Table 1.

The fraction affected level (Fa) of Huaier and 5-FU in individual or in combination, and the combination index (CI) values of combination after 24 h

Huaier (mg/ml)	5-FU (μg/ml)	Concentration ratio (Hauier: 5-FU)	Fa of Huaier	Fa of 5-FU	Fa of combination	CI
1.5	7.5		3.30%	17.10%	18.10%	1.09
3	15		9.10%	21.20%	25.20%	1.16
6	30	1:05	25.20%	27.40%	50.90%	0.59
12	60		43.40%	37.90%	67.40%	0.63
24	120		69.80%	45.40%	81.20%	0.71

CI was used for a quantitative measure of the extent of the interaction between two drugs. The CI > 1 indicates antagonism; CI < 1 means synergy; CI = 1 indicates additive effects. The CI values< 1 indicates that the combination (24 h) of Huaier (1.5–24 mg/ml) and 5-FU (7.5–120 μg/ml) was synergistic on Huh28 cells