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

Abstract

We have previously reported that epigallocatechin gallate (EGCG) strongly inhibits the in vitro phenol sulfotransferase (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 microM; this value is similar to that obtained from in vitro assays (14 microM) [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.

• Authors: T Isozaki, H Tamura
• Journal: Biological & pharmaceutical bulletin (Biol Pharm Bull) Vol. 24 Issue 9 Pg. 1076-8 (Sep 2001) ISSN: 0918-6158 [Print] Japan
• PMID: 11558573 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Enzyme Inhibitors
• Naphthols
• Sulfates
• 1-naphthol
• Catechin
• epigallocatechin gallate
• Arylsulfotransferase

Topics

• Antineoplastic Agents (pharmacology)
• Arylsulfotransferase (antagonists & inhibitors)
• Caco-2 Cells
• Catechin (analogs & derivatives, pharmacology)
• Chromatography, High Pressure Liquid
• Depression, Chemical
• Enzyme Inhibitors (pharmacology)
• Humans
• Naphthols (metabolism)
• Sulfates (metabolism)