Lipid-Modulating Effects of Aqueous Extract of Rubus Occidentalis in Hepatocarcinoma HepG2 Cells

Abstract

Little knowledge exists on the lipid-modulating effect of Rubus occidentalis (RO). The present study investigated the molecular mechanisms of lipid-modulating effects of aqueous extract of RO (ROW) in hepatocarcinoma HepG2 cells. ROW decreased apolipoprotein B100 (ApoB100)/apolipoprotein A-1 (ApoA-1) ratio. ROW increased the expression of LDL-receptor (LDL-R). ROW decreased the gene expression of sterol regulatory element-binding protein 1c (SREBP-1c) as well as fatty acid synthase in a concentration-dependent manner. ROW not only down-regulated gene expression of SREBP-2 and HMG-CoA synthase mRNA expression, but also inhibited HMG-CoA reductase activity in a concentration-dependent manner (IC50 = 240.6 μg/ml). These results indicate that ROW decreases the level of bad cholesterol and increases good cholesterol levels by lowering the gene expression of transcription factors, SREBP-1c and SREBP-2, and by inhibiting the expression and/or activity of their downstream enzymes such as fatty acid synthase and HMG-CoA synthase and reductase.