Melanie Esselen

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Supercritical fluid reactive deposition was used for the deposition of highly dispersed platinum nanoparticles with controllable metal content and particle size distribution on beta-cyclodextrin. The average particle size and size distribution were steered by the precursor reduction conditions, resulting in particle preparations <20, <100, and >100 nm as(More)
The use of nanostructured silica (SiO2) particles is no longer restricted to biomedical and (bio-) technological fields but rather finding applications in products of the food industry. Thus, our studies on the toxicological relevance of SiO2 nanoparticles focused on cytotoxic effects, the modulation of the cellular redox status and the impact on DNA(More)
Methyleugenol is a substituted alkenylbenzene classified by the European Union's Scientific Committee on Food as a genotoxic carcinogen. We addressed cytotoxicity, genotoxicity and mutagenicity caused by methyleugenol and selected oxidative methyleugenol metabolites in Chinese hamster lung fibroblasts V79 cells. Cytotoxicity was measured by two cell(More)
SCOPE The effect of two anthocyanin-rich berry extracts (A, bilberry; B, red grape) on topoisomerases was investigated in a cell-free system and in human HT29 colon carcinoma cells. In parallel, their impact on DNA integrity was determined. METHODS AND RESULTS The berry extracts suppressed the activity of topoisomerase I at concentrations ≥50 μg/mL. The(More)
In the present study, delphinidin was found to suppress the phosphorylation of the epidermal growth factor receptor (EGFR) within human tumour cells (human colon carcinoma cell line (HT29), human vulva carcinoma cell line (A431)), albeit less effective than the flavonol quercetin. The higher potency of quercetin was also observed downstream on the level of(More)
The anthocyanidin delphinidin (DEL) has recently been shown to inhibit human topoisomerase I and II, without stabilizing the covalent DNA/topoisomerase intermediate [Habermeyer, M., Fritz, J., Barthelmes, H. U., Christensen, M. O., Larsen, M. K., Boege, F., and Marko, D. (2005) Anthocyanidins modulate the activity of human DNA topoisomerases I and II and(More)
Evidence has been provided that diet and environmental factors directly influence epigenetic mechanisms associated with cancer development in humans. The inhibition of histone deacetylase (HDAC) activity and the disruption of the HDAC complex have been recognized as a potent strategy for cancer therapy and chemoprevention. In the present study, we(More)
Having chosen the utilization of a Teflon prosthesis, interposed in preperitoneal position by medial incision, in a series of 58 patients presenting 94 hernias, the authors wish to express a preference to this method for reoccurring and bilateral hernias. They underline the simplicity of the technique, its reduced morbidity, and they focus on the(More)
The ellagitannins castalagin and vescalagin, and the C-glycosides grandinin and roburin E as well as ellagic acid were found to potently inhibit the growth of human colon carcinoma cells (HT29) in vitro. In a cell-free system these compounds were identified as potent inhibitors of the protein tyrosine kinase activity of the epidermal growth factor receptor(More)
Irinotecan is an anticancer agent that stabilizes topoisomerase I/DNA complexes. So far, no test system has been reported for directly determining irinotecan-induced stabilization of topoisomerase I/DNA complexes in organs in vivo. We adapted an 'in vivo complexes of enzyme to DNA' (ICE) bioassay to assess irinotecan activity in the stomach, duodenum, colon(More)