Paraoxon and glyphosate induce DNA double-strand breaks but are not type II topoisomerase poisons.

We tested the hypothesis that the pesticides paraoxon and glyphosate cause DNA double-strand breaks (DSB) by poisoning the enzyme Type II topoisomerase (topo II). Peripheral lymphocytes in G0 phase, treated with the pesticides, plus or minus ICRF-187, an inhibitor of Topo II, were stimulated to proliferate; induced cytogenetic damage was measured. Micronuclei, chromatin buds, nucleoplasmic bridges, and extranuclear fragments were induced by treatments with the pesticides, irrespective of the pre-treatment with ICRF-187.

DNA methylation and lipid metabolism: an EWAS of 226 metabolic measures.

Background: The discovery of robust and trans-ethnically replicated DNA methylation markers of metabolic phenotypes, has hinted at a potential role of epigenetic mechanisms in lipid metabolism. However, DNA methylation and the lipid compositions and lipid concentrations of lipoprotein sizes have been scarcely studied. Here, we present an epigenome-wide association study (EWAS) (N = 5414 total) of mostly lipid-related metabolic measures, including a fine profiling of lipoproteins.

Increased micronucleus frequencies in reticulocytes of children exposed to industrial pollution: oxidative stress and the OGG1 S326C polymorphism.

We examined possible early-effect biomarkers and polymorphisms of susceptibility in primary school children living near the Atoyac River in central México, which receives waste from multiple industries. We observed a significant increase in micronucleated reticulocytes associated with the oxidative stress index (OSI) and the OGG1 GG (S326C) genotype, and a significant decrease of reticulocytes carrying the transferrin receptor, inversely correlated with OSI.

Micronuclei in bone marrow and liver in relation to hepatic metabolism and antioxidant response due to coexposure to chloroform, dichloromethane, and toluene in the rat model.

Genotoxicity in cells may occur in different ways, direct interaction, production of electrophilic metabolites, and secondary genotoxicity via oxidative stress. Chloroform, dichloromethane, and toluene are primarily metabolized in liver by CYP2E1, producing reactive electrophilic metabolites, and may also produce oxidative stress via the uncoupled CYP2E1 catalytic cycle. Additionally, GSTT1 also participates in dichloromethane activation.

Assessment of exposure to organochlorine pesticides and levels of DNA damage in mother-infant pairs of an agrarian community.

Exposure to organochlorine pesticides was studied in a group of mother-infant pairs living in a rural area where agriculture is the main economic activity. Fumigation in this zone is performed with airplanes, thus affecting the inhabited areas around them, including schools. Heparinized venous blood of mothers and umbilical cords was used to evaluate the olive tail moment in the comet assay, and micronuclei, chromatin buds, and nucleoplasmic bridges in peripheral blood lymphocytes.

Genotoxic properties of nylon-6/MWNTs nanohybrid.

We performed the micronucleus test to determine the level of biocompatibility of pristine multi-walled carbon nanotubes (MWNTs) and MWNTs functionalized with nylon-6, (referred to as the nylon-6/ MWNTs nanohybrid), when they interact with human lymphocytes in a cell culture medium. A comparative genotoxic analysis demonstrated a better degree of biocompatibility of nylon-6/MWNT with human lymphocytes, as compared to pristine MWNTs, for the concentration range of 10-60 microg/ml. An evidence was found that pristine MWNTs act as clastogenic agents and possibly as aneuploidogenic agents, increasing the frequency of genotoxic bioindicators.