Pre-Treatment with Zirconia Nanoparticles Reduces Inflammation Induced by the Pathogenic H5N1 Influenza Virus

Huo, Caiyun; Xiao, Jin; Xiao, Kai; Zou, Shumei; Wang, Ming; Qi, Peng; Liu, Tianlong; Hu, Yanxin

To further investigate whether ZrO 2 could affect H5N1 virus infection, BALB/c mice received a dose of triple the LD50 of H5N1 on the second day of NP administration via intraperitoneal injection. On days 3 and 6 postinfection, lung tissue samples from three mice per group were collected for histopathological analysis and realtime PCR. As shown in Figure 3A , we examined histopathological changes in the lungs of mice on day 6. Lung lesions in the glucose group included inflammatory cellular infiltration, necrosis of the mucous epithelium of bronchioles, and interstitial edema. Thickening of alveolar walls and alveolar lumen filled with edema fluid mixed with exfoliated alveolar epithelial cells, erythrocytes, and inflammatory cells was also observed in the control group. However, these symptoms appeared to be mitigated in the ZrO 2 groups. Similar symptoms to those observed in the glucose group were seen in the 25 mg/kg ZrO 2 group, but the lesion severity was lower. Both the 50 mg/kg ZrO 2 and 100 mg/kg ZrO 2 groups showed only interstitial edema; in the surrounding lung tissue, inflammatory cell infiltration was observed in the small blood vessels and bronchi. The lung tissues from mice in the 100 mg/kg ZrO 2 group showed markedly milder symptoms than those from other groups. The control group showed no histopathological changes. The scores of pathological changes in lungs of the H5N1-infected mice were determined. The results suggested that NPs could alleviate lung lesions in H5N1-infected mice.