Fig. 4.
Barberine-dependent activation of AMPK inhibits LPS-induced IκBα degradation and cytokine production. A: neutrophils were cultured with barberine (0, 1, 3, or 10 μM) for 60 min followed by stimulation with LPS (0 or 100 ng/ml) for 4 h. Levels of TNF-α and IL-6 in the culture media were measured using ELISA assays. Means ± SE, n = 3; ***P < 0.001 or **P < 0.01 compared with LPS-treated cells. B: representative Western blots show levels of phospho-AMPK (Thr172), total AMPK, IκBα, or actin in cell extracts obtained from neutrophils treated with barberine (0, 1, 3, or 10 μM) for 60 min and then LPS (100 ng/ml) for an additional 1 h. A 2nd experiment with neutrophils obtained from a separate group of mice provided similar results.