INHIBITION OF OCULAR NEOVASCULARIZATION B Y PLANT-DERIVED SUBSTANCES SUCH AS GENISTEIN

Chronic malignant diseases with neovascularization sometimes seem to i mprove when an exclusively plant-based diet is followed. In order to i dentify antiangiogenic substances in such diets, inhibitory factors su ch as genistein were isolated. We investigated the antiangiogenic subs tance genistein with regard to the possibility of an inhibitory effect on corneal angiogenesis in vivo. Methods: Corneal neovascularization was experimentally induced in NZW rabbits by the use of methylcellulos e discs loaded with 250 ng basic fibroblast growth factor (bFGF). Bloo d vessels grew from the limbus towards the pellet and were quantified under the microscope. Genistein was injected subconjunctivally (0.04 m g genistein/day). Results: All eyes which received genistein subconjun ctivally showed a statistically significant reduction of blood vessels at the limbus (from 63 +/- 40 vessels to 36 +/- 11 vessels; P = 0.001 ). Vascularized areas in the eyes treated with genistein also decrease d, from 21.4 +/- 6.7 mm(2) to 10.4 +/- 5.0 mm(2) (P < 0.0001). Conclus ion: Our results show that components of a plant-based diet, such as g enistein, inhibit ocular neovascularization in vivo. The genistein lev el rises significantly in human urine following ingestion of soy produ cts, for example. Therefore, certain vegetarian diets could have a pos itive effect on ocular diseases characterized by progressive neovascul arization.