Zenggu yin decoction alleviates ovariectomy-induced osteoporosis in rats by activating the Wnt/β-catenin pathway

Abstract

This study investigated the therapeutic effects of Zenggu Yin Decoction (ZGYD) on ovariectomy-induced osteoporosis in rats and explored its role in modulating the Wnt/β-catenin signaling pathway. Ovariectomy-induced postmenopausal osteoporosis (PMOP) rat models were administered ZGYD for 12 weeks. We measured femur bone mineral density (BMD), osteoporosis-related protein expression, and serum parameters. The mRNA and protein expression levels of runt-related transcription factor 2 (RUNX2), osteoprotegerin (OPG), Wnt1, and β-catenin were determined using qRT-PCR and western blotting, respectively. Our results demonstrated that ZGYD significantly improved bone microstructure, as evidenced by increased BMD, bone volume/total volume (BV/TV), trabecular number (Tb.N), and trabecular thickness (Tb.Th), while reducing trabecular separation (Tb.Sp) in ovariectomized (OVX) rats. Additionally, ZGYD treatment restored serum calcium (Ca), phosphorus (P), estradiol (E2), osteocalcin, and bone-specific alkaline phosphatase (BALP) levels while decreasing procollagen type I N-terminal propeptide (PINP) levels, indicating enhanced bone formation and reduced resorption. Furthermore, ZGYD attenuated oxidative stress by lowering malondialdehyde (MDA) and elevating superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities. Mechanistically, ZGYD upregulated runt-related transcription factor 2 (RUNX2) and osteoprotegerin (OPG) while suppressing receptor activator of nuclear factor-κB ligand (RANKL) and RANK, thus inhibiting osteoclastogenesis. Importantly, ZGYD activated the Wnt/β-catenin pathway, as evidenced by increased Wnt1 and β-catenin expression at both the mRNA and protein levels. ZGYD alleviated osteoporosis in OVX rats by enhancing bone formation, reducing oxidative stress, and activating the Wnt/β-catenin pathway, suggesting its potential as a therapeutic agent for postmenopausal osteoporosis.