Fructus ligustri lucidi (FLL) is a widely used herb in China that is classically included in antiaging formulas for the treatment of age-related symptoms. Our laboratory previously showed that FLL could regulate calcium balance in young ovariectomized (OVX) rats. In the present study, we aimed to determine whether FLL could regulate calcium balance in aged OVX rats and to study the potential mechanisms that mediate its action in vivo.
Aged OVX rats were orally administered an ethanol extract of FLL and its vehicle and fed with diets containing different levels of calcium [low calcium diet (LCD), 0.1% Ca; medium calcium diet (MCD), 0.6% Ca; and high calcium diet (HCD), 1.2% Ca] for 12 weeks.
Significant reductions in urinary and fecal calcium excretion were found in the FLL-treated animals, resulting in a significant induction of calcium retention in rats fed with the MCD and HCD. FLL treatment significantly increased the serum 1,25-dihydroxyvitamin D3 level and slightly decreased the serum parathyroid hormone level in OVX rats fed with the MCD and HCD. When OVX rats were challenged by LCD, the inductions of serum parathyroid hormone and 1,25-dihydroxyvitamin D3 were decreased by FLL administration. FLL treatment significantly up-regulated duodenal vitamin D receptor and calcium transport protein 1 mRNA expression in rats fed with the HCD. FLL treatment reduced the expression of renal vitamin D receptor and 25-hydroxyvitamin D-24-hydroxylase mRNA in OVX rats fed with the LCD and MCD.
Twelve weeks of FLL treatment could reduce calcium loss, modulate the parathyroid hormone-vitamin D axis, and increase vitamin D-dependent calcium transport in aged OVX rats, suggesting that FLL might be useful as an alternative medicine for improving calcium balance in postmenopausal women.
Treatment with the herb fructus ligustri lucidi (FLL) can improve calcium balance by a well-characterized mechanism of stimulating the gene expression of 1,25-dihydroxyvitamin D3-dependent calcium transport proteins and regulating vitamin D metabolism in aged ovariectomized rats. The results suggest that FLL might be useful as an alternative medicine for improving calcium balance in postmenopausal women.
From the 1Shenzhen Research Institute, The Hong Kong Polytechnic University, State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Shenzhen; 2Central Laboratory of the Institute of Molecular Technology for Drug Discovery and Synthesis, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; 3Department of Medical Psychology and Psychiatry, Medical College of Qingdao University, Qingdao; and 4Department of Orthopaedics and Traumatology and 5School of Chinese Medicine, Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China.
Received May 25, 2007; revised and accepted July 6, 2007.
Funding/support: This work was supported by the Areas of Excellence Scheme established under the University Grants Committee of the Hong Kong Special Administrative Region, China (AOE/P-10/01) and by the CERG grant (POLYU 5402/04M) from the Hong Kong Research Grant Council, Hong Kong SAR.
Financial disclosure: None reported.
Address correspondence to: Dr. Man-Sau Wong, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, PRC. E-mail: firstname.lastname@example.org