Inhibition of folic acid uptake by catechins and tea extracts in Caco-2 cells

Planta Med. 2007 Jan;73(1):27-32. doi: 10.1055/s-2006-951745. Epub 2006 Nov 21.


In this present study it was aimed to determine whether the catechins contained in green tea and the whole extracts of Camellia sinensis (Theaceae) inhibit the uptake of folic acid by Caco-2 cell monolayers. Our results indicate that (-)-epigallocatechin 3-gallate (EGCG) and (-)-epicatechin 3-gallate (ECG) inhibit cellular folic acid uptake with IC50 values of 34.8 micromol/L and 30.8 micromol/L, respectively. Furthermore, green and black tea extracts were also found to inhibit folic acid uptake with IC50 values of approximately 7.5 and 3.6 mg/mL, respectively. According to these results, simultaneous intake of tea and folic acid may inhibit intestinal folic acid absorption. The consequences with respect to the folate status of the body will need to be examined in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / administration & dosage
  • Antioxidants / pharmacology*
  • Antioxidants / therapeutic use
  • Caco-2 Cells / drug effects
  • Caco-2 Cells / metabolism
  • Camellia sinensis*
  • Catechin / administration & dosage
  • Catechin / pharmacology
  • Catechin / therapeutic use
  • Folic Acid / metabolism*
  • Humans
  • Inhibitory Concentration 50
  • Intestinal Absorption / drug effects*
  • Phytotherapy*
  • Plant Extracts / administration & dosage
  • Plant Extracts / pharmacology*
  • Plant Extracts / therapeutic use


  • Antioxidants
  • Plant Extracts
  • Catechin
  • Folic Acid