title: Inhibitory Effects of Hwangryunhaedok-Tang in 3T3-L1 Adipogenesis by Regulation of Raf/MEK1/ERK1/2 Pathway and PDK1/Akt Phosphorylation.
abstract: Hwangryunhaedok-tang (HRT) has been long used as traditional medicine in Asia. However, inhibitory role of HRT is unclear in early stage of 3T3-L1 adipocyte differentiation related to signaling. In the present study, we investigated the inhibitory effects of HRT on upstream signaling of peroxisome proliferation-activity receptor- γ (PPAR- γ ) and CCAAT/enhancer binding protein- β (C/EBP- β ) expression in differentiation of 3T3-L1 preadipocytes. We found that HRT significantly inhibited the adipocyte differentiation by downregulating several adipocyte-specific transcription factors including PPAR- γ , C/EBP- α , and C/EBP- β in 3T3-L1 preadipocytes. Furthermore, we observed that HRT markedly inhibited the differentiation media-mediated phosphorylation of Raf/extracellular mitogen-activated protein kinase 1 (MEK1)/signal-regulated protein kinase 1/2 (ERK1/2) and phosphorylation of phosphoinositide-dependent kinase 1 (PDK1)/Akt. These results indicate that anti-adipogenesis mechanism involves the downregulation of the major transcription factors of adipogenesis including PPAR- γ and C/EBP- α through inhibition of Raf/MEK1/ERK1/2 phosphorylation and PDK1/Akt phosphorylation by HRT. Furthermore, high performance liquid chromatography (HPLC) analysis showed HRT contains active antiobesity constituents such as palmatine, berberine, geniposide, baicalin, baicalein, and wogonin. Taken together, this study suggested that anti-adipogenesis effects of HRT were accounted by downregulation of Raf/MEK1/ERK1/2 pathway and PDK1/Akt pathway during 3T3-L1 adipocyte differentiation.
authors.affiliation: Traditional Korean Medicines- (TKM-) Based Herbal Drug Research, Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 305-811, Republic of Korea.
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Kwak
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Lee
authors.forename: Dong-Gun
authors.initials: DG
authors.lastname: Kim
authors.forename: Taesoo
authors.initials: T
authors.lastname: Kim
authors.forename: Kwang Jin
authors.initials: KJ
authors.lastname: Lee
authors.forename: Jin Yeul
authors.initials: JY
authors.lastname: Ma