Ethanolic extracts of Brazilian red propolis promote adipocyte differentiation through PPARγ activation

Aim of the study: The aim of present study was to investigate the effects of ethanolic extracts of red propolis (EERP) on adipogenesis and evaluate the molecular basis for their anti-obesity effects. Materials and methods: We tested whether EERP alone could induce differentiation of 313-L1 cells, regulate the expression of adipocyte-specific genes and reverse inhibitory effects of TNF-alpha on their differentiation. Next, we performed a luciferase reporter gene assay to test whether EERP could enhance transcriptional activities of PPAR gamma and adiponectin promoter activities. Results: EERP strongly induced differentiation of 313-L1 preadipocytes into adipocytes, and enhanced the PPAR gamma transcriptional activity and adiponectin promoter activity. In addition, EERP attenuated the inhibitory effect of TNF-alpha on adipocyte differentiation and adiponectin production in mature adipocytes. Conclusion: The present study indicates that EERP enhance differentiation of 31341 adipocytes in part by its potency of PPAR gamma activation and are capable of reversing inhibitory effects of TNF-alpha on adipocyte differentiation and adiponectin expression. These results suggest the value of EERP as a diet supplement for prevention and treatment of obesity and obesity-associated disorders. (C) 2010 Elsevier GmbH. All rights reserved.