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Particles generated from numerous anthropogenic and/or natural sources, such as crystalline α-Fe₂O₃ nanoparticles, have the potential to damage lung cells. In our study we investigated the effects of these nanoparticles (12.5 µg/ml) on lipid peroxidation and the antioxidative system in MRC-5 lung fibroblast cells following exposure for 24, 48 or 72h. Exposure to α-Fe₂O₃ nanoparticles increased lipid peroxidation by 81%, 189% and 110% after 24, 48 and 72h, respectively. Conversely, the reduced glutathione concentration decreased by 23.2% and 51.4% after 48 and 72h of treatment, respectively. In addition, an augmentation of the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione transferase and glutathione reductase within the interval between 48-72h was noticed. Taking into account that the reduced glutathione level decreased and the malondialdehyde level, a lipid peroxidation product, remained highly increased up to 72h of exposure, it would appear that the MRC-5 antioxidant defense mechanisms did not efficiently counteract the oxidative stress induced by exposure to hematite nanoparticles.

Silicon-based quantum dots were intraperitoneally injected in individuals of Carassius auratus gibelio. Their effects on white muscle were investigated by following their distribution and impact on the antioxidative system. The GSH level significantly increased after 1 and 3 days of exposure by, respectively, 85.3 and 25.4%. Seven days later, GSH levels were similar to control concentrations. MDA concentration rose after three days by 46.9% and remained at the same level after 7 days. Protein thiol levels significantly decreased by 6.7 and 8.1% after 3 and 7 days, whereas advanced oxidation protein products increased by 12.7, respectively, 28.1% in the same time intervals. The protein reactive carbonyl groups were raised only after the first day of exposure and returned to the control level later on. SOD specific activity increased up to 48% after 7 days, while CAT activity increased by 328, 176, and 26% after 1, 3, and 7 days of treatment. GST specific activity was up-regulated by 87, 18, and 9%, while GR activity increased by 68, 34, and 9%. G6PD activity was up-regulated by 12, 22, and 50%, whereas GPx activity raised by 75 and 109% compared to control after, respectively, 1, 3, and 7 days. Our results suggest that oxidative stress induced by silicon-based quantum dots was not strong enough to cause permanent damage in the white muscle of crucian carp. [ABSTRACT FROM AUTHOR]

The article presents a study on the impact of malathion, a kind of pesticide commonly used in households and agriculture to terminate harmful organisms. It states that the pesticide has toxic substances which could be dangerous to living things particularly to fishes. It investigates its effects on lipid peroxidation and antioxidant systems in the kidney, intestine and gills of Carassius auratus gibelio, a wild form of goldfish. Findings of the study indicate that the lipid peroxidation and antioxidative defense mechanisms show different responses in examined tissues. It notes that they increased after one day of malathion administration and changes in reduced glutathione levels have been recorded after six days of pesticide exposure.

Abstract: The mycotoxin deoxynivalenol (DON), a contaminant of certain foods and feeds, is cytotoxic and genotoxic to mammalians cells. Exposure of human embryonic kidney (Hek-293) cells to DON led to a dose- and time-dependent decrease in cell viability, with an IC50 about 7.6 μM. The DON effects on Hek-293 morphology, reactive oxygen species, lipid peroxidation and antioxidative system and caspase 3 and bcl-2 expression were studied. Cells became round and in some are progressive loss of cell attachment appeared. These biochemical parameters were assessed after 6, 12 and 24 h of treatment with 2.5 and 5 μM DON. An increase in superoxide dismutase activity within the interval 6–12 h and almost complete recovery by the end of experiment for both concentrations was observed, whereas the profile of catalase activity was the same with the superoxide dismutase one for 2.5 μM and decreased in a time-dependent manner for 5 μM. A temporary activation of glutathione peroxidase and glutathione reductase was recorded at 12 h post-exposure, while the glutathione-S-transferase activity was unchanged for both concentrations. The NADP+-dependent isocitrate dehydrogenase activity showed a transient increase at the 12 h post-exposure. The caspase 3 expression remained unchanged and the bcl-2 one decreased after 24 h of exposure for the two concentrations. Our results showed the dose- and time specific changes in the antioxidants system of Hek-293 cells, which could not counteract efficiently the effects DON exposure. The different types of cell death which could be activated by this DON induced changes are mentioned. [Copyright &y& Elsevier]