Epigallocatechin gallate (EGCG) inhibits the sulfation of 1-naphthol in a human colon carcinoma cell line, Caco-2

T. Isozaki, H. O. Tamura

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30 Citations (Scopus)


We have previously reported that epigallocatechin gallate (EGCG) strongly inhibits the in vitro phenol sulfo-transferase (P-ST) activity of a human colon carcinoma cell line, Caco-2. In the present study, we examined the ability of EGCG to inhibit the sulfation of 1-naphthol in intact Caco-2 cells. Sulfation of 1-naphthol was detected in Caco-2 cells after 2 h of incubation, and was observed to continue for 24 h, resulting in an accumulation of sulfated 1-naphthol. Sulfation was strongly inhibited by the addition of EGCG to the culture medium. The IC50 of EGCG was calculated to be 20 μM; this value is similar to that obtained from in vitro assays (14 μM) [Ref. Tamura et al., Biol. Pharm. Bull., 23, 695, (2000)]. These results indicate that catechins are capable of inhibiting P-ST activity in intact cells as well as in vitro. We believe that the inhibitory activity of catechins might be the mechanism by which catechins (and green tea) exert anti-carcinogenic activity against procarcinogenic compounds that require P-ST activation in vivo.

Original languageEnglish
Pages (from-to)1076-1078
Number of pages3
JournalBiological and Pharmaceutical Bulletin
Issue number9
Publication statusPublished - 2001


  • Caco-2
  • EGCG
  • Green tea
  • Inhibition
  • Sulfotransferase

ASJC Scopus subject areas

  • Pharmacology
  • Pharmaceutical Science


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