The present invention discloses a pharmaceutical composition and use for treating or preventing osteoporosis, bone defect or bone fracture by obtusilactone A (ObA) which is extracted from Cinnamomum kotoense leaves. ObA possesses extremely low cytotoxicity and high bioavailability, induces differentiation and osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs), and enhances the effect of new bone formation. In addition, ObA can stimulate the alkaline phosphatase (ALP) activity and mineralization of BMSCs. An in vivo rate model with local administration of ObA via needle implantation reveals that ObA enhances osteogenesis and new bone formation at the bone defect sites and increases trabecular bone formation. Therefore, ObA can be used in prevention and treatment of bone diseases and acts as a potential medicine.本發明揭露一種由蘭嶼肉桂葉萃取出的三椏烏藥內酯A而用於製備治療或預防骨質疏鬆、骨缺損或骨折疾病的醫藥組合物及其用途。三椏烏藥內酯A具有非常低細胞毒殺作用及高生物可利用性，誘導骨髓衍生間質幹細胞(BMSC)的分化作用及促骨新生作用，並增強新骨形成作用的能力。此外，三椏烏藥內酯A可刺激增加BMSC細胞的鹼性磷酸酶活性及礦化能力。原位給藥至大鼠脛骨的埋針實驗也確認，三椏烏藥內酯A增強了骨缺損部位的促骨新生及新骨形成作用並增加小梁骨體積。因此，三椏烏藥內酯A可應用於骨質疾病的預防及治療，成為有效的市售藥物。
