Effects of canthaxanthin , astaxanthin , lycopene and lutein on liver xenobiotic-metabolizing enzymes in the rat

64 ref.International audienc

Enhancement of glutathione transferase activity in rat by dietary administration of flavonoids: organ specificity, dose response and time-course studies

International audienc

Biomolecular study and conjugation of two paraaminobenzoic acid derivatives with serum proteins: drug binding efficacy and protein structural analysis.

Two aminobenzoic acid derivatives DAB-0 and DAB-1 showed distinct biological properties on murine bladder cancer (BCa) cell line MB49-I. In contrast to DAB-1, DAB-0 does not possess any anti-inflammatory activity and is less toxic. Furthermore, DAB-0 does not interfere with INFc-induced STAT1 activation and TNFa-induced IjB phosphorylation, while DAB-1 does. In order to rationalize these results, the binding efficacy of DAB-0 and DAB-1 with serum proteins such a human serum albumin (HSA), bovine serum albumin (BSA) and beta-lactoglobulin (b-LG) was investigated in aqueous solution at physiological pH. Multiple spectroscopic methods and thermodynamic analysis were used to determine the binding efficacy of DAB-0 and DAB-1 with serum proteins. Drug-protein conjugation was observed via through ionic contacts. DAB-1 forms stronger adducts than DAB-0, while b-LG shows more affinity with the order of stability b-LG>BSA>HSA. The stronger complexation of DAB-1 with serum proteins might account for its biological potential and transport in the blood. The binding efficacy ranged from 40 to 60%. Major alterations of protein secondary structures were detected upon drug complexation. Serum proteins are capable of delivering DAB-1 in vitro.Abbreviations: BSA: bovine serum albumin; DAB-0: N0-[4-(2,5-dioxo-pyrrolidin-1-yl)-benzoyl]-hydrazine carboxylic acid tert-butyl ester; DAB-1: N0-[4-(2,5-dioxo-2,5-dihydro-pyrrol-1-yl)-benzoyl]-hydrazine carboxylic acid tert-butyl est; FTIR: Fourier transform infrared; b-LG, beta-lactoglobulin; HAS: human serum albuminFil: Chanphai, P.. Université du Québec a Montreal; CanadáFil: Cloutier, F.. Université du Québec a Montreal; CanadáFil: Oufqir, Y.. Université du Québec a Montreal; CanadáFil: Leclerc, M.F.. Université du Québec a Montreal; CanadáFil: Eijan, Ana Maria. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reyes Moreno, C.. Université du Québec a Montreal; CanadáFil: Bérubé, G.. Université du Québec a Montreal; CanadáFil: Tajmir Riahi, H.A.. Université du Québec a Montreal; Canad

Helium implantation into 4H-SiC

The paper provides the properties of single crystalline 4H-SiC under helium implantation at temperatures of implantation up to 750 ◦C and fluences in the range 5×1015-1×1017 cm−2. The microstructure evolution was studied by transmission electron microscopy cross- section and X-ray diffraction experiments. The mechanical property changes were investigated by using nanoindentation tests followed by atomic force microscopy observations and by using tribological tests. At elevated temperature of implantation and/or in the low fluence regime at room temperature where only the strained state of SiC is obtained, SiC becomes more resistant to crack formation but no significant change in mechanical properties is seen. At room temperature with increasing fluence the damage accumulation leads to the amorphous state for which a strong degradation of the mechanical properties is observed. At elevated temperature of implantation, amorphization is avoided and a thermally activated saturation of the strain is observed in the near surface region whereas defect accumulation occurs near the maximum of damage. Upon annealing subsequent to room temperature implantation, the near surface strain progressively relaxes while the helium ions agglomerate into platelets around the maximum of strain. These platelets evolve into bubble clusters at temperatures where the vacancies become mobile. Under particular conditions of implantation (high fluence and elevated temperature) the swelling of the surface increases during annealing due to the growth of bubbles and the formation of stacking faults resulting from the migration of interstitials towards the maximum of damage. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei