Antiangiogenic potency of vitamin E

Area of Science:

• Biochemistry
• Pharmacology
• Cell Biology

Background:

• Angiogenesis is crucial for tumor growth and metastasis.
• Vitamin E compounds, including tocotrienols (T3) and tocopherol (Toc), are studied for their health benefits.
• Tocotrienols are natural analogues of tocopherols with distinct biological activities.

Purpose of the Study:

• To investigate the antiangiogenic properties and mechanisms of vitamin E compounds, focusing on tocotrienols.
• To compare the efficacy of tocotrienols (T3) and tocopherol (Toc) in inhibiting angiogenesis.
• To explore the molecular pathways involved in the antiangiogenic effects of T3.

Main Methods:

• In vitro assays using bovine aortic endothelial cells and human umbilical vein endothelial cells to assess proliferation and tube formation.
• In vivo assays including the chick embryo chorioallantoic membrane assay and the mouse dorsal air sac assay to evaluate angiogenesis.
• DNA microarray analysis to identify molecular targets and signaling pathways affected by T3.

Main Results:

• Tocotrienols (T3), particularly delta-T3, significantly inhibited endothelial cell proliferation and tube formation.
• Delta-T3 reduced vascular endothelial growth factor (VEGF)-stimulated angiogenesis in vitro and in vivo.
• Orally administered T3 suppressed tumor cell-induced angiogenesis in a mouse model.
• Tocopherol (Toc) exhibited minimal antiangiogenic activity compared to T3.
• DNA microarray analysis indicated that T3's antiangiogenic effects involve the regulation of intracellular VEGF signaling pathways (e.g., phospholipase C-gamma, protein kinase C).

Conclusions:

• Tocotrienols, especially delta-T3, possess potent antiangiogenic properties.
• T3 effectively inhibits angiogenesis through mechanisms involving VEGF signaling.
• Tocotrienols show promise as therapeutic dietary supplements for preventing or managing angiogenic disorders.