Glu-Phe from onion (Allium Cepa L.) attenuates lipogenesis in hepatocytes

Biosci Biotechnol Biochem. 2017 Jul;81(7):1409-1416. doi: 10.1080/09168451.2017.1303358. Epub 2017 Mar 27.

Abstract

A Glu-Phe (EF) was isolated from onion (Allium cepa L. cv. Sunpower). The chemical structure of EF was determined by nuclear magnetic resonance and electrospray ionization-mass (ESI-MS) spectroscopy. We showed that EF reduced lipid accumulation in mouse hepatocytes by inhibiting the expression of sterol regulatory element-binding protein-1c (SREBP-1c) and its lipogenic target genes. We also found that AMP-activated protein kinase (AMPK) was required for the inhibitory effect of EF on lipid accumulation in mouse hepatocytes. Furthermore, EF was qualified in nine onion cultivars by selective multiple reaction-monitoring detection of liquid chromatography-ESI-MS. These results suggest that EF could contribute to the beneficial effect of onion supplement in maintaining hepatic lipid homeostasis.

Keywords: SREBP-1c; dipeptide; hepatocytes; lipogenesis; onion.

MeSH terms

  • AMP-Activated Protein Kinases / genetics
  • AMP-Activated Protein Kinases / metabolism
  • Acetyl-CoA Carboxylase / genetics
  • Acetyl-CoA Carboxylase / metabolism
  • Animals
  • Cell Line
  • Cell Survival / drug effects
  • Dipeptides / isolation & purification
  • Dipeptides / pharmacology*
  • Fatty Acid Synthase, Type I / genetics
  • Fatty Acid Synthase, Type I / metabolism
  • Gene Expression Regulation
  • Hepatocytes / cytology
  • Hepatocytes / drug effects*
  • Hepatocytes / metabolism
  • Hypolipidemic Agents / isolation & purification
  • Hypolipidemic Agents / pharmacology*
  • Lipogenesis / drug effects*
  • Lipogenesis / genetics
  • Mice
  • Onions / chemistry*
  • Plant Extracts / chemistry
  • Signal Transduction
  • Stearoyl-CoA Desaturase / genetics
  • Stearoyl-CoA Desaturase / metabolism
  • Sterol Regulatory Element Binding Protein 1 / antagonists & inhibitors
  • Sterol Regulatory Element Binding Protein 1 / genetics*
  • Sterol Regulatory Element Binding Protein 1 / metabolism

Substances

  • Dipeptides
  • Hypolipidemic Agents
  • Plant Extracts
  • Srebf1 protein, mouse
  • Sterol Regulatory Element Binding Protein 1
  • gamma-glutamylphenylalanine
  • Scd1 protein, mouse
  • Stearoyl-CoA Desaturase
  • Fatty Acid Synthase, Type I
  • AMP-Activated Protein Kinases
  • Acetyl-CoA Carboxylase