Deltamethrin and Its Nanoformulations Induce Behavioral Alteration and Toxicity in Rat Brain through Oxidative Stress and JAK2/STAT3 Signaling Pathway

Abstract

Deltamethrin (DM) is the most powerful synthetic pyrethroid that has toxicity to the central nervous system and results in behavioral changes in both animals and humans. This effect is mediated by inducing alterations in the action of neurotransmitters and brain pathological changes. Nanocarrier encapsulated pesticides may decrease the toxicity of pesticides. Thus, this study aimed to determine the effect of an inorganic metal carrier (silica Nps) and polymeric capsule (chitosan Nps) of deltamethrin nano-formulations on antioxidant levels and oxidative stress in the brain and on behavior of the male albino rat. Sixty male albino rats were equally divided into four groups. Group I: control group; group II given DM liquefied in corn oil at 3.855 mg/kg BW; group III receiving silica-loaded deltamethrin (S/DM Nps) at 8.795 mg/kg BW; and group IV: given chitosan encapsulated deltamethrin (CS/DM Nps) at 30.44 mg/kg BW. All treatments were given orally for four weeks. Following this, behavioral tests were conducted to record locomotor activity, anxiety like behaviors, exploration, and the short memory of rats. In addition, brain antioxidant/oxidant, serum neurotransmitters such as acetylcholine esterase (AchE) and monoamine oxidase (MAO), JAK2 and STAT3 gene and proteins expression were measured. The DM group showed a highly significant elevation in malondialdehyde content, MAO, AchE, vascular endothelial growth factor (VEGF) levels, and the expression level of neurogenic genes, JAK2 and STAT3, in comparison with the control group. Both S/DM Nps and CS/DM Nps significantly decreased MAO, AchE, and VEGF compared with the DM group. Moreover, both S/DM Nps and CS/DM Nps significantly decreased the gene and proteins expression of JAK2 and STAT3 compared with the DM group. These alterations were evidenced by the deficiency in memory and learning behaviors that were accompanied by histopathological findings of the hippocampus and the cortex. It was concluded that the nano formulations containing DM induced less neurobehavioral toxicity than free DM. Additionally, the use of nanocarriers reduced the damage to health and the environment.

Keywords

• nanopesticides
• JAK/STAT
• brain
• neurotoxicity
• deltamethrin