title: Dandelion (Taraxacum officinale) flower extract suppresses both reactive oxygen species and nitric oxide and prevents lipid oxidation in vitro.
abstract: Flavonoids and coumaric acid derivatives were identified from dandelion flower (Taraxacum officinale). Characteristics of chain-breaking antioxidants, such as extended lag phase and reduced propagation rate, were observed in oxidation of linoleic acid emulsion with the addition of dandelion flower extract (DFE). DFE suppressed both superoxide and hydroxyl radical, while the latter was further distinguished by both site-specific and non-specific hydroxyl radical inhibition. DPPH-radical-scavenging activity and a synergistic effect with alpha-tocopherol were attributed to the reducing activity derived from phenolic content of DFE. A significant (p < 0.05) and concentration-dependent, reduced nitric oxide production from acterial-lipopolysaccharide-stimulated mouse macrophage RAW264.7 cells was observed with the addition of DFE. Moreover, peroxyl-radical-induced intracellular oxidation of RAW264.7 cells was inhibited significantly (p < 0.05) by the addition of DFE over a range of concentrations. These results showed that the DFE possessed marked antioxidant activity in both biological and chemical models. Furthermore, the efficacy of DFE in inhibiting both reactive oxygen species and nitric oxide were attributed to its phenolic content.
authors.affiliation: Food, Nutrition and Health, Faculty of Agricultural Sciences, University of British Columbia, 6650 NW Marine Drive, Vancouver, BC, Canada V6T 1Z4.
authors.forename: C
authors.initials: C
authors.lastname: Hu
authors.forename: D D
authors.initials: DD
authors.lastname: Kitts
mesh_terms: D000818:Animals; D001713:Biphenyl Compounds; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D035264:Flowers; D016166:Free Radical Scavengers / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D005609:Free Radicals / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D009569:Nitric Oxide / Q000737:chemistry; D008517:Phytotherapy; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D017382:Reactive Oxygen Species / Q000737:chemistry; D031205:Taraxacum
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D010851:Picrates; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; C004931:1,1-diphenyl-2-picrylhydrazyl