Table 1.

Assessement of anticoronaviral activity of saikosaponins

Test drug	CC50 (µmol/L)	EC50 (µmol/L)	SI
Actinomycin D	2.8 ± 0.3	0.02 ± 0.0	140
Saikosaponin A	228.1 ± 3.8	8.6 ± 0.3	26.6
Saikosaponin B2	383.3 ± 0.2	1.7 ± 0.1*	221.9
Saikosaponin C	121.5 ± 0.1	19.9 ± 0.1[Link], [Link]	19.2
Saikosaponin D	176.2 ± 0.2	13.2 ± 0.3[Link], [Link], [Link]	13.3

Data are the mean±SD of three independent experiments. *P < 0.05 compared with saikosaponin A; ^† P < 0.05 compared with saikosaponin B₂; ^‡ P < 0.05 compared with saikosaponin C (Student's t‐test).

CC₅₀, the concentration that reduces the growth of target (MRC‐5) cells by 50%; EC₅₀, the inhibitory concentration of compound that produces 50% inhibition of virus‐induced cytopathic effects; SI, selectivity index (= CC₅₀/EC₅₀).

Actinomycin D was used as a positive control.