Figure 6: Activation of AMPK signaling pathway by honokiol in HaCaT cells. HaCaT cells were pre-treated with honokiol (10 μM) and/or AICAR (1 μM) for 1 h, and then treated with or without H2O2 (500 μM) for 24 h. (A) Equal amounts of proteins were subjected to Western blotting analysis. Actin was used as an internal control. (B) The percentages of apoptotic cells were determined by counting the percentages of annexin V+ cells. (C) The cell viability was determined by MTT assay. All data are presented as mean ± SD obtained from three independent experiments (*P < 0.05 compared with the control group; #P < 0.05 compared with the H2O2-treated group; &P < 0.05 compared with the honokiol and H2O2-treated group). AICAR: 5-aminoimidazole-4-carboxamide ribonucleotide.