title: The effect of black seed (Nigella sativa) extract on FOXO3 expression in HepG2 cells.
abstract: Black seed extracts are known to alter cellular metabolism through multiple signaling pathways. Since Forkhead box transcription factor 3 (FOXO3) has a significant role in regulating cellular metabolism, the effect of lipid extracts of black seed (Sativa nigella) on FOXO3 levels and AKT and 5-AMP activated protein kinase α (AMPKα) signaling was measured in HepG2 hepatoma cells. FOXO3 levels, phosphorylation, and nuclear exclusion were measured by Western blot, as were AKT and AMPK expression and activity using phosphorylation-specific antibodies. Apolipoprotein A-I expression, a black seed-responsive gene, was measured by Western blot. Treatment with black seed extract increased FOXO3 phosphorylation and decreased its expression. In contrast to control cells where FOXO3 was located primarily in the nucleus, in black seed-treated HepG2 cells, FOXO3 was localized primarily to the cytoplasm. These changes in FOXO3 phosphorylation, expression, and localization were accompanied by increased AKT activity. Black seed also decreased AMPKα activity but increased AMPKα expression. Lipid extracts from black seeds inhibit FOXO3 activity and thereby modulate the expression of FOXO3-dependent genes.
authors.affiliation: Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Florida - Jacksonville, Jacksonville, FL, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Haas
authors.forename: Luisa
authors.initials: L
authors.lastname: Onstead-Haas
authors.forename: Emad
authors.initials: E
authors.lastname: Naem
authors.forename: Alexis
authors.initials: A
authors.lastname: Arnold
authors.forename: Nathcelly
authors.initials: N
authors.lastname: Rohrbaugh
authors.forename: Megan
authors.initials: M
authors.lastname: Flowers
authors.forename: Arshag D
authors.initials: AD
authors.lastname: Mooradian
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D031881:Nigella sativa / Q000737:chemistry*; D010766:Phosphorylation / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012639:Seeds / Q000737:chemistry; D015398:Signal Transduction / Q000187:drug effects
chemical_list: C499517:FOXO3 protein, human; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; D010936:Plant Extracts; D051057:Proto-Oncogene Proteins c-akt; D055372:AMP-Activated Protein Kinases
keywords: AKT; AMPKα; FOXO3; black seed; diabetes