An Increasing Role of Polyphenols as Novel Therapeutics for Alzheimer’s: A Review

2020 ◽  
Vol 16 (8) ◽  
pp. 1007-1021 ◽  
Author(s):  
Nasiara Karim ◽  
Haroon Khan ◽  
Imran Khan ◽  
Ouyang Guo ◽  
Eduardo Sobarzo-Sánchez ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Natural Products ◽  
Immune Responses ◽  
Cognitive Deficits ◽  
Neurodegenerative Disorder ◽  
Therapeutic Agents ◽  
Pharmacological Interventions ◽  
Stress Formation ◽  
Molecular Aspects

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder, with approximately 29 million older people suffering from this disease worldwide. This number is expected to become triple by 2050. AD is a complex and multifactorial neurodegenerative condition, characterized by complex pathology including oxidative stress, formation of aggregates of amyloid and tau, enhanced immune responses, metal deposition and disturbances in cholinesterase enzymes. There is no effective pharmacological treatment for combating the disease to date. The ineffectiveness of current pharmacological interventions in AD has led scientists to search for more safe and effective alternative therapeutic agents. Thus, natural products have become an important avenue for drug discovery in AD research. In this regard, polyphenols are natural products that have been shown to be effective in the modulation of the type of neurodegenerative changes seen in AD, suggesting a possible therapeutic role. The present review focuses on the chemistry of polyphenols, clinical studies for evaluating polyphenols as effective alternatives in AD treatment, cellular and molecular aspects of polyphenols in improving cognitive deficits and the current challenges and futuristic approaches to use polyphenols as safe and effective therapeutic agents in AD treatment.

scholarly journals Protective Effects of Centella asiatica on Cognitive Deficits Induced by D-gal/AlCl3 via Inhibition of Oxidative Stress and Attenuation of Acetylcholinesterase Level

Toxics ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 19 ◽  
Author(s):  
Samaila Chiroma ◽  
Mohamad Baharuldin ◽  
Che Mat Taib ◽  
Zulkhairi Amom ◽  
Saravanan Jagadeesan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cerebral Cortex ◽  
Prefrontal Cortex ◽  
Cognitive Deficits ◽  
Neurodegenerative Disorder ◽  
Centella Asiatica ◽  
Morris Water Maze Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protective Effects ◽  
Ultrastructural Alteration

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with cholinergic dysfunctions and impaired redox homeostasis. The plant Centella asiatica (CA) is renowned for its nutritional benefits and herbal formulas for promoting health, enhancing cognition, and its neuroprotective effects. The present study aims to investigate the protective role of CA on D-gal/AlCl3-induced cognitive deficits in rats. The rats were divided into six groups and administered with donepezil 1 mg/kg/day, CA (200, 400, and 800 mg/kg/day) and D-gal 60 mg/kg/day + AlCl3 200 mg/kg/day for 10 weeks. The ethology of the rats was evaluated by the Morris water maze test. The levels of acetylcholinesterase (AChE), phosphorylated tau (P-tau), malondialdehyde (MDA) and activities of superoxide dismutase (SOD), in the hippocampus and cerebral cortex were estimated by enzyme-linked immunosorbent assay (ELISA). Additionally, the ultrastructure of the prefrontal cortex of the rats’ was observed using transmission electron microscopy (TEM). Rats administered with D-gal/AlCl3 exhibited cognitive deficits, decreased activities of SOD, and marked increase in AChE and MDA levels. Further, prominent alterations in the ultrastructure of the prefrontal cortex were observed. Conversely, co-administration of CA with D-gal/AlCl3 improved cognitive impairment, decreased AChE levels, attenuated the oxidative stress in hippocampus and cerebral cortex, and prevented ultrastructural alteration of neurons in the prefrontal cortex. Irrespective of the dose of CA administered, the protective effects were comparable to donepezil. In conclusion, this study suggests that CA attenuated the cognitive deficits in rats by restoring cholinergic function, attenuating oxidative stress, and preventing the morphological aberrations.

scholarly journals Alzheimer’s Pathogenesis and Its Link to the Mitochondrion

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
C. Simoncini ◽  
D. Orsucci ◽  
E. Caldarazzo Ienco ◽  
G. Siciliano ◽  
U. Bonuccelli ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
Cognitive Functions ◽  
Neurodegenerative Disorder ◽  
The Elderly ◽  
Mitochondria Dysfunction ◽  
Neurodegenerative Process ◽  
Mitochondrial Impairment ◽  
And Oxidative Stress

Alzheimer’s disease (AD) is the most common form of dementia in the elderly. This neurodegenerative disorder is clinically characterized by impairment of cognitive functions and changes in behaviour and personality. The pathogenesis of AD is still unclear. Recent evidence supports some role of mitochondria dysfunction and oxidative stress in the development of the neurodegenerative process. In this review, we discuss the role of mitochondrial dysfunction in AD, focusing on the mechanisms that lead to mitochondrial impairment, oxidative stress, and neurodegeneration, a “vicious circle” that ends in dementia.

scholarly journals Oxidative Stress Is a Key Modulator in the Development of Nonalcoholic Fatty Liver Disease

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 91
Author(s):  
Yuanqiang Ma ◽  
Gyurim Lee ◽  
Su-Young Heo ◽  
Yoon-Seok Roh
Keyword(s):  
Oxidative Stress ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Therapeutic Agents ◽  
Nonalcoholic Fatty Liver ◽  
Stress Oxidative ◽  
The Relationship

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, and scientific studies consistently report that NAFLD development can be accelerated by oxidative stress. Oxidative stress can induce the progression of NAFLD to NASH by stimulating Kupffer cells, hepatic stellate cells, and hepatocytes. Therefore, studies are underway to identify the role of antioxidants in the treatment of NAFLD. In this review, we have summarized the origins of reactive oxygen species (ROS) in cells, the relationship between ROS and NAFLD, and have discussed the use of antioxidants as therapeutic agents for NAFLD.

scholarly journals The potential role of neuroinflammation and transcription factors in Parkinson disease

2017 ◽  
Vol 19 (1) ◽  
pp. 71-80 ◽  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factors ◽  
Substantia Nigra ◽  
Parkinson Disease ◽  
Signaling Pathways ◽  
Dopaminergic Neurons ◽  
Neurodegenerative Disorder ◽  
Brain Regions ◽  
Death Domain

Parkinson disease (PD) is a neurodegenerative disorder characterized by dopaminergic neurons affected by inflammatory processes. Post-mortem analyses of brain and cerebrospinal fluid from PD patients show the accumulation of proinflammatory cytokines, confirming an ongoing neuroinflammation in the affected brain regions. These inflammatory mediators may activate transcription factors—notably nuclear factor κB, Ying-Yang 1 (YY1), fibroblast growth factor 20 (FGF20), and mammalian target of rapamycin (mTOR)—which then regulate downstream signaling pathways that in turn promote death of dopaminergic neurons through death domain-containing receptors. Dopaminergic neurons are vulnerable to oxidative stress and inflammatory attack. An increased level of inducible nitric oxide synthase observed in the substantia nigra and striatum of PD patients suggests that both cytokine—and chemokine-induced toxicity and inflammation lead to oxidative stress that contributes to degeneration of dopaminergic neurons and to disease progression. Lipopolysaccharide activation of microglia in the proximity of dopaminergic neurons in the substantia nigra causes their degeneration, and this appears to be a selective vulnerability of dopaminergic neurons to inflammation. In this review, we will look at the role of various transcription factors and signaling pathways in the development of PD.

scholarly journals Vitamin D Deficiency and the Risk of Cerebrovascular Disease

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 327 ◽  
Author(s):  
Hyun Ah Kim ◽  
Andrea Perrelli ◽  
Alberto Ragni ◽  
Francesca Retta ◽  
T. Michael De Silva ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Inflammatory Responses ◽  
Cerebrovascular Diseases ◽  
Pharmacological Interventions ◽  
Downstream Effects ◽  
Highly Sensitive ◽  
The World

Vitamin D deficiency has been clearly linked to major chronic diseases associated with oxidative stress, inflammation, and aging, including cardiovascular and neurodegenerative diseases, diabetes, and cancer. In particular, the cardiovascular system appears to be highly sensitive to vitamin D deficiency, as this may result in endothelial dysfunction and vascular defects via multiple mechanisms. Accordingly, recent research developments have led to the proposal that pharmacological interventions targeting either vitamin D deficiency or its key downstream effects, including defective autophagy and abnormal pro-oxidant and pro-inflammatory responses, may be able to limit the onset and severity of major cerebrovascular diseases, such as stroke and cerebrovascular malformations. Here we review the available evidence supporting the role of vitamin D in preventing or limiting the development of these cerebrovascular diseases, which are leading causes of disability and death all over the world.

scholarly journals Ceramides in Alzheimer’s Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and AβAccumulation

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Maja Jazvinšćak Jembrek ◽  
Patrick R. Hof ◽  
Goran Šimić
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neuronal Apoptosis ◽  
Neurodegenerative Disorder ◽  
Neuronal Degeneration ◽  
Sphingolipid Metabolism ◽  
Cytochrome C Release ◽  
Biochemical Alterations

Alzheimer’s disease (AD), the most common chronic and progressive neurodegenerative disorder, is characterized by extracellular deposits of amyloidβ-peptides (Aβ) and intracellular deposits of hyperphosphorylated tau (phospho-tau) protein. Ceramides, the major molecules of sphingolipid metabolism and lipid second messengers, have been associated with AD progression and pathology via Aβgeneration. Enhanced levels of ceramides directly increase Aβthrough stabilization ofβ-secretase, the key enzyme in the amyloidogenic processing of Aβprecursor protein (APP). As a positive feedback loop, the generated oligomeric and fibrillar Aβinduces a further increase in ceramide levels by activating sphingomyelinases that catalyze the catabolic breakdown of sphingomyelin to ceramide. Evidence also supports important role of ceramides in neuronal apoptosis. Ceramides may initiate a cascade of biochemical alterations, which ultimately leads to neuronal death by diverse mechanisms, including depolarization and permeabilization of mitochondria, increased production of reactive oxygen species (ROS), cytochrome c release, Bcl-2 depletion, and caspase-3 activation, mainly by modulating intracellular signalling, particularly along the pathways related to Akt/PKB kinase and mitogen-activated protein kinases (MAPKs). This review summarizes recent findings related to the role of ceramides in oxidative stress-driven neuronal apoptosis and interplay with Aβin the cascade of events ending in neuronal degeneration.

scholarly journals Human INCL fibroblasts display abnormal mitochondrial and lysosomal networks and heightened susceptibility to ROS-induced cell death

2020 ◽  
Author(s):  
Bailey Balouch ◽  
Halle Nagorsky ◽  
Truc Pham ◽  
Thai LaGraff ◽  
Quynh Chu-LaGraff
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Endoplasmic Reticulum Stress Response ◽  
Compound Heterozygous ◽  
Storage Material ◽  
Cellular Environment ◽  
And Oxidative Stress

AbstractInfantile Neuronal Ceroid Lipofuscinosis (INCL) is a pediatric neurodegenerative disorder characterized by progressive retinal and central nervous system deterioration during infancy. This lysosomal storage disorder results from a deficiency in the Palmitoyl Protein Thioesterase 1 (PPT1) enzyme - a lysosomal hydrolase which cleaves fatty acid chains such as palmitate from lipid-modified proteins. In the absence of PPT1 activity, these proteins fail to be degraded, leading to the accumulation of autofluorescence storage material in the lysosome. The underlying molecular mechanisms leading to INCL pathology remain poorly understood. A role for oxidative stress has been postulated, yet little evidence has been reported to support this possibility. Here we present a comprehensive cellular characterization of human PPT1-deficient fibroblast cells harboring Met1Ile and Tyr247His compound heterozygous mutations. We detected autofluorescence storage material and observed distinct organellar abnormalities of the lysosomal and mitochondrial structures, which supported previous postulations about the role of ER, mitochondria and oxidative stress in INCL. An increase in the number of lysosomal structures was found in INCL patient fibroblasts, which suggested an upregulation of lysosomal biogenesis, and an association with endoplasmic reticulum stress response. The mitochondrial network also displayed abnormal spherical punctate morphology instead of normal elongated tubules with extensive branching, supporting the involvement of mitochondrial and oxidative stress in INCL cell death. Autofluorescence accumulation and lysosomal pathologies can be mitigated in the presence of conditioned wild type media suggesting that a partial restoration via passive introduction of the enzyme into the cellular environment may be possible. We also demonstrated, for the first time, that human INCL fibroblasts have a heightened susceptibility to exogenous reactive oxygen species (ROS)-induced cell death, which suggested an elevated basal level of endogenous ROS in the mutant cell. Collectively, these findings support the role of intracellular organellar networks in INCL pathology, possibly due to oxidative stress.

scholarly journals An Overview of the Beneficial Role of Antioxidants in the Treatment of Nanoparticle-Induced Toxicities

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Vladimir Mihailovic ◽  
Jelena S. Katanic Stankovic ◽  
Dragica Selakovic ◽  
Gvozden Rosic
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Defense ◽  
Therapeutic Agents ◽  
Protective Mechanisms ◽  
Defense Systems ◽  
Naturally Occurring ◽  
New Findings ◽  
Antioxidant Defense Systems ◽  
Harmful Effects

Nanoparticles (NPs) are used in many products and materials for humans such as electronics, in medicine for drug delivery, as biosensors, in biotechnology, and in agriculture, as ingredients in cosmetics and food supplements. Besides that, NPs may display potentially hazardous properties on human health and the environment as a consequence of their abundant use in life nowadays. Hence, there is increased interest of researchers to provide possible therapeutic agents or dietary supplements for the amelioration of NP-induced toxicity. This review summarizes the new findings in the research of the use of antioxidants as supplements for the prevention and alleviation of harmful effects caused by exposure of organisms to NPs. Also, mechanisms involved in the formation of NP-induced oxidative stress and protective mechanisms using different antioxidant substances have also been elaborated. This review also highlights the potential of naturally occurring antioxidants for the enhancement of the antioxidant defense systems in the prevention and mitigation of organism damage caused by NP-induced oxidative stress. Based on the presented results of the most recent studies, it may be concluded that the role of antioxidants in the prevention and treatment of nanoparticle-induced toxicity is unimpeachable. This is particularly important in terms of oxidative stress suppression.

scholarly journals Pharmacological Modulation of TRPM2 Channels via TRPM2 Pathway Leads to Neuroprotection in MPTP-induced Parkinson’s Disease in Sprague Dawley Rats

2021 ◽  
Author(s):  
Bhupesh Vaidya ◽  
Harpinder Kaur ◽  
Pavan Thapak ◽  
Shyam Sunder Sharma ◽  
Jitendra N Singh
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Deficits ◽  
Intraperitoneal Administration ◽  
Sprague Dawley ◽  
Therapeutic Benefits ◽  
Sprague Dawley Rats ◽  
Trpm2 Channels

Abstract Transient receptor potential melastatin-2 (TRPM2) channels are cation channels activated by oxidative stress and adenosine di-phosphate ribose (ADPR). Role of TRPM2 channels has been postulated in several neurological disorders, but, it has not been explored in animal models of Parkinson’s disease (PD). Thus, the role of TRPM2 and its associated poly (ADP-ribose) polymerase (PARP) signalling pathways were investigated in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD rat model using TRPM2 inhibitor, 2-aminoethyl diphenyl borinate (2-APB) and PARP inhibitor, N-(6-Oxo-5,6-dihydrophenanthridin-2-yl)-(N,N-dimethylamino) acetamide hydrochloride (PJ-34). PD was induced by using a bilateral intranigral administration of MPTP in Sprague-Dawley rats, and different parameters were evaluated. An increase in the oxidative stress was observed, leading to the locomotor and cognitive deficits in the PD rats. PD rats also showed an increased TRPM2 expression in striatum and mid brain accompanied by reduced expression of tyrosine-hydroxylase (TH) in comparison to sham animals. Intraperitoneal administration of 2-aminoethyl diphenyl borinate (2-APB) and N-(6-Oxo-5,6-dihydrophenanthridin-2-yl)-(N,N-dimethylamino) acetamide hydrochloride (PJ-34) led to an improvement in the locomotor and cognitive deficits in comparison to MPTP-induced PD rats. These improvements were accompanied by a reduction in the levels of oxidative stress and an increase in TH levels in striatum and mid brain. In addition, these pharmacological interventions also led to a decrease in the expression of TRPM2 in PD in striatum and mid brain. Our results provide a rationale for the development of potent pharmacological agents targeting TRPM2-PARP pathway to provide therapeutic benefits for the treatment of neurological disease like PD.

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