Daily Caffeine Intake Induces Concentration-Dependent Medial Temporal Plasticity in Humans: A Multimodal Double-Blind Randomized Controlled Trial

Caffeine is commonly used to combat high sleep pressure on a daily basis. However, interference with sleep-wake regulation could disturb neural homeostasis and insufficient sleep could lead to alterations in human gray matter. Hence, in this double-blind, randomized, cross-over study, we examined the impact of 10-day caffeine (3 × 150 mg/day) on human gray matter volumes (GMVs) and cerebral blood flow (CBF) by fMRI MP-RAGE and arterial spin-labeling sequences in 20 habitual caffeine consumers, compared with 10-day placebo (3 × 150 mg/day). Sleep pressure was quantified by electroencephalographic slow-wave activity (SWA) in the previous nighttime sleep. Nonparametric voxel-based analyses revealed a significant reduction in GMV in the medial temporal lobe (mTL) after 10 days of caffeine intake compared with 10 days of placebo, voxel-wisely adjusted for CBF considering the decreased perfusion after caffeine intake compared with placebo. Larger GMV reductions were associated with higher individual concentrations of caffeine and paraxanthine. Sleep SWA was, however, neither different between conditions nor associated with caffeine-induced GMV reductions. Therefore, the data do not suggest a link between sleep depth during daily caffeine intake and changes in brain morphology. In conclusion, daily caffeine intake might induce neural plasticity in the mTL depending on individual metabolic processes

Daily Caffeine Intake Induces Concentration-Dependent Medial Temporal Plasticity in Humans: A Multimodal Double-Blind Randomized Controlled Trial

Caffeine is commonly used to combat high sleep pressure on a daily basis. However, interference with sleep–wake regulation could disturb neural homeostasis and insufficient sleep could lead to alterations in human gray matter. Hence, in this double-blind, randomized, cross-over study, we examined the impact of 10-day caffeine (3 × 150 mg/day) on human gray matter volumes (GMVs) and cerebral blood flow (CBF) by fMRI MP-RAGE and arterial spin-labeling sequences in 20 habitual caffeine consumers, compared with 10-day placebo (3 × 150 mg/day). Sleep pressure was quantified by electroencephalographic slow-wave activity (SWA) in the previous nighttime sleep. Nonparametric voxel-based analyses revealed a significant reduction in GMV in the medial temporal lobe (mTL) after 10 days of caffeine intake compared with 10 days of placebo, voxel-wisely adjusted for CBF considering the decreased perfusion after caffeine intake compared with placebo. Larger GMV reductions were associated with higher individual concentrations of caffeine and paraxanthine. Sleep SWA was, however, neither different between conditions nor associated with caffeine-induced GMV reductions. Therefore, the data do not suggest a link between sleep depth during daily caffeine intake and changes in brain morphology. In conclusion, daily caffeine intake might induce neural plasticity in the mTL depending on individual metabolic processes

Evaluation of individual metabolic parameters by the analysis of finger sweat samples using liquid chromatography-mass spectrometry

Im Rahmen dieser Masterarbeit wurde untersucht, ob individuelle metabolische Parameter durch Extraktion und Analyse von Xenobiotika und deren Metaboliten aus Fingerschweiß und Blut gewonnen werden können. Die Xenobiotika, auf die sich diese Masterarbeit konzentrierte, stammen aus Kaffee und Schokolade und waren hauptsächlich Methylxanthine (Koffein, Theobromin und Theophyllin) und Flavan-3-ole (Epicatechin und Catechin). Beide bioaktiven Gruppen stehen in Zusammenhang mit gesundheitlichen Effekten und sind zu Biomarkern für Lebensmittel geworden. Daher könnte eine genauere Charakterisierung ihrer Absorption und ihres Metabolismus zu einem besseren Verständnis ihrer gesundheitsfördernden Eigenschaften in Bezug auf Krankheitsprävention und andere Gesundheitsfaktoren führen. Zu diesem Zweck wurden elf gesunde Spender gebeten, Kaffee und Schokolade zu konsumieren, und die Analytkonzentrationen der Xenobiotika und ihrer Metaboliten wurden vor und nach dem Kaffee- / Schokoladenkonsum sowohl in Fingerschweiß- als auch in Blutproben gemessen. Die Ergebnisse zeigen eine signifikante und reproduzierbare Zunahme der Xenobiotika in den Fingerscheißproben bei allen Freiwilligen, wenn der Metabolitspiegel vor der Kaffee- /Schockoladeaufnahme mit den Metabolitkonzentration von 15 Minuten nach Verzehr verglichen wurde. Die Methode der Wahl war ein untargeted Screening-Verfahren, bei dem ein Umkehrphasen-UHPLC-System mit der Q Exactive HF (Thermo Fisher ScientificTM) verwendet wurde, das ein Hybridinstrument mit einem Quadrupol als Massenfilter und einer Orbitrap als Massenanalysator ist. Verbindungen wurden identifiziert mit Hilfe der Compound Discoverer Software (Thermo Fisher ScientificTM), manuell überprüft durch Abgleich der aufgenommenen Spektren mit einer online Datenbank und mittels analytischer Standards verifiziert. Ein Probenvorbereitungsverfahren von etwa 5 Minuten für jede Fingerschweißprobe und einer Gesamtlaufzeit des UPHLC-MS-Systems von 7,5 Minuten pro Probe ermöglichten einen hohen Probendurchsatz. Diese Studie zeigt Unterschiede in der Menge an absorbierten Metaboliten, sowie individuelle Geschwindigkeiten in der metabolischen Aktivität, Unterschiede zwischen den linken und rechten Fingerschweißproben und unterschiedliche Kinetiken von Blut und Schweiß. Darüber hinaus konnten nicht alle im Schweiß vorkommenden Verbindungen im Blut nachgewiesen werden, möglicherweise aufgrund von hohen Proteinbindungsaffinitäten dieser Xenobiotika /Metaboliten. Daher ist diese Studie ein Beweis dafür, dass individuelle Stoffwechselparameter aus dem sezernierten Schweiß der Finger gewonnen werden können.The aim of this master thesis was to study individual metabolic parameters via extracting and analysing xenobiotics and their metabolites from finger sweat and whole blood samples. The xenobiotics this master thesis focused on were emerging from coffee and chocolate and were mainly methylxanthines (caffeine, theobromine, and theophylline) and flavan-3-ols (epicatechin and catechin). Both of these bioactive groups are associated with health effects and have become food biomarkers. Thus, a more detailed characterization of their absorption and metabolism could lead to a better understanding of their beneficial properties regarding disease prevention and other health factors. For this purpose, eleven healthy donors were asked to consume coffee and chocolate and analyte levels of the xenobiotics and their metabolites were monitored before and after coffee/chocolate consumption in fingerprint as well as in blood samples. The results show a significant and reproducible increase of the xenobiotics in fingerprints in all donors when comparing the xenobiotics and metabolite levels before coffee and chocolate intake with the levels 15 min thereafter. The method of choice was an untargeted screening method, using a reversed-phase UHPLC system coupled to the Q Exactive HF (Thermo Fisher ScientificTM) which is a hybrid instrument with a quadrupole as a mass filter and an orbitrap as a mass analyzer. Compounds were identified by loading the raw data into the Compound Discoverer Software (Thermo Fisher ScientificTM) and checked manually by comparing the measured spectra to an online database. A sample preparation procedure of about 5 minutes for each fingerprint sample and a total run time of the UPHLC-MS of 7.5 min per sample allowed high sample throughput. This study revealed differences in the amount of absorbed metabolites, as well as different speeds in metabolic activity, differences between the left- and right-hand fingerprint samples and distinct kinetics of blood and sweat. Furthermore, not all compounds found in sweat could also be detected in blood possibly due to high protein binding affinities of these xenobiotics/ metabolites. Therefore, this study is a proof-of-principle that individual metabolic parameters can be drawn from secreted sweat of the fingers

Yellow Twig (<i>Nauclea</i> <i>orientalis</i>) from Thailand: Strictosamide as the Key Alkaloid of This Plant Species

Comprehensive phytochemical examination from different perspectives using preparative and analytical chromatographic techniques combined with spectroscopic/spectrometric methods of the so-called “yellow twig” Nauclea orientalis (L.) L. (Rubiaceae) led to the identification of 13 tryptamine-derived (=monoterpene-indole) alkaloids. The identified alkaloids comprise strictosamide and four of its glucosidic derivatives, three oxindole derivatives, and five yellow-colored angustine-type aglycones. Qualitative and quantitative HPLC analyses showed the enrichment of strictosamide in all studied organs. Based on these results, we performed metabolomic analyses of monoterpene-indole alkaloids and made a 1H NMR in vitro monitoring of enzymatic deglucosylation of strictosamide. A comparison of the stability of strictosamide and its enantiomer vincoside lactam by theoretical calculations was also performed revealing a slightly higher stability of vincoside lactam. Additionally, we conducted two different anti-feedant assays of strictosamide using larvae of the polyphageous moth Spodoptera littoralis Boisduval. The obtained results indicate that generally two different biosynthetic pathways are most likely responsible for the overall alkaloid composition in this plant. Strictosamide is the key compound in the broader pathway and most likely the source of the identified angustine-type aglycones, which may contribute significantly to the yellow color of the wood. Its cross-organ accumulation makes it likely that strictosamide is not only important as a reservoir for the further biosynthesis, but also acts in the plants’ defense strategy

Epithelial Cell Line Derived from Endometriotic Lesion Mimics Macrophage Nervous Mechanism of Pain Generation on Proteome and Metabolome Levels

Endometriosis is a benign disease affecting one in ten women of reproductive age worldwide. Although the pain level is not correlated to the extent of the disease, it is still one of the cardinal symptoms strongly affecting the patients’ quality of life. Yet, a molecular mechanism of this pathology, including the formation of pain, remains to be defined. Recent studies have indicated a close interaction between newly generated nerve cells and macrophages, leading to neurogenic inflammation in the pelvic area. In this context, the responsiveness of an endometriotic cell culture model was characterized upon inflammatory stimulation by employing a multi-omics approach, including proteomics, metabolomics and eicosanoid analysis. Differential proteomic profiling of the 12-Z endometriotic cell line treated with TNFα and IL1β unexpectedly showed that the inflammatory stimulation was able to induce a protein signature associated with neuroangiogenesis, specifically including neuropilins (NRP1/2). Untargeted metabolomic profiling in the same setup further revealed that the endometriotic cells were capable of the autonomous production of 7,8-dihydrobiopterin (BH2), 7,8-dihydroneopterin, normetanephrine and epinephrine. These metabolites are related to the development of neuropathic pain and the former three were found up-regulated upon inflammatory stimulation. Additionally, 12-Z cells were found to secrete the mono-oxygenated oxylipin 16-HETE, a known inhibitor of neutrophil aggregation and adhesion. Thus, inflammatory stimulation of endometriotic 12-Z cells led to specific protein and metabolite expression changes suggesting a direct involvement of these epithelial-like cells in endometriosis pain development