Figure 2. Brevilin A inhibits STAT3 signaling in a dose dependent manner.

(A) Structure of Brevilin A. (B) Brevilin A inhibits STAT3 phosphorylation in A549R cells. A549R cells were plated and cultured in 100 mm dishes at 70% confluence. Cells were then treated with Brevilin A (12.5 µM and 25 µM ) for 24 h. DMSO was used as control. (C) STAT3 signaling was inhibited by Brevilin A in a dose dependent manner. A549R cells were plated in 96-well plates at a density of 1×10⁴ (100 µl/well in DMEM with 10% FBS). Twelve hours later, media was removed and replaced with fresh media in the presence of Brevilin A at different concentrations for another 24 h (20 µM, 17.5 µM, 15 µM, 12.5 µM, 10 µM, 7.5 µM, 5 µM, 2.5 µM and 1 µM). Luciferase and MTT assays were performed then. Bars show the standard deviation (±SD) (3 independent repeats, n = 5 in each repeat).