Fig. 3. (A) Serum concentrations of immunoglobulin M (IgM), lysosomal enzymes, and nitric oxide (NO) in the experimental groups of Oreochromis niloticus after 4 weeks of treatment with Cont, fed the basal diet; Endo, exposed to 1/20 (12.795 μg/L) 96 h LC50 of endosulfan; Lyco, basal diet supplemented with 600 mg/kg of lycopene; Endo + Lyco, exposed to 1/20(12.795 μg/L) 96 h LC50 of endosulfan and basal diet supplemented with 600 mg/kg of lycopene, (mean ± SEM). (B) Fold-change of cytochrome P450 (CYP450 1A) and glutathione S-transferase (GST) mRNA expression in the four experimental groups after 4 weeks of treatment. Values carrying different letters (a, b, and c) are considered significant (P