Figure 2. CO downregulation of LPS-induced IL-1β and IL-8 protein.

CO downregulated LPS-induced production of (A) IL-1β and (B) IL-8 in THP-1 cells (p<0.02 for both), and likewise (C) IL-1β and (D) IL-8 in primary human monocytes (p ≤0.02 for both). THP-1 cells (0.5×10⁶) or primary human monocytes (1×10⁶) were incubated with LPS (1 µg/ml) in the absence or presence of CO (250 ppm) for 2 h. Cytokine production was measured in supernatants by ELISA. Results are mean ± SEM of at least four independent experiments for THP-1 cells and seven healthy blood donors for primary monocytes.