Combination of ginsenosides with low dose estrogen showed synergetic effect on ovariectomy induced osteopenia in rats / 药学学报

ABSTRACT

<p><b>AIM</b>To determine whether low dose of estrogen in combination with ginsenosides can completely prevent bone loss in ovariectomized rats.</p><p><b>METHODS</b>Four-month-old ovariectomized rats were treated either with 100 and 300 mg.kg-1 of ginsenosides or 30 and 100 micrograms.kg-1 of 17 alpha-ethynylestradiol alone, or ginsenosides 100 mg.kg-1 in combination with 17 alpha-ethynylestradiol 30 micrograms.kg-1 for 10 weeks. Double in vivo fluorochrome labeling was made. The undecalcified longitudinal proximal tibial metaphyseal sections were processed and stained with Goldner's trichrome for histomorphometric analysis of the bone.</p><p><b>RESULTS</b>Body weights and serum cholesterol were increased in ovariectomized (OVX) rats. The rats lost 74% of bone volume and high bone turnover was induced after OVX compared with the sham group. Bone volume increased by 205% in the high dose estrogen treated group while it was increased by 105% in the low dose group. The two doses of estrogen were shown to inhibit osteoclasts surface (by -65% and -55%, P < 0.01) and decrease bone turnover rate (by -85% and -83%, P < 0.01). High dose of estrogen was found to inhibit growth and stimulate uterine weight gain in rats while low dose did not. High dose of ginsenosides increased bone volume by 84% (P < 0.01) and decreased bone turnover rate by -64% (P < 0.05) while lower dose of ginsenosides did not. However, low dose ginsenosides combined with low dose estrogen achieved well preventive effects increase of 202% in bone volume, decrease of 66% in bone turnover rate and 72% in osteoclasts surface. The combined effect in preventing bone loss equals to that the high dose of estrogen alone did.</p><p><b>CONCLUSION</b>Use of low dose of estrogen plus ginsenosides showed synergistic effect on prevention of osteoporosis induced by ovariectomy.</p>