Activity-Guided Isolation of Scopoletin and Isoscopoletin, the Inhibitory Active Principles towards CCRF-CEM Leukaemia Cells and Multi-Drug Resistant CEM/ADR5000 Cells, fromArtemisia argyi

The ethyl acetate extract of Artemisia argyi leaves showed substantial inhibition in a cell proliferation assay using human CCRF-CEM leukaemia cells. Bioassay-guided fractionation of the extract led to the isolation of scopoletin and isoscopoletin as the active principles. Their IC50 values were 2.6 and 4.0 microM, respectively. Additionally the two substances were tested against the multidrug resistant subline, CEM/ADR5000 where they both showed IC50 values of 1.6 microM. In contrast to the standard cytostatic drugs doxorubicin, vincristine, and paclitaxel, CEM/ADR5000 cells therefore did not exhibit cross-resistance to scopoletin and isoscopoletin.