Effects of Curcumin on Bone Metabolism Balance in Ovariectomized Osteoporosis Model Rats Based on OPG/ RANKL Signaling Pathway / 中国药房

ABSTRACT

OBJECTIVE：To investigate the effects of curcumin on bone metabolism balance in ovariectomized osteoporosis model rats ，and to investigate its potential mechanism. METHODS ：Totally female Wistar rats were randomly divided into blank group（group A ），model group （group B ），estradiol group [group C （positive control ），estradiol valerate 50 μg（/ kg·d）]， curcumin low-dose ，medium-dose and high-dose groups [group D-F ，55，110，165 μg（/ kg·d）]，with 15 rats in each group. Except for group A ，other rats were ovariectomized to establish osteoporosis model. After modeling ，group A and B were given normal saline intrgastrically ，and administration groups were given relevant medicine intrgastrically 30 mL/kg，once a day ，for consecutive 12 weeks. The contents of serum bone metabolism markers [BALP ，CBF-α1，CTX-Ⅰ，PINP and OC] were determined by ELISA. The bone mineral density （BMD）and trabecular structure indexes [relative bone volume fraction （BV/TV），trabecular number （Tb.N），trabecular thickness （Tb.Th），connectivity density （Conn. D ），trabecular separation （Tb.Sp）and structure model index （SMI）] were determined by micro CT imaging system. The mRNA and protein expression of OPG and RANKL in hypothalamus and femur were determined by RT-PCR and Western blotting assay. RESULTS ：Compared with group A ，the contents of serum bone metabolism markers ，BMD，BV/TV，Tb.N，Tb.Th，Conn.D，mRNA and protein expression of OPG were decreased significantly in group B ，while Tb.Sp ，SMI，mRNA and protein expression of RANKL were increased significantly @qq.com （P＜0.05）. Compared with group B ，the contents of serum bone metabolism markers ，BMD，BV/TV，Tb.N，Tb.Th，Conn.D，mRNA and protein expression of OPG were increased significantly in administration groups ；Tb.Sp，SMI，mRNA and protein expression of RANKL were decreased significantly ，in a dose-dependent manner among curcumin groups （P＜0.05 or P＜0.01）. CONCLUSIONS ：Curcumin can improve the level of bone metabolism，increase BMD ，improve the trabecular microstructure and inhibit bone absorption in ovariectomized osteoporosis model rats. Its mechanism may be related to the regulation of OPG/RANKL signaling pathway.