114 research outputs found

    The Herbal Drug Melampyrum pratense

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    Melampyrum pratense L. (Koch) is used in traditional Austrian medicine for the treatment of different inflammation-related conditions. In this work, we show that the extracts of M. pratense stimulated peroxisome proliferator-activated receptors- (PPARs-)α and -γ that are well recognized for their anti-inflammatory activities. Furthermore, the extract inhibited the activation of the proinflammatory transcription factor NF-κB and induction of its target genes interleukin-8 (IL-8) and E-selectin in vitro. Bioassay-guided fractionation identified several active flavonoids and iridoids including melampyroside and mussaenoside and the phenolic compound lunularin that were identified in this species for the first time. The flavonoids apigenin and luteolin were distinguished as the main components accountable for the anti-inflammatory properties. Apigenin and luteolin effectively inhibited tumor necrosis factor α (TNF-α)-induced NF-κB-mediated transactivation of a luciferase reporter gene. Furthermore, the two compounds dose-dependently reduced IL-8 and E-selectin protein expression after stimulation with lipopolysaccharide (LPS) or TNF-α in endothelial cells (ECs). The iridoids melampyroside and mussaenoside prevented the elevation of E-selectin in LPS-stimulated ECs. Lunularin was found to reduce the protein levels of the proinflammatory mediators E-selectin and IL-8 in ECs in response to LPS. These data validate the ethnomedical use of M. pratense for the treatment of inflammatory conditions and point to the constituents accountable for its anti-inflammatory activity

    Cytotoxic Constituents from Lobaria scrobiculata and a Comparison of Two Bioassays for Their Evaluation

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    Lichens are resilient organisms, known for their unique profiles of secondary metabolites and for exhibiting antioxidative, antibacterial, and cytotoxic effects. Analyzing the cytotoxic potential of Lobaria scrobiculata, a bioassay-guided fractionation strategy yielded seven known metabolites, with two of these compounds, 2 and 3, exhibiting cytotoxicity against HL-60 cells. In order to verify the potential impact of degradation on observed bioactivity, a purity and stability evaluation was conducted. The consistency of results obtained by the water-soluble tetrazolium salt-1 assay and trypan blue cytotoxicity assay was evaluated for selected compounds

    Handling Metadata in a Neurophysiology Laboratory

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    To date, non-reproducibility of neurophysiological research is a matter of intense discussion in the scientific community. A crucial component to enhance reproducibility is to comprehensively collect and store metadata, that is, all information about the experiment, the data, and the applied preprocessing steps on the data, such that they can be accessed and shared in a consistent and simple manner. However, the complexity of experiments, the highly specialized analysis workflows and a lack of knowledge on how to make use of supporting software tools often overburden researchers to perform such a detailed documentation. For this reason, the collected metadata are often incomplete, incomprehensible for outsiders or ambiguous. Based on our research experience in dealing with diverse datasets, we here provide conceptual and technical guidance to overcome the challenges associated with the collection, organization, and storage of metadata in a neurophysiology laboratory. Through the concrete example of managing the metadata of a complex experiment that yields multi-channel recordings from monkeys performing a behavioral motor task, we practically demonstrate the implementation of these approaches and solutions with the intention that they may be generalized to other projects. Moreover, we detail five use cases that demonstrate the resulting benefits of constructing a well-organized metadata collection when processing or analyzing the recorded data, in particular when these are shared between laboratories in a modern scientific collaboration. Finally, we suggest an adaptable workflow to accumulate, structure and store metadata from different sources using, by way of example, the odML metadata framework

    Plant extracts in cell-based anti-inflammatory assays—Pitfalls and considerations related to removal of activity masking bulk components

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    Plants used in traditional medicine represent an important source of new lead compounds. However, cell-based in vitro screening assays with plant material are hampered by the complex nature of plant extracts as mixtures of active and inactive components. Bulk constituents, such as chlorophyll and polyphenols were previously shown to interfere with several biological in vitro assays. Their influence on anti-inflammatory cell-based testing systems has not been thoroughly investigated. Hence, the present study was aimed at comparing different procedures for the removal of bulk constituents from plant extracts and examining the influence of their elimination on selected cell-based anti-inflammatory assays. Malva sp. and Glechoma hederacea L., two plants used in traditional European medicine for the treatment of inflammatory disorders, were subjected to three different methods for the removal of chlorophyll and polyphenols, respectively. Removal of bulk constituents was confirmed by HPLC and mass spectrometry. Extracts were tested before and after the purification procedure, to determine their potential to inhibit the activation of the transcription factor NF-κB in reporter gene assay and to interfere with the secretion of the chemokine IL-8 after stimulation of endothelial cells with tumor necrosis factor (TNF-α) or lipopolysaccharide (LPS). Removal of chlorophyll from tested extracts led to a strong decrease in the anti-inflammatory activities, due to loss of bioactive constituents. In contrast, the effect of the polyphenol-free extracts was either not changed or significantly increased, depending on the purification method used. The study concluded that clearance of bulk compounds represents a valuable strategy for cell-based in vitro anti-inflammatory evaluation of plant extracts. Liquid–liquid partitioning was identified as the optimal method for the elimination of both chlorophyll and polyphenols. It is recommended that removal of chlorophyll from extracts always be accompanied by HPLC profiling to detect a possible loss of active constituents

    The novel atypical dopamine uptake inhibitor (S)-CE-123 partially reverses the effort-related effects of the dopamine depleting agent tetrabenazine and increases progressive ratio responding

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    Animal studies of effort-based choice behavior are being used to model effort-related motivational dysfunctions in humans. With these procedures, animals are offered a choice between high-effort instrumental actions leading to highly valued reinforcers vs. low effort/low reward options. Several previous studies have shown that dopamine (DA) uptake inhibitors, including GBR12909, lisdexamfetamine, methylphenidate, and PRX-14040, can reverse the effort-related effects of the vesicular monoamine transport blocker tetrabenazine, which inhibits DA storage. Because many drugs that block DA transport act as major stimulants that also release DA, and produce a number of undesirable side effects, there is a need to develop and characterize novel atypical DA transport inhibitors. (S)-CE-123 ((S)-5-((benzhydrylsulfinyl) methyl) thiazole) is a recently developed analog of modafinil with the biochemical characteristics of an atypical DA transport blocker. The present paper describes the enantioselective synthesis and initial chemical characterization of (S)-CE-123, as well as behavioral experiments involving effort-based choice and microdialysis studies of extracellular DA. Rats were assessed using the fixed ratio 5/chow feeding choice test. Tetrabenazine (1.0 mg/kg) shifted choice behavior, decreasing lever pressing and increasing chow intake. (S)-CE-123 was coadministered at doses ranging from 6.0 to 24.0 mg/kg, and the highest dose partially but significantly reversed the effects of tetrabenazine, although this dose had no effect on fixed ratio responding when administered alone. Additional experiments showed that (S)-CE-123 significantly increased lever pressing on a progressive ratio/chow feeding choice task and that the effective dose (24.0 mg/kg) increased extracellular DA in nucleus accumbens core. In summary, (S)-CE-123 has the behavioral and neurochemical profile of a compound that can block DA transport, reverse the effort-related effects of tetrabenazine, and increase selection of high-effort progressive ratio responding. This suggests that (S)-CE-123 or a similar compound could be useful as a treatment for effort-related motivational dysfunction in humans
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