A salmon based diet protects mice from behavioural changes in the cuprizone model for demyelination

Abstract

Although many patients with multiple sclerosis (MS) use special diets, the data available at present are insufficient to assess any potential benefit of diet modification. Cuprizone induced demyelination is a commonly used animal model for demyelination in the central nervous system. The present study was designed to analyse behaviour and activity due to demyelination in mice fed with 0.2% cuprizone on three different diets. The diets consisted of (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 continuous cuprizone treatment, animal activity was assessed with the elevated plus maze (EPM) test. After 6 weeks the brains were fixated in paraformaldehyde and stained with luxol fast blue (LFB). There was significantly less demyelination in the salmon-cuprizone group than in the two other cuprizone-treatment groups (P<0.0005). The salmon-cuprizone mice had less weight loss (P<0.001) and showed more visits in both open and closed arms of the elevated plus maze than the other cuprizone-treated groups (P<0.0001). In addition they had more entries in the open arms than both the cod liver oil-cuprizone (P<0.02) and the soybean oil-cuprizone-treated mice (P<0.0001). A diet containing salmon seems to protect against behavioural changes induced by demyelination in the cuprizone model, indicating that a fish diet could have a protective effect in demyelinating diseases.