Abstract
<title>Abstract</title> <p>Ethnopharmacological relevance: GUGU decoction (GG) is a classical traditional Chinese medicine (TCM) formula historically prescribed for "bone impotence" (Gu Wei) and fracture nonunion. Its composition is derived from the TCM principle of "tonifying the kidney to strengthen bone and activating blood to remove stasis," which is the theoretical basis for treating osteoporotic fractures (OPF). Aim of the study: This study aimed to validate the use of GG in OPF management by evaluating its efficacy in promoting fracture healing and elucidating the underlying molecular mechanisms related to bone formation and the local microenvironment. Materials and methods The GG formula was prepared from 13 medicinal plants (e.g., Psoraleae Fructus (Buguzhi) and Drynariae Rhizoma (Gusuibu), etc.) authenticated with voucher specimens. OPF was induced by ovariectomy femoral fracture (OVX) in SD rats. Rats were treated with GG low/high dose, alendronate (ALN), or Liuwei Dihuang (LWDH) for 12 weeks. Bone turnover markers (ALP, OCN, CTX-I, BMP-2), micro-CT, biomechanical testing, histology, and Western blot (Wnt1, β-catenin, PI3K, AKT, RUNX2) were analyzed. Results GG treatment significantly increased serum osteogenic markers (ALP, OCN, BMP-2) and decreased resorption marker CTX-I. Micro-CT and histology showed improved trabecular microstructure and enhanced endochondral ossification at the fracture callus. Biomechanical strength was restored to near-sham levels. Western blot revealed GG upregulated the expression of key proteins in the Wnt/β-catenin and PI3K/AKT pathways. Conclusion GG accelerates osteoporotic fracture healing by rebalancing bone turnover and modulating the Wnt/β-catenin and PI3K/AKT signaling pathways, and offers mechanistic insights into the TCM therapeutic strategy of "kidney-tonifying and blood-activating (promoting blood circulation)</p>