AMELIORATION BY MELATONIN OF CHROMOSOMAL ANOMALIES INDUCED BY ARSENIC AND/OR FLUORIDE IN HUMAN BLOOD LYMPHOCYTE CULTURES a

Abstract

SUMMARY: Standard cytochemical methods were used to investigate the ameliorative effect of melatonin (0.2 mM) on chromosomal aberrations in human lymphocyte cultures induced by arsenic (As 2 O 3 , 1.4 µM) and/or fluoride (NaF, 34 µM). As2O3 and/or NaF generated a significant increase in the incidence of chromosomal aberrations as compared to control levels. Combined treatment with As 2 O 3 and NaF induced more chromosomal aberrations and aneuploidy than either reagent individually. Melatonin supplements brought about a significant decrease in the number of aberrations, with the percentage of amelioration varying between 53% and 88%. This reduction by melatonin of genotoxic effects exerted by As and/or F is probably attributable to its protective antioxidant action.