Investigation of the effect of nigella sativa on nitrosative stres in the brain tissue of rats exposed to ionising radiation

Aim of our study was to investigate the protective effect of Nigella sativa (NS), a known antioxidant agent investigated in previous studies, against radiation-induced oxidative damage in brain tissue. A total of six study groups (n=54) were included in the study; Standard Control Group (Group A, n=8), Control Group of thymoquinone (TQ) (Group B, n=8), Control Group of Nigella sativa oil (Group C, n=8), Ionising Radiation alone Group (IR) (Group D, n=10), thymoquinone plus Ionising Radiation Group (Group E, n=10) and Nigella sativa oil plus Ionising Radiation Group (Group F, n=10). All of the groups except standard control group received 5 Gy ionising radiation in a single dose to total cranium. Nigella sativa oil was administered to the rats 1 hour before irradiation for the first dose and during ten days orally. TQ was administered 30 min before irradiation and during ten days intraperitoneally. At the end of the study, rats were sacrified and brain tissues were removed. The oxidant/antioxidant parameters such as nitric oxide synthase (NOS), nitric oxide (NO) and peroxinitrite (OONO?) were determined. NOS enzyme activity was found to be statistically different among groups and was higher in IR group (p<0.001). NO level was found to be statistically different among groups and was higher in IR group (p<0.001). Also, peroxinitrite level was found to be statistically different among groups and was higher in IR group (p<0.001). When NS and TQ were administered to the rats exposed to irradiation, these parameteres were found lower. As a result, in our study nitrosative stress parameters such as NO, NOS and OONO? were found higher in the rats exposed to ionising radiation and after administration of NS oil and TQ these parameters were found decreased. These results suggest that NS oil and TQ have antioxidant effects on the brain tissue exposed to ionising radiation.