Inhibitory Effect of Galanolactone Isolated from Zingiber officinale Roscoe Extract on Adipogenesis in 3T3-L1 Cells

摘要

Zingiber officinale Roscoe commonly known as ginger, has been used in traditional medicine. Inhibtion effect of galanolactone isolated from Z. officinale Roscoe on adipogenesis in 3T3-L1 cells was evaluated. Effect of galanolactone on 3T3-L1 adipocyte differentiation was measured by Oil Red 0 staining, and cytotoxicity effect of galanolactone was analyzed by 344,5-dimethylthiazol-2-y1]-2,5-diphenyltetrazolium bromide assay. The expression of various genes involved in adipogenic action of galanolactone was determined by real-time PCR and Western blot. Peroxisome proliferator-activated receptor gamma (PPAR gamma) luciferase transactivation assay was used to evaluate the PPAR gamma transcriptional activity of galanolactone in HEK 293T cells. Galanolactone inhibited lipid accumulation and expression of adipocyte fatty acid-binding protein (aP2) and resistin in a dose-dependent manner in 3T3-L1 cells. Treatment with 50 and 100 mu M of galanolactone significantly decreased the troglitazone-induced PPAR gamma transcripitional activity in HEK 293T cells, and suppressed expressions of PPAR gamma and CCAAT-enhancer-binding protein a (C/EBP alpha.) at mRNA and protein levels in 3T3-L1 cells. These findings suggest that galanolactone isolated from Z. officinale Roscoe exerts anti-obesity effect through downregulation of adipogenic transcription factors and adipogenic marker genes.