Inhibition of Irvingia gabonensis seed extract (OB131) on adipogenesis as mediated via down regulation of the PPARgamma and leptin genes and up-regulation of the adiponectin gene.
BACKGROUND
Endeavors to manage obesity have been heavily reliant on controlling energy intake and expenditure equilibrium, but have failed to curtail the overweight and obesity epidemic. This dynamic equilibrium is more complex than originally postulated and is influenced by lifestyle, calorie and nutrient intake, reward cravings and satiation, energy metabolism, stress response capabilities, immune metabolism and genetics. Fat metabolism is an important indicator of how efficiently and to what extent these factors are competently integrating. We investigated whether an Irvingia gabonensis seed extract (IGOB131) would provide a more beneficial comprehensive approach influencing multiple mechanisms and specifically PPAR gamma, leptin and adiponectin gene expressions, important in anti-obesity strategies.


METHODS
Using murine 3T3-L1 adipocytes as a model for adipose cell biology research, the effects of IGOB131 were investigated on PPAR gamma, adiponectin, and leptin. These adipocytes were harvested 8 days after the initiation of differentiation and treated with 0 to 250 microM of IGOB131 for 12 and 24 h at 37 degree C in a humidified 5 percent CO2 incubator. The relative expression of PPAR gamma, adiponectin, and leptin in 3T3-L1 adipocytes was quantified densitometrically using the software LabWorks 4.5, and calculated according to the reference bands of beta-actin.


RESULTS
The IGOB131 significantly inhibited adipogenesis in adipocytes. The effect appears to be mediated through the down-regulated expression of adipogenic transcription factors (PPAR gamma) [P less than 0.05] and adipocyte-specific proteins (leptin) [P less than 0.05], and by up-regulated expression of adiponectin [P less than 0.05].


CONCLUSIONS
IGOB131 may play an important multifaceted role in the control of adipogenesis and have further implications in in-vivo anti obesity effects by targeting the PPAR gamma gene, a known contributory factor to obesity in humans.
Oben
Julius E
JE
Department of Biochemistry, Faculty of Science, Laboratory of Nutrition and Nutritional Biochemistry, University of Yaoundé I, Yaoundé, Cameroon. juliusoben@hotmail.com
Ngondi
Judith L
JL
Blum
Kenneth
K
D050156:Adipogenesis / Q000187:drug effects*; D052242:Adiponectin / Q000235:genetics*; D000818:Animals; D002460:Cell Line; D002482:Cellulose / Q000737:chemistry*; D015536:Down-Regulation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D020738:Leptin / Q000235:genetics*; D051379:Mice; D047495:PPAR gamma / Q000235:genetics*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry; D014280:Triglycerides / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
D052242:Adiponectin; D020738:Leptin; D047495:PPAR gamma; D010936:Plant Extracts; D014280:Triglycerides; C051375:dikanut; D002482:Cellulose; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases