TbPTR1 kinetic direct assay. A direct kinetic assay was carried out to measure NADPH consumption over time using a Jasco V730 double-beam spectrophotometer. The assay was conducted as reported in ref. Cytotoxicity Assay. The cytotoxicity of the compounds on THP-1-derived macrophages was assessed using the colorimetric MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) as described elsewhere . THP-1 cells were suspended in RPMI complete medium at a density of 1 x 10 6 cells/mL and 100 µL/well were seeded in a 96-well plate.