Bergamot Polyphenol Fraction Exerts Effects on Bone Biology by Activating ERK 1/2 and Wnt/β-Catenin Pathway and Regulating Bone Biomarkers in Bone Cell Cultures

Nutrients. 2018 Sep 14;10(9):1305. doi: 10.3390/nu10091305.

Abstract

Epidemiological studies show that fruit consumption may modulate bone mineral density. However, data regarding the effect of the Citrus bergamia Risso (Bergamot orange), a citrus fruit containing a high concentration of flavonoids, on bone health are still lacking. In this study, we investigated the effects of Bergamot polyphenols on the Wnt/β-catenin pathway in two distinct bone cell types (Saos-2 and MG63). Findings showed that exposure to 0.01 and 0.1 mg/mL doses upregulate β-catenin expression (p = 0.001), osteoblast differentiation markers (e.g., RUNX2 and COL1A), and downregulate RANKL (p = 0.028), as compared to the control. Our results highlight, for the first time, that Bergamot polyphenols act on bone cells through the β-catenin pathway. In vivo studies are necessary to fully understand Bergamot's role against bone resorption.

Keywords: Bergamot; Saos-2; bone cells; citrus fruits; osteoporosis; polyphenols; β-catenin.

MeSH terms

  • Biomarkers / metabolism
  • Bone Remodeling / drug effects*
  • Cell Differentiation / drug effects
  • Cell Line
  • Citrus* / chemistry
  • Collagen Type I / genetics
  • Collagen Type I / metabolism
  • Core Binding Factor Alpha 1 Subunit / genetics
  • Core Binding Factor Alpha 1 Subunit / metabolism
  • Enzyme Activation
  • Fruit
  • Humans
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • Osteoblasts / drug effects*
  • Osteoblasts / enzymology
  • Phosphorylation
  • Plant Extracts / isolation & purification
  • Plant Extracts / pharmacology*
  • Polyphenols / isolation & purification
  • Polyphenols / pharmacology*
  • RANK Ligand / genetics
  • RANK Ligand / metabolism
  • Wnt Signaling Pathway / drug effects*
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • Biomarkers
  • CTNNB1 protein, human
  • Collagen Type I
  • Core Binding Factor Alpha 1 Subunit
  • Plant Extracts
  • Polyphenols
  • RANK Ligand
  • RUNX2 protein, human
  • TNFSF11 protein, human
  • beta Catenin
  • MAPK1 protein, human
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3