Figure 6
Effects of inhibition of STAT3 on the effect of ent -Sauchinone on NF-κB activation and A level in cultured astrocytes and in microglial BV-2 cells. To block the STAT3 pathway, cells were treated with the STAT3 inhibitor AG490 (50 μM) or with 50 nM siRNA for STAT3 for 1 hour prior to treatment with ent-Sauchinone. Abolished effect of STAT3 inhibition on the inhibitory effect of ent-Sauchinone on NF-κB DNA binding activity in astrocytes (A) and microglial BV-2 cells (B), and A 1-42 level in astrocytes (C) and microglial BV-2 cells (D). For determination of DNA binding activity of NF-κB and Aβ1-42 levels, cells were treated with 1 μg/ml of LPS alone, or with LPS plus different concentrations (1, 5, and 10 μM) of ent-Sauchinone at 37°C for 24 hours (1 hour for NF-κB) in the absence or presence of STAT3 inhibitor or siRNA. Values are mean ± S.E. for three experiments performed in triplicate. *indicates significantly different from the control group (P <0.05.. #indicates significantly different from the LPS-treated group (P <0.05.. & indicates significantly different from the LPS and ent-Sauchinone treated group (P <0.05.. Values below each figure mean quantified relative DNA binding activity.