Fig. 6

Schematic representation of the possible effects of tocotrienols (T3) in the process of angiogenesis. Tocotrienols do not only reduce expression levels of VEGF but also of its receptors, Flt-1 and KDR, which regulate the proliferation of endothelial cells. Tocotrienols also hinder the expression of IL-8 which regulates proliferation of endothelial cells and production of matrix metalloproteinases (MMPs) which in turn initiate the degradation of basement membrane surrounding blood vessel in the process of angiogenesis. In addition, tocotrienols reduce the expression of IL-6 which increases levels of VEGF through stimulation of platelets. Our previous study has shown that tocotrienols inhibit migration and proliferation of endothelial cells. Hence, the diagram shows the possible sites where tocotrienols inhibit the angiogenic process