Effective separation of potent antiproliferation and antiadhesion components from wild blueberry (Vaccinium angustifolium Ait.) fruits

Extracts from wild blueberry (Vaccinium angustifolium Ait.) were separated into proanthocyanidin-rich fractions using liquid vacuum and open column chromatography on Toyopearl and Sephadex LH-20, respectively. Fractions were characterized using analytical tools including mass spectrometry and NMR spectroscopy; fraction composition was correlated with bioactivity using antiproliferation and antiadhesion in vitro assays. There was a significant positive correlation between proanthocyanidin content of different fractions and biological activity in both the antiproliferation and antiadhesion assays. Two fractions containing primarily 4-->8-linked oligomeric proanthocyanidins with average degrees of polymerization (DPn) of 3.25 and 5.65 inhibited adhesion of Escherichia coli responsible for urinary tract infections. Only the fraction with a DPn of 5.65 had significant antiproliferation activity against human prostate and mouse liver cancer cell lines. These findings suggest both antiadhesion and antiproliferation activity are associated with high molecular weight proanthocyanidin oligomers found in wild blueberry fruits.