BACKGROUND
Cryptotanshinone (CT), a major tanshinone found in Salvia miltiorrhiza Bunge (Lamiaceae), has various pharmacological effects such as antitumor, anti-inflammatory, and antioxidant properties. Despite its well-documented benefits in a wide range of diseases, the effect of CT on adipocyte differentiation has not been well characterized.
OBJECTIVE
The present study was designed to determine the in vitro anti-adipogenic effect and underlying molecular mechanisms of CT using 3T3-L1 murine pre-adipocytes.
METHODS
We measured the levels of intracellular triglyceride accumulation and mRNA and protein expression of key adipogenic transcription factors and their target genes.
RESULTS
Treatment with CT drastically reduced lipid accumulation in a dose- and time-dependent manner. Molecular assays showed that CT effectively suppressed the expression of C/EBPβ, C/EBPα, and PPARγ and of their target adipocyte-specific genes aP2, adiponectin, and GLUT4 but activated the expression of anti-adipogenic genes such as GATA2, CHOP10, and TNF-α. CT treatment also inhibited the phosphorylation of STAT3 in the early phase of adipogenesis. A small-interfering-RNA-mediated knock-down of STAT3 potentiated the anti-adipogenic effect of CT.
CONCLUSIONS
Taken together, the results suggest that CT may be a good anti-adipogenic candidate because it regulates STAT3 during early adipogenesis.