Figure 2.

Curcumin decreased LPS-induced NF-κB activation, but not STAT3, via AhR. (A,B) Primary cultured rat astrocytes were transfected with scrambled siRNA (as the control), or si-AhR for 48 h and then were treated (or not) with LPS (1 μg/mL), curcumin (1 µM), or a combination of curcumin and LPS for 12 h. The levels of NF-κB pp65 (Ser536) and NF-κB p65 (A), as well as pSTAT3 (Tyr705) and total STAT3 (B), were determined by western blotting. Representative images and quantitative data are shown. Note that AhR knockdown blocked curcumin-reduced NF-κB activation in LPS-treated astrocytes, and STAT3 activation was not affected by curcumin. Statistical differences were analyzed using the unpaired t-test, and are represented as: * p < 0.05, ** p < 0.005, *** p < 0.001 compared with individual control group. ^## p < 0.01 compared with the indicated group.