A‐type procyanidin dimers, trimers, and tetramers from cranberries transported across monolayers of human Intestinal epithelial Caco‐2 cells

A‐type procyanidin oligomers in cranberries are known to inhibit the adhesion of uropathogenic bacteria. B‐type procyanidins 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 were added onto the apical side of the Caco‐2 cell membranes. The media at the basolateral side of the membranes were analyzed using HPLC‐MSn after two hours. 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 0.59%, 0.37%, and 0.23%, respectively. This study demonstrated A‐type dimers, trimers, and tetramers were transported across Caco‐2 cells at low rates, suggesting they could be absorbed by humans after cranberry consumption. This research was supported in part by Ocean Spray Cranberries, Inc.