The effects of brusatol on A549 and H1299. (A,B) The cytotoxicity of brusatol was determined under the same conditions for the MTT method; (C,D) A549 and H1299 cells were treated with the indicated concentrations of brusatol, and were collected after 6 h. Then we extracted total proteins for Western blot analysis; (E) A549 cells were treated with, or without, 80 nM brusatol for 4 h, then exposed to 6 Gy γ-irradiation or not. Two hours later, we extracted total proteins for Western blot analysis; (F,G) The Nrf2 protein level of A549 cells was determined under the same experimental conditions as in (E) using the Immunofluorescence method. (The scale bars in Figure 2F are 200 µM) ** p < 0.01, * p < 0.05.