2009 Volume 56 Issue 1 Pages 31-39
Recently, the adipocyte differentiation mechanism and adiponectin secretion have been attracting attention due to their relationship with diabetes and hyperlipidemia. We investigated the effects of propolis extract on differentiation of the 3T3-L1 preadipocytes. These cells were cultured in the presence of propolis extract, and then intracellular lipid droplets were stained with oil Red O to determine the amount of adiponectin produced in culture medium by ELISA. We found that the propolis extract significantly increased triglyceride content in the cells, indicating that 3T3-L1 cells differentiated to adipocytes in the presence of insulin. Furthermore, propolis extract abolished the suppressive effect on adipocyte differentiation and adiponectin secretion of TNF-α in the presence of dexamethasone, methylisobutylxanthine and insulin. In addition, assays of the ligand-activated nuclear receptor proteins showed that propolis extract has potential as a PPAR-γ activator. These results suggest the value of propolis extract as an antidiabetic diet for regulating lipid metabolism and insulin sensitivity.
