Simple method for determining human serum 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity – possible application in clinical studies on dietary antioxidants

摘要: BACKGROUND 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) radical decomposition in alcohol solution is widely used, characterizing plant antioxidants that can rise serum after fruit and vegetable intake. However, this test failed reproducible results with due to protein precipitation. We describe the application of deproteinization acetonitrile relating DPPH test. METHODS Assay sensitivity, linearity, repeatability storage effect were determined samples deproteinized an equal volume acetonitrile. Associations between ferric reducing ability (FRAP) method, measuring total antioxidant potential, evaluated sera from 78 healthy non-smoking men. The a single ingestion 1 L cloudy apple juice on scavenging activity volunteers was also investigated. RESULTS linearity within 5-25 microL (r=0.99, p<0.01). With 25 microL-deproteinized serum, coefficient variation 4.2% detection limit 0.5% initial amount decomposed over 30 min incubation. There no decrease 14 days at -20 degrees C. Mean values FRAP obtained human 11.2+/-3.3% 382.0+/-88.1 micromol/L, respectively. A positive significant linear correlation observed these two methods (r=0.42, Serum supplementation 50 micromol/L catechin, gallic acid, ascorbic acid or uric enhanced results. One brisk serving caused increment (1.9+/-1.9%, p<0.01) 12 subjects h ingestion. CONCLUSIONS Applicability revealed numerous advantages, validating its practicability, simplicity cost effectiveness as tool estimation status humans.