| Objective To investigate the effect of onion powder on bone mineral density (BMD) and serum calcium, phosphorus, and estradiol in ovariectomized rats. Methods Fifty-five female 3-month-old SD rats were divided into two groups, 10 rats in control group and 45 rats in ovariectomized group. After 1 week, the ovariectomized group were randomly divided into model group (OVX) , low dose onion group (LO) , middle dose onion group (MO)，and high dose onion group (HO). BMD was measured on 12 weeks and 24 weeks, respectively. Serum levels of calcium, phosphorus, and estradiol were measured on 24 weeks. Results After 12 weeks of ovariectomy, BMD in MO and LO group increased significantly comparing to that in OVX group (P <0.05). BMD in HO group increased slightly，with no statistical difference (P >0. 05). After 24 weeks，BMD in MO,LO,and HO group elevated significantly comparing to that in OVX group (P < 0.05). The levels of serum calcium and phosphorus in MO，HO, CON and OVX group enhanced significantly, comparing to that in LO group (P< 0. 05). The levels of serum calcium and phosphorus had no statistically significant difference between the other groups (P > 0. 05). The highest E2 level was in rats of MO group，followed in HO，CON，LO，and OVX group. The difference of E2 levels in rats were statistically significant compared between any two groups, except between that in LO group and OVX and CON group. Conclusion Onion increases E2 level in rats, promotes the secretion of estrogen, elevates the function of BMD, and achieves the goal of preventing and treating osteoporosis. |