title: Tiliroside and gnaphaliin inhibit human low density lipoprotein oxidation.
abstract: Two flavonoids, gnaphaliin and tiliroside, isolated from Helichrysum italicum, were studied in vitro for their capacity to inhibit Cu(2+)-induced human low density lipoprotein (LDL) and diluted plasma oxidation. LDL oxidation was monitored by conjugated diene, thiobarbituric acid-reactive substances (TBARS) formation and electrophoretic mobility on agarose gel. Gnaphaliin and tiliroside increased the lag-phase for diene conjugate production in a dose-dependent manner. The reduction of TBARS production confirmed the antioxidant activity of gnaphaliin and tiliroside with 50% inhibitory concentration (IC(50)) values of 8.0+/-3.9 microM and 7.0+/-2.6 microM respectively. Furthermore, the flavonoids negated the Cu(2+)-induced increase in electrophoretic mobility of LDL. Antioxidant activity of gnaphaliin and tiliroside was significantly different when diluted plasma was oxidised by adding 1 mM CuSO(4). Although both flavonoids again reduced the TBARS production, tiliroside showed higher activity than gnaphaliin (IC(50)=10.6+/-2.5 microM vs. IC(50)>50 microM). In conclusion, tiliroside and gnaphaliin are antioxidants against in vitro Cu(2+)-induced LDL oxidation in the same order of magnitude compared to that of the reference drug, probucol.
authors.affiliation: Cátedra de Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Argentina. schinell@uv.es
authors.forename: Guillermo R
authors.initials: GR
authors.lastname: Schinella
authors.forename: Horacio A
authors.initials: HA
authors.lastname: Tournier
authors.forename: Salvador
authors.initials: S
authors.lastname: Máñez
authors.forename: Perla M
authors.initials: PM
authors.lastname: de Buschiazzo
authors.forename: María
authors.initials: M
authors.lastname: Del Carmen Recio
authors.forename: José Luis
authors.initials: JL
authors.lastname: Ríos
mesh_terms: D001578:Benzopyrans / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D008078:Cholesterol, LDL / Q000187:drug effects*; D019327:Copper Sulfate / Q000737:chemistry; D047309:Flavones / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D005419:Flavonoids; D036562:Helichrysum; D006801:Humans; D020128:Inhibitory Concentration 50; D015227:Lipid Peroxidation / Q000187:drug effects*; D008077:Lipoproteins, LDL / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D008517:Phytotherapy; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D017392:Thiobarbituric Acid Reactive Substances / Q000737:chemistry
chemical_list: D001578:Benzopyrans; D008078:Cholesterol, LDL; D047309:Flavones; D005419:Flavonoids; D008077:Lipoproteins, LDL; D010936:Plant Extracts; D017392:Thiobarbituric Acid Reactive Substances; C121845:gnaphalin; C019455:low density lipoprotein inhibitor; C052083:tiliroside; D019327:Copper Sulfate