Figure 3.

Effect of AHE and agerarin on inhibition of the JAK/STAT3 signaling pathway stimulated by IL-4. (A) Chemical structure of agerarin. (B,C) HaCaT cells were pretreated with 20 and 40 μg/mL AHE (B) or 20 and 40 μM agerarin (C) for 30 min before stimulation with (+) or without (−) 20 ng/mL IL-4. After 15 min, cells were harvested, and the phosphorylation of JAK1 at Y1034/1035, JAK2 at Y1007/1008, and STAT3 at Y705 were measured by immunoblotting. Band intensities of phosphorylated proteins were measured using ImageJ and normalized to the corresponding total proteins. GAPDH was used as an internal control. ns, not significant; * p < 0.05, ** p < 0.01, *** p < 0.001 compared to control (n = 3) by an unpaired two-tailed t-test. AHE, ethanolic extract of Ageratum houstonianum.