Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.8 (cholinesterase)
12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The treatments of choice in Alzheimer's disease (AD) are cholinesterase inhibitors and NMDA-receptor antagonists, although doubts remain about the therapeutic effectiveness of these drugs. Herbal medicine products have been used in the treatment of Behavioral and Psychological Symptoms of Dementia (BPSD) but with various responses. The objective of this article was to review evidences from controlled studies in order to determine whether herbs can be useful in the treatment of cognitive disorders in the elderly. Randomized controlled studies assessing AD in individuals older than 65 years were identified through searches of MEDLINE, LILACS, Cochrane Library, dissertation Abstract (USA), ADEAR (Alzheimer's Disease Clinical Trials Database), National Research Register, Current Controlled trials, Centerwatch Trials Database and PsychINFO Journal Articles. The search combined the terms Alzheimer disease, dementia, cognition disorders, Herbal, Phytotherapy. The crossover results were evaluated by the Jadad's measurement scale. The systematic review identified two herbs and herbal formulations with therapeutic effects for the treatment of AD: Melissa officinalis, Salvia officinalis and Yi-Gan San and BDW (Ba Wei Di Huang Wan). Ginkgo biloba was identified in a meta-analysis study. All five herbs are useful for cognitive impairment of AD. M. officinalis and Yi-Gan San are also useful in agitation, for they have sedative effects. These herbs and formulations have demonstrated good therapeutic effectiveness but these results need to be compared with those of traditional drugs. Further large multicenter studies should be conducted in order to test the cost-effectiveness of these herbs for AD and the impact in the control of cognitive deterioration.
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PMID:The use of herbal medicine in Alzheimer's disease-a systematic review. 1717 7

Presenilin-1 (PS1) mutations cause many cases of early-onset inherited Alzheimer's disease, in part, by increasing the production of neurotoxic forms of amyloid beta-peptide (Abeta). However, Abeta-independent effects of mutant PS1 on neuronal Ca(2+) homeostasis and sensitivity to excitatory neurotransmitters have been reported. Here we show that cholinergic modulation of hippocampal synaptic plasticity is impaired in PS1 mutant knockin (PS1KI) mice. Whereas activation of muscarinic receptors enhances LTP at CA1 synapses of normal mice, it impairs LTP in PS1KI mice. Similarly, mutant PS1 impairs the ability of the cholinesterase inhibitor phenserine to enhance LTP. The NMDA current is decreased in CA1 neurons of PS1KI mice and is restored by intracellular Ca(2+)chelation. Similar alterations in acetylcholine and NMDA receptor-mediated components of synaptic plasticity are evident in 3xTgAD mice with PS1, amyloid precursor protein and tau mutations, suggesting that the adverse effects of mutant PS1 on synaptic plasticity can occur in the absence or presence of amyloid and tau pathologies.
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PMID:Presenilin-1 mutation impairs cholinergic modulation of synaptic plasticity and suppresses NMDA currents in hippocampus slices. 1806 71

Due to the heterogeneous course of illness in individual cases, efficacy or "treatment-response" can not be measured in single patients; therefore a clinical distinction between response and non-response is not meaningful. Constructs which are valid for research projects become misnomers in clinical practice. To date there are two groups of antidementia drugs, memantine--an NMDA-receptor modulator licensed for the moderate to severe stages--and the cholinesterase inhibitors donepezil, galantamine, and rivastigmine, licensed for mild to moderate stages of Alzheimer's disease. These substances exert a moderate symptomatic effect on cognition and activities of daily living or clinical global impression, which corresponds to a parallel shift of the natural course of dementia. A low number of contraindications and few serious adverse events are the advantages of memantine. The extensive evidence for their efficacy and safety are the advantages of cholinesterase inhibitors. Symptoms of "cholinopathy" (a severe lack of acetylcholine) predict a favorable treatment response to cholinesterase inhibitors in groups of demented patients with attention deficit disorders, fluctuating course of illness, visual hallucinations, and superimposed states of confusion.
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PMID:[Antidementia drugs--response or non-response?]. 1848 Oct 40

More than 50% of people with dementia experience behavioral and psychological symptoms of dementia (BPSD). BPSD are distressing for patients and their caregivers, and are often the reason for placement into residential care. The development of BPSD is associated with a more rapid rate of cognitive decline, greater impairment in activities of daily living, and diminished quality of life (QOL). Evaluation of BPSD includes a thorough diagnostic investigation, consideration of the etiology of the dementia, and the exclusion of other causes, such as drug-induced delirium, pain, or infection. Care of patients with BPSD involves psychosocial treatments for both the patient and family. BPSD may respond to those environmental and psychosocial interventions, however, drug therapy is often required for more severe presentations. There are multiple classes of drugs used for BPSD, including antipsychotics, anticonvulsants, antidepressants, anxiolytics, cholinesterase inhibitors and NMDA modulators, but the evidence base for pharmacological management is poor, there is no clear standard of care, and treatment is often based on local pharmacotherapy customs. Clinicians should discuss the potential risks and benefits of treatment with patients and their surrogate decision makers, and must ensure a balance between side effects and tolerability compared with clinical benefit and QOL.
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PMID:Management of the behavioral and psychological symptoms of dementia. 1822 62

Amyloid precursor protein (APP) is overexpressed in the developing brain and portions of its extracellular domain, especially amino acid residues 96-110, play an important role in neurite outgrowth and neural cell differentiation. In the current study, we evaluated the developmental abnormalities caused by administration of exogenous APP(96-110) in sea urchin embryos and larvae, which, like the developing mammalian brain, utilize acetylcholine and other neurotransmitters as morphogens; effects were compared to those of beta-amyloid 1-42 (Abeta42), the neurotoxic APP fragment contained within neurodegenerative plaques in Alzheimer's Disease. Although both peptides elicited dysmorphogenesis, Abeta42 was far more potent; in addition, whereas Abeta42 produced abnormalities at developmental stages ranging from early cleavage divisions to the late pluteus, APP(96-110) effects were restricted to the intermediate, mid-blastula stage. For both agents, anomalies were prevented or reduced by addition of lipid-permeable analogs of acetylcholine, serotonin or cannabinoids; physostigmine, a carbamate-derived cholinesterase inhibitor, was also effective. In contrast, agents that act on NMDA receptors (memantine) or alpha-adrenergic receptors (nicergoline), and that are therapeutic in Alzheimer's Disease, were themselves embryotoxic, as was tacrine, a cholinesterase inhibitor from a different chemical class than physostigmine. Protection was also provided by agents acting downstream from receptor-mediated events: increasing cyclic AMP with caffeine or isobutylmethylxanthine, or administering the antioxidant, a-tocopherol, were all partially effective. Our findings reinforce a role for APP in development and point to specific interactions with neurotransmitter systems that act as morphogens in developing sea urchins as well as in the mammalian brain.
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PMID:Amyloid precursor protein 96-110 and beta-amyloid 1-42 elicit developmental anomalies in sea urchin embryos and larvae that are alleviated by neurotransmitter analogs for acetylcholine, serotonin and cannabinoids. 1856 28

While Alzheimer's disease (AD) represents a major healthcare challenge, with 25 to 34 million individuals currently affected worldwide and triple this number of patients projected by 2050, the drugs currently approved for the palliative treatment of AD, the cholinesterase inhibitors and the NMDA antagonist memantine, have demonstrated questionable efficacy, highlighting an urgent need for new therapies. Efforts in targeting the removal of amyloid plaques from the brain of patients with AD have been disappointing, with neither plaque-removing vaccines nor the gamma-secretase modulator, tarenflurbil demonstrating clinical benefit, thus questioning the validity of the amyloid cascade hypothesis that has driven AD research for the past decade. The lack of progress in mechanistic approaches (the amyloid and tau hypotheses) to developing new AD drugs indicates that some of the basic assumptions of AD causality and the search for effective drugs are probably in need of major reassessment and redirection.
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PMID:Progress in Alzheimer's disease drug discovery: an update. 1912 84

Alzheimer's disease is a neurodegenerative disease characterized by senile plaques, neurofibrillary tangles, synaptic loss, neuronal death and cholinergic deficits, causing cognitive, behavioral and psychological deficits, as well as a functional impairment that results in serious caregiver distress and a great economic burden worldwide. High hopes rose with the development of symptomatic treatments,resulting from randomized controlled trials using cholinergic enhancers or cholinesterase inhibitors, such as donepezil, galantamine and rivastigmine. When memantine, an NMDA antagonist,was approved and the first phase III antiamyloid immunization was launched, many clinicians eagerly anticipated the first disease-modifying drugs in their daily practice. For the treatment of behavioral and psychological symptoms of dementia (BPSD), atypical antipsychotics and new-generation antidepressants also seemed to offer great promises, mainly because of their good tolerance and side effect profiles. Hopes, however, were followed by desillusions: subsequent studies demonstrated that cholinesterase inhibitors and memantine had only modest and short-lived effects on cognition and BPSD, and the effect of antipsychotics on BPSD appeared questionable. Disease-modifying drugs such as antiamyloid immunization or amyloid clearance medication had to be abandoned for safety reasons or absence of efficacy. Although the early treatment of vascular risk factors is increasingly recognized in Alzheimer's disease prevention because of their implication in the amyloid cascade, randomized controlled trials have yielded largely negative results. Therefore,pharmacological as well as fundamental research that better underpins the complex pathophysiology of this devastating disease constitutes one of the biggest challenges of the 21st century.
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PMID:Pharmacological interventions in primary care: hopes and illusions. 1918 63

Object location task (OLT) has been used as a model of hippocampal-dependent memory. Despite this application, there is neither a consistent pharmacological validation of NMDA receptor modulation nor an evaluation of hippocampal participation in mice. In the OLT, mice were placed in the open field with two identical objects for 3 min and, after a delay of 30, 90, 180 or 360 min, one object was moved to a new location and the time spent exploring the objects in new, (novel) and old (familiar) locations was recorded. Our results showed that the mice were able to discriminate object location when tested either 90 or 180 min after training. Intraperitoneal administration of MK801 (NMDA receptors antagonist) or scopolamine (mACh antagonist) induced amnesic effects. On the other hand, D-cycloserine (NMDA agonist) or tacrine (cholinesterase inhibitor) were able to improve memory in the mice tested. In addition, lidocaine infusion in the hippocampal CA1 region 10 min before training blocked object location memory. In short, this work indicates that OLT is susceptible to modulation of NMDA receptors, cholinergic neurotransmission and it is the first to characterize the participation of the hippocampal CA1 region, in this task.
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PMID:Object location memory in mice: pharmacological validation and further evidence of hippocampal CA1 participation. 1952 94

Okadaic acid (OKA) is a potent and selective inhibitor of protein phosphatases, PP2A and PP1. In the present study, we evaluated effect of intracerebroventricular (ICV) bilateral injection of OKA (100 and 200 ng) on memory function and oxidative stress in rats. ICV injection of OKA (200 ng) produced memory impairment as evidenced by no significant decrease in latency time to reach the hidden platform in water maze test. It produced increase in malondialdehyde (MDA), nitrite level, reactive oxygen species (ROS) generation, mitochondrial calcium ion [Ca(2)](i) level and decreased glutathione (GSH) level in rat brain areas, indicating oxidative stress. Furthermore, we evaluated the effect of anti-dementia drugs memantine, a NMDA antagonist, and donepezil, a cholinesterase inhibitor, on OKA ICV induced memory impairment. Administration of memantine (10 mg/kg, p.o.) and donepezil (5 mg/kg, p.o.) for 13 days starting from the OKA injection improved performance in memory tests and also significantly restored GSH, MDA, nitrite levels, ROS generation and [Ca(2+)](i) level. This study demonstrates that the clinically used anti-dementic drugs are effective in OKA induced free radical generation and memory impairment in rats. Thus, OKA ICV induced memory impairment in rat appeared as a useful test model to screen anti-dementia drugs.
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PMID:Okadaic acid (ICV) induced memory impairment in rats: a suitable experimental model to test anti-dementia activity. 1988 32

The public health burden of Alzheimer disease (AD), the most common neurodegenerative disease, threatens to explode in the middle of this century. Current FDA-approved AD treatments (e.g. cholinesterase inhibitors, NMDA-receptor agonists) do not provide a "cure", but rather a transient alleviation of symptoms for some individuals. Other available therapies are few and of limited effectiveness so additional avenues are needed. Sphingolipid metabolism is a dynamic process that modulates the formation of a number of bioactive metabolites, or second messengers critical in cellular signaling and apoptosis. In brain, the proper balance of sphingolipids is essential for normal neuronal function, as evidenced by a number of severe brain disorders that are the result of deficiencies in enzymes that control sphingolipid metabolism. Laboratory and animals studies suggest both direct and indirect mechanisms by which sphingolipids contribute to amyloid-beta production and Alzheimer pathogenesis but few studies have translated these findings to humans. Building on the laboratory and animal evidence demonstrating the importance of sphingolipid metabolism in AD, this review highlights relevant translational research incorporating and expanding basic findings to humans. A brief biological overview of sphingolipids (sphingomyelins, ceramides, and sulfatides) in AD is first described, followed by a review of human studies including post-mortem studies, clinical and epidemiological studies. Lastly, the potential role of peripheral ceramides in AD pathogenesis is discussed, as well as the possible use of sphingolipids as biomarkers for AD.
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PMID:Alterations of the sphingolipid pathway in Alzheimer's disease: new biomarkers and treatment targets? 2057 35


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