Figure 3.

Parent OP compounds, but not oxon metabolites, activate NF-κB in THP1 cells. (A–C) Differentiated THP1-XBlue cells were exposed to parathion or paraoxon (A), chlorpyrifos or chlorpyrifos oxon (B), or diazinon or diazoxon (C) for 24 hours. Secreted embryonic alkaline phosphatase (SEAP) released into the culture medium was quantified as a measure of NF-κB activation. Values from OP-exposed cells were normalized to controls (0.1% DMSO) and expressed as a percent change from vehicle controls. Data are presented as the mean ± SEM (n = 8–20 wells per group in 4 different experiments). *Significantly different from vehicle control at P ≤0.05.