Inhibition of RANKL-induced osteoclast differentiation through the downregulation of c-Fos and NFATc1 by Eremochloa ophiuroides (centipedegrass) extract

Mol Med Rep. 2016 May;13(5):4014-22. doi: 10.3892/mmr.2016.5015. Epub 2016 Mar 18.

Abstract

Osteoclasts, derived from hematopoietic stem cells, are specialized macrophages and have a homeostatic role in skeletal modeling and remodeling with bone-forming osteoblasts. However, excessive osteoclast activity induces bone diseases, including osteoporosis, periodontitis and rheumatoid arthritis. Natural substances have received attention as therapeutic drugs in human diseases. In the current study, cells isolated from mouse bone marrow, and a mouse model, were used to determine the effect of centipedegrass extract (CGE) on osteoclasts. Multiple concentrations of CGE were administered to bone marrow cells for 24‑72 hours and, for the in vivo study, mice were treated with CGE for 8 days. The effects of CGE on transcription and translation of osteoclast-associated molecules were then determined using reverse transcription-polymerase chain reaction and immunoblotting, respectively. In the present study it was shown that CGE extracted from Eremochloa ophiuroides (centipedegrass) inhibited receptor activator of nuclear factor κ‑B ligand (RANKL)‑mediated osteoclast differentiation in bone marrow macrophages, without cytotoxicity, in a dose‑dependent manner. CGE decreased the expression levels of osteoclast‑specific genes, including matrix metalloproteinase‑9, osteoclast‑associated immunoglobulin‑like receptor and cathepsin K, however, CGE had no inhibitory effect on the expression levels of mitogen‑activated protein kinases, nuclear factor‑κB and Akt. Furthermore, the protein and RNA levels of RANKL‑induced c‑Fos and nuclear factor of activated T-cell cytoplasmic 1 were suppressed by CGE. These results indicated that CGE may serve as a useful drug in the prevention of bone loss.

MeSH terms

  • Animals
  • Cell Differentiation / drug effects*
  • Cell Line
  • Dose-Response Relationship, Drug
  • Down-Regulation / drug effects*
  • Humans
  • Male
  • Mice
  • Mice, Inbred ICR
  • NFATC Transcription Factors / biosynthesis*
  • Osteoclasts / cytology
  • Osteoclasts / metabolism*
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Poaceae / chemistry*
  • Proto-Oncogene Proteins c-fos / biosynthesis*
  • RANK Ligand / antagonists & inhibitors
  • RANK Ligand / metabolism*

Substances

  • NFATC Transcription Factors
  • Nfatc1 protein, mouse
  • Plant Extracts
  • Proto-Oncogene Proteins c-fos
  • RANK Ligand
  • Tnfsf11 protein, mouse