| Objective To explore the efficacy of homologous point acupuncture therapy on postmenopausal osteoporosis (PMOP) model in ovariectomized rats and its effect on osteoprotegerin (OPG)/receptor activator of nuclear factor-κB ligand (RANKL) signaling pathway. Methods Thirty-six SPF-grade female SD rats were selected and randomly divided into the control group, model group, sham acupuncture group, low-frequency (LF) treatment group, medium-frequency (MF) treatment group, and high-frequency (HF) treatment group, with 6 rats in each group. Except for the control group, the osteoporosis model was established using the ovary removal method in the other five groups. After successful modeling, homologous point acupuncture therapy and sham acupuncture interventions were carried out for 12 weeks. At the end of the intervention, CTX-I, PINP, BALP, TNF-α, and BMP-2 in rat serum were detected using ELISA. BMD of the femur, Tb.Th, Tb.Sp, and Tb.N were analyzed using micro-CT. The femoral tissue morphology was observed with HE staining. The levels of OPG, RANKL, BMP-2, and MMP-2 protein expression in the femur were detected using IHC. WB was used to detect OPG, RANKL, TNF-α, BMP2, and MMP2 protein expression levels in the rat femur. Results Compared to those in the control group, the serum levels of PINP, BALP, BMD of the femur, Tb.Th, Tb.N, OPG, and MMP-2 proteins decreased significantly (P<0.05), and the serum levels of CTX-I, BMP-2, TNF-α, Tb.Sp, and RANKL and BMP-2 proteins increased significantly in the model group (P<0.01). HE staining and micro-CT results showed a decrease in the number of bone trabeculae. Compared to those in the model group, the serum levels of CTX-I, TNF-α,BMP-2, Tb.Sp, and RANKL and BMP-2 proteins decreased significantly in the LF treatment group (P<0.05), and the serum levels of PINP, BALP, BMD of the femur, Tb.Th, Tb.N, and OPG and MMP-2 proteins increased significantly in the LF treatment group (P<0.05). The serum levels of BMP-2, TNF-α, RANKL, and BMP-2 protein decreased significantly in the MF treatment group (P<0.05). BMD of the femur, Tb.Th, and OPG and MMP-2 protein levels increased significantly in the MF treatment group (P<0.05). The serum levels of CTX-I, BMP-2, TNF-α, Tb.Sp, and RANKL protein decreased significantly in the HF treatment group (P<0.05). Tb.N, Tb.Th, and OPG proteins increased significantly (P<0.05). HE staining and micro-CT results showed denser bone trabecular structure in the LF treatment group. Conclusion Homologous point acupuncture therapy improves the bone metabolism in PMOP rats. The improvement effect is more obvious in the LF treatment group, which may work through the regulation of OPG/RANKL signaling pathway. |