Effect of tanshinol on bone mineral density and microstructure of proximal tibias in rats with bone loss induced by glucocorticoid / 中国药理学通报

ABSTRACT

Aim To investigate the effect of tanshinol on bone mineral density and microstructure of proximal tibias in rats with bone loss induced by glucocorticoid. Methods Sixty 7-month-old female SPF SD rats were randomly divided into 6 groups with 1 0 rats per groupcontrol group(saline5 ml·kg -1 ·d -1 ),glucocorti-coid group (prednisone acetate6 mg·kg -1 ·d -1 ), glucocorticoid +low dose of tanshinol group(1 2.5 mg ·kg -1 ·d -1 ),glucocorticoid +medium dose of tan-shinol group (25 mg·kg -1 ·d -1 ),glucocorticoid +high dose of tanshinol group (50 mg·kg -1 ·d -1 ), glucocorticoid +(positive control drug)calcitriol group (0.045 μg · kg -1 · d -1 ).Rats were gavaged with prednisone acetate continuously for 1 4 weeks to estab-lish the bone loss model.Meanwhile,tanshinol and calcitriol were orally administered to the rats which were treated with prednisone acetate for intervention. At the end of the experiment,the left proximal tibias were collected for Micro-CT scanning and three-dimen-sional reconstruction of cortical and trabecular bone re- spectively to observe the changes of bone microstruc-ture and test related parameters.Results Bone min-eral density was decreased and bone microstructure was destroyed in proximal tibias of rats after treatment with glucocorticoid.Both tanshinol (25 mg·kg -1 ·d -1 ) and calcitriol(0.045 μg·kg -1 ·d -1 )could increase bone mineral density and improve bone microstructure in proximal tibias without significant differences be-tween each other.Tanshinol (50 mg · kg -1 · d -1 ) could improve bone microstructure to some extent,but it had no significant effect on bone mineral density. Tanshinol(1 2.5 mg·kg -1 ·d -1 )had no significant effect on bone mineral density or microstructure.Con-clusion Oral administration of tanshinol (25 mg · kg -1 ·d -1 )to the rats treated with glucocorticoid can increase bone mineral density and improve bone micro-structure in proximal tibias.