title: Extract of Ginkgo biloba induces glutamate cysteine ligase catalytic subunit (GCLC).
abstract: The extract of Ginkgo biloba (EGb), containing 24% flavone glycosides and 6% terpenoids, is widely used to treat early-stage Alzheimer's disease, vascular dementia, peripheral claudication and vascular tinnitus. Its marked antioxidant activity has recently been demonstrated in both cell lines and animals. Glutathione (GSH) plays an important role in the antioxidant system by conjugating to xenobiotics to facilitate their export from cells. Glutamate cysteine ligase (GCL) is the rate-limiting enzyme for GSH synthesis and its catalytic subunit (GCLC) determines this de novo synthesis. Thus, induction of GCLC is a strategy to enhance the antioxidant capability in cells. The present study aimed to investigate the induction effect of EGb on GCLC in HepG2 and Hep1c1c7 cell lines. Real-time PCR, Western blot and enzyme activity assay were used to detect induction and it was found that GCLC was induced by EGb in these two cell lines. It is suggested that the antioxidant activity of EGb is (or is partly) through the induction of GCLC.
authors.affiliation: Institute of Clinical Pharmacology, Anhui Medical University, Hefei, Anhui, P. R. China.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Liu
authors.forename: Christopher E P
authors.initials: CE
authors.lastname: Goldring
authors.forename: Hai-Yi
authors.initials: HY
authors.lastname: Wang
authors.forename: Ian M
authors.initials: IM
authors.lastname: Copple
authors.forename: Neil R
authors.initials: NR
authors.lastname: Kitteringham
authors.forename: B Kevin
authors.initials: BK
authors.lastname: Park
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
mesh_terms: D000199:Actins / Q000032:analysis / Q000096:biosynthesis; D000704:Analysis of Variance; D000818:Animals; D000906:Antibodies / Q000378:metabolism; D015153:Blotting, Western; D020134:Catalytic Domain; D002460:Cell Line; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D020441:Ginkgo biloba / Q000737:chemistry*; D005721:Glutamate-Cysteine Ligase / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics*; D005978:Glutathione / Q000032:analysis; D006801:Humans; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000199:Actins; D000906:Antibodies; D010936:Plant Extracts; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione