Displaying publications 1 - 20 of 29 in total

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  1. Lim SY, Poewe W, Tan AH
    JAMA Neurol, 2017 10 01;74(10):1270.
    PMID: 28973082 DOI: 10.1001/jamaneurol.2017.2560
    Matched MeSH terms: Levodopa*
  2. Magalingam KB, Ramdas P, Somanath SD, Selvaduray KR, Bhuvanendran S, Radhakrishnan AK
    Nutrients, 2022 Nov 03;14(21).
    PMID: 36364894 DOI: 10.3390/nu14214632
    Tocotrienol-rich fraction (TRF), a palm oil-derived vitamin E fraction, is reported to possess potent neuroprotective effects. However, the modulation of proteomes in differentiated human neuroblastoma SH-SY5Y cells (diff-neural cells) by TRF has not yet been reported. This study aims to investigate the proteomic changes implicated by TRF in human neural cells using a label-free liquid-chromatography-double mass spectrometry (LC-MS/MS) approach. Levodopa, a drug used in the treatment of Parkinson's disease (PD), was used as a drug control. The human SH-SY5Y neuroblastoma cells were differentiated for six days and treated with TRF or levodopa for 24 h prior to quantitative proteomic analysis. A total of 81 and 57 proteins were differentially expressed in diff-neural cells following treatment with TRF or levodopa, respectively. Among these proteins, 32 similar proteins were detected in both TRF and levodopa-treated neural cells, with 30 of these proteins showing similar expression pattern. The pathway enrichment analysis revealed that most of the proteins regulated by TRF and levodopa are key players in the ubiquitin-proteasome, calcium signalling, protein processing in the endoplasmic reticulum, mitochondrial pathway and axonal transport system. In conclusion, TRF is an essential functional food that affects differential protein expression in human neuronal cells at the cellular and molecular levels.
    Matched MeSH terms: Levodopa/pharmacology
  3. Tan KK, Easaw PE
    Singapore Med J, 1995 Jun;36(3):326-7.
    PMID: 8553105
    A 5-year-old Chinese boy presented with difficulty in walking and weakness of his lower limbs for one year, especially towards the evening. Bilateral equinovarus posturing of the feet and tremors of the upper limbs were noted on physical examination. Dopa-responsive dystonia was diagnosed after a remarkable symptomatic response to levodopa. This disorder is reported here to highlight an often misdiagnosed condition is children which is important because it is treatable. Dopa-responsive dystonia should be considered in the differential diagnosis of gait disturbance in children.
    Matched MeSH terms: Levodopa/therapeutic use*
  4. Sivanandy P, Leey TC, Xiang TC, Ling TC, Wey Han SA, Semilan SLA, et al.
    PMID: 35010624 DOI: 10.3390/ijerph19010364
    Parkinson's Disease (PD) is a disease that involves neurodegeneration and is characterised by the motor symptoms which include muscle rigidity, tremor, and bradykinesia. Other non-motor symptoms include pain, depression, anxiety, and psychosis. This disease affects up to ten million people worldwide. The pathophysiology behind PD is due to the neurodegeneration of the nigrostriatal pathway. There are many conventional drugs used in the treatment of PD. However, there are limitations associated with conventional drugs. For instance, levodopa is associated with the on-off phenomenon, and it may induce wearing off as time progresses. Therefore, this review aimed to analyze the newly approved drugs by the United States-Food and Drug Administration (US-FDA) from 2016-2019 as the adjuvant therapy for the treatment of PD symptoms in terms of efficacy and safety. The new drugs include safinamide, istradefylline and pimavanserin. From this review, safinamide is considered to be more efficacious and safer as the adjunct therapy to levodopa as compared to istradefylline in controlling the motor symptoms. In Study 016, both safinamide 50 mg (p = 0.0138) and 100 mg (p = 0.0006) have improved the Unified Parkinson's Disease Rating Scale (UPDRS) part III score as compared to placebo. Improvement in Clinical Global Impression-Change (CGI-C), Clinical Global Impression-Severity of Illness (CGI-S) and off time were also seen in both groups of patients following the morning levodopa dose. Pimavanserin also showed favorable effects in ameliorating the symptoms of Parkinson's Disease Psychosis (PDP). A combination of conventional therapy and non-pharmacological treatment is warranted to enhance the well-being of PD patients.
    Matched MeSH terms: Levodopa/therapeutic use
  5. Ong LC, Tang SF, Lal TR
    Med J Malaysia, 1994 Jun;49(2):176-8.
    PMID: 8090100
    A 10-year-old girl presented with progressive dystonia with diurnal fluctuation. Response to low dose L-Dopa was dramatic and sustained with no complications. Recurrence of symptoms was observed on attempted withdrawal. Because of the dramatic response to therapy, dopa-responsive dystonia must be considered in the differential diagnosis of disorders presenting as gait disorders in childhood.
    Matched MeSH terms: Levodopa/therapeutic use*
  6. Kura AU, Ain NM, Hussein MZ, Fakurazi S, Hussein-Al-Ali SH
    Int J Mol Sci, 2014;15(4):5916-27.
    PMID: 24722565 DOI: 10.3390/ijms15045916
    Layered hydroxide nanoparticles are generally biocompatible, and less toxic than most inorganic nanoparticles, making them an acceptable alternative drug delivery system. Due to growing concern over animal welfare and the expense of in vivo experiments both the public and the government are interested to find alternatives to animal testing. The toxicity potential of zinc aluminum layered hydroxide (ZAL) nanocomposite containing anti-Parkinsonian agent may be determined using a PC 12 cell model. ZAL nanocomposite demonstrated a decreased cytotoxic effect when compared to levodopa on PC12 cells with more than 80% cell viability at 100 µg/mL compared to less than 20% cell viability in a direct levodopa exposure. Neither levodopa-loaded nanocomposite nor the un-intercalated nanocomposite disturbed the cytoskeletal structure of the neurogenic cells at their IC50 concentration. Levodopa metabolite (HVA) released from the nanocomposite demonstrated the slow sustained and controlled release character of layered hydroxide nanoparticles unlike the burst uptake and release system shown with pure levodopa treatment.
    Matched MeSH terms: Levodopa/adverse effects; Levodopa/metabolism; Levodopa/pharmacology*
  7. Kura AU, Hussein Al Ali SH, Hussein MZ, Fakurazi S, Arulselvan P
    Int J Nanomedicine, 2013;8:1103-10.
    PMID: 23524513 DOI: 10.2147/IJN.S39740
    A new layered organic-inorganic nanocomposite material with an anti-parkinsonian active compound, L-3-(3,4-dihydroxyphenyl) alanine (levodopa), intercalated into the inorganic interlayers of a Zn/Al-layered double hydroxide (LDH) was synthesized using a direct coprecipitation method. The resulting nanocomposite was composed of the organic moiety, levodopa, sandwiched between Zn/Al-LDH inorganic interlayers. The basal spacing of the resulting nano-composite was 10.9 Å. The estimated loading of levodopa in the nanocomposite was approximately 16% (w/w). A Fourier transform infrared study showed that the absorption bands of the nanocomposite were characteristic of both levodopa and Zn/Al-LDH, which further confirmed intercalation, and that the intercalated organic moiety in the nanocomposite was more thermally stable than free levodopa. The resulting nanocomposite showed sustained-release properties, so can be used in a controlled-release formulation. Cytotoxicity analysis using an MTT assay also showed increased cell viability of 3T3 cells exposed to the newly synthesized nanocomposite compared with those exposed to pure levodopa after 72 hours of exposure.
    Matched MeSH terms: Levodopa/administration & dosage; Levodopa/pharmacokinetics; Levodopa/chemistry*
  8. Permatasari HK, Nurkolis F, Vivo CD, Noor SL, Rahmawati R, Radu S, et al.
    F1000Res, 2021;10:789.
    PMID: 36237995 DOI: 10.12688/f1000research.55307.3
    Background: This study aimed to determine the potential anti-aging effects of sea grapes and tempe (fermented soybeans) collagen particle size, by measuring the activities of anti-glycation, antioxidant, and tyrosinase inhibitors. Methods: Collagen was isolated from freeze-dried sea grapes and tempe powder and treated with different NaOH concentrations (0.10 M; 0.20 M; 0.30 M), and CH 3COOH 1 M solution, separately. The collagen particle size was adjusted by stirring at 1000 rpm for 5 and 10 hours. 2,2-diphenyl-1-picrylhydrazyl (DPPH) was used to measure the antioxidant activity, and L-tyrosine and L-DOPA (l-3,4-dihydroxyphenylalanine) was used as a marker of tyrosine inhibition.  Results:  The collagen treated with 0.10 M NaOH produced the highest collagen yield (11.65%), and the largest particle size (2455 nm). Additionally, this collagen, when treated for 5 hours, exhibited 24.70% antioxidant activity, 62.60% anti-glycation, 8.97% L-tyrosine, and 26.77% L-Dopa inhibition activities. Meanwhile, the collagen treated for 10 hours had a 9.98% antioxidant activity, 41.48% anti-glycation, 7.89% L-tyrosine, and 2.67% L-Dopa inhibition activity.  Conclusion: Sea grapes and tempe collagen powder treated with 0.10 M NaOH and stirred for 5 hours, possess the best potential anti-aging properties as a functional food.
    Matched MeSH terms: Levodopa
  9. Hashim HZ, Norlinah MI, Nafisah WY, Tan HJ, Raymond AA, Tamil AM
    Int J Neurosci, 2014 Mar;124(3):187-91.
    PMID: 23952588 DOI: 10.3109/00207454.2013.833511
    Chronic pulsatile levodopa therapy for Parkinson's disease (PD) leads to the development of motor fluctuations and dyskinesia. We studied the prevalence and predictors of levodopa-induced dyskinesia among multiethnic Malaysian patients with PD.
    Matched MeSH terms: Levodopa/adverse effects*
  10. Zainol S, Basri M, Basri HB, Shamsuddin AF, Abdul-Gani SS, Karjiban RA, et al.
    Int J Mol Sci, 2012;13(10):13049-64.
    PMID: 23202937 DOI: 10.3390/ijms131013049
    Response surface methodology (RSM) was utilized to investigate the influence of the main emulsion composition; mixture of palm and medium-chain triglyceride (MCT) oil (6%-12% w/w), lecithin (1%-3% w/w), and Cremophor EL (0.5%-1.5% w/w) as well as the preparation method; addition rate (2-20 mL/min), on the physicochemical properties of palm-based nanoemulsions. The response variables were the three main emulsion properties; particle size, zeta potential and polydispersity index. Optimization of the four independent variables was carried out to obtain an optimum level palm-based nanoemulsion with desirable characteristics. The response surface analysis showed that the variation in the three responses could be depicted as a quadratic function of the main composition of the emulsion and the preparation method. The experimental data could be fitted sufficiently well into a second-order polynomial model. The optimized formulation was stable for six months at 4 °C.
    Matched MeSH terms: Levodopa/chemistry*
  11. Baharuddin FF, Mad Nasir N, Tejo BA, Koh SP, Ramakrishnan S, Nordin NQAA, et al.
    J Asian Nat Prod Res, 2024 May;26(5):575-582.
    PMID: 37796247 DOI: 10.1080/10286020.2023.2264784
    Tyrosinase inhibitors can reduce melanin production for skin whitening, but some existing products may harm the skin. This study discovered six compounds that inhibit tyrosinase in the mushroom Agaricus bisporus by over 50%. Compound 11 displayed strong inhibition (92.2% and 86.7%) for L-tyrosine and L-DOPA substrates, while compound 13 showed high inhibition (96.0% and 62.0%) for both substrates. Molecular docking simulations revealed compounds 11 and 13 bind at the allosteric site of the enzyme. Xanthone derivatives, based on these findings, hold potential as safe skin whitening agents and for pigmentation-related diseases in the cosmetic industry.
    Matched MeSH terms: Levodopa/pharmacology
  12. Ng CF, Tiau PW, Tan HJ, Norlinah MI
    J R Coll Physicians Edinb, 2019 Mar;49(1):37-39.
    PMID: 30838990 DOI: 10.4997/JRCPE.2019.108
    Levodopa is the most effective medical treatment for Parkinson's disease (PD) to date. As dopamine is known to increase cardiac inotropism and vasomotor tone, peripheral dopamine decarboxylase inhibitor is coadministered to suppress the peripheral conversion of levodopa to dopamine. Levodopa poses potential cardiovascular risks, thus its use in patients with existing coronary artery disease needs to be carefully monitored. We report a case of an elderly male with newly diagnosed PD who developed non-ST-elevation myocardial infarction following levodopa (Madopar) initiation.
    Matched MeSH terms: Levodopa/adverse effects*; Levodopa/therapeutic use
  13. Chan, Y.Y., Kim, K.H., Cheah, S.H.
    JUMMEC, 2011;14(2):1-4.
    MyJurnal
    Tyrosinase is a key enzyme that catalyzes melanogenesis in human skin. It oxidizes tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA) and subsequently to dopachrome, which further polymerizes to melanin pigments. Therefore finding an effective tyrosinase inhibitor, either from synthetic or natural sources, is not only useful as skin whitening agents in cosmetic application, but also beneficial in treating melanin-related disorders. The present study reports of the optimized and validated results of a cell-based tyrosinase assay using B16F10 murine melanoma cell line, which produces melanin pigments and has been used extensively in antimelanogenesis studies. The optimization studies involved 3 parameters (1) optimal seeding cell number per well for total protein extraction; (2) optimal dopachrome formation from enzymatic reaction between total protein (tyrosinase source) and L-DOPA (substrate); and (3) optimal incubation period after the addition of substrate. The present study demonstrates that using seeding cell number of 2 × 105 cells/well, total protein of 40 μg, L-Dopa of 5 mM,and at an incubation period of 1 hour at 37°C provided the optimal response on cultured melanoma cells. Kojic acid, a standard tyrosinase inhibitor, was used as a positive control in the optimized cell-based tyrosinase assay to validate the usefulness of the assay. CONCLUSION: The use of the mentioned protocol is sensitive to determine changes in melanoma cells as the result of tyrosine inhibitors.
    Matched MeSH terms: Levodopa
  14. Kura AU, Hussein-Al-Ali SH, Hussein MZ, Fakurazi S
    ScientificWorldJournal, 2014;2014:104246.
    PMID: 24782658 DOI: 10.1155/2014/104246
    We incorporated anti-Parkinsonian drug, levodopa (dopa), in Zn/Al-LDH by coprecipitation method to form dopa-LDH nanocomposite. Further coating of Tween-80 on the external surfaces of dopa-LDH nanocomposite was achieved through the oxygen of C=O group of Tween-80 with the layer of dopa-LDH nanocomposite. The final product is called Tween-dopa-LDH nanocomposite. The X-ray diffraction indicates that the Tween-dopa-LDH nanocomposite was formed by aggregation structure. From the TGA data, the Tween-80 loading on the surface of LDH and dopa-LDH was 8.6 and 7.4%, respectively. The effect of coating process on the dopa release from Tween-dopa-LDH nanocomposite was also studied. The release from Tween-dopa-LDH nanocomposite shows slower release compared to the release of the drug from dopa-LDH nanocomposite as done previously in our study, presumably due to the retarding shielding effect. The cell viability study using PC12 showed improved viability with Tween-80 coating on dopa-LDH nanocomposite as studied by mitochondrial dehydrogenase activity (MTT assay).
    Matched MeSH terms: Levodopa/administration & dosage*
  15. Lim SY, Tan ZK, Ngam PI, Lor TL, Mohamed H, Schee JP, et al.
    Parkinsonism Relat Disord, 2011 Dec;17(10):761-4.
    PMID: 21839665 DOI: 10.1016/j.parkreldis.2011.07.009
    There are limited data on the prevalence of impulsive-compulsive behaviors and subsyndromal impulsive-compulsive behaviors in Asian patients with Parkinson's disease, who are treated with lower dosages of dopaminergic medications.
    Matched MeSH terms: Levodopa/therapeutic use
  16. Bhidayasiri R, Hattori N, Jeon B, Chen RS, Lee MK, Bajwa JA, et al.
    Expert Rev Neurother, 2015;15(11):1285-97.
    PMID: 26390066 DOI: 10.1586/14737175.2015.1088783
    Most Parkinson's disease patients will receive levodopa therapy, and of these, the majority will develop some levodopa-induced complications. For many patients, the first complication to develop is the decline in the duration of therapeutic benefit of each levodopa dose, a phenomenon commonly termed 'wearing-off'. There is already extensive literature documenting the epidemiology and management of wearing-off in Parkinson's disease patients of western descent. However, data derived from these studies might not always apply to patients of Asian descent due to genetic variations, differences in co-morbidities or non-availability of certain drugs. This review summarizes the current literature regarding the epidemiology of wearing-off in Asian (including Arab) patients and discusses the management issues in the context of drug availability in Asia.
    Matched MeSH terms: Levodopa/therapeutic use*
  17. Abdul Halim S, Mohd Amin NA
    BMJ Case Rep, 2018 Oct 21;2018.
    PMID: 30344146 DOI: 10.1136/bcr-2018-225751
    Osmotic demyelination syndrome commonly affects the pons and infrequently involves the extrapontine region. We report a patient with severe hyponatraemia who developed osmotic demyelination syndrome as a consequence of rapid sodium correction. The condition manifested as acute severe parkinsonism, bilateral ptosis and gaze impairment. MRI revealed typical features of central pontine and extrapontine myelinolysis. The patient improved gradually after treatment with a combination of levodopa, intravenous immunoglobulin and dexamethasone. However, it is important to emphasise that the improvement of neurological symptoms is not necessarily causal with these experimental therapies.
    Matched MeSH terms: Levodopa/therapeutic use
  18. Mohamed Ibrahim N, Ramli R, Koya Kutty S, Shah SA
    Mov Disord, 2018 12;33(12):1967-1968.
    PMID: 30427552 DOI: 10.1002/mds.27526
    Matched MeSH terms: Levodopa/therapeutic use*
  19. Rosdinom R, Fazli A, Ruzyanei NJ, Azlin B, Srijit D
    Clin Ter, 2011;162(1):23-9.
    PMID: 21448542
    BACKGROUND AND AIMS: Parkinson disease (PD) is the second most prevalent neurodegenerative disorder after Alzheimer disease. Besides motor presentations, cognitive impairment is among the other likely complications as the illness progresses. This study aimed to determine the prevalence of cognitive impairment in PD and the factors associated with the cognitive impairment.
    MATERIALS AND METHODS: A cross-sectional, descriptive study was conducted on all PD patients at different stages of their illness, in two major tertiary hospitals in Malaysia with their caregivers, over a three month period in 2002. Patients' cognitive functions were tested using the Mini Mental State Examination (MMSE). Important sociodemographic data and relevant clinical information of the patients as well as caregivers' information on income, duration of care-giving, relationship with the patient, and other relevant variables were gathered. Patients' level of functioning was assessed using the Activities of Daily Living (ADL) index. Staging of illness was done based on the Hoehn and Yahr Scale.
    RESULTS: Out of 115 eligible patients, 35% were in the 60-69 age group with 57% in stage 2 of illness, A total of 29% of patients experienced various degrees of cognitive impairment , with almost half (47%) in the stage 3 and 4 exhibiting MMSE scores <24. Factors which were significantly associated with impaired cognitions were race, educational level and stage of illness.
    CONCLUSION: Cognitive impairment was fairly common in PD and the severity of impairment in cognition and physical functioning increased with the advancement of the illness.
    Matched MeSH terms: Levodopa/adverse effects; Levodopa/therapeutic use
  20. Wang M, Ling KH, Tan JJ, Lu CB
    Cells, 2020 06 18;9(6).
    PMID: 32570916 DOI: 10.3390/cells9061489
    Parkinson's Disease (PD) is a neurodegenerative disorder affecting the motor system. It is primarily due to substantial loss of midbrain dopamine (mDA) neurons in the substantia nigra pars compacta and to decreased innervation to the striatum. Although existing drug therapy available can relieve the symptoms in early-stage PD patients, it cannot reverse the pathogenic progression of PD. Thus, regenerating functional mDA neurons in PD patients may be a cure to the disease. The proof-of-principle clinical trials showed that human fetal graft-derived mDA neurons could restore the release of dopamine neurotransmitters, could reinnervate the striatum, and could alleviate clinical symptoms in PD patients. The invention of human-induced pluripotent stem cells (hiPSCs), autologous source of neural progenitors with less ethical consideration, and risk of graft rejection can now be generated in vitro. This advancement also prompts extensive research to decipher important developmental signaling in differentiation, which is key to successful in vitro production of functional mDA neurons and the enabler of mass manufacturing of the cells required for clinical applications. In this review, we summarize the biology and signaling involved in the development of mDA neurons and the current progress and methodology in driving efficient mDA neuron differentiation from pluripotent stem cells.
    Matched MeSH terms: Levodopa/therapeutic use
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