Aim of the study: This study was conducted to elucidate the molecular mechanisms of SH21B, a traditional Korean herbal medicine commonly used for the treatment of obesity.
Materials and 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.
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