Fig. 2. Effects of baicalein on fibronectin (FN)-enhanced calpain-2 protein expression and activity.

a MCF-10A cells were treated with FN (20 μg ml⁻¹) in the presence or absence of baicalein at the indicated concentrations for 48 h. The results were normalized to GAPDH expression and shown as the fold-change compared with control cells. b Calpain activity, in terms of arbitrary fluorescence units (AFUs), was measured by monitoring fluorescence assay (Ex/Em = 400/505 nm). Fluorescence was detected after FN (20 μg ml⁻¹) treatment with or without baicalein at the indicated concentrations for 48 h. Calpain-1 and the calpain inhibitor Z-LLY-FMK were used as positive and negative controls, respectively. c Localization of calpain-1 and calpain-2 in the cytomembrane and cytoplasm were analyzed by western blotting and expression levels were normalized to Na⁺/K⁺-ATPase ɑ1 and GAPDH, respectively. The results are shown as fold-change compared with control cells. Data are shown as mean ± SEM for three separate experiments. *P < 0.05, **P < 0.01, ***P < 0.001