(+)-δ-Tocopherol is a biologically active form of vitamin E, a lipid-soluble antioxidant that protects cellular membranes from oxidative damage.1,2 It reduces cumene hydroperoxide-induced lipid peroxidation in hepatocytes when used at a concentration of 20 ?M but induces lipid peroxidation in hepatic microsomes at 100 ?M.3 (+)-δ-Tocopherol (40 ?M) decreases capillary formation of HMEC-1 blood endothelial cells.4 It also decreases the expression of VCAM in, and the invasiveness of, HMEC-1 cells. (+)-δ-Tocopherol (10 ?M) reduces estrogen-induced increases in the expression of the estrogen-responsive genes encoding TFF/pS2, cathepsin D, PGR, CITED1, and SERPINA1 and the levels of 8-hydroxy-2’-deoxyguanosine (8-oxo-dG) and nitrotyrosine in MCF-7 breast cancer cells.5 Dietary administration of (+)-δ-tocopherol (0.2%) reduces tumor growth in an estrogen-supplemented MCF-7 mouse xenograft model. [Matreya, LLC. Catalog No. 1790]
1.Brigelius-Flohé, R., and Traber, M.G.Vitamin E: Function and metabolismFASEB J.13(10)1145-1155(1999) 2.van Acker, F.A., Schouten, O., Haenen, G.R., et al.Flavonoids can replace α-tocopherol as an antioxidantFEBS Lett.473(2)145-148(2000) 3.Tafazoli, S., Wright, J.S., and O'Brien, P.J.Prooxidant and antioxidant activity of vitamin E analogues and troglitazoneChem. Res. Toxicol.18(10)1567-1574(2005) 4.Wells, S.R., Jennings, M.H., Rome, C., et al.α-, γ- and δ-tocopherols reduce inflammatory angiogenesis in human microvascular endothelial cellsJ. Nutr. Biochem.21(7)589-597(2010) 5.Bak, M.J., Gupta, S.D., Wahler, J., et al.Inhibitory effects of γ- and δ-tocopherols on estrogen-stimulated breast cancer in vitro and in vivoCancer Prev. Res. (Phila.)10(3)188-197(2017)