Evaluation of in vitro anti-genotoxic potential of melatonin against arsenic and fluoride in human blood cultures

Melatonin has been known for its anti-oxidant potential but not much studied for the anti-genotoxic potential. The current study elucidate the role of melatonin against in vitro genototxicity by arsenic (As) and fluoirde (F). Human peripheral blood cultures were exposed to As (1.4 μM) and F (34 μM), alone and in combination, with and without melatonin (0.2 mM). Ethyle methane sulphonate (EMS; 1.9 mM) was selected as the positive control to analyze the genotoxic parameters like sister chrmatid exchanges (SCEs), cell cycle proliferative index (CCPI) and primary DNA damage. The frequency of SCE/cell, SCE/chromosome and primary DNA damage reduced significantly (p<0.001) accompanied with a marked increase in CCPI upon addtion of melatonin. Similarly marked recovery was attained by melatonin from As and F induced primary DNA damage as studied using comet assay. The results clearly indicate towards the protection of lymphocytes from toxic effects af As and F by melatonin in vitro.