Cytotoxic effects of hyperatomarin, a prenylated phloroglucinol from Hypericum annulatum Moris subsp. annulatum, in a panel of malignant cell lines.

The cytotoxic effects of hyperatomarin - a prenylated phloroglucinol isolated from Hypericum annulatum Moris subsp. annulatum were assessed in a broad spectrum of tumor cell lines originating from leukemias, lymphomas and solid malignancies. The tested compound exerted strong concentration-dependent cytotoxic effects (IC50 values ranging 0.14-15.7 µM), comparable to and even outclassing in some cell lines those of the established anti-cancer drug daunorubicin. Exposure of different human tumor cell lines to hyperatomarin resulted in strong mono- and oligo-nucleosomal fragmentation of genomic DNA, as evidenced by 'Cell death detection' ELISA kit and by DNA-electrophoresis, which unambiguously indicates that the induction of apoptosis is implicated in the cytotoxic mode of action of the tested compound.