| Objective To investigate the improvement effect of curculigoside on bone metabolism in osteoporosis rats by regulating the long non-coding RNA (lncRNA) KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1)/miR-214-5p axis. Methods SD rats were randomly divided into control group, model group, curculigoside group, pcDNA group, pcDNA-KCNQ1OT1 group, curculigoside+sh-NC group, and curculigoside+sh-KCNQ1OT1 group. ELISA method was applied to detect the serum levels of osteocalcin (OCN), alkaline phosphatase (ALP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Three-point bending experiment was applied to detect the maximum displacement and maximum load of the femur. Micro-CT was applied to detect changes in bone microstructure. HE staining was applied to detect pathological changes in the femoral tissue. qRT-PCR was applied to detect the expressions of lncRNA KCNQ1OT1 and miR-214-5p in femurs. The relationship between lncRNA KCNQ1OT1 and miR-214-5p was verified. Results Compared to those in the control group, the bone trabecular structure in model group was disordered, the levels of OCN and ALP, the maximum displacement of the femur, maximum load, bone mineral density, trabecular thickness, number of trabeculae, bone volume fraction, and the expression of lncRNA KCNQ1OT1 decreased. Levels of TNF-α and IL-6 and the expression of miR-214-5p increased (P<0.05). Compared to those in the model group, the gap between the arrangement of bone trabeculae in the curculigoside group was smaller, the levels of OCN and ALP, the maximum displacement of the femur, maximum load, bone mineral density, trabecular thickness, number of trabeculae, bone volume fraction, and the expression of lncRNA KCNQ1OT1 increased. Levels of TNF-α and IL-6 and the expression of miR-214-5p decreased (P<0.05). Compared to those in the pcDNA group, the pathological damage of the femoral tissue in the pcDNA-KCNQ1OT1 group was alleviated, the levels of OCN and ALP, the maximum displacement of the femur, maximum load, bone mineral density, trabecular thickness, number of trabeculae, bone volume fraction, and the expression of lncRNA KCNQ1OT1 increased. Levels of TNF-α and IL-6 and the expression of miR-214-5p decreased (P<0.05). sh-KCNQ1OT1 reversed the improvement of the inflammatory response and biomechanical properties of the bone and the promoting effect of bone formation in osteoporosis rats. LncRNA KCNQ1OT1 was able to target and to regulate miR-214-5p expression. Conclusion Curculigoside may improve bone metabolism in osteoporosis rats by regulating the lncRNA KCNQ1OT1/miR-214-5p axis. |