Synergistic Apoptotic Effects of Tocotrienol Isomers and Acalypha wilkesiana on A549 and U87MG Cancer Cells

Recent studies suggested that combined treatment approaches can be used to improve anticancer potency and circumvent the limitations of high-dose tocotrienols administration. Acalypha wilkesiana is a medicinal plant that has been used as an adjunct treatment for cancers in traditional medicine. Herein, the effects of single and combined treatments of β-, γ- and δ-tocotrienols and ethyl acetate extract (9EA) of Acalypha wilkesiana on lung (A549) and brain (U87MG) cancer cells were investigated. γ- and δ-tocotrienols exhibited higher potent antiproliferative effects against A549 (12.1 μg/ml and 13.6 μg/ml) and U87MG cells (3.3 μg/ml and 5.2 μg/ml) compared to β-tocotrienols (9.4 μg/ml and 92.4 μg/ml), respectively. Whereas, 9EA induced potent antiproliferative effects against U87MG cells only (2.0 μg/ml). Combined treatments of tocotrienols and 9EA induced a synergistic growth inhibition with up to 8.4-fold reduction in potent doses of β-, γ- and δ-tocotrienols on A549 cells. Apoptotic features were also evidenced on A549 cells receiving single and combined treatments. The synergism may greatly improve the therapeutic outcome for lung cancer.