Veronika Butterweck

Prof. Dr.
Fachhochschule Nordwestschweiz · Institute for Pharma Technology (IPT)
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Topics (9) View all

Skills (2)

Publications (82) View all

  • Article: Anxiolytic effects of fractions obtained from Passiflora incarnata L. in the elevated plus maze in mice.
    C Sampath, M Holbik, L Krenn, V Butterweck
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    ABSTRACT: The purpose of this study was to characterize the putative anxiolytic-like activity of fractions prepared from a hydroethanol extract of Passiflora incarnata L. using the elevated plus-maze (EPM) in mice. The fractions were prepared as published recently, yielding a butanol, petroleum ether and chloroform fraction. From the tested fractions, the butanol fraction showed significant increases in the number of open arm entries in the EPM in concentrations of 2.1 mg/kg and 4.2 mg/kg corresponding to 150 and 300 mg/kg of the original extract. The highest activity was found for the chloroform fraction in doses of 0.17 mg/kg (10.0 ± 1.9, p < 0.001) and 0.34 mg/kg (6.6 ± 0.86; p < 0.05) which corresponds to a total extract dose of 150 and 300 mg/kg, respectively. Interestingly, the petroleum ether fraction did not show any effects in the elevated plus maze. A sedative or stimulatory effect of each of the fractions could be excluded, since none of the compounds had an influence on the total distance that the animals covered during the observation period. The results suggest that the active principle of passion flower seems to be in the chloroform fraction and to a lower extent in the butanol fraction.
    Phytotherapy Research 11/2010; 25(6):789-95. · 2.09 Impact Factor
  • Article: An aqueous extract of Ammi visnaga fruits and its constituents khellin and visnagin prevent cell damage caused by oxalate in renal epithelial cells.
    P Vanachayangkul, K Byer, S Khan, V Butterweck
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    ABSTRACT: Teas prepared from the fruits of Ammi visnaga L. (syn. "Khella") have been traditionally used in Egypt as a remedy to treat kidney stones. It was the aim of our study to evaluate the effect of a Khella extract (KE) as well as the two major constituents khellin and visnagin on renal epithelial injury using LLC-PK1 and Madin-Darby-canine kidney (MDCK) cells. Both cell lines provide suitable model systems to study cellular processes that are possibly involved in the development of a renal stone. LLC-PK1 and MDCK cell lines were exposed to 300 microM oxalate (Ox) or 133 microg/cm(2) calcium oxalate monohydrate (COM) in presence or absence of 10, 50, 100 or 200 microg/mL KE. To evaluate cell damage, cell viability was assessed by determining the release of lactate dehydrogenase (LDH). KE (e.g. 100 microg/ml) significantly decreased LDH release from LLC-PK1 (Ox: 8.46+0.76%; Ox + 100 microg/ml KE: 5.41+0.94%, p<0.001) as well as MDCK cells (Ox: 30.9+6.58%; Ox+100 microg/ml KE: 17.5+2.50%, p<0.001), which indicated a prevention of cell damage. Similar effects for KE were observed in both cell lines when COM crystals were added. In LLC-PK1 cells khellin and visnagin both decreased the % LDH release significantly in cells that were pretreated with Ox or COM crystals. However, khellin and visnagin exhibited different responses in MDCK cells. Whereas khellin slightly reduced the % LDH release after exposure of the cells to Ox and COM crystals, visnagin significantly decreased % LDH release only after COM crystal exposure. Overall both compounds were more active in LLC-PK1 than in MDCK cells. In summary, exposure of renal epithelial cells to Ox or COM crystals was associated with a significant release of LDH indicating cell injury. Our data demonstrate that KE as well as khellin and visnagin could prevent renal epithelial cell damage caused by Ox and COM and could therefore play a potential role in the prevention of stone formation associated with hyperoxaluria.
    Phytomedicine: international journal of phytotherapy and phytopharmacology 07/2010; 17(8-9):653-8. · 2.17 Impact Factor
  • Article: Anxiolytic effects of a passion flower (Passiflora incarnata L.) extract in the elevated plus maze in mice.
    O Grundmann, C Wähling, C Staiger, V Butterweck
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    ABSTRACT: The purpose of this study was to characterize the putative anxiolytic-like activity of an ethanolic extract prepared from passion flower (PF) (Passiflora incarnata L.) using the elevated plus maze (EPM) in mice. The mice were either treated orally with three different concentrations of the PF extract or the positive control diazepam. The number of entries in the open arms was significantly increased after administration of diazepam compared to the control. PF extract showed a significant increase in number of open arm entries at a concentration of 375 mg/kg, whereas no activity was observed in 150 and 600 mg/kg, respectively, indicating an U-shaped dose response curve. In conclusion, using the EPM we were able to detect putative anxiolytic effects of a Passiflora incarnata extract in mice.
    Pharmazie 02/2009; 64(1):63-4. · 1.01 Impact Factor
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    Article: Grapefruit-drug interactions: can interactions with drugs be avoided?
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    ABSTRACT: Grapefruit is rich in flavonoids, which have been demonstrated to have a preventive influence on many chronic diseases, such as cancer and cardiovascular disease. However, since the early 1990s, the potential health benefits of grapefruit have been overshadowed by the possible risk of interactions between drugs and grapefruit and grapefruit juice. Several drugs interacting with grapefruit are known in different drug classes, such as HMG-CoA reductase inhibitors, calcium antagonists, and immunosuppressives. Currently known mechanisms of interaction include the inhibition of cytochrome P450 as a major mechanism, but potential interactions with P-glycoprotein and organic anion transporters have also been reported. This review is designed to provide a comprehensive summary of underlying mechanisms of interaction and human clinical trials performed in the area of grapefruit drug interactions and to point out possible replacements for drugs with a high potential for interactions.
    The Journal of Clinical Pharmacology 01/2007; 46(12):1390-416. · 2.91 Impact Factor
  • Source
    Chapter: Drug Interactions of Grapefruit and other Citrus. What have we Learned?
    01/2006: pages 147-178; , ISBN: 978-0-8247-2538-9

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