Malathion is an insecticide widely used in agriculture and in public health programs that when used indiscriminately in large amounts can cause environmental pollution and risk to human health. However, it is possible that during the metabolism of malathion, reactive oxygen species can be generated, and malathion may produce oxidative stress in intoxicated rats that can be responsible for alterations in DNA molecules related in some studies. As a result, the present study aimed to investigate the DNA damage of cerebral tissue and peripheral blood in rats after acute and chronic malathion exposure. We used single cell gel electrophoresis (Comet assay) to measure early damage in hippocampus and peripheral blood and the Micronucleus test in total erythrocytes samples. Malathion was administered intraperitoneally once a day for one day (acute) or for 28 days (chronic) protocols (in both protocols, malathion was administered at 25, 50, 100, and 150 mg/kg). Our results showed that malathion (100 and 150 mg/kg) increased the DNA damage index in the peripheral blood and in the hippocampus after both chronic and acute treatment. Malathion increased the frequency of micronuclei only in chronic treatment at 150 mg/kg dose, and induced a cytotoxic dose-dependent decrease in the frequency of polychromatic erythrocytes in the peripheral blood of rats. In conclusion, since malathion increased both the peripheral blood and hippocampus DNA damage index using the Comet assay and increased the frequency of micronuclei in the total peripheral blood, it can be regarded as a potential mutagen/carcinogenic agent.

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Background:Thousands of chemical compounds are used in paint products, like pigments, extenders, binders, additives, and solvents (toluene, xylene, ketones, alcohols, esters, and glycol ethers). Paint manufacture workers are potentially exposed to the chemicals present in paint products although the patterns and levels of exposure to individual agents may differ from those of painters. The aim of the present study was to evaluate genome damage induced in peripheral blood lymphocytes and oral mucosa cells of paint industry workers.Materials and Methods:Genotoxicity was evaluated using the alkaline Comet assay in blood lymphocytes and oral mucosa cells, and the Micronucleus test in oral mucosa cells. For the micronucleus test in exfoliated buccal cells, no significant difference was detected between the control and paint industry workers.Results:The Comet assay in epithelia buccal cells showed that the damage index (DI) and damage frequency (DF) observed in the exposed group were significantly higher relative to the control group (P≤0.05). In the same way, the Comet assay data in peripheral blood leukocytes showed that both analysis parameters (DI and DF) were significantly greater than that for the control group (P≤0.05).Conclusions:Chronic occupational exposure to paints may lead to a slightly increased risk of genetic damage among paint industry workers.

In the present article, we report data on the possible antigenotoxic activity of Mikania laevigata extract (MLE) after acute intratracheal instillation of coal dust using the comet assay in peripheral blood, bone marrow, and liver cells and the micronucleus test in peripheral blood of Wistar rats. The animals were pretreated for 2 weeks with saline solution (groups 1 and 2) or MLE (100 mg/kg) (groups 3 and 4). On day 15, the animals were anesthetized with ketamine (80 mg/kg) and xylazine (20 mg/kg), and gross mineral coal dust (3 mg/0.3 mL saline) (groups 2 and 4) or saline solution (0.3 mL) (groups 1 and 3) was administered directly in the lung by intratracheal administration. Fifteen days after coal dust or saline instillation, the animals were sacrificed, and the femur, liver, and peripheral blood were removed. The results showed a general increase in the DNA damage values at 8 hours for all treatment groups, probably related to surgical procedures that had stressed the animals. Also, liver cells from rats treated with coal dust, pretreated or not with MLE, showed statistically higher comet assay values compared to the control group at 14 days after exposure. These results could be expected because the liver metabolizes a variety of organic compounds to more polar by-products. On the other hand, the micronucleus assay results did not show significant differences among groups. Therefore, our data do not support the antimutagenic activity of M. laevigata as a modulator of DNA damage after acute coal dust instillation.