Figure 2. The effect of methotrexate (MTX), 6-mercaptopurine (6-MP) and 5-fluorouracil (5-FLU) when used in combination with apigenin (AP) on ATP levels: in two lymphoid (Jurkat and CCRF-CEM) and two myeloid (THP-1 and KG-1a) leukemia cell lines, evaluated by CellTiter-Glo® assay.

Cells were treated with MTX, 6-MP or 5-FLU and apigenin alone and in combination for 24 hr using their lowest-significant doses (LSD); together with a vehicle control. All data was normalised to the vehicle control which was assigned 100% cell viability. The data was expressed as medians and ranges (n=4). Effects of combination treatments were statistically classified as synergistic (^*) causing a decrease in ATP levels or antagonistic (^#) causing an increase in ATP levels; when compared to vehicle control, drugs alone and expected values of combination treatments. Statistical significant was set at P≤0.05.