Oral Ecology Research Group, Faculty of Dentistry, Université Laval, 2420 rue de la Terrasse, Quebec City, QC G1V 0A6, Canada.
Department of Periodontology, Justus-Liebig-University of Giessen, Schlangenzahl 14, Giessen 35392, Germany.
Pathog Dis. 2018 Jun 1;76(4). doi: 10.1093/femspd/fty030.
The gingival epithelium, a stratified squamous tissue that acts as an interface between the external environment and the underlying connective tissue, plays an active role in maintaining periodontal health. The aim of the present study was to investigate the ability of green tea catechins to enhance gingival epithelial barrier function and protect against the disruption of epithelial integrity induced by Porphyromonas gingivalis. Both the green tea extract and epigallocatechin-3-gallate (EGCG) dose- and time-dependently increased the transepithelial electrical resistance (TER) of a gingival keratinocyte model and decreased the permeability of the cell monolayer to fluorescein isothyocyanate-conjugated 4.4-kDa dextran. This was associated with the increased expression of zonula occludens-1 (ZO-1) and occludin, two tight junction proteins. Treating the gingival keratinocyte monolayer with P. gingivalis caused a reduction in TER and affected the distribution of ZO-1 and occludin, allowing P. gingivalis to translocate through the cell monolayer. These deleterious effects mediated by P. gingivalis were abolished by the green tea extract and EGCG. This protection may be in part related to the ability of tea catechins to inhibit the protease activities of P. gingivalis. Given the above properties, green tea catechins may represent promising preventive and therapeutic molecules against periodontal disease.
牙龈上皮是一种复层鳞状组织，作为外部环境和下方结缔组织之间的界面，在维持牙周健康方面发挥着积极作用。本研究旨在探讨绿茶儿茶素增强牙龈上皮屏障功能和防止牙龈卟啉单胞菌诱导的上皮完整性破坏的能力。绿茶提取物和表没食子儿茶素没食子酸酯（EGCG）均呈剂量和时间依赖性增加牙龈角质形成细胞模型的跨上皮电阻（TER），并降低细胞单层对荧光素异硫氰酸酯标记的 4.4 kDa 葡聚糖的通透性。这与封闭蛋白-1（ZO-1）和闭合蛋白的表达增加有关，它们是两种紧密连接蛋白。用牙龈卟啉单胞菌处理牙龈角质形成细胞单层会降低 TER，并影响 ZO-1 和闭合蛋白的分布，使牙龈卟啉单胞菌能够穿过细胞单层。绿茶提取物和 EGCG 可消除牙龈卟啉单胞菌介导的这些有害影响。这种保护作用可能部分与儿茶素抑制牙龈卟啉单胞菌蛋白酶活性的能力有关。鉴于上述特性，绿茶儿茶素可能是预防和治疗牙周病的有前途的分子。
