The vitamin E of palm oil, unlike most other vegetal fats, consists largely of tocotrienols (TT), products previously reported as having antioxidant and tumor-inhibitory properties. A tocotrienols containing palm oil, in the form of liposomes entrapping dosages of 0.5-0.05 microgTT/mL, was studied in combined treatments with doxorubicin (30 min before drug administration). The IC(50) values of doxorubicin, at 24 h, showed that its cytotoxic effects were decreased by palm oil, in a dose effect relationship (p < 0.01, ANOVA), in both normal (Hfl-1, Huvec) and tumor (HepG2, Mls) cells. These results demonstrated an unselective protective activity of tocotrienols, in vitro, on some normal and tumor cultured cells treated with doxorubicin.
