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1.
Curr Neuropharmacol ; 21(4): 787-807, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36221865

RESUMO

Alzheimer's disease (AD) is a devastating neurodegenerative disease that mostly affects the elderly population. Mechanisms underlying AD pathogenesis are yet to be fully revealed, but there are several hypotheses regarding AD. Even though free radicals and inflammation are likely to be linked with AD pathogenesis, still amyloid-beta (Aß) cascade is the dominant hypothesis. According to the Aß hypothesis, a progressive buildup of extracellular and intracellular Aß aggregates has a significant contribution to the AD-linked neurodegeneration process. Since Aß plays an important role in the etiology of AD, therefore Aß-linked pathways are mainly targeted in order to develop potential AD therapies. Accumulation of Aß plaques in the brains of AD individuals is an important hallmark of AD. These plaques are mainly composed of Aß (a peptide of 39-42 amino acids) aggregates produced via the proteolytic cleavage of the amyloid precursor protein. Numerous studies have demonstrated that various polyphenols (PPHs), including cyanidins, anthocyanins, curcumin, catechins and their gallate esters were found to markedly suppress Aß aggregation and prevent the formation of Aß oligomers and toxicity, which is further suggesting that these PPHs might be regarded as effective therapeutic agents for the AD treatment. This review summarizes the roles of Aß in AD pathogenesis, the Aß aggregation pathway, types of PPHs, and distribution of PPHs in dietary sources. Furthermore, we have predominantly focused on the potential of food-derived PPHs as putative anti-amyloid drugs.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Idoso , Humanos , Doença de Alzheimer/metabolismo , Antocianinas/uso terapêutico , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Amiloide/metabolismo , Placa Amiloide/metabolismo
2.
Ann Med Surg (Lond) ; 84: 104823, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36373066

RESUMO

Introduction: The advent of COVID-19 has led to an exponential rise in related publications to provide a knowledge driven approach to tame the tide of infection and impact in all spheres. This study gives an insight into COVID-19 research publication pattern in Malaysia using bibliometric analysis. Method: COVID-19 publications on Scopus database between January 1, 2020, and August 26, 2022, were extracted using predetermined search strings. Inclusion and exclusion criteria were set, and data was extracted from the database. Descriptive statistics was used to summarize our findings. Results: A total of 3,553 COVID-19 related papers were retrieved out of global count of 392,613 and 16,466 for Southeast Asia (SEA). This implies that 0.9% and 21.6% is contributed globally and SEA respectively. Indonesia, Malaysia and Singapore are the three top countries with highest research outputs in the region. This may be correlated to high GDP per capita, research and development, and research and development expenditure. Most of the publications are article/original research (n = 2832, 67%). Ministry of Higher education is the top funding sponsor and Universiti Malaya is the highest contributor and the most cited (n = 466, 4920 citations). The majority of publications are from physical sciences (30.3%), but medicine subcategory produced the highest number of papers (1,586). The top journal was International Journal of Environmental and Public Health (n = 96 publications). Most active collaborating country was the United Kingdom and most active author was from Monash University. Conclusion: Malaysian institutions have made profound contributions to COVID-19 research globally and in SEA. However, there is a need for continuous efforts to improve research outputs on the topic.

3.
Front Aging Neurosci ; 14: 878276, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072483

RESUMO

Alzheimer's disease (AD) is a severe neurodegenerative disorder of the brain that manifests as dementia, disorientation, difficulty in speech, and progressive cognitive and behavioral impairment. The emerging therapeutic approach to AD management is the inhibition of ß-site APP cleaving enzyme-1 (BACE1), known to be one of the two aspartyl proteases that cleave ß-amyloid precursor protein (APP). Studies confirmed the association of high BACE1 activity with the proficiency in the formation of ß-amyloid-containing neurotic plaques, the characteristics of AD. Only a few FDA-approved BACE1 inhibitors are available in the market, but their adverse off-target effects limit their usage. In this paper, we have used both ligand-based and target-based approaches for drug design. The QSAR study entails creating a multivariate GA-MLR (Genetic Algorithm-Multilinear Regression) model using 552 molecules with acceptable statistical performance (R 2 = 0.82, Q 2 loo = 0.81). According to the QSAR study, the activity has a strong link with various atoms such as aromatic carbons and ring Sulfur, acceptor atoms, sp2-hybridized oxygen, etc. Following that, a database of 26,467 food compounds was primarily used for QSAR-based virtual screening accompanied by the application of the Lipinski rule of five; the elimination of duplicates, salts, and metal derivatives resulted in a truncated dataset of 8,453 molecules. The molecular descriptor was calculated and a well-validated 6-parametric version of the QSAR model was used to predict the bioactivity of the 8,453 food compounds. Following this, the food compounds whose predicted activity (pKi) was observed above 7.0 M were further docked into the BACE1 receptor which gave rise to the Identification of 4-(3,4-Dihydroxyphenyl)-2-hydroxy-1H-phenalen-1-one (PubChem I.D: 4468; Food I.D: FDB017657) as a hit molecule (Binding Affinity = -8.9 kcal/mol, pKi = 7.97 nM, Ki = 10.715 M). Furthermore, molecular dynamics simulation for 150 ns and molecular mechanics generalized born and surface area (MMGBSA) study aided in identifying structural motifs involved in interactions with the BACE1 enzyme. Molecular docking and QSAR yielded complementary and congruent results. The validated analyses can be used to improve a drug/lead candidate's inhibitory efficacy against the BACE1. Thus, our approach is expected to widen the field of study of repurposing nutraceuticals into neuroprotective as well as anti-cancer and anti-viral therapeutic interventions.

4.
Semin Cancer Biol ; 86(Pt 2): 101-116, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36084815

RESUMO

Brain cancer is an aggressive type of cancer with poor prognosis. While the immune system protects against cancer in the early stages, the tumor exploits the healing arm of inflammatory reactions to accelerate its growth and spread. Various immune cells penetrate the developing tumor region, establishing a pro-inflammatory tumor milieu. Additionally, tumor cells may release chemokines and cytokines to attract immune cells and promote cancer growth. Inflammation and its associated mechanisms in the progression of cancer have been extensively studied in the majority of solid tumors, especially brain tumors. However, treatment of the malignant brain cancer is hindered by several obstacles, such as the blood-brain barrier, transportation inside the brain interstitium, inflammatory mediators that promote tumor growth and invasiveness, complications in administering therapies to tumor cells specifically, the highly invasive nature of gliomas, and the resistance to drugs. To resolve these obstacles, nanomedicine could be a potential strategy that has facilitated advancements in diagnosing and treating brain cancer. Due to the numerous benefits provided by their small size and other features, nanoparticles have been a prominent focus of research in the drug-delivery field. The purpose of this article is to discuss the role of inflammatory mediators and signaling pathways in brain cancer as well as the recent advances in understanding the nano-carrier approaches for enhancing drug delivery to the brain in the treatment of brain cancer.


Assuntos
Neoplasias Encefálicas , Nanomedicina , Humanos , Neoplasias Encefálicas/metabolismo , Sistemas de Liberação de Medicamentos , Inflamação/tratamento farmacológico , Mediadores da Inflamação/uso terapêutico
5.
Curr Alzheimer Res ; 19(4): 285-301, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35440308

RESUMO

Behavioral and psychotic manifestations, including aggression, delusions, and hallucinations, are frequent comorbidities in patients with debilitating nervous illnesses such as Alzheimer's disease (AD), Amyotrophic Lateral Sclerosis, Multiple Sclerosis, and Parkinson's disease. ADrelated psychosis may be linked to a poor disease prognosis, highlighting that early detection and management are mandatory. The manifestations are variable and may be very heterogeneous, imposing a real diagnostic issue. Some assessment tools such as BEHAVE-AD, CERAD-BRSD, and the Psycho-Sensory Hallucinations Scale have been designed to facilitate the diagnosis. The mechanisms behind neurodegeneration-related psychosis are complex and are not fully understood, imposing a burden on researchers to find appropriate management modalities. Familial history and some genetic disturbances may have a determinant role in these delusions and hallucinations in cases with AD. The loss of neuronal cells, atrophy in some regions of the central nervous, and synaptic dysfunction may also contribute to these comorbidities. Furthermore, inflammatory disturbances triggered by pro-inflammatory agents such as interleukins and tumor necrosis factors are stratified among the potential risk factors for the onset of numerous psychotic symptoms in Alzheimer's patients. Little is known about the possible management tools; therefore, it is urgent to conduct well-designed trials to investigate pharmacological and non-pharmacological interventions that can improve the care process of these patients. This review summarizes the current findings regarding the AD-related psychosis symptoms, pathological features, assessment, and management.


Assuntos
Doença de Alzheimer , Transtornos Psicóticos , Doença de Alzheimer/complicações , Doença de Alzheimer/diagnóstico , Comorbidade , Delusões/genética , Alucinações/genética , Humanos , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/etiologia , Transtornos Psicóticos/terapia , Fatores de Risco
6.
Curr Pharm Des ; 27(3): 402-414, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33213314

RESUMO

Alzheimer's disease (AD) is an irrevocable chronic brain disorder featured by neuronal loss, microglial accumulation, and progressive cognitive impairment. The proper pathophysiology of this life-threatening disorder is not completely understood and no exact remedies have been found yet. Over the last few decades, research on AD has mainly highlighted pathomechanisms linked to a couple of the major pathological hallmarks, including extracellular senile plaques made of amyloid-ß (Aß) peptides, and intracellular neurofibrillary tangles (NFTs) made of tau proteins. Aß can induce apoptosis, trigger an inflammatory response, and inhibit the synaptic plasticity of the hippocampus, which ultimately contributes to reducing cognitive functions and memory impairment. Recently, a third disease hallmark, the neuroinflammatory reaction that is mediated by cerebral innate immune cells, has become a spotlight in the current research area, assured by pre-clinical, clinical, and genetic investigations. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a cytokine producer, is significantly associated with physiological inflammatory proceedings and thus shows a promising candidate for inflammation- based AD therapy. Recent data reveal that phytochemicals, mainly polyphenol compounds, exhibit potential neuroprotective functions and these may be considered as a vital resource for discovering several drug candidates against AD. Interestingly, phytochemicals can easily interfere with the signaling pathway of NF-κB. This review represents the anti-neuroinflammatory potential of polyphenols as inhibitors of NF-κB to combat AD pathogenesis.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides , Humanos , Microglia , NF-kappa B , Polifenóis/farmacologia , Polifenóis/uso terapêutico
7.
Curr Top Med Chem ; 20(25): 2263-2278, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32493192

RESUMO

Alzheimer's disease (AD) is progressive brain amyloidosis that damages brain regions associated with memory, thinking, behavioral and social skills. Neuropathologically, AD is characterized by intraneuronal hyperphosphorylated tau inclusions as neurofibrillary tangles (NFTs), and buildup of extracellular amyloid-beta (Aß) peptide as senile plaques. Several biomarker tests capturing these pathologies have been developed. However, for the full clinical expression of the neurodegenerative events of AD, there exist other central molecular pathways. In terms of understanding the unidentified underlying processes for the progression and development of AD, a complete comprehension of the structure and composition of atypical aggregation of proteins is essential. Presently, to aid the prognosis, diagnosis, detection, and development of drug targets in AD, neuroproteomics is elected as one of the leading essential tools for the efficient exploratory discovery of prospective biomarker candidates estimated to play a crucial role. Therefore, the aim of this review is to present the role of neuroproteomics to analyze the complexity of AD.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Agregados Proteicos , Agregação Patológica de Proteínas/diagnóstico , Agregação Patológica de Proteínas/metabolismo , Proteômica , Peptídeos beta-Amiloides/análise , Peptídeos beta-Amiloides/metabolismo , Biomarcadores/análise , Biomarcadores/metabolismo , Humanos
8.
Materials (Basel) ; 12(20)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614624

RESUMO

The objective of this study is to investigate the feasibility of machining micro-holes on the non-conductive Aluminum Nitride (AlN) ceramics using micro-electro-discharge machining (EDM) process by exploiting various coating techniques. Although ceramics possess excellent mechanical properties under compressive load condition and superior thermal properties, machining of microscale features on ceramics remains challenging due to the extreme brittleness associated with ceramics. Due to the involvement of higher cutting force and tool wear issue, conventional machining process appears to be unsuitable for machining ceramics. On the other hand, non-contact and negligible process force associated with EDM process makes it one of the competitive processes for machining of ceramics. A series of experiments were carried out on AlN ceramics using "Assistive Electrode" micro-EDM process with a goal of machining blind micro-holes into the ceramics with the aid of on-machine fabricated copper tungsten tools. It was found that multi-layer coatings of silver and copper with copper tungsten electrode resulted in successful machining with high-aspect-ratio holes during powder mixed micro-EDM of AlN ceramics, while micro-holes with less than one aspect ratio are machined without powder addition to the dielectric. It was also observed that comparatively lower level of discharge energies, i.e., lower value of voltages and capacitances were favorable for successful machining of micro-holes in ceramics, even though it results in significantly higher machining time. Despite of relatively low discharge energy usage in micro-EDM, machined surfaces appear to be very rough. The machined surfaces indicate that melting and evaporation, as well as thermal spalling, are the dominating material removal mechanisms. The machined surfaces contained many thermal cracks and porosity on the surface. The elemental composition analysis confirms the presence of aluminum and nitrogen elements on the machined surface. Finally, by careful selection of machining conditions and assistive electrode, successful machining of micro-holes is possible on the non-conductive ceramic surfaces using the micro-EDM process.

9.
Curr Drug Metab ; 19(7): 596-604, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29512448

RESUMO

BACKGROUND: Nanotechnology exploits materials and devices with a functional organization that has been engineered at the nanometre scale. The application of nanotechnology in neuroscience involves specific interactions with neurons and glial cells. This property is used for delivering drugs and other small molecules (such as genes, oligonucleotides and contrasting agents) across the blood brain barrier (BBB), an important requirement for delivering the drug successfully to the brain. OBJECTIVE: Nanotechnology based approaches (NBA) favours transcytosis-mediated delivery of nanoparticles to the brain by crossing the BBB. The last five years have witnessed the successful applications of NBA to treat neurological disorders. It is expected that the development of novel NBA will result in important insights on the brain mechanisms, and eventually provide better medical care to patients suffering from neurological disorders. CONCLUSION: This review introduces the emerging work in this area and summarizes the successful NBA used in recent past for treating various neurological disorders ike Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, meningitis and glioblastoma.


Assuntos
Nanopartículas/uso terapêutico , Doenças Neurodegenerativas/tratamento farmacológico , Animais , Encéfalo/metabolismo , Humanos , Nanotecnologia , Transcitose
10.
Curr Vasc Pharmacol ; 15(4): 296-312, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28155611

RESUMO

Cells constantly adapt to external humoral cues like cytokines and hormones, but practically most cellular behavior is under locally guided control via cell-cell interactions. Galectins (Gals) are one of the most prominent members of the group of molecules involved in this intercellular signaling. They are the family of ß-galactoside specific lectins and consist of 15 different types, each with a specific function. They play crucial role in the immune system, inflammation, wound healing and carcinogenesis. In recent times, the role of Gals in the development of cardiovascular disease (CVD) has gained attention. Gals have been reported to act ambiguously by both relieving ischemia and accelerating atherosclerosis. Atherosclerosis can ultimately lead to myocardial infarction or ischemic stroke, which are both associated with Gals. There is also a role for Gals in the development of myocarditis by their influence on inflammatory processes. Moreover, Gal acts as a biomarker for the severity of myocardial ischemia and heart failure (HF). This review summarizes the association between Gals and the development and pathogenesis of CVD like atherosclerosis, stroke, myocardial infarction, and HF. A comprehensive outline of the association between Gals and more general mechanisms such as angiogenesis, arteriogenesis and atherosclerosis has also been provided. Modulation of Gal signaling holds great promise for the treatment of CVD as evident from preclinical studies.


Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/fisiopatologia , Galectinas/efeitos dos fármacos , Galectinas/fisiologia , Animais , Aterosclerose/tratamento farmacológico , Humanos , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/fisiopatologia , Neovascularização Fisiológica/efeitos dos fármacos
11.
Protein Pept Lett ; 22(11): 954-62, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26419242

RESUMO

Lectins are the (glyco)proteins that recognize and bind to specific sugar moieties without altering their structure. Galectins are mammalian lectins characterized by the presence of conserved 134 amino acids carbohydrate recognition domain and specificity for ß-galactosides. The involvement of lectins in diverse biological spectrum, especially some deadly human diseases like cancer, neurological disorders and cardiovascular disorders has proclaimed them as one of the important components of glycobiology, thereby seeking the methods of their detection and identification heavily desirable. In the present manuscript, we have provided a comprehensive outline of various methods of detection and identification of lectins employed till date, with their needs and usage varying according to the level of infrastructure of laboratories and around the world. In addition, a vision for some quick, highly sensitive and advanced methods for lectin detection and identification for diagnostic and therapeutic of various diseases is also provided.


Assuntos
Biomarcadores , Galectinas , Biomarcadores/análise , Biomarcadores/química , Doenças Cardiovasculares/metabolismo , Galectinas/análise , Galectinas/química , Galectinas/isolamento & purificação , Testes de Hemaglutinação , Humanos , Imunoensaio , Análise em Microsséries , Neoplasias/diagnóstico , Neoplasias/metabolismo , Doenças do Sistema Nervoso/metabolismo , Espectrofotometria
12.
Saudi J Biol Sci ; 22(1): 85-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25561889

RESUMO

Galectins are mammalian lectins established to play a crucial role in the progression of various cancer types by the virtue of their differential expression in normal and cancerous cells. In the present study, goat heart galectin-1 (GHG-1) was purified and investigated for its potential role in the detection of post-malignant changes in glycosylation pattern. When exposed to superoxide radicals generated from a pyrogallol auto-oxidation system, GHG-1 treated erythrocyte suspension released higher amount of oxyhemoglobin than the unagglutinated erythrocytes. The extent of erythrocyte hemolysis was found to be directly proportional to concentrations of hypochlorous acid. GHG-1 was used to detect the change in the ß-galactoside expression pattern in erythrocyte membrane from human donors suffering from prostate and breast cancer. No significant change was observed in the hemolysis of lectin agglutinated erythrocytes collected from pre-operated breast cancer patients, whereas significant increase was observed in normal healthy control and post-operated samples. Findings of this study proclaim GHG-1 as an important tool for the detection of post-malignant changes in glycosylation pattern.

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