Triterpenes and steroids in seeds of Solanum dulcamara

In seeds of Solanum dulcamara L. the 4,4-dimethylsterols cycloartenol, lanosterol, cycloartanol, 24-dihydrolanosterol, 24-methylenecycloartanol, and 24-methylenelanost-8-en-3beta-ol, the 4alpha-methylsterols 31-norcycloartenol, 31-norlanosterol, 31-norlanost-8-en-3beta-ol, lophenol, cycloeucalenol, obtusifoliol, gramisterol, and citrostadienol and the sterols cholesterol, 24-methylenecholesterol, campesterol, isofucosterol, sitosterol, and stigmasterol were identified by GC and GC/MS. The biosynthesis of these compounds is discussed. Additionally the spirostanoles tigogenin and diosgenin were isolated. The N-analoges spirosolanoles soladulcidine and solasodine were identified by TLC. The seeds contain 28% oil, of which the fatty acid composition has been examined. The predominant fatty acids are linolic acid (18:2) and oleic acid (18:1).     

Bioavailability and Biokinetics of Anthocyanins From Red Grape Juice and Red Wine

In a comparative study, 9 healthy volunteersingested a single oral dose of 400mL red grape juice or redwine with dose-adjusted anthocyanin content(283.5mg or 279.6mg, resp) incrossover. The content of anthocyanin glucosides was detected inplasma and urinary excretion. Additionally, the plasmaticantioxidant activity was assessed after intake. Based on theplasma content, biokinetic criteria of the single anthocyaninswere calculated, such as AUC, c_max, t_max, and theelimination rate t_1/2. The urinary excretion of totalanthocyanins differed significantly and amounted to0.18% (red wine) and 0.23% (red grapejuice) of the administered dose. Additionally, the plasmaticantioxidant activity increased to higher levels after juiceingestion compared to wine. The intestinal absorption of theanthocyanins of red grape juice seemed to be improved compared tored wine, suggesting a possible synergistic effect of the glucosecontent of the juice. The improved absorption resulted in anenhanced plasmatic bioactivity.     

Bihemispheric reduction of GABAA receptor binding following focal cortical photothrombotic lesions in the rat brain

Focal brain lesions may lead to neuronal dysfunctions in remote (exofocal) brain regions. In the present study, focal lesions were induced in the hindlimb representation area of the parietal cerebral cortex in rats using the technique of photothrombosis. Photothrombosis occurs after illumination of the brain through the intact skull following intravenous injection of the photosensitive dye Rose Bengal. This resulted in cortical lesions with a diameter of about 2 mm. Quantitative receptor autoradiography was used to study alterations in the density of []muscimol binding sites to GABA_A receptors seven days after lesion induction. A reduced GABA_A receptor binding (−13 to −27% of the control value) was found in layers II and III of remote exofocal regions in the ipsi- and contralateral cortex. The reduction was consistently more intense in the ipsilateral cortical areas than in those of the contralateral hemisphere. Using extracellular recordings, significant correlations between GABA_A receptor binding and paired pulse inhibition could be demonstrated. The present investigation demonstrates that focal brain lesions cause a widespread, functionally effective down-regulation of GABA_A receptors. These postlesional changes may result from lesion-induced alterations in cortical connectivity.     

Flavonoid Glycosides and Other Hydrophilic Compounds from Flowers of Heterotheca inuloides

Ten flavonoid glycosides were identified in flowers of HETEROTHECA INULOIDES ("Mexican Arnica"). Their structures were established by spectral data (UV, (1)H-NMR, (13)C-NMR, mass) and total acid hydrolysis as kaempferol 3-beta-glucoside, 3-beta-galactoside, 3-beta-rutinoside, 3-beta-robinobioside, quercetin 3-beta-glucoside, 3-beta-galactoside, 3-beta-glucuronide, 3-beta-glucuronide-6'-methylester, 3-alpha- L-arabinoside, and 3-beta-rutinoside. Additionally, caffeic, protocatechuic, and chlorogenic acid as well as umbelliferone were found.     

Aminochrome Induces Disruption of Actin, Alpha-, and Beta-Tubulin Cytoskeleton Networks in Substantia-Nigra-Derived Cell Line

In previous studies, we observed that cells treated with aminochrome obtained by oxidizing dopamine with oxidizing agents dramatically changed cell morphology, thus posing the question if such morphological changes were dependent on aminochrome or the oxidizing agents used to produce aminochrome. Therefore, to answer this question, we have now purified aminochrome on a CM-Sepharose 50–100 column and, using NMR studies, we have confirmed that the resulting aminochrome was pure and that it retained its structure. Fluorescence microscopy with calcein-AM and transmission electron microscopy showed that RCSN-3 cells presented an elongated shape that did not change when the cells were incubated with 50 μM aminochrome or 100 μM dicoumarol, an inhibitor of DT-diaphorase. However, the cell were reduced in size and the elongated shape become spherical when the cells where incubated with 50 μM aminochrome in the presence of 100 μM dicoumarol. Under these conditions, actin, alpha-, and beta-tubulin cytoskeleton filament networks became condensed around the cell membrane. Actin aggregates were also observed in cells processes that connected the cells in culture. These results suggest that aminochrome one-electron metabolism induces the disruption of the normal morphology of actin, alpha-, and beta-tubulin in the cytoskeleton, and that DT-diaphorase prevents these effects.     

One-Electron Reduction of 6-Hydroxydopamine Quinone is Essential in 6-Hydroxydopamine Neurotoxicity

6-Hydroxydamine has widely been used as neurotoxin in preclinical studies related on the neurodegenerative process of dopaminergic neurons in Parkinson’s disease based on its ability to be neurotoxic as a consequence of free radical formation during its auto-oxidation to topaminequinone. We report that 50-µM 6-hydroxydopamine is not neurotoxic in RCSN-3 cells derived from substantia nigra incubated during 24 h contrasting with a significant sixfold increase in cell death (16 ± 2 %; P < 0.001) was observed in RCSN-3NQ7 cells expressing a siRNA against DT-diaphorase that silence the enzyme expression. To observe a significant cell death in RCSN-3 cells induced by 6-hydroxydopamine (24 ± 1 %; P < 0.01), we have to increase the concentration to 250 μm while a 45 ± 2 % cell death (P < 0.001) was observed at this concentration in RCSN-3NQ7 cells. The cell death induced by 6-hydroxydopamine in RCSN-3NQ7 cells was accompanied with a (i) significant increase in oxygen consumption (P < 0.01), (ii) depletion of reduced glutathione and (iii) a significant decrease in ATP level (P < 0.05) in comparison with RCSN-3 cells. In conclusion, our results suggest that one-electron reduction of 6-hydroxydopamine quinone seems to be the main reaction responsible for 6-hydroxydopamine neurotoxic effects in dopaminergic neurons and DT-diaphorase seems to play an important neuroprotective role by preventing one-electron reduction of topaminequinone.     

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