BIONATURE

Aims: To evaluate the in vitro immunotoxic potential of the fungicide mancozeb in chicken splenic lymphocytes by assessing its effects on B- and T-cell proliferation and nitric oxide (NO) production as an indicator of oxidative stress. 

Study Design: An in vitro experimental laboratory study using isolated chicken splenic lymphocytes to investigate immunomodulatory and oxidative stress–mediated effects of mancozeb exposure. 

Place of Study: The study was conducted in the Department of Veterinary Pathology, College of Veterinary and Animal Sciences and Department of Molecular Biology and Genetic Engineering, G.B. Pant University of Agriculture and Technology, Pantnagar, India. 

Methodology: Avian splenic lymphocytes were isolated under aseptic conditions and exposed in vitro to a thousand-fold diluted No Observable Effect Level (NOEL/10³) dose of mancozeb. B- and T-cell proliferation was evaluated using the lymphocyte proliferation assay (LPA), with lipopolysaccharide (LPS) and concanavalin-A (ConA) serving as B- and T-cell mitogens, respectively. Oxidative stress was assessed by estimating nitric oxide (NO) production in culture supernatants using the Griess reagent method. Statistical analysis was performed to compare treated and control groups. 

Results: Mancozeb exposure significantly suppressed lymphocyte proliferation. B-cell and T-cell blastogenesis showed a reduction as compared to control. Additionally, nitric oxide production increased in mancozeb-treated cells relative to untreated controls, indicating enhanced oxidative/nitrosative stress.

Conclusion: In vitro exposure to low-level mancozeb significantly suppresses B- and T-lymphocyte proliferation and increases nitric oxide production, indicating oxidative stress–mediated immunotoxic effects. The chicken splenic lymphocyte culture system serves as a sensitive and reliable in vitro model for preliminary screening of pesticide-induced immunomodulatory toxicity.