The WNT/β-catenin pathway mediates the anti-adipogenic mechanism of SH21B, a traditional herbal medicine for the treatment of obesity.
OBJECTIVE
This study was conducted to elucidate the molecular mechanisms of SH21B, a traditional Korean herbal medicine commonly used for the treatment of obesity.


METHODS
3T3-L1 preadipocytes were differentiated into adipocytes in the presence or absence of SH21B. Changes in mRNA or protein levels were analyzed using microarray, real-time polymerase chain reaction and western blotting analyses. Small interference (si)RNA transfection experiments were conducted to elucidate the essential role of β-catenin.


RESULTS
Microarray analyses showed that components of the WNT/β-catenin pathway including β-catenin, cyclin D1 and dishevelled 2 were up-regulated more than two-fold as a result of SH21B treatment during adipogenesis, which were confirmed by real-time PCR and western blotting. Modulation of the WNT/β-catenin pathway by SH21B resulted in the nuclear accumulation of β-catenin. Both intracellular lipid droplet formation and expressions of adipogenic genes including PPARγ, C/EBPα, FABP4 and LPL, which were inhibited by SH21B, were significantly recovered by β-catenin siRNA transfection.


CONCLUSIONS
SH21B modulates components of the WNT/β-catenin pathway during adipogenesis, and β-catenin plays a crucial role in the anti-adipogenic mechanism of SH21B.
Department of Microbiology, Chung-Ang University College of Medicine, 221 Heukseok-dong, Dongjak-gu, Seoul 156-756, Republic of Korea.
Haeyong
H
Lee
Sungmin
S
Bae
Yoosik
Y
Yoon
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D020834:Ethnopharmacology; D006801:Humans; D055670:Medicine, Korean Traditional; D051379:Mice; D009765:Obesity / Q000188:drug therapy* / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D008517:Phytotherapy; D028321:Plant Preparations / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D056910:Republic of Korea; D015398:Signal Transduction / Q000187:drug effects; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
C495267:CTNNB1 protein, mouse; D028321:Plant Preparations; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051153:Wnt Proteins; D051176:beta Catenin