title: Flavonoids of an extract of Pterospartum tridentatum showing endothelial protection against oxidative injury.
abstract: Pterospartum tridentatum is a Leguminosae that grows spontaneously in Portugal. The flowers are used in popular medicine for the treatment of throat irritation conditions and in herbal mixtures for diabetes. Diabetic vascular complications are due, among other reasons, to increased oxidative stress and for that reason antioxidants are believed to be beneficial for the diabetic patient. The flower water extract of this herbal drug showed dose-dependent protective effect of cultured human endothelial cells against oxidative injury induced by H2O2, at concentrations > or =0.3 mg/ml. This water extract, after liquid-liquid and chromatographic fractionation afforded one new isoflavone (5,5'-dihydroxy-3'-metoxi-isoflavone-7-O-beta-glucoside) and three other known isoflavones (prunetin, genistin and sissotrin). The structural characterisation of isolated compounds was achieved by UV, NMR and MS analysis. The flavonol glycoside isoquercitrin was also identified in the extract by HPLC analysis. Isoquercitrin is one of the active antioxidant principles of the extract since it showed dose-dependent protective effect against oxidative injury at concentrations > or =0.3 mM. Isoflavones were inactive at the same concentrations. The results suggest that the water extract of this herbal drug may prevent or reduce the development of diabetic vascular complications.
authors.affiliation: CECF, Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
authors.forename: Rute F
authors.initials: RF
authors.lastname: Vitor
authors.forename: Helder
authors.initials: H
authors.lastname: Mota-Filipe
authors.forename: Generosa
authors.initials: G
authors.lastname: Teixeira
authors.forename: Carlos
authors.initials: C
authors.lastname: Borges
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Rodrigues
authors.forename: Adriano
authors.initials: A
authors.lastname: Teixeira
authors.forename: Alexandra
authors.initials: A
authors.lastname: Paulo
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D003920:Diabetes Mellitus / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects*; D007887:Fabaceae; D005419:Flavonoids / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D035264:Flowers; D006801:Humans; D006861:Hydrogen Peroxide; D018384:Oxidative Stress / Q000187:drug effects*; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D014471:Umbilical Veins
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D006861:Hydrogen Peroxide