細菌由来因子に対する培養歯髄線維芽細胞の動態と緑茶カテキンの抗炎症作用

Pulpitis mainly results from the invasion of dental caries-related bacteria into dental pulp. It is known that various proinflammatory cytokines and adhesion molecules play important roles in the exacerbation of pulpitis but detail expression mechanisms are not fully elucidated. Recently, green tea catechins have been reported to exhibit anti-inflammatory properties ; however, it is unclear whether the catechins have anti-inflammatory effects on inflamed dental pulp tissue. The purpose of this study is to determine the effect of bacteria-derived factors on cultured dental pulp fibroblasts and to clarify the anti-inflammatory potential of catechin. We used epigalocatechin-3-gallate (EGCG) and epicatechin gallate (ECG), the major components of green tea catechins. The expressions of proinflammatory cytokines and adhesion molecules were examined in cultured human pulp fibroblasts treated with bacteria-derived factors, i.e., lipopolysaccharide (LPS) and peptidoglycan (PGN). The expressions of interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF) in pulp fibroblasts exposed to LPS or PGN were examined by RT-PCR, and by enzyme-linked immunosorbent assay (ELISA). In addition, adhesion molecule (ICAM-1 and VCAM-1) expression on pulp fibroblasts was analyzed by flow cytometry. Both LPS and PGN increased not only IL-8 and VEGF expressions but also ICAM-1 and VCAM-1 expressions in pulp fibroblasts. When pulp fibroblasts pre-treated with EGCG or ECG were exposed to LPS or PGN, EGCG and ECG treatment significantly reduced IL-8, IL-6 and VEGF levels in a dose-dependent manner. ICAM-1 and VCAM-1 expressions on pulp fibroblasts were also decreased by EGCG and ECG treatment. Catechins themselves were not cytotoxic to pulp fibroblasts. When catechins were applied after treatment with LPS or PGN, the result showed an anti-inflammatory effect similarly to pre-treatment with catechin. By treatments of EGCG and ECG, mRNA expressions of DSP and DSPP, involved in tooth formation and mineralization, decreased in pulp fibroblasts. These findings suggest that green tea catechins may have sedative action against pulpitis and show the possibility of clinical application.

公開日:2010年1月24日で登録したコンテンツは、国立情報学研究所において電子化したものです。