Anti-angiogenic properties of carnosol and carnosic acid, two major dietary compounds from rosemary.

The use of rosemary (Rosmarinus officinalis) leaves and their constituents as a source of dietary antioxidants and flavoring agents is continuously growing. Carnosol and carnosic acid, two major components of rosemary extracts, have shown activity for cancer prevention and therapy. In this study, we investigate the cytotoxic and anti-angiogenic activities of carnosol and carnosic acid, in order to get further insight into their mechanism of action. Our results demonstrate that the mentioned diterpenes inhibit certain functions of endothelial cells, namely, differentiation, proliferation, migration and proteolytic capability. Our data indicate that their growth inhibitory effect, exerted on proliferative endothelial and tumor cells, could be due to, at least in part, an induction of apoptosis. Inhibition of the mentioned essential steps of in vitro angiogenesis agrees with the observed inhibition of the in vivo angiogenesis, substantiated by using the chick chorioallantoic membrane assay. The anti-angiogenic activity of carnosol and carnosic acid could contribute to the chemopreventive, antitumoral and antimetastatic activities of rosemary extracts and suggests their potential in the treatment of other angiogenesis-related malignancies.