Green tea polyphenols enhance gingival keratinocyte integrity and protect against invasion by Porphyromonas gingivalis

Pathog Dis. 2018 Jun 1;76(4). doi: 10.1093/femspd/fty030.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adhesins, Bacterial / genetics
  • Adhesins, Bacterial / metabolism
  • Anti-Bacterial Agents / isolation & purification
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Translocation
  • Catechin / analogs & derivatives*
  • Catechin / isolation & purification
  • Catechin / pharmacology
  • Cell Line, Transformed
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / metabolism
  • Dextrans / metabolism
  • Electric Impedance
  • Enzyme Assays
  • Fluorescein-5-isothiocyanate / analogs & derivatives
  • Fluorescein-5-isothiocyanate / metabolism
  • Gene Expression Regulation / drug effects
  • Gingipain Cysteine Endopeptidases
  • Gingiva / drug effects
  • Gingiva / metabolism
  • Gingiva / microbiology
  • Humans
  • Keratinocytes / drug effects*
  • Keratinocytes / metabolism
  • Keratinocytes / microbiology
  • Models, Biological
  • Occludin / genetics
  • Occludin / metabolism
  • Porphyromonas gingivalis / drug effects*
  • Porphyromonas gingivalis / enzymology
  • Porphyromonas gingivalis / growth & development
  • Porphyromonas gingivalis / pathogenicity
  • Tea / chemistry*
  • Zonula Occludens-1 Protein / genetics
  • Zonula Occludens-1 Protein / metabolism

Substances

  • Adhesins, Bacterial
  • Anti-Bacterial Agents
  • Dextrans
  • Gingipain Cysteine Endopeptidases
  • OCLN protein, human
  • Occludin
  • TJP1 protein, human
  • Tea
  • Zonula Occludens-1 Protein
  • fluorescein isothiocyanate dextran
  • Catechin
  • epigallocatechin gallate
  • Cysteine Endopeptidases
  • Fluorescein-5-isothiocyanate