Table 1.

 Inhibitory effects of SHXT‐frC combined with various inhibitors on HCV replication. Ava5 cells were treated with SHXT‐frC and IFN‐α, VX‐950 and NM‐107 at various concentrations either alone or in combinations for 3 days. Anti‐HCV activity was performed using RT‐qPCR analysis for measurement of HCV RNA levels

Combination compound	CI values at			Influence
	EC50	EC75	EC90
IFN‐α	0.85	0.81	0.78	Synergistic
VX‐950	0.57	0.61	0.67	Synergistic
NM‐107	0.53	0.55	0.58	Synergistic

The combination index (CI) value for an effective concentration of 50% (EC₅₀), 75% (EC₇₅) or 90% inhibition (EC₉₀) was calculated using the CalcuSyn2^™ program [36]. CI values indicate the degree of interaction of potential drugs; values of <1, =1 and >1 are indicative of synergistic, additive and antagonistic effects, respectively. HCV, hepatitis C virus; SHXT, San‐Huang‐Xie‐Xin‐Tang.