Effects of dietary intervention on MRI activity, de- and remyelination in the cuprizone model for demyelination

Abstract

Whether differences in diet composition may influence demyelinating diseases remains controversial. The aim of this study was to analyse if diets with a different composition of polyunsaturated fatty acids (PUFAs) could influence demyelination and remyelination in cuprizone fed mice, a widely used animal model for de- and remyelination. C57Bl/6 mice were fed with 0.2% cuprizone on three different diets. The diets consisted of the same ingredients, except the lipid source, which came from 1) salmon fillets rich in marine n − 3 polyunsaturated fatty acids (PUFAs), 2) cod liver oil rich in marine n − 3 PUFAs, or 3) a control diet containing soybean oil rich in n − 6 PUFAs. After 5 weeks of cuprizone treatment, the mice given salmon-cuprizone had significantly less hyperintense lesion volume on brain magnetic resonance imaging (MRI) than the two other groups ( P < 0.0005). After 6 weeks of cuprizone treatment, the salmon-cuprizone group had less demyelination in the corpus callosum, as measured with luxol fast blue (LFB) ( P < 0.0005) and anti-proteolipid protein (PLP) ( P = 0.014). The salmon-cuprizone group also had enhanced remyelination compared to the cod liver oil-cuprizone group (LFB; P = 0.003, PLP; P = 0.018). This study indicates that a fish rich diet may offer a protective role in demyelination. The source of N − 3 PUFAs, or other components in the fish, may be important, as no effect of a cod liver oil based diet was observed. This may be of importance related to the discrepant results in dietary intervention studies for demyelinating diseases.