Blasts were separated from the specimens of peripheral blood by Ficoll (Histopaque ®-1077, Sigma-Aldrich) gradient centrifugation, and cultured with silibinin (added at time zero) and deltanoids (added at 30 min dissolved in ethanol) for periods of time ranging from 5-9 days in RPMI plus 10% bovine calf serum. Control groups received equivalent amount of DMSO and ethanol. The duration varied depending on maintenance of culture viability, monitored by Trypan Blue exclusion. Before harvesting, the cultures were observed under an inverted microscope for adherence of the cells to the bottom of the flask. When adherence was noted, the cells were harvested by scraping with a rubber “policeman”.