Transport of cranberry A-type procyanidin dimers, trimers, and tetramers across monolayers of human intestinal epithelial Caco-2 cells

J Agric Food Chem. 2012 Feb 15;60(6):1390-6. doi: 10.1021/jf2040912. Epub 2012 Feb 2.


A-type procyanidin oligomers in cranberries are known to inhibit the adhesion of uropathogenic bacteria. B-type procyanidin dimers and trimers are absorbed by humans. The absorption of A-type procyanidins from cranberries in humans has not been demonstrated. This study examined the transport of A-type cranberry procyanidin dimers, trimers, and tetramers on differentiated human intestinal epithelial Caco-2 cell monolayers. Procyanidins were extracted from cranberries and purified using chromatographic methods. Fraction I contained predominantly A-type procyanidin dimer A2 [epicatechin-(2-O-7, 4-8)-epicatechin]. Fraction II contained primarily A-type trimers and tetramers, with B-type trimers, A-type pentamers, and A-type hexamers being minor components. Fraction I or II in solution was added onto the apical side of the Caco-2 cell membranes. The media at the basolateral side of the membranes were analyzed using HPLC-MS(n) after 2 h. Data indicated that procyanidin dimer A2 in fraction I and A-type trimers and tetramers in fraction II traversed across Caco-2 cell monolayers with transport ratio of 0.6%, 0.4%, and 0.2%, respectively. This study demonstrated that A-type dimers, trimers, and tetramers were transported across Caco-2 cells at low rates, suggesting that they could be absorbed by humans after cranberry consumption.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Availability
  • Biological Transport
  • Caco-2 Cells
  • Fruit / chemistry*
  • Humans
  • Intestinal Absorption
  • Intestinal Mucosa / metabolism*
  • Proanthocyanidins / metabolism
  • Proanthocyanidins / pharmacokinetics*
  • Vaccinium macrocarpon / chemistry*


  • Proanthocyanidins