INHIBITION OF TUMOR PROMOTION BY VARIOUS PALM-OIL TOCOTRIENOLS

Inhibition of tumour promotion by various vitamin E compounds (tocophe rols and tocotrienols) and some of their dimers was examined by an in vitro assay utilizing the activation of Epstein-Barr virus (EBV) early antigen (EA) expression in EBV-genome-carrying human lymphoblastoid c ells. The results reveal that gamma- and delta-tocotrienols derived fr om palm oil exhibit a strong activity against tumour promotion by inhi biting EBV EA expression in Raji cells induced by 12-O-tetradecanoylph orbol-13-acetate (TPA). However, alpha- and gamma-tocopherols and dime rs of gamma-tocotrienol or gamma-tocopherol lack this activity. (C) 19 94 Wiley-Liss, Inc.