Biochemical and histological evaluation of kidney damage after sub-acute exposure to 2,4-dichlorophenoxyacetic herbicide in rats: involvement of oxidative stress.

The present study evaluated the effects of sub-acute exposure to different doses of 2,4-dichlorophenoxyacetic acid (2,4-D) on rat kidney. Forty animals were divided into four equal groups and treated with different doses of 2,4-D: 0, 15, 75 and 150 mg/kg body weight per day via oral gavage for 28 consecutive days. Renal function, histopathology, tissue malondialdehyde and antioxidant enzyme activities were evaluated. The results showed a significant decrease (p < 0.01) in uric acid level and an increase in plasma levels of urea and creatinine (p < 0.01) in rats administered 2,4-D at the three studied doses. The activities of catalase and superoxide dismutase were significantly affected for all treated rats, while glutathione peroxidase significantly decreased in rats exposed to 2,4-D at a dose of 150 mg/kg. Through sub-acute treatment, starting from the low to the high doses of 2,4-D, there were significant increase in kidney MDA as compared to controls. The histopathological study revealed tubular damages, glomerular alterations, vascular congestion and increased number of pyknotic nuclei in kidneys of all 2,4-D treated groups. The severity of these alterations increase in a dose-dependent manner. Our findings confirm that sub-acute exposure to 2,4-D induced oxidative renal dysfunction in rats. Therefore, at higher doses, 2,4-D may be implicated in the pathogenesis of kidney failure via lipid peroxidation and oxidative stress.