title: Andrographolide inhibits adipogenesis of 3T3-L1 cells by suppressing C/EBPβ expression and activation.
abstract: Andrographolide, a diterpenoid, is the most abundant terpenoid in Andrographis paniculata, a popular Chinese herbal medicine. Andrographolide displays diverse biological activities including hypoglycemia, hypolipidemia, anti-inflammation, and anti-tumorigenesis. Recent evidence indicates that andrographolide displays anti-obesity property by inhibiting lipogenic gene expression, however, the underlying mechanisms remain to be elucidated. In this study, the effects of andrographolide on transcription factor cascade and mitotic clonal expansion in 3T3-L1 preadipocyte differentiation into adipocyte were determined. Andrographolide dose-dependently (0-15μM) inhibited CCAAT/enhancer-binding protein α (C/EBPα) and C/EBPβ mRNA and protein expression as well as peroxisome proliferator-activated receptor γ (PPARγ) protein level during the adipogenesis of 3T3-L1 cells. Concomitantly, fatty acid synthase and stearoyl-CoA desaturase expression and lipid accumulation were attenuated by andrographolide. Oil-red O staining further showed that the first 48h after the initiation of differentiation was critical for andrographolide inhibition of adipocyte formation. Andrographolide inhibited the phosphorylation of PKA and the activation of cAMP response element-binding protein (CREB) in response to a differentiation cocktail, which led to attenuated C/EBPβ expression. In addition, ERK and GSK3β-dependent C/EBPβ phosphorylation was attenuated by andrographolide. Moreover, andrographolide suppressed cyclin A, cyclin E, and CDK2 expression and impaired the progression of mitotic clonal expansion (MCE) by arresting the cell cycle at the Go/G1 phase. Taken together, these results indicate that andrographolide has a potent anti-obesity action by inhibiting PKA-CREB-mediated C/EBPβ expression as well as C/EBPβ transcriptional activity, which halts MCE progression and attenuates C/EBPα and PPARγ expression.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, China Medical University Hospital, Taichung, Taiwan; Division of Endocrinology and Metabolism, Department of Chinese Medicine, China Medical University, China Medical University, Taichung, Taiwan.
authors.forename: Ching-Chu
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan.
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Chuang
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan.
authors.forename: Ai-Hsuan
authors.initials: AH
authors.lastname: Lin
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan.
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Tsai
authors.affiliation: Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan; Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chin-Shiu
authors.initials: CS
authors.lastname: Huang
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan.
authors.forename: Yun-Ting
authors.initials: YT
authors.lastname: Chen
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan. Electronic address: chenhw@mail.cmu.edu.tw.
authors.forename: Haw-Wen
authors.initials: HW
authors.lastname: Chen
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan; Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan. Electronic address: cklii@mail.cmu.edu.tw.
authors.forename: Chong-Kuei
authors.initials: CK
authors.lastname: Lii
mesh_terms: D041721:3T3-L1 Cells; D050156:Adipogenesis / Q000187:drug effects*; D000818:Animals; D019440:Anti-Obesity Agents / Q000494:pharmacology*; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004224:Diterpenes / Q000494:pharmacology*; D051379:Mice; D047495:PPAR gamma / Q000378:metabolism
chemical_list: D019440:Anti-Obesity Agents; D022782:CCAAT-Enhancer-Binding Protein-beta; C492004:Creb1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D004224:Diterpenes; D047495:PPAR gamma; C030419:andrographolide; D017868:Cyclic AMP-Dependent Protein Kinases
keywords: 3T3-L1; Adipogenesis; Andrographolide; CCAAT/enhancer-binding protein; Mitotic clonal expansion; cAMP response element-binding protein