Abstract

Objectives: Pilose antler protein extract (PAE) was investigated for its therapeutic efficacy against ovariectomy (OVX)-induced osteoporosis and its underlying molecular mechanism.Methods: An OVX rat model was established to evaluate the effects of PAE on bone microarchitecture, histopathological changes, and bone metabolism-related parameters. Bone structure was assessed using Micro-CT and histological analysis, and biochemical and bone turnover markers were quantified. In vitro, Mouse calvarial pre-osteoblast subclone 14 (MC3T3-E1) Subclone 14 cells were used to examine the effects of PAE on cell viability, proliferation, osteogenic differentiation, and osteogenesis-related protein expression.Results: High-dose PAE markedly improved trabecular bone microarchitecture in OVX rats, as reflected by increased bone surface area and bone volume fraction and reduced trabecular separation. PAE significantly enhanced bone calcium content and elevated serum Bone Morphogenetic Protein 2 (BMP-2) and Procollagen Type I N-Terminal Propeptide (PINP) levels, while decreasing serum Alkaline Phosphatase (ALP) activity and C-Terminal Telopeptide of Type I Collagen (CTX-I) levels, indicating a shift toward bone formation. Mechanistically, PAE activated the Wnt-3a/β-Catenin signaling pathway in bone tissue and MC3T3-E1 cells, as evidenced by increased expression of Wnt-3a and β-Catenin proteins. In vitro experiments further demonstrated that PAE promoted MC3T3-E1 cell proliferation and upregulated osteogenic markers, i.e., Runt-related transcription factor 2 (RUNX2) and Osteocalcin (OCN).Conclusions: Collectively, these findings suggest that PAE exerts pronounced anti-osteoporotic effects and is associated with activation of the Wnt/β-Catenin signaling pathway.