Document Detail

Enhancement of gap junctional intercellular communication in tumor promoter-treated cells by components of green tea.
MedLine Citation:
PMID:  8481889     Owner:  NLM     Status:  MEDLINE    
Green tea (Camellia sinensis) has been reported to inhibit tumor promotion in vivo and in vitro. Many tumor promoters inhibit gap junctional intercellular communication (GJIC) which may be an important mechanism of promotion. In the present study, we hypothesized that green tea would enhance GJIC in promoter-treated cells. An aqueous extract of green tea (GTE) and several of its constituents were tested for their effects on GJIC in p,p'-dichlorodiphenyltrichloroethane (DDT)-, 12-O-tetradecanoylphorbol-13-acetate (TPA)- and dieldrin-treated WB-F344 rat liver epithelial cells. All three promoters inhibited GJIC in a dose-responsive manner at non-cytolethal concentrations. (GTE (10-80 gamma/ml) enhanced GJIC 20-80% in promoter-treated cells. (-)-Epigallocatechin gallate and (-)-epicatechin gallate also enhanced GJIC in DDT-treated cells, but no effects were seen with (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, caffeine, or theobromine. These data suggest GTE may inhibit tumor promotion by enhancing GJIC and that the most active components are the catechin gallates.
K Sigler; R J Ruch
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Cancer letters     Volume:  69     ISSN:  0304-3835     ISO Abbreviation:  Cancer Lett.     Publication Date:  1993 Apr 
Date Detail:
Created Date:  1993-06-03     Completed Date:  1993-06-03     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7600053     Medline TA:  Cancer Lett     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  15-9     Citation Subset:  IM    
Department of Pathology, Medical College of Ohio, Toledo 43699.
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MeSH Terms
Cell Communication / drug effects*
Cells, Cultured
Epithelium / drug effects
Intercellular Junctions / drug effects*
Liver / drug effects*
Plant Extracts / pharmacology*
Tetradecanoylphorbol Acetate
Reg. No./Substance:
0/Plant Extracts; 16561-29-8/Tetradecanoylphorbol Acetate; 50-29-3/DDT; 60-57-1/Dieldrin

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