The ascorbic acid system in seeds: to protect and to serve

2003 ◽  
Vol 13 (4) ◽  
pp. 249-260 ◽  
Author(s):  
Mario C. De Tullio ◽  
Oreste Arrigoni
Keyword(s):  
Ascorbic Acid ◽  
Peroxidase Activity ◽  
Dehydroascorbic Acid ◽  
Acid System ◽  
Antioxidant Defences ◽  
Activity Increase ◽  
Orthodox Seeds ◽  
Aminocyclopropane Carboxylate Oxidase ◽  
Aminocyclopropane Carboxylate

The ascorbic acid (ASC) system functions dynamically in seeds, although the strategies for ASC production and utilization may vary according to seed developmental and functional stages. In orthodox seeds, ASC content and ASC peroxidase activity increase during the early stages of development, then decrease during the desiccation stage, so that, at quiescence, seeds have neither ASC nor ASC peroxidase, but retain a small amount of dehydroascorbic acid (DHA) and significant activities of ASC recycling enzymes. ASC and ASC peroxidase activity re-start after a few hours from the onset of imbibition. In contrast, the ASC system is little affected during germination of recalcitrant seeds. Although the presence of the ASC system in seeds has often been considered only within the framework of seed antioxidant defences, ASC function in seeds is also likely to be related to its action as a specific co-substrate required for the activity of dioxygenases (e.g. 1-aminocyclopropane carboxylate oxidase, gibberellic acid hydroxylases and 9-cis-epoxycarotenoid dioxygenases) involved in the synthesis of ethylene, gibberellins and abscisic acid, respectively. The possible role of ASC in coordinating the activities of these key enzymes is discussed.

An ESR study of the peroxidase reaction catalyzed by human methaemoglobin and methaemoglobin-haptoglobin complex

1991 ◽  
Vol 56 (4) ◽  
pp. 923-932
Author(s):  
Jana Stejskalová ◽  
Pavel Stopka ◽  
Zdeněk Pavlíček
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Amino Acid ◽  
Peroxidase Activity ◽  
Amino Acid Analysis ◽  
Superoxide Radical ◽  
Esr Spectra ◽  
The Other ◽  
Delocalized Electron

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.

scholarly journals Vitamin C and the Role of Citrus Juices as Functional Food

2009 ◽  
Vol 4 (5) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Nuria Martí ◽  
Pedro Mena ◽  
Jose Antonio Cánovas ◽  
Vicente Micol ◽  
Domingo Saura
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Dehydroascorbic Acid ◽  
Antioxidant Response ◽  
Intestinal Wall ◽  
Processing Temperature ◽  
High Concentration ◽  
Citrus Juices ◽  
Citrus Extract

The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Nonthermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life. The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidized to dehydroascorbic acid (DHAA), which is easily transported across the cell membrane and immediately reduced back to AA by two major pathways. AA bioavailability in the presence of flavonoids has yielded controversial results. Whereas flavonoids seem to inhibit intestinal absorption of AA, some studies have shown that AA in citrus extract was more available than synthetic ascorbic acid alone. DHAA is reported to possess equivalent biological activity to AA, so recent studies often consider the vitamin C activity in the diet as the sum of AA plus DHAA. However, this claimed equivalence should be carefully reexamined. Humans are one of the few species lacking the enzyme (L-gulonolactone oxidase, GLO) to convert glucose to vitamin C. It has been suggested that this is due to a mutation that provided a survival advantage to early primates, since GLO produces toxic H2O2. Furthermore, the high concentration of AA (and DHAA) in neural tissues could have been the key factor that caused primates (vertebrates with relative big brain) to lose the capacity to synthesize vitamin C. Oxidative damage has many pathological implications in human health, and AA may play a central role in maintaining the metabolic antioxidant response. The abundance of citrus juices in the Mediterranean diet may provide the main dietary source for natural vitamin C.

A basic peroxidase isoenzyme from the grape pedicel is induced by gibberellic acid

1999 ◽  
Vol 26 (4) ◽  
pp. 387 ◽  
Author(s):  
Francisco J. Pérez ◽  
Verónica Morales
Keyword(s):  
Ascorbic Acid ◽  
Gibberellic Acid ◽  
Peroxidase Activity ◽  
Hormone Treatment ◽  
Table Grape ◽  
Guaiacol Peroxidase ◽  
Peroxidase Isoenzymes ◽  
Peroxidase Isoenzyme ◽  
Soluble Peroxidase

Soluble peroxidase activity from pedicels of seedless table grape cv. Sultana was highly stimulated by post-bloom applications of gibberellic acid (GA3) to vines. The increase in peroxidase activity was mainly due to the induction of a basic peroxidase isoenzyme (pI > 9; BPrx-HpI). The activity of two other peroxidase isoenzymes of pI 6.5 and 3.2 was not altered by the hormone treatment. BPrx-HpI was induced by GA3 in pedicels and rachis but not in berries, although in berries peroxidase activity was also stimulated by post-bloom GA3 applications. BPrx-HpI oxidised guaiacol and ortho-phenylenediamine (o-PDA), while the others peroxidases found in the pedicel and in the berry oxidised only o-PDA. Hence, BPrx-HpI was characterised as a guaiacol-peroxidase showing no activity towards ascorbic acid (ASC). The possible role of BPrx-HpI in pedicel lignification and berry-drop caused by GA3 applications to cv. Sultana vines is discussed.

scholarly journals Content of vitamine C metabolites in rats organs at acute blood loss

2018 ◽  
Keyword(s):  
Oxidative Stress ◽  
Ascorbic Acid ◽  
Blood Loss ◽  
Dehydroascorbic Acid ◽  
Acute Blood Loss ◽  
Acid System ◽  
Control Value ◽  
Vitamine C ◽  
Acid Metabolites ◽  
Oxidative Processes

There has been studied the effect of acute blood loss, which was modeled by a single loss of 30% of the circulating blood, on the fluctuations in the content of ascorbic (AA), dehydroascorbic (DAA), diketogulonic (DKGA) acid and their sum in the organs of rats in dynamics for the fifth, twelfth, nineteenth and twenty-sixth days after the blood loss. Acute blood loss caused a significant decrease in the content of all parameters of the system of metabolites of ascorbic acid – their sum, AA, DAA and DKGA – by 10–73 % compared to the control. The most significant decrease was in the content of AA, which was not restored in all organs until the end of the study period. The DAA content in all organs increased from the 12th day, and then decreased during the experiment. The content of the DKGA increased from the 19th day of the experiment. At the same time, it was found that on 26th day in the kidneys, the DAA content exceeded the control value by 42%, and the content of DKGA in the liver and blood – by 25–60 %. The content of the amount of ascorbic acid metabolites at the end of the experiment was almost restored, but this recovery occurred in various ways: in the kidneys – due to an increase in the DAA content, in other organs – by increasing the concentration of DKGA. The parts of AA from the sum of acids (in %) after blood loss significantly decreased, starting from the 5th day, and the process of its recovery began to occur only after the 19th day. The ratio of the amount of the vitamin component of the acids of the ascorbic acid system to the content of the non-vitamin DKGA was increased in the kidneys on the 12th and 26th days of the experiment, in other organs this index decreased 2.3–3.1 times in comparison with the control. The obtained data can be explained by the increased consumption of ascorbic acid to neutralize the effects of the intensification of oxidative processes under oxidative stress, which were activated by the action of acute blood loss, due to its reversible conversion to dehydroascorbic acid, and the latter irreversibly to diketogulonic acid.

scholarly journals Hepatotoxicity of Pentavalent Antimonial Drug: Possible Role of Residual Sb(III) and Protective Effect of Ascorbic Acid

2013 ◽  
Vol 58 (1) ◽  
pp. 481-488 ◽  
Author(s):  
Kelly C. Kato ◽  
Eliane Morais-Teixeira ◽  
Priscila G. Reis ◽  
Neila M. Silva-Barcellos ◽  
Pascal Salaün ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Side Effects ◽  
Protective Effect ◽  
Peroxidase Activity ◽  
Hepatic Uptake ◽  
Control Group ◽  
Content Type ◽  
Meglumine Antimoniate ◽  
Effective Strategies

ABSTRACTPentavalent antimonial drugs such as meglumine antimoniate (Glucantime [Glu; Sanofi-Aventis, São Paulo, Brazil]) produce severe side effects, including cardiotoxicity and hepatotoxicity, during the treatment of leishmaniasis. We evaluated the role of residual Sb(III) in the hepatotoxicity of meglumine antimoniate, as well as the protective effect of the antioxidant ascorbic acid (AA) during antimonial chemotherapy in a murine model of visceral leishmaniasis. BALB/c mice infected withLeishmania infantumwere treated intraperitoneally at 80 mg of Sb/kg/day with commercial meglumine antimoniate (Glu) or a synthetic meglumine antimoniate with lower Sb(III) level (MA), in association or not with AA (15 mg/kg/day), for a 20-day period. Control groups received saline or saline plus AA. Livers were evaluated for hepatocytes histological alterations, peroxidase activity, and apoptosis. Increased proportions of swollen and apoptotic hepatocytes were observed in animals treated with Glu compared to animals treated with saline or MA. The peroxidase activity was also enhanced in the liver of animals that received Glu. Cotreatment with AA reduced the extent of histological changes, the apoptotic index, and the peroxidase activity to levels corresponding to the control group. Moreover, the association with AA did not affect the hepatic uptake of Sb and the ability of Glu to reduce the liver and spleen parasite loads in infected mice. In conclusion, our data supports the use of pentavalent antimonials with low residue of Sb(III) and the association of pentavalent antimonials with AA, as effective strategies to reduce side effects in antimonial therapy.

The Role of the Ascorbic Acid System in Delaying the Senescence of Oat (Avena sativa L.) Leaf Segments

1994 ◽  
Vol 144 (2) ◽  
pp. 161-166 ◽  
Author(s):  
G. Borraccino ◽  
L. Mastropasqua ◽  
S. De Leonardis ◽  
S. Dipierro
Keyword(s):  
Ascorbic Acid ◽  
Avena Sativa ◽  
Acid System ◽  
Leaf Segments

A novel biological role of dehydroascorbic acid: Inhibition of Na+-dependent transport of ascorbic acid

2014 ◽  
Vol 84 ◽  
pp. 12-17 ◽  
Author(s):  
Mara Fiorani ◽  
Catia Azzolini ◽  
Andrea Guidarelli ◽  
Liana Cerioni ◽  
Orazio Cantoni
Keyword(s):  
Ascorbic Acid ◽  
Dehydroascorbic Acid ◽  
Acid Inhibition ◽  
Biological Role ◽  
Dependent Transport

The contribution of ascorbic acid and dehydroascorbic acid to the protective role of pleura during inflammatory reactions

2007 ◽  
Vol 68 (4) ◽  
pp. 860-863 ◽  
Author(s):  
Eydoxia Gogou ◽  
Chryssi Hatzoglou ◽  
Vasileios Chamos ◽  
Sotirios Zarogiannis ◽  
Konstantinos. I. Gourgoulianis ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Dehydroascorbic Acid ◽  
Protective Role ◽  
Inflammatory Reactions
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