Compound probiotics alleviate cuprizone-induced demyelination in mice

Abstract:

[Objective] To explore the effects of compound probiotics on demyelination of the mice induced by bis-cyclohexanone-oxalyldihydrazone (cuprizone, CPZ).[Methods] Twenty-seven mice were randomly assigned into normal (NC) group, model (CPZ) group, and probiotics group. The mice in the NC group were fed with normal diet, and those in the CPZ group and probiotics group with the diet containing 0.2% CPZ. The mice in the CPZ group and probiotics group were fed with 0.2 mL normal saline and 0.2 mL compound probiotics (7.5 billion colony-forming units) per day, respectively. All the mice were sacrificed after 6 weeks. Luxol fast blue (LFB) staining was employed to observe myelin sheath in the cerebrum. The histopathological change and the expression of mucin and tight junction proteins (ZO-1 and occludin) in ileum and colon were detected by hematoxylin-eosin (HE) staining, Alcian blue staining, and immunofluorescence staining, respectively. The content of lipopolysaccharide (LPS) in brain homogenate was detected by ELISA. The expression of proteins involved in the Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling pathway was detected by Western blotting.[Results] Compared with the CPZ group, compound probiotics significantly alleviated the demyelination in corpus callosum. In addition, the mice in the probiotics group showed neat and dense ileum villi, increased colon glands, decreased infiltration of inflammatory cells, and up-regulated expression of mucin and tight junction proteins, declined LPS level, and down-regulated expression of TLR4, NF-κB, and P-IκB/IκB in the brain.[Conclusion] Compound probiotics may alleviate CPZ-induced demyelination in mice by reducing intestinal wall permeability.