Anti-obesity effects of galla rhois via genetic regulation of adipogenesis

Abstract

In the present study, we investigated the effects of Galla Rhois (GR) on obesity and gene expression. We prepared a GR extract and various solvent fractions and evaluated the degree to which they inhibited adipocyte differentiation and adipogenesis in vitro. Among them, the GR ethyl acetate fraction (GE) had the lowest EC50 for adipocyte differentiation and adipogenesis and thus was selected for in vivo experiments. We induced obesity in C57BL/6 mice by providing them a high-fat diet (HFD). Then, GE (10-40 mg/kg) or orlistat (positive control, 4 mg/kg) was orally administered daily for six weeks. Mean body weights and weight gain were significantly lower in the GE40 group (40 mg/kg of GE) compared with the HFD group (p < 0.05). The most significant changes in serum glucose, total cholesterol, and triglyceride levels were confirmed in the GE40 group (p < 0.05). Epididymal fat was weighed and stained for body fat measurement, and significant differences were recorded from GE10 to GE40 (p < 0.05). Finally, 3T3-L1 pre-adipocytes were treated with GE, and cDNA from these cells was used for microarray analysis and qRT-PCR. Microarray analysis revealed 13 genes up-regulated and 21 genes down regulated by GE. From the qRT-PCR analysis, we found that GE altered the mRNA expression of eosinophil peroxidase, glucose-dependent insulinotropic polypeptide receptor, and apolipoprotein B. Based on this study, we suggest that GR could be developed as an anti-obesity therapeutic agent.