Green tea polyphenol (-)-epigallocatechin-3-gallate inhibits cyclooxygenase-2 expression in colon carcinogenesis

Guang Peng, Dan A. Dixon, Stephanie J. Muga, Theresa J. Smith, Michael J. Wargovich

Research output: Contribution to journalArticlepeer-review

121 Scopus citations


Tea, one of the most widely consumed beverages worldwide, has been shown to have anti-cancer activity in various cancers including colon cancer. It has been demonstrated that overexpression of the inducible isoform of cyclooxygenase (COX-2) occurs during colon tumorigenesis and inhibition of COX-2 by non-steroidal anti-inflammatory drugs (NSAIDs) is chemopreventive. To determine whether the anti-cancer effect associated with green tea impacted COX-2 expression levels, human colorectal cancer cell lines HT-29 and HCA-7, were treated with (-)-epigallocatechin-3-gallate (EGCG), the most abundant and effective polyphenol of green tea. EGCG significantly inhibited constitutive COX-2 mRNA and protein overexpression. The inhibitory effects of EGCG on signaling pathways controlling COX-2 expression were examined. We observed that EGCG downregulated the ERK1/2 and Akt pathways in colon cancer cells. The effect of EGCG on COX-2 expression resulted in decreased COX-2 promoter activity via inhibition of nuclear factor κB (NF-κB) activation. EGCG also promoted rapid mRNA decay mediated through the COX-2 3′untranslated region (3′UTR). In conclusion, these data suggest that inhibition of COX-2 is a mechanism for the anti-proliferative effect of green tea and emphasizes the role that dietary factors have as anti-cancer agents.

Original languageEnglish (US)
Pages (from-to)309-319
Number of pages11
JournalMolecular Carcinogenesis
Issue number5
StatePublished - May 2006
Externally publishedYes


  • COX-2
  • Colon cancer cells
  • EGCG
  • Gene expression
  • MAPKs
  • NF-κB

ASJC Scopus subject areas

  • Molecular Biology
  • Cancer Research


Dive into the research topics of 'Green tea polyphenol (-)-epigallocatechin-3-gallate inhibits cyclooxygenase-2 expression in colon carcinogenesis'. Together they form a unique fingerprint.

Cite this