ANTITUMOR EFFECTS OF PALM CAROTENES AND TOCOTRIENOLS IN HRS/J HAIRLESS FEMALE MICE

The effect of palm carotenes (PC) and palm tocotrienols (T3) on the development of papilloma (chemical-induced skin cancer) and lymphoma (viral-induced lymph cancer) was studied in genetically recessive HRS/J female hairless mice. The two T3 groups had delayed response (2-4 weeks) to subcutaneous lymphoma (SL) formation when compared to the +ve Control group. The order of this SL inhibition phenomenon by PC in the feed was concentration dependent; 0.3% PC > 0.1% PC > 0.05% PC groups. The onset of SL in 0.3% synthetic carotene (SC) group was sooner than the 0.3% PC group. The +ve Control mice had significantly higher (> 2-fold) epithelial papilloma (EP) than the next group, 0.1% T3. All the PC groups completely inhibited EP formation after the mice were 7 months old. The "no EP" groups (0.1% PC, 0.3% PC, mixed, 0.3% S C) responded as if there was no application of DMBA-croton oil. Mechanisms of inhibition by T3 and PC were different. The T3 groups delayed but not regressed SL formation but the PC groups caused SL regression in a concentration dependent fashion. The 0.3% PC group showed the strongest antitumorigenic effect (and the least toxic effect with respect to mortality) while the 0.1% T3 group showed the least antitumorigenic effect to SL and EP formation.