Effect of raloxifene on alveolar bone resorption in ovariectomized rats

Zan Bingxin; Zhao Yu; Dai Qinggang

doi:10.12307/2026.711

Abstract：BACKGROUND:Due to the decline in estrogen levels within the body,postmenopausal women face a significantly increased risk of developing alveolar bone osteoporosis.Raloxifene,as a potential treatment,has shown preliminary positive effects on alveolar bone osteoporosis. OBJECTIVE:To study the effect of raloxifene on alveolar bone resorption in ovariectomized rats. METHODS:Forty-five female Sprague-Dawley rats were divided into three groups:a sham-operated group,a model group,and a raloxifene group.Ovariectomy was performed to establish animal models in the latter two groups.Rats in the raloxifene group received intraperitoneal injections of 10 μL of raloxifene hydrochloride(5 mg/kg).The injection was repeated once 2 weeks after the first dose,and there were two injections in total.After 2 months,the rat molars and alveolar bone were scanned using Micro-CT to analyze bone microstructural parameters,including bone mineral density,bone volume fraction,trabecular thickness,trabecular number,and trabecular separation.Subsequently,alveolar bone samples were subjected to hematoxylin-eosin staining,immunohistochemical staining for osteocalcin,and tartrate-resistant acid phosphatase staining. RESULTS AND CONCLUSION:(1)Compared with the model group,the raloxifene group exhibited an increasing trend in bone mineral density of the rat alveolar bone(P<0.05).Bone volume fraction and trabecular thickness were significantly increased in the raloxifene group(P<0.05),while trabecular separation and trabecular number were significantly decreased(P<0.05).(2)Hematoxylin-eosin staining results showed that,compared with the model group,the alveolar bone structure of rats in the raloxifene group was significantly improved,with a marked increase in the number of new bone formation areas(P<0.05).(3)Immunohistochemical staining results showed that,compared with the model group,the number of osteocalcin-positive cells in the raloxifene group was significantly increased(P<0.05),and the staining intensity was also markedly enhanced.(4)In addition,tartrate-resistant acid phosphatase staining revealed that raloxifene significantly reduced bone loss by inhibiting the activity of osteoclasts.To conclude,raloxifene can significantly inhibit alveolar bone resorption in ovariectomized rats,prevent structural damage to the alveolar bone,and thereby effectively delay the progression of alveolar bone osteoporosis..