Electron microscopic ultrastructural study on the toxicological effects of AgNPs on the liver, kidney and spleen tissues of albino mice

• Transmission electron microscopy were used to find out ultrastructural alterations.
• AgNPs are safe at lower doses but significant alterations were noticed at higher doses.
• Significant decrease glucose level suggested the curious hypoglycemic role of NPs.
• The alterations were more obvious in nuclear membrane, mitochondria, and cytoplasm.
• Severe ultrastructural changes in all target tissues were seen only at higher doses.

The present study deals with the intraperitoneal administration of 500, 1000, 3000, and 5000 mg/kg of AgNPs in albino mice for 28 days to evaluate the potential toxicological effects of AgNPs on blood biochemical parameters and to investigate the light and electron microscopic histopathological alterations on three major targets organs i.e., liver, kidney and spleen. The AgNPs was well tolerated and no mortality was observed even at the highest dose i.e., 5000 mg/kg. Mice treated with 500 and 1000 mg/kg AgNPs did not show significant behavioral, biochemical and ultrastructural pathological changes. Mice treated with 1000 mg/kg AgNPs produces little ultrastructural alteration in liver, kidney and spleen. However, mice treated with 3000 and 5000 mg/kg AgNPs revealed significant changes in biochemical parameters. Electron microscopic ultrastructural investigation of liver and kidney shows that the administration of 3000 and 5000 mg/kg AgNPs revealed irregularity in the nuclear membrane, nuclear chromatin condensations, degenerated hepatocytes, swollen and pleomorphic mitochondria with distorted cristae, extensive dilation of rough endoplasmic reticulum, destructed cytoplasm, hypertrophied and fused podocytes and thickened basement membrane in the endothelial cells of the proximal tubules. The spleen sections at 3000 and 5000 mg/kg AgNPs revealed megakaryocytes hyperplasia, lobulations, invaginations and folding of nuclei and nuclear membrane. The present research indicates that AgNPs were well tolerated at the lower doses, but significant alterations in liver, kidney and spleen were observed at the higher doses tested. It is, therefore, suggested that further studies are needed for the minimization of the observed side effects, especially at higher doses before AgNPs being applied in pharmaceutical application.