Anticholinesterasics in the treatment of cognitive impairment in multiple sclerosis

Anti-inflammatory and Neuroprotective Agents in Clinical Trials for CNS Disease and Injury: Where Do We Go From Here?

Neurological disorders are major contributors to death and disability worldwide. The pathology of injuries and disease processes includes a cascade of events that often involve molecular and cellular components of the immune system and their interaction with cells and structures within the central nervous system. Because of this, there has been great interest in developing neuroprotective therapeutic approaches that target neuroinflammatory pathways. Several neuroprotective anti-inflammatory agents have been investigated in clinical trials for a variety of neurological diseases and injuries, but to date the results from the great majority of these trials has been disappointing. There nevertheless remains great interest in the development of neuroprotective strategies in this arena. With this in mind, the complement system is being increasingly discussed as an attractive therapeutic target for treating brain injury and neurodegenerative conditions, due to emerging data supporting a pivotal role for complement in promoting multiple downstream activities that promote neuroinflammation and degeneration. As we move forward in testing additional neuroprotective and immune-modulating agents, we believe it will be useful to review past trials and discuss potential factors that may have contributed to failure, which will assist with future agent selection and trial design, including for complement inhibitors. In this context, we also discuss inhibition of the complement system as a potential neuroprotective strategy for neuropathologies of the central nervous system.

Therapeutic potential of selanyl amide derivatives in the in vitro anticholinesterase activity and in in vivo antiamnesic action

The present study evaluated the in vitro acetylcholinesterase (AChE) inhibitor activity of two new selanyl amide derivatives in cerebral structures of mice. Our results demonstrated that N-(2-(3-(phenylselanyl)propoxy)phenyl)furan-2-carboxamide (1) and N-(2-(3-(phenylselanyl)propoxy)phenyl)thiophene-2-carboxamide (2) inhibited the in vitro AChE activity in mice. Another objective was to assess the effect of the best AChE inhibitor in an amnesic model induced by scopolamine (SCO) in male Swiss mice. The involvement of AChE activity and lipid peroxidation in the cerebral structures was investigated. Our results showed that compound 1 (10 mg/kg, intragastrically) attenuated the latency to find the escape box and the number of holes visited in the Barnes maze task, without altering the locomotor and exploratory activities in an open-field test. Compound 1 protected against increasing in lipid peroxidation levels and AChE activity caused by SCO in the cerebral cortex and hippocampus of mice. In conclusion, the present study evidenced the in vitro anticholinesterase effect of two new selanyl amide derivatives in the cerebral structures of mice. Moreover, compound 1, a selanyl amide derivative containing a furan ring, demonstrated antiamnesic action due to its antioxidant and anticholinesterase activities in cerebral structures.

Ocimum basilicum attenuates ethidium bromide-induced cognitive deficits and pre-frontal cortical neuroinflammation, astrogliosis and mitochondrial dysfunction in rats

Multiple sclerosis (MS) is a chronic neurodegenerative disorder with clinical symptoms of neuroinflammation and demyelination in the central nervous system. Recently, herbal medicines are clinically effective against MS as the current disease-modifying drugs have limited effectiveness. Hence, the present study evaluated the therapeutic potential of Ocimum basilicum essential oil (OB) in ethidium bromide (EB)-induced cognitive deficits in the male rats. Further, the effect of OB (50, 100 and 200 μL/kg) was evaluated on EB-induced neuroinflammation, astrogliosis and mitochondrial dysfunction in the pre-frontal cortex (PFC) of the animals. The EB was injected through bilateral intracerebroventricular route into hippocampus to induce MS-like manifestations in the rats. OB (100 and 200 μL/kg) and Ursolic acid (UA) significantly reduced the EB-induced cognitive deficits in Morris water maze and Y-maze test paradigms. OB (100 and 200 μL/kg) and UA significantly attenuated the EB-induced neuroinflammation in terms of increase in the levels of pro-inflammatory cytokines (TNF-alpha and IL-6) in the rat PFC. Further, OB (100 and 200 μL/kg) and UA significantly attenuated the EB-induced astrogliosis in terms of increase in the levels of GFAP (Glial fibrillary acidic protein) and Iba-1 (Ionized calcium binding adaptor molecule-1) in the rat PFC. In addition, OB (100 and 200 μL/kg) and UA significantly attenuated the EB-induced decrease in the mitochondrial function, integrity, respiratory control rate and ADP/O in the PFC of the rodents. Moreover, OB (100 and 200 μL/kg) and UA significantly reduced the EB-induced mitochondria-dependent apoptosis in the PFC of the rat. Hence, it can be presumed that OB could be a potential alternative drug candidate in the pharmacotherapy of MS.

Neuropsychological Assessment in Multiple Sclerosis

Abstract. Neuropsychological deficits in multiple sclerosis (MS) are common. Over the past decades, many different procedures have been employed in diagnosing these deficits. Even though certain aspects of cognitive performance such as information processing speed and working memory may be affected more frequently than other cognitive functions, no specific deficit profile has been established in MS. This article provides an overview of the neuropsychological diagnostic procedures in MS and allows the reader to reach an informed decision on the applicability of specific procedures and the availability of study data in the context of MS. Additionally, it makes recommendations on the compilation of both screening procedures and extensive test batteries.

Effect of Donepezil, Tacrine, Galantamine and Rivastigmine on Acetylcholinesterase Inhibition in Dugesia tigrina

Dugesia tigrina is a non-parasitic platyhelminth, which has been recently utilized in pharmacological models, regarding the nervous system, as it presents a wide sensitivity to drugs. Our trials aimed to propose a model for an in vivo screening of substances with inhibitory activity of the enzyme acetylcholinesterase. Trials were performed with four drugs commercialized in Brazil: donepezil, tacrine, galantamine and rivastigmine, utilized in the control of Alzheimer's disease, to inhibit the activity of acetylcholinesterase. We tested five concentrations of the drugs, with an exposure of 24 h, and the mortality and the inhibition of acetylcholinesterase planarian seizure-like activity (pSLA) and planarian locomotor velocity (pLMV) were measured. Galantamine showed high anticholinesterasic activity when compared to the other drugs, with a reduction of 0.05 μmol·min(-1) and 63% of convulsant activity, presenting screw-like movement and hypokinesia, with pLMV of 65 crossed lines during 5 min. Our results showed for the first time the anticholinesterasic and convulsant effect, in addition to the decrease in locomotion induced by those drugs in a model of invertebrates. The experimental model proposed is simple and low cost and could be utilized in the screening of substances with anticholinesterasic action.

The Effects of Cognitive Rehabilitation on Relapsing Remitting Multiple Sclerosis Patients

INTRODUCTION

The aims of this study were to determine the severity of cognitive impairment with Brief Repeatable Battery Neuropsychology (BRB-N) and to show the benefits of cognitive rehabilitation programs to develop coping strategies for the retardation of cognitive losses in relapsing remitting multiple sclerosis (RRMS) patients.

METHODS

The cognitive screening with BRB-N was performed in RRMS patients who had applied to the MS outpatient clinic of Bakırköy Psychiatric and Neurological Diseases Hospital, had an Expanded Disability Status Scale (EDSS) score between 1.0 and 5.5, and had no other cognitive disease or used drugs that effected the cognitive status. Thirty two patients with cognitive impairment underwent consecutive computer-assisted cognitive rehabilitation program once a week for 8 weeks conducted by psychologists. The effects of the program were evaluated with the tests repeated every 4 weeks.

RESULTS

The mean age of the patients was 36.09±7.19 years. Their initial and control test scores were found to be paced auditory serial addition test (PASAT) 29.21±17.97; 42.43±15.43, Selective Reminding Test-Total Learning (SRT-TL) 8.03±2.36; 10.09±1.77, Selective Reminding Test-Long-term Memory (SRT-DR) 6.72±2.74; 9±2.29, Spatial Recall Test-Total Learning (SPART-TL) 4.72±2.02; 4.22±1.74, Spatial Recall Test-Long-term Memory (SPART-DR) 5.94±2.54; 5.16±2.23, Symbol Digit Modalities Test (SDMT) 40.44±17.04; 46.47±17.94, Word Fluency Test (WLG) 32.88±9.87; 40.44±9.95 respectively. There was no significant statistical difference between Multiple Sclerosis Neuropsychological Screening Questionnaire (MSNQ) and SPART values of preface, 1^st control and 2^nd control (p>0.05). There was significant statistical difference between PASAT, WLG, SDMT, SRT-TL, SRT-DR values of Preface, 1^st control, and 2^nd control (p=0.0001).

CONCLUSION

It was determined that on distinctive improvement on sustaining attention, working memory and information processing speed, and verbal fluency and verbal learning with cognitive rehabilitation, no changes were observed on visuospatial learning. This approach is hopeful and further comprehensive studies are needed.

Alterations in the cholinesterase and adenosine deaminase activities and inflammation biomarker levels in patients with multiple sclerosis

Multiple sclerosis (MS) is one of the main chronic inflammatory diseases of the CNS that cause functional disability in young adults. It has unknown etiology characterized by the infiltration of lymphocytes and macrophages into the brain. The aim of this study was to evaluate the acetylcholinesterase (AChE) activity in lymphocytes and whole blood, as well as butyrylcholinesterase (BChE) and adenosine deaminase (ADA) activities in serum. We also checked the levels of nucleotides, nucleosides, biomarkers of inflammation such as cytokines (interleukin (IL)-1, IL-6, interferon (IFN)-γ, tumor necrosis factor-alpha (TNF-α) and IL-10) and C-reactive protein (CRP) in serum from 29 patients with the relapsing-remitting form of MS (RRMS) and 29 healthy subjects as the control group. Results showed that AChE in lymphocytes and whole blood as well as BChE, and ADA activities in serum were significantly increased in RRMS patients when compared to the control group (P<0.05). In addition, we observed a decrease in ATP levels and a significant increase in the levels of ADP, AMP, adenosine and inosine in serum from RRMS patients in relation to the healthy subjects (P<0.05). Results also demonstrated an increase in the IFN-γ, TNF-α, IL-1, IL-6 and CRP (P<0.05) and a significant decrease in the IL-10 (P<0.0001) in RRMS patients when compared to control. Our results suggest that alterations in the biomarkers of inflammation and hydrolysis of nucleotides and nucleosides may contribute to the understanding of the neurological dysfunction of RRMS patients.

Synthesis and acetylcholinesterase inhibitory activity of polyhydroxylated sulfated steroids: structure/activity studies

Disulfated and trisulfated steroids have been synthesized from cholesterol and their acetylcholinesterase inhibitory activity has been evaluated. In our studies we have found that the activity was not only dependent on the location of the sulfate groups but on their configurations. 2β,3α,6α-trihydroxy-5α-cholestan-6-one trisulfate (18) was the most active steroid with an IC50 value of 15.48 μM comparable to that of 2β,3α-dihydroxy-5α-cholestan-6-one disulfate (1). Both compounds were found to be less active than the reference compound eserine. The butyrylcholinesterase activity of 1 and 18 was one magnitude lower than that against acetylcholinesterase revealing a selective inhibitor profile.

Synaptic localization of acylpeptide hydrolase in adult rat telencephalon

Acylpeptide hydrolase (ACPH), a serine protease present in the central nervous system (CNS), is believed to have a function in modulating synaptic plasticity, cleavage of beta amyloid peptide and degradation of aggregated oxidized proteins. In this report, we demonstrate for the first time the presence of ACPH in the synapse and its preferential localization at the pre-synaptic side. We isolated subcellular fractions from the rat telencephalon enriched in pre- versus post-synaptic components by using differential centrifugation steps to evaluate ACPH catalytic activity and expression level. Relative ACPH levels were determined by Western blot techniques while antibodies against synaptophysin and PSD-95 were used as positive pre- and post-synaptic markers, respectively. Our results show that ACPH protein levels are significantly increased at the synapse, which correlates with a 56% increase in ACPH activity. Furthermore, Western blot experiments show that ACPH is preferentially located at the pre-synaptic side and this is consistent with the increase of its enzymatic activity in fractions enriched in pre-synaptic components. These results give new insights regarding the localization and a putative role of ACPH in the CNS.

Cerebral acetylcholinesterase activity is not decreased in MS patients with cognitive impairment

BACKGROUND

Neuropsychological studies have extensively described the presence of cognitive dysfunction in MS patients. One possible pharmacological treatment of the impairment could be based on acetylcholinesterase inhibitors (AChEIs), which have shown efficacy in alleviating cognitive impairment in many other disorders. The findings on the efficacy of AChEI medication in MS associated cognitive symptoms are preliminary and no studies concerning cerebral acetylcholinesterase (AChE) activity in these patients have been published.

OBJECTIVE

The objective of the study was to examine cerebral AChE activity in cognitively deteriorated MS patients. Cerebral AChE activity of 10 MS patients with secondary progressive disease and marked cognitive impairment, and 10 healthy controls, was studied with positron emission tomography using tracer (11)C-MP4A.

METHODS

The cognitive profile of the patients was assessed with CERAD (Consortium to Establish a Registry for Alzheimer's Disease).

RESULTS

No differences in cortical AChE activity between MS patients and controls were seen.

CONCLUSIONS

In the patient group regional AChE activities had inverse correlations with Word learning and MMSE (Mini-Mental State Examination) scores. In the group of cognitively deteriorated MS patients no change in cerebral AChE activity, compared with controls, was observed, but within the patient group more pronounced cognitive symptoms were associated with higher cerebral AChE activity.

Cognitive dysfunction in multiple sclerosis: the effect of pharmacological interventions

Research has recently focused on cognitive dysfunction in multiple sclerosis (MS). Cognitive deficits are frequently encountered in patients and account for important impairment in quality of life, therefore posing a major therapeutic challenge for the disease. We presently review studies on cognitive effects of pharmacological treatments in MS. There is evidence for a possible beneficial effect of immunomodulatory treatments, particularly of interferons, and also of acetylcholinesterase inhibitors on cognition in MS, which, however, requires evaluation in larger, multi-centre, longitudinal studies. Methodological issues and future prospects regarding the investigation of this issue are also discussed.

Quality of life in multiple sclerosis: effects of current treatment options

Multiple sclerosis is the most common non-traumatic neurodegenerative disease in adults. Most of the patients present with both physical and mental deficits which reflect the dissemination of the lesions in the central nervous system, produced by the inflammatory process. The incomplete recovery after relapses, the accumulation of new deficits and the progressive nature of the condition interfere with daily activities of individuals and have a negative impact on their well-being. Indeed, studies show that quality of life measurements are constantly lower in patients with multiple sclerosis. Estimation of health-related quality of life is being increasingly recognized as necessary when analysing the effectiveness of treatment modalities and for the follow up of patients with chronic diseases such as multiple sclerosis. Current immunomodulatory interventions that are shown to reduce the frequency of relapses and delay disease progression might also have a positive effect on quality of life measurements. Additive pharmacological agents that target cognitive impairments and common symptoms such as depression, fatigue and pain, along with life-style modifications and rehabilitation programmes are also important for the appropriate management that aims to improve quality of life.

Prise en charge thérapeutique des troubles cognitifs dans la sclérose en plaques : données et perspectives

Taking in charge cognitive disorders is a new concept in the global care of MS patients. Cognitive disorders are observed in the all forms of the disease, sometimes early on in the evolution. These disorders can be evaluated in details even detected despite any complain in the patient. Because of the lack of clear demonstration that disease-modifying treatments could act on cognition, new specific therapeutic issues have emerged during last years. This article first discusses relationships between disease-modifying treatments and cognition for the different forms of the disease, then analyse the effects of symptomatic drug therapy especially the use of anticholinesterasics. In the last part of the article new issues about antagonists of excitatory amino-acids and individual or group cognitive training are discussed. Recent functional imaging data concerning cerebral adaptation and their modifications by drug or non-drug procedures in MS patients suggest interesting therapeutic development in a next future.

Cyclosporine A inhibits acetylcholinesterase activity in rats experimentally demyelinated with ethidium bromide

Cyclosporine A is the major immunosuppressive agent used for organ transplantation and for the treatment of a variety of autoimmune disorders such as multiple sclerosis. In this work, we investigated the effect of the cyclosporine A on the acetylcholinesterase activity in the cerebral cortex, striatum, hippocampus, hypothalamus, cerebellum and pons of the rats experimentally demyelinated by ethidium bromide. Rats were divided into four groups: I control (injected with saline), II (treated with cyclosporine A), III (injected with 0.1% ethidium bromide) and IV (injected with 0.1% the ethidium bromide and treated with cyclosporine A). The results showed a significant inhibition (p<0.05) of acetylcholinesterase activity in the groups II, III and IV in all brain structures analyzed. In the striatum, hippocampus, hypothalamus and pons the inhibition was greater (p<0.005) when ethidium bromide was associated with cyclosporine A. In conclusion, the present investigation demonstrated that cyclosporine A is an inhibitor of acetylcholinesterase activity and this effect is increased after an event of toxic demyelination of the central nervous system.