Table 2.

The ratio of combined GTT and HC compounds at growth inhibition of 50% (IC50) on glioma cancer 1321N1, SW1783, LN18 cells and combination index (CI) for each combination

Type of cell line	GTT:HC	IC50 a [μg/ml]	GTT b [μg/ml]	HC b [μg/ml]	Combination Index c (CI)
1321N1	10 : 3	12	100	75	0.55 ± 0.07
SW1783	20 : 1	2	79	95	0.54 ± 0.03
LN18	2 : 3	29	42	119	0.73 ± 0.03

^aIC50 of combined compounds.

^bIC50 of individual compound.

^cCI < 1.0 indicates synergism; 0.9 < CI < 1.10, near additive; CI > 1.10 indicates antagonism.

The data are the average of three independent experiments.