Objective        To determine the treatment effect of cannabine WIN55

212-2 (WIN) in cuprizone (CPZ)-induced demyelination model in C57BL/6 mice.       Methods        A total of 50 6-week-old male C57BL/6 mice were randomly divided into 5 groups

that is

normal group

the WIN treatment groups

and the corresponding DMSO groups. The mice of normal group were fed with

normal lab chow everyday

and those of other groups were fed with normal lab chow containing 0.25% cuprizone. In 1 and 2 weeks after CPZ feeding

WIN dissolved in 10% DMSO was injected intraperitoneally at a dose of 1 mg/kg to the mice of WIN treatment groups

and 10% DMSO was given to the control group for 2 weeks. Overall functions of mice were observed by their weight. Their motor function was observed by Rotarod test. Luxol fast blue (LFB) staining and myelin basic protein (MBP)immunohistochemical staining were used to observe the myelination of corpus callosum

and GFAP immunohistochemical staining for astrocyte.       Results        The weight of WIN treatment groups was decreased slowly than the DMSO control group(

P

0.05). Rotarod test found that the motor function was weak in WIN treatment groups than normal mice

but significantly improved than the DMSO control (

P

0.01). LFB staining displayed that demyelination was very obvious in the DMSO control groups

and that in the WIN treatment groups was better than the DMSO groups

but worse than the normal control (

P

0.05)

and the same results were found in  immunohistochemical assay for MBP (

P

0.05). The expression of GFAP was widely in corpus callosum of the DMSO control groups

but it was significantly lower in the WIN treatment groups (

P

0.05).       Conclusion        Cannabine WIN alleviates demyeination through attenuating the myeline loss and astrocyte activation.