In vitro activity: Ellipticine, originally identified as a natural product, is a DNA-damaging agent acting as a prodrug whose pharmacological efficiencies and genotoxic side effects are dictated by activation with cytochrome P450 (CYP). Ellipticine is a potent antineoplastic agent exhibiting multiple mechanisms of action including DNA intercalating and inhibiting DNA topoisomerase II. Ellipticine can also act as an inhibitor or inducer of biotransformation enzymes, thereby modulating its own metabolism leading to its genotoxic and pharmacological effects. Treatment of all cells tested with ellipticine resulted in inhibition of cell growth and proliferation. This effect was associated with formation of two covalent ellipticine-derived DNA adducts, identical to those formed by 13-hydroxy- and 12-hydroxyellipticine, the ellipticine metabolites generated by CYP and peroxidase enzymes, in MCF-7, HL-60, CCRF-CEM, UKF-NB-3, UKF-NB-4 and U87MG cells, but not in neuroblastoma UKF-NB-3 cells. Therefore, DNA adduct formation in most cancer cell lines tested in this comparative study might be the predominant cause of their sensitivity to ellipticine treatment, whereas other mechanisms of ellipticine action also contribute to its cytotoxicity to neuroblastoma UKF-NB-3 cells.

Kinase Assay: Ellipticine is a potent antineoplastic agent exhibiting the multimodal mechanism of its action. The mechanisms of ellipticine antitumor, mutagenic and cytotoxic activities are suggested to be intercalation into DNA and inhibition of DNA topoisomerase II activity. Another mode of ellipticine action is the formation of covalent DNA adducts mediated by its oxidation with cytochromes P450 (CYP) and peroxidases[1]. Ellipticine can also act as an inhibitor or inducer of biotransformation enzymes, thereby modulating its own metabolism leading to its genotoxic and pharmacological effects. Treatment of cells with ellipticine results in inhibition of cell growth and proliferation. This effect is associated with formation of two covalent ellipticine-derived DNA adducts.

Cell Assay: The cytotoxicity of ellipticine is determined by MTT test. Ellipticine is dissolved in DMSO (1 mM) and diluted in culture medium to final concentrations of 0, 0.1, 1, 5 or 10 μM. Cells in exponential growth are seeded at 1×104 per well in a 96-well microplate. After incubation the MTT solution is added, the microplates are incubated for 4 hours and cells lysed in 50% N,N-dimethylformamide containing 20% of sodium dodecyl sulfate (SDS), pH 4.5. The absorbance at 570 nm is measured. The mean absorbance of medium controls is subtracted as a background. The viability of control cells is taken as 100% and the values of treated cells are calculated as a percentage of control. The IC50 values are calculated using linear regression of the dose-log response curves.