Effects of Luteolin and Apigenin on Adipogenesis Markers PPARγ and FABP4 and Thermogenesis Marker UCP1 in 3T3-L1 Preadipocyte Cell Line.

Peroxisome proliferator-activated receptor γ (PPARγ) plays a crucial role in the differentiation and maturation of preadipocytes. PPARγ promotes adipogenesis by inducing the expression of fatty acid-binding protein 4 (FABP4). Uncoupling protein 1 (UCP1) is involved in non-shivering thermogenesis and adipocyte browning. The present study aimed to examine the effects of luteolin and apigenin on the gene expression levels and protein concentrations of PPARγ and FABP4, which are involved in adipogenesis, and their effect on UCP1, a thermogenic protein, in the 3T3-L1 preadipocyte cell line. Luteolin and apigenin were prepared at concentrations of 10, 20, and 40 µM and applied to 3T3-L1 preadipocytes during differentiation and maturation. Gene expression levels were measured by real-time PCR, and protein concentrations were measured by ELISA. It was found that the doses used did not cause cytotoxicity in the cells. Luteolin treatment during differentiation and maturation resulted in a decrease in PPARγ and FABP4 gene expression, although the protein concentrations remained unchanged. Additionally, while luteolin treatment did not significantly alter UCP1 gene expression or protein levels during differentiation, it led to a decrease in UCP1 protein concentration during maturation. Apigenin treatment also tended to decrease PPARγ and FABP4 gene expression compared to the control, although no statistical difference was observed. These results suggest that luteolin and apigenin may have regulatory effects on adipogenesis by modulating PPARγ, FABP4, and UCP1 gene expression.