title: Radical scavenging activity of flavonoids from Trollius chinensis Bunge.
abstract: OBJECTIVE
  Flos trollii is considered as functional tea, as well as a traditional medicinal herb, in China. In this study, total phenolic and flavonoid contents of Flos trollii were determined by a colorimetric method. The antioxidative potential of the hydroalcoholic extract of Flos trollii (FTE, extracted by alcohol:water, 80:20) was also evaluated by various antioxidant assays.
  
  
  METHODS
  Chemiluminescence technique was used to determine the radical scavenging activities of FTE toward different reactive oxygen species, including superoxide anion (O(-2)·), hydroxyl radical (OH·), lipid-derived radicals (R·), and singlet oxygen ((1)O(2)).
  
  
  RESULTS
  FTE could effectively scavenge O(-2)·, OH·, R·, and (1)O(2) at an efficient concentration (EC(50)) of 46, 5.64, 5.19, and 3.97 mg/mL, respectively. Moreover, the radical scavenging activities of FTE were higher than those of ascorbic acid. Further, FTE had higher 1,1 diphenyl-2-picrylhydrazyl radical (DPPH) radical-scavenging activity with EC(50) 44 mg/mL, compared with butylated hydroxytoluenesynthetic antioxidant with EC(50) 52 mg/mL.
  
  
  CONCLUSIONS
  All results indicated that FTE is a powerful antioxidant, deserving of better utilization of the extracted Flos trollii as antioxidants.
authors.affiliation: Tianjin Key Laboratory of Food Biotechnology, Faculty of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, 300134, PR China. hhppli@163.com
authors.forename: Haiping
authors.initials: H
authors.lastname: Li
authors.forename: Mingming
authors.initials: M
authors.lastname: Zhang
authors.forename: Guiji
authors.initials: G
authors.lastname: Ma
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000378:metabolism; D003124:Colorimetry / Q000379:methods; D005419:Flavonoids / Q000032:analysis / Q000494:pharmacology*; D035264:Flowers / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000032:analysis / Q000494:pharmacology*; D010636:Phenols / Q000032:analysis / Q000494:pharmacology*; D010851:Picrates / Q000378:metabolism; D029626:Ranunculaceae / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D001713:Biphenyl Compounds; D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D017382:Reactive Oxygen Species; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid