Abstract

Introduction: Chlorpyrifos is an organophosphorus insecticide that can produce reactive oxygen species, and oxidative stress in the kidney. On the other hand, rosemary extract is an antioxidant playing a protective role against free radicals. Therefore, the aim of this study was to evaluate the oxidative stress in rat kidney due to the exposure to chlorpyrifos and to assess the antioxidant effect of two concentrations of 100 and 200 mg / kg rosemary extract on the nephrotoxicity caused by this pesticide. Material and method: In the current study, 30 male Wistar Rats, weighing 200-220 g were used. They were randomly divided into five groups and selected as the study groups, each group including six rats for further comparison. They were as following groupd: Group I: served as control (received dissilated water, i.p) , Group II: the chlorpyrifos exposure group (13.5 mg/kg, i.p.), Group Iii: the group exposed to rosemary extract (100 mg/kg) by gavage, Group IV: the exposure group with rosemary 100 mg/kg concentration (by gavage) and after 30 minutes exposure to chlorpyrifos (13.5 mg/kg, i.p.) and Group V: simultaneous exposure of rosemary 200 mg/kg concentration (by gavage) and after 30 minutes exposure to chlorpyrifos (13.5 mg/kg, i.p.). After 2 and 4 weeks, the rats were weighed and killed. A section of kidney tissue was examined for changes of Malondialdehyde (MDA) and Glutathione peroxidase (GPx) and another section was tested for histopathological alterations. Results: The results showed that chlorpyrifos significantly damaged the kidney tissue and altered the activity of GPx and MDA compared to the control group, as well as it damaged the kidney tissue. Moreover, the simultaneous exposure to chlorpyrifos and rosemary extract with concentration of 100 mg/kg significantly made modifications to the MDA and GPx levels. In addition, with the increasing of rosemary doses from 100 to 200 mg/kg, changes in the levels of MDA and GPx were closer to those of the control group. Conclusion: The rosemary extract can reduce the oxidative stress caused by chlorpyrifos and, therefore, can be used to treat the poisoning caused by this pesticide.