A 24-week, double-blind, placebo-controlled study of three dosages of Cerebrolysin in patients with mild to moderate Alzheimer's disease

Current biomarkers and treatment strategies in Alzheimer disease: An overview and future perspectives

Alzheimer's disease (AD), a progressive degenerative disorder first identified by Alois Alzheimer in 1907, poses a significant public health challenge. Despite its prevalence and impact, there is currently no definitive ante mortem diagnosis for AD pathogenesis. By 2050, the United States may face a staggering 13.8 million AD patients. This review provides a concise summary of current AD biomarkers, available treatments, and potential future therapeutic approaches. The review begins by outlining existing drug targets and mechanisms in AD, along with a discussion of current treatment options. We explore various approaches targeting Amyloid β (Aβ), Tau Protein aggregation, Tau Kinases, Glycogen Synthase kinase-3β, CDK-5 inhibitors, Heat Shock Proteins (HSP), oxidative stress, inflammation, metals, Apolipoprotein E (ApoE) modulators, and Notch signaling. Additionally, we examine the historical use of Estradiol (E2) as an AD therapy, as well as the outcomes of Randomized Controlled Trials (RCTs) that evaluated antioxidants (e.g., vitamin E) and omega-3 polyunsaturated fatty acids as alternative treatment options. Notably, positive effects of docosahexaenoic acid nutriment in older adults with cognitive impairment or AD are highlighted. Furthermore, this review offers insights into ongoing clinical trials and potential therapies, shedding light on the dynamic research landscape in AD treatment.

Modulation of neurotrophic factors in the treatment of dementia, stroke and TBI: Effects of Cerebrolysin

Neurotrophic factors (NTFs) are involved in the pathophysiology of neurological disorders such as dementia, stroke and traumatic brain injury (TBI), and constitute molecular targets of high interest for the therapy of these pathologies. In this review we provide an overview of current knowledge of the definition, discovery and mode of action of five NTFs, nerve growth factor, insulin-like growth factor 1, brain derived NTF, vascular endothelial growth factor and tumor necrosis factor alpha; as well as on their contribution to brain pathology and potential therapeutic use in dementia, stroke and TBI. Within the concept of NTFs in the treatment of these pathologies, we also review the neuropeptide preparation Cerebrolysin, which has been shown to resemble the activities of NTFs and to modulate the expression level of endogenous NTFs. Cerebrolysin has demonstrated beneficial treatment capabilities in vitro and in clinical studies, which are discussed within the context of the biochemistry of NTFs. The review focuses on the interactions of different NTFs, rather than addressing a single NTF, by outlining their signaling network and by reviewing their effect on clinical outcome in prevalent brain pathologies. The effects of the interactions of these NTFs and Cerebrolysin on neuroplasticity, neurogenesis, angiogenesis and inflammation, and their relevance for the treatment of dementia, stroke and TBI are summarized.

Synergistic effects of combined therapy with cerebrolysin and enriched environment on anxiety-like behavior and spatial cognitive deficits in posttraumatic stress disorder-like mouse model

Posttraumatic stress disorder (PTSD) is a serious neuropsychiatric disorder that occurs after exposure to stressful, fearful, or troubling events. Cerebrolysin (CBL), consists of low molecular weights neurotrophic factors and amino acids obtained from purified porcine brain proteins. This study aimed to evaluate the possible therapeutic effects of enriched environment (EE) and CBL alone or combined for reducing anxiety and cognitive deficits in PTSD-like mouse models. For this purpose, inescapable electric foot shocks were delivered to Balb/c mice for two consecutive days. Then mice were treated with CBL (2.5 mL/kg) and/or were kept in EE (2 h per day) or received their combination for 14 consecutive days. The hole-board test and Lashley III paradigm were used to assess anxiety and spatial learning and memory, respectively. Changes in the serum corticosterone level and expression of synaptic elements, including; growth-associated protein 43, post-synaptic density 95, and synaptophysin were assessed in the hippocampus. This model caused anxiety and spatial memory impairment associated with increased serum corticosterone levels and decreased synaptic elements. Nevertheless, CBL and/or combination treatment could reverse behavioral and molecular alterations. Our findings indicated that CBL, separately or in combination with EE, is effective in reducing anxiety and spatial memory impairment in PTSD-like mice.

[Therapy of moderate cognitive impairment in the early recovery period of ischemic stroke]

OBJECTIVE

To assess the efficacy and safety of prospecta in the treatment of moderate cognitive impairment in the early recovery period of ischemic stroke.

MATERIAL AND METHODS

The study included 275 patients (mean age 64.0±8.1 years) with a history of single ischemic stroke from 3 to 6 months, with moderate cognitive impairment, and moderate activity in everyday life, who were randomized in two groups. During the screening phase, the severity of cognitive impairment was assessed with the Mini-Mental State Examination and Montreal Cognitive Assessment scales; the level of activity in everyday life was evaluated with the Barthel Scale; and quality of life was assessed with the Stroke Specific Quality of Life Scale. Patients took 2 tablets of prospecta or placebo 2 times a day for 24 weeks. The follow-up period was 4 weeks. The primary endpoint of the study was the proportion of patients with improvement in cognitive function (+1 or more on the MoCA test) after 24 weeks of treatment. The occurrence and type of adverse events (AEs), their severity, relationship to the drug, outcome, changes in vital signs, and the proportion of patients with clinically significant abnormality in laboratory tests were analyzed to assess the safety.

RESULTS

A clinically significant improvement in cognitive function was obtained in 91.9% of patients in the prospecta group vs 82.,1% in the placebo group, (p=0.02). There were 57 AEs in 37 (27.4%) Prospecta group patients and 53 AEs in 39 (27.9%) Placebo group participants (p=1.00). No AEs were certainly associated with taking the medication. No clinically significant changes in vital signs or abnormal laboratory results were detected during the study.

CONCLUSION

Prospecta is an effective and safe treatment option for patients with moderate cognitive impairment in the early recovery period of ischemic stroke.

The efficacy and safety of animal-derived nootropics in cognitive disorders: Systematic review and meta-analysis

•

Animal-derived nootropics may have potential in treating cognitive disorders, especially vascular cognitive impairment.

•

Despite widespread use, there are few randomized controlled trials on animal derived nootropics for cognitive disorders.

•

Our review suggested modest beneficial effects of these nootropics, but the strength of supporting evidence was limited.

•

The clinical significance of the reviewed nootropics in treating vascular cognitive impairment remains unclear.

•

The findings of this review indicate promising evidence to justify further large-scale randomized controlled trials.

Background

The animal-derived nootropics, Cerebrolysin, Actovegin and Cortexin, may have potential in treating neurocognitive disorders. Although these drugs have international usage, reports on their efficacy have been conflicting. These agents have been suggested for all dementia types, but may have particular utility in vascular cognitive impairment (VCI). We used systematic review and meta-analyses to summarize evidence of efficacy in all cause dementia, with a subgroup analysis restricted to VCI.

Methods

We searched multidisciplinary, electronic databases from inception to August 2020. We assessed risk of bias using the Cochrane tool and framed results using GRADE criteria. We used random effects models to create summary estimates. Our primary outcome was change in cognition based on any quantitative cognitive assessment scale using standardized mean difference (SMD). We assessed various secondary efficacy outcomes and a safety outcome of serious adverse events. We performed subgroup analyses limited to VCI.

Results

Summary estimates suggested Cerebrolysin was potentially beneficial in improving cognition (8 trials,793 participants, SMD:-0.16, 95%CI:-0.30 to -0.03) and global function (4 trials,479 participants, OR:2.64, 95%CI:1.17 to 5.98) in the short term. There was no difference in incidence of serious adverse events (6 trials,1014 participants, RR:0.96, 95%CI:0.78 to 1.18). In our VCI subgroup, results were similar to the main analysis, with a beneficial effect on cognition (SMD:-0.22, 95%CI:-0.42 to -0.03) and clinical global impression (OR 2.99, 95%CI:1.02 to 8.73). The limited number of eligible studies for Actovegin (n = 2 trials,563 participants) and Cortexin, (n = 1 trial,80 participants) precluded meta-analyses but data suggested potential efficacy and no safety concerns. Across all included studies, risk of bias was moderate to high, there was imprecision, and certainty of evidence was considered low to very low.

Conclusion

Although published data suggest potential benefits and relative safety of animal derived nootropics, the supporting evidence is weak. The size of the effects demonstrated were modest and probably less than would be considered clinically relevant.

[The use of neuroprotectors in the treatment of late depression]

OBJECTIVE

Comparative evaluation of the effectiveness and safety of antidepressant monotherapy and combined antidepressant therapy with the inclusion of neuroprotectors in the treatment of depression in old and very old patients in a psychiatric hospital.

MATERIALS AND METHODS

The study included 2 groups of patients from the cohort of patients hospitalized in the gerontopsychiatric unit with mild and moderate depression (according to the ICD-10 classification) aged 60 years and older. The groups are comparable in their main demographic and clinical characteristics. Both groups received antidepressant monotherapy with venlafaxine (21 people) or combined therapy with the same antidepressant, but in combination with cerebrolysin or carnicetine (40 people) for 8 weeks. The efficacy of antidepressant therapy was evaluated with HAMD-17 and HARS; the effect of treatment on the level of cognitive activity of patients with MMSE and the 10-word memory test.

RESULTS

In the group of patients receiving combined antidepressant therapy, a significantly faster and more pronounced therapeutic response was observed compared to the group of patients treated with antidepressant monotherapy. In the group of combined therapy, an earlier (by 4 weeks) and significant (p<0.001) reduction of depressive and anxiety symptoms was established by the end of treatment, this group had a significantly higher number of respondents, as well as a better quality of therapeutic remission and a significant improvement in the cognitive functioning of patients compared to the monotherapy group. When comparing the effectiveness of different neuroprotectors (cerebrolysin or carnicetine), significant differences in the reduction of depressive and anxiety disorders in favor of carnicetine were established only at the end of the therapeutic course.

CONCLUSION

Combined antidepressant therapy with a combination of treatment with an antidepressant and a drug with neuroprotective properties can increase the effectiveness of antidepressant therapy in old and very old patients. Both cerebrolysin and carnicetine can be recommended for use in a psychiatric hospital to improve the quality of the therapeutic response and reduce the time of hospitalization.

Cerebrolysin in the therapy of mild cognitive impairment and dementia due to Alzheimer's disease: 30 years of clinical use

Alzheimer's disease (AD) is the most common neurocognitive disorder and a global health problem. The prevalence of AD is growing dramatically, especially in low- and middle-income countries, and will reach 131.5 million cases worldwide by 2050. Therefore, developing a disease-modifying therapy capable of delaying or even preventing the onset and progression of AD has become a world priority, and is an unmet need. The pathogenesis of AD, considered as the result of an imbalance between resilience and risk factors, begins many years before the typical clinical picture develops and involves multiple pathophysiological mechanisms. Since the pathophysiology of AD is multifactorial, it is not surprising that all attempts done to modify the disease course with drugs directed towards a single therapeutic target have been unsuccessful. Thus, combined modality therapy, using multiple drugs with a single mechanism of action or multi-target drugs, appears as the most promising strategy for both effective AD therapy and prevention. Cerebrolysin, acting as a multitarget peptidergic drug with a neurotrophic mode of action, exerts long-lasting therapeutic effects on AD that could reflect its potential utility for disease modification. Clinical trials demonstrated that Cerebrolysin is safe and efficacious in the treatment of AD, and may enhance and prolong the efficacy of cholinergic drugs, particularly in moderate to advanced AD patients. In this review, we summarize advances of therapeutic relevance in the pathogenesis and the biomarkers of AD, paying special attention to neurotrophic factors, and present results of preclinical and clinical investigations with Cerebrolysin in AD.

Cerebrolysin for vascular dementia

BACKGROUND

Although vascular dementia is the second most common cause of dementia globally, evidence-based treatments are still lacking. Cerebrolysin is a porcine brain-derived preparation that is said to have neurotrophic and neuroprotective activity. In many parts of the world Cerebrolysin, given as a series of daily intravenous infusions, is used as a potential intervention for vascular dementia. A previous Cochrane Review on Cerebrolysin in vascular dementia yielded inconsistent results. We wished to update the review to add new studies from the international literature and employ contemporary methods for appraising the strength of the evidence. This is the first update of a review first published in 2013.

OBJECTIVES

Primary: to assess the effect of Cerebrolysin on cognitive function, global function, and all-cause mortality in people living with vascular dementia. Secondary: to assess the adverse effects of Cerebrolysin and to assess the effect of Cerebrolysin on quality of life and caregiver burden.

SEARCH METHODS

We searched ALOIS, MEDLINE, Embase, PsycINFO, CINAHL, ISI Web of Knowledge, LILACS, the Cochrane Library, ClinicalTrials.gov, and the WHO ICTRP on 16 June 2017, 9 May 2018, and 9 May 2019. We expanded the search by adding four Chinese databases, searched from 1 January 2012 to 19 May 2019. We checked bibliographies of relevant papers identified and contacted pharmaceutical companies, trial authors, and experts in the field to identify any additional published or unpublished data.

SELECTION CRITERIA

We included all randomised controlled trials of Cerebrolysin used in people living with vascular dementia. We applied no language restriction.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and evaluated their methodological quality. Data were extracted and analysed using mean differences (MDs) or standardised mean differences (SMDs) with 95% confidence intervals (95% CI) for continuous outcomes. We reported dichotomous outcomes as risk ratio (RR) with 95% CI. We assessed the strength of the available evidence using the GRADE approach.

MAIN RESULTS

We identified six randomised controlled trials with a total of 597 participants that were eligible for inclusion in the 2013 review. No new studies were eligible for inclusion in this update. Participants in the included studies, where dementia severity was reported, had mild to moderate severity of vascular dementia (four trials). The included studies tested varying doses and duration of Cerebrolysin treatment. Follow-up ranged from 15 days to three years. Five of included studies were conducted in China (three studies), Russia (one study), and Romania (one study), while relevant information of other study was unclear. Where details of funding were available, all studies were supported by the pharmaceutical industry (three studies). Cognitive function was measured using the Mini-Mental State Examination (MMSE) or Alzheimer's Disease Assessment Scale Cognitive Subpart, extended version (ADAS-cog+). Combining the MMSE and ADAS-cog+ data (three studies, 420 people), there was a beneficial effect of Cerebrolysin (SMD 0.36, 95% CI 0.13 to 0.58; very low-quality evidence). Global function was measured by Clinician's Interview-Based Impression of Change plus Caregiver Input (CIBIC+) or Investigator's Clinical Global Impression (CGI). We assessed response rates on these measures (the proportion of participants with a CIBIC+ score of < 3; or at least moderate improvement of the CGI rating at the last visit). There was a beneficial effect of Cerebrolysin (two studies, 379 participants, RR 2.69, 95% CI 1.82 to 3.98; very low-quality evidence). Only one trial described mortality and reported no deaths. Four studies reported adverse events; data from two studies (379 people) were in a format that permitted meta-analysis, and there was no difference in rates of adverse effects (RR 0.91, 95% CI 0.29 to 2.85; very low-quality evidence). No studies reported on quality of life or caregiver burden.

AUTHORS' CONCLUSIONS

Courses of intravenous Cerebrolysin improved cognition and general function in people living with vascular dementia, with no suggestion of adverse effects. However, these data are not definitive. Our analyses were limited by heterogeneity, and the included papers had high risk of bias. If there are benefits of Cerebrolysin, the effects may be too small to be clinically meaningful. There have been no new studies of Cerebrolysin in vascular dementia since the last Cochrane Review. Cerebrolysin continues to be used and promoted as a treatment for vascular dementia, but the supporting evidence base is weak. Adequately powered, methodologically robust trials are needed to properly assess the effects of Cerebrolysin in vascular dementia.

Effects of combining modern recovery techniques with neurotrophic medication and standard treatment in stroke patients

Stroke is the main cause of disability after age 65, leaving survivors with sequels that require care and recovery treatment lasting years. It is estimated that by the year 2030 this pathology will be leading cause of mortality. To determine the efficacy of Lokomat training combined with neurotrophic medication and balneo-physiotherapeutic treatment in rehabilitation of post-stroke patients, a prospective study of 3 parallel groups was conducted: Group I (n = 22) - Lokomat, balneo-physiotherapy, and Cerebrolysin; Group II (n = 18) - Lokomat associated with balneo-physiotherapy; and Group III (n = 30) - balneo-physiotherapy alone (Control group). Patients were evaluated physically, neurologically, and functionally, according to the evolution of their motor deficiency, spasticity, functional independence and health-related quality of life. Patient improvement is significantly better (p < 0.05) in the group with associated therapies, especially during the first 6 months. Evolution was significantly better in all groups at 12 months than initially (p < 0.05), for all studied parameters and with the best effects in Group I (the three therapies combined). Association of Lokomat training with neurotrophic factors and classic recovery techniques improves the rehabilitation process in stroke patients.

Calotropis gigantea Promotes Neuritogenesis and Synaptogenesis through Activation of NGF-TrkA-Erk1/2 Signaling in Rat Hippocampal Neurons

Calotropis gigantea (L.) R. Br (Apocynaceae) (commonly known as milkweed or crown flower) is a large shrub native to temperate regions of Asia, including China, Bangladesh and India and has a long history of use in traditional medicines. In this study, we investigated the neuromodulatory effects of the ethanol extracts of C. gigantea leaves (CGE) during synaptogenesis in the late stage of neuronal development and during early stage neuritogenesis in cultured rat hippocampal neurons. Maximum neuritogenic activity was achieved at a CGE concentration of 7.5[Formula: see text][Formula: see text]g/ml. At this concentration, CGE facilitated the early development of cytoarchitecture, as evidenced by increases in morphometric parameters, such as, the numbers, lengths, and number of branches of initial neurites, axon and dendrites. During the synaptogenic stage (DIV 14), immunocytochemistry (ICC) showed that CGE upregulated synaptic vesicle 2 (SV2, a marker of axon terminals) and postsynaptic density-95 (PSD-95, a postsynaptic marker) and their colocalization. CGE upregulated nerve growth factor (NGF) and activated extracellular signal-regulated kinase 1/2 (Erk1/2), which is blocked by a TrkA-specific inhibitor suggesting the neuritogenic and synaptogenic potential of CGE was due to the activation of NGF-TrkA-Erk1/2 signaling. Moreover, UPLC of CGE did not detect stigmasterol, an active component of C. gigantea. However, the chloroform-methanol and ethyl acetate subfractions of CGE exhibited initial neuritogenic activity, suggesting that multiple active components were responsible for the neurotrophic-mimetic properties of CGE. Our data prove the neuromodulatory ability of CGE and provide a means of identifying new active phytochemicals with potential nootropic, preventative or therapeutic effects on the human brain.

Quantifying placebo responses in clinical evaluation of neuropsychiatric symptoms in Alzheimer's disease

PURPOSE

This study aimed to establish a non-linear mixed effects model to quantitatively analyze the placebo responses of neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD).

METHODS

A comprehensive literature search was conducted in public databases. Placebo-controlled randomized AD clinical trials using the neuropsychiatric inventory (NPI) score as the primary or secondary outcome were included. Non-linear mixed effects model was used to describe the time course of the placebo responses of NPS in AD clinical trials. Potential affecting factors were tested as covariates.

RESULTS

A total of 32 clinical studies (involving 3942 subjects) were included in model-based analysis. We found that the maximal placebo responses of NPS were reached at week 4 approximately, after which rebound effects appeared. The baseline NPI score had a significant impact on the placebo responses. Higher baseline NPI score tended to cause greater reductions in NPI score at week 8 and a smaller degree of rebound. For AD patients whose normalized baseline NPI score was 10 points and 30 points, the reduction in normalized NPI score at week 8 was estimated to be 0.83 and 7.43 points, respectively; and the rebound rate after week 8 was estimated to be 0.1 points/week and 0.08 points/week, respectively.

CONCLUSIONS

The duration of 4 weeks is sufficient to determine the drug efficacy for assessing NPS in AD clinical trials. The baseline NPI score was a key factor associated with placebo responses of NPS, which should be considered when designing future clinical trials and conducting comparisons across trials.

Prevention of memory impairment induced by post-traumatic stress disorder by cerebrolysin

Post-traumatic stress disorder (PTSD) may occur after exposure to stressful, fearful or troubling events. Until now, there is no curable medication for this disorder. Cerebrolysin is a neuropeptide, which has an important role in the treatment of vascular dementia. In this study, the probable protective effect of cerebrolysin on PTSD-induced memory impairment was investigated. To induce PTSD, the single prolonged stress (SPS) model was used. Rats were allocated into four groups: control (vehicle-treated), CBL (administrated cerebrolysin 2.5 ml/kg by intraperitoneal route for 4 weeks), SPS (as a model of PTSD and administered vehicle), and CBL-SPS (exposed to SPS and administered cerebrolysin for 4 weeks). Learning and memory were assessed using the radial arm water maze (RAWM). Results showed that SPS impaired both short- and long- term memories; and chronic cerebrolysin administration prevented such effect. Cerebrolysin also prevented decreases in hippocampal GSH levels and GSH/GSSG ratios, and increased GSSG and TBARs, levels induced by PTSD. In conclusion, a protective effect of cerebrolysin administration against SPS model of PTSD induced short- and long- term memory impairment was characterized. This protection could be accomplished, at least partly, by prevention of PTSD induced increase in oxidative stress in the hippocampus via the use of cerebrolysin.

Development of a core outcome set for disease modification trials in mild to moderate dementia: a systematic review, patient and public consultation and consensus recommendations

BACKGROUND

There is currently no disease-modifying treatment available to halt or delay the progression of the disease pathology in dementia. An agreed core set of the best-available and most appropriate outcomes for disease modification would facilitate the design of trials and ensure consistency across disease modification trials, as well as making results comparable and meta-analysable in future trials.

OBJECTIVES

To agree a set of core outcomes for disease modification trials for mild to moderate dementia with the UK dementia research community and patient and public involvement (PPI).

DATA SOURCES

We included disease modification trials with quantitative outcomes of efficacy from (1) references from related systematic reviews in workstream 1; (2) searches of the Cochrane Dementia and Cognitive Improvement Group study register, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, EMBASE, Latin American and Caribbean Health Sciences Literature and PsycINFO on 11 December 2015, and clinical trial registries [International Standard Randomised Controlled Trial Number (ISRCTN) and clinicaltrials.gov] on 22 and 29 January 2016; and (3) hand-searches of reference lists of relevant systematic reviews from database searches.

REVIEW METHODS

The project consisted of four workstreams. (1) We obtained related core outcome sets and work from co-applicants. (2) We systematically reviewed published and ongoing disease modification trials to identify the outcomes used in different domains. We extracted outcomes used in each trial, recording how many used each outcome and with how many participants. We divided outcomes into the domains measured and searched for validation data. (3) We consulted with PPI participants about recommended outcomes. (4) We presented all the synthesised information at a conference attended by the wider body of National Institute for Health Research (NIHR) dementia researchers to reach consensus on a core set of outcomes.

RESULTS

We included 149 papers from the 22,918 papers screened, referring to 125 individual trials. Eighty-one outcomes were used across trials, including 72 scales [31 cognitive, 12 activities of daily living (ADLs), 10 global, 16 neuropsychiatric and three quality of life] and nine biological techniques. We consulted with 18 people for PPI. The conference decided that only cognition and biological markers are core measures of disease modification. Cognition should be measured by the Mini Mental State Examination (MMSE) or the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog), and brain changes through structural magnetic resonance imaging (MRI) in a subset of participants. All other domains are important but not core. We recommend using the Neuropsychiatric Inventory for neuropsychiatric symptoms: the Disability Assessment for Dementia for ADLs, the Dementia Quality of Life Measure for quality of life and the Clinical Dementia Rating scale to measure dementia globally.

LIMITATIONS

Most of the trials included participants with Alzheimer's disease, so recommendations may not apply to other types of dementia. We did not conduct economic analyses. The PPI consultation was limited to members of the Alzheimer's Society Research Network.

CONCLUSIONS

Cognitive outcomes and biological markers form the core outcome set for future disease modification trials, measured by the MMSE or ADAS-Cog, and structural MRI in a subset of participants.

FUTURE WORK

We envisage that the core set may be superseded in the future, particularly for other types of dementia. There is a need to develop an algorithm to compare scores on the MMSE and ADAS-Cog.

STUDY REGISTRATION

The project was registered with Core Outcome Measures in Effectiveness Trials [ www.comet-initiative.org/studies/details/819?result=true (accessed 7 April 2016)]. The systematic review protocol is registered as PROSPERO CRD42015027346.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Maintenance of Cognitive Performance and Mood for Individuals with Alzheimer's Disease Following Consumption of a Nutraceutical Formulation: A One-Year, Open-Label Study

Nutritional interventions have shown varied efficacy on cognitive performance during Alzheimer's disease (AD). Twenty-four individuals diagnosed with AD received a nutraceutical formulation (NF: folate, alpha-tocopherol, B12, S-adenosyl methioinine, N-acetyl cysteine, acetyl-L-carnitine) under open-label conditions (ClinicalTrials.gov NCT01320527). Primary outcome was cognitive performance. Secondary outcomes were behavioral and psychological symptoms of dementia (BPSD) and activities of daily living. Participants maintained their baseline cognitive performance and BPSD over 12 months. These findings are consistent with improvement in cognitive performance and BPSD in prior placebo-controlled studies with NF, and contrast with the routine decline for participants receiving placebo.

Neuropeptide Treatment with Cerebrolysin Enhances the Survival of Grafted Neural Stem Cell in an α-Synuclein Transgenic Model of Parkinson's Disease

Neuronal stem cell (NSC) grafts have been investigated as a potential neuro-restorative therapy in Parkinson’s disease (PD) but their use is compromised by the death of grafted cells. We investigated the use of Cerebrolysin (CBL), a neurotrophic peptide mixture, as an adjunct to NSC therapy in the α-synuclein (α-syn) transgenic (tg) model of PD. In vehicle-treated α-syn tg mice, there was decreased survival of NSCs. In contrast, CBL treatment enhanced the survival of NSCs in α-syn tg groups and ameliorated behavioral deficits. The grafted NSCs showed lower levels of terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells in the CBL-treated mice when compared with vehicle-treated α-syn tg mice. No evidence of tumor growth was detected. Levels of α-syn were similar in the vehicle in CBL-treated tg mice. In conclusion, CBL treatment might be a potential adjuvant for therapeutic NSC grafting in PD.

Cerebrolysin in mild-to-moderate Alzheimer's disease: a meta-analysis of randomized controlled clinical trials

OBJECTIVE

The aim of this study was to provide a systematic and quantitative summary of benefit and risk of Cerebrolysin in patients with mild-to-moderate Alzheimer's disease (AD) and to avoid major deficiencies of an earlier meta-analysis.

DESIGN

This is a meta-analysis of randomized double-blind placebo-controlled clinical trials.

DATA SOURCES

Trials were identified with the help of PubMed, the Cochrane Dementia Group database, the Center for Collaborative Neurosciences, and references from reviews; no language restrictions were applied.

STUDY SELECTION

All randomized double-blind placebo-controlled studies on 30 ml/day of Cerebrolysin in mild-to-moderate AD were included.

RESULTS

There were 6 eligible randomized controlled trials comparing Cerebrolysin with placebo. For all studies, either individual patient data and/or published data (aggregate data) were available. Analyses were based on the odds ratio (OR) for dichotomized global clinical change and for safety criteria, on the standardized mean difference (SMD) for pooling of cognitive function, and on the Mann-Whitney statistic (MW) for multivariate analysis of 'global benefit' (combined effect of global clinical change and cognitive function). Cerebrolysin was significantly more effective than placebo at 4 weeks regarding cognitive function (4 weeks: SMD -0.40 points; 95% CI -0.66 to -0.13; p = 0.0031; 6 months: SMD -0.37 points; 95% CI -0.90 to 0.16; p = 0.1710), at 4 weeks and 6 months regarding global clinical change (4 weeks: OR 3.32; 95% CI 1.20-9.21; p = 0.0212; 6 months: OR 4.98; 95% CI 1.37-18.13; p = 0.0150), and at 4 weeks and 6 months regarding 'global benefit' (combined efficacy criteria; 4 weeks: MW 0.57, 95% CI 0.53-0.61; p = 0.0006; 6 months: MW 0.57; 95% CI 0.53-0.61; p = 0.0010). The safety aspects of Cerebrolysin were comparable to placebo.

CONCLUSION

This meta-analysis provides evidence that Cerebrolysin has an overall beneficial effect and a favorable benefit-risk ratio in patients with mild-to-moderate AD. Cerebrolysin as a therapeutic agent should be considered by clinicians seeking treatment options for mild-to-moderate AD.

Safety and Efficacy of Cerebrolysin in Infants with Communication Defects due to Severe Perinatal Brain Insult: A Randomized Controlled Clinical Trial

Background and Purpose

The neuroregenerative drug Cerebrolysin has demonstrated efficacy in improving cognition in adults with stroke and Alzheimer's disease. The aim of this study was to determine the efficacy and safety of Cerebrolysin in the treatment of communication defects in infants with severe perinatal brain insult.

Methods

A randomized placebo-controlled clinical trial was conducted in which 158 infants (age 6-21 months) with communication defects due to severe perinatal brain insult were enrolled; 120 infants completed the study. The Cerebrolysin group (n=60) received twice-weekly Cerebrolysin injections of 0.1 mL/kg body weight for 5 weeks (total of ten injections). The placebo group (n=60) received the same amount and number of normal saline injections.

Results

The baseline Communication and Symbolic-Behavior-Scale-Developmental Profile scores were comparable between the two groups. After 3 months, the placebo group exhibited improvements in the social (p<0.01) and speech composite (p=0.02) scores, with 10% and 1.5% increases from baseline, respectively. The scores of the Cerebrolysin group changed from concern to no concern, with increases of 65.44%, 45.54%, 358.06%, and 96.00% from baseline in the social (p<0.001), speech (p<0.001), symbolic (p<0.001), and total (p<0.001) scores.

Conclusions

Cerebrolysin dramatically improved infants' communication especially symbolic behavior which positively affected social interaction. These findings suggest that cerebrolysin may be an effective and feasible way equivalent to stem cell therapy.

Neuro-peptide treatment with Cerebrolysin improves the survival of neural stem cell grafts in an APP transgenic model of Alzheimer disease

Neural stem cells (NSCs) have been considered as potential therapy in Alzheimer's disease (AD) but their use is hampered by the poor survival of grafted cells. Supply of neurotrophic factors to the grafted cells has been proposed as a way to augment survival of the stem cells. In this context, we investigated the utility of Cerebrolysin (CBL), a peptidergic mixture with neurotrophic-like properties, as an adjunct to stem cell therapy in an APP transgenic (tg) model of AD. We grafted murine NSCs into the hippocampus of non-tg and APP tg that were treated systemically with CBL and analyzed after 1, 3, 6 and 9months post grafting. Compared to vehicle-treated non-tg mice, in the vehicle-treated APP tg mice there was considerable reduction in the survival of the grafted NSCs. Whereas, CBL treatment enhanced the survival of NSCs in both non-tg and APP tg with the majority of the surviving NSCs remaining as neuroblasts. The NSCs of the CBL treated mice displayed reduced numbers of caspase-3 and TUNEL positive cells and increased brain derived neurotrophic factor (BDNF) and furin immunoreactivity. These results suggest that CBL might protect grafted NSCs and as such be a potential adjuvant therapy when combined with grafting.

Cerebrolysin improves cognitive performance in rats after mild traumatic brain injury

OBJECT

Long-term memory deficits occur after mild traumatic brain injuries (mTBIs), and effective treatment modalities are currently unavailable. Cerebrolysin, a peptide preparation mimicking the action of neurotrophic factors, has beneficial effects on neurodegenerative diseases and brain injuries. The present study investigated the long-term effects of Cerebrolysin treatment on cognitive function in rats after mTBI.

METHODS

Rats subjected to closed-head mTBI were treated with saline (n = 11) or Cerebrolysin (2.5 ml/kg, n = 11) starting 24 hours after injury and then daily for 28 days. Sham animals underwent surgery without injury (n = 8). To evaluate cognitive function, the modified Morris water maze (MWM) test and a social odor-based novelty recognition task were performed after mTBI. All rats were killed on Day 90 after mTBI, and brain sections were immunostained for histological analyses of amyloid precursor protein (APP), astrogliosis, neuroblasts, and neurogenesis.

RESULTS

Mild TBI caused long-lasting cognitive memory deficits in the MWM and social odor recognition tests up to 90 days after injury. Compared with saline treatment, Cerebrolysin treatment significantly improved both long-term spatial learning and memory in the MWM test and nonspatial recognition memory in the social odor recognition task up to 90 days after mTBI (p < 0.05). Cerebrolysin significantly increased the number of neuroblasts and promoted neurogenesis in the dentate gyrus, and it reduced APP levels and astrogliosis in the corpus callosum, cortex, dentate gyrus, CA1, and CA3 regions (p < 0.05).

CONCLUSIONS

These results indicate that Cerebrolysin treatment of mTBI improves long-term cognitive function, and this improvement may be partially related to decreased brain APP accumulation and astrogliosis as well as increased neuroblasts and neurogenesis.

Cerebrolysin™ efficacy in a transgenic model of tauopathy: role in regulation of mitochondrial structure

Background

Alzheimer’s Disease (AD) and Fronto temporal lobar dementia (FTLD) are common causes of dementia in the aging population for which limited therapeutical options are available. These disorders are associated with Tau accumulation. We have previously shown that Cerebrolysin^TM (CBL), a neuropeptide mixture with neurotrophic effects, ameliorates the behavioral deficits and neuropathological alterations in amyloid precursor protein (APP) transgenic (tg) mouse model of AD by reducing hyper-phosphorylated Tau. CBL has been tested in clinical trials for AD, however it’s potential beneficial effects in FTLD are unknown. For this purpose we sought to investigate the effects of CBL in a tg model of tauopathy. Accordingly, double tg mice expressing mutant Tau under the mThy-1 promoter and GSK3β (to enhance Tau phosphorylation) were treated with CBL and evaluated neuropathologically.

Results

Compared to single Tau tg mice the Tau/GSK3β double tg model displayed elevated levels of Tau phosphorylation and neurodegeneration in the hippocampus. CBL treatment reduced the levels of Tau phosphorylation in the dentate gyrus and the degeneration of pyramidal neurons in the temporal cortex and hippocampus of the Tau/GSK3β double tg mice. Interestingly, the Tau/GSK3β double tg mice also displayed elevated levels of Dynamin-related protein-1 (Drp-1), a protein that hydrolyzes GTP and is required for mitochondrial division. Ultrastructural analysis of the mitochondria in the Tau/GSK3β double tg mice demonstrated increased numbers and fragmentation of mitochondria in comparison to non-tg mice. CBL treatment normalized levels of Drp-1 and restored mitochondrial structure.

Conclusions

These results suggest that the ability of CBL to ameliorate neurodegenerative pathology in the tauopathy model may involve reducing accumulation of hyper-phosphorylated Tau and reducing alterations in mitochondrial biogenesis associated with Tau.

Cerebrolysin modulates pronerve growth factor/nerve growth factor ratio and ameliorates the cholinergic deficit in a transgenic model of Alzheimer's disease

Alzheimer's disease (AD) is characterized by degeneration of neocortex, limbic system, and basal forebrain, accompanied by accumulation of amyloid-β and tangle formation. Cerebrolysin (CBL), a peptide mixture with neurotrophic-like effects, is reported to improve cognition and activities of daily living in patients with AD. Likewise, CBL reduces synaptic and behavioral deficits in transgenic (tg) mice overexpressing the human amyloid precursor protein (hAPP). The neuroprotective effects of CBL may involve multiple mechanisms, including signaling regulation, control of APP metabolism, and expression of neurotrophic factors. We investigate the effects of CBL in the hAPP tg model of AD on levels of neurotrophic factors, including pro-nerve growth factor (NGF), NGF, brain-derived neurotrophic factor (BDNF), neurotropin (NT)-3, NT4, and ciliary neurotrophic factor (CNTF). Immunoblot analysis demonstrated that levels of pro-NGF were increased in saline-treated hAPP tg mice. In contrast, CBL-treated hAPP tg mice showed levels of pro-NGF comparable to control and increased levels of mature NGF. Consistently with these results, immunohistochemical analysis demonstrated increased NGF immunoreactivity in the hippocampus of CBL-treated hAPP tg mice. Protein levels of other neurotrophic factors, including BDNF, NT3, NT4, and CNTF, were unchanged. mRNA levels of NGF and other neurotrophins were also unchanged. Analysis of neurotrophin receptors showed preservation of the levels of TrKA and p75(NTR) immunoreactivity per cell in the nucleus basalis. Cholinergic cells in the nucleus basalis were reduced in the saline-treated hAPP tg mice, and treatment with CBL reduced these cholinergic deficits. These results suggest that the neurotrophic effects of CBL might involve modulation of the pro-NGF/NGF balance and a concomitant protection of cholinergic neurons.

Cerebrolysin for vascular dementia

BACKGROUND

Vascular dementia is a common disorder without definitive treatments. Cerebrolysin seems to be a promising intervention based on its potential neurotrophic and pro-cognitive effects, but studies of its efficacy have yielded inconsistent results.

OBJECTIVES

To assess the efficacy and safety of Cerebrolysin for vascular dementia.

SEARCH METHODS

We searched ALOIS - the Cochrane Dementia and Cognitive Improvement Group's Specialized Register on 4 November 2012 using the terms: Cerebrolysin, Cere, FPF1070, FPF-1070. ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources.

SELECTION CRITERIA

All randomized controlled trials of Cerebrolysin for treating vascular dementia without language restriction.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials and evaluated the methodological quality, then extracted and analysed data from the included trials.

MAIN RESULTS

Six randomized controlled trials with a total of 597 participants were eligible. The meta-analyses revealed a beneficial effect of Cerebrolysin on general cognitive function measured by mini-mental state examination (MMSE) (weighted mean difference (WMD) 1.10; 95% confidence interval (CI) 0.37 to 1.82) or Alzheimer's Disease Assessment Scale Cognitive Subpart, extended version (ADAS-cog+) (WMD -4.01; 95% CI -5.36 to -2.66). It also improved patients' global clinical function evaluated by the response rates (relative risk (RR) 2.71, 95% CI 1.83 to 4.00). Only non-serious adverse events were observed in the included trials, and there was no significant difference in occurrence of non-serious side effects between groups (RR 0.97, 95% CI 0.49 to 1.94).

AUTHORS' CONCLUSIONS

Cerebrolysin may have positive effects on cognitive function and global function in elderly patients with vascular dementia of mild to moderate severity, but there is still insufficient evidence to recommend Cerebrolysin as a routine treatment for vascular dementia due to the limited number of included trials, wide variety of treatment durations and short-term follow-up in most of the trials.

Recommended measures for the assessment of cognitive and physical performance in older patients with dementia: a systematic review

Aim/Goal

To recommend a set of neuropsychological and physical exercise tests for researchers to assess cognition and physical fitness in clinical trials with older patients with dementia; to create consensus, decrease heterogeneity, and improve research quality.

Methods

A literature search (2005–2011) yielded 89 randomized controlled trials. To provide information on test recommendations the frequency of test use, effect size of the test outcome, study quality, and psychometric properties of tests were analyzed.

Results

Fifty-nine neuropsychological tests (cognitive domains: global cognition, executive functioning, memory, and attention) and 10 exercise tests (physical domains: endurance capacity, muscle strength, balance, and mobility) were found.

Conclusion

The Severe Impairment Battery, Mini Mental State Examination, and Alzheimer Disease Assessment Scale – cognitive subscale were recommended to measure global cognition. The Verbal Fluency Test Category/Letters, Clock Drawing Test, and Trail Making Test-B were recommended to measure executive functioning. No specific memory test could be recommended. The Digit Span Forward, Digit Span Backward, and Trail Making Test-A were recommended to measure attention. As physical exercise tests, the Timed Up and Go and Six Meter Walk for mobility, the Six Minute Walk Distance for endurance capacity, and the Tinetti Balance Scale were recommended.

Beneficial effects of a neurotrophic peptidergic mixture persist for a prolonged period following treatment interruption in a transgenic model of Alzheimer's disease

Neurodegenerative disorders such as Alzheimer's disease (AD) are characterized by the loss of neurotrophic factors, and experimental therapeutical approaches to AD have investigated the efficacy of replacing or augmenting neurotrophic factor activity. Cerebrolysin, a peptide mixture with neurotrophic-like effects, has been shown to improve cognition in patients with AD and to reduce synaptic and behavioral deficits in transgenic (tg) mice overexpressing the amyloid precursor protein (APP). However, it is unclear how long-lasting the beneficial effects of Cerebrolysin are and whether or not behavioral and neuropathological alterations will reappear following treatment interruption. The objective of the present study was to investigate the consequences of interrupting Cerebrolysin treatment (washout effect) 3 and 6 months after the completion of a 3-month treatment period in APP tg mice. We demonstrate that, in APP tg mice, Cerebrolysin-induced amelioration of memory deficits in the water maze and reduction of neurodegenerative pathology persist for 3 months after treatment interruption; however, these effects dissipate 6 months following treatment termination. Immunohistochemical analysis demonstrated that the decrease in neocortical and hippocampal amyloid plaque load observed in Cerebrolysin-treated APP tg mice immediately after treatment was no longer apparent at 3 months after treatment interruption, indicating that the beneficial effects of Cerebrolysin at this time point were independent of its effect on amyloid-β deposition. In conclusion, the results demonstrate that the effects of Cerebrolysin persist for a significant period of time following treatment termination and suggest that this prolonged effect may involve the neurotrophic factor-like activity of Cerebrolysin.

Efficacy and safety of Cerebrolysin in moderate to moderately severe Alzheimer's disease: results of a randomized, double-blind, controlled trial investigating three dosages of Cerebrolysin

BACKGROUND

cerebrolysin is a neuropeptide preparation mimicking the effects of neurotrophic factors. This subgroup analysis assessed safety and efficacy of Cerebrolysin in patients with moderate to moderately severe Alzheimer's disease (AD) (ITT data set: N = 133; MMSE: 14-20) included in a dose-finding study (ITT data set: N = 51; MMSE: 14-25). Results of the mild AD subgroup (ITT data set: N = 118; MMSE: 21-25) are also presented.

METHODS

patients with AD received 100 ml IV infusions of Cerebrolysin (10, 30 or 60 ml diluted in saline; N = 32, 34 and 35, respectively) or placebo (saline; N = 32) over twelve weeks (5 days per week for 4 weeks and 2 days per week for another 8 weeks). Primary efficacy criteria ADAS-cog+ (Alzheimer's Disease Assessment Scale Cognitive Subpart Modified) and CIBIC+ (Clinical Interview-based Impression of Change with Caregiver Input) were assessed 24 weeks after baseline.

RESULTS

at week 24, Cerebrolysin improved the global clinical function significantly with all three dosages and induced significant improvements in cognition, initiation of activities of daily living (ADL) and neuropsychiatric symptoms at 10-, 30- and 60-ml doses, respectively. Treatment effects on total ADL and other secondary parameters (MMSE, Trail-making test) were not significant. Cerebrolysin was safe and well tolerated.

CONCLUSIONS

these results demonstrate the efficacy of Cerebrolysin in moderate to moderately severe AD, showing dose-specific effects similar to those reported for patients with mild to moderate AD. The benefits of Cerebrolysin in advanced AD need to be confirmed in larger trials.

Novel insights for the treatment of Alzheimer's disease

The development of treatments for Alzheimer's disease (AD) is currently shifting away from the correction of neurotransmitter abnormalities and from attempts to remove the pathognomonic protein deposits. Drug discovery is heading towards novel types of pharmacological interventions which are aimed at more central and upstream pathophysiological events. The large number of upcoming treatment targets can be grouped into two major categories. The first category consists of antecedents of beta amyloid peptide (Aβ) and TAU deposition including Aβ production, degradation and clearance, TAU hyperphosphorylation and aggregation. The second consists of protectors against neuronal dysfunction and premature death such as mitochondrial functioning, nerve growth and regeneration, and neuronal membrane integrity. It is hoped that some of these strategies will not only have larger symptomatic effects than the currently available drugs but also an impact on the underlying neurodegeneration. Since the novel treatments will be typically administered over years they must meet high standards of safety, drug-drug compatibility, and tolerability. Probably the most important target groups for novel treatments are carriers of mutations causing AD, and individuals with minor cognitive impairment representing a pre-dementia stage of the disease. To minimise incorrect case identifications, drug development must be paralleled by improved diagnostic techniques. Novel pharmacological strategies may be cost-effective if disability and need of full-time care can be postponed or prevented without prolonging time lived with dementia or extending survival. We are uncertain whether the advent of novel disease-retarding strategies will revolutionise the management of AD. Symptomatic treatments will continue to be needed, and psychosocial approaches will retain an essential role in supporting affected individuals and their families.

Neurotrophic activity of obovatol on the cultured embryonic rat neuronal cells by increase of neurotrophin release through activation of ERK pathway

Previously, we found that obovatol, a lignan compound isolated from Magnolia officinalis, has anti-cancer, anti-inflammatory, and anxiolytic effects. Recent studies showed that honokiol, magnolol, and 4-O-methylhonokiol, lignin compounds isolated from the Magnolia family have neurotrophic activity. In this study, we examined whether or not obovatol also exhibits neurite-promoting effects on rat embryonic neuronal cells. Obovatol increased neurite outgrowth in a concentration-dependent manner. Consistent with the neurite outgrowth effect, the expression of neurite differentiation markers also increased in response to obovatol. We also found that obovatol increased levels of NGF and BDNF released into the culture medium. In addition, the combination of low concentrations of obovatol (1 and 2 μM) with NGF (50 ng/ml) or with BDNF (10 ng/ml) greatly enhanced neurite outgrowth. Subsequently, we found that obovatol increased phosphorylation of ERK. However, the neurite outgrowth, and NGF and BDNF release induced by obovatol were prevented by an ERK-specific inhibitor. These results suggest that obovatol promotes neurite outgrowth due to the increased release of neurotrophic factors via activation of the ERK pathway.

Cerebrolysin in vascular dementia: improvement of clinical outcome in a randomized, double-blind, placebo-controlled multicenter trial

No drug to treat vascular dementia (VaD) has yet been approved by the American or European authorities, leaving a large population of patients without effective therapy. Cerebrolysin has a long record of safety and might be efficacious in this condition. We conducted a large, multicenter, double-blind, placebo-controlled study in 242 patients meeting the criteria for VaD. The primary endpoint was the combined outcome of cognition (based on Alzheimer's Disease Assessment Scale Cognitive Subpart, Extended Version [ADAS-cog+] score) and overall clinical functioning (based on Clinician's Interview-Based Impression of Change plus Caregiver Input [CIBIC+] score) assessed after 24 weeks of treatment. Intravenous Cerebrolysin 20 mL was administered once daily over the course of 2 treatment cycles as add-on therapy to basic treatment with acetylsalicylic acid. The addition of Cerebrolysin was associated with significant improvement in both primary parameters. At week 24, ADAS-cog+ score improved by 10.6 points in the Cerebrolysin group, compared with 4.4 points in the placebo group (least squares mean difference, -6.17; P < .0001 vs placebo). CIBIC+ showed a mean improvement of 2.84 in the treatment arm and 3.68 in the placebo arm, a treatment difference of 0.84 (P < .0001 vs placebo). These findings were confirmed by responder analyses demonstrating higher rates in the Cerebrolysin group (ADAS-cog+ improvement of ≥4 points from baseline, 82.1% vs 52.2%; CIBIC+ score of <4 at week 24, 75.3% vs 37.4%; combined response in ADAS-cog+ and CIBIC+, 67.5% vs 27.0%). For Cerebrolysin, the odds ratio for achieving a favorable CIBIC+ response was 5.08 (P < .05), and that for achieving a favorable combined response was 5.63 (P < .05). Our data indicate that the addition of Cerebrolysin significantly improved clinical outcome, and that the benefits persisted for at least 24 weeks. Cerebrolysin was safe and well tolerated.

Neurotrophic peptides incorporating adamantane improve learning and memory, promote neurogenesis and synaptic plasticity in mice

Development of neurotrophic peptidergic drugs that can mimic neurotrophins and promote neurogenesis and maturation of newborn cells into mature functional neurons represents an exciting therapeutic opportunity for treatment of Alzheimer disease and other learning and memory disorders as well as enhancing cognition of normal individuals. Here we report the design of a peptidergic compound, Ac-DGGLAG-NH2, called P21, when administered peripherally, enhanced learning as well as both short-term and spatial reference memories of normal adult C57Bl6 mice. P21 induced enhancement of neurogenesis and maturation of newly born neurons in the granular cell layer and subgranular zone of the dentate gyrus.

Current therapeutic targets for the treatment of Alzheimer's disease

Alzheimer's disease is a progressive neurodegenerative disease for which no cure exists. There is a substantial need for new therapies that offer improved symptomatic benefit and disease-slowing capabilities. In recent decades there has been substantial progress in understanding the molecular and cellular changes associated with Alzheimer's disease pathology. This has resulted in identification of a large number of new drug targets. These targets include, but are not limited to, therapies that aim to prevent production of or remove the amyloid-beta protein that accumulates in neuritic plaques; to prevent the hyperphosphorylation and aggregation into paired helical filaments of the microtubule-associated protein tau; and to keep neurons alive and functioning normally in the face of these pathologic challenges. We provide a review of these targets for drug development.

Spotlight on cerebrolysin in dementia

Cerebrolysin is a parenterally administered, porcine brain-derived peptide preparation that has pharmacodynamic properties similar to those of endogenous neurotrophic factors. In several randomized, double-blind trials of up to 28 weeks' duration in patients with Alzheimer's disease, Cerebrolysin was superior to placebo in improving global outcome measures and cognitive ability. A large, randomized comparison of Cerebrolysin, donepezil or combination therapy showed beneficial effects on global measures and cognition for all three treatment groups compared with baseline. Although not as extensively studied in patients with vascular dementia, Cerebrolysin has also shown beneficial effects on global measures and cognition in this patient population. Cerebrolysin was generally well tolerated in clinical trials, with dizziness (or vertigo) being the most frequently reported adverse event. Although further studies with Cerebrolysin, including longer term trials and further exploration of its use in combination with cholinesterase inhibitors, are needed to more clearly determine its place in the management of Alzheimer's disease and vascular dementia, available data suggest that Cerebrolysin is a useful addition to the treatment options available for dementia.

Cerebrolysin: a review of its use in dementia

Cerebrolysin is a parenterally administered, porcine brain-derived peptide preparation that has pharmacodynamic properties similar to those of endogenous neurotrophic factors. In several randomized, double-blind trials of up to 28 weeks' duration in patients with Alzheimer's disease, Cerebrolysin was superior to placebo in improving global outcome measures and cognitive ability. A large, randomized comparison of Cerebrolysin, donepezil or combination therapy showed beneficial effects on global measures and cognition for all three treatment groups compared with baseline. Although not as extensively studied in patients with vascular dementia, Cerebrolysin has also shown beneficial effects on global measures and cognition in this patient population. Cerebrolysin was generally well tolerated in clinical trials, with dizziness (or vertigo) being the most frequently reported adverse event. Although further studies with Cerebrolysin, including longer term trials and further exploration of its use in combination with cholinesterase inhibitors, are needed to more clearly determine its place in the management of Alzheimer's disease and vascular dementia, available data suggest that Cerebrolysin is a useful addition to the treatment options available for dementia.

Strategies to promote differentiation of newborn neurons into mature functional cells in Alzheimer brain

Adult neurogenesis occurs in the subgranular zone (SGZ) and subventricular zone (SVZ). New SGZ neurons migrate into the granule cell layer of the dentate gyrus (DG). New SVZ neurons seem to enter the association neocortex and entorhinal cortex besides the olfactory bulb. Alzheimer disease (AD) is characterized by neuron loss in the hippocampus (DG and CA1 field), entorhinal cortex, and association neocortex, which underlies the learning and memory deficits. We hypothesized that, if the AD brain can support neurogenesis, strategies to stimulate the neurogenesis process could have therapeutic value in AD. We reviewed the literature on: (a) the functional significance of adult-born neurons; (b) the occurrence of endogenous neurogenesis in AD; and (c) strategies to stimulate the adult neurogenesis process. We found that: (a) new neurons in the adult DG contribute to memory function; (b) new neurons are generated in the SGZ and SVZ of AD brains, but they fail to differentiate into mature neurons in the target regions; and (c) numerous strategies (Lithium, Glatiramer Acetate, nerve growth factor, environmental enrichment) can enhance adult neurogenesis and promote maturation of newly generated neurons. Such strategies might help to compensate for the loss of neurons and improve the memory function in AD.

Reduced TNF-α and increased IGF-I levels in the serum of Alzheimer's disease patients treated with the neurotrophic agent cerebrolysin

According to current scientific knowledge, excess tumour necrosis factor-α (TNF-α) and low insulin-like growth factor-I (IGF-I) are pathogenic-risk factors that constitute therapeutic targets for Alzheimer's disease (AD). Changes in serum TNF-α, total and dissociable IGF-I levels were determined by ELISA in 207 AD patients completing a 24-wk, double-blind, placebo-controlled trial to evaluate the effects of the neurotrophic compound Cerebrolysin (Cere: 10, 30 or 60 ml for 12 wk). At week 24, Cere reduced TNF-α and enhanced dissociable IGF-I with respect to placebo in a dose-related manner. TNF-α decreased in parallel with behavioural disturbances. Increases in total IGF-I were induced by 60 ml Cere and correlated significantly with improvements in global function, disabilities and behaviour in late-onset AD patients. These results showing for the first time the opposite influence of one anti-dementia treatment on serum TNF-α and IGF-I suggest the contribution of both factors to the clinical effects of Cere, and probably other drugs.

Neurofibrillary and neurodegenerative pathology in APP-transgenic mice injected with AAV2-mutant TAU: neuroprotective effects of Cerebrolysin

Alzheimer's disease (AD) continues to be the most common cause of cognitive and motor alterations in the aging population. Accumulation of amyloid beta (Abeta)-protein oligomers and the microtubule associated protein-TAU might be responsible for the neurological damage. We have previously shown that Cerebrolysin (CBL) reduces the synaptic and behavioral deficits in amyloid precursor protein (APP) transgenic (tg) mice by decreasing APP phosphorylation via modulation of glycogen synthase kinase-3beta (GSK3beta) and cyclin-dependent kinase-5 (CDK5) activity. These kinases also regulate TAU phosphorylation and are involved in promoting neurofibrillary pathology. In order to investigate the neuroprotective effects of CBL on TAU pathology, a new model for neurofibrillary alterations was developed using somatic gene transfer with adeno-associated virus (AAV2)-mutant (mut) TAU (P301L). The Thy1-APP tg mice (3 m/o) received bilateral injections of AAV2-mutTAU or AAV2-GFP, into the hippocampus. After 3 months, compared to non-tg controls, in APP tg mice intra-hippocampal injections with AAV2-mutTAU resulted in localized increased accumulation of phosphorylated TAU and neurodegeneration. Compared with vehicle controls, treatment with CBL in APP tg injected with AAV2-mutTAU resulted in a significant decrease in the levels of TAU phosphorylation at critical sites dependent on GSK3beta and CDK5 activity. This was accompanied by amelioration of the neurodegenerative alterations in the hippocampus. This study supports the concept that the neuroprotective effects of CBL may involve the reduction of TAU phosphorylation by regulating kinase activity.

Cerebrolysin lowers kynurenic acid formation--an in vitro study

The therapeutic effect of Cerebrolysin in the treatment of dementia and brain injury has been proposed because of neurotrophic properties of this compound. Since an increased kynurenine metabolism has been documented in several brain pathologies including dementia the aim of the present study was to investigate the biochemical properties of Cerebrolysin with respect to kynurenic acid (KYNA) formation in an in vitro study. KYNA is an endogenous metabolite of the kynurenine pathway of tryptophan degradation and is an antagonist of the glutamate ionotropic excitatory amino acid and of the nicotine cholinergic receptors. The activities of the KYNA synthesizing enzymes kynurenine aminotransferases I, II and III (KAT I, KAT II and KAT III) in rat liver, and rat and human brain homogenates were analysed in the presence of Cerebrolysin. KAT I, II and III activities were measured using a radio-enzymatic method in the presence of 1 mM pyruvate and 100 microM [H(3)]L-kynurenine. Cerebrolysin, dose-dependently and significantly reduced KAT I, KAT II and KAT III activities of rat liver homogenate. Furthermore, Cerebrolysin exerted a dose-dependent inhibition of rat and human brain KAT I, KAT II and KAT III activities, too. The inhibitory effect of Cerebrolysin was more pronounced for KAT I than for KAT II and KAT III. The present study for the first time demonstrates the ability of Cerebrolysin to lower KYNA formation in rat liver as well as in rat and human brain homogenates. We propose Cerebrolysin as a compound susceptible of therapeutic exploitation in some disorders associated with elevated KYNA metabolism in the brain and/or other tissues. We suggest that the anti-dementia effect of Cerebrolysin observed in Alzheimer patients could be in part due to Cerebrolysin induced reduction of KYNA levels, thus modulating the cholinergic and glutamatergic neurotransmissions.

Neurotrophic factors in neurodegenerative disorders : potential for therapy

Finding an effective therapy to treat chronic neurodegenerative disorders still represents an unmet and elusive goal, mainly because so many pathogenic variables come into play in these diseases. Recent emphasis has been placed on the role of neurotrophic factors in the aetiology of such disorders because of their role in the survival of different cell phenotypes under various adverse conditions, including neurodegeneration.This review summarizes the current status and the efforts to treat neurodegenerative disorders by the exogenous administration of neurotrophic factors in an attempt to replenish trophic supply, the paucity of which may contribute to the development of the illness. Although promising results have been seen in animal models, this approach still meets disparate and often insurmountable problems in clinical settings, presumably related to the unique nature of the human being.