The present study aimed to explain the mechanisms involved in cell-mediated immunotoxicity of atrazine (ATR) in rabbits and to evaluate the ameliorative role of glycyrrhizic acid (GA) against such toxic effects. Forty rabbits were assigned into 4 equal groups: control, ATR, GA, and ATR + GA groups. ATR (2475 ppm) and GA (60 μg of GA/ml of water) were administrated via food and drinking water, respectively, for 60 consecutive days. The cell-mediated immunotoxicity of ATR was clarified by the induced thymus immunotoxicity through downregulation of interleukin (IL)-9 gene and interferon-γ (IFN-γ) gene expression, upregulation in caspase-3, and significant decrease in the total leukocytic and lymphocyte counts. Histopathological investigations demonstrated severe depletion of lymphoid follicles in the medulla of the thymus gland. On the other hand, co-administration of GA for group 4 improved most of the undesirable impacts of ATR. In conclusion, the alteration in IL-9/IFN-γ expression may involve ATR-induced thymocyte apoptosis which may explain the mechanisms of ATR-induced cell-mediated immunotoxicity with a possible amelioration influence of GA administration.
Keywords: Apoptosis; Atrazine; Glycyrrhizic acid; Immunotoxicity; Rabbits; Thymus.