Combined curcumin (CUR) and luteolin (LUT) synergistically inhibited protein expression of Notch 1 and TGF-β in CL-188 cells: (A). Bar graph indicating the level of Notch1 in CL-188 cells treated with the CUR and LUT and their combinations after 72 h. (B). Bar graph indicating the level of TGF-β in CL-188 cells treated with the CUR and LUT and their combinations after 72 h. Data were expressed in means ± SEM of at least four independent experiments. *, Significant difference between DMSO and group, +, Significant difference between C10L30 and C10, L30 or C15L30 and C15 or L30; #, Significant difference between C10L30 and C15L30. *, +, # p < 0.05, **, or ++, p < 0.01, ***, p < 0.001. Please see original WB images in Supplementary Figure S1.