Guinea Pig Spinal Cord Research Articles

The protective effect of total glucosides of white paeony capsules on experimental autoimmune encephalomyelitis

AimsTo learn about the effect and mechanism of total glucosides of white peony capsule (TGP), on experimental autoimmune encephalomyelitis (EAE), an acknowledged animal model of multiple sclerosis (MS). MethodsThe rat model of EAE was induced by subcutaneous injection with guinea pig spinal cord homogenate. The severity of the disease model was assessed by clinical score, hematoxylin and eosin (H&E) and luxol fast blue (LFB). Immunohistochemical assay was used to observe the types of inflammatory cells and adhesive molecule expression. Enzyme-linked immunosorbent assay (ELISA) was applied to detect content of the stem cell growth factor / mast cell growth factor (scf/MGF), interleukin-6 (IL-6) and IL-2. Immunofluorescence assay was applied to observe the expression of connexin43 (Cx43), glial fibrillary acidic protein (GFAP), connexin47 (Cx47) and the monoclonal antibody anti-adenomatous polyposis coli (APC) clone CC1. ResultsCompare with the animals in EAE model group, TGP treated rats (particularly those treated with high doses) showed a significant decrease in morbidity, clinical scores, CNS infiltration of inflammatory cells (including mononuclear macrophages, CD4+ and CD8+ T cells) and demyelination. The key adhesion molecule ICAM-1, cytokines IL-2、IL-6 and scf/MGF were significantly decreased with TGP treatment. Oppositely, PD-1, connexin47 in oligodendrocytes and connexin43 in astrocytes were elevated with TGP treatment. ConclusionTo sum up, TGP exhibited a significantly prevention and treatment effect on EAE rat model, and this improvement was achieved through a combination way composed of glial and inflammatory cells, junction proteins, various factors including adhesion factors, interleukins and scf/MGF.

Exercise training improves memory and produces changes in the adrenal gland morphology in the experimental autoimmune encephalomyelitis.

Objective. The present study sought to verify the effects of an exercise training on the memory along with the morphological assessment of the adrenal gland tissue in the rats with experimental autoimmune encephalomyelitis (EAE). Methods. Female Lewis rats were randomly divided into three groups: EAE group, EAE group with exercise (EAE+Ex), and control group (CO). Each group contained 10 rats. To evaluate the memory, all rats were subjected to the Morris water maze learning test for four consecutive days and one day for a prop test. EAE was induced by guinea pig spinal cord homogenate emulsified in incomplete Freund's adjuvant and heat-mycobacterium. The exercise training on a motorized treadmill was initiated 3 weeks before EAE induction and disconnected 2 weeks post-induction. Results. We found that exercise training for five weeks produced an improved swimming velocity related to memory improvement in EAE+Ex group in comparison with EAE group, but not an incurable adrenal gland tissue after EAE induction. Conclusions. The experimental design selected for this study appears to be an effective treatment for memory in rats with experimental autoimmune encephalomyelitis.

Molecular effects of curcumin on the experimental autoimmune encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis (MS). Previous studies have shown that myelin degradation during MS and EAE resulted in reduced expression of some of the proteins, e.g., the MBP (myelin basic protein), and increased expression of genes such as iNOS (Inducible nitric oxide synthase) and NOGO-A in the affected patients. In the present study, EAE was induced by immunizing Wistar rats (n=12) with homogenized spinal cord of guinea pig and Freund's complete adjuvant. Curcumin is an active ingredient in turmeric with anti-inflammatory properties, which has been studied in this article. In this study, the effect of curcumin administration on the change of the expression of MBP, NOGO-A, and iNOS genes was evaluated using the RT-PCR (Reverse transcription-polymerase chain reaction) technique. The obtained results indicated it could be concluded that curcumin was able to improve EAE by increasing the amount of MBP gene expression and reducing the intensity of NOGO-A expression.

Ghrelin Attenuates Neuroinflammation and Demyelination in Experimental Autoimmune Encephalomyelitis Involving NLRP3 Inflammasome Signaling Pathway and Pyroptosis.

Multiple sclerosis (MS) is a chronic autoimmune and degenerative disease of the central nervous system, and conventional treatments have limited efficacy or side effects. Ghrelin, a 28-amino acid octanoylated peptide, has been reported to have neuroprotective effects, including anti-oxidation, anti-inflammation, and anti-apoptosis. Pyroptosis, also called inflammatory cell death, is triggered by overly active inflammasomes and accompanied by the production of numerous cytokines. As immune dysfunction is primarily involved in the pathogenesis of MS, this study aimed to explore the therapeutic effects and precise functional mechanisms of ghrelin against the nod-like receptor protein 3 (NLRP3) inflammasome and pyroptosis in experimental autoimmune encephalomyelitis (EAE). Sprague Dawley rats were immunized with guinea pig spinal cord homogenates and pertussis toxin to develop an EAE model. All rats were randomly divided into four groups: normal control group, EAE group, EAE + ghrelin group, and ghrelin control group. EAE rats showed abnormal behavioral scores and body weight changes. Histologic analysis displayed severe inflammatory infiltration and demyelination in the brain and spinal cord of EAE rats. Ghrelin treatments potently restored these abnormal changes. In addition, the ghrelin-treated EAE group showed significantly downregulated expression of inflammatory cytokines. The expression of proteins involved in the NLRP3 signaling pathway and pyroptosis was decreased as well. We also found that the anti-inflammatory effect of ghrelin was associated with inhibition of nuclear factor (NF)-κB activation. Compared with rats in the healthy control group, rats in the ghrelin control group did not show statistically significant changes in histologic examinations, pro-inflammatory cytokines production, or molecules involved in the NLRP3 signaling pathway, which indicated that ghrelin induced no side effects in the animals of our study. Our findings provide more insight into the use of ghrelin as a novel candidate for MS.

The effects of transplanted mesenchymal stem cells treated with 17-b estradiol on experimental autoimmune encephalomyelitis.

The present study was conducted aimed at exploring the modulatory effects of 17-b estradiol (17-bED) on mesenchymal stem cells (MSCs) in the EAE (experimental autoimmune encephalomyelitis) animal model of multiple sclerosis (MS). Following the isolation of bone marrow-derived MSCs from the bilateral femurs and tibias of the male Wistar rats, the cells were harvested and cultured in the presence of 100nM 17-bED for 24h. EAE was induced in male Wistar rats (8-12weeks old) using guinea pig spinal cord homogenate, in combination with the complete Freund's adjuvant. The MSC therapy was triggered when all of the animals obtained a disability score. The symptoms were monitored on a daily basis throughout the study until the rats were euthanized. The mRNA expression of cytokines, including IL-17, IFN-γ, TNF-α, IL-10, IL-4, and TGF-β together with MMP8 and MMP9 as the family members of matrix metalloproteinases(MMPs) in the brain and spinal cord tissues were examined using real-time PCR. The levels of splenocytes-originated IL-10 and IFN-γ cytokines were also measured by ELISA. The MTT-based research findings showed that the infiltration of lymphocytes into the spleen decreased considerably. It was also observed that the mRNA expression of proinflammatory cytokines decreased significantly, while the mRNA levels of anti-inflammatory cytokines increased remarkably. It was also found that the mRNA levels of the examined matrix metalloproteinases(MMP8 and MMP9) were downregulated significantly. The findings of the present study indicated that the administration of 17-bED enhanced the efficacy of MSCs transplantation and modulated immune responses relatively in the EAE model, via the regulation of either pro- or anti-inflammatory cytokines and matrix metalloproteinases.

Comparison of the effects of 17β- estradiol treated and untreated mesenchymal stem cells on ameliorating animal model of multiple sclerosis.

Objectives:The current investigation was undertaken to evaluate the effects of 17β- estradiol (17β-ED) on the potential of the mesenchymal stem cells (MSCs) for modulation of immunity responses in an animal model of multiple sclerosis (MS).Materials and Methods:After isolation of MSCs, cells were cultured in presence of 100 nM 17β-ED for 24 hr. Modeling of experimental autoimmune encephalomyelitis (EAE) was achieved by using guinea pig spinal cord homogenate, in addition to complete Freund’s adjuvant in male Wistar rats. The processes of cell therapy were started following 12 days post-immunization. This duration allows all animals to develop a disability score. The achieved EAE clinical symptoms were regularly monitored every day until day 36, when all of examined rats were euthanized. Results:Cell therapy in the EAE rats with 17β-ED-primed MSCs exhibited more desirable consequences, which in turn lead to regression of the cumulative clinical score and neuropathological changes that are more than the therapy with untreated MSCs. The serum measures of myeloperoxidase (MPO), nitric oxide (NO) as well as splenocytes-originated pro-inflammatory interleukin-17 (IL-17) and tumor necrosis factor alpha (TNF-α) were significantly decreased in EAE rats treated by 17β-ED primed-MSCs compared to EAE rats that received untreated MScs. Conclusion:Combination of 17β-ED and MSCs more effectively improved the signs and symptoms of EAE.

Ellagic acid protects from myelin-associated sphingolipid loss in experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE), the most common model for multiple sclerosis, is characterized by inflammatory cell infiltration into the central nervous system and demyelination. Previous studies have demonstrated that administration of some polyphenols may reduce the neurological alterations of EAE. In this work, we show that ellagic acid, a polyphenolic compound, is beneficial in EAE, most likely through stimulation of ceramide biosynthesis within the brain. EAE was induced in Lewis rats by injection of guinea-pig spinal cord tissue along with Freund's complete adjuvant containing Mycobacterium tuberculosis. Clinical signs first appeared at day 8 post-immunization and reached a peak within 3 days, coincident with reduction of myelin basic protein (MBP) in the cortex. Sphingolipids, the other major components of myelin, also decreased at the acute phase of EAE, both in the cerebral cortex and in the spinal cord. In rats receiving ellagic acid in the drinking water from 2 days before immunization, the onset of the disease was delayed and clinical signs were reduced. This amelioration of clinical signs was accompanied by sustained levels of both MBP and sphingolipid in the cortex, without apparent changes in infiltration of inflammatory CD3+ T-cells, microglial activation, or weight loss, which together suggest a neuroprotective effect of ellagic acid. Finally, in glioma and oligodendroglioma cells we demonstrate that urolithins, the ellagic acid metabolites that circulate in plasma, stimulate the synthesis of ceramide. Together these data suggest that ellagic acid consumption protects against demyelination in rats with induced EAE, likely by a mechanism involving sphingolipid synthesis.

Nicotine Augments the Beneficial Effects of Mesenchymal Stem Cell-based Therapy in Rat Model of Multiple Sclerosis

ABSTRACTExperimental autoimmune encephalomyelitis (EAE) in rats through immunization with guinea pig spinal cord homogenate (GPSCH) produces a chronic disease with a relapsing pattern such as multiple sclerosis (MS) in humans. In previous studies, the immunomodulatory benefits of mesenchymal stem cells (MSCs) and nicotine have already been determined. Thus, this research was conducted to assess the additional benefits of the combination therapy of MSCs and nicotine in a rat model of MS. EAE was induced by GPSCH and complete Freund’s adjuvant (CFA) in female Wistar rats. The therapies were initiated at day 12 post-immunization (p.i.), when the rats developed a neurological disability score. The symptoms were recorded daily until day 33, when the rats were sacrificed. Finally, the splenocytes were evaluated by Enzyme-linked immunosorbent assay (ELISA) for cytokine production. The therapeutic treatment in the EAE rats with a combination of MSCs and nicotine exhibited a more desirable outcome, causing the regression of the average mean clinical score and neuropathological features to be more favorable than the treatment with either therapy alone. The combination therapy led to a significant reduction in the cumulative disease disability from day 21. For the EAE rats treated with nicotine and MSCs, this period was started from day 22 and 28 p.i., respectively. Besides the increase in the levels of IL-10, the combined therapy significantly reduced the splenocytes production of pro-inflammatory IL-17 as well as TNF-α more profoundly than either of the medications alone. In conclusion, the combination of MSCs and nicotine can be suggested as a promising strategy for further MS therapeutics improvement.

Neuroimmunomodulation by allogeneic seminal vesicle fluid in CNS is sex-independent

Objectives: Thymus-arisen FoxP3 regulatory T cells (Tregs) are one of the most important immunoregulatory mechanisms in the central nervous system (CNS) and pregnancy. Multiple sclerosis (MS) is an inflammatory disease of CNS associated with a reduced frequency and/or function of Tregs. Previous works have shown that seminal vesicle fluid affects female immune system and causes expansion of Tregs pool in the female reproductive tissue upon mating. Accordingly, it has been demonstrated that intra-CSF administration of seminal vesicle fluid from Wistar rats can ameliorate clinical sign of a female Lewis rat model of experimental autoimmune encephalomyelitis (EAE), the animal model of MS. The results indicated an up-regulation of FoxP3 expression in the brain and spinal cord. However, there are sex-based differences in the CNS structure & composition, sex hormones influence immune system, and gender-based differences affect treatment response. Therefore, we decided to find out if anti-inflammatory effect of seminal vesicle fluid is sex-dependent or -independent.Methods: EAE was induced in male Lewis rats using guinea pig spinal cord and complete Freund’s adjuvant. Intra-CSF injection was done on day 7 after EAE induction and the animals were followed-up until on day 14 after EAE induction when sacrificed. Then, brain and spinal cord of the animals were isolated, total RNA was extracted, and expression of mRNA for IFN-γ, IL-4, IL-17, and FoxP3 was determined using real-time PCR where β-actin was used as reference gene.Result: demonstrated that intra-CSF administration of seminal vesicle fluid from male Wistar rats ameliorated EAE in male Lewis rats and increased FoxP3 in the brain and spinal cord.Conclusion: This study suggests that seminal vesicle fluid from Wistar rats has anti-inflammatory effect on Lewis rats in a sex-independent manner. In addition, seminal vesicle fluid from Lewis rats had not beneficial effect on EAE in male Lewis rats. This is consistent with Tregs increase in allogeneic mating. More research is required to find out the immunologic aspect of allogeneic versus syngeneic administration of seminal vesicle fluid.

Pertussis toxin promotes relapsing–remitting experimental autoimmune encephalomyelitis in Lewis rats

Animal models simulate different aspects of human diseases and are essential to get a better understanding of the disease, studying treatments and producing new drugs. Experimental autoimmune encephalomyelitis (EAE) is a preferred model in multiple sclerosis research. Common EAE model in Lewis rats is induced using MBP peptide as a myelin antigen which results in a monophasic disease course. In the present study, EAE was induced in Lewis rats by homogenized guinea pig spinal cord along with or without pertussis toxin (PT). When PT was used, EAE turned into remitting–relapsing form and worsen the clinical symptoms. Higher inflammation and oxidative stress marker gene expression was observed when PT was administrated.

Liver Damage and Mortality in a Male Lewis Rat of Experimental Autoimmune Encephalomyelitis.

Multiple sclerosis is an inflammatory disease of the central nervous system. This is due to migration of peripherally activated lymphocytes to central nervous system leading to inflammatory lesions. However, liver has an anti-inflammatory microenvironment. Myelin expression in the liver of transgenic mice suppresses inflammatory lesions within central nervous system. Considering the notion that the inflammatory events originate from periphery, we investigated if the liver was affected in an animal model for multiple sclerosis. Experimental autoimmune encephalomyelitis was induced in male Lewis rats using guinea pig spinal cord and complete Freund's adjuvant. Weight, clinical score, and survival rate were evaluated for 14 days post immunization. Liver sections were taken and stained with Hematoxylin and Eosin and examined with an Olympus microscope. Mortality was accompanied by liver damage. Sinusoidal congestion, pycnotic nuclei within hepatocytes, hepatocyte necrosis, and severe widespread congestion along with fat accumulation within hepatocytes (fatty degeneration) were observed in liver tissue sections. Liver damage occurs in experimental autoimmune encephalomyelitis. The perpetuation of self antigen leading to continuous migration of extrahepatically activated T cells makes an inflammatory milieu in the liver. It follows migration and development of more inflammatory cells and may paralyses tolerance inducing mechanisms. Apart from central nervous system lesion, liver injury may act as synergistic factor for debilitation and mortality.

Oral Administration of Lactococcus lactis Expressing Synthetic Genes of Myelin Antigens in Decreasing Experimental Autoimmune Encephalomyelitis in Rats.

BackgroundMultiple sclerosis is a human autoimmunological disease that causes neurodegeneration. One of the potential ways to stop its development is induction of oral tolerance, whose effect lies in decreasing immune response to the fed antigen. It was shown in animal models that administration of specific epitopes of the three main myelin proteins – myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP), and proteolipid protein (PLP) – results in induction of oral tolerance and suppression of disease symptoms. Use of bacterial cells to produce and deliver antigens to gut mucosa seems to be an attractive method for oral tolerance induction in treatment of diseases with autoimmune background.Material/MethodsSynthetic genes of MOG35-55, MBP85-97, and PLP139-151 myelin epitopes were generated and cloned in Lactococcus lactis under a CcpA-regulated promoter. The tolerogenic effect of bacterial preparations was tested on experimental autoimmune encephalomyelitis, which is the animal model of MS. EAE was induced in rats by intradermal injection of guinea pig spinal cord homogenate into hind paws.ResultsRats were administered preparations containing whole-cell lysates of L. lactis producing myelin antigens using different feeding schemes. Our study demonstrates that 20-fold, but not 4-fold, intragastric administration of autoantigen-expressing L. lactis cells under specific conditions reduces the clinical symptoms of EAE in rats.ConclusionsThe present study evaluated the use of myelin antigens produced in L. lactis in inhibiting the onset of experimental autoimmune encephalomyelitis in rats. Obtained results indicate that application of such recombinant cells can be an attractive method of oral tolerance induction.

Effects of beta 2 adrenergic agonists on axonal injury and mitochondrial metabolism in experimental autoimmune encephalomyelitis rats.

The primary aims of this study were to investigate mitochondrial metabolism during experimental allergic encephalomyelitis (EAE) animal model axonal injury and to determine the correlation among neurological function scores, pathological changes, and the activities of the BB isoenzyme of creatine kinase (CK-BB), catalase (CAT), and calpain in the brain tissues of EAE rats. Another goal was to preliminarily define the mechanism of mitochondrial metabolism resulting from the effect of beta 2 adrenergic agonists in the process of EAE animal model axonal damage. EAE was induced in specific pathogen free Wistar rats by guinea pig spinal cord homogenate, complete Freund's adjuvant, and pertussis vaccine. We recorded the behavioral change in EAE rats, detected pathological changes in central nervous tissue, and observed the changes of the CK-BB, CAT, and calpain in the EAE rat brain and spinal cord. The results indicated that the average neurologic function score increased in the EAE group compared to that of the controls (P < 0.01). In addition, CAT and CK-BB activities significantly decreased and the calpain activity significantly increased compared with those of the control group (P < 0.05). The decrease of the activity of central nervous CK-BB and CAT content, as well as the increase of calpain activity at the highest time point were considered to be the consequences of EAE. Furthermore, the results revealed that use of salbutamol could alleviate disease symptoms and reduce the recurrence of the EAE disease.

Valproic Acid Attenuates Disease Symptoms and Increases Endogenous Myelin Repair by Recruiting Neural Stem Cells and Oligodendrocyte Progenitors in Experimental Autoimmune Encephalomyelitis

Background: Inefficient remyelination of demyelinated plaques in multiple sclerosis (MS) leads to secondary axon degeneration and progressive disability. Therapies that potentiate remyelination would be of immense help for managing MS. Objective: Here, we report the effects of valproic acid (VPA) on focal experimental autoimmune encephalomyelitis (fEAE). Methods: fEAE was induced in Wistar rats by immunizing the animals with guinea pig spinal cord homogenate emulsified in complete Freund's adjuvant and with pertussis toxin (PT) injection into the spinal cord at the level of T8 vertebra on day 18 after immunization. VPA 300 mg/kg was applied for 4 days after or 8 days before PT administration. Behavioral evaluation, histological assessment and immunohistofluorescence assays were used to evaluate the outcomes. Results: VPA administration had no effect on the development of symptoms, but after discontinuing VPA, animals showed faster recovery. Eight days of pretreatment with VPA accelerated the recovery phase of EAE and increased the number of remyelinated axons in the lesion area. VPA pretreatment also increased the recruitment of neural stem cells and oligodendrocyte precursors within the lesion. Conclusions: Results suggest VPA as a potential therapy for remyelinating the lesions in MS and for faster recovery from disease relapses. The effect of VPA seems to be mediated by endogenous progenitors recruitment.

Pushing the science forward: chitosan nanoparticles and functional repair of CNS tissue after spinal cord injury.

BackgroundWe continue our exploration of the large polysaccharide polymer Chitosan as an acute therapy for severe damage to the nervous system. We tested the action of subcutaneously injected nanoparticles (~ 100 – 200 nanometers in diameter; 1 mg per ml) against control injections (silica particle of the same size and concentration) in a standardized in vivo spinal cord injury model. These functional tests used standardized physiological measurements of evoked potentials arriving at the sensorimotor cortex subsequent to stimulation of the tibial nerve of the contralateral hindlimb. We further explored the degree of acetylation and molecular weight of chitosan on the success of sealing cell damage using specific probes of membrane integrity.ResultsNot one of the control group showed restored conduction of evoked potentials stimulated from the tibial nerve of the hindleg – through the lesion – and recorded at the sensorimotor cortex of the brain. Investigation if the degree of acetylation and molecular weight impacted “membrane sealing” properties of Chitosan were unsuccessful. Dye - exchange membrane probes failed to show a difference between the comparators in the function of Chitosan in ex vivo injured spinal cord tests.ConclusionsWe found that Chitosan nanoparticles effectively restore nerve impulse transmission through the crushed adult guinea pig spinal cord in vivo after severe crush/compression injury. The tests of the molecular weight (MW) and degree of acetylation did not produce any improvement in Chitosan’s membrane sealing properties.

Rostral ventromedial medulla connections in Cavia porcellus and their relation with tonic immobility defensive behavior: A biotinylated dextran amine neurotracing study

The rostroventromedial medulla (RVM), together with the periaqueductal gray matter (PAG), constitutes the descendent antinociceptive system. Additionally, these structures mutually regulate defensive behaviors, including tonic immobility (TI) in guinea pigs. The current study was undertaken to evaluate the connections of the RVM with the PAG and the spinal cord in guinea pigs in order to provide an anatomical basis for the role played by RVM in the modulation of TI. To address this goal, five guinea pigs were treated with non-fluorescent biotinylated dextran amine (BDA) neurotracer by injection into the RVM. After four days of survival, the encephalon and spinal cord were removed from each rodent, and BDA labeling was visualized with a standard avidin-biotinylated horseradish peroxidase method through reaction with nickel-intensified peroxidase 3,3′-diaminobenzidine dihydrochloride. The microinjection of BDA into the RVM stained fibers in the ventral horn, dorsal horn and intermediate gray matter of the spinal cord. BDA-labeled fibers, terminal buttons suggesting synaptic contacts, and perikarya were found in the dorsomedial, dorsolateral, lateral and ventrolateral PAG, and neuronal somata were identified in the cuneiform nucleus. Together, the current data demonstrate neuroanatomical evidence that supports the role of the RVM in the modulation of TI defensive behavior.

Effect of Colquhounia root tablet on IL-2 and IFN-γ mRNA expression in rats with experimental allergic encephalomyelitis

To investigate the effect of Colquhounia root tablet on IL-2 and IFN-γ mRNA expression in experimental allergic encephalomyelitis (EAE) of rats. The allergic encephalomyelitis model was established in Wistar rats by immunization with myelin basic protein of spinal cord of guinea pig and complete Freund's adjuvant. The rats in treatment group received Colquhounia root tablet (300 mg*kg(-1), BID). The symptom of EAE was observed; pathological feature and myelin of brain and spinal cord were detected with HE stain and Loyez's stain, respectively. The expressions of IL-2 and IFN-γ mRNA were assayed by RT-PCR. No EAE symptoms were developed in treatment group, the expressions of IL-2 and IFN-γ mRNA were 0.345 ± 0.032 and 0.353 ± 0.023, which were significantly lower than those of model group (P<0.01). The histopathologic examinations revealed that less inflammation cells around vessels and demyelination in white matter of brain and spinal cords were observed in treatment group than in model group. Colquhounia root tablets are effective in treatment of EAE of rats, which may be associated with inhibition of the expression of IL-2 and IFN-γ mRNA.

Epimedium flavonoids ameliorate experimental autoimmune encephalomyelitis in rats by modulating neuroinflammatory and neurotrophic responses

The present study was designed to determine whether epimedium flavonoids (EF) had effect on the development of experimental autoimmune encephalomyelitis (EAE) in rats and to elucidate its underlying mechanisms. EAE was induced by immunization of adult female Lewis rats with partially purified myelin basic protein (MBP) prepared from guinea-pig spinal cord homogenate. EF was administrated intragastrically once a day after immunization until day 14 post immunization (p.i.). Histopathological staining, enzyme-linked immunosorbent assay (ELISA), biochemical methods and western blotting approaches were used to evaluate the disease incidence and severity, neuroinflammatory and neurotrophic response in the central nervous system (CNS). Intragastrical administration of EF (20 and 60 mg/kg) significantly reduced clinical score of neurological deficit in EAE rats; alleviated demyelination and inflammatory infiltration; and inhibited astrocytes activation, production of proinflammatory molecules such as interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), nitric oxide (NO) and nuclear transcription factor (NF-κB) in the spinal cord of EAE rats. Treatment with EF also enhanced the expression of 2′, 3′-cyclic nucleotide 3′-phosphohydrolase (CNPase) and nerve growth factor (NGF), increased the number of oligodendrocytes and protected the ultrastructure of myelin sheaths and axons in the spinal cord of EAE rats. Our results showed that EF inhibited the development of partial MBP-induced EAE in rats. This effect involved reducing neuroinflammation and enhancing myelination and neurotrophins and our findings suggest that EF may be useful for the treatment of multiple sclerosis.

Fluoxetine Promotes Remission in Acute Experimental Autoimmune Encephalomyelitis in Rats

Objective: This study was carried out to clarify the effects of the antidepressant fluoxetine, a selective serotonin reuptake inhibitor, for its potential use in autoimmune diseases like multiple sclerosis in a rat model of experimental autoimmune encephalomyelitis (EAE). Methods: The rat EAE model was induced by subcutaneous injection of guinea pig spinal cord homogenate. Rats received fluoxetine via daily intragastric administration, starting 2 weeks prior to immune induction (fluoxetine pretreatment). Clinical scores and pathological changes in EAE rats were analyzed. Changes in serum cytokine levels were assessed by ELISA. Results: Fluoxetine pretreatment significantly promoted remission in EAE. Histologically, fluoxetine-induced neuroprotection was accompanied by reductions in inflammatory foci and in the degree of demyelination in the spinal cord of EAE rats. The increase in serum IFN-γ in the EAE model was also suppressed by fluoxetine administration. Conclusions: These findings suggest that the prophylactic use of fluoxetine can relieve symptoms during remission in the acute EAE model, and these neuroprotective effects are associated with its anti-inflammatory effects.

Effect of honey bee venom on lewis rats with experimental allergic encephalomyelitis, a model for multiple sclerosis.

Multiple sclerosis (MS) is a progressive and autoimmune neurodegenerative disease of the central nervous system (CNS). This disease is recognized through symptoms like inflammation, demyelination and the destruction of neurological actions. Experimental allergic encephalomyelitis (EAE) is a widely accepted animal model for MS. EAE is created in animals by injecting the tissue of myelin basic protein (MBP), CNS, or myelin oligodendrocyte glycoprotein (MOG) along with the adjuvant. EAE and MS are similar diseases. Honey Bee venom (Apis mellifera) contains a variety of low and high molecular weight peptides and proteins, including melittin, apamin, adolapin, mast cell degranulating peptide and phospholipase A2. Bee venom (BV) could exert anti-inflammatory and antinociceptive effects on the inflammatory reactions. The guinea pig spinal cord homogenate (GPSCH) is with the Complete Freund's Adjuvant (CFA), consisting of 1 mg/mL Mycobacterium tuberculosis. It was used for inducting EAE in Lewis rats for creating the MS model. The hematoxylin and eosin and luxol fast blue methods were used respectively in analyses of inflammation and detection of demyelination in the central nervous system. Furthermore, the ELISA and the high performance liquid chromatography (HPLC) were used for the assessment of tumor necrosis factor alpha (TNF-α) and nitrate in rats serum. In this study, we indicated that the treatment of EAE with Bee venom decreased the symptoms of clinical disorder, pathological changes, inflammatory cell infiltration, demyelination in the central nervous system, level of serum TNF-α, and the serum nitrates in rat EAE induced through GPSCH.