Ibandronate alleviates inflammatory damage in diabetic osteoporosis rats by activating Nrf2/HO-1 signaling pathway
Objective To investigate the potential mechanism of ibandronate sodium(IB)in alleviating inflammatory damage in diabetic osteoporosis rats by activating the nuclear transcription factor erythro 2-associated factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway.Methods Intraperitoneal injection of streptozotocin at several low doess was used to induce rat model of diabetes mellitus,then bilateral oophorectomy were used to establish type 2 diabetic osteoporosis(T2DOP)rat model.T2DOP model rats were divided into model group,control group,combined group and experimental-L,-M,-H groups,with 8 rats in each group;another 8 diabetic rats were selected as blank group.Model group was treated with normal saline.Control group was given the same volume of solvent.Experimental-L,-M,-H groups were given 2,10 and 50 mg·kg-1 IB.Combined group was treated with 50 mg·kg-1 IB and 50 mg·kg-1 ML385.Seven groups were administered intraperitoneally once a day for 12 weeks.After 12 weeks of treatment,the bone morphologic parameters were detected by calxanthoprotein double labeling method,the expression levels of Nrf2 and HO-1 pathway protein were detected by Western blot.Results The bone morphologic parameters of experimental-M,-H groups,combined group,control group,model group and blank group were 1.74±0.32,2.94±0.58,0.98±0.32,1.01±0.24,0.98±0.42 and 2.92±0.42;the relative expression levels of Nrf2 protein were 0.99±0.09,1.47±0.12,0.51±0.06,0.52±0.06,0.52±0.05 and 1.48±0.12;the relative expression levels of HO-1 protein were 1.02±0.11,1.33±0.14,0.61±0.05,0.59±0.06,0.62±0.06 and 1.29±0.13,respectively.The above indexes in the control group were statistically different with those in the experimental-M,-H groups(all P<0.05).Conclusion IB repairs bone microstructure and alleviates inflammation in diabetic osteoporosis rats by activating the Nrf2/HO-1 signaling pathway.