Icariin protects against bone loss induced by oestrogen deficiency and activates oestrogen receptor-dependent osteoblastic functions in UMR 106 cells

Man Sau Wong, Sao Keng Mok, Wen Fang Chen, Wan Ping Lai, Ping Chung Leung, Xin Luan Wang, Xin Sheng Yao

Research output: Journal article publicationJournal articleAcademic researchpeer-review

122 Citations (Scopus)

Abstract

Background and purpose: Icariin may be the active ingredient in Herba Epimedii, a Chinese herb commonly used for treatment of osteoporosis. The present study aims to delineate the mechanism(s) by which icariin prevents bone loss after ovariectomy (OVX) in vivo and stimulates osteoblastic functions in vitro. Experimental approach: Ovariectomized or sham-operated C57BL/6 mice were treated with vehicle, 17-oestradiol or icariin for 6 weeks. Total and trabecular bome mineral density (BMD) as well as polar stress-strain index of distal femur were measured by peripheral computed tomography. The mRNA expressions of OPG and RANKL in tibia were studied by RT-PCR. Interactions between the oestrogen receptor (ER) antagonist ICI182,780 and icariin were studied in UMR 106 cells. The functional transactivation of ER and ER as well as ER phosphorylation by icariin were also assessed. Key results: Icariin suppressed the loss of bone mass and strength in distal femur and increased the mRNA expression ratio of OPG/RANKL in tibia, following OVX. Icariin increased ER-dependent cell proliferation, alkaline phosphatase (ALP) activity, gene expression of OPG and the OPG/RANKL ratio in UMR 106 cells. Icariin did not activate ERE-luciferase activity in UMR 106 cells, via the ER or the ER-mediated pathway, but it did increase ER phosphorylation at Ser118. Conclusions and implications: Our results indicate that icariin exerts anabolic effects in bone possibly by activating ER in a ligand-independent manner. Its ability to prevent OVX-induced bone loss without inducing uterotrophic effects supports its use as an alternative regimen for management of postmenopausal osteoporosis.
Original languageEnglish
Pages (from-to)939-949
Number of pages11
JournalBritish Journal of Pharmacology
Volume159
Issue number4
DOIs
Publication statusPublished - 1 Feb 2010

Keywords

  • BMD
  • Estrogen receptors
  • Icariin
  • Osteoprotegerin
  • RANKL

ASJC Scopus subject areas

  • Pharmacology

Cite this