骨質疏鬆症是由於骨形成作用與骨溶蝕作用失衡而使骨質量減少的疾病。尋求更安全的治療方式及藥物是一個重要目標。芝麻酚是一種芝麻木質酚，為酚類的衍生物，具有抗氧化、保護神經及抗發炎等功能。本研究針對芝麻酚對於人類骨肉瘤細胞株 MG-63 和小鼠巨噬細胞株 RAW 264.7 在細胞上的影響進行評估。在成骨細胞方面，XTT 檢測數據顯示低於 50 μM 以下濃度的芝麻酚不會影響 MG-63 細胞增生，而20 μM 芝麻酚可明顯增強成骨細胞分化早期指標鹼性磷酸酶 (ALP) 活性，也可以使 MG-63 細胞的礦化結節 (mineralized nodules) 效果提高。利用 RT-PCR 與西方墨點法檢測芝麻酚對成骨細胞指標基因或蛋白質的影響，結果顯示 Runx2 和 OPG 基因表現及蛋白質含量並未隨著劑量增加而被增強；但是可以促進 RANKL 蛋白質水平含量。進一步分析芝麻酚對成骨細胞分化訊息傳遞徑路的影響，發現芝麻酚有劑量增強 BMP2 含量的效果，而 BMP 徑路的 Smad1/5/8 和 MAPKs徑路的 p38 蛋白質磷酸化的活化現象也被增加。另一方面評估芝麻酚對於蝕骨細胞的作用，數據顯示低於 10 μM 以下濃度的芝麻酚不會影響 RAW 264.7 細胞增生。利用抗酒石酸酸性磷酸酶 (TRAP) 染色法、RT-PCR 和西方墨點法分析皆發現 RAW 264.7 細胞被芝麻酚預處理後，可以抑制被 RANKL 誘導分化的作用；而且蝕骨細胞分化相關基因 TRAP、CTSK、MMP9 和 NFATc1 等，也顯示皆受到芝麻酚的抑制；並且芝麻酚的作用機制可能與透過抑制 MAPKs 徑路的 phospho-p44/42 和 NF-κB 徑路的 NF-κB p52 訊息活化有關。因此，綜合實驗結果顯示芝麻酚可能具有治療骨質疏鬆症之藥物開發的潛力。 Osteoporosis is a skeletal disorder characterized by an imbalance between bone resorption and bone formation results in loss of bone mass. To search for safer treatment approaches and drug is an important objective. Sesamol, which is derived from sesame lignans, was reported as an antioxidant, neuroprotective, and anti-inflammatory chemical. In this study, sesamol assess the impact of human osteosarcoma cell line MG-63 and murine macrophage cell line RAW 264.7. In the osteoblasts, XTT assay show lower than 50 μM sesamol will not affect the MG-63 cell proliferation, and 20 μM sesamol significantly increased the activity of alkaline phosphatase (ALP), an early-stage marker of osteoblast differentiation. In addition, the mineralized bone nodule formation increased in response to 20 μM sesamol stimulate the MG-63 cells. The effect of sesamol on the osteoblast marker gene or protein expression using RT-PCR or western blotting analysis, the results showed that Runx2 and OPG gene and protein expression did not increase with the dose-dependent manner, but can promote the protein level of RANKL. Further analysis of sesamol on the signal pathways of osteoblastic differentiation. The observation that enhance BMP2 protein expression, and at the level of Smad1/5/8 in the BMP pathway and p38 in the MAPK pathway phosphorylations. On the other hand, our study was to explore the effect of sesamol in the osteoclasts. The data show lower than 10 μM sesamol will not affect the RAW 264.7 cell proliferation. The data obtained from tartrate-resistant acid phosphatase (TRAP) staining, RT-PCR and western blotting analyses indicated that RAW 264.7 cells after sesamol pretreatment can inhibit RANKL-induced osteoclast differentiation; and suppress the expression of osteoclast differentiation-related genes such as TRAP, CTSK and MMP9 and NFATc1; and sesamol attenuated the RANKL-induced p44/42 MAPK and NF-κB p52 activation. Therefore, sesamol may have the potential treatment of osteoporosis therapy.
