| Popis: |
Forty years after the use of DDT has been restricted to malaria affected areas, this pesticide and its metabolites can be detected in water, food, and human tissue around the world. People chronically exposed to DDT have higher risk of suffering from hormonal, reproduction, and psychiatric illnesses. Also, DDT has possible carcinogenic effect on humans as it increases the incidence of cancer. Lack of data regarding genotoxicity of environmental doses of DDT, as well as its metabolites DDE and DDD, encouraged us to study effects of these compounds on human lymphocytes. After exposure period of 1, 6, and 24 h to DDT (0.1 μg/mL), DDE (4.1 μg/mL), and DDD (3.9 μg/mL) cytogenetic damage was evaluated using cytokinesis-block micronucleus assay while DNA diffusion assay was applied in order to determined the type of cell death. The most significant results were observed at exposure period of 24 h where number of micronucleated cells increased from control 2.5 ± 0.71 to 23.5 ± 3.54, 13.5 ± 0.71, and 16.5 ± 6.36 for each compound, respectively. At the same exposure time total number of nucleoplasmic bridges and nuclear buds also increased for all tested compounds. Additionally, cytokinesis-block proliferation index after 24-hour exposure decreased from control 1.92 ± 0.01 to 1.64 ± 0.03, 1.7 ± 0.06, and 1.63 ± 0.07, respectively. Increase in both apoptotic and necrotic type of cell death was noticed. Necrosis, however, dominated. Present study revealed that DDT and its metabolites are capable of inducing cytogenetic damage even at low concentrations used in this study. Gained results also confirm previous findings that DDT is possible carcinogen and suggest that these compounds can be labelled as cancer initiators rather than promoters because they produce DNA damage, and at the same time lower the number of mitotic divisions and cause necrosis. |
