Anti-invasive activity of 3,7-dimethoxyflavone in vitro.

Invasion of MCF-7/6 human mammary carcinoma cells into embryonic chick heart fragments was studied in organ culture during 8 days. The effect of 31 polyphenolic compounds, belonging to the flavonoids, chalcones, or coumarins, was tested in this assay for invasion. The anti-invasive activity of 3,7-dimethoxyflavone was found at concentrations ranging from 1 to 100 microM. At these anti-invasive concentrations, no cytotoxic effects could be detected: the anti-invasive effect was reversible upon omission of the molecule from the medium, and treatment of MCF-7/6 cells or heart fragments did not affect subsequent outgrowth from explants on tissue culture plastic. The molecule did not inhibit growth of MCF-7/6 cell aggregates nor of heart fragments kept in suspension culture. The action mechanism of 3,7-dimethoxyflavone is the subject of our ongoing research.