Gushu pills ameliorate interleukin-1β-induced osteoblast injury and osteoarthritis in rats via regulation of the OPG/RANKL/RANK pathway.

Abstract

Gushu pills (GSW), a traditional Chinese medicine formulation, have demonstrated clinical efficacy in treating bone metabolic disorders, including osteoarthritis (OA). However, the underlying molecular mechanisms remain poorly understood. This study aimed to investigate the therapeutic effects of GSW on IL-1β-induced osteoblast injury and OA in rats, focusing on the potential involvement of the OPG/RANKL/RANK signaling pathway. A rat OA model was established by anterior cruciate ligament transection and medial meniscus resection (ACLT + MMx). After 8 weeks of GSW treatment, cartilage integrity was evaluated by histology (H&E and Safranin O-Fast Green staining), and inflammation (TNF-α, IL-1β) and apoptosis (TUNEL) were assessed. In IL-1β-stimulated human osteoblasts (hFOB1.19), GSW's effects on proliferation (CCK-8), apoptosis (flow cytometry), differentiation (ALP activity), and mineralization (Alizarin Red S) were examined. Key signaling molecules (OPG, RANKL, NF-κB, β-catenin) were analyzed by RT-qPCR, western blot, and ELISA. GSW ameliorated cartilage degradation, inflammation, and apoptosis in OA rats. In IL-1β-injured osteoblasts, GSW promoted proliferation, differentiation, and mineralization while reducing apoptosis. Mechanistically, GSW increased the OPG/RANKL ratio and inhibited NF-κB activation, while promoting β-catenin signaling. The protective effects of GSW were reversed by exogenous RANKL and enhanced by OPG. GSW mitigates osteoblast injury and OA progression. The mechanism is associated with the restoration of the OPG/RANKL balance, potentially via suppression of NF-κB.