Effects of extracts from Linum usitatissimum on cell vitality, proliferation and cytotoxicity in human breast cancer cell lines

The seeds of flax (binomial name: Linum usitatissimum L.) are well known for their high content of phytoestrogens. In the present study, extracts from roots, leaves and stems of flax were analysed for their content of compounds, which might have phytoestrogen-like properties, by pyrolysis field ionisation mass spectrometry. All extracts were tested on the human breast cancer cell lines MCF7 (estrogen receptor positive) and BT20 (estrogen receptor negative). Specific tests were applied for cell vitality ((3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) colorimetric assay (MTT) test), proliferation (BrdU test) and cytotoxicity (lactate dehydrogenase (LDH) test). In the flax root extract, the amounts of monolignols and polyphenols were three times higher than in the stem and leaf extracts. Even at higher concentrations, the root extract also was the least cytotoxic one of all extracts in MCF7 cells, while it showed a dose-dependent and much higher cytotoxicity in BT20 cells. Furthermore, at higher concentrations (> 100 µg/ml), the root extract reduced cell vitality in MCF7 significantly less than in BT20 cells and inhibited proliferation in MCF7 by up to 85%. Since flax root extracts induce significant inhibition of cell vitality and proliferation without performing strong cytotoxicity in the human mamma carcinoma cell lines MCF7, the potential phytoestrogens in flax root extracts could have beneficial effects in hormone-dependent tumours. Key words: Flax, Linum usitatissimum, phytoestrogens, MCF7, cell proliferation, breast cancer.