Antiangiogenic and anticancer potential of unsaturated vitamin E (tocotrienol).

Several lines of evidence support the beneficial effect of tocotrienol (T3; an unsaturated vitamin E) on inhibition of tumor development. Many factors, including decrease in oxidative stress and modulation of cell signaling pathways in tumor and endothelial cells, have been implicated in such anticancer action of T3, while the in vivo potency and exact intracellular mechanisms for the anticancer properties of T3 remain not fully understood. We have hypothesized that the inhibitory effect of T3 on cancer may be attributable to the antiangiogenic activity of T3, and we found that T3 acts as a potent regulator of growth-factor-dependent signaling in endothelial cells and as an antiangiogenic agent minimizing tumor growth. In this work, we review the history and biological action (i.e., anticancer) of vitamin E and describe current research on the antiangiogenic effects of T3 and its mechanisms.