397 results on '"Merfort I"'
Search Results
152. Lipoprotein turnover and possible remnant accumulation in preeclampsia: insights from the Freiburg Preeclampsia H.E.L.P.-apheresis study.
- Author
-
Contini C, Jansen M, König B, Markfeld-Erol F, Kunze M, Zschiedrich S, Massing U, Merfort I, Prömpeler H, Pecks U, Winkler K, and Pütz G
- Subjects
- Adult, Apolipoproteins B blood, Blood Component Removal, Female, Humans, Pre-Eclampsia pathology, Pregnancy, Triglycerides blood, Cholesterol blood, Cholesterol, LDL blood, Lipid Metabolism, Lipoproteins blood, Pre-Eclampsia blood
- Abstract
Background: Preeclampsia is a life-threatening disease in pregnancy, and its complex pathomechanisms are poorly understood. In preeclampsia, lipid metabolism is substantially altered. In late onset preeclampsia, remnant removal disease like lipoprotein profiles have been observed. Lipid apheresis is currently being explored as a possible therapeutic approach to prolong preeclamptic pregnancies. Here, apheresis-induced changes in serum lipid parameters are analyzed in detail and their implications for preeclamptic lipid metabolism are discussed., Methods: In the Freiburg H.E.L.P.-Apheresis Study, 6 early onset preeclamptic patients underwent repeated apheresis treatments. Serum lipids pre- and post-apheresis and during lipid rebound were analyzed in depth via ultracentrifugation to yield lipoprotein subclasses., Results: The net elimination of Apolipoprotein B and plasma lipids was lower than theoretically expected. Lipids returned to previous pre-apheresis levels before the next apheresis even though apheresis was repeated within 2.9 ± 1.2 days. Apparent fractional catabolic rates and synthetic rates were substantially elevated, with fractional catabolic rates for Apolipoprotein B / LDL-cholesterol being 0.7 ± 0.3 / 0.4 ± 0.2 [day
- 1 ] and synthetic rates being 26 ± 8 / 17 ± 8 [mg*kg- 1 *day- 1 ]. The distribution of LDL-subclasses after apheresis shifted to larger buoyant LDL, while intermediate-density lipoprotein-levels remained unaffected, supporting the notion of an underlying remnant removal disorder in preeclampsia., Conclusion: Lipid metabolism seems to be highly accelerated in preeclampsia, likely outbalancing remnant removal mechanisms. Since cholesterol-rich lipoprotein remnants are able to accumulate in the vessel wall, remnant lipoproteins may contribute to the severe endothelial dysfunction observed in preeclampsia., Trial Registration: ClinicalTrails.gov, NCT01967355 .- Published
- 2018
- Full Text
- View/download PDF
153. Phase-contrast MR flow imaging: A tool to determine hepatic hemodynamics in rats with a healthy, fibrotic, or cirrhotic liver.
- Author
-
Schaffner D, von Elverfeldt D, Deibert P, Lazaro A, Merfort I, Lutz L, Neubauer J, Baumstark MW, Kreisel W, and Reichardt W
- Subjects
- Animals, Hemodynamics, Humans, Hypertension, Portal pathology, Image Processing, Computer-Assisted, Liver blood supply, Liver pathology, Male, Observer Variation, Portal Vein pathology, Rats, Rats, Wistar, Regional Blood Flow, Thioacetamide chemistry, Water chemistry, Liver diagnostic imaging, Liver Cirrhosis diagnostic imaging, Magnetic Resonance Imaging
- Abstract
Purpose: To test a magnetic resonance (MR) scanning protocol as a noninvasive tool to determine hepatic hemodynamics and to assess the degree of liver fibrosis in an animal model of liver fibrosis and cirrhosis., Materials and Methods: Fifty-four male Wistar rats were studied. Thirty-nine received thioacetamide (TAA) in their drinking water for either 12 or 16 weeks. MR measurements were performed using flow-sensitive 2D phase-contrast MRI and a 9.4T preclinical scanner. The following hemodynamic parameters were investigated: portal cross-sectional area, mean portal flow velocity, and portal and aortic flow volume rate. Therefore, rats (n = 46) were divided into three groups: CON (control, n = 13), FIB (fibrosis, n = 25), and CIR (cirrhosis, n = 8). Furthermore, the degree of liver fibrosis was assessed by a self-established MR score and verified by a standardized histological score (n = 48)., Results: Portal and aortic flow parameters could be reliably detected. A significant decrease in portal flow velocity was found in FIB (FIB vs. CON: -21%, P = 0.006 and CIR vs. CON: -17%, P = 0.105) and in portal flow volume rate in FIB and CIR (FIB vs. CON: -20%, P = 0.009 and CIR vs. CON: -25%, P = 0.024). If the histological score is taken as standard, the self-established MR score enabled discrimination between healthy and diseased livers (sensitivity to identify diseased livers: 89% and specificity to identify healthy livers: 100%)., Conclusion: This MR scanning protocol presents a noninvasive tool to determine hepatic hemodynamics in healthy and diseased rats., Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1526-1534., (© 2017 International Society for Magnetic Resonance in Medicine.)
- Published
- 2017
- Full Text
- View/download PDF
154. Disease relevant modifications of the methylome and transcriptome by particulate matter (PM 2.5 ) from biomass combustion.
- Author
-
Heßelbach K, Kim GJ, Flemming S, Häupl T, Bonin M, Dornhof R, Günther S, Merfort I, and Humar M
- Subjects
- Biomass, Cell Line, CpG Islands, Environmental Exposure analysis, Epigenesis, Genetic, Humans, MicroRNAs genetics, DNA Methylation, Environmental Pollutants adverse effects, Particulate Matter adverse effects, Transcriptome drug effects
- Abstract
Exposure to particulate matter (PM) is recognized as a major health hazard, but molecular responses are still insufficiently described. We analyzed the epigenetic impact of ambient PM
2.5 from biomass combustion on the methylome of primary human bronchial epithelial BEAS-2B cells using the Illumina HumanMethylation450 BeadChip. The transcriptome was determined by the Affymetrix HG-U133 Plus 2.0 Array. PM2.5 induced genome wide alterations of the DNA methylation pattern, including differentially methylated CpGs in the promoter region associated with CpG islands. Gene ontology analysis revealed that differentially methylated genes were significantly clustered in pathways associated with the extracellular matrix, cellular adhesion, function of GTPases, and responses to extracellular stimuli, or were involved in ion binding and shuttling. Differential methylations also affected tandem repeats. Additionally, 45 different miRNA CpG loci showed differential DNA methylation, most of them proximal to their promoter. These miRNAs are functionally relevant for lung cancer, inflammation, asthma, and other PM-associated diseases. Correlation of the methylome and transcriptome demonstrated a clear bias toward transcriptional activation by hypomethylation. Genes that exhibited both differential methylation and expression were functionally linked to cytokine and immune responses, cellular motility, angiogenesis, inflammation, wound healing, cell growth, differentiation and development, or responses to exogenous matter. Disease ontology of differentially methylated and expressed genes indicated their prominent role in lung cancer and their participation in dominant cancer related signaling pathways. Thus, in lung epithelial cells, PM2.5 alters the methylome of genes and noncoding transcripts or elements that might be relevant for PM- and lung-associated diseases.- Published
- 2017
- Full Text
- View/download PDF
155. Revised editorial guidelines for manuscripts on the pharmacology of plant extracts.
- Author
-
Merfort I, Michel MC, and Seifert R
- Published
- 2017
- Full Text
- View/download PDF
156. Stress fibers, autophagy and necrosis by persistent exposure to PM2.5 from biomass combustion.
- Author
-
Dornhof R, Maschowski C, Osipova A, Gieré R, Seidl M, Merfort I, and Humar M
- Subjects
- AMP-Activated Protein Kinases metabolism, Cell Cycle, Cell Death, Cell Line, Transformed, HSP27 Heat-Shock Proteins metabolism, Humans, Microscopy, Electron, Transmission, Necrosis, Phosphorylation, rhoA GTP-Binding Protein metabolism, Autophagy, Biomass, Environmental Exposure, Particulate Matter, Stress Fibers metabolism
- Abstract
Fine particulate matter (PM2.5) can adversely affect human health. Emissions from residential energy sources have the largest impact on premature mortality globally, but their pathological and molecular implications on cellular physiology are still elusive. In the present study potential molecular consequences were investigated during long-term exposure of human bronchial epithelial BEAS-2B cells to PM2.5, collected from a biomass power plant. Initially, we observed that PM2.5 did not affect cellular survival or proliferation. However, it triggered an activation of the stress response p38 MAPK which, along with RhoA GTPase and HSP27, mediated morphological changes in BEAS-2B cells, including actin cytoskeletal rearrangements and paracellular gap formation. The p38 inhibitor SB203580 prevented phosphorylation of HSP27 and ameliorated morphological changes. During an intermediate phase of long-term exposure, PM2.5 triggered proliferative regression and activation of an adaptive stress response necessary to maintain energy homeostasis, including AMPK, repression of translational elongation, and autophagy. Finally, accumulation of intracellular PM2.5 promoted lysosomal destabilization and cell death, which was dependent on lysosomal hydrolases and p38 MAPK, but not on the inflammasome and pyroptosis. TEM images revealed formation of protrusions and cellular internalization of PM2.5, induction of autophagosomes, amphisomes, autophagosome-lysosomal fusion, multiple compartmental fusion, lysosomal burst, swollen mitochondria and finally necrosis. In consequence, persistent exposure to PM2.5 may impair epithelial barriers and reduce regenerative capacity. Hence, our results contribute to a better understanding of PM-associated lung and systemic diseases on the basis of molecular events.
- Published
- 2017
- Full Text
- View/download PDF
157. Wide Distribution of Foxicin Biosynthetic Gene Clusters in Streptomyces Strains - An Unusual Secondary Metabolite with Various Properties.
- Author
-
Greule A, Marolt M, Deubel D, Peintner I, Zhang S, Jessen-Trefzer C, De Ford C, Burschel S, Li SM, Friedrich T, Merfort I, Lüdeke S, Bisel P, Müller M, Paululat T, and Bechthold A
- Abstract
Streptomyces diastatochromogenes Tü6028 is known to produce the polyketide antibiotic polyketomycin. The deletion of the pokOIV oxygenase gene led to a non-polyketomycin-producing mutant. Instead, novel compounds were produced by the mutant, which have not been detected before in the wild type strain. Four different compounds were identified and named foxicins A-D. Foxicin A was isolated and its structure was elucidated as an unusual nitrogen-containing quinone derivative using various spectroscopic methods. Through genome mining, the foxicin biosynthetic gene cluster was identified in the draft genome sequence of S. diastatochromogenes . The cluster spans 57 kb and encodes three PKS type I modules, one NRPS module and 41 additional enzymes. A foxBII gene-inactivated mutant of S. diastatochromogenes Tü6028 Δ pokOIV is unable to produce foxicins. Homologous fox biosynthetic gene clusters were found in more than 20 additional Streptomyces strains, overall in about 2.6% of all sequenced Streptomyces genomes. However, the production of foxicin-like compounds in these strains has never been described indicating that the clusters are expressed at a very low level or are silent under fermentation conditions. Foxicin A acts as a siderophore through interacting with ferric ions. Furthermore, it is a weak inhibitor of the Escherichia coli aerobic respiratory chain and shows moderate antibiotic activity. The wide distribution of the cluster and the various properties of the compound indicate a major role of foxicins in Streptomyces strains.
- Published
- 2017
- Full Text
- View/download PDF
158. In vitro studies to evaluate the wound healing properties of Calendula officinalis extracts.
- Author
-
Nicolaus C, Junghanns S, Hartmann A, Murillo R, Ganzera M, and Merfort I
- Subjects
- Cell Movement drug effects, Cells, Cultured, Collagen metabolism, Collagenases metabolism, Ethanol chemistry, Fibroblasts drug effects, Fibroblasts metabolism, Flowers, Foreskin cytology, Hexanes chemistry, Humans, Interleukin-8 genetics, Interleukin-8 metabolism, Keratinocytes drug effects, Keratinocytes metabolism, Keratinocytes physiology, Male, Solvents chemistry, Calendula, Plant Extracts pharmacology, Wound Healing drug effects
- Abstract
Ethnopharmacological Relevance: Calendula officinalis (pot marigold) flower extracts have a long-lasting tradition in ethnopharmacology. Currently, the European Medicines Agency (EMA) has approved its lipophilic and aqueous alcoholic extracts as traditional medicinal products for the treatment of minor inflammation of the skin and as an aid in the healing of minor wounds., Aim of the Study: The purpose of this study was to analyse the molecular mechanism of the wound healing effects of Calendula extracts, which may reflect the phytomedicines currently used in the market., Materials and Methods: The effect of three different extracts from Calendula flowers (n-hexanic, ethanolic, aqueous) on the inflammatory phase of wound healing was studied in human immortalized keratinocytes and human dermal fibroblasts. An electrophoretic mobility shift assay on NF-κB-DNA binding, qRT-PCR and ELISA experiments were performed. The effect of Calendula extracts on the new tissue formation phase of wound healing was evaluated by studying the migratory properties of these extracts, triterpene mixtures and single compounds in human immortalized keratinocytes using the scratch assay. Finally, the effect of the extracts on the formation of granulation tissue in wound healing was studied using bacterial collagenase isolated from Clostridium histolyticum and the determination of soluble collagen in the supernatant of human dermal fibroblasts., Results: The n-hexanic and the ethanolic extracts from Calendula flowers influence the inflammatory phase by activating the transcription factor NF-κB and by increasing the amount of the chemokine IL-8, both at the transcriptional and protein level, in human immortalized keratinocytes. The migration of the keratinocytes during the new tissue formation phase was only marginally influenced in the scratch assay. However, it can be assumed that the granulation tissue was affected, as the ethanolic extract inhibited the activity of collagenase in vitro and enhanced the amount of collagen in the supernatant of human dermal fibroblasts., Conclusions: Our results contribute to a better understanding of the wound healing properties of the traditional medicinal plant Calendula officinalis. However, further studies are necessary to evaluate which of its known constituents are responsible for these effects. Triterpenes seem to play only a marginal role, but carotene and xanthophyll derivatives should garner more attention in future studies., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
159. Comparison of In-Vitro and Ex-Vivo Wound Healing Assays for the Investigation of Diabetic Wound Healing and Demonstration of a Beneficial Effect of a Triterpene Extract.
- Author
-
Ueck C, Volksdorf T, Houdek P, Vidal-Y-Sy S, Sehner S, Ellinger B, Lobmann R, Larena-Avellaneda A, Reinshagen K, Ridderbusch I, Kohrmeyer K, Moll I, Daniels R, Werner P, Merfort I, and Brandner JM
- Subjects
- Adult, Aged, Aged, 80 and over, Animals, Child, Preschool, Cytokines metabolism, Epithelium drug effects, Epithelium pathology, Female, Fibroblasts drug effects, Fibroblasts metabolism, Glucose pharmacology, Humans, Hyperglycemia complications, Hyperglycemia drug therapy, Keratinocytes drug effects, Keratinocytes pathology, Male, Sus scrofa, Diabetes Mellitus drug therapy, Diabetes Mellitus pathology, Triterpenes pharmacology, Triterpenes therapeutic use, Wound Healing drug effects
- Abstract
Diabetes mellitus is a frequent cause for chronic, difficult-to-treat wounds. New therapies for diabetic wounds are urgently needed and in-vitro or ex-vivo test systems are essential for the initial identification of new active molecules. The aim of this study is to compare in-vitro and ex-vivo test systems for their usability for early drug screening and to investigate the efficacy of a birch bark triterpene extract (TE) that has been proven ex-vivo and clinically to accelerate non-diabetic wound healing (WH), in a diabetic context. We investigated in-vitro models for diabetic WH, i.e. scratch assays with human keratinocytes from diabetic donors or cultured under hyperglycaemic conditions and a newly developed porcine ex-vivo hyperglycaemic WH model for their potential to mimic delayed diabetic WH and for the influence of TE in these test systems. We show that keratinocytes from diabetic donors often fail to exhibit significantly delayed WH. For cells under hyperglycaemic conditions significant decrease is observed but is influenced by choice of medium and presence of supplements. Also, donor age plays a role. Interestingly, hyperglycaemic effects are mainly hyperosmolaric effects in scratch assays. Ex-vivo models under hyperglycaemic conditions show a clear and substantial decrease of WH, and here both glucose and hyperosmolarity effects are involved. Finally, we provide evidence that TE is also beneficial for ex-vivo hyperglycaemic WH, resulting in significantly increased length of regenerated epidermis to 188±16% and 183±11% (SEM; p<0.05) compared to controls when using two different TE formulations. In conclusion, our results suggest that microenvironmental influences are important in WH test systems and that therefore the more complex hyperglycaemic ex-vivo model is more suitable for early drug screening. Limitations of the in-vitro and ex-vivo models are discussed. Furthermore our data recommend TE as a promising candidate for in-vivo testings in diabetic wounds., Competing Interests: This study was supported by Birken AG. However, the company was only involved in study design (for some of the experiments) but not in data collection, analysis, decision to publish or preparation of the manuscript. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. Therefore they declare that no competing interests exist.
- Published
- 2017
- Full Text
- View/download PDF
160. Hyaluronidase decreases neutrophils infiltration to the inflammatory site.
- Author
-
Fronza M, Muhr C, da Silveira DS, Sorgi CA, Rodrigues SF, Farsky SH, Paula-Silva FW, Merfort I, and Faccioli LH
- Subjects
- Animals, Blood Vessels, Carrageenan, Cell Adhesion drug effects, Cytokines immunology, Inflammation chemically induced, Inflammation drug therapy, Inflammation immunology, Leukocyte Count, Leukocyte Rolling drug effects, Leukocytes cytology, Leukocytes physiology, Lipopolysaccharides, Male, Mice, Inbred C57BL, Anti-Inflammatory Agents pharmacology, Hyaluronoglucosaminidase pharmacology, Leukocytes drug effects
- Abstract
Objective: To evaluate the in vivo anti-inflammatory potential of bovine hyaluronidase (HYAL) using two different models of acute inflammation., Methods: Air pouches were produced in the dorsal subcutaneous of mice and injected with phosphate saline solution or HYAL. The antiinflammatory action of HYAL was evaluated in carrageenan (Cg)-inflamed air pouches. After 4 and 24 h the cellular influx, protein exudation, cytokines and lipid mediators were evaluated. The action of HYAL on the rolling and adhesion of leukocytes was investigated in the LPS-stimulated mesenteric microcirculation by intravital microscopic., Results: Treatment with HYAL reduced the cellular influx and protein exudation in non-inflamed and inflamed air pouches. HYAL treatment of Cg-inflamed air pouch reduced the production of tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL-8), leukotriene B4 (LTB4) and LTC4, whereas prostaglandins E2 (PGE2) and D2 (PGD2) concentrations were unchanged. Histological analyses showed that HYAL administration diminished cell infiltration in the air-pouch lining. In LPS-stimulated mesenteric microcirculation, HYAL usage decreased rolling and adhesion of leukocytes, but did not affect the blood vessels diameters., Conclusion: The results demonstrate that HYAL inhibited cellular recruitment, edema formation and pro-inflammatory mediators production, resulting in decreased adherence of leukocytes to blood vessels and tissue infiltration. Our data suggest that HYAL may be considered an effective candidate to ameliorate acute inflammation.
- Published
- 2016
- Full Text
- View/download PDF
161. Influence of Birch Bark Triterpenes on Keratinocytes and Fibroblasts from Diabetic and Nondiabetic Donors.
- Author
-
Wardecki T, Werner P, Thomas M, Templin MF, Schmidt G, Brandner JM, and Merfort I
- Subjects
- Cytokines metabolism, Female, Fibroblasts metabolism, Humans, Interleukin-6 metabolism, Interleukin-8 metabolism, Pentacyclic Triterpenes chemistry, Pentacyclic Triterpenes isolation & purification, Plant Bark chemistry, Triterpenes chemistry, Wound Healing drug effects, p38 Mitogen-Activated Protein Kinases metabolism, rho GTP-Binding Proteins metabolism, Betula chemistry, Diabetes Mellitus drug therapy, Keratinocytes drug effects, Pentacyclic Triterpenes pharmacology, Triterpenes isolation & purification, Triterpenes pharmacology
- Abstract
Impaired wound healing is one of the main risk factors associated with diabetes mellitus. Few options are available to treat diabetic wounds, and therefore efficient remedies are urgently needed. An interesting option might be an extract of birch bark (TE) that has been clinically proven to accelerate acute wound healing. We investigated the effects of TE and its main components betulin and lupeol in cultured normal keratinocytes and dermal fibroblasts from diabetic and nondiabetic donors. These in vitro models can provide insights into possible beneficial effects in wound healing. TE and betulin treatment led to increased mRNA levels of chemokines, pro-inflammatory cytokines, and mediators important in wound healing, e.g., IL-6, TNFα, IL-8, and RANTES. We observed a pronounced upregulation of MIF, IL-8, and RANTES on the protein level. Furthermore, a shape change of the actin cytoskeleton was seen in keratinocytes and fibroblasts, and the Rho-GTPases and p38-MAPK were found to be activated in keratinocytes. On the basis of our results, TE is worthy of further study as a potential option to influence wound-healing processes under diabetic conditions. These first insights need to be confirmed by clinical studies with diabetic patients.
- Published
- 2016
- Full Text
- View/download PDF
162. Evaluating ancient Egyptian prescriptions today: Anti-inflammatory activity of Ziziphus spina-christi.
- Author
-
Kadioglu O, Jacob S, Bohnert S, Naß J, Saeed ME, Khalid H, Merfort I, Thines E, Pommerening T, and Efferth T
- Subjects
- Cell Line, Tumor, Egypt, Ancient, Herbal Medicine history, History, Ancient, Humans, Inflammation drug therapy, Leupeptins, Molecular Docking Simulation, Plant Roots chemistry, Plant Stems chemistry, Seeds chemistry, Transcription Factor RelA metabolism, Anti-Inflammatory Agents pharmacology, Plant Extracts pharmacology, Plants, Medicinal chemistry, Ziziphus chemistry
- Abstract
Background: Ziziphus spina-christi (L.) Desf. (Christ's Thorn Jujube) is a wild tree today found in Jordan, Israel, Egypt, and some parts of Africa, which was already in use as a medicinal plant in Ancient Egypt. In ancient Egyptian prescriptions, it was used in remedies against swellings, pain, and heat, and thus should have anti-inflammatory effects. Nowadays, Z. spina-christi, is used in Egypt (by Bedouins, and Nubians), the Arabian Peninsula, Jordan, Iraq, and Morocco against a wide range of illnesses, most of them associated with inflammation. Pharmacological research undertaken to date suggests that it possesses anti-inflammatory, hypoglycemic, hypotensive and anti-microbial effects. The transcription factor NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) is critical in inflammation, proliferation and involved in various types of cancer. Identification of new anti-inflammatory compounds might be an effective strategy to target inflammatory disorders and cancer. Therefore, extracts from Z. spina-christi are investigated in terms of their anti-inflammatory effects. Our intention is to evaluate the effects of Z. spina-christi described in ancient Egyptian papyri, and to show whether the effects can be proven with modern pharmacological methods. Furthermore, we determine the active ingredients in crude extracts for their inhibitory activity toward NF-κB pathway., Materials and Methods: To determine the active ingredients of Z. spina-christi, we fractionated the extracts for bioassays and identified the active compounds. Epigallocatechin, gallocatechin, spinosin, 6''' feruloylspinosin and 6''' sinapoylspinosin and crude extracts of seed, leaf, root or stem were analyzed for their effect on NF-κB DNA binding by electromobility shift assay (EMSA) and nuclear translocation of NF-κB-p65 by Western blot analysis. The binding mode of the compounds to NF-κB pathway proteins was compared with the known inhibitor, MG-132, by in silico molecular docking calculations. Log10IC50 values of gallocatechin and epigallocatechin as two main compounds of the plant were correlated to the microarray-based mRNA expression of 79 inflammation-related genes in cell lines of the National Cancer Institute (NCI, USA) as determined. The expression of 17 genes significantly correlated to the log10IC50 values for gallocatechin or epigallocatechin., Results: Nuclear p65 protein level decreased upon treatment with each extract and compound. Root and seed extracts inhibited NF-κB-DNA binding as shown by EMSA. The compounds showed comparable binding energies and similar docking poses as MG-132 on the target proteins., Conclusion: Z. spina-christi might possess anti-inflammatory activity as assumed by ancient Egyptian prescriptions. Five compounds contributed to this bioactivity, i.e. epigallocatechin, gallocatechin, spinosin, 6''' feruloylspinosin and 6''' sinapoylspinosin as shown in vitro and in silico., (Copyright © 2016 Elsevier GmbH. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
163. Isolation of Flavonoids from Deguelia duckeana and Their Effect on Cellular Viability, AMPK, eEF2, eIF2 and eIF4E.
- Author
-
Cursino LM, Lima NM, Murillo R, Nunez CV, Merfort I, and Humar M
- Subjects
- Adenylate Kinase metabolism, Cell Line, Tumor, Cell Survival drug effects, Eukaryotic Initiation Factor-2 metabolism, Eukaryotic Initiation Factor-4E metabolism, Flavonoids isolation & purification, Humans, Peptide Elongation Factor 2 metabolism, Phosphorylation, Plant Extracts isolation & purification, Fabaceae chemistry, Flavonoids toxicity, Plant Extracts toxicity, Protein Processing, Post-Translational drug effects
- Abstract
Preparations of Deguelia duckeana, known in Brazil as timbó, are used by indigenous people to kill fish. Reinvestigation of its extracts resulted in the isolation and identification of 11 known flavonoids identified as 3,5,4'-trimethoxy-4-prenylstilbene (1), 4-methoxyderricidine (2), lonchocarpine (3), 4-hydroxylonchocarpine (4), 4-methoxylonchocarpine (5), 5-hydroxy-4',7-dimethoxy-6-prenylflavanone (6), 4'-hydroxyisolonchocarpine (7), 4'-methoxyisolonchocarpine (8), 3',4',7-trimethoxyflavone (9), 3',4'-methylenedioxy-7-methoxyflavone (10), and 2,2-dimethyl-chromone-5,4'-hydroxy-5'-methoxyflavone (11). Except for 1, 3, and 4 all of these flavonoids have been described for the first time in D. duckeana and the flavanone 6 for the first time in nature. Compounds 2, 3, 4, 7, 9, and 10 were studied for their potential to induce cell death in neuronal SK-N-SH cells. Only the chalcone 4 and the flavanone 7 significantly induced lactate dehydrogenase (LDH) release, which was accompanied by activation of caspase-3 and impairment of energy homeostasis in the MTT assay and may explain the killing effect on fish. Interestingly, the flavone 10 reduced cell metabolism in the MTT assay without inducing cytotoxicity in the LDH assay. Furthermore, the flavonoids 2, 3, 4, 7, and 10 induced phosphorylation of the AMP-activated protein kinase (AMPK) and the eukaryotic elongation factor 2 (eEF2). The initiation factor eIF4E was dephosphorylated in the presence of these compounds. The initiation factor eIF2alpha was not affected. Further studies are needed to elucidate the importance of the observed effects on protein synthesis and potential therapeutic perspectives.
- Published
- 2016
- Full Text
- View/download PDF
164. Mastering analytical challenges for the characterization of pentacyclic triterpene mono- and diesters of Calendula officinalis flowers by non-aqueous C30 HPLC and hyphenation with APCI-QTOF-MS.
- Author
-
Nicolaus C, Sievers-Engler A, Murillo R, D'Ambrosio M, Lämmerhofer M, and Merfort I
- Subjects
- Chromatography, High Pressure Liquid methods, Pentacyclic Triterpenes chemistry, Plant Extracts chemistry, Calendula, Flowers, Pentacyclic Triterpenes analysis, Plant Extracts analysis, Tandem Mass Spectrometry methods
- Abstract
Pentacyclic triterpene mono- and diesters have been isolated from Calendula officinalis flowers. GC-MS, APCI-Exactive Orbitrap HR-MS and NMR allowed to identify the triterpene skeleton in various samples (different triterpene mixtures from Calendula n-hexane extract). NMR provided evidence that triterpene diesters are present in the samples as well. However, the corresponding quasi-molecular ions could not be detected by APCI-Exactive Orbitrap HR-MS. Instability of triterpene diesters and loss of a fatty acid residue, respectively, in the ion-source made their MS detection challenging. Thus, a set of new APCI-QTOF-MS methods (using the TripleTOF 5600+ mass spectrometer) were developed which made it eventually possible to solve this problem and confirm the diester structures by MS via quasi-molecular ion [M+H](+) detection. Direct infusion APCI-QTOF MS experiments in MS/MS high sensitivity scan mode with low collision energy and multi-channel averaging acquisition (MCA) allowed the detection of quasi-molecular ions of triterpene diesters for the first time and unequivocally confirmed the presence of faradiol 3,16-dimyristate and -dipalmitate, as well as the corresponding mixed diesters faradiol 3-myristate,16-palmitate and faradiol 3-palmitate,16-myristate. Preferential loss of the fatty acid in 16-position made it possible to distinguish the mixed diesters by MS/MS spectra. Their chromatographic separations turned out to be challenging due to their bulkiness and extended molecular dimensions. However, separation could be achieved by an uncommon non-aqueous RPLC mode with an in-house synthesized C30 phase. Finally, two (U)HPLC-APCI-QTOF-MS methods with C18- and C30-based non-aqueous RPLC provided suitable, sensitive assays to monitor the presence of monoesters and diesters of various triterpenes (faradiol, maniladiol, arnidiol, arnitriol A and lupane-3β,16β,20-triol esters) in the n-hexane extract of C. officinalis with high mass resolution and good mass accuracy., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
165. The sesquiterpene lactone polymatin B from Smallanthus sonchifolius induces different cell death mechanisms in three cancer cell lines.
- Author
-
De Ford C, Ulloa JL, Catalán CAN, Grau A, Martino VS, Muschietti LV, and Merfort I
- Subjects
- Antineoplastic Agents, Phytogenic chemistry, Cell Cycle drug effects, Cell Death drug effects, Cell Line, Tumor drug effects, Drug Evaluation, Preclinical methods, Drug Screening Assays, Antitumor methods, Humans, Lactones chemistry, Leukemia, T-Cell drug therapy, Leukemia, T-Cell pathology, Leukocytes, Mononuclear drug effects, Magnetic Resonance Spectroscopy, Molecular Structure, Oxidative Stress drug effects, Sesquiterpenes chemistry, Sesquiterpenes, Germacrane chemistry, Sesquiterpenes, Germacrane pharmacology, Antineoplastic Agents, Phytogenic pharmacology, Asteraceae chemistry, Lactones pharmacology, Sesquiterpenes pharmacology
- Abstract
A 8β-angeloyloxy-9α-hydroxy-14-oxo-acanthospermolide and five known melampolide sesquiterpene lactones (uvedalin, enhydrin, polymatin B, sonchifolin, and fluctuanin) were isolated from the leaves of Smallanthus sonchifolius. The compounds were identified by 1D-, 2D-NMR, HRMS, IR and UV analyses. In vitro cytotoxicity assays (MTT) showed that these sesquiterpene lactones display poor cytotoxic effects on peripheral blood mononuclear cells (PBMC) of healthy human subjects, whereas a strong cytotoxicity was observed in leukemia and pancreas cancer cells. For the mechanism of action of polymatin B, oxidative stress seems to be involved. Interestingly, reactive oxygen species (ROS) formation mainly induced different effects: apoptosis in CCRF-CEM cells, necroptosis in CEM-ADR5000 cells through induction of RIP1K, neither apoptosis nor necroptosis in MIA-PaCa-2 cells. Additionally, cells also died partly by necrosis., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
166. Endophytic Streptomyces in the traditional medicinal plant Arnica montana L.: secondary metabolites and biological activity.
- Author
-
Wardecki T, Brötz E, De Ford C, von Loewenich FD, Rebets Y, Tokovenko B, Luzhetskyy A, and Merfort I
- Subjects
- Anti-Bacterial Agents analysis, Biological Products analysis, Biosynthetic Pathways genetics, Endophytes classification, Endophytes metabolism, Gas Chromatography-Mass Spectrometry, Metabolome, Multigene Family, Secondary Metabolism, Streptomyces classification, Streptomyces metabolism, Arnica microbiology, Endophytes chemistry, Endophytes isolation & purification, Plants, Medicinal microbiology, Streptomyces chemistry, Streptomyces isolation & purification
- Abstract
Arnica montana L. is a medical plant of the Asteraceae family and grows preferably on nutrient poor soils in mountainous environments. Such surroundings are known to make plants dependent on symbiosis with other organisms. Up to now only arbuscular mycorrhizal fungi were found to act as endophytic symbiosis partners for A. montana. Here we identified five Streptomyces strains, microorganisms also known to occur as endophytes in plants and to produce a huge variety of active secondary metabolites, as inhabitants of A. montana. The secondary metabolite spectrum of these strains does not contain sesquiterpene lactones, but consists of the glutarimide antibiotics cycloheximide and actiphenol as well as the diketopiperazines cyclo-prolyl-valyl, cyclo-prolyl-isoleucyl, cyclo-prolyl-leucyl and cyclo-prolyl-phenylalanyl. Notably, genome analysis of one strain was performed and indicated a huge genome size with a high number of natural products gene clusters among which genes for cycloheximide production were detected. Only weak activity against the Gram-positive bacterium Staphylococcus aureus was revealed, but the extracts showed a marked cytotoxic activity as well as an antifungal activity against Candida parapsilosis and Fusarium verticillioides. Altogether, our results provide evidence that A. montana and its endophytic Streptomyces benefit from each other by completing their protection against competitors and pathogens and by exchanging plant growth promoting signals with nutrients.
- Published
- 2015
- Full Text
- View/download PDF
167. Target Fishing by Cross-Docking to Explain Polypharmacological Effects.
- Author
-
Patel H, Lucas X, Bendik I, Günther S, and Merfort I
- Subjects
- Ethacrynic Acid chemistry, Humans, Models, Molecular, Molecular Structure, PPAR gamma chemistry, Structure-Activity Relationship, Ethacrynic Acid pharmacology, PPAR gamma antagonists & inhibitors
- Abstract
Drugs may have polypharmacological phenomena, that is, in addition to the desired target, they may also bind to many undesired or unknown physiological targets. As a result, they often exert side effects. In some cases, off-target interactions may lead to drug repositioning or to explaining a drug's mode of action. Herein we present an in silico approach for target fishing by cross-docking as a method to identify new drug-protein interactions. As an example and proof of concept, this method predicted the peroxisome proliferator-activated receptor (PPAR)-γ as a target of ethacrynic acid, which may explain the hyperglycemic effect brought on by this molecule. The antagonistic effect of ethacrynic acid on PPAR-γ was validated in a transient transactivation assay using human HEK293 cells. The cross-docking approach also predicted the potential mechanisms of many other drug side effects and discloses new drug repositioning opportunities. These putative interactions are described herein, and can be readily used to discover therapeutically relevant drug effects., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2015
- Full Text
- View/download PDF
168. Discovery of Tricyclic Clerodane Diterpenes as Sarco/Endoplasmic Reticulum Ca(2+)-ATPase Inhibitors and Structure-Activity Relationships.
- Author
-
De Ford C, Calderón C, Sehgal P, Fedosova NU, Murillo R, Olesen C, Nissen P, Møller JV, and Merfort I
- Subjects
- Amino Acid Metabolism, Inborn Errors, Animals, Binding Sites, Diterpenes, Clerodane chemistry, Drug Screening Assays, Antitumor, Endoplasmic Reticulum metabolism, Humans, Mitochondrial Diseases, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Rabbits, Sarcoplasmic Reticulum metabolism, Sarcosine Dehydrogenase deficiency, Structure-Activity Relationship, Thapsigargin pharmacology, Adenosine Triphosphatases antagonists & inhibitors, Diterpenes, Clerodane isolation & purification, Diterpenes, Clerodane pharmacology
- Abstract
Tricyclic clerodane diterpenes (TCDs) are natural compounds that often show potent cytotoxicity for cancer cells, but their mode of action remains elusive. A computationally based similarity search (CDRUG), combined with principal component analysis (ChemGPS-NP) and docking calculations (GOLD 5.2), suggested TCDs to be inhibitors of the sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) pump, which is also the target of the sesquiterpene lactone thapsigargin. Biochemical studies were performed with 11 TCDs on purified rabbit skeletal muscle sarcoplasmic reticulum membranes, which are highly enriched with the SERCA1a isoform. Casearborin D (2) exhibited the highest affinity, with a KD value of 2 μM and giving rise to complete inhibition of SERCA1a activity. Structure-activity relationships revealed that functionalization of two acyl side chains (R1 and R4) and the hydrophobicity imparted by the aliphatic chain at C-9, as well as a C-3,C-4 double bond, play crucial roles for inhibitory activity. Docking studies also suggested that hydrophobic interactions in the binding site, especially with Phe256 and Phe834, may be important for a strong inhibitory activity of the TCDs. In conclusion, a novel class of SERCA inhibitory compounds is presented.
- Published
- 2015
- Full Text
- View/download PDF
169. Ceramide-1-phosphate inhibits cigarette smoke-induced airway inflammation.
- Author
-
Baudiß K, Ayata CK, Lazar Z, Cicko S, Beckert J, Meyer A, Zech A, Vieira RP, Bittman R, Gómez-Muñoz A, Merfort I, and Idzko M
- Subjects
- Adult, Aged, Animals, Bronchoalveolar Lavage Fluid cytology, Bronchoalveolar Lavage Fluid immunology, Cells, Cultured, Cross-Sectional Studies, Cytokines immunology, Disease Models, Animal, Epithelial Cells immunology, Epithelial Cells pathology, Female, Humans, Inflammation, Lung immunology, Lung pathology, Male, Mice, Mice, Inbred C57BL, Middle Aged, NF-kappa B drug effects, NF-kappa B genetics, NF-kappa B metabolism, Neutrophils immunology, Pulmonary Disease, Chronic Obstructive immunology, Pulmonary Disease, Chronic Obstructive pathology, Pulmonary Emphysema pathology, RNA, Messenger metabolism, Respiratory Mucosa immunology, Respiratory Mucosa pathology, Smoke, Sphingomyelin Phosphodiesterase drug effects, Sphingomyelin Phosphodiesterase genetics, Sphingomyelin Phosphodiesterase metabolism, Nicotiana, Ceramides pharmacology, Cytokines drug effects, Epithelial Cells drug effects, Lung drug effects, Pulmonary Emphysema immunology, RNA, Messenger drug effects, Respiratory Mucosa drug effects
- Abstract
Sphingolipids are involved in the pathogenesis of inflammatory diseases. The central molecule is ceramide, which can be converted into ceramide-1-phosphate (C1P). Although C1P can exert anti- and pro-inflammatory effects, its influence on cigarette smoke (CS)-induced lung inflammation is unknown. We aimed to clarify the role of C1P in the pathogenesis of CS-triggered pulmonary inflammation and emphysema in humans and mice. The effects of C1P were addressed on CS-induced lung inflammation in C57BL/6 mice, CS extract-triggered activation of human airway epithelial cells (AECs) and neutrophils from patients with chronic obstructive pulmonary disease. Differential cell counts in bronchoalveolar lavage fluid were determined by flow cytometry and pro-inflammatory cytokines were measured by ELISA. Expression and DNA binding of nuclear factor (NF)-κB and neutral sphingomyelinase (nSMase) were quantified by PCR, electrophoretic mobility shift and fluorometric assays. C1P reduced CS-induced acute and chronic lung inflammation and development of emphysema in mice, which was associated with a reduction in nSMase and NF-κB activity in the lungs. nSMase activity in human serum correlated negatively with forced expiratory volume in 1 s % predicted. In human AECs and neutrophils, C1P inhibited CS-induced activation of NF-κB and nSMase, and reduced pro-inflammatory cytokine release. Our results suggest that C1P is a potential target for anti-inflammatory treatment in CS-induced lung inflammation., (Copyright ©ERS 2015.)
- Published
- 2015
- Full Text
- View/download PDF
170. Interleukin-1β enhances FasL-induced caspase-3/-7 activity without increasing apoptosis in primary mouse hepatocytes.
- Author
-
Lutz A, Sanwald J, Thomas M, Feuer R, Sawodny O, Ederer M, Borner C, Humar M, and Merfort I
- Subjects
- Animals, Apoptosis Regulatory Proteins metabolism, BH3 Interacting Domain Death Agonist Protein metabolism, Bcl-2-Like Protein 11, Cell Survival drug effects, Cytochromes c metabolism, Enzyme Activation drug effects, Hepatocytes metabolism, JNK Mitogen-Activated Protein Kinases metabolism, Membrane Proteins metabolism, Mice, Models, Biological, NF-kappa B metabolism, Proto-Oncogene Proteins metabolism, Tumor Necrosis Factor-alpha pharmacology, Apoptosis drug effects, Caspase 3 metabolism, Caspase 7 metabolism, Fas Ligand Protein pharmacology, Hepatocytes cytology, Hepatocytes drug effects, Interleukin-1beta pharmacology
- Abstract
Sustained inflammation may increase the susceptibility of hepatocytes to apoptotic cell death and therefore exacerbate liver damage. Here we report that the pro-inflammatory cytokine IL-1β sensitizes primary murine hepatocytes to Fas ligand (FasL)-induced caspase-3/-7 activity. This process was dependent on JNK1/2 and the BH3-only proteins Bim and Bid. Mathematical modeling revealed that incubation of hepatocytes with IL-1β depleted the anti-apoptotic Bcl-2 protein pool and thus shifted hepatocytes to mitochondrial type II apoptosis following Fas activation. As a consequence, IL-1β and FasL treatment enhanced cytochrome c release. Surprisingly, despite increased caspase-3/-7 activation, FasL-induced cell death was reduced by IL-1β pre-treatment. This protective effect was independent of JNK1/2, Bim or Bid. Furthermore, elevated caspase-3/-7 activity upon IL-1β and FasL treatment did not result in enhanced PARP cleavage. The protective effect of IL-1β was seen after 3 h of pre-incubation, indicating an anti-apoptotic transcriptional response. Indeed, NF-κB DNA binding was increased in response to IL-1β plus FasL and gene-expression profiling of NF-κB regulated genes revealed a transcriptional and translational upregulation of the caspase-8 inhibitor A20. A mathematical model was developed to explain the contradictious occurrence of both increased caspase-3/-7 activity and elevated cell viability by including a heterogeneous distribution of Bcl-2 proteins and variations in Fas signaling resulting in different subpopulations of hepatocytes.
- Published
- 2014
- Full Text
- View/download PDF
171. Hyaluronidase modulates inflammatory response and accelerates the cutaneous wound healing.
- Author
-
Fronza M, Caetano GF, Leite MN, Bitencourt CS, Paula-Silva FW, Andrade TA, Frade MA, Merfort I, and Faccioli LH
- Subjects
- Animals, Cell Movement, Cell Proliferation, Collagen drug effects, Cytokines drug effects, Cytokines metabolism, Eicosanoids metabolism, Fibroblasts drug effects, Granulation Tissue drug effects, Granulation Tissue growth & development, Male, Mice, Peroxisome Proliferator-Activated Receptors drug effects, Rats, Rats, Wistar, Wound Healing drug effects, Fibroblasts physiology, Hyaluronoglucosaminidase pharmacology, Inflammation immunology, Skin Physiological Phenomena, Wound Healing physiology
- Abstract
Hyaluronidases are enzymes that degrade hyaluronan an important constituent of the extracellular matrix. They have been used as a spreading agent, improving the absorption of drugs and facilitating the subcutaneous infusion of fluids. Here, we investigated the influence of bovine testes hyaluronidase (HYAL) during cutaneous wound healing in in vitro and in vivo assays. We demonstrated in the wound scratch assay that HYAL increased the migration and proliferation of fibroblasts in vitro at low concentration, e.g. 0.1 U HYAL enhanced the cell number by 20%. HYAL presented faster and higher reepithelialization in in vivo full-thickness excisional wounds generated on adult Wistar rats back skin already in the early phase at 2nd day post operatory compared to vehicle-control group. Wound closured area observed in the 16 U and 32 U HYAL treated rats reached 38% and 46% compared to 19% in the controls, respectively. Histological and biochemical analyses supported the clinical observations and showed that HYAL treated wounds exhibited increased granulation tissue, diminished edema formation and regulated the inflammatory response by modulating the release of pro and anti-inflammatory cytokines, growth factor and eicosanoids mediators. Moreover, HYAL increased gene expression of peroxisome proliferator-activated receptors (PPAR) γ and PPAR β/δ, the collagen content in the early stages of healing processes as well as angiogenesis. Altogether these data revealed that HYAL accelerates wound healing processes and might be beneficial for treating wound disorders.
- Published
- 2014
- Full Text
- View/download PDF
172. PyWATER: a PyMOL plug-in to find conserved water molecules in proteins by clustering.
- Author
-
Patel H, Grüning BA, Günther S, and Merfort I
- Subjects
- Cluster Analysis, Computer Graphics, Crystallography, X-Ray, Models, Molecular, Protein Structure, Secondary, User-Computer Interface, Computational Biology methods, Proteins chemistry, Software, Water
- Abstract
Summary: Conserved water molecules play a crucial role in protein structure, stabilization of secondary structure, protein activity, flexibility and ligand binding. Clustering of water molecules in superimposed protein structures, obtained by X-ray crystallography at high resolution, is an established method to identify consensus water molecules in all known protein structures of the same family. PyWATER is an easy-to-use PyMOL plug-in and identifies conserved water molecules in the protein structure of interest. PyWATER can be installed via the user interface of PyMOL. No programming or command-line knowledge is required for its use., Availability and Implementation: PyWATER and a tutorial are available at https://github.com/hiteshpatel379/PyWATER. PyMOL is available at http://www.pymol.org/ or http://sourceforge.net/projects/pymol/., Contact: stefan.guenther@pharmazie.uni-freiburg.de., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2014
- Full Text
- View/download PDF
173. Four new flavonol glycosides from the leaves of Brugmansia suaveolens.
- Author
-
Geller F, Murillo R, Steinhauser L, Heinzmann B, Albert K, Merfort I, and Laufer S
- Subjects
- Flavonols isolation & purification, Glycosides chemistry, Kaempferols chemistry, Magnetic Resonance Spectroscopy, Molecular Structure, Oligosaccharides chemistry, Plant Leaves chemistry, Flavonols chemistry, Solanaceae chemistry
- Abstract
Four new flavonol glycosides were isolated from the leaves of Brugmansia suaveolens: kaempferol 3-O-β-D-glucopyranosyl-(1'''→2'')-O-α-L-arabinopyranoside (1), kaempferol 3-O-β-D-glucopyranosyl-(1'''→2'')-O-α-L-arabinopyranoside-7-O-į-D-gluco-pyranoside (2), kaempferol 3-O-β-D-[6'''-O-(E-caffeoyl)]-glucopyranosyl-(1'''→2'')-O-α-l-arabinopyranoside-7-O-β-D-glucopyranoside (3), and kaempferol 3-O-β-D-[2'''-O-(E-caffeoyl)]-glucopyranosyl-(1'''→2'')-O-α-l-arabinopyranoside-7-O-β-D-glucopyranoside (4). The structure elucidation was performed by MS, 1D and 2D NMR analyses.
- Published
- 2014
- Full Text
- View/download PDF
174. Cytotoxic clerodane diterpenes from Zuelania guidonia.
- Author
-
Calderón C, De Ford C, Castro V, Merfort I, and Murillo R
- Subjects
- Antineoplastic Agents, Phytogenic chemistry, Costa Rica, Diterpenes, Clerodane chemistry, Drug Screening Assays, Antitumor, Humans, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Plant Leaves chemistry, Antineoplastic Agents, Phytogenic isolation & purification, Antineoplastic Agents, Phytogenic pharmacology, Diterpenes, Clerodane isolation & purification, Diterpenes, Clerodane pharmacology, Salicaceae chemistry
- Abstract
The leaves of Zuelania guidonia yielded eight new clerodane diterpenes, namely, zuelaguidins A-H (1-8), and the known clerodane diterpene esculentin A (9). Some of these structures contained a 3,6-dihydro-1,2-dioxin moiety. The new compounds were isolated and identified using 1D- and 2D-NMR experiments. All compounds were evaluated for cytotoxicity against the CCRF-CEM (human acute lymphocytic leukemia), CEM-ADR5000 (human acute lymphocytic leukemia resistant to doxorubicin), and MIA-PaCa-2 (human pancreatic carcinoma) cell lines as well as for their selectivity against peripheral blood mononuclear cells from healthy human subjects. Zuelaguidins B, C, and E were the most potent compounds against the CCRF-CEM cell line, with IC50 values ranging from 1.6 to 2.5 μM.
- Published
- 2014
- Full Text
- View/download PDF
175. From a traditional medicinal plant to a rational drug: understanding the clinically proven wound healing efficacy of birch bark extract.
- Author
-
Ebeling S, Naumann K, Pollok S, Wardecki T, Vidal-Y-Sy S, Nascimento JM, Boerries M, Schmidt G, Brandner JM, and Merfort I
- Subjects
- Actins metabolism, Animals, Cell Movement drug effects, Cell Proliferation, Cyclooxygenase 2 genetics, Cyclooxygenase 2 metabolism, Cytokines genetics, Cytokines metabolism, Disease Models, Animal, ELAV Proteins metabolism, Gene Expression Regulation drug effects, Humans, Inflammation Mediators metabolism, Keratinocytes drug effects, Keratinocytes metabolism, NF-kappa B metabolism, Plant Extracts chemistry, RNA Stability drug effects, RNA, Messenger genetics, STAT3 Transcription Factor metabolism, Skin drug effects, Skin metabolism, Swine, Triterpenes pharmacology, p38 Mitogen-Activated Protein Kinases metabolism, rho GTP-Binding Proteins metabolism, Betula chemistry, Plant Bark chemistry, Plant Extracts pharmacology, Plants, Medicinal chemistry, Wound Healing drug effects
- Abstract
Background: Birch bark has a long lasting history as a traditional medicinal remedy to accelerate wound healing. Recently, the efficacy of birch bark preparations has also been proven clinically. As active principle pentacyclic triterpenes are generally accepted. Here, we report a comprehensive study on the underlying molecular mechanisms of the wound healing properties of a well-defined birch bark preparation named as TE (triterpene extract) as well as the isolated single triterpenes in human primary keratinocytes and porcine ex-vivo wound healing models., Methodology/principal Findings: We show positive wound healing effects of TE and betulin in scratch assay experiments with primary human keratinocytes and in a porcine ex-vivo wound healing model (WHM). Mechanistical studies elucidate that TE and betulin transiently upregulate pro-inflammatory cytokines, chemokines and cyclooxygenase-2 on gene and protein level. For COX-2 and IL-6 this increase of mRNA is due to an mRNA stabilizing effect of TE and betulin, a process in which p38 MAPK and HuR are involved. TE promotes keratinocyte migration, putatively by increasing the formation of actin filopodia, lamellipodia and stress fibers. Detailed analyses show that the TE components betulin, lupeol and erythrodiol exert this effect even in nanomolar concentrations. Targeting the actin cytoskeleton is dependent on the activation of Rho GTPases., Conclusion/significance: Our results provide insights to understand the molecular mechanism of the clinically proven wound healing effect of birch bark. TE and betulin address the inflammatory phase of wound healing by transient up-regulation of several pro-inflammatory mediators. Further, they enhance migration of keratinocytes, which is essential in the second phase of wound healing. Our results, together with the clinically proven efficacy, identify birch bark as the first medical plant with a high potential to improve wound healing, a field which urgently needs effective remedies.
- Published
- 2014
- Full Text
- View/download PDF
176. Steroids with anti-inflammatory activity from Vernonia nigritiana Oliv. & Hiern.
- Author
-
Vassallo A, De Tommasi N, Merfort I, Sanogo R, Severino L, Pelin M, Della Loggia R, Tubaro A, and Sosa S
- Subjects
- Animals, Anti-Inflammatory Agents pharmacology, Croton Oil pharmacology, Dermatitis drug therapy, Ear pathology, Glycosides chemistry, Hydrocortisone pharmacology, Indomethacin pharmacology, Mali, Mice, Molecular Structure, NF-kappa B analysis, Nuclear Magnetic Resonance, Biomolecular, Plant Leaves chemistry, Stigmasterol chemistry, Glycosides isolation & purification, Glycosides pharmacology, Stigmasterol analogs & derivatives, Stigmasterol isolation & purification, Stigmasterol pharmacology, Vernonia chemistry
- Abstract
The leaves of Vernonia nigritiana Oliv. & Hiern. (Asteraceae) were investigated for their in vivo topical anti-inflammatory properties, following a bioassay-oriented fractionation approach. Petroleum ether, chloroform and chloroform-methanol extracts inhibited the Croton oil-induced ear dermatitis in mice. The chloroform extract was only about half as active as the non steroidal anti-inflammatory drug indomethacin (ID50=237 and 93 μg/cm(2), respectively). Phytochemical investigation of this extract led to the isolation of nine polyhydroxylated stigmasterol glycosides and six polyhydroxylated stigmasterols. Their structures were elucidated by NMR, MS and chemical methods. Each compound exerted a significant anti-oedema activity, the most active being 1 (3β-O-β-D-glucopyranosyloxy-5α-stigmasta-7,9(11),24(28)Z-triene-6β,16β,26,29-tetrol) and 3 (3β-O-β-D-glucopyranosyloxy-5α-stigmasta-7,9(11),24(28)Z-triene-6β,16β,29-triol), only two and five fold less potent than the steroidal drug hydrocortisone (ID50=0.10, 0.21 and 0.04 μmol/cm(2), respectively). Compound 1 (50 μM) also completely inhibited the transcription factor NF-κB in vitro., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
177. Recent advances in 2D and 3D in vitro systems using primary hepatocytes, alternative hepatocyte sources and non-parenchymal liver cells and their use in investigating mechanisms of hepatotoxicity, cell signaling and ADME.
- Author
-
Godoy P, Hewitt NJ, Albrecht U, Andersen ME, Ansari N, Bhattacharya S, Bode JG, Bolleyn J, Borner C, Böttger J, Braeuning A, Budinsky RA, Burkhardt B, Cameron NR, Camussi G, Cho CS, Choi YJ, Craig Rowlands J, Dahmen U, Damm G, Dirsch O, Donato MT, Dong J, Dooley S, Drasdo D, Eakins R, Ferreira KS, Fonsato V, Fraczek J, Gebhardt R, Gibson A, Glanemann M, Goldring CE, Gómez-Lechón MJ, Groothuis GM, Gustavsson L, Guyot C, Hallifax D, Hammad S, Hayward A, Häussinger D, Hellerbrand C, Hewitt P, Hoehme S, Holzhütter HG, Houston JB, Hrach J, Ito K, Jaeschke H, Keitel V, Kelm JM, Kevin Park B, Kordes C, Kullak-Ublick GA, LeCluyse EL, Lu P, Luebke-Wheeler J, Lutz A, Maltman DJ, Matz-Soja M, McMullen P, Merfort I, Messner S, Meyer C, Mwinyi J, Naisbitt DJ, Nussler AK, Olinga P, Pampaloni F, Pi J, Pluta L, Przyborski SA, Ramachandran A, Rogiers V, Rowe C, Schelcher C, Schmich K, Schwarz M, Singh B, Stelzer EH, Stieger B, Stöber R, Sugiyama Y, Tetta C, Thasler WE, Vanhaecke T, Vinken M, Weiss TS, Widera A, Woods CG, Xu JJ, Yarborough KM, and Hengstler JG
- Subjects
- Animals, Coculture Techniques, Gene Expression Regulation, Hepatocytes drug effects, Hepatocytes metabolism, High-Throughput Screening Assays, Humans, Liver drug effects, Organ Culture Techniques, Receptors, Cytoplasmic and Nuclear genetics, Receptors, Cytoplasmic and Nuclear metabolism, Signal Transduction, Toxicogenetics, Culture Techniques methods, Hepatocytes cytology, Inactivation, Metabolic, Liver cytology, Liver physiology, Toxicity Tests methods
- Abstract
This review encompasses the most important advances in liver functions and hepatotoxicity and analyzes which mechanisms can be studied in vitro. In a complex architecture of nested, zonated lobules, the liver consists of approximately 80 % hepatocytes and 20 % non-parenchymal cells, the latter being involved in a secondary phase that may dramatically aggravate the initial damage. Hepatotoxicity, as well as hepatic metabolism, is controlled by a set of nuclear receptors (including PXR, CAR, HNF-4α, FXR, LXR, SHP, VDR and PPAR) and signaling pathways. When isolating liver cells, some pathways are activated, e.g., the RAS/MEK/ERK pathway, whereas others are silenced (e.g. HNF-4α), resulting in up- and downregulation of hundreds of genes. An understanding of these changes is crucial for a correct interpretation of in vitro data. The possibilities and limitations of the most useful liver in vitro systems are summarized, including three-dimensional culture techniques, co-cultures with non-parenchymal cells, hepatospheres, precision cut liver slices and the isolated perfused liver. Also discussed is how closely hepatoma, stem cell and iPS cell-derived hepatocyte-like-cells resemble real hepatocytes. Finally, a summary is given of the state of the art of liver in vitro and mathematical modeling systems that are currently used in the pharmaceutical industry with an emphasis on drug metabolism, prediction of clearance, drug interaction, transporter studies and hepatotoxicity. One key message is that despite our enthusiasm for in vitro systems, we must never lose sight of the in vivo situation. Although hepatocytes have been isolated for decades, the hunt for relevant alternative systems has only just begun.
- Published
- 2013
- Full Text
- View/download PDF
178. Cell-cycle changes and oxidative stress response to magnetite in A549 human lung cells.
- Author
-
Könczöl M, Weiss A, Stangenberg E, Gminski R, Garcia-Käufer M, Gieré R, Merfort I, and Mersch-Sundermann V
- Subjects
- Electron Spin Resonance Spectroscopy, Humans, Onium Compounds pharmacology, Reactive Oxygen Species metabolism, Tumor Cells, Cultured, p21-Activated Kinases metabolism, Cell Cycle drug effects, Lung pathology, Magnetite Nanoparticles chemistry, Oxidative Stress drug effects
- Abstract
In a recent study, magnetite was investigated for its potential to induce toxic effects and influence signaling pathways. It was clearly demonstrated that ROS formation leads to mitochondrial damage and genotoxic effects in A549 cells. On the basis of these findings, we wanted to elucidate the origin of magnetite-mediated ROS formation and its influence on the cell cycle of A549 and H1299 human lung epithelial cells. Concentration- and size-dependent superoxide formation, measured by electron paramagnetic resonance (EPR), was observed. Furthermore, we could show that the GSH level decreased significantly after exposure to magnetite particles, while catalase (CAT) activity was increased. These effects were also dependent on particle size, albeit less pronounced than those observed with EPR. We were able to show that incubation of A549 cells prior to particle treatment with diphenyleneiodonium (DPI), a NADPH-oxidase (NOX) inhibitor, leads to decreased ROS formation, but this effect was not observed for the NOX inhibitor apocynin. Soluble iron does not contribute considerably to ROS production. Analysis of cell-cycle distribution revealed a pronounced sub-G1 peak, which cannot be linked to increased cell death. Western blot analysis did not show activation of p53 but upregulation of p21 in A549. Here, we were unexpectedly able to demonstrate that exposure to magnetite leads to p21-mediated G1-like arrest. This has been reported previously only for low concentrations of microtubule stabilization drugs. Importantly, the arrested sub-G1 cells were viable and showed no caspase 3/7 activation.
- Published
- 2013
- Full Text
- View/download PDF
179. Oxidative stress and inflammatory response to printer toner particles in human epithelial A549 lung cells.
- Author
-
Könczöl M, Weiß A, Gminski R, Merfort I, and Mersch-Sundermann V
- Subjects
- Caspases metabolism, Cell Line, Tumor, Cell Survival drug effects, Electrophoretic Mobility Shift Assay, Humans, Interleukin-6 metabolism, Interleukin-8 metabolism, Lung metabolism, Membrane Potential, Mitochondrial drug effects, NF-kappa B metabolism, Neutral Red chemistry, Particle Size, Pneumonia metabolism, Pneumonia pathology, Reactive Oxygen Species metabolism, Tetrazolium Salts chemistry, Ferric Compounds toxicity, Lung drug effects, Oxidative Stress drug effects, Pneumonia chemically induced
- Abstract
Reports on adverse health effects related to occupational exposure to toner powder are still inconclusive. Therefore, we have previously conducted an in vitro-study to characterize the genotoxic potential of three commercially available black printer toner powders in A549 lung cells. In these cell-based assays it was clearly demonstrated that the tested toner powders damage DNA and induce micronucleus (MN) formation. Here, we have studied the cytotoxic and proinflammatory potential of these three types of printer toner particles and the influence of ROS and NF-κB induction in order to unravel the underlying mechanisms. A549 cells were exposed to various concentrations of printer toner particle suspensions for 24 h. The toner particles were observed to exert significant cytotoxic effects in the WST-1 and neutral red (NR)-assays, although to a varying extent. Caspase 3/7 activity increased, while the mitochondrial membrane potential (MMP) was not affected. Particles of all three printer toner powders induced concentration-dependent formation of reactive oxygen species (ROS), as measured in the DCFH-DA assay. Furthermore, toner particle exposure enhanced interleukin-6 and interleukin-8 production, which is in agreement with activation of the transcription factor NF-κB in A549 cells shown by the electrophoretic mobility shift assay (EMSA). Therefore, it can be concluded that exposure of A549 lung cells to three selected printer toner powders caused oxidative stress through induction of ROS. Increased ROS formation may trigger genotoxic effects and activate proinflammatory pathways., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
180. Traditionally used Veronica officinalis inhibits proinflammatory mediators via the NF-κB signalling pathway in a human lung cell line.
- Author
-
Gründemann C, Garcia-Käufer M, Sauer B, Stangenberg E, Könczöl M, Merfort I, Zehl M, and Huber R
- Subjects
- Animals, Bone Marrow Cells drug effects, Bone Marrow Cells metabolism, Cell Line, Cell Survival drug effects, Cyclooxygenase 2 biosynthesis, Dexamethasone pharmacology, Epithelial Cells drug effects, Epithelial Cells metabolism, Gene Expression drug effects, Humans, Inflammation Mediators metabolism, Iridoid Glucosides analysis, Iridoids analysis, Lung metabolism, Mast Cells drug effects, Mast Cells metabolism, Medicine, Traditional methods, Mice, Mitogen-Activated Protein Kinases metabolism, Phosphorylation, Phthalazines pharmacology, Plant Extracts chemistry, Signal Transduction drug effects, Inflammation Mediators antagonists & inhibitors, Lung drug effects, NF-kappa B metabolism, Plant Extracts pharmacology, Veronica chemistry
- Abstract
Ethnopharmacological Relevance: Extracts from Veronica officinalis L. are traditionally used for the treatment of lung diseases; however, the effective compounds and the mode of action are still unknown., Aim of the Study: Here we analyzed the effects of a standardized Veronica extract on genes expression and signalling protein production associated with the development of inflammatory lung diseases., Material and Methods: The degranulation capacity of primary mast cells, as well as gene expression and release of inflammatory mediators from human lung epithelial cells (A549 cells) were analyzed in relation to the synthetic drugs azelastine and dexamethasone. Gene and protein expression of cyclooxygenase-2 were investigated by semi-quantitative RT-PCR and western blotting, respectively. The involvement of phosphorylated mitogen-activated protein kinases and NF-κB signaling in regulation of these molecules were characterized by western blotting and electrophoretic mobility shift assays. Characteristic extract components were identified by LC-MS and verminoside was quantified by HPLC analysis., Results: We demonstrated that Veronica officinalis has a small influence on the degranulation capacity of mast cells but rather inhibits gene and protein expression of the chemokine eotaxin in A549 lung epithelial cells, which is essential for recruitment of inflammatory-associated cells in lung diseases. Furthermore, release of the inflammatory mediator PGE(2) was diminished through inhibition of COX-2 expression via the NF-κB signaling pathway in TNF-α-activated A549 cells. Phytochemical analysis identified verproside and verminoside as the most abundant iridoid glycosides., Conclusion: Our results are a contribution to explaining the observed anti-inflammatory effects of Veronica offcinalis extract on a molecular level. However, its clinical potency has at first to be proven in animals and subsequently in clinical trials., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
181. Cellular uptake and toxic effects of fine and ultrafine metal-sulfate particles in human A549 lung epithelial cells.
- Author
-
Könczöl M, Goldenberg E, Ebeling S, Schäfer B, Garcia-Käufer M, Gminski R, Grobéty B, Rothen-Rutishauser B, Merfort I, Gieré R, and Mersch-Sundermann V
- Subjects
- Biological Transport, Cell Line, Tumor, Cell Survival drug effects, Coal, Epithelial Cells drug effects, Epithelial Cells metabolism, Humans, Power Plants, Air Pollutants toxicity, Particulate Matter toxicity, Sulfates toxicity
- Abstract
Ambient airborne particulate matter is known to cause various adverse health effects in humans. In a recent study on the environmental impacts of coal and tire combustion in a thermal power station, fine crystals of PbSO(4) (anglesite), ZnSO(4)·H(2)O (gunningite), and CaSO(4) (anhydrite) were identified in the stack emissions. Here, we have studied the toxic potential of these sulfate phases as particulates and their uptake in human alveolar epithelial cells (A549). Both PbSO(4) and CaSO(4) yielded no loss of cell viability, as determined by the WST-1 and NR assays. In contrast, a concentration-dependent increase in cytotoxicity was observed for Zn sulfate. For all analyzed sulfates, an increase in the production of reactive oxygen species (ROS), assessed by the DCFH-DA assay and EPR, was observed, although to a varying extent. Again, Zn sulfate was the most active compound. Genotoxicity assays revealed concentration-dependent DNA damage and induction of micronuclei for Zn sulfate and, to a lower extent, for CaSO(4), whereas only slight effects could be found for PbSO(4). Moreover, changes of the cell cycle were observed for Zn sulfate and PbSO(4). It could be shown further that Zn sulfate increased the nuclear factor kappa-B (NF-κB) DNA binding activity and activated JNK. During our TEM investigations, no effect on the appearance of the A549 cells exposed to CaSO(4) compared to the nonexposed cells was observed, and in our experiments, only one CaSO(4) particle was detected in the cytoplasm. In the case of exposure to Zn sulfate, no particles were found in the cytoplasm of A549 cells, but we observed a concentration-dependent increase in the number and size of dark vesicles (presumably zincosomes). After exposure to PbSO(4), the A549 cells contained isolated particles as well as agglomerates both in vesicles and in the cytoplasm. Since these metal-sulfate particles are emitted into the atmosphere via the flue gas of coal-fired power stations, they may be globally abundant. Therefore, our study is of direct relevance to populations living near such power plants.
- Published
- 2012
- Full Text
- View/download PDF
182. Noxa/Mcl-1 balance influences the effect of the proteasome inhibitor MG-132 in combination with anticancer agents in pancreatic cancer cell lines.
- Author
-
Naumann K, Schmich K, Jaeger C, Kratz F, and Merfort I
- Subjects
- Antineoplastic Agents administration & dosage, Apoptosis drug effects, Camptothecin administration & dosage, Caspase 3 metabolism, Caspase 7 metabolism, Cell Line, Tumor, Doxorubicin administration & dosage, Doxorubicin pharmacology, Humans, Myeloid Cell Leukemia Sequence 1 Protein, NF-kappa B metabolism, Paclitaxel administration & dosage, Paclitaxel pharmacology, Pancreatic Neoplasms metabolism, Pancreatic Neoplasms pathology, Antineoplastic Agents pharmacology, Antineoplastic Combined Chemotherapy Protocols pharmacology, Camptothecin pharmacology, Leupeptins pharmacology, Pancreatic Neoplasms drug therapy, Proteasome Inhibitors, Proto-Oncogene Proteins c-bcl-2 metabolism
- Abstract
Pancreatic cancer progresses aggressively and owing to chemoresistance responds poorly to chemotherapy. Thus, there is an urgent need to understand the mechanisms of cancer cell resistance to generate effective strategies to circumvent intrinsic chemoresistance in this tumour indication. In this study, three pancreatic cancer cell lines, MIA PaCa-2, MDAPanc-3 and AsPC-1, were treated with the proteasome inhibitor MG-132 together with camptothecin, doxorubicin or paclitaxel, and cytotoxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The combination of MG-132 and camptothecin at a ratio of 5 : 1 gave the most promising results and enhanced cytotoxicity compared with the single compounds in MIA PaCa-2 cells. The increase was shown to be due to enhanced caspase-3 activity resulting in apoptosis. Moreover, this combination upregulated the levels of the proapoptotic protein Noxa and reduced the levels of the antiapoptotic protein Mcl-1, as demonstrated by western blotting. In contrast, the combination of MG-132 with doxorubicin also induced increased cytotoxicity, but apoptosis was decreased. The lack of an enhanced apoptosis induction could be correlated with high levels of Mcl-1 in response to the combined treatment with MG-132 and doxorubicin. Thus, the results indicate that regulation of the antiapoptotic and proapoptotic Bcl-2 family members Noxa and Mcl-1 is predicative of the effectiveness of the combination of MG-132 with different anticancer agents on apoptosis induction in pancreatic cancer cells.
- Published
- 2012
- Full Text
- View/download PDF
183. Free energy calculations on snake venom metalloproteinase BaP1.
- Author
-
Lingott T, Merfort I, and Steinbrecher T
- Subjects
- Animals, Binding Sites, Catalytic Domain, Hydrogen Bonding, Kinetics, Ligands, Matrix Metalloproteinase 13 chemistry, Matrix Metalloproteinase 13 metabolism, Metalloendopeptidases metabolism, Molecular Dynamics Simulation, Snake Venoms enzymology, Thermodynamics, Tumor Necrosis Factor-alpha chemistry, Tumor Necrosis Factor-alpha metabolism, Bothrops metabolism, Metalloendopeptidases antagonists & inhibitors
- Abstract
BaP1 is a snake venom metalloproteinase from the venom of Bothrops asper, showing high structural homology with the catalytic domain of human adamalysins and matrix metalloproteinases. It induces the release of cytokines, like interleukin-1 and tumor necrosis factor alpha. Recently, the high-resolution crystal structure of BaP1 with a bound inhibitor became available, representing an interesting model concerning inhibitor design for medicinally important metalloproteinases such as tumor necrosis factor alpha-converting enzyme and MMP13. We here use computational modeling to gain a better understanding about the binding properties of various ligands to BaP1, with a focus on computing ligand binding free energies. The obtained results should be of general significance for future research on medicinally important metalloproteinases. We have investigated the binding of the original inhibitor in detail and calculated its binding strength using MMP/GBSA free energy calculations. Additionally, the binding strengths of alternative ligands have been computed, and two of them are predicted and experimentally verified to strongly inhibit the enzyme. A suggestion for chemical modifications of BaP1 inhibitors could be made to guide future synthesis efforts. Furthermore, a contribution to the proteolytic reaction mechanism of metzincins is given. The pK value of the catalytically active glutamic acid residue 143 has been found to be significantly raised when compared with a free glutamate side chain. Calculations on other matrix metalloproteinases confirmed that this is not confined to BaP1, but seems to be a common feature of metzincins., (© 2012 John Wiley & Sons A/S.)
- Published
- 2012
- Full Text
- View/download PDF
184. Abietane diterpenes induce cytotoxic effects in human pancreatic cancer cell line MIA PaCa-2 through different modes of action.
- Author
-
Fronza M, Lamy E, Günther S, Heinzmann B, Laufer S, and Merfort I
- Subjects
- Abietanes chemistry, Antineoplastic Agents, Phytogenic chemistry, Antineoplastic Agents, Phytogenic pharmacology, Camptothecin pharmacology, Cell Cycle drug effects, Diterpenes chemistry, Diterpenes isolation & purification, Drug Screening Assays, Antitumor, Humans, Pancreatic Neoplasms drug therapy, Pyridines pharmacology, Topoisomerase I Inhibitors chemistry, Topoisomerase I Inhibitors pharmacology, Abietanes isolation & purification, Abietanes pharmacology, Antineoplastic Agents, Phytogenic isolation & purification, Plants, Medicinal chemistry, Topoisomerase I Inhibitors isolation & purification
- Abstract
Abietane diterpenes, especially those containing quinone moieties, are often reported to have cytotoxic effects on cancer cell lines. They deserve greater attention because several cancer chemotherapeutic agents also possess the quinone structural feature. To date, very little is known about their cytotoxic molecular modes of action. In the present study, five diterpenes, 7 alpha-acetoxyroyleanone, horminone, royleanone, 7-ketoroyleanone and sugiol which have been previously isolated from the medicinal plant Peltodon longipes were shown to possess cytotoxic activity against the human pancreatic cancer cell line MIA PaCa-2. 7 alpha-Acetoxyroyleanone, horminone and royleanone were demonstrated to possess alkylating properties using the nucleophile 4-(4-nitrobenzyl)pyridine. However, no clear correlation between the alkylating properties and cytotoxicity of these diterpenes was observed. Furthermore, the relaxation activity of human DNA topoisomerases I and II was found to be influenced by these compounds, with 7-ketoroyleanone and sugiol being the most active. These two diterpenes preferentially inhibited topoisomerase I and exhibited lower IC(50) values than the classical topoisomerase I inhibitor camptothecin. Molecular docking studies revealed possible interactions of diterpenes with topoisomerase I, indicating that these compounds do not form the drug-enzyme-DNA covalent ternary complex as observed with camptothecin. A binding pocket located at the surface of the DNA-interaction site was proposed. Moreover, the ability of the five diterpenes to generate DNA-strand breaks in single cells was confirmed using the alkaline comet assay. As expected, these diterpenes also influenced cell cycle progression and arrested cells in different phases of the cell cycle, primarily the G1/G0 and S-phases. Interestingly, the diterpenes only exhibited a slight ability to induce apoptotic cell death and failed to generate intracellular reactive oxygen species. These results provide additional understanding of the cytotoxic effects of abietane diterpenes. Depending on their functional groups, we propose that abietane diterpenes utilise different mechanisms to induce cell death., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
185. Fermentation enhances the biological activity of Allium cepa bulb extracts.
- Author
-
Millet A, Lamy E, Jonas D, Stintzing F, Mersch-Sundermann V, and Merfort I
- Subjects
- Anti-Bacterial Agents pharmacology, Antimutagenic Agents pharmacology, Antineoplastic Agents, Phytogenic pharmacology, Cell Proliferation drug effects, Chromatography, High Pressure Liquid, Flavonoids analysis, Lactic Acid metabolism, Methanol, Water, Fermentation, Onions chemistry, Plant Extracts metabolism, Plant Extracts pharmacology, Plant Roots chemistry
- Abstract
In this study, we compared the analytical fingerprint and bioactivity of three onion extracts, including an aqueous, a methanol, and a fermented aqueous extract. The extracts were characterized by HPLC-DAD, LC-MS, and GC-MS analyses. The antibacterial, antigenotoxic, and antiproliferative activity of these extracts was assessed by means of agar disk diffusion, bacterial growth kinetics, a comet assay, cell cycle distribution analysis, and cell viability testing. Both the aqueous and methanolic extracts showed a typical flavonol-fingerprint as assessed by HPLC measurements and showed little to no bioactivity. The fermented aqueous extract, which lacks the usual onion flavonoid profile, was found to be the most active in all of the assays. This finding indicates that metabolites of onion compounds, generated by lactic acid fermentation, may be more active than their precursor substances.
- Published
- 2012
- Full Text
- View/download PDF
186. Mining and evaluation of molecular relationships in literature.
- Author
-
Senger C, Grüning BA, Erxleben A, Döring K, Patel H, Flemming S, Merfort I, and Günther S
- Subjects
- Drug Discovery, Internet, Proteins metabolism, PubMed, Data Mining, Databases, Protein
- Abstract
Motivation: Specific information on newly discovered proteins is often difficult to find in literature. Particularly if only sequences and no common names of proteins or genes are available, preceding sequence similarity searches can be crucial for the process of information collection. In drug research, it is important to know whether a small molecule targets only one specific protein or whether similar or homologous proteins are also influenced that may account for possible side effects., Results: prolific (protein-literature investigation for interacting compounds) provides a one-step solution to investigate available information on given protein names, sequences, similar proteins or sequences on the gene level. Co-occurrences of UniProtKB/Swiss-Prot proteins and PubChem compounds in all PubMed abstracts are retrievable. Concise 'heat-maps' and tables display frequencies of co-occurrences. They provide links to processed literature with highlighted found protein and compound synonyms. Evaluation with manually curated drug-protein relationships showed that up to 69% could be discovered by automatic text-processing. Examples are presented to demonstrate the capabilities of prolific., Availability: The web-application is available at http://prolific.pharmaceutical-bioinformatics.de and a web service at http://www.pharmaceutical-bioinformatics.de/prolific/soap/prolific.wsdl., Supplementary Information: Supplementary data are available at Bioinformatics online.
- Published
- 2012
- Full Text
- View/download PDF
187. IκBα glutathionylation and reduced histone H3 phosphorylation inhibit eotaxin and RANTES.
- Author
-
Seidel P, Roth M, Ge Q, Merfort I, S'ng CT, and Ammit AJ
- Subjects
- Adult, Aged, Cells, Cultured, Chemokine CCL5 metabolism, Chemokines, CC metabolism, Diamide pharmacology, Dimethyl Fumarate, Fumarates pharmacology, Humans, Male, Middle Aged, NF-KappaB Inhibitor alpha, NF-kappa B antagonists & inhibitors, Phosphorylation, Respiratory Function Tests, Ribosomal Protein S6 Kinases, 90-kDa metabolism, Sulfhydryl Reagents pharmacology, Tumor Necrosis Factor-alpha pharmacology, Chemokine CCL5 antagonists & inhibitors, Chemokines, CC antagonists & inhibitors, Glutathione metabolism, Histones metabolism, I-kappa B Proteins metabolism, Myocytes, Smooth Muscle metabolism
- Abstract
Airway smooth muscle cells (ASMCs) secrete eotaxin and RANTES (regulated on activation, normal T-cell expressed and secreted) in response to tumour necrosis factor (TNF)-α, which is inhibited by the nuclear factor (NF)-κB inhibitor dimethylfumarate (DMF). NF-κB/IκB (inhibitor of NF-κB) glutathionylation and changes in chromatin remodelling can inhibit NF-κB activity. In this study, we determined whether NF-κB/IκB glutathionylation and reduced histone H3 phosphorylation might underlie the inhibitory effect of DMF on NF-κB activity, and eotaxin and RANTES secretion. Primary human ASMCs were treated with DMF, diamide and/or glutathione (GSH) ethylester (OEt) prior to TNF-α stimulation and were subsequently analysed by ELISA, electrophoretic mobility shift assay, immunofluorescence, co-immunoprecipitation or immunoblotting. DMF reduced intracellular GSH and induced IκBα glutathionylation (IκBα-SSG), which inhibited IκBα degradation, NF-κB p65 nuclear entry and NF-κB/DNA binding. In addition, DMF inhibited the phosphorylation of histone H3, which was possibly mediated by the inhibitory effect of DMF on mitogen- and stress-activated protein kinase (MSK)-1. However, p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase MAPK and MAPK phosphatase-1, upstream of MSK-1, were not inhibited by DMF. Importantly, DMF-mediated effects on NF-κB, histone H3, eotaxin and RANTES were reversed by addition of GSH-OEt. Our data suggest that DMF inhibits NF-κB-dependent eotaxin and RANTES secretion by reduction of GSH with subsequent induction of IκBα-SSG and inhibition of histone H3 phosphorylation. Our findings offer new potential drug targets to reduce airway inflammation in asthma.
- Published
- 2011
- Full Text
- View/download PDF
188. Perspectives on sesquiterpene lactones in inflammation and cancer.
- Author
-
Merfort I
- Subjects
- Humans, Lactones chemistry, Lactones pharmacology, Models, Molecular, Quantitative Structure-Activity Relationship, Sesquiterpenes chemistry, Sesquiterpenes pharmacology, Inflammation drug therapy, Lactones therapeutic use, Neoplasms drug therapy, Sesquiterpenes therapeutic use
- Abstract
Sesquiterpene lactones are a large group of secondary plant metabolites mostly known from the Asteraceae family. They exert a broad variety of different biological activities. This review attempts to critically summarise the knowledge on the anti-inflammatory and cytotoxic activity of SLs, with a special focus on parthenolide and helenalin. Recent advances on their molecular modes of action, allergic potential and also QSAR studies with SLs are presented. Therapeutic areas are highlighted in which SLs may play a role in the future. Thus, SLs may possess therapeutic relevance as single components for the local treatment of inflammation, such as rheumatoid complaints. In cancer therapy, SLs may be favourable in dual therapy or in the inhibition of leukaemia cell growth. In each case, native SLs serve as leads that have to be optimised in terms of their specificity, pharmacokinetics and absorption, distribution, metabolism and excretion (=ADME) properties. Finally, appropriate in vivo studies will decide whether SLs will become therapeutics or remain interesting research compounds.
- Published
- 2011
- Full Text
- View/download PDF
189. Cytotoxicity and genotoxicity of size-fractionated iron oxide (magnetite) in A549 human lung epithelial cells: role of ROS, JNK, and NF-κB.
- Author
-
Könczöl M, Ebeling S, Goldenberg E, Treude F, Gminski R, Gieré R, Grobéty B, Rothen-Rutishauser B, Merfort I, and Mersch-Sundermann V
- Subjects
- Cell Line, Tumor, Enzyme Activation, Humans, Particulate Matter toxicity, Ferrosoferric Oxide toxicity, JNK Mitogen-Activated Protein Kinases metabolism, Lung cytology, Mutagens toxicity, NF-kappa B metabolism, Reactive Oxygen Species metabolism
- Abstract
Airborne particulate matter (PM) of varying size and composition is known to cause health problems in humans. The iron oxide Fe(3)O(4) (magnetite) may be a major anthropogenic component in ambient PM and is derived mainly from industrial sources. In the present study, we have investigated the effects of four different size fractions of magnetite on signaling pathways, free radical generation, cytotoxicity, and genotoxicity in human alveolar epithelial-like type-II cells (A549). The magnetite particles used in the exposure experiments were characterized by mineralogical and chemical techniques. Four size fractions were investigated: bulk magnetite (0.2-10 μm), respirable fraction (2-3 μm), alveolar fraction (0.5-1.0 μm), and nanoparticles (20-60 nm). After 24 h of exposure, the A549 cells were investigated by transmission electron microscopy (TEM) to study particle uptake. TEM images showed an incorporation of magnetite particles in A549 cells by endocytosis. Particles were found as agglomerates in cytoplasm-bound vesicles, and few particles were detected in the cytoplasm but none in the nucleus. Increased production of reactive oxygen species (ROS), as determined by the 2',7'-dichlorfluorescein-diacetate assay (DCFH-DA), as well as genotoxic effects, as measured by the cytokinesis block-micronucleus test and the Comet assay, were observed for all of the studied fractions after 24 h of exposure. Moreover, activation of c-Jun N-terminal kinases (JNK) without increased nuclear factor kappa-B (NF-κB)-binding activity but delayed IκB-degradation was observed. Interestingly, pretreatment of cells with magnetite and subsequent stimulation with the pro-inflammatory cytokine tumor necrosis factor-alpha (TNFα) led to a reduction of NF-κB DNA binding compared to that in stimulation with TNFα alone. Altogether, these experiments suggest that ROS formation may play an important role in the genotoxicity of magnetite in A549 cells but that activation of JNK seems to be ROS-independent.
- Published
- 2011
- Full Text
- View/download PDF
190. In vitro cytotoxic activity of abietane diterpenes from Peltodon longipes as well as Salvia miltiorrhiza and Salvia sahendica.
- Author
-
Fronza M, Murillo R, Ślusarczyk S, Adams M, Hamburger M, Heinzmann B, Laufer S, and Merfort I
- Subjects
- Abietanes analysis, Abietanes chemistry, Abietanes isolation & purification, Antineoplastic Agents, Phytogenic analysis, Antineoplastic Agents, Phytogenic chemistry, Antineoplastic Agents, Phytogenic isolation & purification, Cell Line, Tumor, Cytotoxins chemistry, Cytotoxins isolation & purification, Drug Screening Assays, Antitumor, Humans, Phytotherapy, Plant Extracts analysis, Plant Extracts chemistry, Plant Extracts isolation & purification, Plant Roots, Structure-Activity Relationship, Abietanes pharmacology, Antineoplastic Agents, Phytogenic pharmacology, Cytotoxins pharmacology, Lamiaceae, Plant Extracts pharmacology, Salvia
- Abstract
Phytochemical investigations of the n-hexane extract from the roots of Peltodon longipes (Lamiaceae) resulted in the isolation of 12 known abietane diterpenes (1-12). Structures were established on the basis of one and two dimensional nuclear magnetic resonance spectroscopic data ((1)H and (13)C, COSY, HSQC and HMBC), electron ionization mass spectrometric analysis (EIMS) as well as comparison with data from literature. These compounds, as well as eight known diterpenes (13-19) from Salvia miltiorrhiza, and two from Salvia sahendica (20 and 21) were evaluated for their cytotoxic effects in human pancreatic (MIAPaCa-2) and melanoma (MV-3) tumor cell lines using the MTT assay. Tanshinone IIa (13), 7α-acetoxyroyleanone (1), 1,2-dihydrotanshinone (16) and cryptotanshinone (14) had the highest cytotoxic effects in MIAPaCa-2, displaying IC(50) of 1.9, 4.7, 5.6, and 5.8 μM, respectively. Structure-activity relationships of abietane diterpenoid quinones are discussed., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
191. Structural and conformational analysis of proanthocyanidins from Parapiptadenia rigida and their wound-healing properties.
- Author
-
Schmidt CA, Murillo R, Heinzmann B, Laufer S, Wray V, and Merfort I
- Subjects
- Brazil, Crystallography, X-Ray, Humans, Molecular Conformation, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Plant Bark chemistry, Fabaceae chemistry, Proanthocyanidins chemistry, Proanthocyanidins isolation & purification, Proanthocyanidins pharmacology, Wound Healing drug effects
- Abstract
Structure elucidation and conformation analysis of four proanthocyanidins isolated from the bark of Parapiptadenia rigida were performed by two-dimensional NMR spectroscopy, HRESIMS, CD, and molecular mechanics (MM+) force field calculations. The known prodelphinidin, epigallocatechin-(4β→8)-epigallocatechin-3-O-gallate (1) was accompanied by the new epigallocatechin-(4β→8)-4'-O-methylgallocatechin (2), epicatechin-(4β→8)-4'-O-methylgallocatechin (3), and (4α→8)-bis-4'-O-methylgallocatechin (4). Compound 4 was previously published but the earlier structure must presumably be revised to 4'-O-methylgallocatechin-(4α→8)-4'-O-methylepigallocatechin. Conformational studies showed the compact rotamer with B and E rings in quasi-equatorial orientations as the preferred conformation for compounds 1-3, whereas 4 consists of two stable rotamers, each with a quasi-equatorial orientation of ring B and E, respectively. The isolated compounds were studied for their wound-healing effects in a scratch assay and showed promising results.
- Published
- 2011
- Full Text
- View/download PDF
192. Modeling the TNFα-induced apoptosis pathway in hepatocytes.
- Author
-
Schlatter R, Schmich K, Lutz A, Trefzger J, Sawodny O, Ederer M, and Merfort I
- Subjects
- Animals, Base Sequence, Blotting, Western, Cytochromes c metabolism, DNA Primers, Dactinomycin pharmacology, Enzyme Activation, Enzyme-Linked Immunosorbent Assay, Hepatocytes drug effects, Hepatocytes enzymology, Hepatocytes metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, Reactive Oxygen Species metabolism, Apoptosis physiology, Hepatocytes cytology, Models, Biological, Tumor Necrosis Factor-alpha physiology
- Abstract
The proinflammatory cytokine TNFα fails to provoke cell death in isolated hepatocytes but has been implicated in hepatocyte apoptosis during liver diseases associated with chronic inflammation. Recently, we showed that TNFα is able to sensitize primary murine hepatocytes cultured on collagen to Fas ligand-induced apoptosis and presented a mathematical model of the sensitizing effect. Here, we analyze how TNFα induces apoptosis in combination with the transcriptional inhibitor actinomycin D (ActD). Accumulation of reactive oxygen species (ROS) in response to TNFR activation turns out to be critical for sustained activation of JNK which then triggers mitochondrial pathway-dependent apoptosis. In addition, the amount of JNK is strongly upregulated in a ROS-dependent way. In contrast to TNFα plus cycloheximide no cFLIP degradation is observed suggesting a different apoptosis pathway in which the Itch-mediated cFLIP degradation and predominantly caspase-8 activation is not involved. Time-resolved data of the respective pro- and antiapoptotic factors are obtained and subjected to mathematical modeling. On the basis of these data we developed a mathematical model which reproduces the complex interplay regulating the phosphorylation status of JNK and generation of ROS. This model was fully integrated with our model of TNFα/Fas ligand sensitizing as well as with a published NF-κB-model. The resulting comprehensive model delivers insight in the dynamical interplay between the TNFα and FasL pathways, NF-κB and ROS and gives an example for successful model integration.
- Published
- 2011
- Full Text
- View/download PDF
193. NF-κB DNA binding activity of sesquiterpene lactones from Anthemis arvensis and Anthemis cotula.
- Author
-
Vucković I, Vujisić L, Klaas CA, Merfort I, and Milosavljević S
- Subjects
- Gene Expression Regulation drug effects, Humans, Jurkat Cells, Lactones pharmacology, Molecular Structure, Sesquiterpenes pharmacology, Structure-Activity Relationship, Anthemis chemistry, DNA metabolism, Lactones chemistry, NF-kappa B antagonists & inhibitors, NF-kappa B metabolism, Sesquiterpenes chemistry
- Abstract
Previous investigations of Anthemis arvensis L. and Anthemis cotula L., species growing wild in Serbia, revealed linear sesquiterpene lactones (SLs) with unusual types of skeleton, named antheindurolides and anthecotuloides. The NF-κB DNA binding activity of four of those SLs as well as from compounds representing structural parts of the SLs is reported in this article. The relationship between their structure and NF-κB inhibition potency is briefly discussed.
- Published
- 2011
- Full Text
- View/download PDF
194. Glycyrol induces apoptosis in human Jurkat T cell lymphocytes via the Fas-FasL/caspase-8 pathway.
- Author
-
Shin EM, Kim S, Merfort I, and Kim YS
- Subjects
- Caspase 9 metabolism, Cell Cycle drug effects, Dose-Response Relationship, Drug, Fas Ligand Protein metabolism, Humans, Apoptosis drug effects, Caspase 8 metabolism, Flavonoids pharmacology, Glycyrrhiza chemistry, Jurkat Cells drug effects, Plant Extracts pharmacology, fas Receptor metabolism
- Abstract
Glycyrrhiza uralensis (Leguminosae) has long been used to treat inflammatory ailments, such as gastric ulcers, arthritis, and rheumatism. From this traditional herbal plant, glycyrol, a coumestan with anti-bacterial and anti-inflammatory activities, was first isolated and synthesized to test its apoptosis-inducing properties in human Jurkat cells. Flow cytometry analysis indicated that glycyrol can arrest the cell cycle in S phase and subsequently induce apoptosis in both time- and dose-dependent manners. Consequently, it was shown that caspase-8 and -9 were involved in the activation of apoptosis after glycyrol treatment. Despite its known NF- κB inhibitory activity, glycyrol did not influence the prosurvival Bcl-2 and the proapoptotic Bax. Interestingly, glycyrol was revealed to enhance the Fas level independently from p53, which even slightly decreased. Thus, glycyrol acts in a similar manner as known cytostatic drugs and may have a potential as lead for the development of drugs for cancer treatment., (© Georg Thieme Verlag KG Stuttgart · New York.)
- Published
- 2011
- Full Text
- View/download PDF
195. Tumor necrosis factor α sensitizes primary murine hepatocytes to Fas/CD95-induced apoptosis in a Bim- and Bid-dependent manner.
- Author
-
Schmich K, Schlatter R, Corazza N, Sá Ferreira K, Ederer M, Brunner T, Borner C, and Merfort I
- Subjects
- Animals, Antibodies pharmacology, Bcl-2-Like Protein 11, Caspase 3 metabolism, Caspase 7 metabolism, Cells, Cultured, Fas Ligand Protein physiology, Hepatocytes pathology, MAP Kinase Kinase 4 antagonists & inhibitors, MAP Kinase Kinase 4 metabolism, Mice, Signal Transduction drug effects, Tumor Necrosis Factor-alpha pharmacology, Up-Regulation, X-Linked Inhibitor of Apoptosis Protein physiology, Apoptosis drug effects, Apoptosis Regulatory Proteins physiology, BH3 Interacting Domain Death Agonist Protein physiology, Liver Diseases etiology, Membrane Proteins physiology, Proto-Oncogene Proteins physiology, Tumor Necrosis Factor-alpha physiology, fas Receptor immunology
- Abstract
Unlabelled: Fas/CD95 is a critical mediator of cell death in many chronic and acute liver diseases and induces apoptosis in primary hepatocytes in vitro. In contrast, the proinflammatory cytokine tumor necrosis factor α (TNFα) fails to provoke cell death in isolated hepatocytes but has been implicated in hepatocyte apoptosis during liver diseases associated with chronic inflammation. Here we report that TNFα sensitizes primary murine hepatocytes cultured on collagen to Fas ligand (FasL)-induced apoptosis. This synergism is time-dependent and is specifically mediated by TNFα. Fas itself is essential for the sensitization, but neither Fas up-regulation nor endogenous FasL is responsible for this effect. Although FasL is shown to induce Bid-independent apoptosis in hepatocytes cultured on collagen, the sensitizing effect of TNFα is clearly dependent on Bid. Moreover, both c-Jun N-terminal kinase activation and Bim, another B cell lymphoma 2 homology domain 3 (BH3)-only protein, are crucial mediators of TNFα-induced apoptosis sensitization. Bim and Bid activate the mitochondrial amplification loop and induce cytochrome c release, a hallmark of type II apoptosis. The mechanism of TNFα-induced sensitization is supported by a mathematical model that correctly reproduces the biological findings. Finally, our results are physiologically relevant because TNFα also induces sensitivity to agonistic anti-Fas-induced liver damage., Conclusion: Our data suggest that TNFα can cooperate with FasL to induce hepatocyte apoptosis by activating the BH3-only proteins Bim and Bid., (Copyright © 2010 American Association for the Study of Liver Diseases.)
- Published
- 2011
- Full Text
- View/download PDF
196. Catechin derivatives from Parapiptadenia rigida with in vitro wound-healing properties.
- Author
-
Schmidt CA, Murillo R, Bruhn T, Bringmann G, Goettert M, Heinzmann B, Brecht V, Laufer SA, and Merfort I
- Subjects
- Animals, Brazil, Catechin chemistry, DNA metabolism, Mice, NF-kappa B antagonists & inhibitors, NF-kappa B metabolism, Nuclear Magnetic Resonance, Biomolecular, Plant Bark chemistry, Swiss 3T3 Cells, Catechin analogs & derivatives, Catechin pharmacology, Fabaceae chemistry, Mitogen-Activated Protein Kinase 14 antagonists & inhibitors, Molecular Structure, Wound Healing drug effects
- Abstract
Analysis of the ethanolic extract of the bark from Parapiptadenia rigida resulted in the isolation of the new catechin derivatives 4',3''-di-O-methylapocynin-D (10), 4',3''-di-O-methylapocynin-B (11), epigallocatechin-3-O-ferulate (8), and 4'-O-methylepigallocatechin-3-O-ferulate (9) and the catechins 4'-O-methylepigallocatechin-3-O-gallate (6) and 4'-O-methylepicatechin-3-O-gallate (7). These compounds, isolated for the first time from a natural source, are accompanied by the five known catechins 4'-O-methylgallocatechin (1), 4'-O-methylepigallocatechin (2), 3'-O-methylepicatechin (3), epigallocatechin-3-O-gallate (4), and epicatechin-3-O-gallate (5). Compounds 5 and 7 displayed promising wound-healing effects in a scratch assay. Some of the catechin derivatives showed inhibitory effects on NF-κB DNA binding and p38α MAPK activity.
- Published
- 2010
- Full Text
- View/download PDF
197. Biological evaluation and structural determinants of p38α mitogen-activated-protein kinase and c-Jun-N-terminal kinase 3 inhibition by flavonoids.
- Author
-
Goettert M, Schattel V, Koch P, Merfort I, and Laufer S
- Subjects
- Animals, Humans, Mitogen-Activated Protein Kinase 10 chemistry, Mitogen-Activated Protein Kinase 10 metabolism, Mitogen-Activated Protein Kinase 14 chemistry, Mitogen-Activated Protein Kinase 14 metabolism, Models, Molecular, Structure-Activity Relationship, Flavonoids chemistry, Flavonoids pharmacology, Mitogen-Activated Protein Kinase 10 antagonists & inhibitors, Mitogen-Activated Protein Kinase 14 antagonists & inhibitors, Protein Kinase Inhibitors chemistry, Protein Kinase Inhibitors pharmacology
- Abstract
A series of 42 naturally occurring flavonoids and one flavonoid glucuronide were tested for their ability to inhibit p38α mitogen-activated protein kinase (p38α) and c-Jun-N-terminal kinase 3 (JNK3). Potent inhibitors with IC(50) values in the low micromolar range were identified. Structure-activity relationships were evaluated and the most promising compounds were docked into the ATP binding site of these kinases. Among the different classes of flavonoids, the flavonol group showed better inhibition of p38α. Of this class, kaempferol-7,4'-dimethylether was a potent p38α inhibitor, displaying 13-fold selectivity for p38α over JNK3. The flavone compounds without a 6-methoxy group preferentially inhibited JNK3. The flavone glycoside, luteolin-7-O-glycoside, was identified as a potent inhibitor with the greatest selectivity toward JNK3. In contrast, the flavanol compounds displayed similar inhibitory activities toward both kinases.
- Published
- 2010
- Full Text
- View/download PDF
198. Inhibition of NF-κB and AP-1 by dimethylfumarate correlates with down-regulated IL-6 secretion and proliferation in human lung fibroblasts.
- Author
-
Seidel P, Merfort I, Tamm M, and Roth M
- Subjects
- Cells, Cultured, Dimethyl Fumarate, Humans, Lung cytology, Cell Proliferation drug effects, Down-Regulation drug effects, Fibroblasts cytology, Fibroblasts drug effects, Fumarates pharmacology, Interleukin-6 metabolism, NF-kappa B antagonists & inhibitors, Transcription Factor AP-1 antagonists & inhibitors
- Abstract
Unlabelled: QUESTION UNDER STUDY/PRINCIPLES: Dimethylfumarate (DMF) had been reported to reduce asthma symptoms and to improve the quality of life of asthma patients. Therefore, we assessed the anti-inflammatory and anti-remodeling effect of DMF on isolated lung fibroblasts, which are relevant to inflammatory lung diseases. We determined the effect of DMF on platelet derived growth factor (PDGF)-BB induced proliferation, as well as on PDGF-BB and tumor necrosis factor (TNF)-α induced interleukin (IL)-6 secretion and on activation of activated protein (AP)-1 and nuclear factor kappaB (NF-ĸB)., Methods: Confluent lung fibroblasts were incubated with DMF (0.1-100 μM) 1 hour before stimulation with PDGF-BB or TNF-α (both 10 ng/ml). IL-6 secretion was measured by ELISA. NF-ĸB and AP-1 activation was determined by immuno-blotting and EMSA. Cell proliferation was assessed by [3H]-thymidine incorporation in subconfluent fibroblasts., Results: PDGF-BB but not TNF-α induced fibroblast proliferation. This was dose dependently reduced by DMF in a concentration range of 10-100 μM. PDGF-BB and TNF-α induced IL-6 secretion by lung fibroblasts and this was inhibited by DMF in a dose-dependent manner. However, PDGF-BB induced IL-6 secretion did not correlate with NF-ĸB activity, while TNF-α did. DMF inhibited the TNF-α induced NF-ĸB-DNA binding, but had neither an inhibitory effect on NF-ĸB nuclear entry nor on the degradation of IκB-α. PDGF-BB and TNF-α activated AP-1, which was also inhibited by DMF., Conclusions: Our data suggest that DMF down-regulates TNF-α-induced IL-6 secretion and proliferation by inhibiting NF-ĸB and AP-1 activity, indicating its potential beneficial use for the treatment of inflammatory lung diseases.
- Published
- 2010
- Full Text
- View/download PDF
199. Transcription factors ETF, E2F, and SP-1 are involved in cytokine-independent proliferation of murine hepatocytes.
- Author
-
Zellmer S, Schmidt-Heck W, Godoy P, Weng H, Meyer C, Lehmann T, Sparna T, Schormann W, Hammad S, Kreutz C, Timmer J, von Weizsäcker F, Thürmann PA, Merfort I, Guthke R, Dooley S, Hengstler JG, and Gebhardt R
- Subjects
- Animals, Binding Sites physiology, Carbon Tetrachloride Poisoning physiopathology, Gene Expression, Hepatectomy, Male, Mice, Mice, Inbred C57BL, Mitogen-Activated Protein Kinase 1 physiology, Mitogen-Activated Protein Kinase 3 physiology, Signal Transduction drug effects, TEA Domain Transcription Factors, Up-Regulation, Cell Proliferation, DNA-Binding Proteins physiology, E2F1 Transcription Factor physiology, Hepatocytes cytology, Sp1 Transcription Factor physiology, Transcription Factors physiology
- Abstract
Unlabelled: The cellular basis of liver regeneration has been intensely investigated for many years. However, the mechanisms initiating hepatocyte "plasticity" and priming for proliferation are not yet fully clear. We investigated alterations in gene expression patterns during the first 72 hours of C57BL/6N mouse hepatocyte culture on collagen monolayers (CM), which display a high basal frequency of proliferation in the absence of cytokines. Although many metabolic genes were down-regulated, genes related to mitogen-activated protein kinase (MAPK) signaling and cell cycle were up-regulated. The latter genes showed an overrepresentation of transcription factor binding sites (TFBS) for ETF (TEA domain family member 2), E2F1 (E2F transcription factor 1), and SP-1 (Sp1 transcription factor) (P < 0.001), all depending on MAPK signaling. Time-dependent increase of ERK1/2 phosphorylation occurred during the first 48 hours (and beyond) in the absence of cytokines, accompanied by an enhanced bromodeoxyuridine labeling index of 20%. The MEK inhibitor PD98059 blunted these effects indicating MAPK signaling as major trigger for this cytokine-independent proliferative response. In line with these in vitro findings, liver tissue of mice challenged with CCl(4) displayed hepatocytes with intense p-ERK1/2 staining and nuclear SP-1 and E2F1 expression. Furthermore, differentially expressed genes in mice after partial hepatectomy contained overrepresented TFBS for ETF, E2F1, and SP-1 and displayed increased expression of E2F1., Conclusion: Cultivation of murine hepatocytes on CM primes cells for proliferation through cytokine-independent activation of MAPK signaling. The transcription factors ETF, E2F1, and SP-1 seem to play a pronounced role in mediating proliferation-dependent differential gene expression. Similar events, but on a shorter time-scale, occur very early after liver damage in vivo., (Copyright © 2010 American Association for the Study of Liver Diseases.)
- Published
- 2010
- Full Text
- View/download PDF
200. In vitro and in vivo analysis of pro- and anti-inflammatory effects of weak and strong contact allergens.
- Author
-
Lass C, Merfort I, and Martin SF
- Subjects
- Adoptive Transfer, Animals, Arnica chemistry, Arnica immunology, CD8-Positive T-Lymphocytes cytology, CD8-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes transplantation, Cell Movement immunology, Cytokines genetics, Cytokines metabolism, Dermatitis, Allergic Contact metabolism, Dose-Response Relationship, Immunologic, Ear, External immunology, Ear, External metabolism, Female, Gene Expression genetics, Gene Expression immunology, Immunization, Inflammation immunology, Inflammation metabolism, Interleukin-10 genetics, Interleukin-10 metabolism, Interleukin-1beta genetics, Mice, Mice, Inbred C57BL, Mice, Transgenic, Plant Extracts immunology, Receptors, Antigen, T-Cell genetics, Receptors, Antigen, T-Cell immunology, Skin immunology, Skin metabolism, Trinitrobenzenes immunology, Allergens immunology, Dermatitis, Allergic Contact immunology
- Abstract
Inflammation is a crucial step in the development of allergic contact dermatitis. The primary contact with chemical allergens, called sensitization, and the secondary contact, called elicitation, result in an inflammatory response in the skin. The ability of contact allergens to induce allergic contact dermatitis correlates to a great extent with their inflammatory potential. Therefore, the analysis of the sensitizing potential of a putative contact allergen should include the examination of its ability and potency to cause an inflammation. In this study, we examined the inflammatory potential of different weak contact allergens and of the strong sensitizer 2,4,6-trinitrochlorobenzene (TNCB) in vitro and in vivo using the contact hypersensitivity model, the mouse model for allergic contact dermatitis. Cytokine induction was analysed by PCR and ELISA to determine mRNA and protein levels, respectively. Inflammation-dependent recruitment of skin-homing effector T cells was measured in correlation with the other methods. We show that the sensitizing potential of a contact allergen correlates with the strength of the inflammatory response. The different methods used gave similar results. Quantitative cytokine profiling may be used to determine the sensitizing potential of chemicals for hazard identification and risk assessment., (© 2010 John Wiley & Sons A/S.)
- Published
- 2010
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.