Hydergine for dementia

Finding Drug Repurposing Candidates for Neurodegenerative Diseases using Zebrafish Behavioral Profiles

Drug repurposing can accelerate drug development while reducing the cost and risk of toxicity typically associated with de novo drug design. Several disorders lacking pharmacological solutions and exhibiting poor results in clinical trials - such as Alzheimer's disease (AD) - could benefit from a cost-effective approach to finding new therapeutics. We previously developed a neural network model, Z-LaP Tracker, capable of quantifying behaviors in zebrafish larvae relevant to cognitive function, including activity, reactivity, swimming patterns, and optomotor response in the presence of visual and acoustic stimuli. Using this model, we performed a high-throughput screening of FDA-approved drugs to identify compounds that affect zebrafish larval behavior in a manner consistent with the distinct behavior induced by calcineurin inhibitors. Cyclosporine (CsA) and other calcineurin inhibitors have garnered interest for their potential role in the prevention of AD. We generated behavioral profiles suitable for cluster analysis, through which we identified 64 candidate therapeutics for neurodegenerative disorders.

Mitochondrial Protection and Against Glutamate Neurotoxicity via Shh/Ptch1 Signaling Pathway to Ameliorate Cognitive Dysfunction by Kaixin San in Multi-Infarct Dementia Rats

Multi-infarct dementia (MID), a prominent subtype of vascular dementia (VD), is responsible for at least 15 to 20 percent of dementia in the elderly. Mitochondrial dysfunctions and glutamate neurotoxicity due to chronic hypoperfusion and oxidative stress were regarded as the major risk factors in the pathogenesis. Kaixin San (KXS), a classic prescription of Beiji Qianjin Yaofang, was applied to treatment for "amnesia" and has been demonstrated to alleviate the cognitive deficit in a variety of dementias, including MID. However, little is known whether mitochondria and glutamate are associated with the protection of KXS in MID treatment. The aim of this study was to investigate the role of KXS in improving the cognitive function of MID rats through strengthening mitochondrial functions and antagonizing glutamate neurotoxicity via the Shh/Ptch1 signaling pathway. Our data showed that KXS significantly ameliorated memory impairment and hippocampal neuron damage in MID rats. Moreover, KXS improved hippocampal mitochondrial functions by reducing the degree of mitochondrial swelling, increasing the mitochondrial membrane potential (MMP), and elevating the energy charge (EC) and ATP content in MID rats. As expected, the concentration of glutamate and the expression of p-NMDAR1 were significantly reduced by KXS in the brain tissue of MID rats. Furthermore, our results showed that KXS noticeably activated the Shh/Ptch1 signaling pathway which was demonstrated by remarkable elevations of Ptch1, Smo, and Gli1 protein levels in the brain tissue of MID rats. Intriguingly, the inhibition of the Shh signaling pathway with cyclopamine significantly inhibited the protective effects of KXS on glutamate-induced neurotoxicity in PC12 cells. To sum up, these findings suggested that KXS protected MID rats from memory loss by rescuing mitochondrial functions as well as against glutamate neurotoxicity through activating Shh/Ptch1 signaling pathway.

The FDA-approved natural product dihydroergocristine reduces the production of the Alzheimer's disease amyloid-β peptides

Known γ-secretase inhibitors or modulators display an undesirable pharmacokinetic profile and toxicity and have therefore not been successful in clinical trials for Alzheimer's disease (AD). So far, no compounds from natural products have been identified as direct inhibitors of γ-secretase. To search for bioactive molecules that can reduce the amount of amyloid-beta peptides (Aβ) and that have better pharmacokinetics and an improved safety profile, we completed a screen of ~400 natural products by using cell-based and cell-free γ-secretase activity assays. We identified dihydroergocristine (DHEC), a component of an FDA- (Food and Drug Administration)-approved drug, to be a direct inhibitor of γ-secretase. Micromolar concentrations of DHEC substantially reduced Aβ levels in different cell types, including a cell line derived from an AD patient. Structure-activity relationship studies implied that the key moiety for inhibiting γ-secretase is the cyclized tripeptide moiety of DHEC. A Surface Plasmon Resonance assay showed that DHEC binds directly to γ-secretase and Nicastrin, with equilibrium dissociation constants (Kd) of 25.7 nM and 9.8 μM, respectively. This study offers DHEC not only as a new chemical moiety for selectively modulating the activity of γ-secretase but also a candidate for drug repositioning in Alzheimer's disease.

Clinical Advances in Geriatric Psychiatry: A Focus on Prevention of Mood and Cognitive Disorders

The world population is aging at a rate unprecedented in human history, placing substantial pressure on health systems across the world along with concurrent rises in chronic diseases. In particular, rates of cognitive disorders and late-life affective disorders are expected to increase. In tandem with aging, there are robust predictions suggesting that rates of age-related cognitive decline and dementia, and geriatric depression, will increase, with serious consequences. Clearly innovative prevention and treatment strategies are needed. This article reviews the latest promising clinical advances that hold promise for assisting the prevention and treatment of depression, cognitive decline, and dementia.

Treatment of vascular dementia. Recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology

Scientific Department of Cognitive Neurology and Aging of ABN had a consensus meeting to write recommendations on treatment of vascular dementia, there was no previous issue. This disease has numerous particularities and can be considered a preventable dementia. Prevention treatment is primary care of vascular risk factors or a secondary prevention of factors that could cause recurrence of ischemic or hemorrhagic brain modifications. In these guidelines we suggested only symptomatic treatment, pharmacologic or non-pharmacologic. We have reviewed current publications on MEDLINE (PubMed), LILACS e Cochrane Library databases. Recommendations are concern to the following factors and their prevention evidences, association, or treatment of vascular dementia: physical activity, tobacco use, diet and food supplements, arterial hypertension, diabetes mellitus, obesity, statins, cardiac failure, atrial fibrillation, antithrombotics, sleep apnea, carotid revascularization, symptomatic pharmacological treatment.

Vascular cognitive impairment: disease mechanisms and therapeutic implications

The prevalence of vascular cognitive impairment (VCI) is likely to increase as the population ages and cardiovascular disease survival improves. We provide an overview of the definition and disease mechanisms of VCI and present a systematic literature review of the current evidence for the pharmacologic and nonpharmacologic therapies used to treat the VCI symptoms of cognitive dysfunction or to modify VCI through primary and secondary prevention. The Cochrane Database of Systematic Reviews was searched from 2005 to October 2010 using the keywords "vascular dementia" or "vascular cognitive impairment and therapy." MEDLINE was searched for English-language articles published within the last 10 years using the combined Medical Subject Headings (MeSH) "therapeutics and dementia," "vascular" or "vascular cognitive impairment." Although cholinesterase inhibitors and memantine produce small cognitive improvements in patients with VCI, these drugs do not improve global clinical outcomes and have adverse effects and costs. Selective serotonin reuptake inhibitors and dihydropyridine calcium channel blockers may improve short-term cognitive function in patients with VCI. Anti-hypertensive therapy with an ACE inhibitor-based regimen and statins may prevent the major subtype of VCI known as poststroke cognitive decline. Clinical and effectiveness studies with long-term follow-up are needed to determine the benefits and risks of pharmacologic and nonpharmacologic therapies to prevent and treat VCI. Given its growing health, social, and economic burden, the prevention and treatment of VCI are critical priorities for clinical care and research.

Therapy for Alzheimer's Disease: How Effective are Current Treatments?

Available symptomatic therapies for the treatment of Alzheimer's disease (AD) have been based on known neurotransmitter dysfunctions associated with the illness. The second-generation cholinesterase inhibitors and the N-methyl D-aspartate receptor antagonist memantine have been widely prescribed and studied. Meta-analyses of these therapies were reviewed, focusing on effectiveness and tolerability. Although many of the meta-analyses demonstrate statistically significant improvements, some question if these benefits are sufficient to justify their current widespread and protracted use. This has spurred the development of new disease-modifying therapies that aim to have a greater impact on this debilitating illness.

The prevention and treatment of cognitive decline and dementia: An overview of recent research on experimental treatments

The prevention and treatment of cognitive impairment in the elderly has assumed increasing importance in an aging population. This article presents a qualitative review of recent research on experimental interventions for the prevention and treatment of mild cognitive impairment and Alzheimer's disease in elderly subjects. Interventions addressed range from lifestyle measures to pharmacological treatments. Epidemiological studies suggest that dietary measures, physical exercise, and mental activity may reduce the risk of cognitive impairment and Alzheimer's disease in elderly subjects. Statins may protect against incident dementia, and lithium may convey similar benefits to bipolar patients. Ginkgo appears ineffective as a primary preventive measure. Donepezil but not Vitamin E may benefit persons with mild cognitive impairment. Experimental treatments potentially useful for Alzheimer's disease include dimebon, PBT2 and etanercept; the safety and efficacy of the Alzheimer's vaccine remains to be proven, and growth hormone secretagogue and tarenflurbil are likely ineffective. Herbal treatments merit study in elderly subjects with cognitive syndromes.

A composite screening tool for medication reviews of outpatients: general issues with specific examples

Regular performance of medication reviews is prominent among methods that have been advocated to reduce the extent and seriousness of drug-related problems, such as adverse drug reactions, drug-disease interactions, drug-drug interactions, drug ineffectiveness and cost ineffectiveness. Several screening tools have been developed to guide practising healthcare professionals and researchers in reviewing the medication patterns of elderly patients; however, each of these tools has its own limitations. This review discusses a wide range of general prescription-, treatment- and patient-related issues that should be taken into account when reviewing medication patterns by implicit screening. These include generic and therapeutic substitution; potentially superfluous or inappropriate medications; potentially inappropriate dosages or duration of treatment; drug-disease and drug-drug interactions; under-treatment; making use of laboratory test results; patient adherence, experiences and habits; appropriate dosage forms and packaging. A broad selection of specific examples and references that can be used as a basis for explicit screening of medication patterns in outpatients is also offered.

Prescription patterns and efficacy of drugs for patients with dementia: physicians' perspective in Italy

BACKGROUND AND AIMS

The aim of this study was to assess the prescription practices and judgment of efficacy of physicians of drugs used for the cognitive and non-cognitive symptoms of dementia.

METHODS

Physicians from 88 Italian Alzheimer Evaluation Units were surveyed by means of a structured questionnaire assessing the proportion of patients with four different types of dementia prescribed with drugs for cognitive and non-cognitive symptoms, and physicians' perceived efficacy of cholinesterase inhibitors. The Units prescribed cholinesterase inhibitors for 73 patients per year on average.

RESULTS

Cholinesterase inhibitors are prescribed to 90% of patients with Alzheimer's disease (AD), 80% with with Lewy body dementia (LBD), and 35-45% with vascular dementia (VD) and frontotemporal lobar degeneration (FTLD). Selective serotonin uptake inhibitors (SSRIs) are prescribed for 28-45% of patients with all dementias except LBD (16%). Atypical neuroleptics were prescribed for 23-31% of patients, with no difference across types of dementia. Other drugs, such as ginkgo and nootropics, were prescribed less frequently, except in VD (20%). The perceived efficacy on cognitive and non-cognitive symptoms, assessed on a 0-to-10 ordinal scale, was highest in AD (4.3-6.1), intermediate in LBD (3.5-5.3) and VD (3.3- 4.7), and lowest in FTLD (2.0-2.7).

CONCLUSIONS

The data indicate that, in specialized Italian centers, cholinesterase inhibitors and atypical neuroleptics are largely used in patients with AD and LBD, but the former are prescribed off-label to a remarkable proportion of patients with VD and FTLD. The efficacy of cholinesterase inhibitors is perceived to be highest in AD and poorest in FTLD. Perceived efficacy is affected more by whom is treated than by what is used.

Hypoxia facilitates Alzheimer's disease pathogenesis by up-regulating BACE1 gene expression

The molecular mechanism underlying the pathogenesis of the majority of cases of sporadic Alzheimer's disease (AD) is unknown. A history of stroke was found to be associated with development of some AD cases, especially in the presence of vascular risk factors. Reduced cerebral perfusion is a common vascular component among AD risk factors, and hypoxia is a direct consequence of hypoperfusion. Previously we showed that expression of the beta-site beta-amyloid precursor protein (APP) cleavage enzyme 1 (BACE1) gene BACE1 is tightly controlled at both the transcriptional and translational levels and that increased BACE1 maturation contributes to the AD pathogenesis in Down's syndrome. Here we have identified a functional hypoxia-responsive element in the BACE1 gene promoter. Hypoxia up-regulated beta-secretase cleavage of APP and amyloid-beta protein (Abeta) production by increasing BACE1 gene transcription and expression both in vitro and in vivo. Hypoxia treatment markedly increased Abeta deposition and neuritic plaque formation and potentiated the memory deficit in Swedish mutant APP transgenic mice. Taken together, our results clearly demonstrate that hypoxia can facilitate AD pathogenesis, and they provide a molecular mechanism linking vascular factors to AD. Our study suggests that interventions to improve cerebral perfusion may benefit AD patients.

Drug metabolism and pharmacokinetics, the blood-brain barrier, and central nervous system drug discovery

The worldwide market for therapies for CNS disorders is worth more than 50 billion dollars and is set to grow substantially in the years ahead. This is because: 1) the incidence of many CNS disorders (e.g., Alzheimer's disease, stroke, and Parkinson's disease) increase exponentially after age 65 and 2) the number of people in the world over 65 is about to increase sharply because of a marked rise in fertility after World War II. However, CNS research and development are associated with significant challenges: it takes longer to get a CNS drug to market (12-16 years) compared with a non-CNS drug (10-12 years) and there is a higher attrition rate for CNS drug candidates than for non-CNS drug candidates. This is attributable to a variety of factors, including the complexity of the brain, the liability of CNS drugs to cause CNS side effects, and the requirement of CNS drugs to cross the blood-brain barrier (BBB). This review focuses on BBB penetration, along with pharmacokinetics and drug metabolism, in the process of the discovery and development of safe and effective medicines for CNS disorders.

Hydergine for dementia

BACKGROUND

Currently hydergine is used almost exclusively for treating patients with either dementia, or 'age-related' cognitive symptoms. Since the early eighties there have been over a dozen more clinical trials, yet hydergine's efficacy remains uncertain. Although previous reviews offer generally favorable support for hydergine's efficacy, they were, however, limited by a bias with respect to the particular clinical studies chosen (eg, the inclusion of case reports, and uncontrolled trials), and by authors' impressionistic assessments of results. Not surprisingly, there has been a lack of consensus among reviewers with regard to the efficacy of hydergine. In 1994, a meta-analysis was published by the present reviewers who reported that overall, hydergine was more effective than placebo. However they also observed that the statistical evidence for efficacy in 'possible or probable Alzheimer's disease' patients was so modest that one additional statistically non-significant trial would have reduced the results to non significance.

OBJECTIVES

Because of uncertainty surrounding the efficacy of hydergine, the goals of this overview were to assess its overall effect in patients with possible dementia, and to investigate potential moderators of an effect.

SEARCH STRATEGY

The Cochrane Dementia Group Register of Clinical Trials was searched using the terms 'hydergine', 'ergoloids,' 'ergoloid mesylates,' 'dihydroergocristine,' 'dihydroergocryptine,' 'dihydroergotoxine,' and 'dihydroergocornine. MEDLINE, EMBASE, and two proprietary databases were searched also. Published reviews were inspected for further sources.

SELECTION CRITERIA

Trials to be included must be randomized, double-blind, parallel-group, and unconfounded comparisons of hydergine with placebo for a treatment duration of greater than 1 week in subjects with dementia or symptoms consistent with dementia.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by the reviewers, pooled where appropriate and possible, and the pooled odds ratios (95%CI) or the average differences (95%CI) were estimated. Where possible, intention-to-treat data were used. Outcomes of interest included clinical global impressions of change and comprehensive rating scales. Potential moderating variables of a treatment effect included: inpatient/outpatient status, trial duration, age, sex, medication dose, publication year, and diagnostic grouping.

MAIN RESULTS

There were a total of nineteen trials that met inclusion criteria and that had data sufficient for analysis. Thirteen trials reported sufficient information to use a global rating of improvement and nine trials provided information on a comprehensive rating scale. Three trials provided both outcome measures. It was not possible to use many of the published results in a combined analysis owing to the lack of sufficient data to perform statistical analyses. For the twelve trials that used global ratings, there was a significant effect favoring hydergine (OR 3.78, 95%CI, 2.72-5.27). For the nine trials that used comprehensive ratings, there was a significant mean difference favoring hydergine (WMD 0.96, 95%CI, 0. 54-1.37). Hydergine was well tolerated in these trials, with 78% of randomized subjects available for data analyses. Greater effect sizes on global ratings were associated with younger age, and possibly higher dose, although most of the subgroup analyses were statistically insignificant.

REVIEWER'S CONCLUSIONS

As in an earlier systematic review, we found hydergine to show significant treatment effects when assessed by either global ratings or comprehensive rating scales (based here on a smaller set of trials than in the earlier published systematic review because trials were required to have data that could conform with MetaView, the Cochrane Collaboration statistics software). The small number of trials available for analysis, however, limited the ability of subgroup analyses to identify statistically significant modera