Meinke M.C.,Charite - Medical University of Berlin |
Darvin M.E.,Charite - Medical University of Berlin |
Vollert H.,BioActive Food GmbH |
Lademann J.,Charite - Medical University of Berlin
European Journal of Pharmaceutics and Biopharmaceutics | Year: 2010
Skin functions and structure are significantly influenced by nutrients. Antioxidants protect the supportive layer of the skin against any damaging irradiation effects and the action of free radicals. A lack of suitable methods means that the pharmacokinetic properties of systemically applied carotenoids transferred into the skin remain poorly understood. In this study, a natural kale extract or placebo oil were given orally to 22 healthy volunteers for 4 weeks. Carotenoid bioaccessibility was evaluated using non-invasive resonance Raman spectroscopy on the palm and forehead skin. For the analysis of the blood serum, the standard HPLC method was used. The blood and skin levels of the carotenoids increased significantly during the study but compared to the blood serum values, increases in skin were delayed and depended on the dermal area as well as on the carotenoid. Lycopene, measured as being low in the extract, increases more in the skin compared to the blood indicating that the natural mixture of the extract stabilizes the antioxidative network in the skin. After supplementation had ended, the carotenoids decreased much faster in the blood than in the skin. The delayed decrease in the skin may indicate a peripheral buffer function of the skin for carotenoids. © 2010 Elsevier B.V.
Meinke M.C.,Charite - Medical University of Berlin |
Friedrich A.,Charite - Medical University of Berlin |
Tscherch K.,University of Hamburg |
Haag S.F.,Charite - Medical University of Berlin |
And 5 more authors.
European Journal of Pharmaceutics and Biopharmaceutics | Year: 2013
Nutrition rich in carotenoids is well known to prevent cell damage, premature skin aging, and skin cancer. Cutaneous carotenoids can be enriched in the skin by nutrition and topically applied antioxidants have shown an increase in radical protection after VIS/NIR irradiation. In this paper, it was investigated whether orally administered carotenoids increase the radical scavenging activity and the radical protection of the skin using in vivo electron paramagnetic resonance spectroscopy and the skin lipid profile was investigated applying HPTLC on skin lipid extracts. Furthermore, in vivo Raman resonance spectroscopy was used to measure the cutaneous carotenoid concentration. A double blind placebo controlled clinical study was performed with 24 healthy volunteers, who have shown a slow but significant and effective increase in cutaneous carotenoids in the verum group. The enhancement in carotenoids increases the radical scavenging activity of the skin and provides a significant protection against stress induced radical formation. Furthermore, the skin lipids in the verum group increased compared to the placebo group but only significantly for ceramide [NS]. These results indicate that a supplementation with dietary products containing carotenoids in physiological concentrations can protect the skin against reactive oxygen species and could avoid premature skin aging and other radical associated skin diseases. © 2013 Elsevier B.V. All rights reserved.
Schulze C.,TU Munich |
Bangert A.,TU Munich |
Kottra G.,TU Munich |
Geillinger K.E.,TU Munich |
And 4 more authors.
Molecular Nutrition and Food Research | Year: 2014
Scope: There is a growing interest in food constituents that could reduce intestinal glucose absorption to prevent overshooting plasma glucose and insulin levels in patients with prediabetes and diabetes mellitus type 2. Methods and results: We here demonstrate that an extract and individual polyphenols from apple diminish sodium-coupled glucose transporter 1 (SGLT1) mediated glucose uptake in vitro and in vivo. Inhibition of transport of sugars by SGLT1 was shown in Xenopus oocytes and in mice jejunal segments. Strongest inhibition was observed for phlorizin with IC50 values for transport inhibition of 0.46 ± 0.19 and 4.1 ± 0.6 μM in oocytes and intestinal segments, respectively. An oral glucose tolerance test performed in volunteers with prior administration of the apple extract reduced venous blood glucose and plasma insulin levels, similar to findings obtained in C57BL/6N mice. Analysis of human urine samples revealed that the extract increased modestly renal glucose loss that is most likely a result of inhibition of renal glucose reabsorption by phloretin derivatives found in plasma of the volunteers. Conclusion: Although the apple extract substantially decreased intestinal glucose absorption in all test systems, the finding that there are systemic effects that relate to inhibition of glucose transport processes beyond the intestine addresses safety issues that need further exploitation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Gaiko O.,MPI for Biophysics |
Gaiko O.,University of California at San Diego |
Janausch I.,MPI for Biophysics |
Janausch I.,University of Heidelberg |
And 7 more authors.
Australian Journal of Chemistry | Year: 2011
An electrophysiological assay platform based on solid supported membranes (SSM) for the organic cation transporter (OCT) is presented. Stable Chinese hamster ovary (CHO) cell lines overexpressing the human (hOCT2) and rat transporters (rOCT2) were generated and validated. Membrane preparations from the cell lines were investigated using SSM-based electrophysiology. Baculovirus transfected insect cells (HighFive and Mimic Sf9) were also tested with the same assay but yielded less than optimal results. The assays were validated by the determination of substrate affinities and inhibition by standard inhibitors. The study demonstrates the suitability of the SSM-based electrophysiological OCT assay for rapid and automatic screening of drug candidates. © CSIRO 2011.