Effect Of Minocyline On Expression Of Interleukin-23 And Interleukin-17 In Rats With Experimental Autoimmune Encephalomyelitis

Objective To analyze the effect of minocycline on expression of IL-23 and IL-17 proteins in the brain and spinal cord of rats with experimental autoimmune encephalomyelitis(EAE).Methods EAE was induced in rats by immunization with guinea pig spinal cord homogenate (GPSCH). Minocycline was administered by gavage to the treated group rats at 50 mg/kg daily after immunization, and the rats in the control and model groups received equal volume of physiological saline daily. The symptom of rats in three groups was observed and the pathological changes were determined by HE staining. The expression of IL-23 and IL-17 proteins in the brain and spinal cord of three groups were measured with immunohistochemical method.Results Compared with those for model group rats,significant attenuation of the mean clinical score was observed in the minocycline-treated group rats (P=0.018) . Pathological analysis demonstrated a significant decrease in the numbers of inflammation cells in the brain and spinal cord of rats treated with minocycline,compared to the model group rats. The numbers of IL-23 and IL-17 positive cells in the brain and spinal cord in treated group rats decreased obviously compared with these in model group rats and there was statistical difference between the two groups(P<0.01).The mean optical density of IL-23 and IL-17 proteins in the brain and spinal cord of minocycline-treated rats were lower than these of model group rats and the differences is significan(tP<0.01). Conclusions Our findings suggest that minocycline inhibited the expression of IL-23 and IL-17 proteins in the brain and spinal cord of rats with EAE, as well as ameliorated clinical severity of EAE.