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

Abstract

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.