Oral exposure to zinc oxide nanoparticles induced oxidative damage, inflammation and genotoxicity in rat’s lung

This study aimed to investigate the toxicity of oral ZnONPs on the rat's lung. Rats were divided into four groups each of ten rats. Groups I and II were treated orally with 40 and 100 mg/kg ZnONPs for 24 hrs. Groups III and IV received daily 40 and 100 mg/kg ZnONPs orally for 1 week. Ten untreated rats were used as control. Oral administration of ZnONPs induced eosinophilia and lymphocytes infiltration in the lungs in the four tested groups that peaked at 100 mg/kg/day for 1 week. Lipid peroxidation was significantly higher, while levels of reduced glutathione and catalase activity were lower in all ZnONPs-treated groups. Nitrite concentrations increased significantly in rat’s lung treated with 100 mg/kg for 24 hrs and in those treated with 40 and 100 mg/kg daily for 1 week. Levels of lung TNF-α were significantly higher after 24 hrs at high dose and after 1 week at both low and high doses. Interleukin-1β and pentraxin-3 levels were significantly increased at 1 week only at both low and high doses. There were lower levels of paraoxonase-1 and increased DNA damage in the four studied groups. Oral administration of ZnONPs induced lung injury possibly through oxidative stress, inflammatory response and DNA damage. [Nounou H, Attia H, Shalaby M, Arafah M. Oral exposure to zinc oxide nanoparticles induced oxidative damage, inflammation and genotoxicity in rat’s lung. Life Sci J 2013;10(1):1969-1979] (ISSN:1097-8135). http://www.lifesciencesite.com. 282