Anti-adipogenic activity of compounds isolated from Idesia polycarpa on 3T3-L1 cells

Abstract

Recently, obesity is a complex multifactorial chronic disease increasing the risk for type 2 diabetes, coronary heart disease and hypertension, and has become a major worldwide health problem. In the course of screening natural products employing 3T3-L1 cells as an in vitro system, the methanol extract of Idesia polycarpa Maxim. Fruits (Flacourtiaceae) significantly inhibited adipocyte differentiation by measuring lipid contents using oil red O staining. One new compound, 6-(oxymethyl)-2-hydroxyphenyl-O- beta-D-glucopyranosyl-(1 -> 6)-beta-D-glucopyranoside (8), was isolated along with nine known compounds (1-7 and 9-10) from CHCl3 and n-BuOH fractions of the methanol extract of I. polycarpa fruits. Among them, idescarpin (1) with 1-hydroxy-6-oxo-2-cyclohexenecarboxylate moiety showed the most potent inhibitory activity on adipocyte differentiation with IC50 values of 23.2 mu M. Idescarpin (1) dramatically suppressed the induction of C/EBP alpha expression, whereas it significantly increased the induction of PPAR gamma expression, supported by quantitative real time PCR and Western blot analysis. The down-regulation in mRNA levels of SREBP1c, SCD-1, and FAS by idescarpin (1) during adipocyte differentiation revealed that the inhibition of adipocyte differentiation was mediated by the regulation of lipogenesis. Taken together, we suggest that idescarpin (1) shows a great potential against obesity and diabetes though the anti-adipogenic activity and the up-regulation of PPAR gamma. (C) 2013 Elsevier Ltd. All rights reserved.