Cytotoxicity of δ-tocotrienols from Kielmeyera coriacea against cancer cell lines

A mixture of δ-tocotrienol (1) and its peroxy-dimer (2) from the hexane root bark extract of the Kielmeyera coriacea was obtained as part of an effort to discover new anticancer drugs from Brazilian Cerrado plants. In the search for new anti-cancer compounds, Brazilian Cerrado plant species have been investigated. The hexane root bark extract of Kielmeyera coriacea lead to a mixture of δ-tocotrienol (1) and its dimer (2). The structures of both compounds 1 and 2 were established based on detailed 1D and 2D NMR and EI-MS analyses. The cytotoxicity of the mixture was tested against four human tumor cell lines in the following cultures: MDA-MB-435 (melanoma), HCT-8 (colon), HL-60 (leukemia), and SF-295 (glioblastoma), and displayed IC50 values ranging from 8.08 to 23.58μg/mL. Additional assays were performed in order to investigate the mechanism of action of the mixture (1+2) against the human leukemia cell line HL-60. The results suggested that the mixture suppressed leukemia growth and reduced cell survival, triggering both apoptosis and necrosis, depending on the concentration.