Effect of raloxifene on alveolar bone resorption in ovariectomized rats

doi:10.12307/2026.711

Abstract

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.

Key words: postmenopausal osteoporosis, raloxifene, alveolar bone osteoporosis, estrogen, selective estrogen receptor modulator

CLC Number:

Zan Bingxin, Zhao Yu, Dai Qinggang. Effect of raloxifene on alveolar bone resorption in ovariectomized rats[J]. Chinese Journal of Tissue Engineering Research, 2026, 30(18): 4594-4601.

Figures/Tables 3

2.3 各组大鼠牙槽骨骨密度比较与假手术组比较，模型组骨密度降低(P < 0.05)；与模型组比较，雷洛昔芬组骨密度升高(P < 0.05)，见图2。结合Micro-CT牙槽骨的冠状面显示模型组大鼠骨量明显少于雷洛昔芬组，说明雷洛昔芬能够提高去势大鼠的骨密度。 2.4 各组大鼠牙槽骨骨微结构参数比较与假手术组相比，模型组大鼠的骨体积分数和骨小梁厚度显著降低(P < 0.05)，而骨小梁间隙和骨小梁数量显著升高(P < 0.05)，差异均有显著性意义。与模型组相比，雷洛昔芬组大鼠的骨体积分数和骨小梁厚度显著升高(P < 0.05)，骨小梁间隙和骨小梁数量显著降低(P < 0.05)，差异均有显著性意义，见图2。上述结果表明，雷洛昔芬能够有效改善去卵巢大鼠的骨微结构，具体表现为增加骨体积分数和骨小梁厚度，减少骨小梁间隙和骨小梁数量。 2.5 各组大鼠牙槽骨组织学观察结果苏木精-伊红染色显示，与假手术组相比，模型组大鼠牙槽骨骨组织结构呈现明显的骨质疏松特征，具体表现为骨小梁面积百分比显著减少，骨小梁形态纤细且分布稀疏，骨小梁间隙显著增大，整体排列紊乱且缺乏规则性。相比之下，雷洛昔芬组大鼠牙槽骨结构得到显著改善，新骨形成区域明显增多，骨小梁厚度增加，排列更加规则且有序，骨小梁间隙缩小，骨微结构趋于完整，见图3。骨钙素免疫组织化学染色显示，各组间骨钙素阳性细胞数量和表达强度存在显著差异。假手术组骨钙素阳性细胞数量显著高于模型组(P < 0.05)，且阳性细胞呈密集分布，染色强度明显增强。与模型组相比，雷洛昔芬组骨钙素阳性细胞数量显著增加 (P < 0.05)，染色强度也明显增强，见图4。抗酒石酸酸性磷酸酶染色显示，与假手术组相比，模型组破骨细胞面积显著增加(P < 0.05)。与模型组相比，雷洛昔芬组破骨细胞面积明显减少(P < 0.05)，见图5。上述结果表明，雷洛昔芬可能通过双重机制影响牙槽骨代谢：一方面抑制破骨细胞的分化形成，另一方面调控成骨细胞的功能活性，从而干预牙槽骨的重吸收过程。"

References

[1] GAO Y, CHEN N, FU Z, et al. Progress of Wnt Signaling Pathway in Osteoporosis. Biomolecules. 2023;13(3):483.
[2] 何海洋,杨嘉玲,雷迅.绝经后女性骨质疏松症患病率及影响因素的Meta 分析[J].中国全科医学,2024,27(11):1370-1379.
[3] 谢丽华,柴昊,叶云金,等.续苓健骨颗粒治疗肾虚血瘀型绝经后骨质疏松症的疗效及转录机制研究[J].中国骨质疏松杂志,2022, 28(4):558-561,600.
[4] WU D, CLINE-SMITH A, SHASHKOVA E, et al. T-Cell Mediated Inflammation in Postmenopausal Osteoporosis. Front Immunol. 2021; 12:687551.
[5] 代庆刚,房兵,张鹏,等.不同去势时间大鼠牙槽骨微结构变化的Micro-CT 研究[J].上海口腔医学,2014,23(6):641-645.
[6] DAI QG, ZHANG P, WU YQ, et al. Ovariectomy induces osteoporosis in the maxillary alveolar bone: an in vivo micro-CT and histomorphometric analysis in rats. Oral Dis. 2014;20(5):514-520.
[7] CHANG HJ, LEE SJ, YONG TH, et al. Deep Learning Hybrid Method to Automatically Diagnose Periodontal Bone Loss and Stage Periodontitis. Sci Rep. 2020;10(1):7531.
[8] ARCEO-MENDOZA RM, CAMACHO PM. Postmenopausal Osteoporosis: Latest Guidelines. Endocrinol Metab Clin North Am. 2021;50(2):167-178.
[9] NOSHADI N, BONYADIAN A, ZARIAN S, et al. The effect of raloxifene supplementation on blood pressure and Apo-lipoproteins in postmenopausal women: A systematic review and meta-analysis. Prostaglandins Other Lipid Mediat. 2024;175:106912.
[10] MOHD-DOM T, AYOB R, MOHD-NUR A, et al. Cost analysis of periodontitis management in public sector specialist dental clinics. BMC Oral Health. 2014;14:56.
[11] MOHD DOM TN, AYOB R, ABD MUTTALIB K, et al. National Economic Burden Associated with Management of Periodontitis in Malaysia. Int J Dent. 2016;2016:1891074.
[12] KIM J, MUNSTER PN. Estrogens and breast cancer. Ann Oncol. 2025; 36(2):134-148.
[13] BARZAMAN K, KARAMI J, ZAREI Z, et al. Breast cancer: Biology, biomarkers, and treatments. Int Immunopharmacol. 2020;84:106535.
[14] GALLANT MA, BROWN DM, HAMMOND M, et al. Bone cell-independent benefits of raloxifene on the skeleton: a novel mechanism for improving bone material properties. Bone. 2014;61:191-200.
[15] LIU Q, MA L, CHEN F, et al. Raloxifene-driven benzothiophene derivatives: Discovery, structural refinement, and biological evaluation as potent PPARγ modulators based on drug repurposing. Eur J Med Chem. 2024;269:116325.
[16] MOSHI MR, NICOLOPOULOS K, STRINGER D, et al. The Clinical Effectiveness of Denosumab (Prolia®) for the Treatment of Osteoporosis in Postmenopausal Women, Compared to Bisphosphonates, Selective Estrogen Receptor Modulators (SERM), and Placebo: A Systematic Review and Network Meta-Analysis. Calcif Tissue Int. 2023;112(6):631-646.
[17] HAO X, WANG Y, HOU MJ, et al. Raloxifene Prevents Chemically-Induced Ferroptotic Neuronal Death In Vitro and In Vivo. Mol Neurobiol. 2025;62(3):3934-3955.
[18] BERMAN AG, DAMRATH JG, HATCH J, et al. Effects of Raloxifene and tibial loading on bone mass and mechanics in male and female mice. Connect Tissue Res. 2022;63(1):3-15.
[19] MOTLANI G, MOTLANI V, ACHARYA N, et al. Novel Advances in the Role of Selective Estrogen Receptor Modulators in Hormonal Replacement Therapy: A Paradigm Shift. Cureus. 2023;15(11):e49079.
[20] 李剑平,刘培.雷洛昔芬对骨质疏松性颌骨骨折大鼠骨折愈合及 OPG/RANKL/RANK 系统的影响[J].中国口腔颌面外科杂志,2021, 19(3):213-216.
[21] 杨正祥,李航,李鲲.雷洛昔芬对牙周炎合并系统性绝经后骨质疏松症小鼠模型局部牙槽骨破坏的影响[J].中国口腔颌面外科杂志,2020,18(5):407-411.
[22] DEMIRBAŞ AE, MOHSEN F, TOPAN C, et al. The Combined Therapy of Teriparatide and Raloxifene Improves Osseointegration of Dental Implants in the Osteoporotic Rabbit Model. Int J Oral Maxillofac Implants. 2024;(3):435-445.
[23] TAŃSKI W, KOSIOROWSKA J, SZYMAŃSKA-CHABOWSKA A. Osteoporosis - risk factors, pharmaceutical and non-pharmaceutical treatment. Eur Rev Med Pharmacol Sci. 2021;25(9):3557-3566.
[24] 郭峰,李正南,刘晋平,等.六月龄大鼠去卵巢后建立骨质疏松症模型的可行性[J].中国组织工程研究,2012,16(24):4459-4462.
[25] 魏伟,吴希美,李元建.药理实验方法学[M].4版.北京:人民卫生出版社,2010:56-57.
[26] QIAN H, JIA J, YANG Y, et al. A Follicle-Stimulating Hormone Exacerbates the Progression of Periapical Inflammation Through Modulating the Cytokine Release in Periodontal Tissue. Inflammation. 2020;43(4): 1572-1585.
[27] CONDI FLF, FUCHS LFP, CARVALHO KC, et al. Treatment with Raloxifene Induces the Expression of Kisspeptin, Insulin, and Androgen Receptors in Bones of Castrated Adult Female Rats. Rev Bras Ortop (Sao Paulo). 2024;59(2):e228-e234.
[28] YUAN C, LIANG Y, ZHU K, et al. Clinical efficacy of denosumab, teriparatide, and oral bisphosphonates in the prevention of glucocorticoid-induced osteoporosis: a systematic review and meta-analysis. J Orthop Surg Res. 2023;18(1):447.
[29] LIAO X, DENG J, DU L, et al. Effect of Raloxifene Treatment on Apolipoproteins and Lipoprotein(a) Concentrations in Postmenopausal Women: A Meta-Analysis of Randomized Controlled Trials. Clin Ther. 2024;46(10):799-807.
[30] RIZZOLI R. Postmenopausal osteoporosis: Assessment and management. Best Pract Res Clin Endocrinol Metab. 2018;32(5):739-757.
[31] LAMA A, SANTORO A, CORRADO B, et al. Extracorporeal shock waves alone or combined with raloxifene promote bone formation and suppress resorption in ovariectomized rats. PLoS One. 2017;12(2): e0171276.
[32] 王丽随,范哲华,陈海英.雷洛昔芬联合仙灵骨葆对骨质疏松骨微结构和生物力学性能的影响[J].中国骨质疏松杂志,2018,24(11): 1429-1432.
[33] ICHIMARU R, TOMINARI T, YOSHINOUCHI S, et al. Raloxifene reduces the risk of local alveolar bone destruction in a mouse model of periodontitis combined with systemic postmenopausal osteoporosis. Arch Oral Biol. 2018;85:98-103.
[34] TANAKA M, EJIRI S, TOYOOKA E, et al. Effects of ovariectomy on trabecular structures of rat alveolar bone. J Periodontal Res. 2002; 37(2):161-165.
[35] MILLER SC, WRONSKI TJ. Long-term osteopenic changes in cancellous bone structure in ovariectomized rats. Anat Rec. 1993;236(3):433-441.
[36] POSRITONG S, HONG JM, ELENISTE PP, et al. Pyk2 deficiency potentiates osteoblast differentiation and mineralizing activity in response to estrogen or raloxifene. Mol Cell Endocrinol. 2018;474:35-47.
[37] BROMMAGE R. New Targets and Emergent Therapies for Osteoporosis. Handb Exp Pharmacol. 2020;262:451-473.
[38] ALVA-CHAVARRÍA D, SOTO-NÚÑEZ M, FLORES-SOTO E, et al. Hemostatic Effects of Raloxifene in Ovariectomized Rats. Life (Basel). 2023;13(7):1612.
[39] SHIN S, HONG N, RHEE Y. A randomized controlled trial of the effect of raloxifene plus cholecalciferol versus cholecalciferol alone on bone mineral density in postmenopausal women with osteopenia. JBMR Plus. 2024;8(7):ziae073.
[40] 马学智,马勇,郭杨.补肾健脾活血法治疗绝经后骨质疏松症疗效的Meta分析[J].中国骨质疏松杂志,2022,28(4):527-535.
[41] JAYUSMAN PA, NASRUDDIN NS, BAHARIN B, et al. Overview on postmenopausal osteoporosis and periodontitis: The therapeutic potential of phytoestrogens against alveolar bone loss. Front Pharmacol. 2023;14:1120457.