INHIBITORY EFFECTS OF ANCHUSA AZUREA EXTRACTS ON XANTHINE OXIDASE ACTIVITY AND ITS HYPOURICEMIC EFFECTS ON MICE

Objective: The aim of the present study was to determine the effects of the polyphenols and flavonoids from Anchusa azurea on XO activities in vitro and on serum and liver uric acid levels in normal and potassium oxonate-induced hyper uricemic mice. In addition, the renal function of the mice after flavonoid administration was estimated by the determination of blood urea and creatinine analysis.Methods: In the present study, Anchusa azurea were extracted with solvent of varying polarity allowed its separation into four subfractions: crude extract (Cr) chloroform extract (ChE), ethyl acetate extract (AcE), and aqueous extracts (AqE). Total polyphenol and flavonoids contents of Anchusa azurea extracts were determined. The inhibitory activity of the extracts on the XO was evaluated and the type of inhibition was determined. Hyperuricemia is induced by intraperitoneally injection of potassium oxonate, the uric acid, urea and creatinine were measured in serum and supernatant of the liver. The effect of the extracts on renal function was evaluated. The rate of urea and creatinine levels can be indicators for the assessment of renal function.Results: AcE were the richest in polyphenols and ChE was the richest fraction in flavonoids. The inhibitory activity of the extracts on the XO was evaluated, the results obtained showed that the inhibition is dose-dependent and ChE and AcE have the best inhibitory effect (IC50= 0.334±0.006 and 0.263±0.002 mg/ml, respectively), and both showed a noncompetitive type of inhibition. For antihyperuricemic effect, AqE and CrE caused a decrease in serum uric acid (a decrease of 66%) followed by ChE with a percentage of 29.22 %. The AcE keeps almost the same value of uric acid of "PO" group. For the supernatant, only CrE caused a significant decrease of liver uric acid (18.5±4.83 mg/l). This decrease can be explained by the significant inhibition of the XO by inhibition of the synthesis pathways of uric acid. Comparing the urea level of "OP" group (0.48 g/l), only extracts CrE-AA, AqE-AA (0.41g/l, 0.39 g/l) decreased the level of urea significantly (P ≤ 0.05) to the normal values of urea (0.34 g/l), we can conclude that the rate of urea and creatinine after treatment with plant extracts are normal and that the results of this study indicate the absence of renal damage in miceConclusion: Anchusa azurea fractions have a strong inhibitory effect on xanthine oxidase and also have a significant lowering effect on serum and liver creatinine and urea levels in hyper uricemic mice.Â

Effet de quelques flavonoïdes sur une pénicillinase de Bacillus cereus

L’effet inhibiteur de certains flavonoïdes sur l’activité d’une β-lactamase d’une souche de Bacillus cereus a été testé et la relation structure-fonction a été établie. L’activité de La β-lactamase est déterminée en présence de différentes concentrations de la pénicilline G; le Km est de 106,3256 ± 32,0861 µM et la Vmax est de 0,6836 ± 0.00974 µM/min. Ces résultats reflètent une affinité de l’enzyme sur la pénicilline G. Six molécules de flavonoïdes ont été testées pour leur capacité à inhiber la b-lactamase. Le type d’inhibition et les constantes d’inhibition (Ki) ont été déterminés à une concentration de 150 µM. Parmi les molécules testées, l’épicatéchine et la naringine sont des inhibiteurs incompétitifs. La catéchine, la morine et la rutine sont des inhibiteurs compétitifs. La naringénine ne présente aucun effet inhibiteur. Les flavonoïdes ont une fonction 4-oxo semblable à celle de l’acide clavulanique et la pénicilline G. Il semble que le type du cycle, la position de OH et la présence d’un sucre dans les structures des molécules ont une importance majeure

Effect of a thermoplastic elastomer compatibilizer (sebs-g-mah) on the properties of PP/PET blends

10 pags., 9 figs., 2 tabs.Polyethylene terephthalate (PET) and polypropylene (PP) are widely used and frequently encountered in domestic and industrial plastics, especially in the soft drink bottles. In the present work, different compositions of PP/PET blends were prepared and compatibilized by various contents of SEBS-g-MAH. The compatibilizing efficiency was examined using macro- (tensile and impact strength) and micro-mechanical testing (microhardness measurement), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), and melt flow index (MFI) determinations. The results show that the addition of SEBS-g-MAH improves the processability and the toughness of these blends. The changes in the melting enthalpies (ΔH) of the PP and PET components and the decrease of MFI values in the compatibilized blends indicated enhanced interactions between the discrete PET and PP phases induced by the functional compatibilizer. The DSC crystallinity of each component depended on the blend composition, and was slightly influenced by the presence of the compatibilizer. In the samples subjected to compression molding, the WAXS crystallinity of PP component slightly decreased in the presence of increasing amounts of compatibilizer.One of the authors (MEC) wishes to thank the Spanish Ministry of Science and Innovation MICINN for the financial support of this investigation (Grant MAT2009-07789).Peer Reviewe

Kinetics of Inhibition of Xanthine Oxidase by Lycium arabicum and its Protective Effect against Oxonate- Induced Hyperuricemia and Renal Dysfunction in Mice

Purpose: To evaluate the in-vitro inhibition of xanthine oxidase (purified from bovine milk) by extracts of Lycium arabicum, as well as it is in vivo hypouricemic and renal protective effects.Methods: Four extracts of Lycium arabicum, methanol (CrE), chloroform (ChE), ethyl acetate (EaE) and aqueous (AqE) extracts, were screened for their total phenolics and potential inhibitory effects on purified bovine milk xanthine oxidase (XO) activity by measuring the formation of uric acid or superoxide radical. The mode of inhibition was investigated and compared with the standard drugs, allopurinol, quercitin and catechin. To evaluate their hypouricemic effect, the extracts were administered to potassium oxonate-induced hyperuricemic mice at a dose of 50 mg/kg body weight.Results: The results showed that EaE had the highest content of phenolic compounds and was the most potent inhibitor of uric acid formation (IC50 = 0.017 ± 0.001 mg/mL) and formation of superoxide (IC50 = 0.035 ± 0.001 mg/ml). Lineweaver-Burk analysis showed that CrE and EaE inhibited XO competitively, whereas the inhibitory activities exerted by ChE and AqE were of a mixed type. Intraperetoneal injection of L. arabicum extracts (50 mg/kg) elicited hypouricemic actions in hyperuricemic mice. Hyperuricemic mice presented a serum uric acid concentration of 4.71 ± 0.29 mg/L but this was reduced to 1.78 ± 0.11 mg/L by EaE, which was the most potent hyporuricemic extract.Conclusion: L. arabicum fractions have a strong inhibitory effect on xanthine oxidase and and also have a significantly lowering effect on serum and liver creatinine and urea levels in hyperuricemic mice.Keywords: Lycium arabicum, Uric acid, Creatinine, Superoxide, Phenolic compounds, Flavonoids, Hyperuricemi

On a contribution to study some mechanical properties of WEEE recycled polymer blends

This research deals with the study of acrylonitrile-butadiene-styrene/polycarbonate (ABS/PC) totally derived from wastes of electrical and electronic equipment (WEEE). The aim of this study is to investigate the macroscopic use properties of 100% recycled polymers and compare them with the virgin materials. First, a preliminary work of sorting and characterization of the wastes was necessary to identify the predominant polymer components in the lots. Then, four compositions of blends (ABS/PC) were performed at laboratory using the twin-screw extruder and injection techniques. Next, a series of experimental tests were carried out to investigate the morphology of the blends, their mechanical and thermo-mechanical behavior. The experimental results highlighted the synergistic effect by blending ABS and PC wastes. In addition, the comparison with the virgin mixtures has shown a decrease in the mechanical properties of the waste blends, however, the mechanical behavior is still ductile and the blends stiffness was enhanced