Cynomorium songaricum prevents bone resorption in ovariectomized rats through RANKL/RANK/TRAF6 mediated suppression of PI3K/AKT and NF-κB pathways

Life Sci. 2018 Sep 15:209:140-148. doi: 10.1016/j.lfs.2018.08.008. Epub 2018 Aug 6.

Abstract

Aim: Cynomorium songaricum Rupr., an edible and important Traditional Chinese medicine has long been used in folk for treatment of kidney deficiency, was chosen to estimate the antiosteoporotic activity and underlying molecular mechanism on rats induced by ovariectomy (OVX).

Main methods: 9 of 45 rats were underwent bilateral laparotomy without removing the ovaries as sham group, remains were underwent bilateral ovariectomy and equally randomized into four groups: with vehicle (0.5% CMC-Na) as model group, estradiol valerate (1 mg/kg body weight/day) as positive control, with 100 and 300 mg/kg body weight/day of ethanol extracts of C. songaricum extract (CSE) as low and high dosage groups, respectively.

Key findings: After 12 weeks of continues orally intervention, the decreases of bone mineral density, bone mineral content, tissue mineral content, as well as the increases of bone trabecular separation and bone resorption markers were significantly reversed by CSE in the OVX rats, and in particular, a contradictory phenomenon on calcium and phosphorus contents was observed and elucidated. Mechanistically, the expressions of tumor-necrosis factor receptor-associated factor 6 (TRAF 6), nuclear factor kappa B (RANK) and its ligand (RANKL), as well as the nuclear factor kappa B (NF-κB), phosphoinositide 3‑kinase (PI3K) and protein kinase B (AKT) levels were significantly down-regulated by CSE intervention, whereas the osteoprotegerin (OPG) was significantly up-regulated by CSE as compared to the control.

Significance: Concisely, C. songaricum exhibited potential therapeutic effect on bone metabolism of ovariectomized rats, and this effect was possibly exerted by RANKL/RANK/TRAF6 mediated down-regulation of NF-κB and PI3K/AKT pathways.

Keywords: Bone formation; Bone resorption; Cynomorium songaricum Rupr.; Ovariectomized rats; TRAF6.

MeSH terms

  • Animals
  • Bone Resorption / etiology
  • Bone Resorption / metabolism
  • Bone Resorption / pathology
  • Bone Resorption / prevention & control*
  • Cynomorium / chemistry*
  • Female
  • Gene Expression Regulation / drug effects*
  • NF-kappa B / metabolism
  • Ovariectomy / adverse effects*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Plant Extracts / pharmacology*
  • Proto-Oncogene Proteins c-akt / metabolism
  • RANK Ligand / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptor Activator of Nuclear Factor-kappa B / metabolism
  • TNF Receptor-Associated Factor 6 / metabolism

Substances

  • NF-kappa B
  • Plant Extracts
  • RANK Ligand
  • Receptor Activator of Nuclear Factor-kappa B
  • TNF Receptor-Associated Factor 6
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt