RESUMEN
Objective:To observe the effect of icariin on the osteoporosis of the ovariectomized rats,and to explore the mechanism.Methods:Fifty female rats aged 6 months were randomly divided into sham operation group, model group,positive drug group,low dose of icariin group and high dose of icariin group (n= 10).The rats in positive drug group were given with 1 mg· kg-1 nilestriol every week;the rats in low and high doses of icariin groups were given with 50 and 100 mg · kg-1 icariin every day.The bilateral ovaries of rats were excised by operation to establish the osteoporosis models.2 weeks after operation,the rats were treated with icariin for 12 weeks,and then they were sacrificed by drawing blood from abdominal aorta under anesthesia condion.The bone mineral density (BMD),serum biochemical indicators,bone histomorphology and the expressions of apoptosis-related proteins were detected.Results:Compared with sham operation group,the BMD of the rats in model group was decreased (P <0.01),the serum calcium level was decreased (P <0.05),and the serum phosphorus level was increased (P <0.05),and the serum BGP,ALP,NO and NOS levels were significantly decreased (P <0.05 or P <0.01).Compared with model group,the BMD of the rats in positive drug group and high dose of icariin group were obviously increased (P < 0.01 ), the serum calcium levels were increased, the phosphorus levels were decreased (P <0.05),and the BGP and ALP levels were increased significantly (P < 0.05 ). Compared with control group,the cortical in model group was thinned,the width of bone trabecula was reduced,the Bax and Caspase-3 expression levels in bone tissue were increased,and the Bcl-2 expression level was decreased.Compared with model group,the cortical in icariin group was thicked,the width of bone trabecula was increased,the Bax and Caspase-3 expression levels were decreased,and the Bcl-2 expression level was increased (P <0.05 or P <0.01). Conclusion:Icariin can protect the osteoporosis of ovariectomized rats,the function may be related to the inhibition of apoptosis.