Protective Effect of Standardized Extract of Passiflora incarnata Flower in Parkinson's and Alzheimer's Disease

Gastrodin Protects Neuronal Cells Against Oxidative Stress Through miRNA-125b-5p/Mamdc2 Axis

Deregulated reactive oxygen species (ROS) levels trigger oxidative stress (OS) injury that is closely associated with the pathophysiology of various neurological disorders. Therefore, therapeutic efforts at oxidative events in the pathway of neuronal degeneration would be promisingly helpful for intervention and treatment of related diseases. Here, we report that gastrodin, the main bioactive constituent of Rhizoma Gastrodiae, protects the mouse hippocampal HT22 cells from OS caused by hydrogen peroxide (H2O2), including the increased cell viability, elevated Glutathione (GSH) levels, decreased Malondialdehyde (MDA) activity, and down-regulated ROS levels with restored cell morphology. Through RNA-sequencing (RNA-Seq) and multiple experiments, we screened the gene Mamdc2 that could be a potential regulating target of gastrodin. Mechanistically, gastrodin exerts its protective effects on neuronal cells from oxidative injury by suppressing miRNA-125b-5p, which increases its target Mamdc2 expression. Overexpression of miR-125b-5p mimics significantly attenuates the gastrodin-triggered protective effects against H2O2 in HT22 cells, including the decreased cell viability, down-regulated GSH activity, increased MDA activity, and up-regulated ROS production, compared to the gastrodin-administration with control miRNA group. However, these results could be effectively restored by the ectopic expression of Mamdc2, leading to the opposite outcomes to those of miR-125b-5p mimics-overexpression. Thus, the current study provides evidence that gastrodin has the potential for intervention and therapy of OS injury-associated neurological diseases in future.

Passiflora incarnate extract attenuates neuronal loss and memory impairment in stressed rats

The present study investigated the protective effects of hydroalcoholic Passiflora incarnate extract on memory, anxiety-like behaviors, inflammatory factors, and cell density in the brain following stress. This study randomly divided 40 adult Wistar rats into 5 groups: control, normal saline, stress, stress + Passiflora incarnata, and Passiflora incarnata groups. For 21 consecutive days, the stress group and the Passiflora incarnata + stress group were exposed to immobilizing stress for 2 h each day. The Passiflora incarnata and the stress + Passiflora incarnata groups were gavaged with Passiflora incarnata extract half an hour before stress for 21 days. One day after the last stress, the Barnes and elevated plus maze were used to measure learning, memory, and anxiety-like behavior, respectively. Additionally, the MDA (malondialdehyde), TNF-α, IL-1, and gamma-glutamyl transferase (GGT) factors in the serum, as well as the cell density in the hippocampus, amygdala, and prefrontal regions, were investigated. The results of the Barnes maze showed that immobility stress increases the number of errors and the distance traveled to reach the target hole. Administering Passiflora incarnata extract prior to stress led to fewer errors and a shorter distance covered to reach the target hole. The use of Passiflora incarnata before stress in the elevated plus maze reduced anxiety-like behaviours (less frequent entries into the open arm, reduced duration of time in the open arm) compared to the stress group. The stress group caused a significant enhance in MDA, TNF-α, and IL-1 and a decrease in GGT, while treatment with Passiflora incarnata significantly improved these factors than the stress group. The immobility stress caused a significant decrease in cell density in the hippocampus, amygdala, and prefrontal region, and treatment with Passiflora incarnata increased cell density in these areas than the stress animals. In conclusion, Passiflora incarnata improves learning and memory impairment, anxiety-like behaviors, inflammatory factors, and damage caused by stress in the hippocampus, amygdala, and prefrontal areas.

Movement disorders associated with acetylcholinesterase inhibitors in Alzheimer's dementia: A systematic review

BACKGROUND

Acetylcholinesterase inhibitors (AChEIs) are widely used in Alzheimer's disease (AD). This study aims to systematically review the literature about movement disorders (MDs) associated with AChEIs for AD, which include donepezil, galantamine, rivastigmine, tacrine, and ipidacrine.

METHODOLOGY

Two reviewers conducted a comprehensive review of relevant studies across six databases, without language restrictions, covering publications from 1992 to 2024.

RESULTS

Overall, 74 studies containing 92 cases were found of MDs related to ACHEIs. The MDs found were Pisa syndrome in 33 patients, parkinsonism in 31, myoclonus in 11, dystonia in 10, dyskinesia in 6, and extrapyramidal symptoms in 1. Regarding the medications, the abnormal movements were associated with donepezil in 62 cases, rivastigmine in 15, galantamine in 10, and tacrine in 5. No case of ipidacrine-induced MD was found. Overall, the most commonly affected sex was the female, accounting for 61.9% of the cases. The mean and median age was 74.1 (standard deviation: 8.9) and 75 years (range: 49-93 years). The MD occurred within 6 months of the starting of AChEI in approximately 70% of the patients. Furthermore, the full recovery of the MD after the main management was noticed within 6 months in about 80% of the patients. About 86.3% of the individuals fully recovered after treatment, which included AChEI discontinuation, dose adjustment, and prescription of additional therapy.

CONCLUSIONS

The occurrence of tacrine-induced tremor indicated a potential predisposition to movement disorders associated with AChEI therapy. Based on the drug class side effect profile, it is possible that future studies may observe abnormal movements with other AChEIs.

Secondary Bioactive Metabolites from Foods of Plant Origin as Theravention Agents against Neurodegenerative Disorders

Neurodegenerative disorders (NDDs) such as Alzheimer's (AD) and Parkinson's (PD) are on the rise, robbing people of their memories and independence. While risk factors such as age and genetics play an important role, exciting studies suggest that a diet rich in foods from plant origin may offer a line of defense. These kinds of foods, namely fruits and vegetables, are packed with a plethora of powerful bioactive secondary metabolites (SBMs), including terpenoids, polyphenols, glucosinolates, phytosterols and capsaicinoids, which exhibit a wide range of biological activities including antioxidant, antidiabetic, antihypertensive, anti-Alzheimer's, antiproliferative, and antimicrobial properties, associated with preventive effects in the development of chronic diseases mediated by oxidative stress such as type 2 diabetes mellitus, respiratory diseases, cancer, cardiovascular diseases, and NDDs. This review explores the potential of SBMs as theravention agents (metabolites with therapeutic and preventive action) against NDDs. By understanding the science behind plant-based prevention, we may be able to develop new strategies to promote brain health and prevent the rise in NDDs. The proposed review stands out by emphasizing the integration of multiple SBMs in plant-based foods and their potential in preventing NDDs. Previous research has often focused on individual compounds or specific foods, but this review aims to present a comprehensive fingerprint of how a diet rich in various SBMs can synergistically contribute to brain health. The risk factors related to NDD development and the diagnostic process, in addition to some examples of food-related products and medicinal plants that significantly reduce the inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), are highlighted.

Phytomolecules from conventional to nano form: Next-generation approach for Parkinson's disease

The incidence of neurodegenerative diseases is increasing exponentially worldwide. Parkinson's disease (PD) is a neurodegenerative disease caused by factors like oxidative stress, gene mutation, mitochondrial dysfunction, neurotoxins, activation of microglial inflammatory mediators, deposition of Lewy's bodies, and α- synuclein proteins in the neurons leading to neuroinflammation and neurodegeneration in the substantia nigra. Hence the development of efficacious neuro-therapy is in demand which can prevent neurodegeneration and protect the nigrostriatal pathway. One of the approaches for managing PD is reducing oxidative stress due to aging and other co-morbid diseased conditions. The phytomolecules are reported as safe and efficacious antioxidants as they contain different secondary metabolites. However, the limitations of low solubility restricted permeability through the blood-brain barrier, and low bioavailability limits their clinical evaluation and application. This review discusses the therapeutic efficacy of phytomolecules in PD and different nanotechnological approaches to improve their brain permeability.

A Review on Natural Antioxidants for Their Role in the Treatment of Parkinson's Disease

The neurodegenerative condition known as Parkinson's disease (PD) is brought on by the depletion of dopaminergic neurons in the basal ganglia, which is the brain region that controls body movement. PD occurs due to many factors, from which one of the acknowledged effects of oxidative stress is pathogenic pathways that play a role in the development of Parkinson's disease. Antioxidants, including flavonoids, vitamins E and C, and polyphenolic substances, help to reduce the oxidative stress brought on by free radicals. Consequently, this lowers the risk of neurodegenerative disorders in the long term. Although there is currently no cure for neurodegenerative illnesses, these conditions can be controlled. The treatment of this disease lessens its symptoms, which helps to preserve the patient's quality of life. Therefore, the use of naturally occurring antioxidants, such as polyphenols, which may be obtained through food or nutritional supplements and have a variety of positive effects, has emerged as an appealing alternative management strategy. This article will examine the extent of knowledge about antioxidants in the treatment of neurodegenerative illnesses, as well as future directions for research. Additionally, an evaluation of the value of antioxidants as neuroprotective agents will be provided.

Current trends in natural products for the treatment and management of dementia: Computational to clinical studies

The number of preclinical and clinical studies evaluating natural products-based management of dementia has gradually increased, with an exponential rise in 2020 and 2021. Keeping this in mind, we examined current trends from 2016 to 2021 in order to assess the growth potential of natural products in the treatment of dementia. Publicly available literature was collected from various databases like PubMed and Google Scholar. Oxidative stress-related targets, NF-κB pathway, anti-tau aggregation, anti-AChE, and A-β aggregation were found to be common targets and pathways. A retrospective analysis of 33 antidementia natural compounds identified 125 sustainable resources distributed among 65 families, 39 orders, and 7 classes. We found that families such as Berberidaceae, Zingiberaceae, and Fabaceae, as well as orders such as Lamiales, Sapindales, and Myrtales, appear to be important and should be researched further for antidementia compounds. Moreover, some natural products, such as quercetin, curcumin, icariside II, berberine, and resveratrol, have a wide range of applications. Clinical studies and patents support the importance of dietary supplements and natural products, which we will also discuss. Finally, we conclude with the broad scope, future challenges, and opportunities for field researchers.

Multifunctional role of natural products for the treatment of Parkinson's disease: At a glance

Natural substances originating from plants have long been used to treat neurodegenerative disorders (NDs). Parkinson's disease (PD) is a ND. The deterioration and subsequent cognitive impairments of the midbrain nigral dopaminergic neurons distinguish by this characteristic. Various pathogenic mechanisms and critical components have been reported, despite the fact that the origin is unknown, such as protein aggregation, iron buildup, mitochondrial dysfunction, neuroinflammation and oxidative stress. Anti-Parkinson drugs like dopamine (DA) agonists, levodopa, carbidopa, monoamine oxidase type B inhibitors and anticholinergics are used to replace DA in the current treatment model. Surgery is advised in cases where drug therapy is ineffective. Unfortunately, the current conventional treatments for PD have a number of harmful side effects and are expensive. As a result, new therapeutic strategies that control the mechanisms that contribute to neuronal death and dysfunction must be addressed. Natural resources have long been a useful source of possible treatments. PD can be treated with a variety of natural therapies made from medicinal herbs, fruits, and vegetables. In addition to their well-known anti-oxidative and anti-inflammatory capabilities, these natural products also play inhibitory roles in iron buildup, protein misfolding, the maintenance of proteasomal breakdown, mitochondrial homeostasis, and other neuroprotective processes. The goal of this research is to systematically characterize the currently available medications for Parkinson's and their therapeutic effects, which target diverse pathways. Overall, this analysis looks at the kinds of natural things that could be used in the future to treat PD in new ways or as supplements to existing treatments. We looked at the medicinal plants that can be used to treat PD. The use of natural remedies, especially those derived from plants, to treat PD has been on the rise. This article examines the fundamental characteristics of medicinal plants and the bioactive substances found in them that may be utilized to treat PD.

The Role of Olfactory System in the Etiogenesis of Parkinson’s Diseases: An Overview

Parkinson’s disease (PD) mainly affects the dopaminergic neuronal networks of the substantia nigra, which leads to both motor and nonmotor symptoms of the disease. Based on the reports from the previous studies, 95% of the cases are presented along with olfactory dysfunction. The relevant publications from 2002 to 2021 were searched and shortlisted using PubMed and Google Scholar. In this review, we have discussed the correlation between olfactory dysfunction and PD. Olfactory damage presents earlier than the motor symptoms. Because there are no current methodologies for the early detection of PD, olfactory dysfunction can be used as a potential marker for the early detection of PD and hence paving the way for better therapeutic approaches.

Potential of Sorghum Polyphenols to Prevent and Treat Alzheimer's Disease: A Review Article

Alzheimer's disease (AD) is characterized by the excessive deposition of extracellular amyloid-beta peptide (Aβ) and the build-up of intracellular neurofibrillary tangles containing hyperphosphorylated tau proteins. This leads to neuronal damage, cell death and consequently results in memory and learning impairments leading to dementia. Although the exact cause of AD is not yet clear, numerous studies indicate that oxidative stress, inflammation, and mitochondrial dysfunction significantly contribute to its onset and progression. There is no effective therapeutic approach to stop the progression of AD and its associated symptoms. Thus, early intervention, preferably, pre-clinically when the brain is not significantly affected, is a better option for effective treatment. Natural polyphenols (PP) target multiple AD-related pathways such as protecting the brain from Aβ and tau neurotoxicity, ameliorating oxidative damage and mitochondrial dysfunction. Among natural products, the cereal crop sorghum has some unique features. It is one of the major global grain crops but in the developed world, it is primarily used as feed for farm animals. A broad range of PP, including phenolic acids, flavonoids, and condensed tannins are present in sorghum grain including some classes such as proanthocyanidins that are rarely found in others plants. Pigmented varieties of sorghum have the highest polyphenolic content and antioxidant activity which potentially makes their consumption beneficial for human health through different pathways such as oxidative stress reduction and thus the prevention and treatment of neurodegenerative diseases. This review summarizes the potential of sorghum PP to beneficially affect the neuropathology of AD.

Role of natural plant products against Alzheimer's disease

Alzheimer's disease (AD) is one of the major neurodegenerative disorder. Deposition of amyloid fibrils and tau protein are associated with various pathological symptoms. Currently limited medication is available for AD treatment. Most of the drugs are basically cholinesterase inhibitors and associated with various side effects. Natural plant products have shown potential as a therapeutic agent for the treatment of AD symptoms. Variety of secondary metabolites like flavonoids, tannins, terpenoids, alkaloids and phenols are used to reduce the progression of the disease. Plant products have less or no side effect and are easily available. The present review gives a detailed account of the potential of natural plant products against the AD symptoms.

Haloperidol-induced catalepsy as an animal model for parkinsonism: A systematic review of experimental studies

Several useful animal models for parkinsonism have been developed so far. Haloperidol-induced catalepsy is often used as a rodent model for the study of motor impairments observed in Parkinson's disease and related disorders and for the screening of potential antiparkinsonian compounds. The objective of this systematic review is to identify publications that used the haloperidol-induced catalepsy model for parkinsonism and to explore the methodological characteristics and the main questions addressed in these studies. A careful systematic search of the literature was carried out by accessing articles in three different databases: Web of Science, PubMed and SCOPUS. The selection and inclusion of studies were performed based on the abstract and, subsequently, on full-text analysis. Data extraction included the objective of the study, study design and outcome of interest. Two hundred and fifty-five articles were included in the review. Publication years ranged from 1981 to 2020. Most studies used the model to explore the effects of potential treatments for parkinsonism. Although the methodological characteristics used are quite varied, most studies used Wistar rats as experimental subjects. The most frequent dose of haloperidol used was 1.0 mg/kg, and the horizontal bar test was the most used to assess catalepsy. The data presented here provide a framework for an evidence-based approach to the design of preclinical research on parkinsonism using the haloperidol-induced catalepsy model. This model has been used routinely and successfully and is likely to continue to play a critical role in the ongoing search for the next generation of therapeutic interventions for parkinsonism.

Natural Compounds for the Management of Parkinson's Disease and Attention-Deficit/Hyperactivity Disorder

Parkinson's disease (PD) is the second most common neurodegenerative disorder with an unknown aetiology. The pathogenic mechanisms include oxidative stress, mitochondrial dysfunction, protein dysfunction, inflammation, autophagy, apoptosis, and abnormal deposition of α-synuclein. Currently, the existing pharmacological treatments for PD cannot improve fundamentally the degenerative process of dopaminergic neurons and have numerous side effects. On the other hand, attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder of childhood and is characterised by hyperactivity, impulsivity, and inattention. The aetiology of ADHD remains unknown, although it has been suggested that its pathophysiology involves abnormalities in several brain regions, disturbances of the catecholaminergic pathway, and oxidative stress. Psychostimulants and nonpsychostimulants are the drugs prescribed for the treatment of ADHD; however, they have been associated with increased risk of substance use and have several side effects. Today, there are very few tools available to prevent or to counteract the progression of such neurological disorders. Thus, therapeutic approaches with high efficiency and fewer side effects are needed. This review presents a brief overview of the two neurological disorders and their current treatments, followed by a discussion of the natural compounds which have been studied as therapeutic agents and the mechanisms underlying the beneficial effects, in particular, the decrease in oxidative stress.