Epimedium brevicornu Maxim.-derived extracellular vesicle-like particles stimulate VEGF-mediated angiogenesis to alleviate postmenopausal osteoporosis.

BACKGROUND: Postmenopausal osteoporosis (PMOP), a bone disease causing fragility fractures, affects millions of postmenopausal women. Epimedium brevicornu Maxim.(EP) shows anti-osteoporotic potential, but its active components and mechanisms remain unclear. Epimedium brevicornu Maxim.-derived extracellular vesicle-like particles (EP-EVLPs) are naturally occurring bioactive constituents. To date, no studies have comprehensively addressed the dual regulatory role of EP-EVLPs in PMOP.

PURPOSE: To investigate the bone-targeting capability and therapeutic efficacy of EP-EVLPs against PMOP.

METHODS: EP-EVLPs were isolated from fresh EP leaves via differential ultracentrifugation and systematically characterized using transmission electron microscopy, nanoparticle tracking analysis, SDS-PAGE, agarose gel electrophoresis, thin-layer chromatography, and high-performance liquid chromatography. In vivo studies evaluated bone-targeting specificity, anti-osteoporotic activity, and biocompatibility in PMOP models. In vitro analyses included: 1) Osteogenic differentiation assessment of hBMSCs and MC3T3 cells through immunohistochemical staining and RT-qPCR; 2) HUVEC proliferation and apoptosis assays via CCK-8 and flow cytometry; 3) Angiogenic potential evaluation using bioinformatic analysis, wound healing, transwell migration, tube formation assays and ELISA.

RESULTS: EP-EVLPs were isolated from Epimedium brevicornu Maxim. in the form of cup-shaped, bilayer nanoparticles, containing nucleic acids, proteins, lipids, epimedin C, and key anti-osteoporotic compounds (icariin). In vivo experiments revealed their preferential accumulation in osteoporotic femora, effectively mitigating bone loss without hepatorenal toxicity. Mechanistically, EP-EVLPs dose-dependently upregulated VEGF expression, enhancing HUVEC proliferation, migration, and tube formation. This angiogenesis-driven remodeling of the osseous vascular niche correlated with restored bone homeostasis.

CONCLUSION: We identify EP-EVLPs rescue postmenopausal osteoporosis through icariin-mediated activation of VEGF-driven angiogenesis. This plant-derived nano-platform restores bone homeostasis by revascularization-coupled osteogenesis, establishing a targeted therapeutic strategy with translational promise.