Effects of eugenol on osteoblasts and macrophages－the implications of eugenol in the treatment of apical periodontitis
| Autor: | Ya-Yun Lee, 李亞芸 |
|---|---|
| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 Eugenol is applied widely in dentistry. Eugenol is commonly used as an analgesic agent during acute pulpitis and is a major component of root canal sealers. Despite the frequent applications of eugenol in the practice of dentistry, little is known about the role of eugenol under the status of inflammation and its effects on the periapical bone healing. In this study, the effects of eugenol on the activation of nuclear factor-kappa B (NF-κB) and the expression of cyclooxygenase-2 (COX-2) in human osteoblasts (MG-63) were investigated. In addition, the influence of eugenol on human macrophages (U937) under the stimulation of lipopolysaccharide (LPS) was examined. The results showed that eugenol enhanced the intracellular levels of reative oxygen species (ROS) and activated the nuclear translocation of NF-κB in MG-63 cells. The mRNA expression levels of interleukin-6 and interleukin-8 were up-regulated by eugenol. In addition, the expression of COX-2 protein in osteoblasts was induced by eugenol in a dose-dependent manner, and the presence of the pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α), augmented the effect of eugenol on COX-2 expression in osteoblasts. Furthermore, the eugenol-modulated COX-2 expression was inhibited by an antioxidant, N-acetylcysteine (NAC). Eugenol was shown to block the release of the bone resorbing mediators, including interleukin-1β (IL-1β), TNF-α, prostaglandin E2 and matrix metalloproteinase-9 (MMP-9) from LPS-stimulated macrophages (U937). Consistent with down regulation of bone resorbing mediators, eugenol suppressed the mRNA expression of LPS-induced IL-1β, TNF-α, COX-2, and MMP-9 in macrophages. Taken together, eugenol might modulate COX-2 expression through a ROS/NF-κB-dependent pathway in human osteoblasts. On the other hand, eugenol may suppress the release of proinflammatory cytokines and mediators in macrophages during inflammation. These results suggest a potential anti-inflammatory effect of eugenol in the acute inflamed pulps and apical periodontitis. However, because eugenol might induce adverse effects on osteoblasts, care should be taken not to introduce eugenol-containing materials into periapical region since eugenol may be involved in periapical healing by impairing the functions of osteoblasts. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|