Introduction: Zinc oxide nanoparticles (ZnO-NPs) are one of metal nanoparticles that have broadly utilized in numerous fields. Nowadays, they are increasingly utilized in food as a preservative. Therefore, humans become more susceptible to their hazards via oral route.
Objective: To assess the impact of different doses of ZnO-NPs on the pancreatic acini and the effect of their withdrawal.
Materials and Methods: Thirty adult male albino rats were distributed into three equal groups at random. Group I acted as control. Group II (ZnO-NPs treated group): subdivided into two subgroups received ZnO-NPs in doses of 100 and 400 mg/kg body weight/day respectively for 28 days by oral gavage. Group III (withdrawal group): subdivided into two subgroups administered ZnO-NPs as in group II then left for 1 month without treatment. At the designated time, blood samples were collected for biochemical analysis. After scarification, pancreatic tissue was obtained and managed for light and electron microscopic studies. All the gained data underwent statistical analysis.
Results: ZnO-NPs treated group showed dose-dependent pancreatic acinar cell damage. The cells exhibited vacuolations, rarefaction, dilated rough endoplasmic reticulum, nuclear condensation and mitochondrial degeneration which were more apparent in high doses. Moreover, biochemical studies showed a statistically significant rise in pancreatic and oxidant markers. In addition, morphometrical analysis revealed a statistically significant increase in area percentage of collagen deposition. However, ZnO-NPs withdrawal induced a great recovery concerning 100mg-treated rats but incomplete improvement was detected in 400mg-treated rats.
Conclusion: ZnO-NPs induce structural and functional alterations on the pancreatic acini which are dose- dependent. When ZnO-NPs were withdrawn, these changes were reversible at low doses but partially improved with high doses.