Morphological, Histological Changes and Acetyl Cholinesterase Activity in Chick Embryos After Exposure to Abamectin Insecticide

Abamectin is a bio-insecticide, derived from the soil bacteria Streptomyces avermitilis. This insecticide is used in public health and agriculture to protect crops. Major adverse impacts of Abamectin are neurological symptoms acting on the peripheral nervous system. The aim of the current study is to reveal the toxic effects of Abamectin on chick embryo Ross 308 including morphological and histological changes and acetyl cholinesterase activity. 120 fresh fertilized eggs were divided into 6 groups; two of them were used as control. After 2 days of incubation, the eggs were injected with 100 µL of Abamectin solution (diluted at concentrations 360, 540, 900 and 1800 ppm) into the yolk sac. The Results showed that the mortality increased significantly in chicks treated with Abamectin, but had a lower weight in comparison to the control groups. Treated chicks started hatching at day 22 but were physically weak with drooping limbs, paralysis and then died after 24 hours of hatching. Some chicks did not normally hatch and needed assistance. They characterized by limb defects, failure retraction of yolk sac with bleeding. Histological examination of the liver showed hepatic cell degeneration, congestion in the central vein, infiltration of inflammatory cells and hepatocytes necrosis. Furthermore, the Acetyl cholinesterase enzyme analysis showed a significant decrease in the enzyme activity which leads to inhibition the activity of the body systems. It is concluded that low and high concentration of Abamectin has adverse impacts on chick embryo by changing some of morphological, histological characteristics and acetyl cholinesterase activity.

Pharmaceutical Products and Pesticides Toxicity Associated with Microplastics (Polyvinyl Chloride) in Artemia salina

Pharmaceutical products, as well as insecticides and antimicrobials, have been extensively studied, but knowledge of their effects—especially those caused by their mixtures with microplastics—on aquatic organisms remains limited. However, it should be borne in mind that the state of knowledge on acute and chronic effects in aquatic organisms for pharmaceuticals and pesticides is not similar. In response, this investigation analyzed the presence of microplastics (polyvinyl chloride) and their impacts on the toxicity of chlorpyrifos (an insecticide) and triclosan (an antibacterial) when they coincide in the environment, alongside the two most consumed drugs of their type (hypolipemic and anticonvulsant, respectively), namely simvastatin and carbamazepine, in Artemia salina. LC50 and cholinesterase enzyme activity were calculated to determine the possible neurotoxicity associated with emergent contaminants in the treatments. The LC50 values obtained were 0.006 mg/dm3 for chlorpyrifos, 0.012 mg/dm3 for chlorpyrifos associated with microplastics, 4.979 mg/dm3 for triclosan, 4.957 mg/dm3 for triclosan associated with microplastics, 9.35 mg/dm3 for simvastatin, 10.29 mg/dm3 for simvastatin associated with microplastics, 43.25 mg/dm3 for carbamazepine and 46.50 mg/dm3 for carbamazepine associated with microplastics in acute exposure. These results indicate that the presence of microplastics in the medium reduces toxicity, considering the LC50 values. However, exposure to chlorpyrifos and carbamazepine, both alone and associated with microplastics, showed a decline in cholinesterase activity, confirming their neurotoxic effect. Nevertheless, no significant differences were observed with the biomarker cholinesterase between the toxicant and the toxicant with microplastics.

Association between Exposure to Pesticides and Cognitive Function in Greenhouse Workers (Case Study: Ahmadabad Village of Yazd Province)

Introduction: Exposure to pesticides in greenhouse workers is associated with several health outcomes, such as cognitive impairment. This study aimed to investigate the association between exposure to pesticides and cognitive function in Yazd city greenhouse workers and those living in the proximity of the greenhouses. Materials and Methods: In this study, three groups of participants were selected, including the greenhouse workers, the residents in the proximity of the greenhouses, and the control group. A semi-quantitative assessment of pesticide exposure was used to calculate the subjects’ cumulative pesticide exposure as a proxy for long-term exposure to pesticides. Blood level of acetylcholinesterase (AChE) activity was measured as a biomarker of effect. Frontal Assessment Battery (FAB), and Mini–mental State Examination (MMSE) were used to assess cognitive functions (including memory, executive functions, attention, visual, and verbal functions). Results: Mean cholinesterase activity in the greenhouse workers (average = 7009.3 U/L) was lower than the two other groups. The results of the cognitive function score for both FAB and MMSE tests did not show a significant difference between the direct exposure and indirect exposure groups, although the cognitive function score in the pesticide applicators was lower than the two other study groups (e.g. for FAB score: 13.89, 14.55, and 15.4 for the greenhouse workers, the residents in the proximity of greenhouses, and the control group). The results also showed that in the direct exposure group, those with lower levels of cholinesterase activity also had a lower cognitive function. Conclusion: The findings indicated that there is a potential link between impaired cognitive function and exposure to pesticides in the greenhouse workers.