Bixin Attenuates High-Fat Diet-Caused Liver Steatosis and Inflammatory Injury through Nrf2/PPARα Signals

Figure 4

Bixin protects LO2 cells from FFA-induced lipid accumulation and cytotoxicity in an Nrf2-dependent manner. (a) LO2 cells were treated with the indicated time points of bixin (40 μM). The cell lysates were subjected to the immunoblot analyses with the indicated antibodies. (b) LO2 cells were transfected with Ctrl or Nrf2 siRNA for 24 h. After pretreatment of bixin (40 μM) for 24 h, the indicated protein expression was detected by immunoblot analysis. Quantification of relative protein expression was determined; results are expressed as the (, Ctrl vs. treatment). (c) After transfected with siRNAs, the cells were exposed with FFA 1 mM for another 24 h cells. Cells were fixed and subjected to Oil Red O staining. The representative images from each treatment are shown (scale bar: 50 μm). (d) Cells were harvested for the detection of oxidative stress caused by FFA. Harvested cells were stained with H₂DCFA; then, the levels of ROS were detected. (e) The levels of cell apoptosis were determined. Results are expressed as the (, Ctrl vs. treatment groups; ^#, FFA group vs. FFA+bixin group). (f) The cell lysates were subjected to immunoblot analyses with the indicated antibodies to investigate the efficiency of Nrf2 siRNA transfection. Quantification of relative protein expression was determined; results are expressed as the (, Ctrl vs. treatments).

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