Phytoestrogens and inhibition of angiogenesis

The consumption of a plant-based diet can prevent the development and progr ession of chronic diseases associated with extensive neovascularization, in cluding the progression and growth of solid malignant tumours. We have prev iously shown that the plant-derived isoflavonoid genistein is a potent inhi bitor of cell proliferation and in vitro angiogenesis. Moreover, the concen tration of genistein in the urine of subjects consuming a plant-based diet is 30-fold higher than that in subjects consuming a traditional Western die t. We have also reported that certain structurally related flavonoids are m ore potent inhibitors than genistein. Indeed, 3-hydroxyflavone, 3',4'-dihyd roxyflavone, 2',3'-dihydroxyflavone, fisetin, apigenin and luteolin inhibit the proliferation of normal and tumour cells as well as in vitro angiogene sis at half-maximal concentrations in the lower micromolar range. The wide distribution of isoflavonoids and flavonoids in the plant kingdom, together with their anti-angiogenic and anti-mitotic properties, suggest that these phytoestrogens may contribute to the preventive effect of a plant-based di et on chronic diseases, including solid tumours.