Science.gov

Sample records for dietary ascorbic acid

  1. Ascorbic Acid

    MedlinePlus

    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 ...

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    2010-03-15

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

  4. Effect of excess dietary iron as ferrous sulfate and excess dietary ascorbic acid on liver zinc, copper and sulfhydryl groups and the ovary

    SciTech Connect

    Edwards, C.H.; Adkins, J.S.; Harrison, B.

    1986-03-05

    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 ..mu..g and 19.6 +/- 1.6 ..mu..g, 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 ..mu..g to 10.5 +/- 4.8 ..mu..g) in liver copper. Excess dietary ascorbic acid decreased ovarian zinc significantly when increased to 8 g per kg of diet, 2929 +/- 919 ..mu..g vs 1661 +/- 471 ..mu..g, respectively, when compared to the control group.

  5. Volumetric Titrations Using Electrolytically Generated Reagents for the Determination of Ascorbic Acid and Iron in Dietary Supplement Tablets: An Undergraduate Laboratory Experiment

    ERIC Educational Resources Information Center

    Scanlon, Christopher; Gebeyehu, Zewdu; Griffin, Kameron; Dabke, Rajeev B.

    2014-01-01

    An undergraduate laboratory experiment for the volumetric quantitative analysis of ascorbic acid and iron in dietary supplement tablets is presented. Powdered samples of the dietary supplement tablets were volumetrically titrated against electrolytically generated reagents, and the mass of dietary reagent in the tablet was determined from the…

  6. Effect of dietary alpha-tocopherol, ascorbic acid, selenium, and iron on oxidative stress in sub-yearling Chinook salmon (Oncorhynchus tshawytscha)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A three-variable central composite design coupled with surface-response analysis was used to examine the effects of dietary alpha-tocopherol + ascorbic acid (TOCAA), selenium (Se), and iron (Fe) on indices of oxidative stress in juvenile spring Chinook salmon. Each dietary factor was tested at five ...

  7. 21 CFR 582.5013 - Ascorbic acid.

    Code of Federal Regulations, 2010 CFR

    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, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5013 Ascorbic acid. (a)...

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

    PubMed Central

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

    2015-01-01

    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 (0.25 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. PMID:26609560

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

    PubMed

    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. PMID:26609560

  10. Effect of Dietary Ascorbic Acid on Osteogenesis of Expanding Midpalatal Suture in Rats

    PubMed Central

    Farhadian, Nasrin; Miresmaeili, Amirfarhang; Azar, Ramin; Zargaran, Massoumeh; Moghimbeigi, Abbas; Soheilifar, Sanaz

    2015-01-01

    Objectives: After maxillary expansion, a long period of retention is necessary to prevent early relapse. Therefore, it is beneficial to accelerate bone formation in the expanding midpalatal suture to reduce relapse. This study was designed to evaluate the effect of dietary vitamin C on osteogenesis of rat midpalatal suture during expansion. Materials and Methods: Fifty-four male Wistar rats were randomly divided into three groups, each with a control and an experimental subgroup. An open-loop spring was bonded to maxillary incisors of each animal to expand the premaxillary suture. Experimental groups received dietary vitamin C in their water. The rats in the three groups were sacrificed at three, nine or 17-day intervals after bonding the spring. Then, the premaxilla was dissected and sections were made and stained with hematoxylin and eosin and osteopontin marker. Osteoblasts and osteoclasts were counted in the suture. Two-way ANOVA and the Mann-Whitney-U test were used for analyzing the data. Results: After three days, the number of osteoblasts was significantly higher in the vitamin C group but after nine days it was significantly higher in the control group and after seventeen days there were no significant differences between the groups. Osteoclast counts were not significantly different between vitamin C and control groups. Conclusion: Vitamin C had a positive effect on osteogenesis at the beginning of bone formation in the expanding suture, but after nine days it had a negative effect on suture osteogenesis in rats. PMID:26005453

  11. Connective tissue responses to some heavy metals. III. Silver and dietary supplements of ascorbic acid. Histology and ultrastructure.

    PubMed Central

    Ellender, G.; Ham, K. N.

    1989-01-01

    Silver-loaded ion exchange resin beads implanted into loose connective tissue of the rat pinna produced a local reaction. Initially the lesion comprised local necrosis and tissue disruption with predominantly small round cell infiltration. The subsequent organization was delayed and disordered. Fibroblasts developed grossly dilated cisternae of the rough endoplasmic reticulum. The matrix contained poorly orientated collagen fibrils of varying size and ground substance appeared condensed and granular. Distorted collagen fibrils were identified within membrane-bound vacuoles in the cytoplasm of both fibroblasts and macrophages. Abnormalities of the silver lesion were indicative of disordered collagen biosynthesis. Silver interfered with the biosynthesis and assembly of matrix components of the connective tissue. The reaction to silver beads in rats maintained on a diet heavily supplemented with ascorbic acid approached that of the control (sodium-loaded bead) with respect to the time scale, tissue reaction and tissue organization. The collagen matrix which formed was more organized and of greater density than that in the rat maintained on a normal diet. However, the repair tissue retained some of the morphological features of the legacy of silver toxicity, in particular delayed repair and dense intracellular fibrils within fibroblasts and macrophages. The excess of ascorbic acid partially ameliorated the effect of silver, possibly by compensating catabolysis of ascorbic acid caused by the presence of the released silver. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 PMID:2923787

  12. Dietary vitamin A, ascorbic acid and α-tocopherol affect the gonad development and reproductive performance of starry flounder Platichthys stellatus broodstock

    NASA Astrophysics Data System (ADS)

    Wang, Jiying; Li, Baoshan; Liu, Xudong; Ma, Jingjing; Wang, Shixin; Zhang, Limin

    2014-03-01

    The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and α-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitamin A (VA group), 500 mg/kg diet ascorbic acid (Vcpp group), or 250 mg/kg diet α-tocopherol (α-TA group) was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index (GSI) of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity (AF) and relative fecundity (RF) of α-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and α-tocopherol affected the development of the eggs.

  13. 21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and... the controlled reaction between ascorbic acid and nicotinamide, melting in the range 141 °C to 145...

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

    PubMed Central

    Kim, Eun-Young; Ham, Soo-Kyung; Bradke, Daniel; Ma, Qianyi; Han, Okhee

    2011-01-01

    We previously reported that (-)-epigallocatechin-3-gallate (EGCG) and grape seed extract (GSE) at high concentration nearly blocked intestinal iron transport across the enterocyte. In this study, we aimed to determine whether small amounts of EGCG, GSE, and green tea extract (GT) are capable of inhibiting iron absorption, to examine if ascorbic acid counteracts the inhibitory action of polyphenols on iron absorption, and to explore the mechanisms of polyphenol-mediated apical iron uptake and basolateral iron release. An55Fe absorption study was conducted by adding various concentrations of EGCG, GSE, and GT using Caco-2 intestinal cells. Polyphenols were found to inhibit the transepithelial 55Fe transport in a dose-dependent manner. The addition of ascorbic acid offset the inhibitory effects of polyphenols on iron transport. Ascorbic acid modulated the transepithelial iron transport without changing the apical iron uptake and the expression of ferroportin-1 protein in the presence of EGCG. The polyphenol-mediated apical iron uptake was inhibited by membrane impermeable Fe2+ chelators (P < 0.001), but at a low temperature (4°C), the apical iron uptake was still higher than the control values at 37°C (P < 0.001). These results suggest that polyphenols enhance the apical iron uptake partially by reducing the conversion of ferric to ferrous ions and possibly by increasing the uptake of polyphenol-iron complexes via the energy-independent pathway. The present results indicate that the inhibitory effects of dietary polyphenols on iron absorption can be offset by ascorbic acid. Further studies are needed to confirm the current findings in vivo. PMID:21430251

  15. 21 CFR 582.5013 - Ascorbic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 1 § 582.5013 Ascorbic acid. (a) Product. Ascorbic acid. 1 Amino acids listed in this subpart may be... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ascorbic acid. 582.5013 Section 582.5013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

  16. 21 CFR 582.5013 - Ascorbic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 1 § 582.5013 Ascorbic acid. (a) Product. Ascorbic acid. 1 Amino acids listed in this subpart may be... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ascorbic acid. 582.5013 Section 582.5013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

  17. 21 CFR 582.5013 - Ascorbic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 1 § 582.5013 Ascorbic acid. (a) Product. Ascorbic acid. 1 Amino acids listed in this subpart may be... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ascorbic acid. 582.5013 Section 582.5013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

  18. 21 CFR 582.5013 - Ascorbic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 1 § 582.5013 Ascorbic acid. (a) Product. Ascorbic acid. 1 Amino acids listed in this subpart may be... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ascorbic acid. 582.5013 Section 582.5013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

  19. Effect of Dietary L-ascorbic Acid (L-AA) on Production Performance, Egg Quality Traits and Fertility in Japanese Quail (Coturnix japonica) at Low Ambient Temperature.

    PubMed

    Shit, N; Singh, R P; Sastry, K V H; Agarwal, R; Singh, R; Pandey, N K; Mohan, J

    2012-07-01

    Environmental stress boosts the levels of stress hormones and accelerates energy expenditure which subsequently imbalance the body's homeostasis. L-ascorbic acid (L-AA) has been recognized to mitigate the negative impact of environmental stress on production performances in birds. The present investigation was carried out to elucidate the effect of different dietary levels of L-AA on production performance, egg quality traits and fertility in Japanese quail at low ambient temperature. Sixty matured females (15 wks) were equally divided into three groups (20/group) based on the different dietary levels of L-AA (0, 250 and 500 ppm) and coupled with an equal number of males (1:1) obtained from the same hatch. They were managed in uniform husbandry conditions without restriction of feed and water at 14 h photo-schedule. Except for feed efficiency, body weight change, feed consumption and hen-day egg production were recorded highest in 500 ppm L-AA supplemented groups. Among the all egg quality traits studied, only specific gravity, shell weight and thickness differed significantly (p<0.05) in the present study. Fertility was improved significantly (p<0.01) to a dose dependent manner of L-AA. The findings of the present study concluded that dietary L-AA can be a caring management practice at least in part to alleviate the adverse effect of cold induced stress on production performance in Japanese quail. PMID:25049657

  20. Dietary ascorbic acid modulates the expression profile of stress protein genes in hepatopancreas of adult Pacific abalone Haliotis discus hannai Ino.

    PubMed

    Wu, Chenglong; Wang, Jia; Xu, Wei; Zhang, Wenbing; Mai, Kangsen

    2014-12-01

    This study was conducted to investigate the effects of dietary ascorbic acid (AA) on transcriptional expression patterns of antioxidant proteins, heat shock proteins (HSP) and nuclear factor kappa B (NF-κB) in the hepatopancreas of Pacific abalone Haliotis discus hannai Ino (initial average length: 84.36 ± 0.24 mm) using real-time quantitative PCR assays. L-ascorbyl-2-molyphosphate (LAMP) was added to the basal diet to formulate four experimental diets containing 0.0, 70.3, 829.8 and 4967.5 mg AA equivalent kg(-1) diets, respectively. Each diet was fed to triplicate groups of adult abalone in acrylic tanks (200 L) in a flow-through seawater system. Each tank was stocked with 15 abalone. Animals were fed once daily (17:00) to apparent satiation for 24 weeks. The results showed that the dietary AA (70.3 mg kg(-1)) could significantly up-regulate the expression levels of Cu/Zn superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), feritin (FT) and heat shock protein 26 (HSP26) in the hepatopancreas of abalone in this treatment compared to the controls. However, the expression levels of Mn-SOD, glutathione peroxidase (GPX), thioredoxin peroxidase (TPx), selenium-binding protein (SEBP), HSP70 and HSP90 were significantly down-regulated. Compared with those in the group with 70.3 mg kg(-1) dietary AA, the expression levels of CAT, GST and HSP26 were decreased in abalone fed with very high dietary AA (4967.5 mg kg(-1)). In addition, significant up-regulations of expression levels of Mn-SOD, GPX, TPx, SEBP, FT, HSP70, HSP90 and NF-κB were observed in abalone fed with apparently excessive dietary AA (829.8 and 4967.5 mg kg(-1)) as compared to those fed 70.3 mg kg(-1) dietary AA. These findings showed that dietary AA influenced the expression levels of antioxidant proteins, heat shock proteins and NF-κB in the hepatopancreas of abalone at transcriptional level. Levels of dietary AA that appeared adequate (70.3 mg kg(-1)) reduced the oxidative stress

  1. Effect of dietary α-tocopherol + ascorbic acid, selenium, and iron on oxidative stress in sub-yearling Chinook salmon (Oncorhynchus tshawytscha Walbaum)

    USGS Publications Warehouse

    Welker, T.L.; Congleton, J.L.

    2009-01-01

    A three-variable central composite design coupled with surface-response analysis was used to examine the effects of dietary ??-tocopherol + ascorbic acid (TOCAA), selenium (Se), and iron (Fe) on indices of oxidative stress in juvenile spring Chinook salmon. Each dietary factor was tested at five levels for a total of fifteen dietary combinations (diets). Oxidative damage in liver and kidney (lipid peroxidation, protein carbonyls) and erythrocytes (erythrocyte resistance to peroxidative lysis, ERPL) was determined after feeding experimental diets for 16 (early December) and 28 (early March) weeks. Only TOCAA influenced oxidative stress in this study, with most measures of oxidative damage decreasing (liver lipid peroxidation in December and March; ERPL in December; liver protein carbonyl in March) with increasing levels of TOCAA. We also observed a TOCAA-stimulated increase in susceptibility of erythrocytes to peroxidative lysis in March at the highest levels of TOCAA. The data suggest that under most circumstances a progressive decrease in oxidative stress occurs as dietary TOCAA increases, but higher TOCAA concentrations can stimulate oxidative damage in some situations. Higher levels of TOCAA in the diet were required in March than in December to achieve comparable levels of protection against oxidative damage, which may have been due to physiological changes associated with the parr-smolt transformation. Erythrocytes appeared to be more sensitive to variation in dietary levels of TOCAA than liver and kidney tissues. Using the March ERPL assay results as a baseline, a TOCAA level of approximately 350-600 mg/kg diet would provide adequate protection against lipid peroxidation under most circumstances in juvenile Chinook salmon. ?? 2008 The Authors.

  2. 21 CFR 582.3013 - Ascorbic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 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...

  3. 21 CFR 182.8013 - Ascorbic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ascorbic acid. 182.8013 Section 182.8013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a) Product. Ascorbic acid. (b)...

  4. 21 CFR 182.8013 - Ascorbic acid.

    Code of Federal Regulations, 2010 CFR

    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...

  5. 21 CFR 582.3013 - Ascorbic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 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...

  6. 21 CFR 582.3013 - Ascorbic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 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...

  7. 21 CFR 182.8013 - Ascorbic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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...

  8. 21 CFR 582.3013 - Ascorbic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...

  9. 21 CFR 182.3013 - Ascorbic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ascorbic acid. 182.3013 Section 182.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3013 Ascorbic acid. (a) Product. Ascorbic acid....

  10. 21 CFR 182.8013 - Ascorbic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  11. 21 CFR 582.3013 - Ascorbic acid.

    Code of Federal Regulations, 2010 CFR

    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...

  12. 21 CFR 182.8013 - Ascorbic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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...

  13. Degradation of ascorbic acid in ethanolic solutions.

    PubMed

    Hsu, Hsin-Yun; Tsai, Yi-Chin; Fu, Chi-Chang; Wu, James Swi-Bea

    2012-10-24

    Ascorbic acid occurs naturally in many wine-making fruits. The industry also uses ascorbic acid as an antioxidant and color stabilizer in the making of alcoholic beverages including white wine, wine cooler, alcopop, and fruit liqueur. However, the degradation of ascorbic acid itself may cause browning and the deterioration of color quality. This study was aimed to monitor the degradation of ascorbic acid, the formation of degradation products, and the browning in storage of ascorbic acid containing 0-40% (v/v) ethanolic solutions buffered at pH 3.2 as models of alcoholic beverages. The results show that ascorbic acid degradation in the ethanolic solutions during storage follows first-order reaction, that the degradation and browning rates increase with the increase of ethanol concentration, that the activation energy for the degradation of ascorbic acid is in the range 10.35-23.10 (kcal/mol), that 3-hydroxy-2-pyrone is an indicator and a major product of ascorbic acid degradation, and that aerobic degradation pathway dominants over anaerobic pathway in ascorbic acid degradation in ethanolic solutions. PMID:22994409

  14. 21 CFR 182.3013 - Ascorbic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false 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...

  15. 21 CFR 182.3013 - Ascorbic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false 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...

  16. 21 CFR 182.3013 - Ascorbic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false 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...

  17. 21 CFR 182.3013 - Ascorbic acid.

    Code of Federal Regulations, 2010 CFR

    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...

  18. Modulation of interleukin production by ascorbic acid.

    PubMed

    Schwager, J; Schulze, J

    1998-06-30

    We studied the influence of ascorbate (vitamin C) on peripheral blood mononuclear cells (PBMC) of pigs with hereditary deficiency in ascorbate synthesis. Groups of animals were depleted of, or supplemented with dietary ascorbate for up to 5 weeks. B lymphocytes and T lymphocyte subsets differed in the two experimental groups only marginally and transiently as determined by analysis of cell surface markers. The proliferative response of PBMC to B and T lymphocyte mitogens was lower in depleted as compared to supplemented animals. Interleukin (IL)-2 and IL-6 were determined by bioassays and were secreted within few hours after mitogenic activation of PBMC which contained normal physiological concentrations of ascorbate. IL-2 production peaked at about 24 h of in vitro culture after Con A activation, but it lasted for 2-3 days after PWM activation. The production of IL-2 and IL-6 were compared during systemic depletion and supplementation with ascorbate. Depleted PBMC produced IL-2 which accumulated in cultures instead of being rapidly consumed by IL-2 dependent cell growth. This suggests that cellular ascorbate influences the production of IL-2. Secretion of IL-6 by mitogen activated PBMC was also affected by prolonged dietary ascorbate depletion. The results suggest that ascorbate levels exert an early effect on immune homeostasis via reactive oxygen intermediates (ROI)-dependent expression of interleukin genes, since the transcription factor NF-kappa B is sensitive to ROI and regulates the expression of interleukin genes. PMID:9656430

  19. Covalent interaction of ascorbic acid with natural products

    PubMed Central

    Kesinger, Nicholas G.; Stevens, Jan F.

    2009-01-01

    While ascorbic acid (Vitamin C) is mostly known as a cofactor for proline hydroxylase and as a biological antioxidant, it also forms covalent bonds with natural products which we here refer to as ‘ascorbylation’. A number of natural products containing an ascorbate moiety has been isolated and characterized from a variety of biological sources, ranging from marine algae to flowering plants. Most of these compounds are formed as a result of nucleophilic substitution or addition by ascorbate, e.g. the ascorbigens from Brassica species are ascorbylated indole derivatives. Some ascorbylated tannins appear to be formed from electrophilic addition to dehydroascorbic acid. There are also examples of annulations of ascorbate with dietary polyphenols, e.g., epigallocatechin gallate (EGCG) and resveratrol derivatives. Herein is a survey of thirty-three ascorbylated natural products and their reported biological activities. PMID:19875138

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

    PubMed

    Elmore, Amy R

    2005-01-01

    L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate function in cosmetic formulations primarily as antioxidants. Ascorbic Acid is commonly called Vitamin C. Ascorbic Acid is used as an antioxidant and pH adjuster in a large variety of cosmetic formulations, over 3/4 of which were hair dyes and colors at concentrations between 0.3% and 0.6%. For other uses, the reported concentrations were either very low (<0.01%) or in the 5% to 10% range. Calcium Ascorbate and Magnesium Ascorbate are described as antioxidants and skin conditioning agents--miscellaneous for use in cosmetics, but are not currently used. Sodium Ascorbyl Phosphate functions as an antioxidant in cosmetic products and is used at concentrations ranging from 0.01% to 3%. Magnesium Ascorbyl Phosphate functions as an antioxidant in cosmetics and was reported being used at concentrations from 0.001% to 3%. Sodium Ascorbate also functions as an antioxidant in cosmetics at concentrations from 0.0003% to 0.3%. Related ingredients (Ascorbyl Palmitate, Ascorbyl Dipalmitate, Ascorbyl Stearate, Erythorbic Acid, and Sodium Erythorbate) have been previously reviewed by the Cosmetic Ingredient Review (CIR) Expert Panel and found "to be safe for use as cosmetic ingredients in the present practices of good use." Ascorbic Acid is a generally recognized as safe (GRAS) substance for use as a chemical preservative in foods and as a nutrient and/or dietary supplement. Calcium Ascorbate and Sodium Ascorbate are listed as GRAS substances for use as chemical preservatives. L-Ascorbic Acid is readily and reversibly oxidized to L-dehydroascorbic acid and both forms exist in equilibrium in the body. Permeation rates of Ascorbic Acid through whole and stripped mouse skin were 3.43 +/- 0.74 microg/cm(2)/h and 33.2 +/- 5.2 microg/cm(2)/h. Acute oral and parenteral studies in mice, rats, rabbits, guinea pigs, dogs, and cats demonstrated little toxicity

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

    PubMed

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

    2015-02-01

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

  2. Ascorbic acid in fetal human brain

    PubMed Central

    Adlard, B. P. F.; De Souza, S. W.; Moon, Susan

    1974-01-01

    Ascorbic acid concentrations in fetal human forebrain in the period 11 to 19 weeks' gestational age were 4 to 11 times higher than those of adults. Levels fell progressively with increasing gestational age but, in term babies dying within 4 weeks of birth, were still at least 3 times those of adults. It was confirmed that, in women delivering at term, ascorbic acid concentrations are approximately 4 times higher in cord blood plasma than in maternal blood plasma. The possible importance of ascorbic acid for normal human brain development is discussed. PMID:4830116

  3. Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives

    PubMed Central

    Moribe, Kunikazu; Limwikrant, Waree; Higashi, Kenjirou; Yamamoto, Keiji

    2011-01-01

    Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs or carrier components. Ascorbyl n-alkyl fatty acid derivatives have been formulated as antioxidants or anticancer drugs for nanoparticle formulations such as micelles, microemulsions, and liposomes. ASC-P vesicles called aspasomes are submicron-sized particles that can encapsulate hydrophilic drugs. Several transdermal and injectable formulations of ascorbyl n-alkyl fatty acid derivatives were used, including ascorbyl palmitate. PMID:21603195

  4. Dietary supplementation with phytosterol and ascorbic acid reduces body mass accumulation and alters food transit time in a diet-induced obesity mouse model

    PubMed Central

    2011-01-01

    Previous research indicates that animals fed a high fat (HF) diet supplemented with disodium ascorbyl phytostanyl phosphate (DAPP) exhibit reduced mass accumulation when compared to HF control. This compound is a water-soluble phytostanol ester and consists of a hydrophobic plant stanol covalently bonded to ascorbic acid (Vitamin C). To provide insight into the mechanism of this response, we examined the in vivo effects of a high fat diet supplemented with ascorbic acid (AA) in the presence and absence of unesterified phytosterols (PS), and set out to establish whether the supplements have a synergistic effect in a diet-induced obesity mouse model. Our data indicate that HF diet supplementation with a combination of 1% w/w phytosterol and 1% w/w ascorbic acid results in reduced mass accumulation, with mean differences in absolute mass between PSAA and HF control of 10.05%; and differences in mass accumulation of 21.6% (i.e. the PSAA group gained on average 21% less mass each week from weeks 7-12 than the HF control group). In our previous study, the absolute mass difference between the 2% DAPP and HF control was 41%, while the mean difference in mass accumulation between the two groups for weeks 7-12 was 67.9%. Mass loss was not observed in animals supplemented with PS or AA alone. These data suggest that the supplements are synergistic with respect to mass accumulation, and the esterification of the compounds further potentiates the response. Our data also indicate that chronic administration of PS, both in the presence and absence of AA, results in changes to fecal output and food transit time, providing insight into the possibility of long-term changes in intestinal function related to PS supplementation. PMID:21711516

  5. Ascorbic acid intake and oxalate synthesis.

    PubMed

    Knight, John; Madduma-Liyanage, Kumudu; Mobley, James A; Assimos, Dean G; Holmes, Ross P

    2016-08-01

    In humans, approximately 60 mg of ascorbic acid (AA) breaks down in the body each day and has to be replaced by a dietary intake of 70 mg in women and 90 mg in men to maintain optimal health and AA homeostasis. The breakdown of AA is non-enzymatic and results in oxalate formation. The exact amount of oxalate formed has been difficult to ascertain primarily due to the limited availability of healthy human tissue for such research and the difficulty in measuring AA and its breakdown products. The breakdown of 60 mg of AA to oxalate could potentially result in the formation of up to 30 mg oxalate per day. This exceeds our estimates of the endogenous production of 10-25 mg oxalate per day, indicating that degradative pathways that do not form oxalate exist. In this review, we examine what is known about the pathways of AA metabolism and how oxalate forms. We further identify how gaps in our knowledge may be filled to more precisely determine the contribution of AA breakdown to oxalate production in humans. The use of stable isotopes of AA to directly assess the conversion of vitamin to oxalate should help fill this void. PMID:27002809

  6. Impulsive mathematical modeling of ascorbic acid metabolism in healthy subjects.

    PubMed

    Bachar, Mostafa; Raimann, Jochen G; Kotanko, Peter

    2016-03-01

    In this work, we develop an impulsive mathematical model of Vitamin C (ascorbic acid) metabolism in healthy subjects for daily intake over a long period of time. The model includes the dynamics of ascorbic acid plasma concentration, the ascorbic acid absorption in the intestines and a novel approach to quantify the glomerular excretion of ascorbic acid. We investigate qualitative and quantitative dynamics. We show the existence and uniqueness of the global asymptotic stability of the periodic solution. We also perform a numerical simulation for the entire time period based on published data reporting parameters reflecting ascorbic acid metabolism at different oral doses of ascorbic acid. PMID:26724712

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

    PubMed

    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. PMID:26593628

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

    PubMed

    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'. PMID:26041210

  9. Regeneration of ascorbic acid in human placenta

    SciTech Connect

    Rose, R.C.; Bode, A.M. )

    1990-02-26

    The free radical scavenging function of ascorbic acid (AA) results in the formation of the oxidized form of the vitamin, dehydro-L-ascorbic acid (DHAA). The enzymatic reduction of DHAA may be an important means of recycling and conserving ascorbic acid in various tissues. The role of the human placenta in the enzymatic reduction of the potentially toxic oxidized form was examined in tissue homogenized in 50 mM MOPs buffer. Assay of DHAA, AA, DKG (diketogulonic acid) were made by HPLC and liquid scintillation counting. Activity of the placental factor in reducing DHAA was dependent on the presence of both NADPH and GSH. Activity was reduced 81% by incubation with 2% trypsin and was unaffected by BSA, glycerol, EtOH, or Na-AZIDE. Inhibition was observed with 10 mM EDTA and 0.2M KCI but not with 1 mM EDTA or 0.1 M KCI or less. Studies are underway to further purify and characterize the enzyme(s) responsible for the observed activity.

  10. Featured Molecules: Ascorbic Acid and Methylene Blue

    NASA Astrophysics Data System (ADS)

    Coleman, William F.; Wildman, Randall J.

    2003-05-01

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

  11. Titrimetric determination of ascorbic acid using chloranil.

    PubMed

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

    1984-01-01

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

  12. L-ascorbic acid metabolism in the ascorbate-deficient arabidopsis mutant vtc1.

    PubMed Central

    Conklin, P L; Pallanca, J E; Last, R L; Smirnoff, N

    1997-01-01

    The biosynthesis of L-ascorbic acid (vitamin C) is not well understood in plants. The ozone-sensitive Arabidopsis thaliana mutant vitamin c-1 (vtc1; formerly known as soz1) is deficient in ascorbic acid, accumulating approximately 30% of wild-type levels. This deficiency could result from elevated catabolism or decreased biosynthesis. No differences that could account for the deficiency were found in the activities of enzymes that catalyze the oxidation or reduction of ascorbic acid. The absolute rate of ascorbic acid turnover is actually less in vtc1 than in wild type; however, the turnover rate relative to the pool of ascorbic acid is not significantly different. The results from [U-14C]Glc labeling experiments suggest that the deficiency is the result of a biosynthetic defect: less L-[14C]ascorbic acid as a percentage of total soluble 14C accumulates in vtc1 than in wild type. The feeding of two putative biosynthetic intermediates, D-glucosone and L-sorbosone, had no positive effect on ascorbic acid levels in either genotype. The vtc1 defect does not appear to be the result of a deficiency in L-galactono-1,4-lactone dehydrogenase, an enzyme able to convert L-galactono-1,4-lactone to ascorbic acid. PMID:9390448

  13. Depletion of Ascorbic Acid Restricts Angiogenesis and Retards Tumor Growth in a Mouse Model

    PubMed Central

    Telang, Sucheta; Clem, Amy L; Eaton, John W; Chesney, Jason

    2007-01-01

    Abstract Angiogenesis requires the deposition of type IV collagen by endothelial cells into the basement membrane of new blood vessels. Stabilization of type IV collagen triple helix depends on the hydroxylation of proline, which is catalyzed by the iron-containing enzyme prolyl hydroxylase. This enzyme, in turn, requires ascorbic acid to maintain the enzyme-bound iron in its reduced state. We hypothesized that dietary ascorbic acid might be required for tumor angiogenesis and, therefore, tumor growth. Here, we show that, not surprisingly, ascorbic acid is necessary for the synthesis of collagen type IV by human endothelial cells and for their effective migration and tube formation on a basement membrane matrix. Furthermore, ascorbic acid depletion in mice incapable of synthesizing ascorbic acid (Gulo-/-) dramatically restricts the in vivo growth of implanted Lewis lung carcinoma tumors. Histopathological analyses of these tumors reveal poorly formed blood vessels, extensive hemorrhagic foci, and decreased collagen and von Willebrand factor expression. Our data indicate that ascorbic acid plays an essential role in tumor angiogenesis and growth, and that restriction of ascorbic acid or pharmacological inhibition of prolyl hydroxylase may prove to be novel therapeutic approaches to the treatment of cancer. PMID:17325743

  14. Evaluation of ascorbic acid in protecting labile folic acid derivatives.

    PubMed Central

    Wilson, S D; Horne, D W

    1983-01-01

    The use of ascorbic acid as a reducing agent to protect labile, reduced derivatives of folic acid has been evaluated by high-performance liquid chromatographic separations and Lactobacillus casei microbiological assay of eluate fractions. Upon heating for 10 min at 100 degrees C, solutions of tetrahydropteroylglutamic acid (H4PteGlu) in 2% sodium ascorbate gave rise to 5,10-methylene-H4PteGlu and 5-methyl-H4PteGlu. H2PteGlu acid gave rise to 5-methyl-H4PteGlu and PteGlu. 10-Formyl-H4PteGlu gave rise to 5-formyl-H4PteGlu and 10-formyl-PteGlu. 5-Formyl-H4-PteGlu gave rise to a small amount of 10-formyl-PteGlu. 5-Methyl-H4PteGlu and PteGlu appeared stable to these conditions. These interconversions were not seen when solutions of these folate derivatives were kept at 0 degrees C in 1% ascorbate. These observations indicate that elevated temperatures are necessary for the interconversions of folates in ascorbate solutions. Assays of ascorbic acid solutions indicated the presence of formaldehyde (approximately equal to 6 mM). This was confirmed by the identification of 3,5-diacetyl-1,4-dihydrolutidine by UV, visible, and fluorescence spectroscopy and by thin-layer chromatography of chloroform extracts of the reaction mixture of ascorbic acid solutions, acetylacetone, and ammonium acetate. These results indicate that solutions of sodium ascorbate used at elevated temperatures are not suitable for extracting tissue for the subsequent assay of the individual folic acid derivatives. PMID:6415653

  15. Effects of ascorbic acid and sodium ascorbate on cyclic nucleotide metabolism in human lymphocytes.

    PubMed

    Atkinson, J P; Weiss, A; Ito, M; Kelly, J; Parker, C W

    1979-01-01

    L-ascorbic acid (LAA) augmented cGMP many-fold in highly purified human peripheral blood lymphocytes. The cGMP response occurred within 10 sec and persisted for at least 60 min. D-ascorbic acid (DAA) and dehydroascorbic acid (DHAA) were also equally active in enhancing cGMP concentrations but metabolic precursors of ascorbic acid and other inorganic acids did not increase cGMP levels. Determination of the amount of DHAA contaminating the LAA precluded the possibility that it was solely responsible for the enhanced cGMP levels. The sodium or calcium salts of ascorbic acid did not increase cGMP concentrations. If these neutralized preparations were acidified, increased cGMP concentrations were then noted. In broken cell preparations, LAA, DAA, and DHAA and to a lesser extent sodium ascorbate (NaA) enhanced guanylate cyclase activity while neither inhibited cAMP or cGMP phosphodiesterase (PDE) activity. The possible role of H2O2, fatty acid liberation, prostaglandin production, oxidizing-reducing agents, and free radical formation in mediating the effects of ascorbic acid on cGMP levels were evaluated, but none of these potential mechanisms were definitively proven to be a required intermediary for the cGMP enhancing activity of ascorbic acid. LAA, DHAA or NaA did not induce lymphocyte transformation or modulate lectin-induced mitogenesis. PMID:36416

  16. Regulation of collagen biosynthesis by ascorbic acid: a review.

    PubMed Central

    Pinnell, S. R.

    1985-01-01

    L-ascorbic acid is an essential cofactor for lysyl hydroxylase and prolyl hydroxylase, enzymes essential for collagen biosynthesis. In addition, L-ascorbic acid preferentially stimulates collagen synthesis in a manner which appears unrelated to the effect of L-ascorbic acid on hydroxylation reactions. This reaction is stereospecific and unrelated to intracellular degradation of collagen. The effect apparently occurs at a transcriptional or translational level, since L-ascorbic acid preferentially stimulates collagen-specific mRNA. In addition, it stimulates lysyl hydroxylase activity but inhibits prolyl hydroxylase activity in human skin fibroblasts in culture. PMID:3008449

  17. Orthomolecular oncology review: ascorbic acid and cancer 25 years later.

    PubMed

    González, Michael J; Miranda-Massari, Jorge R; Mora, Edna M; Guzmán, Angelik; Riordan, Neil H; Riordan, Hugh D; Casciari, Joseph J; Jackson, James A; Román-Franco, Angel

    2005-03-01

    The effect of ascorbic acid on cancer has been a subject of great controversy. This is a follow-up review of the 1979 article by Cameron, Pauling, and Leibovitz published in Cancer Research. In this updated version, the authors address general aspects of ascorbic acid and cancer that have been presented before, while reviewing, analyzing, and updating new existing literature on the subject. In addition, they present and discuss their own mechanistic hypothesis on the effect of ascorbic acid on the cancer cell. The objective of this review is to provide an updated scientific basis for the use of ascorbic acid, especially intravenously as adjuvant treatment in pharmacological nutritional oncology. PMID:15695476

  18. Heavy metals influence on ascorbic acid level

    NASA Astrophysics Data System (ADS)

    Kamaldinov, E. V.; Patrashkov, S. A.; Batenyeva, E. V.; Korotkevich, O. S.

    2003-05-01

    It is well known that heavy metals (HM) are extremely dangerous pollutants influencing to metabolism in animals' organisms. The vitamin C is one of the most important metabolites taking part in many biochemical processes. We studied the influence of main essential HM-Zn and Cu as well as the based supertoxical elements - Cd and Pd on ascorbic acid level in serum. The studies were carried out in Tulinskoe farm of Novosibirsk region. The objects of investigations were piglets (2 month after weaning) and 6-month pigs of Early Ripe Meat breed. The levels of HM in bristle were found by stripping voltammetric analysis using the TA-2 analyzer. Vitamin C content was determined by I.P. Kondrakhin (1985) method using 2,2-dipyridyl. The significant negative correlations between Pb, Cd content and vitamin C (-0.46 ± 0.18, -0.47 ± 0.19) in 6-month pigs were determined. The tendencies of negative correlation between all HM levels in hair and ascorbic acid level in plasma of piglets were revealed. Thus, the obtained correlations let us to suppose that all studied HM influence on 1-gulono-gamma-lactone oxidase and other vitamin C metabolism enzymes activity.

  19. Ascorbic acid deficiency in liver disease.

    PubMed Central

    Beattie, A D; Sherlock, S

    1976-01-01

    Leucocyte ascorbic acid (LAA) levels were measured in 138 patients with liver disease. Significantly reduced levels were found in 37 patients with alcoholic liver disease (P less than 0-01) and 25 patients with primary biliary cirrhosis (P less than 0-05). In the primary biliary cirrhosis patients, cholestyramine therapy was associated with significantly lower levels of the vitamin (P less than 0-05). Liver ascorbic acid measured in Menghini needle biopsies in 20 patients was significantly correlated with LAA (r=0-807, P less than 0-001). No significant correlation was found between LAA and haematological indices, conventional liver function tests, or cholesterol levels in any group of patients. Patients with LAA levels below 100 nM/10(8) WBC had significantly higher antipyrine half-lives (mean=28-3 h) than patients with LAA levels above this level (mean=18-6 h) (P less than 0-05). Delayed drug metabolism related to low LAA should be considered when drugs metabolised by the liver are prescribed for patients with alcoholic liver disease or primary biliary cirrhosis. PMID:976794

  20. MODULATION OF HEALTH AND PRODUCTION BY ORAL BETA-GLUCAN AND ASCORBIC ACID AFTER TRANSPORT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yeast cell-wall Beta-glucan works synergistically with ascorbic acid to enhance growth of neonatal calves in indoor, raised crates. Objectives of this study were to determine 1) if this combination of dietary supplements would improve neonatal calves' stress responses to transport, 2) production an...

  1. Allosteric modulation of retinal GABA receptors by ascorbic acid

    PubMed Central

    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

  2. Characteristics of the transport of ascorbic acid into leucocytes

    SciTech Connect

    Raghoebar, M.; Huisman, J.A.M.; van den Berg, W.B.; van Ginneken, C.A.M.

    1987-02-02

    The degree and the mode of association of (/sup 14/C)-ascorbic acid with leucocytes are examined. The degree of association of ascorbic acid with polymorphonuclear leucocytes (1-3 %) is dependent on cell type, extracellular concentration of ascorbic acid, incubation temperature, intactness of the cells and the extracellular pH. All experiments are performed according to strict protocols as these compounds are labile in aqueous solutions. Further it is noticed that in all experiments an outward gradient of leucocyte endogenic ascorbic acid exists. The results suggest that the association process comprises at least one saturable pathway. The activation of polymorphonuclear leucocytes by phorbol myristate acetate increases the accumulation of ascorbic acid threefold. 30 references, 7 figures, 3 tables.

  3. Kinetics of Fe(III)*EDTA reduction by ascorbic acid

    SciTech Connect

    Li, W.; Harkness, J.B.L.; Mendelsohn, M.H.

    1992-01-01

    The kinetics of the reduction of ferric chelate by ascorbic acid have been determined at a typical flue-gas scrubber-system operating temperature ([approximately]55[degrees]C). The ascorbic acid reaction has the same reduction rate expression as the reduction by bisulfite ions, namely, first order with respect to the concentrations of both Fe(III)*EDTA and monoionic species of ascorbic acid. The reaction rate isnegative first order with respect to Fe(II)*EDTA concentration. In the pH range of 6--8, reduction of the hydrolyzed form of the metal chelate compound was negligible. The rate constant for the ascorbic acid reduction reaction is almost 400 times larger than that for the bisulfite reduction reaction under the same reaction conditions. There was no contribution associated with the nonionized form of ascorbic acid.

  4. Kinetics of Fe(III)*EDTA reduction by ascorbic acid

    SciTech Connect

    Li, W.; Harkness, J.B.L.; Mendelsohn, M.H.

    1992-12-01

    The kinetics of the reduction of ferric chelate by ascorbic acid have been determined at a typical flue-gas scrubber-system operating temperature ({approximately}55{degrees}C). The ascorbic acid reaction has the same reduction rate expression as the reduction by bisulfite ions, namely, first order with respect to the concentrations of both Fe(III)*EDTA and monoionic species of ascorbic acid. The reaction rate isnegative first order with respect to Fe(II)*EDTA concentration. In the pH range of 6--8, reduction of the hydrolyzed form of the metal chelate compound was negligible. The rate constant for the ascorbic acid reduction reaction is almost 400 times larger than that for the bisulfite reduction reaction under the same reaction conditions. There was no contribution associated with the nonionized form of ascorbic acid.

  5. Ascorbic acid-induced chondrocyte terminal differentiation: the role of the extracellular matrix and 1,25-dihydroxyvitamin D.

    PubMed

    Farquharson, C; Berry, J L; Mawer, E B; Seawright, E; Whitehead, C C

    1998-06-01

    Chondrocyte terminal differentiation is associated with cellular hypertrophy increased activity of plasma membrane alkaline phosphatase and the synthesis of collagen type X. The hypertrophic phenotype of cultured chondrocytes can be stimulated by ascorbic acid but the underlying mechanisms for this phenotypic change are unclear. As ascorbic acid is central to many hydroxylation reactions, the possibility was examined that its pro-differentiating effects are mediated by its effects on collagen and vitamin D metabolite formation. In vitro studies indicated that ascorbic acid-induced chondrocyte alkaline phosphatase activity was inhibited by the addition of both collagen and proteoglycan synthesis inhibitors. The addition of arginine-glycine-aspartic acid (RGD)-containing peptides also resulted in lower alkaline phosphatase activity. Chicks supplemented with dietary ascorbic acid had higher concentrations of both collagen and proteoglycans within their growth plates but the chondrocyte maturation rate was unaltered. No evidence was obtained to suggest that ascorbic acid-induced collagen production was mediated by lipid peroxidation. In addition, supplementation with dietary ascorbic acid resulted in higher serum 1,25-dihydroxyvitamin D3 concentrations and increased chondrocyte vitamin D receptor number. Ascorbic acid-treated chondrocytes maintained in vitro also had increased vitamin D receptor numbers but chondrocyte receptor affinity for 1,25-dihydroxyvitamin D3 was unaltered. These results indicate that ascorbic acid promotes both chondrocyte matrix production and 1,25-dihydroxyvitamin D3 synthesis, accompanied by upregulation of the vitamin D receptor. Thus, ascorbic acid may be causing amplification of the vitamin D receptor-dependent genomic response to 1,25-dihydroxyvitamin D, resulting in promotion of terminal differentiation. Strong evidence is provided to support the hypothesis that ascorbic acid-induced chondrocyte terminal differentiation is mediated by

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

    SciTech Connect

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

    1989-04-01

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

  7. Ascorbic acid contents of Pakistani fruits and vegetables.

    PubMed

    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. PMID:17105704

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

    SciTech Connect

    Bowers-Komro, D.M.; McCormick, D.B. )

    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.

  9. Acute effect of ascorbic acid on fibrinolytic activity.

    PubMed

    Bordia, A; Paliwal, D K; Jain, K; Kothari, L K

    1978-08-01

    The acute effect of 1 g oral ascorbic acid on serum fibrinolytic activity was studied in 40 adult males. In Group I (healthy adults) administration of ascorbic acid raised the serum level by about 71%, while the fibrinolytic activity increased to a peak of 137% at 6 h. In patients with CAD (Group II) an essentially similar increase in FA was observed. In Group III, simultaneous administration of ascorbic acid with 100 g fat effectively prevented a fall in fibrinolytic activity and actually raised it by 64% above the fasting level. PMID:568476

  10. A theoretical study on ascorbic acid dissociation in water clusters.

    PubMed

    Demianenko, Eugeniy; Ilchenko, Mykola; Grebenyuk, Anatoliy; Lobanov, Victor; Tsendra, Oksana

    2014-03-01

    Dissociation of ascorbic acid in water has been studied by using a cluster model. It was examined by density functional theory (DFT) with the В3LYP, M06, and wB97XD functionals and a 6-311++G(d,p) basis set. The thermodynamic and kinetic characteristics of proton transfer from ascorbic acid molecule to water clusters were calculated as well as the equilibrium constants (pK a ) for the related processes. The used functionals in the DFT method together with continuum solvent models provided results close to the experimental data for the dissociation constant of ascorbic acid in aqueous solution. PMID:24567154

  11. Photostability and interaction of ascorbic acid in cream formulations.

    PubMed

    Ahmad, Iqbal; Sheraz, Muhammad Ali; Ahmed, Sofia; Shaikh, Riaz Hussain; Vaid, Faiyaz H M; ur Rehman Khattak, Saif; Ansari, Shakeel A

    2011-09-01

    The kinetics of photolysis of ascorbic acid in cream formulations on UV irradiation has been studied using a specific spectrophotometric method with a reproducibility of ± 5%. The apparent first-order rate constants (k(obs)) for the photolysis of ascorbic acid in creams have been determined. The photoproducts formed in the cream formulations include dehydroascorbic acid and 2,3-diketogulonic acid. The photolysis of ascorbic acid appears to be affected by the concentration of active ingredient, pH, and viscosity of the medium and formulation characteristics. The study indicates that the ionized state and redox potentials of ascorbic acid are important factors in the photostability of the vitamin in cream formulations. The viscosity of the humectant present in the creams appears to influence the photostability of ascorbic acid. The results show that the physical stability of the creams is an important factor in the stabilization of the vitamin. In the cream formulations stored in the dark, ascorbic acid undergoes aerobic oxidation and the degradation is affected by similar factors as indicated in the photolysis reactions. The rate of oxidative degradation in the dark is about seventy times slower than that observed in the presence of light. PMID:21735345

  12. Pharmacokinetic study of ascorbic acid in sheep.

    PubMed Central

    Black, W D; Hidiroglou, M

    1996-01-01

    Four groups of sheep (5/group) were used in the experiment. Group 1 sheep were given 1 g of ascorbic acid (AA) intravenously (i.v.), group 2 were given 3 g i.v., group 3 were given 1 g intramuscularly (i.m.) and group 4 received 3 g i.m. Blood was collected for 7 h after i.v. administration and for 48 h following i.m. administration. Plasma was analyzed for AA using HPLC techniques. After i.v. administration the rate of elimination was greater at the high dose than the low (0.8560 vs 0.5231 h-1) but the area under the curve (AUC) parameter was proportional to the dosage (127.9 vs 39.7 mcg*h/mL). After i.m. administration AUC parameters were higher than following the i.v. injections. When the times that AA levels were > or = 5 mcg/mL after i.m. injection were compared there was no significant difference between the 1 and 3 g dosages. Times that levels were > or = 10 mcg/mL were significantly longer for the 3 g dose. Using the AUC (area under the curve) parameter as an index of drug exposure, supplementation of adult sheep with AA by the i.m. route should have a greater effect on the animal than i.v. administration. PMID:8809386

  13. 21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR...: (a) The additive is the product of the controlled reaction between ascorbic acid and...

  14. 21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR...: (a) The additive is the product of the controlled reaction between ascorbic acid and...

  15. 21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR...: (a) The additive is the product of the controlled reaction between ascorbic acid and...

  16. 21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR...: (a) The additive is the product of the controlled reaction between ascorbic acid and...

  17. New method for the estimation of platelet ascorbic acid

    PubMed Central

    Lloyd, J. V.; Davis, P. S.; Lander, Harry

    1969-01-01

    Present techniques for the estimation of platelet ascorbic acid allow interference by other substances in the sample. A new and more specific method of analysis is presented. The proposed method owes its increased specificity to resolution of the extract by thin-layer chromatography. By this means ascorbic acid is separated from other reducing substances present. The separated ascorbic acid is eluted from the thin layer and estimated by a new and very sensitive procedure: ascorbic acid is made to react with ferric chloride and the ferrous ions so formed are estimated spectrophotometrically by the coloured derivative which they form with tripyridyl-Striazine. Results obtained with normal blood platelets were consistently lower than simultaneous determinations by the dinitrophenylhydrazine (DNPH) method. PMID:5798633

  18. Distribution of ascorbate-2-sulfate and distribution, half-life and turnover rates of (1-/sup 14/C)ascorbic acid in rainbow trout

    SciTech Connect

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

    1984-06-01

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

  19. Optimization of ascorbic acid-2-phosphate production from ascorbic acid using resting cell of Brevundimonas diminuta.

    PubMed

    Shin, Woo-Jung; Kim, Byung-Yong; Bang, Won-Gi

    2007-05-01

    With the aim to produce ascorbic acid-2-phosphate (AsA-2-P) from L-ascorbic acid (AsA, Vitamin C), nine bacteria conferring the ability to transform AsA to AsA-2-P were isolated from soil samples alongside known strains from culture collections. Most isolates were classified to the genus Brevundimonas by 16S phylogenetic analysis. Among them, Brevundimonas diminuta KACC 10306 was selected as the experimental strain because of its the highest productivity of AsA-2-P. The optimum set of conditions for the AsA-2-P production from AsA using resting cells as the source of the enzyme was also investigated. The optimum cultivation time was 16 h and the cell concentration was 120 g/l (wet weight). The optimum concentrations of AsA and pyrophosphate were 550 mM and 450 mM, respectively. The most effective buffer was 50 mM sodium formate. The optimum pH was 4.5 and temperature was 40 degrees C. Under the above conditions, 27.5 g/l of AsA-2-P was produced from AsA after 36 h of incubation, which corresponded to a 19.7% conversion efficiency based on the initial concentration of AsA. PMID:18051298

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

    PubMed Central

    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. PMID:26683190

  1. Study of interaction between human serum albumin and three antioxidants: ascorbic acid, α-tocopherol, and proanthocyanidins.

    PubMed

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

    2013-01-01

    Ascorbic acid, α-tocopherol and proanthocyanidins are three classic dietary antioxidants. In this study, the interaction between the three antioxidants and human serum albumin (HSA) was investigated by several spectroscopic techniques. Experimental results proved that the three antioxidants quench the fluorescence of HSA through a static (proanthocyanidins) or static-dynamic combined quenching mechanism (ascorbic acid and α-tocopherol). Thermodynamic investigations revealed that the combination between ascorbic acid or proanthocyanidins and HSA was driven mainly by electrostatic interaction, and the hydrophobic interactions play a major role for α-tocopherol-HSA association. Binding site I was found to be the primary binding site for ascorbic acid and proanthocyanidins, and site II for α-tocopherol. Additionally, the three antioxidants may induce conformational and microenvironmental changes of HSA. PMID:24140914

  2. Ascorbic acid: Chemistry, biology and the treatment of cancer☆

    PubMed Central

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

    2013-01-01

    Since the discovery of vitamin C, the number of its known biological functions is continually expanding. Both the names ascorbic acid and vitamin C reflect its antiscorbutic properties due to its role in the synthesis of collagen in connective tissues. Ascorbate acts as an electron-donor keeping iron in the ferrous state thereby maintaining the full activity of collagen hydroxylases; parallel reactions with a variety of dioxygenases affect the expression of a wide array of genes, for example via the HIF system, as well as via the epigenetic landscape of cells and tissues. In fact, all known physiological and biochemical functions of ascorbate are due to its action as an electron donor. The ability to donate one or two electrons makes AscH− an excellent reducing agent and antioxidant. Ascorbate readily undergoes pH-dependent autoxidation producing hydrogen peroxide (H2O2). In the presence of catalytic metals this oxidation is accelerated. In this review, we show that the chemical and biochemical nature of ascorbate contribute to its antioxidant as well as its prooxidant properties. Recent pharmacokinetic data indicate that intravenous (i.v.) administration of ascorbate bypasses the tight control of the gut producing highly elevated plasma levels; ascorbate at very high levels can act as prodrug to deliver a significant flux of H2O2 to tumors. This new knowledge has rekindled interest and spurred new research into the clinical potential of pharmacological ascorbate. Knowledge and understanding of the mechanisms of action of pharmacological ascorbate bring a rationale to its use to treat disease especially the use of i.v. delivery of pharmacological ascorbate as an adjuvant in the treatment of cancer. PMID:22728050

  3. ESR Study on Irradiated Ascorbic Acid Single Crystal

    SciTech Connect

    Tuner, H.; Korkmaz, M.

    2007-04-23

    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.

  4. Ascorbic acid and L-gulonolactone oxidase in lagomorphs.

    PubMed

    Jenness, R; Birney, E C; Ayaz, K L

    1978-01-01

    1. The activity of L-gulonolactone oxidase (EC 1.1.3.8) in the liver of eastern cottontail rabbits (Sylvilagus floridanus) is about 10-fold greater in winter than in summer. 2. L-gulonolactone oxidase activity is low and tissue ascorbate high during all seasons in snowshoe hares (Lepus americanus). 3. Liver contents of ascorbate fall to low levels in L. americanus fed on rabbit chow in the laboratory. 4. The activity of L-gulonolactone oxidase in liver of Sylvilagus and Oryctolagus is depressed by feeding high levels of L-ascorbic acid. 5. The New Zealand White breed of domestic rabbit (Oryctolagus cuniculus) has considerably higher levels of L-gulonolactone oxidase and liver ascorbate than does the Dutch breed. 6. In a wild population of Oryctolagus sampled in Australia L-gulonolactone oxidase levels were intermediate between those of the two domestic breeds and more variable than either. PMID:318384

  5. Ascorbic acid and rates of cognitive decline in Alzheimer's disease.

    PubMed

    Bowman, Gene L; Dodge, Hiroko; Frei, Balz; Calabrese, Carlo; Oken, Barry S; Kaye, Jeffrey A; Quinn, Joseph F

    2009-01-01

    The brain maintains high levels of ascorbic acid (AA) despite a concentration gradient favoring diffusion from brain to peripheral tissues. Dietary antioxidants, including AA, appear to modify the risk of Alzheimer's disease (AD). The objective of this study was to test the hypothesis that neurodegeneration in AD is modified by brain levels of AA. Thirty-two patients with mild to moderate AD participated in a biomarker study involving standardized clinical assessments over one year. Cerebrospinal fluid (CSF) and serum were collected at baseline for AA and albumin content. Cognitive measures were collected at baseline and one year. CSF and plasma AA failed to predict cognitive decline independently, however, CSF: plasma AA ratio did. After adding CSF Albumin Index (an established marker of blood-brain barrier integrity) to the regression models the effect of CSF: plasma AA ratio as a predictor of cognitive decline was weakened. CSF: plasma AA ratio predicts rate of decline in AD. This relationship may indicate that the CSF: plasma AA ratio is an index of AA availability to the brain or may be an artifact of a relationship between blood-brain barrier impairment and neurodegeneration. PMID:19158425

  6. Effect of ascorbic acid deficiency on primary and reparative dentinogenesis in non-ascorbate-synthesizing ODS rats.

    PubMed

    Ogawara, M; Aoki, K; Okiji, T; Suda, H

    1997-01-01

    Ascorbic acid is essential to the biosynthesis of collagen, the major organic matrix component of dentine. The ODS rat is a mutant strain of Wistar rat characterized by hereditary lack of L-gulono-gamma-lactone oxidase and thus is unable to synthesize ascorbic acid. ODS rats were given an ascorbic acid-free diet to investigate how ascorbic acid deficiency affects dentine formation in vivo. Histomorphometric analysis on their growing molars and incisors showed a significant reduction in both size and mineral apposition rate of dentine, as revealed by contact microradiography and fluorescent time-marking, respectively. A similar reduction in bone formation was simultaneously demonstrated in the mandible, confirming the previously reported osteopathic effects of ascorbic acid deficiency. When pulp inflammation was induced in lower first molars by making unsealed pulp exposures, specimens from control animals showed continuous deposition of an osteodentine-like tissue in the radicular pulp chamber; this type of mineralized tissue formation was greatly reduced in ascorbic acid-deprived animals. These results indicate that ascorbic acid deficiency hampers dentine formation under both physiological and pathological conditions of the dentine/pulp complex. ODS rats could be useful in investigating in vivo effects of ascorbic acid deficiency on the formation of dentine and other dental mineralized tissues. PMID:9447259

  7. Vacuolar deposition of ascorbate-derived oxalic acid in barley

    SciTech Connect

    Wagner, G.J.

    1981-03-01

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

  8. Effect of ascorbic acid on the human electroencephalogram.

    PubMed

    Kerxhalli, J S; Vogel, W; Broverman, D M; Klaiber, E L

    1975-10-01

    Controversy exists over whether ascorbic acid (vitamin C) in doses in excess of known physiological requirements has demonstrable biological effects. The present study reports that such megadoses of vitamin C do significantly effect an objective electrophysiological measure, i.e., electroencephalogram (EEG) driving responses to photic stimulation. Four thousand milligrams of vitamin C administered 27 and 3 hours prior to assessment produced an effect on the EEGs of 18 healthy adolescent human males that was significantly different from a placebo. Fifty milligrams of ascorbic acid administered in this manner did not produce an effect on the EEG significantly different from placebo administration. PMID:1099176

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

    PubMed

    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. PMID:26084697

  10. 21 CFR 862.1095 - Ascorbic acid test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 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 §...

  11. 21 CFR 862.1095 - Ascorbic acid test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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 §...

  12. 21 CFR 862.1095 - Ascorbic acid test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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 §...

  13. 21 CFR 862.1095 - Ascorbic acid test system.

    Code of Federal Regulations, 2010 CFR

    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 §...

  14. 21 CFR 862.1095 - Ascorbic acid test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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 §...

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

    ERIC Educational Resources Information Center

    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…

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

    EPA Science Inventory

    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...

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

    PubMed Central

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

    2012-01-01

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

  18. Performance of structured lipids incorporating selected phenolic and ascorbic acids.

    PubMed

    Gruczynska, Eliza; Przybylski, Roman; Aladedunye, Felix

    2015-04-15

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

  19. The effect of high ascorbic acid supplementation on body iron stores

    SciTech Connect

    Cook, J.D.; Watson, S.S.; Simpson, K.M.; Lipschitz, D.A.; Skikne, B.S.

    1984-09-01

    The level of assimilation of dietary iron is believed to have an important influence on iron status. To examine the effect of enhancing the availability of dietary iron on iron balance, 17 adult volunteer subjects were given 2 g of ascorbic acid daily with meals for 16 weeks. Serum ferritin levels before and after the study averaged 46 and 43 micrograms/L, respectively, indicating a negligible effect on iron stores. When vitamin C supplementation was continued for an additional 20 months in five iron-replete and four iron-deficient subjects, serum ferritin determinations again failed to indicate any significant effect of the vitamin C on iron reserves. These findings were not explained by intestinal adaptation to the enhancing effect of the vitamin, because radioisotopic measurements of nonheme iron absorption showed no reduction in the enhancing effect of 1 g of ascorbic acid after four months of megadoses of vitamin C. It is concluded that altering the availability of nonheme dietary iron has little effect on iron status when the diet contains substantial amounts of meat.

  20. Effect of antacid and ascorbic acid on serum salicylate concentration.

    PubMed

    Hansten, P D; Hayton, W L

    1980-01-01

    To determine the effect of antacid or ascorbic acid administration on plateau serum salicylate concentrations, nine healthy subjects were given each of the following treatments by balanced block design: choline salicylate (equivalent to 3.76 or 5.62 Gm/day of aspirin); choline salicylate plus magnesium-aluminum hydroxide (120 ml/day); or choline salicylate plus ascorbic acid (3 Gm/day). In subjects developing a control serum salicylate level above 10 mg/dl, antacid administration produced a decrease in serum salicylate level (mean 19.8 mg/dl vs. 15.8 mg/dl) (P less than 0.01). Ascorbic acid administration was not associated with a significant change in serum salicylate. The reduction in serum salicylate following antacid appears to be due to antacid-induced alkalinization of the urine with resultant increase in renal salicylate clearance. Antacid administration should be considered a potential cause of altered serum salicylate concentration in patients receiving large doses of salicylate. PMID:7400368

  1. Effect of ascorbic acid and other adjuvants on manganese absorption

    SciTech Connect

    Papaioannou, R.; Sohler, A.; Pfeiffer, C.C.

    1986-03-01

    Animal experiments have demonstrated that manganese is poorly absorbed from the gut and that it is rapidly removed from the blood by liver uptake and bilary excretion. Zinc supplements which are readily absorbed can induce a Mn deficiency so that Mn supplementation is necessary. Supplementation with a diet rich in Mn (high in legumes, nuts, whole grains, tea) failed to influence blood Mn levels. The present study is concerned with the route of Mn administration and the effect of various adjuvants on the absorption and availability of Mn. Oral and sublingual administration of 20 mgs of Mn as the chloride failed to elicit a blood level rise. A rise was noted after the intramuscular injection of 2.5 mgs Mn as Mn Cl/sub 2/. Blood Mn levels rose to a maximum in thirty minutes and were back to basal levels within three hours. Adjuvants such as arginine, lecithin, taurine, biotin, bioflavinoids, were tested with essentially negative results. Mn orotate also failed to increase absorption. Oral absorption was obtained with ascorbic acid in five female subjects when 20 mgs of Mn as the chloride was given orally with 1 gm of ascorbic acid. This effect was not observed with five male subjects. A 30-40% increase in blood Mn after 2 hours was found when Mn was administered with ascorbic acid in the female subjects.

  2. Kinetic-spectrophotometric determination of ascorbic acid by inhibition of the hydrochloric acid-bromate reaction

    NASA Astrophysics Data System (ADS)

    Ensafi, Ali A.; Rezaei, B.; Movahedinia, H.

    2002-10-01

    A new analytical method was developed for the determination of ascorbic acid in fruit juice and pharmaceuticals. The method is based on its inhibition effect on the reaction between hydrochloric acid and bromate. The decolourisation of Methyl Orange by the reaction products was used to monitor the reaction spectrophotometrically at 510 nm. The linearity range of the calibration graph depends on bromate concentration. The variable affecting the rate of the reaction was investigated. The method is simple, rapid, relatively sensitive and precise. The limit of detection is 7.6×10 -6 M and calibration rang is 8×10 -6-1.2×10 -3 M ascorbic acid. The relative standard deviation of seven replication determinations of 8×10 -6 and 2×10 -5 M ascorbic acid was 2.8 and 1.7%, respectively. The influence of potential interfering substance was studied. The method was successfully applied for the determination of ascorbic acid in pharmaceuticals.

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

    PubMed Central

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

    2016-01-01

    Objective 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. Materials and methods 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 2 weeks. Cell attachment, viability and total collagen production were evaluated as well as mechanical properties. Results 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. Conclusion 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. Statement of significance 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

  4. L-Ascorbic Acid: A Multifunctional Molecule Supporting Plant Growth and Development

    PubMed Central

    Gallie, Daniel R.

    2013-01-01

    L-Ascorbic acid (vitamin C) is as essential to plants as it is to animals. Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants. Ascorbic acid regulates cell division and growth and is involved in signal transduction. In contrast to the single pathway responsible for ascorbic acid biosynthesis in animals, plants use multiple pathways to synthesize ascorbic acid, perhaps reflecting the importance of this molecule to plant health. Given the importance of ascorbic acid to human nutrition, several technologies have been developed to increase the ascorbic acid content of plants through the manipulation of biosynthetic or recycling pathways. This paper provides an overview of these approaches as well as the consequences that changes in ascorbic acid content have on plant growth and function. Discussed is the capacity of plants to tolerate changes in ascorbic acid content. The many functions that ascorbic acid serves in plants, however, will require highly targeted approaches to improve their nutritional quality without compromising their health. PMID:24278786

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

    PubMed Central

    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

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

    EPA Science Inventory

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

    ABSTRACT

    Both dimethylarsinic acid (DMA(V)) and dimethylarsinous acid (DMA(III)) release iron from human liver ferritin (HLF) with or without the presence of ascorbic acid. ...

  7. A novel system combining biocatalytic dephosphorylation of L-ascorbic acid 2-phosphate and electrochemical oxidation of resulting ascorbic acid.

    PubMed

    Kuwahara, Takashi; Homma, Toshimasa; Kondo, Mizuki; Shimomura, Masato

    2011-03-15

    An enzyme electrode was prepared with acid phosphatase (ACP) for development of a new electric power generation system using ascorbic acid 2-phosphate (AA2P) as a fuel. The properties of the electrode were investigated with respect to biocatalytic dephosphorylation of AA2P and electrochemical oxidation of resulting ascorbic acid (AA). The enzyme electrode was fabricated by immobilization of ACP through amide linkage onto a self-assembled monolayer of 3-mercaptopropionic acid on a gold electrode. AA2P was not oxidized on a bare gold electrode in the potential sweep range from -0.1 to +0.5 V vs. Ag/AgCl. However, the enzyme electrode gave an oxidation current in citric buffer solution of pH 5 containing 10 mM of AA2P. The oxidation current began to increase at +0.2V, and reached to 5.0 μA cm(-2) at +0.5 V. The potential +0.2 V corresponded to the onset of oxidation of ascorbic acid (AA). These results suggest that the oxidation current observed with the enzyme electrode is due to AA resulting from dephosphorylation of AA2P. The oxidation current increased with increasing concentration of AA2P and almost leveled off at around the concentration of 5mM. Thus the enzyme electrode brought about biocatalytic conversion of AA2P to AA, followed by electrochemical oxidation of the AA. The oxidation current is likely to be controlled by the biocatalytic reaction. PMID:21247749

  8. POTENTIATING AND PROTECTIVE EFFECTS OF ASCORBATE ON OXIDATIVE STRESS DEPENDS UPON DIETARY IRON CONCENTRATION FED TO C3H MICE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ascorbic acid (AA) is an antioxidant that in the presence of iron and hydrogen peroxide increases the production of hydroxyl radicals in vitro. Whether AA has similar pro-oxidant properties in vivo may depend upon the relative balance of iron and ascorbic acid concentrations. In this study, C3H mice...

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Interaction of glutathione and ascorbic acid in guinea pig lungs exposed to nitrogen dioxide

    SciTech Connect

    Leung, H.-W.; Morrow, P.E.

    1981-01-01

    The interaction of two important water-soluble antioxidants, glutathione and ascorbic acid, was studied. The perfused guinea pig lung was found to contain about twice as much reduced glutathione as ascorbic acid. Nitrogen dioxide exposure decreased the levels of the two antioxidants both in vitro and in vivo. Ascorbic acid concentration was lowered to a greater extent than glutathione. The pulmonary ascorbic acid level was identical in both control and glutathione-deficient guinea pigs exposed to nitrogen dioxide, suggesting that there was little interaction between the two antioxidants in the lungs during oxidant stress.

  11. CML10, a variant of calmodulin, modulates ascorbic acid synthesis.

    PubMed

    Cho, Kwang-Moon; Nguyen, Ha Thi Kim; Kim, Soo Youn; Shin, Jin Seok; Cho, Dong Hwa; Hong, Seung Beom; Shin, Jeong Sheop; Ok, Sung Han

    2016-01-01

    Calmodulins (CaMs) regulate numerous Ca(2+) -mediated cellular processes in plants by interacting with their respective downstream effectors. Due to the limited number of CaMs, other calcium sensors modulate the regulation of Ca(2+) -mediated cellular processes that are not managed by CaMs. Of 50 CaM-like (CML) proteins identified in Arabidopsis thaliana, we characterized the function of CML10. Yeast two-hybrid screening revealed phosphomannomutase (PMM) as a putative interaction partner of CML10. In vitro and in vivo interaction assays were performed to analyze the interaction mechanisms of CML10 and PMM. PMM activity and the phenotypes of cml10 knock-down mutants were studied to elucidate the role(s) of the CML10-PMM interaction. PMM interacted specifically with CML10 in the presence of Ca(2+) through its multiple interaction motifs. This interaction promoted the activity of PMM. The phenotypes of cml10 knock-down mutants were more sensitive to stress conditions than wild-type plants, corresponding with the fact that PMM is an enzyme which modulates the biosynthesis of ascorbic acid, an antioxidant. The results of this research demonstrate that a calcium sensor, CML10, which is an evolutionary variant of CaM, modulates the stress responses in Arabidopsis by regulating ascorbic acid production. PMID:26315131

  12. An ascorbic acid sensor based on cadmium sulphide quantum dots.

    PubMed

    Ganiga, Manjunatha; Cyriac, Jobin

    2016-05-01

    We present a Förster resonance energy transfer (FRET)-based fluorescence detection of vitamin C [ascorbic acid (AA)] using cadmium sulphide quantum dots (CdS QDs) and diphenylcarbazide (DPC). Initially, DPC was converted to diphenylcarbadiazone (DPCD) in the presence of CdS QDs to form QD-DPCD. This enabled excited-state energy transfer from the QDs to DPCD, which led to the fluorescence quenching of QDs. The QD-DPCD solution was used as the sensor solution. In the presence of AA, DPCD was converted back to DPC, resulting in the fluorescence recovery of CdS QDs. This fluorescence recovery can be used to detect and quantify AA. Dynamic range and detection limit of this sensing system were found to be 60-300 nM and 2 nM, respectively. We also performed fluorescence lifetime analyses to confirm existence of FRET. Finally, the sensor responded with equal accuracy to actual samples such as orange juice and vitamin C tablets. Graphical abstract Schematic showing the FRET based fluorescence detection of ascorbic acid. PMID:27023220

  13. Ascorbic acid repletion: A possible therapy for diabetic macular edema?

    PubMed

    May, James M

    2016-05-01

    Macular edema poses a significant risk for visual loss in persons with diabetic retinopathy. It occurs when plasma constituents and fluid leak out of damaged retinal microvasculature in the area of the macula, causing loss of central vision. Apoptotic loss of pericytes surrounding capillaries is perhaps the earliest feature of diabetic vascular damage in the macula, which is also associated with dysfunction of the endothelium and loss of the otherwise very tight endothelial permeability barrier. Increased oxidative stress is a key feature of damage to both cell types, mediated by excess superoxide from glucose-induced increases in mitochondrial metabolism, as well as by activation of the receptor for advanced glycation end products (RAGE). The latter in turn activates multiple pathways, some of which lead to increased oxidative stress, such as those involving NF-ĸB, NADPH oxidase, and endothelial nitric oxide synthase. Such cellular oxidative stress is associated with low cellular and plasma ascorbic acid levels in many subjects with diabetes in poor glycemic control. Whether repletion of low ascorbate in retinal endothelium and pericytes might help to prevent diabetic macular edema is unknown. However, cell culture studies show that the vitamin prevents high-glucose and RAGE-induced apoptosis in both cell types, that it preserves nitric oxide generated by endothelial cells, and that it tightens the leaky endothelial permeability barrier. Although these findings need to be confirmed in pre-clinical animal studies, it is worth considering clinical trials to determine whether adequate ascorbate repletion is possible and whether it might help to delay or even reverse early diabetic macular edema. PMID:26898503

  14. Effect of mitochondrial ascorbic acid synthesis on photosynthesis.

    PubMed

    Senn, M E; Gergoff Grozeff, G E; Alegre, M L; Barrile, F; De Tullio, M C; Bartoli, C G

    2016-07-01

    Ascorbic acid (AA) is synthesized in plant mitochondria through the oxidation of l-galactono-1,4-lactone (l-GalL) and then distributed to different cell compartments. AA-deficient Arabidopsis thaliana mutants (vtc2) and exogenous applications of l-GalL were used to generate plants with different AA content in their leaves. This experimental approach allows determining specific AA-dependent effects on carbon metabolism. No differences in O2 uptake, malic and citric acid and NADH content suggest that AA synthesis or accumulation did not affect mitochondrial activity; however, l-GalL treatment increased CO2 assimilation and photosynthetic electron transport rate in vtc2 (but not wt) leaves demonstrating a stimulation of photosynthesis after l-GalL treatment. Increased CO2 assimilation correlated with increased leaf stomatal conductance observed in l-GalL-treated vtc2 plants. PMID:27010742

  15. Therapeutic efficacy of dimercaptosuccinic acid and thiamine/ascorbic acid on lead intoxication in rats

    SciTech Connect

    Tandon, S.K.; Flora, S.J.S. )

    1989-11-01

    Thiamine, folic acid, pyridoxine and ascorbic acid either individually or in combination have been proven to be effective in reducing the toxic manifestations of lead and in enhancing the antidotal efficacy of CaNa{sub 2}EDTA. In a recent report from the authors' laboratory, it was observed that given combination of thiamine and ascorbic acid with thiol chelators improved the ability of the animals to excrete lead thereby reducing body lead burden. In view of the beneficial effect of these two vitamins, it was considered of interest to evaluate their potential to modify the prophylactic action of DMS in lead intoxication in rat after repeated administration.

  16. Individual and simultaneous determination of uric acid and ascorbic acid by flow injection analysis.

    PubMed

    Almuaibed, A M; Townshend, A

    1992-11-01

    Flow injection methods for the individual and simultaneous determination of ascorbic acid and uric acid are proposed. A spectrophotometer and a miniamperometric detector are connected in sequence. The calibration graphs for uric acid obtained by measuring its absorbance at 293 nm and its current at +0.6 V are linear up to at least 80 and 70 mug/ml, respectively, with an rsd (n = 10) of 1 % for both methods at mid-range concentrations. The calibration graph for ascorbic acid with amperometric detection is linear up to 80 mg/l. with an rsd (n = 10) of 0.8% at 30 mg/l. The simultaneous determination of uric acid and ascorbic acid is based on measurement of the absorbance of uric acid at 393 nm and amperometric determination of both analytes at +0.6 V. The average relative errors of the analysis of binary mixtures of uric acid and ascorbic acid are 2.2 and 4.2%, respectively. PMID:18965554

  17. Control of enzymatic browning in apple slices by using ascorbic acid under different conditions.

    PubMed

    el-Shimi, N M

    1993-01-01

    Control of phenol oxidase activity in apple slices by the use of ascorbic acid at different pH values, temperature and time of incubation was investigated. The enzyme was almost inactivated at 1% and 1.5% ascorbic acid. Ascorbic acid solution (1%) caused a remarkable inhibition with the increasing acidity up to pH = 1. Heating treatments for apple slices dipped in 1% ascorbic acid caused a reduction of enzymatic browning, optimum temperature for inactivation of the enzyme was between 60-70 degrees C for 15 minutes. Increasing the time of dipping apple slices in 1% ascorbic acid solutions and at different pH values reduce phenolase activity. PMID:8464847

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

    PubMed

    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. PMID:25641731

  19. Ascorbic Acid Influences the Development and Immunocompetence of Larval Heliothis virescens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report that ascorbic acid, which is known to be a free radical scavenger, to be important not only in insect development but also in larval resistance to baculovirus infection. We sequentially elevated the ascorbic acid content in diet and evaluated the effect on larval H. virescens development ...

  20. Plant resistance mechanisms to air pollutants: rhythms in ascorbic acid production during growth under ozone stress

    SciTech Connect

    Lee, E.H. )

    1991-01-01

    Relationships between ozone (O3) tolerance and leaf ascorbic acid concentrations in O3-susceptible (O3-S) 'Hark' and O3-resistant (O3-R) 'Hood' soybean, Glycine max (L.) Merr., cultivars were examined with high-performance liquid chromatography (HPLC). Leaf samples were analyzed at 4 intervals during a 24 h period. Soybean cultivars grown in the greenhouse with charcoal filtered (CF) and nonfiltered (NF) air showed daily oscillations in ascorbic acid production. Highest ascorbic acid levels in leaves during light coincided with highest concentrations of photochemical oxidants in the atmosphere at 2:00 p.m. The resistant genotype produced more ascorbic acid in its trifoliate leaves than did the corresponding susceptible genotype. Under CF air (an O3-reduced environment) O3-S and O3-R cultivars showed rhythms in ascorbic acid production. In NF air (an O3 stress environment) the O3-R cultivar alone showed rhythms in ascorbic acid production. Results indicated that superior O3 tolerance in the Hood soybean cultivar (compared with Hark) was associated with a greater increase in endogenous levels of ascorbic acid. Ascorbic acid may scavenge free radicals and thereby protect cells from injury by O3 or other oxyradical products. Plants defend themselves against photochemical oxidant stress, such as O3, by several mechanisms. Experimental evidence indicates that antioxidant defense systems existing in plant tissues may function to protect cellular components from deleterious effects of photochemical oxidants through endogenous and exogenous controls.

  1. Dietary fatty acids and minerals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accumulating evidence in animals and humans shows that dietary fatty acids influence the absorption and utilization of certain mineral elements. Fat intake exceeding 10% of energy intake reduces calcium uptake and use by the body, and this effect is more pronounced with saturated compared to unsatu...

  2. Effects of toxic work environments on sperm quality and ascorbic acid levels

    SciTech Connect

    Dawson, E.B.; Harris, W.A.; Powell, L.C. )

    1990-02-26

    Surveys have shown that toxic work environments lower sperm quality, and controlled studies indicate that ascorbic acid supplementation improves sperm viability and agglutination. The sperm quality of 50 subjects each from: (1) office workers, (2) a lead smelter, (3) petroleum refineries, and (4) a herbicide plant were compared with serum and semen ascorbic acid levels. The sperm characteristics studied were: count as million/ml and as percent; viability, motility, clumping, and abnormal morphology. The serum ascorbic acid levels were directly proportional to sperm viability and inversely correlated to clumping of all groups. Moreover, serum ascorbic acid levels were also inversely correlated to twin tail and amorphous forms of abnormal sperm morphology. The results of the study indicate that toxic environments depress sperm quality and suggest that ascorbic acid supplementation will improve sperm quality and fertility.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Ascorbic acid and protein glycation in vitro.

    PubMed

    Sadowska-Bartosz, Izabela; Bartosz, Grzegorz

    2015-10-01

    The aim of the study was to compare the effects of ascorbic acid (AA) in vitro in the absence and in the presence of cell-dependent recycling. In a cell-free system, AA enhanced glycoxidation of bovine serum albumin (BSA) by glucose and induced BSA glycation in the absence of sugars. On the other hand, AA did not affect erythrocyte hemolysis, glycation of hemoglobin and erythrocyte membranes, and inactivation of catalase, protected against inactivation of acetylcholinesterase of erythrocytes incubated with high glucose concentrations and enhanced the loss of glutathione. These results can be explained by assumption that AA acts as a proglycating agent in the absence of recycling while is an antiglycating agent when metabolic recycling occurs. PMID:26163454

  5. Effects of ascorbate and ATP upon amino acid transport in the toad's cornea.

    PubMed

    Cooperstein, D F; Scott, W N

    1978-04-01

    We have examined the effects of ascorbate upon amino acid uptake by the in vitro toad cornea. Physiologic levels of ascorbate increase the uptake of leucine by approximately 35% but have no effect upon the uptake of alanine. Uncouplers of oxidative phosphorylation do not inhibit the stimulation by ascorbic acid of leucine accumulation, indicating the increased synthesis of ATP is not the mechanism; exogenous ATP, unlike ascorbate, stimulates the uptake of both alanine and leucine. Carbon monoxide blocks the effects of ascorbate, whereas 2-heptyl-4-hydroxyquinoline-N-oxide (HOQNO), which inhibits "reverse" electron transfer, enhances the accumulation of leucine. The evidence suggests that ascorbate serves as an energy source for the uptake of leucine. PMID:417042

  6. Anti-angiogenic effect of high doses of ascorbic acid

    PubMed Central

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

    2008-01-01

    Pharmaceutical doses of ascorbic acid (AA, vitamin C, or its salts) have been reported to exert anticancer activity in vitro and in vivo. One proposed mechanism involves direct cytotoxicity mediated by accumulation of ascorbic acid radicals and hydrogen peroxide in the extracellular environment of tumor cells. However, therapeutic effects have been reported at concentrations insufficient to induce direct tumor cell death. We hypothesized that AA may exert anti-angiogenic effects. To test this, we expanded endothelial progenitor cells (EPCs) from peripheral blood and assessed, whether or not high dose AA would inhibit EPC ability to migrate, change energy metabolism, and tube formation ability. We also evaluated the effects of high dose AA on angiogenic activities of HUVECs (human umbilical vein endothelial cells) and HUAECs (human umbilical arterial endothelial cells). According to our data, concentrations of AA higher than 100 mg/dl suppressed capillary-like tube formation on Matrigel for all cells tested and the effect was more pronounced for progenitor cells in comparison with mature cells. Co-culture of differentiated endothelial cells with progenitor cells showed that there was incorporation of EPCs in vessels formed by HUVECs and HUAECs. Cell migration was assessed using an in vitro wound healing model. The results of these experiments showed an inverse correlation between AA concentrations relative to both cell migration and gap filling capacity. Suppression of NO (nitric oxide) generation appeared to be one of the mechanisms by which AA mediated angiostatic effects. This study supports further investigation into non-cytotoxic antitumor activities of AA. PMID:18789157

  7. Thermal stability of ascorbic acid and ascorbic acid oxidase in african cowpea leaves ( Vigna unguiculata ) of different maturities.

    PubMed

    Wawire, Michael; Oey, Indrawati; Mathooko, Francis; Njoroge, Charles; Shitanda, Douglas; Hendrickx, Marc

    2011-03-01

    Cowpea, an African leafy vegetable ( Vigna unguiculata ), contains a high level of vitamin C. The leaves harvested at 4-9 weeks are highly prone to vitamin C losses during handling and processing. Therefore, the purpose of this research was to study the effect of thermal treatment on the stability of ascorbic acid oxidase (AAO), total vitamin C content (l-ascorbic acid, l-AA), and dehydroascorbic acid (DHAA) and l-AA/DHAA ratio in cowpea leaves harvested at different maturities (4, 6, and 8 weeks old). The results showed that AAO activity, total vitamin C content, and l-AA/DHAA ratio in cowpea leaves increased with increasing maturity (up to 8 weeks). Eight-week-old leaves were the best source of total vitamin C and showed a high ratio of l-AA/DHAA (4:1). Thermal inactivation of AAO followed first-order reaction kinetics. Heating at temperatures above 90 °C for short times resulted in a complete AAO inactivation, resulting in a protective effect of l-AA toward enzyme-catalyzed oxidation. Total vitamin C in young leaves (harvested at 4 and 6 weeks) was predominantly in the form of DHAA, and therefore temperature treatment at 30-90 °C for 10 min decreased the total vitamin C content, whereas total vitamin C in 8-week-old cowpea leaves was more than 80% in the form of l-AA, so that a high retention of the total vitamin C can be obtained even after heating and/or reheating (30-90 °C for 10 min) before consumption. The results indicated that the stability of total vitamin C in situ was strongly dependent on the plant maturity stage and the processing conditions applied. PMID:21309563

  8. Reductive dechlorination of carbon tetrachloride using buffered alkaline ascorbic acid.

    PubMed

    Lin, Ya-Ting; Liang, Chenju

    2015-10-01

    Alkaline ascorbic acid (AA) was recently discovered as a novel in-situ chemical reduction (ISCR) reagent for remediating chlorinated solvents in the subsurface. For this ISCR process, the maintenance of an alkaline pH is essential. This study investigated the possibility of the reduction of carbon tetrachloride (CT) using alkaline AA solution buffered by phosphate and by NaOH. The results indicated that CT was reduced by AA, and chloroform (CF) was a major byproduct at a phosphate buffered pH of 12. However, CT was completely reduced by AA in 2M NaOH without CF formation. In the presence of iron/soil minerals, iron could be reduced by AA and Fe(2+) tends to precipitate on the mineral surface to accelerate CT degradation. A simultaneous transfer of hydrogenolysis and dichloroelimination would occur under phosphate buffered pH 12. This implies that a high alkaline environment is a crucial factor for maintaining the dominant pathway of two electron transfer from dianionic AA to dehydroascorbic acid, and to undergo dichloroelimination of CT. Moreover, threonic acid and oxalic acid were identified to be the major AA decomposition products in alkaline solutions. PMID:25912910

  9. Expression of Ascorbic Acid Oxidase in Zucchini Squash (Cucurbita pepo L.).

    PubMed

    Lin, L S; Varner, J E

    1991-05-01

    The expression of ascorbic acid oxidase was studied in zucchini squash (Cucurbita pepo L.), one of the most abundant natural sources of the enzyme. In the developing fruit, specific activity of ascorbic acid oxidase was highest between 4 and 6 days after anthesis. Protein and mRNA levels followed the same trend as enzyme activity. Highest growth rate of the fruit occurred before 6 days after anthesis. Within a given fruit, ascorbic acid oxidase activity and mRNA level were highest in the epidermis, and lowest in the central placental region. In leaf tissue, ascorbic acid oxidase activity was higher in young leaves, and very low in old leaves. Within a given leaf, enzyme activity was highest in the fast-growing region (approximately the lower third of the blade), and lowest in the slow-growing region (near leaf apex). High expression of ascorbic acid oxidase at a stage when rapid growth is occurring (in both fruits and leaves), and localization of the enzyme in the fruit epidermis, where cells are under greatest tension during rapid growth in girth, suggest that ascorbic acid oxidase might be involved in reorganization of the cell wall to allow for expansion. Based on the known chemistry of dehydroascorbic acid, the end product of the ascorbic acid oxidase-catalyzed reaction, we have proposed several hypotheses to explain how dehydroascorbic acid might cause cell wall "loosening." PMID:16668145

  10. Oxidation of L-ascorbic acid to dehydroascorbic acid on the surface of the red blood cell

    SciTech Connect

    Wagner, E.; Jennings, M.; Bennett, K.

    1986-05-01

    L-ascorbic acid-1-/sup 14/C when incubated with human blood did not bind irreversibly to any of the protein components of plasma but did migrate irreversibly into erythrocytes. Isolation and characterization via IR of the moiety trapped within the cell established its identity as apparently, unchanged L-ascorbic acid. When dehydroascorbic acid-1-/sup 14/C was incubated with human blood, the results were identical including the identity of the entrapped moiety, L-ascorbic acid. It was found that L-ascorbic acid was enzymatically oxidized on the surface of the red blood cell to dehydroascorbic acid which diffused through the lipid soluble portion of the cell membrane and was enzymatically reduced back to ascorbic acid within the cell.

  11. Photostabilization of ascorbic acid with citric acid, tartaric acid and boric acid in cream formulations.

    PubMed

    Ahmad, I; Ali Sheraz, M; Ahmed, S; Shad, Z; Vaid, F H M

    2012-06-01

    This study involves the evaluation of the effect of certain stabilizers, that is, citric acid (CT), tartaric acid (TA) and boric acid (BA) on the degradation of ascorbic acid (AH(2) ) in oil-in-water cream formulations exposed to the UV light and stored in the dark. The apparent first-order rate constants (0.34-0.95 × 10(-3) min(-1) in light, 0.38-1.24 × 10(-2) day(-1) in dark) for the degradation reactions in the presence of the stabilizers have been determined. These rate constants have been used to derive the second-order rate constants (0.26-1.45 × 10(-2) M(-1) min(-1) in light, 3.75-8.50 × 10(-3) M(-1) day(-1) in dark) for the interaction of AH(2) and the individual stabilizers. These stabilizers are effective in causing the inhibition of the rate of degradation of AH(2) both in the light and in the dark. The inhibitory effect of the stabilizers is in the order of CT > TA > BA. The rate of degradation of AH(2) in the presence of these stabilizers in the light is about 120 times higher than that in the dark. This could be explained on the basis of the deactivation of AH(2) -excited triplet state by CT and TA and by the inhibition of AH(2) degradation through complex formation with BA. AH(2) leads to the formation of dehydroascorbic acid (A) by chemical and photooxidation in cream formulations. PMID:22296174

  12. Polyethylene glycol plus ascorbic acid for bowel preparation in chronic kidney disease.

    PubMed

    Lee, Jae Min; Keum, Bora; Yoo, In Kyung; Kim, Seung Han; Choi, Hyuk Soon; Kim, Eun Sun; Seo, Yeon Seok; Jeen, Yoon Tae; Chun, Hoon Jai; Lee, Hong Sik; Um, Soon Ho; Kim, Chang Duck; Kim, Myung Gyu; Jo, Sang Kyung

    2016-09-01

    The safety of polyethylene glycol plus ascorbic acid has not been fully investigated in patients with renal insufficiency. High-dose ascorbic acid could induce hyperoxaluria, thereby causing tubule-interstitial nephritis and renal failure. This study aims to evaluate the safety and efficacy of polyethylene glycol plus ascorbic acid in patients with chronic kidney disease.We retrospectively reviewed prospectively collected data on colonoscopy in patients with impaired renal function. Patients were divided into 2 groups: 2 L polyethylene glycol plus ascorbic acid (n = 61) and 4 L polyethylene glycol (n = 80). The safety of the 2 groups was compared by assessing the differences in laboratory findings before and after bowel cleansing.The laboratory findings were not significantly different before and after the administration of 2 L polyethylene glycol plus ascorbic acid or 4 L polyethylene glycol. In both groups, the estimated glomerular filtration rate was not influenced by the administration of the bowel-cleansing agent. Patients' reports on tolerance and acceptability were better in the 2 L polyethylene glycol plus ascorbic acid group than in the 4 L polyethylene glycol group.The 2 L polyethylene glycol plus ascorbic acid solution is a safe choice for bowel preparation before colonoscopy in patients with impaired renal function. PMID:27603372

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

    NASA Astrophysics Data System (ADS)

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

    2004-09-01

    Beef loins with 3 different aging times after slaughter were ground, added with none, 0.1% ascorbic acid, 0.01% sesamol+0.01% α-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+α-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.

  14. Fluorescence probe for the convenient and sensitive detection of ascorbic acid

    PubMed Central

    Matsuoka, Yuta; Yamato, Mayumi; Yamada, Ken-ichi

    2016-01-01

    Ascorbic acid is an important antioxidant that plays an essential role in the biosynthesis of numerous bioactive substances. The detection of ascorbic acid has traditionally been achieved using high-performance liquid chromatography and absorption spectrophotometry assays. However, the development of fluorescence probes for this purpose is highly desired because they provide a much more convenient and highly sensitive technique for the detection of this material. OFF-ON-type fluorescent probes have been developed for the detection of non-fluorescent compounds. Photo-induced electron transfer and fluorescence resonance energy transfer are the two main fluorescence quenching mechanisms for the detection of ascorbic acid, and several fluorescence probes have been reported based on redox-responsive metals and quantum dots. Profluorescent nitroxide compounds have also been developed as non-metal organic fluorescence probes for ascorbic acid. These nitroxide systems have a stable unpaired electron and can therefore react with ascorbic acid and a strong fluorescence quencher. Furthermore, recent synthetic advances have allowed for the synthesis of α-substituted nitroxides with varying levels of reactivity towards ascorbic acid. In this review, we have discussed the design strategies used for the preparation of fluorescent probes for ascorbic acid, with particular emphasis on profluorescent nitroxides, which are unique radical-based redox-active fluorescent probes. PMID:26798193

  15. Inhibition of sugar uptake by ascorbic acid in Escherichia coli.

    PubMed

    Loewen, P C; Richter, H E

    1983-10-15

    The uptake of glucose by the glucose phosphotransferase system in Escherichia coli was inhibited greater than 90% by ascorbate. The uptake of the nonmetabolizable analog of glucose, methyl-alpha-glucoside, was also inhibited to the same extent, confirming that it was the transport process that was sensitive to ascorbate. Similarly, it was the transport function of mannose phosphotransferase for which mannose and nonmetabolizable 2-deoxyglucose were substrates that was partially inhibited by ascorbate. Other phosphotransferase systems, including those for the uptake of sorbitol, fructose and N-acetylglucosamine, but not mannitol, were also inhibited to varying degrees by ascorbate. The inhibitory effect on the phosphotransferase systems was reversible, required the active oxidation of ascorbate, was sensitive to the presence of free-radical scavengers, and was insensitive to uncouplers. Because ascorbate was not taken up by E. coli, it was concluded that the active inhibitory species was the ascorbate free radical and that it was interacting reversibly with a membrane component, possibly the different enzyme IIB components of the phosphotransferase systems. Ascorbate also inhibited other transport systems causing a slight reduction in the passive diffusion of glycerol, a 50% inhibition of the shock-sensitive uptake of maltose, and a complete inhibition of the proton-symport uptake of lactose. Radical scavengers had little or no effect on the inhibition of these systems. PMID:6357094

  16. Reduction of hexavalent chromium by ascorbic acid in aqueous solutions.

    PubMed

    Xu, Xiang-Rong; Li, Hua-Bin; Li, Xiao-Yan; Gu, Ji-Dong

    2004-11-01

    Hexavalent chromium is a priority pollutant in the USA and many other countries. Reduction of Cr(VI) to Cr(III) is environmentally favorable as the latter species is not toxic to most living organisms and also has a low mobility and bioavailability. Reduction of Cr(VI) by ascorbic acid (vitamin C) as a reductant was studied using potassium dichromate solution as the model pollutant. Effects of concentration of vitamin C, pH, temperature, irradiation and reaction time on the reduction of Cr(VI) were examined. Cr(VI) might be reduced by vitamin C not only in acidic conditions but also in weakly alkaline solutions. The reduction of Cr(VI) by vitamin C might occur not only under irradiation but also in the dark. Vitamin C is an important biological reductant in humans and animals, and not toxic. It is water-soluble and can easily permeate through various types of soils. The results indicate that vitamin C could be used in effective remediation of Cr(VI)-contaminated soils and groundwater in a wide range of pH, with or without sunlight. PMID:15488923

  17. Effects of ascorbic acid supplementation on copper-induced oxidative changes in human erythrocytes

    SciTech Connect

    Calabrese, E.J.; Kemp, J.

    1985-01-01

    A previously reported study indicated that ascorbic acid reduces the occurrence of copper acetate-induced methemoglobin (METHB) formation in vitro. The present study was designed to evaluate these findings in an in vivo exposure of ascorbic acid (1 gm/day) for up to four weeks with an in vitro copper acetate incubation stress at baseline (just prior to supplementation) and at two and four weeks after initiation of treatment. The results indicated that the ascorbic acid supplementation had no significant effects on the occurrence of copper acetate induced oxidant stress (i.e. METHB increase and GSH decrease). Possible explanations for this apparent discrepancy are provided.

  18. Optical properties of chitosan in aqueous solution of L- and D-ascorbic acids

    NASA Astrophysics Data System (ADS)

    Malinkina, Olga N.; Shipovskaya, Anna B.; Kazmicheva, Olga F.

    2016-04-01

    The optical properties of aqueous chitosan solutions in L- and D-ascorbic acids were studied by optical rotatory dispersion and spectrophotometry. The specific optical rotation [α] of all chitosan solutions tested was positive, in contrast to aqueous solutions of the ascorbic acid enantiomers, which exhibit an inverse relationship of [α] values. Significant differences in the absolute values of [α] of the chitosan solutions at polymer-acid ratios exceeding the equimolar one were found.

  19. Fluorimetric determination of total ascorbic acid by a stopped-flow mixing technique.

    PubMed

    Pérez-Ruiz, T; Martínez-Lozano, C; Tomás, V; Fenoll, J; Fenol, J

    2001-08-01

    A simple, rapid and automatic fluorimetric method for the determination of total ascorbic acid is described. The method makes use of the stopped-flow mixing technique in order to achieve the rapid oxidation of ascorbic acid by dissolved oxygen to dehydroascorbic acid, which then reacts with o-phenylenediamine to form a fluorescent quinoxaline. The initial rate and fluorescence signal of this system are directly proportional to the ascorbic acid concentration. The calibration graph was linear over the range 0.1-30 microg ml(-1) (kinetic method) and 0.25-34 microg ml(-1) (equilibrium method). The precision (% RSD) was close to 0.5%. The method has been used for the determination of ascorbic acid in pharmaceutical formulations, fruit juices, soft drinks and blood serum. PMID:11534621

  20. Ascorbic acid (AA) metabolism in protection against radiation damage

    SciTech Connect

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

    1986-03-05

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

  1. Ascorbic acid iontophoresis for chondral gain in rats with arthritis

    PubMed Central

    de Arruda, Mauricio Ferraz; Cassettari, Lucas Langoni; Neves, Lais Mara Siqueira das; Oliveira, Olga Maria Mascarenhas de Faria; Marcolino, Alexandre Márcio

    2014-01-01

    OBJECTIVES: To examine the cellularity and thickness of the articular cartilage of the femur in rats with arthritis after treatment with iontophoresis. METHODS: To evaluate these objectives, a histological analysis was performed on hematoxylin and eosin, where cellularity and cartilage thickness were observed and evaluated qualitatively and quantitatively by manual counting by 700.09µm² area. RESULTS: The group treated with IAA had normal cellularity (40.1 cells/μm2) and maintenance of non-calcified cartilage (75.5μm), suggesting normal thickness. The non-treated group C+, on the other hand, had a lower mean number of chondrocytes (13.0μm2) (P <0.05) and, when the cartilage thickness was compared, it showed higher average thickness of calcified cartilage (104.8 mm) and lower mean of non-calcified cartilage (53.3μm) CONCLUSION: The use of iontophoresis with L-ascorbic acid by continuous electric current contributed to a quantitative gain of chondrocytes and improved the thickness distribution of calcified and non-calcified cartilage. Level of Evidence III, Case Control Study. PMID:25246850

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

    ERIC Educational Resources Information Center

    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)

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

    PubMed Central

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

    2015-01-01

    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. PMID:26633354

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

    PubMed

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

    2015-01-01

    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. PMID:26633354

  5. Transcriptome Profiling of Tomato Fruit Development Reveals Transcription Factors Associated with Ascorbic Acid, Carotenoid and Flavonoid Biosynthesis

    PubMed Central

    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

  6. Evidence of carrier mediated transport of ascorbic acid through mammalian cornea.

    PubMed

    Singla, Shivali; Majumdar, D K; Goyal, Sachin; Khilnani, Gurudas

    2011-07-01

    The purpose of the present study was to evaluate the transport of ascorbic acid, a water soluble molecule, through a predominantly lipophilic cornea. Thus in-vitro permeation of ascorbic acid from aqueous drops through freshly excised mammalian cornea was studied. Aqueous isotonic ophthalmic solutions of ascorbic acid of different concentrations (0.125% w/v to 2% w/v) (pH 5.4) were made. Further 1.0% w/v or 0.5% w/v ascorbic acid solution containing NaCl or dextrose as tonicity modifiers or Na(+)K(+)-ATPase inhibitors were also made. Permeation characteristics of drug were evaluated by putting 1 ml formulation on freshly excised cornea fixed between donor and receptor compartments of an all-glass modified Franz diffusion cell and measuring the drug permeated in the receptor by spectrophotometry at 265 nm, after 120 min. Statistical analysis was done by one-way analysis of variance (ANOVA) followed by Dunnett's test or paired t-test. Increase in drug concentration in the formulation resulted in an increase in the quantity permeated but after a certain level increase in permeation with increase in concentration was minimal. Aqueous drops made isotonic with dextrose showed decreased permeation through paired cornea compared with aqueous drops made isotonic with NaCl from 1% w/v ascorbic acid solution suggesting likely involvement of Na(+) co-transporter but there was decreased permeation through 0.5% w/v ascorbic acid solution made isotonic with NaCl as compared to solution made isotonic with dextrose. Further aqueous drops containing Na(+)K(+)-ATPase inhibitor {MAG-Mono Ammonium Glycyrrhizinate (25 μmol)} showed decreased corneal permeation from 0.5% w/v ascorbic acid solution but there was not significant decrease from 1% ascorbic acid solution since MAG is a competitive inhibitor of ascorbic acid. Aqueous drops containing Na(+)K(+)-ATPase inhibitor {MAG (50 μmol) or Ouabain (1 mmol)} showed decreased corneal permeation of ascorbic acid compared with control

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

    PubMed

    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. PMID:25204396

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

    SciTech Connect

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

    1981-11-16

    The effects of ascorbic acid on dopaminergic /sup 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 /sup 3/H-agonists N-propylnorapomorphine (NPA), apomorphine, or dopamine could be demonstrated in the absence of ascorbic acid. Although levels of total /sup 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 /sup 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 /sup 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 /sup 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 /sup 3/H-agonist binding to dopamine receptors.

  9. Ascorbic Acid Ameliorates Nicotine Exposure Induced Impaired Spatial Memory Performance in Rats

    PubMed Central

    Sirasanagandla, SR; Rooben, RK; Rajkumar; Narayanan, SN; Jetti, R

    2014-01-01

    Introduction: The long lasting behavioural and cognitive impairments in offspring prenatally exposed to nicotine have been confirmed in animal models. In the present study, we investigated the effect of ascorbic acid on prenatal nicotine exposure induced behavioural deficits in male offspring of rats. Methods: The pregnant Wistar dams were divided into four groups of six rats: control, vehicle control, nicotine and nicotine+ascorbic acid groups. The nicotine group received daily dose of subcutaneous injections of 0.96 mg/kg body weight (bw) nicotine free base throughout gestation. Pregnant dams in nicotine+ascorbic acid group were first given nicotine free base (0.96 mg/kg bw/day; subcutaneous route) followed by ascorbic acid (50 mg/kg bw/day, orally) daily throughout gestation. The cognitive function of male offspring of all the experimental groups was studied using Morris water maze test at postnatal day 40. Results: Prenatal nicotine exposure altered spatial learning and memory in male offspring. However, treatment with ascorbic acid ameliorated these changes in rats. Conclusion: Ascorbic acid supplementation was found to be effective in preventing the prenatal nicotine exposure induced cognitive deficits in rat offspring to some extent. PMID:25429474

  10. Ascorbic acid protects against cadmium-induced endoplasmic reticulum stress and germ cell apoptosis in testes.

    PubMed

    Ji, Yan-Li; Wang, Zhen; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Meng, Xiu-Hong; Xu, De-Xiang

    2012-11-01

    Cadmium (Cd) is a testicular toxicant which induces endoplasmic reticulum (ER) stress and germ cell apoptosis in testes. This study investigated the effects of ascorbic acid on Cd-evoked ER stress and germ cell apoptosis in testes. Male mice were intraperitoneally injected with CdCl(2) (2.0 mg/kg). As expected, a single dose of Cd induced testicular germ cell apoptosis. Interestingly, Cd-triggered testicular germ cell apoptosis was almost completely inhibited in mice treated with ascorbic acid. Interestingly, ascorbic acid significantly attenuated Cd-induced upregulation of GRP78 in testes. In addition, ascorbic acid significantly attenuated Cd-triggered testicular IRE1α and eIF2α phosphorylation and XBP-1 activation, indicating that this antioxidant counteracts Cd-induced unfolded protein response (UPR) in testes. Finally, ascorbic acid significantly attenuated Cd-evoked upregulation of CHOP and JNK phosphorylation, two components in ER stress-mediated apoptotic pathway. In conclusion, ascorbic acid protects mice from Cd-triggered germ cell apoptosis via inhibiting ER stress and UPR in testes. PMID:22569276

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

    PubMed

    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. PMID:25466074

  12. Quantitative Determination of Citric and Ascorbic Acid in Powdered Drink Mixes

    ERIC Educational Resources Information Center

    Sigmann, Samuella B.; Wheeler, Dale E.

    2004-01-01

    A procedure by which the reactions are used to quantitatively determine the amount of total acid, the amount of total ascorbic acid and the amount of citric acid in a given sample of powdered drink mix, are described. A safe, reliable and low-cost quantitative method to analyze consumer product for acid content is provided.

  13. Ascorbic acid metabolism in protection against free radicals: A radiation model

    SciTech Connect

    Rose, R.C. )

    1990-06-15

    The role of ascorbic acid in scavenging free radicals was evaluated in a model of mammalian colonic epithelium homogenized in physiologic buffer and exposed to ionizing radiation. Ascorbic acid interacts with hydroxyl free radicals, resulting in production of the ascorbate free radical (AFR). Colonic mucosa contains a soluble factor that is heat sensitive, PCA precipitable and is contained within 1,000 MW dialysis tubing; it uses GSH and cysteine to reduce AFR. The factor from rat colon is fractionated between 55 and 70% saturation with solid (NH4)2SO4; a 3-4 fold increase in enzyme activity was achieved. We suggest that the factor is a cytosolic enzyme appropriately referred to as soluble AFR-reductase. This information provides insight into the mechanism by which ascorbic acid protects against damage by hydroxyl free radicals.

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

    SciTech Connect

    Lin, Liangshiou; Varner, J.E. )

    1991-05-01

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

  15. Ascorbic acid recycling by cultured beta cells: effects of increased glucose metabolism.

    PubMed

    Steffner, Robert J; Wu, Lan; Powers, Alvin C; May, James M

    2004-11-15

    Ascorbic acid is necessary for optimal insulin secretion from pancreatic islets. We evaluated ascorbate recycling and whether it is impaired by increased glucose metabolism in the rat beta-cell line INS-1. INS-1 cells, engineered with the potential for overexpression of glucokinase under the control of a tetracycline-inducible gene expression system, took up and reduced dehydroascorbic acid to ascorbate in a concentration-dependent manner that was optimal in the presence of physiologic D-glucose concentrations. Ascorbate uptake did not affect intracellular GSH concentrations. Whereas depletion of GSH in culture to levels about 25% of normal also did not affect the ability of the cells to reduce dehydroascorbic acid, more severe acute GSH depletion to less than 10% of normal levels did impair dehydroascorbic acid reduction. Culture of inducible cells in 11.8 mM D-glucose and doxycycline for 48 h enhanced glucokinase activity, increased glucose utilization, abolished D-glucose-dependent insulin secretion, and increased generation of reactive oxygen species. The latter may have contributed to subsequent decreases in the ability of the cells both to maintain intracellular ascorbate and to recycle it from dehydroascorbic acid. Cultured beta cells have a high capacity to recycle ascorbate, but this is sensitive to oxidant stress generated by increased glucose metabolism due to culture in high glucose concentrations and increased glucokinase expression. Impaired ascorbate recycling as a result of increased glucose metabolism may have implications for the role of ascorbate in insulin secretion in diabetes mellitus and may partially explain glucose toxicity in beta cells. PMID:15477012

  16. Ascorbic Acid Determination in Commercial Fruit Juice Samples by Cyclic Voltammetry

    PubMed Central

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

    2008-01-01

    A method was developed for assessing ascorbic acid concentration in commercial fruit juice by cyclic voltammetry. The anodic oxidation peak for ascorbic acid occurs at about 490 mV on a Pt disc working electrode (versus SCE). The influence of the potential sweep speed on the peak height was studied. The obtained calibration graph shows a linear dependence between peak height and ascorbic acid concentration in the domain (0.1–10 mmol·L−1). The equation of the calibration graph was y = 6.391x + 0.1903 (where y represents the value of intensity measured for the anodic peak height, expressed as μA and x the analyte concentration, as mmol·L−1, r2 = 0.9995, r.s.d. = 1.14%, n = 10, Cascorbic acid = 2 mmol·L−1). The developed method was applied to ascorbic acid assessment in fruit juice. The ascorbic acid content determined ranged from 0.83 to 1.67 mmol·L−1 for orange juice, from 0.58 to 1.93 mmol·L−1 for lemon juice, and from 0.46 to 1.84 mmol·L−1 for grapefruit juice. Different ascorbic acid concentrations (from standard solutions) were added to the analysed samples, the degree of recovery being comprised between 94.35% and 104%. Ascorbic acid determination results obtained by cyclic voltammetry were compared with those obtained by the volumetric method with dichlorophenol indophenol. The results obtained by the two methods were in good agreement. PMID:19343183

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

    PubMed Central

    2011-01-01

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

  18. Effect of high-dose Ascorbic acid on vasopressor's requirement in septic shock

    PubMed Central

    Zabet, Mohadeseh Hosseini; Mohammadi, Mostafa; Ramezani, Masoud; Khalili, Hossein

    2016-01-01

    Objective: Effects of ascorbic acid on hemodynamic parameters of septic shock were evaluated in nonsurgical critically ill patients in limited previous studies. In this study, the effect of high-dose ascorbic acid on vasopressor drug requirement was evaluated in surgical critically ill patients with septic shock. Methods: Patients with septic shock who required a vasopressor drug to maintain mean arterial pressure >65 mmHg were assigned to receive either 25 mg/kg intravenous ascorbic acid every 6 h or matching placebo for 72 h. Vasopressor dose and duration were considered as the primary outcomes. Duration of Intensive Care Unit (ICU) stay and 28-day mortality has been defined as secondary outcomes. Findings: During the study period, 28 patients (14 in each group) completed the trial. Mean dose of norepinephrine during the study period (7.44 ± 3.65 vs. 13.79 ± 6.48 mcg/min, P = 0.004) and duration of norepinephrine administration (49.64 ± 25.67 vs. 71.57 ± 1.60 h, P = 0.007) were significantly lower in the ascorbic acid than the placebo group. No statistically significant difference was detected between the groups regarding the length of ICU stay. However, 28-day mortality was significantly lower in the ascorbic acid than the placebo group (14.28% vs. 64.28%, respectively; P = 0.009). Conclusion: High-dose ascorbic acid may be considered as an effective and safe adjuvant therapy in surgical critically ill patients with septic shock. The most effective dose of ascorbic acid and the best time for its administration should be determined in future studies. PMID:27162802

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    SciTech Connect

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

    1986-03-01

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

  2. Simultaneous determination of rutin and ascorbic acid mixture in their pure forms and combined dosage form.

    PubMed

    Attia, Tamer Z

    2016-12-01

    A simple, rapid, sensitive and selective high performance liquid chromatographic (HPLC) method with ultraviolet detection has been developed for simultaneous determination of ascorbic acid and rutin in pure forms and pharmaceutical dosage form. HPLC separation was performed on Phenomenex C18 analytical column with 0.1% v/v acetic acid in water and acetonitrile (75:25, v/v), as mobile phase. The separation was done at ambient temperature with flow rate of 1mL·min(-1) in isocratic mode. HPLC measurements were carried out using ultraviolet detection wavelength at 257nm. The average retention times were 2.72 and 7.00min for ascorbic acid and rutin, respectively. The calibration plots were constructed over the concentration range of 5.0-30.0 for ascorbic acid and 10.0-60.0μg·mL(-1) for rutin. The limits of detection were 1.06 and 1.89μg·mL(-1) and limits of quantification were 3.54 and 6.31μg·mL(-1) for ascorbic acid and rutin, respectively. The proposed HPLC-UV method was successfully applied for determination of ascorbic acid in its tablets and for simultaneous determination of the studied drugs in their laboratory prepared mixtures and in pharmaceutical formulation. Statistical comparisons of the results with the reference method show an excellent agreement and indicate no significant difference in respect to accuracy and precision. PMID:27341400

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

    SciTech Connect

    Frei, B. )

    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.

  4. Genotoxicity is modulated by ascorbic acid. Studies using the wing spot test in Drosophila.

    PubMed

    Kaya, Bülent; Creus, Amadeu; Velázquez, Antonia; Yanikoğlu, Atila; Marcos, Ricardo

    2002-09-26

    The ability of ascorbic acid (Vitamin C) to modulate the genotoxic action of several mutagens was investigated in the wing spot test of Drosophila melanogaster. In this assay, 3-day-old transheterozygous larvae for the multiple wing hairs (mwh, 3-0.3) and flare (flr, 3-38.8) genes were treated with three reference mutagenic compounds, namely cobalt chloride (CoCl2), 4-nitroquinoline 1-oxide (4-NQO) and potassium dichromate (K2Cr2O7). The results obtained show that the three reference mutagens tested were clearly genotoxic in the Drosophila wing somatic mutation and recombination test (SMART). None of the three concentrations tested of ascorbic acid (25, 75 and 250mM) induced significant increases in the frequency of the mutant clones recorded. When co-treatment experiments with ascorbic acid were carried out, different results were found. Thus, ascorbic acid was effective in reducing the genotoxicity of K2Cr2O7 virtually to the control level; on the contrary, it did not show any antigenotoxic effect on the genotoxicity of 4-NQO. Finally, co-treatments with CoCl2 and ascorbic acid show a significant increase in the frequency of mutant clones over the values obtained with CoCl2 alone. PMID:12297148

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

    SciTech Connect

    Chang, Soo Im; Jin, Bohwan; Youn, Pilju; Park, Changbo; Park, Jung-Duck; Ryu, Doug-Young . E-mail: dyryu@snu.ac.kr

    2007-01-15

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

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

    PubMed

    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. PMID:21384873

  7. The relationship between low leucocyte ascorbic-acid levels and tyrosine metabolism in the elderly.

    PubMed

    Windsor, A C; Hobbs, C B; Treby, D A; Gupta, C B

    1975-11-01

    Twenty-seven elderly men aged 69-94 years had tyrosine tolerance tests measured before and after receiving ascorbic acid 1 g daily for four days. There was a significant rise in the fasting and half-hourly mean plasma tyrosine levels after ascorbic acid administration in those subjects with an initial leucocyte ascorbic-acid level (LAA) below 15 micrograms/10(8) w.c.c. The peak of the tyrosine tolerance curve was also advanced following administration of ascorbic acid in those subjects with an initial LAA below 15 micrograms/10(8) w.c.c. A further ten elderly men aged 73-89 years had simultaneous measurements of the circadian rhythms of LAA, plasma cortisol and plasma tyrosine levels before and after receiving ascorbic acid 1 g daily for four days. All ten subjects showed a peak LAA level at 5 p.m. when saturated with vitamin C but there was no significant correlation between plasma cortisol changes and plasma tyrosine changes. Possible explanations for the results are discussed. PMID:803133

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

    PubMed

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

    2014-04-15

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

  9. A novel approach for reliable activity determination of ascorbic acid depending myrosinases.

    PubMed

    Kleinwächter, Maik; Selmar, Dirk

    2004-06-30

    Up to now, a wide array of methods for the determination of myrosinase activity has been described. These vary from the simple photometric estimation to highly sophisticated assays using radioactively labelled substrates. However, ascorbic acid--an effective activator of myrosinases--interferes with most of these enzyme tests. Unfortunately, in the past, such interferences were disregarded in many scientific examinations of myrosinases. Whereas such failings have less effects when the activation of myrosinases is not very distinctive, they are quite relevant in all cases where myrosinases are completely inactive in the absence of ascorbic acid. In this paper, the current methods for myrosinase determination are reviewed critically with special emphasis on putative interferences with ascorbic acid. Thereafter, an alternative and interference-free HPLC-based quantification method of the enzymatically produced glucose is presented. Due to the benzoylation of glucose, it becomes possible to quantify even those exiguous glucose concentrations, which are indispensable for correct determination of kinetic enzyme data in the presence of ascorbic acid. Using this new method, the activity of Tropaeolum majus myrosinase towards glucotropaeolin was analyzed. This enzyme shows a distinctive activation by ascorbic acid with maximal activation at a concentration of about 2 mM. PMID:15165756

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

    PubMed

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

    2014-02-01

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

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

    PubMed

    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. PMID:27240727

  12. Effect of L-ascorbic acid pretreatment on cadmium toxicity in the male Fischer (F344/NCr) rat.

    PubMed

    Shiraishi, N; Uno, H; Waalkes, M P

    1993-12-31

    Some studies have indicated that cadmium-induced lethality and selective injurious effects to specific tissues, such as testes or liver, can be prevented by pretreatment with the antioxidant L-ascorbic acid (ascorbic acid). However, the basis of this tolerance is unclear. We examined the effects of ascorbic acid pretreatment on cadmium toxicity in male Fischer (F344/NCr) rats. Cadmium treatment alone (25 mumol CdCl2/kg, s.c.) proved lethal, causing a 93% mortality within 72 h, but in rats pretreated with ascorbic acid (2 g/kg, s.c. 24, 12 and 1 h) cadmium-induced lethality was nearly prevented. Hepatic lesions, including hepatocellular necrosis, induced by cadmium were at least partially ameliorated by ascorbic acid pretreatment. Ascorbic acid pretreatment had no effect on cadmium-induced testicular lesions nor on cadmium content in testes, liver, kidney and urine. Ascorbic acid alone modestly increased hepatic metallothionein (MT), but not renal MT and had no effect on induction of hepatic or renal MT by cadmium. In contrast to liver and kidney, testicular cadmium-binding protein (TCBP) in rats exposed to cadmium alone decreased markedly. Moreover, the level of TCBP decreased unexpectedly in ascorbic acid pretreated rats as compared with control. These results indicate that ascorbic acid pretreatment decreases the toxicity of cadmium in the rat without markedly modifying its toxicokinetics or markedly stimulating MT synthesis. PMID:8303714

  13. Simultaneous detection of ascorbate and uric acid using a selectively catalytic surface.

    PubMed

    Nassef, Hossam M; Radi, Abd-Elgawad; O'Sullivan, Ciara

    2007-01-30

    The direct and selective detection of ascorbate at conventional carbon or metal electrodes is difficult due to its large overpotential and fouling by oxidation products. Electrode modification by electrochemical reduction of diazonium salts of different aryl derivatives is useful for catalytic, analytical and biotechnological applications. A monolayer of o-aminophenol (o-AP) was grafted on a glassy carbon electrode (GCE) via the electrochemical reduction of its in situ prepared diazonium salts in aqueous solution. The o-aminophenol confined surface was characterized by cyclic voltammetry. The grafted film demonstrated an excellent electrocatalytic activity towards the oxidation of ascorbate in phosphate buffer of pH 7.0 shifting the overpotential from +462 to +263 mV versus Ag/AgCl. Cyclic voltammetry and d.c. amperometric measurements were carried out for the quantitative determination of ascorbate and uric acid. The catalytic oxidation peak current was linearly dependent on the ascorbate concentration and a linear calibration curve was obtained using d.c. amperometry in the range of 2-20 microM of ascorbate with a correlation coefficient 0.9998, and limit of detection 0.3 microM. The effect of H2O2 on the electrocatalytic oxidation of ascorbate at o-aminophenol modified GC electrode has been studied, the half-life time and rate constant was estimated as 270 s, and 2.57x10(-3) s(-1), respectively. The catalytically selective electrode was applied to the simultaneous detection of ascorbate and uric acid, and used for their determination in real urine samples. This o-AP/GCE showed high stability with time, and was used as a simple and precise amperometric sensor for the selective determination of ascorbate. PMID:17386544

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  15. Thermodynamic and Ultrasonic Properties of Ascorbic Acid in Aqueous Protic Ionic Liquid Solutions

    PubMed Central

    Singh, Vickramjeet; Sharma, Gyanendra; Gardas, Ramesh L.

    2015-01-01

    In this work, we report the thermodynamic and ultrasonic properties of ascorbic acid (vitamin C) in water and in presence of newly synthesized ammonium based protic ionic liquid (diethylethanolammonium propionate) as a function of concentration and temperature. Apparent molar volume and apparent molar isentropic compression, which characterize the solvation state of ascorbic acid (AA) in presence of protic ionic liquid (PIL) has been determined from precise density and speed of sound measurements at temperatures (293.15 to 328.15) K with 5 K interval. The strength of molecular interactions prevailing in ternary solutions has been discussed on the basis of infinite dilution partial molar volume and partial molar isentropic compression, corresponding volume of transfer and interaction coefficients. Result has been discussed in terms of solute-solute and solute-solvent interactions occurring between ascorbic acid and PIL in ternary solutions (AA + water + PIL). PMID:26009887

  16. Enhancement of the Electrical Properties of CVD-Grown Graphene with Ascorbic Acid Treatment

    NASA Astrophysics Data System (ADS)

    Tang, Chunmiao; Chen, Zhiying; Zhang, Haoran; Zhang, Yaqian; Zhang, Yanhui; Sui, Yanping; Yu, Guanghui; Cao, Yijiang

    2016-02-01

    Ascorbic acid was used to modify to chemical vapor deposition (CVD)-grown graphene films transferred onto SiO2 substrate. Residual polymer (polymethyl methacrylate), Fe3+, Cl-, H2O, and O2 affected the electrical and thermal properties on graphene during the transfer or device fabrication processes. Exposure of transferred graphene to ascorbic acid resulted in significantly enhanced electrical properties with increased charge carrier mobility. All devices exhibited more than 30% improvement in room temperature carrier mobility in air. The carrier mobility of the treated graphene did not significantly decrease in 21 days. This result can be attributed to electron donation to graphene through the -OH functional group in ascorbic acid that is absorbed in graphene. This work provides a method to enhance the electrical properties of CVD-grown graphene.

  17. Simultaneous determination of iron (II) and ascorbic acid in pharmaceuticas based on flow sandwich technique.

    PubMed

    Vakh, Christina; Freze, Elena; Pochivalov, Alexsey; Evdokimova, Ekaterina; Kamencev, Mihail; Moskvin, Leonid; Bulatov, Andrey

    2015-01-01

    The simple and easy performed flow system based on sandwich technique has been developed for the simultaneous separate determination of iron (II) and ascorbic acid in pharmaceuticals. The implementation of sandwich technique assumed the injection of sample solution between two selective reagents and allowed the carrying out in reaction coil two chemical reactions simultaneously: iron (II) with 1,10-phenanthroline and ascorbic acid with sodium 2,6-dichlorophenolindophenol. For achieving of excellent repeatability and considerable reagent saving the various parameters such as flow rate, sample and reagent volumes, reaction coil length were also optimized. The limits of detection (LODs) obtained by using the developed flow sandwich-type approach were 0.2 mg L(-1) for iron (II) and 0.7 mg L(-1) for ascorbic acid. The suggested approach was validated according to the following parameters: linearity and sensitivity, precision, recoveries and accuracy. The sampling frequency was 41 h(-1). PMID:25862995

  18. Electrochemical impedance based chiral analysis of anti-ascorbutic drug: l-Ascorbic acid and d-ascorbic acid using C-dots decorated conductive polymer nano-composite electrode.

    PubMed

    Pandey, Indu; Kant, Rama

    2016-03-15

    Clinical manifestations owing to l-ascorbic acid for scurvy as comparison to d-ascorbic acid and challenges of chiral purity are overcome by using chiral selective conductive polymer nanocomposite which mimics antibodies and enzymes. A novel chiral selective imprinted polyaniline-ferrocene-sulfonic acid film has been electrochemically fabricated on C-dots modified pencil graphite electrode. The performance of the obtained l-ascorbic acid or d-ascorbic acid chiral selective sensor was investigated by electrochemical impedance spectroscopy, cyclic and differential pulse voltammetry. The surface characteristics of the C-dots, chiral sensor before and after the de-doping of chiral d- and l-ascorbic acid were characterized by scanning electron microscopy, Raman spectroscopy and X-ray diffraction spectroscopy. Excellent recognition results were obtained by difference in electron transfer resistance. The proposed chiral sensor is capable of measuring d-ascorbic acid or l-ascorbic acid in aqueous as well as in real and commercial samples within the range of 0.020-0.187 nM and 0.003-0.232 nM with detection limit of 0.00073 nM and 0.00016 nM, respectively. The proposed method has also been examined for the chiral selective recognition of ascorbic acid isomers (d- and l-) quantitatively, in complicated matrices of real samples. PMID:26499067

  19. Split-dose menthol-enhanced PEG vs PEG-ascorbic acid for colonoscopy preparation

    PubMed Central

    Sharara, Ala I; Harb, Ali H; Sarkis, Fayez S; Chalhoub, Jean M; Badreddine, Rami; Mourad, Fadi H; Othman, Mahmoud; Masri, Omar

    2015-01-01

    AIM: 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). METHODS: 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. RESULTS: 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). CONCLUSION: 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. PMID:25684963

  20. Phosphatidylcholine liposomes as carriers to improve topical ascorbic acid treatment of skin disorders

    PubMed Central

    Serrano, Gabriel; Almudéver, Patricia; Serrano, Juan-Manuel; Milara, Javier; Torrens, Ana; Expósito, Inmaculada; Cortijo, Julio

    2015-01-01

    Liposomes have been intensively investigated as carriers for different applications in dermatology and cosmetics. Ascorbic acid has potent antioxidant and anti-inflammatory properties preventing photodamage of keratinocytes; however, due to its instability and low skin penetration, an appropriate carrier is mandatory to obtain desirable efficacy. The present work investigates the ability of a specific ascorbate phosphatidylcholine (PC) liposome to overcome the barrier of the stratum corneum and deliver the active agent into the dermis to prevent photodamage. Abdominal skin from ten patients was used. Penetration of PC liposomes was tested ex vivo in whole skin, epidermis, and dermis by means of fluorescein and sodium ascorbate. Histology and Franz diffusion cells were used to monitor the percutaneous absorption. Ultraviolet (UV)-high performance liquid chromatography was used to analyze diffusion of sodium ascorbate through the different skin layers, while spectrofluorimetry and fluorescent microscopy were used for fluorescein monitoring. UVA/UVB irradiation of whole skin was applied to analyze the antioxidant capacity by Trolox assay and anti-inflammatory effects by tumor necrosis factor alpha and interleukin 1 beta enzyme-linked immunoassay. PC liposomal formulation improved skin penetration of fluorescein and ascorbate. Fluorescein PC liposomes showed better diffusion through epidermis than dermis while ascorbate liposomes showed better diffusion through the dermis than the epidermis. Ascorbate PC liposomes showed preventive antioxidant and anti-inflammatory properties on whole human skin irradiated with UVA/UVB. In summary, ascorbate PC liposomes penetrate through the epidermis and allow nonstable hydrophilic active ingredients reach epidermis and dermis preventing skin photodamage. PMID:26719718

  1. Study on NO2 absorption by ascorbic acid and various chemicals*

    PubMed Central

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

    2006-01-01

    Study on NO2 absorption aimed at seeking a better NO2 absorption chemical at pH 4.5~7.0 for application to existing wet flue gas desulfurization (FGD). The results from the double-stirred reactor indicated that ascorbic acid has very high absorption rate at this pH range. The rate constant of ascorbic acid reaction with NO2 (0~1000×10−6 mol/mol) is about 3.54×106 mol/(L·s) at pH 5.4~6.5 at 55 °C. PMID:16365924

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

    SciTech Connect

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

    1980-04-01

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

  3. Easy modification of glassy carbon electrode for simultaneous determination of ascorbic acid, dopamine and uric acid.

    PubMed

    Thiagarajan, Soundappan; Tsai, Tsung-Hsuan; Chen, Shen-Ming

    2009-04-15

    A glassy carbon electrode (GCE) has been modified by electrochemical oxidation in mild acidic media (0.1 mol l(-1) H(2)SO(4)) and could be applied for individual and simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Oxidized GCE shows a single redox couple (E(0)'=-2.5 mV) which is based on the formation functional groups during the electrochemical pretreatment process. Proposed GCE successfully decreases the over potentials for the oxidation process of these species (AA, DA and UA) comparing with bare GCE. The oxidized GCE has its own simplicity, stability, high sensitivity and possesses the potential for simultaneous determination of AA, DA and UA. PMID:19162467

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

    PubMed

    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. PMID:16159160

  5. Nanostructure Modified Microelectrode for Electrochemical Detection of Dopamine with Ascorbic Acid and Uric Acid.

    PubMed

    Kim, Kyeong-Jun; Choi, Jin-Ha; Pyo, Su-Hyun; Yun, Kwang-Seok; Lee, Ji-Young; Choi, Jeong-Woo; Oh, Byung-Keun

    2016-03-01

    Dopamine (DA) is one kind of neurotransmitter in central nervous system which is indicator of neural disease. For this reason, determination of DA concentration in central nervous system is very important for early diagnosis of neural disease. In this study, we designed micro electrode array and fabricated by MEMS technology. Furthermore, we fabricated 3-D conducting nanostructure on electrode surface for enhanced sensitivity and selectivity due to increased surface area. Compared with macro and normal micro electrode, the 3-D nanostructure modified micro electrode shows better electrical performance. These surface modified pin type electrode was applied to detect low concentration of DA and successfully detect various concentration of DA from 100 μM to 1 μM with linear relationship in the presence of ascorbic acid and uric acid. From these results, our newly designed electrode shows possibility to be applied as brain biosensor for neural disease diagnosis such as Parkinson's diseases. PMID:27455760

  6. The Planetary Biology of Ascorbate and Uric acid and their Relationship with the Epidemic of Obesity and Cardiovascular Disease

    PubMed Central

    Johnson, Richard J.; Gaucher, Eric A.; Sautin, Yuri Y.; Henderson, George N.; Angerhofer, Alex J.; Benner, Steven A.

    2008-01-01

    Humans have relatively low plasma ascorbate levels and high serum uric acid levels compared to most mammals due to the presence of genetic mutations in L-gulonolactone oxidase and uricase, respectively. We review the major hypotheses for why these mutations may have occurred. In particular, we suggest that both mutations may have provided a survival advantage to early primates by helping maintain blood pressure during periods of dietary change and environmental stress. We further propose that these mutations have the inadvertent disadvantage of increasing our risk for hypertension and cardiovascular disease in today’s society characterized by Western diet and increasing physical inactivity. Finally, we suggest that a “planetary biology” approach in which genetic changes are analyzed in relation to their biologic action and historical context may provide the ideal approach towards understanding the biology of the past, present and future. PMID:18331782

  7. NITROGEN DIOXIDE EXPOSURE AND LUNG ANTIOXIDANTS IN ASCORBIC ACID-DEFICIENT GUINEA PIGS

    EPA Science Inventory

    The authors have previously found that ascorbic acid (AA) deficiency in guinea pigs enhances the pulmonary toxicity of nitrogen dioxide (NO2). The present study showed that exposure to NO2 (4.8 ppm, 3 hr) significantly increased lung lavage fluid protein (a sensitive indicator of...

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

    EPA Science Inventory

    Plasmid DNA damage caused by methylated arsenicals, ascorbic acid and human liver ferritin.

    Arsenic causes cancer in human skin, urinary bladder, lung, liver and kidney and is a significant world-wide public health problem. Although the metabolism of inorganic arsenic is ...

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

    PubMed

    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. PMID:22419527

  10. Ascorbic Acid Profiles in 'Delicious' and 'Honeycrisp' Apples During on-Tree Development and Cold Storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reactive oxygen species (ROS) produced in plants are involved in a number of processes both beneficial (signal transduction) and detrimental (induction of physiological disorders). ROS toxicity can be ameliorated by a number of metabolic systems or compounds in plant tissue including L-Ascorbic acid...

  11. Interactive enhancements of ascorbic acid and iron in hydroxyl radical generation in quinone redox cycling.

    PubMed

    Li, Yi; Zhu, Tong; Zhao, Jincai; Xu, Bingye

    2012-09-18

    Quinones are toxicological substances in inhalable particulate matter (PM). The mechanisms by which quinones cause hazardous effects can be complex. Quinones are highly active redox molecules that can go through a redox cycle with their semiquinone radicals, leading to formation of reactive oxygen species. Electron spin resonance spectra have been reported for semiquinone radicals in PM, indicating the importance of ascorbic acid and iron in quinone redox cycling. However, these findings are insufficient for understanding the toxicity associated with quinone exposure. Herein, we investigated the interactions among anthraquinone (AQ), ascorbic acid, and iron in hydroxyl radical (·OH) generation through the AQ redox cycling process in a physiological buffer. We measured ·OH concentration and analyzed the free radical process. Our results showed that AQ, ascorbic acid, and iron have synergistic effects on ·OH generation in quinone redox cycling; i.e., ascorbyl radical oxidized AQ to semiquinone radical and started the redox cycling, iron accelerated this oxidation and enhanced ·OH generation through Fenton reactions, while ascorbic acid and AQ could help iron to release from quartz surface and enhance its bioavailability. Our findings provide direct evidence for the redox cycling hypothesis about airborne particle surface quinone in lung fluid. PMID:22891791

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

    PubMed Central

    Ragab-Depre, N J

    1982-01-01

    Treatment of secondary effluents with hydrogen peroxide (10 mg/liter)-ascorbic acid (10 mg/liter)-Cu2+ (0.5 mg/liter) for 60 min resulted in around 99% reduction of the initial plate count. Hydrogen peroxide could be replaced by other peroxygen compounds; ascorbic acid could be replaced by other reducing agents, of which sodium sulfite and ethanol were the most effective. Cu2+, however, could not be replaced by other metal ions without loss of bactericidal efficiency of the ternary combination. Enterobacteriaceae, total and fecal coliforms, staphylococci, and micrococci were reduced by 99.0 to 99.9%. Group D streptococci aerobic spores were reduced by 80 and 15%, respectively. Clostridium perfringens, yeasts, and molds were not killed by the disinfectant combinations. The effect of pH was only minor in the range from 6 to 7.5. At a higher pH value the bactericidal effects tended to decrease. The hydrogen peroxide-ascorbic acid-Cu2+ combination made it possible to obtain 99% reduction within 30 min. When using the hydrogen peroxide-sodium sulfite-Cu2+ or the hydrogen peroxide-ethanol-Cu2+ combinations, 60 min of contact time was necessary to obtain 99% reduction of the initial plate count. Cu2+ combined to an intermediate product of the ascorbic acid autoxidation is the toxic agent, and its penetration into the cell is promoted by hydrogen peroxide. PMID:7138000

  13. Plasma ascorbic acid level and erythrocyte fragility in preeclampsia and eclampsia.

    PubMed

    Ozan, H; Esmer, A; Kolsal, N; Copur, O U; Ediz, B

    1997-01-01

    An imbalance between oxidants and antioxidants in the circulation is blamed to cause preeclampsia and eclampsia. In this study plasma ascorbic acid level was analysed in 13 eclamptic, 14 mild preeclamptic, 12 severe preeclamptic and 20 uncomplicated pregnancies to see whether there is any correlation with blood pressure, proteinuria, serum triglyceride level, erythrocyte fragility and leukocyte count. Plasma ascorbic acid level was normal and had no significant difference among the groups. Fasting serum triglyceride level was significantly higher in the study group than in the control group but it did not differ among the three study groups. Erythrocyte fragility was found to be increased in all three study groups. Blood leukocyte count was increased in the study groups, especially in the eclampsia group. However, plasma ascorbic acid level and erythrocyte fragility were found to have no significant correlation with blood pressure and proteinuria. It was concluded that though the ascorbic acid levels were normal in both the study and the control groups, erythrocyte fragility increased probably due to an elevation in peroxide and free radical levels in preeclampsia and eclampsia groups, but without any correlation with the severity of the clinical picture. PMID:9031958

  14. Aortic ascorbic acid, trace elements, and superoxide dismutase activity in human aneurysmal and occlusive disease

    SciTech Connect

    Dubick, M.A.; Hunter, G.C.; Casey, S.M.; Keen, C.L.

    1987-02-01

    Altered trace elements and ascorbic acid metabolism have been implicated in the pathogenesis of atherosclerotic cardiovascular disease. However, their role in the disease process, or the effect of atherosclerosis on their tissue levels within plaque, is poorly understood. The presence study analyzes the concentrations of Fe, Cu, Zn, and Mn, and ascorbic acid and superoxide dismutase (SOD) activity in tissue samples from 29 patients with abdominal aortic aneurysms (AAA) and 14 patients with atherosclerotic occlusive disease (AOD). It was observed that the Fe and Mn concentrations in AAA and AOD tissue were higher than the levels in nondiseased control aorta, whereas Cu and Zn levels in AAA and AOD tissue were similar to the levels in controls. The Zn:Cu ratio was significantly lower in the AAA tissue in comparison to both AOD and control tissue. In addition, AAA and AOD tissue had low ascorbic acid levels and low Cu, Zn-SOD activity with Cu,Zn-SOD:Mn-SOD ratios of 0.27 and 0.19, respectively, compared to a ratio of 3.20 in control aorta. These data indicate that aorta affected by aneurysms and occlusive disease have altered trace element and ascorbic acid concentrations, as well as low Cu,Zn-SOD activity. Although these observations do not directly support the hypothesis that AAA is associated with aortic Cu deficiency they do suggest a role for oxygen radicals or increased lipid peroxidation in occlusive and aneurysmal disease of the aorta.

  15. No evidence of carcinogenicity for L-ascorbic acid (vitamin C) in rodents

    SciTech Connect

    Douglas, J.F.; Huff, J.

    1984-01-01

    Carcinogenesis studies of L-ascorbic acid were conducted by offering diets containing 0, 25,000 or 50,000 ppm L-ascorbic acid to groups of 50 F344/N rats and 50 B6C3F/sub 1/ mice of each sex for 103 wk. Survival of dosed and control female rats and of dosed and control female mice were comparable. Survival of high-dose male rats was slightly greater than that of the controls, whereas survival of high-dose male mice was significantly greater than that of the controls. There were not observed differences in neoplasms between treated and control groups that were considered related to L-ascorbic acid. In female rats, several lesions usually seen in aged animals showed a dose-related decline. Under the conditions of these studies, L-ascorbic acid given at 2.5% or 5.0% in the diet for 103 wk was not toxic or carcinogenic for male and female F344/N rats or for male and female B6C3F/sub 1/ mice. 13 references, 2 table.

  16. Phasor transform to extract glucose and ascorbic acid data in an amperometric sensor.

    PubMed

    Iyengar, S; Hall, E A

    2000-11-01

    A method for separating the signals from glucose and ascorbic acid on a single recognition surface using an ac immittance technique is presented. It is proposed that each oxidation process can be represented by a unique vector based on psi and YO, and that the concentration of each analyte can be determined by monitoring the change in the admittance magnitude in the direction of the characteristic angle for that particular species. The total Faradaic admittance (YF,total) for all electroactive species present is given by a linear combination of the independent vectors from the different species. In the system tested, the analytes are glucose and ascorbic acid, the former being estimated via the measurand, hydrogen peroxide. Thus, one of the electroactive species (hydrogen peroxide) is not a bulk solution species, but is 'generated' in the enzyme matrix. The admittance measurements from ascorbic acid and the enzyme-generated hydrogen peroxide showed the characteristic phase angles of each oxidation signal, allowing for good spatial resolution. The behaviour of each of these analytes is presented and calibration curves tested. Based on the calibration curves and the basis vectors, samples containing both glucose and ascorbic acid were measured by transforming the measured total admittance from the complex Cartesian space into 'analyte space', where the X-Y axes are given by the basis vectors ŷEGHP,GOD and ŷAA,GOD, respectively. PMID:11193087

  17. Ascorbic acid abrogates microparticle generation and vascular injuries associated with high-pressure exposure.

    PubMed

    Yang, Ming; Bhopale, Veena M; Thom, Stephen R

    2015-07-01

    We hypothesized that pathological changes associated with elevations in annexin V-positive microparticles (MPs) following high-pressure exposures can be abrogated by ascorbic acid in a murine model. Mice exposed for 2 h to 790-kPa air and killed at 2 or 13 h postdecompression exhibited over threefold elevations in circulating MPs, as well as subgroups bearing Ly6G, CD41, Ter119, CD31, and CD142 surface proteins. There was evidence of significant neutrophil activation, platelet-neutrophil interactions, and vascular injury to brain, omentum, psoas, and skeletal muscles assessed as leakage of high-molecular-weight dextran. Prophylactic ascorbic acid (500 mg/kg ip) administration prevented all postdecompression neutrophil changes and vascular injuries. Ascorbic acid administration immediately after decompression abrogated most changes, but evidence of vascular leakage in the brain and skeletal muscle at 13 h postdecompression persisted. No significant elevations in these parameters occurred after injection of ascorbic acid alone. The findings support the idea that MP production occurring with exposures to elevated gas pressure is an oxidative stress response and that antioxidants may offer protection from pathological effects associated with decompression. PMID:25977448

  18. Impact of Ascorbic Acid Fortification on the Effectiveness of Biological Control Agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent developments in genetic engineering have paved the way for researchers to produce crops of high nutritional and yield value, in addition to being resistant to diseases and pests. Ascorbic acid content is one of the nutritive parameters researchers are trying to enhance in plants. This study ...

  19. The concentration of ascorbic acid and glutathione in 13 provenances of Acacia melanoxylon.

    PubMed

    Wujeska-Klause, Agnieszka; Bossinger, Gerd; Tausz, Michael

    2016-04-01

    Climate change can negatively affect sensitive tree species, affecting their acclimation and adaptation strategies. A common garden experiment provides an opportunity to test whether responses of trees from different provenances are genetically driven and if this response is related to factors at the site of origin. We hypothesized that antioxidative defence systems and leaf mass area ofAcacia melanoxylonR. Br. samples collected from different provenances will vary depending on local rainfall. Thirteen provenances ofA. melanoxylonoriginating from different rainfall habitats (500-2000 mm) were grown for 5 years in a common garden. For 2 years, phyllode samples were collected during winter and summer, for measurements of leaf mass area and concentrations of glutathione and ascorbic acid. Leaf mass area varied between seasons, years and provenances ofA. melanoxylon, and an increase was associated with decreasing rainfall at the site of origin. Ascorbic acid and glutathione concentrations varied between seasons, years (i.e., environmental factors) and among provenances ofA. melanoxylon In general, glutathione and ascorbic acid concentrations were higher in winter compared with summer. Ascorbic acid and glutathione were different among provenances, but this was not associated with rainfall at the site of origin. PMID:26960387

  20. Ascorbic acid attenuates the pressor response to voluntary apnea in postmenopausal women

    PubMed Central

    Randolph, Brittney J; Patel, Hardikkumar M; Muller, Matthew D

    2015-01-01

    We recently demonstrated that postmenopausal women have an augmented blood pressure response to voluntary apnea compared to premenopausal women. Both obstructive sleep apnea (OSA) and healthy aging are associated with increased oxidative stress, which may impair cardiovascular function. Restoring physiological responses could have clinical relevance since transient surges in blood pressure are thought to be an important stimulus for end-organ damage in aging and disease. We tested the hypothesis that acute antioxidant infusion improves physiological responses to voluntary apnea in healthy postmenopausal women (n = 8, 64 ± 2 year). We measured beat-by-beat mean arterial pressure (MAP), heart rate (HR), and brachial artery blood flow velocity (BBFV, Doppler ultrasound) following intravenous infusion of normal saline and ascorbic acid (∼3500 mg). Subjects performed maximal voluntary end-expiratory apneas and changes (Δ) from baseline were compared between infusions. The breath hold duration and oxygen saturation nadir were similar between saline (29 ± 6 sec, 94 ± 1%) and ascorbic acid (29 ± 5 sec, 94 ± 1%). Ascorbic acid attenuated the pressor response to voluntary apnea (ΔMAP: 6 ± 2 mmHg) as compared to saline (ΔMAP: 12 ± 2 mmHg, P = 0.034) and also attenuated forearm vasoconstriction (ΔBBFV: 4 ± 9 vs. −12 ± 7%, P = 0.049) but did not affect ΔHR. We conclude that ascorbic acid lowers the blood pressure response to voluntary apnea in postmenopausal women by inhibiting vasoconstriction in the limb vasculature. Whether ascorbic acid has similar effects in OSA patients remains to be prospectively tested. PMID:25907792

  1. Preliminary Clinical Study of the Effect of Ascorbic Acid on Colistin-Associated Nephrotoxicity

    PubMed Central

    Sirijatuphat, Rujipas; Limmahakhun, Samornrod; Sirivatanauksorn, Vorapan; Nation, Roger L.; Li, Jian

    2015-01-01

    Nephrotoxicity is a dose-limiting factor of colistin, a last-line therapy for multidrug-resistant Gram-negative bacterial infections. An earlier animal study revealed a protective effect of ascorbic acid against colistin-induced nephrotoxicity. The present randomized controlled study was conducted in 28 patients and aimed to investigate the potential nephroprotective effect of intravenous ascorbic acid (2 g every 12 h) against colistin-associated nephrotoxicity in patients requiring intravenous colistin. Thirteen patients received colistin plus ascorbic acid, whereas 15 received colistin alone. Nephrotoxicity was defined by the RIFLE classification system. Additionally, urinary neutrophil gelatinase-associated lipocalin (NGAL) and N-acetyl-beta-d-glucosaminidase (NAG) were measured as markers of renal damage, and plasma colistin concentrations were quantified. The baseline characteristics, clinical features, and concomitant treatments of the patients in the two groups were comparable. The incidences of nephrotoxicity were 53.8% (7/13) and 60.0% (9/15) in the colistin-ascorbic acid group and the colistin group, respectively (P = 0.956; relative risk [RR], 0.9; 95% confidence interval, 0.47 to 1.72). In both groups, the urinary excretion rates of NGAL and NAG on day 3 or 5 of colistin treatment and at the end of colistin treatment were significantly higher than those at the respective baselines (P < 0.05). However, the urinary excretion rates of these biomarkers at the various times during colistin treatment did not differ significantly between the groups (P > 0.05). The plasma colistin concentrations in the two groups were not significantly different (P > 0.28). The clinical and microbiological outcomes and mortality of the patients in the two groups were not significantly different. This preliminary study suggests that ascorbic acid does not offer a nephroprotective effect for patients receiving intravenous colistin. (This study has been registered at Clinical

  2. Myenteric neurons and intestinal mucosa of diabetic rats after ascorbic acid supplementation

    PubMed Central

    de Freitas, Priscila; Natali, Maria Raquel Marçal; Pereira, Renata Virginia Fernandes; Neto, Marcilio Hubner Miranda; Zanoni, Jacqueline Nelisis

    2008-01-01

    AIM: To investigate the effect of ascorbic acid (AA) dietary supplementation on myenteric neurons and epithelial cell proliferation of the jejunum of adult rats with chronic diabetes mellitus. METHODS: Thirty rats at 90 d of age were divided into three groups: Non-diabetic, diabetic and diabetic treated with AA (DA) (1 g/L). After 120 d of treatment with AA the animals were killed. The myenteric neurons were stained for myosin-V and analyzed quantitatively in an area of 11.2 mm2/animal. We further measured the cellular area of 500 neurons per group. We also determined the metaphasic index (MI) of the jejunum mucosa layer of about 2500 cells in the intestinal crypts, as well as the dimensions of 30 villi and 30 crypts/animal. The data area was analyzed using the Olympus BX40 microscope. RESULTS: There was an increase of 14% in the neuronal density (792.6 ± 46.52 vs 680.6 ± 30.27) and 4.4% in the cellular area (303.4 ± 5.19 vs 291.1 ± 6.0) respectively of the diabetic group treated with AA when compared to control diabetic animals. There were no significant differences in MI parameters, villi height or crypt depths among the groups. CONCLUSION: Supplementation with AA in the diabetic animal promoted moderate neuroprotection. There was no observation of alteration of the cellular proliferation of the jejunum mucosa layer of rats with chronic diabetes mellitus with or without supplementation with AA. PMID:19030205

  3. The determination of ascorbic acid and uric acid in human seminal plasma using an HPLC with UV detection.

    PubMed

    Kanďár, Roman; Drábková, Petra; Hampl, Radek

    2011-09-15

    Oxidative stress has been proposed as one of the potential causes for infertility in men. Ascorbic acid and uric acid play important role in protection of spermatozoa against free radicals. A method for the simultaneous determination of ascorbic acid and uric acid in human seminal plasma using HPLC with UV detection and investigation their clinical significance as antioxidants protecting male germ cells against oxidative damage are described. Semen samples were obtained from consecutive male partners of couples presenting for a fertility evaluation. After liquefaction, the samples were centrifuged and the supernatants were diluted with dithiothreitol solution and after a filtration injected onto an analytical column. For the separation, a reverse-phase column MAG 1, 250 mm × 4.6 mm, Labiospher PSI 100 C18, 5 μm, was used. The mixture of ethanol and 25 mmol/L sodium dihydrogenphosphate (2.5:97.5, v/v), pH 4.70 was used as a mobile phase. Analytical performance of this method is satisfactory for both ascorbic acid and uric acid: the intra-assay and inter-assay coefficients of variation were below 10%. Quantitative recoveries from spiked seminal plasma were between 92.1 and 102.1%. We have found no significant differences in both ascorbic acid and uric acid concentration between the smokers and non-smokers (351.0 ± 237.9 μmol/L and 323.7 ± 99.5 μmol/L vs. 444.8 ± 245.5 μmol/L and 316.6 ± 108.9 μmol/L, p>0.05). This assay is a simple and reproducible HPLC method for the simultaneous measurement of ascorbic acid and uric acid in human seminal plasma. PMID:21871848

  4. Elimination of the interfering effects of ascorbic acid in the electrochemical monitoring of bio-active constituents in body fluid samples by using the powder microelectrode technique

    NASA Astrophysics Data System (ADS)

    Cha, Chuan-sin; Chen, Jianyong

    2001-09-01

    Interference caused by ascorbic acid has been one of the most frequently encountered problems in the design of amperometric biosensors. The accuracy of the nowadays well- commercialized amperometric blood glucose monitor is still more or less affected by the fluctuation of ascorbic acid level in blood. The interference of ascorbic acid is serious and widespread.

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

    PubMed Central

    2009-01-01

    Background Fresh fruits are well accepted as a good source of the dietary antioxidant ascorbic acid (Asc, Vitamin C). However, fruits such as grapes do not accumulate exceptionally high quantities of Asc. Grapes, unlike most other cultivated fruits do however use Asc as a precursor for the synthesis of both oxalic (OA) and tartaric acids (TA). TA is a commercially important product in the wine industry and due to its acidifying effect on crushed juice it can influence the organoleptic properties of the wine. Despite the interest in Asc accumulation in fruits, little is known about the mechanisms whereby Asc concentration is regulated. The purpose of this study was to gain insights into Asc metabolism in wine grapes (Vitis vinifera c.v. Shiraz.) and thus ascertain whether the developmental demand for TA and OA synthesis influences Asc accumulation in the berry. Results We provide evidence for developmentally differentiated up-regulation of Asc biosynthetic pathways and subsequent fluctuations in Asc, TA and OA accumulation. Rapid accumulation of Asc and a low Asc to dehydroascorbate (DHA) ratio in young berries was co-ordinated with up-regulation of three of the primary Asc biosynthetic (Smirnoff-Wheeler) pathway genes. Immature berries synthesised Asc in-situ from the primary pathway precursors D-mannose and L-galactose. Immature berries also accumulated TA in early berry development in co-ordination with up-regulation of a TA biosynthetic gene. In contrast, ripe berries have up-regulated expression of the alternative Asc biosynthetic pathway gene D-galacturonic acid reductase with only residual expression of Smirnoff-Wheeler Asc biosynthetic pathway genes and of the TA biosynthetic gene. The ripening phase was further associated with up-regulation of Asc recycling genes, a secondary phase of increased accumulation of Asc and an increase in the Asc to DHA ratio. Conclusion We demonstrate strong developmental regulation of Asc biosynthetic, recycling and catabolic

  6. Metabolic engineering of Kluyveromyces lactis for L-ascorbic acid (vitamin C) biosynthesis

    PubMed Central

    2013-01-01

    Background L-ascorbic acid (L-AA) is naturally synthesized in plants from D-glucose by 10 steps pathway. The pathway branch to synthesize L-galactose, the key intermediate for L-ascorbic acid biosynthesis, has been recently elucidated. Budding yeast produces an 5-carbon ascorbic acid analogue Dehydro-D-arabinono 1,4-lactone (D-DAL), which is synthesized from D-arabinose. Yeast is able to synthesize L-ascorbic acid only if it is cultivated in the presence of one of its precursors: L-galactose, L-galactono 1,4-lactone, or L-gulono 1,4-lactone extracted from plants or animals. To avoid feeding the yeast culture with this “L” enantiomer, we engineered Kluyveromyces lactis with L-galactose biosynthesis pathway genes: GDP-mannose 3,5-epimerase (GME), GDP-L-galactose phosphorylase (VTC2) and L-galactose-1-phosphate phosphatase (VTC4) isolated from Arabidopsis thaliana. Results Plasmids were constructed and modified such that the cloned plant genes were targeted to the K. lactis LAC4 Locus by homologous recombination and that the expression was associated to the growth on D-galactose or lactose. Upon K. lactis transformation, GME was under the control of the native LAC4 promoter whereas VTC2 and VTC4 were expressed from the S. cerevisiae promoters GPD1 and ADH1 respectively. The expression in K. lactis, of the L-galactose biosynthesis genes was determined by Reverse Transcriptase-PCR and western blotting. The recombinant yeasts were capable to produce about 30 mg.L-1 of L-ascorbic acid in 48 hours of cultivation when cultured on rich medium with 2% (w/v) D-galactose. We also evaluated the L-AA production culturing recombinant recombinant strains in cheese whey, a waste product during cheese production, as an alternative source of lactose. Conclusions This work is the first attempt to engineer K. lactis cells for L-ascorbic acid biosynthesis by a fermentation process without any trace of “L” isomers precursors in the culture medium. We have engineered K. lactis

  7. Topical activity of ascorbic acid: from in vitro optimization to in vivo efficacy.

    PubMed

    Raschke, T; Koop, U; Düsing, H-J; Filbry, A; Sauermann, K; Jaspers, S; Wenck, H; Wittern, K-P

    2004-01-01

    We present here a new cosmetic formula system containing 3% ascorbic acid based on an optimized oil-in-water (O/W) emulsion. This formulation demonstrated a good long-term stability of the active ingredient and also of the emulsion itself. It could be deduced from in vitro release studies that this O/W emulsion enabled a better release of the hydrophilic active agent than an alternative W/O emulsion. By measuring the ultraweak photon emission, which is a well-established parameter for the oxidative stress in the skin, the high in vivo antioxidant capacity of 3% ascorbic acid was demonstrated after 1 week of product application. This placebo-controlled study also proved that ascorbic acid in an O/W cream reduced oxidative stress in human skin significantly better than the derivative sodium ascorbyl-2-phosphate, a more stable vitamin C replacement commonly used in cosmetic formulations. With increasing age, the number of papillae in the epidermal-dermal junction zone in human skin are reduced. This implies a possible consequence of reduced mechanical resistance of the skin and impaired supply of the epidermis with nutrients. In a 1-month placebo-controlled study on 25 human volunteers, a significant increase in the number of dermal papillae after application of the 3% ascorbic acid cream was demonstrated, using a confocal laser scanning microscope. Fine lines and wrinkles are a characteristic sign of aged and especially photo-aged skin. Application of 3% ascorbic acid in a 12-week placebo-controlled usage study indicated a significant reduction of facial wrinkles. Altogether, 3% ascorbic acid in a cosmetic O/W emulsion has been shown to be appropriately stable and to enable a good release of the active agent in vitro as a precondition for a high efficacy in vivo. Application in vivo resulted in a significant reduction of oxidative stress in the skin, an improvement of the epidermal-dermal microstructure and a reduction of fine lines and wrinkles in aged skin. These

  8. Effect of 3-methylcholanthrene-induced increases in ascorbic acid levels on tissue. beta. -glucuronidase activity in rats

    SciTech Connect

    Calabrese, E.J.; Barrett, T.J.; Leonard, D.A.; Horton, H.M.; Kenyon, E.M.

    1988-01-01

    The interrelationship between tissue ascorbic acid levels and tissue ..beta..-glucuronidase activity was examined in rats injected with 3-methylcholanthrene, an agent which induces ascorbic acid synthesis in rats. Six Fisher 344 rats were dosed intraperitoneally (IP) with 30 mg/kg of 3-methylcholanthrene. Ascorbic acid levels and ..beta..-glucuronidase (..beta..-G) activity were determined for lung, liver and kidney tissues. In a follow-up study, rats were dosed for three consecutive days with 3-methylcholanthrene. Controls in both groups were dosed IP with Emulphor (EL-620). Animals were sacrificed one week after the final dosage and lung, liver and kidney tissues were examined.

  9. A relationship between vitamin B sub 12 , folic acid, ascorbic acid, and mercury uptake and methylation

    SciTech Connect

    Zorn, N.E.; Smith, J.T. )

    1990-01-01

    Ingestion of megadoses of certain vitamins appears to influence the in vivo methylation of mercuric chloride in guinea pigs. The addition of megadoses of vitamin B{sub 12} fed either singularly or in combination with folic acid resulted in increased methylmercury concentrations in the liver. Moreover, percent methylmercury levels were significantly increased with B{sub 12} treatment in the liver (B{sub 12} only and B{sub 12}/folic acid) and brain (B{sub 12}/vitamin C). Incorporation of high levels of folic acid into the dietary regime also increased the methylmercury concentration particularly in the liver and hair tissues. The addition of vitamin C in the diet, particularly in combination with B{sub 12} (brain) or folic acid (muscle) resulted in increased methylmercury levels in these tissues and percent methylmercury values with B{sub 12} in the muscle and brain tissue.

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

    SciTech Connect

    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.

  11. Structure, spectra and antioxidant action of ascorbic acid studied by density functional theory, Raman spectroscopic and nuclear magnetic resonance techniques

    NASA Astrophysics Data System (ADS)

    Singh, Gurpreet; Mohanty, B. P.; Saini, G. S. S.

    2016-02-01

    Structure, vibrational and nuclear magnetic resonance spectra, and antioxidant action of ascorbic acid towards hydroxyl radicals have been studied computationally and in vitro by ultraviolet-visible, nuclear magnetic resonance and vibrational spectroscopic techniques. Time dependant density functional theory calculations have been employed to specify various electronic transitions in ultraviolet-visible spectra. Observed chemical shifts and vibrational bands in nuclear magnetic resonance and vibrational spectra, respectively have been assigned with the help of calculations. Changes in the structure of ascorbic acid in aqueous phase have been examined computationally and experimentally by recording Raman spectra in aqueous medium. Theoretical calculations of the interaction between ascorbic acid molecule and hydroxyl radical predicted the formation of dehydroascorbic acid as first product, which has been confirmed by comparing its simulated spectra with the corresponding spectra of ascorbic acid in presence of hydrogen peroxide.

  12. Impairment of ascorbic acid's anti-oxidant properties in confined media: inter and intramolecular reactions with air and vanadate at acidic pH.

    PubMed

    Crans, Debbie C; Baruah, Bharat; Gaidamauskas, Ernestas; Lemons, Brant G; Lorenz, Bret B; Johnson, Michael D

    2008-01-01

    The anti-oxidant properties of L-ascorbic acid were investigated in the confined medium produced by a sodium bis(2-ethylhexyl)sulfosuccinate (aerosol-OT, AOT) self-assembled reverse micelle. Using 1H-1H NOESY (proton-proton 2D nuclear overhauser enhancement correlation spectroscopy) NMR spectroscopy, the location of ascorbic acid was investigated and found to be at the AOT-interface in contrast to earlier studies where the ascorbate was assumed to be in the water pool in these microemulsions. The reaction of ascorbic acid with oxygen was investigated using EPR spectroscopy. A delocalized monoanionic ascorbate radical was observed in microemulsions prepared from pH 5.6 stock solutions. This is in contrast to studies carried out in aqueous media where no radical formation was observed. The oxidation of ascorbic acid by aqueous V(V) was investigated in reverse micelles. Modest changes in the kinetic parameters were observed for this system compared to that in water. Details of these reactions were examined and can be summarized as the microemulsion solvating and stabilizing reactive intermediates via rate inhibition or enhancement. The inhibition of the oxidation is due to solvation stabilization of ascorbic acid in microemulsion media. Since ascorbate is a valuable marker of oxidative stress, our results suggest that compartmentization can modify the stabilization of the ascorbate radical and the changes in properties could be important in biological systems. PMID:18331759

  13. Combined inhalational and oral supplementation of ascorbic acid may prevent influenza pandemic emergency: a hypothesis.

    PubMed

    Banerjee, Dibyajyoti; Kaul, Deepak

    2010-01-01

    Occurrence of influenza pandemics is a worldwide phenomenon and a significant cause of mortality and morbidity throughout the globe. It is due to mutations in the influenza virus genetic material creating antigenic drift of pathogenic viral proteins resulting in emergence of new influenza virus strains. Therefore, the vaccines available for prevention of influenza offer no protection against influenza pandemics caused by new virus strains. Moreover, the existing drugs used to combat influenza may be ineffective to treat influenza pandemics due to the emergence of drug resistance in the pandemic virus strain. Therefore, a working strategy must be developed to combat influenza pandemics. In this review we have addressed this problem and reviewed the published studies on ascorbic acid in the common cold and influenza and laboratory studies on the effect of ascorbic acid on influenza virus. We have also correlated the clinical and laboratory studies and developed a hypothesis to prevent influenza pandemics. PMID:20005468

  14. Miniaturized ascorbic acid fuel cells with flexible electrodes made of graphene-coated carbon fiber cloth

    NASA Astrophysics Data System (ADS)

    Hoshi, Kazuki; Muramatsu, Kazuo; Sumi, Hisato; Nishioka, Yasushiro

    2016-04-01

    Ascorbic acid (AA) is a biologically friendly compound and exists in many products such as sports drinks, fruit, and even in human blood. Thus, a miniaturized and flexible ascorbic acid fuel cell (AAFC) is expected be a power source for portable or implantable electric devices. In this study, we fabricated an AAFC with anode and cathode dimensions of 3 × 10 mm2 made of a graphene-coated carbon fiber cloth (GCFC) and found that GCFC electrodes significantly improve the power generated by the AAFC. This is because the GCFC has more than two times the effective surface area of a conventional carbon fiber cloth and it can contain more enzymes. The power density of the AAFC in a phosphate buffer solution containing 100 mM AA at room temperature was 34.1 µW/cm2 at 0.46 V. Technical issues in applying the AAFC to portable devices are also discussed.

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

    PubMed

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

    2013-03-15

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

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

    PubMed

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

    2014-09-01

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

  17. Spectroscopic investigation of the interaction between β-cyclodextrin and ascorbic acid

    NASA Astrophysics Data System (ADS)

    Bratu, Ioan; Muresan-Pop, Marieta; Kacso, Irina; Fărcaş, Sorin I.

    2009-08-01

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

  18. Sequence of morphological transitions in two-dimensional pattern growth from aqueous ascorbic Acid solutions.

    PubMed

    Paranjpe, A S

    2002-08-12

    A sequence of morphological transitions in two-dimensional dehydration patterns of aqueous solutions of ascorbic acid is observed with humidity as a control parameter. Change in morphology occurs due to humidity induced variation in the concentration of the metastable supersaturated solution phase formed after initial solvent evaporation. As percent humidity is varied from 40 to 80, patterns change from compact circular --> radial --> density modulated radial (a new morphology) --> density modulated circular --> density modulated dendritic (a new morphology) --> dense branching. PMID:12190528

  19. A clinical pilot study of lignin--ascorbic acid combination treatment of herpes simplex virus.

    PubMed

    Lopez, Blanca Silvia Gonzalez; Yamamoto, Masaji; Utsumi, Katsuaki; Aratsu, Chiaki; Sakagami, Hiroshi

    2009-01-01

    Antiviral drugs as well as natural remedies have been used to reduce symptoms and the rate of recurrences of herpes simplex virus type 1 (HSV-1) infection, a common disease. To evaluate anti-HSV-1 activity of a pine cone lignin and ascorbic acid treatment, a clinical pilot study was carried out. Forty-eight healthy patients of both genders between 4 and 61 years old (mean: 31+/-16 years), with active lesions of HSV-1, took part in the study. According to the HSV-1 stage at the presentation, the patients were classified into the prodromic (16 patients), erythema (11 patients), papule edema (1 patient), vesicle/pustule (13 patients) and ulcer stages (7 patients). One mg of lignin-ascorbic acid tablet or solution was orally administered three times daily for a month. Clinical evaluations were made daily the first week and at least three times a week during the second week after the onset and every six months during the subsequent year to identify recurrence episodes. The patients who began the lignin-ascorbic acid treatment within the first 48 hours of symptom onset did not develop HSV-1 characteristic lesions, whereas those patients who began the treatment later experienced a shorter duration of cold sore lesions and a decrease in the symptoms compared with previous episodes. The majority of the patients reported the reduction in the severity of symptoms and the reduction in the recurrence episodes after the lignin-ascorbic acid treatment compared with previous episodes, suggesting its possible applicability for the prevention and treatment of HSV-1 infection. PMID:20023248

  20. [Research on L-Ascorbic Acid and Thiamine Based on Wide-Band Terahertz Spectroscopy Technique].

    PubMed

    Li, Chun; Li, Miao; Jiang, Ling

    2015-03-01

    We employed terahertz time-domain spectra (THz-TDS) and Fourier transform infrared spectra (FTIR) to measure the terahertz spectroscopy of L-ascorbic acid and thiamine in the frequency region ranging from 0.10 to 3.50 THz. Molecular models of two vitamins have been shown, and based on above two spectroscopies, we compared the differences about the absorption spectra between the L-ascorbic acid and the thiamine. The measured results show that the absorption spectra obtained based on THz-TDS and FTIR are completely consistent in the frequency range of 0.70 to 3.00 THz. New fingerprint peaks obtained by the FTIR in the low frequency region from 0.30 to 0.50 THz in terms of high sensitive silicon bolometer detector, which are not found by the THz-TDS. Furthermore, several bands at 8.75, 8.85, 9.00, 9.30 and 10.30 THz, fingerprint peaks have been found in the frequency region from 8.00 to 12.00 THz for the thiamine sample obtained by the FTIR. Measurement results indicate the absorption spectra depend on the ratio of polyethylene powder mixed with the L-ascorbic acid. L-ascorbic acid has a lower absorption ability at THz band, so pure samples should be used for testing experiment. In addition, we calculated the refractive index for the two samples. This study has important implications for the discriminatory analysis of vitamins and the establishment of vitamin spectroscopy standard database. PMID:26117861

  1. Novel graphene flowers modified carbon fibers for simultaneous determination of ascorbic acid, dopamine and uric acid.

    PubMed

    Du, Jiao; Yue, Ruirui; Ren, Fangfang; Yao, Zhangquan; Jiang, Fengxing; Yang, Ping; Du, Yukou

    2014-03-15

    A novel and sensitive carbon fiber electrode (CFE) modified by graphene flowers was prepared and used to simultaneously determine ascorbic acid (AA), dopamine (DA) and uric acid (UA). SEM images showed that beautiful and layer-petal graphene flowers homogeneously bloomed on the surface of CFE. Moreover, sharp and obvious oxidation peaks were found at the obtained electrode when compared with CFE and glassy carbon electrode (GCE) for the oxidation of AA, DA and UA. Also, the linear calibration plots for AA, DA and UA were observed, respectively, in the ranges of 45.4-1489.23 μM, 0.7-45.21 μM and 3.78-183.87 μM in the individual detection of each component. By simultaneously changing the concentrations of AA, DA and UA, their oxidation peaks appeared at -0.05 V, 0.16 V and 2.6 V, and the good linear responses ranges were 73.52-2305.53 μM, 1.36-125.69 μM and 3.98-371.49 μM, respectively. In addition, the obtained electrode showed satisfactory results when applied to the determination of AA, DA and UA in urine and serum samples. PMID:24140872

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

    PubMed Central

    Moreau, Régis; Dabrowski, Konrad

    1998-01-01

    Although many vertebrates can synthesize ascorbic acid (vitamin C), it is still unclear from the evolutionary perspective when the ability to synthesize the vitamin first appeared in the animal kingdom and how frequently the trait has been lost. We report here ascorbic acid biosynthesis ability in sea lamprey (Petromyzon marinus) which represent the most ancient vertebrate lineage examined thus far for presence of gulonolactone oxidase, the enzyme catalyzing the terminal step in biosynthesis of vitamin C. This finding supports the view that the ancestors of living vertebrates were not scurvy prone and that the loss of gulonolactone oxidase activity subsequently occurred several times in vertebrate phylogeny. Adult sea lamprey allocate significant amounts of ascorbic acid to the gonads to guaranty high-quality gametes. Tissue stores of ascorbate were maintained by de novo synthesis (1.2–1.3 mg of ascorbic acid/300-g sea lamprey per day at 15°C) while sea lamprey fast during spawning migration. We estimate that the in vivo daily renewal rate of ascorbate is 4–5% of the whole-body ascorbate pool based on measurement of its biosynthesis and concentration in the whole animal. PMID:9707638

  3. Influence of rutin and ascorbic acid in colour, plum anthocyanins and antioxidant capacity stability in model juices.

    PubMed

    Hernández-Herrero, J A; Frutos, M J

    2015-04-15

    Model juices at pH 3.7 were prepared with different combinations of ascorbic acid, rutin (quercetin 3-rutinoside) and concentrated anthocyanin extract of plums (cv. Black Gold). The anthocyanins in the concentrated extract were cyanidin 3-glucoside and cyanidin 3-rutinoside, in a proportion of 76% and 24% respectively. The model juices were stored during 17 weeks in darkness at 20 °C. The colour stability was improved by the presence of rutin and strongly damaged by the ascorbic acid. The fortification of anthocyanin model juices with ascorbic acid originated the degradation of most of anthocyanins. However, anthocyanins improved ascorbic acid stability during storage. The copigmentation of anthocyanin and rutin showed a beneficial effect on colour stability from the 5 weeks of storage. In model juices prepared exclusively with purified plum extract a high correlation (R(2)=0.881) between anthocyanins and antioxidant capacity was found. PMID:25466051

  4. Evaluation of non-thermal effects of electricity on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating.

    PubMed

    Jaeschke, Débora Pez; Marczak, Ligia Damasceno Ferreira; Mercali, Giovana Domeneghini

    2016-05-15

    The effect of electric field on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating was evaluated. Ascorbic acid kinetic degradation was evaluated at 80, 85, 90 and 95°C during 60 min of thermal treatment by ohmic and conventional heating. Carotenoid degradation was evaluated at 90 and 95°C after 50 min of treatment. The different temperatures evaluated showed the same effect on degradation rates. To investigate the influence of oxygen concentration on the degradation process, ohmic heating was also carried out under rich and poor oxygen modified atmospheres at 90°C. Ascorbic acid and carotenoid degradation was higher under a rich oxygen atmosphere, indicating that oxygen is the limiting reagent of the degradation reaction. Ascorbic acid and carotenoid degradation was similar for both heating technologies, demonstrating that the presence of the oscillating electric field did not influence the mechanisms and rates of reactions associated with the degradation process. PMID:26775953

  5. Multicommutated stepwise injection determination of ascorbic acid in medicinal plants and food samples by capillary zone electrophoresis ultraviolet detection.

    PubMed

    Falkova, Marina T; Bulatov, Andrey V; Pushina, Maria O; Ekimov, Aleksey A; Alekseeva, Galina M; Moskvin, Leonid N

    2015-02-01

    An automation of the extraction of analytes from solid samples into the aqueous phase based on multicommutated stepwise injection analysis concept has been suggested. The feasibility of the approach has been demonstrated by determination of ascorbic acid as model analyte. The method includes automated extraction of ascorbic acid from solid sample into borate buffer solution pH 8 in mixing chamber during vigorous mixing by nitrogen stream, and subsequent detection by capillary zone electrophoresis at 254 nm. The method has a linear range of 0.1-5.0 mg g(-1) for ascorbic acid with the LOD of 0.03 mg g(-1). The sample throughput was 7 h(-1). This method was applied for determination of ascorbic acid in various medicinal plants and food samples. PMID:25435231

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

    PubMed Central

    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

  7. Effect of the electric field frequency on ascorbic acid degradation during thermal treatment by ohmic heating.

    PubMed

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

    2014-06-25

    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

  8. Facile synthesis of graphene from graphite using ascorbic acid as reducing agent

    NASA Astrophysics Data System (ADS)

    Andrijanto, Eko; Shoelarta, Shoerya; Subiyanto, Gatot; Rifki, Sadur

    2016-04-01

    Graphene has attracted a tremendous attention in recent years due to its unique properties such as mechanical, thermal, optical and electrical properties. However, a large scale production of this material is still an issue and subjected to intense research efforts. Here, we show a simple and green approach of the graphene synthesis from graphene oxide using ascorbic acid as reduction agent. A facile synthesis of graphene (rGO) through chemical oxidation of graphite into graphene oxide (GO) was described using modified Hummers method (Improved Tour Method/ITM). The ITM method does not produce toxic gas and the temperature of the oxidation is easily controlled using ice bath. The synthesized of graphene oxide was highly soluble and stable in water. The reduction of graphene oxide into graphene was performed using ascorbic acid (AA) in mild condition. The combined ITM method and green reduction using ascorbic acid open the avenue of replacing hydrazine in the reduction of graphite oxide into graphene and may be very important step for bulk production of graphene.

  9. Integrated bioinformatics to decipher the ascorbic acid metabolic network in tomato.

    PubMed

    Ruggieri, Valentino; Bostan, Hamed; Barone, Amalia; Frusciante, Luigi; Chiusano, Maria Luisa

    2016-07-01

    Ascorbic acid is involved in a plethora of reactions in both plant and animal metabolism. It plays an essential role neutralizing free radicals and acting as enzyme co-factor in several reaction. Since humans are ascorbate auxotrophs, enhancing the nutritional quality of a widely consumed vegetable like tomato is a desirable goal. Although the main reactions of the ascorbate biosynthesis, recycling and translocation pathways have been characterized, the assignment of tomato genes to each enzymatic step of the entire network has never been reported to date. By integrating bioinformatics approaches, omics resources and transcriptome collections today available for tomato, this study provides an overview on the architecture of the ascorbate pathway. In particular, 237 tomato loci were associated with the different enzymatic steps of the network, establishing the first comprehensive reference collection of candidate genes based on the recently released tomato gene annotation. The co-expression analyses performed by using RNA-Seq data supported the functional investigation of main expression patterns for the candidate genes and highlighted a coordinated spatial-temporal regulation of genes of the different pathways across tissues and developmental stages. Taken together these results provide evidence of a complex interplaying mechanism and highlight the pivotal role of functional related genes. The definition of genes contributing to alternative pathways and their expression profiles corroborates previous hypothesis on mechanisms of accumulation of ascorbate in the later stages of fruit ripening. Results and evidences here provided may facilitate the development of novel strategies for biofortification of tomato fruit with Vitamin C and offer an example framework for similar studies concerning other metabolic pathways and species. PMID:27007138

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

    PubMed

    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. PMID:27012422

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

    NASA Astrophysics Data System (ADS)

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

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

  12. Accumulation of ascorbate by endocrine-regulated and glucose-sensitive transport of dehydroascorbic acid in luteinized rat ovarian cells.

    PubMed

    Kodaman, P H; Aten, R F; Behrman, H R

    1998-02-01

    The corpus luteum is notable for very high levels of ascorbic acid. In luteal cells, ascorbic acid depletion occurs as a result of consumption during radical scavenging, inhibition of ascorbic acid uptake, and stimulation of its secretion. Oxidation of ascorbic acid generates dehydroascorbic acid (DHAA). Although levels of DHAA in blood are much lower than those of ascorbic acid, DHAA serves as the major transportable form of ascorbate for certain cell types. The aim of the present studies was to investigate whether DHAA transport is a potential mechanism for conserving ascorbic acid in the corpus luteum. DHAA uptake by rat luteal cells precultured for 24 h was linear for up to 30 min. Kinetics studies showed that uptake of DHAA was a concentration-dependent and saturable process with an estimated Michaelis constant (Km) of 830 microM and a maximum velocity (Vmax) of 700 pmol/min per 10(6) cells, a rate 50 times that of ascorbate transport. More than 90% of DHAA was reduced to ascorbic acid within 2 h of cellular uptake. DHAA uptake was energy- and microfilament-dependent, as transport was inhibited by 2,4-dinitrophenol (1 mM) and cytochalasin B (10 microM). Menadione (50 microM), an intracellular generator of reactive oxygen species, also markedly reduced DHAA uptake. In contrast to ascorbic acid transport, DHAA uptake was potently inhibited by glucose and phloretin, an inhibitor of glucose transporters, with IC50s of approximately 5 mM and 10 microM, respectively. DHAA uptake appears to occur via an insulin-insensitive transporter, as insulin (10 nM) had no effect on uptake. However, 24-h preincubation with insulin-like growth factor (IGF)-I dose-dependently (10-100 ng/ml) stimulated DHAA uptake; similar concentrations of IGF-II had no effect. The secretion of radioactivity by cells preloaded with radiolabeled DHAA was significantly increased by prostaglandin F2alpha (1 microM). The ability of luteal cells to transport DHAA in a regulated manner may serve to

  13. The protective role of ascorbic acid on hippocampal CA1 pyramidal neurons in a rat model of maternal lead exposure.

    PubMed

    Sepehri, Hamid; Ganji, Farzaneh

    2016-07-01

    Oxidative stress is a major pathogenic mechanism of lead neurotoxicity. The antioxidant ascorbic acid protects hippocampal pyramidal neurons against cell death during congenital lead exposure; however, critical functions like synaptic transmission, integration, and plasticity depend on preservation of dendritic and somal morphology. This study was designed to examine if ascorbic acid also protects neuronal morphology during developmental lead exposure. Timed pregnant rats were divided into four treatment groups: (1) control, (2) 100mg/kg ascorbic acid once a day via gavage, (3) 0.05% lead acetate in drinking water, and (4) 0.05% lead+100mg/kg oral ascorbic acid. Brains of eight male pups (P25) per treatment group were processed for Golgi staining. Changes in hippocampal CA1 pyramidal neurons' somal size were estimated by cross-sectional area and changes in dendritic arborization by Sholl's analysis. One-way ANOVA was used to compare results among treatment groups. Lead-exposed pups exhibited a significant decrease in somal size compared to controls (P<0.01) that was reversed by cotreatment with ascorbic acid. Sholl's analysis revealed a significant increase in apical dendritic branch points near cell body (P<0.05) and a decreased total dendritic length in both apical and basal dendritic trees of CA1 neurons (P<0.05). Ascorbic acid significantly but only partially reversed the somal and dendritic damage caused by developmental lead exposure. Oxidative stress thus contributes to lead neurotoxicity but other pathogenic mechanisms are also involved. PMID:26783884

  14. Anti-obesity effects of chitosan and psyllium husk with L-ascorbic acid in guinea pigs.

    PubMed

    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 < 0.05) lower than that in F-controls (high-fat diet group), and was similar to that in controls (normal diet group). L-Ascorbic acid enhanced significantly (p < 0.05) the increases of total fecal weight and fecal fat excretion by chitosan. The addition of L-Ascorbic acid to psyllium husk did not differ from psyllium husk alone in terms of changes in weight gain, plasma lipid levels, and fat pad weight. We found that the addition of L-Ascorbic acid to chitosan influenced the reduction in body weight gain and FER, and the increase in total fecal weight and fecal fat excretion in guinea pigs fed a high-fat diet. PMID:23065836

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  16. Evaluation of a sunscreen photoprotective effect by ascorbic acid assessment in human dermis using microdialysis and gas chromatography mass spectrometry.

    PubMed

    Lévêque, Nathalie; Mac-Mary, Sophie; Muret, Patrice; Makki, Safwat; Aubin, Francois; Kantelip, Jean-Pierre; Heusèle, Catherine; S, Schnebert; Humbert, Philippe

    2005-03-01

    Ultraviolet irradiation causes adverse effects like sunburn, photosensitivity reactions or immunologic suppression. The aim of this study was to evaluate the photo-protective outcome of a sunscreen cream (SPF8) by the determination of erythema indexes and the assessment of ascorbic acid and its metabolites in human dermis. These substances were used as markers of oxidative effect. Eight healthy female subjects were enrolled in this study. Two abdominal areas were exposed to solar simulated irradiation with three minimal erythema dose, one with SPF8 application and the other site without SPF8 application. Two other areas were used as control, one without SPF8 application and the other site after SPF8 application. Ascorbic acid and its metabolites (dehydroascorbic acid, threonic acid, oxalic acid and xylose) were collected from human dermis by microdialysis and assessed by gas chromatography mass spectrometry. Irradiated site without sunscreen application had significantly demonstrated lower dermis ascorbic acid concentrations and a higher erythema index than the three other sites (P < 0.05). Threonic acid, oxalic acid and xylose dermis concentrations were significantly higher in site III than in the control site I (P < 0.05). The protected-irradiated site did not show erythema formation and there was stability of ascorbic acid dermis concentrations with non-variation in its metabolites. The assessment of ascorbic acid and its metabolites in human dermis could be an efficient tool to demonstrate the oxidative process and consequently to control the efficiency of sunscreen creams against undesirable UV effects. PMID:15740589

  17. Antioxidant poly(lactic-co-glycolic) acid nanoparticles made with α-tocopherol-ascorbic acid surfactant.

    PubMed

    Astete, Carlos E; Dolliver, Debra; Whaley, Meocha; Khachatryan, Lavrent; Sabliov, Cristina M

    2011-12-27

    The goal of the study was to synthesize a surfactant made of α-tocopherol (vitamin E) and ascorbic acid (vitamin C) of antioxidant properties dubbed as EC, and to use this surfactant to make poly(lactic-co-glycolic) acid (PLGA) nanoparticles. Self-assembled EC nanostructures and PLGA-EC nanoparticles were made by nanoprecipitation, and their physical properties (size, size distribution, morphology) were studied at different salt concentrations, surfactant concentrations, and polymer/surfactant ratios. EC surfactant was shown to form self-assembled nanostructures in water with a size of 22 to 138 nm in the presence of sodium chloride, or 12 to 31 nm when synthesis was carried out in sodium bicarbonate. Polymeric PLGA-EC nanoparticles presented a size of 90 to 126 nm for 40% to 120% mass ratio PLGA to surfactant. For the same mass ratios, the PLGA-Span80 formed particles measured 155 to 216 nm. Span80 formed bilayers, whereas EC formed monolayers at the interfaces. PLGA-EC nanoparticles and EC showed antioxidant activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay measurements using UV and EPR techniques, antioxidant activity which is not characteristic to commercially available Span80. The thiobarbituric acid reactive substances (TBARS) assay for lipid peroxidation showed that PLGA nanoparticles with EC performed better as antioxidants than the EC nanoassembly or the free vitamin C. Nanoparticles were readily internalized by HepG2 cells and were localized in the cytoplasm. The newly synthesized EC surfactant was therefore found successful in forming uniform, small size polymeric nanoparticles of intrinsic antioxidant properties. PMID:22017172

  18. Enzymatic recycling of ascorbic acid from dehydroascorbic acid by glutathione-like peptides in the extracellular loops of aminergic G-protein coupled receptors.

    PubMed

    Root-Bernstein, Robert; Fewins, Jenna; Rhinesmith, Tyler; Koch, Ariana; Dillon, Patrick F

    2016-07-01

    The intracellular recycling of ascorbic acid from dehydroascorbic acid by the glutathione-glutathione reductase system has been well-characterized. We propose that extracellular recycling of ascorbic acid is performed in a similar manner by cysteine-rich, glutathione-like regions of the first and second extracellular loops of some aminergic receptors including adrenergic, histaminergic, and dopaminergic receptors. Previous research in our laboratory demonstrated that ascorbic acid binds to these receptors at a site on their first or second extracellular loops, significantly enhancing ligand activity, and apparently recycling hundreds of times their own concentration of ascorbate in an enzymatic fashion. In this study, we have synthesized 25 peptides from the first and second extracellular loops of aminergic and insulin receptors and compared them directly to glutathione for their ability to prevent the oxidation of ascorbate and to regenerate ascorbate from dehydroascorbic acid. Peptide sequences that mimic glutathione in containing a cysteine and a glutamic acid-like amino acid also mimic glutathione activity in effects and in kinetics. Some (but not all) peptide sequences that contain one or more methionines instead of cysteine can significantly retard the oxidation of ascorbic acid but do not recycle it from dehydroascorbate into ascorbate. Peptides lacking both cysteines and methionines uniformly failed to alter significantly ascorbate or dehydroascorbate oxidation or reduction. We believe that this is the first proof that receptors may carry out both ligand binding and enzymatic activity extracellularly. Our results suggest the existence of a previously unknown extracellular system for recycling ascorbate. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26749062

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Performance enhanced UV/vis spectroscopic microfluidic sensor for ascorbic acid quantification in human blood.

    PubMed

    Bi, Hongyan; Duarte, Carla M; Brito, Marina; Vilas-Boas, Vânia; Cardoso, Susana; Freitas, Paulo

    2016-11-15

    Quantitative analysis of antioxidants in a fast, simple and accurate manner is of great importance in the view of real-time monitoring the health of individuals. Recently, we have developed a UV/vis spectroscopic microfluidic sensor to specifically quantify ascorbic acid based on the immobilization of ascorbate oxidase, a relatively unstable enzyme. In this work, three different strategies for the immobilization of the unstable enzyme, including alumina sol-gel encapsulation, physisorption to PDMS channels with, and without alumina xerogel modification, were compared to build a microsensor. We found that the loading amount of the enzyme is not the determinative factor for the performance of the microfluidic biosensor but the retained activity of the enzyme and diffusion in the microfluidic channel. Taking into account of the two factors, the protocol of adsorbing enzymes to alumina (Al2O3) xerogel modified PDMS surface was demonstrated to be the best for preparing the microfluidic sensor among the utilized protocols. The microsensor prepared under the optimized protocol was further used to quantify ascorbic acid in human blood, where only dozens of microliters of blood (few drops) was required, demonstrating its potential application in clinical diagnosis. The developed strategy is featured with optimized enzymatic activity, simple process of microfluidic platform, low sample consumption, and straightforward spectrophotometry based detection. PMID:27236140

  1. Glycation by Ascorbic Acid Oxidation Products Leads to the Aggregation of Lens Proteins

    PubMed Central

    Linetsky, Mikhail; Shipova, Ekaterina; Cheng, Rongzhu; Ortwerth, Beryl J.

    2008-01-01

    Previous studies from this laboratory have shown that there are striking similarities between the yellow chromophores, fluorophores and modified amino acids released by proteolytic digestion from calf lens proteins ascorbylated in vitro and their counterparts isolated from aged and cataractous lens proteins. The studies reported in this communication were conducted to further investigate whether ascorbic acid-mediated modification of lens proteins could lead to the formation of lens protein aggregates capable of scattering visible light, similar to the high molecular aggregates found in aged human lenses. Ascorbic acid, but not glucose, fructose, ribose or erythrulose, caused the aggregation of calf lens proteins to proteins ranging from 2.2 × 106 up to 3.0 × 108 Da. This compared to proteins ranging from 1.8 × 106 up to 3.6 × 108 Da for the water-soluble (WS) proteins isolated from aged human lenses. This aggregation was likely due to the glycation of lens crystallins because [U-14C] ascorbate was incorporated into the aggregate fraction and because CNBH3, which reduces the initial Schiff base, prevented any protein aggregation. Reactions of ascorbate with purified crystallin fractions showed little or no aggregation of α-crystallin, significant aggregation of βH-crystallin, but rapid precipitation of purified βL- and γ-crystallin. The aggregation of lens proteins can be prevented by the binding of damaged crystallins to alpha-crystallin due to its chaperone activity. Depending upon the ratios between the components of the incubation mixtures, α-crystallin prevented the precipitation of the purified βL- and γ-crystallin fractions during ascorbylation. The addition of at least 20% of alpha-crystallin by weight into glycation mixtures with βL-, or γ-crystallins completely inhibited protein precipitation, and increased the amount of the high molecular weight aggregates in solution. Static and dynamic light scattering measurements of the supernatants from

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

    SciTech Connect

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

    1980-05-01

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

  3. Effects of protein deficiency and food restriction on lung ascorbic acid and glutathione in rats exposed to ozone

    SciTech Connect

    Dubick, M.A.; Heng, H.; Rucker, R.B.

    1985-08-01

    Weanling (52 +/- 4 g) or adult (259 +/- 16 g) male Sprague-Dawley rats were fed ad libitum casein-based diets containing 4 or 16% protein. A third group (food restricted) was fed daily the 16% protein diet, but at the food intake level of the 4% protein group. After 3 wk (weanling) or 5 wk (adults), half of the rats in each group were continuously exposed to 0.64 ppm ozone for 7 d. Ascorbic acid and reduced glutathione levels were then measured. In the heart and liver from weanling rats, ascorbic acid concentrations were lower in the protein-deficient group than in either control group. In the liver from weanling rats glutathione concentrations were also reduced in response to protein deficiency. Exposure to ozone produced no additional response. For adult rats the response for liver glutathione was similar to that of the weanlings. The liver ascorbate concentration, however, was consistently lower in adult rats compared to weanlings exposed to ozone. In lungs from adult rats, the ascorbic acid concentration was lower in the protein-deficient group than in either control group. On a whole-organ basis, both ascorbic acid and glutathione were usually higher in lungs from rats exposed to ozone than from those exposed to air. Interestingly, protein deficiency did not appear to compromise the lung's ability to maintain, in relative terms, the ascorbic acid or glutathione concentration in response to ozone.

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

    PubMed

    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. PMID:25407241

  5. Ameliorative Effect of Chronic Supplementation of Protocatechuic Acid Alone and in Combination with Ascorbic Acid in Aniline Hydrochloride Induced Spleen Toxicity in Rats

    PubMed Central

    Khairnar, Upasana; Upaganlawar, Aman; Upasani, Chandrashekhar

    2016-01-01

    Background. Present study was designed to evaluate the protective effects of protocatechuic acid alone and in combination with ascorbic acid in aniline hydrochloride induced spleen toxicity in rats. Materials and Methods. Male Wistar rats of either sex (200–250 g) were used and divided into different groups. Spleen toxicity was induced by aniline hydrochloride (100 ppm) in drinking water for a period of 28 days. Treatment group received protocatechuic acid (40 mg/kg/day, p.o.), ascorbic acid (40 mg/kg/day, p.o.), and combination of protocatechuic acid (20 mg/kg/day, p.o.) and ascorbic acid (20 mg/kg/day, p.o.) followed by aniline hydrochloride. At the end of treatment period serum and tissue parameters were evaluated. Result. Rats supplemented with aniline hydrochloride showed a significant alteration in body weight, spleen weight, feed consumption, water intake, hematological parameters (haemoglobin content, red blood cells, white blood cells, and total iron content), tissue parameters (lipid peroxidation, reduced glutathione, and nitric oxide content), and membrane bound phosphatase (ATPase) compared to control group. Histopathology of aniline hydrochloride induced spleen showed significant damage compared to control rats. Treatment with protocatechuic acid along with ascorbic acid showed better protection as compared to protocatechuic acid or ascorbic acid alone in aniline hydrochloride induced spleen toxicity. Conclusion. Treatment with protocatechuic acid and ascorbic acid in combination showed significant protection in aniline hydrochloride induced splenic toxicity in rats. PMID:27418998

  6. Ameliorative Effect of Chronic Supplementation of Protocatechuic Acid Alone and in Combination with Ascorbic Acid in Aniline Hydrochloride Induced Spleen Toxicity in Rats.

    PubMed

    Khairnar, Upasana; Upaganlawar, Aman; Upasani, Chandrashekhar

    2016-01-01

    Background. Present study was designed to evaluate the protective effects of protocatechuic acid alone and in combination with ascorbic acid in aniline hydrochloride induced spleen toxicity in rats. Materials and Methods. Male Wistar rats of either sex (200-250 g) were used and divided into different groups. Spleen toxicity was induced by aniline hydrochloride (100 ppm) in drinking water for a period of 28 days. Treatment group received protocatechuic acid (40 mg/kg/day, p.o.), ascorbic acid (40 mg/kg/day, p.o.), and combination of protocatechuic acid (20 mg/kg/day, p.o.) and ascorbic acid (20 mg/kg/day, p.o.) followed by aniline hydrochloride. At the end of treatment period serum and tissue parameters were evaluated. Result. Rats supplemented with aniline hydrochloride showed a significant alteration in body weight, spleen weight, feed consumption, water intake, hematological parameters (haemoglobin content, red blood cells, white blood cells, and total iron content), tissue parameters (lipid peroxidation, reduced glutathione, and nitric oxide content), and membrane bound phosphatase (ATPase) compared to control group. Histopathology of aniline hydrochloride induced spleen showed significant damage compared to control rats. Treatment with protocatechuic acid along with ascorbic acid showed better protection as compared to protocatechuic acid or ascorbic acid alone in aniline hydrochloride induced spleen toxicity. Conclusion. Treatment with protocatechuic acid and ascorbic acid in combination showed significant protection in aniline hydrochloride induced splenic toxicity in rats. PMID:27418998

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

    PubMed

    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

  8. Nitric Oxide Mediates Tightening of the Endothelial Barrier by Ascorbic Acid

    PubMed Central

    May, James M.; Qu, Zhi-chao

    2010-01-01

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

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

    PubMed Central

    Wong, Samuel Z. H.; Ching, Biyun; Chng, You R.; Wong, Wai P.; Chew, Shit F.; Ip, Yuen K.

    2013-01-01

    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. PMID:23825042

  10. Antioxidant activity, ascorbic acid and total phenol of exotic fruits occurring in Brazil.

    PubMed

    de Assis, Sandra Aparecida; Vellosa, José Carlos Rebuglio; Brunetti, Iguatemy Lourenço; Khalil, Najeh Maissar; Leite, Kátia Maria da Silva Cerqueira; Martins, Antonio Baldo Geraldo; Oliveira, Olga Maria Mascarenhas de Faria

    2009-08-01

    The antioxidant activity, ascorbic acid and phenolic content were studied in 10 exotic fruits from Brazil: abiu, acerola, wax jambu, cashew, mamey sapote, carambola or star fruit, Surinam cherry, longan, sapodilla and jaboticaba. The ascorbic acid was determined by 2,6-dichloroindophenol titrimetic methods and total phenols were measured colorimetrically using the Folin-Ciocalteu reagent. The antioxidant activity was investigated with three different methods: hypochlorous acid scavenging activity, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging method. The highest content of vitamin C (1,525.00 mg/100 g pulp) occurred in acerola. The total phenol content was higher in abiu, acerola, Surinam cherry and sapodilla. In relation to antioxidant activity, acerola has showed the great values in all three different methods tested. It was found that the fruits have a significant antioxidant effect when tested by each method, respectively, and these antioxidant capacities are promising. The sample concentration also influenced its antioxidant power. PMID:18785051