In vitro anti-coxsackievirus B3 effect of ethyl acetate extract of Tian-hua-fen

Table 4 The value of A₆₀₀ obtained from various infective phase

Dilution/A600	1:256	1:512	1:1024	1:2048	1:4096	1:8192
First group	0.45 ± 0.041	0.56 ± 0.011	0.63 ± 0.036	0.65 ± 0.043	0.37 ± 0.076	0.38 ± 0.029
Second group	0.72 ± 0.022	0.96 ± 0.013	0.69 ± 0.009	65.00 ± 0.025	0.78 ± 0.056	0.73 ± 0.054
Third group	0.53 ± 0.030	0.48 ± 0.036	0.40 ± 0.049	0.39 ± 0.066	0.39 ± 0.077	0.32 ± 0.015

The A₆₀₀ value of the cells co-cultured only with RPMI1640, cells co-cultured only with 10 ^-5 CVB_3m and cells co-cultured only with extract (1:256 mg/mL) was 1.29 ± 0.011, 0.24 ± 0.023 and 1.20 ± 0.029, respectively. The value of A₆₀₀ of the cells treated with extract of variable concentration at different time of CVB_3m infection was higher than that of the cells infected with CVB_3m and not treated with the extract, which indicated the protective effect of the extract existed through all the processes of CVB_3m attachment, entry, biosynthesis and assemble in cells.