Cytotoxic and genotoxic effects of the quercetin/lanthanum complex on human cervical carcinoma cells in vitro

Quercetin is the main flavonoid in diet with a potential in the treatment of cancer, cardiovascular, and neurodegenerative diseases. Due to its specific planar chemical structure, quercetin readily forms chelates with metal ions. Complexes of bioactive compounds and metal ions such as lanthanum often show strong cytotoxic and antitumour properties. The aim of this study was to compare the genotoxic effects of the quercetin/lanthanum complex on human cervical carcinoma cells with compare it to the effects of free ligands, quercetin, and lanthanum alone. The quercetin/lanthanum complex showed considerable cytotoxicity in the concentration range of (100 to 1000) mmol mL-1 and exposure time of three hours. The complex also induced a dose-dependent pro-oxidative effects and the formation of single-strand and double-strand DNA breaks. Although we obtained promising results on the cell level, future experiments should answer whether the quercetin/lanthanum complex is cancer-specific and stable enough in physiological conditions to make a potential new antitumour drug.