2023, Vol. 27 ›› Issue (2): 184-191

Mechanism of Bushen Huoxue Capsule in repair of bone defects due to steroid-induced osteonecrosis of the femoral head in rats

Luo Di1, 2, Liang Xuezhen1, 2, Yan Bozhao2, Li Jiacheng1, Xu Bo1, 2, Li Gang1, 2   

Abstract: BACKGROUND: Glucocorticoids can inhibit the expression of key genes in the Hedgehog signaling pathway, thereby disrupting the differentiation of bone marrow mesenchymal stem cells into osteogenesis, adipogenesis, and angiogenesis, thereby destroying the blood supply and bone tissue structure in the bone. We found that Bushen Huoxue Capsule has a certain therapeutic effect on these changes.
OBJECTIVE: To observe the effect of Bushen Huoxue Capsule on the repair and reconstruction of bone defect due to steroid-induced osteonecrosis of the femoral head in Sprague-Dawley rats, and to further study the mechanism of Bushen Huoxue Capsule on osteogenesis and hedgehog signaling pathway related factors.
METHODS: Animal model of steroid-induced osteonecrosis of the femoral head was established by injecting methylprednisolone sodium succinate into the gluteal muscle of Sprague-Dawley rats, and low-, middle- and high-dose Bushen Huoxue Capsule was given by gavage. Another rats given normal saline to the gluteal muscles were used as controls. After 8 weeks of injection, the effect of Bushen Huoxue Capsule on bone tissue repair in rats with steroid-induced osteonecrosis of the femoral head and its mechanism were comprehensively evaluated at different aspects through gross observation, histopathological examination, qPCR and western blot analysis.
RESULTS AND CONCLUSION: Gross observation indicated no significant difference in the femoral head samples from different groups after 8 weeks of intervention. Hematoxylin-eosin staining revealed that Bushen Huoxue Capsule at different doses could significantly increase the trabecular area and decrease the empty bone lacuna ratio in rats. Immunohistochemical staining indicated that Bushen Huoxue Capsule at different doses could significantly upregulate the expression of alkaline phosphatase, core binding factor α1, type I collagen and osteopontin in rats. qPCR findings showed that compared with the control group, Bushen Huoxue Capsule at different doses could upregulate the mRNA expression of alkaline phosphatase, type I collagen, core binding factor α1 and Hedgehog signaling pathway-related indicators (sonic hedgehog, nuclear transcription factor 1, and nuclear transcription factor 2). Findings from western blot assay indicated that compared with the control group, Bushen Huoxue Capsule at different doses could upregulate the protein expression of alkaline phosphatase, type I collagen, core binding factor α1, osteopontin and Hedgehog signaling pathway-related indicators (sonic hedgehog and nuclear transcription factor 2). This study has preliminarily confirmed that Bushen Huoxue Capsule has a certain therapeutic effect on steroid-induced osteonecrosis of the femoral head, and its mechanism of action is related to the Hedgehog signaling pathway.
Key words: osteonecrosis of the femoral head, Bushen Huoxue Capsule, methylprednisolone sodium succinate, Hedgehog signaling pathway, osteogenesis