Saffron ethanolic extract attenuates oxidative stress, spatial learning, and memory impairments induced by local injection of ethidium bromide

Cognitive deficits have been observed in patients with multiple sclerosis (MS) because of hippocampal insults. Oxidative stress plays a key role in the pathophysiology of MS. The aim of this study was to evaluate the effects of Crocus sativus L., commonly known as saffron, on learning and memory loss and the induction of oxidative stress in the hippocampus of toxic models of MS. One week after MS induction by intrahippocampal injection of ethidium bromide (EB), animals were treated with two doses of saffron extract (5 and 10 µg/rat) for a week. Learning and spatial memory status was assessed using Morris Water Maze. After termination of behavioral testing days, animals were decapitated and the bilateral hippocampi dissected to measure some of the oxidative stress markers including the level of hippocampi thiobarbituric acid reactive substances and the activity of antioxidant enzymes such as glutathione peroxidase and superoxide dismutase. Treatment with saffron extract ameliorated spatial learning and memory impairment (P<0.05). Total antioxidant reactivity capacity, lipid peroxidation products and antioxidant enzymes activity in the hippocampus homogenates of EB treated group were significantly higher than those of all other groups (P<0.01). Indeed, treatment with a saffron extract for 7 consecutive days significantly restored the antioxidant status to the normal levels (P<0.01). These observations reveal that saffron extract can ameliorate the impairment of learning and memory as well as the disturbances in oxidative stress parameters in the hippocampus of experimental models of MS.