Grifola frondosa (Maitake) extract activates PPARδ and improves glucose intolerance in high-fat diet-induced obese mice

Biosci Biotechnol Biochem. 2018 Sep;82(9):1550-1559. doi: 10.1080/09168451.2018.1480348. Epub 2018 Jun 6.

Abstract

Grifola frondosa is a mushroom that has anti-obesity effects, but the detailed mechanism is poorly understood. In this study, we found that lipid soluble extracts derived from G. frondosa (GFE) had peroxisome proliferator-activated receptor δ (PPARδ) agonist activity, inducing the expression of PPARδ-target genes in vitro. Furthermore, administration of GFE to high-fat diet-induced obese mice lowered the total blood cholesterol levels, upregulated the expression of PPARδ-target genes in skeletal muscles and improved glucose intolerance. Additionally, analyses of C2C12 myotubes revealed that GFE restored glucose uptake, which was inhibited by sodium palmitate, to normal levels. Unexpectedly, such acceleration was not abolished by a PPARδ antagonist. These results suggest that G. frondosa is a novel functional food that may prevent life-style related diseases like obesity and diabetes, and that these beneficial effects are likely to be mediated through the activation of PPARδ and a PPARδ-independent insulin signaling pathway.

Keywords: Maitake mushroom; basidiomycetes; luciferase assay; myotubes; obesity.

MeSH terms

  • Adipose Tissue / metabolism
  • Animals
  • Cell Line
  • Cholesterol / blood
  • Diet, High-Fat*
  • Gene Expression Regulation
  • Glucose Tolerance Test*
  • Grifola / chemistry*
  • HEK293 Cells
  • Humans
  • Insulin / metabolism
  • Liver / metabolism
  • Male
  • Metabolic Syndrome / metabolism
  • Mice, Inbred C57BL
  • Muscle, Skeletal / metabolism
  • Obesity / etiology
  • Obesity / metabolism*
  • PPAR delta / agonists*
  • Signal Transduction
  • Up-Regulation

Substances

  • Insulin
  • PPAR delta
  • Cholesterol