Effects of oral exposure to zinc oxide nanoparticles on the peripheral organs of C57BL/6J mice

Abstract

To investigate the effects of oral exposure of zinc oxide nanoparticles on multiple peripheral organs of C57BL/6J mice. ;Methods: Twenty male C57BL/6J mice were randomly divided into control group and experimental group, with 10 mice in each group. The experimental group was treated with continuous gavage administration of zinc oxide nanoparticle solution at a dose of 20 mg/kg body weight for 60 days, and the control group was given the corresponding amount of normal saline; the mice were weighed once a week. After the end of the exposure, blood samples was collected from the eyeballs, and the levels of blood sugar and lipids, liver and kidney function, and inflammatory factors such as platelet activating factor (PAF), interleukin-6 (IL-6) and tumor septicemia (TNF-α) were detected. Then, tissues sections of the heart, liver, spleen, lung, kidney and small intestine were prepared and their morphological changes were observed after hematoxylin-eosin staining. ;Results: There was no significant difference in body weight between control group and the experimental group. Compared with control group, the serum levels of albumin (ALB), albumin/globulin ratio(A/G), alkaline phosphatase (ALP) activity, aspartate aminotransferase/alanine aminotransferase ratio(AST/ALT), uric acid (UA) and blood urea in the experimental group were increased significantly (P＜0.05 or P＜0.01). There was no significant change in serum inflammatory factors. Pathological examination showed myocardial turbidity, mild inflammatory lesions (focal or small necrosis) in liver, decreased pigmentation in spleen, mild or moderate interstitial inflammation in lungs, and no obvious pathological changes in the kidneys or small intestine. ;Conclusion: Sixty days of oral exposure to nanometer zinc oxide did not cause inflammation in the blood system of C57BL / 6J mice, but it could induce mild pathological changes in the heart, liver, spleen and lungs, and lead to abnormal liver and kidney function.