Browsing by Author "Lodge, John K."

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    Ascorbate enhances iron uptake into intestinal cells through formation of a FeCl3-ascorbate complex
    (Elsevier Science B.V., Amsterdam., 2010-11-15T00:00:00Z) Thumser, Alfred E.; Rashed, Aswir Abd; Sharp, Paul A.; Lodge, John K.
    It has been well documented that ascorbate enhances iron uptake, with a proposed mechanism based on reduction to the more absorbable ferrous form. We have performed a study on the effects of ascorbate on ferric iron uptake in the human epithelial Caco-2 cell-line. Ascorbate increased uptake in a concentration- dependent manner with a significant difference between iron uptake and reduction. Uptake kinetics are characteristic of a non-essential activator and the formation of an Fe3+-ascorbate complex. This investigation provides evidence that ascorbate enhances the apical uptake of ferric iron into Caco-2 cells through the formation of a Fe3+-ascorbate complex. (C) 2010 Elsevier Ltd. All rights reserved.
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    Gene-regulatory activity of alpha-tocopherol.
    (MDPI, 2010-03-12T00:00:00Z) Rimbach, G.; Moehring, J.; Huebbe, P.; Lodge, John K.
    Vitamin E is an essential vitamin and a lipid soluble antioxidant, at least, under in vitro conditions. The antioxidant properties of vitamin E are exerted through its phenolic hydroxyl group, which donates hydrogen to peroxyl radicals, resulting in the formation of stable lipid species. Beside an antioxidant role, important cell signalling properties of vitamin E have been described. By using gene chip technology we have identified alpha-tocopherol sensitive molecular targets in vivo including christmas factor (involved in the blood coagulation) and 5alpha-steroid reductase type 1 (catalyzes the conversion of testosterone to 5alpha-dihydrotestosterone) being upregulated and gamma-glutamyl-cysteinyl synthetase (the rate limiting enzyme in GSH synthesis) being downregulated due to alpha-tocopherol deficiency. Alpha-tocopherol regulates signal transduction cascades not only at the mRNA but also at the miRNA level since miRNA 122a (involved in lipid metabolism) and miRNA 125b (involved in inflammation) are downregulated by alpha-tocopherol. Genetic polymorphisms may determine the biological and gene-regulatory activity of alpha-tocopherol. In this context we have recently shown that genes encoding for proteins involved in peripheral alpha-tocopherol transport and degradation are significantly affected by the apoE genotype.
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    Symposium 2: Modern approaches to nutritional research challenges: Targeted and non-targeted approaches for metabolite profiling in nutritional research.
    (CABI Publishing; 1999, 2010-02-28T00:00:00Z) Lodge, John K.
    The present report discusses targeted and non-targeted approaches to monitor single nutrients and global metabolite profiles in nutritional research. Non- targeted approaches such as metabolomics allow for the global description of metabolites in a biological sample and combine an analytical platform with multivariate data analysis to visualise patterns between sample groups. In nutritional research metabolomics has generated much interest as it has the potential to identify changes to metabolic pathways induced by diet or single nutrients, to explore relationships between diet and disease and to discover biomarkers of diet and disease. Although still in its infancy, a number of studies applying this technology have been performed; for example, the first study in 2003 investigated isoflavone metabolism in females, while the most recent study has demonstrated changes to various metabolic pathways during a glucose tolerance test. As a relatively new technology metabolomics is faced with a number of limitations and challenges including the standardisation of study design and methodology and the need for careful consideration of data analysis, interpretation and identification. Targeted approaches are used to monitor single or multiple nutrient and/or metabolite status to obtain information on concentration, absorption, distribution, metabolism and elimination. Such applications are currently widespread in nutritional research and one example, using stable isotopes to monitor nutrient status, is discussed in more detail. These applications represent innovative approaches in nutritional research to investigate the role of both single nutrients and diet in health and disease.