Assessment of Oxidative Stress Induced Immunotoxic Effect Mediated by in Vitro Exposure to Methyl Parathion in Lymphocytes Isolated from Chicken Spleen

Immunotoxicology examines the adverse effects of xenobiotics- including pesticides, heavy metals from emissions, drugs and other substances- on the body’s defense system of humans and animals. The term pesticide encompasses a diverse array of substances, including insecticides, fungicides, herbicides, rodenticides, etc. Pesticides are widely used around the globe; however, there has been an increase in reports highlighting their harmful effects. The broad-spectrum activity of methyl parathion allows elimination a vast range of pests, making it a popular choice for pest control in agriculture. However, its use is increasingly regulated due to its high toxicity to humans, non-target organisms and the environment. Methyl parathion, a widely used organophosphate pesticide, is reported to pose significant health risks through its neurotoxic, immunotoxic and oxidative stress-inducing effects. Methyl parathion primarily exerts toxicity by inhibiting acetylcholinesterase, leading to neural overstimulation. This study investigates the in vitro immunotoxic effects of methyl parathion induced due to increased oxidant stress (OS) in mitogen-stimulated avian lymphocytes. Utilizing lymphocyte proliferation and nitric oxide (NO) estimation assays, the findings showed a marked reduction in B and T-cell proliferation following exposure to a thousand-fold dilution of the No Observable Effect Level (NOEL/103) dose of methyl parathion. Additionally, oxidative stress, as indicated by NO levels, was significantly elevated in methyl parathion treated cells as compared to control cells. Thus, our results indicate that in vitro exposure to methyl parathion caused considerable immunotoxic effects in the exposed lymphocytes that could be linked with enhanced OS.