Combinational effect of phytochemicals on the action of chemotherapy drugs on acute myeloid leukaemic cell lines

There is increasing evidence for the anticancer effect of natural compounds from plants which are important resources for drug development. Some cancer patients choose to combine chemotherapy drugs with herbal medicines which could lead to possible herb-drug interactions. Herbs contain a mixture of natural compounds often poorly defined, which could interact to give synergistic or opposing effects with chemotherapy drugs. The aim of this study is to investigate in vitro, the anticancer effects of the phytochemicals, α-mangostin, ascorbic acid and gallic acid, against myeloid leukaemic cells. Chronic (K562) and acute (MOLM13) myeloid leukaemic cell lines were treated with the above phytochemicals, either singly or in combination with the chemotherapy drug, doxorubicin. CyQuant cell proliferation and Annexin V/PI assays were used to determine the cell viability and cell apoptosis, respectively. α- mangostin (5-50 µM) inhibited the proliferation of both chronic and acute leukaemic cell lines in dose- and time- dependent manner. However, ascorbic acid (10-30 uM) and gallic acid (5-100 µM) were able to inhibit in a dose dependent manner the growth of acute but not the chronic leukaemic cells. When individually combined with the chemotherapy drug, doxorubicin (1 µM), α mangostin (20 µM), ascorbic acid (15 µM) and gallic acid (15µM) enhanced apoptosis of the cancer cells. Further analysis will be carried out to determine apoptotic pathways of these phytochemicals. Findings from this research could provide relevant information on combination therapy.