Acer okamotoanum inhibits adipocyte differentiation by the regulation of adipogenesis and lipolysis in 3T3-L1 cells

Abstract

Acer okamotoanum is reported to have various antioxidant, anti-inflammatory and beneficial immune system effects. The anti-adipocyte differentiation effects and mechanisms of the ethyl acetate (EtOAc) fraction of an A. okamotoanum extraction was investigated in 3T3-L1 adipocyte cells. Treatment with differentiation inducers increased the level of triglycerides (TGs) in 3T3-L1 adipocyte cells compared with an untreated control. However, the EtOAc fraction of A. okamotoanum significantly decreased TGs. Treatment with 1, 2.5 and 5 mu g/ml showed weak activity, but TG production was inhibited at 10 mu g/ml compared with the control. In addition, A. okamotoanum caused a significant downregulation of proteins related to adipogenesis, such as gamma-cytidine-cytidine-adenosine-adenosine-thymidine/enhancer binding protein-alpha, -beta and peroxisome proliferator-activated receptor-gamma, compared with the untreated control. Furthermore, A. okamotoanum significantly upregulated lipolysis related protein, hormone-sensitive lipase and the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK). Therefore, these results indicate that A. okamotoanum suppressed adipogenesis and increased lipolysis and the activation of AMPK, suggesting a protective role in adipocyte differentiation.