Biochemical and histopathological evaluation of Al 2 O 3 nanomaterials in kidney of Wistar rats.

The present study was conducted to evaluate the response of kidneys in Wistar rats following long-term exposure to AlO nanomaterials (NMs). To achieve this objective, AlO of three different sizes (30 nm, 40 nm and bulk) was orally administered for 28 days to 9 groups of 10 Wistar rats each at the dose of 500, 1000 and 2000 mg/kg/rat. A tenth group of 10 rats received distilled water and served as control. After 28 days of exposure the animals were sacrificed and the serum was collected and tested for the activity levels of creatinine and urea following standard methods. Induction of oxidative stress was also investigated by assessing thiobarbituric acid reactive substances (TBARS) (MDA), protein carbonyl, reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) activities. A histopathological evaluation was also performed to determine the extent of kidney damage. The results showed that both serum creatinine and serum urea levels increased significantly in the treated rats compared to control animals. The increase was found to be more in AlO-30 nm treated rats followed by AlO-40 nm and AlO-bulk treated rats in a dose-dependent manner. Further administration of AlO significantly increased the activities of TBARS, protein carbonyl, catalase and decreased the activities of GSH and SOD in a dose-dependent manner in the kidney of rats compared with the control group. Histopathological evaluation showed significant morphological alterations in kidney tissues of treated rats in accordance with biochemical parameters. Taken together, the results of this study demonstrate that AlO is nephrotoxic and its toxicity may be mediated through oxidative stress. Further, the results suggest that prolonged oral exposure to AlO NMs has the potential to cause biochemical and histological alterations in kidney of rats at high concentration.