The effect of fulvic acid (FA) on homocysteine-induced NF-κB activation in U937 monocyte. U937 cells were kept as CL or stimulated with 200 μg/mL homocysteine for 4 h. Before being kept as CL or stimulated with homocysteine, cells were pretreated FA (0–10 μg/mL) for 4 h. (A) NF-κB activation was determined by TF ELISA assays in U937 cells. *P < 0.05 versus CL. (B) ChIP assays were performed for NF-κB using p65 antibody. The results shown are representative of three independent experiments with similar results.