Health Risks and Toxicity of Zinc Oxide Nanoparticles in Rats: Assessment of Inflammatory and Oxidative Stress Effects

Abstract

Zinc oxide (ZnO) nanoparticles are widely used in various medical and health products, including cosmetics, sunscreens, and antimicrobial agents. However, their potential toxicity raises significant concerns. This study investigates the in vivo toxicity of ZnO NPs using a rat model. Male Wistar rats were divided into four groups and treated intraperitoneally with different doses of ZnO NPs (50, 100, and 150 mg/kg) for three weeks, with a control group receiving normal saline. Post-treatment, rats were assessed for body weight changes, and were sacrificed for hematological, biochemical, and molecular analyses.Findings revealed that ZnO NPs led to reduced weight gain and persistence in brain cells, particularly in lysosomes, as observed via transmission electron microscopy. Hematological analysis showed decreased RBC count, hemoglobin, MCH, and MCHC, with an increase in WBC count, indicating hematotoxicity. Hepatotoxicity was evident through reduced levels of ALT, AST, and ALP, along with increased oxidative stress markers. Neurotoxic effects were indicated by disrupted AChE activity and reduced Na+/K+ ATPase activity in brain mitochondria. Molecular analysis showed elevated pro-inflammatory mediators and disturbances in neurotransmission. These results highlight the potential toxicological impacts of ZnO NPs and stress the need for caution in their use.