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Bean A C - - 2006
The temporomandibular joint (TMJ) disc is a specialized fibrocartilaginous tissue. When the disc becomes an obstacle and becomes damaged, surgeons have no choice but to perform a discectomy. Tissue engineering may provide a novel treatment modality for TMJ disorder patients who undergo discectomy. No studies have been conducted on the ...
Takebayashi Jun - - 2006
The aim of this study was to characterize the antioxidant activity of three ascorbic acid (AA) derivatives O-substituted at the C-2 position of AA: ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S). The radical-scavenging activities of these AA derivatives and some common low molecular-weight antioxidants ...
Ajay Machha - - 2006
1. There is a growing interest in the anti-oxidant characteristics and use of flavonoids in the management of cardiovascular diseases. The cardiovascular mechanism of action of these plant derivatives remains controversial. This study compared the effects of the flavonoid quercetin with those of the anti-oxidant vitamin ascorbic acid (vitamin C) ...
Candelario-Jalil Eduardo - - 2006
Inhibition of neuronal cyclooxygenase-2 (COX-2) and hence prostaglandin E2 (PGE2) synthesis by non-steroidal anti-inflammatory drugs has been suggested to protect neuronal cells in a variety of pathophysiological situations including Alzheimer's disease and ischemic stroke. Ascorbic acid (vitamin C) has also been shown to protect cerebral tissue in a variety of ...
Bremus Christoph - - 2006
L-Ascorbic acid has been industrially produced for around 70 years. Over the past two decades, several innovative bioconversion systems have been proposed in order to simplify the long time market-dominating Reichstein method, a largely chemical synthesis by which still a considerable part of L-ascorbic acid is produced. Here, we describe ...
Kirkova Margarita - - 2006
The effects of histamine H2-receptor antagonists, alone or in a combination with bismuth, on *OH-provoked degradation of deoxyribose were studied. The histamine H2-receptor antagonists (cimetidine, ranitidine and roxatidine), themselves decreased the deoxyribose damage in Fenton-type systems. In combinations with bismuth, their inhibitory effect in Fenton system (Fe(III)/ascorbic acid + H2O2 ...
Hernández-Guerra Manuel - - 2006
Patients with cirrhosis show intrahepatic endothelial dysfunction, characterized by an impaired flow-dependent vasorelaxation. This alteration is responsible for the marked postprandial increase in portal pressure and is attributed to an insufficient release of nitric oxide (NO). Ascorbic acid reverts endothelial dysfunction in other vascular disorders, via the increase of NO ...
Wang Yongzhong - - 2006
In human body ascorbic acid plays an essential role in the synthesis and function of skeletal tissues and immune system factors. Ascorbic acid is also a major physiological antioxidant, repairing oxidatively damaged biomolecules, preventing the formation of excessive reactive oxygen species or scavenging these species. We recently reported the synthesis ...
Das S - - 2006
The notion that oxidation of lipids and propagation of free radicals may contribute to the pathogenesis of atherosclerosis is supported by a large body of evidence. To circumvent the damage caused by oxygen free radicals, antioxidants are needed which provide the much needed neutralization of free radical by allowing the ...
Sato Hajime - - 2006
Ascorbic acid has been reported to promote the differentiation of embryonic stem (ES) cells into cardiomyocytes; however, the specific functions of ascorbic acid have not been defined. A stable form of ascorbic acid, namely, l-ascorbic acid 2-phosphate (A2-P), significantly enhanced cardiac differentiation; this was assessed by spontaneous beating of cardiomyocytes ...
Miyamoto Yuka - - 2006
We examined the participation of the superoxide anion radical (O(2)(-)) in the beneficial effects of L-ascorbic acid on heat-induced fish gel (Kamaboko). The generation of a thiyl radical (S.) in glutathione, ovalbumin, and actomyosin was examined by electron spin resonance spectroscopy coupled with spin trapping. O(2)(-) was provided by the ...
Rojas-Gonzalez Juan A - - 2006
The influence of thermal treatment (frying of plantain) on the micronutrients ascorbic acid, potassium and carotenoids is evaluated. Cylinders (diameter 30 mm, thickness 10 mm) of plantain (Musa AAB 'barraganete') were fried at four thermal treatments (120-180 degrees C and from 24 to 4 min) to obtain products with approximately ...
Horio Fumihiko - - 2006
ODS rat has a hereditary defect in ascorbic acid biosynthesis and is a useful animal model for elucidating the physiological role of ascorbic acid. We previously demonstrated by using ODS rats that ascorbic acid deficiency changes the hepatic gene expression of acute phase proteins, as seen in acute inflammation. In ...
Atkinson C J - - 2006
A number of strawberry varieties were surveyed for their total ellagic acid concentration, and attempts were made to determine if ellagic acid and ascorbic acid concentrations of two strawberry cultivars could be increased by polythene reflective mulches. After adjusting crop yields and cultivation using polythene mulches with two different PAR ...
Wang Chun-Chi - - 2006
L-ascorbic acid (LAA) can be used as a whitening agent in cosmetics. Because of its instability, some more stable derivatives have been developed to control melanin production, such as ascorbic acid-2-phosphate magnesium salt (AAPM) and ascorbic acid-6-palmitate (AA6P). To assess the quality of cosmetics, a micellar electrokinetic capillary electrophoresis technique ...
Eşrefoğlu Mukaddes M Department of Histology and Embryology, Faculty of Medicine, Inonu Universitesi, 44280, Malatya, Turkey. - - 2006
To investigate the role of oxidative injury in pancreatitis-induced hepatic damage and the effect of antioxidant agents such as melatonin, ascorbic acid and N-acetyl cysteine on caerulein-induced pancreatitis and associated liver injury in rats. Thirty-eight female Wistar rats were used. Acute pancreatitis (AP) was induced by two i.p. injections of ...
Suzuki Tatsuro - - 2006
A peroxidase (POX)-containing fraction was purified from buckwheat seed. The POX consisted of two isozymes, POX I and POX II, that were purified 6.6- and 67.4-fold, respectively. Their molecular weights were estimated to be 46.1 kDa (POX I) and 58.1 kDa (POX II) by gel filtration. While POX I and ...
Singh Biswajit K - - 2006
BACKGROUND: Tetramic acids with polyenyl substituents are an important class of compounds in medicinal chemistry. Both solid and solution phase syntheses of such molecules have been reported recently. Thiolactomycin, a clinical candidate for treatment of tuberculosis has led to further explorations in this class. We have recently developed an efficient ...
Barth Carina - - 2006
Ascorbic acid (AA) is not only an important antioxidant, it also appears to link flowering time, developmental senescence, programmed cell death, and responses to pathogens through a complex signal transduction network. The biological activity of AA is defined by its oxidation and subsequent regeneration into the reduced form. Some studies ...
Li Shu-De - - 2006
In the present work, we investigated the effect of ascorbic acid and glutathione on hemolysis induced by hemin in erythrocytes. Ascorbic acid not only enhanced hemolysis, but also induced formation of thiobarbituric acid-reactive substances in the presence of hemin. It has been shown that glutathione inhibits hemin-induced hemolysis by mediating ...
Ishikawa Takeshi - - 2006
Helicobacter pylori (H. pylori) infection, the main cause of chronic gastritis, increases gastric cancer risk. The infection causes inflammatory cells to produce reactive oxygen metabolites that may damage DNA and promote carcinogenesis. However, its precise role in gastric carcinogenesis is as yet unknown. Recently we reported that H. pylori water ...
Bhat Showket Hussain - - 2006
Several decades back ascorbic acid was proposed as an effective anticancer agent. However, this idea remained controversial and the mechanism of action unclear. In this paper, we show that ascorbic acid at a concentration reported to be achievable through high doses of oral consumption is capable of cytotoxic action against ...
Ramalingam K - - 2006
Juvenile shrimps (Penaeus monodon) weighing about 15-20 gms were procured from the grow-out ponds and reared under laboratory conditions. They were challenged with Vibrio parahaemolyticus MTCC 451 and their LD50 value was evaluated. The ascorbic acid and the histamine activity of both the control and experimental groups were assessed. The ...
Abdulmajed K - - 2006
Chemical and enzymatic hydrolysis of the co-drug of retinoic acid (vitamin A) and ascorbic acid (vitamin C) - retinyl ascorbate (RA-AsA)--have been studied. Firstly, the amount of protein and ester hydrolysis activity was determined in crude cellular extracts from freshly excised porcine ear skin (<3 h) and stored porcine ear ...
Saffi Jenifer - - 2006
Much has been published on the non-enzymatic antioxidant L-ascorbic acid (vitamin C), but even so its interaction with endogenous cellular defense systems has not yet been fully elucidated. Our study investigated the antioxidant activity of L-ascorbic acid in wild-type strain EG103 (SOD) Saccharomyces cerevisiae and isogenic mutant strains deficient in ...
H A Okeri - - 2006
The fresh and dried leaves of two edible plants, Oldenlandia corymbosa and Dissotis rotundifolia have been assayed for their ascorbic acid content. They were found to be rich sources of ascorbic acid (vitamin C) when compared with some common garden fruits and vegetables. Students' t-test statistical analysis using INSTAT.EXE program ...
Karim Mohammad Mainul - - 2006
A simple, sensitive, and selective method for the determination of cerium(IV), based on the oxidative reaction between cerium(IV) and ascorbic acid, has been described. The fluorescence comes from Ce(III) at lambda(excitation) 298 nm and lambda(emission) 358 nm, which, in turn, is obtained from the oxidation of ascorbic acid by Ce(IV) ...
Eşrefoğlu Mukaddes - - 2006
BACKGROUND: Oxygen free radicals (OFR) have been implicated in the induction of acute pancreatitis (AP). AIMS: The aim of this study was to determine the effect of ascorbic acid and N-acetylcysteine (NAC), potent antioxidants, against oxidative stress in AP. METHODS: AP was induced by two i.p. injections of caerulein at ...
Nagel Dietmar - - 2006
Ascorbic acid at higher concentration in urine samples can lead to false negative results in a number of urine tests, with a potential risk of clinical findings being overlooked, particularly with glucose and hemoglobin. For this reason, the ascorbic acid status of urine samples should always be routinely known so ...
Degl'Innocenti E - - 2005
A series of biochemical parameters, including the concentration of total ascorbic acid (ASA(tot)) and the activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), and peroxidases (PODs), was investigated during cold storage (72 h at 4 degrees C in the dark) in fresh-cut (minimally processed) leaves of two lettuce (Lactuca ...
De Tullio Mario C - - 2007
Ascorbic acid oxidase (AAO) is a plant blue-copper protein catalyzing dioxygen reduction to water using ascorbic acid as the electron donor. In spite of extensive molecular characterization the physiological role of AAO is still uncertain. Abundant mRNA, protein and activity of AAO were observed in illuminated leaves of Cucurbita pepo. ...
Parsons Kelly K - - 2006
The mouse has become the most important model organism for the study of human physiology and disease. However, until the recent generation of mice lacking the enzyme gulanolactone oxidase (Gulo), the final enzyme in the ascorbic acid biosynthesis pathway, examination of the role of ascorbic acid in various biochemical processes ...
Canoy Dexter - - 2005
BACKGROUND: Antioxidants, such as ascorbic acid, play a role in scavenging free radicals to protect against oxidative endothelial damage. Excess fat may promote fatty acid oxidation and increase free radical concentrations, which could result in increased antioxidant use. Whether plasma ascorbic acid concentrations are associated with fat distribution remains unclear. ...
Sanghi Rashmi - - 2006
Investigations were carried out for possible exploitation of Cassia javahikai seeds as potential source of commercial gum for the textile wastewater treatment. Graft copolymerization with acrylamide was done to modify the seed gum for the favorable properties. C. javahikai seed gum, and its copolymer grafted with acrylamide were synthesized in ...
Saether Oddbjørn - - 2005
Metabolic changes in rabbit cornea after combined long-term steroid treatment and UV-B exposure were investigated. Corneas were exposed to UV-B radiation (2.05 J/cm2) after 36 days topical pretreatment with either 0.1% dexamethasone or saline. Twenty-four hours after UV-B exposure, corneas were excised and aqueous humour aspirated. Intact corneal tissues were ...
Sircelj Helena - - 2005
The influence of water deprivation on potted apple trees (Malus domestica Borkh.) was investigated. Biochemical responses including ascorbic acid, glutathione (GSH), tocopherols, chlorophylls, carotenoids, free amino acids, and soluble carbohydrates were measured in leaves of diploid 'Elstar' and triploid 'Jonagold Wilmuta' subjected to progressive drought. Leaf water potential was chosen ...
Pukacka Stanisława - - 2006
Ascorbate-glutathione systems were studied during desiccation of recalcitrant seeds of the silver maple (Acer saccharinum L.). The desiccated seeds gradually lost their germination capacity and this was strongly correlated with an increase in electrolyte leakage from seeds. Simultaneously the increase of reactive oxygen species (ROS) (superoxide radical - O(2)(-*) and ...
Bruno Richard S - - 2006
Vitamin E disappearance is accelerated in cigarette smokers due to their increased oxidative stress and is inversely correlated with plasma vitamin C concentrations. Therefore, we hypothesized that ascorbic acid supplementation (500 mg, twice daily; 2 weeks) would normalize smokers' plasma alpha- and gamma-tocopherol disappearance rates and conducted a double-blind, placebo-controlled, ...
Harmon R Christopher - - 2005
p-Aminophenol (PAP), a metabolite of acetaminophen, is nephrotoxic. This study investigated PAP-mediated changes as a function of time that occur prior to loss of membrane integrity. Experiments further evaluated the development of oxidative stress by PAP. Renal slices from male Fischer 344 (F344) rats (N = 4-6) were exposed to ...
Poljsak B - - 2005
The effect of antioxidant ascorbic acid (vitamin C) pretreatment on chromium(VI)-induced damage was investigated using the yeast Saccharomyces cerevisiae as a model organism. The objective of this study was to pretreat yeast cells with the antioxidant ascorbic acid in an effort to increase cell tolerance against reactive chromium intermediates and ...
Jansson Patric J - - 2005
Ascorbic acid (vitamin C) induced hydrogen peroxide (H(2)O(2)) formation was measured in household drinking water and metal supplemented Milli-Q water by using the FOX assay. Here we show that ascorbic acid readily induces H(2)O(2) formation in Cu(II) supplemented Milli-Q water and poorly buffered household drinking water. In contrast to Cu(II), ...
Meng Qing H - - 2005
BACKGROUND: Ascorbic acid can interfere with methodologies involving redox reactions, while comprehensive studies on main chemistry analysers have not been reported. We therefore attempted to determine the interference of ascorbic acid with analytes on the Beckman Synchron LX20. METHODS: Various concentrations of ascorbic acid were added to serum, and the ...
Rocchitta Gaia - - 2005
A capillary apparatus for in vitro microdialysis was used to investigate melatonin and ascorbic acid effects on dopamine (DA) autoxidation or nitric oxide (NO)-mediated oxidation in suspended PC12 cells. Following high K+ (KCl 75 mm) infusion, secreted DA underwent a partial autoxidation or peroxynitrite-mediated oxidation when the potential peroxynitrite generator ...
Wang Kun - - 2005
A novel solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles (NanoCoPc) as ionophore was fabricated without any need of auxiliary materials (such as membrane matrix, plasticizer, and other additives). The electrode was prepared by simple drop-coating NanoCoPc colloid on the surface of a glassy carbon electrode. A ...
Scartezzini P - - 2006
Emblica officinalis Gaertn. is one of the most important plants of Ayurved, the traditional Indian medicine. In this ancient medicine, the fruit of Emblica officinalis is processed according to a method named "Svaras Bhavana", whereby the therapeutic potential of the plant is enhanced by treating the main herb with its ...
Fan Xuetong - - 2005
This study was conducted to investigate the formation of furan from sugars, ascorbic acid, and organic acids as affected by ionizing radiation and thermal treatments. Results showed that both thermal treatments and irradiation induced formation of furan from ascorbic acid, fructose, sucrose, or glucose. Little furan was produced from malic ...
Yamamoto Fumihiko - - 2005
The relationship between in vivo biodistribution of 6-deoxy-6-[18F]fluoro-L-ascorbic acid (18F-DFA) and the content of tissue glutathione (GSH) was investigated in Wistar male rats. Following intravenous administration of 18F-DFA, the accumulation of radioactivity in most tissues, including the adrenal glands, liver and brain, was significantly reduced together with a decrease in ...
Dilgin Yusuf - - 2005
In this study, a simple and sensitive fluorimetric method was described for the determination of Ascorbic Acid (AA). The procedure is based on the reaction between AA and Methylene Blue (MB). The fluorescence intensity of MB was measured at excitation and emission of 664 and 682 nm, respectively. MB concentration ...
Karlsen Anette - - 2005
Vitamin C plays a central role in the body. One of its important functions is its role as an antioxidant, and accurate measurements are important for interpretations of this role. However, its reactive nature and instability complicates the assessment, especially in biological samples. A high-throughput chromatographic method using monolithic column ...
López-Alarcón Camilo - - 2005
PURPOSE: The aims of the study are to analyze the interaction between 5-aminosalicylic acid (5-ASA) and peroxyl radicals and to evaluate the effect of some endogenous compounds such as ascorbic acid and amino acids on the oxidation of 5-ASA induced by 2,2'-azo-bis(2-amidinopropane) dihydrochloride. METHODS: The consumption and/or the recovery of ...
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