title: Restoration of impaired phosphorylation of cyclic AMP response element-binding protein (CREB) by EGb 761 and its constituents in Abeta-expressing neuroblastoma cells.
abstract: Cyclic AMP response element-binding protein (CREB) plays important roles in neuronal plasticity and amyloid beta-peptide (Abeta)-induced cognitive impairment in Alzheimer's disease (AD). Here we demonstrated that Ginkgo biloba extract, EGb 761, displayed the neuron protective effect by activating the CREB signaling pathway. Wild-type neuroblastoma cells cultured in a conditioned medium containing cell-secreted Alphabeta exhibited reduced levels of phosphorylated CREB (pCREB). Addition of EGb 761 (100 microg/mL) or an anti-oligomer-specific antibody (A-11) to the conditioned medium could restore pCREB level. In a neuroblastoma cell line expressing Alphabeta, treatment with EGb 761 increased levels of pCREB and brain-derived neurotrophic factor. Furthermore, CREB phosphorylation induced by EGb 761 was blocked by inhibitors of several upstream signaling pathways of CREB, including protein kinase C, ERK, ribosomal S6 kinase(RSK)90 and nitric oxide pathway. Moreover, these inhibitors differentially blocked the effects of individual components of EGb 761, ginkgolide C, quercetin and bilobalide, which suggest diverse effects of the EGb 761 individual components. Actions of individual EGb 761 components provide further insights into direct mechanisms underlying the effect of EGb 761 on enhancing the cognitive performance of patients with AD.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland Baltimore, MD 21201, USA.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Xu
authors.forename: Changhai
authors.initials: C
authors.lastname: Cui
authors.forename: Cheuk
authors.initials: C
authors.lastname: Pang
authors.forename: Yves
authors.initials: Y
authors.lastname: Christen
authors.forename: Yuan
authors.initials: Y
authors.lastname: Luo
mesh_terms: D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism / Q000494:pharmacology; D050882:CREB-Binding Protein / Q000187:drug effects / Q000378:metabolism*; D045744:Cell Line, Tumor; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects*; D020441:Ginkgo biloba; D051379:Mice; D009154:Mutation / Q000502:physiology; D009447:Neuroblastoma / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D013997:Time Factors; D000096983:Ginkgo Extract
chemical_list: D016229:Amyloid beta-Peptides; D000906:Antibodies; D019208:Brain-Derived Neurotrophic Factor; D050882:CREB-Binding Protein; D004791:Enzyme Inhibitors; D010936:Plant Extracts; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract