Naringenin chalcone improves adipocyte functions by enhancing adiponectin production

Naringenin chalcone is a flavonoid contained in tomato peel. In this study, we investigated its effects on adipocyte functions related to metabolic processes, including adipocytokine production. Naringenin chalcone promoted the gene expression (8.0-fold, p<0.001) and protein secretion (2.2-fold, p<0.001) of Adiponectin from 3T3-L1 adipocytes. Reporter gene assays revealed that naringenin enhanced the activity of Peroxisome Proliferator-activated Receptor gamma. DNA microarray experiments and Gene Ontology analysis revealed that naringenin chalcone also up-regulated the genes associated with mitochondrial energy metabolism, reflecting its insulin-sensitizing effects. Conversely, genes in categories such as those for cell adhesion were down-regulated. The expression of one Adiponectin Receptor, AdipoR2, was also increased (1.8-fold, p<0.01), suggesting that naringenin chalcone could activate the Adiponectin pathway through the elevation of both the ligand and its receptor. These results indicate that naringenin chalcone is a potent tomato flavonoid that improves adipocyte metabolic functions and exerts insulin-sensitizing effects by activating an adiponectin-related pathway.