ascorbic-acid and ascorbigen

Glucosinolates (thioglucoside-N-hydroxysulphates) constitute a homogeneous class of naturally occurring thiosaccharidic compounds mainly found in the botanical order Brassicales. They can be hydrolyzed by myrosinase to produce D-glucose and various other degradation products like isothiocyanates (ITCs)-depending on the aglycon part. The exact function of glucosinolates (GLSs) in the plant is unclear, however their potent odour and taste suggests a role in herbivore and microbial defense. They are known for their fungicidal, bacteriocidal, nematocidal and allelopathic properties and have recently attracted intense research interest because of their cancer chemo-protective attributes. Iso-thiocyanates, one of the hydrolyzed products, show best anti-carcinogenic activity.

Topics: Apoptosis; Ascorbic Acid; Brassicaceae; Diet; Fruit; Glucosinolates; Glycoside Hydrolases; Humans; Indoles; Neoplasms; Oxidative Stress; Signal Transduction; Vegetables

Chemopreventive effects of broccoli, a highly valued vegetable, have been known for a long time. Several studies have demonstrated that broccoli might be beneficial by reducing the risk for the development of certain forms of cancer. These effects are generally attributed to glucosinolate-derived degradation products like isothiocyanates and indoles which are formed by the hydrolytic action of plant myrosinase and/or glucosidases deriving from the human microbial flora. However, recent in vitro and experimental animal studies indicate that broccoli, its extracts and the glucosinolate-derived degradation products might also have undesirable effects, especially genotoxic activities. However, the relevance of the genotoxic activities to human health is not known yet. This paper gives an overview on genotoxic, anti-genotoxic/chemopreventive, nutritive and antinutritive properties of broccoli, its ingredients and their degradation products. A qualitative comparison of the benefit and risk of broccoli consumption benefit-risk assessment shows that the benefit from intake in modest quantities and in processed form outweighs potential risks. For other preparations (fortified broccoli-based dietary supplements, diets with extraordinary high daily intake, consumption as a raw vegetable) further studies both for potential risks and beneficial effects are needed in order to assess the benefit and risk in the future.

Topics: Animals; Antineoplastic Agents; Ascorbic Acid; Brassica; DNA Damage; Glucosinolates; Glycoside Hydrolases; Humans; Indoles; Isothiocyanates; Models, Animal; Neoplasms; Plant Extracts; Risk Assessment; Sulfoxides; Thiocyanates; Vegetables

Searches for the natural compounds that determine the anticarcinogenic properties of a cruciferous-vegetable diet, revealed the products of alkaloid glucobrassicin biotransformations; among these, ascorbigen, an indole-containing derivative of L-ascorbic acid, was found to be the most abundant. Study of chemical properties of ascorbigen showed that it is capable of different transformations in acidic (including gastric juice) and slightly alkaline (including blood) media. The stable and unstable products of ascorbigen transformation determine the biological properties of the compound. The most important product of ascorbigen transformation in gastric juice is 5,11-dihydroindolo[3,2-b]-carbazole, with a binding affinity to the Ah receptor only 3.7 x 10(-2) lower than that of tetrachlorodibenzodioxin. This compound may be responsible for modifying P450 enzyme activities. Ascorbigen and its analogs are available synthetically. Their biological evaluation showed that some of the compounds of these series are immunomodulators. The most active is N-methylascorbigen, which demonstrates therapeutic effects (inhibition of tumor growth, protection of animals from bacterial and viral infections). The immunomodulatory activity of natural ascorbigen may be an additional factor of importance for the anticarcinogenic properties of a cruciferous-vegetable diet.

Topics: Adjuvants, Immunologic; Animals; Anticarcinogenic Agents; Ascorbic Acid; Biotransformation; Brassica; Glucosinolates; Humans; Hydrogen-Ion Concentration; Indoles; Molecular Sequence Data; Neoplasms, Experimental

Twelve female fibromyalgia syndrome (FMS) patients were given 500 mg per day of a blend containing 100 mg ascorbigen and 400 mg broccoli powder in a preliminary, one-month, open-label trial. This group of patients showed a mean 20.1 percent (p=0.044) decrease in their physical impairment score and a mean 17.8 percent (p=0.016) decrease in their total fibromyalgia impact scores as measured by the Fibromyalgia Impact Questionnaire. The mean physical impairment score two weeks post-treatment showed a significant return to near pre-treatment level (p=0.028). Analysis of ten of the patients' mean threshold pain levels at the 18 possible tender points obtained before and at the end of treatment showed a strong trend toward an increase in the mean threshold pain level (p=0.059). The reduced sensitivity to pain and improvement in quality of life measured in this study appear to be clinically relevant and a larger, double-blind study is warranted.

Topics: Ascorbic Acid; Brassica; Female; Fibromyalgia; Humans; Indoles; Pain Threshold; Phytotherapy; Surveys and Questionnaires

The connectivities of all atoms in ascorbigen A, an important metabolite, were determined unambiguously for the first time. The connectivity between carbon atoms was established by 2D INADEQUATE, and one-bond

Topics: Ascorbic Acid; Density Functional Theory; Indoles; Magnetic Resonance Spectroscopy; Molecular Conformation

The aim of the study was to investigate the effect of storage on the contents of glucosinolates (GLS) and their degradation products in a boiled white cabbage. A 24h storage at 4 °C resulted in a decrease in GLS content (20-40%, depending on the cooking time applied) in the edible parts. The most significant losses were observed for sinigrin (20-45%), and the least for glucobrassicin (12-32%). Storage had a diversified effect on GLS breakdown products (indole-3-acetonitrile, indole-3-carbinol, ascorbigen and 3,3'-diindolylmethane released from glucobrassicin and 4-methylsulfinylbutanenitrile released from glucoiberin) in the boiled cabbage. The increase in the content of indole-3-acetonitrile, especially considerable within the first 24h of storage (and a simultaneous decrease in glucobrassicin) clearly indicates that degradation of GLS may occur during storage or cooling to 4 °C.

Topics: Ascorbic Acid; Brassica; Drug Stability; Fermentation; Food Handling; Food Preservation; Glucosinolates; Hot Temperature; Indoles

The antioxidative properties of ascorbigen, one of the major indole-derived compounds of Brassica vegetables, were systematically evaluated using multiple assay systems with comparison to the well-known antioxidants ascorbic acid and Trolox. We first performed assays using model radicals, DPPH radical, galvinoxyl radical, and ABTS radical cation (ABTS(•+)). Ascorbigen showed stronger activity than that of ascorbic acid in the ABTS(•+)-scavenging assay but showed no activity in the DPPH radical- and galvinoxyl radical-scavenging assays. In the ABTS(•+)-scavenging assay, the indole moiety of ascorbigen contributed to scavenging of the radicals to produce indole-3-aldehyde as one of the final reaction products. The activity of ascorbigen was then evaluated by an oxygen radical absorbance capacity assay and an oxidative hemolysis inhibition assay using physiologically relevant peroxyl radicals, AAPH-derived radicals. Ascorbigen showed much stronger antioxidant activity than did ascorbic acid and Trolox. Therefore, antioxidant activity of ascorbigen might be more beneficial than has been thought for daily health care.

Topics: Ascorbic Acid; Biological Assay; Free Radical Scavengers; Free Radicals; Indoles

Ascorbigen (ABG) is the predominant indole-derived compound from Brassica vegetables. In this study, we attempted to evaluate the effects of ABG on hair growth. To this end, we examined the proliferation of isolated human dermal papilla (DP) cells and keratinocytes after incubation in various concentrations (0-1.25 mM) of ABG. Furthermore, hair shaft regrowth was monitored in a mouse model of chemotherapy-induced alopecia (CIA), and hematoxylin and eosin staining was performed for histological analyses. We found that 1.25 mM ABG induced a 1.2-fold increase in the growth of DP cells, but not keratinocytes. However, ABG did not exert significant protective effects against CIA in the mouse model. These findings suggest that ABG may not be able to counteract CIA and that further investigation of the therapeutic potential of ABG in disease models is required.

Topics: Alopecia; Animals; Ascorbic Acid; Brassica; Cell Proliferation; Cells, Cultured; Cyclophosphamide; Dermis; Hair; Humans; Indoles; Keratinocytes; Mice; Mice, Inbred C57BL

The aim of the study was to investigate the effect of the pasteurization process on the content of ascorbigen, indole-3-carbinol, indole-3-acetonitrile, and 3,3'-diindolylmethane in fermented cabbage. Pasteurization was run at a temperature of 80 °C for 5-30 min. Significant changes were only observed in contents of ascorbigen and 3,3'-diindolylmethane. The total content of the compounds analyzed in cabbage pasteurized for 10-30 min was found to be decreased by ca. 20%, and the losses were due to thermal degradation of the predominating ascorbigen. Pasteurization was found not to exert any considerable effect on contents of indole-3-acetonitrile and indole-3-carbinol in cabbage nor did it affect contents of the compounds analyzed in juice.

Topics: Ascorbic Acid; Brassica; Fermentation; Glucosinolates; Hot Temperature; Indoles; Pasteurization

The effect of ascorbigen and 1'-methylascorbigen on the disease resistance of bean (Phaseolus vulgaris L.,. cv. Debreceni Tarka) to the fungal pathogen Uromyces phaseoli Pers. is reported. Contrary to ascorbigen, pretreatment of bean plants with l'-methylascorbigen, as in the case of other endogenous N-, O- and S-methyl compounds, induced the double immune response leading to the biochemical immunization of plants. The effectiveness of protection depended on the dosage of the applied l'-methylascorbigen and on the time interval between the chemical pretreatment and inoculation. Results of our greenhouse experiments revealed, in accordance with previous results, that the presence of the N-methyl group in the 1'-methylascorbigen molecule is the precondition of the effect, and formaldehyde formed from this N-methyl group and its reaction products (e.g. singlet oxygen, ozone) can have a determining role in the manifestation of the effect.

Topics: Ascorbic Acid; Basidiomycota; Immunity, Innate; Indoles; Phaseolus; Plant Diseases; Time Factors

Nrf2 is a basic leucine zipper transcriptional activator essential for the coordinated transcriptional induction of phase-2 and antioxidant enzymes. Brassica vegetables contain phytochemicals including glucoraphanin, the precursor of sulforaphane (SFN) and glucobrassicin, the precursor of indole-3-carbinole (I3C) and ascorbigen (ABG). The degradation products SFN, I3C and ABG may be capable of inducing cytoprotective genes in skin. In this study, we tested the potency of SFN, ABG and I3C in affecting Nrf2-dependent gene expression in human keratinocytes in culture. SFN but not ABG and its precursors I3C and ascorbic acid induced Nrf2 dependent gene expression at a relatively low concentration (5 micromol/l). Induction of Nrf2 due to SFN was accompanied by an increase in mRNA and protein levels of NADPH quinone oxidoreductase 1, heme oxygenase 1 and gamma-glutamylcysteine-synthetase. Furthermore, SFN elevated cellular glutathione levels and antagonized tumor necrosis factor-alpha-induced NFkappaB transactivation. Therefore, SFN treatment may present a strategy for enhancing the cellular defense mechanisms in skin.

Topics: Anticarcinogenic Agents; Ascorbic Acid; Cells, Cultured; Gene Expression; Glutamate-Cysteine Ligase; Glutathione; Heme Oxygenase-1; Humans; Indoles; Isothiocyanates; Keratinocytes; NAD(P)H Dehydrogenase (Quinone); NF-E2-Related Factor 2; NF-kappa B; RNA, Messenger; Sulfoxides; Thiocyanates

The aim of the present work was to optimize fermentation conditions of white cabbage ( Brassica oleracea L. var. capitata cv. Bronco) grown in winter in eastern Spain. The influence of two salt concentrations (0.5 and 1.5% NaCl) in combination with spontaneous or induced cabbage fermentation on the content of ascorbigen (ABG) and vitamin C as well as on the sensory quality of sauerkraut was investigated. The effect of storage at 4 degrees C for 1-3 months was also studied. ABG content increased from 14 micromol/100 g of dm in raw cabbage to 63-137 micromol/100 g of dm during fermentation, whereas vitamin C decreased from 354 to 236-277 mg/100 g of dm, and the variations depended on the fermentation conditions. Sauerkrauts obtained by Leuconostoc mesenteroides at 0.5% NaCl showed the highest ABG content and a large amount of vitamin C. Refrigeration for 1-3 months led to a reduction of ABG and vitamin C levels, but L. mesenteroides sauerkrauts presented considerable amounts of both compounds at the end of the storage period (74-82 micromol/100 g of dm and 33-44 mg/100 g of dm, respectively), higher than those found with Lactobacillus plantarum and the mixed starter culture before storage. Experimental sauerkrauts presented better organoleptic properties than the commercial products, and no differences in overall acceptability were found among natural fermentations and those performed with starter cultures. These results suggest than low-salted sauerkraut produced with L. mesenteroides provided highly beneficial antioxidant and anticarcinogenic compounds and low sodium content, which is in accordance with the general trend in industrialized countries of reducing the salt level of foods to prevent cardiovascular diseases.

Topics: Ascorbic Acid; Brassica; Fermentation; Food Handling; Food Microbiology; Humans; Indoles; Leuconostoc; Sodium Chloride; Spain; Taste

From the methanol extract of Cardamine diphylla rhizome, 5'-O-beta-d-glucopyranosyl-dihydroascorbigen (1) and 6-hydroxyindole-3-carboxylic acid 6-O-beta-d-glucopyranoside (2) were isolated. The structures of the compounds were elucidated using spectroscopic methods. This is the second report on the presence of a glucosylated indole ascorbigen in plants.

Topics: Ascorbic Acid; Biological Products; Cardamine; Glucosides; Indoles; Rhizome

The effect of ascorbigen and 1'-methylascorbigen as a model compound pair was studied on the phytopathogenic bacterium Pseudomonas savastanoi pv. phaseolicola in the BioArena experimental system after overpressured layer chromatography. Results showed a characteristic, strong antibacterial effect of 1'-methylascorbigen and weak effect of ascorbigen present on the adsorbent layer as chromatographic spot. Addition of formaldehyde capture compounds (L-arginine, glutathione, dimedone) partially or totally reduced the antibacterial effect of 1'-methylascorbigen and ascorbigen. On adding Cu(II) ions--which mobilize and coordinate formaldehyde--to the culture medium, the antibacterial effect of both compounds became stronger. It is supposed that the weak antibacterial effect of ascorbigen may have originated from the 1'-methylascorbigen formed in situ on the adsorbent layer by partial enzymatic methylation of ascorbigen.

Topics: Anti-Bacterial Agents; Arginine; Ascorbic Acid; Chromatography, Thin Layer; Copper; Cyclohexanones; Formaldehyde; Glutathione; Indoles; Pseudomonas

The aim of the study was to investigate the effect of the boiling process on the content of ascorbigen, indole-3-carbinol, indole-3-acetonitrile, and 3,3'-diindolylmethane in fermented cabbage. The cabbage was boiled for 5 to 60 min. Boiling resulted in a decrease of the total content of the compounds analysed. The changes were mainly caused by leaching of ascorbigen predominating in cabbage into cooking water and by its thermal hydrolysis. Ascorbigen losses resulting from thermal hydrolysis accounted for 30% after 10 min of boiling and for 90% after 60 min of boiling. One of the ascorbigen breakdown products was indole 3 carbinol; the decrease in ascorbigen content was accompanied by a drastic increase in the content of 3,3'-diindolylmethane, a condensation product of indole-3-carbinol. After 40 and 50 min of boiling, the total content of 3,3'-diindolylmethane in cabbage and cooking water was approximately 0.2 micromol/100 g and was 6-fold higher than that in uncooked cabbage. 3,3'-Diindolylmethane synthesis proceeded within the plant tissue. After 10 min of boiling, the content of free indole-3-carbinol and indole-3-acetonitrile stabilized at the level of about 80% as compared to the uncooked cabbage.

Topics: Anticarcinogenic Agents; Ascorbic Acid; Brassica; Fermentation; Food Handling; Hot Temperature; Indoles

Cruciferous vegetables contain significant amounts of ascorbigen and related substances with known molecular structures. This study tested the hypothesis that ascorbigen demonstrates antioxidant properties and protects human umbilical cord endothelial cells against hyperglycemic toxicity in vitro. It was observed that ascorbigen, in micromolar concentrations, protected against endothelial cell death from glucose toxicity. Additionally, ascorbigen at 3.0 mm shifted the concentration response curve of l-phenylephrine to the right, with a reduction in the maximal contractile effects of the agonist. This action was not related to alpha-adrenoceptor blockade. Ascorbigen also relaxed the vascular tone induced by l-phenylephrine, which is not mediated by an endothelial cell nitric oxide-dependent mechanism. On the guinea-pig ileum, the spasmogenic effects of carbachol, histamine and serotonin were reduced in the presence of 3 mM ascorbigen. Spasm of the gut induced by the acetylcholinesterase inhibitor, physostigmine, was antagonized by ascorbigen with an IC50 of 286 microM. This natural product also has a weak antiparasitic activity. The cytoprotective effects of ascorbigen may be highly relevant in the optimum physiological regulation of the function and the therapeutic value of this substance in disease settings needs to be further investigated.

Topics: Animals; Antioxidants; Antiprotozoal Agents; Aorta; Ascorbic Acid; Biological Products; Carbachol; Cell Survival; Cells, Cultured; Cytoprotection; Endothelial Cells; Glucose; Guinea Pigs; Histamine; Humans; Ileum; Indoles; Leishmania donovani; Muscle Contraction; Muscle, Skeletal; Phenylephrine; Physostigmine; Rana catesbeiana; Rats; Serotonin; Trachea

Ascorbigen (ABG) is a natural compound that represents a breakdown product of the glucosinolates that are present in Brassica vegetables. It is postulated that ABG may have anticarcinogenic activity; however, the underlying molecular and cellular mechanisms are largely unknown. In the present study we investigated the effect of ABG on the mRNA and enzyme activity levels of NADPH-quinone oxidoreductase (NQO1), which is centrally involved in the detoxification of xenobiotics, in cultured liver cells and in rats. The mRNA levels of NQO1 showed an increase of up to 100% in cultured liver cells (HepG2) following incubation with different concentrations of ABG (3-100 micromol/l) compared to control cells. Furthermore, NQO1 activity was elevated (up to 20%) by ABG treatment. The in vitro results were confirmed in rats who received either 5 mg/day ABG or vehicle for 7 days. Significantly higher mRNA (a 90% increase) and enzyme activity levels (a 40% increase) of NQO1 were detected in the liver of ABG-treated rats as compared to control animals. Current data indicate that ABG is a moderate inducer of the phase II enzyme NQO1, both in cultured hepatocytes and in vivo.

Topics: Animals; Ascorbic Acid; Cell Line; Cytoprotection; Dose-Response Relationship, Drug; Enzyme Induction; Humans; Indoles; Liver; Male; NAD(P)H Dehydrogenase (Quinone); NADPH Dehydrogenase; Rats; Rats, Wistar; RNA, Messenger; Signal Transduction

Ascorbigen (ABG) is formed by indole-3-carbinole and ascorbic acid in brassica vegetables. In the present study, ABG has been systematically analyzed for its free radical scavenging and antioxidant capacity. To directly measure the free scavenging activity of ABG and ascorbic acid (used as a positive control), electron spin resonance and spin trapping experiments were performed. Ascorbic acid exhibited a potent free radical scavenging activity, whereas ABG did not scavenge superoxide anion free radicals and showed only little scavenging activity toward 2,2-diphenyl-1-picrylhydrazyl free radicals. Similar data were obtained for the ferric reducing ability of plasma and trolox equivalent antioxidant capacity assays. In cultured human keratinocytes, ABG counteracted tert-buthylhydroperoxide-induced cytotoxicity, whereas ascorbic acid did not exhibit any protective activity. Furthermore, in ABG-treated human keratinocytes, a decrease in tert-buthylhydroperoxide-induced lipid peroxidation was detected, whereas an ascorbic acid pretreatment did not result in the prevention of lipid peroxidation. These data indicate that ascorbic acid seems to be a more potent free radical scavenger than ABG in vitro, while ABG prevented tert-buthylhydroperoxide cytotoxicity more effectively as compared to ascorbic acid in cultured cells.

Topics: Antioxidants; Ascorbic Acid; Cell Line; Cell Survival; Free Radicals; Humans; Indoles; Keratinocytes; Lipid Peroxidation

Ascorbigen, a natural product, is an indole derivative of L-ascorbic acid. Its effect on postnatal development and antibacterial resistance of the small intestine was studied on newborn mice. Ascorbigen was administered to 3-5-day old mice in a dose of 100 mg/kg orally every day for 7-10 days. 30 minutes before the last administration of the drug clinical isolates of Staphylococcus aureus or Escherichia coli were administered intragastrically to the young mice. The animals were killed in 24 hours and the frequency of the isolation of the microbes from the blood, spleen, kidneys and liver was developed. The oral use of the drug normalized the intestinal microflora, provided a reliable decrease of the bacteria isolation from the blood, spleen, kidneys and liver and prevented the animal death. The morphological examination showed that ascorbigen significantly increased the number and activity of the Paneth cells in the gland crypts, the goblet cells in the villi and mononuclear cells in the selfplate of the intestine mucous membrane vs. the intact control.

Topics: Administration, Oral; Animals; Animals, Newborn; Ascorbic Acid; Blood; Enteritis; Escherichia coli; Female; Indoles; Intestinal Mucosa; Intestine, Small; Kidney; Liver; Mice; Mice, Inbred Strains; Spleen; Staphylococcus aureus

The research focused on the glucosinolate (GLS) breakdown products formed during the fermentation of cabbage. A relationship between the contents of degradation products in fermented cabbage and native GLS in raw cabbage was investigated. The effect of fermented cabbage storage on the contents of individual compounds was also assayed. Ascorbigen formed from one of the degradation products of glucobrassicin (indole GLS) was found to be a dominating compound in fermented cabbage. Irrespective of the time of fermented cabbage storage, the content of ascorbigen reached approximately 14 micromol/100 g. Neither the content of isothiocyanates, the major degradation products of aliphatic GLS, nor that of cyanides exceeded 2.5 microM. Storage of cabbage caused periodical increases and decreases in the contents of cyanides and consequent declines in the contents of isothiocyanates. The highest relative contents (expressed as a percentage of the native GLS content) of degradation products--ranging from >70 to 96%--were reported for the products of glucoraphanin degradation, whereas the lowest-- <5% --were reported for the products of sinigrin degradation.

Topics: Ascorbic Acid; Brassica; Fermentation; Food Preservation; Glucosinolates; Indoles

Alkaline degradation of the ascorbigen 2-C-[(indol-3-yl)methyl]-alpha-L-xylo-hex-3-ulofuranosono-1,4-lactone (1a) led to a mixture of 1-deoxy-1-(indol-3-yl)-L-sorbose (2a) and 1-deoxy-1-(indol-3-yl)-L-tagatose (3a). The mixture of diastereomeric ketoses underwent acetylation and pyranose ring opening under the action of acetic anhydride in pyridine in the presence of 4-dimethylaminopyridine (DMAP) with the formation of a mixture of (E)-2,3,4,5,6-penta-O-acetyl-1-deoxy-1-(indol-3-yl)-L-xylo-hex-1-enitol (4a) and (E)-2,3,4,5,6-penta-O-acetyl-1-deoxy-1-(indol-3-yl)-L-lyxo-hex-1-enitol (5a), which were separated chromatographically. Deacetylation of 4a or 5a afforded cyclised tetrols, tosylation of which in admixture resulted in 1-deoxy-1-(indol-3-yl)-3,5-di-O-tosyl-alpha-L-sorbopyranose (12a) and 1-deoxy-1-(indol-3-yl)-4,5-di-O-tosyl-alpha-L-tagatopyranose (13a). Under alkaline conditions 13a readily formed 2-hydroxy-4-hydroxymethyl-3-(indol-3-yl)cyclopenten-2-one (15a) in 90% yield. Similar transformations were performed for N-methyl- and N-methoxyindole derivatives.

Topics: Alkalies; Ascorbic Acid; Hexoses; Indoles; Magnetic Resonance Spectroscopy; Sorbose

A facile preparation is described of 3-(indol-3-yl)-2-hydroxy-4-hydroxymethylcyclopent-2-enone and its N-derivatives in 15-40% yields by the degradation of ascorbigen or its N-derivatives in a warm solution of L-ascorbic acid through a sequential domino reaction. The same cyclopentenone derivatives were obtained in 30-40% yields by the condensation of (N-alkylindol-3-yl)glycolic acids with ascorbic acid. 2,6-Dihydroxy-1-(indol-3-yl)hexa-1,4-diene-3-one and 2-hydroxy-4-hydroxymethyl-5-(indol-3-yl)cyclopent-2-enone were identified as intermediates in this reaction.

Topics: Ascorbic Acid; Cyclopentanes; Hot Temperature; Hydrolysis; Indoles; Molecular Conformation; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular

Experiments on Wistar rats showed that feeding a ration containing 0.1% concentrate of food indoles (indole-3-carbinole and ascorbigen) for 3 weeks increased activity of phases I and II xenobiotic metabolism enzymes in the liver and intestinal mucosa and weakened the toxic effects of trichothecene T-2 mycotoxin. Activity of the key enzymes of T-2 detoxification, microsomal carboxylesterase and UDP-glucuronosyl transferase, was 1.5-2-fold higher in rats receiving T-2 toxin against the background of indole-enriched diet compared to toxin-treated rats kept on standard ration.

Topics: Animals; Ascorbic Acid; Cytochrome P-450 Enzyme System; Diet; Indoles; Intestinal Mucosa; Liver; Male; Rats; Rats, Wistar; T-2 Toxin; Xenobiotics

A new method of analysis based on normal phase supercritical fluid chromatography (SFC) has been developed for investigation of ascorbigens [2-C-(indol-3-ylmethyl)-beta-L-xylo-3-hexulofuranosonic acid gamma-lactone derivatives]. This method has been adapted to preparative isolation and quantitative determinations of individual ascorbigens comprising ascorbigen, neoascorbigen, and 4-methoxyascorbigen. The structures of these compounds have been revealed from 1D ((1)H, (13)C) and 2D (COSY, HMQC, HMBC) NMR experiments. The developed SFC method had an acceptable linearity for the ascorbigens with correlation coefficients (R(2)) > 0.9995 (n = 10) in the range of 0.13-4.9 nmol injected, detection limits were below 13 pmol, retention time stabilities were excellent, and relative response factors have been determined. The SFC method has been used for determination of ascorbigens produced during autolysis of indol-3-ylmethylglucosinolates in various Brassica vegetables and rapeseed seedlings. Generally, 30-60% of the indol-3-ylmethylglucosinolates in the plants were transformed into ascorbigens, with the concentration in autolysates varying from 0.51 +/- 0.002 to 3.72 +/- 0.21 micromol/g of dry weight (DW) for ascorbigen, from 0.05 +/- 0.01 to 2.42 +/- 0.23 micromol/g of DW for neoascorbigen, and from 0.03 +/- 0.002 to 0.84 +/- 0.07 micromol/g of DW for 4-methoxyascorbigen.

Topics: Ascorbic Acid; Brassica; Chromatography, Liquid; Indoles; Magnetic Resonance Spectroscopy

Modulation of cytochrome P4501A1 (CYP1A1) activity is a mechanism whereby indoles present in cruciferous vegetables could affect the metabolism of xenobiotics. Ascorbigen (ASG) is the predominant indole formed during the degradation of glucobrassicin, although the mechanism by which ASG modulates CYP1A1 activity is not known. The major focus of this study was to examine the mechanism of CYP induction by ASG using a murine hepatoma-derived cell line (Hepa 1c1c7). ASG was shown to induce the activity of 7-ethoxyresorufin O-deethylase, a marker for CYP1A1, in a concentration-responsive manner with a maximum induction at 700 microM. Maximum ASG induction after 24-hr treatment was 7% of maximal CYP1Al activity induced by the well-known potent CYP1A1 inducer, indolo[3,2-b]carbazole (ICZ) (1 microM), and the EC50 values differed by 2-fold. The CYP1A1 activity increased continuously up to 72 hr, where ASG showed an induction efficiency in the same range as for the positive control (1 microM ICZ) after 24 hr, whereas the CYP1A1 protein level, measured by Western blot analysis, was maximally induced after 24 hr. ASG significantly inhibited CYP1A1 activity in whole cells at concentrations above 1 microM. ASG increased the chloramphenicol acetyl transferase (CAT) activity via a CAT reporter construct containing a dioxin-responsive element in Hepa 1c1c7 cells, indicating involvement of the aryl hydrocarbon receptor. ASG was shown to be transformed into ICZ, or a compound with the same chromatographic mobility as ICZ, in the medium. Taken together, the results indicate that ASG inhibits CYP1A1 activity at low concentrations, but induces the same activity at higher concentrations.

Topics: Animals; Ascorbic Acid; Carbazoles; Carcinoma, Hepatocellular; Chromatography, High Pressure Liquid; Cytochrome P-450 CYP1A1; Enzyme Induction; Indoles; Kinetics; Mice; Tumor Cells, Cultured

Compounds like indole-3-carbinol (I3C) have been shown to increase catechol estrogen formation and reduce mammary tumor incidence in mice. These compounds may exert a protective effect for breast cancer development by decreasing the overall estrogen pool available for the formation of 16 alpha-hydroxyestrone (16 alpha-OHE1), a metabolite that retains significant estrogenic activity, may be mutagenic and could represent a potential carcinogenic intermediate of estradiol degradation. I3C and ascorbigen originate from the breakdown of glucobrassicin. We have compared the inductive effects of I3C with ascorbigen and beta-naphthaflavone (Bnf) in microsomes from rats pretreated with these compounds using isotope dilution GC-MS and a radiometric method. Incubated microsomes from rats pretreated with I3C and ascorbigen yielded high levels of 2-hydroxyestradiol (2-OHE2) that were comparable to levels induced by Bnf and were significantly above control group levels (p < 0.005). Absolute values determined by the radiometric method were approximately 40% lower than 2-OHE2 concentrations determined by GC-MS, although the relative changes in each group were the same. These differences may be attributed to the radiolabel becoming trapped in microsomal intermediates in the sequence leading to tritium entering the aqueous compartment. Both ascorbigen- and Bnf-treated animals exhibited significant increases in 2-hydroxyestrone (2-OHE1) (p < 0.05). The ability of ascorbigen to induce estradiol C-2 hydroxylation has not been previously reported. Based on these data, we speculate that ascorbigen will act as an anticarcinogenic agent and will inhibit or reduce the incidence of mammary tumor formation.

Topics: Animals; Ascorbic Acid; Benzoflavones; beta-Naphthoflavone; Estradiol; Estrogens, Catechol; Female; Gas Chromatography-Mass Spectrometry; Hydroxyestrones; Hydroxylation; Indoles; Microsomes, Liver; Radiometry; Rats; Rats, Sprague-Dawley

New derivatives of 2-C-/(indolyl-3)methyl/-beta-L-threo-L-glycero-3-hexulofuranosono- 1,4-lactone, vis. 1'-ethylascorbigen, 1'-benzylascorbigen and 1',2'-dimethyl-5'-methoxyascorbigen were obtained. In aquous solutions at physiological temperature and pH values ascorbigens disintegrate rather rapidly to yield L-ascorbic acid, the rate of the latter's formation depending on the substituent in the indole nucleus and increasing with growth of pH and temperature. Intraperitoneal injection of 1'-methylascorbigen to mice leads to steady rise of L-ascorbic acid level in blood plasma.

Topics: Animals; Ascorbic Acid; Chemical Phenomena; Chemistry; Delayed-Action Preparations; Indoles; Kinetics; Magnetic Resonance Spectroscopy; Mice

Topics: Ascorbic Acid; Data Collection; Indoles; Plants

Topics: Ascorbic Acid; Indoles; Metabolism; Plant Growth Regulators; Plants; Research; Seeds; Viridiplantae

Topics: Animals; Ascorbic Acid; Carbohydrate Metabolism; Guinea Pigs; Indoles; Scurvy

Topics: Ascorbic Acid; Carbohydrate Metabolism; Glucosinolates; Glycoside Hydrolases; Humans; In Vitro Techniques; Indoles

Topics: Ascorbic Acid; Humans; Indoles; Research; Vitamins

Topics: Ascorbic Acid; Brassicaceae; Indoles; Plants

Topics: Acetonitriles; Ascorbic Acid; Brassica; Brassicaceae; Indoles; Plants; Tryptophan

Topics: Ascorbic Acid; Indoles; Vitamins

Topics: Ascorbic Acid; Humans; Indoles