Induction of ARE luciferase activity by SWT and z-LIG in MCF-7 cells. The cells were seeded at a density of 1.5 × 104 cells per well in 96-well tissue culture plate and treated with SWT or z-LIG for 24 hours. Data are expressed as fold change, first normalized to the Renilla internal control, then to the untreated control. Data are from three replicates; bars, S.E. **: p < 0.05; ***: p < 0.0001 compared to untreated control.