牙周病是一種由牙菌斑引發之慢性炎症反應所造成的牙周組織破壞，其中包含牙周韌帶以及齒槽骨。由於牙周組織破壞，牙菌斑便會持續累積在牙齦內側而成為牙周囊袋並造成牙齦炎更為嚴重進而發展為持續性牙周炎。 因為齒槽骨破壞的不可逆性質，透過控制口腔衛生預防牙齦炎便是減少牙周病爆發的最佳策略。香芹酚是到手香葉片的主要揮發性成份；在台灣，到手香通常使用於減緩局部發炎與疼痛。香芹酚俱有多種活性，其中，抗發炎、抗微生物以及抗氧化作用已經有相關研究。然而，香芹酚分子在生物體內的作用機智尚未明瞭，且長期的毒理學研究亦尚未建立，因此鮮少有香芹酚的實際應用。在這篇研究中，除了透過顯微斷層掃描以及病理組織的評估分析，並且經由相關炎症反應介質的信使核糖核酸表現量，以及相關蛋白質活性評估炎症反應的強度，來展示腹腔注射投與不同劑量之香芹酚對於大鼠牙周結紮線所引發之實驗性牙周炎的保護作用。研究結果顯示，隨著香芹酚投與劑量的增加，於牙周結紮線所引發的實驗性炎症反應會趨於減緩。在投與香芹酚的兩個實驗組中，發炎前細胞介質的信使核糖核酸表現量以及巨噬細胞特異的九號基質金屬蛋白的活性有顯著的減少，並有統計上的差異。而在組織形態上，在牙周結紮線周圍之齒槽骨流失的程度皆有顯著地減少。總體而言，我們對於香芹酚在牙周結紮線誘導牙周炎之影響有了非常初步的瞭解，然而，對於香芹酚透過抗微生物活性而影響牙周炎程度的相關研究卻尚未進行；在實際應用上，為減少未知毒性的疑慮，透過不同的投藥途徑效果亦是未來研究的方向之一。此外，透過此研究，香芹酚在牙周炎的相關應用方向應可重新檢視與修正。

]Periodontal disease is a chronic inflammatory response to dental plaque with irreversible periodontal destruction including the periodontal ligament and the alveolar bone. Because of the destruction, a gingival pocket is formed pathologically with subgingival plaque accumulation constantly that makes gingivitis more intensive and a periodontitis established consequently. Because of irreversible property of the destruction of alveolar bone, prophylaxis of gingivitis with controlled oral hygiene is the prime strategy to reduce the burst of periodontal disease. Carvacrol is the main constituent of the essential oil of Plectranthus amboinicus that has been utilized for pain relief and inflammation control in Taiwan. The diverse activities of carvacrol including anti-inflammatory, anti-microorganism, and antioxidant properties have been investigated. However, because the molecular mechanism of these activities and long-term toxicity of carvacrol are not clear and estimated, the practical use of carvacrol is still rare. In this study, we demonstrate a protective activity of carvacrol on the animal model of ligation-induced periodontitis through not only the analysis of morphology by micro-CT and histometric assessment, but also the inspection of severity of inflammation by mRNA expression of related proteins and enzyme activities. The result of this study exhibits the dose-dependent intensity of anti-inflammatory activity of carvacrol against ligation-induced activity. The mRNA expression of pro-inflammatory cytokines and the activity of macrophage-specific MMP9 were significantly reduced in the carvacrol-treated group. Morphologically, the level periodontitis-induced alveolar bone loss around ligation sites was decreased. In conclusion, the effect of carvacrol on ligation-induced periodontitis has been discovered to a limited extent, hence, more investigation will be needed in the anti-microorganism properties and delivery route of carvacrol. Moreover, the orientation of carvacrol application on periodontal disease should be reinspected and revised.

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