MyMedR

Displaying publications 21 - 29 of 29 in total

Abstract:

Sort:

Osmotic Demyelination Syndrome With Evolving Movement Disorders

Tan AH, Lim SY, Ng RX

JAMA Neurol, 2018 07 01;75(7):888-889.
PMID: 29799978 DOI: 10.1001/jamaneurol.2018.0983
Matched MeSH terms: Levodopa/therapeutic use
Fulltext Palm Fruit Bioactives augment expression of Tyrosine Hydroxylase in the Nile Grass Rat basal ganglia and alter the colonic microbiome

Weinberg RP, Koledova VV, Subramaniam A, Schneider K, Artamonova A, Sambanthamurthi R, et al.

Sci Rep, 2019 Dec 09;9(1):18625.
PMID: 31819070 DOI: 10.1038/s41598-019-54461-y

Tyrosine hydroxylase (TH) catalyzes the hydroxylation of L-tyrosine to L-DOPA. This is the rate-limiting step in the biosynthesis of the catecholamines - dopamine (DA), norepinephrine (NE), and epinephrine (EP). Catecholamines (CA) play a key role as neurotransmitters and hormones. Aberrant levels of CA are associated with multiple medical conditions, including Parkinson's disease. Palm Fruit Bioactives (PFB) significantly increased the levels of tyrosine hydroxylase in the brain of the Nile Grass rat (NGR), a novel and potentially significant finding, unique to PFB among known botanical sources. Increases were most pronounced in the basal ganglia, including the caudate-putamen, striatum and substantia nigra. The NGR represents an animal model of diet-induced Type 2 Diabetes Mellitus (T2DM), exhibiting hyperglycemia, hyperinsulinemia, and insulin resistance associated with hyperphagia and accelerated postweaning weight gain induced by a high-carbohydrate diet (hiCHO). The PFB-induced increase of TH in the basal ganglia of the NGR was documented by immuno-histochemical staining (IHC). This increase in TH occurred equally in both diabetes-susceptible and diabetes-resistant NGR fed a hiCHO. PFB also stimulated growth of the colon microbiota evidenced by an increase in cecal weight and altered microbiome. The metabolites of colon microbiota, e.g. short-chain fatty acids, may influence the brain and behavior significantly.

Matched MeSH terms: Levodopa/chemistry
Pivotal Role of Fyn Kinase in Parkinson's Disease and Levodopa-Induced Dyskinesia: a Novel Therapeutic Target?

Angelopoulou E, Paudel YN, Julian T, Shaikh MF, Piperi C

Mol Neurobiol, 2021 Apr;58(4):1372-1391.
PMID: 33175322 DOI: 10.1007/s12035-020-02201-z

The exact etiology of Parkinson's disease (PD) remains obscure, although many cellular mechanisms including α-synuclein aggregation, oxidative damage, excessive neuroinflammation, and dopaminergic neuronal apoptosis are implicated in its pathogenesis. There is still no disease-modifying treatment for PD and the gold standard therapy, chronic use of levodopa is usually accompanied by severe side effects, mainly levodopa-induced dyskinesia (LID). Hence, the elucidation of the precise underlying molecular mechanisms is of paramount importance. Fyn is a tyrosine phospho-transferase of the Src family nonreceptor kinases that is highly implicated in immune regulation, cell proliferation and normal brain development. Accumulating preclinical evidence highlights the emerging role of Fyn in key aspects of PD and LID pathogenesis: it may regulate α-synuclein phosphorylation, oxidative stress-induced dopaminergic neuronal death, enhanced neuroinflammation and glutamate excitotoxicity by mediating key signaling pathways, such as BDNF/TrkB, PKCδ, MAPK, AMPK, NF-κB, Nrf2, and NMDAR axes. These findings suggest that therapeutic targeting of Fyn or Fyn-related pathways may represent a novel approach in PD treatment. Saracatinib, a nonselective Fyn inhibitor, has already been tested in clinical trials for Alzheimer's disease, and novel selective Fyn inhibitors are under investigation. In this comprehensive review, we discuss recent evidence on the role of Fyn in the pathogenesis of PD and LID and provide insights on additional Fyn-related molecular mechanisms to be explored in PD and LID pathology that could aid in the development of future Fyn-targeted therapeutic approaches.

Matched MeSH terms: Levodopa
Fulltext Delayed neuropsychiatric sequelae of carbon monoxide poisoning: a case report

Nurul Azreen Hashim, Norley Shuib, Salina Mohamed, Ling SL, Khariah Mat Nor

Journal of Clinical and Health Sciences, 2016;1:64-68.

Delayed neuropsychiatric sequelae is an important condition which commonly occur during recovery from acute carbon monoxide poisoning. Typical presentation would be apathy, disorientation, amnesia, hypokinesia, bizarre behavior, insomnia and neurological manifestations such as gait disturbance, hypertonia and tremor. We report here a case of a man presented with delayed neuropsychiatric sequelae one month after the carbon monoxide poisoning in his suicidal attempt. He presented with the typical presentation and diagnosis confirmed with the MRI findings. His MRI showed abnormal signal in subcortical hemisphere white matter of both temporo-fronto-parietal-occipital regions along the insula and both globus pallidus. He was treated with Olanzapine, Fluvoxamine, Chlorpromazine and Levodopa and his condition slowly improved. It is important for clinicians to recognize the symptoms and risk factors to develop delayed neuropsychiatric sequelae in patients who previously had carbon monoxide poisoning.

Matched MeSH terms: Levodopa
Fulltext An inhibited dopamine synthesizing cell model of AADC deficiency

Melati Khalid, Mohamad Aris Mohd Moklas

Life Sciences, Medicine and Biomedicine, 2019;3(2):1-7.
MyJurnal

Aromatic L-amino acid decarboxylase deficiency (AADC) is a rare autosomal recessive pediatric neurotransmitter disease. To date it remains poorly understood mainly due to an absence of a disease model. The dopaminergic neuroblastoma cell SH-SY5Y was chosen to develop our AADC deficiency model. These cells are not native dopamine synthesizers. Objective: To develop a dopamine-producing cellular model of AADC deficiency using SH-SY5Y neuroblastoma cells. Methods: Dopamine pathway proteins were identified with Western Blotting. Dopaminergic differentiation was attempted using all-trans retinoic acid (ATRA) with dopamine detection via HPLC-ECD post alumina extraction. Treatment with L-DOPA provided SH-SY5Y with excess precursor. RT-PCR was used to determine the expression of markers of mature neurons. Results: Western Blot screening identified AADC, dopamine β-hydroxylase and tyrosine hyrdoxylase proteins, indicative of a dopaminergic pathway. ATRA was unsuccessful in producing dopamine from the cells. L-DOPA treatment however, generated dopamine first visible as a HPLC-ECD peak 30 minutes post-incubation. Prior to this, SH-SY5Y dopamine synthesis from L-DOPA has never been documented. This de novo synthesis is then inhibited using benserazide to form our AADC deficiency cell model. RT-PCR showed that SH-SY5Y cells express markers of mature neurons in its ‘native’ state and is not affected by L-DOPA and benserazide treatment. This cell model will potentially benefit many areas of AADC deficiency research. Conclusion: SH-SY5Y cells produced HPLC-ECD measureable amounts of dopamine with the addition of L-DOPA. Our model of AADC deficiency is generated by quelling the dopamine production with Benserazide.

Matched MeSH terms: Levodopa
Natural Products Combating Neurodegeneration: Parkinson's Disease

Solayman M, Islam MA, Alam F, Khalil MI, Kamal MA, Gan SH

Curr Drug Metab, 2017;18(1):50-61.
PMID: 27396919 DOI: 10.2174/1389200217666160709204826

Parkinson's disease (PD) is characterized by neurodegeneration and a progressive functional impairment of the midbrain nigral dopaminergic neurons. The cause remains unknown; however, several pathological processes and central factors, such as protein aggregation, mitochondrial dysfunction, iron accumulation, neuroinflammation and oxidative stress, have been reported. The current treatment method primarily targets symptoms by using anti-Parkinson drugs such as levodopa, carbidopa, dopamine (DA) agonists, monoamine oxidase type B inhibitors and anticholinergics to replace DA. When drug therapy is not satisfactory, surgical treatments are recommended. Unfortunately, the existing conventional strategies that target PD are associated with numerous side effects and possess an economic burden. Therefore, novel therapeutic approaches that regulate the pathways leading to neuronal death and dysfunction are necessary. For many years, nature has provided the primary resource for the discovery of potential therapeutic agents. Remarkably, many natural products from medicinal plants, fruits and vegetables have been demonstrated to be efficacious anti-Parkinson agents. These products possess neuroprotective properties as a result of not only their wellrecognized anti-oxidative and anti-inflammatory activities but also their inhibitory roles regarding iron accumulation, protein misfolding and the maintenance of proteasomal degradation, as well as mitochondrial homeostasis. The aim of this review is to report the available anti-Parkinson agents based on natural products and delineate their therapeutic actions, which act on various pathways. Overall, this review emphasizes the types of natural products that are potential future resources in the treatment of PD as novel regimens or supplementary agents.

Matched MeSH terms: Levodopa
Fulltext Incorporation of Levodopa into Biopolymer Coatings Based on Carboxylated Carbon Nanotubes for pH-Dependent Sustained Release Drug Delivery

Tan JM, Saifullah B, Kura AU, Fakurazi S, Hussein MZ

Nanomaterials (Basel), 2018 May 31;8(6).
PMID: 29857532 DOI: 10.3390/nano8060389

Four drug delivery systems were formulated by non-covalent functionalization of carboxylated single walled carbon nanotubes using biocompatible polymers as coating agent (i.e., Tween 20, Tween 80, chitosan or polyethylene glycol) for the delivery of levodopa, a drug used in Parkinson's disease. The chemical interaction between the coating agent and carbon nanotubes-levodopa conjugate was confirmed by Fourier transform infrared (FTIR) and Raman studies. The drug release profiles were revealed to be dependent upon the type of applied coating material and this could be further adjusted to a desired rate to meet different biomedical conditions. In vitro drug release experiments measured using UV-Vis spectrometry demonstrated that the coated conjugates yielded a more prolonged and sustained release pattern compared to the uncoated conjugate. Cytotoxicity of the formulated conjugates was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using normal mouse embryonic fibroblast 3T3 cell line. Compared to the non-coated conjugate, the MTT data indicated that the coating procedure improved the biocompatibility of all systems by 34⁻41% when the concentration used exceeded 100 μg/mL. In conclusion, the comprehensive results of this study suggest that carbon nanotubes-based drug carrier coated with a suitable biomaterial may possibly be a potential nanoparticle system that could facilitate drug delivery to the brain with tunable physicochemical properties.

Matched MeSH terms: Levodopa
Fulltext Eradication of Helicobacter pylori infection improves levodopa action, clinical symptoms and quality of life in patients with Parkinson's disease

Hashim H, Azmin S, Razlan H, Yahya NW, Tan HJ, Manaf MR, et al.

PLoS One, 2014;9(11):e112330.
PMID: 25411976 DOI: 10.1371/journal.pone.0112330

BACKGROUND: Previous studies have demonstrated a higher prevalence of Helicobacter pylori (H. pylori) infection in patients with Parkinson's disease (PD) compared to controls. H. pylori infection affects levodopa absorption and its eradication significantly improves clinical response to levodopa. Here, we studied the prevalence of H. pylori infection and its eradication effects among our PD patients.
METHODS: A prospective study involving idiopathic PD patients on levodopa therapy. 13C-urea breath test (UBT) was used to detect H. pylori. UBT-positive patients were given standard eradication therapy and followed up at 6 and 12 weeks in an open label single arm design. Repeat UBT was performed at 12 weeks. The UPDRS, PD NMQ, PD NMSS and PDQ-39 were administered at baseline and post-eradication (6 and 12 weeks). Levodopa 'onset' time and ON-duration were recorded.
RESULTS: Of 82 patients recruited, 27 (32.9%) had positive UBT. H. pylori-positive patients had significantly poorer total UPDRS (p = 0.005) and PDQ39 (p<0.0001) scores compared to H. pylori-negative patients. At 12 weeks post-eradication, the mean levodopa onset time shortened by 14 minutes (p = 0.011). The mean ON duration time increased by 56 minutes at week 6 (p = 0.041) and 38 minutes at week 12 (p = 0.035). The total UPDRS scores (p<0.0001), scores for parts II (p = 0.001), III (p<0.0001) and IV (p = 0.009) were significantly better. The total PDQ-39 scores (p = 0.001) and subdomains mobility (p = 0.002), ADL (p = 0.001), emotional well being (p = 0.026) and stigma (p = 0.034) significantly improved. The PD NMSQ did not show significant improvement.
CONCLUSIONS: H. pylori eradication improved levodopa onset time, ON duration, motor severity and quality of life parameters. Screening and eradication of H. pylori is inexpensive and should be recommended in PD patients, particularly those with erratic response to levodopa.
TRIAL REGISTRATION: ClinicalTrials.gov NCT02112812.

Matched MeSH terms: Levodopa/therapeutic use*
Pharmacological evaluation of vanillic acid in rotenone-induced Parkinson's disease rat model

Sharma N, Khurana N, Muthuraman A, Utreja P

Eur J Pharmacol, 2021 Jul 15;903:174112.
PMID: 33901458 DOI: 10.1016/j.ejphar.2021.174112

In the present study, we investigated the anti-Parkinson's effect of vanillic acid (VA) (12 mg/kg, 25 mg/kg, 50 mg/kg p.o.) against rotenone (2 mg/kg s.c.) induced Parkinson's disease (PD) in rats. The continuous administration of rotenone for 35 days resulted in rigidity in muscles, catalepsy, and decrease in locomotor activity, body weight, and rearing behaviour along with the generation of oxidative stress in the brain (rise in the TBARS, and SAG level and reduced CAT, and GSH levels). Co-treatment of VA and levodopa-carbidopa (100 mg/kg + 25 mg/kg p.o.) lead to a significant (P levodopa-carbidopa, significantly protected the brain from neuronal damage due to oxidative stress and attenuated the motor defects indicating the possible therapeutic potential of VA as a neuroprotective in PD.

Matched MeSH terms: Levodopa/pharmacology; Levodopa/therapeutic use