ubiquinone and Parkinson-Disease

Parkinson's disease (PD) occurs in approximately 1% of the population over 65 years of age and has become increasingly more common with advances in age. The number of individuals older than 60 years has been increasing in modern societies, as well as life expectancy in developing countries; therefore, PD may pose an impact on the economic, social, and health structures of these countries. Oxidative stress is highlighted as an important factor in the genesis of PD, involving several enzymes and signaling molecules in the underlying mechanisms of the disease. This review presents updated data on the involvement of oxidative stress in the disease, as well as the use of antioxidant supplements in its therapy.

Topics: Animals; Antioxidants; Humans; Oxidative Stress; Parkinson Disease; Phenols; Reactive Oxygen Species; Superoxide Dismutase; Terpenes; Ubiquinone

The objective of this meta-analysis was to evaluate the effects of coenzyme Q10 (CoQ10) for the treatment of Parkinson's disease (PD) patients in order to arrive at qualitative and quantitative conclusions about the efficacy of CoQ10. Databases searched included PubMed, Google scholar, CNKI, Wan-Fang, and the Cochrane Library from inception to March 2016. We only included sham-controlled, randomized clinical trials of CoQ10 intervention for motor dysfunction in patients with PD. Relevant measures were extracted independently by two investigators. Weighted mean differences (WMD) were calculated with random-effects models. Eight studies with a total of 899 patients were included. Random-effects analysis revealed a pooled WMD of 1.02, indicating no significant difference when CoQ10 treatment compared with placebo in terms of UPDRS part 3 (p = 0.54). Meanwhile, the effect size of UPDRS part 1, UPDRS part 2, and total UPDRS scores were similar in CoQ10 group with in placebo group (p > 0.05). Moreover, we found CoQ10 was well tolerated compared with placebo group. Subgroup analysis showed that the effect size of CoQ10 in monocentric studies was larger than in multicenter studies. Using the GRADE criteria, we characterized the quality of evidence presented in this meta-analysis as moderate to high level. The current meta-analysis provided evidence that CoQ10 was safe and well tolerated in participants with PD and no superior to placebo in terms of motor symptoms. According to these results, we cannot recommend CoQ10 for the routine treatment of PD right now.

Topics: Humans; Neuroprotective Agents; Outcome Assessment, Health Care; Parkinson Disease; Randomized Controlled Trials as Topic; Ubiquinone

Coenzyme Q10 (CoQ10) is a component of electron transport chain and acts as an antioxidant. It is also used for preventing neurodegeneration against mitochondrial deficiency and oxidative stress. Therefore, CoQ10 has received increasing attention as therapeutic and preventive intervention for neurodegenerative diseases. This review article focuses mainly on the structure of CoQ10, the function of CoQ10 and the relationship between mitochondrial impairment, oxidative stress and neurodegenerative diseases. In addition, the effects of CoQ10 on Alzheimer's disease, Parkinson's disease, and Huntington's disease are also discussed. Finally, future perspectives regarding development of successful treatment for neurodegenerative diseases are proposed.

Topics: Alzheimer Disease; Humans; Huntington Disease; Neurodegenerative Diseases; Neuroprotection; Neuroprotective Agents; Oxidative Stress; Parkinson Disease; Ubiquinone

Coenzyme Q10 (CoQ10) is an antioxidant that enhances the activity of complex I and II in the Electron Transport Chain. Many preclinical and clinical studies evaluated CoQ10 for neuroprotection against Parkinson's disease (PD). The aim of this study is to synthesize evidence from published randomized controlled trials (RCTs) about the benefit of CoQ10 supplementation for patients with Parkinson's disease.. We followed the PRISMA statement guidelines during the preparation of this systematic review and metaanalysis. A computer literature search for (PubMed, EBSCO, Web of science and Ovid Midline) was carried out. We included RCTs comparing CoQ10 with placebo in terms of motor functions and quality of life. Outcomes of total Unified Parkinson's Disease Rating Scale (UPDRS), UPDRS I, UPDRS II, UPDRS III and Schwab and England scores were pooled as standardized mean difference (SMD) between two groups from baseline to the endpoint.. Five RCTs (981 patients) were included in this study. The overall effect did not favor either of the two groups in terms of: total UPDRS score (SMD -0.05, 95%CI [-0.10, 0.15]), UPDRS I (SMD -0.03, 95% CI [-0.23, 0.17]), UPDRS II (SMD -0.10, 95%CI [-0.35, 0.15]), UPDRS III (SMD -0.05, 95%CI [-0.07, 0.17]) or Schwab and England score (SMD 0.08, 95%CI [-0.13, 0.29]).. CoQ10 supplementation does not slow functional decline nor provide any symptomatic benefit for patients with Parkinson's disease.

Topics: Antioxidants; Clinical Trials as Topic; Humans; Oxidative Stress; Parkinson Disease; Treatment Outcome; Ubiquinone

The aging risk factor for Parkinson's disease is described in terms of specific disease markers including mitochondrial and gene dysfunctions relevant to energy metabolism. This review details evidence for the ability of nutritional agents to manage these aging risk factors. The combination of alpha lipoic acid, acetyl-l-carnitine, coenzyme Q10, and melatonin supports energy metabolism via carbohydrate and fatty acid utilization, assists electron transport and adenosine triphosphate synthesis, counters oxidative and nitrosative stress, and raises defenses against protein misfolding, inflammatory stimuli, iron, and other endogenous or xenobiotic toxins. These effects are supported by gene expression via the antioxidant response element (ARE; Keap/Nrf2 pathway), and by peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1 alpha), a transcription coactivator, which regulates gene expression for energy metabolism and mitochondrial biogenesis, and maintains the structural integrity of mitochondria. The effectiveness and synergies of the combination against disease risks are discussed in relation to gene action, dopamine cell loss, and the accumulation and spread of pathology via misfolded alpha-synuclein. In addition there are potential synergies to support a neurorestorative role via glial derived neurotrophic factor expression.

Topics: Acetylcarnitine; Adenosine Triphosphate; Aging; alpha-Synuclein; Antioxidant Response Elements; Carbohydrate Metabolism; Electron Transport; Energy Metabolism; Fatty Acids; Glial Cell Line-Derived Neurotrophic Factor; Humans; Inflammation; Melatonin; Mitochondria; Nitric Oxide; Oxidative Stress; Parkinson Disease; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Proteostasis Deficiencies; Risk Factors; Thioctic Acid; Transcription Factors; Ubiquinone

A number of preclinical studies in both in vitro and in vivo models of Parkinson's disease have demonstrated that coenzyme Q10 can protect the nigrostriatal dopaminergic system. Some clinical trials have looked at the neuroprotective effects of coenzyme Q10 in patients with early and midstage Parkinson's disease.. To assess the evidence from randomized controlled trials on the efficacy and safety of treatment with coenzyme Q10 compared to placebo in patients with early and midstage Parkinson's disease.. We searched the Cochrane Movment Disorders Group Trials Register, CENTRAL (The Cochrane Library 2009, Issue 4), MEDLINE (January 1966 to March 2011), and EMBASE (January 1985 to March 2011). We handsearched the references quoted in the identified trials, congress reports from the most important neurological association and movement disorder societies in Europe and America (March 2011), checked reference lists of relevant studies and contacted other researchers.. We included randomized controlled trials (RCTs) that compared coenzyme Q10 to placebo for patients who suffered early and midstage primary Parkinson's disease. Studies in which the method of randomization or concealment were unknown were included. Cross-over studies were excluded.. Two review authors independently assessed trial quality and extracted data. All disagreements were resolved by consensus between authors and were explained. We attempted to contact the authors of studies for further details if any data were missing and to establish the characteristics of unpublished trials through correspondence with the trial coordinator or principal investigator. Adverse effects information was collected from the trials.. Four randomized, double-blind, placebo-controlled trials with a total of 452 patients met the inclusion criteria and were included in the review. In overall, there were improvements in activities of daily living (ADL) UPDRS (WMD -3.12, 95% CI -5.88 to -0.36) and Schwab and England (WMD 4.43, 95% CI 0.05 to 8.81) for coenzyme Q10 at 1200 mg/d for 16 months versus placebo.In safety outcomes, only the risk ratios (RR) of pharyngitis (RR 1.04, 95% CI 0.18 to 5.89) and diarrhea (RR 1.39, 95% CI 0.62 to 3.16) are mild elevated between coenzyme Q10 therapy and placebo and there were no differences in the number of withdrawals due to adverse effects (RR 0.61, 95% CI 0.23 to 1.62).. Coenzyme Q10 therapy with 1200 mg/d for 16 months was well tolerated by patients with Parkinson's disease. The improvements in ADL UPDRS and Schwab and England were positive, but it need to be further confirmed by larger sample. For total and other subscores of UPDRS, the effects of coenzyme Q10 seemed to be less clear.

Topics: Activities of Daily Living; Diarrhea; Humans; Neuroprotective Agents; Parkinson Disease; Pharyngitis; Randomized Controlled Trials as Topic; Ubiquinone; Vitamins

Parkinson's disease (PD) is a neurodegenerative movement disorder characterized by the degeneration and progressive loss of dopaminergic neurons in the substantia nigra pars compacta. It has been suggested that oxidative stress plays a role in the etiology and progression of PD. For instance, low levels of endogenous antioxidants, increased reactive species, augmented dopamine oxidation, and high iron levels have been found in brains from PD patients. In vitro and in vivo studies of Parkinson models evaluating natural and endogenous antioxidants such as polyphenols, coenzyme Q10, and vitamins A, C, and E have shown protective effects against oxidative-induced neuronal death. In this paper, we will review the mechanisms by which polyphenols and endogenous antioxidants can produce protection. Some of the mechanisms reviewed include: scavenging nitrogen and oxygen reactive species, regulation of signaling pathways associated with cell survival and inflammation, and inhibition of synphilin-1 and alpha-synuclein aggregation.

Topics: alpha-Synuclein; Animals; Antioxidants; Ascorbic Acid; Carrier Proteins; Cell Death; Dopamine; Dopaminergic Neurons; Humans; Inflammation; Nerve Tissue Proteins; Oxidation-Reduction; Oxidative Stress; Parkinson Disease; Polyphenols; Reactive Oxygen Species; Signal Transduction; Substantia Nigra; Ubiquinone; Vitamin A; Vitamin E

A number of preclinical studies in both in vitro and in vivo models of Parkinson's disease have demonstrated that coenzyme Q10 can protect the nigrostriatal dopaminergic system. Some clinical trials have looked at the neuroprotective effects of coenzyme Q10 in patients with early and midstage Parkinson's disease.. To assess the evidence from randomized controlled trials on the efficacy and safety of treatment with coenzyme Q10 compared to placebo in patients with early and midstage Parkinson's disease.. We searched the Cochrane Movment Disorders Group Trials Register, CENTRAL (The Cochrane Library 2009, Issue 4), MEDLINE (January 1966 to March 2011), and EMBASE (January 1985 to March 2011). We handsearched the references quoted in the identified trials, congress reports from the most important neurological association and movement disorder societies in Europe and America (March 2011), checked reference lists of relevant studies and contacted other researchers.. We included randomized controlled trials (RCTs) that compared coenzyme Q10 to placebo for patients who suffered early and midstage primary Parkinson's disease. Studies in which the method of randomization or concealment were unknown were included. Cross-over studies were excluded.. Two review authors independently assessed trial quality and extracted data. All disagreements were resolved by consensus between authors and were explained. We attempted to contact the authors of studies for further details if any data were missing and to establish the characteristics of unpublished trials through correspondence with the trial coordinator or principal investigator. Adverse effects information was collected from the trials.. Four randomized, double-blind, placebo-controlled trials with a total of 452 patients met the inclusion criteria and were included in the review. In overall, there were improvements in activities of daily living (ADL) UPDRS (WMD -3.12, 95% CI -5.88 to -0.36) and Schwab and England (WMD 4.43, 95% CI 0.05 to 8.81) for coenzyme Q10 at 1200 mg/d for 16 months versus placebo.In safety outcomes, only the risk ratios (RR) of pharyngitis (RR 1.04, 95% CI 0.18 to 5.89) and diarrhea (RR 1.39, 95% CI 0.62 to 3.16) are mild elevated between coenzyme Q10 therapy and placebo and there were no differences in the number of withdrawals due to adverse effects (RR 0.61, 95% CI 0.23 to 1.62).. Coenzyme Q10 therapy with 1200 mg/d for 16 months was well tolerated by patients with Parkinson's disease. The improvements in ADL UPDRS and Schwab and England were positive, but it need to be further confirmed by larger sample. For total and other subscores of UPDRS, the effects of coenzyme Q10 seemed to be less clear.

Topics: Activities of Daily Living; Diarrhea; Humans; Neuroprotective Agents; Parkinson Disease; Pharyngitis; Randomized Controlled Trials as Topic; Ubiquinone; Vitamins

Early treatment of Parkinson's disease (PD) affords an opportunity to forestall clinical progression. Levodopa is the most effective treatment for PD motor signs and symptoms, but its use is associated with the development of motor fluctuations and dyskinesias. Because of this, levodopa use is commonly withheld until the patient experiences functional disability. Other medications are available for the treatment of early PD and can be initiated at or near the time of diagnosis. Monoamine oxidase type B (MAO-B) inhibitors provide mild symptomatic benefit, delay the need for levodopa, are very well tolerated, and may provide long-term disease-modifying effects. Dopamine agonists provide moderate symptomatic benefit, delay the need for levodopa, and cause fewer motor complications than levodopa. Compared with levodopa, however, dopamine agonists cause more somnolence and sudden-onset sleep as well as impulse control disorders. The treatment of early PD depends in part on the individual patient's anticipated risk of side effects and the degree of motor improvement required. Physicians should also consider the early use of MAO-B inhibitors in light of their very good tolerability and the recent evidence suggesting long-term disease-modifying effects.

Topics: Antiparkinson Agents; Disease Progression; Dopamine Agonists; Early Diagnosis; Humans; Levodopa; Monoamine Oxidase Inhibitors; Parkinson Disease; Ubiquinone; Vitamin E

Pathological hallmarks of Parkinson's disease are destruction of dopaminergic neurons in the basal ganglia, especially the substantia nigra, and the presence of Lewy bodies within nerve cells. Environmental toxins are associated with the disease and, in a minority of cases, genetic factors have been identified. Inflammation-with activation of phagocytic microglia, release of cytokines, invasion by T cells, and complement activation-plays a role in damaging these neurons. Excessive production of reactive oxygen species, mitochondrial dysfunction leading to apoptosis, accumulation and oligomerization of the protein alpha-synuclein, and defective protein disposal by the ubiquitin proteasome system are involved in the complex web of events mediating nigral cell demise. Two agents of current interest, coenzyme Q10 and creatine, may be disease modifying, and large studies are in progress. Related mechanisms of other substances, including omega-3 fatty acids and vitamin D, are included in this review. The association with serum cholesterol levels and the effects of statin drugs are uncertain but important.

Topics: Anti-Inflammatory Agents; Cholesterol; Creatine; Diet Therapy; Fatty Acids, Omega-3; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Inflammation; Mitochondria; Neuroprotective Agents; Parkinson Disease; Ubiquinone; Vitamin D; Vitamins

The authors summarized the evidence supporting neuroprotection based on the data available in the literature. In vivo and in vitro studies have indicated that many compounds can decrease neurodegeneration, excitotoxicity, oxidative stress, protein aggregation, disturbance of Ca2+ homeostasis and compensate the energy impairment. Selegiline, rasagiline, dopamine agonists and other molecules (ubiquinone, kynurenic acid, tocopherol, creatine, glatiramer acetate) exert neuroprotective effects in preclinical studies. Much less clinical data are available regarding neuroprotection in different neurological disorders. In this review, such preclinical and clinical evidences are summarized.

Topics: Animals; Creatine; Dopamine Agonists; Glatiramer Acetate; Humans; Indans; Kynurenic Acid; Micronutrients; Nerve Degeneration; Neurodegenerative Diseases; Neuroprotective Agents; Oxidative Stress; Parkinson Disease; Peptides; Selegiline; Tocopherols; Ubiquinone

Parkinson disease (PD) is associated with progressive loss of dopaminergic neurons in the substantia nigra, as well as with more-widespread neuronal changes that cause complex and variable motor and nonmotor symptoms. Recent rapid advances in PD genetics have revealed a prominent role for mitochondrial dysfunction in the pathogenesis of the disease, and the products of several PD-associated genes, including SNCA, Parkin, PINK1, DJ-1, LRRK2 and HTR2A, show a degree of localization to the mitochondria under certain conditions. Impaired mitochondrial function is likely to increase oxidative stress and might render cells more vulnerable to this and other related processes, including excitotoxicity. The mitochondria, therefore, represent a highly promising target for the development of disease biomarkers by use of genetic, biochemical and bioimaging approaches. Novel therapeutic interventions that modify mitochondrial function are currently under development, and a large phase III clinical trial is underway to examine whether high-dose oral coenzyme Q10 will slow disease progression. In this Review, we examine evidence for the roles of mitochondrial dysfunction and increased oxidative stress in the neuronal loss that leads to PD and discuss how this knowledge might further improve patient management and aid in the development of 'mitochondrial therapy' for PD.

Topics: Animals; Humans; Mitochondria; Oxidative Stress; Parkinson Disease; Ubiquinone; Vitamins

Coenzyme Q10 (CoQ10) is a powerful antioxidant that buffers the potential adverse consequences of free radicals produced during oxidative phosphorylation in the inner mitochondrial membrane. Oxidative stress, resulting in glutathione loss and oxidative DNA and protein damage, has been implicated in many neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and Huntington's disease. Experimental studies in animal models suggest that CoQ10 may protect against neuronal damage that is produced by ischemia, atherosclerosis and toxic injury. Though most have tended to be pilot studies, there are published preliminary clinical trials showing that CoQ10 may offer promise in many brain disorders. For example, a 16-month randomized, placebo-controlled pilot trial in 80 subjects with mild Parkinson's disease found significant benefits for oral CoQ10 1,200 mg/day to slow functional deterioration. However, to date, there are no published clinical trials of CoQ10 in Alzheimer's disease. Available data suggests that oral CoQ10 seems to be relatively safe and tolerated across the range of 300-2,400 mg/day. Randomized controlled trials are warranted to confirm CoQ10's safety and promise as a clinically effective neuroprotectant.

Topics: Alzheimer Disease; Animals; Antioxidants; Brain; Coenzymes; Humans; Huntington Disease; Neurodegenerative Diseases; Neurons; Neuroprotective Agents; Parkinson Disease; Randomized Controlled Trials as Topic; Ubiquinone; Vitamins

The etiology of several neurodegenerative disorders is thought to involve impaired mitochondrial function and oxidative stress. Coenzyme Q-10 (CoQ10) acts both as an antioxidant and as an electron acceptor at the level of the mitochondria. In several animal models of neurodegenerative diseases including amyotrophic lateral sclerosis, Huntington's disease, and Parkinson's disease, CoQ10 has shown beneficial effects. Based on its biochemical properties and the effects in animal models, several clinical trials evaluating CoQ10 have been undertaken in many neurodegenerative diseases. CoQ10 appears to be safe and well tolerated, and several efficacy trials are planned.

Topics: Aging; Amyotrophic Lateral Sclerosis; Animals; Clinical Trials as Topic; Humans; Huntington Disease; Models, Biological; Mutation; Neurodegenerative Diseases; Parkinson Disease; Time Factors; Treatment Outcome; Ubiquinone

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive loss of dopaminergic neurons within the substantia nigra pars compacta. Experimental and clinical data point to a defect of the mitochondrial respiratory chain as a major pathogenetic factor in PD. Although the restoration of mitochondrial respiration and reduction of oxidative stress by coenzyme Q(10) (CoQ10) could induce neuroprotective effects against the dopaminergic cell death in PD, these effects of CoQ10 could also improve the dopaminergic dysfunction. Thus CoQ10 might theoretically exert both neuroprotective and symptomatic effects in PD. Current data from controlled clinical trials are not sufficient to answer conclusively whether CoQ10 is neuroprotective in PD. Moreover, several open and controlled pilot studies on symptomatic effects of CoQ10 revealed inconsistent results. A recent randomized, double-blind, placebo-controlled trial showed no symptomatic effects in PD. CoQ10 is well tolerated and safe as both monotherapy and add-on medication in PD patients. The present review discusses the current knowledge on neuroprotective and symptomatic actions of CoQ10 in PD.

Topics: Antiparkinson Agents; Brain; Clinical Trials as Topic; Humans; Mitochondria; Models, Neurological; Neuroprotective Agents; Parkinson Disease; Treatment Outcome; Ubiquinone

MitoQ is an orally active antioxidant that has the ability to target mitochondrial dysfunction. The agent is currently under development by Antipodean Pharmaceuticals Inc in phase II clinical trials for Parkinson's disease and liver damage associated with HCV infection. MitoQ has demonstrated encouraging preclinical results in numerous studies in isolated mitochondria, cells and tissues undergoing oxidative stress and apoptotic death. MitoQ aims to not only mimic the role of the endogenous mitochondrial antioxidant coenzyme Q10 (CoQ10), but also to augment substantially the antioxidant capacity of CoQ to supraphysiological levels in a mitochondrial membrane potential-dependent manner. MitoQ represents the first foray into the clinic in an attempt to deliver an antioxidant to an intracellular region that is responsible for the formation of increased levels of potentially deleterious reactive oxygen species. Results from the clinical trials with MitoQ will have important repercussions on the relevance of a mitochondrial-targeted approach.

Topics: Alzheimer Disease; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Antiparkinson Agents; Apoptosis; Clinical Trials as Topic; Friedreich Ataxia; Hepatitis C; Humans; Mitochondria; Myocardial Reperfusion Injury; Neuroprotective Agents; Organophosphorus Compounds; Oxidative Stress; Parkinson Disease; Ubiquinone

The development of treatment for the symptoms of Parkinson's disease (PD) has been one of the most notable successes of neurology. Dopaminergic therapies in the form of levodopa, dopamine agonists, or monoamine oxidase B inhibitors significantly improve the characteristic motor symptoms of bradykinesia and rigidity, with a beneficial effect upon tremor in a proportion of patients. Novel delivery of dopaminergic drugs whether in the form of once a day sustained release preparations or transdermal applications ensures that they remain at the forefront of PD treatment. The development of drugs to slow the progression of PD has attracted considerable attention and there appears to be some measure of success although additional studies need to be performed. A range of nondopaminergic drugs including alpha 2-adrenergic antagonists, serotoninergics, and adenosine A2a antagonists are in late-stage development for PD and offer benefit for motor symptoms and motor complications.

Topics: Cholinergic Antagonists; Coenzymes; Dopamine Agonists; Drug Therapy; Forecasting; Humans; Intercellular Signaling Peptides and Proteins; Monoamine Oxidase Inhibitors; Parkinson Disease; Ubiquinone

Topics: Amyotrophic Lateral Sclerosis; Antioxidants; Clinical Trials as Topic; Coenzymes; Costs and Cost Analysis; Heart Failure; Humans; Hypertension; Migraine Disorders; Mitochondrial Encephalomyopathies; Parkinson Disease; Ubiquinone

To review the use of antioxidants and other supplements for the prevention and treatment of Parkinson's disease (PD).. Biomedical literature was accessed through MEDLINE (1996-June 2005); key search terms included Parkinson's disease, coenzyme Q10 (CoQ10), antioxidants, supplements, and glutathione. Pertinent references cited in those articles were also evaluated for inclusion in this review.. Three main antioxidants or supplements have been studied for use in the prevention or treatment of PD: tocopherol, CoQ10, and glutathione. These agents have been studied because of their potential to alter the course of 2 common theories of PD pathogenesis: free radical generation and mitochondrial complex-1 deficiency. The literature search revealed 3 large clinical studies of tocopherol (2 observational, 1 prospective randomized), 4 trials of CoQ10, and 1 study of glutathione. With the exception of the large observational studies with tocopherol and one study of CoQ10 that enrolled 80 patients, each of the other studies retrieved included fewer than 30 patients and were conducted for 3 months or less. Antioxidant supplementation, in particular tocopherol, did not appear to alter the course of PD. However, in 2 of the studies of CoQ10 and in the study of glutathione, a small but statistically significant improvement in PD symptoms was observed.. At present, antioxidants and supplements appear to have a limited role in the prevention or treatment of PD. Of those reviewed here, CoQ10 appears to provide some minor treatment benefits. More study is necessary to determine whether CoQ10 has a significant role as primary or adjunctive therapy in PD.

Topics: Antioxidants; Clinical Trials as Topic; Dietary Supplements; Glutathione; Humans; Parkinson Disease; Tocopherols; Ubiquinone; Vitamins

Although still a disorder of unknown etiology, Parkinson's disease (PD) has provided a number of clues that have led to clinical trials of neuroprotection. For example, defects in mitochondrial metabolism and evidence for oxidative stress in PD have fostered therapeutic interventions aimed at slowing disease progression. More than a dozen compounds already have been tested in PD for disease modification, and others are in planning stages for clinical trials. The challenge is to find a highly effective therapy halting disease progression (beyond the relatively modest clinical effect exemplified by recent findings with coenzyme Q-10 treatment administered at 1200mg/day). Clinical exam-based ratings and disability assessments still serve at providing the primary evidence of efficacy. However, with surrogate biomarkers such as radiotracer neuroimaging of the dopaminergic system, the pace of clinical investigation can be increased. Recent years have seen the utilization of more sensitive study methods in PD neuroprotection research, such as staggered wash-in, 2 x 2 factorial, and "futility" trial designs. The results of several ongoing PD neuroprotection trials are planned for release in the near future.

Topics: Animals; Coenzymes; Humans; Metabolic Networks and Pathways; Mitochondria; Neuroprotective Agents; Parkinson Disease; Ubiquinone

After a brief reminding of the synthesis and function of coenzyme Q10, this article tries to summarise the current state of knowledge about the consequences of its deficiency and about the potential benefits of an increased intake of this coenzyme. We then describe the arguments in favour of such an increase in cardiac diseases and in Parkinson's disease.

Topics: Animals; Cardiovascular Diseases; Coenzymes; Humans; Parkinson Disease; Ubiquinone

Parkinson's disease is characterized by a progressive loss of dopaminergic neurons in the substantia nigra zona compacta, and in other sub-cortical nuclei associated with a widespread occurrence of Lewy bodies. The cause of cell death in Parkinson's disease is still poorly understood, but a defect in mitochondrial oxidative phosphorylation and enhanced oxidative and nitrative stresses have been proposed. We have studied control(wt) (C57B1/6), metallothionein transgenic (MTtrans), metallothionein double gene knock (MTdko), alpha-synuclein knock out (alpha-syn(ko)), alpha-synuclein-metallothionein triple knock out (alpha-syn-MTtko), weaver mutant (wv/wv) mice, and Ames dwarf mice to examine the role of peroxynitrite in the etiopathogenesis of Parkinson's disease and aging. Although MTdko mice were genetically susceptible to 1, methyl, 4-phenyl, 1,2,3,6-tetrahydropyridine (MPTP) Parkinsonism, they did not exhibit any overt clinical symptoms of neurodegeneration and gross neuropathological changes as observed in wv/wv mice. Progressive neurodegenerative changes were associated with typical Parkinsonism in wv/wv mice. Neurodegenerative changes in wv/wv mice were observed primarily in the striatum, hippocampus and cerebellum. Various hallmarks of apoptosis including caspase-3, TNFalpha, NFkappaB, metallothioneins (MT-1, 2) and complex-1 nitration were increased; whereas glutathione, complex-1, ATP, and Ser(40)-phosphorylation of tyrosine hydroxylase, and striatal 18F-DOPA uptake were reduced in wv/wv mice as compared to other experimental genotypes. Striatal neurons of wv/wv mice exhibited age-dependent increase in dense cored intra-neuronal inclusions, cellular aggregation, proto-oncogenes (c-fos, c-jun, caspase-3, and GAPDH) induction, inter-nucleosomal DNA fragmentation, and neuro-apoptosis. MTtrans and alpha-Syn(ko) mice were genetically resistant to MPTP-Parkinsonism and Ames dwarf mice possessed significantly higher concentrations of striatal coenzyme Q10 and metallothioneins (MT 1, 2) and lived almost 2.5 times longer as compared to control(wt) mice. A potent peroxynitrite ion generator, 3-morpholinosydnonimine (SIN-1)-induced apoptosis was significantly attenuated in MTtrans fetal stem cells. These data are interpreted to suggest that peroxynitrite ions are involved in the etiopathogenesis of Parkinson's disease, and metallothionein-mediated coenzyme Q10 synthesis may provide neuroprotection.

Topics: alpha-Synuclein; Animals; Apoptosis; Brain; Coenzymes; Disease Models, Animal; Dopamine; Gene Expression Regulation; Humans; Metallothionein; Mice; Mice, Neurologic Mutants; Mice, Transgenic; MPTP Poisoning; Nerve Tissue Proteins; Parkinson Disease; Synucleins; Ubiquinone

The introduction of levodopa in the late 1960s represented a landmark in the therapy of Parkinson's disease (PD). However, motor complications of chronic levodopa therapy have emerged as a major limitation of this otherwise effective therapy. Advancing medical and surgical treatment of these complications has been the main objective of clinical trials during the past few decades. In addition, basic research has focused on better understanding of the mechanisms of motor complications and how to prevent them. Slowing or delaying the progression of the disease delays the need for levodopa therapy; therefore, neuroprotective strategies may play an important role in preventing the onset and reducing the severity of levodopa-related adverse effects. In this introductory review, we present the rationale for current and experimental therapies designed to favorably modify the progression of PD. If implemented early in the course of the disease, such treatments, if found effective, may not only alter the natural progression of the disease but may also delay or minimize motor and nonmotor complications associated with levodopa.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Antiparkinson Agents; Coenzymes; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dose-Response Relationship, Drug; Dyskinesia, Drug-Induced; Humans; Indans; Levodopa; Membrane Proteins; N-Methylaspartate; Neuroprotective Agents; Parkinson Disease; Prostaglandin-Endoperoxide Synthases; Ubiquinone; Vitamin E

Mitochondrial dysfunction has been well established to occur in Parkinson's disease (PD) and appears to play a role in the pathogenesis of the disorder. A key component of the mitochondrial electron transport chain (ETC) is coenzyme Q(10), which not only serves as the electron acceptor for complexes I and II of the ETC but is also an antioxidant. In addition to being crucial to the bioenergetics of the cell, mitochondria play a central role in apoptotic cell death through a number of mechanisms, and coenzyme Q(10) can affect certain of these processes. Levels of coenzyme Q(10) have been reported to be decreased in blood and platelet mitochondria from PD patients. A number of preclinical studies in in vitro and in vivo models of PD have demonstrated that coenzyme Q(10) can protect the nigrostriatal dopaminergic system. A phase II trial of coenzyme Q(10) in patients with early, untreated PD demonstrated a positive trend for coenzyme Q(10) to slow progressive disability that occurs in PD.

Topics: Animals; Apoptosis; Clinical Trials as Topic; Energy Metabolism; Humans; Mitochondria; Oxidative Stress; Parkinson Disease; Ubiquinone

Coenzyme Q10 is a vitamin-like substance used in the treatment of a variety of disorders primarily related to suboptimal cellular energy metabolism and oxidative injury. Studies supporting the efficacy of coenzyme Q10 appear most promising for neurodegenerative disorders such as Parkinson's disease and certain encephalomyopathies for which coenzyme Q10 has gained orphan drug status. Results in other areas of research, induding treatment of congestive heart failure and diabetes, appear to be contradictory or need further clarification before proceeding with recommendations. Coenzyme Q10 appears to be a safe supplement with minimal side effects and low drug interaction potential.

Topics: Humans; Mitochondrial Encephalomyopathies; Parkinson Disease; Ubiquinone

Topics: Amyotrophic Lateral Sclerosis; Child; Clinical Trials as Topic; Coenzymes; Friedreich Ataxia; Heart Arrest; Humans; Huntington Disease; Mitochondrial Diseases; Nervous System Diseases; Parkinson Disease; Ubiquinone

Parkinson disease is an age-related neurodegenerative disease that affects approximately 1 million persons in the United States. Current therapies provide effective control of symptoms, particularly in the early stages of the disease, but most patients develop motor complications with long-term treatment, and features develop such as postural instability, falling, and dementia that are not adequately controlled with existing medications. Accordingly, neuroprotective therapy that might slow, stop, or reverse disease progression is urgently needed. While many agents appear to be promising based on laboratory studies, selecting clinical end points for clinical trials that are not confounded by symptomatic effects of the study intervention has been difficult. More recently, neuroimaging end points have been used as biomarkers of disease progression, but again there are concerns that they may be influenced by regulatory effects of the drugs used. We review clinical trials aimed at detecting neuroprotection in Parkinson disease and address the controversies surrounding the interpretation of these studies.

Topics: Antioxidants; Antiparkinson Agents; Clinical Trials as Topic; Coenzymes; Dopamine Agonists; Humans; Levodopa; Neuroprotective Agents; Parkinson Disease; Ubiquinone

Topics: Animals; Brain; Coenzymes; Humans; Neuroprotective Agents; Parkinson Disease; Ubiquinone

Coenzyme Q10 (Q10) is available as an over-the-counter dietary supplement in the United States. While its use could be considered a form of alternative therapy, the medical profession has embraced the use of Q10 in specific disease states, including a series of neurologic and muscular diseases. Clinical laboratory monitoring is available for measurement of total Q10 in plasma and tissue and for measurement of redox status, ie, the ratio of reduced and oxidized forms of Q10. Many published studies have been anecdotal, in part owing to the rarity of some diseases involved. Unfortunately, many studies do not report Q10 levels, and, thus, the relationship of clinical response to Q10 concentration in plasma frequently is not discernible. Consistent laboratory monitoring of patients treated with this compound would help ease interpretation of the results of the treatment, especially because so many formulations of Q10 exist in the marketplace, each with its own bioavailability characteristics. Q10 has an enviable safety profile and, thus, is ideal to study as an adjunct to more conventional therapy. Defining patient subpopulations and characteristics that predict benefit from exogenous Q10 and defining therapeutic ranges for those particular applications are major challenges in this field.

Topics: Coenzymes; Epilepsies, Myoclonic; Friedreich Ataxia; Humans; Huntington Disease; Kearns-Sayre Syndrome; Mitochondrial Encephalomyopathies; Muscular Diseases; Nervous System Diseases; Parkinson Disease; Ubiquinone

There is substantial evidence that mitochondrial dysfunction and oxidative damage may play a key role in the pathogenesis of neurodegenerative disease. Evidence supporting this in both Alzheimer's and Parkinson's diseases is continuing to accumulate. This review discusses the increasing evidence for a role of both mitochondrial dysfunction and oxidative damage in contributing to beta-amyloid deposition in Alzheimer's disease. I also discuss the increasing evidence that Parkinson's disease is associated with abnormalities in the electron transport gene as well as oxidative damage. Lastly, I reviewed the potential efficacy of coenzyme Q as well as a number of other antioxidants in the treatment of both Parkinson's and Alzheimer's diseases.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Brain; Coenzymes; Humans; Mitochondria; Mitochondrial Diseases; Neurons; Neuroprotective Agents; Oxidation-Reduction; Oxidative Stress; Parkinson Disease; Reactive Oxygen Species; Ubiquinone

Topics: Antiparkinson Agents; Clinical Trials as Topic; Creatine; Dopamine Agonists; Double-Blind Method; Humans; Indans; Minocycline; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Multicenter Studies as Topic; Nerve Tissue Proteins; Neuroprotective Agents; Oxepins; Parkinson Disease; Picolinic Acids; Randomized Controlled Trials as Topic; Riluzole; Selegiline; Ubiquinone

Topics: Amyotrophic Lateral Sclerosis; Antiparkinson Agents; Behavioral Symptoms; Coenzymes; Controlled Clinical Trials as Topic; Disease Progression; Humans; Levodopa; Neuroprotective Agents; Parkinson Disease; Ubiquinone

In Parkinson's disease advanced symptoms (fluctuation, dyskinesia) and/or psychiatric side-effects of medication require a very individual and often complicated therapeutic regime. All pharmacological groups can be useful. The adjustment of medication needs clinical control, especially when psychiatric symptoms occur. Ideally, this task should be left to specially trained medical staff. Moreover, there are a number of complementary strategies recommended by various suppliers. Physiotherapy, speech therapy and ear acupuncture have in the past been shown to be useful even in advanced cases. The German Parkinson Society (dPV) has supported clinical trials in respect of the application of ear acupuncture, Qigong and the coenzyme Q10. Positive results are expected from Q10. Acupuncture cannot be recommended, while Qigong may be helpful for some patients.

Topics: Acupuncture, Ear; Antioxidants; Breathing Exercises; Clinical Trials as Topic; Coenzymes; Complementary Therapies; Dopamine Agonists; Humans; Parkinson Disease; Physical Therapy Modalities; Relaxation Therapy; Ubiquinone

Ubiquitinated inclusions and selective neuronal cell death are considered the pathological hallmarks of Parkinson's disease and other neurodegenerative diseases. Recent genetic, pathological and biochemical evidence suggests that dysfunction of ubiquitin-dependent protein degradation by the proteasome might be a contributing, if not initiating factor in the pathogenesis of these diseases. In neuronal cell culture models inhibition of the proteasome leads to cell death and formation of fibrillar ubiquitin and alpha-synuclein-positive inclusions, thus modeling some aspects of Lewy body diseases. The processes of inclusion formation and neuronal cell death share some common mechanisms, but can also be dissociated at a certain level.

Topics: alpha-Synuclein; Alzheimer Disease; Animals; Cell Death; Humans; Inclusion Bodies; Nerve Tissue Proteins; Neurodegenerative Diseases; Neurons; Parkinson Disease; Synucleins; Ubiquinone

There is considerable evidence suggesting that mitochondrial dysfunction and oxidative damage may play a role in the pathogenesis of Parkinson's disease (PD). This possibility has been strengthened by recent studies in animal models, which have shown that a selective inhibitor of complex I of the electron transport gene can produce an animal model that closely mimics both the biochemical and histopathological findings of PD. Several agents are available that can modulate cellular energy metabolism and that may exert antioxidative effects. There is substantial evidence that mitochondria are a major source of free radicals within the cell. These appear to be produced at both the iron-sulfur clusters of complex I as well as the ubiquinone site. Agents that have shown to be beneficial in animal models of PD include creatine, coenzyme Q(10), Ginkgo biloba, nicotinamide, and acetyl-L-carnitine. Creatine has been shown to be effective in several animal models of neurodegenerative diseases and currently is being evaluated in early stage trials in PD. Similarly, coenzyme Q(10) is also effective in animal models and has shown promising effects both in clinical trials of PD as well as in clinical trials in Huntington's disease and Friedreich's ataxia. Many other agents show good human tolerability. These agents therefore are promising candidates for further study as neuroprotective agents in PD.

Topics: Acetylcarnitine; Coenzymes; Creatine; Energy Metabolism; Free Radicals; Ginkgo biloba; Humans; Mitochondria; Neuroprotective Agents; Niacinamide; Nootropic Agents; Parkinson Disease; Phytotherapy; Thioctic Acid; Ubiquinone

The pathogenesis of Parkinson's disease (PD) remains obscure, but there is increasing evidence that impairment of mitochondrial function, oxidative damage, and inflammation are contributing factors. The present paper reviews the experimental and clinical evidence implicating these processes in PD. There is substantial evidence that there is a deficiency of complex I activity of the mitochondrial electron transport chain in PD. There is also evidence for increased numbers of activated microglia in both PD postmortem tissue as well as in animal models of PD. Impaired mitochondrial function and activated microglia may both contribute to oxidative damage in PD. A number of therapies targeting inflammation and mitochondrial dysfunction are efficacious in the MPTP model of PD. Of these, coenzyme Q(10) appears to be particularly promising based on the results of a recent phase 2 clinical trial in which it significantly slowed the progression of PD.

Topics: Animals; Anti-Inflammatory Agents; Coenzymes; Creatine; Disease Models, Animal; Free Radicals; Humans; Inflammation; Mitochondria; Oxidative Stress; Parkinson Disease; Ubiquinone

Alpha-synuclein belongs to a family of vertebrate proteins, encoded by three different genes: alpha, ss, and gamma. The protein has become of interest to the neuroscience community in the last few years after the discovery that a mutation in the alpha-synuclein gene is associated with familial autosomal-dominant early-onset forms of Parkinson Disease. However, it is not yet clear how the protein is involved in the disease. Several studies have suggested that alpha-synuclein plays a role in neurotransmitter release and synaptic plasticity. This hypothesis might help elucidate how alpha-synuclein malfunctioning contributes to the development of a series of disorders known as synucleinopathies.

Topics: alpha-Synuclein; Animals; Environment; Humans; Mutation; Nerve Tissue Proteins; Neurodegenerative Diseases; Parkinson Disease; Synapses; Synaptic Transmission; Synucleins; Ubiquinone; Ubiquitin-Protein Ligases

Topics: Animals; Antioxidants; Coenzymes; Humans; Huntington Disease; Kinetics; Liver; Parkinson Disease; Ubiquinone

Topics: Animals; Brain; Humans; Metallothionein; Mitochondria; Neurodegenerative Diseases; Neuroprotective Agents; Oxidative Phosphorylation; Parkinson Disease; Ubiquinone

Topics: Animals; Electron Transport Complex I; Humans; Mitochondria; NADH, NADPH Oxidoreductases; Oxidation-Reduction; Parkinson Disease; Ubiquinone

Coenzyme Q10 (CoQ10) is an essential cofactor of the electron transport chain as well as an important antioxidant. Previous studies have suggested that it may exert therapeutic effects in patients with known mitochondrial disorders. We investigated whether it can exert neuroprotective effects in a variety of animal models. We have demonstrated that CoQ10 can protect against striatal lesions produced by both malonate and 3-nitropropionic acid. It also protects against MPTP toxicity in mice. It extended survival in a transgenic mouse model of amyotrophic lateral sclerosis. We demonstrated that oral administration can increase plasma levels in patients with Parkinson's disease. Oral administration of CoQ10 significantly decreased elevated lactate levels in patients with Huntington's disease. These studies therefore raise the prospect that administration of CoQ10 may be useful for the treatment of neurodegenerative diseases.

Topics: Administration, Oral; Animals; Antioxidants; Coenzymes; Humans; Huntington Disease; Lactates; Mice; Mice, Transgenic; Neurodegenerative Diseases; Parkinson Disease; Ubiquinone

Parkinson's disease (PD) is a degenerative neurological disorder. Recent studies have demonstrated reduced activity of complex I of the electron transport chain in brain and platelets from patients with PD. Platelet mitochondria from parkinsonian patients were found to have lower levels of coenzyme Q10 (CoQ10) than mitochondria from age/sex-matched controls. There was a strong correlation between the levels of CoQ10 and the activities of complexes I and II/III. Oral CoQ10 was found to protect the nigrostriatal dopaminergic system in one-year-old mice treated with MPTP, a toxin injurious to the nigrostriatal dopaminergic system. We further found that oral CoQ10 was well absorbed in parkinsonian patients and caused a trend toward increased complex I activity. These data suggest that CoQ10 may play a role in cellular dysfunction found in PD and may be a potential protective agent for parkinsonian patients.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Administration, Oral; Animals; Antioxidants; Blood Platelets; Coenzymes; Humans; Mice; Mitochondria; Parkinson Disease; Parkinson Disease, Secondary; Ubiquinone

To investigate the effect of creatine and coenzyme Q10 (CoQ10) combination therapy on mild cognitive impairment (MCI) in Parkinson's disease (PD; PD-MCI) and its influences on plasma phospholipid (PL) levels in PD-MCI.. The demographic data of 75 PD-MCI patients who enrolled in this collaborative PD study were collected. These patients were evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS) III and the Montreal Cognitive Assessment (MoCA). These 75 PD-MCI patients were randomly treated with creatine monohydrate 5 g b.i.d. and CoQ10 100 mg t.i.d. orally or placebo. MoCA evaluation and PL level measurements were performed after 12 and 18 months of treatment.. After 12 and 18 months of treatment, the differences in the MoCA scores of the combination therapy and control groups were statistically significant (p < 0.05 at 12 months and p < 0.01 at 18 months), and the plasma PL levels of the combination therapy group were significantly lower than those of the control group (p < 0.01 at 12 months and p < 0.001 at 18 months).. Combination therapy with creatine and CoQ10 could delay the decline of cognitive function in PD-MCI patients and could lower their plasma PL levels; therefore, this combination therapy may have a neuroprotective function.

Topics: Aged; Cognition; Cognitive Dysfunction; Creatine; Drug Therapy, Combination; Female; Humans; Male; Middle Aged; Parkinson Disease; Ubiquinone

Mitochondrial complex I deficiencies have been found in post-mortem brains of patients with Parkinson's disease (PD). Coenzyme Q10 (CoQ10) is the electron acceptor found in complexes I and II, and is a potent antioxidant. A recent trial of the oxidized form of CoQ10 for PD failed to show benefits; however, the reduced form of CoQ10 (ubiquinol-10) has shown better neuroprotective effects in animal models.. Randomized, double-blind, placebo-controlled, parallel-group pilot trials were conducted to assess the efficacy of ubiquinol-10 in Japanese patients with PD. Participants were divided into two groups: PD experiencing wearing off (Group A), and early PD, without levodopa (with or without a dopamine agonist) (Group B). Participants took 300 mg of ubiquinol-10 or placebo per day for 48 weeks (Group A) or 96 weeks (Group B).. In Group A, total Unified Parkinson's Disease Rating Scale (UPDRS) scores decreased in the ubiquinol-10 group (n = 14; mean ± SD [-4.2 ± 8.2]), indicating improvement in symptoms. There was a statistically significant difference (p < 0.05) compared with the placebo group (n = 12; 2.9 ± 8.9). In Group B, UPDRS increased in the ubiquinol-10 group (n = 14; 3.9 ± 8.0), as well as in the placebo group (n = 8; 5.1 ± 10.3).. This is the first report showing that ubiquinol-10 may significantly improve PD with wearing off, as judged by total UPDRS scores, and that ubiquinol-10 is safe and well tolerated.

Topics: Aged; Antioxidants; Double-Blind Method; Female; Humans; Male; Middle Aged; Neuroprotective Agents; Parkinson Disease; Pilot Projects; Treatment Outcome; Ubiquinone

Evidence on the efficacy of high-dose coenzyme Q10 (CoQ10) in Parkinson's disease (PD) is conflicting. An open-label dose-escalation study was performed to examine the effects of CoQ10 on biomarkers of oxidative damage and clinical outcomes in 16 subjects with early idiopathic PD. Each dose (400, 800, 1200, and 2400 mg/day) was consumed daily for 2 weeks. High-dose CoQ10 was well tolerated and improvements in the total Unified Parkinson's Disease Rating Scale (median, 37 vs. 27; p=0.048) were observed following study completion. Plasma F2-isoprostanes (adjusted for arachidonate) were significantly reduced in the 400-1200 mg/day dose range, but increased at 2400 mg/day dosage. A similar pattern of change was observed with serum phospholipase A2 activities. Levels of plasma all trans-retinol, plasma total tocopherol, serum uric acid, and serum total cholesterol were unchanged despite an increase in the CoQ10 dosage. Subjects with symptomatic benefits from CoQ10 (decrease in total UPDRS >10 points) had lower baseline plasma ubiquinol (p=0.07, Mann-Whitney U test) and decreased F2-isoprostanes per unit arachidonate (p=0.04, Wilcoxon Signed-Ranks test). These results lead to the hypothesis that the therapeutic response to CoQ10 depends on baseline levels of ubiquinol and whether the dosage of CoQ10 used can ameliorate the burden of oxidative damage.

Topics: Biomarkers, Tumor; Dose-Response Relationship, Drug; Female; Humans; Male; Middle Aged; Oxidation-Reduction; Oxidative Stress; Parkinson Disease; Treatment Outcome; Ubiquinone

Coenzyme Q10 (CoQ10), an antioxidant that supports mitochondrial function, has been shown in preclinical Parkinson disease (PD) models to reduce the loss of dopamine neurons, and was safe and well tolerated in early-phase human studies. A previous phase II study suggested possible clinical benefit.. To examine whether CoQ10 could slow disease progression in early PD.. A phase III randomized, placebo-controlled, double-blind clinical trial at 67 North American sites consisting of participants 30 years of age or older who received a diagnosis of PD within 5 years and who had the following inclusion criteria: the presence of a rest tremor, bradykinesia, and rigidity; a modified Hoehn and Yahr stage of 2.5 or less; and no anticipated need for dopaminergic therapy within 3 months. Exclusion criteria included the use of any PD medication within 60 days, the use of any symptomatic PD medication for more than 90 days, atypical or drug-induced parkinsonism, a Unified Parkinson's Disease Rating Scale (UPDRS) rest tremor score of 3 or greater for any limb, a Mini-Mental State Examination score of 25 or less, a history of stroke, the use of certain supplements, and substantial recent exposure to CoQ10. Of 696 participants screened, 78 were found to be ineligible, and 18 declined participation.. The remaining 600 participants were randomly assigned to receive placebo, 1200 mg/d of CoQ10, or 2400 mg/d of CoQ10; all participants received 1200 IU/d of vitamin E.. Participants were observed for 16 months or until a disability requiring dopaminergic treatment. The prospectively defined primary outcome measure was the change in total UPDRS score (Parts I-III) from baseline to final visit. The study was powered to detect a 3-point difference between an active treatment and placebo.. The baseline characteristics of the participants were well balanced, the mean age was 62.5 years, 66% of participants were male, and the mean baseline total UPDRS score was 22.7. A total of 267 participants required treatment (94 received placebo, 87 received 1200 mg/d of CoQ10, and 86 received 2400 mg/d of CoQ10), and 65 participants (29 who received placebo, 19 who received 1200 mg/d of CoQ10, and 17 who received 2400 mg/d of CoQ10) withdrew prematurely. Treatments were well tolerated with no safety concerns. The study was terminated after a prespecified futility criterion was reached. At study termination, both active treatment groups showed slight adverse trends relative to placebo. Adjusted mean changes (worsening) in total UPDRS scores from baseline to final visit were 6.9 points (placebo), 7.5 points (1200 mg/d of CoQ10; P = .49 relative to placebo), and 8.0 points (2400 mg/d of CoQ10; P = .21 relative to placebo).. Coenzyme Q10 was safe and well tolerated in this population, but showed no evidence of clinical benefit.. clinicaltrials.gov Identifier: NCT00740714.

Topics: Aged; Antioxidants; Dose-Response Relationship, Drug; Double-Blind Method; Early Diagnosis; Female; Humans; Male; Middle Aged; Parkinson Disease; Prospective Studies; Treatment Outcome; Ubiquinone

Reactive oxygen species (ROS) are well known to contribute to the pathophysiology of Parkinson's disease (PD). Clinical trials of antioxidants are currently underway in PD patients, however, antioxidant research has been hindered by a lack of peripheral biomarkers.. Twenty-two patients with PD elected to have a novel antioxidant assessment (Functional Intracellular Assay (FIA), SpectraCell Lab, Houston, TX) performed between 2004 and 2008. Each PD case was compared to four age- and gender-matched controls (n=88) in four separate, random iterations using laboratory data submitted during the same time period. Logistic regression was used to determine the odds of functional deficiency in antioxidant nutrients (i.e., glutathione, coenzyme Q10, selenium, vitamin E and alpha-lipoic acid) by case-control status. The proportion of cases with functional deficiency was also compared to that for controls by chi(2) test.. Compared to cases, PD patients had a significantly greater odds of deficiency in coenzyme Q10 status (OR: 4.7-5.4; 95% CI: 1.5-17.7; P=0.003-0.009) based on FIA results, but not of vitamin E, selenium, lipoic acid, or glutathione (all P>0.05). The proportion of cases with coenzyme Q10 deficiency was also significantly greater in cases than in controls (32-36% vs. 8-9%; P=0.0012-0.006).. Deficiency of coenzyme Q10 assessed via FIA should be explored as a potential peripheral biomarker of antioxidant status in PD.

Topics: Antioxidants; Case-Control Studies; Cells, Cultured; Cohort Studies; Female; Humans; Male; Oxidative Stress; Parkinson Disease; Ubiquinone

Multiple lines of evidence point to mitochondrial oxidative stress as a potential pathogenic cause for Parkinson's disease (PD). MitoQ is a powerful mitochondrial antioxidant. It is absorbed orally and concentrates within mitochondria where it has been shown to protect against oxidative damage. We enrolled 128 newly diagnosed untreated patients with PD in a double-blind study of two doses of MitoQ compared with placebo to explore the hypothesis that, over 12 months, MitoQ would slow the progression of PD as measured by clinical scores, particularly the Unified Parkinson Disease Rating Scale. We showed no difference between MitoQ and placebo on any measure of PD progression. MitoQ does not slow the progression of PD, and this finding should be taken into account when considering the oxidative stress hypothesis for the pathogenesis of PD.

Topics: Adult; Aged; Antioxidants; Dose-Response Relationship, Drug; Double-Blind Method; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Parkinson Disease; Time Factors; Treatment Outcome; Ubiquinone

To assess the predictive value of baseline measures of impairment, disability, and quality of life for the timing of initiation of symptomatic treatment in early Parkinson disease (PD).. Inception cohort analysis.. Ambulatory population from multiple sites in the United States and Canada.. Four hundred thirteen patients with early, untreated PD who participated in 2 double-blind trials that assessed the potential of experimental drugs to serve as disease-modifying agents in PD. Intervention Participants were randomized into treatment groups: creatine (n = 67), minocycline (n = 66), coenzyme Q10 (n = 71), GPI-1485 (n = 71), and placebo (n = 138). Main Outcome Measure Time between baseline assessment and need for the initiation of symptomatic treatment for PD. The following baseline variables were assessed for their relation to the main outcome measure, while adjusting for possible treatment effect: sex; age; level of education; race/ethnicity; disease duration; occupational status; and Unified Parkinson Disease Rating Scale (UPDRS), Medical Outcomes Study Short Form Survey, Modified Rankin Scale, Schwab and England Activities of Daily Living Scale, Total Functional Capacity Scale, 39-item Parkinson Disease Questionnaire, and Geriatric Depression Scale scores. Variables reaching statistical threshold in univariate analyses (alpha = .15) were entered into a multivariable Cox proportional hazards regression model using time to symptomatic treatment as the dependent variable.. Approximately half (48.5%) of the participants reached end point within 12 months. Higher baseline impairment and disability, as determined by UPDRS III (motor section), UPDRS II (activities of daily living section, participant rating), and Modified Rankin Scale scores and level of education were independently associated with an earlier need for symptomatic treatment.. In early PD, greater impairment and disability and higher level of education are independently associated with an earlier need for symptomatic treatment.

Topics: Activities of Daily Living; Adult; Aged; Antiparkinson Agents; Creatine; Disability Evaluation; Disease Management; Drug Administration Schedule; Endpoint Determination; Female; Humans; Male; Middle Aged; Minocycline; Mobility Limitation; Neuropsychological Tests; Parkinson Disease; Predictive Value of Tests; Severity of Illness Index; Surveys and Questionnaires; Tacrolimus; Time Factors; Ubiquinone

To determine if future studies of coenzyme Q(10) and GPI-1485 in Parkinson disease (PD) may be warranted.. We conducted a randomized, double-blind, calibrated futility clinical trial of coenzyme Q10 and GPI-1485 in early untreated PD using placebo data from the DATATOP study to establish the futility threshold.. The primary outcome measure (change in total Unified Parkinson's Disease Rating Scale scores over 1 year) did not meet the prespecified criteria for futility for either agent. Secondary analyses using calibration controls and other more recent placebo data question the appropriateness of the predetermined definition of futility, and suggest that a more restrictive threshold may be needed.. Coenzyme Q(10) and GPI-1485 may warrant further study in Parkinson disease, although the data are inconsistent. Additional factors (cost, availability of other agents, more recent data on placebo outcomes, other ongoing trials) should also be considered in the selection of agents for Phase III studies.

Topics: Aged; Coenzymes; Double-Blind Method; Female; Headache; Humans; Male; Middle Aged; Nausea; Parkinson Disease; Tacrolimus; Ubiquinone

Major hallmarks in the pathophysiology of Parkinson disease are cellular energy depletion and oxidative stress leading to cellular dysfunction and death. Coenzyme Q(10) (CoQ(10)) is an electron acceptor bridging mitochondrial complexes I and II/III and a potent antioxidant that consistently partially recovers the function of dopaminergic neurons.. To determine whether nanoparticular CoQ(10) is safe and displays symptomatic effects in patients with midstage Parkinson disease without motor fluctuations.. Multicenter, randomized, double-blind, placebo-controlled, stratified, parallel-group, single-dose trial.. Academic and nonacademic movement disorder clinics.. One hundred thirty-one patients with Parkinson disease without motor fluctuations and a stable antiparkinsonian treatment. Intervention Random assignment to placebo or nanoparticular CoQ(10) (100 mg 3 times a day) for a treatment period of 3 months. Stratification criterion was levodopa treatment.. The subjects underwent evaluation with the Unified Parkinson's Disease Rating Scale (UPDRS) at each visit on a monthly basis. The primary outcome variable was the change of the sum score of the UPDRS parts II and III between the baseline and 3-month visits.. One hundred thirty-one subjects were randomized according to the protocol. The mean changes of the sum UPDRS parts II/III score were -3.69 for the placebo group and -3.33 for the CoQ(10) group (P = .82). Statistical analysis according to the stratification did not result in significant changes of the primary outcome variable. No secondary outcome measure showed a significant change between the placebo group and the CoQ(10) group. The frequency and quality of adverse events were similar in both treatment groups.. Nanoparticular CoQ(10) at a dosage of 300 mg/d is safe and well tolerated and leads to plasma levels similar to 1200 mg/d of standard formulations. Add-on CoQ(10) does not display symptomatic effects in midstage Parkinson disease.

Topics: Adult; Aged; Antioxidants; Cell Respiration; Coenzymes; Dopamine; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Energy Metabolism; Female; Humans; Levodopa; Male; Middle Aged; Neurons; Oxidative Stress; Parkinson Disease; Placebos; Substantia Nigra; Treatment Outcome; Ubiquinone; Vitamins

O'Brien (1984, Biometrics 40, 1079-1087) introduced a simple nonparametric test procedure for testing whether multiple outcomes in one treatment group have consistently larger values than outcomes in the other treatment group. We first explore the theoretical properties of O'Brien's test. We then extend it to the general nonparametric Behrens-Fisher hypothesis problem when no assumption is made regarding the shape of the distributions. We provide conditions when O'Brien's test controls its error probability asymptotically and when it fails. We also provide adjusted tests when the conditions do not hold. Throughout this article, we do not assume that all outcomes are continuous. Simulations are performed to compare the adjusted tests to O'Brien's test. The difference is also illustrated using data from a Parkinson's disease clinical trial.

Topics: Algorithms; Analysis of Variance; Biometry; Clinical Trials as Topic; Computational Biology; Data Interpretation, Statistical; Humans; Models, Statistical; Models, Theoretical; Multivariate Analysis; Parkinson Disease; Proportional Hazards Models; Randomized Controlled Trials as Topic; Research Design; Statistics, Nonparametric; Survival Analysis; Treatment Outcome; Ubiquinone

The safety and tolerability of high dosages of coenzyme Q10 were studied in 17 patients with Parkinson's disease (PD) in an open label study. The subjects received an escalating dosage of coenzyme Q10--1200, 1800, 2400, and 3000 mg/day with a stable dosage of vitamin E (alpha-tocopherol) 1200 IU/day. The plasma level of coenzyme Q10 was measured at each dosage. Thirteen of the subjects achieved the maximal dosage, and adverse events were typically considered to be unrelated to coenzyme Q10. The plasma level reached a plateau at the 2400 mg/day dosage and did not increase further at the 3000 mg/day dosage. Our data suggest that in future studies of coenzyme Q10 in PD, a dosage of 2400 mg/day (with vitamin E/alpha-tocopherol 1200 IU/day) is an appropriate highest dosage to be studied.

Topics: Calcium; Coenzymes; Cognition; Dose-Response Relationship, Drug; Drug Therapy, Combination; Dyspepsia; Female; Humans; Male; Middle Aged; Motor Activity; Parkinson Disease; Pilot Projects; Safety; Time Factors; Ubiquinone; Vitamin E

Features of Parkinson's disease (PD) include oxidative stress, nigral mitochondrial complex I deficiency and visual dysfunction, all of which are also associated with coenzyme Q(10) (CoQ(10)) deficiency. The objective of this monocenter, parallel group, placebo controlled, double-blind trial was to determine the symptomatic response of daily oral application of 360 mg CoQ(10) lasting 4 weeks on scored PD symptoms and visual function, measured with the Farnsworth-Munsell 100 Hue test (FMT), in 28 treated and stable PD patients. CoQ(10) supplementation provided a significant (P=0.01) mild symptomatic benefit on PD symptoms and a significantly (F((1,24))=8.48, P=0.008) better improvement of FMT performance compared with placebo. Our results indicate a moderate beneficial effect of oral CoQ(10) supplementation in PD patients.

Topics: Aged; Analysis of Variance; Coenzymes; Double-Blind Method; Female; Humans; Male; Middle Aged; Parkinson Disease; Ubiquinone

The isoprenoid pathway produces four key metabolites important in cellular function--digoxin (endogenous membrane Na(+)-K+ ATPase inhibitor), dolichol (important in N-glycosylation of proteins), ubiquinone (free-radical scavenger), and cholesterol (component of cellular membranes). This study assessed the changes in the isoprenoid pathway and the consequences of its dysfunction in Parkinson's disease (PD). There was an elevation in plasma HMG CoA reductase activity, serum digoxin and dolichol levels, and a reduction in serum magnesium, RBC membrane Na(+)-K+ ATPase activity, and serum ubiquinone levels. Serum tryptophan, serotonin, strychnine, nicotine, and quinolinic acid were elevated, while tyrosine, morphine, dopamine, and noradrenaline were decreased. The total serum glycosaminoglycans (GAG) and glycosaminoglycan fractions (except chondroitin sulphates and hyaluronic acid), the activity of GAG degrading enzymes, carbohydrate residues of serum glycoproteins, the activity of glycohydrolase-beta galactosidase, and serum glycolipids were elevated. HDL cholesterol was reduced and free fatty acids increased. The RBC membrane glycosaminoglycans, hexose and fucose residues of glycoproteins and cholesterol were reduced, while phospholipid was increased. The activity of all serum free-radical scavenging enzymes, concentration of glutathione, alpha tocopherol, iron binding capacity, and ceruloplasmin decreased significantly in PD, while the concentration of serum lipid peroxidation products and nitric oxide increased. A dysfunctional isoprenoid pathway and related cascade are important in the pathogenesis of Parkinson's disease. A hypothalamic digoxin mediated model for Parkinson's disease is also postulated.

Topics: Aged; Digoxin; Dolichols; Enzyme Inhibitors; Erythrocytes; Female; Glycoconjugates; Glycosaminoglycans; Humans; Hydroxymethylglutaryl CoA Reductases; Hypothalamus; Male; Membrane Proteins; Middle Aged; Models, Biological; Neurons; Parkinson Disease; Polyisoprenyl Phosphates; Sodium-Potassium-Exchanging ATPase; Tryptophan; Tyrosine; Ubiquinone

Parkinson disease (PD) is a degenerative neurological disorder for which no treatment has been shown to slow the progression.. To determine whether a range of dosages of coenzyme Q10 is safe and well tolerated and could slow the functional decline in PD.. Multicenter, randomized, parallel-group, placebo-controlled, double-blind, dosage-ranging trial.. Academic movement disorders clinics.. Eighty subjects with early PD who did not require treatment for their disability.. Random assignment to placebo or coenzyme Q10 at dosages of 300, 600, or 1200 mg/d.. The subjects underwent evaluation with the Unified Parkinson Disease Rating Scale (UPDRS) at the screening, baseline, and 1-, 4-, 8-, 12-, and 16-month visits. They were followed up for 16 months or until disability requiring treatment with levodopa had developed. The primary response variable was the change in the total score on the UPDRS from baseline to the last visit.. The adjusted mean total UPDRS changes were +11.99 for the placebo group, +8.81 for the 300-mg/d group, +10.82 for the 600-mg/d group, and +6.69 for the 1200-mg/d group. The P value for the primary analysis, a test for a linear trend between the dosage and the mean change in the total UPDRS score, was.09, which met our prespecified criteria for a positive trend for the trial. A prespecified, secondary analysis was the comparison of each treatment group with the placebo group, and the difference between the 1200-mg/d and placebo groups was significant (P =.04).. Coenzyme Q10 was safe and well tolerated at dosages of up to 1200 mg/d. Less disability developed in subjects assigned to coenzyme Q10 than in those assigned to placebo, and the benefit was greatest in subjects receiving the highest dosage. Coenzyme Q10 appears to slow the progressive deterioration of function in PD, but these results need to be confirmed in a larger study.

Topics: Administration, Oral; Aged; Antioxidants; Coenzymes; Cytoprotection; Disabled Persons; Disease Progression; Dose-Response Relationship, Drug; Double-Blind Method; Female; Humans; Male; Middle Aged; Parkinson Disease; Treatment Outcome; Ubiquinone

A 3-month open-label trial was performed to evaluate the efficacy of 200 mg Q10 daily in 10 patients with Parkinson's disease. Motor performance was assessed with UPDRS and motor tests. There was no significant effect on the clinical ratings.

Topics: Aged; Antioxidants; Coenzymes; Humans; Middle Aged; Neuroprotective Agents; Parkinson Disease; Psychomotor Performance; Severity of Illness Index; Ubiquinone

Gut microbiome alterations in Parkinson disease (PD) have been reported repeatedly, but their functional relevance remains unclear. Fecal metabolomics, which provide a functional readout of microbial activity, have scarcely been investigated. We investigated fecal microbiome and metabolome alterations in PD, and their clinical relevance.. Two hundred subjects (104 patients, 96 controls) underwent extensive clinical phenotyping. Stool samples were analyzed using 16S rRNA gene sequencing. Fecal metabolomics were performed using two platforms, nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry.. Fecal microbiome and metabolome composition in PD was significantly different from controls, with the largest effect size seen in NMR-based metabolome. Microbiome and NMR-based metabolome compositional differences remained significant after comprehensive confounder analyses. Differentially abundant fecal metabolite features and predicted functional changes in PD versus controls included bioactive molecules with putative neuroprotective effects (eg, short chain fatty acids [SCFAs], ubiquinones, and salicylate) and other compounds increasingly implicated in neurodegeneration (eg, ceramides, sphingosine, and trimethylamine N-oxide). In the PD group, cognitive impairment, low body mass index (BMI), frailty, constipation, and low physical activity were associated with fecal metabolome compositional differences. Notably, low SCFAs in PD were significantly associated with poorer cognition and low BMI. Lower butyrate levels correlated with worse postural instability-gait disorder scores.. Gut microbial function is altered in PD, characterized by differentially abundant metabolic features that provide important biological insights into gut-brain pathophysiology. Their clinical relevance further supports a role for microbial metabolites as potential targets for the development of new biomarkers and therapies in PD. ANN NEUROL 2021;89:546-559.

Topics: Aged; Ceramides; Chromatography, Liquid; Cognitive Dysfunction; Constipation; Fatty Acids, Volatile; Feces; Female; Frailty; Gastrointestinal Microbiome; Humans; Male; Mass Spectrometry; Metabolomics; Methylamines; Middle Aged; Parkinson Disease; Proton Magnetic Resonance Spectroscopy; RNA, Ribosomal, 16S; Salicylates; Sedentary Behavior; Sphingosine; Thinness; Ubiquinone

Parkinson's disease (PD) is a complex neurodegenerative disease in which the understanding of the underlying molecular mechanisms can be constructive in the diagnosis and treatment. Matrix metalloproteinase (MMPs) elevation and damage to the blood-brain barrier (BBB) are critical mechanisms involved in the PD separation. Studies have revealed that changes in miR-149-5p and CoQ10 are associated with BBB damage, and CoQ10 can affect the levels of some miRs. Hence, in the present study, we aimed to evaluate CoQ10 and miR-149-5p mimic on miR-149-5p, MMPs and TH expression, and behavioral functions of the PD models. PD was induced by injection of 6-OHDA into the rats' Medial Forbrain Bundle (MFB). The behavioral tests, including the Rotation test, Rotarod test, and Open field test, have been directed two weeks after PD induction. Next, the MiR-149-5p mimic (miR-mimic) and CoQ10 have been administered to rats. The same behavioral tests have been evaluated two weeks after administration to investigate the effect of miR-149-5p mimic and CoQ10. The rats were followed extra four weeks, and the behavioral tests have performed again. Finally, the expression of MMPs and miR-149-5p genes was measured using RT-qPCR, and tyrosine hydroxylase (TH) was assessed through immunohistochemistry analysis. According to the obtained results, the level of miR-149-5p has decreased, followed by PD induction in rats. RT-qPCR analysis has represented upregulation and downregulation of miR-149-5p and MMP-2,9, respectively, after miR-mimic and CoQ10 treatment. The treated rats have also represented improved motor function and increased TH +  cells in the striatum according to the behavioral tests and immunohistochemistry assay. Taking together miR-149 and CoQ10 has shown to have an impressive potential to prevent damage to dopaminergic neurons caused by 6-OHDA injection through reducing MMP-2,9, increased TH expression, and improved motor function.

Topics: Animals; Disease Models, Animal; Matrix Metalloproteinases; MicroRNAs; Neurodegenerative Diseases; Neuroprotective Agents; Oxidopamine; Parkinson Disease; Rats; Ubiquinone

Topics: Animals; Cardenolides; Disease Models, Animal; Female; Fish Proteins; Gene Expression; Locomotion; Male; Mitochondria; Neuroprotective Agents; Organophosphorus Compounds; Parkinson Disease; Parkinsonian Disorders; Rotenone; Synucleins; Ubiquinone; Zebrafish

Multiple system atrophy (MSA) is a neurodegenerative disease characterised by glial cytoplasmic inclusions (GCIs), containing α-synuclein. Mutated COQ2, encoding an enzyme essential for co-enzyme Q10 (CoQ10) biosynthesis, has been associated with MSA. CoQ10 is an electron carrier in the mitochondrial electron transport chain (ETC) and antioxidant. It has been shown to be deficient in MSA brain tissue, thus implicating mitochondrial dysfunction in MSA. To investigate mitochondrial dysfunction in MSA further we examined ETC activity in MSA and control brain tissue, compared with Parkinson's disease (PD) where mitochondrial dysfunction is known to be important. Using cerebellar and occipital white matter ETC complex I, II/III and IV activities were measured spectrophotometrically, selected individual components of the ETC were assessed by immunoblotting and cellular complex IV activity was analysed by enzyme histochemistry. We show decreased complex II/III activity with increased complex I and IV activity in MSA cerebellar white matter. This corresponds with the deficit in CoQ10 previously described in MSA and reflects the high regional pathological burden of GCIs. This study highlights mitochondrial dysfunction in MSA pathogenesis, suggests an influence on selective regional vulnerability to disease and points to shared disease mechanisms in α-synucleinopathies.

Topics: alpha-Synuclein; Cerebellum; Electron Transport; Humans; Immunoblotting; Inclusion Bodies; Mitochondria; Multiple System Atrophy; Parkinson Disease; Ubiquinone

Coenzyme Q

Topics: Administration, Oral; Animals; Antioxidants; Biological Availability; Catalepsy; Disease Models, Animal; Emulsions; Female; Male; Microscopy, Electron; Movement; Oxidative Stress; Parkinson Disease; Rats; Rats, Wistar; Refractometry; Solubility; Surface-Active Agents; Swimming; Thiobarbituric Acid Reactive Substances; Ubiquinone; Viscosity

Parkinson's disease (PD) affects ∼1-2% of the elderly population. Development of a neuroprotective therapy that may be initiated early in the course of the disease to retard/prevent disease progression is highly desirable. This study aimed to investigate prophylactic treatment with coenzyme Q10 (CoQ10) before paraquat (PQ) exposure, a herbicide known to increase the risk for PD, to attain neuroprotection. In addition, therapeutic intervention with CoQ10 in mice already exposed to PQ (24 h) might halt ongoing neurodegeneration and behavioural deterioration. PD was induced experimentally in mice by an injection of PQ (10 mg/kg, intraperitoneal), twice a week for 3 consecutive weeks, either before or after the initiation of treatment with CoQ10 (200 mg/kg). The results of the sustained supplementation with CoQ10, prophylactically and therapeutically, were compared with L-DOPA (100 mg/kg). A battery of behavioural tests was performed, in addition to estimation of protein carbonyl in the brain. CoQ10 elicited a remarkable improvement in most of the behavioural tests and decreased protein carbonyl content in the brain, particularly when it was initiated before rather than after PQ induction of PD. Therefore, CoQ10, which protects against mitochondrial damage, may be beneficial in slowing the progression of PD, particularly when initiated as prophylactic treatment.

Topics: Animals; Disease Models, Animal; Levodopa; Male; Mice; Mitochondria; Neurons; Neuroprotective Agents; Oxidative Stress; Paraquat; Parkinson Disease; Protein Carbonylation; Ubiquinone

The finding of mutations of the COQ2 gene and reduced coenzyme Q10 levels in the cerebellum in multiple system atrophy (MSA) suggest that coenzyme Q10 is relevant to MSA pathophysiology. Two recent studies have reported reduced coenzyme Q10 levels in plasma and serum (respectively) of MSA patients compared to Parkinson's disease and/or control subjects, but with largely overlapping values, limited comparison with other parkinsonisms, or dependence on cholesterol levels. We hypothesized that cerebrospinal fluid (CSF) is reliable to assess reductions in coenzyme Q10 as a candidate biomarker of MSA.. In this preliminary cross-sectional study we assessed CSF coenzyme Q10 levels in 20 patients with MSA from the multicenter Catalan MSA Registry and of 15 PD patients, 10 patients with progressive supranuclear palsy (PSP), and 15 control subjects from the Movement Disorders Unit Biosample Collection of Hospital Clinic de Barcelona. A specific ELISA kit was used to determine CSF coenzyme Q10 levels. CSF coenzyme Q10 levels were compared in MSA vs. the other groups globally, pair-wise, and by binary logistic regression models adjusted for age, sex, disease severity, disease duration, and dopaminergic treatment.. CSF coenzyme Q10 levels were significantly lower in MSA than in other groups in global and pair-wise comparisons, as well as in multivariate regression models. Receiver operating characteristic curve analyses yielded significant areas under the curve for MSA vs. PD, PSP and controls.. These findings support coenzyme Q10 relevance in MSA. Low CSF coenzyme Q10 levels deserve further consideration as a biomarker of MSA.

Topics: Aged; Biomarkers; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Multiple System Atrophy; Parkinson Disease; Registries; Supranuclear Palsy, Progressive; Ubiquinone

Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons in the substantia nigra compacta (SNc). Although mitochondrial dysfunction is the critical factor in the pathogenesis of PD, the underlying molecular mechanisms are not well understood, and as a result, effective medical interventions are lacking. Mitochondrial fission and fusion play important roles in the maintenance of mitochondrial function and cell viability. Here, we investigated the effects of MitoQ, a mitochondria-targeted antioxidant, in 6-hydroxydopamine (6-OHDA)-induced in vitro and in vivo PD models. We observed that 6-OHDA enhanced mitochondrial fission by decreasing the expression of Mfn1, Mfn2 and OPA1 as well as by increasing the expression of Drp1 in the dopaminergic (DA) cell line SN4741. Notably, MitoQ treatment particularly upregulated the Mfn2 protein and mRNA levels and promoted mitochondrial fusion in the presence of 6-OHDA in a Mfn2-dependent manner. In addition, MitoQ also stabilized mitochondrial morphology and function in the presence of 6-OHDA, which further suppressed the formation of reactive oxygen species (ROS), as well as ameliorated mitochondrial fragmentation and cellular apoptosis. Moreover, the activation of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) was attributed to the upregulation of Mfn2 induced by MitoQ. Consistent with these findings, administration of MitoQ in 6-OHDA-treated mice significantly rescued the decrease of Mfn2 expression and the loss of DA neurons in the SNc. Taken together, our findings suggest that MitoQ protects DA neurons in a 6-OHDA induced PD model by activating PGC-1α to enhance Mfn2-dependent mitochondrial fusion.

Topics: Animals; Antioxidants; Cell Line; Cell Survival; Disease Models, Animal; Dopaminergic Neurons; GTP Phosphohydrolases; Humans; Male; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial Dynamics; Organophosphorus Compounds; Oxidopamine; Parkinson Disease; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Phosphorylation; RNA, Messenger; Substantia Nigra; Ubiquinone; Up-Regulation

The COQ2 gene encodes an essential enzyme for biogenesis, coenzyme Q10 (CoQ10). Recessive mutations in this gene have recently been identified in families with multiple system atrophy (MSA). Moreover, specific heterozygous variants in the COQ2 gene have also been reported to confer susceptibility to sporadic MSA in Japanese cohorts. These findings have suggested the potential usefulness of CoQ10 as a blood-based biomarker for diagnosing MSA. This study measured serum levels of CoQ10 in 18 patients with MSA, 20 patients with Parkinson's disease and 18 control participants. Although differences in total CoQ10 (i.e., total levels of serum CoQ10 and its reduced form) among the three groups were not significant, total CoQ10 level corrected by serum cholesterol was significantly lower in the MSA group than in the Control group. Our findings suggest that serum CoQ10 can be used as a biomarker in the diagnosis of MSA and to provide supportive evidence for the hypothesis that decreased levels of CoQ10 in brain tissue lead to an increased risk of MSA.

Topics: Adult; Aged; Biomarkers; Brain; Case-Control Studies; Cholesterol; Chromatography, High Pressure Liquid; Demography; Female; Follow-Up Studies; Humans; Male; Middle Aged; Multiple System Atrophy; Parkinson Disease; Risk; Ubiquinone

Brain mitochondrial function declines with age; however, the accompanying behavioral and histological alterations that are characteristic of Parkinson's disease (PD) are poorly understood. We found that the mitochondrial oxygen consumption rate (OCR) and coenzyme Q (CoQ) content were reduced in aged (15-month-old) male mice compared to those in young (6-month-old) male mice. Concomitantly, motor functions, including the rate of movement and exploratory and voluntary motor activities, were significantly reduced in the aged mice compared to the young mice. In the motor cortex of the aged mouse brain, the accumulation of α-synuclein (α-syn) phosphorylated at serine129 (Ser129) significantly increased, and the level of vesicular glutamate transporter 1 (VGluT1) decreased compared with that in the young mouse brain. The administration of exogenous water-soluble CoQ10 to aged mice via drinking water restored the mitochondrial OCR, motor function, and phosphorylated α-syn and VGluT1 levels in the motor cortex. These results suggest that early-onset motor impairment and the increased accumulation of Ser129-phosphorylated α-syn in the motor cortex are ameliorated by the exogenous administration of CoQ10.

Topics: Aging; alpha-Synuclein; Animals; Male; Mice; Mice, Inbred C57BL; Mitochondria; Motor Activity; Motor Cortex; Oxygen Consumption; Parkinson Disease; Phosphorylation; Ubiquinone; Vesicular Glutamate Transport Protein 1

Paraquat, still used as an herbicide in some parts of the world, is now regarded as a dangerous environmental neurotoxin and is linked to the development Parkinson's disease (PD). Paraquat interacts with cellular redox systems and causes mitochondrial dysfunction and the formation of reactive oxygen species, which in turn, plays a crucial role in the pathophysiology of PD. Various antioxidant therapies have been explored with the expectations that they deliver health benefits to the PD patients, however, no such therapies were effective. Here we have tested the neuroprotective efficacy of a novel water-soluble CoQ10 (Ubisol-Q10), in a rat model of paraquat-induced neurodegeneration in order to evaluate its potential application in the management of PD.. We have developed a rat model of progressive nigrostriatal degeneration by giving rats five intraperitoneal injections of paraquat (10 mg/kg/injection), once every five days. Neuronal death occurred over a period of 8 weeks with close to 50% reduction in the number of tyrosine hydroxylase-positive cells. Ubisol-Q10, at 6 mg CoQ10/kg body weight/day, was delivered as a supplement in drinking water. The intervention begun after the completion of paraquat injections when the neurodegenerative process had already began and about 20% of TH-positive neurons were lost. Ubisol-Q10 treatment halted the progression of neurodegeneration and remaining neurons were protected. The outcomes were evaluated based on the number of surviving tyrosine hydroxylase-positive neurons in the substantia nigra region and improved motor skills in response to the Ubisol-Q10 intervention. To maintain this neuroprotection, however, continuous Ubisol- Q10 supplementation was required, if withdrawn, the neuronal death pathway resumed, suggesting that the presence of CoQ10 was essential for blocking the pathway.. The CoQ10, given orally as Ubisol-Q10 in drinking solution, was effective in blocking the progression of neurodegeneration when administered therapeutically (post-toxin injection), at a much lower concentration than other previously tested oil soluble formulations and well within the acceptable daily intake of 12 mg/kg/day. Such unprecedented neuroprotection has never been reported before. These results are very encouraging and suggest that Ubisol-Q10 should be further tested and developed as a therapy for halting the progression of PD.

Topics: Administration, Oral; Animals; Cell Survival; Feasibility Studies; Male; Neurons; Neuroprotective Agents; Paraquat; Parkinson Disease; Rats; Rats, Long-Evans; Rifabutin; Solubility; Substantia Nigra; Treatment Outcome; Ubiquinone; Vitamins; Water

Biosynthesis of ubiquinones requires the intramembrane UbiA enzyme, an archetypal member of a superfamily of prenyltransferases that generates lipophilic aromatic compounds. Mutations in eukaryotic superfamily members have been linked to cardiovascular degeneration and Parkinson's disease. To understand how quinones are produced within membranes, we report the crystal structures of an archaeal UbiA in its apo and substrate-bound states at 3.3 and 3.6 angstrom resolution, respectively. The structures reveal nine transmembrane helices and an extramembrane cap domain that surround a large central cavity containing the active site. To facilitate the catalysis inside membranes, UbiA has an unusual active site that opens laterally to the lipid bilayer. Our studies illuminate general mechanisms for substrate recognition and catalysis in the UbiA superfamily and rationalize disease-related mutations in humans.

Topics: Aeropyrum; Archaeal Proteins; Cardiovascular Abnormalities; Catalysis; Catalytic Domain; Cell Membrane; Dimethylallyltranstransferase; Humans; Lipid Bilayers; Models, Chemical; Mutation; Parkinson Disease; Periplasm; Protein Structure, Secondary; Substrate Specificity; Ubiquinone

Topics: Antioxidants; Female; Humans; Male; Parkinson Disease; Ubiquinone

Although the support for the use of antioxidants, such as coenzyme Q(10) (CoQ(10)), to treat Parkinson's disease (PD) comes from the extensive scientific evidence, the results of conducted thus far clinical trials are inconclusive. It is assumed that the efficacy of CoQ(10) is hindered by insolubility, poor bioavailability, and lack of brain penetration. We have developed a nanomicellar formulation of CoQ(10) (Ubisol-Q(10)) with improved properties, including the brain penetration, and tested its effectiveness in mouse MPTP (1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine) model with the objectives to assess its potential use as an adjuvant therapy for PD. We used a subchronic MPTP model (5-daily MPTP injections), characterized by 50% loss of dopamine neurons over a period of 28 days. Ubisol-Q(10) was delivered in drinking water. Prophylactic application of Ubisol-Q(10), started 2 weeks before the MPTP exposure, significantly offset the neurotoxicity (approximately 50% neurons died in MPTP group vs. 17% in MPTP+ Ubisol-Q(10) group by day 28). Therapeutic application of Ubisol-Q(10), given after the last MPTP injection, was equally effective. At the time of intervention on day 5 nearly 25% of dopamine neurons were already lost, but the treatment saved the remaining 25% of cells, which otherwise would have died by day 28. This was confirmed by cell counts, analyses of striatal dopamine levels, and improved animals' motor skill on a beam walk test. Similar levels of neuroprotection were obtained with 3 different Ubisol-Q(10) concentrations tested, that is, 30 mg, 6 mg, or 3 mg CoQ(10)/kg body weight/day, showing clearly that high doses of CoQ(10) were not required to deliver these effects. Furthermore, the Ubisol-Q(10) treatments brought about a robust astrocytic activation in the brain parenchyma, indicating that astroglia played an active role in this neuroprotection. Thus, we have shown for the first time that Ubisol-Q(10) was capable of halting the neurodegeneration already in progress; however, to maintain it a continuous supplementation of Ubisol-Q(10) was required. The pathologic processes initiated by MPTP resumed if supplementation was withdrawn. We suggest that in addition to brain delivery of powerful antioxidants, Ubisol-Q(10) might have also supported subcellular oxidoreductase systems allowing them to maintain a favorable cellular redox status, especially in astroglia, facilitating their role in neuroprotection. Based on this data further clini

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Antioxidants; Astrocytes; Chemistry, Pharmaceutical; Disease Models, Animal; Dopaminergic Neurons; Male; Mice, Inbred C57BL; Micelles; Nanoparticles; Neuroprotective Agents; Oxidation-Reduction; Parkinson Disease; Ubiquinone

Quantum dots (QDs) have attracted increasing interest in bioimaging and sensing. Here, we report a biosensor of complex I using ubiquinone-terminated disulphides with different alkyl spacers (QnNS, n = 2, 5 and 10) as surface-capping ligands to functionalise CdSe/ZnS QDs. The enhancement or quenching of the QD bioconjugates fluorescence changes as a function of the redox state of QnNS, since QDs are highly sensitive to the electron-transfer processes. The bioconjugated QnNS-QDs emission could be modulated by complex I in the presence of NADH, which simulates an electron-transfer system part of the mitochondrial respiratory chain, providing an in vitro and intracellular complex I sensor. Epidemiological studies suggest that Parkinson's patients have the impaired activity of complex I in the electron-transfer chain of mitochondria. We have demonstrated that the QnNS-QDs system could aid in early stage Parkinson's disease diagnosis and progression monitoring by following different complex I levels in SH-SY5Y cells.

Topics: Biosensing Techniques; Cadmium; Electrochemical Techniques; Electron Transport; Electron Transport Complex I; Humans; Mitochondria; NAD; Oxidation-Reduction; Parkinson Disease; Quantum Dots; Respiration; Selenium; Ubiquinone; Zinc

Parkinson's disease (PD) is a neurodegenerative disorder for which available treatments provide symptom relief but do not stop disease progression. Mitochondria, and in particular mitochondrial dynamics, have been postulated as plausible pharmacological targets. Mitochondria-targeted antioxidants have been developed to prevent mitochondrial oxidative damage, and to alter the involvement of reactive oxygen species (ROS) in signaling pathways. In this study, we have dissected the effect of MitoQ, which is produced by covalent attachment of ubiquinone to a triphenylphosphonium lipophilic cation by a ten carbon alkyl chain. MitoQ was tested in an in vitro PD model which involves addition of 6-hydroxydopamine (6-OHDA) to SH-SY5Y cell cultures. At sublethal concentrations of 50μM, 6-OHDA did not induce increases in protein carbonyl, mitochondrial lipid peroxidation or mitochondrial DNA damage. However, after 3h of treatment, 6-OHDA disrupts the mitochondrial morphology and activates the machinery of mitochondrial fission, but not fusion. Addition of 6-OHDA did not increase the levels of fission 1, mitofusins 1 and 2 or optic atrophy 1 proteins, but does lead to the translocation of dynamin related protein 1 from the cytosol to the mitochondria. Pre-treatment with MitoQ (50nM, 30min) results in the inhibition of the mitochondrial translocation of Drp1. Furthermore, MitoQ also inhibited the translocation of the pro-apoptotic protein Bax to the mitochondria. These findings provide mechanistic evidence for a role for redox events contributing to mitochondrial fission and suggest the potential of mitochondria-targeted therapeutics in diseases that involve mitochondrial fragmentation due to oxidative stress.

Topics: Antioxidants; Cell Line; Humans; Mitochondria; Mitochondrial Dynamics; Organophosphorus Compounds; Oxidative Stress; Oxidopamine; Parkinson Disease; Reactive Oxygen Species; Ubiquinone

There is evidence that increased homocysteine (Hcy) levels might accelerate dopaminergic cell death in Parkinson's disease (PD) through neurotoxic effects. Homocysteine neurotoxicity mainly relies on redox state alterations. The present work was aimed at investigating the relationships between plasma Hcy concentrations and percent content of oxidized versus total Coenzyme Q10 (%CoQ10) in 60 PD patients and 82 healthy subjects. Both groups were screened for plasma levels of Hcy, vitamin B12, folate, %CoQ10 and C677T methylenetetrahydrofolate reductase (MTHFR) gene polymorphism. The MTHFR TT677 mutated genotype was found more frequently in patients than in controls (p = 0.01). In a multivariate analysis, Hcy levels and %CoQ10 were associated with the case/control category (p < 0.0001), MTHFR genotype (p < 0.0001) and their interaction term (p = 0.0015), even after adjusting for age, sex, folate and vitamin B12. Patients carrying the TT677 genotype exhibited the highest values of Hcy and %CoQ10 (p < 0.0001). Structural equation modelling evidenced that the TT677 genotype and levodopa daily dose were independently and directly correlated with Hcy (p < 0.0001, and p = 0.003, respectively), which, in turn, showed a significant correlation (p < 0.0001) with the %CoQ10 in PD patients. Our results suggest that increased Hcy levels act as mediator of the systemic oxidative stress occurring in PD, and %CoQ10 determination might be regarded as a predictor of toxic Hcy effects.

Topics: Aged; Antiparkinson Agents; Female; Folic Acid; Homocysteine; Humans; Hyperhomocysteinemia; Levodopa; Male; Methylenetetrahydrofolate Reductase (NADPH2); Middle Aged; Parkinson Disease; Polymorphism, Genetic; Ubiquinone; Vitamin B 12

Parkinson's disease (PD) is a common neurodegenerative disorder caused by genetic and environmental factors that results in degeneration of the nigrostriatal dopaminergic pathway in the brain. We analyzed neural cells generated from induced pluripotent stem cells (iPSCs) derived from PD patients and presymptomatic individuals carrying mutations in the PINK1 (PTEN-induced putative kinase 1) and LRRK2 (leucine-rich repeat kinase 2) genes, and compared them to those of healthy control subjects. We measured several aspects of mitochondrial responses in the iPSC-derived neural cells including production of reactive oxygen species, mitochondrial respiration, proton leakage, and intraneuronal movement of mitochondria. Cellular vulnerability associated with mitochondrial dysfunction in iPSC-derived neural cells from familial PD patients and at-risk individuals could be rescued with coenzyme Q(10), rapamycin, or the LRRK2 kinase inhibitor GW5074. Analysis of mitochondrial responses in iPSC-derived neural cells from PD patients carrying different mutations provides insight into convergence of cellular disease mechanisms between different familial forms of PD and highlights the importance of oxidative stress and mitochondrial dysfunction in this neurodegenerative disease.

Topics: Humans; Indoles; Induced Pluripotent Stem Cells; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Mitochondria; Neurons; Parkinson Disease; Phenols; Protein Serine-Threonine Kinases; Sirolimus; Ubiquinone

Little is known about research participants' understanding of consent information over the course of a clinical study and the relationship of this information with participant behavior.. We conducted a cross sectional patient completed questionnaire of comprehension and satisfaction administered at the end of a Parkinson's disease clinical trial.. Scores on 9 comprehension items in a 30 item questionnaire covering the key elements of informed consent.. 78% of eligible trial participants completed this substudy. Greater than 90% of respondents showed good comprehension of the study purpose, method of treatment assignment, experimental nature of drugs, voluntary participation, and expected effect of the trial on their PD. However, 42.3% of subjects incorrectly endorsed that participating in the study was part of the "usual treatment" for their PD. We found no relationship between comprehension, compliance, and satisfaction with whether or not one's own neurologist was also the study doctor. Years of education and cognitive function at baseline were correlated with comprehension of study information.. Overall comprehension of key study information presented in the consent was high after 12 months of trial participation, although there were inconsistencies in responses that need further study.

Topics: Adult; Aged; Clinical Trials as Topic; Cognition; Comprehension; Cross-Sectional Studies; Female; Follow-Up Studies; Humans; Informed Consent; Male; Medication Adherence; Middle Aged; Parkinson Disease; Research Subjects; Surveys and Questionnaires; Treatment Outcome; Ubiquinone; Vitamins

The aim of this study was to investigate the possibility that mitochondrial oxidative damage, oxidative DNA damage or both contribute to the neurodegenerative process of Parkinson's disease (PD). We employed high-performance liquid chromatography (HPLC) using an electrochemical detector to measure concentrations of the reduced and oxidized forms of coenzyme Q-10 (CoQ-10) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the cerebrospinal fluid (CSF) of 20 patients with PD and 20 age-matched controls with no neurological disease. The percentage of oxidized to total CoQ-10 (%CoQ-10) in the CSF of the PD group (80.3+/-17.9%) was significantly higher than in the control group (68.2+/-20.4%, P<0.05). In addition, the concentration of 8-OHdG in the CSF of PD patients was greater than in the CSF of controls (P<0.0001) and was positively correlated with the duration of illness (r(s)=0.87, P<0.001). Finally, the %CoQ-10 was correlated with concentrations of 8-OHdG in the CSF of PD patients (r(s)=0.56, P<0.01). The present study suggests that both mitochondrial oxidative damage and oxidative DNA damage play important roles in the pathogenesis of early PD development.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Deoxyguanosine; DNA Damage; Female; Humans; Male; Mitochondria; Oxidation-Reduction; Oxidative Stress; Parkinson Disease; Severity of Illness Index; Ubiquinone

We explored the hypotheses that an investigator's belief in a putative neuroprotective agent might influence the timing of symptomatic intervention and the assessment of signs and symptoms of patients with Parkinson's disease with the Unified Parkinson's Disease Rating Scale (UPDRS). These hypotheses were tested with Cox and general linear modeling, using data from a previously published double-blind placebo-controlled futility trial of coenzyme Q(10) and GPI-1485. We found the investigators' level of confidence in these agents had no effect on the time to symptomatic therapy or on the change in UPDRS during 12 months of treatment.

Topics: Adult; Aged; Dose-Response Relationship, Drug; Double-Blind Method; Female; Humans; Male; Middle Aged; Neuroprotective Agents; Parkinson Disease; Randomized Controlled Trials as Topic; Severity of Illness Index; Statistics, Nonparametric; Treatment Outcome; Ubiquinone

Multicenter clinical research involves parallel Institutional Review Board (IRB) reviews based on the premise that local review reflects aspects of the research environment. We examined the costs and effects of local IRB review of the consent and protocol in a multicenter clinical trial in Parkinson disease. Seventy-six percent of changes to the consent reflected standard institutional language, with no substantive changes to the protocol. The costs of this process exceeded $100,000. These findings support initiatives by the Office of Human Research Protections (OHRP) and the National Cancer Institute (NCI) to facilitate centralized reviews. This may be an opportune time for the National Institute of Neurological Disorders and Stroke (NINDS) to adopt a central review model.

Topics: Antioxidants; Biomedical Research; Double-Blind Method; Ethics Committees, Research; Humans; Multicenter Studies as Topic; Parkinson Disease; Randomized Controlled Trials as Topic; Ubiquinone; United States; Vitamin E

Topics: Antiparkinson Agents; Clinical Trials as Topic; Creatine; Humans; Indans; Parkinson Disease; Selegiline; Ubiquinone

Mitochondrial dysfunction, oxidative stress, and alpha-synuclein oligomerization occur in Parkinson disease (PD). We used an in vitro PD cybrid approach that models these three phenomena specifically to evaluate the impact of mitochondria-derived oxidative stress on alpha-synuclein oligomerization. Compared with control cybrid cell lines, reactive oxygen species (ROS) production and protein oxidative stress markers were elevated in PD cybrids. The antioxidants CoQ(10) and GSH attenuated changes in PD cybrid peroxide, protein carbonyl, and protein sulfhydryl levels. Elevated PD cybrid alpha-synuclein oligomer levels were also attenuated by CoQ(10) and GSH. In PD cybrids, alpha-synuclein oligomerization was activated via a complex I-mediated increase in the free tubulin/polymerized tubulin ratio. CoQ(10) but not GSH increased complex I activity, restored ATP to control levels, and normalized the PD cybrid free tubulin/polymerized tubulin ratio. Overall, we conclude that two different antioxidants can decrease alpha-synuclein oligomerization whether by improving mitochondrial function or by preventing protein carbonylation or both. We conclude that mitochondrial dysfunction can induce alpha-synuclein oligomerization via ATP depletion-driven microtubule depolymerization and via ROS increase-driven protein oxidation.

Topics: alpha-Synuclein; Biopolymers; Blotting, Western; Electrophoresis, Polyacrylamide Gel; Glutathione; Humans; Immunohistochemistry; Oxidative Stress; Parkinson Disease; Reactive Oxygen Species; Ubiquinone

Coenzyme Q(10) (CoQ(10)) and creatine are promising agents for neuroprotection in neurodegenerative diseases via their effects on improving mitochondrial function and cellular bioenergetics and their properties as antioxidants. We examined whether a combination of CoQ(10) with creatine can exert additive neuroprotective effects in a MPTP mouse model of Parkinson's disease, a 3-NP rat model of Huntington's disease (HD) and the R6/2 transgenic mouse model of HD. The combination of the two agents produced additive neuroprotective effects against dopamine depletion in the striatum and loss of tyrosine hydroxylase neurons in the substantia nigra pars compacta (SNpc) following chronic subcutaneous administration of MPTP. The combination treatment resulted in significant reduction in lipid peroxidation and pathologic alpha-synuclein accumulation in the SNpc neurons of the MPTP-treated mice. We also observed additive neuroprotective effects in reducing striatal lesion volumes produced by chronic subcutaneous administration of 3-NP to rats. The combination treatment showed significant effects on blocking 3-NP-induced impairment of glutathione homeostasis and reducing lipid peroxidation and DNA oxidative damage in the striatum. Lastly, the combination of CoQ(10) and creatine produced additive neuroprotective effects on improving motor performance and extending survival in the transgenic R6/2 HD mice. These findings suggest that combination therapy using CoQ(10) and creatine may be useful in the treatment of neurodegenerative diseases such as Parkinson's disease and HD.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; 8-Hydroxy-2'-Deoxyguanosine; alpha-Synuclein; Analysis of Variance; Animals; Chromatography, High Pressure Liquid; Creatine; Deoxyguanosine; Disease Models, Animal; Dopamine; Drug Therapy, Combination; Glutathione; Glutathione Disulfide; Huntington Disease; Lipid Peroxidation; Male; Malondialdehyde; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Nitro Compounds; Parkinson Disease; Propionates; Rats; Rats, Inbred Lew; Tyrosine 3-Monooxygenase; Ubiquinone

There is increasing evidence that impairment of mitochondrial function and oxidative damage are contributing factors to the pathophysiology of Parkinson's disease (PD). Studies have reported decreased levels of the mitochondrial electron transport chain carrier, coenzyme Q(10) (CoQ(10)) in plasma and platelets from PD patients. Although a deficit in peripheral CoQ(10) has been reported no studies have assessed the CoQ(10) status of the PD brain. In this study we investigated the CoQ(10) status of the substantia nigra, cerebellum, cortex and striatum brain regions of both PD patients and age-matched controls. The results of this study indicate a significant reduction (p=0.007) in CoQ(10) concentration in the cortex region of the brain. In conclusion, the results of this study indicate evidence of a deficit in brain CoQ(10) status may be involved in the pathophysiology of PD.

Topics: Aged; Brain; Case-Control Studies; Female; Humans; Male; Parkinson Disease; Ubiquinone

The concentrations of oxidized coenzyme Q-10 (CoQ-10) and reduced CoQ-10 in the cerebrospinal fluid (CSF) of patients with Parkinson's disease (PD) was examined in order to determine whether the balance in oxidized and reduced CoQ-10 is related to the pathogenesis of PD. The percentage of oxidized/total CoQ-10 (%CoQ-10) in the CSF was significantly higher in the untreated PD group (80.3+/-17.9%) compared to the normal control group (68.2+/-20.4%) (p<0.05). The %CoQ-10 in the CSF of PD patients showed significant negative correlation with the duration of illness. These findings in living patients provide in vivo evidence for a possible role for %CoQ-10 in the pathogenesis in the early stages of PD development.

Topics: Aged; Biomarkers; Case-Control Studies; Female; Humans; Male; Matched-Pair Analysis; Middle Aged; Oxidative Stress; Parkinson Disease; Reference Values; Statistics, Nonparametric; Ubiquinone

Alpha-synuclein (alphaS) is the major component of the filamentous inclusions that constitute defining characteristics of Lewy body diseases (LBD) and multiple system atrophy (MSA). Clinically, antioxidant vitamins, such as vitamin E and the vitamin-like substance coenzyme Q10, have been used in the treatment of LBD with some efficacy. Using fluorescence spectroscopy with thioflavin S, electron microscopy and atomic force microscopy, here we examined the effects of ten antioxidant vitamins and vitamin-like substances, vitamin A (retinol, retinal and retinoic acid), beta-carotene, vitamins B2, B6, C, E, coenzyme Q10 and alpha-lipoic acid, on the formation of alphaS fibrils (falphaS) and on preformed falphaS. Among them, vitamin A, beta-carotene and coenzyme Q10 dose-dependently inhibited the formation of falphaS. Moreover, they also dose-dependently destabilized preformed falphaS. With such potent anti-fibrillogenic as well as fibril-destabilizing activities, these compounds could be useful in the treatment and prevention of LBD and MSA.

Topics: alpha-Synuclein; Antioxidants; Benzothiazoles; beta Carotene; Coenzymes; Humans; Lewy Body Disease; Microscopy, Atomic Force; Microscopy, Electron; Microscopy, Fluorescence; Neurofibrils; Neuroprotective Agents; Parkinson Disease; Thiazoles; Ubiquinone; Vitamin A; Vitamins

Topics: Aged; Anticholesteremic Agents; Cholesterol; Cholesterol, LDL; Coenzymes; Cohort Studies; Female; Follow-Up Studies; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Middle Aged; Parkinson Disease; Proportional Hazards Models; Prospective Studies; Risk Factors; Ubiquinone

The exact molecular mechanism of progressive loss of neuromelanin containing nigrostriatal dopaminergic neurons in Parkinson's disease (PD) remains unknown, yet evidence suggests that iron might play an important role in PD pathology. In this study we have determined the neuroprotective role of coenzyme Q(10) (CoQ(10)) in ironinduced apoptosis in cultured human dopaminergic (SK-N-SH) neurons, in metallothionein gene- manipulated mice, and in alpha-synuclein knockout (alpha-synko) mice with a primary objective to assess a possible therapeutic and anti-inflammatory potential for CoQ(10) in PD. Iron-induced mitochondrial damage and apoptosis were characterized by reactive oxygen species production, increased metallothionein and glutathione synthesis, caspase- 3 activation, NF-kappaB induction, and decreased Bcl-2 expression, without any significant change in Bax expression. Lower concentrations of FeSO4 (1-10 microM) induced perinuclear aggregation of mitochondria, whereas higher concentrations (100-250 microM) induced CoQ(10) depletion, plasma membrane perforations, mitochondrial damage, and nuclear DNA condensation and fragmentation. FeSO(4)-induced deleterious changes were attenuated by pretreatment with CoQ(10) and by deferoxamine, a potent iron chelator, in SK-N-SH cells. 1-Methyl, 4-phenyl, 1,2,3,6- tetrahydropyridine (MPTP)-induced striatal release of free iron, and NF-kappaB expression were significantly increased; whereas ferritin and melanin synthesis were significantly reduced in the substantia nigra pars compacta (SNpc) of MT(dko) mice as compared with control(wt) mice, MT(trans) mice, and alpha-synko mice. CoQ(10) treatment inhibited MPTP-induced NF-kappaB induction in all of the genotypes. These data suggest that glutathione and metallothionein synthesis might be induced as an attempt to combat iron-induced oxidative stress, whereas exogenous administration of CoQ(10) or of metallothionein induction might provide CoQ(10)-mediated neuroprotection in PD.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Apoptosis; Cell Line; Coenzymes; Deferoxamine; Dopamine; Dopamine Agents; Glutathione; Humans; Iron; Lipid Peroxidation; Melanins; Metallothionein; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Neurons; Neuroprotective Agents; NF-kappa B; Parkinson Disease; Reactive Oxygen Species; Siderophores; Ubiquinone; Vitamins

Regional distribution of coenzyme Q10 and mitochondrial complex-1 activity were estimated in the brains of control-(C57BL/6), metallothionein knock out-, metallothionein transgenic-, and homozygous weaver mutant mice; and human dopaminergic (SK-N-SH) cells with a primary objective to determine the neuroprotective potential of coenzyme Q10 in Parkinson's disease. Complex-1 activity as well as coenzyme Q10 were significantly higher in the cerebral cortex as compared to the striatum in all the genotypes examined. Complex-1 activity and coenzyme Q10 were significantly reduced in weaver mutant mice and metallothionein knock out mice, but were significantly increased in metallothionein transgenic mice. The reduced complex-1 activity and 18F-DOPA uptake occurred concomitantly with negligible differences in the coenzyme Q10 between in the cerebral cortex and striatum of weaver mutant mice. Administration of coenzyme Q10 increased complex-1 activity and partially improved motoric performance in weaver mutant mice. Direct exposure of rotenone also reduced coenzyme Q10, complex-1 activity, and mitochondrial membrane potential in SK-N-SH cells. Rotenone-induced down-regulation of complex-1 activity was attenuated by coenzyme Q10 treatment, suggesting that complex-1 may be down regulated due to depletion of coenzyme Q10 in the brain. Therefore, metallothionein-induced coenzyme Q10 synthesis may provide neuroprotection by augmenting mitochondrial complex-1 activity in Parkinson's disease.

Topics: Analysis of Variance; Animals; Brain; Cell Line, Tumor; Chromatography, High Pressure Liquid; Coenzymes; Dihydroxyphenylalanine; Disease Models, Animal; Electron Transport Complex I; Fluorine Radioisotopes; Humans; Male; Metallothionein; Mice; Mice, Inbred C57BL; Mice, Neurologic Mutants; Mice, Transgenic; Neuroblastoma; Neuroprotective Agents; Parkinson Disease; Positron-Emission Tomography; Statistics as Topic; Tissue Distribution; Ubiquinone

Several recent findings suggest a role of lipid and cholesterol metabolism in the pathogenesis of Parkinson's disease. Therefore, the authors examined the association between serum levels of cholesterol and the risk of Parkinson's disease in the prospective, population-based Rotterdam Study among 6,465 subjects aged 55 or more years with repeated in-person examination and on average 9.4 years of follow-up (1990-2004). Higher serum levels of total cholesterol were associated with a significantly decreased risk of Parkinson's disease (age- and sex-adjusted hazard ratio per mmol/liter increase in cholesterol = 0.77, 95% confidence interval: 0.64, 0.94), with evidence for a dose-effect relation. The association was restricted to women and remained unchanged after adjustment for multiple potential confounders. These findings may indicate a role of lipids in the pathogenesis of Parkinson's disease. Alternatively, they could reflect the strong correlation-especially in women-between levels of serum cholesterol and the antioxidant coenzyme Q10. If confirmed, this would provide further support for an important role of oxidative stress in the pathogenesis of Parkinson's disease.

Topics: Aged; Cholesterol; Coenzymes; Female; Humans; Male; Middle Aged; Netherlands; Oxidative Stress; Parkinson Disease; Prospective Studies; Risk Factors; Ubiquinone

We have examined potent peroxynitrite ion (ONOO-) generator 3-morpholinosydnonimine (SIN-1)-induced neurotoxicity in control wild-type (control(wt)) mice, metallothionein double knockout (MT(dko)) mice, metallothionein-transgenic (MT(trans)) mice, and in cultured human dopaminergic (SK-N-SH) neurons to determine the neuroprotective potential of metallothionein against ONOO(-)-induced neurodegeneration in Parkinson disease (PD). SIN-1-induced lipid peroxidation, reactive oxygen species synthesis, caspase-3 activation, and apoptosis were attenuated by metallothionein gene overexpression and augmented by metallothionein gene down-regulation. A progressive nigrostriatal dopaminergic neurodegeneration in weaver mutant (wv/wv) mice was associated with enhanced nitrite ion synthesis, metallothionein down-regulation, and significantly reduced dopamine synthesis and 18F-DOPA uptake as determined by high-resolution micropositron emission tomography neuroimaging. The striatal (18)F-DOPA uptake was significantly higher in MT(trans) mice than in MT(dko) and alpha-synuclein knockout (alpha-Syn(ko)) mice. These observations provide further evidence that nitric oxide synthase activation and ONOO- synthesis may be involved in the etiopathogenesis of PD, and that metallothionein gene induction may provide neuroprotection.

Topics: Animals; Apoptosis; Caspase 3; Caspases; Coenzymes; Dopamine; Enzyme Activation; Lipid Peroxidation; Metallothionein; Mice; Mice, Inbred C57BL; Mice, Transgenic; Molsidomine; Oxidative Stress; Parkinson Disease; Reactive Oxygen Species; Ubiquinone

'Statins', drugs that lower cholesterol are widely used. Statins block cholesterol in the body and brain by inhibiting HMG-Co-A reductase. This pathway is shared by CoQ-10. An unintended consequence of the statins is lowering of CoQ-10. As CoQ-10 may play a role in PD, its possible statins may worsen PD. Such a report has appeared. Statins came into wide use in 1997-1998, 6 years before our study began. Thus 74% of our patients on a statin had a PD duration of 1-6 years versus 56% of our patients not on a statin. A direct comparison of patients on a statin and not on a statin would bias the study in favor of the statins: patients on a statin would have a shorter disease duration and less advanced PD. Therefore we divided the patients into two groups. Group I consisted of 128 patients on a statin, and 252 not on a statin who had PD for 1-6 years. In this group, disease severity (Hoehn & Yahr Stage), levodopa dose, Co-enzyme Q10 use, prevalence of 'wearing off', dyskinesia and dementia were similar. Group II consisted of 45 patients on a statin and 200 patients not on a statin who had PD for 7-22 years. In this group disease severity, levodopa dose, Co-enzyme Q10 use, prevalence of wearing off, dyskinesia and dementia were similar. Statins although they may affect Co-enzyme Q10 levels in the body and the brain, do not worsen PD at least as assessed by stage, and prevalence of wearing-off, dyskinesia, and dementia.

Topics: Aged; Antiparkinson Agents; Cholesterol; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipidemias; Levodopa; Male; Middle Aged; Parkinson Disease; Severity of Illness Index; Ubiquinone

We determined systemic oxidative stress in Parkinson's disease (PD) patients, patients with other neurological diseases (OND) and healthy controls by measurement of in vitro lipoprotein oxidation and levels of hydro- and lipophilic antioxidants in plasma and cerebrospinal fluid (CSF). Additionally, we investigated the influence of levodopa (LD) and dopamine agonist therapy (DA) on the oxidative status in PD patients. We found increased oxidative stress, seen as higher levels of lipoprotein oxidation in plasma and CSF, decrease of plasma levels of protein sulfhydryl (SH) groups and lower CSF levels of alpha-tocopherol in PD patients compared to OND patients and controls. Levodopa treatment did not significantly change the plasma lipoprotein oxidation but LD monotherapy tended to result in an increase of autooxidation and in a decrease of plasma antioxidants with significance for ubiquinol-10. DA monotherapy was significantly associated with higher alpha-tocopherol levels. Patients with DA monotherapy or co-medication with DA showed a trend to lower lipoprotein oxidation. These data support the concept of oxidative stress as a factor in the pathogenesis of PD and might be an indicator of a potential prooxidative role of LD and a possible antioxidative effect of DA in PD treatment.

Topics: Adult; alpha-Tocopherol; Antioxidants; Antiparkinson Agents; Ascorbic Acid; Biomarkers; Brain; Dopamine; Female; Humans; Levodopa; Lipoproteins; Male; Middle Aged; Oxidative Stress; Parkinson Disease; Reference Values; Sulfhydryl Compounds; Ubiquinone; Up-Regulation

Several lines of evidence suggest an impairment of mitochondrial function in the brain of patients with Parkinson's disease (PD). However, the presence of a detectable mitochondrial defect in extracerebral tissue of these patients remains a matter of dispute. Therefore, we investigated mitochondrial function in fibroblasts of 18 PD patients applying biochemical micromethods. Putative beneficial effects of coenzyme Q(10) (CoQ(10)), a potent antioxidant, on the mitochondrial function of skin fibroblast cultures were evaluated. Applying inhibitor titrations of the mitochondrial respiration to calculate flux control coefficients of respiratory chain complexes I and IV, we observed deficiencies of both complexes in cultivated skin fibroblasts of PD patients. Cultivation of fibroblasts in the presence of 5 microM CoQ(10) restored the activity of impaired respiratory chain complexes in the fibroblast cultures of 9 out of 18 PD patients. Our data support the presence of a generalised mitochondrial defect in at least a subgroup of patients with PD that can be partially ameliorated in vitro by coenzyme Q(10) treatment.

Topics: Adenosine Diphosphate; Adult; Aged; Amobarbital; Antioxidants; Cells, Cultured; Coenzymes; Drug Interactions; Female; Fibroblasts; Glutamic Acid; Humans; Male; Middle Aged; Mitochondria; NAD; Oxygen; Parkinson Disease; Pyruvic Acid; Skin; Ubiquinone

Topics: Antioxidants; Antiparkinson Agents; Coenzymes; Humans; Neurologic Examination; Neuroprotective Agents; Parkinson Disease; Ubiquinone

The effects of exogenous toxins (MPP(+), rotenone) and potentially neurotoxic properties of levodopa (L-DOPA) on the survival rate of dopaminergic neurons in dissociated primary culture are presented. Dopamine agonists show a capacity to counteract MPP(+)-toxicity. Moreover, a preserving potential of the antioxidant and bioenergetic coenzyme Q(10) (CoQ(10)) on the activities of tyrosine hydroxylase (TH), complexes I and II of the respiratory chain, and hexokinase activity in striatal slice cultures against MPP(+) is demonstrated.

Topics: Animals; Coenzymes; Disease Models, Animal; Dopamine; Dopamine Agonists; Mice; Mice, Inbred C57BL; Neurons; Neurotoxins; Oxidative Stress; Parkinson Disease; Tyrosine 3-Monooxygenase; Ubiquinone

Oxidative stress is suggested to play an important role in the pathogenesis of Parkinson's disease (PD). However, no elevation of plasma oxidative stress marker has been reported. We measured percent content of the oxidized form of coenzyme Q10 in total coenzyme Q10 (%CoQ-10) because %CoQ-10 has been shown to be a sensitive marker of oxidative stress. A slight but significant elevation in %CoQ-10 was observed in PD patients when compared with age/gender-matched normal subjects, suggesting elevated systemic oxidative stress in PD patients.

Topics: Adult; Aged; Aged, 80 and over; Alzheimer Disease; Case-Control Studies; Chromatography, High Pressure Liquid; Coenzymes; Electrochemistry; Female; Humans; Male; Middle Aged; Oxidation-Reduction; Oxidative Stress; Parkinson Disease; Plasma; Statistics, Nonparametric; Ubiquinone

Topics: Aged; Animals; Antioxidants; Coenzymes; Disease Progression; Dose-Response Relationship, Drug; Drug Interactions; Humans; Middle Aged; Parkinson Disease; Rats; Treatment Outcome; Ubiquinone; Vitamin E

Topics: Animals; Antioxidants; Coenzymes; Drug Interactions; Humans; Parkinson Disease; Rats; Ubiquinone; Vitamin E

Topics: Antioxidants; Clinical Trials as Topic; Coenzymes; Cytoprotection; Humans; Mitochondrial Diseases; Parkinson Disease; Severity of Illness Index; Ubiquinone

An increasing body of evidence now suggests the involvement of mitochondrial abnormalities in the etiology of neurodegenerative diseases, such as Parkinson's disease (PD) and Alzheimer disease. In this Perspective, we describe a recent study that shows that treatment of human patients with the antioxidant coenzyme Q(10'), which functions in concert with certain mitochondrial enzymes, reduced the worsening of symptoms associated with PD. These findings are consistent with the hypothesis that mitochondrial dysfunction plays a role in the pathogenesis of PD and that treatments that target mitochondrial biochemistry might ameliorate the functional decline observed in patients suffering from PD.

Topics: Coenzymes; Humans; Mitochondria; Oxygen; Parkinson Disease; Ubiquinone

The reduced form of coenzyme Q10 (CoQ10) acts as a lipophilic antioxidant and participates in electron and proton transport of the respiratory chain in the inner mitochondrial membrane. An alteration in CoQ10 redox state may thus reflect a change in membrane electron transport and the effectiveness of defense against toxic reactive oxygen species such as hydrogen peroxide and superoxide. In Parkinson's disease alterations in the activities of complex I have been reported in substantia nigra and platelets. Deficiency of mitochondrial enzyme activities could affect electron transport which might be reflected by the platelet CoQ10 redox state.. We have determined concentrations of the reduced and oxidized forms of CoQ10 and the activity of monoamine oxidase B in platelets isolated from parkinsonian patients and age- and gender-matched controls.. Platelet CoQ10 redox ratios (reduced CoQ10 to oxidized CoQ10) and the ratio of the reduced form, compared with total platelet CoQ10, were significantly decreased in de novo parkinsonian patients. Platelet CoQ10 redox ratios were further decreased by L-DOPA treatment (not significant), whilst selegiline treatment partially restored CoQ10 redox ratios. Monoamine oxidase activities in non-selegiline treated patients were similar to controls.. Our results either suggest an impairment of electron transport or a higher need for reduced forms of CoQ10 in the platelets of even de novo parkinsonian patients. However, the CoQ10 redox ratio was not correlated to disease severity, as determined by the Hoehn and Yahr PD disability classification, suggesting that this parameter may not be useful as a peripheral trait marker for the severity of PD but as an early state marker of PD.

Topics: Aged; Aged, 80 and over; Antioxidants; Antiparkinson Agents; Biomarkers; Blood Platelets; Coenzymes; Female; Humans; Levodopa; Male; Middle Aged; Monoamine Oxidase; Oxidation-Reduction; Parkinson Disease; Selegiline; Ubiquinone

We compared serum levels of coenzyme Q10 and the coenzyme Q10/cholesterol ratio in 33 patients with Parkinson's disease (PD) and 31 matched controls. The mean serum coenzyme Q10 levels did not differ significantly between the 2 study groups. Coenzyme Q10 levels were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale (UPDRS) or the Hoehn and Yahr staging in the PD group. The coenzyme Q10/cholesterol ratio had a significant correlation (although low) with duration of the disease (r = -0.46), total UPDRS score (r = -0.39), motor examination of the UPDRS (r = 0.45). These values were not influenced significantly by therapy with levodopa or dopamine agonists. The normality of serum coenzyme Q10 and coenzyme Q10/cholesterol ratio suggest that these values are not related with the risk for PD.

Topics: Age of Onset; Aged; Cholesterol; Coenzymes; Female; Humans; Male; Mitochondria; Oxidative Stress; Parkinson Disease; Risk Factors; Time Factors; Ubiquinone

Catabolism of tryptophan and tyrosine in relation to the isoprenoid pathway was studied in neurological and psychiatric disorders. The concentration of trytophan, quinolinic acid, kynurenic acid, serotonin and 5-hydroxyindoleacetic acid was found to be higher in the plasma of patients with all these disorders; while that of tyrosine, dopamine, epinephrine and norepinephrine was lower. There was increase in free fatty acids and decrease in albumin (factors modulating tryptophan transport) in the plasma of these patients. Concentration of digoxin, a modulator of amino acid transport, and the activity of HMG CoA reductase, which synthesizes digoxin, were higher in these patients; while RBC membrane Na+-K+ ATPase activity showed a decrease. Concentration of plasma ubiquinone (part of which is synthesised from tyrosine) and magnesium was also lower in these patients. No morphine could be detected in the plasma of these patients except in MS. On the other hand, strychnine and nicotine were detectable. These results indicate hypercatabolism of tryptophan and hypocatabolism of tyrosine in these disorders, which could be a consequence of the modulating effect of hypothalamic digoxin on amino acid transport.

Topics: Adult; Biogenic Monoamines; Brain Diseases; Brain Neoplasms; Digoxin; Epilepsy, Generalized; Erythrocytes; Fatty Acids, Nonesterified; Female; Glioma; Glycine Agents; Humans; Hydroxymethylglutaryl CoA Reductases; Kynurenic Acid; Magnesium; Male; Microvascular Angina; Middle Aged; Morphine; Narcotics; Nicotine; Nicotinic Agonists; Parkinson Disease; Quinolinic Acid; Schizophrenia; Serum Albumin; Sodium-Potassium-Exchanging ATPase; Strychnine; Tryptophan; Tyrosine; Ubiquinone

Two substances which are products of the isoprenoid pathway, can participate in lipid peroxidation. One is digoxin, which by inhibiting membrane Na(+)-K+ ATPase, causes increase in intracellular Ca2+ and depletion of intracellular Mg2+, both effects contributing to increase in lipid peroxidation. Ubiquinone, another products of the pathway is a powerful membrane antioxidant and its deficiency can also result in defective electron transport and generation of reactive oxygen species. In view of this and also in the light of some preliminary reports on alteration in lipid peroxidation in neuropsychiatric disorders, a study was undertaken on the following aspects in some of these disorders (primary generalised epilepsy, schizophrenia, multiple sclerosis, Parkinson's disease and CNS glioma)--1) concentration of digoxin, ubiquinone, activity of HMG CoA reductase and RBC membrane Na(+)-K+ ATPase 2) activity of enzymes involved in free radical scavenging 3) parameters of lipid peroxidation and 4) antioxidant status. The result obtained indicates an increase in the concentration of digoxin and activity of HMG CoA reductase, decrease in ubiquinone levels and in the activity of membrane Na(+)-K+ ATPase. There is increased lipid peroxidation as evidenced from the increase in the concentration of MDA, conjugated dienes, hydroperoxides and NO with decreased antioxidant protection as indicated by decrease in ubiquinone, vit E and reduced glutathione in schizophrenia, Parkinson's disease and CNS glioma. The activity of enzymes involved in free radical scavenging like SOD, catalase, glutathione peroxidase and glutathione reductase is decreased in the above diseases. However, there is no evidence of any increase in lipid peroxidation in epilepsy or MS. The role of increased operation of the isoprenoid pathway as evidenced by alteration in the concentration of digoxin and ubiquinone in the generation of free radicals and protection against them in these disorders is discussed.

Topics: Central Nervous System Neoplasms; Digoxin; Epilepsy, Generalized; Free Radicals; Glioma; Humans; Lipid Peroxidation; Multiple Sclerosis; Nervous System Diseases; Parkinson Disease; Schizophrenia; Ubiquinone

The activities of complex I and complex II/III in platelet mitochondria are reduced in patients with early, untreated Parkinson's disease. Coenzyme Q10 is the electron acceptor for complex I and complex II. We found that the level of coenzyme Q10 was significantly lower in mitochondria from parkinsonian patients than in mitochondria from age- and sex-matched control subjects and that the levels of coenzyme Q10 and the activities of complex I and complex II/III were significantly correlated.

Topics: Blood Platelets; Coenzymes; Electron Transport Complex II; Electron Transport Complex III; Female; Humans; Male; Mitochondria; Multienzyme Complexes; NAD(P)H Dehydrogenase (Quinone); Oxidoreductases; Parkinson Disease; Reference Values; Succinate Dehydrogenase; Ubiquinone