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Irmgard Merfort - One of the best experts on this subject based on the ideXlab platform.

  • endophytic streptomyces in the traditional medicinal plant Arnica Montana l secondary metabolites and biological activity
    Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 2015
    Co-Authors: Tina Wardecki, Elke Brotz, Christian De Ford, Friederike D Von Loewenich, Yuriy Rebets, Bogdan Tokovenko, Andriy Luzhetskyy, Irmgard Merfort
    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.

  • altitudinal variation of secondary metabolite profiles in flowering heads of Arnica Montana cv arbo
    Phytochemistry, 2006
    Co-Authors: Renate Spitaler, Irmgard Merfort, Daniel P Schlorhaufer, Ernst P Ellmerer, Sigmar Bortenschlager, Hermann Stuppner, Christian Zidorn
    Abstract:

    The altitudinal variation on the contents of secondary metabolites in flowering heads of Arnica Montana was assessed. Plants of A. Montana cultivar ARBO were grown in nine experimental plots at altitudes between 590 and 2230m at Mount Patscherkofel near Innsbruck/Austria. The total contents of sesquiterpene lactones and flavonoids were not positively correlated with the altitude of the growing site. However, the proportion of flavonoids with vicinal free hydroxy groups in ring B to flavonoids lacking this feature significantly increased with elevation. Additionally, the level of caffeic acid derivatives also positively correlated with the altitude of the growing site. In particular amounts of 1-methoxyoxaloyl-3,5-dicaffeoylquinic acid significantly increased in higher sites and samples from the summit region contained 85% more of this compound than samples from valley sites. These results are discussed with regards to chemosystematic studies comparing samples collected in different altitudes as well as in the light of a UV-B protective and radical scavenging function of phenolics and their significance for plant life in environments with elevated UV-B radiation.

  • new sesquiterpene lactones from Arnica tincture prepared from fresh flowerheads of Arnica Montana
    Planta Medica, 2005
    Co-Authors: Olha Kos, Maja T Lindenmeyer, Aurelia Tubaro, Silvio Sosa, Irmgard Merfort
    Abstract:

    Investigation of an ethanolic extract prepared from fresh Arnica Montana flowers afforded three new 1,5- trans-guaianolides, of which 11alpha,13-dihydro-2-O-tigloylflorilenalin and the respective 2-O-isovaleryl derivative are reported for the first time. Additionally, three new and one known 2beta-ethoxy-2,3-dihydrohelenalin esters were isolated. GC/MS studies of the extract after a two year storage at 4 degrees C demonstrated that the latter were artefacts that had been formed by addition of ethanol to the cyclopentenone structure of helenalin. Formation of these adducts gave compounds possessing an inhibitory activity comparable to that of 11alpha,13-dihydrohelenalin derivatives in the NF-kappaB EMSA and the IL-8 ELISA in vitro assays as well as in the in vivo croton oil-induced mouse ear edema test for one adduct, namely 2beta-ethoxy-6-O-acetyl-2,3-dihydrohelenalin. As expected, 6-O-(2-methylbutyryl)- and 6-O-methacryloyl-helenalin exhibited a stronger activity in the NF-kappaB EMSA and IL-8 ELISA. Sesquiterpene lactones seem to be the most important NF-kappaB inhibiting compounds in the Arnica extract. Bioguided fractionation using the luciferase reporter gene assay resulted in the isolation of only moderately active compounds, such as 6-acetoxy-2,2-dimethylchroman-4-one and 10-acetoxy-8,9-epoxythymol isobutyrate.

  • Caffeoylquinic acids from flowers of Arnica Montana and Arnica chamissonis
    Phytochemistry, 1992
    Co-Authors: Irmgard Merfort
    Abstract:

    Abstract Two caffeoylquinic acids were isolated from flowers of Arnica Montana and three from A. chamissonis ssp. foliosa var. incana . Their structures were established on the basis of spectral data (UV, 1 H NMR, 13 C NMR, FABMS) as 1,4,5-tri- O -caffeoylquinic acid, 1,5-di- O -caffeoylquinic acid and 3,4,5-tri- O -caffeoylquinic acid methyl ester. The first compound is a new natural product.

Christian Zidorn - One of the best experts on this subject based on the ideXlab platform.

  • Temperature is the key to altitudinal variation of phenolics in Arnica Montana L. cv. ARBO
    Oecologia, 2009
    Co-Authors: Andreas Albert, Vipaporn Sareedenchai, Werner Heller, Harald K. Seidlitz, Christian Zidorn
    Abstract:

    Plants in alpine habitats are exposed to many environmental stresses, in particular temperature and radiation extremes. Recent field experiments on Arnica Montana L. cv. ARBO indicated pronounced altitudinal variation in plant phenolics. Ortho -diphenolics increased with altitude compared to other phenolic compounds, resulting in an increase in antioxidative capacity of the tissues involved. Factors causing these variations were investigated by climate chamber (CC) experiments focusing on temperature and ultraviolet (UV)-B radiation. Plants of A. Montana L. cv. ARBO were grown in CCs under realistic climatic and radiation regimes. Key factors temperature and UV-B radiation were altered between different groups of plants. Subsequently, flowering heads were analyzed by HPLC for their contents of flavonoids and caffeic acid derivatives. Surprisingly, increased UV-B radiation did not trigger any change in phenolic metabolites in Arnica . In contrast, a pronounced increase in the ratio of B-ring ortho -diphenolic (quercetin) compared to B-ring monophenolic (kaempferol) flavonols resulted from a decrease in temperature by 5°C in the applied climate regime. In conclusion, enhanced UV-B radiation is probably not the key factor triggering shifts in the phenolic composition in Arnica grown at higher altitudes but rather temperature, which decreases with altitude.

  • quantitative analysis of flavonoids and phenolic acids in Arnica Montana l by micellar electrokinetic capillary chromatography
    Analytica Chimica Acta, 2008
    Co-Authors: Markus Ganzera, Christian Zidorn, Christoph Egger, Hermann Stuppner
    Abstract:

    Abstract Arnica Montana preparations have been used in Europe for centuries to treat skin disorders. Among the biologically active ingredients in the flower heads of the plant are sequiterpenes, flavonoids and phenolic acids. For the simultaneous determination of compounds belonging to the latter two groups a micellar electrokinetic capillary chromatography (MEKC) method was developed and validated. By using an electrolyte solution containing 50 mM borax, 25 mM sodium dodecyl sulfate and 30% of acetonitrile the separation of seven flavonoids and four caffeic acid derivatives was feasible in less than 20 min. The optimized system was validated for repeatability ( σ rel  ≤ 4.4%), precision (inter-day σ rel  ≤ 8.13%, intra-day σ rel  ≤ 4.32%), accuracy (recovery rates from 96.8 to 102.4%), sensitivity (limit of detection (LOD) ≤ 4.5 μg mL −1 ) and linearity ( R 2  ≥ 0.9996), and then successfully applied to assay several plant samples. In all of them the most dominant flavonoid was found to be quercetin 3- O -glucuronic acid, whereas 3,5-dicaffeoylquinic acid was the major phenolic acid; the total content of flavonoids and phenolic acids varied in the samples from 0.60 to 1.70%, and 1.03 to 2.24%, respectively.

  • altitudinal variation of secondary metabolite profiles in flowering heads of Arnica Montana cv arbo
    Phytochemistry, 2006
    Co-Authors: Renate Spitaler, Irmgard Merfort, Daniel P Schlorhaufer, Ernst P Ellmerer, Sigmar Bortenschlager, Hermann Stuppner, Christian Zidorn
    Abstract:

    The altitudinal variation on the contents of secondary metabolites in flowering heads of Arnica Montana was assessed. Plants of A. Montana cultivar ARBO were grown in nine experimental plots at altitudes between 590 and 2230m at Mount Patscherkofel near Innsbruck/Austria. The total contents of sesquiterpene lactones and flavonoids were not positively correlated with the altitude of the growing site. However, the proportion of flavonoids with vicinal free hydroxy groups in ring B to flavonoids lacking this feature significantly increased with elevation. Additionally, the level of caffeic acid derivatives also positively correlated with the altitude of the growing site. In particular amounts of 1-methoxyoxaloyl-3,5-dicaffeoylquinic acid significantly increased in higher sites and samples from the summit region contained 85% more of this compound than samples from valley sites. These results are discussed with regards to chemosystematic studies comparing samples collected in different altitudes as well as in the light of a UV-B protective and radical scavenging function of phenolics and their significance for plant life in environments with elevated UV-B radiation.

Paolo Bellavite - One of the best experts on this subject based on the ideXlab platform.

  • Fibronectin Gene Up-regulation by Arnica Montana in Human Macrophages: Validation by Real-Time Polymerase Chain Reaction Assay.
    Homeopathy : the journal of the Faculty of Homeopathy, 2020
    Co-Authors: Marta Marzotto, Fabio Arruda-silva, Paolo Bellavite
    Abstract:

    Background and Aim Arnica Montana L. (Arnica m.) is a popular traditional medicine, used for its therapeutic properties in healing traumas, but little is known about its biological action on tissue formation and repair. This new work tested the effects of Arnica m. homeopathic dilutions on human macrophages, key cells in tissue defence and repair. Materials and Methods Macrophages derived from the THP-1 cell line were differentiated with interleukin-4 to induce a ‘wound-healing’-like phenotype, and treated with various dilutions of Arnica m. centesimal (100 times) dilutions (2c, 3c, 5c, 9c, and 15c) or control solvent for 24 hours. RNA samples from cultured cells were analysed by real-time quantitative polymerase chain reaction in five separate experiments. Results Arnica Montana at the 2c dilution (final concentration of sesquiterpene lactones in cell culture = 10−8 mol/L) significantly stimulated the expression of three genes which code for regulatory proteins of the extracellular matrix, namely FN1 (fibronectin 1, % increase of 21.8 ± standard error of the mean 4.6), low-density lipoprotein-receptor-related protein 1 (% increase of 33.4 ± 6.1) and heparan sulphate proteoglycan 2 (% increase of 21.6 ± 9.1). Among these genes, the most quantitatively expressed was FN1. In addition, FN1, unlike other candidate genes, was upregulated in cells treated with higher dilutions/dynamisations (3c, 5c, and 15c) of Arnica m. Conclusion The results support evidence that the extracellular matrix is a potential therapeutic target of Arnica m., with positive effects on cell adhesion and migration during tissue development and healing.

  • comments on the retraction by plos one of a laboratory study on Arnica Montana
    Homeopathy, 2019
    Co-Authors: Paolo Bellavite, Marta Marzotto
    Abstract:

    In June 2019, the journal PLoS ONE retracted an original research article, published in 2016, which described the effects of homeopathic Arnica Montana on interleukin-4 treated human macrophages. The results showed an increase in extracellular matrix gene expression, including the gene encoding fibronectin, which is one of the main proteins involved in connective tissue healing. Here, the authors of the article discuss the critical points raised by the journal in the retraction note, with a focus on the specific methodological aspects of research on high dilutions of natural compounds. The editorial arguments made to justify the retraction did not prove any methodological errors, nor scientific misconduct. As a general rule, when a study published by a group of researchers raises scientific doubts because the results appear at variation with the commonly accepted knowledge in a field, the study is repeated by other scholars and any contrasting results are published and/or discussed. Therefore, retraction of the Arnica m. study by PLoS ONE is a violation of the conventions of scientific publication and knowledge-sharing methods derived from honest experimental method.

  • Arnica Montana experimental studies: confounders and biases?
    Journal of integrative medicine, 2018
    Co-Authors: Paolo Bellavite, Marta Marzotto, Clara Bonafini
    Abstract:

    Arnica Montana is a popular traditional remedy widely used in complementary and alternative medicine, in part for its wound-healing properties. The authors recently showed that this plant extract and several of its homeopathic dilutions are able to modify the expression of a series of genes involved in inflammation and connective tissue regeneration. Their studies opened a debate, including criticisms to the "errors" in the methods used and the "confounders and biases". Here the authors show that the criticisms raised on methodology and statistics are not consistent and cannot be considered pertinent. The present comment also updates and reviews information concerning the action of A. Montana dilutions in human macrophage cells while summarizing the major experimental advances reported on this interesting medicinal plant.

  • Arnica Montana Stimulates Extracellular Matrix Gene Expression in a Macrophage Cell Line Differentiated to Wound-Healing Phenotype
    PloS one, 2016
    Co-Authors: Marta Marzotto, Clara Bonafini, Debora Olioso, Anna Baruzzi, Laura Bettinetti, Francesca Di Leva, Elisabetta Galbiati, Paolo Bellavite
    Abstract:

    Arnica Montana (Arnica m.) is used for its purported anti-inflammatory and tissue healing actions after trauma, bruises, or tissue injuries, but its cellular and molecular mechanisms are largely unknown. This work tested Arnica m. effects on gene expression using an in vitro model of macrophages polarized towards a "wound-healing" phenotype. The monocyte-macrophage human THP-1 cell line was cultured and differentiated with phorbol-myristate acetate and Interleukin-4, then exposed for 24h to Arnica m. centesimal (c) dilutions 2c, 3c, 5c, 9c, 15c or Control. Total RNA was isolated and cDNA libraries were sequenced with a NextSeq500 sequencer. Genes with significantly positive (up-regulated) or negative (down-regulated) fold changes were defined as differentially expressed genes (DEGs). A total of 20 DEGs were identified in Arnica m. 2c treated cells. Of these, 7 genes were up-regulated and 13 were down-regulated. The most significantly up-regulated function concerned 4 genes with a conserved site of epidermal growth factor-like region (p

  • Effectiveness and Safety of Arnica Montana in Post-Surgical Setting, Pain and Inflammation.
    American journal of therapeutics, 2016
    Co-Authors: Tommaso Iannitti, Paolo Bellavite, Julio Cesar Morales-medina, Valentina Rottigni, Beniamino Palmieri
    Abstract:

    Arnica Montana has been widely used as a homeopathic remedy for the treatment of several inflammatory conditions in pain management and postoperative settings. This review gives an overview of the therapeutic use of Arnica Montana in the above-mentioned fields also focusing on its mechanisms of action learned from animal models and in vitro studies. Arnica Montana is more effective than placebo when used for the treatment of several conditions including post-traumatic and postoperative pain, edema, and ecchymosis. However, its dosages and preparations used have produced substantial differences in the clinical outcome. Cumulative evidence suggests that Arnica Montana may represent a valid alternative to non-steroidal anti-inflammatory drugs, at least when treating some specific conditions.

Hermann Stuppner - One of the best experts on this subject based on the ideXlab platform.

  • quantitative analysis of flavonoids and phenolic acids in Arnica Montana l by micellar electrokinetic capillary chromatography
    Analytica Chimica Acta, 2008
    Co-Authors: Markus Ganzera, Christian Zidorn, Christoph Egger, Hermann Stuppner
    Abstract:

    Abstract Arnica Montana preparations have been used in Europe for centuries to treat skin disorders. Among the biologically active ingredients in the flower heads of the plant are sequiterpenes, flavonoids and phenolic acids. For the simultaneous determination of compounds belonging to the latter two groups a micellar electrokinetic capillary chromatography (MEKC) method was developed and validated. By using an electrolyte solution containing 50 mM borax, 25 mM sodium dodecyl sulfate and 30% of acetonitrile the separation of seven flavonoids and four caffeic acid derivatives was feasible in less than 20 min. The optimized system was validated for repeatability ( σ rel  ≤ 4.4%), precision (inter-day σ rel  ≤ 8.13%, intra-day σ rel  ≤ 4.32%), accuracy (recovery rates from 96.8 to 102.4%), sensitivity (limit of detection (LOD) ≤ 4.5 μg mL −1 ) and linearity ( R 2  ≥ 0.9996), and then successfully applied to assay several plant samples. In all of them the most dominant flavonoid was found to be quercetin 3- O -glucuronic acid, whereas 3,5-dicaffeoylquinic acid was the major phenolic acid; the total content of flavonoids and phenolic acids varied in the samples from 0.60 to 1.70%, and 1.03 to 2.24%, respectively.

  • altitudinal variation of secondary metabolite profiles in flowering heads of Arnica Montana cv arbo
    Phytochemistry, 2006
    Co-Authors: Renate Spitaler, Irmgard Merfort, Daniel P Schlorhaufer, Ernst P Ellmerer, Sigmar Bortenschlager, Hermann Stuppner, Christian Zidorn
    Abstract:

    The altitudinal variation on the contents of secondary metabolites in flowering heads of Arnica Montana was assessed. Plants of A. Montana cultivar ARBO were grown in nine experimental plots at altitudes between 590 and 2230m at Mount Patscherkofel near Innsbruck/Austria. The total contents of sesquiterpene lactones and flavonoids were not positively correlated with the altitude of the growing site. However, the proportion of flavonoids with vicinal free hydroxy groups in ring B to flavonoids lacking this feature significantly increased with elevation. Additionally, the level of caffeic acid derivatives also positively correlated with the altitude of the growing site. In particular amounts of 1-methoxyoxaloyl-3,5-dicaffeoylquinic acid significantly increased in higher sites and samples from the summit region contained 85% more of this compound than samples from valley sites. These results are discussed with regards to chemosystematic studies comparing samples collected in different altitudes as well as in the light of a UV-B protective and radical scavenging function of phenolics and their significance for plant life in environments with elevated UV-B radiation.

Marta Marzotto - One of the best experts on this subject based on the ideXlab platform.

  • Fibronectin Gene Up-regulation by Arnica Montana in Human Macrophages: Validation by Real-Time Polymerase Chain Reaction Assay.
    Homeopathy : the journal of the Faculty of Homeopathy, 2020
    Co-Authors: Marta Marzotto, Fabio Arruda-silva, Paolo Bellavite
    Abstract:

    Background and Aim Arnica Montana L. (Arnica m.) is a popular traditional medicine, used for its therapeutic properties in healing traumas, but little is known about its biological action on tissue formation and repair. This new work tested the effects of Arnica m. homeopathic dilutions on human macrophages, key cells in tissue defence and repair. Materials and Methods Macrophages derived from the THP-1 cell line were differentiated with interleukin-4 to induce a ‘wound-healing’-like phenotype, and treated with various dilutions of Arnica m. centesimal (100 times) dilutions (2c, 3c, 5c, 9c, and 15c) or control solvent for 24 hours. RNA samples from cultured cells were analysed by real-time quantitative polymerase chain reaction in five separate experiments. Results Arnica Montana at the 2c dilution (final concentration of sesquiterpene lactones in cell culture = 10−8 mol/L) significantly stimulated the expression of three genes which code for regulatory proteins of the extracellular matrix, namely FN1 (fibronectin 1, % increase of 21.8 ± standard error of the mean 4.6), low-density lipoprotein-receptor-related protein 1 (% increase of 33.4 ± 6.1) and heparan sulphate proteoglycan 2 (% increase of 21.6 ± 9.1). Among these genes, the most quantitatively expressed was FN1. In addition, FN1, unlike other candidate genes, was upregulated in cells treated with higher dilutions/dynamisations (3c, 5c, and 15c) of Arnica m. Conclusion The results support evidence that the extracellular matrix is a potential therapeutic target of Arnica m., with positive effects on cell adhesion and migration during tissue development and healing.

  • comments on the retraction by plos one of a laboratory study on Arnica Montana
    Homeopathy, 2019
    Co-Authors: Paolo Bellavite, Marta Marzotto
    Abstract:

    In June 2019, the journal PLoS ONE retracted an original research article, published in 2016, which described the effects of homeopathic Arnica Montana on interleukin-4 treated human macrophages. The results showed an increase in extracellular matrix gene expression, including the gene encoding fibronectin, which is one of the main proteins involved in connective tissue healing. Here, the authors of the article discuss the critical points raised by the journal in the retraction note, with a focus on the specific methodological aspects of research on high dilutions of natural compounds. The editorial arguments made to justify the retraction did not prove any methodological errors, nor scientific misconduct. As a general rule, when a study published by a group of researchers raises scientific doubts because the results appear at variation with the commonly accepted knowledge in a field, the study is repeated by other scholars and any contrasting results are published and/or discussed. Therefore, retraction of the Arnica m. study by PLoS ONE is a violation of the conventions of scientific publication and knowledge-sharing methods derived from honest experimental method.

  • Arnica Montana experimental studies: confounders and biases?
    Journal of integrative medicine, 2018
    Co-Authors: Paolo Bellavite, Marta Marzotto, Clara Bonafini
    Abstract:

    Arnica Montana is a popular traditional remedy widely used in complementary and alternative medicine, in part for its wound-healing properties. The authors recently showed that this plant extract and several of its homeopathic dilutions are able to modify the expression of a series of genes involved in inflammation and connective tissue regeneration. Their studies opened a debate, including criticisms to the "errors" in the methods used and the "confounders and biases". Here the authors show that the criticisms raised on methodology and statistics are not consistent and cannot be considered pertinent. The present comment also updates and reviews information concerning the action of A. Montana dilutions in human macrophage cells while summarizing the major experimental advances reported on this interesting medicinal plant.

  • Arnica Montana Stimulates Extracellular Matrix Gene Expression in a Macrophage Cell Line Differentiated to Wound-Healing Phenotype
    PloS one, 2016
    Co-Authors: Marta Marzotto, Clara Bonafini, Debora Olioso, Anna Baruzzi, Laura Bettinetti, Francesca Di Leva, Elisabetta Galbiati, Paolo Bellavite
    Abstract:

    Arnica Montana (Arnica m.) is used for its purported anti-inflammatory and tissue healing actions after trauma, bruises, or tissue injuries, but its cellular and molecular mechanisms are largely unknown. This work tested Arnica m. effects on gene expression using an in vitro model of macrophages polarized towards a "wound-healing" phenotype. The monocyte-macrophage human THP-1 cell line was cultured and differentiated with phorbol-myristate acetate and Interleukin-4, then exposed for 24h to Arnica m. centesimal (c) dilutions 2c, 3c, 5c, 9c, 15c or Control. Total RNA was isolated and cDNA libraries were sequenced with a NextSeq500 sequencer. Genes with significantly positive (up-regulated) or negative (down-regulated) fold changes were defined as differentially expressed genes (DEGs). A total of 20 DEGs were identified in Arnica m. 2c treated cells. Of these, 7 genes were up-regulated and 13 were down-regulated. The most significantly up-regulated function concerned 4 genes with a conserved site of epidermal growth factor-like region (p