Effect of MAP kinase and NF-κB inhibitors on tumour necrosis factor (TNF), interleukin (IL)-1β and IL-8 secretion by THP-1 cells stimulated with bovine glycomacropeptide (BGMP). Cytokine concentrations were determined by ELISA in the supernatants of cells pre-incubated for 1 h with the signal transduction inhibitors [MAP kinase inhibitors PD98059 (ERK1/2 inhibitor), SB203580 (ERK1/2 inhibitor), SP600125 (JNK inhibitor) or the NF-κB inhibitor Bay 11-7082] followed by a 24 h incubation with BGMP. Data are mean ± SEM from at least three independent experiments. Means marked with the same letter were not different from each other, but were different from means marked with a different letter; P < 0.05. C, control group.