Bionic Tiger‐Bone Powder Improves Bone Microstructure and Bone Biomechanical Strength of Ovariectomized Rats

OBJECTIVE: To study the curative effect of bionic tiger‐bone powder on osteoporosis in ovariectomized rats and investigate its mechanism. METHODS: Overall, a 120 female Wistar rats were randomly divided into Sham (sham‐operated group), ovariectomy (OVX, ovariectomized group), TB (bionic tiger‐bone powder treatment group after ovariectomy) and TB + VD groups (bionic tiger‐bone powder + vitamin D treatment group after ovariectomy). The osteoporotic rat model was established 3 months after ovariectomy, and rats were intragastrically administrated with the corresponding drugs. Serum and bone tissue samples were collected from 10 rats in each group at weeks 4, 12 and 24 after intragastric administration. The bone microstructure of L(6) vertebrae was analyzed by MicroCT, the biomechanical strength of left femurs was measured by the three‐point bending test, and serum bone metabolism markers (P1NP and CTX) were detected by ELISA. Changes in bone collagen were analyzed by Masson's trichrome staining and hydroxyproline detection, and members of the BMP2/SMAD/RUNX2 and OPG/RANKL/RANK signal pathways were detected by immunoblotting. RESULTS: Compared with the OVX group, the serum level of P1NP in the TB and TB + VD groups was higher (P < 0.05), while the CTX level was lower (P < 0.05). Bone collagen fiber structures in the TB and TB + VD groups were repaired, and the collagen content was significantly higher than that in the OVX group (P < 0.05). In the TB group, BMP‐2, P‐SMAD1/5, RUNX2 and OPG levels were increased in bone tissue (P < 0.01), RANKL levels were decreased (P < 0.01), and the bone microstructure and biomechanical strength were improved. CONCLUSION: Bionic tiger‐bone powder promotes osteogenesis by activating the BMP2/SMAD/RUNX2 signaling pathway, suppresses osteoclasts by downregulating the OPG/RANK/RANKL signaling pathway, increases bone collagen content, and improves bone microstructure and bone biomechanical strength.