The effects of KF on the production of NO, PGE2, and TNF-α in macrophages, the neutralization of ROS, and macrophage viability. (a) Chemical structure of KF. (b, c, and d) RAW264.7 cells or peritoneal macrophages (1 × 106 cells/mL) were incubated with LPS (1 μg/mL) under either single treatment (b, c, and d left panel) of KF, Indo, L-NAME, and Pred or combination treatment (d right panel) of KF with Pred for 24 h. The supernatants were collected and the NO or PGE2 concentrations in the supernatants were determined using the Griess assay or EIA. (e) Effect of KF on cell-matrix protein adhesion was evaluated by using fibronectin (FN) coated conditions. U937 cells were pretreated with KF and seeded on FN (50 μg/mL) coated plates for 4 h. The number of attached cells was determined by crystal violet staining. (f) RAW264.7 cells preincubated with KF were treated with DHR123 (20 μM) in the presence or absence of SNP (0.25 mM) for 2 h. The level of radicals was determined by flow cytometric analysis. (g) RAW264.7 cells (1 × 106 cells/mL) were treated with KF or standard compounds (Indo and L-NAME) for 24 h. Cell viability was evaluated using the MTT assay. All of the data are expressed as the mean ± SD of experiments that were performed with six samples. ∗
P < 0.05 and ∗∗
P < 0.01 compared to the normal or control groups.