Preparation of ethoxyquin salts and their genotoxic and antioxidant effects on human lymphocytes

Ethoxyquin phosphate (EQ-P) and ethoxyquin hydrochloride (EQ-HCl) were synthesized and studied for genotoxic and antioxidant activities with the use of comet assay and micronucleus test performed on human lymphocytes. The results were compared with the activities of the earlier studied ethoxyquin (EQ; 1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline), a strong antioxidant used mainly as a preservative in animal feeds. Study has demonstrated genotoxic activity of EQ salts in the comet assay performed on human lymphocytes but micronucleus test indicated that the substances are safe to use. EQ salts were significantly less effective in inducing DNA fragmentation than EQ. The protective effects of the studied compounds against H2O2- induced DNA damage were also observed only in the comet assay. The antioxidant activity of EQ-HCl was slightly higher than that of EQ-P but the difference was not statistically significant. On the other hand, both EQ salts were weaker protectors from the effect of H2O2 than EQ itself.