Fig. (4) Modulation of macrophage pro-inflammatory cytokine production by Niacin. Macrophages from control (white) or AGD (gray) mice were incubated in the presence or absence of increasing concentrations of Niacin (µM) and stimulated with LPS (10 mg/ml) + IFN-γ (100 U/ml) for 24 h. Cytokine levels, namely IL-1 (Panel A), TNF-α (Panel B) and IL-6 (Panel C) were measured in cell free supernatants, using commercial kits. Results shown are the mean ± SEM of 3 independent experiments performed in duplicate. + p< 0.05 Basal (B) AGD vs Control mice; * p< 0.05, ** p<0.01 vs the corresponding B value.