Ethanol extract of Fructus Ligustri Lucidi increases circulating 1,25-dihydroxyvitamin D3by inducing renal 25-hydroxyvitamin D-1α hydroxylase activity

Xiao Li Dong, Yan Zhang, Murray J. Favus, Chun Tao Che, Man Sau Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)

Abstract

Objective: The present study was designed to determine whether Fructus Ligustri Lucidi (FLL) ethanol extract can directly regulate vitamin D metabolism both in vivo and in vitro. Methods: Eleven-month-old, aged Sprague-Dawley sham-operated and ovariectomized (OVX) female rats were fed a normal-calcium (Ca) diet (0.6% Ca, 0.65% phosphorus) and received either FLL (700 mg/kg) or vehicle daily for 12 weeks. The in vitro effects of FLL on vitamin D metabolism were studied using primary cultures of the rat renal proximal tubules. mRNA and protein expressions of 25-hydroxyvitamin D-1α hydroxylase (1-OHase) and vitamin D receptor (VDR) in the kidney and proximal tubule were measured using real-time polymerase chain reaction and Western blotting, respectively. The concentrations of 1,25-dihydroxyvitamin D3(1,25(OH)2D3) synthesized by renal 1-OHase were measured by a competitive enzyme immunoassay. Results: FLL treatment significantly increased serum 1,25(OH)2D3levels in both sham (P < 0.01) and OVX (P < 0.05) rats. FLL increased renal 1-OHase and VDR protein and mRNA expressions in sham rats. Protein expression of renal 1-OHase, but not VDR, was also up-regulated in OVX rats during FLL treatment. 1-OHase mRNA and 1-OHase activity were increased by FLL treatment in primary cultures of renal proximal tubule cells. Conclusions: FLL could increase the circulating levels of 1,25(OH)2D3in vivo in aged female rats by directly stimulating 1-OHase activity. Thus, it might be an ideal oral agent that can help to improve the ability to induce 1,25(OH)2D3synthesis and Ca balance in postmenopausal women who are of high risk of developing osteoporosis.
Original languageEnglish
Pages (from-to)1174-1181
Number of pages8
JournalMenopause
Volume17
Issue number6
DOIs
Publication statusPublished - 1 Nov 2010

Keywords

  • 1,25-Hydroxyvitamin D 3
  • 25-Hydroxyvitamin D 1-α hydroxylase
  • Fructus Ligustri Lucidi
  • Vitamin D metabolism
  • Vitamin D receptor

ASJC Scopus subject areas

  • Obstetrics and Gynaecology

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