Abstract
Syringaresinol-4-O-β-d-glucoside (SSG), a furofuran-type lignan, was found to modulate lipid and glucose metabolism through an activity screen of lipid accumulation and glucose consumption, and was therefore considered as a promising candidate for the prevention and treatment of metabolic disorder, especially in lipid and glucose metabolic homeostasis. In this study, the effects of SSG on lipogenesis and glucose consumption in HepG2 cells and C2C12 myotubes were further investigated. Treatment with SSG significantly inhibited lipid accumulation by oil red O staining and reduced the intracellular contents of total lipid, cholesterol and triglyceride in HepG2 cells. No effect was observed on cell viability in the MTT assay at concentrations of 0.1-10 μmol/L. SSG also increased glucose consumption by HepG2 cells and glucose uptake by C2C12 myotubes. Furthermore, real-time quantitative PCR revealed that the beneficial effects were associated with the down-regulation of sterol regulatory element-binding proteins-1c, -2 (SREBP-1c, -2), fatty acid synthase (FAS), acetyl CoA carboxylase (ACC) and hydroxyl methylglutaryl CoA reductase (HMGR), and up-regulation of peroxisome proliferator-activated receptors alpha and gamma (PPARα and PPARγ). SSG also significantly elevated transcription activity of PPARγ tested by luciferase assay. These results suggest that SSG is an effective regulator of lipogenesis and glucose consumption and might be a candidate for further research in the prevention and treatment of lipid and glucose metabolic diseases.