ACTA ENDOCRINOLOGICA (BUC)

Background. Pomegranate is a rich source of many polyphenolic compounds including ellagitannins (punicalagin, punicalin and others). Aim. The effects of punicalagin and punicalin on adipogenesis were investigated in this study. Materials and Methods. To examine the effect of punicalagin and punicalin on adipocyte differentiation, various concentrations of punicalagin and punicalin (2- 10 μM) were applied to differentiated 3T3-L1 cells. Glyceraldehyde-3-phosphate dehydrogenase (GPDH) activity, Oil red O staining, intracellular triglyceride levels, and gene expressions of transcription factors (Peroxisome proliferator-activated receptor-γ (PPARγ), CCAATenhancer- binding proteins-α (C/EBPα), Sterol regulatory element-binding protein 1c (SREBP-1c)) and lipolysisassociated genes (hormone-sensitive lipase (HSL), Perilipin A, tumor necrosis factor-α (TNF-α)) were examined in order to investigate the effects of punicalagin and punicalin on adipocyte differentiation. Results. Punicalagin and punicalin applications caused a continuous decrease in cell size and intracellular triglyceride accumulation. GPDH activity and transcription gene expressions decreased significantly in groups that were applicated punicalagin and punicalin at high concentrations. Punicalagin, but not punicalin, down-regulated the expression of HSL and perilipin A and up-regulated the expression of TNF-α in a dose-dependent manner. In conclusion, both punicalagin and punicalin were able to inhibit the adipocyte differentiation.

Abstract Context. The inhibition of adipocyte differentiation has a significant role on the prevention of obesity and obesity-associated complications. Objective. In this study, we aimed to detect whether hyperoside is able to inhibit the conversion of pre-adiposits into mature adiposits. Design and Methods. 3T3-L1 pre-adipocytes were stimulated so as to differentiate into mature adipocytes. Hyperoside in non-cytotoxic concentrations (1, 2, 5, and 10 μM) were separately applied to differentiated 3T3-L1 cells. Oil red O staining was performed and triacylglycerol contents were measured. Furthermore, gene and protein expressions of transcription factors, adipogenic genes and adipokines were examined in order to investigate the effect of hyperoside on adipocyte differentiation. Results. Hyperoside in high concentrations significantly suppressed the adipogenic process by inhibiting the expression of transcription factors and adipogenic genes and reducing lipid accumulation in adipocytes (p<0.05). Low doses of hyperoside are able to inhibit adipogenesis, but higher doses are needed to reduce fat accumulation in mature adipocytes. In the case of maturing preadipocytes, 5 μ M of hyperoside exerts its antiadipogenic effect at the early stages of adipogenesis, whereas 10 μ M of hyperoside acts at the later stages (p<0.05). Conclusion. These results suggest that hyperoside has a beneficial effect on the prevention and treatment of obesity.