Nephrotoxic effects of low-dose zinc oxide nanoparticles in rats

The use of zinc oxide nanoparticles (ZNPs) in various products such as biosensors, sunscreens and nourishment added substances is increasing.
In the present work the impacts of ZNP on kidney of rats was explored.
In this experimental study male Wistar rats were used. Trial groups received 5, 50 and 300 mg/kg ZNP (ZNP-1 to ZNP-3) for 2 weeks. Control group received only normal saline. blood urea nitrogen (BUN), creatinine (Cr) and uric acid were considered as biomarkers to indicate nephrotoxicity. To evaluate the oxidative stress in the kidney, malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) enzymes activity were measured. Histopathological and apoptotic cell death was also evaluated in renal tissues.
Blood density of zinc (Zn) was significantly increased in the low dose-treated rats. Concentration of Zn in the renal tissue was significantly increased in the high dose treated rats. Weight of kidney was significantly elevated in both ZNP-1 and ZNP-2 groups. ZNP resulted in a significant increment in MDA content in the low measurements and a critical reduction in the activity of the SOD and GPx enzymes. Exposure of ZNP at low dose induced a significant elevation in blood concentration of BUN, Cr and uric acid. Treatment with low dose of ZNP caused a significant increase in histological changes and apoptotic index. ZNP at the high dose induced poor nephrotoxicity.
In conclusion, ZNP has dose-dependent nephrotoxic effects on rats and lower doses have more toxic action.