Synergistic inhibition of cancer cell proliferation with a combination of δ-tocotrienol and ferulic acid

Rice bran consists of many functional compounds and thus much attention has been focused on the health benefits of its components. Here, we investigated the synergistic inhibitory effects of its components, particularly delta-tocotrienol (delta-13) and ferulic acid (FA), against the proliferation of an array of cancer cells, including DU-145 (prostate cancer), MCF-7 (breast cancer), and PANC-1 (pancreatic cancer) cells. The combination of delta-T3 and FA markedly reduced cell proliferation relative to delta-T3 alone, and FA had no effect when used alone. Although 6-T3 induced G1 arrest by up-regulating p21 in PANC-1 cells, more cells accumulated in G1 phase with the combination of delta-T3 and FA. This synergistic effect was attributed to an increase in the cellular concentration of delta-T3 by FA. Our results suggest that the combination of delta-T3 and FA may present a new strategy for cancer prevention and therapy. (C) 2014 Elsevier Inc. All rights reserved.