scholarly journals In vitro antioxidant and in vivo xanthine oxidase inhibitory activities of Pandanus amaryllifolius in potassium oxonate-induced hyperuricemic rats

2018 ◽  
Vol 53 (6) ◽  
pp. 1476-1485 ◽  
Author(s):  
Nur Afira Ahmad Shukor ◽  
Abdulwali Ablat ◽  
Nur Airina Muhamad ◽  
Jamaludin Mohamad
2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Chen-Yu Chen ◽  
Chi-Chang Huang ◽  
Keng-Chang Tsai ◽  
Wei-Jan Huang ◽  
Wen-Ching Huang ◽  
...  

Abnormal serum urate levels are recognized as a critical factor in the progression of several chronic diseases. To evaluate the antihyperuricemic effect ofDavallia formosana, the inhibitory activities of 15 isolated phytochemicals, including five novel compounds of 6,8-dihydroxychromone-7-C-β-d-glucopyranoside (1), 6,8,3′,4′-tetrahydroxyflavanone-7-C-β-d-glucopyranoside (2), 6,8,4′-trihydroxyflavanone-7-C-β-d-glucopyranoside (3), 8-(2-pyrrolidinone-5-yl)-catechin-3-O-β-d-allopyranoside (4), and epiphyllocoumarin-3-O-β-d-allopyranoside (5), were examined against xanthine oxidase (XOD) and in a potassium oxonate-(PTO-) induced acute hyperuricemic mice model. The results indicated that compounds3and5significantly inhibited XOD activityin vitroand reduced serum uric acid levelsin vivo. This is the first report providing new insights into the antihyperuricemic activities of flavonoid glycosides which can possibly be developed into potential hypouricemic agents.


1981 ◽  
Vol 45 (03) ◽  
pp. 290-293 ◽  
Author(s):  
Peter H Levine ◽  
Danielle G Sladdin ◽  
Norman I Krinsky

SummaryIn the course of studying the effects on platelets of the oxidant species superoxide (O- 2), Of was generated by the interaction of xanthine oxidase plus xanthine. Surprisingly, gel-filtered platelets, when exposed to xanthine oxidase in the absence of xanthine substrate, were found to generate superoxide (O- 2), as determined by the reduction of added cytochrome c and by the inhibition of this reduction in the presence of superoxide dismutase.In addition to generating Of, the xanthine oxidase-treated platelets display both aggregation and evidence of the release reaction. This xanthine oxidase induced aggreagtion is not inhibited by the addition of either superoxide dismutase or cytochrome c, suggesting that it is due to either a further metabolite of O- 2, or that O- 2 itself exerts no important direct effect on platelet function under these experimental conditions. The ability of Of to modulate platelet reactions in vivo or in vitro remains in doubt, and xanthine oxidase is an unsuitable source of O- 2 in platelet studies because of its own effects on platelets.


2015 ◽  
Vol 59 (4) ◽  
pp. 2113-2121 ◽  
Author(s):  
U. Malik ◽  
O. N. Silva ◽  
I. C. M. Fensterseifer ◽  
L. Y. Chan ◽  
R. J. Clark ◽  
...  

ABSTRACTStaphylococcus aureusis a virulent pathogen that is responsible for a wide range of superficial and invasive infections. Its resistance to existing antimicrobial drugs is a global problem, and the development of novel antimicrobial agents is crucial. Antimicrobial peptides from natural resources offer potential as new treatments against staphylococcal infections. In the current study, we have examined the antimicrobial properties of peptides isolated from anuran skin secretions and cyclized synthetic analogues of these peptides. The structures of the peptides were elucidated by nuclear magnetic resonance (NMR) spectroscopy, revealing high structural and sequence similarity with each other and with sunflower trypsin inhibitor 1 (SFTI-1). SFTI-1 is an ultrastable cyclic peptide isolated from sunflower seeds that has subnanomolar trypsin inhibitory activity, and this scaffold offers pharmaceutically relevant characteristics. The five anuran peptides were nonhemolytic and noncytotoxic and had trypsin inhibitory activities similar to that of SFTI-1. They demonstrated weakin vitroinhibitory activities againstS. aureus, but several had strong antibacterial activities againstS. aureusin anin vivomurine wound infection model. pYR, an immunomodulatory peptide fromRana sevosa, was the most potent, with complete bacterial clearance at 3 mg · kg−1. Cyclization of the peptides improved their stability but was associated with a concomitant decrease in antimicrobial activity. In summary, these anuran peptides are promising as novel therapeutic agents for treating infections from a clinically resistant pathogen.


1991 ◽  
Vol 58 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Thomas J. Hayden ◽  
Denise Brennan ◽  
Katherine Quirke ◽  
Paddie Murphy

SummaryXanthine oxidase/dehydrogenase (XO/XDH) increases at mid gestation in mammary gland but not in liver of the mouse and remains elevated until the pups are weaned at 20 d post partum. The increase in enzyme activity is due neither to alteration in activators or inhibitors nor to a production of a variant enzyme with altered catalytic properties. The increase is preceded in vivo by a surge of prolactin-like activity (placental lactogen) in plasma, and prolactin is required for induction of XO/XDH in explant culture in vitro. Induction of XO/XDH in vivo and in vitro precedes the full histological differentiation of the gland. In addition, induction of XO/XDH in vitro occurs more rapidly and at lower concentrations of prolactin than does histological differentiation. Thus although XO/XDH is present in milk, increased XO/XDH activity is an early event in mammogenesis in vivo and in vitro rather than a terminal component of differentiation.


Author(s):  
Emadeldin M. Kamel ◽  
Noha A. Ahmed ◽  
Ashraf A. El-Bassuony ◽  
Omnia E. Hussein ◽  
Barakat Alrashdi ◽  
...  

Background: Various phenolics show inhibitory activity towards xanthine oxidase (XO), an enzyme that generates reactive oxygen species which cause oxidative damage. Objective: This study investigated the XO inhibitory activity of Euphorbia peplus phenolics. Methods: The dried powdered aerial parts of E. peplus were extracted, fractioned and phenolics were isolated and identified. The XO inhibitory activity of E. peplus extract (EPE) and the isolated phenolics was investigated in vitro and in vivo. Results: Three phenolics were isolated from the ethyl acetate fraction of E. peplus. All isolated compounds and the EPE showed inhibitory activity towards XO in vitro. In hyperuricemic rats, EPE and the isolated phenolics decreased uric acid and XO activity. Molecular docking showed the binding modes of isolated phenolics with XO, depicting significant interactions with the active site amino acid residues. Molecular dynamics simulation trajectories confirmed the interaction of isolated phenolics with XO by forming hydrogen bonds with the active site residues. Also, the root mean square (RMS) deviations of XO and phenolics-XO complexes achieved equilibrium and fluctuated during the 10 ns MD simulations. The radius of gyration and solvent accessible surface area investigations showed that different systems were stabilized at ≈ 2500 ps. The RMS fluctuations profile depicted that the drug binding site exhibited a rigidity behavior during the simulation. Conclusion: In vitro, in vivo and computational investigations showed the XO inhibitory activity of E. peplus phenolics. These phenolics might represent promising candidates for the development of XO inhibitors.


2010 ◽  
Vol 13 (8) ◽  
pp. 362-368 ◽  
Author(s):  
N.T.R. Meda ◽  
A. Lamien-Med ◽  
M. Kiendrebeo ◽  
C.E. Lamien ◽  
A.Y. Coulibaly ◽  
...  

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