Inhibitory effects of Aster spathulifolius extract on adipogenesis and lipid accumulation in 3T3-L1 preadipocytes.

Abstract

Aster spathulifolius Maxim (AS), known for its anti-viral and anti-allergic activity, is also known to reduce body weight gain in high fat diet-induced obese rats. But its molecular mechanism of the anti-obesity effects is still unclear. So, we investigated the inhibitory effect of AS extract (ASE) on adipogenesis and lipid accumulation to determine the underlying cellular molecular mechanism. To perform this study, the contents of intracellular triglyceride were analysed. Real-time polymerase chain reaction and Western blotting were carried out to investigate the expression of adipogenic transcriptional factors. ASE showed the suppression of adipogenic differentiation and the considerable reduction of the lipid accumulation in 3T3-L1 cells. Especially, ASE inhibited the early stage of differentiation via the downregulation of C/EBP-β and C/EBP-δ, which are early adipogenic factors. Major adipogenic factors, such as PPAR-γ and C/EBP-α, were also subsequently inhibited. These findings were supported by Oil Red O staining and intracellular triglyceride levels. A molecular mechanism liking the effect of ASE was identified through the activation of AMPKα pathway. ASE increased protein levels of phosphorylated AMPKα and phosphorylated ACC. ASE showed anti-adipogenic and anti-lipogenic effects through the regulation of adipogenic factors and AMPKα pathway.