Chronic Zinc Oxide Nanoparticles Exposure Produces Hepatic and Pancreatic Impairment in Female Rats

Background: Zinc oxide (ZnO) nanoparticles are used for various industrial and domestic purposes and its release into the environment leads to the adverse effects among humans. This study aimed to evaluate the effect of rat exposure to ZnO nanoparticles on the histopathology of the liver and pancreas tissues, and serum oxidative stress parameters. Methods: Eighty female adult Wistar rats were divided into eight experimental, control and sham groups. They received ZnO nanoparticles at 4, 8, 25, 50, 100, or 200 mg/kg, or normal saline intraperitoneally for 30 days twice a week. Then, the blood samples of the rats were collected by heart puncture for biochemical analyses, and then sacrificed. Finally, the liver and pancreas tissues were harvested for histopathological examinations. Results: Significant amounts of nanoparticles were accumulated in the liver and pancreas of the rats, causing tissue and cellular damages. The ZnO nanoparticles reduced the levels of serum triglyceride, glucose, cholesterol, albumin, and increased the bilirubin and liver enzymes, such as ALT, AST, ALP, amylase and lipase at high doses. In addition, the evidence of histopathological lesions, hyperemia, inflammatory cell infiltration, and necrosis were noted in the liver and pancreas tissue slides upon microscopic examinations. Finally, the body and liver weights decreased in the rat groups receiving ZnO nanoparticle dose dependently. Conclusion: ZnO nanoparticles had toxic effects on the liver and pancreas, leading to destructive tissue and cellular changes in the rats.