Alpha-Hederin (Tauroside E) is a water-soluble pentacyclic triterpenoid saponin found in the seeds of Nigella sativa, with hemolytic and apoptotic properties.

For affinity determination, Nuciferine is subjected to primary radioligand binding assays tested at a single 10 μM concentration to displace 50% of the radioligand at a given receptor target. If a more than 50% of the radioligand is displaced, Nuciferine is selected for a secondary binding assay tested at 11 concentrations in triplicate in competition with the radioligand to generate an IC50 and Ki. Binding assays are performed in 96-well plates with 125 μL per well in appropriate binding buffer using radioligand at or near the Kd. Plates are incubated at room temperature in the dark for 90 min. Reactions are stopped by vacuum filtrations onto 0.3% polyethyleneimine soaked 96-well filter mats using a 96-well Filtermate harvester, followed by at least three washes of cold wash buffer. Scintillation cocktail is melted onto dried filters and radioactivity is counted using a Wallac Trilux Microbeta[1].