medicine for various conditions including cancer. Cytotoxicity to cancer cell lines has been observed with millimolar concentrations of AA. Little is known about the pharmacokinetics of high dose...... IV AA. The purpose of the present study was to assess the basic kinetic variables in human beings over a relevant AA dosing interval for proper design of future clinical trials. Ten patients with metastatic prostate cancer were treated for four weeks with fixed AA doses of 5, 30 and 60 g. AA...

  10. Nitrate, Nitrite and ascorbic acid content of commercial and home ...

    African Journals Online (AJOL)

    The contents of nitrate, nitrite and ascorbic acid were determined in four samples of commercial and fifteen samples of home - prepared complementary infant foods common in Nigeria. The nitrate and nitrite values of the commercial food samples ranged from 3.1– 3.9mgNO3- N/100g and 5.0 - 16.0ug N02 - N/100g ...

  11. Production of ascorbic acid releasing biomaterials for pelvic floor repair.

    Science.gov (United States)

    Mangır, Naşide; Bullock, Anthony J; Roman, Sabiniano; Osman, Nadir; Chapple, Christopher; MacNeil, Sheila

    2016-01-01

    An underlying abnormality in collagen turnover is implied in the occurrence of complications and recurrences after mesh augmented pelvic floor repair surgeries. Ascorbic acid is a potent stimulant of collagen synthesis. The aim of this study is to produce ascorbic acid releasing poly-lactic acid (PLA) scaffolds and evaluate them for their effects on extracellular matrix production and the strength of the materials. Scaffolds which contained either l-ascorbic acid (AA) and Ascorbate-2-Phosphate (A2P) were produced with emulsion electrospinning. The release of both drugs was measured by UV spectrophotometry. Human dermal fibroblasts were seeded on scaffolds and cultured for 2weeks. Cell attachment, viability and total collagen production were evaluated as well as mechanical properties. No significant differences were observed between AA, A2P, Vehicle and PLA scaffolds in terms of fibre diameter and pore size. The encapsulation efficiency and successful release of both AA and A2P were demonstrated. Both AA and A2P containing scaffolds were significantly more hydrophilic and stronger in both dry and wet states compared to PLA scaffolds. Fibroblasts produced more collagen on scaffolds containing either AA or A2P compared to cells grown on control scaffolds. This study is the first to directly compare the two ascorbic acid derivatives in a tissue engineered scaffold and shows that both AA and A2P releasing electrospun PLA scaffolds increased collagen production of fibroblasts to similar extents but AA scaffolds seemed to be more hydrophilic and stronger compared to A2P scaffolds. Mesh augmented surgical repair of the pelvic floor currently relies on non-degradable materials which results in severe complications in some patients. There is an unmet and urgent need for better pelvic floor repair materials. Our current understanding suggests that the ideal material should be able to better integrate into sites of implantation both biologically and mechanically. The impact of

  12. Treatment of Irradiated Mice with High-Dose Ascorbic Acid Reduced Lethality

    Science.gov (United States)

    Sato, Tomohito; Kinoshita, Manabu; Yamamoto, Tetsuo; Ito, Masataka; Nishida, Takafumi; Takeuchi, Masaru; Saitoh, Daizoh; Seki, Shuhji; Mukai, Yasuo

    2015-01-01

    Ascorbic acid is an effective antioxidant and free radical scavenger. Therefore, it is expected that ascorbic acid should act as a radioprotectant. We investigated the effects of post-radiation treatment with ascorbic acid on mouse survival. Mice received whole body irradiation (WBI) followed by intraperitoneal administration of ascorbic acid. Administration of 3 g/kg of ascorbic acid immediately after exposure significantly increased mouse survival after WBI at 7 to 8 Gy. However, administration of less than 3 g/kg of ascorbic acid was ineffective, and 4 or more g/kg was harmful to the mice. Post-exposure treatment with 3 g/kg of ascorbic acid reduced radiation-induced apoptosis in bone marrow cells and restored hematopoietic function. Treatment with ascorbic acid (3 g/kg) up to 24 h (1, 6, 12, or 24 h) after WBI at 7.5 Gy effectively improved mouse survival; however, treatments beyond 36 h were ineffective. Two treatments with ascorbic acid (1.5 g/kg × 2, immediately and 24 h after radiation, 3 g/kg in total) also improved mouse survival after WBI at 7.5 Gy, accompanied with suppression of radiation-induced free radical metabolites. In conclusion, administration of high-dose ascorbic acid might reduce radiation lethality in mice even after exposure. PMID:25651298

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

    Science.gov (United States)

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

    2015-06-01

    The effects of relative humidity (RH) on the antioxidant properties of ascorbic acid (10, 20, 42, and 84ppm) were investigated in stripped corn oils stored at 60°C. The degree of oxidation in oils was determined by analysing headspace oxygen content and conjugated dienoic acids. The oxidative stability of bulk oils without addition of ascorbic acid was significantly different depending on the RH. As the concentration of ascorbic acid increased from 10 to 84ppm, oxidative stability increased significantly irrespective of RH (p<0.05). Generally, oils containing ascorbic acid at low RH had higher oxidative stability after storage at 60°C than those at high RH. The antioxidant properties of ascorbic acid were greatly influenced by both the moisture content in the oil and the ascorbic acid concentration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The preparation and the sustained release of titanium dioxide hollow particles encapsulating L-ascorbic acid

    Science.gov (United States)

    Tominaga, Yoko; Kadota, Kazunori; Shimosaka, Atsuko; Yoshida, Mikio; Oshima, Kotaro; Shirakawa, Yoshiyuki

    2018-05-01

    The preparation of the titanium dioxide hollow particles encapsulating L-ascorbic acid via sol-gel process using inkjet nozzle has been performed, and the sustained release and the effect protecting against degradation of L-ascorbic acid in the particles were investigated. The morphology of titanium dioxide particles was evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The sustained release and the effect protecting against degradation of L-ascorbic acid were estimated by dialysis bag method in phosphate buffer saline (PBS) (pH = 7.4) as release media. The prepared titanium dioxide particles exhibited spherical porous structures. The particle size distribution of the titanium dioxide particles was uniform. The hollow titanium dioxide particles encapsulating L-ascorbic acid showed the sustained release. It was also found that the degradation of L-ascorbic acid could be inhibited by encapsulating L-ascorbic acid in the titanium dioxide hollow particles.

  15. Reduction of nitrobenzene with alkaline ascorbic acid: Kinetics and pathways

    International Nuclear Information System (INIS)

    Liang, Chenju; Lin, Ya-Ting; Shiu, Jia-Wei

    2016-01-01

    Highlights: • Alkaline ascorbic acid (a.k.a. vitamin C) is capable of reductively degrading NB. • The pH above the pK a2 of ascorbic acid increases reductive electron transfer to NB. • The rate equation for the reactions between NB and AA is determined. • NSB, AZOXY, and AZO are identified as intermediates and aniline as a final product. • Alkaline pH is essential for AA remediation of NB contaminated soils. - Abstract: Alkaline ascorbic acid (AA) exhibits the potential to reductively degrade nitrobenzene (NB), which is the simplest of the nitroaromatic compounds. The nitro group (NO 2 − ) of NB has a +III oxidation state of the N atom and tends to gain electrons. The effect of alkaline pH ranging from 9 to 13 was initially assessed and the results demonstrated that the solution pH, when approaching or above the pK a2 of AA (11.79), would increase reductive electron transfer to NB. The rate equation for the reactions between NB and AA at pH 12 can be described as r = ((0.89 ± 0.11) × 10 −4 mM 1−(a + b) h −1 ) × [NB] a = 1.35 ± 0.10 [AA] b = 0.89 ± 0.01 . The GC/MS analytical method identified nitrosobenzene, azoxybenzene, and azobenzene as NB reduction intermediates, and aniline (AN) as a final product. These experimental results indicate that the alkaline AA reduction of NB to AN mainly proceeds via the direct route, consisting of a series of two-electron or four-electron transfers, and the condensation reaction plays a minor route. Preliminary evaluation of the remediation of spiked NB contaminated soils revealed that maintenance of alkaline pH and a higher water to soil ratio are essential for a successful alkaline AA application.

  16. Thermal stability of L-ascorbic acid and ascorbic acid oxidase in broccoli (Brassica oleracea var. italica).

    Science.gov (United States)

    Munyaka, Ann Wambui; Makule, Edna Edward; Oey, Indrawati; Van Loey, Ann; Hendrickx, Marc

    2010-05-01

    The thermal stability of vitamin C (including l-ascorbic acid [l-AA] and dehydroascorbic acid [DHAA]) in crushed broccoli was evaluated in the temperature range of 30 to 90 degrees C whereas that of ascorbic acid oxidase (AAO) was evaluated in the temperature range of 20 to 95 degrees C. Thermal treatments (for 15 min) of crushed broccoli at 30 to 60 degrees C resulted in conversion of l-AA to DHAA whereas treatments at 70 to 90 degrees C retained vitamin C as l-AA. These observations indicated that enzymes (for example, AAO) could play a major role in the initial phase (that is, oxidation of l-AA to DHAA) of vitamin C degradation in broccoli. Consequently, a study to evaluate the temperature-time conditions that could result in AAO inactivation in broccoli was carried out. In this study, higher AAO activity was observed in broccoli florets than stalks. During thermal treatments for 10 min, AAO in broccoli florets and stalks was stable until around 50 degrees C. A 10-min thermal treatment at 80 degrees C almost completely inactivated AAO in broccoli. AAO inactivation followed 1st order kinetics in the temperature range of 55 to 65 degrees C. Based on this study, a thermal treatment above 70 degrees C is recommended for crushed vegetable products to prevent oxidation of l-AA to DHAA, the onset of vitamin C degradation. The results reported in this study are applicable for both domestic and industrial processing of vegetables into products such as juices, soups, and purees. In this report, we have demonstrated that processing crushed broccoli in a temperature range of 30 to 60 degrees C could result in the conversion of l-ascorbic acid to dehydroascorbic (DHAA), a very important reaction in regard to vitamin C degradation because DHAA could be easily converted to other compounds that do not have the biological activity of vitamin C.

  17. Measurement of binding of ascorbic acid to myrosinase by rate of dialysis

    International Nuclear Information System (INIS)

    Ohtsuru, Masaru; Hata, Tadao

    1975-01-01

    The activation mechanism of myrosinase by L-ascorbic acid depends on the slight conformational change of enzyme protein induced by ascorbic acid. Ascorbic acid binds to enzyme like Michaelis-complex, and then the value of Km had been evaluated to be 1 x 10 -3 M. The authors determined the binding constant and the number of binding sites using dialysis rate technique. Rate dialysis was carried out with a dialysis cell, and the ordinary cellophane tubing membrane was used. ( 14 C) - ascorbic acid was added, and counted by liquid scintillation counting. By the time course of two dialysis rate measurement with and without enzyme. The concentrations of free and bound ascorbic acids were counted. From the results, the enzyme was activated to the maximum level at 10 -3 M of ascorbic acid, and four molecules of ascorbic acid bound to the enzyme on Kd=0.1x10 -4 M. However, when more than 4 molecules of L-ascorbic acid bound to the enzyme, Kd increased to 0.9x10 -4 M, and L-ascorbic acid acted as an inhibitor. (Kubatake, H.)

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

    International Nuclear Information System (INIS)

    Arya, S. P.; Mahajan, M.

    1998-01-01

    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 μg 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 [it

  19. Role Of Ascorbic Acid In Imparting Tolerance To Plants Against Oxidizing Pollutants

    Directory of Open Access Journals (Sweden)

    Priyanka Sharma

    2015-08-01

    Full Text Available Ascorbic acid is an antioxidant in plants which play important role in activation of many physiological and defense mechanisms. The level of ascorbic acid in plants is determinant of its tolerance against the adverse effect of oxidizing pollutants. The present study tries to relate the variation in ascorbic acid content with the tolerance and sensitivity of two selected plant species viz. Azadirachtaindica and Pongamiapinnata by calculating their Air Pollution Tolerance Index APTI during winter season from November to March in the urban city Delhi of North India. Moreover ascorbic acid is also an important part of chloroplast it protects different components of photosynthetic system from oxidative stress. Thus to understand the role of ascorbic acid in imparting tolerance to plants against oxidizing pollutants the changes in chlorophyll content of the selected plant species with variation in ambient ozone concentration was analysed. It was found that as per APTI values Azadirachta sp. came under tolerant range with highest ascorbic acid content whereas Pongamia sp. was under intermediate range with less ascorbic acid content. It was statistically established that ozone has no significant relation with chlorophyll content of Azadirachta sp. which has the highest ascorbic acid content. Whereas ambient ozone concentrations showed significant negative relation with the chlorophyll content of Pongamia sp. p 0.05. Thus it was observed that the plants with high ascorbic acid content are tolerant and have greater ability to remediate pollutants.

  20. The Effects of Various Levels of Ascorbic Acid Intake Upon Oral Wound Healing in Guinea Pigs.

    Science.gov (United States)

    1983-01-01

    and deteriorates in air. L-ascorbic acid is the active form of vitamin C.. Ultraviolet light absorption of L-ascorbic acid occurs at 245 rm. if the pH ...ascorbic acid. 3 SkO Odontoblasts degenerate and are unable to form dental matrix in a deficient state. 7󈧼 Dentin becomes porous and pulpal tissues...would not increase tissue saturation in guinea pigs. 87 Five hundredths of a milligram of ascorbic acid was 12 adequate to prevent pulpal degeneration

  1. Neutron scattering and HPLC study on L-ascorbic acid and its degradation

    International Nuclear Information System (INIS)

    Bellocco, E.; Barreca, D.; Lagana, G.; Leuzzi, U.; Migliardo, F.; Torre, R. La; Galli, G.; Galtieri, A.; Minutoli, L.; Squadrito, F.

    2008-01-01

    The present paper shows a systematic dynamic and kinetic study on L-ascorbic acid and its degradation at high temperature. The neutron scattering study allows, through the behavior of quasi-elastic neutron scattering (QENS) spectra, to characterize the diffusive dynamics of L-ascorbic acid in water mixtures. Ascorbic acid undergoes degradation process at high temperature, but the presence of trehalose in solution markedly avoids ascorbic acid loss enhancing its t 1/2 (half life time), as determined by high performance liquid chromatography (HPLC)

  2. Water-dispersible ascorbic-acid-coated magnetite nanoparticles for contrast enhancement in MRI

    Science.gov (United States)

    Sreeja, V.; Jayaprabha, K. N.; Joy, P. A.

    2015-04-01

    Superparamagnetic iron oxide nanoparticles of size ~5 nm surface functionalized with ascorbic acid (vitamin C) form a stable dispersion in water with a hydrodynamic size of ~30 nm. The anti-oxidant property of ascorbic acid is retained after capping, as evidenced from the capability of converting methylene blue to its reduced leuco form. NMR relaxivity studies show that the ascorbic-acid-coated superparamagnetic iron oxide aqueous nanofluid is suitable as a contrast enhancement agent for MRI applications, coupled with the excellent biocompatibility and medicinal values of ascorbic acid.

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

    Science.gov (United States)

    Fenoglio, I; Martra, G; Coluccia, S; Fubini, B

    2000-10-01

    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 amount of ascorbic acid exceeds the amount of silicon that is released. Silicon tetrahedra bearing free silanols at the quartz surface are selectively attached by ascorbic acid. The particle-derived hydroxyl radical yield in the presence of hydrogen peroxide is increased on ascorbic acid-treated quartz in comparison with the original sample. The results presented herein are relevant because the depletion of ascorbic acid from the lung lining layer and the increased potential in particle-derived free radical generation may both contribute to the oxidative damage following inhalation of crystalline silica.

  4. The effect of water, ascorbic acid, and cranberry derived supplementation on human urine and uropathogen adhesion to silicone rubber

    NARCIS (Netherlands)

    Habash, MB; van der Mei, HC; Busscher, HJ; Reid, G

    In this study, urine was collected from groups of volunteers following the consumption of water, ascorbic acid, or cranberry supplements. Only ascorbic acid intake consistently produced acidic urine. Photospectroscopy data indicated that increased water consumption produced urine with lower protein

  5. Importance of ascorbic acid in the absorption of iron from infant foods

    International Nuclear Information System (INIS)

    Derman, D.P.; Bothwell, T.H.; MacPhail, A.P.; Torrance, J.D.; Bezwoda, W.R.; Charlton, R.W.; Mayet, F.G.H.

    1980-01-01

    The absorption of fortification iron from an infant milk formula and from 3 infant cereals was studied in 121 multiparous women. The mean absorption was less than 3.2% when no added ascorbic acid was present. The nature of the iron compound added to infant cereals did not seem to influence the amount absorbed. Absorption was significantly improved when ascorbic acid was added, the mean increase being threefold with an iron:ascorbic ratio of 1:1.5 molar and more than sixfold with a ratio of 1:3 molar (about 10 mg ascorbic acid per mg iron). (author)

  6. Microencapsulation of ascorbic acid: effect of process variables on product characteristics.

    Science.gov (United States)

    Uddin, M S; Hawlader, M N; Zhu, H J

    2001-01-01

    This study deals with a comparative investigation of the characteristics of ascorbic acid microcapsules prepared by different methods, such as thermal phase separation, melt dispersion, solvent evaporation and spray drying. Scanning electron microscopy (SEM), release tests and size distribution were used for the evaluation of product characteristics. The results show that microencapsulated ascorbic acid could prevent the ascorbic acid colour change, retard its core release rate, and generally mask its acid taste. In the thermal phase separation, molecular weight (Mw) of ethyl cellulose (EC) and the addition of polyisobutylene (PIB) significantly influenced the aggregation and release rate of microcapsules. In the melt dispersion method, spherical particles were prepared by using carnauba. The ascorbic acid release rate was found to be slower in the case of carnauba-encapsulated ascorbic acid than that made by EC using other methods. In the solvent evaporation method, a higher Mw of EC and the addition of plastizer were also found to be important for good encapsulation. In the spray drying method, loss of ascorbic acid was found to be minimum during microencapsulation. Starch and beta-cyclodextrin encapsulated ascorbic acid delayed the degradation of ascorbic acid during storage at 38 degrees C and relative humidity 84.0%.

  7. The effects of ascorbic acid on diphtheria toxin and intoxicated hela cells

    International Nuclear Information System (INIS)

    Clark, C.E.; Smith, T.J.

    1976-01-01

    Ascorbic acid (vitamin C) prevented diphtheria toxin from inhibiting the incorporation of [U- 14 C]-alanine into trichloroacetic acid precipitable material in HeLa cells. Ascorbic acid did not exhibit an effect on the adenosine diphosphate-ribosylation of amino acyl transferase 2 nor did it separate fragment A from fragment B in ''nicked'' toxin. A non-specific reducing agent, para-methylaminophenol sulfate, exhibited an effect of HeLa cells very similar to the results of ascorbic acid. Citric acid, a tricarboxylic acid, had no effect on HeLa cells. (auth.)

  8. Ascorbic acid effects on in vitro maturation of mouse oocyte with or ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... However, further studies on the potential effects of different concentrations of ascorbic acid on oocyte maturation are needed. Key words: Ascorbic acid, cumulus cell, in vitro maturation, mice. INTRODUCTION. Maturation process in mammalian oocytes includes important nuclear and cytoplasmic changes, ...

  9. the effect of ascorbic acid and propranolol on normal sleep and ...

    African Journals Online (AJOL)

    ascorbic acid on open field locomotor activity and normal sleep in healthy adult rats and evaluate how these correlate with those of propranolol. MethodS: Eighty healthy adult Wistar rats of both sexes were divided into two groups of 40 animals each group. One group received ascorbic acid treatment while the other group ...

  10. Effect of ascorbic acid and hydrogen peroxide on mouse neuroblastoma cells

    Science.gov (United States)

    HARDAWAY, CHRISITNA M.; BADISA, RAMESH B.; SOLIMAN, KARAM F.A.

    2012-01-01

    Ascorbic acid is one of the antioxidant compounds widely used against free radical stress. The present study was undertaken to examine whether ascorbic acid and hydrogen peroxide (H2O2), alone or in combination, could influence cell viability. The murine neuroblastoma cell line, N2a, was used to perform a dose response curve for ascorbic acid. It was observed that ascorbic acid alone at physiological concentrations (0.1–0.4 mM) did not cause any cell death. However, at pharmacological concentrations (1–6 mM), ascorbic acid caused dose-dependent cell death. The lethal concentration at which 50% cells were killed (LC50) was determined to be approximately 3.141 mM ascorbic acid at 24 h. H2O2 up to 300 μM alone did not cause significant cell death. In the combined treatment, when the cells were treated with ascorbic acid at physiological concentrations (0.4 mM) and H2O2 at 400 μM, higher rates of cell death were observed compared to the cell death rates caused by either compound alone. Subsequent experiments revealed that cell death was partly mediated through the loss of total glutathione levels in the cells. These data suggest that the combination of ascorbic acid and H2O2 is disadvantageous for cancer cell survival. Further studies are required to ascertain the physiological significance of these observations. PMID:22469841

  11. Randomized clinical trial of ascorbic acid in the treatment of pressure ulcers

    NARCIS (Netherlands)

    ter Riet, G.; Kessels, A. G.; Knipschild, P. G.

    1995-01-01

    The objective of this study was to assess the effects of ascorbic acid supplementation, 500 mg twice daily in the treatment of pressure ulcers as an adjunct to standardized treatment. The design consisted of a multicenter blinded randomized trial. The control group received 10 mg of ascorbic acid

  12. Control of lethal browning by using ascorbic acid on shoot tip ...

    African Journals Online (AJOL)

    The use of ascorbic acid during explants preparation and the effect of different concentrations of ascorbic acid in controlling lethal browning and survival of the explants in local banana cv. Mzuzu banana were investigated. The explants were taken from young suckers. The shoot tips were cultured on Murashige and Skoog's ...

  13. Increasing Thai Catfish's Immunity (Pangasius hypophthalmus Fowler Using Ascorbic Acid

    Directory of Open Access Journals (Sweden)

    , Ilmiah

    2007-08-01

    Full Text Available ABSTRACTAn experiment to determine Thai catfish's (Pangasius hypophthalmus Fowler immunity was carried out using different levels of ascorbic acid (0, 1.000, 2.000 and 3.000 mg/kg feed.  Fish of 15-20 g in weight were kept in aquaria for 6 weeks with density of 15 fish/aquaria.  Feed was given at 5-10 % of total biomass with frequency of three times a day.  The blood sampling was taken every week and the challenge test with Aeromonas hydrophila (106cells/mm3 injection intramuscular was done on the 30th day.   The result of this experiment shown that feed with ascorbic acid of 2.000 mg/kg was elevated the cellular responses such as: leucocyte total (34.850 cels/mm3, differential of leucocyte (lymphocyte: 72,2%, monocyte: 8,0%, neutrophyl: 7,8%, phagocytic index (13% and humoral response (titre antibody: 0.829 serum aglutination unit, which at the same time proves high level of survival rate against the artificial injection using A. hydrophila. Key words :  Ascorbic acid, fish immunity, Thai catfish, Pangasius hypophthalmus.   ABSTRAK Suatu penelitian telah dilakukan di laboratorium dengan menggunakan ikan jambal Siam (Pangasius hypophthalmus Fowler untuk melihat tingkat kekebalan ikan dengan menambahkan vitamin C pada pakan (0, 1.000, 2.000 dan 3.000 mg/kg pakan.  Ikan jambal Siam ukuran 15-20 g dipelihara dalam aquarium selama 6 minggu dengan kepadatan 15 ekor/wadah.  Pemberian pakan dilakukan 3 kali sehari sebanyak 5-10% dari bobot biomasa, pengambilan contoh darah dilakukan setiap minggu dan uji tantang dilakukan pada hari ke-30 dengan bakteri Aeromonas hydrophila (106 sel/mm3 secara intramuskular.  Hasil penelitian menunjukkan bahwa penambahan vitamin C sebanyak 2.000 mg/kg pakan menyebabkan meningkatnya respon seluler antara lain: total lekosit (34.850 sel/mm3, jenis lekosit (limfosit: 72,2%, monosit: 8,0%, netrofil: 7,7% dan trombosit: 17,6% indeks fagositik 13% dan respon humoral (titer antibodi: 0,829 unit serum aglutinasi

  14. Reduction of nitrobenzene with alkaline ascorbic acid: Kinetics and pathways

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chenju, E-mail: cliang@nchu.edu.tw [Department of Environmental Engineering, National Chung Hsing University 250, Kuo-kuang Road, Taichung 402, Taiwan (China); Lin, Ya-Ting [Department of Environmental Engineering, Chung Yuan Christian University, 200 Chung Pei Road, Chung Li District, Taoyuan City 320, Taiwan (China); Shiu, Jia-Wei [Department of Environmental Engineering, National Chung Hsing University 250, Kuo-kuang Road, Taichung 402, Taiwan (China)

    2016-01-25

    Highlights: • Alkaline ascorbic acid (a.k.a. vitamin C) is capable of reductively degrading NB. • The pH above the pK{sub a2} of ascorbic acid increases reductive electron transfer to NB. • The rate equation for the reactions between NB and AA is determined. • NSB, AZOXY, and AZO are identified as intermediates and aniline as a final product. • Alkaline pH is essential for AA remediation of NB contaminated soils. - Abstract: Alkaline ascorbic acid (AA) exhibits the potential to reductively degrade nitrobenzene (NB), which is the simplest of the nitroaromatic compounds. The nitro group (NO{sub 2}{sup −}) of NB has a +III oxidation state of the N atom and tends to gain electrons. The effect of alkaline pH ranging from 9 to 13 was initially assessed and the results demonstrated that the solution pH, when approaching or above the pK{sub a2} of AA (11.79), would increase reductive electron transfer to NB. The rate equation for the reactions between NB and AA at pH 12 can be described as r = ((0.89 ± 0.11) × 10{sup −4} mM{sup 1−(a} {sup +} {sup b)} h{sup −1}) × [NB]{sup a} {sup =} {sup 1.35} {sup ±} {sup 0.10}[AA]{sup b} {sup =} {sup 0.89} {sup ±} {sup 0.01}. The GC/MS analytical method identified nitrosobenzene, azoxybenzene, and azobenzene as NB reduction intermediates, and aniline (AN) as a final product. These experimental results indicate that the alkaline AA reduction of NB to AN mainly proceeds via the direct route, consisting of a series of two-electron or four-electron transfers, and the condensation reaction plays a minor route. Preliminary evaluation of the remediation of spiked NB contaminated soils revealed that maintenance of alkaline pH and a higher water to soil ratio are essential for a successful alkaline AA application.

  15. Chemistry of ascorbic acid and sulfur dioxide as an antioxidant system relevant to white wine.

    Science.gov (United States)

    Barril, Célia; Clark, Andrew C; Scollary, Geoffrey R

    2012-06-30

    The impact of the combined ascorbic acid and sulfur dioxide antioxidants on white wine oxidation processes was investigated using a range of analytical techniques, including flow injection analysis for free and total sulfur dioxide and two chromatographic methods for ascorbic acid, its oxidative degradation products and phenolic compounds. The combination of different analytical techniques provided a fast and simultaneous means for the monitoring of oxidation processes in a model wine system. In addition, the initial mole ratio of sulfur dioxide to ascorbic acid was varied and the model wine complexity was increased by the inclusion of metal ions (copper(II) and iron(II)). Sulfur dioxide was found not to be a significant binder of ascorbic acid oxidative degradation products and could not prevent the formation of certain phenolic pigment precursors. The results provide a detailed insight into the ascorbic acid/sulfur dioxide antioxidant system in wine conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Encapsulation of ascorbic acid promotes the reduction of Maillard reaction products in UHT milk.

    Science.gov (United States)

    Troise, Antonio Dario; Vitiello, Daniele; Tsang, Catherine; Fiore, Alberto

    2016-06-15

    The presence of amino groups and carbonyls renders fortified milk with ascorbic acid particularly susceptible to the reduction of available lysine and to the formation of Maillard reaction products (MRPs), as Nε-(carboxyethyl)-l-lysine (CEL), Nε-(carboxymethyl)-l-lysine (CML), Amadori products (APs) and off-flavors. A novel approach was proposed to control the Maillard reaction (MR) in fortified milk: ascorbic acid was encapsulated in a lipid coating and the effects were tested after a lab scale UHT treatment. Encapsulation promoted a delayed release of ascorbic acid and a reduction in the formation of MRPs. Total lysine increased up to 45% in milk with encapsulated ascorbic acid, while reductions in CML, CEL and furosine ranged from 10% to 53% compared with control samples. The effects were also investigated towards the formation of amide-AGEs (advanced glycation end products) by high resolution mass spectrometry (HRMS) revealing that several mechanisms coincide with the MR in the presence of ascorbic acid.

  17. Simultaneous detection of dopamine, ascorbic acid, and uric acid at electrochemically pretreated carbon nanotube biosensors.

    Science.gov (United States)

    Alwarappan, Subbiah; Liu, Guodong; Li, Chen-Zhong

    2010-02-01

    In this work we have evaluated the performance of electrochemically pretreated single-walled carbon nanotubes (SWCNTs) toward the electrochemical detection of dopamine in the presence of ascorbic acid and uric acid at physiological pH. Results indicated that the electrochemically pretreated SWCNTs showed a selective and enhanced electroanalytical response with minimal electrode fouling toward the detection of dopamine than their untreated counterparts. The observed behavior is attributed to the negatively charged layer present on the SWCNTs originating from the rupture of the basal plane present on the end caps following electrochemical pretreatment. The rupture of basal plane is evident from surface Raman measurements. The negatively charged surface selectively allows the cationic dopamine toward the electrode and repels the anionic ascorbate and uric acid when they coexist in the same solution under physiological pH. A limit of detection of about 15 nM is obtained with these electrodes for the detection of dopamine in the presence of ascorbic acid and uric acid. The performance of electrochemically pretreated single-walled carbon nanotubes (SWCNTs) was studied toward the electrochemical detection of dopamine. These SWCNTs showed a selective and enhanced response toward the detection of dopamine. A limit of detection of about 15 nM is obtained with these electrodes for the detection of dopamine in the presence of ascorbic acid and uric acid. Copyright 2010 Elsevier Inc. All rights reserved.

  18. Biotechnological approaches for L-ascorbic acid production.

    Science.gov (United States)

    Hancock, Robert D; Viola, Roberto

    2002-07-01

    Over the past decade there has been increasing pressure to develop alternatives to the Reichstein process, a largely chemical synthesis by which the vast majority of world vitamin C (L-ascorbic acid, L-AA) is produced. The pressures include increasing environmental concerns and legislation, and the need to increase process efficiency and reduce capital costs. The development of efficient fermentation processes in the past ten years has also represented a catalyst for change. Here, we describe the development of biotechnological alternatives for the synthesis of Reichstein intermediates by industrial microorganisms. The recent elucidation of the plant biosynthetic pathway represents new opportunities not only for the direct synthesis of L-AA by fermentation but also for the production of human crop plants and animal fodder with enhanced nutritional value. We discuss the potential for these developments in the light of recent findings concerning L-AA biosynthesis in plants.

  19. A flexible micro biofuel cell utilizing hydrogel containing ascorbic acid

    Science.gov (United States)

    Goto, Hideaki; Fukushi, Yudai; Nishioka, Yasushiro

    2014-11-01

    This paper reports on a biofuel cell with a dimension of 13×24 mm2 fabricated on a flexible polyimide substrate. I its porous carbon-coated platinum (Pt) electrodes of 3 mm in width and 10 mm in length were fabricated using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Pt electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. It utilizes a solidified ascorbic acid (AA) aqueous solution in an agarose hydrogel to increase the portability. The maximum power and power density for the biofuel cell with the fuel unit containing 100 mM AA were 0.063 μW and 0.21 μW/cm2 at 0.019 V, respectively.

  20. A flexible micro biofuel cell utilizing hydrogel containing ascorbic acid

    International Nuclear Information System (INIS)

    Goto, Hideaki; Fukushi, Yudai; Nishioka, Yasushiro

    2014-01-01

    This paper reports on a biofuel cell with a dimension of 13×24 mm 2 fabricated on a flexible polyimide substrate. I its porous carbon-coated platinum (Pt) electrodes of 3 mm in width and 10 mm in length were fabricated using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Pt electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. It utilizes a solidified ascorbic acid (AA) aqueous solution in an agarose hydrogel to increase the portability. The maximum power and power density for the biofuel cell with the fuel unit containing 100 mM AA were 0.063 μW and 0.21 μW/cm 2 at 0.019 V, respectively

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

    Directory of Open Access Journals (Sweden)

    Bisht Surendra S

    2006-12-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Ioana Ieremia

    2006-08-01

    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.

  3. The browning kinetics of the non-enzymatic browning reaction in L-ascorbic acid/basic amino acid systems

    Directory of Open Access Journals (Sweden)

    Ai-Nong YU

    Full Text Available Abstract Under the conditions of weak basis and the reaction temperature range of 110-150 °C, lysine, arginine and histidine were reacted with L-ascorbic acid at equal amount for 30-150 min, respectively and the formation of browning products was monitored with UV–vis spectrometry. The kinetic characteristics of their non-enzymatic browning reaction were investigated. The study results indicated that the non-enzymatic browning reaction of these three amino acids with L-ascorbic acid to form browning products was zero-order reaction. The apparent activation energies for the formation of browning products from L-ascorbic acid/lysine, L-ascorbic acid/arginine and L-ascorbic acid/histidine systems were 54.94, 50.08 and 35.31kJ/mol. The activation energy data indicated the degree of effects of reaction temperature on non-enzymatic browning reaction. Within the temperature range of 110-150 °C, the reaction rate of L-ascorbic acid/lysine system was the fastest one, followed by that of the L-ascorbic acid/arginine system. The reaction rate of L-ascorbic acid/histidine system was the slowest one. Based on the observed kinetic data, the formation mechanisms of browning products were proposed.

  4. Exogenous ascorbic acid improves defence responses of sunflower (Helianthus annuus) exposed to multiple stresses.

    Science.gov (United States)

    Kaya, Armagan

    2017-09-01

    Ascorbic acid is an important antioxidant that plays role both on growth and development and also stress response of the plant. The purpose of this study was to determine the effect of ascorbate on physiological and biochemical changes of sunflower that was exposed to multiple stresses. Chlorophyll and carotenoid contents decreased and glutathione, ascorbate and malondialdehyde contents as well as antioxidant enzyme activities increased for sunflower plant that was exposed to 50 mM NaCl and pendimethalin at different concentrations. These changes were found to be more significant in groups simultaneously exposed to both stress factors. While malondialdehyde content decreased, chlorophyll, carotenoid, ascorbate, glutathione contents and antioxidant enzyme activities increased in plants treated exogenously with ascorbate, compared to the untreated samples. According to the findings of our study; compared to individual stress, the effect of stress is more pronounced in sunflower exposed to multiple stresses, and treatment with exogenous ascorbate reduces the negative effects of stress.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-10-01

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

  6. Distribution and metabolism of ascorbic acid in pear fruits ( Pyrus ...

    African Journals Online (AJOL)

    Ascorbate accumulation levels, distribution and key enzyme activities involved in synthesizing via Smirnoff-Wheeler pathway and recycling in different pear fruit tissues during development were studied. Results show that the ascorbate contents increased with the fruit development, and reached the highest titers in 30 days ...

  7. Investigation of L(+)-Ascorbic Acid with Raman Spectroscopy in Visible and UV Light

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2015-01-01

    calculations with 6-311++G(d,p) basis sets for several conformations of ascorbic acid and the anions. Raman spectra were measured during titration with NaOH base in an oxygen-poor environment to avoid fluorescence when solutions were alkaline. The ultraviolet (UV) absorption band for ascorbic acid in aqueous......Abstract: Raman spectroscopy investigations of l(+)-ascorbic acid and its mono- and di-deprotonated anions (AH(-) and A(2-)) are reviewed and new measurements reported with several wavelengths, 229, 244, 266, 488, and 532nm. Results are interpreted, assisted by new DFT/B3LYP quantum chemical...

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

    Science.gov (United States)

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

    2014-11-01

    Tomato fruits are an important source of l-Ascorbic acid, which is an essential compound of human diet. The effect of the widespread practice of cold storing (5-10 °C) tomato fruits was monitored to determine its impact on the concentration and redox status of l-Ascorbic acid. Total l-Ascorbic acid levels were well maintained in both attached fruits and cold treated fruits, while in other treatments its levels were considerably reduced. However, low temperature storage conditions enhanced the expression of most genes coding for enzymes involved in l-Ascorbic acid biosynthesis and redox reactions. The findings suggest that the transcriptional up-regulation under chilling stress conditions of most genes coding for l-Ascorbic acid biosynthetic genes galactono-1,4-lactone dehydrogenase, GDP-d-mannose 3,5-epimerase but also for the isoenzymes of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase enzyme, glutathione reductase that are strongly correlated to the l-Ascorbic redox status. Moreover, fruits stored at 10 °C exhibited higher levels of transcript accumulation of MDHAR2, DHAR1, DHAR2, GR1 and GR2 genes, pointing to a better ability to manage chilling stress in comparison to fruits stored at 5 °C. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. Metabolic engineering of the fungal D-galacturonate pathway for L-ascorbic acid production.

    Science.gov (United States)

    Kuivanen, Joosu; Penttilä, Merja; Richard, Peter

    2015-01-08

    Synthetic L-ascorbic acid (vitamin C) is widely used as a preservative and nutrient in food and pharmaceutical industries. In the current production method, D-glucose is converted to L-ascorbic acid via several biochemical and chemical steps. The main source of L-ascorbic acid in human nutrition is plants. Several alternative metabolic pathways for L-ascorbic acid biosynthesis are known in plants. In one of them, D-galacturonic acid is the precursor. D-Galacturonic acid is also the main monomer in pectin, a plant cell wall polysaccharide. Pectin is abundant in biomass and is readily available from several waste streams from fruit and sugar processing industries. In the present work, we engineered the filamentous fungus Aspergillus niger for the conversion of D-galacturonic acid to L-ascorbic acid. In the generated pathway, the native D-galacturonate reductase activity was utilized while the gene coding for the second enzyme in the fungal D-galacturonic acid pathway, an L-galactonate consuming dehydratase, was deleted. Two heterologous genes coding for enzymes from the plant L-ascorbic acid pathway--L-galactono-1,4-lactone lactonase from Euglena gracilis (EgALase) and L-galactono-1,4-lactone dehydrogenase from Malpighia glabra (MgGALDH)--were introduced into the A. niger strain. Alternatively, an unspecific L-gulono-1,4-lactone lactonase (smp30) from the animal L-ascorbic acid pathway was introduced in the fungal strain instead of the plant L-galactono-1,4-lactone lactonase. In addition, a strain with the production pathway inducible with D-galacturonic acid was generated by using a bidirectional and D-galacturonic acid inducible promoter from the fungus. Even though, the lactonase enzyme activity was not observed in the resulting strains, they were capable of producing L-ascorbic acid from pure D-galacturonic acid or pectin-rich biomass in a consolidated bioprocess. Product titers up to 170 mg/l were achieved. In the current study, an L-ascorbic acid pathway using

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

    International Nuclear Information System (INIS)

    Rafique, N.; Raza, S.H.; Qasim, M.; Iqbal, N.

    2011-01-01

    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)

  11. Ascorbic acid promotes a TGFβ1-induced myofibroblast phenotype switch.

    Science.gov (United States)

    Piersma, Bram; Wouters, Olaf Y; de Rond, Saskia; Boersema, Miriam; Gjaltema, Rutger A F; Bank, Ruud A

    2017-09-01

    l-Ascorbic acid (AA), generally known as vitamin C, is a crucial cofactor for a variety of enzymes, including prolyl-3-hydroxylase (P3H), prolyl-4-hydroxylase (P4H), and lysyl hydroxylase (LH)-mediated collagen maturation. Here, we investigated whether AA has additional functions in the regulation of the myofibroblast phenotype, besides its function in collagen biosynthesis. We found that AA positively influences TGF β 1-induced expression of COL1A1 , ACTA2 , and COL4A1 Moreover, we demonstrated that AA promotes α SMA stress fiber formation as well as the synthesis and deposition of collagens type I and IV Additionally, AA amplified the contractile phenotype of the myofibroblasts, as seen by increased contraction of a 3D collagen lattice. Moreover, AA increased the expression of several TGF β 1-induced genes, including DDR1 and CCN2 Finally, we demonstrated that the mechanism of AA action seems independent of Smad2/3 signaling. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  12. ESR study of ascorbic acid irradiated with gamma-ray

    International Nuclear Information System (INIS)

    Tuner, H.; Korkmaz, M.

    2007-01-01

    The interest in application of high-energy ionizing radiation for sterilization of pharmaceutical products and foodstuffs has led a number of workers to investigate the radiation sensitivity of vitamins. Aside from its use as a vitamin, ascorbic acid (AA) or some derivatives are employed as antioxidants in foodstuffs. The effects of ionizing radiation on AA in simple solutions and in mixture of naturally occurring compounds have been extensively reported in the literature. However, the effects of ionizing radiation on solid AA were reported in few works which described rather dosimetric features of AA. No reports, except one, are available describing the characteristic features of the radiolytic intermediates produced after irradiation of polycrystalline AA. Irradiation studies performed on single crystal of AA has led us to reinvestigate our previous work on the radiolytic intermediates produced in irradiated polycrystalline AA. Three radical species, rather than two, having different characteristics were decided contributing to the formation of experimental electron spin resonance (ESR) spectrum of γ-irradiated polycrystalline AA. Spectral parameters of these species were calculated after exhaustive spectrum simulation calculations based on data derived from experimental microwave saturation and dose-response studies. (author)

  13. Kinetics of degradation of ascorbic acid by cyclic voltammetry method

    Directory of Open Access Journals (Sweden)

    Grudić Veselinka V.

    2015-01-01

    Full Text Available Cyclic voltammetry was used to examine the kinetics of degradation of ascorbic acid (AA at different temperatures. It has been shown that the reduction of the concentration of AA in all temperatures follow the kinetics of the first order reaction. The rate constant of the oxidation reaction increases with temperature as follows: 5x10-5; 2x10-4; 1x10-3 and 3x10-3 min-1 at temperatures of 25°C, 35°C, 65°C and 90°C, respectively. The temperature dependence of the rate constant follows Arrhenius equation, and the value of activation energy of the reaction degradation is 48.2 kJ mol-1 . The effect of storage time at a temperature of 90 °C on AA content in fresh juice of green peppers was investigated. It was shown that AA oxidation reaction in the juice is also the first order reaction, while the lower rate constant in relation to the pure AA (5x10-3 min-1 indicates the influence of other substances present in peppers.

  14. Ascorbic Acid Determination in Natural Orange Juice: As a Teaching Tool of Coulometry and Polarography.

    Science.gov (United States)

    Bertotti, Mauro; And Others

    1995-01-01

    Describes an experiment designed to determine ascorbic acid concentrations in natural orange juice. The experiment is used with undergraduate pharmacy students to allow understanding of the principles of operation of the coulometer and polarograph. (DDR)

  15. Ascorbic acid inhibits human insulin aggregation and protects against amyloid induced cytotoxicity.

    Science.gov (United States)

    Alam, Parvez; Beg, Ayesha Zainab; Siddiqi, Mohammad Khursheed; Chaturvedi, Sumit Kumar; Rajpoot, Ravi Kant; Ajmal, Mohd Rehan; Zaman, Masihuz; Abdelhameed, Ali S; Khan, Rizwan Hasan

    2017-05-01

    Protein aggregation into oligomers and fibrils are associated with many human pathophysiologies. Compounds that modulate protein aggregation and interact with preformed fibrils and convert them to less toxic species, expect to serve as promising drug candidates and aid to the drug development efforts against aggregation diseases. In present study, the kinetics of amyloid fibril formation by human insulin (HI) and the anti-amyloidogenic activity of ascorbic acid (AA) were investigated by employing various spectroscopic, imaging and computational approaches. We demonstrate that ascorbic acid significantly inhibits the fibrillation of HI in a dose-dependent manner. Interestingly ascorbic acid destabilise the preformed amyloid fibrils and protects human neuroblastoma cell line (SH- SY5Y) against amyloid induced cytotoxicity. The present data signifies the role of ascorbic acid that can serve as potential molecule in preventing human insulin aggregation and associated pathophysiologies. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Terekhova, Irina V.; Kulikov, Oleg V.; Titova, Elena S.

    2004-01-01

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

  17. Old Things New View: Ascorbic Acid Protects the Brain in Neurodegenerative Disorders.

    Science.gov (United States)

    Covarrubias-Pinto, Adriana; Acuña, Aníbal Ignacio; Beltrán, Felipe Andrés; Torres-Díaz, Leandro; Castro, Maite Aintzane

    2015-11-27

    Ascorbic acid is a key antioxidant of the Central Nervous System (CNS). Under brain activity, ascorbic acid is released from glial reservoirs to the synaptic cleft, where it is taken up by neurons. In neurons, ascorbic acid scavenges reactive oxygen species (ROS) generated during synaptic activity and neuronal metabolism where it is then oxidized to dehydroascorbic acid and released into the extracellular space, where it can be recycled by astrocytes. Other intrinsic properties of ascorbic acid, beyond acting as an antioxidant, are important in its role as a key molecule of the CNS. Ascorbic acid can switch neuronal metabolism from glucose consumption to uptake and use of lactate as a metabolic substrate to sustain synaptic activity. Multiple evidence links oxidative stress with neurodegeneration, positioning redox imbalance and ROS as a cause of neurodegeneration. In this review, we focus on ascorbic acid homeostasis, its functions, how it is used by neurons and recycled to ensure antioxidant supply during synaptic activity and how this antioxidant is dysregulated in neurodegenerative disorders.

  18. Degradation of L-Ascorbic Acid in the Amorphous Solid State.

    Science.gov (United States)

    Sanchez, Juan O; Ismail, Yahya; Christina, Belinda; Mauer, Lisa J

    2018-03-01

    Ascorbic acid degradation in amorphous solid dispersions was compared to its degradation in the crystalline state. Physical blends and lyophiles of ascorbic acid and polymers (pectins and polyvinylpyrrolidone [PVP]) were prepared initially at 50:50 (w/w), with further studies using the polymer that best inhibited ascorbic acid crystallization in the lyophiles in 14 vitamin : PVP ratios. Samples were stored in controlled environments (25 to 60 °C, 0% to 23% RH) for 1 mo and analyzed periodically to track the physical appearance, change in moisture content, physical state (powder x-ray diffraction and polarized light microscopy), and vitamin loss (high performance liquid chromatography) over time. The glass transition temperatures of select samples were determined using differential scanning calorimetry, and moisture sorption profiles were generated. Ascorbic acid in the amorphous form, even in the glassy amorphous state, was more labile than in the crystalline form in some formulations at the highest storage temperature. Lyophiles stored at 25 and 40 °C and those in which ascorbic acid had crystallized at 60 °C (≥70% ascorbic acid : PVP) had no significant difference in vitamin loss (P > 0.05) relative to physical blend controls, and the length of storage had little effect. At 60 °C, amorphous ascorbic acid lyophiles (≤60% ascorbic acid : PVP) lost significantly more vitamin (P degradation also significantly increased (P < 0.05) at lower proportions of ascorbic acid, a scenario likely encountered in foods wherein vitamins are naturally present or added at low concentrations and production practices may promote amorphization of the vitamin. Vitamin C is one of the most unstable vitamins in foods. This study documents that amorphous ascorbic acid is less stable than crystalline ascorbic acid in some environments (for example, higher temperatures within 1 wk), especially when the vitamin is present at low concentrations in a product. These findings increase the

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

    Science.gov (United States)

    Chen, Hongxing; Gu, Zhengbiao

    2014-09-01

    Ammonia caramels are among the most widely used colorant additives in the food industry. They are commonly prepared through the Maillard reaction and caramelization of mixtures of reducing sugars with ammonia or ammonium salts. Antioxidants are known to inhibit acrylamide formation during the Maillard reaction, and they may affect the properties of the ammonia caramel products. Thus, the objective of this study was to investigate the effect of the antioxidant ascorbic acid on the properties of ammonia caramel. A mixture of glucose and ammonia was allowed to react at 120 °C for 60 min in the presence of ascorbic acid at final concentrations of 0 to 0.08 M. The ammonia caramels obtained from these reactions were all positively charged. As the concentration of ascorbic acid increased, the color intensity of the ammonia caramel showed a decreasing trend, while the intensity of the fluorescence and total amount of pyrazines in the volatiles showed a tendency to increase. The addition of ascorbic acid did not result in obvious changes in the UV-visible spectra of the ammonia caramels and the types of pyrazines in the volatiles were also unchanged. It is noteworthy that the addition of 0.02 to 0.08 M ascorbic acid did reduce the formation of the by-product acrylamide, a harmful substance in food. When the concentration of ascorbic acid added reached 0.04 M, the content of acrylamide in the ammonia caramel was 20.53 μg/L, which was approximately 44% lower than that without ascorbic acid. As a result, ascorbic acid can be considered to improve the quality and safety of ammonia caramels. © 2014 Institute of Food Technologists®

  20. Ascorbic Acid may Exacerbate Aspirin-Induced Increase in Intestinal Permeability.

    Science.gov (United States)

    Sequeira, Ivana R; Kruger, Marlena C; Hurst, Roger D; Lentle, Roger G

    2015-09-01

    Ascorbic acid in combination with aspirin has been used to prevent aspirin-induced oxidative GI damage. We aimed to determine whether ascorbic acid reduces or prevents aspirin-induced changes in intestinal permeability over a 6-hr period using saccharidic probes mannitol and lactulose. The effects of administration of 600 mg aspirin alone, 500 mg ascorbic acid alone and simultaneous dosage of both agents were compared in a cross-over study in 28 healthy female volunteers. These effects were also compared with that of a placebo. The ability of ascorbic acid to mitigate the effects of aspirin when administered either half an hour before or after dosage with aspirin was also assessed in 19 healthy female volunteers. The excretion of lactulose over the 6-hr period was augmented after consumption of either aspirin or ascorbic acid compared with that after consumption of placebo. Dosage with ascorbic acid alone augmented the excretion of lactulose more than did aspirin alone. Simultaneous dosage with both agents augmented the excretion of lactulose in an additive manner. The timing of dosage with ascorbic acid in relation to that with aspirin had no significant effect on the excretion of the two sugars. These findings indicate that ascorbic acid does not prevent aspirin-induced increase in gut permeability rather that both agents augment it to a similar extent. The additive effect on simultaneous dosage with both agents in augmenting the absorption of lactulose suggests that each influences paracellular permeability by different pathways. © 2015 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  1. Ascorbic acid reverses the prolonged anesthetic action of pentobarbital in Akr1a-knockout mice.

    Science.gov (United States)

    Ito, Junitsu; Otsuki, Noriyuki; Zhang, Xuhong; Konno, Tasuku; Kurahashi, Toshihiro; Takahashi, Motoko; Yamato, Mayumi; Matsuoka, Yuta; Yamada, Ken-ichi; Miyata, Satoshi; Fujii, Junichi

    2014-01-24

    Aldehyde reductase (AKR1A), a member of the aldo-keto reductase superfamily, is highly expressed in the liver and is involved in both the detoxification of carbonyl compounds and ascorbic acid biosynthesis. By comparison with wild-type mice, Akr1a-knockout (Akr1a(-/-)) mice and human Akrla-transgenic (Akr1a(tg/+)) mice experience different anesthetic actions from pentobarbital-prolonged in Akr1a-knockout (Akr1a(-/-)) mice and shortened in human Akrla-transgenic (Akr1a(tg/+)) mice. We investigated this alteration in the anesthetic efficacy of pentobarbital in Akr1a genetically modified mice. Neither the cytosolic protein of wild-type mouse liver nor purified rat AKR1A directly reduced pentobarbital. Ascorbic acid administration neutralized the prolonged duration of the loss of the righting reflex (LORR) in Akr1a(-/-) mice, but preincubation of pentobarbital with ascorbic acid prior to administration did not change the anesthetic effect. Those results indicated that ascorbic acid does not directly reduce pentobarbital. Enzymatic activities and levels of the proteins of some cytochrome P450s that make up a potent detoxification system for pentobarbital showed no changes in the genetically modified mice examined. Thus, ascorbic acid also had no effect on the detoxification system in the liver. The prolonged duration of LORR in the Akr1a(-/-) mice caused by pentobarbital and the neutralization of the anesthetic effect by ascorbic acid together with other results imply that ascorbic acid alters the responses of the neuronal system to anesthetics. Pentobarbital action is increased under conditions of ascorbic acid deficiency, and this may have to be taken into account when anesthetizing malnourished patients. Copyright © 2013. Published by Elsevier Inc.

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

    Science.gov (United States)

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

    2015-04-15

    The stability of ascorbic acid and colour intensity in pasteurised blood orange juice (Citrus sinensis [L.] Osbeck) during one month of storage was investigated at 4-37 °C. The effects of ascorbic acid fortification (at 100, 200 mg L(-1)) and deaeration, temperature/time storage on the kinetic behaviour were determined. Ascorbic acid was monitored by HPLC-DAD and colour intensity by spectrophotometric measurements. Degradation kinetics were best fitted by first-order reaction models for both ascorbic acid and colour intensity. Three models (Arrhenius, Eyring and Ball) were used to assess the temperature-dependent degradation. Following the Arrhenius model, activation energies were ranged from 51 to 135 kJ mol(-1) for ascorbic acid and from 49 to 99 kJ mol(-1) for colour intensity. The effect of storage temperature and deaeration are the most influent factors on kinetics degradation, while the fortification revealed no significant effect on ascorbic acid content and colour intensity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Ascorbic acid enables reversible dopamine receptor 3H-agonist binding

    International Nuclear Information System (INIS)

    Leff, S.; Sibley, D.R.; Hamblin, M.; Creese, I.

    1981-01-01

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

  4. L-ascorbic acid addition to chitosan reduces body weight in overweight women.

    Science.gov (United States)

    Jung, Eun Young; Jun, Sung Chul; Chang, Un Jae; Suh, Hyung Joo

    2014-01-01

    Previously, we have found that the addition of L-ascorbic acid to chitosan enhanced the reduction in body weight gain in guinea pigs fed a high-fat diet. We hypothesized that the addition of L-ascorbic acid to chitosan would accelerate the reduction of body weight in humans, similar to the animal model. Overweight subjects administered chitosan with or without L-ascorbic acid for 8 weeks, were assigned to three groups: Control group (N=26, placebo, vehicle only), Chito group (N=27, 3 g/day chitosan), and Chito-vita group (N=27, 3 g/day chitosan plus 2 g/day L-ascorbic acid). The body weights and body mass index (BMI) of the Chito and Chito-vita groups decreased significantly (preduction of body weight and BMI was accentuated by the addition of L-ascorbic acid. The fat mass, percentage body fat, body circumference, and skinfold thickness in the Chito and Chito-vita groups decreased more than the Control group; however, these parameters were not significantly different between the three groups. Chitosan combined with L-ascorbic acid may be useful for controlling body weight.

  5. Further investigations on the role of ascorbic acid in stratum corneum lipid models after UV exposure.

    Science.gov (United States)

    Trommer, Hagen; Böttcher, Rolf; Huschka, Christoph; Wohlrab, Wolfgang; Neubert, Reinhard H H

    2005-08-01

    This study is the continuation of our research into vitamin C and its possible effects on human skin after topical administration. The effects of ascorbic acid, iron ions and UV irradiation on stratum corneum lipid models were investigated. The lipid models used were: a simple system (linolenic acid dispersion), a complex system (liposomes consisting of dipalmitoylphosphatidylcholine, cholesterol and linolenic acid) and complex systems with additionally incorporated ceramides (types III and IV). The lipid peroxidation was quantified by the thiobarbituric acid assay. A human adult low-calcium high-temperature (HaCaT) keratinocytes cell culture was used as a second in-vitro model. The amount of intracellular peroxides was determined by measuring the fluorescence intensity using the dihydrorhodamine 123 assay. Electron paramagnetic resonance spectroscopy was used to study the influence of ascorbic acid and iron ions on the signal intensity of 5-doxylstearic acid during UV exposure. Ascorbic acid showed prooxidative properties in the thiobarbituric acid assay whereas cell protection was measured in the HaCaT keratinocytes experiments. Electron paramagnetic resonance investigations revealed different extents of free radical production generated by iron ions, ascorbic acid and UV irradiation. In evaluating the results from this study new aspects of the mechanism of lipid damage caused by these three factors were suggested, transcending the simple redox behaviour of ascorbic acid.

  6. Synthesis of L-ascorbic acid in the phloem

    Directory of Open Access Journals (Sweden)

    Haupt Sophie

    2003-11-01

    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.

  7. The effects of Α-tocopherol and ascorbic acid glucosides on radiation- and H2O2-induced decomposition of thymine in aqueous solution

    International Nuclear Information System (INIS)

    Brinkevich, S.D.; Lagutin, P.Yu.; Shadyro, O.I.

    2008-01-01

    The effects of ascorbic acid, ascorbic acid glycoside and α-tocopherol monoglycoside on radiation- and H 2 O 2 -induced decomposition of thymine in aqueous solutions were investigated. Of the three compounds studied, ascorbic acid glycoside was found to possess the most marked protecting properties. An explanation of this phenomenon has been given in terms of differences in molecular structures of ascorbic acid and ascorbic acid glycoside, as well as properties of radical adducts formed during their interaction with OH radicals. (authors)

  8. Combined effect of ascorbic acid and gamma irradiation on microbial and sensorial characteristics of beef patties during refrigerated storage.

    Science.gov (United States)

    Giroux, M; Ouattara, B; Yefsah, R; Smoragiewicz, W; Saucier, L; Lacroix, M

    2001-02-01

    The present study was undertaken to evaluate the effect of ascorbic acid concentrations (0.03 to 0.5%) and irradiation doses (0.5 to 4 kGy) on microbial growth, color coordinates (L, a, and b), and sensory characteristics (taste and odor) of beef patties during storage at 4 +/- 1 degrees C. Ascorbic acid was also compared to citric acid at a similar pH value in order to differentiate the effects of ascorbic acid from those of pH reduction. Results showed significant reduction (pmeat. However, incorporation of ascorbic acid into the meat before irradiation resulted in significant (p< or = 0.05) stabilization of color parameters. The color improvement obtained with ascorbic acid was not related to the pH reduction. Also, no significant detrimental effect on taste or odor was found in irradiated samples containing ascorbic acid.

  9. Ascorbic acid for the treatment of Charcot-Marie-Tooth disease.

    Science.gov (United States)

    Gess, Burkhard; Baets, Jonathan; De Jonghe, Peter; Reilly, Mary M; Pareyson, Davide; Young, Peter

    2015-12-11

    Charcot-Marie-Tooth disease (CMT) comprises a large group of different forms of hereditary motor and sensory neuropathy. The molecular basis of several CMT subtypes has been clarified during the last 20 years. Since slowly progressive muscle weakness and sensory disturbances are the main features of these syndromes, treatments aim to improve motor impairment and sensory disturbances to improve abilities. Pharmacological treatment trials in CMT are rare. This review was derived from a Cochrane review, Treatment for Charcot Marie Tooth disease, which will be updated via this review and a forthcoming title, Treatments other than ascorbic acid for Charcot-Marie-Tooth disease. To assess the effects of ascorbic acid (vitamin C) treatment for CMT. On 21 September 2015, we searched the Cochrane Neuromuscular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and LILACS for randomised controlled trials (RCTs) of treatment for CMT. We also checked clinical trials registries for ongoing studies. We included RCTs and quasi-RCTs of any ascorbic acid treatment for people with CMT. Where a study aimed to evaluate the treatment of general neuromuscular symptoms of people with peripheral neuropathy including CMT, we included the study if we were able to identify the effect of treatment in the CMT group. We did not include observational studies or case reports of ascorbic acid treatment in people with CMT. Two review authors (BG and JB) independently extracted the data and assessed study quality. Six RCTs compared the effect of oral ascorbic acid (1 to 4 grams) and placebo treatment in CMT1A. In five trials involving adults with CMT1A, a total of 622 participants received ascorbic acid or placebo. Trials were largely at low risk of bias. There is high-quality evidence that ascorbic acid does not improve the course of CMT1A in adults as measured by the CMT neuropathy score (0 to 36 scale) at 12 months (mean difference (MD) -0.37; 95

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

    Science.gov (United States)

    Salkić, M.; Selimović, A.; Pašalić, H.; Keran, H.

    2014-03-01

    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 μg/ml. The detection limit was 0.11 μg/ml, and the relative standard deviation was 0.9 % (n = 7) for 8.00 μg/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.

  11. The effects of ascorbic acid on salt induced alfalfa ( Medicago sativa ...

    African Journals Online (AJOL)

    Ascorbic acid as an antioxidant agent has already been used for increasing of stress tolerance. Callus was produced from stem segments of alfalfa (Medicago sativa L.) on MS medium supplemented with 2,4 dichlorophenoxy acetic acid, naphthalene acetic acid and kinetin (2 mg/l each).Calli were then transferred to the ...

  12. Oxidative Stress in The Hippocampus During Experimental Seizures Can Be Ameliorated With The Antioxidant Ascorbic Acid

    Directory of Open Access Journals (Sweden)

    Ítala Mônica Sales Santos

    2009-01-01

    Full Text Available Ascorbic acid has many nonenzymatic actions and is a powerful water-soluble antioxidant. It protects low density lipoproteins from oxidation and reduces harmful oxidants in the central nervous system. Pilocarpine-induced seizures have been suggested to be mediated by increases in oxidative stress. Current studies have suggested that antioxidant compounds may afford some level of neuroprotection against the neurotoxicity of seizures. The objective of the present study was to evaluate the neuroprotective effects of ascorbic acid (AA in rats, against the observed oxidative stress during seizures induced by pilocarpine. Wistar rats were treated with 0.9% saline (i.p., control group, ascorbic acid (500 mg/kg, i.p., AA group, pilocarpine (400 mg/kg, i.p., pilocarpine group, and the association of ascorbic acid (500 mg/kg, i.p. plus pilocarpine (400 mg/kg, i.p., 30 min before of administration of ascorbic acid (AA plus pilocarpine group. After the treatments all groups were observed for 6 h. The enzyme activities as well as the lipid peroxidation and nitrite concentrations were measured using spectrophotometric methods and the results compared to values obtained from saline and pilocarpine-treated animals. Protective effects of ascorbic acid were also evaluated on the same parameters. In pilocarpine group there was a significant increase in lipid peroxidation and nitrite level. However, no alteration was observed in superoxide dismutase and catalase activities. Antioxidant treatment significantly reduced the lipid peroxidation level and nitrite content as well as increased the superoxide dismutase and catalase activities in hippocampus of adult rats after seizures induced by pilocarpine. Our findings strongly support the hypothesis that oxidative stress in hippocampus occurs during seizures induced by pilocarpine, proving that brain damage induced by the oxidative process plays a crucial role in seizures pathogenic consequences, and also imply that a

  13. Plasma Ascorbic Acid, A Priori Diet Quality Score, and Incident Hypertension: A Prospective Cohort Study.

    Science.gov (United States)

    Buijsse, Brian; Jacobs, David R; Steffen, Lyn M; Kromhout, Daan; Gross, Myron D

    2015-01-01

    Vitamin C may reduce risk of hypertension, either in itself or by marking a healthy diet pattern. We assessed whether plasma ascorbic acid and the a priori diet quality score relate to incident hypertension and whether they explain each other's predictive abilities. Data were from 2884 black and white adults (43% black, mean age 35 years) initially hypertension-free in the Coronary Artery Risk Development in Young Adults Study (study year 10, 1995-1996). Plasma ascorbic acid was assessed at year 10 and the diet quality score at year 7. Eight-hundred-and-forty cases of hypertension were documented between years 10 and 25. After multiple adjustments, each 12-point (1 SD) higher diet quality score at year 7 related to mean 3.7 μmol/L (95% CI 2.9 to 4.6) higher plasma ascorbic acid at year 10. In separate multiple-adjusted Cox regression models, the hazard ratio of hypertension per 19.6-μmol/L (1 SD) higher ascorbic acid was 0.85 (95% CI 0.79-0.92) and per 12-points higher diet score 0.86 (95% CI 0.79-0.94). These hazard ratios changed little with mutual adjustment of ascorbic acid and diet quality score for each other, or when adjusted for anthropometric variables, diabetes, and systolic blood pressure at year 10. Intake of dietary vitamin C and several food groups high in vitamin C content were inversely related to hypertension, whereas supplemental vitamin C was not. In conclusion, plasma ascorbic acid and the a priori diet quality score independently predict hypertension. This suggests that hypertension risk is reduced by improving overall diet quality and/or vitamin C status. The inverse association seen for dietary but not for supplemental vitamin C suggests that vitamin C status is preferably improved by eating foods rich in vitamin C, in addition to not smoking and other dietary habits that prevent ascorbic acid from depletion.

  14. Mechanisms of Ascorbic Acid Stimulation of Norepinephrine Synthesis in Neuronal Cells

    OpenAIRE

    May, James M.; Qu, Zhi-chao; Meredith, M. Elizabeth

    2012-01-01

    Ascorbic acid is well known to acutely stimulate norepinephrine synthesis in neurosecretory cells, but it has also been shown over several days to increase tyrosine hydroxylase mRNA and norepinephrine synthesis in cultured neurons. Since tyrosine hydroxylase is the rate-limiting step in catecholamine synthesis, an effect of ascorbate to increase tyrosine hydroxylase protein could contribute to its ability to increase or sustain catecholamine synthesis. Therefore, we evaluated whether tyrosine...

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

    International Nuclear Information System (INIS)

    Selvaraju, T.; Ramaraj, R.

    2007-01-01

    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 μM for AA and 20-50 μM 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

  16. Ameliorative effects of betaine and ascorbic acid administration to ...

    African Journals Online (AJOL)

    This review highlights the huge challenges heat stress pose to profitable production of broiler chickens during the hot-dry season. It also enumerates the negative effects of heat stress due to excess production of reactive oxygen species (ROS) in broiler chickens. It emphasizes that administration of betaine and/or ascorbic ...

  17. Sensitive spectrophotometric determination of ascorbic acid in drugs and foods using surface plasmon resonance band of silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Kobra Zarei

    2015-12-01

    Full Text Available A simple and sensitive procedure was proposed for spectrophotometric determination of ascorbic acid. It was found that the reduction of Ag+ to silver nanoparticles (Ag-NPs by ascorbic acid in the presence of polyvinylpyrrolidone (PVP as a stabilizing agent produce very intense surface plasmon resonance peak of Ag-NPs. The plasmon absorbance of the Ag-NPs at λ = 440 nm allows the quantitative spectrophotometric detection of the ascorbic acid. The calibration curve was linear with concentration of ascorbic acid in the range of 0.5–60 μM. The detection limit was obtained as 0.08 μM. The influence of potential interfering substances on the determination of ascorbic acid was studied. The proposed method was successfully applied for the determination of ascorbic acid in some powdered drink mixtures, commercial orange juice, natural orange juice, vitamin C injection, effervescent tablet, and multivitamin tablet.

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

    Directory of Open Access Journals (Sweden)

    Cvetković Biljana R.

    2012-01-01

    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.

  19. Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage

    Energy Technology Data Exchange (ETDEWEB)

    Frei, B. (Department of Nutrition, Harvard School of Public Health, Boston, MA (Unites States))

    1991-12-01

    The authors exposed human blood plasma and low-density lipoprotein (LDL) to many different oxidative challenges and followed the temporal consumption of endogenous antioxidants in relation to the initiation of oxidative damage. Under all types of oxidizing conditions, ascorbic acid completely protects lipids in plasma and LDL against detectable peroxidative damage as assessed by a specific and highly sensitive assay for lipid peroxidation. Ascorbic acid proved to be superior to the other water-soluble plasma antioxidants bilirubin, uric acid, and protein thiols as well as to the lipoprotein-associated antioxidants alpha-tocopherol, ubiquinol-10, lycopene, and beta-carotene. Although these antioxidants can lower the rate of detectable lipid peroxidation, they are not able to prevent its initiation. Only ascorbic acid is reactive enough to effectively intercept oxidants in the aqueous phase before they can attack and cause detectable oxidative damage to lipids.

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

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Timm Heinrich, Maike; Meyer, Anne S.

    2001-01-01

    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...

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

    International Nuclear Information System (INIS)

    Goh, J.K.; Tan, W.T.

    2008-01-01

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

  2. Thermal degradation kinetics of ascorbic acid, thiamine and riboflavin in rosehip (Rosa canina L nectar

    Directory of Open Access Journals (Sweden)

    Çetin KADAKAL

    2017-10-01

    Full Text Available Abstract In this paper, the loss of L-ascorbic acid, thiamine and riboflavin in rosehip nectar with the heating periods (0, 5, 10, 15, 20 and 30 min at temperatures ranging from 70 to 95 °C is analyzed and experimental results are presented. Firstly, dried rosehip fruits were processed to rosehip nectar and then thermal treatment is performed. Liquid chromatographic (HPLC method was used for the analysis of the contents of L-ascorbic acid, thiamine and riboflavin and examined compounds are thoroughly separated within 25 min. During thermal processing, degradation of L-ascorbic acid, thiamine and riboflavin in rosehip nectar were fitted to a first-order reaction kinetic model. Arrhenius relationship was used for the description of temperature dependence of reaction. Activation energies for L-ascorbic acid, thiamine and riboflavin between 70 to 95 ºC were found to be 55.30, 36.38 and 37.15 kJ/mol, respectively. To the best of the author’s knowledge, due to lack of study on the thermal degradation of L-ascorbic acid, thiamine and riboflavin in rosehip nectar, this manuscript will be the first reported study to enable future analysis.

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

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Timm Heinrich, Maike; Meyer, Anne S.

    2001-01-01

    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......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...

  4. Antioxidant action of glutathione and the ascorbic acid/glutathione pair in a model white wine.

    Science.gov (United States)

    Sonni, Francesca; Clark, Andrew C; Prenzler, Paul D; Riponi, Claudio; Scollary, Geoffrey R

    2011-04-27

    Glutathione was assessed individually, and in combination with ascorbic acid, for its ability to act as an antioxidant with respect to color development in an oxidizing model white wine system. Glutathione was utilized at concentrations normally found in wine (30 mg/L), as well as at concentrations 20-fold higher (860 mg/L), the latter to afford ascorbic acid (500 mg/L) to glutathione ratios of 1:1. The model wine systems were stored at 45 °C without sulfur dioxide and at saturated oxygen levels, thereby in conditions highly conducive to oxidation. Under these conditions the results demonstrated the higher concentration of glutathione could initially provide protection against oxidative coloration, but eventually induced color formation. In the period during which glutathione offered a protective effect, the production of xanthylium cation pigment precursors and o-quinone-derived phenolic compounds was limited. When glutathione induced coloration, polymeric pigments were formed, but these were different from those found in model wine solutions without glutathione. In the presence of ascorbic acid, high concentrations of glutathione were able to delay the decay in ascorbic acid and inhibit the reaction of ascorbic acid degradation products with the wine flavanol compound (+)-catechin. However, on depletion, the glutathione again induced the production of a range of different polymeric pigments. These results highlight new mechanisms through which glutathione can offer both protection and spoilage during the oxidative coloration of a model wine.

  5. Ascorbic acid reduced mutagenicity at the HPRT locus in CHO cells against thermal neutron radiation

    International Nuclear Information System (INIS)

    Kinashi, Yuko; Sakurai, Yoshinori; Masunaga, Shinichiro; Suzuki, Minoru; Nagata, Kenji; Ono, Koji

    2004-01-01

    We investigated the biological effects of the long-lived radicals induced following neutron irradiation. It has been reported that radiation-induced long-lived radicals were scavenged by post-irradiation treatment of ascorbic acid (Koyama, 1998). We studied the effects of ascorbic acid acting as a long-lived radical scavenger on cell killing and mutagenicity in Chinese hamster ovary cells against thermal neutrons produced at the Kyoto University Research reactor. Ascorbic acid was added to cells 30 min after neutron irradiation and removed 150 min after irradiation. The biological end point of cell survival was measured by colony formation assay. The mutagenicity was measured by the mutant frequency in the HPRT locus. The post-irradiation treatment of ascorbic acid did not alter the cell killing effect of neutron radiation. However, the mutagenicity was decreased, especially when the cells were irradiated with boron. Our results suggested that ascorbic acid scavenged long-lived radicals effectively and caused apparent protective effects against mutagenicity of boron neutron capture therapy

  6. Determination of Ascorbic Acid in Oman Citrus Fruits

    Directory of Open Access Journals (Sweden)

    KS.M.Z. Al-Kindi

    2007-12-01

    Full Text Available Omani citrus fruits were analyzed for their Vitamin C (ascorbic and AA content by a titration method involving  N-bromosuccinimide (NBS as an oxidizing  agent and by high performance liquid  chromatography. Vitamin C content was also determined after storage at different temperatures. Vitamin C contents of the fruits were found to lie within  the values reported in the literature.

  7. pH level, ascorbic acid, proline and soluble sugar as bio - indicators ...

    African Journals Online (AJOL)

    The pH of the leave samples were measured after calibrating the pH meter; Ascorbic acid content (expressed in mg/g) was measured using spectrophotometric method; Proline content in the leaves of plants was determined following the protocol based on the formation of red colored formazone with ninhydrin in acidic ...

  8. Environmental Method to Determine Dopamine and Ascorbic Acid Simultaneously via Derivative Spectrophotometry

    Directory of Open Access Journals (Sweden)

    Ahmed M. El-Zohry

    2013-01-01

    Full Text Available Many various methods were applied to determine dopamine and ascorbic acid simultaneously using hazardous materials and complex procedures. Derivative absorption spectra can give safely and five sensitive derivative equations that are used for the simultaneous determination of dopamine and ascorbic acid in the UV region, using first and second derivative spectroscopy with high precision at pH value of 9.2. Dopamine and ascorbic acid can be detected in the ranges of 0.375–9.45 mg L−1 and 0.352–5.28 mg L−1, respectively. These obtained methods could be used to determine both reagents in real and synthesized samples.

  9. Dietary ascorbic acid and subsequent change in body weight and waist circumference

    DEFF Research Database (Denmark)

    Larsen, Sofus C; Angquist, Lars; Ahluwalia, Tarun Veer Singh

    2014-01-01

    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...... 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...

  10. Synthesis of colloidal silver nanoparticle clusters and their application in ascorbic acid detection by SERS.

    Science.gov (United States)

    Cholula-Díaz, Jorge L; Lomelí-Marroquín, Diana; Pramanick, Bidhan; Nieto-Argüello, Alfonso; Cantú-Castillo, Luis A; Hwang, Hyundoo

    2018-03-01

    Ascorbic acid (vitamin C) has an essential role in the human body mainly due to its antioxidant function. In this work, metallic silver nanoparticle (AgNP) colloids were used in SERS experiments to detect ascorbic acid in aqueous solution. The AgNPs were synthesized by a green method using potato starch as reducing and stabilizing agent, and water as the solvent. The optical properties of the yellowish as-synthesized silver colloids were characterized by UV-vis spectroscopy, in which besides a typical band at 410 nm related to the localized surface plasmon resonance of the silver nanoparticles, a shoulder band around 500 nm, due to silver nanoparticle cluster formation, is presented when relatively higher concentrations of starch are used in the synthesis. These starch-capped silver nanoparticles show an intrinsic Raman peak at 1386 cm -1 assigned to deformation modes of the starch structure. The increase of the intensity of the SERS peak at 1386 cm -1 with an increase in the concentration of the ascorbic acid is related to a decrease of the gap between dimers and trimers of the silver nanoparticle clusters produced by the presence of ascorbic acid in the colloid. The limit of detection of this technique for ascorbic acid is 0.02 mM with a measurement concentration range of 0.02-10 mM, which is relevant for the application of this method for detecting ascorbic acid in biological specimen. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen, S.; Karhu, M.

    1986-01-01

    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.

  12. The Use of Ascorbic Acid as a Food Additive: Technical-Legal Issues

    Science.gov (United States)

    Varvara, Michele; Bozzo, Giancarlo; Celano, Giuseppe; Disanto, Chiara; Pagliarone, Cosimo Nicola

    2016-01-01

    Ascorbic acid (C6H8O6) is an organic compound belonging to the family of monosaccharide. It is highly soluble in water, and is often called one of the secrets of the Mediterranean diet. Its use is widespread in the food industry is also important, having always been exploited for its antioxidant and stabilising ability. Many indeed are the additive formulations that take advantage of these properties. The purpose of this paper is to explain the characteristics that make ascorbic acid an important food additive and to emphasise the technical and legal issues related to its use in food productions. In particular, in the course of this employment, laws and scientific studies have been applied to the resolution of a lawsuit, having as its object the use of ascorbic acid in preparations of ground beef sold at a butcher shop. The views expressed in court by the technical consultant have led to the acquittal of the accused, in the light of the demonstrated and proven non-toxicity of the molecule and the use of a mixture of additives for the production of sausage. The European and national legislations, supported by numerous scientific studies, define the possible use of ascorbic acid according to the principle of quantum satis, and it can be used in foods for children. Our work aims to represent further evidence of the safety of use of ascorbic acid as a food additive, and – as confirmed by the legal decision reported – it wants to bring out the prospects for use of ascorbic acid for technological purposes even by registered establishments. PMID:27800425

  13. Application of super absorbent polymer and ascorbic acid to mitigate deleterious effects of cadmium in wheat

    Directory of Open Access Journals (Sweden)

    Hamid Reza Tohidi Moghadam

    2016-03-01

    Full Text Available The growing use of chemical fertilizers, insecticides and pesticides can cause potential contamination with heavy metals to soil and groundwater, posing environmental and health threats. Heavy metals can also affect crop yield. A greenhouse experiment was conducted to explore the role of ascorbic acid foliar application and soil-applied super absorbent to mitigate adverse effects of cadmium (Cd, in terms of biochemical parameters in wheat. The experiment was installed in a completely randomized design, with treatments arranged in a factorial scheme with three levels of super absorbent polymer (0 g kg-1, 4 g kg-1 and 8 g kg-1 of soil by three levels of ascorbic acid (0 mM, 50 mM and 100 mM, with four replicates. The Cd contamination caused a significant increase in the accumulation of Cd in leaves and seeds, as well as in antioxidant enzymes activity and lipid peroxidation. It also decreased seed weight and chlorophyll content in wheat plants. The super absorbent increased seed yield (22.68 %, seed weight (19.31 %, chlorophyll (27.97 % and ascorbic acid content (65.51 %, while it reduced the Cd accumulation in leaves (34.27 % and seeds (32.97 %, as well as antioxidant enzymes activity and lipid peroxidation (43.77 %. Similar results were found when ascorbic acid was applied. Ascorbic acid increased seed yield, seed weight and chlorophyll content by 12.62 %, 17.66 % and 13.17 %, respectively. As a result, the super absorbent polymer and ascorbic acid could improve the survival capacity and yield of wheat plants in response to Cd contamination in the soil.

  14. Effect of Ascorbic Acid on Noise Induced Hearing Loss in Rats

    Directory of Open Access Journals (Sweden)

    Ziba Loukzadeh

    2015-07-01

    Full Text Available Introduction: After presbycusis, noise-induced hearing loss is the second most common cause of acquired hearing loss. Numerous studies have shown that high-intensity noise exposure increases free radical species; therefore, use of antioxidants to detoxify the free radicals can prevent cellular damage in the cochlea. We studied the potential hearing protective effect of different doses of ascorbic acid administered prior to noise exposure in rats.   Materials and Methods: Twenty-four male albino Wistar rats were randomly allocated into four groups: groups A, B, and C received 1250, 250, and 50 mg/kg/day of ascorbic acid, respectively, and group D acted as the control group. After 14 days of ascorbic acid administration, the rats were exposed to noise (105 dB sound pressure level for 2 h. Distortion product otoacoustic emissions (DPOAE were recorded prior to starting the ascorbic acid as baseline and 1 h after the noise exposure.   Results: The amplitude decrease was 14.99 dB for group A, 16.11 dB for group B, 28.82 dB for group C, and 29.91 dB for the control group. Moderate and high doses of ascorbic acid significantly reduced the transient threshold shift in the rats.   Conclusion:  The results of present study support the concept of cochlea protection by antioxidant agents. This dose-dependent protective effect was shown through the use of ascorbic acid treatment prior to noise exposure.

  15. Endoplasmic Reticulum Thiol Oxidase Deficiency Leads to Ascorbic Acid Depletion and Noncanonical Scurvy in Mice

    Science.gov (United States)

    Zito, Ester; Hansen, Henning Gram; Yeo, Giles S.H.; Fujii, Junichi; Ron, David

    2012-01-01

    Summary Endoplasmic reticulum (ER) thiol oxidases initiate a disulfide relay to oxidatively fold secreted proteins. We found that combined loss-of-function mutations in genes encoding the ER thiol oxidases ERO1α, ERO1β, and PRDX4 compromised the extracellular matrix in mice and interfered with the intracellular maturation of procollagen. These severe abnormalities were associated with an unexpectedly modest delay in disulfide bond formation in secreted proteins but a profound, 5-fold lower procollagen 4-hydroxyproline content and enhanced cysteinyl sulfenic acid modification of ER proteins. Tissue ascorbic acid content was lower in mutant mice, and ascorbic acid supplementation improved procollagen maturation and lowered sulfenic acid content in vivo. In vitro, the presence of a sulfenic acid donor accelerated the oxidative inactivation of ascorbate by an H2O2-generating system. Compromised ER disulfide relay thus exposes protein thiols to competing oxidation to sulfenic acid, resulting in depletion of ascorbic acid, impaired procollagen proline 4-hydroxylation, and a noncanonical form of scurvy. PMID:22981861

  16. Enzymatic Production of Ascorbic Acid-2-phosphate by Recombinant Acid Phosphatase.

    Science.gov (United States)

    Zheng, Kai; Song, Wei; Sun, Anran; Chen, Xiulai; Liu, Jia; Luo, Qiuling; Wu, Jing

    2017-05-24

    In this study, an environmentally friendly and efficient enzymatic method for the synthesis of l-ascorbic acid-2-phosphate (AsA-2P) from l-ascorbic acid (AsA) was developed. The Pseudomonas aeruginosa acid phosphatase (PaAPase) was expressed in Escherichia coli BL21. The optimal temperature, optimal pH, K m , k cat , and catalytic efficiency of recombinant PaAPase were 50 °C, 5.0, 93 mM, 4.2 s -1 , and 2.7 mM -1 min -1 , respectively. The maximal dry cell weight and PaAPase phosphorylating activity reached 8.5 g/L and 1127.7 U/L, respectively. The highest AsA-2P concentration (50.0 g/L) and the maximal conversion (39.2%) were obtained by incubating 75 g/L intact cells with 88 g/L AsA and 160 g/L sodium pyrophosphate under optimal conditions (0.1 mM Ca 2+ , pH 4.0, 30 °C) for 10 h; the average AsA-2P production rate was 5.0 g/L/h, and the AsA-2P production system was successfully scaled up to a 7.5 L fermenter. Therefore, the enzymatic process showed great potential for production of AsA-2P in industry.

  17. Determination of ascorbic acid and carotenoids in food commodities by liquid chromatography with mass spectrometry detection.

    Science.gov (United States)

    Frenich, A Garrido; Torres, M E Hernández; Vega, A Belmonte; Vidal, J L Martínez; Bolaños, P Plaza

    2005-09-21

    Two methods, one to determine ascorbic acid and one to determine lycopene and beta-carotene, in vegetables and fruits by liquid chromatography coupled with mass spectrometry (LC-MS) have been established. The chromatographic separation of the studied compounds and their MS parameters were optimized to improve selectivity and sensitivity. In both methods, separation was carried out with two coupled columns, first a C(18) and then a dC(18), using as mobile phase 70% methanol (0.005% acetic acid) and 30% acetic acid 0.05% for ascorbic acid determination and a mixture of methanol, tetrahydrofuran, and acetonitrile (60:30:10 v/v/v) for carotenoid analysis in isocratic mode. The molecular ion was selected for the quantification in selective ion monitoring (SIM) mode. Ascorbic acid was detected with electrospray ionization probe (ESI) in negative mode, while chemical ionization atmospheric pressure (APCI) in positive mode was used for the target carotenoids. The methodology for ascorbic acid analysis is based on an extraction with polytron using methanol and a mixture of methaphosphoric acid and acetic acid. Extraction of the carotenoids was carried out with tetrahydrofuran/methanol (1:1) (v/v). The proposed methods were applied, after their corresponding validations, to the analysis of four varieties of tomatoes, tomato in tin enriched and dried tomato, and to the analysis of mango and kiwi fruits, to compare the content in these compounds. Moreover, the influence of the process of freezing and the effect that the manipulation/preservation has in the content of ascorbic acid in tomato have also been studied.

  18. Ascorbic acid inhibits TPA-induced HL-60 cell differentiation by decreasing cellular H₂O₂ and ERK phosphorylation.

    Science.gov (United States)

    Yiang, Giou-Teng; Chen, Jen-Ni; Wu, Tsai-Kun; Wang, Hsueh-Fang; Hung, Yu-Ting; Chang, Wei-Jung; Chen, Chinshuh; Wei, Chyou-Wei; Yu, Yung-Luen

    2015-10-01

    Retinoic acid (RA), vitamin D and 12-O‑tetradecanoyl phorbol-13-acetate (TPA) can induce HL-60 cells to differentiate into granulocytes, monocytes and macrophages, respectively. Similar to RA and vitamin D, ascorbic acid also belongs to the vitamin family. High‑dose ascorbic acid (>100 µM) induces HL‑60 cell apoptosis and induces a small fraction of HL‑60 cells to express the granulocyte marker, CD66b. In addition, ascorbic acid exerts an anti‑oxidative stress function. Oxidative stress is required for HL‑60 cell differentiation following treatment with TPA, however, the effect of ascorbic acid on HL‑60 cell differentiation in combination with TPA treatment remains to be fully elucidated. The aim of the present study was to investigate the cellular effects of ascorbic acid treatment on TPA-differentiated HL-60 cells. TPA-differentiated HL-60 cells were used for this investigation, this study and the levels of cellular hydrogen peroxide (H2O2), caspase activity and ERK phosphorylation were determined following combined treatment with TPA and ascorbic acid. The results demonstrated that low‑dose ascorbic acid (5 µM) reduced the cellular levels of H2O2 and inhibited the differentiation of HL‑60 cells into macrophages following treatment with TPA. In addition, the results of the present study further demonstrated that low‑dose ascorbic acid inactivates the ERK phosphorylation pathway, which inhibited HL‑60 cell differentiation following treatment with TPA.

  19. A facile "green" synthesis of ascorbic acid-capped ZnSe nanoparticles.

    Science.gov (United States)

    Oluwafemi, Oluwatobi S; Revaprasadu, N; Adeyemi, Olufemi O

    2010-08-01

    A simple, green room temperature synthesis of ascorbic acid-capped ZnSe nanoparticles is hereby reported. By varying the pH of the solution, the temporal evolution of the optical properties and shape of the nanocrystals was investigated. The nanoparticles were characterized by UV-vis absorption and photoluminescence spectroscopy (PL), transmission electron microscope (TEM) and infra-red spectroscopy (IR). All the particles exhibited quantum confinement in their optical spectra. An atypical optical spectrum was observed at pH 11 after 5h attributed to digestive ripening and shrinkage of ZnSe core. From the TEM image we inferred that the reaction is kinetically driven at pH 7 producing elongated particles as the reaction times increases, while spherical particles are produced at pH 4 and 11. The IR spectroscopy confirmed the capping of ascorbic acid and its deprotonation to give ascorbate ions. Copyright 2010 Elsevier B.V. All rights reserved.

  20. UlaR activates expression of the ula operon in Streptococcus pneumoniae in the presence of ascorbic acid

    NARCIS (Netherlands)

    Afzal, Muhammad; Shafeeq, Sulman; Henriques-Normark, Birgitta; Kuipers, Oscar P

    In this study, the regulatory mechanism of the ula (utilization of l-ascorbic acid) operon, putatively responsible for transport and utilization of ascorbic acid in Streptococcus pneumoniae strain D39, is studied. β-Galactosidase assay data demonstrate that expression of the ula operon is increased

  1. Influence of ascorbic acid on in vivo amidation of alpha-melanocyte stimulating hormone in guinea pig pituitary

    DEFF Research Database (Denmark)

    Fenger, M; Hilsted, L

    1988-01-01

    The effect of ascorbic acid depletion on the amidation of alphamelanocyte stimulating hormone (alpha MSH) was studied in vivo in guinea pig pituitary. After four weeks, the concentration of ascorbic acid was 1.20 +/- 0.11 mumol/g tissue (mean +/- SD) in the pituitary and 0.34 +/- 0.07 mumol/g tis...

  2. Effect of salinity and ascorbic acid on growth, water and osmotic relations of Lepidium sativum

    Directory of Open Access Journals (Sweden)

    Azadeh Najjar-Khodabakhsh

    2015-06-01

    Full Text Available Soil salinity is a serious environmental problem in arid and semi-arid regions that have negative impacts on crop production. In this research, because of medicinal and nutritional importance of the garden cress (Lepidium sativum plant, the interactive effects of salinity (225 mM NaCl and ascorbic acid (1 mM were evaluated on growth and its water relations. A completely randomized design with four replications was conducted under controlled conditions. The results showed that salinity decreased growth, relative water content, osmotic potential and soluble proteins and increased soluble sugars, amino acids and proline contents. Many of salinity damaged characteristic were improved by adding exogenous ascorbic acid to salty environment. Exogenous ascorbic acid alone, in comparison with control, enhanced the growth of garden cress by increasing relative water content, soluble sugars and soluble proteins contents. The results indicated that usage of ascorbic acid, as an antioxidant, reduced harmful effects of salinity stress and led to growth improvement in garden cress plants.

  3. Synergistic protective effects of ceftriaxone and ascorbic acid against subacute deltamethrin-induced nephrotoxicity in rats.

    Science.gov (United States)

    Abdel-Daim, Mohamed M; El-Ghoneimy, Ashraf

    2015-03-01

    Deltamethrin (DLM) is a synthetic class II pyrethroid acaricide and insecticide widely used for veterinary and agricultural purposes. However, its animal and human exposure leads to nephrotoxicity. Our experimental objective was to evaluate protective effects of ceftriaxone and/or ascorbic acid against DLM-induced renal injury in male Wistar albino rats. DLM-treated animals revealed significant alterations in serum biochemical parameters related to renal injury; urea, uric acid and creatinine. There was a significant increase in renal lipid peroxidation and a significant inhibition in antioxidant biomarkers. Moreover, DLM significantly reduced serum acetylcholinesterase (AChE) activity. In addition, It induced serum and kidney tumor necrosis factor-α (TNF-α). Both ceftriaxone and ascorbic acid protect against DLM-induced biochemical alterations in serum and renal tissue when used alone or in combination along with DLM-intoxication. Furthermore, both ceftriaxone and ascorbic acid produced synergetic nephroprotective and antioxidant effects. Therefore, it could be concluded that ceftriaxone and/or ascorbic acid administration able to minimize the toxic effects of DLM through their free radical-scavenging and potent antioxidant activity.

  4. Antinociceptive Properties of Ascorbic Acid: Evidence for the Mechanism of Action

    Directory of Open Access Journals (Sweden)

    Zeraati

    2014-09-01

    Full Text Available Background Ascorbic acid is amongst important water-soluble vitamins and when used orally in high-doses it has been observed to relieve pain and reduce opioid use in patients. However no controlled trial has compared the antinociceptive effects of ascorbic acid with other analgesic groups on animal models, and investigated the involved mechanisms. Objectives In the present study, the antinociceptive effect of vitamin C on male mice was investigated and compared with morphine and diclofenac. Also, possible mechanisms were assayed. Materials and Methods Male albino mice were used in this study. Antinociception was measured using the writhing test, tail flick and formalin tests. Ascorbic acid was used in three doses (30, 150 and 300 mg/kg, IP and compared with the antinociceptive effects of 10 mg/kg of morphine as an opioid analgesic agent and 5-10 mg/kg of diclofenac as a nonsteroidal anti-inflammatory drug (NSAID analgesic agent.The antinociceptive effect of ascorbic acid (300 mg/kg was compared before and after treatment with naloxone (4 mg/kg, ondansetron (0.5 mg/kg, atropine (5 mg/kg and metoclopramide (1 mg/kg in the writhing test. Results Vitamin C caused dose-dependent antinociceptive effects in acetic acid writhing test (P < 0.05. It had no significant effect in the tail flick test. Meanwhile, vitamin C in high doses reduced pain in the second phase of the formalin test (P < 0.05. Morphine had higher nociceptive effects in comparison to ascorbic acid in the writhing test (P < 0.05. In the second phase of the formalin test the antinociceptive effects of vitamin C (300 mg/kg was not significantly different with morphine at dose of 10 mg/kg. There was not significant difference between vitamin C (300 mg/kg and diclofenac (10 mg/kg in the second phase of the formalin test. Metoclopramide and ondansetrone reduced the antinociceptive effects of vitamin C. Conclusions The results obtained from the acetic acid induced writhing test and second

  5. 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)

    Tucker, B.W.; Halver, J.E.

    1984-01-01

    Rainbow trout (250 g) were maintained at 15 degrees C for 3 months on a low ascorbic acid diet, given [1- 14 C]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 14 C, 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 14 C 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

  6. Factors that affect leaf extracellular ascorbic acid content and redox status

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

  7. Ascorbic acid and vitamin C-containing beverages delay the leucomalachite green reaction to detect latent bloodstains.

    Science.gov (United States)

    Lee, Haeyong; Park, Myung Jin; Sun, Seol Hee; Choi, Dong-Ho; Lee, Yang-Han; Park, Ki-Won; Chun, Byung Won

    2016-11-01

    The leucomalachite green (LMG) test is one of catalytic tests for the detection of latent bloodstains and generally used in forensic field because of convenience and cost/time-effectiveness. However, contamination of latent bloodstains at crime scenes can interfere with the LMG reaction, resulting in false-negative or false-positive decisions. Herein, we examined if ascorbic acid and vitamin C (l-ascorbic acid or ascorbate)-containing beverages affect the LMG reaction. Ascorbic acid showed the inhibitory activities on the LMG reaction in a dose-dependent manner. Similarly, vitamin C-containing beverages also inhibited the LMG reaction and the inhibitory effects were proportional to the concentrations of vitamin C in beverages. It was also identified that as incubation time after adding LMG reagent to the mixtures of blood and ascorbic acid or beverages was increased, the inhibitory effects of ascorbic acid vitamin C-containing beverages on LMG test were disappeared. These results suggest that the LMG reaction is delayed but not stopped by ascorbic acid and vitamin C-containing beverages. Neither incubation at room temperature around 20-25°C nor the addition of acetic acid affects the inhibitory activity of ascorbic acid on LMG reaction. We also showed that ascorbic acid does not affect DNA stability, allowing us to obtain full short tandem repeat (STR) profiles through amplification of DNA using commercial STR kits. In conclusion, ascorbic acid and vitamin C-containing beverages delayed the LMG reaction, suggesting that it should be considered that negative results of LMG test could be false negative due to contamination of bloodstains with inhibitory factors on LMG test. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Plasma ascorbic acid, a priori diet quality score, and incident hypertension

    NARCIS (Netherlands)

    Buijsse, Brian; Jacobs, D.R.; Steffen, L.M.; Kromhout, Daan; Gross, M.D.

    2015-01-01

    Vitamin C may reduce risk of hypertension, either in itself or by marking a healthy diet pattern. We assessed whether plasma ascorbic acid and the a priori diet quality score relate to incident hypertension and whether they explain each other's predictive abilities. Data were from 2884 black and

  9. Interaction between xylanase, glucose oxidase and ascorbic acid on the technological quality of whole wheat bread

    Directory of Open Access Journals (Sweden)

    Camila Batista da Silva

    Full Text Available ABSTRACT: This study aimed to verify the performance of xylanase and its interaction with oxidants agents (glucose oxidase and ascorbic acid on the quality of whole wheat bread. The experiment was based on a central composite rotational design and the Response Surface Methodology was used to analyze the results. None of the xylanase, glucose oxidase or ascorbic acid concentrations within the studied range led to a significant difference in the specific volume. The highest moisture content and the lowest firmness values were reported in the bread with lower and intermediate levels of xylanase and larger amounts of glucose oxidase and ascorbic acid. This effect was observed mainly at the end of the storage period. A minimum amount of xylanase (from 33 to 63 EDX kg-1 flour showed to be essential for obtaining best results. Levels of ascorbic acid above 63mg kg-1 and glucose oxidase above 91 SRU kg-1 proved to be necessary to offer the beneficial effect of xylanase.

  10. Effect of Ascorbic Acid and Allium Sativum on Tissue lead Level in ...

    African Journals Online (AJOL)

    The effects of Ascorbic acid (vitamin C) and Allium sativum (garlic) on the lead levels in bone, brain, muscle, liver and kidney tissues of female rats (Rattus navigicus) were investigated. Group I was Control, rats in Groups II – IV were injected intraperitoneally with 100µmol/kg body weight of lead acetate for 7 days. In addition ...

  11. The effects of ascorbic acid and á-tocopherole on leukocyte count of ...

    African Journals Online (AJOL)

    The experiments were performed with the aim of investigating the possible ameliorative effects of ascorbic acid and á-tocopherole supplements administered to sodium nitrate-treated rats on total and differential leukocyte counts. Seventy (70) adult Wistar rats, divided into seven groups of 10 rats each were used for the ...

  12. Ascorbic acid and heat stress in domestic chicken nutrition: A review ...

    African Journals Online (AJOL)

    Therefore, it is necessary to adopt effective measures to control heat stress and its adverse effects on livestock. Vitamin C alleviates the side effects of stress, thus increased heat tolerance in birds, and improved chickens response to cell functional immunity. Therefore ascorbic acid could be included at the rate of 250mg/kg ...

  13. Functional role of ascorbic acid in bread-making | Dadzie-Mensah ...

    African Journals Online (AJOL)

    bread characteristics. Various levels of ascorbic acid and bromate were used in the bread production to compare critical functional properties of bread. The results showed that the specific volume of the loaves increased from 2.80 cm3/g ...

  14. [Nickel exposure to A549 cell damage and L-ascorbic acid interference effect].

    Science.gov (United States)

    Fu, Yao; Wang, Yue; Dan, Han; Zhang, Lin; Ma, Wenhan; Pan, Yulin; Wu, Yonghui

    2015-05-01

    Studying different concentrations of nickel smelting smoke subjects of human lung adenocarcinoma cells (A549) carcinogenic effects, discusses the influence of L-ascorbic acid protection. The A549 cells were divided into experimental and L-ascorbic acid in the intervention group. Plus exposure group concentration of nickel refining dusts were formulated 0.00, 6.25, 12.50, 25.00, 50.00, 100.00 µg/ml suspension, the intervention group on the basis of the added exposure group containing L-ascorbic acid (100 mmol/L), contact 24 h. Detection of cell viability by MTT assay. When the test substance concentration select 0.00, 25.00, 50.00, 100.00 µg/ml experiment for internal Flou-3 fluorescent probe to detect cell Ca²⁺ concentration, within DCFH-DA detect intracellular reactive oxygen (ROS) content, real-time quantitative PCR (real time, in the RT-PCR) was used to detect cell HIF-1α gene expression. With the increase of concentration, subjects increased cell growth inhibition rate, intracellular Ca²⁺ concentration increases, ROS content increased, HIF-1α gene expression increased, differences were statistically significant (P nickel exposure damage to cells. With subjects following exposure to nickel concentration increased, its effect on A549 cell damage increases, L-ascorbic acid cell damage caused by nickel has certain protective effect.

  15. Use of equimolar cysteine/ascorbic acids to recover MCP synthesized Ti(Mg) alloy

    CSIR Research Space (South Africa)

    Mushove, T

    2010-10-01

    Full Text Available Dissolution of waste by-products of mechanochemical processing (MCP) synthesis of Ti(Mg) alloy, from TiO2 and 15 wt.% excess Mg, was conducted in equimolar cysteine/ascorbic acids. The synthesized alloy is inherently mixed with MgO and other oxides...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-05-01

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

  17. The effect of ascorbic acid and propranolol on normal sleep and ...

    African Journals Online (AJOL)

    This study was designed to investigate the possible effects of ascorbic acid on open field locomotor activity and normal sleep in healthy adult rats and evaluate how these correlate with those of propranolol. MethodS: Eighty healthy adult Wistar rats of both sexes were divided into two groups of 40 animals each group.

  18. Ascorbic acid, cognitive function, and Alzheimer’s disease: a current review and future direction

    OpenAIRE

    Bowman, Gene L.

    2012-01-01

    This narrative review appraises the human and animal studies implicating ascorbic acid (AA) in normal cognitive function and Alzheimer’s disease. A research framework for how nutrition affects brain aging is proposed with emphasis on AA intake, status, metabolism, and transport into brain tissue. A final synopsis highlights areas for future research regarding AA nourishment and healthy brain aging.

  19. Evaluation of the effects of ascorbic acid on azathioprine-induced ...

    African Journals Online (AJOL)

    The use of azathioprine (AZA) in the prevention of organ rejection during transplantation has been noted in different organs of the body. This study investigates the effect of ascorbic acid on azathioprineinduced alteration in the testes of adult Wistar rats. Thirty male adult Wistar rats were randomly assigned into 5 groups ...

  20. Existence of thickness threshold for crystal growth rate of ascorbic acid from its thin solution film

    Science.gov (United States)

    Yamazaki, Yoshihiro; Yoshino, Hiroki; Kikuchi, Mitsunobu; Kashiwase, Sakiko

    2017-06-01

    Growth rate of ascorbic acid crystal domains from its aqueous solution film depends on the film thickness. Existence of a thickness threshold is experimentally confirmed below which growth rate becomes quite low and is considered to almost stop. This threshold is one of the essential factors for the dynamical transition between uniform and rhythmic growth modes.

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

    DEFF Research Database (Denmark)

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

    1990-01-01

    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...

  2. L-ascorbic acid losses in Kenyan vegetables during cooking as ...

    African Journals Online (AJOL)

    The loss of L-ascorbic acid (L-AA) in 14 different cooked local vegetables found in Nairobi markets was determined by high performance liquid chromatography. The effect of quantity of water on the loss of L-AA during cooking was studied with cowpea leaves. It was found that more L-AA was lost when larger amount of ...

  3. Effects of dietary lead exposure and graded levels of ascorbic acid ...

    African Journals Online (AJOL)

    The effects of dietary lead acetate (LA) exposure on growth performance and haematological characteristics of broiler chickens and possible ameliorative effect of ascorb ic acid (AA) were investigated. One hundred and twenty day-old broiler chicks were randomly divided into six treatment groups of 20 birds with two ...

  4. The effect of Quinine and Ascorbic acid on rat testes | Osinubi | West ...

    African Journals Online (AJOL)

    The effect of Quinine and Ascorbic acid on rat testes. A A Osinubi, A O Daramola, C C Noronha, A O Okanlawon, O A Ashiru. Abstract. No Abstract. West African Journal of Medicine Vol. 26 (3) 2007 pp. 217-221. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  5. Ascorbic acid prevents cimetidine-induced decrease of serum hydrocortisone concentrations

    NARCIS (Netherlands)

    M.P. Boidin (Marinus Pieter); A. Stuurman (Arie); W. Erdmann (Wilhelm)

    1990-01-01

    markdownabstractAbstract A blind, parallel, prospective, clinical study was conducted to investigate the effect of ascorbic acid on human serum hydrocortisone concentrations which were decreased by the administration of cimetidine. The study population included 16 male adults scheduled for major

  6. Effects of Ascorbic Acid and Reduced Glutathione on the Alleviation of Salinity Stress in Olive Plants

    NARCIS (Netherlands)

    Aliniaeifard, S.; Hajilou, J.; Tabatabaei, S.J.; Seifi Kalhor, Maryam

    2016-01-01

    The aim of this study was to evaluate the effects of low molecular mass antioxidants and NaCl salinity on growth, ionic balance, proline, and water contents of ‘Zard’ olive trees under controlled greenhouse conditions. The experiment was carried out by spraying 2 mM of ascorbic acid (Asc) and 3

  7. Plasma Ascorbic Acid in Insulin and Non-insulin Dependent Diabetes

    African Journals Online (AJOL)

    Blood glucose, plasma ascorbic acid and haemoglobin levels were estimated in insulin dependent diabetics, non-insulin dependent diabetics and controls matched for number, sex and age. Significantly higher levels of these parameters were found in control group than in the other two groups. Statistically differences were ...

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

    OpenAIRE

    Barry-Ryan, Catherine; O'Beirne, David

    1998-01-01

    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 (~...

  9. Effects of Ascorbic Acid on Garlic-induced Alterations in Semen ...

    African Journals Online (AJOL)

    Effects of Ascorbic Acid on Garlic-induced Alterations in Semen Parameters Of Wistar Rats. GO Omotoso, IO Onanuga, AAG Jimoh. Abstract. No Abstract. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/tjhc.v18i2.69616 · AJOL African Journals ...

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

    Directory of Open Access Journals (Sweden)

    Samina Malik and Muhammad Ashraf

    2012-05-01

    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. `

  11. Effects of supplemental vitamin C (Ascorbic Acid) on the growth and ...

    African Journals Online (AJOL)

    Four different diets each containing 37.4% crude protein were formulated from locally available feed materials to contain 0 (control), 23, 46 and 92 mg/Kg supplemental Ascorbic acid (AA) respectively. Catfish with average weight of 2 - 6g were stocked and fed twice daily to satiation initially with Coppens fish feed for the first ...

  12. Copper/ascorbic acid dyad as a catalytic system for selective aerobic oxidation of amines

    Czech Academy of Sciences Publication Activity Database

    Šrogl, Jiří; Voltrová, Svatava

    2009-01-01

    Roč. 11, č. 4 (2009), s. 843-845 ISSN 1523-7060 Institutional research plan: CEZ:AV0Z40550506 Keywords : copper * ascorbic acid * oxidative deamination Subject RIV: CC - Organic Chemistry Impact factor: 5.420, year: 2009

  13. Effects of L-ascorbic acid and alpha-tocopherol on biochemical ...

    African Journals Online (AJOL)

    Background: The purpose of this study is to determine the effect of L-ascorbic acid and alpha-tocopherol as well as combination of these vitamins with or without exposure to physical exercise on intensity of lipid peroxidation, activity of xanthine oxidase, activity of total antioxidative system, concentration of glutathione, and ...

  14. Effect of Combined Intake of Garcinia Kola and Ascorbic Acid on ...

    African Journals Online (AJOL)

    This study was carried out to determine the effect of combined intake of Garcinia kola and Ascorbic acid on Intraocular pressure (IOP) of normotensive Nigerians. A total of one hundred and sixty (n= 160) parcipants, males, and females within the age range of 18-50 years (Mean age = 29.29± 8.74) were used for this study.

  15. A proposed relationship between pH and ascorbic acid content of ...

    African Journals Online (AJOL)

    A relationship between the ascorbic acid content of fresh squeezed juice of orange, lemon, grape and lime and the pH was presented. The relationship established were statistically compared with those obtained by the 2,6 dichlorophenol indophenol titration method. It was shown that they do not differ significantly (p≥0.05) ...

  16. Foliar application of ascorbic acid mitigates sodium chloride induced stress in eggplant (solanum melongena l.)

    International Nuclear Information System (INIS)

    Jan, S.; Hamayun, M.

    2016-01-01

    The current work was designed to test the effect of sodium chloride on germination, seedling establishment, vegetative growth, yield, chemical contents and ionic composition of eggplant. The consequences of foliar application of ascorbic acid (AA) on mitigation of adverse effects of sodium chloride were also tested. The seeds of Solanum melongena were germinated using NaCl (60 mM, 100 mM) and ascorbic acid (100 and 200 mM). High levels of salinity significantly affected the seed germination and seedling fresh and dry weights. Plants grown under salinity stress with foliar application of ascorbic acid showed significant increase in germination percentage and seedlings growth as compare to control plants. Sodium chloride stress showed adverse effects on plant height, root length, number of leaves, leaf area, fresh and dry biomass, total chlorophyll, carbohydrates and proteins as compared to untreated plants. The relative water content, electrolyte leakage were increased and Na+ and K+ ions balance was disturbed in different plant parts. Ascorbic acid (100 and 200ppm) enhanced all the growth parameters affected adversely by sodium chloride stress. (author)

  17. pH level, Ascorbic Acid, Proline and Soluble Sugar as Bio ...

    African Journals Online (AJOL)

    2017-08-12

    Aug 12, 2017 ... the combustion of bones, rubber wheel cover, bush burning among other. Hence, the aims and objectives of this study is to examine and compare the concentration of ascorbic acid, proline and soluble sugar from the leaves of fifteen plant species collected within two semi – urban cities in. Delta State term ...

  18. Ascorbic acid effects on in vitro maturation of mouse oocyte with or ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... These results indicate that exposure ascorbic acid promotes the development of mouse DOs and COCs from germinal vesicle breakdown (GVBD) to metaphase II (MII) and ... by-product of aerobic metabolism (Miwa and Brand,. 2003). ROS have been recognized to pose a constant threat to cells as they ...

  19. Determination of ascorbic acid in pharmaceutical preparation and fruit juice using modified carbon paste electrode

    Directory of Open Access Journals (Sweden)

    Simona Žabčíková

    2016-06-01

    Full Text Available Acrobic acid is key substance in the human metabolism and the rapid and accurate determination in food is of a great interest. Ascorbic acid is an electroactive compound, however poorly responded on the bare carbon paste electrodes. In this paper, brilliant cresyl blue and multi-walled carbon nanotubes were used for the modification of carbon paste electrode. Brilliant cresyl blue acts as a mediator improving the transition of electrons, whereas multiwalled carbon nanotubes increased the surface of the electrode. Both brilliant cresyl blue and multiwalled carbon nanotubes were added directly to the composite material. The electrochemical behavior of modified electode was determined in electrolyte at various pH, and the effect of the scan rate was also performed. It was shown that the electrochemical process on the surface of the modified carbon paste electrode was diffusion-controlled. The resulted modified carbon paste electrode showed a good electrocatalytic activity towards the oxidation of ascorbic acid at a reduced overpotential of +100 mV descreasing the risk of interferences. A linear response of the ascorbic acid oxidation current measured by the amperometry in the range of 0.1 - 350 µmol.L-1 was obtained applying the sensor for the standard solution. The limit of detection and limit of quantification was found to be 0.05 and 0.15 µmol.L-1, respectively. The novel method was applied for the determination of ascorbic acid in pharmaceutical vitamin preparation and fruit juice, and the results were in good agreement with the standard HPLC method. The presented modification of carbon paste electrode is suitable for the fast, sensitive and very accurate determination of ascorbic acid in fruit juices and pharmaceutical preparation.

  20. Effect of Short Term Salicylic Acid and Ascorbic Acid Treatments on Delaying Flowers’ Senescence of Cut Rose Cv. Red Naomy

    Directory of Open Access Journals (Sweden)

    H. Samady

    2015-01-01

    Full Text Available This experiment was conducted on rose cut flowers, Red Naomy cultivar, with the length of 35 cm, for 18 hours as a short-term treatment in a factorial based on completely randomized design with five treatments including sucrose + 8-Hydroxyquinoline sulfate, salicylic acid + sucrose + 8-Hydroxyquinoline sulfate, ascorbic acid + sucrose + 8-Hydroxyquinoline sulfate, Salicylic acid + ascorbic acid + sucrose‌ + 8-Hydroxyquinoline sulfate and distilled water as control, and three replications in bottles. Morphological traits such as shelf life, changes in water uptake, fresh weight, flower diameter and physiological traits such as total protein and proline contents were measured. The results showed that combination of Salicylic acid + sucrose + 8-Hydroxyquinoline sulfate treatment significantly affected shelf life compared to control and other treatments. The results also revealed that the combination of Salicylic acid + ascorbic acid + sucrose‌ + 8-Hydroxyquinoline sulfate delayed flowers senescence and increased the amount of water uptake, fresh weight and flower diameter. Moreover, the greatest protein and proline contents were obtained under ascorbic acid + sucrose + 8-Hydroxyquinoline sulfate treatment and sucrose + 8-Hydroxyquinoline sulfate, respectively.

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

    International Nuclear Information System (INIS)

    Slyus, M.A. van; Oliveira, R.L.B. da C.; Felzenszwalb, I.; Gomes, R.A.; Menck, C.F.

    1985-01-01

    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.) [pt

  2. Expression and/or activity of the SVCT2 ascorbate transporter may be decreased in many aggressive cancers, suggesting potential utility for sodium bicarbonate and dehydroascorbic acid in cancer therapy.

    Science.gov (United States)

    McCarty, Mark F

    2013-10-01

    Hypoxia-inducible factor-1 (HIF-1) is a heterodimer transcription factor whose elevated activity in many cancers helps them to survive under hypoxic conditions and enhances their capacity to grow invasively, establish metastases, and survive chemo- or radiotherapy. Optimal intracellular levels of ascorbate suppress the level and transcriptional activity of HIF-1under normoxic or mildly hypoxic conditions by supporting the activity of proly and asparagyl hydroxylases that target HIF-1alpha. High intracellular ascorbate can also work in various ways to down-regulate activation of NF-kappaB which, like HIF-1 is constitutively active in many cancers and promotes aggressive behavior - in part by promoting transcription of HIF-1alpha. Yet recent evidence suggests that, even in the context of adequate ascorbate nutrition, the intracellular ascorbate content of many aggressive cancers may be supoptimal for effective HIF-1 control. This likely reflects low expression or activity of the SVCT2 ascorbate transporter. The expression of SVCT2 in cancers has so far received little study; but the extracellular acidity characteristic of many tumors would be expected to reduce the activity of this transporter, which has a mildly alkaline pH optimum. Unfortunately, since SVCT2 has a high affinity for ascorbate, and its activity is nearly saturated at normal healthy serum levels of this vitamin, increased oral administration of ascorbate would be unlikely to have much impact on the intracellular ascorbate content of tumors. However, cancers in which HIF-1 is active express high levels of glucose transporters such as GLUT-1, and these transporters can promote influx of dehydroascorbic acid (DHA) via facilitated diffusion; once inside the cell, DHA is rapidly reduced to ascorbate, which effectively is "trapped" within the cell. Hence, episodic intravenous infusions of modest doses of DHA may have potential for optimizing the intracellular ascorbate content of cancers, potentially

  3. Meta-analysis of ascorbic acid for prevention of postoperative atrial fibrillation after cardiac surgery.

    Science.gov (United States)

    Baker, William L; Coleman, Craig I

    2016-12-15

    Results of a systematic review and meta-analysis of published data on use of ascorbic acid to prevent postoperative atrial fibrillation (POAF) after cardiac surgery are presented. MEDLINE and other sources were searched for reports on trials evaluating the effects of preoperative and/or postoperative use of ascorbic acid in patients undergoing cardiac surgery. For each study selected for meta-analysis, an assessment for risks of methodological bias was performed. Data on POAF frequency and length of stay (LOS) outcomes were pooled and analyzed via random-effects modeling. The 11 identified studies involved patients receiving coronary artery bypass grafts with or without valve replacement; both i.v. and oral ascorbic acid formulations were used. Analysis of pooled outcomes data on treatment and control groups indicated that ascorbic acid prophylaxis was associated with reductions in POAF frequency (odds ratio, 0.44; 95% confidence interval [CI], 0.32 to 0.61), intensive care unit (ICU) LOS (difference in means, -0.24 day; 95% CI, -0.45 to -0.03 day), and total hospital LOS (difference in means, -0.94 day; 95% CI, -1.65 to -0.23 day). Significant statistical, methodological, and clinical heterogeneity were observed. A meta-analysis revealed that, compared with use of a placebo or a nonplacebo control, perioperative administration of ascorbic acid to patients undergoing cardiac surgery was associated with a reduced frequency of POAF and a shorter ICU LOS and total hospital LOS. Copyright © 2016 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  4. Ascorbic acid supplementation diminishes microparticle elevations and neutrophil activation following SCUBA diving.

    Science.gov (United States)

    Yang, Ming; Barak, Otto F; Dujic, Zeljko; Madden, Dennis; Bhopale, Veena M; Bhullar, Jasjeet; Thom, Stephen R

    2015-08-15

    Predicated on evidence that diving-related microparticle generation is an oxidative stress response, this study investigated the role that oxygen plays in augmenting production of annexin V-positive microparticles associated with open-water SCUBA diving and whether elevations can be abrogated by ascorbic acid. Following a cross-over study design, 14 male subjects ingested placebo and 2-3 wk later ascorbic acid (2 g) daily for 6 days prior to performing either a 47-min dive to 18 m of sea water while breathing air (∼222 kPa N2/59 kPa O2) or breathing a mixture of 60% O2/balance N2 from a tight-fitting face mask at atmospheric pressure for 47 min (∼40 kPa N2/59 kPa O2). Within 30 min after the 18-m dive in the placebo group, neutrophil activation, and platelet-neutrophil interactions occurred, and the total number of microparticles, as well as subgroups bearing CD66b, CD41, CD31, CD142 proteins or nitrotyrosine, increased approximately twofold. No significant elevations occurred among divers after ingesting ascorbic acid, nor were elevations identified in either group after breathing 60% O2. Ascorbic acid had no significant effect on post-dive intravascular bubble production quantified by transthoracic echocardiography. We conclude that high-pressure nitrogen plays a key role in neutrophil and microparticle-associated changes with diving and that responses can be abrogated by dietary ascorbic acid supplementation. Copyright © 2015 the American Physiological Society.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-04-01

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

  6. SKIN PERMEATION ENHANCEMENT EFFECTS OF ASCORBIC ACID AND TRIETHYL CITRATE ON ROFECOXIB

    Directory of Open Access Journals (Sweden)

    MALAY K. DAS

    2008-01-01

    Full Text Available The enhancing effect of ascorbic acid and triethyl citrate (TEC on the in vitro skin permeation of rofecoxib across rat epidermis was investigated. Skin pre-treatment with ascorbic acid and TEC at different concentrations, followed by application of rofecoxib gel, showed higher permeation flux than the control condition. The mechanism underlying this permeation enhancement was probed with fourier transform infrared spectroscopy (FTIR. The FTIR spectra of rat epidermis treated with ascorbic acid revealed that ascorbic acid at low concentration appears to interact with dermal keratin, whereas at higher concentration it appears to interact with both dermal proteins and lipids. The FTIR spectra of rat epidermis treated with TEC showed a decrease in peak heights for both asymmetric and symmetric C-H stretching absorbance, indicating a change in the fluidity of alkyl chains in the intercellular lipids in the stratum corneum (SC. The protein disruption effect of TEC was probably due to the solvation of keratin by the formation of hydrogen bonds between TEC hydroxyl groups and keratin chain C=O groups. Skin pre-treatment with different concentrations of permeation enhancers did not show any significant change in lag time in comparison to control. The amount of rofecoxib retained in the skin after skin pre-treatment with enhancers was found to be higher than in the experiment without skin pre-treatment. Scanning electron microscopy (SEM confirmed the maintenance of skin integrity throughout the permeation experiment. The observed permeation enhancing effects of ascorbic acid and TEC in the present study indicate that a rapid percutaneous absorption of rofecoxib at effective therapeutic levels may facilitate faster anti-inflammatory activity.

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

    International Nuclear Information System (INIS)

    Zare, H.R.; Memarzadeh, F.; Ardakani, M. Mazloum; Namazian, M.; Golabi, S.M.

    2005-01-01

    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, α, 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 10 3 M -1 s -1 . Amperometric determination of AA in stirred solution exhibits a linear range of 2.0-1300.0 μM (correlation coefficient 0.9999) and a detection limit of 0.076 μM. The precision of amperometry was found to be 1.9% for replicate determination of a 49.0 μM 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

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

    OpenAIRE

    Sumaya-Mart?nez, Mar?a Teresa; Cruz-Jaime, Sandra; Madrigal-Santill?n, Eduardo; Garc?a-Paredes, Juan Diego; Cari?o-Cort?s, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alan?s-Garc?a, Ernesto

    2011-01-01

    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 β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betac...

  9. Intravenous tranexamic acid for hyperacute primary intracerebral hemorrhage

    DEFF Research Database (Denmark)

    Sprigg, Nikola; Robson, Katie; Bath, Philip

    2016-01-01

    RATIONALE: Outcome after intracerebral hemorrhage remains poor. Tranexamic acid is easy to administer, readily available, inexpensive, and effective in other hemorrhagic conditions. AIM: This randomized trial aims to test the hypothesis that intravenous tranexamic acid given within 8 h...... of spontaneous intracerebral hemorrhage reduces death or dependency. DESIGN: Phase III prospective double-blind randomized placebo-controlled trial. Participants within 8 h of spontaneous intracerebral hemorrhage are randomized to receive either intravenous tranexamic acid 1 g 10 min bolus followed by 1 g 8 h......, and institutionalization. DISCUSSION: This pragmatic trial is assessing efficacy of tranexamic acid after spontaneous intracerebral hemorrhage. Recruitment started in 2013; as of 15th January 2016 1355 participants have been enrolled, from 95 centers in seven countries. Recruitment is due to end in 2017. TICH-2 Trial...

  10. Ascorbic acid levels in human tears after photorefractive keratectomy, transepithelial photorefractive keratectomy, and laser in situ keratomileusis.

    Science.gov (United States)

    Bilgihan, A; Bilgihan, K; Toklu, Y; Konuk, O; Yis, O; Hasanreisoğlu, B

    2001-04-01

    To investigate the level of ascorbic acid in human tear fluid after photorefractive keratectomy (PRK), transepithelial PRK, and laser in situ keratomileusis (LASIK). Departments of Ophthalmology and Biochemistry, School of Medicine, Gazi University, Ankara, Turkey. Twenty patients (7 women and 13 men) were included in this study. Traditional PRK with epithelial scraping by a blunt spatula followed by surface ablation (7 eyes), transepithelial PRK (7 eyes), or LASIK (6 eyes) was performed. Tears were collected preoperatively and 1 and 5 days postoperatively. Ascorbic acid levels were measured using 2-4 dinitrophenylhydrazine. Ascorbic acid levels in the tear fluid were decreased significantly 1 day after PRK, transepithelial PRK, and LASIK (P <.05). On the fifth day, the ascorbic acid levels were significantly lower than preoperatively in all groups. After PRK, transepithelial PRK, and LASIK, the ascorbic acid levels of the tear fluid decreased significantly. Because ascorbic acid is the major scavenger of superoxide radicals in tears, topical ascorbic acid therapy may help eliminate the harmful effect of free radicals from excimer laser surgery.

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

    Science.gov (United States)

    Ito, Yasutoshi; Kinoshita, Manabu; Yamamoto, Tetsuo; Sato, Tomohito; Obara, Takeyuki; Saitoh, Daizoh; Seki, Shuhji; Takahashi, Yukihiro

    2013-01-01

    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. PMID:24084715

  12. An ascorbic acid-enriched tomato genotype to fight UVA-induced oxidative stress in normal human keratinocytes.

    Science.gov (United States)

    Petruk, Ganna; Raiola, Assunta; Del Giudice, Rita; Barone, Amalia; Frusciante, Luigi; Rigano, Maria Manuela; Monti, Daria Maria

    2016-10-01

    UVA radiations contribute up to 95% of the total UV exposure and are known to induce cell damage, leading to apoptosis. Since the benefic effects of ascorbic acid on human health are well known, a new tomato genotype (named DHO4), highly rich in ascorbic acid, has been recently obtained. Here, we compared the effects of ascorbic acid and hydrophilic DHO4 extracts in protecting human keratinocytes exposed to UVA stress. Keratinocytes were pre-incubated with ascorbic acid or with extracts from the ascorbic acid enriched tomato genotype and irradiated with UVA light. Then, ROS production, intracellular GSH and lipid peroxidation levels were quantified. Western blots were carried out to evaluate mitogen-activated protein kinases cascade, activation of caspase-3 and inflammation levels. We demonstrated that ROS, GSH and lipid peroxidation levels were not altered in cell exposed to UVA stress when cells were pre-treated with ascorbic acid or with tomato extracts. In addition, no evidence of apoptosis and inflammation were observed in irradiated pre-treated cells. Altogether, we demonstrated the ability of an ascorbic acid enriched tomato genotype to counteract UVA-oxidative stress on human keratinocytes. This protective effect is due to the high concentration of vitamin C that acts as free radical scavenger. This novel tomato genotype may be used as genetic material in breeding schemes to produce improved varieties with higher antioxidant levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Application of 10% Ascorbic Acid Improves Resin Shear Bond Stregth in Bleached Dentin

    Directory of Open Access Journals (Sweden)

    Kamizar Kamizar

    2014-10-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Restoration of the teeth immediately after bleaching with H2O2 35% is contraindicated due to the remnants of free radical that will stay inside dentin for 2-3 weeks which will compromise the adhesiveness of composite resin. Objective: The aim of this study was to evaluate the influence of 10% ascorbic acid on shear bond strength of composite placed on bleached dentin. Methods:Twenty seven samples were divided equally into three groups. Group 1: dentin was etched with 35% phosphoric acid; Group 2: dentin was bleached with 35% H2O2 followed by etching with 35% phosphoric acid; Group 3: dentin was bleached with 35% H2O2, followed by application of 10% ascorbic acid and etched with 35% phosphoric acid. All samples were then stored at 370C for 24 hours. The Universal Testing Machine was used to measure shear bond strength and the results were analyzed with Kruskal Wallis and Mann Whitney test. Results: After nine independent experiments, 10% ascorbic acid application on bleached dentin resulted in highest increased in bond stregth (56.04±11.06MPa compared to Group 2 (29.09±7.63MPa and Group 1 (25.55±2.22MPa and the difference was statistically significant (p<0.05. Conclusion: Application of 10% ascorbic acid to the bleached dentin improved the shear bond strength of resin composite.

  14. TNF-α-induced depressive-like phenotype and p38(MAPK) activation are abolished by ascorbic acid treatment.

    Science.gov (United States)

    Moretti, Morgana; Budni, Josiane; Freitas, Andiara Espíndola; Neis, Vivian Binder; Ribeiro, Camille Mertins; de Oliveira Balen, Grasiela; Rieger, Débora Kurrle; Leal, Rodrigo Bainy; Rodrigues, Ana Lúcia S

    2015-06-01

    We investigated the effects of ascorbic acid on depressive-like behavior induced by tumor necrosis factor (TNF-α) in mice. Additionally, we examined the effects of combined administration of ascorbic acid and antidepressants, MK-801 and 7-nitroindazole in mice exposed or not to TNF-α and the capacity of TNF-α and ascorbic acid to modulate hippocampal and cerebrocortical phosphorylation of extracellular signal-regulated kinase (ERK), p38(MAPK) and c-Jun N-terminal kinase (JNK). In control animals, ascorbic acid reduced the immobility time in the tail suspension test (TST). Unilateral intracerebroventricular administration of TNF-α produced a depressive-like behavior in the TST, and the treatment with ascorbic acid prevented this effect. Sub-effective dose of ascorbic acid combined with sub-effective doses of fluoxetine, imipramine, bupropion, MK-801 or 7-nitroindazole produced a synergistic antidepressant-like effect in mice exposed or not to TNF-α. No treatment caused significant alterations in the locomotor activity of mice. Administration of TNF-α increased the phosphorylation of p38(MAPK) in hippocampus and cerebral cortex, and the treatment with ascorbic acid prevented this effect. Ascorbic acid increased phosphorylation of ERK1 in the hippocampus of saline- and TNF-α-treated animals, however it did not produce alterations in the cerebral cortex. No effects on phosphorylation of ERK2 or JNK were found. The observed effect of ascorbic acid seems to be associated, at least partially, with a reduced p38(MAPK) phosphorylation, activation of the monoaminergic systems as well as inhibition of N-methyl-D-aspartate (NMDA) receptors and nitric oxide (NO) synthesis. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  15. Effects of orally administered ascorbic acid on the athletic performance in Arab horses

    Directory of Open Access Journals (Sweden)

    M Mashayekhi

    2008-08-01

    Full Text Available The aim of this study was to evaluate the athletic performance of Arab horses fallowing oral administration of ascorbic acid. The study was conducted on two groups each consisting of 20 Arab horses with the age range of 4-9 years and body weight of 450-550 kg. After general examination of all horses, those in the treatment group received 20 grams of oral ascorbic acid daily for 30 days. At the end of 30 days period, general examination was performed once again and two jugular blood samples along with the electrocardiography after exercise at the 2160 meter track. Statistical analysis of the results indicated that the mean serumic levels of aspartate aminotransferase, lactate dehydrogenase, creatine phosphokinase, lactate and uric acid had significantly increased (p

  16. Study of radio-protective effects of ascorbic acid in rates

    International Nuclear Information System (INIS)

    Bakir, A.M.; Mohammad, A.

    2011-06-01

    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 ( 60 Co 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 ( 60 Co 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Ara; Kang, Minkyung; Cha, Areum; Jang, Hye Su [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Shim, Jun Ho [Department of Chemistry, Daegu University, Gyeongsan 712-714 (Korea, Republic of); Lee, Nam-Suk [National Center for Nanomaterials Technology (NCNT), Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Kim, Myung Hwa [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Lee, Youngmi, E-mail: youngmilee@ewha.ac.kr [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Lee, Chongmok, E-mail: cmlee@ewha.ac.kr [Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of)

    2014-03-01

    Highlights: • We synthesized hollow gold/ruthenium (hAu–Ru) nanoshells for ascorbic acid sensing. • The hAu–Ru nanoshells showed sensitivity of 426 μA mM⁻¹ cm⁻² for ascorbic acid. • Good selectivity against glucose, uric acid, dopamine, 4-acetamidophenol, and NADH. • The linear dynamic range appeared from zero to 2.0 mM (R = 0.9995). • Response time (1.6 s) and low detection limit (2.2 μM) were obtained at pH 7.40. Abstract: 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 μA mM⁻¹ cm⁻² (normalized to the GC disk area) for the linear dynamic range of <5 μM to 2 mM AA at physiological pH. The response time and detection limit were 1.6 s and 2.2 μM, 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.

  18. Ascorbic acid as a bifunctional hydrogen bond donor for the synthesis of cyclic carbonates from CO2 under ambient conditions

    KAUST Repository

    Arayachukiat, Sunatda

    2017-07-14

    Readily available ascorbic acid was discovered as an environmentally benign hydrogen bond donor (HBD) for the synthe-sis of cyclic organic carbonates from CO2 and epoxides in the presence of nucleophilic co-catalysts. The ascorbic acid/TBAI (TBAI: tetrabutylammonium iodide) binary system could be applied for the cycloaddition of CO2 to various epoxides under ambient or mild conditions. DFT calculations and catalysis experiments revealed an intriguing bifunctional mechanism in the step of CO2 insertion involving different hydroxyl moieties (enediol, ethyldiol) of the ascorbic acid scaffold.

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

    International Nuclear Information System (INIS)

    Wang Guangfeng; Meng Jian; Liu Hongying; Jiao Shoufeng; Zhang Wei; Chen Daolei; Fang Bin

    2008-01-01

    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 -7 to 1.0 x 10 -4 mol/L with the detection limit (signal-to-noise ratio was 3) for UA 1.0 x 10 -7 mol/L. The proposed method showed excellent selectivity and stability, and the determination of UA and AA simultaneously in urine was satisfactory

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

    Science.gov (United States)

    Rai, L C; Raizada, M

    1987-08-01

    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.

  1. The effect of water, ascorbic acid, and cranberry derived supplementation on human urine and uropathogen adhesion to silicone rubber.

    Science.gov (United States)

    Habash, M B; Van der Mei, H C; Busscher, H J; Reid, G

    1999-08-01

    In this study, urine was collected from groups of volunteers following the consumption of water, ascorbic acid, or cranberry supplements. Only ascorbic acid intake consistently produced acidic urine. Photospectroscopy data indicated that increased water consumption produced urine with lower protein content. Surface tension measurements of the collected urine showed that both water and cranberry supplementation consistently produced urine with surface tensions higher than the control or urine collected following ascorbic acid intake. These urine samples were also employed to study uropathogen adhesion to silicone rubber in a parallel plate flow chamber. Urine obtained after ascorbic acid or cranberry supplementation reduced the initial deposition rates and numbers of adherent Escherichia coli and Enterococcus faecalis, but not Pseudomonas aeruginosa, Staphylococcus epidermidis, or Candida albicans. Conversely, urine obtained from subjects with increased water intake vastly increased the initial deposition rates and numbers of adherent E. coli and E. faecalis (P < 0.05).

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

    DEFF Research Database (Denmark)

    Zhou, A; Matsumoto, T; Farver, O

    1990-01-01

    of uptake occurred when mechanically isolated cells were incubated with increasing ascorbic acid concentrations up to 0.6 mM. But if such cells were purified on a Percoll gradient, a clear saturation of uptake could be observed. Acetylsalicylic acid reduced the uptake markedly. When cells loaded with L-[14C......Mechanically isolated cells from the intermediate lobe of ox hypophyses contained 40.6 +/- 3.7 nmol mg-1 protein (mean +/- SE, n = 5) of ascorbic acid. They accumulated radioactivity time dependently, on incubation with L-[14C]ascorbic acid in ionic medium dominated by NaCl. No definite saturation......]ascorbic acid were homogenized and placed on a Percoll gradient, the radioactivity was recovered in several subcellular fractions. Decrease of the Na+ concentration or presence of ouabain in the medium did not cause noticeable changes in uptake by non-purified cells, whereas uptake by purified cells was clearly...

  3. Characteristic of ascorbic acid in crosslinked chitosan edible film as drug delivery system membrane

    Directory of Open Access Journals (Sweden)

    Kistriyani Lilis

    2018-01-01

    Full Text Available Chitosan is a polysaccharide compound in the form of a linear polysaccharide consisting of N-acetyl glucosamine (GlcNAc and D-glucosamine (GlcN monomer, which is a derivative of deacetylization of chitin polymer. Chitin is one of common type of polysaccharide on earth after the excess cellulose from inveterbrata skeletons. Chitosan has anti-microbial properties. Based on this properties, chitosan is potentially used to be an edible film as drug delivery system membrane. Edible film was made by dissolving chitosan in 100 mL acetic acid 1%, then the plasticizer and crosslinker was added while heated at 60° C. It was molded and dried in oven at 50°C for 48 hours. Drug loading in the edible film could be controlled by remodeling membrane characteristics in the presence of crosslinker additions. The purpose of this study was to estimate the mass transfer coefficient (kCa of drug loading in various concentrations of ascorbic acid in the edible film. The characteristics of ascorbic acid in chitosan edible film could be seen from the number of drugs that could be loaded through the uv-vis spectrophotometric analysis. The higher concentration of ascorbic acid was added, the drug would be loaded more into edible film.

  4. L-dehydroascorbic acid can substitute L-ascorbic acid as dietary vitamin C source in guinea pigs

    DEFF Research Database (Denmark)

    Frikke-Schmidt, Henriette Rønne; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-01-01

    Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)-commonly found in vitamin C containing food...... products prone to oxidation-was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain), only sporadic differences...... in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25mg/ml in the drinking water), where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats...

  5. Effects of dietary chromium exposure to rockfish, Sebastes schlegelii are ameliorated by ascorbic acid.

    Science.gov (United States)

    Kim, Jun-Hwan; Kang, Ju-Chan

    2017-05-01

    Juvenile rockfish Sebastes schlegelii (mean length 10.8±1.4cm, and mean weight 31.7±3.6g) were exposed for 4 weeks with the different levels of dietary chromium (Cr 6+ ) at 0, 120 and 240mg/L and ascorbic acids (AsA) at 100, 200 and 400mg/L. Significant accumulation occurred in specific tissues and hematological parameters were altered: red blood cell count, hematocrit, and hemoglobin increased; plasma components were altered including calcium, glucose, cholesterol, total protein, glutamic oxalate transaminase, and glutamic pyruvate transaminase. However, magnesium and alkaline phosphatase concentrations were unchanged. Ascorbic acids reduced both chromium uptake into tissues and altered hematological parameters. Copyright © 2017. Published by Elsevier Inc.

  6. Retention of Ascorbic Acid and Solid Concentration via Centrifugal Freeze Concentration of Orange Juice

    Directory of Open Access Journals (Sweden)

    P. Orellana-Palma

    2017-01-01

    Full Text Available Freeze concentration of liquid foods produces high-quality concentrates while retaining the heat-labile compounds found in fresh samples. Centrifugal freeze concentration is a cryoconcentration method assisted by an external force, centrifugation, to enhance the separation of concentrate from the ice. When applying centrifugal freeze concentration to orange juice, after the third cryoconcentration cycle, the ascorbic acid content in the concentrate showed retention close to 70% of the initial value. After the third cycle, the solutes in the concentrate increased 4 times the initial value of the fresh sample with 70% efficiency. The color evaluation showed that the final concentrated fraction was darker than the fresh juice. The centrifugal freeze concentration in orange juice was effective for obtaining a high-quality concentrate with a higher concentration of solids and ascorbic acid retention.

  7. Radical-regulating and antiviral properties of ascorbic acid and its derivatives.

    Science.gov (United States)

    Brinkevich, Sviatoslav D; Boreko, Eugene I; Savinova, Olga V; Pavlova, Natalia I; Shadyro, Oleg I

    2012-04-01

    The ability of ascorbic acid and a number of its derivatives to suppress replication of Herpes simplex virus type I was investigated in human rhabdomyosarcoma cell line. In parallel, interaction of the test compounds with carbon- and oxygen-centered radicals formed on radiolysis of hydroxyl-containing organic compounds was studied using the steady state radiolysis method. It has been shown that 2-O-glycoside of ascorbic acid, displaying marked antiviral properties against Herpes simplex virus type I, is also capable of inhibiting fragmentation and recombination reactions of α-hydroxyl-containing carbon-centered radicals while not affecting processes involving oxygen-centered radicals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. [The effect of gamma rays on glutathion and ascorbic acid content in rabbit lenses (author's transl)].

    Science.gov (United States)

    Zygulska-Mach, H; Mach, Z

    1975-01-01

    It is pointed out that the partner non radiated eye is also influenced after employment of high radiation on an eye. The authors radiated rabbit eyes with gamma rays employing Stallard-applicators and determined the glutathion and ascorbic acid content in the lenses. The lenses of the partner eye were also examined for comparison. In those eyes which were directly radiated there was a fall of concentration of the two substances indirectly proportional to the dose of rays employed. In the partner eyes which were not directly subjected to direct radiation there were changes of similar character which were however not so much pronounced. The role of glutathion and ascorbic acid in lens metabolism is pointed out.

  9. Improvement of 2-O-α-D-Glucopyranosyl-L-Ascorbic Acid ...

    African Journals Online (AJOL)

    Purpose: To improve 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) production using ultrasonic radiation (UR) treatment. Methods: The production of AA-2G using UR or ultrasonic radiation with shaking (URS) at 150 rpm, at varying power (100 − 500 W), temperature (30 – 65 °C), pH 4.0 −9.0, and time (2−24 h) was ...

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

    OpenAIRE

    Marjanović Nikola J.; Jovanić Saša I.; Stanić Aleksandar R.; Suturović Zvonimir J.

    2009-01-01

    Arsenic speciation, besides total arsenic content determination, is very important in analysis of water, foodstuffs, and environmental samples, because of varying degrees of toxicity of different species. For such purpose hydride generation atomic absorption spectrometry can be used based on the generation of certain types of hydride, depending on the pH value and pretreatment in different reaction media. In this study, we have investigated the effect of L-ascorbic acid as the reaction medium...

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

    Science.gov (United States)

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

    2014-11-01

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

  12. Application of super absorbent polymer and ascorbic acid to mitigate deleterious effects of cadmium in wheat

    OpenAIRE

    Moghadam,Hamid Reza Tohidi

    2016-01-01

    ABSTRACT The growing use of chemical fertilizers, insecticides and pesticides can cause potential contamination with heavy metals to soil and groundwater, posing environmental and health threats. Heavy metals can also affect crop yield. A greenhouse experiment was conducted to explore the role of ascorbic acid foliar application and soil-applied super absorbent to mitigate adverse effects of cadmium (Cd), in terms of biochemical parameters in wheat. The experiment was installed in a completel...

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

    Directory of Open Access Journals (Sweden)

    Martín Roberto Alvarez

    2009-06-01

    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.

  14. Selective response of dopamine in the presence of ascorbic acid ...

    African Journals Online (AJOL)

    By grafting with ethylene diamine tetraacetic acid (EDTA), novel multi-walled carbon nanotube nano-composites (EDTA-MWCNTs) have been successfully prepared. The integration of gold nanoparticles (AuNPs) and novel functionalized matrix shows very promising applications in the fabrication of biosensors for sensitive ...

  15. Delphinidin immobilized on silver nanoparticles for the simultaneous determination of ascorbic acid, noradrenalin, uric acid, and tryptophan

    Directory of Open Access Journals (Sweden)

    Navid Nasirizadeh

    2016-04-01

    Full Text Available In the present study, the fabrication of a new modified electrode for electrocatalytic oxidation of noradrenalin, based on the delphinidin immobilized on silver nanoparticles modified glassy carbon electrode. Cyclic voltammetry was used to investigate the redox properties of this modified electrode. The surface charge transfer rate constant (ks and the charge transfer coefficient (α for the electron transfer between the glassy carbon electrode and the immobilized delphinidin were calculated. The differential pulse voltammetry exhibited two linear dynamic ranges and a detection limit of 0.40μM for noradrenalin determination. Moreover, the present electrode could separate the oxidation peak potentials of ascorbic acid, noradrenalin, uric acid, and tryptophan in a mixture. The usefulness of this nanosensor was also investigated for the determination of ascorbic acid, noradrenalin, and uric acid in pharmaceutical and biological fluid samples with satisfactory results.

  16. Influence of ascorbic acid on in vivo amidation of alpha-melanocyte stimulating hormone in guinea pig pituitary

    DEFF Research Database (Denmark)

    Fenger, M; Hilsted, L

    1988-01-01

    The effect of ascorbic acid depletion on the amidation of alphamelanocyte stimulating hormone (alpha MSH) was studied in vivo in guinea pig pituitary. After four weeks, the concentration of ascorbic acid was 1.20 +/- 0.11 mumol/g tissue (mean +/- SD) in the pituitary and 0.34 +/- 0.07 mumol......-39) immunoreactivity was observed in the depleted guinea pigs. Gel chromatography and reversed-phase high-performance luquid chromatography showed that the alpha MSH and ACTH (1-14) immunoreactivity was of low molecular weight and partly mono- or diacetylated. Depletion of ascorbic acid had no influence on the degree...... of acetylation of alpha MSH and ACTH (1-14). It is concluded that depletion of ascorbic acid reduces the in vivo amidation of ACTH (1-14) in the guinea pig pituitary....

  17. Clinical efficacy of 25% L-ascorbic acid (C'ensil) in the treatment of melasma.

    Science.gov (United States)

    Hwang, Seon-Wook; Oh, Doo-Jin; Lee, Deborah; Kim, Jung-Wook; Park, Sung-Wook

    2009-01-01

    L-Ascorbic acid is used to treat melasma; however, it is quickly oxidized in aqueous solutions. Thus, C'ensil, a formulation containing 25% l-ascorbic acid and a chemical penetration enhancer, was created to promote the penetration of l-ascorbic acid into the skin. To evaluate the efficacy of C'ensil in patients with melasma. Forty subjects with melasma were treated with C'ensil during an open-label trial over a period of 16 weeks. Each subject's skin pigmentation was assessed every 4 weeks using the Melasma Area and Severity Index (MASI) and mexameter score. In addition, transepidermal water loss, skin dryness and irritation, and quality of life (Melasma Quality of Life Scale [MelasQoL]) were evaluated. After 16 weeks, a significant decrease was noted in the degree of pigmentation based on the patients' MASI and mexameter scores. MelasQoL scores also decreased, indicating an increase in the subjects' quality of life. Our data indicate that C'ensil is an effective treatment modality for melasma.

  18. Study Of Blood Lead Levels, Hemoglobin & Plasma AscorbicAcid In ACarCompanyWelders

    Directory of Open Access Journals (Sweden)

    AR Dorosti

    2006-04-01

    Full Text Available Background and Aims: Background and aim: About 30-40% of lead entered the respiratorysystem, is absorbed to the bloodstream. Some studies have demonstrated that cigarette smokingresults in blood-lead levels elevation as well as decreased blood ascorbic acid. This study hasperformed on this issue in lead exposed welder workers.Method:Adescriptive cross-sectional study was performed to evaluate associations of smokinghabit with blood lead, hemoglobin and plasma ascorbic acid levels in 32 welders. All the casesused to work in a car factory in Tehran suburb as welders 8 hours a day. They were divided intothree groups based on blood lead level quartiles.The blood lead levels were determined by 8003 NAIOSH method and blood ascorbic acid levelwas determined by Lowery method. Results were compared (based on mean values usingindependent sample t-test and analysis of variance (ANOVA methods.Results: Results indicated that the blood lead levels in those who smoke 7+ cigarettes per day wassignificantly higher than those who smoke <7 cigarettes per day (p<0.05 or no smoking group(p<0.001. The hemoglobin concentrations in 7+ group was significantly lower than of the <7(p<0.01 and no smoking (p<0.05 groups.Conclusion :Smoking hait in population, who occupationally exposed to lead, causes an increaseexposure to lead and, hence, elevation of blood-lead levels as well as inhibition of hemoglobinsynthesis and therefore reduces hemoglobin concentration.

  19. Xyloglucan from Hymenaea courbaril var. courbaril seeds as encapsulating agent of l-ascorbic acid.

    Science.gov (United States)

    Farias, Mirla D P; Albuquerque, Priscilla B S; Soares, Paulo A G; de Sá, Daniele M A T; Vicente, António A; Carneiro-da-Cunha, Maria G

    2018-02-01

    This study evaluated the l-ascorbic acid (AA) encapsulation in microparticles of xyloglucan (XAA) extracted from Hymenaea courbaril seeds by spray drying (SD) and its application in tilapia fish burgers. The encapsulation efficiency was 96.34±1.6% and the retention of the antioxidant activity was of 89.48±0.88% after 60days at 25°C. SEM images showed microspheres with diameters ranging from 4.4 to 34.0μm. FTIR spectrum confirmed the presence of AA in xyloglucan microparticles, which was corroborated by DSC and TGA. The release of ascorbic acid was found to be pH-dependent. The application of XAA in tilapia fish burger did not change the pH after heating and the ascorbic acid retention was greater compared to its free form. The results indicate that xyloglucan can be used to encapsulate AA by SD and suggest that XAA was able to reduce undesirable organoleptic changes in fish burgers. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Burkey, Kent O.; Neufeld, Howard S.; Souza, Lara; Chappelka, Arthur H.; Davison, Alan W.

    2006-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-15

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

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

    Science.gov (United States)

    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

    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. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Ascorbic acid and beta-carotene reduce stress-induced oxidative organ damage in rats.

    Science.gov (United States)

    Esrefoglu, M; Akinci, A; Taslidere, E; Elbe, H; Cetin, A; Ates, B

    2016-10-01

    Antioxidants are potential therapeutic agents for reducing stress-induced organ damage. We investigated the effects of ascorbic acid and β-carotene on oxidative stress-induced cerebral, cerebellar, cardiac and hepatic damage using microscopy and biochemistry. Male Wistar albino rats were divided into five groups: untreated control, stressed, stressed + saline, stressed + ascorbic acid and stressed + β-carotene. The rats in the stressed groups were subjected to starvation, immobilization and cold. The histopathological damage scores for the stressed and stressed + saline groups were higher than those of the control group for all organs examined. The histopathological damage scores and mean tissue malondialdehyde levels for the groups treated with antioxidants were lower than those for the stressed and stressed + saline groups. Mean tissue superoxide dismutase activities for groups that received antioxidants were higher than those for the stressed + saline group for most organs evaluated. Ascorbic acid and β-carotene can reduce stress-induced organ damage by both inhibiting lipid oxidation and supporting the cellular antioxidant defense system.

  4. Effect of the Electric Field Frequency on Ascorbic Acid Degradation during Thermal Treatment by Ohmic Heating

    Science.gov (United States)

    Mercali, Giovana Domeneghini; Schwartz, Steven; Marczak, Ligia Damasceno Ferreira; Tessaro, Isabel Cristina; Sastry, Sudhir

    2014-01-01

    In this work, the influence of the electric field frequency and solids content on the degradation kinetics of ascorbic acid during ohmic heating of acerola pulp and acerola serum was investigated. The degradation percentage of ascorbic acid in the pulp after 120 min of heating varied between 12 and 17%. For the serum, the degradation percentage was in the range of 13 and 18%. The results were fitted to the first-order model, and the kinetic rate constants ranged from 1.1 to 1.6 × 10−3 min−1 and from 1.1 to 1.5 × 10−3 min−1 for pulp and serum, respectively. D values ranged between 1480 and 2145 min for the pulp and between 1524 and 1951 min for the serum. A distinct behavior between the kinetic parameters of the pulp and serum in electric field frequencies ranging from 10 to 1000 Hz indicates that the presence of distinct amounts and types of solids might affect the rate of the electron transfer in electrochemical reactions. These variables may also affect the polarization process stimulated by the oscillating electric field. The non-achievement of the equilibrium of the polarization process may have an influence on oxidation reactions, affecting the predisposition to hydrogen donation from the ascorbic acid molecule. PMID:24892902

  5. Radioprotective and Apoptotic Properties of a Combination of α-Tocopherol Acetate and Ascorbic Acid.

    Science.gov (United States)

    Vasil'eva, I N; Bespalov, V G; Baranenko, D A

    2016-06-01

    We studied radioprotective and apoptotic properties of a combination of α-tocopherol acetate and ascorbic acid. α-Tocopherol acetate (10 mg/kg body weight) or ascorbic acid (20 mg/kg) or combination of these agents in the same doses was orally administered to male rats at various terms before and after single whole-body exposure to γ-irradiation in the doses of 2 and 8 Gy. Irradiation increased the frequency of chromosome aberrations in bone marrow cells and plasma level of low-molecular-weight DNA. Vitamin combination administered before or after irradiation significantly reduced the frequency of chromosome aberrations by 2-2.5 times. Administration of this combination 10 min before irradiation 1.5-fold increased the content of low-molecular-weight DNA in blood plasma in comparison with the control animals exposed to radiation. The combination of α-tocopherol acetate and ascorbic acid produced radioprotective effects and enhanced apoptosis in irradiated cells.

  6. Influence of ascorbic acid against radiation induced cytogenetic damage in mouse bone marrow

    International Nuclear Information System (INIS)

    Singh, Neelima; Goyal, P.K.

    2001-01-01

    Vitamins have generated a great deal of interest in recent years for a wide range of protective effects in biological systems. The present study is an attempt to determine the prophylactic role of ascorbic acid (Vitamin C) against radiation induced clastogenic changes in mouse bone marrow after exposure to a sublethal dose of gamma radiation. For this purpose, Swiss albino mice were irradiated to 1.60 Gy gamma radiation in the presence (experimental) and absence (control) of ascorbic acid. These animals were sacrificed between 6 h and 20 d post-irradiation, and cytogenetic alterations were noted in the form of chromosomal aberrations and micronuclei. Frequency of aberrant cells increased from 6 h by reaching to the highest at 12 h, but gradually declined thereafter, without returning to normal throughout experimentation in both the groups. The counts of such cells were significantly lower in experimental animals. When individual types of aberrations were studied, the experimental values were found to be significantly lower than the corresponding controls. The pattern of micronuclei appearance in ascorbic acid treated animals was alike control, but the counts were significantly lesser throughout the period of study. (author)

  7. Solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles as ionophore.

    Science.gov (United States)

    Wang, Kun; Xu, Jing-Juan; Tang, Kai-Shi; Chen, Hong-Yuan

    2005-10-15

    A novel solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles (NanoCoPc) as ionophore was fabricated without any need of auxiliary materials (such as membrane matrix, plasticizer, and other additives). The electrode was prepared by simple drop-coating NanoCoPc colloid on the surface of a glassy carbon electrode. A smooth, bright and blue thin film was strongly attached on the surface of the glassy carbon electrode. The electrode showed high selectivity for ascorbic acid, as compared with many common anions. The influences of the amount of NanoCoPc at the electrode surface and pH on the response characteristics of the electrode were investigated. To overcome the instability of the formal potential of the coated wire electrode, a novel electrochemical pretreatment method was proposed for the potentiometric sensor based on redox mechanism. This resulting sensor demonstrates potentiometric response over a wide linear range of ascorbic acid concentration (5.5 x 10(-7) to 5.5 x 10(-2)M) with a fast response (determination of practical samples.

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

    International Nuclear Information System (INIS)

    Rodriguez Hernandez, Yaslenis; Suarez Perez, Yania; Izquierdo Castro, Idalberto

    2009-01-01

    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 μm 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 μg/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)

  9. O-Anisidine as Indicator in Titrimetric Determination of Ascorbic Acid and Isonicotinic Acid Hydrazide in Pharmaceutical Formulations

    OpenAIRE

    B.S.A.Andrews; B.Sreenivas Rao; Som Shankar Dubey; B.Venkata Kiran

    2010-01-01

    Inspite of the beautiful red coloured oxidized product of O-anisidine, the studies on its application in analytical techniques are scanty. So, authors have taken up the investigation on the utility of O-anisidine as a new Analytical reagent in the bromatometric-Indicator reaction. The detailed reaction on the potassium bromate and OAnisidine has enabled the authors to utilize O-Anisidine in titration of Ascorbic Acid and Isonicitonic Acid Hydrazide. Suitable conditions has been established wi...

  10. L-Ascorbic acid can abrogate SVCT-2-dependent cetuximab resistance mediated by mutant KRAS in human colon cancer cells.

    Science.gov (United States)

    Jung, Soo-A; Lee, Dae-Hee; Moon, Jai-Hee; Hong, Seung-Woo; Shin, Jae-Sik; Hwang, Ih Yeon; Shin, Yu Jin; Kim, Jeong Hee; Gong, Eun-Yeung; Kim, Seung-Mi; Lee, Eun Young; Lee, Seul; Kim, Jeong Eun; Kim, Kyu-Pyo; Hong, Yong Sang; Lee, Jung Shin; Jin, Dong-Hoon; Kim, TaeWon; Lee, Wang Jae

    2016-06-01

    Colon cancer patients with mutant KRAS are resistant to cetuximab, an antibody directed against the epidermal growth factor receptor, which is an effective clinical therapy for patients with wild-type KRAS. Numerous combinatorial therapies have been tested to overcome the resistance to cetuximab. However, no combinations have been found that can be used as effective therapeutic strategies. In this study, we demonstrate that L-ascorbic acid partners with cetuximab to induce killing effects, which are influenced by sodium-dependent vitamin C transporter 2 (SVCT-2) in human colon cancer cells with a mutant KRAS. L-Ascorbic acid treatment of human colon cancer cells that express a mutant KRAS differentially and synergistically induced cell death with cetuximab in a SVCT-2-dependent manner. The ectopic expression of SVCT-2 induced sensitivity to L-ascorbic acid treatment in human colon cancer cells that do not express SVCT-2, whereas the knockdown of endogenous SVCT-2 induced resistance to L-ascorbic acid treatment in SVCT-2-positive cells. Moreover, tumor regression via the administration of L-ascorbic acid and cetuximab in mice bearing tumor cell xenografts corresponded to SVCT-2 protein levels. Interestingly, cell death induced by the combination of L-ascorbic acid and cetuximab resulted in both apoptotic and necrotic cell death. These cell death mechanisms were related to a disruption of the ERK pathway and were represented by the impaired activation of RAFs and the activation of the ASK-1-p38 pathway. Taken together, these results suggest that resistance to cetuximab in human colon cancer patients with a mutant KRAS can be bypassed by L-ascorbic acid in an SVCT-2-dependent manner. Furthermore, SVCT-2 in mutant KRAS colon cancer may act as a potent marker for potentiating L-ascorbic acid co-treatment with cetuximab. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Ascorbic acid-pretreated quartz enhances cyclo-oxygenase-2 expression in RAW 264.7 murine macrophages.

    Science.gov (United States)

    Scarfì, Sonia; Benatti, Umberto; Pozzolini, Marina; Clavarino, Emanuela; Ferraris, Chiara; Magnone, Mirko; Valisano, Laura; Giovine, Marco

    2007-01-01

    Exposure to quartz particles induces a pathological process named silicosis. Alveolar macrophages initiate the disease through their activation, which is the origin of the later dysfunctions. Ascorbic acid is known to selectively dissolve the quartz surface. During the reaction, ascorbic acid progressively disappears and hydroxyl radicals are generated from the quartz surface. These observations may be relevant to mammalian quartz toxicity, as substantial amounts of ascorbic acid are present in the lung epithelium. We studied the inflammatory response of the murine macrophage cell line RAW 264.7 incubated with ascorbic acid-treated quartz, through the expression and activity of the enzyme cyclo-oxygenase-2 (COX-2). COX-2 expression and prostaglandin secretion were enhanced in cells incubated with ascorbic acid-treated quartz. In contrast, no changes were observed in cells incubated with Aerosil OX50, an amorphous form of silica. Quantification of COX-2 mRNA showed a threefold increase in cells incubated with ascorbic acid-treated quartz compared with controls. The transcription factors, NF-kappaB, pCREB and AP-1, were all implicated in the increased inflammatory response. Reactive oxygen species (H(2)O(2) and OH(*)) were involved in COX-2 expression in this experimental model. Parallel experiments performed on rat alveolar macrophages from bronchoalveolar lavage confirmed the enhanced COX-2 expression and activity in the cells incubated with ascorbic acid-treated quartz compared with untreated quartz. In conclusion, the selective interaction with, and modification of, quartz particles by ascorbic acid may be a crucial event determining the inflammatory response of macrophages, which may subsequently develop into acute inflammation, eventually leading to the chronic pulmonary disease silicosis.

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

    Science.gov (United States)

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

    2014-03-01

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

  13. Effect of copper on ascorbic acid content, redox potential and development of oxidized flavor in milk of cows and buffaloes

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, V.; Rao, D.S.; Rao, M.B.

    1976-06-01

    The effect of copper on ascorbic acid content, redox potential (E/sub h/) of milk, and development of oxidized flavor is discussed. Oxidized flavor appeared in cow milk only after a marked rise in E/sub h/ due to the oxidation of ascorbic acid, whereas in buffalo milk oxidized flavor developed without any appreciable change in E/sub h/. In buffalo milk, copper at low concentrations failed to cause sufficient oxidation of ascorbic acid to effect an increase in E/sub h/. The E/sub h/ of cow milk began to rise appreciably when more than half of the ascorbic acid normally present in milk was oxidized. The pro-oxidant action of ascorbic acid in cow milk at concentrations normal to milk is not merely due to conversion of copper to cuprous form; it is suggested that the activation energy involved in this conversion is an important factor in the lipid oxidation which follows. Ascorbic acid did not promote copper-catalyzed oxidation of buffalo milk as it is not involved in the reversible oxidation. 23 references.

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

    Directory of Open Access Journals (Sweden)

    HAMIDAH HAMAMA

    2010-09-01

    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 ascorbic 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.

  15. Evaluating the protective effects of radon inhalation or ascorbic acid treatment after transient global cerebral ischemic injury in gerbils

    International Nuclear Information System (INIS)

    Kataoka, Takahiro; Etani, Reo; Kanzaki, Norie; Sasaoka, Kaori; Kobashi, Yusuke; Hanamoto, Katsumi; Taguchi, Takehito; Yamaoka, Kiyonori

    2016-01-01

    In this study, we compared the protective effects of radon inhalation and ascorbic acid administration on transient global cerebral ischemic injury in gerbils. Gerbils were treated with radon inhalation (2000 Bq/m 3 , 24 hours) or ascorbic acid (100, 300, or 500 mg/kg body weight). Then, transient global cerebral ischemia was induced by bilateral occlusion of the common carotid artery. Results showed that the number of damaged neurons was significantly increased in gerbils that underwent ischemia compared with that in control gerbils. However, the number of damaged neurons in gerbils treated with radon or 500 mg/kg of ascorbic acid before ischemia was significantly lower than gerbils who were subjected to ischemia without any pretreatment, and the protective effects of radon inhalation were similar to the effects of administering 500 mg/kg ascorbic acid. The levels of superoxide dismutase (SOD) and total glutathione (t-GSH) in brain tissue were increased to a similar extent by pretreatment with radon inhalation or 500 mg/kg of ascorbic acid. These findings suggested that radon inhalation has a protective antioxidative effect against transient global cerebral ischemic injury similar to 500 mg/kg ascorbic acid treatment. (author)

  16. Improvement of bioavailability for iron from vegetarian meals by ascorbic acid

    International Nuclear Information System (INIS)

    Sritongkul, N.; Tuntawiroon, M.; Pleehachinda, R.; Suwanik, R.

    1996-01-01

    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 ( 59 Fe/ 55 Fe) 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

  17. Uptake of dehydroascorbic acid and ascorbic acid to isolated nerve terminals and secretory granules from ox neurohypophyses

    DEFF Research Database (Denmark)

    Thorn, N A; Nielsen, F S; Jeppesen, C K

    1986-01-01

    When uptake of L-[14C]ascorbic acid ([14C]AA) to various organs in guinea-pigs was studied after intracardiac injection, the adenohypophysis, pars intermedia, and the neurohypophysis had an uptake per milligramme protein which was about half of the uptake to the adrenals. Adrenal uptake was 20 +/......): 15.6 +/- 1.9, (B): 6.92 +/- 0.32, (C): 3.15 +/- 0.43. In all preparations the cobalt content was below the detection limit (less than 5 pmol mg-1 protein)....... labelled dehydroascorbic acid ([14C]DHA), the uptake was much slower than when the medium contained labelled ascorbic acid. The uptake of [14C]DHA showed a linear dependence on concentration, and was not influenced by addition of Mg2+ and ATP. Addition of Mg2+ + ATP, omission of Ca2+ and Mg2+ or exchange...

  18. Effect of L (+) ascorbic acid and monosodium glutamate concentration on the morphology of calcium carbonate

    Science.gov (United States)

    Saraya, Mohamed El-shahte Ismaiel

    2015-11-01

    In this study, monosodium glutamate and ascorbic acid were used as crystal and growth modifiers to control the crystallization of CaCO3. Calcium carbonate prepared by reacting a mixed solution of Na2CO3 with CaCl2 at ambient temperature, (25 °C), constant Ca++/ CO3- - molar ratio and pH with stirring. The polymorph and morphology of the crystals were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The results indicate that rhombohedral calcite was only formed in water without organic additives, and both calcite and spherical vaterite with various morphologies were produced in the presence of monosodium glutamate. The content of vaterite increased as the monosodium glutamate increased. In addition, spherical vaterite was obtained in the presence of different concentrations of ascorbic acid. The spherical vaterite posses an aggregate shape composed of nano-particles, ranging from 30 to 50 nm as demonstrated by the SEM and TEM analyses. Therefore, the ascorbic stabilizes vaterite and result in nano-particles compared to monosodium glutamate.

  19. Ascorbic acid: new role of an age-old micronutrient in the management of periodontal disease in older adults.

    Science.gov (United States)

    Alagl, Adel S; Bhat, Subraya Giliyar

    2015-03-01

    To review the new role of an age-old micronutrient - ascorbic acid - in the management of periodontal disease. Articles pertaining to the topic were searched in PubMed and other search engines from year 1974 to April 2014 with the following key words: "ascorbic acid," "ascorbate," "vitamin C," "periodontal disease," "gingivitis," "periodontitis," "anti-oxidants" and "elderly." Balanced nutrition is an essential factor in the elderly. Modification of nutritional requirement is important to overcome the effect of an unbalanced diet in older individuals as a result of several external and internal host-associated factors. Micronutrient requirements as aging advances could change, and require due attention. Ascorbic acid and its relationship with periodontal disease are very well known. However, recent changes in the concept of understanding the pathogenicity has led to a new path of therapeutic intervention with ascorbic acid in many chronic diseases. Oxidative stress with its associated burden might alter the disease process. In the era of "periodontal medicine," the impact of remote tissue changes on systemic disease has to be taken into serious consideration. Deficiency of nutritional impact on the host, with micronutrient vitamin C detailed in this review with sources, absorption, interaction and its relationship with systemic disease, and thereby the impact on periodontal disease. Ascorbic acid plays an important role in the aging process, and in the maintenance of periodontal health in the elderly. © 2014 Japan Geriatrics Society.

  20. Improvement of development of equine preantral follicles after 6 days of in vitro culture with ascorbic acid supplementation.

    Science.gov (United States)

    Gomes, R G; Lisboa, L A; Silva, C B; Max, M C; Marino, P C; Oliveira, R L; González, S M; Barreiros, T R R; Marinho, L S R; Seneda, M M

    2015-09-15

    The aim of this study was to evaluate the effects of different concentrations of ascorbic acid (25, 50, and 100 μg/mL) in supplemented minimum essential medium (MEM+) on the development of equine preantral follicles that were cultured in vitro for 2 or 6 days. The contralateral ovaries (n = 5) from five mares in seasonal anestrus were collected from a local abattoir. Nine ovarian tissue fragments of approximately 5 × 5 × 1 mm were obtained from each animal. One fragment was immediately fixed and subjected to histologic analysis (control group; Day 0), and the other eight were placed in PBS supplemented with penicillin (200 IU/mL) and streptomycin (200 mg/mL) at 4 °C for 1 hour (during transport to the laboratory). The fragments were cultured in situ for 2 days (D2) or 6 days (D6) in MEM+ or MEM+ plus ascorbic acid at three different concentrations, establishing the following nine groups: control; MEM+ (D2); MEM+ (D6); MEM+ 25 μg/mL of ascorbic acid (D2); MEM+ 25 μg/mL of ascorbic acid (D6); MEM+ 50 μg/mL of ascorbic acid (D2); MEM+ 50 μg/mL of ascorbic acid (D6); MEM+ 100 μg/mL of ascorbic acid (D2); and MEM+ 100 μg/mL of ascorbic acid (D6). The preantral follicles were classified according to their stage (primordial, primary, secondary, or antral) and their morphology (normal or abnormal). Slides (n = 951) including 4450 histologic sections were evaluated. Follicles were observed in only 4.85% (216 of 4450) of the histologic sections. Of the 407 follicles evaluated, 120 were in the primordial stage and 287 were in different developmental stages; additionally, 43.5% were morphologically normal. After 6 days of culture, the groups cultured with 50 and 100 μg/mL of ascorbic acid differed in terms of follicular development compared with the other groups. On the basis of occurrence of follicular development and the presence of viable follicles, it can be concluded that a positive effect of culture for 6 days in MEM+ supplemented with 50 and 100 μg/mL of

  1. Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070 (China); 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); Zhou, Xibin, E-mail: zhouxb@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070 (China)

    2014-05-01

    Highlights: • Trp-GR was synthesized by utilizing a facile ultrasonic method. • The material as prepared had well dispersivity in water and better conductivity than pure GR. • Trp-GR/GCE showed excellent potential for the determination of AA, DA and UA. • The proposed method was applied for the analysis of AA, DA and UA in real samples. - Abstract: A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π–π conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA–DA, DA–UA and UA–AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2–12.9 mM, 0.5–110 μM, and 10–1000 μM, with the detection limits (S/N = 3) of 10.09 μM, 0.29 μM and 1.24 μM, respectively. Furthermore, the modified electrode was investigated for real sample analysis.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    International Nuclear Information System (INIS)

    Lima, Antonio Luis dos Santos; Lima, Keila dos Santos Cople; Silva, Jaqueline Michele; Coelho, Maysa Joppert; Godoy, Ronoel Luiz de Oliveira; Pacheco, Sidney

    2009-01-01

    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 μg/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)

  4. Ascorbic Acid Biosynthesis and Brackish Water Acclimation in the Euryhaline Freshwater White-Rimmed Stingray, Himantura signifer.

    Directory of Open Access Journals (Sweden)

    Samuel Z H Wong

    Full Text Available L-gulono-γ-lactone oxidase (Gulo catalyzes the last step of ascorbic acid biosynthesis, which occurs in the kidney of elasmobranchs. This study aimed to clone and sequence gulonolactone oxidase (gulo from the kidney of the euryhaline freshwater stingray, Himantura signifer, and to determine the effects of acclimation from freshwater to brackish water (salinity 20 on its renal gulo mRNA expression and Gulo activity. We also examined the effects of brackish water acclimation on concentrations of ascorbate, dehydroascorbate and ascorbate + dehydroascorbate in the kidney, brain and gill. The complete cDNA coding sequence of gulo from the kidney of H. signifer contained 1323 bp coding for 440 amino acids. The expression of gulo was kidney-specific, and renal gulo expression decreased significantly by 67% and 50% in fish acclimated to brackish water for 1 day and 6 days, respectively. There was also a significant decrease in renal Gulo activity after 6 days of acclimation to brackish water. Hence, brackish water acclimation led to a decrease in the ascorbic acid synthetic capacity in the kidney of H. signifer. However, there were significant increases in concentrations of ascorbate and ascorbate + dehydroascorbate in the gills (after 1 or 6 days, and a significant increase in the concentration of ascorbate and a significant decrease in the concentration of dehydroascorbate in the brain (after 1 day of fish acclimated to brackish water. Taken together, our results indicate that H. signifer might experience greater salinity-induced oxidative stress in freshwater than in brackish water, possibly related to its short history of freshwater invasion. These results also suggest for the first time a possible relationship between the successful invasion of the freshwater environment by some euryhaline marine elasmobranchs and the ability of these elasmobranchs to increase the capacity of ascorbic acid synthesis in response to hyposalinity stress.

  5. Partial characterization of chayotextle starch-based films added with ascorbic acid encapsulated in resistant starch.

    Science.gov (United States)

    Martínez-Ortiz, Miguel A; Vargas-Torres, Apolonio; Román-Gutiérrez, Alma D; Chavarría-Hernández, Norberto; Zamudio-Flores, Paul B; Meza-Nieto, Martín; Palma-Rodríguez, Heidi M

    2017-05-01

    Chayotextle starch was modified by subjecting it to a dual treatment with acid and heating-cooling cycles. This caused a decrease in the content of amylose, which showed values of 30.22%, 4.80%, 3.27% and 3.57% for native chayotextle starch (NCS), starch modified by acid hydrolysis (CMS), and CMS with one (CMS1AC) and three autoclave cycles (CMS3AC), respectively. The percentage of crystallinity showed an increase of 36.9%-62% for NCS and CMS3AC. The highest content of resistant starch (RS) was observed in CMS3AC (37.05%). The microcapsules were made with CMS3AC due to its higher RS content; the total content of ascorbic acid of the microcapsules was 82.3%. The addition of different concentrations of CMS3AC microcapsules (0%, 2.5%, 6.255% and 12.5%) to chayotextle starch-based films (CSF) increased their tensile strength and elastic modulus. The content of ascorbic acid and RS in CSF was ranged from 0% to 59.4% and from 4.84% to 37.05% in the control film and in the film mixed with CMS3AC microcapsules, respectively. Water vapor permeability (WVP) values decreased with increasing concentrations of microcapsules in the films. Microscopy observations showed that higher concentrations of microcapsules caused agglomerations due their poor distribution in the matrix of the films. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Hussein, O.S.

    2010-01-01

    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.

  7. Intravenous amino acids in third trimester isolated oligohydramnios

    International Nuclear Information System (INIS)

    Qureshi, F.U.

    2011-01-01

    To determine the efficacy of maternal administration of intravenous amino acid solution in improving amniotic fluid volume in cases of isolated oligohydramnios and to observe its impact on mode of delivery and neonatal outcome. Study Design: A prospective case series. Methodology: Forty two women with singleton pregnancy, well established gestational age and clinically and sonographically proven isolated oligohydramnios in the third trimester before 36 weeks were administered amino acid solution intravenously after excluding cases of premature rupture of membranes, congenital anomaly of fetus, maternal pulmonary, cardiovascular and hypertensive disorders, and severe placental insufficiency (raised S/D ratio). Pre-infusion and postinfusion Amniotic fluid Index (AFI) was measured and repeated weekly. Women were followed till delivery. Results: According to repeated measurement analysis of variance, mean pre-infusion AFI was 4.7 cm, mean one week postinfusion AFI was 5.8 cm, mean two week post-infusion AFI was 6.2 cm and mean three week AFI was 6.3 cm (p-value 0.029, significant). Cesarean section became a predominant mode of delivery in this group without a firm evidence of associated fetal compromise. Conclusion: Amino acid infusion is an effective therapy for raising AFI in isolated oligohydramnios in this case series. Liberal use of cesarean section in this selected group should be carefully re-evaluated. (author)

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

    Directory of Open Access Journals (Sweden)

    HAMIDAH HAMAMA

    2010-09-01

    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.

  9. Effect of Thiamine, Ascorbic acid and Gibberellic acid (GA3 on Growth Characteristics, Pigment Content and Reduced Sugars of Petunia

    Directory of Open Access Journals (Sweden)

    moslem salehi

    2017-02-01

    Full Text Available Introduction: Bedding plants, especially petunia is important element for urban landscaping and attracted the attention of landscapers. This is due to some properties such as growth habit and color. The petunia (Petunia hybrida L. belongs to Solanaceae family that has annual and perennial varieties. This plant is originally from Argentina, Brazil and Uruguay. Some plant growth regulators such as gibberellic acid (GA3 and vitamins including thiamine and ascorbic acid affect plant growth and development and may extend flowering period. Vitamin C affects cell division and cell growth in plants and is effective on the feeding cycle activity in higher plants and it has an important role in electron transport system. The concentrations of 50 and 100 ppm of vitamin C and thiamine can increase the plant height, leaf number, leaf area, fresh and dry weight, and chemical compounds of the Syngonium plant. The application of 100 mg/l of GA3 significantly increased plant height and the number of leaves of gladiolus. Material and methods: The experiment was arranged in a factorial based on a completely randomized design with five replications. In this research, growth characteristics (lateral branch number, flower number, flower diameter, stem diameter, root length, and lateral branch length and biochemical characteristics (chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, and reducing sugar were measured. After seeding and transplanting the seedling at 6 leaf stage, plants sprayed at 4 various growth stages with following treatments: 1-\tControl 2-\tVitamin C(100 mg/l 3-\tThiamin (100 mg/l 4-\tGibberellic acid (100 mg/l 5-\tVitamin C and Thiamin (The concentration of both 100 mg/l 6-\tVitamin C and Gibberellic acid (The concentration of both 100 mg/l 7-\tThiamin and Gibberellic acid (The concentration of both 100 mg/l 8-\tVitamin C, Thiamin and Gibberellic acid (The concentration of three 100 mg/l Data obtained from the measured parameters

  10. Changes of Ascorbic Acid Contents in Various Market Forms of Spinach (Spinacea oleracea L.) during Postharvest Storage in Light and Dark Conditions

    OpenAIRE

    TOLEDO, Merry Evelyn A.; UEDA, Yoshinori; SHIROSAKI, Takashi

    2003-01-01

    Changes in ascorbic acid contents in various market forms of spinach (Spinacia oleracea L.) during postharvest storage in light (20-25 μmole m^2 s^) and dark conditions were investigated. In the leaves of whole spinach plants, the decline in ascorbic acid contents, specifically in mature leaves which comprise the bulk of the plants, was effectively minimized with the provision of supplemental lighting. Supplemental lighting has likewise been demonstrated to positively affect the ascorbic acid...

  11. Anti-Genotoxic Effect of Ascorbic Acid on Mutagenic Dose of Three Alkylating Agents

    OpenAIRE

    KAYA, Bülent

    2014-01-01

    The antimutagenic effect of ascorbic acid (vitamin C) was investigated by using the Drosophila wing spot test. In this assay, 3-day-old transheterozygous larvae for the multiple wing hair (mwh, 3-0.3) and flare (flr, 3-38.8) genes were treated with 3 direct acting mutagens: ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS) and N-nitroso N-ethylurea (ENU). The results obtained from 3 reference mutagens were clearly genotoxic in the Drosophila wing somatic mutation and recombination t...

  12. Chemical composition and sensory characteristics of Feta cheese fortified with iron and ascorbic acid

    OpenAIRE

    Jalili, Maryam

    2016-01-01

    International audience; AbstractFeta cheese is an excellent source of calcium and protein, but as typical dairy products, it contains very low amount of iron. The present study was designed to investigate the effect of iron fortification on quality of Feta cheese. The cheese samples were made from cow milk and fortified with iron compounds, namely ferrous sulfate (FeSO4), ferric chloride (FeCl3), and microencapsulated ferrous sulfate at level of 80 mg.kg−1 with or without l-ascorbic acid at a...

  13. Action of ascorbic acid on the healing of malnourished rats'skin wounds

    OpenAIRE

    Nai, Gisele Alborghetti; Manzoli, Louise Maria Freitas; SILVA, Tayane Carvalho Isidoro da; Mamede, Larissa de Queiroz; Disconzi, Mary Ellen de Oliveira Martins; Giuffrida, Rogério

    2014-01-01

    Objective: To evaluate the action of ascorbic acid on the healing of malnourished rats' cutaneous wounds compared with normal weight rats. Methods: We used 92 adult, male Wistar rats divided into four groups: 24 normal weight rats given only water and chow; 24 normal weight rats given vitamin C by gavage (340 mg/kg 12/12 hours); 22 malnourished rats given only water and chow; and 22 malnourished rats given vitamin C by gavage (340 mg/kg 12/12 hours). Malnutrition was induced by feeding the...

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

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    Fiona E. Harrison

    2014-04-01

    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.

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

    Science.gov (United States)

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

    2014-01-01

    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. PMID:24763117

  16. POLYPHENOLS, ASCORBIC ACID AND CAROTENOIDS CONTENTS AND ANTIOXIDANT PROPERTIES IN FRUITS OF CAPSICUM CHINENSE JACQ.

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    M. I. Mamedov

    2016-01-01

    Full Text Available Capsicum chinense Jacq. is the rich source of phytochemical substances, such as vitamin C, phenolic compounds, carotenoids, and occupies a significant place in the cooking of many peoples. The pigment composition, the amount of carotenoids, ascorbic acid and their contribution to the formation of antioxidant properties were studied. The total content of carotenoids and red/yellow pigments varied greatly among the accessions of C. chinense. The highest content of carotenoids 0.581 mg/g was observed in the varieties ‘Ognennaya Deva’ with the red fruit color in the phase of biological ripeness, where red pigments accumulated 56% more than in yellow ones. Fruits of accessions ‘Kolokolchik’ only accumulated yellow pigments, 0.318 mg/g. Presence of significant amount, 2.03 times as much red pigments as yellow ones in the variety ‘Trinidad Scorpion Chocolate’, with protein complex could cause the formation of a brown fruit color. Another tendency was observed in ‘Trinidad Dglahou’. The yellow pigment is 1.5 times as much amount as red, as estimated 0.119 mg/g of yellow and 0.077 mg/g of red pigment. The ascorbic acid content did not depend on the fruit color. Fruits of the ‘Ognennaya Deva’ accumulated the highest amount of ascorbic acid, 301 mg%. The maximum total antioxidant content, was detected in the variety ‘Ognennaya Deva’ 2.65 (TAC, mg.eq. GA/g. Analysis of the dependence of the content of thermo stable antioxidants to the total ones showed the contribution of the unstable antioxidants to thermal effects (particularly ascorbic acid on the level of 16%, on average. A comparative assessment of the pungency level and quantitative capsaicin content in the fruit was carried out by organoleptic, spectrophotometric and HPLC methods. The intervals of observed concentrations of capsaicin were 1.0-7.5 mg/g of dry weight (HPLC, the level of pungency on the Scoville scale was 17440-153120 SHU. There

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

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    Leonardo Martinez-Cardenas

    2011-09-01

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

  18. Methane formation by oxidation of ascorbic acid using iron minerals and hydrogen peroxide.

    Science.gov (United States)

    Althoff, Frederik; Jugold, Alke; Keppler, Frank

    2010-06-01

    The possibility of methane formation in an oxidative environment has been intensely debated, especially since the discovery of methane generation by living plants. However, recent studies with animal tissue suggested that under specific conditions aerobic methane formation is also possible. Here, we investigated the generation of methane in an abiotic model system using bioavailable substances. We show formation of methane in a highly oxidative media, using ascorbic acid, ferrihydrite and hydrogen peroxide as reagents. Methane production was shown to be related to reagent ratio, reaction volume and pH. A 2:1 ratio of hydrogen peroxide to ascorbic acid, catalytic amounts of ferrihydrite and acidic conditions (pH 3) enhanced formation of methane. We further show that gaseous oxygen has a strong influence with higher levels found to inhibit methane formation. This study is a first step towards providing an insight for the reaction mechanism of methane formation that would be applicable to aerobic environments. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  19. Topical application of disodium isostearyl 2-O-L-ascorbyl phosphate, an amphiphilic ascorbic acid derivative, reduces neuropathic hyperalgesia in rats

    Science.gov (United States)

    Okubo, Kazumasa; Nakanishi, Hiroki; Matsunami, Maho; Shibayama, Hiroharu; Kawabata, Atsufumi

    2012-01-01

    BACKGROUND AND PURPOSE Cav3.2 T-type calcium channels, targeted by H2S, are involved in neuropathic hyperalgesia in rats and ascorbic acid inhibits Cav3.2 channels. Therefore, we evaluated the effects of intraplantar (i.pl.) administration of ascorbic acid or topical application of disodium isostearyl 2-O-L-ascorbyl phosphate (DI-VCP), a skin-permeable ascorbate derivative on hyperalgesia induced by NaHS, an H2S donor, and on neuropathic hyperalgesia. EXPERIMENTAL APPROACH In rats mechanical hyperalgesia was evoked by i.pl. NaHS, and neuropathic hyperalgesia was induced by L5 spinal nerve cutting (L5SNC) or by repeated administration of paclitaxel, an anti-cancer drug. Dermal ascorbic acid levels were determined colorimetrically. KEY RESULTS The NaHS-evoked Cav3.2 channel-dependent hyperalgesia was inhibited by co-administered ascorbic acid. Topical application of DI-VCP, but not ascorbic acid, prevented the NaHS-evoked hyperalgesia, and also increased dermal ascorbic acid levels. Neuropathic hyperalgesia induced by L5SNC or paclitaxel was reversed by i.pl. NNC 55–0396, a selective T-type calcium channel blocker, ascorbic acid or DI-VCP, and by topical DI-VCP, but not by topical ascorbic acid. The effects of i.pl. ascorbic acid and topical DI-VCP in the paclitaxel-treated rats were characterized by the faster onset and greater magnitude, compared with their effects in the L5SNC rats. Dermal ascorbic acid levels in the hindpaw significantly decreased after paclitaxel treatment, but not L5SNC, which was reversed by topical DI-VCP. CONCLUSIONS AND IMPLICATIONS Ascorbic acid, known to inhibit Cav3.2 channels, suppressed neuropathic hyperalgesia. DI-VCP ointment for topical application may be of benefit in the treatment of neuropathic pain. PMID:22229645

  20. Immunomodulatory Role of Ocimum gratissimum and Ascorbic Acid against Nicotine-Induced Murine Peritoneal Macrophages In Vitro

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    Santanu Kar Mahapatra

    2011-01-01

    Full Text Available The aim of this present study was to evaluate the immune functions and immune responses in nicotine-induced (10 mM macrophages and concurrently establish the immunomodulatory role of aqueous extract of Ocimum gratissimum (Ae-Og and ascorbic acid. In this study, nitrite generations and some phenotype functions by macrophages were studied. Beside that, release of Th1 cytokines (TNF-α, IL-12 and Th2 cytokines (IL-10, TGF-β was measured by ELISA, and the expression of these cytokines at mRNA level was analyzed by real-time PCR. Ae-Og, at a dose of 10 μg/mL, significantly reduced the nicotine-induced NO generation and iNOSII expression. Similar kinds of response were observed with supplementation of ascorbic acid (0.01 mM. The administration of Ae-Og and ascorbic acid increased the decreased adherence, chemotaxis, phagocytosis, and intracellular killing of bacteria in nicotine-treated macrophages. Ae-Og and ascorbic acid were found to protect the murine peritoneal macrophages through downregulation of Th1 cytokines in nicotine-treated macrophages with concurrent activation of Th2 responses. These findings strongly enhanced our understanding of the molecular mechanism leading to nicotine-induced suppression of immune functions and provide additional rationale for application of anti-inflammatory therapeutic approaches by O. gratissimum and ascorbic acid for different inflammatory disease prevention and treatment during nicotine toxicity.

  1. Glutathione and ascorbic acid enhance recovery of Guinea pig spinal cord white matter following ischemia and acrolein exposure.

    Science.gov (United States)

    Logan, Melissa Peasley; Parker, Steven; Shi, Riyi

    2005-01-01

    We have shown that acrolein, a lipid peroxidation byproduct, can inflict significant damage in isolated spinal cord white matter following oxygen glucose deprivation (OGD). The mechanism of such acrolein-induced damage is unclear. The aim of this study was to examine whether glutathione (GSH) and ascorbic acid, two reactive oxygen species (ROS) scavengers, can alleviate functional and anatomical damage due to acrolein. We used an OGD injury model with isolated guinea pig spinal cord white matter. Sucrose gap recording was used to monitor axonal impulse conduction, and a horseradish peroxidase exclusion test was employed to determine membrane integrity. The functional and anatomical parameters were compared in three groups: acrolein, acrolein/GSH and acrolein/ascorbic acid. We found that while GSH resulted in an 87% recovery of compound action potential conductance, ascorbic acid produced a 97% recovery, compared with a 69% recovery in an injured group without treatment. It is noted that GSH, and to a lesser extent ascorbic acid, preferentially enhanced functional recovery in smaller axons. Acrolein-induced neuronal damage is likely mediated by ROS. Furthermore, GSH and ascorbic acid are effective in suppressing acrolein and free radical-induced injury in spinal cord white matter. Copyright (c) 2005 S. Karger AG, Basel.

  2. Ascorbic Acid Inhibition of Candida albicans Hsp90-Mediated Morphogenesis Occurs via the Transcriptional Regulator Upc2

    Science.gov (United States)

    Van Hauwenhuyse, Frédérique; Fiori, Alessandro

    2014-01-01

    Morphogenetic transitions of the opportunistic fungal pathogen Candida albicans are influenced by temperature changes, with induction of filamentation upon a shift from 30 to 37°C. Hsp90 was identified as a major repressor of an elongated cell morphology at low temperatures, as treatment with specific inhibitors of Hsp90 results in elongated growth forms at 30°C. Elongated growth resulting from a compromised Hsp90 is considered neither hyphal nor pseudohyphal growth. It has been reported that ascorbic acid (vitamin C) interferes with the yeast-to-hypha transition in C. albicans. In the present study, we show that ascorbic acid also antagonizes the morphogenetic change caused by hampered Hsp90 function. Further analysis revealed that Upc2, a transcriptional regulator of genes involved in ergosterol biosynthesis, and Erg11, the target of azole antifungals, whose expression is in turn regulated by Upc2, are required for this antagonism. Ergosterol levels correlate with elongated growth and are reduced in cells treated with the Hsp90 inhibitor geldanamycin (GdA) and restored by cotreatment with ascorbic acid. In addition, we show that Upc2 appears to be required for ascorbic acid-mediated inhibition of the antifungal activity of fluconazole. These results identify Upc2 as a major regulator of ascorbic acid-induced effects in C. albicans and suggest an association between ergosterol content and elongated growth upon Hsp90 compromise. PMID:25084864

  3. Sodium Bicarbonate-Ascorbic Acid Combination for Prevention of Contrast-Induced Nephropathy in Chronic Kidney Disease Patients Undergoing Catheterization.

    Science.gov (United States)

    Komiyama, Kota; Ashikaga, Takashi; Inagaki, Dai; Miyabe, Tomonori; Arai, Marina; Yoshida, Kiyotaka; Miyazawa, Satoshi; Nakada, Akihiro; Kawamura, Iwanari; Masuda, Shinichiro; Nagamine, Sho; Hojo, Rintaro; Aoyama, Yuya; Tsuchiyama, Takaaki; Fukamizu, Seiji; Shibui, Takashi; Sakurada, Harumizu

    2017-01-25

    Sodium bicarbonate and ascorbic acid have been proposed to prevent contrast-induced nephropathy (CIN). The present study evaluated the effect of their combined use on CIN incidence.Methods and Results:We prospectively enrolled 429 patients with chronic kidney disease (CKD: baseline estimated glomerular filtration rate ascorbic acid (n=211) groups, a total of 1,500-2,500 mL 0.9% saline was given before and after the procedure. In addition, the combination group received 20 mEq sodium bicarbonate and 3 g ascorbic acid i.v. before the procedure, followed by 2 g ascorbic acid after the procedure and a further 2 g after 12 h. There were no significant differences between the basic characteristics and contrast volume in the 2 groups. CIN occurred in 19 patients (8.7%) in the saline group, and in 6 patients (2.8%) in the combined treatment group (P=0.008). Combined sodium bicarbonate and ascorbic acid could prevent CIN following catheterization in CKD patients.

  4. Effect of ascorbic acid postharvest treatment on enzymatic browning, phenolics and antioxidant capacity of stored mung bean sprouts.

    Science.gov (United States)

    Sikora, Małgorzata; Świeca, Michał

    2018-01-15

    Enzymatic browning limits the postharvest life of minimally processed foods, thus the study selected the optimal inhibitors of polyphenol oxidase (PPO) and evaluated their effect on enzymatic browning, phenolics and antioxidant capacity of stored mung bean sprouts. The sprouts treated with 2mM and 20mM ascorbic acid had a lowered PPO activity; compared to the control by 51% and 60%, respectively. The inhibition was reflected in a significant decrease in enzymatic browning. The sprouts treated with 20mM ascorbic acid had 22% and 23% higher phenolic content after 3 and 7days of storage, respectively. Both storage and ascorbic acid treatment increased potential bioaccessibility of phenolics. Generally, there was no effect of the treatments on the antioxidant capacity; however, a significant increase in the reducing potential was determined for the sprouts washed with 20mM ascorbic acid. In conclusion, ascorbic acid treatments may improve consumer quality of stored sprouts. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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    Šimurina Olivera D.

    2014-01-01

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

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

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    Yücel Sahin

    2008-09-01

    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.

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

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    Ondrej Zitka

    2008-11-01

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

  8. EFFECT OF α-TOCOPHEROL AND ASCORBIC ACIDS ON PERFORMANCE AND BLOOD IMMUNITY PROFILE OF MALE NATIVE MUSCOVY DUCK

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    E. Tugiyanti

    2016-08-01

    Full Text Available The purpose of the research was to assess the effect of α-tocopherol and ascobic acids on the performance and immunity blood profile of male native Muscovy duck. The materials used were 84 male Muscovy ducks at 9 weeks old. The research used completely randomized design with 7 treatments. The treatments were E0C0 : basal diet without α-tocopherol and ascobic acids, E400: basal diet+ α-tocopherol 400IU, E600: basal diet+α-tocopherol 600IU, C400: basal diet+ascorbic acid 400mg/kg, C600: basal diet+ascorbic acid 600mg/kg, E200C200: basal diet+α-tocopherol 200IU+ ascorbic acid 200mg/kg, and E300C300: basal diet+α-tocopherol 300IU+ ascorbic acid 300mg/kg. Each treatment was repeated 4 times and each replication consisted of 3 ducks. The observed variables were body weight, feed consumption, feed conversion ratio, packed cell volume (PCV, total of plasma protein (TPP, leucocyte count, basophil, heterophil, eosinophil, monocyte, lymphocytes count and heterophil/lymphocyte (H/L ratio of Muscovy duck. The result indicated that E0C0, E400, E600, C400, C600, E200C200 and E300C300 had no significant difference in body weight, feed intake and feed conversion. There were significant effects on PCV, leucocyte count, percentage of heterophil and lymphocytes, but had no significant effect on eosinophil, monocyte and the H/L ratio. The C400 resulted a higher PCV count, percentage of heterophil, and H/L ratio. The C 600 produced the highest leucocyte count. In conclusion, the supplementation of ascorbic acid at 400 - 600 mg/kg feed ascorbic acid could improve the immune profile, but could not improve the performance of Muscovy duck.

  9. Investigation of excipients’ nature influence on the quality indices of effervescent tablets of acetylsalicylic acid, paracetamol and ascorbic acid

    Directory of Open Access Journals (Sweden)

    О. V. Tryhubchak

    2018-03-01

    Full Text Available The priority objective of pharmaceutical science remains the creation and rational use of medicines. In recent years among these medicines particular attention is paid to the form of sparkling (fast-dissolving, gaseous or effervescent solid dosage forms – tablets, granules, powders, microspheres, capsules, suppositories and others. In the development of effervescent tablets, which are absent in the domestic market, a combination of acetylsalicylic acid, paracetamol and ascorbic acid was selected for experimental studies. The purpose of the work is to study the influence of excipients on the pharmaco-technological properties of effervescent tablets of acetylsalicylic acid, paracetamol and ascorbic acid. Materials and methods. In the course of the experiment, nine excipients from groups of fillers, leavens and binders were investigated. By studying qualitative factors, one of the plans of dispersion analysis was used, namely a three-factorial experiment based on the Hyper-Greek-Latin square. In experiments we used modern equipment for determining the bulk density of powders (ERWEKA GT, Germany, bulk density (ERWEKA SVM 202, Germany, tablet press (Korsh XL-100, Germany, uniformity of the weight of tablets (Mettler Toledo AB54-S, Switzerland, crushing resistance (ERWEKA TBH-525 WTO, Germany, abradability (ERWEKA TAR 200, Germany, disintegration time (ERWEKA ZT 33, Germany. Results. As a result of the statistical processing of experimental results, the influence of excipients on the pharmaco-technological parameters of mass for tableting (bulk density, density after compression, Carr's index, flow ability, slope angle, tableting process, tablet appearance, mass uniformity, abradability, resistance to crushing, disintegration and transparency of the solution were investigated. Conclusions. The influence of nine excipients on the pharmaco-technological characteristics of effervescent tablets of acetylsalicylic acid, paracetamol and ascorbic acid was

  10. Influence of ascorbic acid on iron absorption from an iron-fortified, chocolate-flavored milk drink in Jamaican children.

    Science.gov (United States)

    Davidsson, L; Walczyk, T; Morris, A; Hurrell, R F

    1998-05-01

    The influence of ascorbic acid on iron absorption from an iron-fortified, chocolate-flavored milk drink (6.3 mg total Fe per serving) was evaluated with a stable-isotope technique in 20 6-7-y-old Jamaican children. Each child received two test meals labeled with 5.6 mg 57Fe and 3.0 mg 58Fe as ferrous sulfate on 2 consecutive days. Three different doses of ascorbic acid (0, 25, and 50 mg per 25-g serving) were evaluated in two separate studies by using a crossover design. Iron isotope ratios were measured by negative thermal ionization mass spectrometry. In the first study, iron absorption was significantly greater (P iron absorption was 1.6% (range: 0.9-4.2%) and 5.1% (2.2-17.3%) for the test meals containing 0 and 25 mg ascorbic acid, respectively. In the second study, a significant difference (P iron absorption was observed when the ascorbic acid content was increased from 25 to 50 mg: geometric mean iron absorption was 5.4% (range: 2.7-10.8%) compared with 7.7% (range: 4.7-16.5%), respectively. The chocolate drink contained relatively high amounts of polyphenolic compounds, phytic acid, and calcium, all well-known inhibitors of iron absorption. The low iron absorption without added ascorbic acid shows that chocolate milk is a poor vehicle for iron fortification unless sufficient amounts of an iron-absorption enhancer are added. Regular consumption of iron-fortified chocolate milk drinks containing added ascorbic acid could have a positive effect on iron nutrition in population groups vulnerable to iron deficiency.

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

    International Nuclear Information System (INIS)

    Manzoor, S.; Mehboob, K.; Naveed, A.K.

    2014-01-01

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

  12. Production of L-ascorbic acid by metabolically engineered Saccharomyces cerevisiae and Zygosaccharomyces bailii.

    Science.gov (United States)

    Sauer, Michael; Branduardi, Paola; Valli, Minoska; Porro, Danilo

    2004-10-01

    Yeasts do not possess an endogenous biochemical pathway for the synthesis of vitamin C. However, incubated with l-galactose, L-galactono-1,4-lactone, or L-gulono-1,4-lactone intermediates from the plant or animal pathway leading to l-ascorbic acid, Saccharomyces cerevisiae and Zygosaccharomyces bailii cells accumulate the vitamin intracellularly. Overexpression of the S. cerevisiae enzymes d-arabinose dehydrogenase and D-arabinono-1,4-lactone oxidase enhances this ability significantly. In fact, the respective recombinant yeast strains even gain the capability to accumulate the vitamin in the culture medium. An even better result is obtainable by expression of the plant enzyme L-galactose dehydrogenase from Arabidopsis thaliana. Budding yeast cells overexpressing the endogenous D-arabinono-1,4-lactone oxidase as well as L-galactose dehydrogenase are capable of producing about 100 mg of L-ascorbic acid liter(-1), converting 40% (wt/vol) of the starting compound L-galactose.

  13. Combined therapy of Ulmo honey (Eucryphia cordifolia and ascorbic acid to treat venous ulcers

    Directory of Open Access Journals (Sweden)

    Mariano del Sol Calderon

    2015-04-01

    Full Text Available OBJECTIVE: to assess the clinical effect of topical treatment using Ulmo honey associated with oral ascorbic acid in patients with venous ulcers. METHOD: longitudinal and descriptive quantitative study. During one year, 18 patients were assessed who were clinically diagnosed with venous ulcer in different stages, male and female, adult, with a mean injury time of 13 months. Ulmo honey was topically applied daily. The dressing was applied in accordance with the technical standard for advanced dressings, combined with the daily oral consumptions of 500 mg of ascorbic acid. The monitoring instrument is the assessment table of venous ulcers. RESULTS: full healing was achieved in 100% of the venous ulcers. No signs of complications were observed, such as allergies or infection. CONCLUSION: the proposed treatment showed excellent clinical results for the healing of venous ulcers. The honey demonstrated debriding and non-adherent properties, was easy to apply and remove and was well accepted by the users. The described results generated a research line on chronic wound treatment.

  14. Physiological responses of erythrocytes of goats to transportation and the mondulatory role of ascorbic acid.

    Science.gov (United States)

    Minka, Ndazo Salka; Ayo, Joseph Olusegun

    2010-07-01

    Experiments were performed with the aim of investigating the effect of road transportation for 12 hr on erythrocytes of goats during the hot-dry season and the modulatory role of ascorbic acid. Forty 2.5-3-year-old Red Sokoto goats weighing 23-25 kg and belonging to both sexes served as the subjects of the study. Twenty of the goats served as the experimental group and were administered ascorbic acid (AA) per os at a dosage rate of 100 mg/kg body weight; the other 20 served as controls and were given 10 ml each of sterile water. Forty minutes after the administration and loading, the goats were transported for 12 hr. EDTA blood samples collected before loading, after loading, immediately after transportation and subsequently on the 3rd and 7th days of post-transportation were used to determine the red blood cell (RBC) count, packed cell volume (PCV), hemoglobin (Hb), erythrocyte osmotic fragility (EOF), hematimetric (intrinsic) indices and hemoglobin index levels. The obtained results showed that handling, loading and transportation of the control goats induced significant (Ptransportation for 12 hr during the hot-dry season could induce serious stress, resulting in hemolysis of erythrocytes, which was ameliorated by AA administration. In addition, the results demonstrated that EOF could be used as a diagnostic tool in road transportation stress.

  15. Association of Lactobacillus crispatus with fructo-oligosaccharides and ascorbic acid in hydroxypropyl methylcellulose vaginal insert.

    Science.gov (United States)

    Vitali, Beatrice; Abruzzo, Angela; Parolin, Carola; Palomino, Rogers Alberto Ñahui; Dalena, Francesco; Bigucci, Federica; Cerchiara, Teresa; Luppi, Barbara

    2016-01-20

    The aim of this work was to develop a synbiotic vaginal insert containing the probiotic strain Lactobacillus crispatus BC5, the prebiotic substrate fructo-oligosaccharide and the antioxidant agent ascorbic acid, for the prophylaxis and therapy of vaginal infections. Mucoadhesive in situ gelling vaginal inserts based on hydroxypropyl methylcellulose were prepared by freeze-drying, stored at +2-8 °C for 90 days and characterized in terms of technological and functional properties. Complete survival of L. crispatus BC5 was found immediately after insert preparation (96.08%) as well as after 90 days of storage (95.82%) in the vaginal inserts containing fructo-oligosaccharide, ascorbic acid and skimmed milk. Synbiotic inserts showed improved mucoadhesion ability (from three- to five-fold) with respect to a standard formulation based on hydroxypropyl methylcellulose alone. Moreover, inserts allowed to modulate lactobacilli release in virtue of the different amounts of fructo-oligosaccharide. Finally, antimicrobial activity was exerted by L. crispatus BC5 released from the vaginal formulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Valorizing Dairy Waste: Thermophilic Biosynthesis of a Novel Ascorbic Acid Derivative.

    Science.gov (United States)

    Yang, Jingwen; Pérez, Bianca; Anankanbil, Sampson; Li, Jingbo; Zhou, Ye; Gao, Renjun; Guo, Zheng

    2017-10-18

    l-Ascorbic acid (l-AA) is an essential nutrient that is extremely unstable and cannot be synthesized by the human body. Therefore, attempts have been performed to develop biologically active l-AA derivatives with improved stability. This work presents a facile, scalable, and efficient enzymatic transgalactosylation of lactose to l-AA using β-glucosidase (TN0602) from Thermotoga naphthophila RKU-10. β-Glucosidase TN0602 displays high transgalactosylation activity at pH 5.0, 75 °C, and l-AA/lactose ratio of 2:1 to form a novel l-AA derivative [2-O-β-d-galactopyranosyl-l-ascorbic acid (l-AA-Gal)] with a maximal productivity of 138.88 mmol L -1 in 12 h, which is higher than most reports of enzymatic synthesis of l-AA-α-glucoside. Synthetic l-AA-Gal retains most l-AA antioxidant capability and presents dramatically higher stability than l-AA in an oxidative environment (Cu 2+ ). In conclusion, this work reports a new way to valorize dairy waste lactose into a novel molecule l-AA-Gal, which could be a promising l-AA derivative to be used in a wide range of applications.

  17. Comparative evaluation of polymeric and waxy microspheres for combined colon delivery of ascorbic acid and ketoprofen.

    Science.gov (United States)

    Maestrelli, F; Zerrouk, N; Cirri, M; Mura, P

    2015-05-15

    The goal of this work was to combine the ketoprofen anti-inflammatory effect with the ascorbic acid antioxidant properties for a more efficient treatment of colonic pathologies. With this aim, microspheres (MS) based on both waxy materials (ceresine, Precirol(®) and Compritol(®)) or hydrophilic biopolymers (pectine, alginate and chitosan) loaded with the two drugs were developed, physicochemically characterized and compared in terms of entrapment efficiency, in vitro release profiles, potential toxicity and drug permeation properties across the Caco-2 cell line. Waxy MS revealed an high encapsulation efficiency of ketoprofen but a not detectable entrapment of ascorbic acid, while polymeric MS showed a good entrapment efficiency of both drugs. All MS need a gastro-resistant coating, to avoid any premature release of the drugs. Ketoprofen release rate from polymeric matrices was clearly higher than from the waxy ones. In contrast, the ASC release rate was higher, due to its high hydro-solubility. Cytotoxicity studies revealed the safety of all the formulations. Transport studies showed that the ketoprofen apparent permeability increased, when formulated with the different MS. In conclusion, only polymeric MS enabled an efficient double encapsulation of both the hydrophilic and lipophilic drugs, and, in addition, presented higher drug release rate and stronger enhancer properties. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Encapsulation of L-ascorbic acid via polycaprolactone-polyethylene glycol-casein bioblends

    Directory of Open Access Journals (Sweden)

    Ozsagiroglu Erhan

    2015-12-01

    Full Text Available The aim of this study was to encapsulate, L-ascorbic acid, in biopolymers in order to obtain (i enhancing its encapsulation efficiency (ii increasing drug release ratio using different pH mediums. Microparticles based on polycaprolactone, polyethylene glycol and casein are prepared by spray drying technique. Microparticles are in vitro characterized in terms of yield of production, particle size, morphology, encapsulation efficiency, and drug release. In this manner, the importance of the study is producing of a stable and effective drug encapsulation system by PCL-PEG-CS polymer mixture by spray dryer. We achieved minimum 27.540±0.656 μm particle size with 0.512 m2/g surface area, 84.05% maximum drug loading, and 68.92% drug release ratio at pH 9.6. Release profiles are fitted to previously developed kinetic models to differentiate possible release mechanisms. The Korsmeyer–Peppas model is the best described each release scenario, and the drug release is governed by non-Fickian diffusion at pH 9.6. Our study proposed as an alternative or adjuvants for controlling release of L-ascorbic acid.

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

    Science.gov (United States)

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

    2013-12-01

    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 μm was fabricated using a hot-embossing technique. A maximum power of 0.60 μW at 0.58 V that corresponds to a power density of 1.83 μW/cm2 was realized by introducing a 200 mM concentrated AA solution at room temperature.

  20. EXTRACTION AND QUANTITATIVE DETERMINATION OF ASCORBIC ACID FROM BANANA PEEL MUSA ACUMINATA ‘KEPOK’

    Directory of Open Access Journals (Sweden)

    Khairul Anwar Mohamad Said

    2016-04-01

    Full Text Available This paper discusses the extraction of an antioxidant compound, which is ascorbic acid or vitamin C, from a banana peel using an ultrasound-assisted extraction (UAE method. The type of banana used was Musa acuminata also known as “PisangKepok” in Malaysia. The investigation includes the effect of solvent/solid ratio (4.5, 5 g and 10  ml/g, sonication time (15, 30 and 45 mins and temperature variation (30 , 45  and 60oC on the extraction of ascorbic acid compounds from the banana peel to determine the best or optimum condition of the operation. Out of all extract samples analyzed by redox titration method using iodine solution, it was found that the highest yield was 0.04939 ± 0.00080 mg that resulted from an extraction at 30oC for 15 mins with 5 ml/g solvent-to-solute ratio.KEYWORDS:  Musa acuminata; ultrasound-assisted extraction; vitamin C; redox titration

  1. A mixed solvent system for preparation of spherically agglomerated crystals of ascorbic acid.

    Science.gov (United States)

    Ren, Fuzheng; Zhou, Yaru; Liu, Yan; Fu, Jinping; Jing, Qiufang; Ren, Guobin

    2017-09-01

    The objective of this research was to develop a novel solvent system to prepare spherically agglomerated crystals (SAC) of ascorbic acid with improved flowability for direct compression. A spherical agglomeration method was developed by selecting the mixed solvents (n-butyl and ethyl acetate) as a poor solvent and the process was further optimized by using triangular phase diagram and particle vision measurement. Physiochemical properties of SAC were characterized and compared with original drug crystals. It showed that amount of poor solvent, ratio of solvent mixture, and drug concentration are critical for preparation of SAC with desirable properties. The solid state of SAC was same as original crystals according to DSC, XRD, and FT-IR results. There was no significant difference in solubility and dissolution rate of drug between SAC and original crystals. The flowability and packability of SAC as well as the tensile strength and elastic recovery of tablets made from SAC were all significantly improved when compared with original crystals and tablets from crystals. It is concluded that the present method was suitable to prepare SAC of ascorbic acid for direct compression.

  2. Antimicrobial activity optimization of nisin, ascorbic acid and ethylenediamine tetraacetic acid disodium salt (EDTA against Salmonella Enteritidis ATCC 13076 using response surface methodology

    Directory of Open Access Journals (Sweden)

    Nongpanga Sangcharoen

    2017-10-01

    Full Text Available Nisin is a commercial bacteriocin produced by Lactococcus lactis subsp. lactis and widely used as a natural preservative in the food industry. However, while nisin alone cannot inhibit the growth of Gram-negative bacteria, it can in combination with a chelating agent or organic acid. This study combined nisin with some chelating agents, weak organic acids and their salts to inhibit Salmonella Enteritidis ATCC 13076. The combinations of nisin (2000 parts per million; ppm and ascorbic acid (2000 ppm or ethylenediamine tetraacetic acid disodium salt (EDTA; 7400 ppm showed significant inhibitory effects on the target strain. Due to regulatory limits, the second part of the study reduced the concentrations of nisin, ascorbic acid and EDTA to 500 ppm, 2000 ppm and 250 ppm, respectively. The mixture of nisin, ascorbic acid and EDTA showed the highest inhibitory effect with a reduction number of 3.41 log colony forming units (p < 0.05. To minimize the growth of S. Enteritidis ATCC 13076, central composite design and response surface methodology were applied to investigate the combined effect of nisin (0–500 ppm, ascorbic acid (0–2000 ppm, and EDTA (0–250 ppm on the target strain growth. Among the three factors, nisin had a higher antimicrobial effect than ascorbic acid or EDTA, while an increase in nisin resulted in a decrease in S. Enteritidis ATCC 13076 growth. The optimum concentration was 500 ppm nisin with 1515 ppm ascorbic acid and 250 ppm EDTA. Under these conditions, the growth of S. Enteritidis ATCC 13076 predicted by the model was 24.99%. Keywords: Antimicrobial activity, Ascorbic acid, Ethylenediamine tetraacetic acid disodium salt (EDTA, Nisin, Salmonella enteritidis

  3. Calcium and ascorbic acid affect cellular structure and water mobility in apple tissue during osmotic dehydration in sucrose solutions.

    Science.gov (United States)

    Mauro, Maria A; Dellarosa, Nicolò; Tylewicz, Urszula; Tappi, Silvia; Laghi, Luca; Rocculi, Pietro; Rosa, Marco Dalla

    2016-03-15

    The effects of the addition of calcium lactate and ascorbic acid to sucrose osmotic solutions on cell viability and microstructure of apple tissue were studied. In addition, water distribution and mobility modification of the different cellular compartments were observed. Fluorescence microscopy, light microscopy and time domain nuclear magnetic resonance (TD-NMR) were respectively used to evaluate cell viability and microstructural changes during osmotic dehydration. Tissues treated in a sucrose-calcium lactate-ascorbic acid solution did not show viability. Calcium lactate had some effects on cell walls and membranes. Sucrose solution visibly preserved the protoplast viability and slightly influenced the water distribution within the apple tissue, as highlighted by TD-NMR, which showed higher proton intensity in the vacuoles and lower intensity in cytoplasm-free spaces compared to other treatments. The presence of ascorbic acid enhanced calcium impregnation, which was associated with permeability changes of the cellular wall and membranes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effects of gamma irradiation and storage temperature on carotenoids and ascorbic acid content of mangoes on ripening

    International Nuclear Information System (INIS)

    Thomas, P.; Janave, M.T.

    1975-01-01

    Synthesis and accumulation of carotenoids in the flesh of Alphonso mangoes on ripening was found to be maximal in fruits stored at tropical ambient temperatures (28 0 to 32 0 C). Gamma irradiation of preclimacteric fruits at 25 krad did not affect the formation of carotenoids. Storage of preclimacteric fruits either irradiated or unirradiated at 7 to 20 0 C for 16 to 43 days caused a substantial reduction in carotenoid formation even when these fruits were subsequently ripened under optimal conditions. Regardless of storage temperature, carotenes always exceeded xanthophylls in the ripe fruits and, in general, irradiated fruits showed higher levels of carotenes in comparison with unirradiated samples. Ascorbic acid loss during ripening was maximum at ambient temperatures while lengthy storage at low temperatures caused a net increase in ascorbic acid levels. Irradiation seemed to accentuate the loss in ascorbic acid during ripening. (author)

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

    Science.gov (United States)

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

    2014-03-15

    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 μL/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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Nitrogen dioxide reducing ascorbic acid technologies in the ventilator circuit leads to uniform NO concentration during inspiration.

    Science.gov (United States)

    Pezone, Matthew J; Wakim, Matthew G; Denton, Ryan J; Gamero, Lucas G; Roscigno, Robert F; Gilbert, Richard J; Lovich, Mark A

    2016-08-31

    Conventional inhaled NO systems deliver NO by synchronized injection or continuous NO flow in the ventilator circuitry. Such methods can lead to variable concentrations during inspiration that may differ from desired dosing. NO concentrations in these systems are generally monitored through electrochemical methods that are too slow to capture this nuance and potential dosing error. A novel technology that reduces NO2 into NO via low-resistance ascorbic-acid cartridges just prior to inhalation has recently been described. The gas volume of these cartridges may enhance gas mixing and reduce dosing inconsistency throughout inhalation. The impact of the ascorbic-acid cartridge technology on NO concentration during inspiration was characterized through rapid chemiluminescence detection during volume control ventilation, pressure control ventilation, synchronized intermittent mandatory ventilation and continuous positive airway pressure using an in vitro lung model configured to simulate the complete uptake of NO. Two ascorbic acid cartridges in series provided uniform and consistent dosing during inspiration during all modes of ventilation. The use of one cartridge showed variable inspiratory concentration of NO at the largest tidal volumes, whereas the use of no ascorbic acid cartridge led to highly inconsistent NO inspiratory waveforms. The use of ascorbic acid cartridges also decreased breath-to-breath variation in SIMV and CPAP ventilation. The ascorbic-acid cartridges, which are designed to convert NO2 (either as substrate or resulting from NO oxidation during injection) into NO, also provide the benefit of minimizing the variation of inhaled NO concentration during inspiration. It is expected that the implementation of this method will lead to more consistent and predictable dosing. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Vulcu, Adriana; Grosan, Camelia; Muresan, Liana Maria; Pruneanu, Stela; Olenic, Liliana

    2013-01-01

    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 ( t hiocytosine (Au T C) and gold g uanine (Au G U) layers

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

    Science.gov (United States)

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

    2011-01-01

    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 β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p stability when exposed to OH•.

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

    Directory of Open Access Journals (Sweden)

    Marjanović Nikola J.

    2009-01-01

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

  10. L-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs.

    Science.gov (United States)

    Frikke-Schmidt, Henriette; Tveden-Nyborg, Pernille; Lykkesfeldt, Jens

    2016-04-01

    Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)-commonly found in vitamin C containing food products prone to oxidation-was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain), only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25mg/ml in the drinking water), where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs-as in humans-is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  11. l-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs

    Directory of Open Access Journals (Sweden)

    Henriette Frikke-Schmidt

    2016-04-01

    Full Text Available Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA—commonly found in vitamin C containing food products prone to oxidation—was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain, only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25 mg/ml in the drinking water, where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs—as in humans—is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis.

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

    Science.gov (United States)

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

    2004-11-01

    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.

  13. 2-O-α-glucopytanosyl L-ascorbic acid reduced mutagenicity at HPRT locus of mouse splenocytes following BNCT

    International Nuclear Information System (INIS)

    Kinashi, Yuko; Masunaga, Shin-ichiro; Suzuki, Minoru; Nagata, Kanji; Ono, Koji

    2006-01-01

    In boron neutron capture therapy (BNCT), normal tissue surrounding the tumor cells sometimes take up boron compounds resulting in radiation-induced damage to normal tissue. We have previously reported the evidence for increased the mutagenicity of thermal neutron in the presence of boron. In addition, we described the biological radio-protective effects of the ascorbic acid for mutation induction following BNCT in vitro. Here, we investigated these radio-protective effects of ascorbic acid for mutation induction in mouse splenocytes on HPRT locus following a BNCT study in vivo. (author)

  14. Furan Occurrence in Starchy Food Model Systems Processed at High Temperatures: Effect of Ascorbic Acid and Heating Conditions

    DEFF Research Database (Denmark)

    Mariotti, María; Granby, Kit; Fromberg, Arvid

    2012-01-01

    Furan, a potential carcinogen, has been detected in highly consumed starchy foods, such as bread and snacks; however, research on furan generation in these food matrixes has not been undertaken, thus far. The present study explored the effect of ascorbic acid addition and cooking methods (frying...... and baking) over furan occurrence and its relation with the non-enzymatic browning in a wheat flour starchy food model system. Results showed that furan generation significantly increased in the presence of ascorbic acid after 7 min of heating (p

  15. Regulation of ascorbic acid and of xylulose synthesis in liver extracts. The effect of starvation in various animals

    Science.gov (United States)

    Stirpe, F.; Comporti, M.; Della Corte, E.

    1965-01-01

    1. The effect of starvation on the synthesis of ascorbic acid and of xylulose from glucuronolactone and from gulonate has been studied with liver extracts from cats, rabbits, hamsters, mice and guinea pigs. 2. The synthesis of ascorbic acid from glucuronolactone is decreased in all species except cats, and that from gulonate is decreased in hamsters and mice only. 3. The synthesis of xylulose from glucuronolactone was decreased in all species except cats and mice, whereas from gulonate it was enhanced in all the species examined. PMID:14340085

  16. The effects of reactants ratios, reaction temperatures and times on Maillard reaction products of the L-ascorbic acid/L-glutamic acid system

    Directory of Open Access Journals (Sweden)

    Yong-Yan ZHOU

    2016-01-01

    Full Text Available Abstract The transformation law of the Maillard reaction products with three different reactants ratios - equimolar reactants, excess L-glutamic acid and excess L-ascorbic acid reaction respectively, five different temperatures, and different time conditions for the L-ascorbic acid / L-glutamic acid system were investigated. Results showed that, the increase of the reaction time and temperature led to the increase of the browning products, uncoloured intermediate products, as well as aroma compounds. Compared with the equimolar reaction system, the excess L-ascorbic acid reaction system produced more browning products and uncoloured intermediate products, while the aroma compounds production remained the same. In the excess L-glutamic acid system, the uncoloured intermediate products increased slightly, the browning products remained the same, while the aroma compounds increased.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-07-01

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

  18. Ascorbic acid-dependent gene expression in Streptococcus pneumoniae and the activator function of the transcriptional regulator UlaR2

    NARCIS (Netherlands)

    Afzal, Muhammad; Shafeeq, Sulman; Kuipers, Oscar P

    2015-01-01

    In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been

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

    NARCIS (Netherlands)

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

    2009-01-01

    ABSTRACT: BACKGROUND: High dose oral ascorbic acid substantially improved myelination and locomotor function in a Charcot-Marie-Tooth type 1A mouse model. A phase II study was warranted to investigate whether high dose ascorbic acid also has such a substantial effect on myelination in

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

    NARCIS (Netherlands)

    Verhamme, C.; de Haan, R.J.; Vermeulen, M.; Baas, F.; de Visser, M.; van Schaik, I.N.

    2009-01-01

    BACKGROUND: High dose oral ascorbic acid substantially improved myelination and locomotor function in a Charcot-Marie-Tooth type 1A mouse model. A phase II study was warranted to investigate whether high dose ascorbic acid also has such a substantial effect on myelination in Charcot-Marie-Tooth type

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    Graphical abstract: -- Highlights: •Gold microelectrode array (Au/MEA) with electrode of 12 μm 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 μm 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 μm 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 μM and linear range of 10 μM 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.

  2. Acute Ascorbic Acid Infusion Increases Left Ventricular Diastolic Function in Postmenopausal Women

    Science.gov (United States)

    Ozemek, Cemal; Hildreth, Kerry L.; Groves, Daniel W.; Moreau, Kerrie L.

    2016-01-01

    Objectives We tested the hypothesis that oxidative stress contributes to reductions in left ventricular diastolic function in estrogen-deficient postmenopausal women, related in part to reduced nitric oxide (NO) bioavailability. Study design LV diastolic function – recorded using transthoracic echocardiography and determined as the peak early (E) to late (A) mitral inflow velocity ratio and the E to peak early (e’) mitral annular velocity ratio – and brachial artery flow mediated dilation (FMD), a biomarker of NO bioavailability, were measured during acute systemic infusions of saline (control) and ascorbic acid (experimental model to decrease oxidative stress) in healthy premenopausal women (N=14, 18-40 years) and postmenopausal women (N=23, 45-75 years). Results The E/A ratio was lower (1.16[1.06−1.33] vs 1.65[1.5−2.3]; median[interquartile range]) and the E/e’ ratio was elevated (8.8[7.6−9.9] vs. 6.6[5.5−7.3]) in postmenopausal compared with premenopausal women, indicating reduced LV diastolic function. E/A and E/e’ were correlated with FMD (r=0.54 and r=−0.59, respectively, both PAscorbic acid infusion improved both FMD (5.4±2.0% to 7.8±2.6%) and E/e’ (to 8.1[7.2−9.7], P=0.01) in postmenopausal women but not in premenopausal women. Ascorbic acid did not change E/A in either group. Conclusion The current study provides evidence that oxidative stress contributes to reduced LV diastolic function in estrogen-deficient postmenopausal women, possibly by reducing the availability of NO. PMID:27621254

  3. Shelf life of minimally processed pineapples treated with ascorbic and citric acids

    Directory of Open Access Journals (Sweden)

    Lucimara Rogéria Antoniolli

    2012-01-01

    Full Text Available The purpose of this research was to determine the shelf life of minimally processed (MP 'Pérola' pineapples treated with ascorbic acid (AA and citric acid (CA based on physical, chemical, sensorial and microbiological attributes. Slices were dipped into drinking water (control or combined solutions of AA:CA (% (1.0:0.5 and 1.0:1.0 with sodium hypochlorite (NaClO 20 mg L-1 for 30 seconds. The samples were conditioned in polyethylene terephtalate packages and stored at 4±1 °C per 13 days. The low peroxidase activity in the slices treated with antioxidant combinations was related to low pH values observed in these samples. The treatments 1.0:0.5 and 1.0:1.0 (AA:CA, % favored maintenance of the initial a* values and avoided the pulp browning. The ascorbic acid increased more than double on the 2nd day in the treated slices. By the 4th day the CO2 values suggested a higher respiratory activity in the slices treated with anti-browning compounds. The antioxidant treatments did not produce detectable residual flavors in the MP pineapple. Regardless of microbiological safety during the 13 days of cold storage, the control slices can be kept by 6 days, afterwards the color and dehydration become strong enough to affect the appearance. On the other hand, MP 'Pérola' pineapples treated with 1.0:0.5 (AA:CA, % and NaClO (20 mg L-1 can be stored for 8 days at 4±1 ºC, which represents the extension of the shelf life in 2 days. After this period the overripe odor starts to develop.

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

    Directory of Open Access Journals (Sweden)

    Aurel Pisoschi

    2011-02-01

    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.

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

    International Nuclear Information System (INIS)

    Zhou, Chunlei; Li, Shuang; Zhu, Wei; Pang, Haijun; Ma, Huiyuan

    2013-01-01

    A composite film based on K 8 P 2 W 16 V 2 O 62 ·18H 2 O 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 K 8 P 2 W 16 V 2 O 62 ·18H 2 O (P 2 W 16 V 2 ) 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, CH 3 OH, CH 3 CH 2 OH and H 2 O 2 . 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

  6. Manganese dioxide graphite composite electrodes: application to the electroanalysis of hydrogen peroxide, ascorbic acid and nitrite.

    Science.gov (United States)

    Langley, Cathryn E; Sljukić, Biljana; Banks, Craig E; Compton, Richard G

    2007-02-01

    The modification of carbon powder with manganese dioxide using a wet impregnation procedure with electrochemical characterisation of the modified powder is described. The process involves saturation of the carbon powder with manganese(II) nitrate followed by thermal treatment at ca. 773 K leading to formation of manganese(IV) oxide on the surface of the carbon powder. The construction of composite electrodes based on manganese dioxide modified carbon powder and epoxy resin is also described, including optimisation of the percentage of the modified carbon powder. Composite electrodes showed attractive performances for electroanalytical applications, proving to be suitable for the electrochemical detection of hydrogen peroxide, ascorbic acid and nitrite ions with limits of detection comparable to the detection limits achieved by other analytical techniques. The results obtained for detection of these analytes, together with composite electrodes flexible design and low cost offers potential application of composite electrodes in biosensors.

  7. Multiple Myeloma Tumor Cells are Selectively Killed by Pharmacologically-dosed Ascorbic Acid.

    Science.gov (United States)

    Xia, Jiliang; Xu, Hongwei; Zhang, Xiaoyan; Allamargot, Chantal; Coleman, Kristen L; Nessler, Randy; Frech, Ivana; Tricot, Guido; Zhan, Fenghuang

    2017-04-01

    High-dose chemotherapies to treat multiple myeloma (MM) can be life-threatening due to toxicities to normal cells and there is a need to target only tumor cells and/or lower standard drug dosage without losing efficacy. We show that pharmacologically-dosed ascorbic acid (PAA), in the presence of iron, leads to the formation of highly reactive oxygen species (ROS) resulting in cell death. PAA selectively kills CD138 + MM tumor cells derived from MM and smoldering MM (SMM) but not from monoclonal gammopathy undetermined significance (MGUS) patients. PAA alone or in combination with melphalan inhibits tumor formation in MM xenograft mice. This study shows PAA efficacy on primary cancer cells and cell lines in vitro and in vivo. Copyright © 2017 The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. Published by Elsevier B.V. All rights reserved.

  8. Multiple Myeloma Tumor Cells are Selectively Killed by Pharmacologically-dosed Ascorbic Acid

    Directory of Open Access Journals (Sweden)

    Jiliang Xia

    2017-04-01

    Full Text Available High-dose chemotherapies to treat multiple myeloma (MM can be life-threatening due to toxicities to normal cells and there is a need to target only tumor cells and/or lower standard drug dosage without losing efficacy. We show that pharmacologically-dosed ascorbic acid (PAA, in the presence of iron, leads to the formation of highly reactive oxygen species (ROS resulting in cell death. PAA selectively kills CD138+ MM tumor cells derived from MM and smoldering MM (SMM but not from monoclonal gammopathy undetermined significance (MGUS patients. PAA alone or in combination with melphalan inhibits tumor formation in MM xenograft mice. This study shows PAA efficacy on primary cancer cells and cell lines in vitro and in vivo.

  9. Active biopolymer film based on carboxymethyl cellulose and ascorbic acid for food preservation

    Science.gov (United States)

    Halim, Al Luqman Abdul; Kamari, Azlan

    2017-05-01

    In the present study, an active biopolymer film based on carboxymethyl cellulose (CMC) and ascorbic acid (AA) was synthesised at an incorporation rate of 15% (w/w). Several analytical instruments such as Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetry Analyser (TGA), UV-Visible Spectrophotometer (UV-Vis), Scanning Electron Microscope (SEM) and Universal Testing Machine were used to characterise the physical and chemical properties of CMC-AA film. The addition of AA significantly reduced elongation at break (322%) and tensile strength (10 MPa) of CMC-AA film. However, CMC-AA film shows a better antimicrobial property against two bacteria, namely Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as compared to CMC film. The CMC-AA film was able to preserve cherry tomato with low weight loss and browning index. Overall, results from this study highlight the feasibility of CSAA film for food preservation.

  10. Ascorbic Acid Modulation of Iron Homeostasis and Lysosomal Function in Trabecular Meshwork Cells

    Science.gov (United States)

    Xu, Ping; Lin, Yizhi; Porter, Kristine

    2014-01-01

    Abstract Purpose: To investigate the antioxidant properties and biological functions of ascorbic acid (AA) on trabecular meshwork (TM) cells. Methods: Primary cultures of porcine TM cells were supplemented for 10 days with increasing concentrations of AA. Antioxidant properties against cytotoxic effect of H2O2 were evaluated by monitoring cell viability. Redox-active iron was quantified using calcein-AM. Intracellular reactive oxygen species (iROS) production was quantified using H2DCFDA. Ferritin and cathepsin protein levels were analyzed by Western blot. Autophagy was evaluated by monitoring lipidation of LC3-I to LC3-II. Lysosomal proteolysis and cathepsins activities were quantified using specific fluorogenic substrates. Results: AA exerts a dual effect against oxidative stress in TM cells, acting as an anti-oxidant or a pro-oxidant, depending on the concentration used. The pro-oxidant effect of AA was mediated by free intracellular iron and correlated with increased protein levels of ferritin and elevated iROS. In contrast, antioxidant properties correlated with lower ferritin and basal iROS content. Ascorbic acid supplementation also caused induction of autophagy, as well as increased lysosomal proteolysis, with the latter resulting from higher proteolytic activation of lysosomal cathepsins in treated cultures. Conclusions: Our results suggest that the reported decrease of AA levels in plasma and aqueous humor can compromise lysosomal degradation in the outflow pathway cells with aging and contribute to the pathogenesis of glaucoma. Restoration of physiological levels of vitamin C inside the cells might improve their ability to degrade proteins within the lysosomal compartment and recover tissue function. PMID:24552277

  11. Ascorbic acid deficiency activates cell death and disease resistance responses in Arabidopsis.

    Science.gov (United States)

    Pavet, Valeria; Olmos, Enrique; Kiddle, Guy; Mowla, Shaheen; Kumar, Sanjay; Antoniw, John; Alvarez, María E; Foyer, Christine H

    2005-11-01

    Programmed cell death, developmental senescence, and responses to pathogens are linked through complex genetic controls that are influenced by redox regulation. Here we show that the Arabidopsis (Arabidopsis thaliana) low vitamin C mutants, vtc1 and vtc2, which have between 10% and 25% of wild-type ascorbic acid, exhibit microlesions, express pathogenesis-related (PR) proteins, and have enhanced basal resistance against infections caused by Pseudomonas syringae. The mutants have a delayed senescence phenotype with smaller leaf cells than the wild type at maturity. The vtc leaves have more glutathione than the wild type, with higher ratios of reduced glutathione to glutathione disulfide. Expression of green fluorescence protein (GFP) fused to the nonexpressor of PR protein 1 (GFP-NPR1) was used to detect the presence of NPR1 in the nuclei of transformed plants. Fluorescence was observed in the nuclei of 6- to 8-week-old GFP-NPR1 vtc1 plants, but not in the nuclei of transformed GFP-NPR1 wild-type plants at any developmental stage. The absence of senescence-associated gene 12 (SAG12) mRNA at the time when constitutive cell death and basal resistance were detected confirms that elaboration of innate immune responses in vtc plants does not result from activation of early senescence. Moreover, H2O2-sensitive genes are not induced at the time of systemic acquired resistance execution. These results demonstrate that ascorbic acid abundance modifies the threshold for activation of plant innate defense responses via redox mechanisms that are independent of the natural senescence program.

  12. Effects of Pre-Converted Nitrite from Red Beet and Ascorbic Acid on Quality Characteristics in Meat Emulsions

    OpenAIRE

    Choi, Yun-Sang; Kim, Tae-Kyung; Jeon, Ki-Hong; Park, Jong-Dae; Kim, Hyun-Wook; Hwang, Ko-Eun; Kim, Young-Boong

    2017-01-01

    We investigated the effects of fermented red beet extract and ascorbic acid on color development in meat emulsions. The pH of meat emulsions containing red beet extract decreased with an increase in the amount of extract added. The redness of the treated meat emulsions was higher than that of the control with no added nitrite or fermented red beet extract (p

  13. Effects of ascorbic acid, salt, lemon juice, and honey on drying kinetics and sensory characteristic of dried mango

    Directory of Open Access Journals (Sweden)

    E. E. Abano

    2013-01-01

    Full Text Available The effects of ascorbic acid, salt solution, lemon juice, and honey pretreatment on the drying kinetics and sensory characteristics were studied. Pretreatments used affected the effective moisture diffusivity and rehydration properties of the dried mangoes. The effective moisture diffusivity values were 2.22 × 10-10 m2/s for ascorbic acid, 1.80 × 10-10 m2/s for salt solution, 2.01 × 10-10 m2/s for lemon juice, 1.93 × 10-10 m2/s for honey pretreated mangoes, and 2.31 × 10-10 m2/s for the control slices. Pretreatments enhanced the drying rate potential of mangoes. Among the thin-layer drying models fitted to the experimental data, the Middil model gave the best fit. The ascorbic acid pretreated samples were the best while the salt solution ones were the poorest with respect to reconstitution capacity. Consumer studies for overall preference for taste, colour, texture, flavour and chewiness of the dried products revealed that there was a higher preference for honey pretreated dried samples followed by the ascorbic acid, control, lemon juice, and salt solution pretreated samples. The results demonstrate that these pretreatments can be applied to enhance the moisture transport during drying and the quality of the dried products.

  14. UlaR activates expression of the ula operon in Streptococcus pneumoniae in the presence of ascorbic acid.

    Science.gov (United States)

    Afzal, Muhammad; Shafeeq, Sulman; Henriques-Normark, Birgitta; Kuipers, Oscar P

    2015-01-01

    In this study, the regulatory mechanism of the ula (utilization of l-ascorbic acid) operon, putatively responsible for transport and utilization of ascorbic acid in Streptococcus pneumoniae strain D39, is studied. β-Galactosidase assay data demonstrate that expression of the ula operon is increased in the presence of ascorbic acid as compared with the effects of other sugar sources including glucose. The ula operon consists of nine genes, including a transcriptional regulator UlaR, and is transcribed as a single transcriptional unit. We demonstrate the role of the transcriptional regulator UlaR as a transcriptional activator of the ula operon in the presence of ascorbic acid and show that activation of the ula operon genes by UlaR is CcpA-independent. Furthermore, we predict a 16 bp regulatory site (5'-AACAGTCCGCTGTGTA-3') for UlaR in the promoter region of ulaA. Deletion of the half or full UlaR regulatory site in PulaA confirmed that the UlaR regulatory site present in PulaA is functional. © 2015 The Authors.

  15. Low-volume PEG plus ascorbic acid versus high-volume PEG as bowel preparation for colonoscopy

    NARCIS (Netherlands)

    Corporaal, Sietske; Kleibeuker, Jan H.; Koornstra, Jan J.

    2010-01-01

    Objective. High volumes of polyethylene glycol (PEG)-based solutions as bowel preparation for colonoscopy are effective, but often poorly tolerated. To compare a 2 l PEG-based solution combined with ascorbic acid (PEG + Asc) with 4 l PEG-based solution (PEG). Methods. In a single blind,

  16. Effect of ascorbate and 5-aminosalicylic acid on light-induced 8-hydroxydeoxyguanosine formation in V79 Chinese hamster cells

    DEFF Research Database (Denmark)

    Fischer-Nielsen, A; Loft, S; Jensen, K G

    1993-01-01

    Recently we showed that ascorbate and 5-aminosalicylic acid (5-ASA) prevented 8-hydroxydeoxyguanosine (8-OHdG) formation in calf thymus DNA exposed to UV-visible light. However, the ultimate defense against oxidative DNA damage depends on an intracellular/intranuclear effect of the compounds...

  17. Ascorbic Acid-Initiated Tandem Radical Cyclization of N-Arylacrylamides to Give 3,3-Disubstituted Oxindoles

    Directory of Open Access Journals (Sweden)

    Sheng Liu

    2015-08-01

    Full Text Available An ascorbic acid-promoted and metal-free tandem room temperature cyclization of N-arylacrylamides with 4-nitrobenzenediazonium generated in situ was developed. This reaction proceeds smoothly through a radical mechanism and provides an environmentally friendly alternative approach to biologically active 3-alkyl-3-benzyloxindoles, avoiding the use of excess oxidants and light irradiation.

  18. Effect of high doses of L-ascorbic acid on the antioxidative/oxidative state in the rats

    DEFF Research Database (Denmark)

    Niemiec, T.; Sawosz, E.; Chwalibog, André

    2005-01-01

    (TAS) in plasma did not increase with increasing vitamin C supply. The results indicate that high doses of L-ascorbic acid (0.3 and 0.9 but not 0.6%) increased the concentration of this antioxidant in plasma. Supplementation of vitamin C above 0.3% to the diets had pro-oxidative effects on lipid...

  19. Anti-obesity effects of chitosan and psyllium husk with L-ascorbic acid in guinea pigs.

    Science.gov (United States)

    Jun, Sung Chul; Jung, Eun Young; Hong, Yang Hee; Park, Yooheon; Kang, Duk ho; Chang, Un Jae; Suh, Hyung Joo

    2012-04-01

    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.

  20. STABILITY OF BETACYANIN PIGMENTS FROM RED PURPLE PITAYA FRUIT (Hylocereus polyrhizus : INFLUENCE OF PH, TEMPERATURE, METAL IONS AND ASCORBIC ACID

    Directory of Open Access Journals (Sweden)

    Tang, C.S Tang, C.S

    2010-06-01

    Full Text Available Betacyanin pigments from red-purple pitaya fruit (Hylocereus polyrhizus could be an attractive source of red colourant for food application. This paper presents results on the extraction of betacyanin pigments from pitaya fruits grown locally in Malaysia. Both the flesh of the fruit and its mesocarp were investigated and it was found that the flesh had higher pigment contents compared to its peel component. The concentration of betacyanins expressed as betanin equivalents per 100 g of flesh and peel were 10.1 ± 0.6 mg and 6.7 ± 0.2 mg, respectively when 80% methanol was used.  The stability of betacyanin pigments were investigated at different pH, temperature and in presence of different concentrations of metal ions (Cu2+ and Fe2+ and ascorbic acid. The results showed that the pigment was most stable at pH range between 5 and 6. However, it forfeited its stability to the heat induced at elevated temperatures. Metal ions (Cu2+ and Fe2+ proved to be capable of accelerating betacyanin degradation, with Cu2+ exhibiting the greatest effect. By contrast, supplementation with ascorbic acid could enhance the pigment stability against the detrimental effects caused by pH, temperature and metal ions. Nevertheless, if the concentration of ascorbic acid exceeds 0.7 %, it may change its role from pigment stabilizer to become a pro-oxidant.    Keywords: Betacyanin, pigments, pitaya fruit, Hylocereus polyrhizus, ascorbic acid

  1. ASCORBIC ACID STATUS IN PREGNANCY AND POSTPARTUM WOMEN IN ENUGU, SOUTH-EAST, NIGERIA: ARE VITAMIN SUPPLEMENTS SUFFICIENT?

    Directory of Open Access Journals (Sweden)

    2017-01-01

    Full Text Available Pregnancy has been shown to be a period of stress, during which the nutritional needs of the foetus is dependent on that of the mother. It is also a condition exhibiting increased susceptibility to oxidative stress, leading to potential damage. Ascorbic acid is a strong antioxidant as well as a reducing agent and is increasingly utilized to normalize the pro-oxidant - antioxidant balance during pregnancy. Since ascorbic acid cannot be synthesized by the body, leading to total dependence on exogenous supply in diets, there is need to evaluate the level of the vitamin in pregnant women and determine their predisposition or otherwise to avitaminosis C. Ascorbic acid levels of 60 apparently healthy pregnant women, aged between 20-40 years old and attending the antenatal clinic at the UNTH, Enugu, 60 age-matched women in their postpartum and 60 age-matched non-pregnant women (controls were assayed using the 2,4-dinitrophenyl hydrazine method. The serum ascorbic acid levels were significantly lower (P and lt;0.05 in pregnant women, showing a steady decline with gestational age increase. There were statistically significant decreases (P and lt;0.05 in the second and third trimesters whereas a significant increase (P and lt;0.05 was observed in the postpartum period, when compared to the controls. The serum levels of ascorbic acid were decreased significantly as pregnancy progresses; in spite of the supplements given Significant increases in the postpartum period may be attributed to the absence of oxidative stress and recovery from stress. Additional supplementation and increased dietary intake should be encouraged in pregnant women.

  2. The role of topically applied L-ascorbic acid in ex-vivo examination of burn-injured human skin

    Science.gov (United States)

    Pielesz, Anna; Biniaś, Dorota; Bobiński, Rafał; Sarna, Ewa; Paluch, Jadwiga; Waksmańska, Wioletta

    2017-10-01

    Wound treatment and healing is complex and is comprised of an elaborate set of processes including cellular, spectroscopic and biochemical ones as well as the ;reaction; of local tissue to thermal injury. Vitamin C as L-ascorbic acid (LA) prevents injurious effects of oxidants because it reduces reactive oxygen species to stable molecules, it becomes oxidized to the short-lived ascorbyl radical. As a result, antioxidant treatment may contribute to minimizing injury in burn patients. The aim of this study is to assess changes in molecular structure of collagen extracted from human epidermis burn wound scab during incubation of the epidermis in L-ascorbic acid solution. The study will be performed using FTIR and FT Raman spectroscopies. During this research it was observed that the intensity of Raman peaks increased where healing was being modified by LA. The intensity of the amide III band at 1247 cm- 1 relative to the intensity at 1326 cm- 1 was used to test tissue repair degree at the incision site. FTIR spectra were recorded from frozen specimens of serum modified by LA; an analysis of shifts in the amide I band position was conducted. The appearance of a new band for frozen samples modified by LA was observed around 1149-1220 cm- 1. The above conclusions confirmed the creation of hydrogen bonds between Nsbnd H stretch and Cdbnd O. Samples being incubated in solutions of L-ascorbic acid demonstrated the absence of electrophoretic bands of albumin. Alterations in the surface of the skin incubated in L-ascorbic acid were investigated with the use of Scanning Electron Microscopy (SEM). A decrease in external symptoms of burn injury was noted in the damaged epidermis incubated in L-ascorbic acid.

  3. Synthesis and characterization of cycloaliphatic hydrophilic polyurethanes, modified with l-ascorbic acid, as materials for soft tissue regeneration.

    Science.gov (United States)

    Kucinska-Lipka, J; Gubanska, I; Strankowski, M; Cieśliński, H; Filipowicz, N; Janik, H

    2017-06-01

    In this paper we described synthesis and characteristic of obtained hydrophilic polyurethanes (PURs) modified with ascorbic acid (commonly known as vitamin C). Such materials may find an application in the biomedical field, for example in the regenerative medicine of soft tissues, according to ascorbic acid wide influence on tissue regeneration Flora (2009), Szymańska-Pasternak et al. (2011), Taikarimi and Ibrahim (2011), Myrvik and Volk (1954), Li et al. (2001), Cursino et al. (2005) . Hydrophilic PURs were obtained with the use of amorphous α,ω-dihydroxy(ethylene-butylene adipate) (dHEBA) polyol, 1,4-butanediol (BDO) chain extender and aliphatic 4,4'-methylenebis(cyclohexyl isocyanate) (HMDI). HMDI was chosen as a nontoxic diisocyanate, suitable for biomedical PUR synthesis. Modification with l-ascorbic acid (AA) was performed to improve obtained PUR materials biocompatibility. Chemical structure of obtained PURs was provided and confirmed by Fourier transform infrared spectroscopy (FTIR) and Proton nuclear magnetic resonance spectroscopy ( 1 HNMR). Differential scanning calorimetry (DSC) was used to indicate the influence of ascorbic acid modification on such parameters as glass transition temperature, melting temperature and melting enthalpies of obtained materials. To determine how these materials may potentially behave, after implementation in tissue, degradation behavior of obtained PURs in various chemical environments, which were represented by canola oil, saline solution, distilled water and phosphate buffered saline (PBS) was estimated. The influence of AA on hydrophilic-hydrophobic character of obtained PURs was established by contact angle study. This experiment revealed that ascorbic acid significantly improves hydrophilicity of obtained PUR materials and the same cause that they are more suitable candidates for biomedical applications. Good hemocompatibility characteristic of studied PUR materials was confirmed by the hemocompatibility test with

  4. Promoting extracellular matrix remodeling via ascorbic acid enhances the survival of primary ovarian follicles encapsulated in alginate hydrogels.

    Science.gov (United States)

    Tagler, David; Makanji, Yogeshwar; Tu, Tao; Bernabé, Beatriz Peñalver; Lee, Raymond; Zhu, Jie; Kniazeva, Ekaterina; Hornick, Jessica E; Woodruff, Teresa K; Shea, Lonnie D

    2014-07-01

    The in vitro growth of ovarian follicles is an emerging technology for fertility preservation. Various strategies support the culture of secondary and multilayer follicles from various species including mice, non-human primate, and human; however, the culture of early stage (primary and primordial) follicles, which are more abundant in the ovary and survive cryopreservation, has been limited. Hydrogel-encapsulating follicle culture systems that employed feeder cells, such as mouse embryonic fibroblasts (MEFs), stimulated the growth of primary follicles (70-80 µm); yet, survival was low and smaller follicles (ascorbic acid based on its role in extracellular matrix (ECM) deposition/remodeling for other applications. The selection of ascorbic acid was further supported by a microarray analysis that suggested a decrease in mRNA levels of enzymes within the ascorbate pathway between primordial, primary, and secondary follicles. The supplementation of ascorbic acid (50 µg/mL) significantly enhanced the survival of primary follicles (<80 µm) cultured in alginate hydrogels, which coincided with improved structural integrity. Follicles developed antral cavities and increased to diameters exceeding 250 µm. Consistent with improved structural integrity, the gene/protein expression of ECM and cell adhesion molecules was significantly changed. This research supports the notion that modifying the culture environment (medium components) can substantially enhance the survival and growth of early stage follicles. © 2013 Wiley Periodicals, Inc.

  5. A biosensor based on zucchini (Cucurbita pepo L.) homogenate as a biorecognition layer for ascorbic acid determination.

    Science.gov (United States)

    Sezgintürk, Mustafa Kemal; Koca, Halit Buğra; Ozben, Yavuz Selim; Dinçkaya, Erhan

    2010-08-01

    An amperometric biosensor based on zucchini (Cucurbita pepo) tissue homogenate is presented. The zucchini tissue homogenate was crosslinked with gelatine using glutaraldehyde and fixed on a pretreated teflon membrane. The zucchini tissue contained the enzyme ascorbate oxidase and this enzyme catalyzed the oxidation of ascorbic acid in the presence of dissolved oxygen. The principle of the measurements was based on the determination of the decrease in the dissolved oxygen level. Determinations were carried out by standard curves, which were obtained by the measurement of the decrease in the oxygen level related to ascorbic acid concentration. Optimization and characterization studies of the biosensor were carried out in detail. First of all, the amounts of zucchini tissue homogenate, gelatin, and glutaraldehyde percentage were optimized. Experimental parameters such as buffer system, pH, buffer concentration, and temperature were also optimized carefully. Thermal stability, storage stability, and repeatability of the biosensor were investigated. A linear response was observed from 5x10(-6) M to 1.2x10(-3) M ascorbic acid. Finally, the results of some plant and drug samples analyzed with the presented biosensor compared with the spectrophotometric method (Tillman reagent) used as a reference.

  6. Determination of ascorbic acid, dopamine, and uric acid by a novel electrochemical sensor based on pristine graphene

    International Nuclear Information System (INIS)

    Qi, Shaopeng; Zhao, Bo; Tang, Heqing; Jiang, Xiaoqing

    2015-01-01

    In this article, a novel electrochemical sensor based on pristine graphene (PG) is successfully constructed to detect ascorbic acid (AA), dopamine (DA), and uric acid (UA). The PG is obtained by liquid-phase exfoliation of graphite and characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The sensor based on PG prepared by this method to realize simultaneous determination of AA, DA, and UA is firstly reported. The linear detection ranges for AA, DA, and UA are 9.00–2314 μM, 5.00–710 μM, and 6.00–1330 μM, respectively, with detection limits of 6.45, 2.00, and 4.82 μM. This PG based sensor exhibits excellent performance for detection of AA, DA, and UA, which is much better than those electrochemical sensors based on chemical converted graphene

  7. Hierarchical nanoporous platinum-copper alloy for simultaneous electrochemical determination of ascorbic acid, dopamine, and uric acid

    International Nuclear Information System (INIS)

    Zhao, Dianyun; Fan, Dawei; Wang, Jinping; Xu, Caixia

    2015-01-01

    A hierarchical nanoporous PtCu alloy was fabricated by two-step dealloying of a PtCuAl precursor alloy followed by annealing. The new alloy possesses interconnected hierarchical network architecture with bimodal distributions of ligaments and pores. It exhibits high electrochemical activity towards the oxidation of ascorbic acid (AA), dopamine (DA), and uric acid (UA) at working potentials of 0.32, 0.47 and 0.61 V (vs. a mercury sulfate reference electrode), respectively. The new alloy was placed on a glassy carbon electrode and then displayed a wide linear response to AA, DA, and UA in the concentration ranges from 25 to 800 μM, 4 to 20 μM, and 10 to 70 μM, respectively. The lower detection limits are 17.5 μM, 2.8 µM and 5.7 μM at an S/N ratio of 3. (author)

  8. Variation of ascorbic acid concentration in fruits of cultivated and wild apples.

    Science.gov (United States)

    Fang, Ting; Zhen, Qiaoling; Liao, Liao; Owiti, Albert; Zhao, Li; Korban, Schuyler S; Han, Yuepeng

    2017-06-15

    Ascorbic acid (AsA) content in mature fruits of 457 apple accessions were measured, and a great variation in AsA concentration was detected. Wild fruits showed significantly higher level of AsA than cultivated fruits. Fruit AsA content was positively correlated with malic acid content, but negatively correlated with fruit weight and soluble solid content. Thus, the difference in AsA content between the wild and cultivated fruits could be attributed to an indirect consequence of human selection for larger fruit size, less acidity, and increased sweetness during apple domestication. Additionally, AsA concentration was extremely high in fruit at the juvenile stage, but dramatically decreased at the expanding and mature stages. The expression levels of three genes controlling AsA accumulation, MdGGP1, MdDHAR3-3, and MdNAT7-2, were significantly negatively correlated with AsA contents in fruits, suggesting a feedback regulation mechanism in AsA-related gene expression. Our results could be helpful for future apple breeding. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Study on the Ascorbic Acid Content of rose Hip fruit Depending on Stationary Conditions

    Directory of Open Access Journals (Sweden)

    Sorina Ropciuc

    2011-10-01

    Full Text Available The dog rose area includes southern and central Europe, reaching southern Scandinavia; it is also found in Asia Minor, Central Asia and North Africa. In our country, Rosa canina is the most widespread of the many species of Rosa, common in all areas. The components of the station, known also as the „stationary factors” affect differently the plant life and their chemical composition. Cynosbati fructus is the false fruit of Rosa canina L. (Rosaceae, known in Romanian as rose hip. The rose hip contain as active ingredients 500-1000 % vitamin C, 600-10000 mg% carotenoids, pectin, dextrin, vitamins B2, E, PP, flavone, sugars, organic acids, tannins, volatile oil, vanillin, triterpenoid saponosides, beta-sitosterol, fat (lecithin, glycerides of fatty acids in seeds, minerals (potassium, calcium, magnesium, iron. Vitamin C (ascorbic acid plays an important role in human body. The greatest amount is found in plants which reached maturity. It is concentrated in the rose hip flesh. Solutions easily destroyit in the presence of UV, of copper, silver, iron and oxidative enzymes traces. Vitamin C participates actively in all processes of oxidoreductions of the living cell. Its lack in food causes the disease called scurvy which manifests itself by inflammated and bleeding gums, tooth loss. Rose hip fruits are known as medicines since prehistoric times.

  10. All-solid-state potentiometric sensors for ascorbic acid by using a screen-printed compatible solid contact

    International Nuclear Information System (INIS)

    Veltsistas, Panayotis G.; Prodromidis, Mamas I.; Efstathiou, Constantinos

    2004-01-01

    The development of all-solid-state potentiometric ion selective electrodes for monitoring of ascorbic acid, by using a screen-printed compatible solid contact is described. The applied methodology is based on the use of PVC membrane modified with some firstly-tested ionophores (triphenyltin(IV)chloride, triphenyltin(IV)hydroxide and palmitoyl-L-ascorbic acid) and a novel one synthesized in our laboratory (dibutyltin(IV) diascorbate). Synthesis protocol and some preliminary identification studies are given. A conductive graphite-based polymer thick film ink was used as an internal solid contact between the graphite electrode and the PVC membrane. The presence and the nature of the solid contact (plain or doped with lanthanum 2,6-dichlorophenolindophenol (DCPI)) seem to enhance the analytical performance of the electrodes in terms of sensitivity, dynamic range, and response time. The analytical performance of the constructed electrodes was evaluated with potentiometry, constant-current chronopotentiometry and electrochemical impedance spectroscopy (EIS). The interference effect of various compounds was also tested. The potential response of the optimized Ph 3 SnCl-based electrode was linear against ascorbic acid concentration range 0.005-5.0 mM. The applicability of the proposed sensors in real samples was also tested. The detection limit was 0.002 mM ascorbic acid (50 mM phosphate, pH 5 in 50 mM KCl). The slope of the electrodes was super-Nernstian and pH dependent, indicating a mechanism involving a combination of charge transfer and ion exchange processes. Fabrication of screen-printed ascorbate ISEs has also been demonstrated

  11. Role of ascorbic acid and α tocopherol in alleviating salinity stress on flax plant (Linum usitatissimum L.

    Directory of Open Access Journals (Sweden)

    Mervat Sh. Sadak

    2014-03-01

    Full Text Available Salinity is one of the environmental challenges in the world affecting on several physiological processes and the most limiting factor of plant productivity and quality. Two pot experiments were conducted at the wire house of National Research Centre, Cairo, Egypt during two successive seasons of 2010/2011 and 2011/2012 to assess the efficiency of two antioxidant vitamins (ascorbic acid at 1.13 and 2.27 mM or α tocopherol at 0.46 and 0.93 mM and/or salinity stress at (0.0, 3.08, 6.16, 9.23 ds/m on photosynthetic pigments, protein, carbohydrate, minerals, oil contents and yield as well as fatty acids composition of the yielded oils of three flax cultivars (Sakha 3, Giza 8 and Ariane. The data revealed that salinity stress caused significant and gradual decreases in total photosynthetic pigments, polysaccharides, total carbohydrates, total proteins and the uptake of Mg, K, Ca and P in the leaves of three flax cultivars with increasing salinity levels (3.08, 6.16, 9.23 ds/m. Otherwise, significant and gradual increase appeared in both Na and Cl. Ascorbic acid and α tocopherol at different concentrations caused significant increases in photosynthetic pigments, total carbohydrates and protein contents in the leaves of flax plants irrigated either with tap water or saline solution as compared with their corresponding controls. Exogenous application of ascorbic and α tocopherol at different concentrations exhibited decreases in Na and Cl whereas increases appeared in Mg, K, Ca and P relative to their corresponding control. Ascorbic acid (1.13 and 2.27 mM and α tocopherol (0.46 and 0.93 mM caused marked increases in yield and yield attributes of three flax cultivars either in plants irrigated with tap water or saline solution as compared to corresponding control. Ascorbic acid effects were more pronounced than α tocopherol effects. In addition, the higher level of two vitamins was more pronounced than the lower level. Regarding plants irrigated

  12. Novel halogenated 3-deazapurine, 7-deazapurine and alkylated 9-deazapurine derivatives of L-ascorbic or imino-L-ascorbic acid: Synthesis, antitumour and antiviral activity evaluations.

    Science.gov (United States)

    Stipković Babić, Maja; Makuc, Damjan; Plavec, Janez; Martinović, Tamara; Kraljević Pavelić, Sandra; Pavelić, Krešimir; Snoeck, Robert; Andrei, Graciela; Schols, Dominique; Wittine, Karlo; Mintas, Mladen

    2015-09-18

    Keeping the potential synergy of biological activity of synthetic anomalous derivatives of deazapurines and l-ascorbic acid (l-AA) in mind, we have synthesized new 3-, 7- and 9-deazapurine derivatives of l-ascorbic (1-4, 8-10, 13-15) and imino-l-ascorbic acid (5-7, 11, 12, 16-19). These novel compounds were evaluated for their cytostatic and antiviral activity in vitro against a panel of human malignant tumour cell lines and normal murine fibroblasts (3T3). Among all evaluated compounds, the 9-deazapurine derivative of l-AA (13) exerted the most potent inhibitory activity on the growth of CEM/0 cells (IC50 = 4.1 ± 1.8 μM) and strong antiproliferative effect against L1210/0 (IC50 = 4.7 ± 0.1 μM) while the 9-deazahypoxanthine derivative of l-AA (15) showed the best effect against HeLa cells (IC50 = 5.6 ± 1.3 μM) and prominent effect on L1210/0 (IC50 = 4.5 ± 0.5 μM). Furthermore, the 9-deazapurine derivative disubstituted with two imino-l-AA moieties (18) showed the best activity against L1210/0 tumour cells (IC50 = 4.4 ± 0.3 μM) and the most pronounced antiproliferative effects against MiaPaCa-2 cells (IC50 = 5.7 ± 0.2 μM). All these compounds showed selective cytostatic effect on tumour cell lines in comparison with embryonal murine fibroblasts (3T3). When evaluating their antiviral activity, the 3-deazapurine derivative of l-AA (3) exhibited the highest activity against both laboratory-adapted strains of human cytomegalovirus (HCMV) (AD-169 and Davis) with EC50 values comparable to those of the well-known anti-HCMV drug ganciclovir and without cytotoxic effects on normal human embryonal lung (HEL) cells. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  13. Ascorbic Acid Kills Epstein-Barr Virus (EBV) Positive Burkitt Lymphoma Cells and EBV Transformed B-Cells in Vitro, but not in Vivo

    Science.gov (United States)

    Shatzer, Amber N.; Espey, Michael G.; Chavez, Mayra; Tu, Hongbin; Levine, Mark; Cohen, Jeffrey I.

    2014-01-01

    Ascorbic acid has been shown to kill various cancer cell lines at pharmacologic concentrations. We found that Epstein-Barr virus (EBV)-positive Burkitt lymphoma (BL) cells were more susceptible to ascorbic acid-induced cell killing than EBV-negative BL cells or EBV-transformed lymphoblastoid cells (LCLs). Ascorbic acid did not induce apoptosis in any of the tested cells but did induce the production of reactive oxygen species and cell death. Previously, we showed that bortezomib, a proteasome inhibitor, induces cell death in LCLs and EBV-positive BL cells. We found that ascorbic acid is strongly antagonistic for ascorbic acid-induced cell death in LCLs and EBV-positive BL cells. Finally, ascorbic acid did not prolong survival of severe combined immunodefiency mice inoculated with LCLs either intraperitoneally or subcutaneously. Thus, while ascorbic acid was highly effective at killing EBV-positive BL cells and LCLs in vitro, it antagonized cell killing by bortezomib and was ineffective in an animal model. PMID:23067008

  14. Exploring isoxsuprine hydrochloride binding with human serum albumin in the presence of folic acid and ascorbic acid using multispectroscopic and molecular modeling methods.

    Science.gov (United States)

    Shiri, Fereshteh; Shahraki, Somaye; Shahriyar, Amin; Majd, Mostafa Heidari

    2017-05-01

    Isoxsuprine hydrochloride (vasodilator drug), folic acid and ascorbic acid are medicines which can be utilized alone or simultaneously by pregnant women. In the present work the competitive binding of isoxsuprine hydrochloride (ISO) with human serum albumin (HSA) in the absence and presence of folic acid (FOL) and ascorbic acid (AS) was investigated using different spectroscopic probes and molecular docking studies. The results of fluorescence suggested that isoxsuprine alone or in the presence of ascorbic acid can bind to HSA and quench the fluorescence of HSA with static mechanism but For HSA-folic acid-isoxsuprine system, dynamic type of quenching mechanisms is involved. The values of binding constants (K HSA-ISO ~1.2×10 3 M -1 , K HSA-AS-ISO ~2.1×10 3 M -1 and K HSA-FOL-ISO ~0.7×10 3 M -1 ) suggested that affinity of HSA to isoxsuprine increased in the presence of ascorbic acid while the presence of folic acid reduced the affinity of protein to isoxsuprine. The results of FT-IR and circular dichroism measurements indicated that the binding of isoxsuprine to HSA in the absence and the presence of folic acid and ascorbic acid may induce conformational and microenvironmental changes of protein. Not only do these types of spectroscopy techniques provide all the information about the systems, molecular docking, also emphasizes the results and is employed for the identification of the active site residues, bioactive conformer of Isoxsuprine and their critical interactions. Copyright © 2017. Published by Elsevier B.V.

  15. Effect of high hydrostatic pressure on phenolic compounds, ascorbic acid and antioxidant activity in cashew apple juice

    Science.gov (United States)

    Queiroz, C.; Moreira, C. F. F.; Lavinas, F. C.; Lopes, M. L. M.; Fialho, E.; Valente-Mesquita, V. L.

    2010-12-01

    The cashew apple is native to Brazil, but there is insufficient information regarding the nutritional properties of this fruit. The objective of this study was to evaluate the impact of high pressure processing (HPP) at room temperature (25 °C) on phenolic compound and ascorbic acid contents and antioxidant capacity of cashew apple juice. This study showed that HPP at 250 or 400 MPa for 3, 5 and 7 min did not change pH, acidity, total soluble solids, ascorbic acid or hydrolysable polyphenol contents. However, juice pressurized for 3 and 5 min showed higher soluble polyphenol contents. Antioxidant capacity, measured by the ferric-reducing antioxidant power method, was not altered by HPP, but when treated at 250 MPa for 3 min, it resulted in an increased value when 2,2-diphenyl-1-picrylhydrazyl was used. These data demonstrate that HPP can be used in the food industry for the generation of products with higher nutritional quality.

  16. Lipophilization of ascorbic acid: a monolayer study and biological and antileishmanial activities.

    Science.gov (United States)

    Kharrat, Nadia; Aissa, Imen; Sghaier, Manel; Bouaziz, Mohamed; Sellami, Mohamed; Laouini, Dhafer; Gargouri, Youssef

    2014-09-17

    Ascorbyl lipophilic derivatives (Asc-C2 to Asc-C(18:1)) were synthesized in a good yield using lipase from Staphylococcus xylosus produced in our laboratory and immobilized onto silica aerogel. Results showed that esterification had little effect on radical-scavenging capacity of purified ascorbyl esters using DPPH assay in ethanol. However, long chain fatty acid esters displayed higher protection of target lipids from oxidation. Moreover, compared to ascorbic acid, synthesized derivatives exhibited an antibacterial effect. Furthermore, ascorbyl derivatives were evaluated, for the first time, for their antileishmanial effects against visceral (Leishmania infantum) and cutaneous parasites (Leishmania major). Among all the tested compounds, only Asc-C10, Asc-C12, and Asc-C(18:1) exhibited antileishmanial activities. The interaction of ascorbyl esters with a phospholipid monolayer showed that only medium and unsaturated long chain (Asc-C10 to Asc-C(18:1)) derivative esters were found to interact efficiently with mimetic membrane of leishmania. These properties would make ascorbyl derivatives good candidates to be used in cosmetic and pharmaceutical lipophilic formulations.

  17. Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)

    International Nuclear Information System (INIS)

    Kumar, Puneet; Prasad, Y.; Patra, A.K.; Ranjan, R.; Swarup, D.; Patra, R.C.; Pal, Satya

    2009-01-01

    An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 ± 4 cm and weight of 86 ± 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl 2 .H 2 O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl 2 .H 2 O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to

  18. Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish (Clarias batrachus)

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Puneet, E-mail: puneetbiochem@gmail.com [Aquatic Biotechnology and Fish Pathology Laboratory, Department of Animal Science, M.J.P. Rohilkhand University, Bareilly-243 006 (India); Prasad, Y. [Aquatic Biotechnology and Fish Pathology Laboratory, Department of Animal Science, M.J.P. Rohilkhand University, Bareilly-243 006 (India); Patra, A.K. [West Bengal University of Animal and Fishery Sciences, Kolkata-700037 (India); Ranjan, R.; Swarup, D.; Patra, R.C. [Division of Medicine, Indian Veterinary Research Institute, Izatnagar-243122 (India); Pal, Satya [Env. Eng. Lab., Deptt. of Civil Engineering, I.I.T., Roorkee-247667 (India)

    2009-09-01

    An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish (Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus (n = 324) with average length of 20 {+-} 4 cm and weight of 86 {+-} 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl{sub 2}.H{sub 2}O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl{sub 2}.H{sub 2}O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and

  19. Culturing bone marrow cells with dexamethasone and ascorbic acid improves osteogenic cell sheet structure.

    Science.gov (United States)

    Akahane, M; Shimizu, T; Kira, T; Onishi, T; Uchihara, Y; Imamura, T; Tanaka, Y

    2016-11-01

    To assess the structure and extracellular matrix molecule expression of osteogenic cell sheets created via culture in medium with both dexamethasone (Dex) and ascorbic acid phosphate (AscP) compared either Dex or AscP alone. Osteogenic cell sheets were prepared by culturing rat bone marrow stromal cells in a minimal essential medium (MEM), MEM with AscP, MEM with Dex, and MEM with Dex and AscP (Dex/AscP). The cell number and messenger (m)RNA expression were assessed in vitro, and the appearance of the cell sheets was observed after mechanical retrieval using a scraper. β-tricalcium phosphate (β-TCP) was then wrapped with the cell sheets from the four different groups and subcutaneously implanted into rats. After mechanical retrieval, the osteogenic cell sheets from the MEM, MEM with AscP, and MEM with Dex groups appeared to be fragmented or incomplete structures. The cell sheets cultured with Dex/AscP remained intact after mechanical retrieval, without any identifiable tears. Culture with Dex/AscP increased the mRNA and protein expression of extracellular matrix proteins and cell number compared with those of the other three groups. More bridging bone formation was observed after transplantation of the β-TCP scaffold wrapped with cell sheets cultured with Dex/AscP, than in the other groups. These results suggest that culture with Dex/AscP improves the mechanical integrity of the osteogenic cell sheets, allowing retrieval of the confluent cells in a single cell sheet structure. This method may be beneficial when applied in cases of difficult tissue reconstruction, such as nonunion, bone defects, and osteonecrosis.Cite this article: M. Akahane, T. Shimizu, T. Kira, T. Onishi, Y. Uchihara, T. Imamura, Y. Tanaka. Culturing bone marrow cells with dexamethasone and ascorbic acid improves osteogenic cell sheet structure. Bone Joint Res 2016;5:569-576. DOI: 10.1302/2046-3758.511.BJR-2016-0013.R1. © 2016 Akahane et al.

  20. Split-dose menthol-enhanced PEG vs PEG-ascorbic acid for colonoscopy preparation.

    Science.gov (United States)

    Sharara, Ala I; Harb, Ali H; Sarkis, Fayez S; Chalhoub, Jean M; Badreddine, Rami; Mourad, Fadi H; Othman, Mahmoud; Masri, Omar

    2015-02-14

    To compare the efficacy and palatability of 4 L polyethylene glycol electrolyte (PEG) plus sugar-free menthol candy (PEG + M) vs reduced-volume 2 L ascorbic acid-supplemented PEG (AscPEG). In a randomized controlled trial setting, ambulatory patients scheduled for elective colonoscopy were prospectively enrolled. Patients were randomized to receive either PEG + M or AscPEG, both split-dosed with minimal dietary restriction. Palatability was assessed on a linear scale of 1 to 5 (1 = disgusting; 5 = tasty). Quality of preparation was scored by assignment-blinded endoscopists using the modified Aronchick and Ottawa scales. The main outcomes were the palatability and efficacy of the preparation. Secondary outcomes included patient willingness to retake the same preparation again in the future and completion of the prescribed preparation. Overall, 200 patients were enrolled (100 patients per arm). PEG + M was more palatable than AscPEG (76% vs 62%, P = 0.03). Completing the preparation was not different between study groups (91% PEG + M vs 86% AscPEG, P = 0.38) but more patients were willing to retake PEG + M (54% vs 40% respectively, P = 0.047). There was no significant difference between PEG + M vs AscPEG in adequate cleansing on both the modified Aronchick (82% vs 77%, P = 0.31) and the Ottawa scale (85% vs 74%, P = 0.054). However, PEG + M was superior in the left colon on the Ottawa subsegmental score (score 0-2: 94% for PEG + M vs 81% for AscPEG, P = 0.005) and received significantly more excellent ratings than AscPEG on the modified Aronchick scale (61% vs 43%, P = 0.009). Both preparations performed less well in afternoon vs morning examinations (inadequate: 29% vs 15.2%, P = 0.02). 4 L PEG plus menthol has better palatability and acceptability than 2 L ascorbic acid- PEG and is associated with a higher rate of excellent preparations; Clinicaltrial.gov identifier: NCT01788709.

  1. Combined effect of metformin with ascorbic acid versus acetyl salicylic acid on diabetes-related cardiovascular complication; a 12-month single blind multicenter randomized control trial.

    Science.gov (United States)

    Gillani, Syed Wasif; Sulaiman, Syed Azhar Syed; Abdul, Mohi Iqbal Mohammad; Baig, Mirza R

    2017-08-14

    We aimed to investigate the efficacy of ascorbic acid and acetylsalicylic acid among type II diabetes mellitus patients using metformin (only) for diabetes management therapy. A 12-month single blinded multicenter randomized control trial was designed to investigate the measured variables [Glycated Hemoglobin (HbA1c), Renal function, Albumin Creatinine Ratio (ACR) etc.]. The trial was randomized into 2 experimental parallel arms (ascorbic acid vs acetylsalicylic acid) were blinded with study supplements in combination with metformin and findings were compared to control arm with metformin alone and blinded with placebo. Withdrawal criteria was defined to maintain the equity and balance in the participants in the whole trial. Patients with metformin and ascorbic acid (parallel arm I) was twice more likely to reduce HbA1c than metformin alone (control arm) in a year (OR 2.31 (95% CI 1.87-4.42) p ascorbic acid with metformin is more effective against reducing risks for diabetes related long-term complications (including ACR). TRIAL details Registration No: NTR-6100, Registry Name: Netherlands Trial Registry, URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6100 , Date of Registration: 20th October, 2016, Date of first Enrollment: 1 November, 2015.

  2. Growth and characterization of strontium oxalate crystals by the decomposition of ascorbic acid in presence of strontium chloride

    International Nuclear Information System (INIS)

    Bijini, B.R.; Prasanna, S.; Rajendra Babu, K.; Deepa, M.

    2010-01-01

    Full text: Ascorbic acid (vitamin c) is an important organic compound that helps to maintain the optimal health of human body. It is essential for the development and maintenance of connective tissues. Vitamin C plays an important role in a number of metabolic functions including the activation of the B vitamin, folic acid, the conversion of cholesterol to bile acids and the conversion of the amino acid, tryptophan, to the neurotransmitter, serotonin. During the process of metabolism it decomposes into oxalic acid. This compound is photosensitive and has least thermal stability. The decomposition of Ascorbic acid has been studied in various conditions. It is reported that decomposition of ascorbic acid in presence of Cd 2+ ions leads to the formation of cadmium oxalate crystals. In the present work, in presence of Sr 2+ ion the ascorbic acid is decomposed to Strontium Oxalate in gel media. In this technique, silica gel is used as a medium to grow crystals. Slow diffusion of reactants in the gel medium can be considered to mimic the growth of crystals in the human body. Gels were prepared by mixing appropriate quantities of sodium meta silicate and ascorbic acid, adjusting the pH in the range 5-7.5. Over the set gel, the feed solution of 1M Strontium chloride was added. Yellowish prismatic and bar shaped crystals were obtained within 24 hours. The nucleation density is maximum at a pH of 6 and minimum at 5. Good quality crystals were obtained for a pH of 5 and gel density 1.05g/cc. The FTIR spectra of grown crystals are recorded and analyzed.The band at 3431 cm -1 is assigned to OH stretching frequency of co-ordinated water molecule and the band at 1637cm -1 corresponds to C=O Stretching of carbonyl group. The band at 1319cm -1 is assigned to symmetric stretching of COO- group. The IR band at 767cm -1 corresponds to the combined effect of inplane deformation of CO 2 and the presence of metal oxygen bond .The band at 505cm -1 is due to wagging mode

  3. Adding of ascorbic acid to the culture medium influences the antioxidant status and some biochemical parameters in the hen granulosa cells.

    Science.gov (United States)

    Capcarova, M; Kolesarova, A; Kalafova, A; Bulla, J; Sirotkin, A V

    2015-07-01

    The aim of the present study was to determine the activity of superoxide dismutase (SOD), total antioxidant status (TAS) of the hen granulosa cells, and selected biochemical parameters, including calcium, phosphorus, sodium, potassium, glucose, cholesterol, proteins, in the culture medium of granulosa cells after exposing them to ascorbic acid in vitro conditions. Ovarian granulosa cells of hens were incubated with various doses of ascorbic acid (E1 0.09 mg/ml, E2 0.13 mg/ml, E3 0.17 mg/ml, E4 0.33 mg/ml, E5 0.5 mg/ml). Ascorbic acid did not manifest antioxidant potential and higher doses of ascorbic acid (0.17; 0.33 and 0.5 mg/ml) decreased the activity of SOD in granulosa cells. Vitamin application resulted in a significantly (pascorbic acid might be involved in the regulation of selected biochemical and physiological processes in ovarian granulosa cells.

  4. Ascorbic acid accumulates as a defense response to Turnip mosaic virus in resistant Brassica rapa cultivars.

    Science.gov (United States)

    Fujiwara, Ayaka; Togawa, Satoko; Hikawa, Takahiro; Matsuura, Hideyuki; Masuta, Chikara; Inukai, Tsuyoshi

    2016-07-01

    We initially observed that Brassica rapa cultivars containing the Turnip mosaic virus (TuMV) resistance gene, Rnt1-1, accumulated a high level of endogenous ascorbic acid (AS) and dehydroascobic acid (DHA) when infected with TuMV. We here hypothesized a possible contribution of an elevated level of AS+DHA (TAA) to the Rnt1-1-mediated resistance, and conducted a series of experiments using B. rapa and Arabidopsis plants. The application of l-galactose (the key substrate in AS synthesis) to a susceptible cultivar could increase the TAA level ~2-fold, and simultaneously lead to some degree of enhanced viral resistance. To confirm some positive correlation between TAA levels and viral resistance, we analyzed two Arabidopsis knockout mutants (ao and vtc1) in the AS pathways; the TAA levels were significantly increased and decreased in ao and vtc1 plants, respectively. While the ao plants showed enhanced resistance to TuMV, vtc1 plants were more susceptible than the control, supporting our hypothesis. When we analyzed the expression profiles of the genes involved in the AS pathways upon TuMV infection, we found that the observed TAA increase was mainly brought about by the reduction of AS oxidation and activation of AS recycling. We then investigated the secondary signals that regulate endogenous TAA levels in response to viral infection, and found that jasmonic acid (JA) might play an important role in TAA accumulation. In conclusion, we reason that the elevated TAA accumulation in B. rapa plants would be at least partly mediated by the JA-dependent signaling pathway and may significantly contribute to viral resistance. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  5. Effect of high doses of L-ascorbic acid on the antioxidative/oxidative state in the rats

    DEFF Research Database (Denmark)

    Niemiec, T.; Sawosz, E.; Chwalibog, André

    2005-01-01

    The objective of this study was to determine the effects of mega-doses of vitamin C (0.3, 0.6 and 0.9% of diet) as a dietary supplement for rats on selected indices of the antioxidative/oxidative state in 40 growing Wistar rats (4x10). It was found that L-ascorbic acid and Total Antioxidative State...... (TAS) in plasma did not increase with increasing vitamin C supply. The results indicate that high doses of L-ascorbic acid (0.3 and 0.9 but not 0.6%) increased the concentration of this antioxidant in plasma. Supplementation of vitamin C above 0.3% to the diets had pro-oxidative effects on lipid...

  6. The content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits at vulcan coal dump

    Directory of Open Access Journals (Sweden)

    Andreea BRASOVAN

    2009-11-01

    Full Text Available The study presents data on content determination of calcium, magnesium and ascorbic acid in sea buckthorn fruits collected from Vulcan coal dump. The dump was never covered with soil or fertilizers containing azoth, potassium and phosphorus. The sea buckthorn was planted directly on the sterile and it has an important function in stabilizing the acclivity and fixing the atmospheric azoth with the nodosities on the roots. So, the sea buckthorn becomes widespread plant in coal dumps because it helps to the soil formation. The results obtained after the determination of calcium, magnesium and ascorbic acid from the fruits of this plant were compared with the values already reported in various references, concluding that these differences are insignificant (3.7% for magnesium and 9.4% for calcium. Therefore, the sea buckthorn from the dump can be used in food industry, as well as in pharmaceutics and medicine.

  7. Changes in the contents of kaempherol, quercetin and L-ascorbic acid in sea buckthorn berries during maturation

    Directory of Open Access Journals (Sweden)

    N. JEPPSON

    2008-12-01

    Full Text Available The contents of kaempherol, quercetin and L-ascorbic acid in sea buckthorn berries were measured at different maturation stages using High Performance Liquid Chromatography (HPLC methods. The content of ascorbic acid decreased over time with significant differences between sampling dates for the five cultivars studied. The mean decrease was 25% in 19 days, from 1.48 to 1.10 g kg-1. Quercetin decreased whereas kaempherol increased during maturation. Among three studied cultivars, the decrease in quercetin was significant (from 0.028 to 0.014 g kg-1 in 'Otradnaja', where as the increase (from 0.012 to 0.016 g kg-1 in kaempherol was significant in the others two, 'Prozratnaja' and 'Gibrid Pertjik'.;

  8. Facile synthesis of graphene hybrid tube-like structure for simultaneous detection of ascorbic acid, dopamine, uric acid and tryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wen [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Chai Yaqin, E-mail: yqchai@swu.edu.cn [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yuan Ruo, E-mail: yuanruo@swu.edu.cn [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Chen Shihong; Han Jing; Yuan Dehua [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2012-12-05

    Graphical abstract: A tube-like structure of graphene hybrid (GS-PTCA) was synthesized via {pi}-{pi} stacking interaction, and was used as modifier to fabricate electrode for simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (Trp). SEM images of GS, PTCA and GS-PTCA were presented. Under the synergistic effects between GS and PTCA, the modified electrode displayed high catalytic activity and selectivity toward the oxidation of AA, DA, UA, and Trp. Highlights: Black-Right-Pointing-Pointer A simple strategy for simultaneous detection of AA, DA, UA and Trp has been constructed. Black-Right-Pointing-Pointer The tube-like structure of graphene hybrid (GS-PTCA) was synthesized. Black-Right-Pointing-Pointer The GS-PTCA provided a selective interface for discrimination of AA, DA, UA and Trp. - Abstract: In the present work, a tube-like structure of graphene hybrid as modifier to fabricate electrode for simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (Trp) was reported. The hybrid was synthesized by a simple method based on graphene sheets (GS) and 3,4,9,10-perylenetetracarboxylic acid (PTCA) via {pi}-{pi} stacking interaction under ultrasonic condition. The combination of GS and PTCA could effectively improve the dispersion of GS, owing to PTCA with the carboxylic-functionalized interface. Comparing with pure GS or PTCA modified electrode, GS-PTCA displayed high catalytic activity and selectivity toward the oxidation of AA, DA, UA, and Trp. Moreover, cyclic voltammetry, different pulse voltammetry and scanning electron microscopy were employed to characterize the sensors. The experiment results showed that the linear response range for simultaneous detection of AA, DA, UA, and Trp were 20-420 {mu}M, 0.40-374 {mu}M, 4-544 {mu}M and 0.40-138 {mu}M, respectively, and the detection limits were 5.60 {mu}M, 0.13 {mu}M, 0.92 {mu}M and 0.06 {mu}M (S/N = 3). Importantly, the proposed method offers

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

    Directory of Open Access Journals (Sweden)

    Ciprian Radovan

    2008-06-01

    Full Text Available 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 correlation parameters. Sensitivity values and RSD of 2-3% were obtained for various situations, involving both individual and simultaneous presence of AA and AC. The chronoamperometric technique associated with standard addition in sequential one step and/or two successive and continuous chronoamperograms at two characteristic potential levels represented a feasible option for the simultaneous determination of AA and AC in real sample systems such as pharmaceutical formulations. The average values indicated by the supplier were confirmed to a very close approximation from chronoamperomgrams by using several additions with the application of suitable current correction factors.

  10. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

    2015-01-07

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe{sup 3+} ion sensing by fluorescence quenching is developed. • The method for Fe{sup 3+} sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe{sup 3+}) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe{sup 3+} permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe{sup 3+} in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%.

  11. Impact of exogenous ascorbic acid on biochemical activities of rice callus treated with salt stress

    Science.gov (United States)

    Alhasnawi, Arshad Naji; Zain, Che Radziah Che Mohd; Kadhimi, Ahsan A.; Isahak, Anizan; Mohamad, Azhar; Ashraf, Mehdi Farshad; Doni, Febri; Yusoff, Wan Mohtar Wan

    2016-11-01

    The application of in vitro systems can lead to new methods of crop amelioration. This method has been widely utilized for breeding tenacities, particularly for stress tolerance selection. Salinity causes oxidative stress in callus by enhancing the production of Reactive Oxygen Species (ROS), resulting in an efficient antioxidant system. The exogenous application of ascorbic acid (AsA) is an important requirement for tolerance. The present study aimed to examine in vitro selection strategy for callus induction in rice mature embryo culture on MS culture medium and to produce salt-tolerant callus under sodium chloride (NaCl) and AsA conditions in callus rice variety, MR269. This study also highlights changes in the activities of proline and antioxidants peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) of callus under NaCl stress to understand their possible role in salt tolerance. However, various levels of exogenously applied AsA under saline conditions improved callus, and the antioxidant enzyme activities of AsA are related to resistance to oxidative stress. Our results provide strong support for the hypothesis that AsA-dependent antioxidant enzymes play a significant role in the salinity tolerance of callus rice.

  12. Enhancement of Dopaminergic Differentiation in Proliferating Midbrain Neuroblasts by Sonic Hedgehog and Ascorbic Acid

    Science.gov (United States)

    Volpicelli, Floriana; Consales, Claudia; Caiazzo, Massimiliano; Colucci-D'Amato, Luca; Perrone-Capano, Carla; di Porzio, Umberto

    2004-01-01

    We analyzed the molecular mechanisms involved in the acquisition and maturation of dopaminergic (DA) neurons generated in vitro from rat ventral mesencephalon (MES) cells in the presence of mitogens or specific signaling molecules. The addition of basic fibroblast growth factor (bFGF) to MES cells in serum-free medium stimulates the proliferation of neuroblasts but delays DA differentiation. Recombinant Sonic hedgehog (SHH) protein increases up to three fold the number of tyrosine hydroxylase (TH)-positive cells and their differentiation, an effect abolished by anti-SHH antibodies. The expanded cultures are rich in nestin-positive neurons, glial cells are rare, all TH+ neurons are DA, and all DA and GABAergic markers analyzed are expressed. Adding ascorbic acid to bFGF/SHH-treated cultures resulted in a further five- to seven-fold enhancement of viable DA neurons. This experimental system also provides a powerful tool to generate DA neurons from single embryos. Our strategy provides an enriched source of MES DA neurons that are useful for analyzing molecular mechanisms controlling their function and for experimental regenerative approaches in DA dysfunction. PMID:15303305

  13. [Effect of ascorbic acid (vitamin C) on the EPR spectra from the black and red hair].

    Science.gov (United States)

    Chikvaidze, E; Miminoshvili, A; Gogoladze, T; Kiparoidze, S

    2012-02-01

    The EPR spectra of melanin's free radicals in natural black and red hair have been investigated. It is show that the EPR spectrum of black hair is slightly asymmetric singlet with g=2,0035 and ΔH=0,5 mTl. The EPR spectrum of red hair with g=2,0053 differs from the spectrum of black hair. Under the influence of visible (blue with λ(max)=450 nm) in both types of hair (black and red), the protoinduced free radicals appear, which indicates an increase in the intensity of already existing EPR spectrum of hair. It should be noted that the EPR spectra of red hair from various donors are different. The antioxidant ascorbic acid has the different effect on the photoinduced free radicals. In particular, in the case of black hair, the concentration of photoinduced free radicals is slightly reduced, whereas in red hair, the disappearance of the triplet in the spectrum is observed, and at the same time, the spectrum becomes a singlet, the intensity of which increases sharply.

  14. Intracellular ascorbic acid inhibits transport of glucose by neurons, but not by astrocytes.

    Science.gov (United States)

    Castro, Maite A; Pozo, Miguel; Cortés, Christian; García, María de Los Angeles; Concha, Ilona I; Nualart, Francisco

    2007-08-01

    It has been demonstrated that glutamatergic activity induces ascorbic acid (AA) depletion in astrocytes. Additionally, different data indicate that AA may inhibit glucose accumulation in primary cultures of rat hippocampal neurons. Thus, our hypothesis postulates that AA released from the astrocytes during glutamatergic synaptic activity may inhibit glucose uptake by neurons. We observed that cultured neurons express the sodium-vitamin C cotransporter 2 and the facilitative glucose transporters (GLUT) 1 and 3, however, in hippocampal brain slices GLUT3 was the main transporter detected. Functional activity of GLUTs was confirmed by means of kinetic analysis using 2-deoxy-d-glucose. Therefore, we showed that AA, once accumulated inside the cell, inhibits glucose transport in both cortical and hippocampal neurons in culture. Additionally, we showed that astrocytes are not affected by AA. Using hippocampal slices, we observed that upon blockade of monocarboxylate utilization by alpha-cyano-4-hydroxycinnamate and after glucose deprivation, glucose could rescue neuronal response to electrical stimulation only if AA uptake is prevented. Finally, using a transwell system of separated neuronal and astrocytic cultures, we observed that glutamate can reduce glucose transport in neurons only in presence of AA-loaded astrocytes, suggesting the essential role of astrocyte-released AA in this effect.

  15. Effects of Socio demographic factors on plasma ascorbic acid and alpha tocopherol anti oxidants during pregnancy

    International Nuclear Information System (INIS)

    Sylvester, I.E.; Paul, A.

    2010-01-01

    Objectives: To assess the plasma levels of vitamins C and E at the various stages of pregnancy and to correlate their plasma levels with the socio-demographic factors of pregnant Nigerians. Methodology: The pregnant cases (n=180) were randomly selected according to gestational ages. And the controls (n=20) were non-pregnant women of the same age. Plasma levels of both vitamins were assayed with well established laboratory methods. Results: The mean plasma vitamins C and E in the pregnant cases was lower (by 17-23%) than controls across the three trimesters, p<0.0001. The correlation of vitamin C versus maternal age was significant; r = - 0.59, p<0.05; the mean plasma level of vitamin C declined by 57% as the maternal age increases from 22-37 years. Conclusion: The mean plasma Ascorbic acid and Alpha-tocopherol are reduced during pregnancy and socio-demographic factors have mild effects on the plasma levels of these vitamins. (author)

  16. Review on effects of hydrazine hydrate and L-ascorbic acid on electrical conductivity of graphene

    Science.gov (United States)

    Zainuddin, Mohammad Fiqri; Him, Nik Raikhan Nik; Othman, Nur Hidayati; So'aib, Mohamad Sufian; Abdullah, Wan Fazlida Hanim

    2017-12-01

    Graphene is a 2D carbon-based materials that comprises one atom-thick planar sheets of sp2-bonded carbon atoms making it as the thinnest compound in the world. Its application in electronics devices has been widely investigated because of the high electron density on monochrome graphene sheets. Graphene can be synthesized using top down approach, which involves oxidation of graphite to GO using Staudenmaier or Hummer's methods and subsequently reducing the GO to graphene. The. At the current state of graphene research, the controlled, large scale synthesis of high quality graphene is still remains a challenge. All the methods and raw materials used for graphene synthesis have their advantages and disadvantages. Thus, the purpose of this study is to review the effects of reducing agents particularly, hydrazine hydrate (HH) and L-ascorbic acid (L-AA) on the electrical conductivity of graphene. The review was carried out by comparing characteristic properties of graphene after the reduction process using several equipment such as FTIR, XRD and four-point probe for conductivity.

  17. New composite materials based on alginate and hydroxyapatite as potential carriers for ascorbic acid.

    Science.gov (United States)

    Ilie, Andreia; Ghiţulică, Cristina; Andronescu, Ecaterina; Cucuruz, Andrei; Ficai, Anton

    2016-08-30

    The purpose of this article was to obtain prolonged drug release systems in which the drug (ascorbic acid) to reach intact the target area in an environment that is able to control the administration of the active component by chemical or physiological pathways. As support for drug, it was used a material based on calcium phosphate - hydroxyapatite and a natural polymer - alginate, since it is one of the most investigated composite materials for medical applications due to its positive response to biological testing: bioactivity, biocompatibility and osteoconductivity. Three composites with different ratios between alginate and hydroxyapatite were obtained: (a) Alg/HA/AA 1:1 (the mass ratio between Alg and HA being of 1:1), (b) Alg/HA/AA 1:3 (Alg:HA mass ratio of 1:3) and (c) Alg/HA/AA 3:1 (Alg:HA mass ratio of 3:1). The synthesized materials were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and to observe the drug release process, UV-vis spectroscopy. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Regulation of ascorbic acid metabolism by blue LED light irradiation in citrus juice sacs.

    Science.gov (United States)

    Zhang, Lancui; Ma, Gang; Yamawaki, Kazuki; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Ohta, Satoshi; Kato, Masaya

    2015-04-01

    In the present study, the effects of red and blue LED lights on the accumulation of ascorbic acid (AsA) were investigated in the juice sacs of three citrus varieties, Satsuma mandarin, Valencia orange, and Lisbon lemon. The results showed that the blue LED light treatment effectively increased the AsA content in the juice sacs of the three citrus varieties, whereas the red LED light treatment did not. By increasing the blue LED light intensity, the juice sacs of the three citrus varieties accumulated more AsA. Moreover, continuous irradiation with blue LED light was more effective than pulsed irradiation for increasing the AsA content in the juice sacs of the three citrus varieties. Gene expression results showed that the modulation of AsA accumulation by blue LED light was highly regulated at the transcription level. The up-regulation of AsA biosynthetic genes (CitVTC1, CitVTC2, CitVTC4, and CitGLDH), AsA regeneration genes (CitMDAR1, CitMDAR2, and CitDHAR) and two GSH-producing genes (CitGR and CitchGR) contributed to these increases in the AsA content in the three citrus varieties. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Seed-mediated grown silver nanoparticles as a colorimetric sensor for detection of ascorbic acid

    Science.gov (United States)

    Rostami, Simindokht; Mehdinia, Ali; Jabbari, Ali

    2017-06-01

    A simple and sensitive approach was demonstrated for detection of ascorbic acid (AA) based on seed-mediated growth of silver nanoparticles (Ag NPs). According to the seeding strategy, silver ions existing in the growth solution were reduced to silver atoms on the surface of silver seeds via redox reaction between silver ions and AA. This process -led to appear an absorption band in near 420 nm owing to the localized surface plasmon resonance peak of the generated Ag NPs. This change in absorption spectra of Ag NPs caused a change in color of the mixture from colorless to yellow. It was found that the changes in absorption intensity at 420 nm have a good relationship with the concentration of AA. Also, detection of AA was achieved through the established colorimetric sensor in the range of 0.25-25 μM with detection limit of 0.054 μM. Moreover, the selectivity of the method was evaluated with considering potential interferences. The method showed high selectivity toward AA rather than potential interferences and coexisted molecules with AA. It was successfully applied for detection and determination of AA in pharmaceutical tablets and commercial lemonade.

  20. Stability of chitosan nanoparticles for L-ascorbic acid during heat treatment in aqueous solution.

    Science.gov (United States)

    Jang, Keum-Il; Lee, Hyeon Gyu

    2008-03-26

    This study investigated the stability and characteristics of L-ascorbic acid (AA)-loaded chitosan (CS) nanoparticles during heat processing in aqueous solutions. AA-loaded CS nanoparticles were prepared by ionic gelation of CS with tripolyphosphate (TPP) anions. The smallest CS nanoparticles (170 nm) were obtained with a CS concentration of 1.5 mg/mL and a TPP concentration of 0.6 mg/mL. As the concentration of AA increased from 0.1 to 0.3 mg/mL, the particle size increased, while the zeta potential decreased, and the encapsulation efficiency of AA remained within a fixed range (10-12%). During heat processing at various temperatures, the size and zeta potential of the particles decreased rapidly in the first 5 min and then slowly fell to the regular range. At the beginning of the release profiles, the burst release-related stability of the surface increased with the temperature. Then, the release of the internal AA was constantly higher with a longer release time. Consequently, it was confirmed that the stability of AA-loaded CS nanoparticles was affected by temperature but that the internal stability was greater than the surface stability. These results demonstrate the stability of CS nanoparticles for AA during heat processing and suggest the possible use of AA-loaded CS nanoparticles to enhance antioxidant effects because of the continuous release of AA from CS nanoparticles in food processing.

  1. Electrochemical determination of ascorbic acid at p-phenylenediamine film-holes modified glassy carbon electrode

    Directory of Open Access Journals (Sweden)

    Olana Bikila Nagasa

    2015-01-01

    Full Text Available In this work the determination of ascorbic acid (AA at glassy carbon electrode (GCE modified with a perforated film produced by reduction of diazonium generated in situ from p-phenylenediamine (PD is reported. Holes were intentionally created in the modifier film by stripping a pre-deposited gold nanoparticles. The modified electrodes were electrochemically characterized by common redox probes: hydroquinone, ferrocyanide and hexamineruthenium(III. The cyclic voltammetric and amperometric response of AA using the modified electrodes was compared with that of bare GCE. The bare GCE showed a linear response to AA in the concentration range of 5 mM to 45 mM with detection limit of 1.656 mM and the modified GCE showed a linear response to AA in the concentration range of 5 μM to 45 μM with detection limit of 0.123 μM. The effect of potential intereferents on amperometric signal of AA at the modified GCE was examined and found to be minimal. The inter-electrode reproducibility, stability, and accuracy were determined. The modified electrode showed excellent inter-electrode reproducibility, accuracy and stability. The modified electrode reported is a promising candidate for use in electroanalysis of AA.

  2. Determination of L-ascorbic acid in Lycopersicon fruits by capillary zone electrophoresis.

    Science.gov (United States)

    Galiana-Balaguer, L; Roselló, S; Herrero-Martínez, J M; Maquieira, A; Nuez, F

    2001-09-15

    This study shows an improved method for the determination of L-ascorbic acid (l-AA) in fruits of Lycopersicon by capillary zone electrophoresis (CZE). Two backgrounds electrolytes (BGEs) have been tested: (i) 400 mM borate at pH 8.0 and 1 x 10(-2)% hexadimethrine bromide, for the separation of Eulycopersicon subgenus species; and (ii) as in BGE(i) but supplemented with 20% (v/v) acetonitrile, for the separation of species of the Eriopersicon subgenus. The present procedures were compared with two routine methods-enzymatic assay and potentiometric titration with 2,6-dichlorophenol-indophenol. While these routine methods presented some difficulties in quantifying l-AA in several Lycopersicon fruits, CZE was successfully applied in all the analyzed samples. The proposed CZE protocols give lower detection limits (<0.4 microg ml(-1)); are cheaper, quicker, and highly reproducible; and can be applied to analyze large series of samples (ca. 50 samples per day) which is utmost importance, not only in screening trials for internal quality and tomato breeding programs, but also in systematic and routine characterization of Lycopersicon fruits. Copyright 2001 Academic Press.

  3. Genetic control of ascorbic acid biosynthesis and recycling in horticultural crops

    Science.gov (United States)

    Mellidou, Ifigeneia; Kanellis, Angelos K.

    2017-07-01

    Ascorbic acid (AsA) is an essential compound present in almost all living organisms that has important functions in several aspects of plant growth and development, hormone signalling, as well as stress defense networks. In recent years, the genetic regulation of AsA metabolic pathways has received much attention due to its beneficial role in human diet. Despite the great variability within species, genotypes, tissues and developmental stages, AsA accumulation is considered to be controlled by the fine orchestration of net biosynthesis, recycling, degradation/oxidation, and/or intercellular and intracellular transport. To date, several structural genes from the AsA metabolic pathways and transcription factors are considered to significantly affect AsA in plant tissues, either at the level of activity, transcription or translation via feedback inhibition. Yet, all the emerging studies support the notion that the steps proceeding through GDP-L-galactose phosphorylase and to a lesser extent through GDP-D-mannose-3,5-epimerase are control points in governing AsA pool size in several species. In this mini review, we discuss the current consensus of the genetic regulation of AsA biosynthesis and recycling, with a focus on horticultural crops. The aspects of AsA degradation and transport are not discussed herein. Novel insights of how this multifaceted trait is regulated are critical to prioritize candidate genes for follow-up studies towards improving the nutritional value of fruits and vegetables.

  4. Transcriptomic analysis reveals the metabolic mechanism of L-ascorbic acid in Ziziphus jujuba Mill.

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    Chunmei eZhang

    2016-02-01

    Full Text Available Chinese jujube (Ziziphus jujuba Mill. is the most economically important member of the Rhamnaceae family and contains a high concentration of ascorbic acid (AsA. To explore the metabolic mechanism of AsA accumulation, we investigated the abundance of AsA in the fruit development stages, the leaf and flower of Z. jujuba cv Junzao, and the mature fruit of one type of wild jujube (Z. jujuba var. spinosa Hu, Yanchuan sour jujube. And the expression patterns of genes involved in AsA biosynthesis, degradation and recycling were analyzed. The result showed that AsA biosynthesis during early fruit development (the enlargement stage is the main reason for jujube high accumulation. The L-galactose pathway plays a predominant role in the biosynthesis of AsA during jujube fruit development, and the genes GMP1, GME1, GGP, and GaLDH involved in the determination of AsA concentration during fruit development and in different genotypes; the myo-inositol pathway along with the genes GME2 and GMP2 in the L-galactose pathway play a compensatory role in maintaining AsA accumulation during the ripening stage. These findings enhance our understanding of the molecular mechanism in regulating AsA accumulation for jujube.

  5. Daytime of Sampling, Tooth-Brushing and Ascorbic Acid Influence Salivary Thiobarbituric Acid Reacting Substances – A Potential Clinical Marker of Gingival Status

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    Július Hodosy

    2005-01-01

    Sialic acid content of saliva is not influenced significantly by any of the investigated factors. Conclusion. TBARS levels in saliva are affected by daytime of sampling, tooth-brushing and ascorbic acid pre-treatment. These results must be considered in clinical research using salivary TBARS levels. Sialic acid seems not to be a major component of TBARS in saliva. Further studies should clarify the molecular compounds of salivary TBARS and uncover the role of oral microbial factors.

  6. Addition of Ascorbic Acid to the Extracellular Environment Activates Lipoplexes of a Ferrocenyl Lipid and Promotes Cell Transfection

    Science.gov (United States)

    Aytar, Burcu S.; Muller, John P. E.; Golan, Sharon; Hata, Shinichi; Takahashi, Hiro; Kondo, Yukishige; Talmon, Yeshayahu; Abbott, Nicholas L.; Lynn, David M.

    2011-01-01

    The level of cell transfection mediated by lipoplexes formed using the ferrocenyl lipid bis(11-ferrocenylundecyl)dimethylammonium bromide (BFDMA) depends strongly on the oxidation state of the two ferrocenyl groups of the lipid (reduced BFDMA generally mediates high levels of transfection, but oxidized BFDMA mediates very low levels of transfection). Here, we report that it is possible to chemically transform inactive lipoplexes (formed using oxidized BFMDA) to “active” lipoplexes that mediate high levels of transfection by treatment with the small-molecule reducing agent ascorbic acid (vitamin C). Our results demonstrate that this transformation can be conducted in cell culture media and in the presence of cells by addition of ascorbic acid to lipoplex-containing media in which cells are growing. Treatment of lipoplexes of oxidized BFDMA with ascorbic acid resulted in lipoplexes composed of reduced BFDMA, as characterized by UV/vis spectrophotometry, and lead to activated lipoplexes that mediated high levels of transgene expression in the COS-7, HEK 293T/17, HeLa, and NIH 3T3 cell lines. Characterization of internalization of DNA by confocal microscopy and measurements of the zeta potentials of lipoplexes suggested that these large differences in cell transfection result from (i) differences in the extents to which these lipoplexes are internalized by cells and (ii) changes in the oxidation state of BFDMA that occur in the extracellular environment (i.e., prior to internalization of lipoplexes by cells). Characterization of lipoplexes by small-angle neutron scattering (SANS) and by cryogenic transmission electron microscopy (cryo-TEM) revealed changes in the nanostructures of lipoplexes upon the addition of ascorbic acid, from aggregates that were generally amorphous, to aggregates with a more extensive multilamellar nanostructure. The results of this study provide guidance for the design of redox-active lipids that could lead to methods that enable spatial

  7. Redox cycles of vitamin E: Hydrolysis and ascorbic acid dependent reduction of 8a-(alkyldioxy)tocopherones

    International Nuclear Information System (INIS)

    Liebler, D.C.; Kaysen, K.L.; Kennedy, T.A.

    1989-01-01

    Oxidation of the biological antioxidant α-tocopherol (vitamin E; TH) by peroxyl radicals yields 8a-(alkyldioxy)tocopherones, which either may hydrolyze to α-tocopheryl quinone (TQ) or may be reduced by ascorbic acid to regenerate TH. To define the chemistry of this putative two-electron TH redox cycle, we studied the hydrolysis and reduction of 8a-[(2,4-dimethyl-1-nitrilopent-2-yl)dioxyl]tocopherone (1) in acetonitrile/buffer mixtures and in phospholipid liposomes. TQ formation in acetonitrile/buffer mixtures, which was monitored spectrophotometrically, declined with increasing pH and could not be detected above pH 4. The rate of TQ formation from 1 first increased with time and then decreased in a first-order terminal phase. Rearrangement of 8a-hydroxy-α-tocopherone (2) to TQ displayed first-order kinetics identical with the terminal phase for TQ formation from 1. Both rate constants increased with decreasing pH. Hydrolysis of 1 in acetonitrile/H 2 18 O yielded [ 18 O]TQ. These observations suggest that 1 loses the 8a-(alkyldioxy) moiety to produce the tocopherone cation (T + ), which hydrolyzes to 2, the TQ-forming intermediate. Incubation of either 1 or 2 with ascorbic acid in acetonitrile/buffer yielded TH. Reduction of both 1 and 2 decreased with increasing pH. In phosphatidylcholine liposomes at pH 7, approximately 10% of the T + generated from 1 was reduced to TH by 5 mM ascorbic acid. The results collectively demonstrate that T + is the ascorbic acid reducible intermediate in a two-electron TH redox cycle, a process that probably would require biocatalysis to proceed in biological membranes

  8. Transcriptome Profiling of Tomato Fruit Development Reveals Transcription Factors Associated with Ascorbic Acid, Carotenoid and Flavonoid Biosynthesis

    Science.gov (United States)

    Ye, Jie; Hu, Tixu; Yang, Congmei; Li, Hanxia; Yang, Mingze; Ijaz, Raina; Ye, Zhibiao; Zhang, Yuyang

    2015-01-01

    Tomato (Solanum lycopersicum) serves as a research model for fruit development; however, while it is an important dietary source of antioxidant nutrients, the transcriptional regulation of genes that determine nutrient levels remains poorly understood. Here, the transcriptomes of fruit at seven developmental stages (7, 14, 21, 28, 35, 42 and 49 days after flowering) from two tomato cultivars (Ailsa Craig and HG6-61) were evaluated using the Illumina sequencing platform. A total of 26,397 genes, which were expressed in at least one developmental stage, were detected in the two cultivars, and the expression patterns of those genes could be divided into 20 groups using a K-mean cluster analysis. Gene Ontology term enrichment analysis indicated that genes involved in RNA regulation, secondary metabolism, hormone metabolism and cell wall metabolism were the most highly differentially expressed genes during fruit development and ripening. A co-expression analysis revealed several transcription factors whose expression patterns correlated with those of genes associated with ascorbic acid, carotenoid and flavonoid biosynthesis. This transcriptional correlation was confirmed by agroinfiltration mediated transient expression, which showed that most of the enzymatic genes in the ascorbic acid biosynthesis were regulated by the overexpression of each of the three transcription factors that were tested. The metabolic dynamics of ascorbic acid, carotenoid and flavonoid were investigated during fruit development and ripening, and some selected transcription factors showed transcriptional correlation with the accumulation of ascorbic acid, carotenoid and flavonoid. This transcriptome study provides insight into the regulatory mechanism of fruit development and presents candidate transcription factors involved in secondary metabolism. PMID:26133783

  9. Glassy carbon electrodes modified with multiwalled carbon nanotubes for the determination of ascorbic acid by square-wave voltammetry

    Directory of Open Access Journals (Sweden)

    Sushil Kumar

    2012-05-01

    Full Text Available Multiwalled carbon nanotubes were used to modify the surface of a glassy carbon electrode to enhance its electroactivity. Nafion served to immobilise the carbon nanotubes on the electrode surface. The modified electrode was used to develop an analytical method for the analysis of ascorbic acid (AA by square-wave voltammetry (SWV. The oxidation of ascorbic acid at the modified glassy carbon electrode showed a peak potential at 315 mV, about 80 mV lower than that observed at the bare (unmodified electrode. The peak current was about threefold higher than the response at the bare electrode. Replicate measurements of peak currents showed good precision (3% rsd. Peak currents increased with increasing ascorbic acid concentration (dynamic range = 0.0047–5.0 mmol/L and displayed good linearity (R2 = 0.994. The limit of detection was 1.4 μmol/L AA, while the limit of quantitation was 4.7 μmol/L AA. The modified electrode was applied to the determination of the amount of ascorbic acid in four brands of commercial orange-juice products. The measured content agreed well (96–104% with the product label claim for all brands tested. Recovery tests on spiked samples of orange juice showed good recovery (99–104%. The reliability of the SWV method was validated by conducting parallel experiments based on high-performance liquid chromatography (HPLC with absorbance detection. The observed mean AA contents of the commercial orange juice samples obtained by the two methods were compared statistically and were found to have no significant difference (P = 0.05.

  10. A pulse radiolysis study of the dynamics of ascorbic acid free radicals within a liposomal environment.

    Science.gov (United States)

    Kobayashi, Kazuo; Seike, Yumiko; Saeki, Akinori; Kozawa, Takahiro; Takeuchi, Fusako; Tsubaki, Motonari

    2014-10-06

    The dynamics of free-radical species in a model cellular system are examined by measuring the formation and decay of ascorbate radicals within a liposome with pulse radiolysis techniques. Upon pulse radiolysis of an N2O-saturated aqueous solution containing ascorbate-loaded liposome vesicles, ascorbate radicals are formed by the reaction of OH(·) radicals with ascorbate in unilamellar vesicles exclusively, irrespective of the presence of vesicle lipids. The radicals are found to decay rapidly compared with the decay kinetics in an aqueous solution. The distinct radical reaction kinetics in the vesicles and in bulk solution are characterized, and the kinetic data are analyzed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Fluctuations in phenolic content, ascorbic acid and total carotenoids and antioxidant activity of fruit beverages during storage

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    C. Castro-López

    2016-09-01

    Full Text Available Stability of the total phenolic content, ascorbic acid, total carotenoids and antioxidant activity in eight fruit beverages was analyzed. The influence of storage temperature (4, 8 and 11 °C during the product shelf-life (20 days was evaluated. Pomegranate Juice presented the highest values for antioxidant activity by DPPH·− assay (552.93 ± 6.00 GAE μg mL−1, total carotenoids (3.18 ± 0.11 βCE μg mL−1, and total phenolic content (3967.07 ± 2.47 GAE μg mL−1; while Splash Blend recorded the highest levels of ascorbic acid (607.39 ± 2.13 AAE μg mL−1. The antioxidant capacity was stable at 4 and 8 °C for the first 8 days of storage; while carotenoids and ascorbic acid were slightly degraded through the storage time, possibly due to oxidation and/or reactions with other compounds. The results suggest that the observed variation during testing could be related to storage conditions of the final product.

  12. An evaluation of the antiaging properties of strawberry hydrolysate treatment enriched with L-ascorbic acid applied with microneedle mesotherapy.

    Science.gov (United States)

    Markiewicz, Agata; Zasada, Malwina; Erkiert-Polguj, Anna; Wieckowska-Szakiel, Marzena; Budzisz, Elzbieta

    2018-04-16

    Mature skin is characterized by a loss of elasticity, hyperpigmentation, and dehydration. L-ascorbic acid stimulates the synthesis of collagen type I, inhibits melanogenesis, and helps to maintain correct skin hydration. Combining microneedle mesotherapy with the application of preparations rich in vitamin C results in better therapeutic effects due to the improved absorption of active substances. The study evaluates the effectiveness of the application of strawberry hydrolysate enriched with L-ascorbic acid using microneedle mesotherapy. Seventeen volunteers aged 45-70 years underwent a series of four microneedle mesotherapy treatments with vitamin C serum, performed every 10 days. The 20% L-ascorbic acid solution (pH = 3.5) was prepared immediately before application. After the treatment, the participants gave a subjective assessment of the effectiveness. Cutometer ® was used to measure skin elasticity and firmness, Corneometer ® to measure skin hydration, and Mexameter ® skin tone. The results of the survey showed improvements in skin hydration and elasticity. In vivo studies confirmed the effectiveness of serum and the impact of the active substance on skin firmness and elasticity, the degree of hydration and skin tone. Microneedling with vitamin C improves skin tone, hydratation and firmness, and decreases the visibility of hyperpigmentation. © 2018 Wiley Periodicals, Inc.

  13. Effect of ascorbic acid on fatigue of skeletal muscle fibres in long term cold exposed sprague dawley rats

    International Nuclear Information System (INIS)

    Rashid, A.; Ayub, M.

    2011-01-01

    On exposure to prolonged cold temperature, the body responds for effective heat production both by shivering and non-shivering thermo genesis. Cold exposure increases the production of reactive oxygen species which influence the sarcoplasmic reticulum Ca/sup ++/ release from the skeletal muscles and affect their contractile properties. The role of ascorbic acid supplementation on force of contraction during fatigue of cold exposed skeletal muscles was evaluated in this study. Method: Ninety healthy, male Sprague Dawley rats were randomly divided into three groups of control, cold exposed, and cold exposed with ascorbic acid 500 mg/L supplementation mixed in drinking water. Group II and III were given cold exposure by keeping their cages in ice-filled tubs for 1 hr/day for one month. After one month, the extensor digitorum longus muscle was dissected out and force of contraction during fatigue in the skeletal muscle fibres was analysed on a computerised data acquisition system. Results: The cold exposed group showed a significant delay in the force of contraction during fatigue of skeletal muscle fibres compared to control group. Group III showed easy fatigability and a better force of contraction than the cold exposed group. Conclusions: Ascorbic acid increases the force of contraction and decreases resistance to fatigue in the muscles exposed to chronic cold. (author)

  14. Dietary ascorbic acid normalizes ribosomal efficiency for collagen production in skin of streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Schneir, M.; Imberman, M.; Ramamurthy, N.; Golub, L.

    1987-01-01

    The objective of this study was to quantify the contribution of both ribosome amount and ribosomal efficiency to decreased collagen production in skin of diabetic rats and diabetic rats treated with dietary ascorbic acid. Male Sprague-Dawley rats were distributed equally into the following categories: non-diabetic controls; diabetics; ascorbic acid-treated diabetics. On day-20, all rats were injected with ( 3 H)proline and killed after 2 h. Absolute rate of collagen production, ribosome content, and ribosomal efficiency of collagen production were quantified. Also ribosomal efficiency was quantified for ribosomes in sucrose-gradient fractionated post-mitochondrial supernatants. The results indicate that decreased ribosomal efficiency was responsible for 70% of the decreased collagen production with 30% caused by decreased ribosome content, when measured for total skin or sucrose gradient-isolated ribosomes. At both levels of analysis, ascorbic acid treatment normalized ribosomal efficiency, indicating diabetes-mediated decreased ribosomal efficiency for collagen production is related to a co-translational event, such as procollagen underhydroxylation

  15. Effect of added sugar and ascorbic acid on the anthocyanin content of high pressure processed strawberry juices during storage

    Science.gov (United States)

    Salamon, B.; Farkas, V.; Kenesei, Gy; Dalmadi, I.

    2017-10-01

    Berries have high nutritional value and can be processed in many kinds of ways. Their pigments (anthocyanins, flavonoids, carotenoids) have antioxidant properties, effectively neutralize the health-damaging free radicals. High hydrostatic pressure (HHP) technology is a minimal processing technique which is a promising alternative solution instead of traditional preservation technologies. Low molecular weight materials such as colour pigments are well preserved by application of HHP. However, the effect can be influenced by the composition of the treated food matrix. The available scientific information related to the impact of sugar and ascorbic acid content on the preservation of anthocyanins in the samples is controversial. Thus, the aim of our study was to determine the effect of HHP treatment parameters (pressure, treatment time) on the preservation of the anthocyanin content of strawberry juice supplemented by different amounts of sugar and ascorbic acid. 2n type factorial experimental design was used to evaluate the effect of four factors (refraction index, ascorbic acid, pressure, treatment time) on the residual content of total anthocyanins immediately after HHP treatment and after 21 days storage at room temperature.

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

    International Nuclear Information System (INIS)

    Debler, E.A.; Hashim, A.; Lajtha, A.; Sershen, H.

    1988-01-01

    The inhibition of uptake of [ 3 H]dopamine and [ 3 H]1-methyl-4-phenylpyridine (MPP + ) was examined in mouse striatal synaptosomal preparations. Kinetic analysis indicated that ascorbic acid is a noncompetitive inhibitor of [ 3 H]MPP + uptake. No inhibition of [ 3 H]dopamine uptake is observed. The dopamine uptake blockers, GBR-12909, cocaine, and mazindol strongly inhibit (IC 50 3 H]dopamine and [ 3 H]MPP + transport. Nicotine, its metabolites, and other tobacco alkaloids are weak inhibitors except 4-phenylpyridine and lobeline, which are moderate inhibitors of both [ 3 H]dopamine and [ 3 H]MPP + uptake. These similarities in potencies are in agreement with the suggestion that [ 3 H]MPP + and [ 3 H] 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 [ 3 H]MPP + transport are related to translocation and/or dissociation processes occurring subsequent to the initial binding event

  17. L-ascorbic acid determination in pharmaceutical formulations using a biosensor based on carbon paste modified with crude extract of zucchini (Cucurbita pepo

    Directory of Open Access Journals (Sweden)

    Fatibello-Filho Orlando

    2000-01-01

    Full Text Available A biosensor based on carbon paste modified with crude extract of zucchini (Cucurbita pepo as a source of peroxidase is proposed for determining L-ascorbic acid in pharmaceutical formulations. This enzyme in the presence of hydrogen peroxide catalyses the oxidation of hydroquinone to p-quinone whose electrochemical reduction back to hydroquinone was obtained at peak potential of -0.14V. Thus, when L-ascorbic acid is added to the solution, this acid can reduce chemically p-quinone to hydroquinone and/or reduce hydrogen peroxide, decreasing the peak current obtained proportionally to the increase of its concentration. The recovery of L-ascorbic acid from five samples ranged from 98.1 to 102.1% and a rectilinear calibration curve for L-ascorbic acid concentration from 2.0x10-4 to 5.5x10-3 mol L-1 (r=0.9992 was obtained. The detection limit was 2.2x10-5 mol L-1 and relative standard deviation was < 1.3% for a solution containing 4.0x10-3 mol L-1 L-ascorbic acid, 7.0x10-3 mol L-1 hydroquinone and 2.0x10-4 mol L-1 hydrogen peroxide. The results obtained for L-ascorbic acid in pharmaceutical formulations using the proposed biosensor and those obtained using the Pharmacopeia method are in agreement at the 95 % confidence level.

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

    Directory of Open Access Journals (Sweden)

    JEM Peña

    2008-06-01

    Full Text Available The aim of this study was to evaluate the effects of increasing doses of ascorbic acid (AA and citric flavonoids (quercetin and rutin on the performance and meat quality characteristics of broilers submitted to cyclic heat stress. Four-hundred one-day-old female Ross 308 were housed in 40 battery cages a in temperature controlled room. Treatments consisted of 0, 250, 500, and 1000 g/ton on of AA + citric flavonoids. Birds were fed ad libitum until 32 day of age. Beginning on day 14 post-hatch until the end of the experiment, in order to simulate cyclic heat stress, the temperature inside the room was increased to 32°C for 5 hours, and decreased until reaching the comfort temperature corresponding to the age of the animals. Birds were slaughtered at 33 days of age, and carcass and commercial cuts yields were determined. Thighs and boneless breast samples were collected and frozen for subsequent analyses of pH, cooking loss, shear force, color, and Thiobarbituric Acid Reactive Substances (TBARS. Significant differences (p <0.05 were found for feed efficiency from 1 to 7 days of age, with the best values for the birds fed 0 and 250 g/ton on of AA + citric flavonoids. At the end of the experiment, there were no differences in other performance variables, carcass and parts yields, pH, shear force, color and TBARS. The meat of the birds supplemented with 250 g/ton on of product presented the lowest cooking loss.

  19. Addition of L-ascorbic acid to culture and vitrification media of IVF porcine blastocysts improves survival and reduces HSPA1A levels of vitrified embryos.

    Science.gov (United States)

    Castillo-Martín, Miriam; Yeste, Marc; Soler, Albert; Morató, Roser; Bonet, Sergi

    2015-09-01

    The aim of the present study was to determine the effect of L-ascorbic acid on embryo quality and gene expression of porcine blastocysts after supplementations of in vitro culture medium and/or vitrification-warming media. Embryo quality, in terms of total cell number (TCN), DNA fragmentation and peroxide levels, together with the relative transcript abundance of BCL-2 associated X protein (BAX), BCL2-like 1 (BCL2L1), POU class 5 homeobox 1 (POU5F1) and heat shock protein 70 (HSPA1A), was analysed. In Experiment 1, gene expression and embryo quality of fresh blastocysts were evaluated after culture with or without L-ascorbic acid; no significant differences were observed between the groups. In Experiment 2, blastocysts cultured with or without L-ascorbic acid were vitrified using two different vitrification solutions, supplemented or not with L-ascorbic acid. Supplementation of culture and vitrification media significantly enhanced survival rates and reduced peroxide levels. No significant differences in TCN, DNA fragmentation and BAX, BCL2L1 and POU5F1 expression were found in vitrified blastocysts among experimental groups. Vitrification procedures increase HSPA1A transcript abundance, but this increase was significantly lower in embryos cultured and/or vitrified with L-ascorbic acid. Thus, supplementing culture and/or vitrification media with L-ascorbic acid enhances survival rates of porcine blastocysts, suggesting a relationship with HSPA1A expression.

  20. Ascorbic acid kills Epstein-Barr virus positive Burkitt lymphoma cells and Epstein-Barr virus transformed B-cells in vitro, but not in vivo.

    Science.gov (United States)

    Shatzer, Amber N; Espey, Michael Graham; Chavez, Mayra; Tu, Hongbin; Levine, Mark; Cohen, Jeffrey I

    2013-05-01

    Ascorbic acid has been shown to kill various cancer cell lines at pharmacologic concentrations. We found that Epstein-Barr virus (EBV)-positive Burkitt lymphoma (BL) cells were more susceptible to ascorbic acid-induced cell killing than EBV-negative BL cells or EBV-transformed lymphoblastoid cells (LCLs). Ascorbic acid did not induce apoptosis in any of the tested cells but did induce the production of reactive oxygen species and cell death. Previously, we showed that bortezomib, a proteasome inhibitor, induces cell death in LCLs and EBV-positive BL cells. We found that ascorbic acid is strongly antagonistic for bortezomib-induced cell death in LCLs and EBV-positive BL cells. Finally, ascorbic acid did not prolong survival of severe combined immunodefiency mice inoculated with LCLs either intraperitoneally or subcutaneously. Thus, while ascorbic acid was highly effective at killing EBV-positive BL cells and LCLs in vitro, it antagonized cell killing by bortezomib and was ineffective in an animal model.

  1. Effect of ascorbic acid on iron release from the emulsifier interface and on the oxidative flavor deterioration in fish oil enriched mayonnaise.

    Science.gov (United States)

    Jacobsen, C; Adler-Nissen, J; Meyer, A S

    1999-12-01

    This research examines the effect of ascorbic acid (0-800 ppm) on the sensory perception of mayonnaises containing 16% fish oil and on the levels of iron and copper in the aqueous phase. Ascorbic acid increased the formation of fishy off-flavors in fresh mayonnaise. Simultaneously, the iron concentration increased from below the detection limit (1.8 microM) to 34 microM in the aqueous phase of mayonnaises. Model mayonnaises with various concentrations of egg yolk (1-7% w/w) and ascorbic acid (0-8000 ppm) were prepared. Iron concentrations in the aqueous phase increased with increasing ascorbic acid levels, whereas iron concentrations in the assumed interfacial layer decreased. It is proposed that ascorbic acid is able to complex and reduce Fe(3+) to Fe(2+) from phosvitin in the egg yolk, whereby iron is released from the interface. The ascorbic acid-iron complex subsequently reacts with lipid hydroperoxides, resulting in increased lipid oxidation and in the immediate formation of rancid and fishy off-flavors.

  2. Amperometric microsensor for direct probing of ascorbic acid in human gastric juice

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, Emily A.; Pauliukaite, Rasa; Hocevar, Samo B. [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Ogorevc, Bozidar, E-mail: bogorevc@ki.s [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Smyth, Malcolm R. [National Centre for Sensor Research, School of Chemical Sciences, Dublin City University, Dublin 9 (Ireland)

    2010-09-30

    This article reports on a novel microsensor for amperometric measurement of ascorbic acid (AA) under acidic conditions (pH 2) based on a carbon fiber microelectrode (CFME) modified with nickel oxide and ruthenium hexacyanoferrate (NiO-RuHCF). This sensing layer was deposited electrochemically in a two-step procedure involving an initial galvanostatic NiO deposition followed by a potentiodynamic RuHCF deposition from solutions containing the precursor salts. Several important parameters were examined to characterize and optimize the NiO-RuHCF sensing layer with respect to its current response to AA by using cyclic voltammetry, and scanning electron microscopy-energy dispersive X-ray spectroscopy methods. With the NiO-RuHCF coated CFME, the AA oxidation potential under acidic conditions was shifted to a less positive value for about 0.2 V (E{sub p} of ca. 0.23 V vs. Ag/AgCl) as compared to a bare CFME, which greatly improves the electrochemical selectivity. Using the hydrodynamic amperometry mode, the current vs. AA concentration in 0.01 M HCl, at a selected operating potential of 0.30 V, was found to be linear over a wide range of 10-1610 {mu}M (n = 22, r = 0.999) with a calculated limit of detection of 1.0 {mu}M. The measurement repeatability was satisfactory with a relative standard deviation (r.s.d.) ranging from 4% to 5% (n = 6), depending on the AA concentration, and with a sensor-to-sensor reproducibility (r.s.d.) of 6.9% at 100 {mu}M AA. The long-term reproducibility, using the same microsensor for 112 consecutive measurements of 20 {mu}M AA over 11 h of periodic probing sets over 4 days, was 16.1% r.s.d., thus showing very good stability at low AA levels and suitability for use over a prolonged period of time. Moreover, using the proposed microsensor, additionally coated with a protective cellulose acetate membrane, the calibration plot obtained in the extremely complex matrix of real undiluted gastric juice was linear from 10 to 520 {mu}M (n = 14, r = 0

  3. Amperometric microsensor for direct probing of ascorbic acid in human gastric juice

    International Nuclear Information System (INIS)

    Hutton, Emily A.; Pauliukaite, Rasa; Hocevar, Samo B.; Ogorevc, Bozidar; Smyth, Malcolm R.

    2010-01-01

    This article reports on a novel microsensor for amperometric measurement of ascorbic acid (AA) under acidic conditions (pH 2) based on a carbon fiber microelectrode (CFME) modified with nickel oxide and ruthenium hexacyanoferrate (NiO-RuHCF). This sensing layer was deposited electrochemically in a two-step procedure involving an initial galvanostatic NiO deposition followed by a potentiodynamic RuHCF deposition from solutions containing the precursor salts. Several important parameters were examined to characterize and optimize the NiO-RuHCF sensing layer with respect to its current response to AA by using cyclic voltammetry, and scanning electron microscopy-energy dispersive X-ray spectroscopy methods. With the NiO-RuHCF coated CFME, the AA oxidation potential under acidic conditions was shifted to a less positive value for about 0.2 V (E p of ca. 0.23 V vs. Ag/AgCl) as compared to a bare CFME, which greatly improves the electrochemical selectivity. Using the hydrodynamic amperometry mode, the current vs. AA concentration in 0.01 M HCl, at a selected operating potential of 0.30 V, was found to be linear over a wide range of 10-1610 μM (n = 22, r = 0.999) with a calculated limit of detection of 1.0 μM. The measurement repeatability was satisfactory with a relative standard deviation (r.s.d.) ranging from 4% to 5% (n = 6), depending on the AA concentration, and with a sensor-to-sensor reproducibility (r.s.d.) of 6.9% at 100 μM AA. The long-term reproducibility, using the same microsensor for 112 consecutive measurements of 20 μM AA over 11 h of periodic probing sets over 4 days, was 16.1% r.s.d., thus showing very good stability at low AA levels and suitability for use over a prolonged period of time. Moreover, using the proposed microsensor, additionally coated with a protective cellulose acetate membrane, the calibration plot obtained in the extremely complex matrix of real undiluted gastric juice was linear from 10 to 520 μM (n = 14, r = 0.998). These

  4. The effect of long term administration of ascorbic acid on the learning and memory deficits induced by diabetes in rat

    Directory of Open Access Journals (Sweden)

    Parisa Hasanein

    2010-04-01

    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:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; 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: Ascorbic acid improves cognitive impairments in several experimental models. Diabetes causes learning and memory deficits. In this study we hypothesized that chronic treatment with ascorbic acid (100mg/kg, p.o would affect on the passive avoidance learning (PAL and memory in control and streptozocin-induced diabetic rats."n"nMethods: Diabetes was induced by a single i.p. injection of STZ (60mg/kg. The rats were considered diabetic if plasma glucose levels exceeded 250mg/dl on three days after STZ injection. Treatment was begun at the onset of hyperglycemia. PAL was assessed 30 days later. Retention test was done 24 h after training. At the end, animals were weighted and blood samples were drawn for plasma glucose measurement."n"nResults: Diabetes caused impairment in acquisition and retrieval processes of PAL and memory in rats. Ascorbic acid treatment improved learning and memory in control rats and reversed learning and memory deficits in diabetic rats. Ascorbic acid administration also improved the body weight loss and hyperglycemia of diabetics. Hypoglycemic and antioxidant properties of the vitamin may be involved in the memory improving effects of such treatment."n"nConclusion: These results show that

  5. Inhibition of iron-catalyzed oxidations by attainable uric acid and ascorbic acid levels: therapeutic implications for Alzheimer's disease and late cognitive impairment.

    Science.gov (United States)

    Waugh, William H

    2008-01-01

    Alzheimer's disease (AD) has become one of the major health problems of the developed world. Previous studies have shown that oxidant-induced changes occur in cerebral tissue in AD and in late-onset amnestic mild cognitive impairment. The oxidative damage begins early and involves free radical-mediated effects that cause lipid peroxidations and oxidative protein and nucleic acid damages which begin before the cardinal neuropathologic manifestations. Impaired cerebral iron homeostasis and iron accumulation are postulated to be primary and seminal in the pathogenesis. To demonstrate that the Fenton reaction involving hydrogen peroxide and iron at very low concentrations as has been found in human plasma and cerebrospinal fluid may produce promptly oxidations which may be inhibited by preventive use of uric acid and ascorbic acid as hydrophilic antioxidants. A photometric study in vitro at physiologic pH using concentrations of uric acid and ascorbic acid readily attainable in human extracellular fluids. Uric acid levels of 0.5 and 6.0 mg/dl (below the saturation level for urate precipitation) and ascorbic acid at a level readily attainable in blood plasma inhibited significantly and completely, respectively, oxidations caused by reactions of 20 microM concentrations of hydrogen peroxide with free bivalent iron at 9.8 muM and at a low hemoglobin level of 12 mg/dl of saline. Results suggest that supplemental use orally of ascorbic acid combined with use of metabolic precursor to uric acid, like inosine or hypoxanthine, has the potential for preventing or attenuating the progression of AD and amnestic mild cognitive impairment. Copyright 2008 S. Karger AG, Basel.

  6. Ascorbic acid attenuates endothelial permeability triggered by cell-free hemoglobin.

    Science.gov (United States)

    Kuck, Jamie L; Bastarache, Julie A; Shaver, Ciara M; Fessel, Joshua P; Dikalov, Sergey I; May, James M; Ware, Lorraine B

    2018-01-01

    Increased endothelial permeability is central to shock and organ dysfunction in sepsis but therapeutics targeted to known mediators of increased endothelial permeability have been unsuccessful in patient studies. We previously reported that cell-free hemoglobin (CFH) is elevated in the majority of patients with sepsis and is associated with organ dysfunction, poor clinical outcomes and elevated markers of oxidant injury. Others have shown that Vitamin C (ascorbate) may have endothelial protective effects in sepsis. In this study, we tested the hypothesis that high levels of CFH, as seen in the circulation of patients with sepsis, disrupt endothelial barrier integrity. Human umbilical vein endothelial cells (HUVEC) were grown to confluence and treated with CFH with or without ascorbate. Monolayer permeability was measured by Electric Cell-substrate Impedance Sensing (ECIS) or transfer of 14 C-inulin. Viability was measured by trypan blue exclusion. Intracellular ascorbate was measured by HPLC. CFH increased permeability in a dose- and time-dependent manner with 1 mg/ml of CFH increasing inulin transfer by 50% without affecting cell viability. CFH (1 mg/ml) also caused a dramatic reduction in intracellular ascorbate in the same time frame (1.4 mM without CFH, 0.23 mM 18 h after 1 mg/ml CFH, p < 0.05). Pre-treatment of HUVECs with ascorbate attenuated CFH induced permeability. CFH increases endothelial permeability in part through depletion of intracellular ascorbate. Supplementation of ascorbate can attenuate increases in permeability mediated by CFH suggesting a possible therapeutic approach in sepsis. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Morphology-dependent Electrochemical Enhancements of Porous Carbon as Sensitive Determination Platform for Ascorbic Acid, Dopamine and Uric Acid

    Science.gov (United States)

    Cheng, Qin; Ji, Liudi; Wu, Kangbing; Zhang, Weikang

    2016-02-01

    Using starch as the carbon precursor and different-sized ZnO naoparticles as the hard template, a series of porous carbon materials for electrochemical sensing were prepared. Experiments of scanning electron microscopy, transmission electron microscopy and Nitrogen adsorption-desorption isotherms reveal that the particle size of ZnO has big impacts on the porous morphology and surface area of the resulting carbon materials. Through ultrasonic dispersion of porous carbon and subsequent solvent evaporation, different sensing interfaces were constructed on the surface of glassy carbon electrode (GCE). The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) were studied. On the surface of porous carbon materials, the accumulation efficiency and electron transfer ability of AA, DA and UA are improved, and consequently their oxidation signals enhance greatly. Moreover, the interface enhancement effects of porous carbon are also controlled by the particle size of hard template. The constructed porous carbon interface displays strong signal amplification ability and holds great promise in constructing a sensitive platform for the simultaneous determination of AA, DA and UA.

  8. Determination of dopamine in presence of ascorbic acid and uric acid using poly (Spands Reagent) modified carbon paste electrode.

    Science.gov (United States)

    Veera Manohara Reddy, Y; Prabhakara Rao, V; Vijaya Bhaskar Reddy, A; Lavanya, M; Venu, M; Lavanya, M; Madhavi, G

    2015-12-01

    In this paper, we have fabricated a modified carbon paste electrode (CPE) by electropolymerisation of spands reagent (SR) onto surface of CPE using cyclic voltammetry (CV). The developed electrode was abbreviated as poly(SR)/CPE and the surface morphology of the modified electrode was studied by using scanning electron microscopy (SEM). The developed electrode showed higher electrocatalytic properties towards the detection of dopamine (DA) in 0.1M phosphate buffer solution (PBS) at pH7.0. The effect of pH, scan rate, accumulation time and concentration of dopamine was studied at poly(SR)/CPE. The poly(SR)/CPE was successfully used as a sensor for the selective determination of DA in presence of ascorbic acid (AA) and uric acid (UA) without any interference. The poly(SR)/CPE showed a good detection limit of 0.7 μM over the linear dynamic range of 1.6 μM to 16 μM, which is extremely lower than the reported methods. The prepared poly(SR)/CPE exhibited good stability, high sensitivity, better reproducibility, low detection limit towards the determination of DA. The developed method was also applied for the determination of DA in real samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Functionalized-graphene modified graphite electrode for the selective determination of dopamine in presence of uric acid and ascorbic acid.

    Science.gov (United States)

    Mallesha, Malledevaru; Manjunatha, Revanasiddappa; Nethravathi, C; Suresh, Gurukar Shivappa; Rajamathi, Michael; Melo, Jose Savio; Venkatesha, Thimmappa Venkatarangaiah

    2011-06-01

    Graphene is chemically synthesized by solvothermal reduction of colloidal dispersions of graphite oxide. Graphite electrode is modified with functionalized-graphene for electrochemical applications. Electrochemical characterization of functionalized-graphene modified graphite electrode (FGGE) is carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The behavior of FGGE towards ascorbic acid (AA), dopamine (DA) and uric acid (UA) has been investigated by CV, differential pulse voltammetry (DPV) and chronoamperommetry (CA). The FGGE showed excellent catalytic activity towards electrochemical oxidation of AA, DA and UA compared to that of the bare graphite electrode. The electrochemical oxidation signals of AA, DA and UA are well separated into three distinct peaks with peak potential separation of 193mv, 172mv and 264mV between AA-DA, DA-UA and AA-UA respectively in CV studies and the corresponding peak potential separations in DPV mode are 204mv, 141mv and 345mv. The FGGE is successfully used for the simultaneous detection of AA, DA and UA in their ternary mixture and DA in serum and pharmaceutical samples. The excellent electrocatalytic behavior of FGGE may lead to new applications in electrochemical analysis. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Graphitic carbon nitride nanosheets doped graphene oxide for electrochemical simultaneous determination of ascorbic acid, dopamine and uric acid

    International Nuclear Information System (INIS)

    Zhang, Hanqiang; Huang, Qitong; Huang, Yihong; Li, Feiming; Zhang, Wuxiang; Wei, Chan; Chen, Jianhua; Dai, Pingwang; Huang, Lizhang; Huang, Zhouyi; Kang, Lianping; Hu, Shirong; Hao, Aiyou

    2014-01-01

    Graphical abstract: Schematic drawing of electrochemical oxidize AA, DA and UA on graphitic carbon nitride nanosheets-graphene oxide composite modified electrode. - Highlights: • Synthesize g-C 3 N 4 , GO and CNNS-GO composite. • CNNS-GO composite was the first time for simultaneous determination of AA, DA and UA. • CNNS-GO/GCE displays fantastic selectivity and sensitivity for AA, DA and UA. • CNNS-GO/GCE was applied to detect real sample with satisfactory results. - Abstract: Graphitic carbon nitride nanosheets with a graphite-like structure have strong covalent bonds between carbon and nitride atoms, and nitrogen atoms in the carbon architecture can accelerate the electron transfer and enhance electrical properties effectually. The graphitic carbon nitride nanosheets-graphene oxide composite was synthesized. And the electrochemical performance of the composite was investigated by cyclic voltammetry and differential pulse voltammetry ulteriorly. Due to the synergistic effects of layer-by-layer structures by π-π stacking or charge-transfer interactions, graphitic carbon nitride nanosheets-graphene oxide composite can improved conductivity, electro-catalytic and selective oxidation performance. The proposed graphitic carbon nitride nanosheets-graphene oxide composite modified electrode was employed for simultaneous determination of ascorbic acid, dopamine and uric acid in their mixture solution, it exhibited distinguished sensitivity, wide linear range and low detection limit. Moreover, the modified electrode was applied to detect urine and dopamine injection sample, and then the samples were spiked with certain concentration of three substances with satisfactory recovery results

  11. Oxidation and sensing of ascorbic acid and dopamine on self-assembled gold nanoparticles incorporated within polyaniline film

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Wenya [College of Chemistry, Chemical Engineering and Materials Science, and Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, Soochow University, Suzhou 215123 (China); Zhou, Qun, E-mail: zhq@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, and Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, Soochow University, Suzhou 215123 (China); Li, Shuangshuang [College of Chemistry, Chemical Engineering and Materials Science, and Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, Soochow University, Suzhou 215123 (China); College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006 (China); Zhao, Wei; Li, Na [College of Chemistry, Chemical Engineering and Materials Science, and Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, Soochow University, Suzhou 215123 (China); Zheng, Junwei, E-mail: jwzheng@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, and Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou, Soochow University, Suzhou 215123 (China); College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006 (China)

    2015-10-30

    Highlights: • Gold nanoparticles assembled on electrodes are incorporated into polyaniline film. • Composite film electrodes exhibit synergistic effect on electrocatalytic oxidation. • Ascorbic acid and dopamine can be detected simultaneously on composite electrodes. - Abstract: Electrochemical biosensors based on conducting polymers incorporated with metallic nanoparticles can greatly enhance sensitivity and selectivity. Herein, we report a facile fabrication approach for polyaniline (PAN) incorporated with a gold nanoparticle (AuNP) composite electrode by electrodeposition of PAN on a self-assembled AuNP layer on the surface of an indium tin oxide electrode. The resulting AuNP/PAN composite electrode exhibits a remarkable synergistic effect on the electrocatalytic oxidation of ascorbic acid (AA) and dopamine (DA). It is demonstrated that the oxidation reaction of AA mainly occurs at AuNPs inside the PAN film as the ascorbate anions are doped into the polymer during the oxidation of the PAN film. Conversely, the oxidation of positively charged DA may only take place at the PAN/solution interface. The different mechanisms of the electrode reactions result in the oxidation of AA and DA occurring at different potentials. As a result, the AuNP/PAN composite electrode can be employed to simultaneously detect AA and DA with a good linear range, high sensitivity, and low detection limit.

  12. Oxidation and sensing of ascorbic acid and dopamine on self-assembled gold nanoparticles incorporated within polyaniline film

    International Nuclear Information System (INIS)

    Chu, Wenya; Zhou, Qun; Li, Shuangshuang; Zhao, Wei; Li, Na; Zheng, Junwei

    2015-01-01

    Highlights: • Gold nanoparticles assembled on electrodes are incorporated into polyaniline film. • Composite film electrodes exhibit synergistic effect on electrocatalytic oxidation. • Ascorbic acid and dopamine can be detected simultaneously on composite electrodes. - Abstract: Electrochemical biosensors based on conducting polymers incorporated with metallic nanoparticles can greatly enhance sensitivity and selectivity. Herein, we report a facile fabrication approach for polyaniline (PAN) incorporated with a gold nanoparticle (AuNP) composite electrode by electrodeposition of PAN on a self-assembled AuNP layer on the surface of an indium tin oxide electrode. The resulting AuNP/PAN composite electrode exhibits a remarkable synergistic effect on the electrocatalytic oxidation of ascorbic acid (AA) and dopamine (DA). It is demonstrated that the oxidation reaction of AA mainly occurs at AuNPs inside the PAN film as the ascorbate anions are doped into the polymer during the oxidation of the PAN film. Conversely, the oxidation of positively charged DA may only take place at the PAN/solution interface. The different mechanisms of the electrode reactions result in the oxidation of AA and DA occurring at different potentials. As a result, the AuNP/PAN composite electrode can be employed to simultaneously detect AA and DA with a good linear range, high sensitivity, and low detection limit.

  13. Effects of GA3, BA, Thiamine and Ascorbic Acid on Some Morphological and Biochemical Characteristics of Periwinkle (Catharanthus roseus L.

    Directory of Open Access Journals (Sweden)

    F. Baniasadi

    2016-07-01

    Full Text Available Introduction: Catharanthus roseus (L. belongs to Apocynaceae family is an important medicinal plant and also cultivated as an ornamental plant almost throughout the tropical and subtropical areas all over the world. Recently, the uses of natural substances are considered very helpful to improve plant growth and development. Application of plant growth regulators (PGRs and vitamins are reported in many horticultural crops. Ascorbic acid is the most abundant antioxidant in plant which protects plant cells. This substance affects cell differentiation and growth. Now a day it is considered as a plant growth regulator. Thiamine or vitamin B1 is water soluble and one of the B complex vitamins. This study was conducted to investigate the effect of the ascorbic acid, thiamine, BA and GA on growth and biochemical parameters of periwinkle. Materials and Methods: The experiment was perform as a completely randomized design with 5 replications at research greenhouse of Shahid Bahonar University of Kerman in 2014.The treatments used include spraying water (control, ascorbic acid 100 mg.l-1, gibberellic acid 100 mg.l-1, thiamine 100 mg.l-1, BA 200 mg. l-1 and combinations of two, three and four of them to determine the response of plants to these substances alone or in combination of them. When the seedlings become on 6-leavs stage, the first foliar spray was carried out. In other two steps was repeated with interval of 10 days. In this study, longevity of the flower, flower diameter, the number of lateral branches, branches length, fresh and dry weight, chlorophyll content and reduced sugars were measured. Chlorophyll content and reduced sugars were measured according to method of Somogy (1952 and Lichtenthder (1987, respectively. Results and Discussion: The results showed that the effect of thiamine on the number of flowers was more pronounced than other substances. The lowest number of flowers per plant was found in plants treated with gibberellic acid

  14. A glassy carbon electrode modified with a nickel(II) norcorrole complex and carbon nanotubes for simultaneous or individual determination of ascorbic acid, dopamine, and uric acid

    International Nuclear Information System (INIS)

    Deng, Keqin; Li, Xiaofang; Huang, Haowen

    2016-01-01

    The authors report on the synthesis of a hybrid material consisting of the porphyrinoid metal complex nickel(II) norcorrole that was noncovalently bound to carbon nanotubes (CNT-NiNC). The hybrid was characterized by UV–vis, FTIR spectroscopy, and thermogravimetric analysis. The CNT-NiNC hybrid possesses high catalytic activity and selectivity toward the oxidation of ascorbic acid, dopamine, and uric acid. It was used to modify a glassy carbon electrode which then is shown to enable simultaneous or individual determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) at pH 6.5 and typical working potentials of −70, 200 and 380 mV (vs. SCE). The detection limits (at an SNR of 3) are 2.0 μM for AA, 0.1 μM for DA, and 0.4 μM for UA. (author)

  15. Modulatory effect of ascorbic acid on physiological responses of transported ostrich chicks

    Directory of Open Access Journals (Sweden)

    Minka N. Salka

    2012-02-01

    Full Text Available The aims of this study were to determine the modulating role of ascorbic acid (AA on rectal temperature (RT, heterophil to lymphocyte (H to L ratio and aberrant behaviours of ostrich chicks transported by road for 4 h during hot-dry conditions. Twenty ostrich chicks aged 2.5 months, of both sexes and belonging to the Red Neck breed, served as subjects of the study. The chicks were assigned randomly to AA-treated and control groups, consisting of 10 chicks each. The AA-treated group was administered orally with 100 mg/kg body weight of AA dissolved in 5 mL of sterile water 30 min before transportation, whilst the control group was given the equivalent of sterile water only. The thermal load (TL experienced in the vehicle during transportation fluctuated between 31 °C and 89 °C, as calculated from the ambient temperature and relative humidity. Transportation induced hyperthermia, lymphopenia, heterophilia and aberrant behaviours of pecking, wing fluffing and panting, which were ameliorated by AA administration. The relationships between the TL, journey duration and physiological variables of RT, H to L ratio and aberrant behaviours recorded during transportation were significantly and positively correlated in the control group. In AA-treated group the relationships were not significantly correlated. In conclusion, the results showed for the first time that AA ameliorated the adverse effects of stress caused by road transportation on the aberrant behaviours, RT and H to L ratio of ostrich chicks during the hot-dry season.

  16. Ozone tolerance in snap bean is associated with elevated ascorbic acid in the leaf apoplast

    Energy Technology Data Exchange (ETDEWEB)

    Burkey, K.O. [North Carolina State Univ., United States Dept. of 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)

    2002-03-01

    Ascorbic acid (AA) in the leaf apoplast has the potential to limit ozone injury by participating in reactions that detoxify ozone and reactive oxygen intermediates and thus prevent plasma membrane damage. Genotypes of snap bean (Phaseolus vulgaris L) were compared in controlled environments and in open-top field chambers to assess the relationship between extracellular AA content and ozone tolerance. Vacuum infiltration methods were employed to separate leaf AA into extracellular and intracellular fractions. For plants grown in controlled environments at low ozone concentration (4 nmol mol{sup -1} ozone), leaf apoplast AA was significantly higher in tolerant genotypes (300-400 nmol g{sup -1} FW) compared with sensitive genotypes (approximately 50 nmol g{sup -1} FW), evidence that ozone tolerance is associated with elevated extracellular AA. For the open top chamber study, plants were grown in pots under charcoal-filtered air (CF) conditions and then either maintained under CF conditions (29 nmol mol{sup -1} ozone) or exposed to elevated ozone (67 nmol mol{sup -1} ozone). Following an 8-day treatment period, leaf apoplast AA was in the range of 100-190 nmol g{sup -1} FW for all genotypes, but no relationship was observed between apoplast AA content and ozone tolerance. The contrasting results in the two studies demonstrated a potential limitation in the interpretation of extracellular AA data. Apoplast AA levels presumably reflect the steady-state condition between supply from the cytoplasm and utilization within the cell wall. The capacity to detoxify ozone in the extracellular space may be underestimated under elevated ozone conditions where the dynamics of AA supply and utilization are not adequately represented by a steady-state measurement. (au)

  17. Novel Spectrophotometric Methods for Determination of Salicylamide and Ascorbic acid in their binary mixture

    International Nuclear Information System (INIS)

    Ali, N.W.; Zaazaa, H.E.S.; Abdelrahman, M.M.

    2014-01-01

    Simple, selective and precise four spectrophotometric methods were developed and validated for quantitative determination of Salicylamide (SAD) and Ascorbic acid (ASC, Vitamin C) in their binary mixture. Method A is Area under curve spectrophotometry, in which the area under curve in the wavelength ranges 225-245 nm and 265-285 nm were selected for determination of SAD and ASC. Method B is based on dual wavelength spectrophotometry, where ASC can be determined by difference in absorbance at 249.8 and 285.8 nm. On the same way; SAD is measured by difference in absorbance at 240.4 and 286.4 nm. Method C utilizes isoabsorptive point spectrophotometry where total concentration of SAD and ASC was calculated at their isoabsorptive points at 246.4 and 287 nm, while SAD concentration alone can be determined by first derivative spectrophotometry (1D) at 315.4 nm, then ASC concentration can be determined by subtraction. Method D is ratio subtraction spectrophotometry, where ASC can be determined by dividing the spectrum of the mixture by the spectrum of the SAD (as a divisor) followed by subtracting the constant absorbance value of the plateau region, then finally multiplying the obtained spectrum by the spectrum of the divisor. The developed methods have been successfully applied for determination of the studied drugs in different laboratory prepared mixtures and in their pharmaceutical formulation. Statistical comparison between the results obtained by applying the proposed methods and the reported HPLC method was done, and it was found that there was no significant difference between them regarding both accuracy and precision. (author)

  18. Melatonin combined with ascorbic acid provides salt adaptation in Citrus aurantium L. seedlings.

    Science.gov (United States)

    Kostopoulou, Zacharoula; Therios, Ioannis; Roumeliotis, Efstathios; Kanellis, Angelos K; Molassiotis, Athanassios

    2015-01-01

    Ascorbic acid (AsA) and melatonin (Mel) are known molecules participating in stress resistance, however, their combined role in counteracting the impact of salinity in plants is still unknown. In this work the effect of exogenous application of 0.50 mΜ AsA, 1 μΜ Mel and their combination (AsA + Mel) on various stress responses in leaves and roots of Citrus aurantium L. seedlings grown under 100 mΜ NaCl for 30 days was investigated. Application of AsA, Mel or AsA + Mel to saline solution decreased NaCl-induced electrolyte leakage and lipid peroxidation and prevented NaCl-associated toxicity symptoms and pigments degradation. Also, leaves exposed to combined AsA + Mel treatment displayed lower Cl(-) accumulation. Treatments with AsA and/or Mel modulated differently carbohydrates, proline, phenols, glutathione and the total antioxidant power of tissues as well as the activities of SOD, APX, POD, GR and PPO compared to NaCl alone treatment. Exposure of leaves and roots to chemical treatments and especially to combined AsA and Mel application was able to regulate CaMIPS, CaSLAH1 and CaMYB73 expression, indicating that sugar metabolism, ion homeostasis and transcription regulation were triggered by AsA and Mel. These results provide evidence that the activation of the metabolic pathways associated with combined AsA and Mel application are linked with salt adaptation in citrus plants. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

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

    DEFF Research Database (Denmark)

    Zhou, A; Farver, O; Thorn, N A

    1991-01-01

    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...

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

    DEFF Research Database (Denmark)

    Zhou, A; Farver, O; Thorn, N A

    1991-01-01

    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...... contained a fairly low concentration of iron but a high concentration of copper....

  1. Application of Haar and Mexican hat wavelets to double divisor-ratio spectra for the multicomponent determination of ascorbic acid, acetylsalicylic acid and paracetamol in effervescent tablets

    OpenAIRE

    Dinç, Erdal; Baleanu, Dumitru

    2008-01-01

    Simultaneous determination of ascorbic acid (AA), acetylsalicylic acid (ASP) and paracetamol (PAR) in their synthetic mixtures and effervescent tablets were performed by Haar and Mexican continuous wavelet transforms (HAAR-CWT and MEXH-CWT, respectively) together with double divisor technique. The signal processing methods are based on the application of HAAR-CWT and MEXH-CWT to the double divisor-ratio spectra (DDRS). These spectra were obtained by dividing the absorption spectra of pure com...

  2. Effect of Oral Coadministration of Ascorbic Acid with Ling Zhi Preparation on Pharmacokinetics of Ganoderic Acid A in Healthy Male Subjects: A Randomized Crossover Study

    Science.gov (United States)

    Tawasri, Patcharanee; Ampasavate, Chadarat; Tharatha, Somsak

    2016-01-01

    The objective of this randomized, open-label, single-dose, two-phase crossover study was to determine the effect of ascorbic acid on pharmacokinetics of ganoderic acid A, an important biologically active triterpenoid compound with anticancer activities, following oral administration of water extract of fruiting bodies of Ling Zhi in 12 healthy male subjects. Each subject was randomized to receive either one of the two regimens: (1) a single dose of 3,000 mg of the Ling Zhi preparation or (2) a single dose of 3,000 mg of the Ling Zhi preparation in combination with 2,500 mg of ascorbic acid. After a washout period of at least two weeks, subjects were switched to receive the alternate regimen. Blood samples were collected in each phase immediately before dosing and at specific time points for 8 hours after dosing. Plasma ganoderic acid A concentrations were quantified using liquid chromatography-mass spectrometry (LC-MS). The pharmacokinetic parameters analyzed were maximal plasma concentration (C max), time to reach peak concentration (T max), area under the plasma concentration-time curve (AUC), and half-life (t 1/2). An oral coadministration of ascorbic acid with Ling Zhi preparation did not significantly alter the pharmacokinetic parameters of ganoderic acid A in healthy male subjects. PMID:27747224

  3. 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)

    2014-01-01

    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 ΔBW or ΔWC. 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. PMID:24886192

  4. 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)

    Larsen, Sofus C; Angquist, Lars; Ahluwalia, Tarunveer Singh; Skaaby, Tea; Roswall, Nina; Tjønneland, Anne; Halkjær, Jytte; Overvad, Kim; Pedersen, Oluf; Hansen, Torben; Linneberg, Allan; Husemoen, Lise Lotte N; Toft, Ulla; Heitmann, Berit L; Sørensen, Thorkild I A

    2014-05-03

    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). 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 ΔBW or ΔWC. SNP-score × ascorbic acid interactions were examined by adding product terms to the models. 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. 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.

  5. Enhancing aspalathin stability in rooibos (Aspalathus linearis) ready-to-drink iced teas during storage: the role of nano-emulsification and beverage ingredients, citric and ascorbic acids.

    Science.gov (United States)

    de Beer, Dalene; Joubert, Elizabeth; Viljoen, Melvi; Manley, Marena

    2012-01-30

    The effects of citric and ascorbic acids on the stability of aspalathin in rooibos (Aspalathus linearis) ready-to-drink (RTD) formulations containing fermented rooibos extract (FR), aspalathin-enriched green rooibos extract (GR) and aspalathin-enriched green rooibos extract ascorbic acid solubilisate (GR-solubilisate) were investigated during storage (12 weeks at 25 °C). Storage of iced tea formulations containing FR and GR extracts reduced their flavonoid content. The aspalathin content of FR iced tea without citric or ascorbic acid was reduced to undetectable levels by week 8 of storage. Addition of citric acid resulted in improved stability of aspalathin, but ascorbic acid did not impart additional stability. Iso-orientin and orientin were less affected than aspalathin, presumably owing to partial conversion of aspalathin to these flavones. Similar results were obtained for GR iced tea formulations. Improved stability of aspalathin was noted in iced tea containing GR-solubilisate with or without citric acid. Lower pH was shown to favour stability, especially for fermented rooibos iced teas. Citric and ascorbic acids contribute to the stability of rooibos flavonoids during storage. Differences in stability between formulations are not due to pH differences but may be related to the matrix. Copyright © 2011 Society of Chemical Industry.

  6. Ascorbic Acid-A Potential Oxidant Scavenger and Its Role in Plant Development and Abiotic Stress Tolerance

    Directory of Open Access Journals (Sweden)

    Nudrat A. Akram

    2017-04-01

    Full Text Available Over-production of reactive oxygen species (ROS in plants under stress conditions is a common phenomenon. Plants tend to counter this problem through their ability to synthesize ROS neutralizing substances including non-enzymatic and enzymatic antioxidants. In this context, ascorbic acid (AsA is one of the universal non-enzymatic antioxidants having substantial potential of not only scavenging ROS, but also modulating a number of fundamental functions in plants both under stress and non-stress conditions. In the present review, the role of AsA, its biosynthesis, and cross-talk with different hormones have been discussed comprehensively. Furthermore, the possible involvement of AsA-hormone crosstalk in the regulation of several key physiological and biochemical processes like seed germination, photosynthesis, floral induction, fruit expansion, ROS regulation and senescence has also been described. A simplified and schematic AsA biosynthetic pathway has been drawn, which reflects key intermediates involved therein. This could pave the way for future research to elucidate the modulation of plant AsA biosynthesis and subsequent responses to environmental stresses. Apart from discussing the role of different ascorbate peroxidase isoforms, the comparative role of two key enzymes, ascorbate peroxidase (APX and ascorbate oxidase (AO involved in AsA metabolism in plant cell apoplast is also discussed particularly focusing on oxidative stress perception and amplification. Limited progress has been made so far in terms of developing transgenics which could over-produce AsA. The prospects of generation of transgenics overexpressing AsA related genes and exogenous application of AsA have been discussed at length in the review.

  7. Perioperative ascorbic acid supplementation does not reduce the incidence of postoperative atrial fibrillation in on-pump coronary artery bypass graft patients.

    Science.gov (United States)

    Antonic, Miha; Lipovec, Robert; Gregorcic, Franc; Juric, Peter; Kosir, Gorazd

    2017-01-01

    Atrial fibrillation is the most common arrhythmia following cardiac surgery. It is associated with increased hemodynamic instability, systemic embolization, and complications linked to anticoagulant therapy. Oxidative stress and consequent electrophysiological remodeling have been proposed as a cause of postoperative atrial fibrillation. Ascorbic acid supplementation was suggested as a novel and effective preventive agent. The aim of this study was to evaluate the capability of ascorbic acid to reduce the incidence of postoperative atrial fibrillation in coronary artery bypass grafting (CABG) patients. A prospective randomized single-center trial was conducted in patients scheduled for an elective on-pump CABG surgery. Subjects in the ascorbic acid group received 2g of ascorbic acid 24h and 2h before the surgery and 1g twice a day for five days after the surgery. Postoperatively, the patients were monitored for atrial fibrillation and other complications. The ascorbic acid group consisted of 52 patients and the control group included 53 patients. The groups were well matched for baseline demographics, preoperative medications, comorbidities, and had similar intraoperative characteristics. The incidence of atrial fibrillation in the ascorbic acid group was 13.5% and 18.9% in the control group (p=0.314). No difference was found between groups in the time of occurrence of atrial fibrillation (3.71±1.89 vs. 2.91±1.58 days after the surgery; p=0.342). There was also no difference in the other observed postoperative complications. The results of this study do not support the effectiveness of ascorbic acid supplementation in reducing the incidence of postoperative atrial fibrillation in elective on-pump CABG patients. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  8. Simultaneous determination of ascorbic, dehydroascorbic, isoascorbic, and dehydroisoascorbic acids in meat-based food products by liquid chromatography with postcolumn fluorescence detection: a method extension.

    Science.gov (United States)

    Ali, M S; Phillippo, E T

    1996-01-01

    A simple and rapid liquid chromatographic (LC) method for determining ascorbic, dehydroascorbic, isoascorbic, and dehydroisoascorbic acids in mostly single-component food products was evaluated for use in analysis of multicomponent meat-based food products such as TV dinners. Ground-beef samples were used as blanks for repeatability studies. Samples were fortified with 5, 10, 20, and 40 ppm of mixed standards of ascorbic acid and isoascorbic acid. Means of 12 recoveries at 4 levels of fortification were 102.5 and 83.5%, respectively, for ascorbic acid and isoascorbic acid, with coefficients of variation of 6.7 and 15.2%, respectively. TV dinner products (21 samples) from a local grocery store were analyzed for vitamin C content. Samples prepared with a commercial food processor and a food grinder were compared. The commercial food processor was more capable than the food grinder in producing a homogeneous sample, which is critical to the method.

  9. Determination of dopamine in presence of ascorbic acid and uric acid using poly (Spands Reagent) modified carbon paste electrode

    Energy Technology Data Exchange (ETDEWEB)

    Veera Manohara Reddy, Y.; Prabhakara Rao, V.; Vijaya Bhaskar Reddy, A.; Lavanya, M.; Venu, M.; Lavanya, M.; Madhavi, G., E-mail: gmchem01@gmail.com

    2015-12-01

    In this paper, we have fabricated a modified carbon paste electrode (CPE) by electropolymerisation of spands reagent (SR) onto surface of CPE using cyclic voltammetry (CV). The developed electrode was abbreviated as poly(SR)/CPE and the surface morphology of the modified electrode was studied by using scanning electron microscopy (SEM). The developed electrode showed higher electrocatalytic properties towards the detection of dopamine (DA) in 0.1 M phosphate buffer solution (PBS) at pH 7.0. The effect of pH, scan rate, accumulation time and concentration of dopamine was studied at poly(SR)/CPE. The poly(SR)/CPE was successfully used as a sensor for the selective determination of DA in presence of ascorbic acid (AA) and uric acid (UA) without any interference. The poly(SR)/CPE showed a good detection limit of 0.7 μM over the linear dynamic range of 1.6 μM to 16 μM, which is extremely lower than the reported methods. The prepared poly(SR)/CPE exhibited good stability, high sensitivity, better reproducibility, low detection limit towards the determination of DA. The developed method was also applied for the determination of DA in real samples. - Highlights: • Electropolymerization of spands reagent was fabricated by cyclic voltammetry • The Poly (spands reagent) electrode shows excellent electrocatalytic activity for the detection of dopamine. • The detection limit for dopamine was found to be 0.7 μM. • The proposed method can be applied for DA in injection and human blood serum samples.

  10. Simultaneous determination of ascorbic acid, dopamine and uric acid using high-performance screen-printed graphene electrode.

    Science.gov (United States)

    Ping, Jianfeng; Wu, Jian; Wang, Yixian; Ying, Yibin

    2012-04-15

    A disposable and sensitive screen-printed electrode using an ink containing graphene was developed. This electrode combined the advantages of graphene and the disposable characteristic of electrode, which possessed wide potential window, low background current and fast electron transfer kinetics. Compared with the electrodes made from other inks, screen-printed graphene electrode (SPGNE) showed excellent electrocatalytic activity for the oxidation of ascorbic acid (AA), dopamine (DA), and uric acid (UA). Three well-defined sharp and fully resolved anodic peaks were found at the developed electrode. Differential pulse voltammetry was used to simultaneous determination of AA, DA, and UA in their ternary mixture. In the co-existence system of these three species, the linear response ranges for the determination of AA, DA, and UA were 4.0-4500 μM, 0.5-2000 μM, and 0.8-2500 μM, respectively. The detection limits (S/N=3) were found to be 0.95 μM, 0.12 μM, and 0.20 μM for the determination of AA, DA, and UA, respectively. Furthermore, the SPGNE displayed high reproducibility and stability for these species determination. The feasibility of the developed electrode for real sample analysis was investigated. Results showed that the SPGNE could be used as a sensitive and selective sensor for simultaneous determination of AA, DA, and UA in biological samples, which may provide a promising alternative in routine sensing applications. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Low Dose Gamma Irradiation Does Not Affect the Quality or Total Ascorbic Acid Concentration of “Sweetheart” Passionfruit (Passiflora edulis

    Directory of Open Access Journals (Sweden)

    John B. Golding

    2015-08-01

    Full Text Available Passionfruit (Passiflora edulis, Sims, cultivar “Sweetheart” were subject to gamma irradiation at levels suitable for phytosanitary purposes (0, 150, 400 and 1000 Gy then stored at 8 °C and assessed for fruit quality and total ascorbic acid concentration after one and fourteen days. Irradiation at any dose (≤1000 Gy did not affect passionfruit quality (overall fruit quality, colour, firmness, fruit shrivel, stem condition, weight loss, total soluble solids level (TSS, titratable acidity (TA level, TSS/TA ratio, juice pH and rot development, nor the total ascorbic acid concentration. The length of time in storage affected some fruit quality parameters and total ascorbic acid concentration, with longer storage periods resulting in lower quality fruit and lower total ascorbic acid concentration, irrespective of irradiation. There was no interaction between irradiation treatment and storage time, indicating that irradiation did not influence the effect of storage on passionfruit quality. The results showed that the application of 150, 400 and 1000 Gy gamma irradiation to “Sweetheart” purple passionfruit did not produce any deleterious effects on fruit quality or total ascorbic acid concentration during cold storage, thus supporting the use of low dose irradiation as a phytosanitary treatment against quarantine pests in purple passionfruit.

  12. The role of salicylic acid, L-ascorbic acid and oxalic acid in promoting the oxidation of alkenes with H(2)O(2) catalysed by [Mn(IV) (2)(O)(3)(tmtacn)(2)](2+)

    NARCIS (Netherlands)

    de Boer, Johannes W.; Alsters, Paul L.; Meetsma, Auke; Hage, Ronald; Browne, Wesley R.; Feringa, Ben L.

    2008-01-01

    The role played by the additives salicylic acid, L-ascorbic acid and oxalic acid in promoting the catalytic activity of [Mn(IV) (2)(O)(3)(tmtacn)(2)](PF(6))(2) {1(PF(6))(2), where tmtacn = N, N ', N ''-trimethyl-1,4,7-triazacyclononane} in the epoxidation and cis-dihydroxylation of alkenes with

  13. Pyruvate diminishes the cytotoxic activity of ascorbic acid in several tumor cell lines in vitro.

    Science.gov (United States)

    Rodemeister, Sandra; Hill, Katharina

    2017-11-25

    The anticancer potential of ascorbic acid (AA) has been controversially discussed for decades. Although the cytotoxic effect of pharmacologic concentrations of ascorbic acid has already been successfully demonstrated in numerous studies in vitro, it could not be verified to the same extent in vivo. We propose that the ubiquitous metabolite pyruvate diminishes the effect of AA by reacting with its presumable cytotoxic mediator hydrogen peroxide (H 2 O 2 ). MTT assays confirm that co-incubation with 1.4 mM pyruvate abolishes the cytotoxic effect of pharmacologic concentrations of AA in all cancer cell lines tested (human melanoma (WM451-Lu), breast (MCF-7) and hypopharyngeal cancer cells (FaDu)). We further investigated whether pyruvate diminishes the anticancer effect of AA by interfering with the generation of H 2 O 2 . Therefore, we analyzed the concentration of AFR, a proposed intermediate in the AA-dependent formation of H 2 O 2, by electron paramagnetic resonance spectroscopy, during incubation with AA and pyruvate in WM451-Lu cells as a model system. In addition, we measured H 2 O 2 concentration by indirect detection with Clark-type oxygen electrode. AFR concentration was not significantly influenced by pyruvate, whereas H 2 O 2 concentration was significantly reduced. In parallel, pyruvate concentrations of the stimulation medium declined with increasing AA and consequently H 2 O 2 concentrations. In summary, pyruvate diminishes the cytotoxic activity of ascorbic acid in vitro. The AFR concentration measured remains unaffected by pyruvate whereas the H 2 O 2 concentration is reduced; confirming that pyruvate directly reacts with AA-induced H 2 O 2 , without influencing its formation. However, further experiments are needed to elucidate the complex mechanisms being responsible for the reduced efficacy of AA in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Effects of ascorbic acid, translutaminase and margarine amounts on the quality of puff pastry made from spelt flour

    Directory of Open Access Journals (Sweden)

    Šimurina Olivera D.

    2015-01-01

    Full Text Available Puff pastry has delicate and flaky texture which comes from unique combination of fat and dough. These bakery products are made from many thin layers of dough which are separated by alternate fat layers because of which they are considered to be high fat food. Properties of puff pastry depend mostly on the quality of flour, which must be specifically tailored for this purpose. The most commonly used flour in the production of puff pastry is refined wheat flour. Lately, the requirements of consumers for healthy bakery products have a great response in the baking industry. On the market there are new products made with ingredients which have high nutritional value. This paper presents an optimization of the composition of puff pastry made of spelt flour by varying the amount of ingredients such as: margarine, ascorbic acid and enzyme transglutaminase. The optimal ratio of these ingredients has been based on the consideration of their major and interaction effects. During the optimization of spelt puff pastry quality, the following goals were set: maximum volume, minimum firmness and maximum overall acceptability. The optimal solutions were in the concentration range from 3.60 mg/kg to 10 mg/kg for ascorbic acid, from 0.03 mg/kg to 3 mg/kg for transglutaminase and from 29.84 to 30% for margarine on dough basis. It is recommended that the composition of spelt puff pastry involve: 10 mg/kg ascorbic acid, 0.03 mg/kg transglutaminase and 30 % margarine on dough basis to provide the desired product characteristics.

  15. Evaluation of the genotype, environment and their interaction on carotenoid and ascorbic acid accumulation in tomato germplasm.

    Science.gov (United States)

    Roselló, Salvador; Adalid, Ana Maria; Cebolla-Cornejo, Jaime; Nuez, Fernando

    2011-04-01

    Tomatoes are an important source of antioxidants (carotenoids, vitamin C, etc.) owing to their high level of consumption. There is great interest in developing cultivars with increased levels of lycopene, β-carotene or L-ascorbic acid. There is necessary to survey new sources of variation. In this study, the potential of improvement for each character in tomato breeding programmes, in a single or joint approach, and the nature of genotype (G), environment (E) and G × E interaction effects in the expression of these characters were investigated. The content of lycopene, β-carotene and ascorbic acid determined was very high in some phenotypes (up to 281, 35 and 346 mg kg(-1) respectively). The important differences in the three environments studied (with some stressing conditions in several situations) had a remarkable influence in the phenotypic expression of the functional characters evaluated. Nevertheless, the major contribution came from the genotypic effect along with a considerable G × E interaction. The joint accumulation of lycopene and β-carotene has a high genetic component. It is possible to select elite genotypes with high content of both carotenoids in tomato breeding programmes but multi-environment trials are recommended. The improvement of ascorbic acid content is more difficult because the interference of uncontrolled factors mask the real genetic potential. Among the accessions evaluated, there are four accessions with an amazing genetic potential for functional properties that can be used as donor parents in tomato breeding programmes or for direct consumption in quality markets. Copyright © 2011 Society of Chemical Industry.

  16. L-ascorbic acid losses in Kenyan vegetables during cooking as determined by high performance liquid chromatography

    OpenAIRE

    N.M.N. Wekesa; S.C. Chhabra; H.M. Thairu

    2001-01-01

    The loss of L-ascorbic acid (L-AA) in 14 different cooked local vegetables found in Nairobi markets was determined by high performance liquid chromatography. The effect of quantity of water on the loss of L-AA during cooking was studied with cowpea leaves. It was found that more L-AA was lost when larger amount of water was used than when smaller amount was used. The effect of the sharpness of the knife on the loss of L-AA was studied with spinach. It was found that more loss of L-AA occurred...

  17. 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

    Directory of Open Access Journals (Sweden)

    Klingelhoeffer Christoph

    2012-05-01

    Full Text Available 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 oxidative stress. Methods Effective concentration (EC50 values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50 > 20 mmol/L and fifty-five percent had an EC50 50 of 2.6–5.5 mmol/L, glioblastoma cells were the most susceptible cancer cell lines analysed in this study. A correlation between catalase activity and the susceptibility to ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L, was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L. Conclusions Fifty-five percent of the human cancer cell lines tested were unable to protect themselves

  18. 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

    Science.gov (United States)

    2012-01-01

    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 oxidative stress. Methods Effective concentration (EC50) values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA) in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50 > 20 mmol/L and fifty-five percent had an EC50 ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L), was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT) became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L). Conclusions Fifty-five percent of the human cancer cell lines tested were unable to protect themselves against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide

  19. The effect of ascorbic acid and fluid flow stimulation on the mechanical properties of a tissue engineered pelvic floor repair material.

    Science.gov (United States)

    Osman, Nadir I; Roman, Sabiniano; Bullock, Anthony J; Chapple, Christopher R; MacNeil, Sheila

    2014-09-01

    Synthetic non-degradable meshes used in pelvic floor surgery can cause serious complications such as tissue erosion. A repair material composed of an autologous oral fibroblast seeded degradable polylactic acid scaffold may be a viable alternative. The aims of this study were to investigate the effects of media supplementation with additives (ascorbic acid-2-phosphate, glycolic acid and 17-β-oestradiol) on the mechanical properties of these scaffolds. Oral fibroblasts were isolated from buccal mucosa. The effects of the three additives were initially compared in two-dimensional culture to select the most promising collagen stimulating additive. Sterile electrospun scaffolds were seeded with 500,000 oral fibroblasts and fixed in 6-well plates and subjected to ascorbic acid-2-phosphate (the best performing additive) and/or mechanical stimulation. Mechanical stimulation by fluid shear stress was induced by rocking scaffolds on a platform shaker for 1 h/day for 10 of 14 days of culture. In two-dimensional culture, ascorbic acid-2-phosphate (concentrations from 0.02 mM to 0.04 M) and glycolic acid (10 µM) led to significantly greater total collagen production, but ascorbic acid-2-phosphate at 0.03 mM produced the greatest stimulation (of the order of >100%). In three-dimensional culture, mechanical stimulation alone gave non-significant increases in stiffness and strength. Ascorbic acid-2-phosphate (0.03 mM) significantly increased collagen production in the order 280% in both static and mechanically stimulated scaffolds (p material with improved mechanical properties can be developed by supplementing culture media with ascorbic acid-2-phosphate to increase collagen I production. Future studies will assess the change in mechanical properties after implantation in an animal model. © IMechE 2014.

  20. Cognitive deficits and decreased locomotor activity induced by single-walled carbon nanotubes and neuroprotective effects of ascorbic acid

    Science.gov (United States)

    Liu, Xudong; Zhang, Yuchao; Li, Jinquan; Wang, Dong; Wu, Yang; Li, Yan; Lu, Zhisong; Yu, Samuel CT; Li, Rui; Yang, Xu

    2014-01-01

    Single-walled carbon nanotubes (SWCNTs) have shown increasing promise in the field of biomedicine, especially in applications related to the nervous system. However, there are limited studies available on the neurotoxicity of SWCNTs used in vivo. In this study, neurobehavioral changes caused by SWCNTs in mice and oxidative stress were investigated. The results of ethological analysis (Morris water maze and open-field test), brain histopathological examination, and assessments of oxidative stress (reactive oxygen species [ROS], malondialdehyde [MDA], and glutathione [GSH]), inflammation (nuclear factor κB, tumor necrosis factor α, interleukin-1β), and apoptosis (cysteine-aspartic acid protease 3) in brains showed that 6.25 and 12.50 mg/kg/day SWCNTs in mice could induce cognitive deficits and decreased locomotor activity, brain histopathological alterations, and increased levels of oxidative stress, inflammation, and apoptosis in mouse brains; however, 3.125 mg/kg/day SWCNTs had zero or minor adverse effects in mice, and these effects were blocked by concurrent administration of ascorbic acid. Down-regulation of oxidative stress, inflammation, and apoptosis were proposed to explain the neuroprotective effects of ascorbic acid. This work suggests SWCNTs could induce cognitive deficits and decreased locomotor activity, and provides a strategy to avoid the adverse effects. PMID:24596461

  1. Pharmacokinetics and pharmacodynamics of acetylsalicylic acid after intravenous and oral administration to healthy volunteers.

    Science.gov (United States)

    Nagelschmitz, J; Blunck, M; Kraetzschmar, J; Ludwig, M; Wensing, G; Hohlfeld, T

    2014-01-01

    The pharmacology of single doses of acetylsalicylic acid (ASA) administered intravenously (250 or 500 mg) or orally (100, 300, or 500 mg) was evaluated in a randomized, placebo-controlled, crossover study. Blood and urine samples were collected before and up to 24 hours after administration of ASA in 22 healthy volunteers. Pharmacokinetic parameters and measurements of platelet aggregation were determined using validated techniques. A comparison between administration routes showed that the geometric mean dose-corrected peak concentrations (Cmax/D) and the geometric mean dose-corrected area under the curve (AUC0-∞/D) were higher following intravenous administration of ASA 500 mg compared with oral administration (estimated ratios were 11.23 and 2.03, respectively). Complete inhibition of platelet aggregation was achieved within 5 minutes with both intravenous ASA doses, reflecting a rapid onset of inhibition that was not observed with oral dosing. At 5 minutes after administration, the mean reduction in arachidonic acid-induced thromboxane B2 synthesis ex vivo was 99.3% with ASA 250 mg intravenously and 99.7% with ASA 500 mg intravenously. In exploratory analyses, thromboxane B2 synthesis was significantly lower after intravenous versus oral ASA 500 mg (P<0.0001) at each observed time point up to the first hour after administration. Concentrations of 6-keto-prostaglandin1α at 5 and 20 minutes after dosing were also significantly lower with ASA 500 mg intravenously than with ASA 500 mg orally. This study demonstrates that intravenous ASA provides more rapid and consistent platelet inhibition than oral ASA within the first hour after dosing.

  2. Effect of turmeric powder (Curcuma longa L.) and ascorbic acid on physical characteristics and oxidative status of fresh and stored rabbit burgers.

    Science.gov (United States)

    Mancini, Simone; Preziuso, Giovanna; Dal Bosco, Alessandro; Roscini, Valentina; Szendrő, Zsolt; Fratini, Filippo; Paci, Gisella

    2015-12-01

    The objective of this study was to evaluate the effect of Curcuma longa powder and ascorbic acid on some quality traits of rabbit burgers. The burgers (burgers control with no additives; burgers with 3.5 g of turmeric powder/100g meat; burgers with 0.1g of ascorbic acid/100g meat) were analyzed at Days 0 and 7 for pH, color, drip loss, cooking loss, fatty acid profile, TBARS, antioxidant capacity (ABTS, DPPH and FRAP) and microbial growth. The addition of turmeric powder modified the meat color, produced an antioxidant capacity similar to ascorbic acid and determined a lower cooking loss than other formulations. Turmeric powder might be considered as a useful natural antioxidant, increasing the quality and extending the shelf life of rabbit burgers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effect of excess dietary iron as ferrous sulfate and excess dietary ascorbic acid on liver zinc, copper and sulfhydryl groups and the ovary

    International Nuclear Information System (INIS)

    Edwards, C.H.; Adkins, J.S.; Harrison, B.

    1986-01-01

    Female guinea pigs of the NIH 13/N strain, weighing between 475 and 512 g, were fed diets supplemented with 50 to 2500 mg of iron per kg of diet as ferrous sulfate and 0.2 to 8.0 g of ascorbic acid per kg of diet. A significant effect was observed on tissue copper and zinc, ovary weight and liver protein sulfhydryl groups. The mean ovary weight for guinea pigs fed 2500 mg of iron was significantly less than that of animals fed 50 mg of iron, 0.045 +/- 0.012 g and 0.061 +/- 0.009 g, respectively. Liver zinc content of animals fed 2500 mg of iron and 200 mg of ascorbic acid per kg of diet was significantly less than that of animals fed 50 mg of iron and 200 mg of ascorbic acid, 16.3 +/- 3.3 μg and 19.6 +/- 1.6 μg, respectively. There was no difference in liver copper due to dietary iron, but when dietary ascorbic acid was increased to 8 g per kg of diet, there was a significant decrease (from 22.8 +/- 8.1 μg to 10.5 +/- 4.8 μg) in liver copper. Excess dietary ascorbic acid decreased ovarian zinc significantly when increased to 8 g per kg of diet, 2929 +/- 919 μg vs 1661 +/- 471 μg, respectively, when compared to the control group

  4. Effects of ascorbic acid and glucose oxidase levels on the viability of probiotic bacteria and the physical and sensory characteristics in symbiotic ice-cream

    Directory of Open Access Journals (Sweden)

    M. B. Akın

    2015-05-01

    Full Text Available In this study, the effects of addition of different amounts of ascorbic acid and glucose oxidase on the properties of symbiotic ice cream were investigated. Ice-cream containing inulin (2 % (w/w was produced by mixing fortified milk fermented with probiotic strains with the ice-cream mixes containing different ascorbic acid and glucose oxidase concentrations (0.025, 0.05, 0.1 (w/w. The cultures were grown (37 °C, 12 h in UHT skimmed milk. The fermented milk was added to the ice-cream mix up to a level of 10 % w/w. Increasing the concentration of ascorbic acid stimulated the growth of Lactobacillus acidophilus LA-5 (L. acidophilus and Bifidobacterium animalis subsp. lactis BB-12 (Bifidobacterium BB-12. On contrary, increasing the concentration of glucose oxidase negatively affected the growth of L. acidophilus and Bifidobacterium BB-12. However, both, ascorbic acid and glucose oxidase concentration had no effect on physical and sensory properties of ice cream. The results suggested that the addition of ascorbic acid stimulated the growth of L. acidophilus and Bifidobacterium BB-12 and could be recommended for ice cream production.

  5. 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

    Science.gov (United States)

    Yeom, Chang-Hwan; Lee, Gunsup; Park, Jin-Hee; Yu, Jaelim; Park, Seyeon; Yi, Sang-Yeop; Lee, Hye Ree; Hong, Young Seon; Yang, Joosung; Lee, Sukchan

    2009-01-01

    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. PMID:19671184

  6. Simultaneous voltammetric determination of paracetamol and ascorbic acid using a boron-doped diamond electrode modified with Nafion and lead films.

    Science.gov (United States)

    Tyszczuk-Rotko, Katarzyna; Bęczkowska, Ilona; Wójciak-Kosior, Magdalena; Sowa, Ireneusz

    2014-11-01

    The paper describes the fabrication and application of a novel sensor (a boron-doped diamond electrode modified with Nafion and lead films) for the simultaneous determination of paracetamol and ascorbic acid by differential pulse voltammetry. The main advantage of the lead film and polymer covered boron-doped diamond electrode is that the sensitivity of the stripping responses is increased and the separation of paracetamol and ascorbic acid signals is improved due to the modification of the boron-doped diamond surface by the lead layer. Additionally, the repeatability of paracetamol and ascorbic acid signals is improved by the application of the Nafion film coating. In the presence of oxygen, linear calibration curves were obtained in a wide concentration range from 5×10(-7) to 2×10(-4) mol L(-1) for paracetamol and from 1×10(-6) to 5×10(-4) mol L(-1) for ascorbic acid. The analytical utility of the differential pulse voltammetric method elaborated was tested in the assay of paracetamol and ascorbic acid in commercially available pharmaceutical formulations and the method was validated by high performance liquid chromatography coupled with diode array detector. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. PENGARUH ASAM AKROBAT TERHADAP PEMBENTUKAN GEL MIOFIBRIL IKAN MATA BESAR (Selar crumenophthalnus [effect of ascorbic acid on gel formation of myofibril from big eye scad fish (Selar crumenophthalnus

    Directory of Open Access Journals (Sweden)

    Yuli Witono

    2005-08-01

    Full Text Available Effect of ascorbic acid on gel formation of myofibril from big eye scad fish (Selar crumenophthalnuswere studied for its development as food ingredient. Myofibril was galled by the addition of various concentrations of ascorbic acid (0, 0.1, 0.2, 0.3 and 0.4% and the gels were then characterized for its cooking loss, of the gel, but at 0.4% the cooking loss of gel increased significantly. Accordingly, the WHC of the gel changed insignificantly with the ascorbic acid addition below 0.3%, and decrease sharply in the addition of 0.4%. Gel textures were affected by the addition of ascorbic acid at all levels, namely 29.9 ± 1.9, 31.0 ± 0.3, 35.4 ± 0.4, 46.7 ± 1.5, and 115.7 ± 3.2 g/7 mm for 0, 0.1, 0.2, 0.3 and 0.4%, respectively. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS-PAGE showed that addition of ascorbic acid drove formation odfdisulphide bond in the myosin heavy chain (MHC and other myofirillar proteins, resulting in the development of a strong three dimensions structure I myofibril gel as shown by microscopic structure.

  8. 2-O-Acyl-3-O-(1-acyloxyalkyl Prodrugs of 5,6-Isopropylidene-l-Ascorbic Acid and l-Ascorbic Acid: Antioxidant Activity and Ability to Permeate Silicone Membranes

    Directory of Open Access Journals (Sweden)

    Nikki A. Thiele

    2016-07-01

    Full Text Available 2-O-Acyl-3-O-(1-acyloxyalkyl prodrug derivatives, 15, of 5,6-isopropylidene-l-ascorbic acid, VCA, and l-ascorbic acid, VC, have been characterized by measuring (1 their solubilities in water (SAQ and in 1-octanol (SOCT; (2 the ability of one member of the homologous series, 15a, to diffuse through a silicone membrane from its application in propylene glycol:water (PG:AQ, 30:70; (3 the ability of another member of the series, 15e, to express cellular antioxidant activity (CAA in HaCaT cells; and (4 the ability of 15e to support cell viability in HaCaT cells. All of the prodrugs were more soluble in 1-octanol than VC or VCA were. 15a, which exhibited a good balance between SOCT and SAQ, was found to deliver approximately 15 times more 15a than VCA delivered VCA through a silicone membrane from PG:AQ, 30:70. Under those conditions, no VC permeated the membrane. 15e, which hydrolyzed to release acetaldehyde as a byproduct instead of the toxin formaldehyde, exhibited approximately 30 times the antioxidant activity of VC in CaHaT cells and supported cell viability up to 900 μM in HaCaT cells.

  9. Kinetics of browning and correlations between browning degree and pyrazine compounds in l-ascorbic acid/acidic amino acid model systems.

    Science.gov (United States)

    Yu, Ai-Nong; Zhou, Yong-Yan; Yang, Yi-Ni

    2017-04-15

    The kinetics of browning and the correlation between browning products (BPs) and pyrazine compounds were investigated by heating equimolar l-ascorbic acid (ASA)/acidic amino acids under weak alkaline conditions at 120-150°C for 10-120min. The formations of BPs and pyrazine compounds from the reaction were monitored by UV-vis and SPME-GC-FID, respectively. The formation of BPs in both ASA/l-glutamic acid and ASA/l-aspartic acid model reaction systems followed zero order reaction kinetics with activation energies (E a ) of 90.13 and 93.38kJ/mol, respectively. ASA/l-aspartic acid browned at a slightly higher rate than ASA/l-glutamic acid. The total concentration of pyrazine compounds was highly and positively correlated with that of BPs. Based on the observed kinetic data, the formation mechanisms of BPs and pyrazine compounds were proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Preparation and antioxidant properties of low molecular holothurian glycosaminoglycans by H2O2/ascorbic acid degradation.

    Science.gov (United States)

    Mou, Jiaojiao; Wang, Cong; Li, Qiang; Qi, Xiaohui; Yang, Jie

    2018-02-01

    An effective method of free radical degradation induced by H 2 O 2 /ascorbic acid, which was different from previously reported H 2 O 2 /Cu 2+ method, was developed to depolymerize a novel glycosaminoglycan from Holothuria mexicana (HmG). The results indicated that the degradation efficiency increased with the reduced solution concentration, increased H 2 O 2 concentration and ascorbic acid concentration. The chemical composition and structure of different molecular HmG were analyzed. The results showed that the primary structure and sulfate esters were well reserved during the degradation. Two dimension nuclear magnetic resonance of a low molecular product (DHmG-2) indicate that it contained chondroitin sulfate backbone and major 4-O-sulfated fucose branches. The antioxidant assays of HmG and DHmG-3 showed a fine scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals in concentration dependent manner. Besides, molecular weight did not obviously affect the antioxidant activities of HmG. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Solution properties and taste behavior of lactose monohydrate in aqueous ascorbic acid solutions at different temperatures: Volumetric and rheological approach.

    Science.gov (United States)

    Sarkar, Abhijit; Sinha, Biswajit

    2016-11-15

    The densities and viscosities of lactose monohydrate in aqueous ascorbic acid solutions with several molal concentrations m=(0.00-0.08)molkg(-1) of ascorbic acid were determined at T=(298.15-318.15)K and pressure p=101kPa. Using experimental data apparent molar volume (ϕV), standard partial molar volume (ϕV(0)), the slope (SV(∗)), apparent specific volumes (ϕVsp), standard isobaric partial molar expansibility (ϕE(0)) and its temperature dependence [Formula: see text] the viscosity B-coefficient and solvation number (Sn) were determined. Viscosity B-coefficients were further employed to obtain the free energies of activation of viscous flow per mole of the solvents (Δμ1(0≠)) and of the solute (Δμ2(0≠)). Effects of molality, solute structure and temperature and taste behavior were analyzed in terms of solute-solute and solute-solvent interactions; results revealed that the solutions are characterized predominantly by solute-solvent interactions and lactose monohydrate behaves as a long-range structure maker. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. ESR identification of γ-irradiated redoxon and determination of ESR parameters of radicals produced in irradiated ascorbic acid

    International Nuclear Information System (INIS)

    Polat, Mustafa; Korkmaz, Mustafa

    2005-01-01

    In the present work, electron spin resonance (ESR) identification of irradiated redoxon and its potential use as a normal and/or accidental dosimetric material were investigated in details. The ground redoxon samples exhibited a single weak resonance line of peak-to-peak width ΔH pp = 0.9 mT appearing at g = 2.0057. γ-Radiation produced many resonance lines beside four different intense lines (denoted as I 1 , I 2 , I 3 and I 4 ) of different spectral features in the studied dose range of 2.5-25 kGy. Experimental dose-response curves associated with I 1 , I 2 , I 3 and I 4 resonance lines were found to follow an exponential function. From stability and kinetic studies at room and above room temperatures it was concluded that radicals contributing to I 3 and I 4 resonance lines were more stable than the radical species contributing to I 1 and I 2 resonance lines. Simulation calculations based on the room temperature ESR intensity data of an ascorbic acid (active ingredient of redoxon) sample irradiated at 10 kGy was performed to determine the structure and spectral parameters of the radiation-induced radical species involved in the formation of experimental ESR spectrum of ascorbic acid. The contributions of these species to the ESR spectrum of irradiated redoxon were discussed

  13. Theoretical study on the adsorption and relative stability of conformers of L-ascorbic acid on γ - alumina (100) surface

    Science.gov (United States)

    Mozaffari Majd, M.; Dabbagh, H. A.; Farrokhpour, H.; Najafi Chermahini, A.

    2017-11-01

    The adsorption energies (Eads) and relative stabilities of selected conformers of the most stable tautomer of L-ascorbic acid (vitamin C) on the dehydroxylated γ-alumina (100) surface were calculated in both gas phase and solvent (water) using the density functional theory (DFT) method. The selected conformers were related to the different rotational angles of OH groups of L-ascorbic acid. The conformational analysis of bare tautomer in both gas and water showed that the conformer No.20 (conf. 20) and 13 (conf. 13) with the dihedral angles of H15sbnd O10sbnd C11sbnd C9 (-73°) and H20sbnd O19sbnd C9sbnd C11 (-135°) were the most stable and unstable conformers, respectively. The performed calculations in the presence of surface showed that the interaction of the conformers with the surface changes their relative stabilities and structures in both gas phase and water. The Ead of each conformer was calculated and it was determined that conf. 8 and conf. 16 have the highest value of Ead in the gas phase (-62.56 kcal/mol) and water (-54.44 kcal/mol), respectively. The optimized structure of each conformer on the surface and the number of hydrogen bonds between it and surface along with their bond lengths were determined.

  14. Ascorbic acid supplementation does not alter oxidative stress markers in healthy volunteers engaged in a supervised exercise program.

    Science.gov (United States)

    Bunpo, Piyawan; Anthony, Tracy G

    2016-02-01

    The purpose of this study was to investigate the impact of ascorbic acid (AA) consumption on the oxidative stress status of untrained volunteers participating in a supervised exercise program. The study included 46 young adults (average age, 23.5 ± 0.59 years; 37 females, 9 males) who remained sedentary (n = 16) or participated in 30 min of outdoor aerobic running (n = 30) at an intensity corresponding to 65%-75% of maximum heart rate for 3 times per week for 12 weeks. Exercised subjects were randomly assigned to an exercise group without AA supplementation (control; n = 10) or received either 250 mg (n = 10) or 500 mg (n = 10) of AA supplementation previous to each exercise session. Blood samples were taken on day 0 and day 84 to evaluate metabolic profiles and antioxidant status. Sedentary subjects underwent in a single bout of aerobic running to determine total antioxidant status (TAS) and malondiadehyde (MDA) at pre- and postexercise with or without AA supplementation. No significant change in TAS was observed. Plasma MDA significantly increased at postexercise (P exercise, there was no significant change in blood glucose, lipid profile, MDA, TAS, superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase activities amongst groups. Supplementation of AA was associated with minor and inconsistent reductions in SOD, GPx, and catalase activities (P exercise supplementation of ascorbic acid does not alter oxidative stress markers in the plasma and erythrocytes of young adults engaged in a supervised exercise program.

  15. Cultivars, culture conditions, and harvest time influence phenolic and ascorbic acid contents and antioxidant capacity of strawberry (Fragaria x ananassa).

    Science.gov (United States)

    Pincemail, Joël; Kevers, Claire; Tabart, Jessica; Defraigne, Jean-Olivier; Dommes, Jacques

    2012-02-01

    Strawberries are a good source of micronutrients, especially antioxidant phenolics. More information is needed to better exploit the health-promoting effect of such fruits. Several studies focused on the effects of genotype, cultural practices, and seasonal variation on the antioxidant potential of strawberries, but often yielding contradictory results and/or focusing on only 1 source of variability. In the present study, we showed that total phenolic compounds, ascorbic acid, and antioxidant capacity strongly differed between genotypes of strawberry. The precise results revealed the importance of genetic background for the antioxidant capacity and for the content of total phenolics (with up to 3.3-fold variations). Other parameters may also influence the antioxidant capacity in strawberry such as harvest time, culture conditions, and environmental factors. Moreover, in this study, the harvesting time (at the same ripening stage) appeared to be very important, more important than genotype. Variations of the antioxidant capacity of up to 4.1-folds were observed following the harvesting time of "Elsanta" cultivar. This article compares the antioxidant capacity and the content in ascorbic acid and phenolic compounds of strawberries of different varieties and of fruits harvested from April to December at the same ripening stage. The importance of strawberry antioxidant capacity resides in its benefits for human health. © 2012 Institute of Food Technologists®

  16. Reduction of the DNA damages, Hepatoprotective Effect and Antioxidant Potential of the Coconut Water, ascorbic and Caffeic Acids in Oxidative Stress Mediated by Ethanol

    Directory of Open Access Journals (Sweden)

    VANDERSON S. BISPO

    Full Text Available ABSTRACT Hepatic disorders such as steatosis and alcoholic steatohepatitis are common diseases that affect thousands of people around the globe. This study aims to identify the main phenol compounds using a new HPLC-ESI+-MS/MS method, to evaluate some oxidative stress parameters and the hepatoprotective action of green dwarf coconut water, caffeic and ascorbic acids on the liver and serum of rats treated with ethanol. The results showed five polyphenols in the lyophilized coconut water spiked with standards: chlorogenic acid (0.18 µM, caffeic acid (1.1 µM, methyl caffeate (0.03 µM, quercetin (0.08 µM and ferulic acid (0.02 µM isomers. In the animals, the activity of the serum γ-glutamyltranspeptidase (γ-GT was reduced to 1.8 I.U/L in the coconut water group, 3.6 I.U/L in the ascorbic acid group and 2.9 I.U/L in the caffeic acid groups, when compared with the ethanol group (5.1 I.U/L, p<0.05. Still in liver, the DNA analysis demonstrated a decrease of oxidized bases compared to ethanol group of 36.2% and 48.0% for pretreated and post treated coconut water group respectively, 42.5% for the caffeic acid group, and 34.5% for the ascorbic acid group. The ascorbic acid was efficient in inhibiting the thiobarbituric acid reactive substances (TBARS in the liver by 16.5% in comparison with the ethanol group. These data indicate that the green dwarf coconut water, caffeic and ascorbic acids have antioxidant, hepatoprotective and reduced DNA damage properties, thus decreasing the oxidative stress induced by ethanol metabolism.

  17. Effects of U-74389G (21-Lazaroid) and Ascorbic Acid on Liver Recovery After Acute Ischemia and Reperfusion in Rats.

    Science.gov (United States)

    Bonatsos, Vasileios; Kappas, Ioannis; Birbas, Konstantine; Vlachodimitropoulos, Dimitrios; Toutouzas, Konstantinos; Karampela, Eleftheria; Syrmos, Nikolaos; Bonatsos, Gerasimos; Papalois, Apostolos E

    2015-01-01

    The free radical-scavenging effects of the lazaroid U-74389G have been shown in several experimental models to protect the liver from ischemia/reperfusion (I/R), however, the mechanism of cytoprotection is not fully understood. Similar findings were observed when ascorbic acid was administered. This study investigates the effects of infusion of lazaroid U-74389G and ascorbic acid on cytokines and liver structure in a liver I/R rat model. Sixty male Wistars rats, weighting 220-290 g, were used in the study. Six experimental groups were formed: Group 1 (control group): ischemia for 30 min and reperfusion for 60 min; group 2 (control group): ischemia for 30 min and reperfusion for 120 min; group 3: ischemia for 30 min, intraportal injection of ascorbic acid, and reperfusion for 60 min; group 4: ischemia for 30 min, ascorbic acid administration, and reperfusion for 120 min; group 5: ischemia for 30 min, U-74389G administration, and reperfusion for 60 min; and group 6: ischemia for 30 min, U-74389G administration, and reperfusion for 120 min. Tissue and blood sampling took place upon completion of each model's reperfusion. U-74389G was administered at 10 mg/kg animal body weight and ascorbic acid at 100 mg/kg. Anesthesia was induced with ketamine and xylazine. Surgery was performed through a midline laparotomy. The portal vein and the common hepatic artery were isolated and prepared for occlusion. Blood samples and wedge liver biopsies were taken to measure levels of liver enzymes, cytokines and for microscopic analysis upon completion of reperfusion once for each model. Histopathological evaluation revealed a statistically significant reduction in the degree of necrosis of liver tissue in the treated groups compared to the control groups 1 and 2 [groups 3, 5 (p=0.010) and 4, 6 (p<0.0005)]. On the other hand, tissue malondialdehyde levels (MDA) were statistically significantly increased only between control group 2 and groups 4, 6 (p<0.0005). There was no statistically

  18. Position 228 in Paenibacillus macerans cyclodextrin glycosyltransferase is critical for 2-O-d-glucopyranosyl-l-ascorbic acid synthesis.

    Science.gov (United States)

    Chen, Sheng; Xiong, Yanjun; Su, Lingqia; Wang, Lei; Wu, Jing

    2017-04-10

    The markedly stable l-ascorbic acid (L-AA) derivative 2-O-d-glucopyranosyl-l-ascorbic acid (AA-2G) has been widely used in the fields of food, medicine, cosmetics, and husbandry. Cyclodextrin glycosyltransferase (CGTase) is considered suitable for the large-scale production of AA-2G. In this work, Paenibacillus macerans CGTase was used to produce AA-2G and the production was 13.5g/l. An amino-acid sequence alignment of α-, β-, and α⁄β-CGTase indicated that the Phe at position 228 of P. macerans CGTase was different from the amino acids at this position in other CGTases (Met, Val, or Ile). In addition, the CGTases from Anaerobranca gottschalkii and Bacillus circulans 251, which have Val and Met at position 228, were shown to produce 28.9 and 35.7g/l AA-2G, respectively, which verified the importance of this position for AA-2G synthesis. Subsequently, P. macerans CGTase mutants F228M and F228V were constructed and shown to produce 24.8g/l and 24.0g/l AA-2G, respectively, which are 84% and 78% higher than that of wild-type P. macerans CGTase, respectively. Kinetic analysis of AA-2G synthesis showed that affinities of the two mutants for L-AA and the catalytic efficiencies increased. Meanwhile, the mutants had lower cyclization activity but higher disproportionation activities, which is beneficial for AA-2G synthesis. All these results indicated that amino acid at position 228 of P. macerans CGTase is crucial to AA-2G synthesis. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Stimulation of gluconeogenesis by intravenous lipids in preterm infants: response depends on fatty acid profile

    NARCIS (Netherlands)

    van Kempen, Anne A. M. W.; van der Crabben, Saskia N.; Ackermans, Mariëtte T.; Endert, Erik; Kok, Joke H.; Sauerwein, Hans P.

    2006-01-01

    In preterm infants, both hypo- and hyperglycemia are a frequent problem. Intravenous lipids can affect glucose metabolism by stimulation of gluconeogenesis by providing glycerol, which is a gluconeogenic precursor, and/or free fatty acids (FFA), which are stimulants of the rate of gluconeogenesis.

  20. Rapid and specific spectrophotometric and RP-HPLC methods for the determination of ascorbic acid in fruits juices and in human plasma

    International Nuclear Information System (INIS)

    Arayne, M.S.; Bibi, Z.; Sultana, N.

    2009-01-01

    Ascorbic acid (AA) is one of the most important water soluble vitamin in the human diet, present naturally in a wide range of foods, especially fruits and vegetables. The objective of this study was to develop a rapid, sensitive and specific method for the determination of ascorbic acid (vitamin C) from a variety of sources like fresh fruits or from human plasma using spectrophotometric technique or by RP-HPLC. Initially, estimation of vitamin C was carried out spectrophotometrically as UV spectroscopy is a trusted technique to monitor small quantities of drugs and vitamins. The assay was linear over the concentration range of 0.05-100 mi cro g/mL/sup -I/. In the second procedure, we attempted to separate and quantitate ascorbic acid from fruit juices as well as from human plasma by RP-HPLC with UV detection. This has been possible because of the diversity of columns and conditions of analysis available. Chromatographic separation was successfully achieved on a pre-packed Kromasil 100, C/sub 18/ (5 macro m 25 x 0.46) column using acetonitrile water (60:40; v/v) as mobile phase at a flow rate of 0.75 mL/sup -min/ and effluent monitored at 265 nm. The assay was also linear over the concentration range of 0.05-100 micro g/mL/sub -1/, with recovery ranging from 99.0-100.0 % and intra and inter day CV <3 % when applied to the analysis of ascorbic acid from fruit juice available in Pakistan at the time of study Grape fruit, malta, mosami, sweetlemon, fruiter, lemon, lime, custard apple, orange, lemon, guava and papaya juice were found to be very rich in as ascorbic acid, while chikoo, pear, apricot, peach, carrot and some other fruits were found to be poor sources of ascorbic acid. (author)