Abstract

Epidemiological, clinical or animal studies have suggested an inverse association between the consumption of polyphenol and polyphenol-rich foods or beverages and the prevention of diseases. Previously, the following effects have been shown on flavonoids from the black elderberry, Sambucus nigra, on cells. Quercetin: apoptosis induction, antioxidant, protein kinase inhibitor, interaction with type II oestrogen-binding site. Chrysin: aromatase inhibitor and apoptosis-induction affect PPAR alpha and synthetic analogue: dihydroxy-8-nitrochrysin (NOC) = apoptosis-induction. Kaempferol: induction of apoptosis, cell proliferation, and reduction in ER-alpha mRNA. Naringenin: cell proliferation. Hesperidin: cell proliferation. The question now arises as to whether the flavonoids, quercetin, chrysin, kaempferol, naringenin and hesperidin are candidates for primary and secondary cancer prevention. The effect of crude extracts of elderflower and elderberries and the aforementioned flavonoids at concentrations of 5, 10, 20 and 50 µg/ml on vitality parameters of the breast cancer cell lines MCF-7 (ER α +, ER β +) and BT20 (ER α-, ER β-) was demonstrated. Cell proliferation (BrdU assay), mitochondrial activity (MTT assay) and cytotoxicity (LDH assay) were examined. Elderflower crude extract inhibits cell proliferation of MCF-7 (62%) and BT20 (10%) cells. Elderberry crude extract inhibits cell proliferation in MCF-7 (50%) cells and proliferation in BT20 (20%) cells. Quercetin, chrysin, kaempferol, naringenin and hesperidin inhibit proliferation in MCF-7 (quercetin, 50 µg/ml (22%); chrysin, 50 µg/ml (30%); kaempferol, 5 µg/ml (36%); naringenin, 5 µg/ml (25%); hesperidin, 5 and 10 µg/ml (21%) and BT20 (quercetin, 5 µg/ml (18%); chrysin, 10 and 50 µg/ml (8%); kaempferol, 20 µg/ml (15%); naringenin, 5 and 50 µg/ml (20%); hesperidin, 5 and 10 µg/ml (14%)) cells, no cytotoxicity, and little effect on mitochondrial activity.

Key words: Sambucus nigra, polyphenols, breast cancer, LC-MS analysis.