Genotoxische Effekte aktuell gebräuchlicher Insektizide auf humane Tonsillenschleimhautepithelien

Cytoprotective and anti-apoptotic action of HSP70 stress protein in Oreochromis niloticus exposed to residual dilutions of insecticides with fipronil and ethiprole

The objective of this research was to investigate the potential damage caused by the residual concentrations of the insecticides Regent^® WS 800 and Curbix^® SC 200, containing fipronil and ethiprole, respectively as active ingredients, on the liver of Oreochromis niloticus. The analyses of HSP70 shock protein labelling and cell death process by TUNEL method were performed in order to measure the effects of the exposure of cell repair system of fish to both insecticides. Statistical analyses showed no significant molecular damage to the hepatic tissue of animals. Nevertheless, variations in HSP70 and DNA fragmentation levels, endpoint of cell repair system response and cellular death, respectively, were observed in several groups. These results indicate that the cell repair machinery was efficient when in contact with residual concentrations of insecticides. However, the DNA fragmentation detected by the TUNEL method suggests that even in face of the cytoprotective action of the HSP70 protein, there are damages that become irreparable. To finish, it is worth mentioning that given the results obtained from residual concentrations, use in the field should be with caution.

Depleted uranium and Gulf War Illness: Updates and comments on possible mechanisms behind the syndrome

Indications of proximal tubule effects have been observed in recent surveillance study of Gulf War veterans exposed to depleted uranium (DU). This gives some support for the suspicion that DU may represent one of the causes for the so-called Persian Gulf syndrome. Proposed effects may be especially harmful if the toxicity hits the mitochondrial DNA since the mitochondria lack the nucleotide excision repair mechanism, which is needed for repairing bulky adducts that have been associated with DU. It is a plausible working hypothesis that a significant part of the symptoms from various organs, which have been observed among veterans from Gulf War 1 and that have been grouped under the name of the Persian Gulf syndrome, may be explained as a consequence of mitochondrial DNA damage in various cell types and organs. Interpretation of observations, on military personnel and civilians after Gulf War 1, is associated with difficulties because of the abundance of potential confounding factors. The symptoms observed on veterans from Gulf War 1 may be attributed to a multiplicity of substances functioning directly or indirectly as mitochondrial mutagens. A concise analysis of the cascade of toxic effects initiated by DU exposure in the human body is the subject of this article.

DNA damage after acute and chronic treatment with malathion in rats

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.