Locomotor and histological changes in a cuprizone-induced animal model of multiple sclerosis: comparison between alpha-tocopherol and fingolimod

Abstract

Background and purpose: Fingolimod is a sphingosine 1-phosphate receptor modulator used to treat multiple sclerosis (MS). Alpha-tocopherol (AT) has been found to improve motor function in an animal model of MS. In the present study, the effects of AT and fingolimod on the locomotor function and histological evidence of demyelination were compared in a cuprizone-induced rat model of MS. Experimental approach: Female Sprague-Dawley rats (8 weeks) were fed with 0.2% (w/w) cuprizone diet for 5 weeks followed by intraperitoneal injections of fingolimod (3 mg/Kg; group F, n = 10) and alpha- tocopherol (100 mg/Kg; group A, n = 10). Vehicle-treated rats (group V, n = 10) were treated intraperitoneally with 1% ethanol in saline on weeks 6 and 7. Open field and beam walking tests were carried out every 10 days. The mean area of demyelination in the corpus callosum was quantified using Luxol fast blue stained histological sections of the forebrain. Findings/Results: The mean speed of movement was increased by 54% and 50% in groups F and A compared to group V. Total distance moved was increased by 61% and 52.7% in groups F and A compared to group V. Mean time to walk the beam was reduced in group A by 52% compared to group V. Mean frequency of crossing lines from the inner squares to outer squares was reduced in groups A and F compared to group V. Mean area of demyelination in corpus callosum showed 62% reduction in group A compared to group V. Conclusion and implications: Both fingolimod and AT treatments improved the locomotor function. However, AT treatment reduced the areas of demyelination in higher proportion and improved motor coordination and exploratory behavior.

Keywords

• alpha-tocopherol; demyelination; fingolimod; cuprizone; multiple sclerosis.