Center Europeen dEtude du Diabete CeeD
Center Europeen dEtude du Diabete CeeD
Clayeux C.,TWISTAROMA |
Marchioni E.,CNRS Hubert Curien Multi-disciplinary Institute |
Van Der Werf R.,CNRS Hubert Curien Multi-disciplinary Institute |
Van Der Werf R.,Center Europeen Detude Du Diabete Ceed |
And 4 more authors.
Current Analytical Chemistry | Year: 2017
Background: Oxidative stress plays a major role in the development of several diseases. A healthy food diet, supplying the organism with antioxidants, is generally believed to help prevent this stress. Methods: With the aim of screening several antioxidants commonly found in food, a method using β pancreatic cells and based on the reduction of a tetrazolium sodium salt into colored formazan in the presence of antioxidant compounds was used. In parallel, the same compounds were investigated using a chromatographic online antioxidant detection system (Coads) based on the detection of the reduced form of the radical cation 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) which is first allowed to react online with the eluting compounds. Results: The obtained data suggested that most phenolic compounds possessed both antioxidant and prooxidant properties. Gallic acid, in particular, showed among the highest antioxidant activities with the Coads method (322±46 μM Trolox equivalent), but caused a decrease in cell viability (-25%). Conclusion: Moreover, when screening natural compounds for their antioxidant activity, combining both chemical and biological methods is a more targeted approach compared with the single use of either method. © 2017 Bentham Science Publishers.
Maillard E.,Center Europeen dEtude du Diabete CeeD |
Maillard E.,University of Oxford |
Juszczak M.T.,University of Oxford |
Langlois A.,Center Europeen dEtude du Diabete CeeD |
And 9 more authors.
Cell Transplantation | Year: 2012
As oxygen carriers, perfluorocarbon emulsions might be useful to decrease hypoxia of pancreatic islets before transplantation. However, their hydrophobicity prevents their homogenisation in culture medium. To increase the surface of contact between islets and Perfluorooctyl bromide (PFOB), and consequently oxygen delivery, we tested effect of a PFOB emulsion in culture medium on β-cell lines and rat pancreatic islets. RINm5F β-cell line or pancreatic rat islets were incubated for 3 days in the presence of PFOB emulsion in media (3.5% w/v). Preoxygenation of the medium was performed before culture. Cell viability was assessed by apoptotic markers (Bax and Bcl-2) and by staining (fluoresceine diacetate and propidium iodide). β-Cell functionality was determined by insulin release during a glucose stimulation test and. Hypoxia markers, HIF-1α and VEGF, were studied at days 1 and 3 using RT-PCR, Western blotting, and ELISA. PFOB emulsions preserved viability and functionality of RINm5F cells with a decrease of HIF-1α and VEGF expression. Islets viability was preserved during 3 days of culture. Secretion of VEGF was higher in untreated control (0.09 ± 0.041 μg VEGF/mg total protein) than in PFOB emulsion incubated islets (0.02 ± 0.19 μg VEGF/ mg total protein, n = 4, p < 0.05) at day 1. At day 3, VEGF secretion was increased as compared to day 1 in control (0.23 ± 0.04 μg VEGF/mg total protein) but it was imbalance by the presence of PFOB emulsion (0.09 ± 0.03 μg VEGF/mg total protein, n = 5, p < 0.05). While insulin secretion was maintained in response to a glucose stimulation test until day 3 when islets were incubated in the presence of PFOB emulsion preoxygenated (0.81 ± 0.16 at day 1 vs. 0.75 ± 0.24 at day 3), the ability to secrete insulin in the presence of high glucose concentration was lost in islets controls (0.51 ± 0.18 at day 1 vs. 0.21 ± 0.13 at day 3). Atmospheric oxygen delivery by PFOB emulsion might be sufficient to decrease islets hypoxia. However, to improve islets functionality, overoxygenation is needed. Finally, maintenance of islet viability and functionality for several days after isolation could improve the outcome of islets transplantation. © 2012 Cognizant Comm. Corp.
Reix N.,Hopitaux Universitaires Of Strasbourg |
Reix N.,University of Strasbourg |
Pinget M.,Hopitaux Universitaires Of Strasbourg |
Pinget M.,University of Strasbourg |
And 3 more authors.
Medecine des Maladies Metaboliques | Year: 2012
Insulin remains the most effective and durable hypoglycemic agent for the treatment of diabetes. The addition of an effective oral insulin dosage form to the antidiabetic armamentarium may have significant benefits in terms of compliance and adherence among patients, as well as physiological advantages due to the fact that such a dosage form replicates the natural route of insulin secretion and absorption through the portal vein and targets the liver directly. Several companies have developed technological systems that protect insulin from enzymatic hydrolysis, enable its transport across the epithelial lining, and promote its absorption from the intestinal tract. A review of the potential physiological rational and advantages, as well as current pertinent technologies used specifically with insulin, is herewith provided. © 2012 - Elsevier Masson SAS - Tous droits réservés.