2-Undecanone inhibits bactericidal activity and LPS-induced immune responses of neutrophils. (A) Mouse neutrophils were co-incubated with serum-opsonized PAO1 with MOI of 25 at 37°C for 1 h and bacterial killing activity was measured. (B) Neutrophils were co-incubated with serum-opsonized green fluorescent protein-tagged PAO1 with an MOI of 25 at 37°C for 1 h. Phagocytic cells with engulfed bacteria were analyzed by flow cytometry. (C) Neutrophils were stimulated with LPS (50 μg/ml) and vehicle or 2-undecanone (200 μM) for 4 h. NET formation was visualized by staining the cells with SYTOX Orange. (D) Intracellular ROS levels were measured by DCF-DA. Neutrophils were stimulated with LPS (1 μg/ml) and vehicle or 2-undecanone (200 μM) for 2 h. (E) Levels of cyto-kines were measured by ELISA. Neutrophils were incubated with LPS (100 ng/ml) and vehicle or 2-undecanone (200 μM) for 24 h. (F) Neutrophils were stimulated with LPS (1 μg/ml) and vehicle or 2-undecanone (200 μM) for 2 h. The data are representative of three independent experiments. Data are expressed as the mean ± SEM *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001 by Student’s t-test (A, B right, C right, D right, E).
