Figure 1.

Effect of EESP on the viability of HT-29 cells. The cells were treated with various concentrations of EESP for the indicated time periods. Cell viability was determined using an MTT assay. The data were normalized to the viability of the control cells (100%, treated with 0.5% DMSO vehicle). The data are presented as the mean ± SD (error bars) from three independent experiments. ^*P<0.05, vs. the control cells. EESP, ethanol extract of Spica Prunellae; MTT, 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide; DMSO, dimethyl sulfoxide.