Introduction: Oxidative stress is resulting from the imbalance between free radicals and antioxidant system of the body. Increased oxidative stress in the brain causes impaired brain activity, neuronal death, and diseases such as multiple sclerosis (MS). In this study, the protective effect of Ferula szowitsiana plant against oxidative stress caused by cerebral ventricular injection of ethidium bromide was evaluated.

Materials & methods: With direct single injection of 0.01 % ethidium bromide (EB) into the Cornu ammonis (CA₁) of hippocampal formation the induction of MS was done. One week after MS induction, animals received intrahippocampal (5 μg/rat and 10 μg/rat) administration of the extract for 3 consecutive days. At the end, the bilateral hippocampi was dissected and used for the measurement of oxidative stress markers. Statistical analysis of the obtained data was performed using one-way ANOVA.

Findings: Hippocampal injection of EB caused significant increment of total antioxidant capacity (p< 0.001) and activity of antioxidant enzymes SOD and decrease activity of CAT (p< 0.01). Short-term local injection of Ferula szowitsiana extract significantly reduced the total antioxidant capacity (p< 0.001) and activity of CAT and SOD enzymes (p< 0.001) to the normal levels.

Discussion & conclusions: The results of the present study show that local injection of EB cause increasing production of the free radicals. The Ferula szowitsiana extract as a potent antioxidant modulates oxidative stress markers, probably through scavenging of reactive oxygen species )ROS( and clearing of free radicals from the cellular milieu.