Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The causative relationship between levodopa and the long-term motor complications of therapy, along with the possibility that levodopa may be toxic to dopaminergic neurones in vivo, has led to a move away from its use in early Parkinson's disease. Alternatives such as amantadine and the anticholinergics suffer from poor efficacy in comparison and a high side effect profile. Selegiline is probably less effective than levodopa and the issue of its safety versus neuroprotective properties remains unresolved. Long-term trials with the old and newer dopamine agonists as monotherapy have shown that as a class they can delay the development of dyskinesia and probably response fluctuations. However, major uncertainties remain about their use as monotherapy in all patients instead of levodopa. No data on their effect on quality of life and health care costs are available. Most of the trials were heavily biased towards younger patients with Parkinson's disease, so little data in the elderly are available. In later disease when patients have already developed motor complications on levodopa, the choice rests between adjuvant therapy with a dopamine agonist, a catechol-O-methyltransferase inhibitor (COMT; e.g. entacapone), and a monoamine oxidase B inhibitor (MAO B; e.g. selegiline). Trials with the former two classes have confirmed that they can reduce 'off' time, reduce levodopa dose, and improve motor impairments and disabilities with acceptable increases in adverse events including dyskinesia. Trials with selegiline as adjuvant therapy were less rigorous but it can allow a reduction in levodopa dose and motor impairments. No studies have compared these three classes of drug as adjuvant therapy so there is no evidence on which to base rational decisions in this type of patient. A large pragmatic trial which includes older patients is needed to clarify which treatment is best for different stages of the disease.
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PMID:Uncertainties in the pharmacotherapy of Parkinson's disease and how to solve them. 1184 27

Factors underlying pathogenesis of diseases are currently being searched. In recent years increasing number of reports on genetic background of central nervous system diseases have appeared. In the search of factors that can precipitate degeneration of dopaminergic neurons the role of enzymes catabolising xenobiotics (CYP2D6, NAT2) and enzymes metabolising catecholamines (COMT, MAO B) has been postulated. Polymorphism of genes coding for isotypes characterised by different biological activity could be responsible for the propensity for Parkinson's disease, progression and efficacy of pharmacotherapy of the disease.
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PMID:[Role of gene polymorphism of catechol-O-methyltransferase (COMT), monoamine oxidase B (MAOB), cytochrome P450 2D6 (CYP2D6) and N-acetyltransferase 2 (NAT2) in pathogenesis of Parkinson's disease]. 1205 3

Cigarette smoking is associated with reduced monoamine oxidase B (MAO B) activity. Polymorphisms of the MAO B gene may modify the relationship between smoking and Parkinson's Disease (PD). We examined the association of MAO B intron 13 G/A polymorphism and risk of PD, and the modulation of the polymorphism on smoking and PD in an Asian study population in Singapore. Two hundred and thirty PD patients (mean age 66.0 +/- 9.4 years, 63% men) and 241 age, gender, and race matched controls (mean age 64 +/- 9.2 years, 58.9% males) were studied. The frequency of G and A alleles in PD and controls was; 66/315 (21.0%) vs. 73/340 (21.5%) and 249/315 (79.0%) vs. 267/340 (78.5%). For women, the genotype frequency in PD and controls was; GG: 7/85 (8.2%) vs. 8/99 (8.1%); GA: 25/85 (29.4%) vs. 27/99 (27.3%); AA: 53/85 (62.4%) vs. 64/99 (64.6%). For men, allele frequency in PD and controls was; A: 118/145 (81.4%) vs. 112/142 (78.9%) and G: 27/145 (18.6%) vs. 30/142 (21.1%). The allele and genotype frequencies were not significantly different between young and late onset PD. The frequency of "ever" smokers in PD and controls was 31/230 (13.5%) vs. 52/241 (21.6%), P = 0.02. A stepwise logistic regression analysis did not reveal any interaction of smoking and the G allele and risk of PD. The MAO B G/A genotype frequency in our Asian population was quite different from Caucasians suggesting that ethnicity specific effects need to be considered in evaluating gene-environmental interaction.
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PMID:Monoamine oxidase B polymorphism, cigarette smoking and risk of Parkinson's disease: a study in an Asian population. 1281 41

Dopamine deficiency is characteristic of Parkinson's disease (PD) and treatments aim at elevating levels by administration of its precursor L-dihydroxyphenylalanine (L-DOPA), or inhibiting monoamine oxidases (MAOs), thus preventing its breakdown. Reports of improvements in PD patients treated with Banisteriopsis caapi extracts stimulated investigation of B. caapi stem extract and its two ingredients, harmine and harmaline for these activities. Tests for MAO inhibition using liver homogenate showed that extract and harmaline showed a concentration-dependent inhibition of MAO A (IC(50) 1.24 microg/ml and IC(50) 4.54 nM, respectively) but had little effect on MAO B activity. The extract at 2.5 mg/ml caused a highly significant increase in release of [3H]dopamine from rat striatal slices, as did 200 microM harmine and 6 microM harmaline. In both these experiments, the amount of harmine present could not account for the total activity of the extract. The ability of harmine and harmaline to stimulate dopamine release is a novel finding. These results give some basis to the reputed usefulness of B. caapi stem extract in the treatment of PD.
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PMID:Activities of extract and constituents of Banisteriopsis caapi relevant to parkinsonism. 1289 80

The effect of He-Ne laser radiation on activity of MAO B, Cu/Zn-SOD, Mn-SOD, and catalase in blood cells from patients with Parkinson's disease was studied in vivo and in vitro. The effects of intravenous in vivo irradiation (intravenous laser therapy) were more pronounced than those observed in similar in vitro experiments. It is concluded that generalized effect of laser therapy involves interaction between blood cells.
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PMID:Laser modification of the blood in vitro and in vivo in patients with Parkinson's disease. 1291 Feb 78

The principal therapeutic agents used in the management of Parkinson's disease (PD) enhance nigrostriatal dopaminergic flux through either replenishment of depleted dopamine stores or the action of dopaminergic agonists. Adenosine A2A receptor antagonists (e.g., KW-6002) may provide symptomatic relief in PD and perhaps also may display neuroprotective properties based on studies in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of nigrostriatal neurodegeneration. A second class of compounds that is neuroprotective in the MPTP model comprises inhibitors of the outer mitochondrial flavoenzyme monoamine oxidase B (MAO B), one of the two forms of MAO that regulate levels of brain neurotransmitter substances, including dopamine. In this article, data are presented that document the overlapping A2A antagonist and MAO B inhibitory properties of several 2-styrylxanthinyl derivatives. A limited structure-activity analysis of these compounds and structurally related analogs is provided. The results raise the possibility that a single structure may offer the combined benefits of two pharmacologic strategies, each with symptomatic and potential neuroprotective benefits, for the management of PD.
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PMID:Monoamine oxidase B inhibition and neuroprotection: studies on selective adenosine A2A receptor antagonists. 1466 13

The influence of laser therapy on the course of Parkinson's disease (PD) was studied in 70 patients. This influence appeared adaptogenic both in the group with elevated and low MAO B and Cu/Zn SOD activity. Laser therapy resulted in reduction of neurological deficit, normalization of the activity of MAO B, Cu/Zn-SOD and immune indices. There was a correlation between humoral immunity and activity of the antioxidant enzymes (SOD, catalase). This justifies pathogenetically the use of laser therapy in PD.
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PMID:[Biochemical and immunological induces of the blood in Parkinson's disease and their correction with the help of laser therapy]. 1505 71

Interest in inhibitors of monoamine oxidase type B (MAO B) has grown in recent years, due to their therapeutic potential in aging-related neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. This study is devoted to the use of human recombinant MAO B obtained from a Baculovirus expression system (Supersomes MAO B, BD Gentest, MA, USA) as reliable and efficient enzyme source for MAO B inhibitor screening. Comparison of inhibition potencies (pIC50 values) determined with human cloned and human platelet MAO B for the two series of MAO B inhibitors, coumarin and 5H-indeno[1,2-c]pyridazin-5-one derivatives, showed that the difference between pIC50 values obtained with the two enzyme sources was not significant (P>0.05, Student's t-test). Hence, recombinant enzyme is validated as convenient enzyme source for MAO B inhibitor screening.
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PMID:Human recombinant monoamine oxidase B as reliable and efficient enzyme source for inhibitor screening. 1605 69

Monoamine oxidase (MAO) is a mitochondrial outer-membrane flavoenzyme involved in brain and peripheral oxidative catabolism of neurotransmitters and xenobiotic amines, including neurotoxic amines, and a well-known target for antidepressant and neuroprotective drugs. Recent epidemiological studies have consistently shown that coffee drinkers have an apparently lower incidence of Parkinson's disease (PD), suggesting that coffee might somehow act as a purported neuroprotectant. In this paper, "ready to drink" coffee brews exhibited inhibitory properties on recombinant human MAO A and B isozymes catalyzing the oxidative deamination of kynuramine, suggesting that coffee contains compounds acting as MAO inhibitors. MAO inhibition was reversible and competitive for MAO A and MAO B. Subsequently, the pyrido-indole (beta-carboline) alkaloids, norharman and harman, were identified and isolated from MAO-inhibiting coffee, and were good inhibitors on MAO A (harman and norharman) and MAO B (norharman) isozymes. beta-carbolines isolated from ready-to-drink coffee were competitive and reversible inhibitors and appeared up to 210 microg/L, confirming that coffee is the most important exogenous source of these alkaloids in addition to cigarette smoking. Inhibition of MAO enzymes by coffee and the presence of MAO inhibitors that are also neuroactive, such as beta-carbolines and eventually others, might play a role in the neuroactive actions including a purported neuroprotection associated with coffee consumption.
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PMID:Human monoamine oxidase enzyme inhibition by coffee and beta-carbolines norharman and harman isolated from coffee. 1613 9

Monoamine oxidases A and B (MAO A and MAO B) are the major enzymes that catalyze the oxidative deamination of monoamine neurotaransmitters such as dopamine (DA), noradrenaline, and serotonin in the central and peripheral nervous systems. MAO B is mainly localized in glial cells. MAO B also oxidizes the xenobiotic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to a parkinsonism-producing neurotoxin, 1-methyl-4-phenyl-pyridinium (MPP+). MAO B may be closely related to the pathogenesis of Parkinson's disease (PD), in which neuromelanin-containing DA neurons in the substantia nigra projecting to the striatum in the brain selectively degenerate. MAO B degrades the neurotransmitter DA that is deficient in the nigro-striatal region in PD, and forms H2O2 and toxic aldehyde metabolites of DA. H2O2 produces highly toxic reactive oxygen species (ROS) by Fenton reaction that is catalyzed by iron and neuromelanin. MAO B inhibitors such as L-(-)-deprenyl (selegiline) and rasagiline are effective for the treatment of PD. Concerning the mechanism of the clinical efficacy of MAO B inhibitors in PD, the inhibition of DA degradation (a symptomatic effect) and also the prevention of the formation of neurotoxic DA metabolites, i.e., ROS and dopamine derived aldehydes have been speculated. As another mechanism of clinical efficacy, MAO B inhibitors such as selegiline are speculated to have neuroprotective effects to prevent progress of PD. The possible mechanism of neuroprotection of MAO B inhibitors may be related not only to MAO B inhibition but also to induction and activation of multiple factors for anti-oxidative stress and anti-apoptosis: i.e., catalase, superoxide dismutase 1 and 2, thioredoxin, Bcl-2, the cellular poly(ADP-ribosyl)ation, and binding to glyceraldehydes-3-phosphate dehydrogenase (GAPDH). Furthermore, it should be noted that selegiline increases production of neurotrophins such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and glial cell line-derived neurotrphic factor (GDNF), possibly from glial cells, to protect neurons from inflammatory process.
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PMID:Molecular mechanism of the relation of monoamine oxidase B and its inhibitors to Parkinson's disease: possible implications of glial cells. 1744 16


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