title: Hepatoprotective action of an oleanolic acid-enriched extract of Ligustrum lucidum fruits is mediated through an enhancement on hepatic glutathione regeneration capacity in mice.
abstract: The fruits of Ligustrum lucidum Ait. (FLL) were fractionated into petroleum ether (FLL-Pe), chloroform (FLL-Ch), butanol (FLL-Bu) and aqueous (FLL-Aq) fractions, of which FLL-Ch and FLL-Bu were found to be enriched with oleanolic acid (OLA). The in vivo antioxidant activities of various FLL fractions and OLA were assessed by examining the effect on carbon tetrachloride (CCl(4))-induced hepatotoxicity in mice. Pretreatment of animals with various FLL fractions could protect against CCl(4)-induced hepatotoxicity to a varying degree, with OLA-enriched FLL-Bu and FLL-Ch being more potent. However, a mortality rate of 60% was observed in the FLL-Ch pretreated and CCl(4)-intoxicated mice. OLA pretreatment also produced a dose-dependent protection against CCl(4) hepatotoxicity. The hepatoprotection afforded by FLL-Bu or OLA pretreatment was associated with an enhancement of hepatic-glutathione regeneration capacity (GRC). In contrast, the inability of FLL-Aq pretreatment to enhance hepatic GRC resulted in a failure to prevent CCl(4)-induced hepatic injury. The results suggest that the hepatoprotective action afforded by OLA-enriched FLL-Bu or OLA pretreatment may be mainly mediated by the enhancement of hepatic GRC, particularly under conditions of CCl(4)-induced oxidative stress.
authors.affiliation: Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: T K
authors.initials: TK
authors.lastname: Yim
authors.forename: W K
authors.initials: WK
authors.lastname: Wu
authors.forename: W F
authors.initials: WF
authors.lastname: Pak
authors.forename: K M
authors.initials: KM
authors.lastname: Ko
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002251:Carbon Tetrachloride; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005260:Female; D005638:Fruit; D022781:Hepatocytes / Q000187:drug effects*; D008099:Liver / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D029592:Oleaceae; D009828:Oleanolic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D009828:Oleanolic Acid; D002251:Carbon Tetrachloride