Harmful effects and acute lethal toxicity of intravenous administration of low concentrations of hydrofluoric acid in rats

Mechanisms of piperonyl butoxide cytotoxicity and its enhancement with imidacloprid and metals in Chinese hamster ovary cells

The widespread use of chemicals and the presence of chemical and metal residues in various foods, beverages, and other consumables have raised concerns about the potential for enhanced toxicity. This study assessed the cytotoxic effects of Piperonyl butoxide (PBO) and its enhancement by combination with major contamination chemicals including Imidacloprid and metals, using different cytotoxic and genotoxic assays in Chinese hamster ovary (CHO) cells. PBO exhibited elevated cytotoxic effects in poly (ADP-ribose) polymerase (PARP) deficient CHO mutants but not in Glutathione S-transferase deficient CHO mutants. PBO cytotoxicity was enhanced by PARP inhibitor, Olaparib. PBO cytotoxicity was also enhanced with co-exposure to Imidacloprid, Lead Chloride, or Sodium Selenite. PBO induces γH2AX foci formation and apoptosis. The induction of DNA damage markers was elevated with PARP deficiency and co-exposure to Imidacloprid, Lead Chloride, or Sodium Selenite. Moreover, PBO triggers to form etch pits on plastic surfaces. These results revealed novel mechanisms of PBO cytotoxicity associated with PARP and synergistic effects with other environmental pollutants. The toxicological mechanisms underlying exposure to various combinations at different concentrations, including concentrations below the permitted limit of intake or the level of concern, require further study.

Effects of acute fluoride exposure on the jejunum and ileum of rats: Insights from proteomic and enteric innervation analysis

Fluoride (F) is largely employed in dentistry, in therapeutic doses, to control caries. However, excessive intake may lead to adverse effects in the body. Since F is absorbed mostly from the gastrointestinal tract (GIT), gastrointestinal symptoms are the first signs following acute F exposure. Nevertheless, little is known about the mechanistic events that lead to these symptoms. Therefore, the present study evaluated changes in the proteomic profile as well as morphological changes in the jejunum and ileum of rats upon acute exposure to F. Male rats received, by gastric gavage, a single dose of F containing 0 (control) or 25 mg/Kg for 30 days. Upon exposure to F, there was a decrease in the thickness of the tunic muscularis for both segments and a decrease in the thickness of the wall only for the ileum. In addition, a decrease in the density of HuC/D-IR neurons and nNOS-IR neurons was found for the jejunum, but for the ileum only nNOS-IR neurons were decreased upon F exposure. Moreover, SP-IR varicosities were increased in both segments, while VIP-IR varicosities were increased in the jejunum and decreased in the ileum. As for the proteomic analysis, the proteins with altered expression were mostly negatively regulated and associated mainly with protein synthesis and energy metabolism. Proteomics also revealed alterations in proteins involved in oxidative/antioxidant defense, apoptosis and as well as in cytoskeletal proteins. Our results, when analyzed together, suggest that the gastrointestinal symptoms found in cases of acute F exposure might be related to the morphological alterations in the gut (decrease in the thickness of the tunica muscularis) that, at the molecular level, can be explained by alterations in the gut vipergic innervation and in proteins that regulate the cytoskeleton.