Fluorometric Plate Assay: To determine the efficacy of various synthesized PAI-1 inhibitor compounds, a fluorometric plate assay was carried out to measure the half maximal inhibitory concentration (IC50) of these compounds on recombinant active human PAI-1 in vitro. An IC50 is a measure of the effectiveness of a compound in inhibiting biological or biochemical function. Stated another way, IC50 represents the concentration of a drug that is required for 50% inhibition in vitro. The IC50 of various compounds was measured using a fluorometric plate assay as set out below, and the results are shown in Table 3.Recombinant active human PAI-1 (Molecular Innovations) (final 1 nM) was incubated for 15 min at 23 C. with increasing concentrations of each compound in 100 mM NaCl, 40 mM HEPES, 0.005% Tween-20, 10% DMSO, pH 7.8. Alternately, the assay has been carried out using low concentrations of DMSO (about 0.1% DMSO or less) in the buffer. In various aspects, the invention does not require a solvent, like DMSO.
Selectivity index, ratio of IC50 for cytotoxicity against HUVEC cells to IC50 for antiplasmodial activity against chloroquine-sensitive Plasmodium falciparum 3D7
Hemolytic activity in RBC (unknown origin) assessed as hemolysis at 100 ug/ml incubated for 1 hrs by absorbance based microplate reader analysis relative to control
Selectivity index, ratio of IC50 for antiplasmodial activity against chloroquine-resistant Plasmodium falciparum FcB1 to IC50 for antiplasmodial activity against chloroquine-sensitive Plasmodium falciparum 3D7
Selectivity index, ratio of IC50 for antiplasmodial activity against chloroquine-resistant Plasmodium falciparum FcB1 to IC50 for antiplasmodial activity against multidrug-resistant Plasmodium falciparum W2