CHEMBL5732142

Nox2 Assay: Cells: Human blood was purchased in buffy coat, prepared the same day for isolation of neutrophils, from Labjoy AB, Lund, Sweden. Blood components were separated by density gradient centrifugation using Ficoll-Paque Plus. Plasma, PBMCs and Ficoll were removed before erythrocytes were removed by dextran sedimentation. Remaining erythrocytes were lyses before neutrophils were washed and counted. Isolated neutrophils were kept on ice resuspended in HBSS without Mg and Ca until assayed.Buffers: The isoluminol buffer contained Isoluminol (0.175 mg/ml) and HRP fraction II (1.75 U/ml). The buffer was prepared by diluting these ingredients at 4× working concentration in HBSS.Procedures: Compounds (Nox inhibitors) were diluted at 4× working concentration and titrated from 100 μM to 0.006 μM in 1:4 steps. PMA was diluted in Isoluminol buffer at 4× working concentration for a final concentration of 30 ng/ml. Compounds had a final DMSO concentration of 1% in the wells; therefore a DMSO control of 1% was included on the plates. 25 μl diluted compound or control/well were added to a white 96-well plate. 25 μl/well of PMA diluted in Isoluminol buffer was added to each well. To non-stimulated control wells only Isoluminol buffer was added. Neutrophils were washed and resuspended at 2×106 cells/ml in HBSS with Mg and Ca just before adding 50 μl of the neutrophil cell suspension/well, which was followed by immediate initiation of luminescence measurement. Luminescence was measured using a FluoStar Optima (BMG Labtech). Graphs were performed using Prism 5 for Mac OS X (Prism 5.0 Software, San Diego Calif. USA). Inhibitors were evaluated at 50% inhibition (IC50) in comparison to cell control without inhibitor present.