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

Table 1 Cytotoxity of ethyl acetate extract to HeLa cells shown in the value of A₆₀₀

Dilution	1:2	1:4	1:8	1:16	1:32	1:64	1:128	1:256	1:512	1:1024
Value of A600	0.20 ± 0.029	0.22 ± 0.030	0.32 ± 0.022	0.29 ± 0.069	0.38 ± 0.043	0.59 ± 0.035	0.69 ± 0.075	1.30 ± 0.069	1.23 ± 0.061	1.29 ± 0.056

The A₆₀₀ value of the cells co-cultured with the extract at concentration from 1:2 to 1: 128 mg/mL was lower than that of normal HeLa cells (1.32 ± 0.034), which showed that the extract had some toxicity to HeLa cells at these concentrations. From 1:256 mg/mL the A₆₀₀ value became close to that of normal HeLa cells, which indicated that from 1:256 mg/mL the extract had no toxicity to HeLa cells again.