title: Hepatoprotective effect of flavonoid glycosides from Lespedeza cuneata against oxidative stress induced by tert-butyl hyperoxide.
abstract: The aerial parts of Lespedeza cuneata G. Don, perennial legume native to Eastern Asia, have been used therapeutically in traditional Asian medicine to protect the function of liver, kidneys and lungs. However, little is known about the pharmaceutical effect of extracts from this plant. In the present study, the aerial parts of L. cuneata were used to prepare an ethanol extract, which was then tested for hepatoprotective effects against injury by tert-butyl hyperoxide (t-BHP). At a dose of 20 μg/mL, the ethanol extract significantly protected HepG2 cells against the cytotoxicity of t-BHP. Further fractionation of the extract with ethyl acetate allowed the isolation of five flavonoid compounds that were structurally identified by ¹H and ¹³C NMR spectroscopy as isovitexin, hirsutrin, trifolin, avicularin and quercetin. Hirsutrin, avicularin and quercetin (10 μM) showed clear hepatoprotective activity against injury by t-BHP in HepG2 cells, whereas isovitexin and trifolin showed no protective effects. The observed hepatoprotective effect of the investigated compounds showed a high correlation with radical scavenging activity, which followed the structure-activity relationships of the flavonoid aglycones.
authors.affiliation: Natural Products Research Center, Korea Institute of Science and Technology Gangneung Institute, Gangneung 210-340, Republic of Korea.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Kim
authors.forename: Kyungsu
authors.initials: K
authors.lastname: Kang
authors.forename: Eun Hye
authors.initials: EH
authors.lastname: Jho
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Jung
authors.forename: Chu Won
authors.initials: CW
authors.lastname: Nho
authors.forename: Byung-Hun
authors.initials: BH
authors.lastname: Um
authors.forename: Cheol-Ho
authors.initials: CH
authors.lastname: Pan
mesh_terms: D005591:Chemical Fractionation; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology; D006027:Glycosides / Q000302:isolation & purification / Q000494:pharmacology*; D056945:Hep G2 Cells; D006801:Humans; D029884:Lespedeza / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology; D020011:Protective Agents / Q000302:isolation & purification / Q000494:pharmacology; D020122:tert-Butylhydroperoxide
chemical_list: D005419:Flavonoids; D016166:Free Radical Scavengers; D006027:Glycosides; D010936:Plant Extracts; D020011:Protective Agents; D020122:tert-Butylhydroperoxide