| Objective To explore whether the influence of isoliquiritigenin on osteoblast differentiation in osteoporosis (OP) rats is related to the regulation of receptor activator of nuclear factor-κB ligand (RANKL)/receptor activator of nuclear factor-κB ( RANK)/tumor necrosis factor receptor-associated factor 6 (TRAF6) signaling pathway. Methods The postmenopausal OP rat model was established by castration. After 2 weeks of modeling, the rats were randomly grouped into model group, positive group (estradiol valerate 0.09 mg/kg), and low dose (10 mg/kg), medium dose (20 mg/kg) and high dose (40 mg/kg) isoliquiritigenin groups, with 10 rats per group, and another 10 rats were taken as the sham operation group. After the administration, ELISA method was applied to detect the levels of alkaline phosphatase (ALP) and estradiol (E2) in rat serum; Micro-CT was applied to scan and observe bone microstructure indicators; HE staining was applied to observe the histopathology of the femur; immunohistochemistry was applied to detect the expression of Runt-related transcription factor 2 (Runx2) protein in rat femur; Western Blot was applied to detect the protein expression of RANKL, RANK and TRAF6 in rat femur. Results Compared with the model group, the bone tissue lesions of the rats in the positive group and the isoliquiritigenin groups were reduced, and new bone trabeculae could be seen; the levels of ALP [(107.94±9.83) U/L, (75.27±7.51) U/L, (89.35±9.14) U/L, (106.33±10.02) U/L vs (53.79±5.62) U/L] and E2 [(27.71±2.67) pg/mL, (18.36±1.82) pg/mL, (23.65±2.28) pg/mL, (27.46±2.71) pg/mL vs (14.64±1.59) pg/mL], the Tb.Th [(0.36±0.04) mm, (0.23±0.02) mm, (0.28±0.03) mm, (0.36±0.03) mm vs (0.12±0.01) mm], Tb.N [(4.45±0.44) 1/mm, (2.67±0.27) 1/mm, (3.36±0.34) 1/mm, (4.41±0.44) 1/mm vs (1.51±0.12) 1/mm], BMD [(0.37±0.04) g/cm2, (0.22±0.02) g/cm2, (0.29±0.03) g/cm2, (0.38±0.03) g/cm2 vs (0.14±0.01) g/cm2], BV/TV [(11.94±1.23) %, (7.12±0.70) %, (8.49±0.85) %, (11.77±1.16) % vs (5.75±0.61) %] and the expression of Runx2 [(0.84±0.08), (0.41±0.04), (0.59±0.06), (0.82±0.08) vs (0.27±0.03)] were increased (P<0.05), while the Tb.Sp [(0.25±0.02) mm, (0.43±0.04) mm, (0.34±0.03) mm, (0.23±0.02) mm vs (0.56±0.06) mm] and the expressions of RANKL [(0.42±0.04), (0.86±0.08), (0.64±0.06), (0.45±0.04) vs (1.09±0.11)], RANK [(0.39±0.04), (0.81±0.08), (0.67±0.06), (0.41±0.04) vs (1.03±0.10)], TRAF6 [(0.47±0.05), (0.77±0.08), (0.61±0.06), (0.49±0.05) vs (0.96±0.09)] proteins were decreased (P<0.05) , and isoliquiritigenin is dose-dependent. Conclusion Isoliquiritigenin may promote the differentiation of osteoblasts and improve femoral lesions by inhibiting the RANKL/RANK/TRAF6 signaling pathway, thus exerting an effective therapeutic effect on OP. |