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Background & objectives: Due to the widespread use of zinc oxide nanoparticles (ZnO-NPs) and their possible unwanted effects in biological environments, we made an attempt to investigate the effect of ZnO-NPs on the blood lipid profile.
Methods: In this study, 24 male Wistar rats were used. The rats were randomly divided into three groups: control group, the group receiving ZnO-NPs at 25 mg/kg (ZnO-NPs 25 mg/kg) and the group receiving ZnO-NPs at 50 mg/kg (ZnO-NPs 50 mg/kg). The duration of the test was two weeks. The blood samples were taken and the serums were separated. Serum levels of triglyceride, cholesterol, VLDL, LDL and HDL were determined using standard kits and methods.
Results: Based on the findings of this study, serum levels of triglyceride and VLDL in both ZnO-NPs receiving groups were significantly increased in comparison with the control group (p<0.05). Also,  the serum levels of HDL , LDL and LDL/HDL ratio decreased significantly in both ZnO-NPs receiving groups compared to the control group (p<0.05), while the  serum cholesterol levels did not change compared with the control group.
Conclusion: Our results showed that 25 and 50 mg/kg doses of ZnO-NPs had both harmful (increase triglyceride and VLDL and reduction of HDL) and beneficial (reduction of LDL and LDL/HDL ratio) effects on the blood lipid profile.