Apoptosis and cytotoxicity caused by ethoxyquin and two of its salts.

In our study, we analyzed the cytotoxicity of ethoxyquin (EQ) and its two salts, ethoxyquin hydrochloride (EQ-HCL) and ethoxyquin phosphate (EQ-P). It was shown that EQ was the most cytotoxic compound (IC(50) = 0.09 mM), while the lowest cytotoxic effect was observed for EQ-P (IC(50) = 0.8 mM). The properties of ethoxyquin and its salts were also analyzed with the TUNEL method, which evaluates their ability to induce apoptosis. It was shown that EQ induced apoptosis in cultured human lymphocytes, especially at concentrations of 0.25 and 0.5 mM.