scholarly journals Favorable effect of hemodialysis on decreased serum antioxidant activity in hemodialysis patients demonstrated by electron spin resonance.

1997 ◽  
Vol 8 (7) ◽  
pp. 1157-1163 ◽  
Author(s):  
S Nagase ◽  
K Aoyagi ◽  
A Hirayama ◽  
M Gotoh ◽  
A Ueda ◽  
...  

There is considerable evidence that uremic patients are in a highly peroxidative state. The purpose of this study was to investigate the serum antioxidant activity that may regulate, or represent, the redox state in vivo. Serum from pre- and posthemodialysis patients and from healthy control subjects was added to a system generating the hydroxyl radical, and then the signal intensities of reactive oxygen species were measured by electron spin resonance and spin-trapping technique. The electron spin resonance signals of the reaction mixture containing prehemodialysis sera were significantly stronger than those of the reaction mixture containing healthy sera (P < 0.001, n = 19), and there was no significant difference in the signals between the reaction mixture containing posthemodialysis and healthy sera. These findings demonstrated that serum antioxidant activity in hemodialysis patients is significantly decreased, and this pathological condition is improved by hemodialysis treatment.

2005 ◽  
pp. 239-246 ◽  
Author(s):  
Sladjana Savatovic ◽  
Sonja Djilas ◽  
Vesna Tumbas ◽  
Jasna Canadanovic-Brunet ◽  
Gordana Cetkovic

Different concentrations ofmethanol aqueous solution with or without 0.5% acetic acid and 80% acetone were used to achieve the highest yield of extraction of phenolics from Induna apple pomace. The highest content of phenolics (6.38 mg/g) was detected in the 80% methanol extract. The influence of 80% methanol extract of Induna apple pomace on stable l,l-diphenyl-2-picrylhydrazyl (DPPH) and reactive hydroxyl radicals has been investigated by electron spin resonance (ESR) spectroscopy. Based on the obtained results it can be concluded that the investigated extract is more effective in the DPPH test than on the DMPO-OH scavenging. In both cases antioxidant activity increased with increasing concentration of the investigated extract. The high contents ofphenolics (6.38 mg/g), flavonoids (1.01 mg/g) and flavan-3-ols (0.70 mg/g) in 80% methanol extract indicated that these compounds contributed to the antioxidant activity of Induna apple pomace.


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