Effects of Fructus Ligustri Lucidi extract on bone turnover and calcium balance in ovariectomized rats

The aim of this study was to evaluate the effect of Fructus Ligustri Lucidi (FLL), a kidney-tonifying Chinese herbal medicine, on the biochemical markers of bone turnover, calcium metabolism and balance in osteoporotic rat model developed by ovariectomy. Four weeks after surgical operation, animals were randomly assigned to one of the four treatments for 14 weeks: sham-operated control treated with vehicle (sham, n=8), ovariectomized group treated with vehicle (OVX, n=8), OVX group treated with 17beta-estradiol (E(2), n=10, 2 microg/kg/d) and OVX group treated with FLL extracts (FLL, n=10, 550 mg/kg/d). Serum osteocalcin and urinary deoxypyridinoline levels were upregulated in rats in response to OVX, suggesting that the bone turnover rate was accelerated in these animals. Treatment of OVX rats with FLL extract could prevent OVX-induced increase in bone turnover by suppression of both serum osteocalcin (p<0.05, vs. OVX) and urinary deoxypyridinoline (p<0.05, vs. OVX) levels. In addition, FLL extract could prevent OVX-induced loss of calcium in rats by increasing the intestinal calcium absorption rate (p<0.01, vs. OVX), suppressing urinary Ca excretion (p<0.05, vs. OVX) as well as increasing bone calcium content (p<0.05, vs. OVX). Our study is the first to report that FLL can modulate bone turnover and calcium balance in OVX rats and it might be a potential candidate for prevention and treatment of postmenopausal osteoporosis.