Toxic Effects of Trichloroethylene on Rat Neuroprogenitor Cells

Acute Toxicity and Ecotoxicological Risk Assessment of Three Volatile Pesticide Additives on the Earthworm-Eisenia fetida

Pesticide adjuvants (PAs) are important components of pesticide. Nonetheless, limited information is available regarding their toxic effects on biota in terrestrial ecosystem. In the present study, the mortality, growth inhibition ratio, and avoidance behavior of Eisenia fetida were examined to investigate the ecotoxicological effects of toluene, xylene, and trichloroethylene and further their mixture. The 24 h median lethal concentration (24 h-LC50) of the three PAs were 300.23, 1190.45, and 5332.36 mg/kg, and the 48 h-LC50 values were 221.62, 962.89, and 4522.41 mg/kg, respectively. The mixture exhibited significant synergistic effect on the E. fetida. There was significant growth inhibition on E. fetida by the tested PAs. The avoidance threshold values of E. fetida for the tested PAs were 1100 mg/kg, 250 mg/kg, 5000 mg/kg, and 25% of the mixture, respectively. The results evaluated the toxic effects of the three PAs and their mixture on E. fetida, provided a basis for ecotoxicological risk assessment of PAs in the soil ecosystem.

Effect of environmental toxicants on neuronal functions

In the last few years, neurodegenerative diseases like Alzheimer's disease (AD) and Parkinson's disease (PD) have attracted attention due to their high prevalence worldwide. Environmental factors may be one of the biggest reasons for these diseases related to neuronal dysfunctions. Most of neuronal disorders are strongly associated with pre- and postnatal exposure to environmental toxins released from industries. Some of the neurotoxic metals such as lead, aluminum, mercury, manganese, cadmium, and arsenic as well as some pesticides and metal-based nanoparticles have been involved in AD and PD due to their ability to produce senile/amyloid plaques and NFTs which are the main feature of these neuronal dysfunctions. Exposure to solvents is also majorly responsible for neurodegenerative disorders. The present review highlights the impact of omnipresent heavy metals with some other neurotoxins on human health and how they give rise to neuronal dysfunctions which in turn causes socio-economic consequences due to increasing pollution worldwide. Graphical abstract.

Trichloroethylene, a ubiquitous environmental contaminant in the risk for Parkinson's disease

Organic solvents are common chemicals used in industry throughout the world, however, there is evidence for adverse health effects from exposure to these compounds. Trichloroethylene (TCE) is a halogenated solvent that has been used as a degreasing agent since the early 20th century. Due to its widespread use, TCE remains one of the most significant environmental contaminants in the US, and extensive research suggests TCE is a causative factor in a number of diseases, including cancer, fetal cardiac development, and neurotoxicity. TCE has also been implicated as a possible risk factor in the development of the most common neurodegenerative movement disorder, Parkinson's disease (PD). However, there is variable concordance across multiple occupational epidemiological studies assessing TCE (or solvent) exposure and risk for PD. In addition, there remains a degree of uncertainty about how TCE elicits toxicity to the dopaminergic system. To this end, we review the specific neurotoxic mechanisms of TCE in the context of selective vulnerability of dopaminergic neurons. In addition, we consider the complexity of combined risk factors that ultimately contribute to neurodegeneration and discuss the limitations of single-factor exposure assessments.

Redox regulation of hepatic NLRP3 inflammasome activation and immune dysregulation in trichloroethene-mediated autoimmunity

Trichloroethene (TCE) exposure is associated with the development of various autoimmune diseases (ADs), including autoimmune hepatitis (AIH) and systemic lupus erythematosus (SLE), potentially through the generation of excessive reactive oxygen and nitrogen species (RONS; oxidative stress). However, the mechanisms by which oxidative stress contributes to these TCE-mediated ADs are not fully understood, and are the focus of current investigation. Female MRL+/+ mice were treated with TCE along with or without antioxidant N-acetylcysteine (NAC) for 6 weeks (TCE, 10 mmol/kg, i. p., every 4th day; NAC, 250 mg/kg/day via drinking water). TCE-treated mice had elevated antinuclear antibodies (ANA) and 4-hydroxynonenal (HNE)-specific circulating immune complexes, suggesting the association of TCE-induced oxidative stress with autoimmune response. In addition, TCE exposure led to prominent lobular inflammation with sinusoid dilation, increased sinusoidal cellularity and increased staining for proliferating cell nuclear antigen (PCNA), confirming inflammatory and hepatocellular cell proliferation. Importantly, TCE exposure resulted in the activation of hepatic inflammasome (NLRP3 and caspase-1) and up-regulation of pro-inflammatory cytokine IL-1β, and these changes were attenuated by NAC supplementation. TCE treatment also led to dysregulation of hepatic immune response as evident from markedly increased hepatic lymphocyte infiltration (especially B cells) and imbalance between Tregs (decreased) and Th17 cells (increased). Interestingly, TCE-mediated dysregulation of various hepatic and splenic immune cells was also effectively attenuated by NAC. Taken together, our findings provide evidence for TCE-mediated inflammasome activation, infiltration of various immune cells, and skewed balance of Treg and Th17 cells in the liver. The attenuation of TCE-mediated hepatic inflammasome activation and immune responses by NAC further supports a critical role of oxidative stress in TCE-mediated inflammation and autoimmunity. These novel findings could help in designing therapeutic strategies for such ADs.