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


METHODS
We tested whether EERP alone could induce differentiation of 3T3-L1 cells, regulate the expression of adipocyte-specific genes and reverse inhibitory effects of TNF-α on their differentiation. Next, we performed a luciferase reporter gene assay to test whether EERP could enhance transcriptional activities of PPARγ and adiponectin promoter activities.


RESULTS
EERP strongly induced differentiation of 3T3-L1 preadipocytes into adipocytes, and enhanced the PPARγ transcriptional activity and adiponectin promoter activity. In addition, EERP attenuated the inhibitory effect of TNF-α on adipocyte differentiation and adiponectin production in mature adipocytes.


CONCLUSIONS
The present study indicates that EERP enhance differentiation of 3T3-L1 adipocytes in part by its potency of PPARγ activation and are capable of reversing inhibitory effects of TNF-α 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.
Iio
Akio
A
Gifu International Institute of Biotechnology, 1-1 Naka-Fudogaoka, Kakamigahara, Gifu 504-0838, Japan. aiio@giib.or.jp
Ohguchi
Kenji
K
Inoue
Hiroyasu
H
Maruyama
Hiroe
H
Araki
Yoko
Y
Nozawa
Yoshinori
Y
Ito
Masafumi
M
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects*; D050156:Adipogenesis / Q000187:drug effects*; D052242:Adiponectin / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019440:Anti-Obesity Agents / Q000494:pharmacology*; D035782:Dalbergia / Q000737:chemistry; D051379:Mice; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism*; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D011429:Propolis / Q000737:chemistry / Q000494:pharmacology*; D015533:Transcriptional Activation / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D052242:Adiponectin; D019440:Anti-Obesity Agents; D047495:PPAR gamma; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha; D011429:Propolis