Sodium fusidate (fusidin) ameliorates the course of monophasic experimental allergic encephalomyelitis in the Lewis rat

N-Palmitoylethanolamine Administration Ameliorates the Clinical Manifestation and Progression of Experimental Autoimmune Encephalomyelitis in Rodents

Experimental autoimmune encephalomyelitis in rodents (EAE) is an accepted in vivo model for immunopathogenic mechanisms underlying multiple sclerosis (MS) and tests possible treatment options because it mimics many of the disease patterns. The current treatments for delaying MS progression include cytostatic, immunomodulatory drugs such as mitoxantrone, cyclophosphamide (CY), biological agents such as interferon (IFN)-beta, natalizumab and random polymer glatiramer acetate. Unfortunately, all of these compounds have potentially serious side effects, some require systemic administration, and the biological agents are costly and immunogenic, causing response failure during prolonged treatment. With this aim in mind, the purpose of the current research was to examine the effects of endogenous substances such as N-palmitoylethanolamine (PEA). PEA is an endogenous fatty acid amide belonging to the family of the N-acylethanolamines (NAEs). Recently, several studies demonstrated that PEA is an important analgesic, anti-inflammatory and neuroprotective mediator, acting at several molecular targets in both central and sensory nervous systems as well as immune cells. The effect of PEA daily administered was investigated in rats and mice developing EAE. A multidisciplinary approach was employed to study behavior and biochemical parameters. In our study we found that PEA counteracts the clinical course and pathology of monophasic EAE in myelin basic protein-immunized Lewis rats and the progression of EAE induced in C57BI/6 mice by immunization with myelin oligodendrocyte glycoprotein. Our results show that PEA treatment had a beneficial effect on the two different EAE models.

Variable effects of cyclophosphamide in rodent models of experimental allergic encephalomyelitis

In this study, we have evaluated the effects of cyclophosphamide on the development of experimental allergic encephalomyelitis (EAE) in four EAE rodent models: monophasic EAE in Lewis rats, protracted relapsing (PR)-EAE in DA rats, myelin oligodendrocyte protein (MOG)-induced EAE in C57Bl/6 mice and proteolipid protein (PLP)-induced EAE in Swiss/Jackson Laboratory (SJL) mice. Cyclophosphamide, administered either prophylactically or therapeutically, suppressed most strongly the clinical symptoms of PR-EAE in DA rats. Treated rats in this group also exhibited the lowest degree of inflammatory infiltration of the spinal cord, as well as the lowest levels of nuclear factor kappa B, interleukin-12 and interferon-gamma. Cyclophosphamide prophylactically, but not therapeutically, also delayed significantly the onset of EAE in Lewis rats. In contrast, regardless of the treatment regimen used, was unable to influence the clinical course of EAE in either MOG-induced EAE in C57Bl/6 mice or PLP-induced EAE in SJL mice. This heterogeneous pharmacological response to cyclophosphamide suggests that significant immunopathogenic differences exist among these EAE rodent models that must be considered when designing preclinical studies. In addition, the effectiveness of cyclophosphamide in dark Agouti (DA) rats with PR-EAE suggests that this may be a particularly useful model for studying novel therapeutic approaches for refractory and rapidly worsening multiple sclerosis in human patients.

New immunosuppressants with potential implication in multiple sclerosis

New immunosuppressants are consistently developed to treat autoimmune diseases and some of them might have implications in multiple sclerosis (MS). A new antiproliferative agent, pixantrone, an analogue of mitoxantrone (MX), has a much lower cardiotoxicity and exerts the same potent immunosuppressive effects in experimental allergic encephalomyelitis (EAE). A phase I trial in MS patients is planned in the next future. New monoclonal antibodies (mAb) and other biological constructs containing foreign proteins are developed but their potential immunogenicity is a considerable drawback to their long-term administration. In addition, their beneficial effects in MS are not evident so far. Small molecules targeting the voltage-gated Kv1.3K+ channel regulating CA2+ signaling in T lymphocytes, specifically target activated, pathogenic T cells. Already found effective in EAE, those agents would be easier to handle than T-cell vaccination. Two new immunosuppressants with a unique mechanism of action (FTY720 and Epomycine M) selectively impair autoreactive T-cell homing, without affecting the other components of the immune response. The potent protective effect of TRY720 has been demonstrated in EAE and a phase I trial in MS appears warranted. Finally, a new concept about immunosuppressive treatments in organ transplantation, "tolerogenic immunosuppression", may have potential in MS.

Curative effects of sodium fusidate on the development of dinitrobenzenesulfonic acid-induced colitis in rats

Fusidic acid and sodium fusidate (fusidin) are antibiotics with low toxicity and powerful immunomodulatory activities in vitro and in vivo. In this study we have evaluated the effect of fusidin on the development of dinitrobenzenesulfonic acid (DNB)-induced colitis in rats that serves as a preclinical model of human inflammatory bowel disease (IBD). The data show that when administered orally at the dose of 80 (but not 40) mg/kg body wt under a "therapeutic" regimen soon after DNB application, fusidin significantly ameliorates clinical, histological, and seroimmunological signs of disease. These entailed a significant reduction in body weight loss, smaller increase in colon weights, milder macroscopic damage, and lower histological scores. In addition, when sacrificed at the end of the study, fusidin-treated rats had significantly lower blood levels of tumor necrosis factor alpha and interferon-gamma compared with untreated controls. The present findings concur with the beneficial actions of fusidin in a pilot study conducted in patients with Crohn's disease and warrant controlled studies in humans with IBD.