Dioscorea polystachya Turcz. Extract attenuates osteoclastogenesis and ovariectomy-induced bone loss in rats

Dioscorea polystachya Turcz. has been traditionally used in East Asian herbal medicine to strengthen bones and treat musculoskeletal conditions. However, the pharmacological mechanisms underlying its anti-osteoporotic effects remain poorly defined.

This study aimed to investigate the anti-osteoporotic potential of D. polystachya root extract (DRE) through its effects on osteoclast differentiation and function, using both in vitro and in vivo models.

Osteoclastogenesis was induced in bone marrow-derived macrophages (BMMs) by stimulation with receptor activator of nuclear factor kappa-B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF), and the effects of DRE on osteoclast formation were assessed by tartrate-resistant acid phosphatase (TRAP) staining and qRT-PCR analysis of key osteoclastogenic genes (e.g., Nfatc1, c-Fos, Ctsk, Mmp9, Acp5). For in vivo analysis, ovariectomized (OVX) rats were orally administered DRE for eight weeks. Micro-computed tomography (micro-CT), histological staining (H&E and IHC for cathepsin K), and serum biomarker assays such as alkaline phosphatase (ALP) and TRAP were used to evaluate trabecular bone preservation and osteoclast activity.

DRE significantly inhibited osteoclast formation and suppressed the expression of osteoclast-related transcription factors and functional markers in vitro. In OVX rats, DRE treatment dose-dependently attenuated trabecular bone loss, reduced serum ALP and TRAP levels, and preserved trabecular architecture. IHC analysis showed a marked reduction in cathepsin K-positive cells in the DRE-treated group compared to OVX controls.

DRE exerts anti-osteoporotic effects by suppressing osteoclast differentiation and activity, thereby mitigating bone loss in estrogen-deficient conditions. These findings highlight the potential of D. polystachya as a promising natural therapeutic agent for the prevention and treatment of postmenopausal osteoporosis.