The redox couple avarol/avarone in the fight with malignant gliomas: the case study of U-251 MG cells

This study aimed to screen in vitro antitumour activity of the redox couple avarol/avarone against the human malignant glioma cell line U-251 MG for the first time. Compared both with avarol and positive controls used (temozolomide and doxorubicin), avarone was found to be the most active compound with IC50 value below 1 mu M (IC50 0.68 +/- 0.04 mu M, 96 h). Considerable less DNA damage in the cells treated with avarol and avarone vs. doxorubicin (105 & 123% vs. 299%, respectively; untreated U-251 MG cells were used as a control, 100%), coupled with no sign of cytotoxicity against the normal human foetal lung fibroblast MRC-5 cells (IC50 > 100 mu M), has actually pointed out the importance of this marine sesquiterpenoid quinone structure as a promising lead compound in development of novel brain chemotherapeutics. [GRAPHICS]