| Background and aimMultiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS), which classically follows a relapsing remitting course associated with increasing neurological deficits. Repeated episodes of inflammation and demyelination in MS result in chronic demyelination, irreversible axonal loss, and persistent neurological disability. Currently ,therapeutic strategies for MS target the immunological component of the disease and, although beneficial, fail to prevent the progression of disease in some patients, hence the vital need to explore new strategies that limit inflammation and demyelination in the CNS. Experimental autoimmune encephalomyelitis (EAE) is a T cell-mediated autoimmune demyelination disease of the animal's CNS and an animal model for the human multiple sclerosis(MS).Ginkgo biloba Extract (EGb761) affords neuroprotection in focal cerebral ischemia and againsts delayed neuronal death. Based on these findings we have evaluated the possible effects of EGb761 in anti-inflammatory and suppression of immune deviation. We investigated minocycline, a second-generation tetracycline that exbits pleiotropic biological effects. In this paper,we used the EAE as the model of MS to discuss the EAE's pathogenesis in tissular, cellular and molecular level.Except that,this study was designed to observe the therapeutic effects of Prednisone,Minocycline and EGB761 respectively,hoping that we could clarify the EAE's etiological and pathophysiological mechanisms. According to the experimental results,this study was also contributing to decide the strategy of the treatments.This study was devided into basic studies and clinical trails.Basic studiesMethodsForty England guinea pigs were involved in this study. Firstly, we emulsified the fresh Guinea pigs' spinal cord in saline with an equal volume of CFA, and then,Guniea pigs were immunized with 0.1ml emulsion to hind footpads of the animals for the initial induction of EAE.Experimetal animals were devided into five groups at random:normal group (n=8),model group (n=8), Prednisone-treated group (n=8),Minocycline-treated group (n=8) and EGB761-treated group (n=8).Normal group animals were immuninized with saline and CFA;model group animals were immunized with emulsion (0.1 ml) and saline;other three group animals,immediately after immunized with emulsion(0.1ml),were treated with Prednisone (0.14mg/100g/d),Minocycline (1.10mg/100g/d) and EGB761 (1.67mg/100g /d) respectively.All animals were anesthetized with diethyl ether,collected the blood by medial canthuson on day 0,16 and 34 postimmunization and the serum were frozen and stored at -80℃. Everyday we observated every animal's behavier and noted the clinical scores.After 5 weeks later,Guinea pigs were deeply anesthetized and perfused with 100 ml saline,followed by 200ml 1% and 4% paraformaldehyde.Brain and spinal cords were removed,fixed in 4% paraformaldehyde and transected.Then light microscopes were performed in brain and spine cords histology.The concentration of IL-10, β-EP,and NPY in serum samples were determined as an direct measurement by radioimmunization, IL-12 was by ELISA.The levels of the TGF-β,MMP-2, NOS, CD3 were determined by immunohistochemistry.Results (1) Generally conditions: Prednisone and EGb761 delayed the development of the EAE .Compared with the model's group, Prednisone and EGb761 markedly suppressed the clinical severity of both the initial phase of disease (day 7-18) and the duration of subsequent remission-relapse(day 23-35).However, Minocycline animals were similar with the model group.The clinical score even increased significantly in the remission-relaps phase(day 23-35).(2) Compared with the normal group,there were sig- nificant increase in concentration of IL-10 and that of IL-12 increased clearly on day 16 and 34(p< 0.05).Especially on day 16,it reached its peak. (3) in three theroputics , the concentration of β-EP increased (p<0.05), NPY decreased (p<0.05). (4) The level of TGF-βin the Prednisone-t... |
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