In Brazil, environmental contamination by
mercury occurs mainly as a result of
gold mining activities, especially in the Amazon region. In this area, human contamination results mainly from consumption of fish. Treatment of current symptoms of acute or chronic
mercury contamination is normally carried out by increasing its excretion through
metal scavenger compounds. In Japan, human contamination by
mercury, which causes
Minamata disease, has been successfully treated by the
metal scavenger
thiola (N-2 mercaptopropionylglycine). Its effects are based on its capacity to couple with the
metal, facilitating its excretion. The possible clastogenic or anticlastogenic effect of
thiola was evaluated by the in vivo micronucleus study in bone marrow erythrocytes of mice and also in human lymphocytes in vitro through
chromosomal aberration analysis. In both experiments, different concentrations of
thiola were used. Treatments with
bleomycin (BLM),
cyclophosphamide (CP), and also treatments combining these drugs with
thiola were carried out with the purpose of studying the anticlastogenicity of
thiola, considering its
antioxidant properties.
Thiola did not induce a significant increase in the micronucleus frequency in polychromatic erythrocytes of mice nor show any protective effect on the damage caused by
bleomycin and
cyclophosphamide in these cells. At a high dose,
thiola showed a cytotoxic effect, significantly decreasing the relative proportion of polychromatic erythrocytes. In human lymphocytes, the tested
drug did not increase the frequency of
chromosomal aberration and also did not have any protective effect on the damage caused by BLM and CP.