Histopathological and Immunohistochemical Evidence of Curcumin's Defence Against Chlorothalonil Toxicity

Chlorothalonil (Cr), a fungicide widely used worldwide to protect crops from fungal diseases. Curcumin (Cm), a natural antioxidant, was investigated for its protective effects. The experiment involved 120 female Swiss albino mice (weighing 20-25 g), randomly assigned to 12 groups of 10 mice each. Group 1 served as a control. Groups 2 and 3 received Cm at concentrations of 0.5% and 2% in their diet for 12 weeks, respectively. Groups 4, 5, and 6 were administered Cr at doses of 0.1, 10 and 100 mg/kg body weight (B.W.) in their diet for 5 weeks. Groups 7, 8 and 9 were given Cm at 0.5% in their diet for 12 weeks, followed by Cr at 0.1, 10 and 100 mg/kg B.W., respectively, for 5 weeks. Similarly, Groups 10, 11 and 12 received Cm at 2% in their diet for 12 weeks, followed by Cr at 0.1, 10 and 100 mg/kg B.W., respectively, for 5 weeks. At the end of the experiment, all mice were sacrificed, and tissue specimens from the liver, kidneys and spleen were collected, respectively, in their diet for 12 weeks and preserved in 10% neutral buffered formalin for 48 hours for histopathological and immunohistochemical analysis. The results demonstrated that Cm at a 2% concentration provided greater protection than 0.5% in mitigating Cr-induced damage in the examined organs. This protective effect was mediated by increased expression of glutathione peroxidase (GPX) and inhibition of inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB) and caspase-3 as observed through immunohistochemistry (IHC).