Anti-osteoporosis effects of zinc oxide and hydroxyapatite nanoparticles in a dexamethasone-induced osteoporosis rat model
摘要
Osteoporosis can be categorized into primary and secondary types, with glucocorticoid-induced osteoporosis (GIOP) being the most common form of secondary osteoporosis and the third most prevalent overall. This study explores the anti-osteoporosis effects of zinc oxide nanoparticles (ZnO NPs) and nano-hydroxyapatite (HA NPs) in a rat model of dexamethasone (DEX)-induced osteoporosis. Nanoparticle characterization was conducted using various techniques to evaluate size, shape, and chemical composition. A total of 48 adult female Swiss albino rats were divided into six groups (n = 8). Osteoporosis was induced in Groups II–VI with DEX (7 mg/kg, IM) weekly for 5 weeks. Subsequently, treatments were administered for 3 months: Group I (negative control), Group II (DEX-induced OP), Group III (alendronate (1 mg/kg) weekly), Group IV (ZnO NPs (0.50 mg/kg) monthly), Group V (HA NPs (8 mg/kg) monthly), and Group VI (combination (ZnO NPs/HA NPs) IV monthly). Serum samples were analyzed for bone metabolism markers—including cross-linked C-telopeptide of type I collagen (CTX-1), tartrate-resistant acid phosphatase 5b (TRACP-5b), alkaline phosphatase (ALP), calcium (Ca2⁺), and phosphorus (P). Molecular analysis and histopathological assessment of femurs were performed. Results indicated that treatment with ZnO NPs or HA NPs significantly up-regulated Runt-related transcription factor-2 (RUNX-2) expression; decreased serum CTX-1, TRACP-5b, and ALP levels; and increased Ca2⁺ and P levels, thereby promoting bone mineralization and ameliorating DEX-induced histological alterations in bone tissues. Notably, the combination treatment of ZnO NPs and HA NPs exhibited superior effects due to synergistic actions. This study highlights the promising anti-osteoporosis potential of ZnO NPs and HA NPs, both individually and in combination, for the treatment of dexamethasone-induced osteoporosis.