Effects of Various 5,7-Dihydroxyflavone Analogs on Adipogenesis in 3T3-L1 Cells

We studied the effects of twelve 5,7-dihydroxyflavone analogs on adipogenesis in 3T3-L1 cells. Among the compounds, luteolin, diosmetin, and chrysoeriol partly inhibited adipogenesis by blocking the accumulation of triacylglycerol in the cells. Conversely, tricetin facilitated triacylglycerol accumulation in the cells. The induction of lipogenesis or lipolysis may depend on the number and bonding position of hydroxyl or methoxy groups on the B ring of 5,7-dihydroxyflavone. The mRNA expression levels of adipogenic and lipogenic genes were suppressed by luteolin treatment in the cells, while the mRNA levels of lipolytic genes were not affected. However, the expression levels of the adipogenic, lipogenic, and lipolytic genes, except for adipocyte protein 2 (aP2), were not affected by the addition of tricetin. Moreover, luteolin suppressed glucose transporter type 4 (GLUT4) gene and protein levels. These results indicate that luteolin decreased triacylglycerol levels in 3T3-L1 cells during adipogenesis through the suppression of adipogenic/lipogenic and GLUT4 genes and GLUT4 protein.