17 results on '"Elke Richling"'
Search Results
2. Beteiligung von ATM an der DNA‐Schadensantwort ausgelöst durch das Phenylpropanoid Methyleugenol in Leberzellen
- Author
-
Caroline Quarz, Max J. Carlsson, Anastasia S. Vollmer, Teodora Nikolova, Markus Christmann, Thomas Hofmann, Simone Stegmüller, Elke Richling, Alexander Cartus, and Jörg Fahrer
- Subjects
Pharmaceutical Science - Published
- 2023
3. HPLC analysis of coumarin in tonka bean and tonka bean containing food
- Author
-
Andreea Claudia Toma, Simone Stegmüller, and Elke Richling
- Subjects
Pharmaceutical Science - Published
- 2022
4. Is the antioxidative effectiveness of a bilberry extract influenced by encapsulation?
- Author
-
Karin Schwarz, Elke Richling, Heinz Rehage, Markus Schantz, Ulrich Kulozik, Heike P. Schuchmann, Sonja Berg, Michael Betz, Kerstin Frank, Matthias Baum, and Sabine Leick
- Subjects
Whey protein ,Nutrition and Dietetics ,Antioxidant ,food.ingredient ,Bilberry ,biology ,Pectin ,DNA damage ,medicine.medical_treatment ,Glutathione ,Vaccinium myrtillus ,biology.organism_classification ,medicine.disease_cause ,chemistry.chemical_compound ,food ,chemistry ,Biochemistry ,medicine ,Agronomy and Crop Science ,Oxidative stress ,Food Science ,Biotechnology - Abstract
BACKGROUND Bilberries (Vaccinium myrtillus L.) have been suggested to have preventive properties against diseases associated with oxidative stress such as colon cancer or inflammatory bowel diseases. Therefore the gastrointestinal tract is regarded as a potential target for prevention. In this study the antioxidative properties of a commercially available anthocyanin-rich bilberry extract (BE) were investigated in comparison with four different BE-loaded microcapsule systems. As markers to describe the antioxidant status in this cellular system, intracellular reactive oxygen species (ROS) levels, oxidative DNA damage and total glutathione (tGSH) levels were monitored. RESULTS Incubations with the BE-loaded capsule systems showed an increase in cellular glutathione levels and reduction of ROS levels at high BE concentrations (100-500 µg mL(-1) ) and a positive effect on the formation of DNA strand breaks (5-10 µg mL(-1) BE). The biological properties of BE-loaded pectin amide core-shell capsules, whey protein matrix capsules and coated apple pectin matrix capsules were comparable to those of the non-encapsulated BE. CONCLUSION Overall, the BE and the encapsulated BE types tested have antioxidative activity under the studied assay conditions in terms of the prevention of oxidative DNA damage, the reduction of intracellular ROS and the enhancement of cellular tGSH.
- Published
- 2014
5. Ist Kaffeetrinken gesund?
- Author
-
Michael Habermeyer and Elke Richling
- Subjects
General Chemistry - Abstract
Bei Kaffee handelt es sich um ein vielfach taglich verzehrtes Lebensmittel mit praventiven Eigenschaften. Bis zum heutigen Zeitpunkt konnten in Kaffee uber 1000 Inhaltsstoffe identifiziert werden. Insgesamt kann bei moderatem Kaffeekonsum (3–4 Tassen pro Tag) von einem gesundheitsfordernden Aspekt ausgegangen werden. Ein positiver Zusammenhang zwischen dem Verzehr von Kaffee konnte fur Diabetes mellitus Typ 2 und Parkinson festgestellt werden. Im Allgemeinen ist das Krebsrisiko nicht erhoht. Bei manchen Krebsarten war eine Reduzierung des Risikos feststellbar. Trotz des Vorkommens von Kontaminanten in Kaffee ist insgesamt von einer positiven Wirkung dieses popularen Getrankes auf den menschlichen Organismus auszugehen.
- Published
- 2014
6. Alkylpyrazines from Coffee are Extensively Metabolized to Pyrazine Carboxylic Acids in the Human Body
- Author
-
Leon Buckel, Lara F. Stadlmair, Tamara Bakuradze, Gerhard Eisenbrand, Anika Glaß‐Theis, Jonathan Isaak Kremer, Stephanie Pickard, and Elke Richling
- Subjects
Adult ,Male ,0301 basic medicine ,Spectrometry, Mass, Electrospray Ionization ,Pyrazine ,Carboxylic Acids ,Coffee consumption ,Urine ,Coffee ,Excretion ,03 medical and health sciences ,chemistry.chemical_compound ,Humans ,Ingestion ,Food science ,Chromatography, High Pressure Liquid ,030109 nutrition & dietetics ,Metabolism ,Pyrazinamide ,Intervention studies ,Healthy Volunteers ,030104 developmental biology ,chemistry ,Pyrazines ,Alkylpyrazine ,Female ,Food Science ,Biotechnology - Abstract
SCOPE Coffee is a complex mixture of over 1000 compounds, including diverse heteroaromatic compounds such as alkylpyrazines. Little is known about the intake, metabolism, and bodily distribution of these compounds. Therefore, a human intervention study is conducted to investigate the excretion of alkylpyrazine metabolites in urine after the ingestion of brewed coffee containing alkylpyrazines. METHODS AND RESULTS After consuming a diet without heat-processed food, ten volunteers consumed 500 mL of freshly brewed coffee prepared from coffee pads, providing intakes of 2-methylpyrazine (2-MeP), 2,5-dimethylpyrazine (2,5-DMeP), and 2,6-dimethylpyrazine (2,6-DMeP) amounting to 17.2, 4.4, and 4.9 µmol, respectively. These alkylpyrazines are metabolized into the corresponding pyrazine carboxylic acids, namely pyrazine-2-carboxylic acid (PA), 5-hydroxypyrazine-2-carboxylic acid (5-OHPA), 5-methylpyrazine-2-carboxylic acid (5-MePA), and 6-methylpyrazine-2-carboxylic acid (6-MePA). In total, 64% of the ingested 2-MeP is excreted as PA, as well as 26% as 5-OHPA, while 91% and 97% of the ingested 2,5-DMeP and 2,6-DMeP are recovered as 5-MePA and 6-MePA, respectively, in urine samples collected after coffee consumption. CONCLUSION This study provides evidence that alkylpyrazines are rapidly metabolized into the corresponding carboxylic acids and excreted via urine by humans, which is consistent with earlier rodent studies.
- Published
- 2019
7. Structure- and dose-absorption relationships of coffee polyphenols
- Author
-
Mathieu Renouf, Fabiola Dionisi, Elke Richling, Gary Williamson, Thomas Erk, Johanna Hauser, and Heike Steiling
- Subjects
Ussing chamber ,Clinical Biochemistry ,General Medicine ,Absorption (skin) ,Biology ,Biochemistry ,Bioavailability ,Jejunum ,Caffeoylquinic acid ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Polyphenol ,medicine ,Caffeic acid ,Molecular Medicine ,Efflux ,Food science - Abstract
Chlorogenic acids (CGAs) from coffee have biological effects related to human health. Thus, specific data on their bioavailability in the upper gastrointestinal tract are of high interest, since some molecules are absorbed here and so are not metabolized by colonic microflora. Up to now, no data on structure-absorption relationships for CGAs have been published, despite this being the most consumed group of polyphenols in the western diet. To address this gap, we performed ex vivo absorption experiments with pig jejunal mucosa using the Ussing chamber model (a model simulating the mucosa and its luminal/apical side). The main coffee polyphenols, caffeoylquinic acid (CQA), feruloylquinic acid (FQA), caffeic acid (CA), dicaffeoylquinic acid (diCQA), and D-(-)-quinic acid (QA), were incubated in individual experiments equivalent to gut lumen physiologically achievable concentrations (0.2-3.5 mM). Identification and quantification were performed with HPLC-diode array detection and HPLC-MS/MS. Additionally, the presence of ABC-efflux transporters was determined by Western blot analysis. The percentages of initially applied CGAs that were absorbed through the jejunal pig mucosa were, in increasing order: diCQA, trace; CQA, ≈ 1%; CA, ≈ 1.5%; FQA, ≈ 2%; and QA, ≈ 4%. No differences were observed within the CGA subgroups. Dose-absorption experiments with 5-CQA suggested a passive diffusion (nonsaturable absorption and a linear dose-flux relationship) and its secretion was affected by NaN3 , indicating an active efflux. The ABC-efflux transporters MDR 1 and MRP 2 were identified in pig jejunal mucosa for the first time. We conclude that active efflux plays a significant role in CGA bioavailability and, further, that the mechanism of CGA absorption in the jejunum is governed by their physicochemical properties.
- Published
- 2013
8. Profiling of mercapturic acids of acrolein and acrylamide in human urine after consumption of potato crisps*
- Author
-
Nico Watzek, Franz Berger, Matthias Baum, Gerhard Eisenbrand, Uwe Fuhr, Dorota Tomalik-Scharte, Julia Feld, Elke Richling, Oxana Doroshyenko, and Denise Scherbl
- Subjects
Adult ,Male ,Hot Temperature ,Food Contamination ,Urine ,Isotope dilution ,Gas Chromatography-Mass Spectrometry ,Excretion ,chemistry.chemical_compound ,Isotopes ,Tandem Mass Spectrometry ,Humans ,Cooking ,Acrolein ,Chromatography, High Pressure Liquid ,Solanum tuberosum ,Acrylamide ,Chromatography ,Acetylcysteine ,Bioavailability ,chemistry ,Creatinine ,Gas chromatography–mass spectrometry ,Biomarkers ,Food Science ,Biotechnology ,Food contaminant - Abstract
Scope Acrolein (AC) and acrylamide (AA) are food contaminants generated by heat treatment. We studied human exposure after consumption of potato crisps by monitoring excretion of mercapturic acids (MAs) in urine. Methods and results MA excretion was monitored in human urine collected up to 72 h after ingestion of a test meal of experimental (study 1: 1 mg AA/150 g) or commercially available (study 2: 44 μg AA plus 4.6 μg AC/175 g) potato crisps. MA contents were analysed after purification via SPE using HPLC-ESI-MS/MS. On the basis of the area under the curve values of MAs excreted in urine, the total excretion of AC-related MAs exceeded that of AA-related MAs up to 12 times in study 1 and up to four times in study 2. Remarkably, AC content of potato crisps of study 2 was found to be only about 1/10 the AA content, as determined by isotope dilution headspace GC/MS. Conclusion Our results indicate substantially higher exposure to AC from potato crisps than to AA. Total AC in such foods may encompass bioavailable AC forms not detected by headspace GC/MS. Both findings may also apply to other heat processed foods.
- Published
- 2012
9. Biological effects of acrylamide after daily ingestion of various foods in comparison to water: A study in rats
- Author
-
Gert Fricker, Julia Feld, Elke Richling, Karl-Heinz Merz, Franz Berger, Daniel Bertow, Gerhard Eisenbrand, Natalie Gerhardt, and Matthias Baum
- Subjects
Male ,Biological Availability ,Urine ,Rats, Sprague-Dawley ,Excretion ,Eating ,Hemoglobins ,chemistry.chemical_compound ,Valine ,Animals ,Ingestion ,Food science ,Mercapturic acid ,Biotransformation ,Carcinogen ,Solanum tuberosum ,Acrylamide ,Water ,Bread ,Acetylcysteine ,Rats ,Bioavailability ,chemistry ,Biochemistry ,Food ,Carcinogens ,Epoxy Compounds ,Biomarkers ,DNA Damage ,Food Science ,Biotechnology - Abstract
Scope: Acrylamide (AA), classified as a genotoxic carcinogen, is generated by heating foods. We studied whether the food matrix modulates bioavailability and/or biotransformation and investigated kinetics and biological effectiveness of AA in rats. Methods and results: AA was given to the animals at a daily intake level of AA containing foods for up to 9 days, resulting in an exposure of 50 or 100 μg AA/kg body weight (b.w.)/day. Positive controls received the same dosages of AA in water, negative controls just water. As biomarkers urinary mercapturic acids, hemoglobin adducts, plasma levels of AA and glycidamide (GA) and DNA integrity in white blood cells and hepatocytes were measured. Altogether, no significant differences in bioavailability of AA from water and the different food matrices were observed. Only with bread crust, biomarkers indicated a slightly reduced bioavailability. Monitoring glycidamide valine adduct adducts did not provide evidence for treatment-related significantly enhanced GA-haemoglobin adduct formation in blood although glycidamide mercapturic acid excretion in urine indicated significant GA formation. Conclusions: The results suggest AA at dietary intake levels, exceeding estimated human mean intake by a factor of at least 100 to become detoxified in Sprague–Dawley rats to a major extent through glutathione coupling.
- Published
- 2010
10. Urinary Excretion of Niacin Metabolites in Humans After Coffee Consumption
- Author
-
Katharina Gömpel, Gerhard Eisenbrand, Elke Richling, Jonathan Isaak Kremer, and Tamara Bakuradze
- Subjects
Adult ,Male ,Niacinamide ,0301 basic medicine ,Spectrometry, Mass, Electrospray Ionization ,Pyridones ,stable isotope dilution analysis (SIVA) ,coffee ,Indicator Dilution Techniques ,nicotinamide ,Coffee roasting ,niacin ,Urine ,Urinalysis ,Methylation ,01 natural sciences ,Excretion ,Young Adult ,03 medical and health sciences ,chemistry.chemical_compound ,Limit of Detection ,Tandem Mass Spectrometry ,Trigonelline ,Humans ,Ingestion ,Food science ,Chromatography, High Pressure Liquid ,Molecular Structure ,Nicotinamide ,010401 analytical chemistry ,Nicotinic Acids ,food and beverages ,Food & Function ,Metabolism ,0104 chemical sciences ,Kinetics ,Renal Elimination ,030104 developmental biology ,chemistry ,Calibration ,Female ,Nutritive Value ,metabolism ,Niacin ,Food Science ,Biotechnology - Abstract
cope Coffee is a major natural source of niacin in the human diet, as it is formed during coffee roasting from the alkaloid trigonelline. The intention of our study was to monitor the urinary excretion of niacin metabolites after coffee consumption under controlled diet. Methods and results We performed a four-day human intervention study on the excretion of major niacin metabolites in the urine of volunteers after ingestion of 500 mL regular coffee containing 34.8 μmol nicotinic acid (NA) and 0.58 μmol nicotinamide (NAM). In addition to NA and NAM, the metabolites N1-methylnicotinamide (NMNAM), N1-methyl-2-pyridone-5-carboxamide (2-Py), and nicotinuric acid (NUA) were identified and quantified in the collected urine samples by stable isotope dilution analysis (SIVA) using HPLC-ESI-MS/MS. Rapid urinary excretion was observed for the main metabolites (NA, NAM, NMNAM, and 2-Py), with tmax values within the first hour after ingestion. NUA appeared in traces even more rapid. In sum, 972 nmol/h of NA, NAM, NMNAM, and 2-Py were excreted within 12 h after coffee consumption, corresponding to 6 % of the ingested NA and NAM. Conclusion The results indicate regular coffee consumption to be a source of niacin in human diet. This article is protected by copyright. All rights reserved
- Published
- 2018
11. Lebensmittelchemie 2009
- Author
-
Leane Lehmann, Harald Esch, and Elke Richling
- Subjects
General Chemical Engineering ,General Chemistry - Published
- 2010
12. Synthesis of [4-14C]-pelargonidin chloride and [4-14C]-delphinidin chloride
- Author
-
Michael R. Kraus, Ellen Biskup, Elke Richling, and Peter Schreier
- Subjects
Organic Chemistry ,Phloroglucinol ,Biochemistry ,Medicinal chemistry ,Chemical synthesis ,Chloride ,Analytical Chemistry ,Anthocyanidins ,chemistry.chemical_compound ,chemistry ,Labelling ,Drug Discovery ,medicine ,Organic chemistry ,Radiology, Nuclear Medicine and imaging ,Carbon-14 ,Hydrogen chloride ,Spectroscopy ,Anthocyanidin ,medicine.drug - Abstract
The synthesis of [4-14C]-pelargonidin chloride and [4-14C]-delphinidin chloride via [formyl-14C]-2-(benzoyloxy)-4,6-dihydroxybenzaldehyde, ω,4-diacetoxyacetophenone and ω,3,4,5-tetraacetoxyacetophenone is described. The first step comprised labelling of the carbonyl group of 2-(benzoyloxy)-4,6-dihydroxybenzaldehyde, verifying that the coupling with ω,4-diacetoxyacetophenone or ω,3,4,5-tetraacetoxyacetophenone under hydrogen chloride atmosphere resulted in the formation of [4-14C] labelled anthocyanidins. Copyright © 2006 John Wiley & Sons, Ltd.
- Published
- 2006
13. Use of the pig caecum model to mimic the human intestinal metabolism of hispidulin and related compounds
- Author
-
Hans-Ulrich Humpf, Elke Richling, Samira Labib, Peter Schreier, and Sylvia Hummel
- Subjects
Spectrometry, Mass, Electrospray Ionization ,Swine ,Flavonoid ,Phloroglucinol ,Biology ,Gas Chromatography-Mass Spectrometry ,chemistry.chemical_compound ,Animals ,Humans ,Apigenin ,Kaempferols ,Luteolin ,Cecum ,Chromatography, High Pressure Liquid ,Flavonoids ,chemistry.chemical_classification ,Bacteria ,Scutellarein ,Flavones ,Galangin ,Kinetics ,Biochemistry ,chemistry ,Models, Animal ,Hispidulin ,Quercetin ,Kaempferol ,Food Science ,Biotechnology - Abstract
Up to now, the metabolism of hispidulin (5,7,4'-trihydroxy-6-methoxyflavone), a potent ligand of the central human benzodiazepine receptor, has not been investigated. To elucidate the metabolism of hispidulin in the large intestine, its biotransformation by the pig caecal microflora was studied. In addition, the efficiency of the pig caecal microflora to degrade galangin (3,5,7-trihydroxyflavone), kaempferol (3,5,7,4'-tetrahydroxyflavone), apigenin (5,7,4'-trihydroxyflavone), and luteolin (5,7,3',4'-tetrahydroxyflavone) was investigated. Identification of the formed metabolites was performed by high-performance liquid chromatography (HPLC)-diode array detection, HPLC-electrospray ionization-tandem mass spectrometry, and high-resolution gas chromatography-mass spectrometry. The caecal microflora transformed hispidulin to scutellarein (5,6,7,4'-tetrahydroxyflavone), an effective alpha-glucosidase inhibitor, and 3-(4-hydroxyphenyl)-propionic acid; galangin to phenylacetic acid and phloroglucinol; kaempferol to 4-hydroxyphenylacetic acid, phloroglucinol, and 4-methylphenol; apigenin to 3-(4-hydroxyphenyl)-propionic acid and 3-phenylpropionic acid, and luteolin to 3-(3-hydroxyphenyl)-propionic acid, respectively. To elucidate to what extent different hydroxylation patterns on the B-ring influence the degradation degree of flavonoids, the conversions of galangin and kaempferol as well as that of apigenin and luteolin were compared with those of quercetin (3,5,7,3',4'-pentahydroxyflavone) and chrysin (5,7-dihydroxyflavone), respectively. Regardless of the flavonoid subclass, the presence of a hydroxy group at the 4'-position seems to be a prerequisite for fast breakdown. An additional hydroxy group at the B-ring did not affect the degradation degree.
- Published
- 2006
14. Cactus pear (Opuntia ficus indica) flavour constituents-chiral evaluation (MDGC-MS) and isotope ratio (HRGC-IRMS) analysis
- Author
-
Elke Richling, Katja Hör, Renate Bastl-Borrmann, Bernhard Weckerle, Christiane Ruff, and Peter Schreier
- Subjects
PEAR ,Chromatography ,biology ,General Chemistry ,Mass spectrometry ,biology.organism_classification ,Crassulaceae ,chemistry.chemical_compound ,Linalool ,chemistry ,Cactus ,Gas chromatography ,Isotope-ratio mass spectrometry ,Flavor ,Food Science - Abstract
Among the volatiles isolated by solvent extraction from cactus pear fruit (Opuntia ficus indica) and identified by HRGC–MS, selected chiral and achiral constituents were characterized by enantiodifferentiation and 13C/12C isotope ratio analysis, using multidimensional gas chromatography–mass spectrometry (MDGC–MS) and on-line gas chromatography–combustion isotope ratio mass spectrometry (HRGC-C-IRMS), respectively. While the enantiodistributions determined for methyl 2-methylbutanoate (98 : 2%, S : R), methyl 3-hydroxybutanoate (73 : 27%, R : S), 1-phenyl-ethanol (74 : 26%, R : S), linalool (68 : 32%, R : S), γ-nonalactone (65 : 35%, S : R), γ-deca-lactone (79 : 21%, R : S) and γ-dodecalactone (>99% R) can be discussed in relation to data previously provided for these compounds from various plant origins, the δ13C values of −22.0‰, −21.8‰, −19.1‰ and −20.9‰, measured for 1-hexanol, E-2-hexenol, E-2-nonenol and E,Z-2,6-nonadienol, respectively, are clear-cut indicators for their origin from plants with Crassulaceae acid metabolism (CAM), and thus may helpful for authenticity evaluations. Copyright © 2001 John Wiley & Sons, Ltd.
- Published
- 2001
15. Kaffeetrinken und DNA schützen
- Author
-
Elke Richling
- Subjects
General Chemistry - Abstract
Kaffee ist mit einem Konsum von uber 160 Litern pro Jahr das beliebteste Getrank der Deutschen [1]. Nun gibt es Hinweise darauf, dass regelmasiger Kaffeekonsum DNA-Strangbruche verhindert.
- Published
- 2015
16. Fractionation of polyphenol-enriched apple juice extracts to identify constituents with cancer chemopreventive potential
- Author
-
Wolfgang Hümmer, Elke Richling, Hans Becker, Karin Klimo, Norbert Frank, Lydia Pan, Peter Schreier, Clarissa Gerhäuser, Robert W. Owen, Henriette Zessner, Frank Will, Jutta Knauft, and Regina Niewöhner
- Subjects
Antioxidant ,DPPH ,Phloretin ,medicine.medical_treatment ,Catechin ,Beverages ,chemistry.chemical_compound ,Caffeic Acids ,Flavonols ,Phenols ,Chlorogenic acid ,medicine ,Anticarcinogenic Agents ,Chromatography, High Pressure Liquid ,Flavonoids ,chemistry.chemical_classification ,Plant Extracts ,Polyphenols ,Aglycone ,chemistry ,Biochemistry ,Polyphenol ,Malus ,Quercetin ,Food Science ,Biotechnology - Abstract
Apples and apple juices are widely consumed and rich sources of phytochemicals. The aim of the present study was to determine which apple constituents contribute to potential chemopreventive activities, using a bioactivity-directed approach. A polyphenol-enriched apple juice extract was fractionated by various techniques. Extract and fractions were tested in a series of test systems indicative of cancer preventive potential. These test systems measured antioxidant effects, modulation of carcinogen metabolism, anti-inflammatory and antihormonal activities, and antiproliferative potential. Regression analyses indicated that 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging potential correlated with the sum of low molecular weight (LMW) antioxidants (including chlorogenic acid, flavan-3-ols, and flavonols) and procyanidins, whereas peroxyl radicals were more effectively scavenged by LMW compounds than by procyanidins. Quercetin aglycone was identified as a potent Cyp1A inhibitor, whereas phloretin and (-)-epicatechin were the most potent cyclooxygenase 1 (Cox-1) inhibitors. Aromatase and Cyp1A inhibitory potential and cytotoxicity toward HCT116 colon cancer cells increased with increasing content in procyanidins. Overall, apple juice constituents belonging to different structural classes have distinct profiles of biological activity in these in vitro test systems. Since carcinogenesis is a complex process, combination of compounds with complementary activities may lead to enhanced preventive effects.
- Published
- 2008
17. Editorial
- Author
-
Elke Richling
- Subjects
Human health ,Chemistry ,Food science ,Food Science ,Biotechnology - Published
- 2011
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.