Evaluation of the Ameliorative Effect of Zinc Nanoparticles against Silver Nanoparticle–Induced Toxicity in Liver and Kidney of Rats

Silver nanoparticles (Ag-NPs) have various pharmaceutical and biomedical applications owing to their unique physicochemical properties. Zinc (Zn) is an essential trace element, a strong antioxidant, and has a primary role in gene expression, enzymatic reactions, and protein synthesis. The present study aims to explore the toxic effects of Ag-NPs (50 nm) on the liver and kidney of rats and also to evaluate the potential protective effect of Zn-NPs (100 nm) against these adverse effects. Forty adult Sprague–Dawley rats were randomly divided into four equal groups: control group, Ag-NPs group, Zn-NPs group, and Ag-NPs + Zn-NPs group. Ag-NPs (50 mg/kg) and/or Zn-NPs (30 mg/kg) were administered daily by gavage for 90 days. The results showed that exposure to Ag-NPs increased serum ALT, AST, urea, and creatinine. Ag-NPs also induced oxidative stress and lipid peroxidation and increased inflammatory cytokines in hepatic and renal tissues. Moreover, histopathological and immunohistochemical examinations revealed various histological alterations and positive caspase-3 expressions in the liver and kidney following exposure to Ag-NPs. On the other hand, most of these toxic effects were ameliorated by co-administration of Zn-NPs. It was concluded that Ag-NPs have hepatotoxic and nephrotoxic effects in rats via different mechanisms including oxidative stress, inflammation, and apoptosis and that Zn-NPs can be used to alleviate these harmful effects by their antioxidative, anti-inflammatory, and antiapoptotic properties.