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PubMed2004

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

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

Anethum graveolens↗
PubMed1992

The role of ascorbic acid in mesenchymal differentiation.

Survival of all higher vertebrates requires that they either synthesize vitamin C (ascorbic acid) or obtain it from their diet. The role of ascorbic acid as a reductant for the iron prosthetic group of hydroxylase enzymes involved in collagen biosynthesis is well established. In contrast, the relationship between the biochemical functions of ascorbic acid and the broad defects in connective tissue formation associated with vitamin C deficiency is less obvious. This review will develop the hypothesis that vitamin C is required for the differentiation of mesenchyme-derived connective tissues such as muscle, cartilage, and bone. It is proposed that the collagen matrix produced by ascorbic acid-treated cells provides a permissive environment for tissue-specific gene expression.

Animals↗
PubMed1979

Ascorbic acid deficiency and hypertrophic osteodystrophy in the dog: a rebuttal.

Plasma ascorbic acid (PAA) in normal Labrador Retriever dogs less than one year of age averaged 1.22 +/- 0.05 mg/dl (x +/- sem) and was significantly higher than the value of 0.89 +/- 0.03, for Labrador Retrievers two years of age and older. No significant diurnal variation in PAA was observed. Oral or intravenous administration of 0.5 or 1.0 g of ascorbic acid (AA) elevated PAA for less than 8 hours. Injection of ACTH caused a significant decline in PAA for the initial 2 days, with variable results thereafter. Labrador Retriever puppies fed a ration high in protein, energy and calcium developed the typical skeletal diseases of overnutrition, including hypertrophic osteodystrophy (HOD). The addition or oral AA (0.5 g twice daily) had no ameliorating effect on the skeletal lesions. Instead AA supplementation resulted in relatively higher serum calcium values which, presumably by enhanced hypercalcitoninism, decreased bone resorption. Thus, AA treatment of dogs with HOD is contraindicated, as it can only aggravate the osseous lesions of HOD. The decreased PAA reported in dogs with HOD is interpreted to be the result of stress from pain.

Adrenocorticotropic Hormone↗
PubMed1974

Ascorbic acid supplementation in the treatment of pressure-sores.

In a prospective double-blind controlled trial the effect of large doses of ascorbic acid on the healing of pressure-sores has been assessed. 20 surgical patients were studied, the pressure areas being assessed by serial photography and ulcer tracings. The mean ascorbic-acid levels in treated and non-treated groups one month after the start of treatment were 65.6 and 25.8 mug per 10-8 white blood-cells. In the group treated with ascorbic acid there was a mean reduction in pressure-sore area of 84% after one month compared with 42.7% in the placebo group. These findings are statistically significant (P less than 0.005) and suggest that ascorbic acid may accelerate the healing of pressure-sores.

Aged↗
PubMed1988

Assessment of L-ascorbic acid requirement for prolonged survival in ODS rats and their susceptibility to urinary bladder carcinogenesis by N-butyl-N-(4-hydroxybutyl)nitrosamine.

Assessment of L-ascorbic acid requirement for prolonged survival in ODS (genotype: od/od) rats and their susceptibility to urinary bladder carcinogenesis by N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) were examined. In ODS rats without L-ascorbic acid synthesizing ability, the 50 ppm dietary total ascorbic acid (TAA) was insufficient to survive for 4 weeks, the 250 ppm dietary TAA was sufficient to survive for 36 weeks. In examination of BBN treatment, ODS rats--although showing a lower availability of TAA than the heterozygotes (+/od) and normal (+/+) rats with L-ascorbic acid synthesizing ability--were equally susceptible to bladder carcinogenesis.

Animals↗
PubMed2003

Effect of ascorbic acid and Vitamin E supplementation on semen quality and biochemical parameters of male rabbits.

The objective of this study was to determine the effects of supplementation of ascorbic acid, Vitamin E (Vit. E) and their combination in drinking water on sperm characteristics, lipid peroxidation (LPO) and seminal plasma enzymes of mature male rabbits. Twenty-four male New Zealand White rabbits (5 months old) were given drinking water supplemented with ascorbic acid (1.5 g/l), Vit. E (1.0 g/l) and ascorbic acid+Vit. E (1.5+1.0 g/l) for 12 weeks. Vitamin supplementation in drinking water increased feed intake, but body weight gain was not significantly affected. Concentrations of thiobarbituric acid-reactive substances (TBARS) were significantly (P<0.05) reduced in seminal plasma of treated groups compared with the control. Treatment with ascorbic acid, Vit. E, and their combination significantly (P<0.05) increased lipido (reaction time), ejaculate volume, sperm concentration, total sperm output, sperm motility index, total motile sperm, packed sperm volume, initial hydrogen ion concentration (pH), and semen initial fructose concentration. Abnormal and dead sperm were significantly (P<0.05) decreased in treated animals. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were significantly (P<0.05) decreased, whereas glutathione S-transferase (GST) showed a significant increase in seminal plasma of treated animals compared with the controls. The results from this study indicated that supplementation of drinking water with antioxidant ascorbic acid, Vit. E and their combination reduced the production of free radicals and can improve rabbit semen quality, but the greater improvement seemed to be from Vit. E.

Alanine Transaminase↗
PubMed1982

Effect of high dose ascorbic acid on vitamin B6 metabolism.

The influence of ascorbic acid intake on vitamin B6 metabolism in humans was determined in three separate studies. Five subjects in study I and two subjects in study II received 0.5 ( 2 days) and 1 g (7 days) doses of L-ascorbic acid (AA), respectively, before supplementation with 2 mg of pyridoxine hydrochloride (PN-HCl). From daily diet records the percentage of the intake of vitamin B6 excreted as urinary 4-pyridoxic acid (4PA) was calculated. Because of the variability in vitamin B6 intake, study III was conducted with four male and four female subjects, who received identical meals on days 2, 3, 9, and 10 and 1 g of AA on days 4 to 10. Two milligrams of PN.HCl were given the day before and the last day of AA administration. In contrast to studies I and II, where excretion of 4PA appeared to increase on the day of PN.HCl supplementation plus AA compared to pre-AA, urinary 4PA excretion in the eight subjects of study III was not significantly different when the same PN.HCl supplemented pre-AA and post-AA days were compared. Also, the fasting plasma pyridoxal 5'-phosphate level was not significantly altered when AA was administered. It is concluded that short-term AA supplementation did not alter vitamin B6 metabolism.

Adult↗
PubMed1997

Effect of antiproliferative flavonoids on ascorbic acid accumulation in human colon adenocarcinoma cells.

Dietary flavonoids were found to be antiproliferative for human colon cancer cells, Caco-2 and HT-29, and rat nontransformed intestinal crypt cells, IEC-6. The antiproliferative potency was found to be structure-dependent. We report here a correlation between the antiproliferative potency of these flavonoids and their ability to inhibit cellular accumulation of ascorbic acid (vitamin C). Caco-2, HT-29 and IEC-6 cells were found to accumulate ascorbic acid in a sodium-dependent fashion although some ascorbic acid may also enter the cells through sodium-independent mechanisms. Flavonoids that have been found to be antiproliferative, quercetin and genistein, inhibited the accumulation of ascorbic acid. The inhibition was dose-dependent and could be observed after as short as 10-min of incubation. The degree of inhibition of accumulation was more during rapid cell division as compared to post-confluency Caco-2 cells. Flavonoids that were found to show little antiproliferative effect, naringenin and catechin, also had little effect on ascorbic acid accumulation. The antiproliferative property of flavonoids could be linked to their ascorbic acid deprivation property.

Animals↗
PubMed1990

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

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.

Animals↗
PubMed1982

Effects of ascorbic acid on in vitro steroidogenesis in guinea pigs.

Guinea pig ovarian whole tissue homogenates were incubated with [14C]-labelled cholesterol, pregnenolone, and progesterone. Testicular homogenates were incubated with [14C]-progesterone. All incubations were carried out in the presence of 0, 0.5, 1.0, or 2.0 mM ascorbic acid. The conversion of cholesterol to pregnenolone was significantly decreased in testosterone and progesterone production. The addition of 0.5 mM ascorbic acid increased the conversion of pregnenolone to delta 4 steroids and decreased its conversion to delta 5 steroids, relative to the other ascorbic acid treatments. The conversion of progesterone to 17 A-hydroxyprogesterone was significantly decreased in the presence of 1.5 mM ascorbic acid over the O mM treatment. The data supports a general inhibitory effect of high ascorbic acid on the steroid hydroxylations, and a possible regulatory role of ascorbic acid on the conversion of pregnenolone to delta 4 and delta 5 steroids.

Animals↗
PubMed1999

Effect of ascorbic acid supplementation on liver and kidney toxicity in cyclophosphamide-treated female albino rats.

Effects of ascorbic acid supplementation on the activity of acid phosphatase (ACP), alkaline phosphatase (ALP), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) on liver, kidney and serum in cyclophosphamide-treated female virgin rats were investigated. Oral administration of cyclophosphamide at the dose of 5 mg/kg body weight/day for 12 days resulted in a significant elevation in ACP and ALP activities in liver, kidney and serum. Ascorbic acid supplementation at the dose of 25 mg/kg body weight/day showed a significant protection in the activity of ACP in liver, kidney and serum, but only in ALP activity in kidney. ALP activities in liver and serum were not restored to control level by ascorbic acid supplementation. Activities of GOT and GPT were elevated significantly in liver, kidney and serum after cyclophosphamide treatment, and were protected and restored to control level by ascorbic acid supplementation.

Acid Phosphatase↗
PubMed1996

Hydrogen peroxide mediates the killing of U937 tumor cells elicited by pharmacologically attainable concentrations of ascorbic acid: cell death prevention by extracellular catalase or catalase from cocultured erythrocytes or fibroblasts.

Pharmacologically attainable concentrations of ascorbic acid are highly toxic for U937 cells (a human promyelocytic cell line), and this response appears to be mediated by H2O2. This inference finds experimental support in the following observations: 1) toxic levels of H2O2 are readily generated upon dissolution of survival-range concentrations of ascorbic acid in the culture medium; 2) the lethal effects elicited by ascorbic acid or reagent H2O2 are prevented by the addition of either catalase or the intracellular iron chelator o-phenanthroline and are characterized by similar temporal dependence; 3) U937 cells resistant to hydrogen peroxide are cross-resistant to ascorbic acid; 4) under the conditions utilized in this study, H2O2 and ascorbate promote similar modes of cell death (i.e., necrosis); and 5) cell killing provoked by H2O2 or ascorbate is an inverse function of cell density and is suppressed by coculturing U937 target cells with human erythrocytes (at a density far below that present in the blood) and human fibroblasts. Cytoprotection was not observed using catalase-depleted erythrocytes. Taken together, these results strongly suggest that H2O2 is entirely responsible for the ascorbate-induced U937 cell killing. We therefore propose that it is unlikely that the vitamin damages or kills tumor cells of normal tissues in vivo via the H2O2 based mechanism, because the oxidant would be removed promptly by the neighboring cells.

Ascorbic Acid↗
PubMed1988

[Ultrastructural restructurings in the rat cerebral cortex after ascorbic acid administration into the ventricular cerebrospinal fluid].

A short increase of the ascorbic acid concentration in the rat cerebral cortex after intraventricular bilateral injection of 20 mcl of 0.1% or 1% solution of ascorbic acid, as well as intracisternal injection of 20 mcl of 0.5% solution results in a prolonged (no less than 21 days) ultrastructural reorganization in the nucleus and cytoplasm of the cortical neurons: amount of lysosomes, polysomes, vesicles of the Golgi complex, subsurface cisterns increases; this demonstrates an increasing RNA and protein synthesis, catabolic processes and neuronal-glial interaction. Changes of ultrastructure of the synaptic terminals--decaying mitochondria in them, formation of myelin-like bodies and after interstitial injection, in addition, protrusions into the adjusting dendrite--demonstrate that synapses are also one of the points, where excess of ascorbic acid affects the CNS. In a long time 3 and 6 months after injection, the changes mentioned are not observed, but in the glial processes there are vacuoles, containing degenerating elements.

Animals↗
PubMed2001

Influences of wet feeding and supplementation with ascorbic acid on performance and carcass composition of broiler chicks exposed to a high ambient temperature.

In two experiments was investigated whether feeding with an air-dry feed mixed with different amounts of water and/or supplemental ascorbic acid affect performance and carcass compositions of broilers exposed to a high ambient temperature (35 to 37 degrees C for 8 h/d and thermoneutral for 16 h/d). In the first trial, 64 one-week-old male broiler chicks were fed ad libitum in four dietary treatment groups for a 6-week period. Experimental mash diets were prepared by mixing a maize-soybean based standard broiler starter or finisher with tap water in the ratios of 0.0:1.0, 0.5:1.0, 1.0:1.0 and 1.5:1.0 (water:air-dry feed, w/w). More water in the diet increased BWG, DMI, abdominal fat and carcass weight, carcass CP, crude fat, but it deteriorated DM conversion efficiency. In the second experiment, 64 one-week-old male broiler chicks were given air-dry or wet (water:feed, 1.5:1) starter or finisher diets without or with ascorbic acid supplementation (0 and 250 mg/kg air-dry feed, resp.) ad libitum for a 6-week period. Ascorbic acid supplementation increased BWG, carcass weight and carcass CP significantly, while reducing carcass crude fat content. However, feeding broilers with a diet mixed with water in a ratio of 1.5:1.0 increased BWG, DMI, carcass weight and carcass lipid markedly, but deteriorated DM conversion efficiency. There was also a significant interaction between ascorbic acid and wet feeding, whereby ascorbic acid supplementation induced a significant reduction in carcass lipid contents of broilers fed on air-dry diets but not on wet diets. It is concluded that wet feeding, especially an addition of 150% water to produce a porridge like consistency, improved growth performance by increasing fat, ash and protein deposition in the body, while reducing DM conversion efficiency. It is also concluded that under heat stress supplemental ascorbic acid in air-dry diets stimulates broiler performance but not in wet diets.

Adipose Tissue↗
PubMed1990

Ascorbic acid modulates the production of fibronectin and laminin by cells from an eye tissue-trabecular meshwork.

Ascorbic acid is a significant component in the aqueous humor of the eye, in which trabecular meshwork cells are immersed. Using immunostaining and Western blot analysis, the effects of ascorbic acid on the extracellular matrix production by cultured bovine trabecular meshwork cells were examined. It was found that, when the cultures were treated with 100, 250, and 500 micrograms/ml of ascorbic acid, the amount of fibronectin and laminin produced was enhanced. An enzyme-linked immunosorbent assay for quantitation further showed that the fibronectin and laminin levels in ascorbate-treated cultures were higher than those found in control cultures. These results indicate that ascorbic acid promotes fibronectin and laminin production and suggest that this substance may be one of the factors modulating basal lamina assembly in the trabecular meshwork.

Animals↗
PubMed2003

Carbon paste electrode modified with copper (II) phosphate immobilized in a polyester resin for voltammetric determination of L-ascorbic acid in pharmaceutical formulations.

A carbon paste electrode modified with copper(II) phosphate immobilized in a polyester resin (CuP-Poly) is proposed for voltammetric determination of L-ascorbic acid in pharmaceutical formulations. The modified electrode allows the detection of L-ascorbic acid at lower anodic potentials than observed at unmodified electrodes. Several parameters that can influence the voltammetric response of the proposed electrode such as carbon paste composition, pH, scan rate, and possible interference were investigated. The peak current was proportional to the concentration of ascorbic acid in the range 2.0 x 10(-5) to 3.2 x 10(-3) mol L(-1) with a detection limit of 1.0 x 10(-5) mol L(-1). The stability and repeatability of the electrode for the determination of L-ascorbic acid are also discussed. Amperometric response was also recorded for electrocatalytic oxidation of the L-ascorbic acid. Concentrations of the vitamin C in pharmaceutical formulations (tablets) measured using the modified electrode and a titrimetric method are in agreement at the 95% confidence level and within an acceptable range of error.

Ascorbic Acid↗
PubMed2000

Ascorbic acid induces spectrin reorganization in bull epididymal spermatozoa.

The acrosome, a complex organelle, plays a key regulatory role in the sperm-egg interaction. We have previously shown that ascorbic acid affects both motility and spectrin protein patterns in sperm. In this study, we further characterized the changes in spectrin in sperm challenged with ascorbic acid, using SDS-PAGE, western blots, and immunofluorescence. Ascorbic acid shifts spectrin to a higher-molecular-weight species based on western blot studies. This shift in the spectrin band correlates with a striking series of changes in spectrin immunofluorescence patterns. Upon ascorbic acid challenge, spectrin localization changes, eventually resulting in the formation of vesicles. These vesicles can reach sizes up to five times the original volume of the sperm cell and sometimes show multiple spikes. These findings indicate that a novel process is taking place in the acrosome upon ascorbic acid challenge and suggest that the cytoskeleton may be a useful target for studying and hopefully controlling the sperm-egg interaction.

Acrosome↗
PubMed2003

Ascorbic acid and infertility treatment.

AIM OF THE STUDY: To assess the ascorbic acid (AA) in the follicular fluid in women treated by in vitro fertilization and embryonic transfer levels (IVF/ET) and to analyse the influence of vitamin C supplementation on the results of infertility treatment. TYPE OF THE STUDY: Prospective study in women treated by IVF/ET. METHODS: The influence of vitamin C supplementation on the outcome of infertility treatment in the assisted reproduction programme in 76 women (38 of them smokers, 38 non-smokers) was studied. Half the women (19 smokers and 19 non-smokers) were administered vitamin C in daily doses of 500 mg in so-called pellets allowing for gradual release over 8 to 12 hours. The control group consisted of the same number of smokers and non-smokers. In all the women, ascorbic acid levels were determined in two urine samples (prior to supplementation and at follicle retrieval) and in follicular fluid by means of a colorimetric method. Ovarian response to hormonal stimulation with gonadotropins (hMG, FSH) at a dosage of 150-225 IU per day combined with GnRH analogues in the short (buserelin) or long (triptorelin) protocols, and 5,000-10,000 IU of human chorionic gonadotropin was evaluated based on the number of follicles created and number of retrieved oocytes. Fertilisation was assessed, based on the number of successfully fertilised oocytes (fertilisation rate) and based on the number of cultivated embryos. The success of the infertility treatment was evaluated based on the number of pregnancies. RESULTS: Ascorbic acid levels in follicles were significantly higher (p < 0.001) in women with vitamin C supplementation than in the control group (8.98 +/- 5.09 vs. 5.04 +/- 2.85 mg/l). The administration of vitamin C during the period of hormonal stimulation showed a statistically insignificant impact in terms of the higher number of pregnancies (34.2% vs. 23.7%). Vitamin supplementation had a greater impact on the number of pregnancies in the non-smokers' group (57.9% vs. 31.6%). The pregnancy rate was significantly higher (p < 0.01) in non-smoking women than in smokers--44.7% vs. 13.2%, which appears to be a reason for asking women to cease smoking prior to infertility treatment.

Adult↗