Modification of cyto- and genotoxicity of mercury and lead by antioxidant on human lymphocytes in vitro

Mercury (30 μM) induced tenfold higher DNA damage, compared to the same amount of lead as measured by comet assay. This damage could be ameliorated in the presence of free-radical antioxidants like Tempol. Lead-induced olive tail moments were higher for low concentrations and decreased at concentration between 20 and 90 μM. Beyond 90 μM lead, the tail moments increased and remained unaffected by antioxidant treatment. For mercury and lead intoxication, dose-dependent formation of micronucleus (MN) was observed along with increase in apoptotic and necrotic cells. Tempol exhibited inhibition of formation of MN along with reduction in apoptotic and necrotic cells. This inhibition was also more pronounced for mercury than lead.