| Objective To observe the effect of imperatorin treatment on bone marrow mesenchymal stem cell function and bone mass in ovariectomized rats and to explore the possible mechanisms. Methods Osteoporosis rat model was established with bilateral ovariectomy. Rats were then randomly divided into sham operation group (Sham), ovariectomy group (OVX), and imperatorin group (BGM), with 10 rats in each group. Rats in BGM group ovariectomy received imperatorin (20 mg/kg) by gavage every day. After 12-week treatment, bone marrow mesenchymal stem cells (BMSCs) of each group were isolated and cultured. Alkaline phosphatase (ALP) and Alizarin red (ARS) staining and Western blotting were used to detect the protein expressions of BMP-2, Runx2, OPN, OCN, ALP, and Col1. Micro-CT and bone biomechanics were used to observe the treatment effect. Results The positive area of ALP and ARS staining and the expression of BMP-2, Runx2, OPN, OCN, ALP, and Col1 in BMSCs differentiated into osteoblasts in the OVX group were significantly lower than those in the Sham group (P<0.05). After imperatorin treatment, the positive area of ALP and ARS staining and the expression of BMP-2, Runx2, OPN, OCN, ALP, and Col1 in BMSCs differentiated into osteoblasts significantly increased compared to those in OVX group (P<0.05). The maximum load and elastic modulus, BMD, BV/TV, Tb.N, and Tb.Th of the femur in OVX group were significantly lower than those in Sham group, while Tb.Sp was significantly increased (P<0.05). The maximum load and elastic modulus, BMD, BV/TV, Tb.N, and Tb.Th of the left femur in the imperatorin group were significantly higher than those in the OVX group (P<0.05), while Tb.Sp was significantly lower than that in the OVX group (P<0.05). Conclusion Imperatorin reduces the decrease of bone mineral density, bone mass, and bone strength in ovariectomized rats by promoting BMSCs to induce osteogenic differentiation. |