Effects of a ZnO-Nanoparticle/Nigella sativa Hybrid on Immune Responses and Splenic Histopathology in Experimental Visceral Leishmaniasis

Visceral leishmaniasis causes marked immune and splenic alterations. This study evaluated the effects of a ZnO-NPs/Nigella sativa hybrid on cytokine responses and splenic histopathology in experimentally infected mice. Fifty male BALB/c mice were randomly divided into five groups (n=10): healthy control, untreated infected, infected treated with Nigella sativa extract (10 mg/kg/day), infected treated with ZnO-NPs (5 mg/kg/day), and infected treated with the ZnO-NPs/Nigella sativa hybrid (10 mg/kg/day). Treatments were administered orally for four weeks. IL-4 and IFN-γ were measured by ELISA, splenic alterations were evaluated histologically, and the nanomaterials were characterized by XRD and EDS. Untreated infected mice showed increased IL-4 (176.14±3.29 U/L) and IFN-γ (177.35±13.88 U/L) compared with controls (119.20±3.44 and 125.20±7.10 U/L, respectively). In the hybrid-treated group, levels were 148.67±10.46 and 140.02±11.21 U/L, respectively. Histological examination showed less severe splenic alterations in the hybrid-treated group than in untreated infected mice. The ZnO-NPs/Nigella sativa hybrid was associated with modulation of IL-4 and IFN-γ levels and less severe splenic histopathological alterations. Further studies using quantitative parasite-burden assessment are warranted.