Aliases: Vitamin E, α-Tocopherol, d-alpha-tocopherol
Pharmacological Mechanism
Lipid-peroxyl-radical scavenger in cell membranes — donates H· from the chromanol hydroxyl to terminate lipid peroxidation chain reactions. Regenerated to active form by ascorbate and glutathione. α-Tocopherol is preferentially retained by hepatic α-TTP; other isoforms (γ, δ, tocotrienols) are largely excreted.
Tocotrienols (caution): α-Tocopherol competes with tocotrienols for α-TTP and accelerates their clearance. Separate by 6+ h or use annatto (α-tocopherol-free) extract.