Time-dependent impact of monosodium urate (MSU) crystals on the generation of reactive oxygen species (ROS) and the production of inflammatory chemokine interleukin-8 (IL-8) by human THP-1 macrophages and anti-inflammatory efficacy of the P6 peptide, colchicine, and colchicine-P6 peptide in MSU stimulated THP-1 macrophages. Treatments with the P6 peptide, colchicine, and colchicine-P6 peptide (1, 10, and 25 μM) were performed for 24 h followed by the addition of MSU crystals (100 μg/mL) for 6 h followed by the determination of ROS generation by flow cytometry and IL-8 production by enzyme-linked immunosorbent assay (ELISA). Data are presented as scatter plots of three independent experiments with the mean and standard deviation highlighted. * p < 0.001; ** p < 0.01; *** p < 0.05. (A) MSU increased ROS generation at 4 and 6 h treatments compared to 2 h. (B) MSU increased IL-8 production by THP-1 macrophages at 6 h compared to 2 and 4 h. (C) Colchicine-P6 peptide was more efficacious than the P6 peptide alone at 1 and 10 μM in reducing ROS generation in THP-1 macrophages. (D) Colchicine-P6 peptide was more efficacious than the P6 peptide alone at 1 and 10 μM in reducing IL-8 production by THP-1 macrophages.