AMPK activators reduce LPS-stimulated pro-inflammatory cytokine production in macrophages. (A–C) BMDMs from wild-type or AMPKα1 knockout mice were stimulated with 100 ng/ml LPS for times stated, and the levels of IL-6, IL-12p40 and IL-10 secreted into the media were determined as described in Methods. (D–I) BMDMs from (D–F) wild-type or (G–I) AMPKα1 knockout mice were pre-treated with 500 μM metformin for 6 h, then stimulated with 100 ng/ml LPS for times stated. Levels of IL-6, IL-12p40 and IL-10 secreted into the media were determined as described in Methods. (J–O) BMDMs from (J–L) wild-type or (M–O) AMPKα1 knockout mice were pre-treated with 50 μM C13 for 1 h, then stimulated with 100 ng/ml LPS for times stated. Levels of IL-6, IL-12p40 and IL-10 secreted into the media were determined as described in Methods. Graphs represent the mean and standard deviation of results from 3 biological replicates. Data are representative of 3 independent experiments. A p < 0.05 is indicated by ∗, p < 0.01 by ∗∗, p < 0.001 by ∗∗∗ and p < 0.0001 by ∗∗∗∗ (two-tailed Student’s t-test assuming unequal variance).