Tocotrienols
Vitamin E consists of four tocopherols and four tocotrienols that demonstrate important and far reaching biological activities. These essential lipids contain a common chromanol ring and either a saturated (tocopherol) or unsaturated (tocotrienol) side chain. The eight common vitamin E isoforms (alpha-, beta-, gamma-, and delta-tocopherols and alpha-, beta-, gamma-, and delta-tocotrienols) are differentiated based on the number and position of methyl groups on the chromanol ring and the presence of a saturated or unsaturated side chain. The unsaturated side chain in tocotrienols gives them physical properties different from tocopherols, such as an increased ability to cross the cell membrane bilayer.1. Vitamin E has become well known for its role as an antioxidant, in lowering cholesterol and other lipids, as a neuroprotective and anti-cancer agent, and in cardiovascular disease protection. Tocotrienols in general may have greater physiological functions than tocopherols2 and may even be inhibited by an unbalanced excess of alpha-tocopherol supplements.3
The vitamin E vitamers are commonly found in vegetables, fruits, seeds, nuts, grains and oils, where they exist in various ratios with each other.
References:
- Ahn, K., et al. "γ-Tocotrienol Inhibits Nuclear Factor-κB Signaling Pathway through Inhibition of Receptor-interacting Protein and TAK1 Leading to Suppression of Antiapoptotic Gene Products and Potentiation of Apoptosis" J Biol Chem. Vol. 282 pp. 809-820, 2007
- Kannappan, R., et al. "γ-Tocotrienol but Not γ-Tocopherol Blocks STAT3 Cell Signaling Pathway through Induction of Protein-tyrosine Phosphatase SHP-1 and Sensitizes Tumor Cells to Chemotherapeutic Agents" J Biol Chem. Vol. 285 pp. 33520-33528, 2010
- Tan, B., "Appropriate Spectrum Vitamin E and New Perspectives on Desmethyl Tocopherols and Tocotrienols" The Journal of the American Neutricutical Association Vol. 8(1) pp. 35-42, 2005