Epigallocatechin-3-gallate attenuates Porphyromonas gingivalis lipopolysaccharide-enhanced matrix metalloproteinase-1 production through inhibition of interleukin-6 in gingival fibroblasts.
BACKGROUND
Recent studies have shown that epigallocatechin-3-gallate (EGCG), a major constituent of green tea extract, exhibits effects of anti-inflammation and antioxidation on periodontal inflammation. The present in vitro study examines the effect of EGCG on Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS)-enhanced expression of interleukin (IL)-6 and matrix metalloproteinase (MMP)-1, as well as the activation of nuclear factor-kappa B (NF-κB). Furthermore, the role of IL-6 on LPS-enhanced MMP-1 production is evaluated using human gingival fibroblasts (HGFs).


METHODS
HGFs were primary cultured from human gingiva specimens. The cytotoxicities of EGCG and LPS were tested by cell viability tests. The cellular mRNA expression of IL-6 was determined by reverse-transcription polymerase chain reaction, and the protein expression of MMP-1 and IL-6 was examined by enzyme-linked immunosorbent assay. The cytosol expression and nuclear translocation of NF-κB was evaluated by immunocytochemistry followed by confocal laser scanning microscopy.


RESULTS
Pg LPS significantly increased MMP-1 production in HGFs, whereas adding EGCG significantly attenuated this enhanced production of MMP-1. LPS treatment also increased the mRNA and protein expression of IL-6 and stimulated NF-κB activation in HGFs. However, the addition of EGCG significantly attenuated the IL-6 expression and NF-κB activation. Supplemental addition of IL-6 significantly enhanced cellular MMP-1 production, whereas anti-IL-6 antibody inhibited LPS-enhanced MMP-1 production.


CONCLUSIONS
EGCG could attenuate Pg LPS-enhanced production of MMP-1 in HGFs, whereas this attenuation might be due to the inhibition of IL-6 by EGCG.
Department of Periodontology, School of Dentistry, National Defense Medical Center and Tri-Service General Hospital, Taipei, Taiwan, ROC.
Wan-Chun
WC
Wen
Po-Jan
PJ
Kuo
Cheng-Yang
CY
Chiang
Yu-Tang
YT
Chin
Martin M J
MM
Fu
Earl
E
Fu
D000328:Adult; D000975:Antioxidants / Q000494:pharmacology* / Q000633:toxicity; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000633:toxicity; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000187:drug effects*; D005881:Gingiva / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000032:analysis / Q000187:drug effects*; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology* / Q000633:toxicity; D018613:Microscopy, Confocal; D016328:NF-kappa B / Q000187:drug effects; D016966:Porphyromonas gingivalis / Q000187:drug effects*; D055815:Young Adult; D000093242:Interleukin-6 Inhibitors
D000975:Antioxidants; D002392:Catechin; D015850:Interleukin-6; D008070:Lipopolysaccharides; D020781:Matrix Metalloproteinase 1; D061965:Matrix Metalloproteinase Inhibitors; D016328:NF-kappa B; D000093242:Interleukin-6 Inhibitors; C508600:IL6 protein, human; C045651:epigallocatechin gallate; C522360:MMP1 protein, human
Epigallocatechin gallate; fibroblasts; gingiva; interleukin-6; lipopolysaccharides; matrix metalloproteinase 1