Figure 3: Emodin and aloe-emodin diminish both nuclear and cytoplasmic ERα levels and transcriptional activity. MCF-7 cells were treated with 25 μM emodin (a) or aloe-emodin (b) for 24 h prior to cell lysis and protein fractionation as described in Section 2. ERα protein was detected by western blotting, and PARP and α-tubulin served as markers for the nuclear and cytoplasmic fractions, respectively. The quantification of ERα levels was presented as fold increase or decrease relative to controls and was evaluated in three independent experiments. The effects of emodin (c) and aloe-emodin (d) on ERα activation were evaluated using a (estrogen-responsive element-) containing luciferase reporter assay in MCF-7 cells for 48 h. β-galactosidase expression served as the internal control. The data were presented as the fold change compared to control levels (0 μM). The results were presented as the mean SEM. * and ** correspond to and , respectively, versus control group. MCF-7 cells were treated with emodin (e) or aloe-emodin (f) in a dose-dependent manner for 48 h, and the expressions of ERα-regulated protein cyclin D1 were detected by western blotting.