9 research outputs found

    Pro- and Antioxidant Effect of Food Items and Matrices during Simulated In Vitro Digestion

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    The digestive tract can be considered a bioreactor. High levels of reactive oxygen species (ROS) during digestion may predispose for local and/or systemic oxidative stress and inflammation, e.g., inflammatory bowel diseases. Food items rich in antioxidants may prevent such aggravation. This investigation analyzed pro-and antioxidant patterns of food matrices/items following in vitro digestion. Gastrointestinal digestion reflecting typically consumed quantities was performed on nine food items (orange and tomato juice, soda, coffee, white chocolate, sausage, vitamin C and E, and curcumin) and their combinations (n = 24), using the INFOGEST model. Antioxidant potential was measured by FRAP, DPPH, and ABTS, and pro-oxidant aspects by MDA (malondialdehyde) and peroxide formation. An anti-pro-oxidant score was developed, combining the five assays. Liquid food items showed moderately high antioxidant values, except for coffee and orange juice, which exhibited a high antioxidant potential. Solid matrices, e.g., white chocolate and sausage, showed both high pro-oxidant (up to 22 mg/L MDA) and high antioxidant potential (up to 336 mg/L vitamin C equivalents) at the same time. Individual vitamins (C and E) at physiological levels (achievable from food items) showed a moderate antioxidant potential (<220 mg/L vitamin C equivalents). Overall, both antioxidant and pro-oxidant assays correlated well, with correlation coefficients of up to 0.894. The effects of food combinations were generally additive, i.e., non-synergistic, except for combinations with sausage, where strong quenching effects for MDA were observed, e.g., with orange juice. In conclusion, as especially highlighted by complex matrices demonstrating both pro- and antioxidant potential, only measuring one aspect would result in physiological misinterpretations. Therefore, it is imperative to employ a combination of assays to evaluate both pro- and antioxidant properties of food digesta to ensure physiological relevance

    Effect of Digested Selected Food Items on Markers of Oxidative Stress and Inflammation in a Caco-2-Based Human Gut Epithelial Model

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    The human gut epithelium presents a crucial interface between ingested food items and the host. Understanding how different food items influence oxidative stress and inflammation in the gut is of great importance. This study assessed the impact of various digested food items on oxidative stress, inflammation, and DNA/RNA damage in human gut epithelial cells. Differentiated Caco-2 cells were exposed to food items and their combinations (n = 22) selected from a previous study, including sausage, white chocolate, soda, coffee, orange juice, and curcumin. Following stimulation with TNF-α/IFN-1β/LPS and H2O2 for 4 h, the cells were exposed to digested food items or appropriate controls (empty digesta and medium) for a further 16 h. Cell viability, antioxidant capacity (ABTS, FRAP), IL-6, IL-8, F2-isoprostanes, lipid peroxidation (MDA), and DNA/RNA oxidative damage were assessed (3 independent triplicates). The ABTS assay revealed that cells treated with “white chocolate” and “sausage + coffee” exhibited significantly reduced antioxidant capacity compared to stimulated control cells (ABTS = 52.3%, 54.8%, respectively, p p p < 0.05) compared to stimulated control cells. This investigation provides insights into how different food items may affect gut health and underscores the complex interplay between food components and the epithelium at this critical interface of absorption

    Valproic Acid Induces Non Apoptotic Cell Death in Myeloma Cells and Cell Lines.

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    Abstract Multiple myeloma is, despite the emergence of new treatment strategies in recent years, still a lethal disease in 2005. Over the last several years, significant insights into the dysregulation of various signal transduction pathways of MM have emerged and have evolved the development of new agents. Histone deacetylase inhibitors as valproic acid are compounds that inhibit HDACs enzymes that, in conjunction with histone acetylases, regulate the acetylation state of histones and, by extension, the conformational status of chromatin. VPA is clinically known to be used in treatment of different types of epileptic disease. Effects and signal transduction pathways of cell death have been studied in cells harvested and purified from routine bone marrow aspirates of several patients with multiple myeloma, as well as on myeloma cell lines (OPM2, U266) treated with a physiologic dose range of valproic acid (1–4 mM). We observe significant in vitro toxicity starting at doses of 1 mM for 24h in cell lines as well as in patient cells using an XTT based cytotoxicity assay. The question we adressed was the mechanisms by which the MM died. Flow cytometric analysis with PI / Annexin V staining does not show apoptosis features, nor do TUNEL staining or DNA fragmentation assays, suggesting non activation of the intrinsic apoptosis pathway. In contrast, cell morphology of treated cells stained with May-Gruenwald-Giemsa staining show increase in multinucleated giant cells. Multinucleation has often been described in cells which die through mitotic catastrophe. Further experiments exploring this hypothesis will be conducted. Effect of 48h valproic ac on myeloma cell lines Effect of 48h valproic ac on myeloma cell lines Effect of 48h valproic ac on CD138 cells from myeloma patients Effect of 48h valproic ac on CD138 cells from myeloma patients</jats:p

    Potential health effects of brewers’ spent grain as a functional food ingredient assessed by markers of oxidative stress and inflammation following gastro-intestinal digestion and in a cell model of the small intestine

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    Brewery spent grain increased dietary fiber when incorporated into bread, together with total phenolics and antioxidant capacity. This was retained after gastro-intestinal digestion. 150 g of such a bread can supply the recommended daily 25 g of fiber.</jats:p

    Determination of genes and microRNAs involved in the resistance to fludarabine in vivo in chronic lymphocytic leukemia

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    Background: Chronic lymphocytic leukemia (CLL) cells are often affected by genomic aberrations targeting key regulatory genes. Although fludarabine is the standard first line therapy to treat CLL, only few data are available about the resistance of B cells to this purine nucleoside analog in vivo. Here we sought to increase our understanding of fludarabine action and describe the mechanisms leading to resistance in vivo. We performed an analysis of genomic aberrations, gene expression profiles, and microRNAs expression in CLL blood B lymphocytes isolated during the course of patients' treatment with fludarabine. Results: In sensitive patients, the differentially expressed genes we identified were mainly involved in p53 signaling, DNA damage response, cell cycle and cell death. In resistant patients, uncommon genomic abnormalities were observed and the resistance toward fludarabine could be characterized based on the expression profiles of genes implicated in lymphocyte proliferation, DNA repair, and cell growth and survival. Of particular interest in some patients was the amplification of MYC (8q) observed both at the gene and transcript levels, together with alterations of myc-transcriptional targets, including genes and miRNAs involved in the regulation of cell cycle and proliferation. Differential expression of the sulfatase SULF2 and of miR-29a, -181a, and -221 was also observed between resistant and sensitive patients before treatment. These observations were further confirmed on a validation cohort of CLL patients treated with fludarabine in vitro. Conclusion: In the present study we identified genes and miRNAs that may predict clinical resistance of CLL to fludarabine, and describe an interesting oncogenic mechanism in CLL patients resistant to fludarabine by which the complete MYC-specific regulatory network was altered (DNA and RNA levels, and transcriptional targets). These results should prove useful for understanding and overcoming refractoriness to fludarabine and also for predicting the clinical outcome of CLL patients before or early during their treatment
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