L6 근육세포에서 포도당 및 지질 대사에 미치는 제주조릿대 (Sasa quelpaertensis Nakai) 추출물과 p-coumaric acid의 영향

Abstract

This study was performed to investigate whether the extract of Sasa quelpaertensis Nakai (Jeju dwarf bamboo extract, JBE) and its main compound, p-coumaric acid (CA) could modulate glucose and lipid metabolism in L6 muscle cells. JBE stimulated uptake of 2-NBD glucose (2-NBDG). JBE also increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), but decreased the phosphorylation of Akt. Futhermore, JBE increased the expression of peroxisome proliferator-activated receptor γ (PPARγ), fatty acid translocase (FAT/CD36) and PPARα. In oleic acid-treated cells, JBE suppressed oleic acid-induced intracellular triglyceride (TG) contents by decreasing the expression of sterol regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase (FAS). Also, it increased the phosphorylation of AMPK and ACC, and the expression of PPARα. A major compound of JBE, p-coumaric acid (CA) increased not only the phosphorylation of AMPK and ACC but also the expression of carnitine palmitoyltransferase-1 (CPT-1) gene. In addition, CA significantly decreased oleic acid-induced intracellular TG contents, and increased uptake of 2-NBDG. Treatment of Compound C (AMPK inhibitor) resulted in a decrease of ACC phosphorylation and an increase of TG contents as well as a decrease of 2-NBDG uptake, while these inhibitions were recovered by CA treatment. In conclusion, these results suggest that JBE and CA may have potential for natural resource to prevent and improve type 2 diabetes by regulating glucose and lipid metabolism via AMPK signaling pathway in L6 muscle cells. Key words: L6 muscle cells, Sasa quelpaertensis Nakai, p-coumaric acid, AMP-activated protein kinase (AMPK), glucose and lipid metabolism