ISOLATION OF BIOACTIVE CONSTITUENTS FROM VACCINIUM-MYRTILLUS (BILBERRY) FRUITS AND CELL-CULTURES

Tissues from bilberry (Vaccinium myrtillus L.) fruits and callus cultu res were extracted and fractionated to investigate phytochemical bioac tivity. Major fractions containing flavonoids (proanthocyanidins and a nthocyanin pigments) and a hexane extract containing largely chlorophy lls, carotenoids, sterols and lipids were isolated, and further screen ed for anticancer activity by in vitro testing of their ability to ind uce the phase II xenobiotic detoxification enzyme quinone reductase (Q R) in murine hepatoma cells. Although flavonoid fractions were inactiv e in the assay, a clear, significant induction of QR activity resulted from testing the hexane extract. The concentration of the extract req uired to double QR specific activity was 9 mu g/150 mu l per well, whi ch indicates that one or more components possess substantial QR-induci ng capacity, comparable to known QR inducers such as furanone and cate chol. beta-sitosterol and the carotenoids lutein and zeaxanthin were i dentified as components of the active hexane extract, which also exhib ited a growth suppressing effect against two human breast cancer cell lines MCF-7 and BT-20. (C) 1998 Elsevier Science Ireland Ltd.