Neurodegenerative diseases: From available treatments to prospective herbal therapy

Exploring the multifaceted role of ginkgolides and bilobalide from Ginkgo biloba in mitigating metabolic disorders

The ancient Ginkgo biloba tree grows across various regions, with distinctive leaves emitting a unique fragrance. Its extract contains flavonoids, organic acids, and terpenoids. Ginkgolide and bilobalide, which are G. biloba leaf extracts, offer diverse pharmaceutical benefits, including antioxidant, anti-inflammatory, and neuroprotective properties. The antioxidant and anti-inflammatory properties of these compounds are crucial for mitigating neurodegeneration, particularly in diseases such as Alzheimer's disease. Additionally, their effectiveness in countering oxidative stress and inflammation highlights their potential to prevent cardiovascular ailments. This study also suggests that these compounds have a promising impact on lipid metabolism, suggesting their significance in addressing obesity-related metabolic disorders. In conclusion, ginkgolides and bilobalide exhibit promising effects in sustaining the integrity of the nervous and endocrine systems, along with the modulation of lipid metabolism. The diverse health benefits suggest that these compounds could serve as promising therapeutic interventions for various conditions, including neurological, cardiovascular, and metabolic diseases.

Basic approach on the protective effects of hesperidin and naringin in Alzheimer's disease

OBJECTIVES

Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive impairment. This situation imposes a great burden on individuals, both economically and socially. Today, an effective method for treating the disease and protective approach to tau accumulation has not been developed yet. Studies have been conducted on the effects of hesperidin and naringin flavonoids found in citrus fruits on many diseases.

METHODS

In this review, the pathophysiology of AD is defined, and the effects of hesperidin and naringin on these factors are summarized.

RESULTS

Studies have shown that both components may potentially affect AD due to their antioxidative and anti-inflammatory properties. Based on these effects of the components, it has been shown that they may have ameliorative effects on Aβ, α-synuclein aggregation, tau pathology, and cognitive functions in the pathophysiology of AD.

DISCUSSION

There are studies suggesting that hesperidin and naringin may be effective in the prevention/treatment of AD. When these studies are examined, it is seen that more studies should be conducted on the subject.

Mechanisms and therapeutic potential of chinonin in nervous system diseases

The flavonoid compound chinonin is one of the main active components of Rhizoma anemarrhena with multiple activities, including anti-inflammatory and antioxidant properties, protection of mitochondrial function and regulation of immunity. In this paper, we reviewed recent research progress on the protective effect of chinonin on brain injury in neurological diseases. "Chinonin" OR "Mangiferin" AND "Nervous system diseases" OR "Neuroprotection" was used as the terms for search in PumMed. After discarding duplicated and irrelevant articles, a total of 23 articles relevant to chinonin published between 2012 and 2023 were identified in our study.

Neuroprotective effects of Tradescantia spathacea tea bioactives in Parkinson's disease: In vivo proof-of-concept

Background and aim

Tradescantia spathacea (T. spathacea) is a traditional medicinal plant from Central America and its tea, obtained by infusion, has been recognized as a functional food. The aim of this work was to investigate the effects of dry tea containing biocompounds from T. spathacea tea on motor and emotional behavior, as well as tyrosine hydroxylase (TH) and glial fibrillary acidic protein (GFAP) expression in 6-hydroxydopamine (6-OHDA)-lesioned rats.

Experimental procedure

Bioactives were identified by Ultra Performance Liquid Chromatography (UPLC) and an in vivo study in male Wistar rats was run as proof of concept of neuroprotective effects of DTTS.

Results and conclusion

We found 15 biocompounds that had not been previously reported in T. spathacea: the UPLC-QTOF-MS/MS allowed identification five phenolic acids, one coumarin, two flavonoids, one iridoid, one phenylpropanoid glycoside, and six fatty acid derivatives. The dry tea of T. spathacea (DTTS) presented significant antioxidant activity and high contents of phenolic compounds and flavonoids. Doses of 10, 30, and 100 mg/kg of DTTS were protective against dopaminergic neurodegeneration and exhibited modulatory action on the astrocyte-mediated neuroinflammatory response. Behavioral tests showed that 30 mg/kg of DTTS counteracted motor impairment, while 100 mg/kg produced an anxiolytic effect. The DTTS could be, therefore, a promising strategy for the management of Parkinson's disease.

The effectiveness of hesperidin on bisphenol A-induced spinal cord toxicity in a diabetic rat model

The potential health risks of bisphenol A (BS) and diabetes (DI) has sparked public concern due to be ubiquitous worldwide. The purpose of this study was to investigate the detrimental impact of BS (200 mg/kg) on the spinal cord tissue in a rat diabetic model. We also evaluated the antioxidant capacity of hesperidin (HS) (100 mg/kg) on spinal cord in BS-treated diabetic rat. Seventy male Wistar albino rats, weighing 180-230 g and 8 weeks old, were randomly chosen, and assigned into seven groups of 10 rats: Control (KON), BS, DI, BS + DI, HS + BS, HS + DI, HS + BS + DI. At the end of the 14-day experimental period, all samples were examined using stereological, biochemical, and histopathological techniques. Our biochemical findings revealed that the SOD level was significantly lower in the BS, DI, and BS + DI groups compared to the KON group (p < 0.05). Compared to the KON group, there was a significant decrease in the number of motor neurons and an increase in the mean volume of central canals in the BS, DI, and BS + DI groups (p < 0.05). In the HS + BC group than the BS group and in the HS + DI group than the DI group, SOD activity and the number of motor neurons were significantly higher; also, the mean volume of spinal central canal was significantly lower (p < 0.05). The novel findings gathered from the histopathological assessment supported our quantitative results. Our speculation was that the exposure to BS and DI was the main cause of neurological alteration in the spinal cord tissues. The administration of HS had the therapeutic potential to mitigate spinal cord abnormalities resulting from BS and DI. However, HS supplementation did not alleviate spinal cord complications in BS-treated diabetic rats.

Sweet basil (Ocimum basilicum) leaf and seed extracts alleviate neuronal dysfunction in aluminum chloride-induced neurotoxicity in Drosophila melanogaster Meigen model

Ocimum basilicum is an important medicinal plant and culinary herb generally known as sweet basil (SB). These plants are effective radical scavengers, that have been employed in treatment of nervous system disorders, and thus, could be beneficial for the management of neurodegenerative diseases (NDs). Current clinical treatments for NDs present several side effects, therefore, there is need to develop new treatments that can mitigate these deadly diseases. Hence, this study investigated the neuroprotective activities of SB leaf and seed in aluminum chloride (AlCl3)-induced toxicity in Drosophila melanogaster. HPLC characterization of the leaves and seeds were carried out. AlCl3-diet was used to induce neurodegeneration and treated flies received SB leaf and seed extracts-supplemented diet. Survival and locomotor performance activities/levels of oxidative biomarkers [reactive oxygen species (ROS), thiobarbituric acid reactive species (TBARS), total thiol, catalase, superoxide dismutase (SOD) and glutathione-S-transferase (GST)], enzymes linked with neurodegeneration (acetylcholinesterase (AChE) and monoamine oxidase (MAO)) were investigated. SB leaf had significantly (p < 0.05) higher polyphenol contents; gallic acid and P-coumaric acid were the most abundant polyphenol in the leaf and seed respectively. Percentage survival and locomotor rates, level/activities of total thiol, catalase, SOD and GST were significantly (p < 0.05) reduced while ROS, TBARS, AChE and MAO activities were significantly (p < 0.05) increased in AlCl3-diet-fed flies. Treatment with SB leaf and seed diet lessened these observed impairments. However, SB leaf had better neuroprotective activities that could be related to the observed higher phenolic constituents. Hence, SB leaf diet may offer improved therapeutic effect in NDs.

Convolamine, a tropane alkaloid extracted from Convolvulus plauricalis, is a potent sigma-1 receptor-positive modulator with cognitive and neuroprotective properties

BACKGROUND AND AIM

By using an in vivo phenotypic screening assay in zebrafish, we identified Convolamine, a tropane alkaloid from Convulvus plauricalis, as a positive modulator of the sigma-1 receptor (S1R). The wfs1abKO zebrafish larva, a model of Wolfram syndrome, exhibits an increased visual-motor response due to a mutation in Wolframin, a protein involved in endoplasmic reticulum-mitochondria communication. We previously reported that ligand activating S1R, restored the cellular and behavioral deficits in patient fibroblasts and zebrafish and mouse models.

EXPERIMENTAL PROCEDURES

We screened a library of 108 repurposing and natural compounds on zebrafish motor response.

KEY RESULTS

One hit, the tropane alkaloid Convolamine, restored normal mobility in wfs1abKO larvae without affecting wfs1abWT controls. They did not bind to the S1R agonist/antagonist binding site nor dissociated S1R from BiP, an S1R activity assay in vitro, but behaved as a positive modulator by shifting the IC50 value of the reference agonist PRE-084 to lower values. Convolamine restored learning in Wfs1∆Exon8 , Dizocilpine-treated, and Aβ25-35 -treated mice. These effects were observed at low ~1 mg/kg doses, not shared by Convolvine, the desmethyl metabolite, and blocked by an S1R antagonist.

CONCLUSION AND IMPLICATIONS

Convolamine therefore acts as an S1R positive modulator and this pharmacological action is relevant to the traditional use of Shankhpushpi in memory and cognitive protection.

Deciphering Neuroprotective Effect of Rosmarinus officinalis L. (syn. Salvia rosmarinus Spenn.) through Preclinical and Clinical Studies

Rosmarinus officinalis L. (RO, rosemary) is a well-known medicinal, aromatic, and culinary herb with traditional use in European folk medicine against memory deficits and neurodegenerative disorders. This review highlights the different neuroprotective activities of RO investigated in both preclinical and clinical studies, as well as in silico molecular docking of bioactive compounds found in RO. The neuroprotective effect of RO was searched through databases including PubMed, Web of Science (WoS), Scopus, and Clinical Trials using the keywords "Rosmarinus officinalis, rosemary, neuroprotective effect, memory, cognitive dysfunction, Alzheimer's disease." RO, which is rich in secondary metabolites that have memory-enhancing potential, has displayed neuroprotection through different molecular mechanisms such as inhibition of cholinesterase, modulation of dopaminergic and oxytocinergic systems, mediation of oxidative and inflammatory proteins, involved in neuropathic pain, among others. RO extracts exhibited antidepressant and anxiolytic activities. Also, the plant has shown efficacy in scopolamine-, lipopolysaccharide-, AlCl3-, and H2O2-induced amnesia as well as amyloid-beta- and ibotenic acid-induced neurotoxicity and chronic constriction injury-related oxidative stress memory and cognitive impairments in animal models. A few clinical studies available supported the neuroprotective effects of RO and its constituents. However, more clinical studies are needed to confirm results from preclinical studies further and should include not only placebo-controlled studies but also studies including positive controls using approved drugs. Many studies underlined that constituents of RO may have the potential for developing drug candidates against Alzheimer's disease that possess high bioavailability, low toxicity, and enhanced penetration to CNS, as revealed from the experimental and molecular docking analysis.

Potential of rosmarinic acid from Orthosiphon aristatus extract for inflammatory induced diseases and its mechanisms of action

Orthosiphon aristatus has been traditionally used as a medicinal herb for various illnesses in Southeast Asia and Europe. The most dominant bioactive compound of the herb is rosmarinic acid (RosA) which has been demonstrated for its remarkable anti-inflammatory properties. This review describes the recent progress of studies on multi-target molecular pathways of RosA in relation to targeted inflammatory-associated diseases. An inclusive literature search was conducted using electronic databases such as Google Scholar, Scopus, Springer Link, PubMed, Medline, Wiley and Science Direct for studies reporting on the anti-inflammatory actions of RosA from 2008 until 2023. The keywords of the search were RosA and anti-inflammatory in relation to hepatoprotective, chondroprotective, cardioprotective, neuroprotective and toxicity. Only publications that are written in English are included in this review. The inhibition and deactivation of pro-inflammatory biomolecules by RosA were explained based on the initial inflammation stimuli and their location in the body. The activation of Nrf2/HO-1 expression to inhibit NF-κB pathway is the key mechanism for hepatoprotection. Besides NF-κB inhibition, RosA activates PPARγ to alleviate ischemia/reperfusion (I/R)-induced myocardial injury for cardioprotection. The regulation of MAPK and T-cell activation is important for chondroprotection, whereas the anti-oxidant property of RosA is the main contributor of neuroprotection. Even though less studies on the anti-inflammation of RosA extracts from O. aristatus, but the effective pharmacological properties of RosA has promoted it as a natural potent lead for further investigation.

Neuroprotective Potential of Pyranocoumarins from Angelica gigas Nakai on Glutamate-Induced Hippocampal Cell Death

Chronic neurodegenerative diseases are typically associated with oxidative stress conditions leading to neuronal cell death. We aimed to investigate the neuroprotective effect of three pyranocoumarins (decursin, decursinol angelate, and decursinol) targeting oxidative stress factors. Decursin (also known as dehydro-8-prenylnaringenin) is a prenylated coumarin compound consisting of a coumarin ring system with a prenyl group attached to one of the carbons in the ring. As a secondary metabolite of plants, pyranocoumarin decursin from Angelica gigas Nakai presented protective effects against glutamate-induced oxidative stress in HT22, a murine hippocampal neuronal cell line. Decursinol (DOH) is a metabolite of decursin, sharing same coumarin ring system but a slightly different chemical structure with the prenyl group replaced by a hydroxyl group (-OH). In our findings, DOH was ineffective while decursin was, suggesting that this prenyl structure may be important for compound absorption and neuroprotection. By diminishing the accumulation of intracellular reactive oxygen species as well as stimulating the expression of HO-1, decursin triggers the self-protection system in neuronal cells. Additionally, decursin also revealed an anti-apoptotic effect by inhibiting chromatin condensation and reducing the forming of annexin-V-positive cells.

Protective effect of Gastrodia elata Blume in a Caenorhabditis elegans model of Alzheimer's disease based on network pharmacology

The aim of the present study was to investigate the protective effect of Gastrodia elata Blume (GEB) against Caenorhabditis elegans (C. elegans) in Alzheimer's disease (AD) through network pharmacology. Firstly, the active constituents of GEB through ETCM and BATMAN-TCM databases were collected and its potential AD-related targets in Swiss Target Prediction were predicted. The potential targets related to AD were collected from the GeneCards, OMIM, CTD and DisGeNET databases, and the differential genes (DEGs) between the normal population and the AD patient population in GSE5281 chip of the Gene Expression Omnibus database were collected at the same time. The intersection of the three targets yielded 59 key targets of GEB for the treatment of AD. The drug-active ingredient-target-AD network diagram was constructed and visualized with Cytoscape software to obtain the core components. Subsequently, protein-protein interaction analysis (PPI) was performed on 59 key targets through STRING database, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses was performed on 59 key targets. Finally, molecular docking was conducted between core components and core targets using AutoDock software, and the C. elegans AD model was used for experimental verification to explore the regulatory paralysis effect of core components on the C. elegans model, β-amyloid (Aβ) plaque deposition, and quantitative polymerase chain reaction verification of the regulatory effect of components on targets. The GEB components 4,4'-dihydroxydiphenyl methane (DM) and protocatechuic aldehyde (PA) were found to be most strongly associated with AD, and five core targets were identified in the PPI network, including GAPDH, EP300, HSP90AB1, KDM6B, and CREBBP. In addition to GAPDH, the other four targets were successfully docked with DM and PA using AutoDock software. Compared with the control group, 0.5 mM DM and 0.25 mM PA significantly delayed C. elegans paralysis (P<0.01), and inhibited the aggregation of Aβ plaques in C. elegans. Both DM and PA could upregulate the expression level of core target gene HSP90AB1 (P<0.01), and DM upregulated the expression of KDM6B (P<0.01), suggesting that DM and PA may be potential active components of GEB in the treatment of AD.

Acteoside palliates d-galactose induced cognitive impairment by regulating intestinal homeostasis

Acteoside, an important phenylethanol glycoside, is the main active component in Osmanthus fragrans flower. Our previous study found that acteoside showed high antiaging effect but its absorption rate was low. We speculated acteoside palliated aging-related cognitive impairment before being absorbed, that was intestinal homeostasis underlie the antiaging effect of acteoside. In this study, acteoside was confirmed to palliate cognitive impairment in d-galactose induced aging mice. Acteoside treatment dramatically reduced oxidative stress, alleviated intestinal inflammation, restored intestinal mucosal barrier, rebuilt gut microbiome structure and upregulated gut microbiome metabolites short-chain fatty acids (SCFAs) and amino acids (AAs). Furthermore, antibiotic treatment revealed that the antiaging ability of acteoside was abolished in microbiota depleted mice, which offered direct evidence for the essential role of gut microbiota in the attenuation of cognitive impairment of acteoside. Together, our study indicated that acteoside palliated cognitive impairment by regulating intestinal homeostasisand acteoside intake might be a promising nutritional intervention in prevention of neurodegenerative diseases.

Phytotherapeutic alternatives for neurodegenerative dementias: Scientific review, discussion and therapeutic proposal

The incidence and prevalence of age-related neurodegenerative dementias have been increasing. There is no curative therapy and conventional drug treatment can cause problems for patients. Medicinal plants traditionally used for problems associated with ageing are emerging as a therapeutic resource. The main aim is to give a proposal for use and future research based on scientific knowledge and tradition. A literature search was conducted in several searchable databases. The keywords used were related to neurodegenerative dementias, ageing and medicinal plants. Boolean operators and filters were used to focus the search. As a result, there is current clinical and preclinical scientific information on 49 species used in traditional medicine for ageing-related problems, including neurodegenerative dementias. There are preclinical and clinical scientific evidences on their properties against protein aggregates in the central nervous system and their effects on neuroinflammation, apoptosis dysregulation, mitochondrial dysfunction, gabaergic, glutamatergic and dopaminergic systems alterations, monoamine oxidase alterations, serotonin depletion and oestrogenic protection. In conclusion, the potential therapeutic effect of the different medicinal plants depends on the type of neurodegenerative dementia and its stage of development, but more clinical and preclinical research is needed to find better, safer and more effective treatments.

Research trends and hotspots of neurodegenerative diseases employing network pharmacology: A bibliometric analysis

Background: Employing network pharmacology in neurodegenerative diseases (NDs) has been extensively studied recently. However, no comprehensive study has conducted on this subject employing bibliometrics so far. The purpose of this study was to find out the developmental trends and hotspots, and to predict potential research directions in this filed. Methods: Relevant research were collected from the Web of Science Core Collection Bibliometrics and visual analysis were executed using CiteSpace, VOSviewer, Histcite and R-bibliometrix. Results: A total of 420 English articles on network pharmacology in NDs published in 2008-2022 were obtained from the WOSCC database. From 2008 to 2022, annual publications showed a steady growing trend, especially in 2014-2022. China, Beijing Univ Chinese Med, Frontiers in Pharmacology, and Geerts H are the most prolific country, institution, journal, and author, respectively. China, Nucleic Acids Research, and Hopkins AL are the most highly cited country, journal, and author, respectively. Moreover, network pharmacology and Alzheimer's disease are the focal areas of current researches according to analysis of co-cited references and keywords. Finally, in the detection of burst keywords, systems pharmacology and database are new approaches to disease and drug research, while traditional Chinese medicine (TCM) and Alzheimer's disease are hot research directions. The above keywords are speculated to be the research frontiers. Conclusion: Network pharmacology and Alzheimers' disease are the main topics of researches on network pharmacology in NDs. Network pharmacology and the TCM treatment of Alzheimer's disease have been the recent research hotspots. To sum up, the potential for exploring TCM treatment of AD with network pharmacology is huge.

Expanding Arsenal against Neurodegenerative Diseases Using Quercetin Based Nanoformulations: Breakthroughs and Bottlenecks

Quercetin (Qu), a dietary flavonoid, is obtained from many fruits and vegetables such as coriander, broccoli, capers, asparagus, onion, figs, radish leaves, cranberry, walnuts, and citrus fruits. It has proven its role as a nutraceutical owing to numerous pharmacological effects against various diseases in preclinical studies. Despite these facts, Qu and its nanoparticles are less explored in clinical research as a nutraceutical. The present review covers various neuroprotective actions of Qu against various neurodegenerative diseases (NDs) such as Alzheimer's, Parkinson's, Huntington's, and Amyotrophic lateral sclerosis. A literature search was conducted to systematically review the various mechanistic pathways through which Qu elicits its neuroprotective actions and the challenges associated with raw Qu that compromise therapeutic efficacy. The nanoformulations developed to enhance Qu's therapeutic efficacy are also covered. Various ongoing/completed clinical trials related to Qu in treating various diseases, including NDs, are also tabulated. Despite these many successes, the exploration of research on Qu-loaded nanoformulations is limited mostly to preclinical studies, probably due to poor drug loading and stability of the formulation, time-consuming steps involved in the formulation, and their poor scale-up capacity. Hence, future efforts are required in this area to reach Qu nanoformulations to the clinical level.

Neurodegenerative Diseases: Implications of Environmental and Climatic Influences on Neurotransmitters and Neuronal Hormones Activities

Neurodegenerative and neuronal-related diseases are major public health concerns. Human vulnerability to neurodegenerative diseases (NDDs) increases with age. Neuronal hormones and neurotransmitters are major determinant factors regulating brain structure and functions. The implications of environmental and climatic changes emerged recently as influence factors on numerous diseases. However, the complex interaction of neurotransmitters and neuronal hormones and their depletion under environmental and climatic influences on NDDs are not well established in the literature. In this review, we aim to explore the connection between the environmental and climatic factors to NDDs and to highlight the available and potential therapeutic interventions that could use to improve the quality of life and reduce susceptibility to NDDs.

Bioavailability of Hesperidin and Its Aglycone Hesperetin—Compounds Found in Citrus Fruits as a Parameter Conditioning the Pro-Health Potential (Neuroprotective and Antidiabetic Activity)—Mini-Review

Hesperidin and hesperetin are polyphenols that can be found predominantly in citrus fruits. They possess a variety of pharmacological properties such as neuroprotective and antidiabetic activity. However, the bioavailability of these compounds is limited due to low solubility and restricts their use as pro-healthy agents. This paper described the limitations resulting from the low bioavailability of the presented compounds and gathered the methods aiming at its improvement. Moreover, this work reviewed studies providing pieces of evidence for neuroprotective and antidiabetic properties of hesperidin and hesperetin as well as providing a detailed look into the significance of reported modes of action in chronic diseases. On account of a well-documented pro-healthy activity, it is important to look for ways to overcome the problem of poor bioavailability.

Natural Products as Novel Neuroprotective Agents; Computational Predictions of the Molecular Targets, ADME Properties, and Safety Profile

Neurodegenerative diseases (NDs) are one of the most challenging public health issues. Despite tremendous advances in our understanding of NDs, little progress has been made in establishing effective treatments. Natural products may have enormous potential in preventing and treating NDs by targeting microglia; yet, there have been several clinical concerns about their usage, primarily due to a lack of scientific evidence for their efficacy, molecular targets, physicochemical properties, and safety. To solve this problem, the secondary bioactive metabolites derived from neuroprotective medicinal plants were identified and selected for computational predictions for anti-inflammatory activity, possible molecular targets, physicochemical properties, and safety evaluation using PASS online, Molinspiration, SwissADME, and ProTox-II, respectively. Most of the phytochemicals were active as anti-inflammatory agents as predicted using the PASS online webserver. Moreover, the molecular target predictions for some phytochemicals were similar to the reported experimental targets. Moreover, the phytochemicals that did not violate important physicochemical properties, including blood-brain barrier penetration, GI absorption, molecular weight, and lipophilicity, were selected for further safety evaluation. After screening 54 neuroprotective phytochemicals, our findings suggest that Aromatic-turmerone, Apocynin, and Matrine are the most promising compounds that could be considered when designing novel neuroprotective agents to treat neurodegenerative diseases via modulating microglial polarization.

Quercetin exhibits potent antioxidant activity, restores motor and non-motor deficits induced by rotenone toxicity

The rotenone-induced animal model of Parkinson's disease (PD) has been used to investigate the pathogenesis of PD. Oxidative stress is one of the main contributors of neurodegeneration in PD. Flavonoids have the potential to modulate neuronal function and combat various neurodegenerative diseases. The pre- and post-supplementation of quercetin (50 mg/kg, p.o) was done in rats injected with rotenone (1.5 mg/kg, s.c). After the treatment, behavioral activities were monitored for motor activity, depression-like behavior, and cognitive changes. Rats were decapitated after behavioral analysis and the brain samples were dissected out for neurochemical and biochemical estimation. Results showed that supplementation of quercetin significantly (p<0.01) restored rotenone-induced motor and non-motor deficits (depression and cognitive impairments), enhanced antioxidant enzyme activities (p<0.01), and attenuated neurotransmitter alterations (p<0.01). It is suggested that quercetin supplementation improves neurotransmitter levels by mitigating oxidative stress via increasing antioxidant enzyme activity and hence improves motor activity, cognitive functions, and reduces depressive behavior. The results of the present study showed that quercetin pre-supplementation produced more significant results as compared to post-supplementation. These findings show that quercetin can be a potential therapeutic agent to reduce the risk and progression of PD.

Ficus deltoidea: Potential inhibitor of pro-inflammatory mediators in lipopolysaccharide-induced activation of microglial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ficus deltoidea Jack (FD) is widely consumed in traditional medicine as a treatment for various diseases in Malaysia. Each part of the plant such as its leave, stem, fruit and root are used traditionally to treat different types of diseases. Vitexin and isovitexin are bioactive compounds abundantly found in the leaves of FD that possessed many pharmacological properties including neuroprotection. Nonetheless, its effects on key events in neuroinflammation are unknown.

AIM OF THE STUDY

To determine the inhibitory properties of FD aqueous extract on pro-inflammatory mediators involved in lipopolysaccharide (LPS)-induced microglial cells.

METHODS

Vitexin and isovitexin in the extract were quantified via high performance liquid chromatography (HPLC). The extract was evaluated for its cytotoxicity activity via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Pre-treatment with the extract on LPS-induced microglial cells was done to determine its antioxidant and anti-neuroinflammatory properties by measuring the level of reactive oxygen species (ROS), nitric oxide (NO), tumour necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) via 2'-7'-dichlorofluorescin diacetate (DCFDA) assay, Griess assay and Western blot respectively.

RESULTS

The extract at all tested concentrations (0.1 μg/mL, 1 μg/mL, 10 μg/mL, 100 μg/mL) were not cytotoxic as the percentage viability of microglial cells were all above ~80%. At the highest concentration (100 μg/mL), the extract significantly reduced the formation of ROS, NO, TNF-α, IL-1β and IL-6 in microglial cells induced by LPS.

CONCLUSION

The extract showed neuroprotective effects by attenuating the levels of pro-inflammatory and cytotoxic factors in LPS-induced microglial cells, possibly by mediating the nuclear factor-kappa B (NF-κB) signalling pathway.

Potentials of autophagy enhancing natural products in the treatment of Parkinson disease

Parkinson disease (PD) is a progressive neurodegenerative movement disorder characterized by motor and non-motor symptoms due to loss of striatal dopaminergic neurons and disruption of degradation signaling leading to the formation of Lewy bodies (aggregation of α-synuclein). Presently, there are no disease modifying therapy for PD despite improvement in the understanding of the disease pathogenesis. However, the drugs currently used in PD management provide symptomatic relieve for motor symptoms without significant improvement in non-motor complications, thus, a public health burden on caregivers and healthcare systems. There is therefore the need to discover disease modifying therapy with strong potential to halt the disease progression. Recent trend has shown that the dysfunction of lysosomal-autophagy pathway is highly implicated in PD pathology, hence, making autophagy a key player owing to its involvement in degradation and clearance of misfolded α-synuclein (a major hallmark in PD pathology). In this review, we described the current drugs/strategy in the management of PD including targeting the autophagy pathway as a novel approach that could serve as potential intervention for PD management. The discovery of small molecules or natural products capable of enhancing autophagy mechanism could be a promising strategy for PD treatment.

Potentials of autophagy enhancing natural products in the treatment of Parkinson disease

Parkinson disease (PD) is a progressive neurodegenerative movement disorder characterized by motor and non-motor symptoms due to loss of striatal dopaminergic neurons and disruption of degradation signaling leading to the formation of Lewy bodies (aggregation of α-synuclein). Presently, there are no disease modifying therapy for PD despite improvement in the understanding of the disease pathogenesis. However, the drugs currently used in PD management provide symptomatic relieve for motor symptoms without significant improvement in non-motor complications, thus, a public health burden on caregivers and healthcare systems. There is therefore the need to discover disease modifying therapy with strong potential to halt the disease progression. Recent trend has shown that the dysfunction of lysosomal-autophagy pathway is highly implicated in PD pathology, hence, making autophagy a key player owing to its involvement in degradation and clearance of misfolded α-synuclein (a major hallmark in PD pathology). In this review, we described the current drugs/strategy in the management of PD including targeting the autophagy pathway as a novel approach that could serve as potential intervention for PD management. The discovery of small molecules or natural products capable of enhancing autophagy mechanism could be a promising strategy for PD treatment.

Green Tea Epigallocatechin-3-gallate (EGCG) Targeting Protein Misfolding in Drug Discovery for Neurodegenerative Diseases

The potential to treat neurodegenerative diseases (NDs) of the major bioactive compound of green tea, epigallocatechin-3-gallate (EGCG), is well documented. Numerous findings now suggest that EGCG targets protein misfolding and aggregation, a common cause and pathological mechanism in many NDs. Several studies have shown that EGCG interacts with misfolded proteins such as amyloid beta-peptide (Aβ), linked to Alzheimer's disease (AD), and α-synuclein, linked to Parkinson's disease (PD). To date, NDs constitute a serious public health problem, causing a financial burden for health care systems worldwide. Although current treatments provide symptomatic relief, they do not stop or even slow the progression of these devastating disorders. Therefore, there is an urgent need to develop effective drugs for these incurable ailments. It is expected that targeting protein misfolding can serve as a therapeutic strategy for many NDs since protein misfolding is a common cause of neurodegeneration. In this context, EGCG may offer great potential opportunities in drug discovery for NDs. Therefore, this review critically discusses the role of EGCG in NDs drug discovery and provides updated information on the scientific evidence that EGCG can potentially be used to treat many of these fatal brain disorders.

Plant Foods Rich in Antioxidants and Human Cognition: A Systematic Review

Oxidative stress can compromise central nervous system integrity, thereby affecting cognitive ability. Consumption of plant foods rich in antioxidants could thereby protect cognition. We systematically reviewed the literature exploring the effects of antioxidant-rich plant foods on cognition. Thirty-one studies were included: 21 intervention, 4 cross-sectional (one with a cohort in prospective observation as well), and 6 prospective studies. Subjects belonged to various age classes (young, adult, and elderly). Some subjects examined were healthy, some had mild cognitive impairment (MCI), and some others were demented. Despite the different plant foods and the cognitive assessments used, the results can be summarized as follows: 7 studies reported a significant improvement in all cognitive domains examined; 19 found significant improvements only in some cognitive areas, or only for some food subsets; and 5 showed no significant improvement or no effectiveness. The impact of dietary plant antioxidants on cognition appears promising: most of the examined studies showed associations with significant beneficial effects on cognitive functions-in some cases global or only in some specific domains. There was typically an acute, preventive, or therapeutic effect in young, adult, and elderly people, whether they were healthy, demented, or affected by MCI. Their effects, however, are not attributable only to anti-oxidation.

Chemical modulation of Kv7 potassium channels

The rising interest in Kv7 modulators originates from their ability to evoke fundamental electrophysiological perturbations in a tissue-specific manner. A large number of therapeutic applications are, in part, based on the clinical experience with two broad-spectrum Kv7 agonists, flupirtine and retigabine. Since precise molecular structures of human Kv7 channel subtypes in closed and open states have only very recently started to emerge, computational studies have traditionally been used to analyze binding modes and direct the development of more potent and selective Kv7 modulators with improved safety profiles. Herein, the synthetic and medicinal chemistry of small molecule modulators and the representative biological properties are summarized. Furthermore, new therapeutic applications supported by in vitro and in vivo assay data are suggested.

Plant-Derived Natural Compounds for the treatment of Amyotrophic Lateral Sclerosis: An Update

Background

Amyotrophic lateral sclerosis (ALS) is a motor neuron disease (MND) that typically causes death within 3-5 years after diagnosis. Regardless of the substantial scientific knowledge accrued more than a century ago, truly effective therapeutic strategies remain distant. Various conventional drugs are being used but are having several adverse effects.

Objective/Aim

The current study aims to thoroughly review plant-derived compounds with well-defined ALS activities and their structure-activity relationships. Moreover, the review also focuses on complex genetics, clinical trials, and the use of natural products that might decrypt the future and novel therapeutics in ALS.

Methods

The collection of data for the compilation of this review work was searched in PubMed Scopus, Google Scholar, and Science Direct.

Results

Results showed that phytochemicals like-Ginkgolides, Protopanaxatriol, Genistein, epigallocatechingallate, resveratrol, cassoside, and others possess Amyotrophic lateral sclerosis (ALS) activity by various mechanisms.

Conclusion

These plant-derived compounds may be considered as supplements for conventional (ALS). Moreover, further preclinical and clinical studies are required to understand the structure-activity relationships, metabolism, absorption, and mechanisms of plant-derived natural agents.

Edible Flowers: Antioxidant Compounds and Their Functional Properties

Edible flowers have been widely consumed for ages until now. The attractive colors and shapes, exotic aroma, and delightful taste make edible flowers very easy to attain. Moreover, they also provide health benefits for consumers due to the unique composition and concentration of antioxidant compounds in the matrices. Knowing the bioactive compounds and their functional properties from edible flowers is necessary to diversify the usage and reach broader consumers. Therefore, this reported review could be useful for functional product development, engaging the discussed edible flowers. We present a comprehensive review of edible flower composition and the functional properties of their antioxidant compounds, mainly phenolics.

Flavonoids from edible fruits as therapeutic agents in neuroinflammation - a comprehensive review and update

Neuroinflammation is a key process in the pathogenesis of many neurological disorders, i.e. Alzheimer's disease and Parkinson's disease. However, there are no anti-inflammatory medical interventions recommended so far in the treatment of neuroinflammation-related brain disorders. Therefore, the burden of searching for effective and safe antineuroinflammatory agents is well founded, especially in the aging society. Compounds of plant origin, mainly (poly)phenols, have attracted considerable attention in recent years. Notably, the role of flavonoids in ameliorating neuroinflammation is in the limelight. Thus, we used comprehensive literature retrieval to summarize the effects and active components of edible fruits and their phenolic compounds. As a result, this review presents a valuable summary of results of in vitro, ex vivo, and in vivo studies on the antineuroinflammatory effects of edible fruits and their (poly)phenolic extracts as well as dietary flavonoids and other selected (poly)phenols based on the detailed description of foregoing studies. Additionally, problems resulting from the limited bioavailability of (poly)phenols were discussed.

Astragalus protects PC12 cells from 6-hydroxydopamine-induced neuronal damage: A serum pharmacological study

Accumulating evidence has already indicated that traditional Chinese medicine (TCM) possesses tremendous potential for treating neurodegenerative diseases. Astragalus, also named Huangqi, is a famous traditional medical herb that can be applied to treat cerebral ischemia and prevent neuronal degeneration. Nevertheless, the underlying mechanisms remain largely unexplored. In the present study, Astragalus-containing serum (ASMES) was prepared and added into the culture medium of PC12 cells to explore its neuroprotective effect on 6-hydroxydopamine (6-OHDA)-caused neuronal toxicity. Our data showed that ASMES significantly ameliorated the cellular viability of cultured PC12 cells against the neurotoxicity induced by 6-OHDA (P < 0.05). Moreover, ASMES significantly decreased the cell apoptosis triggered by 6-OHDA (P < 0.01). Furthermore, 2',7'-dichlorofluorescin diacetate assay was performed to detect the changes in oxidative stress, and we showed that 6-OHDA elevated the production of reactive oxygen species (ROS), whereas ASMES significantly reversed these changes (P < 0.01). Besides, mitochondrial membrane potential (MMP) assay showed that ASMES could restore 6-OHDA-damaged MMP in cultured PC12 cells (P < 0.05). In conclusion, Astragalus could protect PC12 cells from 6-OHDA-caused neuronal toxicity, and possibly, the ROS-mediated apoptotic pathway participated in this process. Collectively, our findings provided valuable insights into the potential in treatment of neurodegenerative diseases.

Cymene consumption and physical activity effect in Alzheimer's disease model: an in vivo and in vitro study

Purpose

Alzheimer's disease (AD) is one of the most important neurodegenerative diseases and accompanied by the production of free radicals and inflammatory factors. Studies have shown that p-cymene has anti-inflammatory and anti-oxidant effects. Here, the effects of this compound were investigated on a rat model of AD.

Methods

In order to create Alzheimer's rat model, bilateral injection of Amyloid β1-42 (Aβ1-42) into rats hippocampus was performed. Both therapeutic (post-AD induction) and preventive effects of p-cymene consumption with doses of 50 and 100 mg/kg were investigated. In addition, the effects of adding short-term exercise to the process were also observed. In vitro, Aβ1-42 peptide was driven toward fibril formation and effect of p-cymene was observed on the resulting fibrils.

Results

Learning and memory indices in the AD rats were significantly reduced compared to the Sham group, while p-cymene consumption with both doses, as well as performing exercise counteracted AD consequences. Moreover, increased neurogenesis and reduced amyloid plaques counts were observed in treated rats. In vitro formed fibrils of Aβ1-42 were partially disaggregated in the presence of p-cymene.

Discussion

p-Cymene could act on this AD model via antioxidant and anti-inflammatory properties as well as direct anti-fibril effect.

Conclusion

p-cymene can improve AD-related disorders including memory impairment.

Centella asiatica promotes early differentiation, axodendritic maturation and synaptic formation in primary hippocampal neurons

BACKGROUND

Centella asiatica is a 'medhya-rasayana (nootrophic or memory booster)' herb that has been indicated in Ayurveda for improving memory function and treating dementia disorders. Although the neuroprotective effects of C. asiatica have been reported in earlier studies, the information on whether this nootropic herb could promote early differentiation and development of axon and dendrites in primary hippocampal neurons is currently limited.

THE AIM OF THE STUDY

To investigate the effects of C. asiatica and asiatic acid, one of the principal active constituents of C. asiatica, on the various stages of neuronal polarity, including early neuronal differentiation, axonal outgrowth, dendritic arborization, axonal maturation, and synaptic formation.

MATERIALS AND METHODS

Embryonic rat hippocampal neurons were incubated with C. asiatica leaf extract (CAE) or asiatic acid. After an indicated time, neurons were fixed and immunolabeled to visualize the neuronal morphology. Morphometric analyses for early neuronal differentiation, axonal and dendritic maturation and synaptogenesis were performed using Image J software. Neuronal viability was determined using trypan blue exclusion assay.

RESULTS

CAE at varying concentrations ranging from 3.75 to 15 μg/mL enhanced neurite outgrowth with the highest optimal concentration of 7.5 μg/mL. The effects of CAE commenced immediately after cell seeding, as indicated by its accelerating effect on neuronal differentiation. Subsequently, CAE significantly elaborated dendritic and axonal morphology and facilitated synapse formation. Asiatic acid also facilitated neurite outgrowth, but to a lesser extent than CAE.

CONCLUSION

These findings revealed that CAE exerted its modulatory effects in every stage of neuronal development, supporting its previously claimed neurotrophic function and suggest that this natural nootropic and its active component asiatic acid can be further investigated to explore a promising solution for degenerative brain disorders and injuries.

Therapeutic and Mechanistic Effects of Curcumin in Huntington's Disease

Curcumin is a spice derived nutraceutical which gained tremendous attention because of its profound medicinal values. It alters a number of molecular pathways such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), signal transducer and activator of transcription 3 (STAT3), nuclear factor erythroid 2-related factor 2 (Nrf2) and cyclooxygenases-2 (COX-2), which make it potential therapeutic choice in treating multiple disorders. It also possesses the potential to prevent protein aggregation and thus protect against degeneration of neurons in neurodegenerative disorders including Huntington's disease (HD). HD is an autosomal dominant disorder linked with altered gene expression which leads to an increase in the size of cytosine, adenine and guanine (CAG) trinucleotide repeats, aids in protein aggregation throughout the brain and thus damages neurons. Upstream regulation of oxidative stress and inflammatory cascade are two important factors that drive HD progression. Available therapies just suppress the severity of symptoms with a number of side effects. Curcumin targets multiple mechanisms in treating or preventing HD including antioxidant and anti-inflammatory potential, metal ion chelation, transcriptional alterations and upregulating activity of molecular chaperons, heat shock proteins (HSPs). Having a favorable safety profile, curcumin can be an alternative therapeutic choice in treating neurodegenerative disorders like HD. This review will focus on mechanistic aspects of curcumin in treating or preventing HD and its potential to arrest disease progression and will open new dimensions for safe and effective therapeutic agents in diminishing HD.

Hesperidin protects against behavioral alterations and loss of dopaminergic neurons in 6-OHDA-lesioned mice: the role of mitochondrial dysfunction and apoptosis

Hesperidin is a flavonoid glycoside that is frequently found in citrus fruits. Our group have demonstrated that hesperidin has neuroprotective effect in 6-hydroxydopamine (6-OHDA) model of Parkinson's disease (PD), mainly by antioxidant mechanisms. Although the pathophysiology of PD remains uncertain, a large body of evidence has demonstrated that mitochondrial dysfunction and apoptosis play a critical role in dopaminergic nigrostriatal degeneration. However, the ability of hesperidin in modulating these mechanisms has not yet been investigated. In the present study, we examined the potential of a 28-day hesperidin treatment (50 mg/kg/day, p.o.) in preventing behavioral alterations induced by 6-OHDA injection via regulating mitochondrial dysfunction, apoptosis and dopaminergic neurons in the substantia nigra pars compacta (SNpc) in C57BL/6 mice. Our results demonstrated that hesperidin treatment improved motor, olfactory and spatial memory impairments elicited by 6-OHDA injection. Moreover, hesperidin treatment attenuated the loss of dopaminergic neurons (TH+ cells) in the SNpc and the depletion of dopamine (DA) and its metabolities 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum of 6-OHDA-lesioned mice. Hesperidin also protected against the inhibition of mitochondrial respiratory chain complex-I, -IV and V, the decrease of Na + -K + -ATPase activity and the increase of caspase-3 and -9 activity in the striatum. Taken together, our findings indicate that hesperidin mitigates the degeneration of dopaminergic neurons in the SNpc by preventing mitochondrial dysfunction and modulating apoptotic pathways in the striatum of 6-OHDA-treated mice, thus improving behavioral alterations. These results provide new insights on neuroprotective mechanisms of hesperidin in a relevant preclinical model of PD.

Carnoquinolines Target Copper Dyshomeostasis, Aberrant Protein-Protein Interactions, and Oxidative Stress

Metal dysregulation, oxidative stress, protein modification, and aggregation are factors strictly interrelated and associated with neurodegenerative pathologies. As such, all of these aspects represent valid targets to counteract neurodegeneration and, therefore, the development of metal-binding compounds with other properties to combat multifactorial disorders is definitely on the rise. Herein, the synthesis and in-depth analysis of the first hybrids of carnosine and 8-hydroxyquinoline, carnoquinolines (CarHQs), which combine the properties of the dipeptide with those of 8-hydroxyquinoline, are reported. CarHQs and their copper complexes were characterized through several techniques, such as ESI-MS and NMR, UV/Vis, and circular dichroism spectroscopy. CarHQs can modulate self- and copper-induced amyloid-β aggregation. These hybrids combine the antioxidant activity of their parent compounds. Therefore, they can simultaneously scavenge free radicals and reactive carbonyl species, thanks to the phenolic group and imidazole ring. These results indicate that CarHQs are promising multifunctional candidates for neurodegenerative disorders and they are worthy of further studies.

Chitosan-coated rosmarinic acid nanoemulsion nasal administration protects against LPS-induced memory deficit, neuroinflammation, and oxidative stress in Wistar rats

Rosmarinic acid (RA) lipid-nanotechnology-based delivery systems associate with mucoadhesive biopolymers for nasal administration has arisen as a new promising neuroprotective therapy for neurodegenerative disorders (ND). We have previously demonstrated the glioprotective effect of chitosan-coated RA nanoemulsions (RA CNE) against lipopolysaccharide (LPS)-induced damage in rat astrocyte primary culture. Here, we further investigate the protective effect of RA CNE nasal administration on LPS-induced memory deficit, neuroinflammation, and oxidative stress in Wistar rats, since these in vivo studies were crucial to understand the impact of developed delivery systems in the RA neuroprotective effects. The animals were treated through nasal route with RA CNE (2 mg·mL-1), free RA (2 mg·mL-1), blank CNE, and saline (control and LPS groups) administrations (n.a., 100 μL per nostril) twice a day (7 a.m./7 p.m.) for six days. On the sixth day, the animals received the last treatments and LPS was intraperitoneally (i.p.) administrated (250 μg·kg-1). Overall results, proved for the first time that the RA CNE nasal administration elicits a neuroprotective effect against LPS-induced damage, which was associated with increased 1.6 times recognition index, decreased 5.0 and 1.9 times in GFAP+ cell count and CD11b expression, respectively, as well as increased 1.7 times SH in cerebellum and decreased 3.9 times TBARS levels in cerebral cortex in comparison with LPS group. RA CNE treatment also facilitates RA bioavailability in the brain, confirmed by RA quantification. Free RA also demonstrates a protective effect in some studied parameters, although no RA was quantified in the brain.

Chemical Constituents from the Aerial Parts of Elsholtzia ciliata and Their Protective Activities on Glutamate-Induced HT22 Cell Death

A new phenolic glucoside, (7E,9E)-3-hydroxyavenalumic acid-3-O-[6'-O-(E)-caffeoyl]-β-d-glucopyranoside (1), and three new acetylated flavone glycosides, acacetin-7-O-[β-d-glucopyranosyl(1″″→2″)-4‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (3), acacetin-7-O-[6″″-O-acetyl-β-d-glucopyranosyl(1″″→2″)-3‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (5), and acacetin-7-O-[3″″,6″″-di-O-acetyl-β-d-glucopyranosyl(1″″→2″)-4‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (7), as well as 34 known compounds (2, 4, 6, and 8-38) were isolated from the aerial parts of Elsholtzia ciliata. The chemical structures of the new compounds were determined by spectroscopic/spectrometric data interpretation using NMR and HRESIMS. The neuroprotective effect of the isolated compounds was evaluated by a cell viability assay on HT22 murine hippocampal neuronal cells. Among them, 23 compounds, including new substances 1 and 3, exhibited neuroprotective effects against glutamate-induced HT22 cell death. In particular, compounds 2, 16, 17, 20, 22, 28, 29, and 31 presented potent neuroprotective effects with EC₅₀ values of 1.5-8.3 μM.

Botanical Drug Puerarin Promotes Neuronal Survival and Neurite Outgrowth against MPTP/MPP+-Induced Toxicity via Progesterone Receptor Signaling

Background

Progesterone receptor (PR) modulates neuroprotective and regenerative responses in Parkinson's disease and related neurological diseases.

Objectives

The present study was designed to determine whether botanical drug puerarin could exhibit neuroprotective and neurorestorative activities via PR signaling.

Methods

The neuroprotective and neurotrophic activities of puerarin were investigated in MPTP-lesioned mice and MPP⁺-challenged primary rat midbrain neurons. Rotarod performance test and tail suspension test were used to assess motor functions. Tyrosine hydroxylase (TH) and PR were determined by immunostaining, Western blotting, and luciferase reporter assays. Neurite outgrowth was assessed by fluorescence staining and immunostaining.

Results

Puerarin effectively ameliorated the MPTP-induced motor abnormalities in MPTP-lesioned mice and protected primary rat midbrain neurons against MPP⁺-induced toxicity via PR signaling although progesterone exhibited the neuroprotection. PR antagonist mifepristone (RU486) diminished the neuroprotection of puerarin in MPTP-lesioned mice and MPP⁺-induced primary rat midbrain neurons. Moreover, puerarin promoted the differentiation of primary rat midbrain neurons and potentiated NGF to induce neuritogenesis in PC12 cells. RU486 and PR-siRNA could inhibit the effect of puerarin. Puerarin and progesterone could enhance the PR promoter.

Conclusion

Puerarin attenuated MPTP- and MPP⁺-induced toxicity and potentiated neurite outgrowth via PR. These results suggested that puerarin may become an alternative hormone for suppressing MPTP- and MPP⁺-induced toxicity in neurodegenerative diseases.

Identifying the Mechanisms and Molecular Targets of Yizhiqingxin Formula on Alzheimer's Disease: Coupling Network Pharmacology with GEO Database

Background

Yizhiqingxin formula (YZQX) is a promising formula for the treatment of Alzheimer’s disease (AD) with significant clinical effects. Here, we coupled a network pharmacology approach with the Gene Expression Omnibus (GEO) database to illustrate comprehensive mechanisms and screen for molecular targets of YZQX for AD treatment.

Methods

First, active ingredients of YZQX were screened for the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database with the absorption, distribution, metabolism, and excretion (ADME) parameters. Subsequently, putative targets of active ingredients were predicted using the DrugBank database. AD-related targets were retrieved by analyzing published microarray data (accession number GSE5281). Protein–protein interaction (PPI) networks of YZQX putative targets and AD-related targets were constructed visually and merged to identify candidate targets for YZQX against AD using Cytoscape 3.7.2 software. We performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to further clarify the biological functions of the candidate targets. The gene-pathway network was established to filter for key target genes.

Results

Forty-three active ingredients were identified, and 193 putative target genes were predicted. Seven hundred and ten targets related to AD were screened with |log2 FC| > 1 and P < 0.05. Based on the PPI network, 110 target genes of YZQX against AD were identified. Moreover, 32 related pathways including the PI3K-Akt signaling pathway, MAPK signaling pathway, ubiquitin-mediated proteolysis, apoptosis and the NF-kappa B signaling pathway were significantly enriched. In the gene-pathway network, MAPK1, AKT1, TP53, MDM2, EGFR, RELA, SRC, GRB2, CUL1, and MYC targets are putative core genes for YZQX in AD treatment.

Conclusion

YZQX against AD may exert its neuroprotective effect via the PI3K-Akt signaling pathway, MAPK signaling pathway, and ubiquitin-mediated proteolysis. YZQX may be a promising drug that can be used in the treatment of AD.

Probing the characteristics and biofunctional effects of disease-affected cells and drug response via machine learning applications

Drug-induced transformations in disease characteristics at the cellular and molecular level offers the opportunity to predict and evaluate the efficacy of pharmaceutical ingredients whilst enabling the optimal design of new and improved drugs with enhanced pharmacokinetics and pharmacodynamics. Machine learning is a promising in-silico tool used to simulate cells with specific disease properties and to determine their response toward drug uptake. Differences in the properties of normal and infected cells, including biophysical, biochemical and physiological characteristics, plays a key role in developing fundamental cellular probing platforms for machine learning applications. Cellular features can be extracted periodically from both the drug treated, infected, and normal cells via image segmentations in order to probe dynamic differences in cell behavior. Cellular segmentation can be evaluated to reflect the levels of drug effect on a distinct cell or group of cells via probability scoring. This article provides an account for the use of machine learning methods to probe differences in the biophysical, biochemical and physiological characteristics of infected cells in response to pharmacokinetics uptake of drug ingredients for application in cancer, diabetes and neurodegenerative disease therapies.

Phytochemical Profile, Pharmacological Attributes and Medicinal Properties of Convolvulus prostratus - A Cognitive Enhancer Herb for the Management of Neurodegenerative Etiologies

Convolvulus prostratus Forssk., a nootropic herb used in traditional medicinal systems, is also frequently known by its taxonomic synonym Convolvulus pluricaulis. In Indian medicinal system - Ayurveda - it is named as Shankhpushpi. According to the ancient literature, this herb has been attributed with several therapeutic properties, such as anxiolytic, neuroprotective, antioxidant, analgesic, immunomodulatory, antimicrobial, antidiabetic and cardioprotective activities. This medicinal herb has been reported to contain many bioactive phytoconstituents, such as, alkaloid (convolamine), flavonoid (kaempferol) and phenolics (scopoletin, β-sitosterol and ceryl alcohol), that have been ascribed to the observed medicinal properties. Several research teams across the globe have highlighted the neuro-pharmacological profile of C. prostratus, wherein, the neuroprotective, nootropic and neuro-modulatory roles have been described. Besides, role of C. prostratus extracts in neurodegeneration has been well demonstrated. Despite of such elaborative preclinical pharmacological profile, detailed clinical investigations and mechanistic mode-of-action studies of this important herb are yet to be executed. The present review is attempted to showcase the phytochemical profile, pharmacological attributes and medicinal information of C. prostratus; with comprehensive research gap analysis. It is hoped that the scientific update on the ethnomedicinal aspects of this herb would thrive research propagation and development of the CNS phytopharmaceuticals, originated from C. prostratus.

Computational investigation on the effect of Oleuropein aglycone on the α-synuclein aggregation

Parkinson's disease (PD) is considered to be the second most common progressive neurodegenerative brain disorder after Alzheimer's disease, which is caused by misfolding and aggregation of Alpha-synuclein (α-synuclein). It is characterized by distinct aggregated fibrillary form of α-synuclein known as the Lewy bodies and Lewy neurites. The most promising approach to combat PD is to prevent the misfolding and subsequent aggregation of α-synuclein. Recently, Oleuropein aglycone (OleA) has been reported to stabilize the monomeric structure of α-synuclein, subsequently favoring the growth of nontoxic aggregates. Therefore, understanding the conformational dynamics of α-synuclein monomer in the presence of OleA is significant. Here, we have investigated the effect of OleA on the conformational dynamics and the aggregation propensity of α-synuclein using molecular dynamics simulation. From molecular dynamics trajectory analysis, we noticed that when OleA is bound to α-synuclein, the intramolecular distance between non-amyloid-β component domain and C-terminal domain of α-synuclein was increased, whereas long-range hydrophobic interactions between the two region were reduced. Oleuropein aglycone was found to interact with the N-terminal domain of α-synuclein, making this region unavailable for interaction with membranes and lipids for the formation of cellular toxic aggregates. From the binding-free energy analysis, we found binding affinity between α-synuclein and OleA to be indeed high (ΔG_bind = -12.56 kcal mol^-1 from MM-PBSA and ΔG_bind = -27.41 kcal mol^-1from MM-GBSA). Our findings in this study thus substantiate the effect of OleA on the structure and stabilization of α-synuclein monomer that subsequently favors the growth of stable and nontoxic aggregates.Communicated by Ramaswamy H. Sarma.

Cognitive impairments in type 2 diabetes, risk factors and preventive strategies

Mild cognitive impairment (MCI) is a modifiable risk factor in progression of several diseases including dementia and type 2 diabetes. If cognitive impairments are not reversed at an early stage of appearance of symptoms, then the prolonged pathogenesis can lead to dementia and Alzheimer's disease (AD). Therefore, it is necessary to detect the risk factors and mechanism of prevention of cognitive dysfunction at an early stage of disease. Poor lifestyle, age, hyperglycemia, hypercholesterolemia, and inflammation are some of the major risk factors that contribute to cognitive and memory impairments in diabetic patients. Mild cognitive impairment was seen in those individuals of type 2 diabetes, who are on an unhealthy diet. Physical inactivity, frequent alcohol consumptions, and use of packed food products that provides an excess of cheap calories are found associated with cognitive impairment and depression in diabetic patients. Omega fatty acids (FAs) and polyphenol-rich foods, especially flavonoids, can reduce the bad effects of an unhealthy lifestyle; therefore, the consumption of omega FAs and flavonoids may be beneficial in maintaining normal cognitive function. These functional foods may improve cognitive functions by targeting many enzymes and molecules in cells chiefly through their anti-inflammatory, antioxidant, or signaling actions. Here, we provide the current concepts on the risk factors of cognitive impairments in type 2 diabetes and the mechanism of prevention, using omega FAs and bioactive compounds obtained from fruits and vegetables. The knowledge derived from such studies may assist physicians in managing the health care of patients with cognitive difficulties.

Glioprotective Effect of Chitosan-Coated Rosmarinic Acid Nanoemulsions Against Lipopolysaccharide-Induced Inflammation and Oxidative Stress in Rat Astrocyte Primary Cultures

Rosmarinic acid (RA) is a natural polyphenolic compound with a well-documented neuroprotective effect mainly associated with its anti-inflammatory and antioxidant activities. Recently, our research group developed and optimized chitosan-coated RA nanoemulsions (RA CNE) intended to be used for nasal delivery as a new potential neuroprotective therapy. In this sense, the present study aimed to evaluate the protective and/or therapeutic potential of RA CNE in inflammation/oxidative stress induced by LPS (1 μg mL-1) in rat astrocyte primary cultures. In summary, pre-treatment with RA CNE before exposure to LPS (protective protocol) reduced significantly the LPS-induced alterations in astrocyte cell viability, proliferation, and cell death by necrosis, which was not observed in therapeutic protocol. RA CNE protective protocol also enhanced anti-oxidative status by ~ 50% by decreasing oxygen reactive species production and nitric oxide levels and preventing total thiol content decrease. Finally, our results demonstrate the protective effect of RA CNE in migratory activation and GFAP expression of reactive astrocytes. Overall, our findings indicate for the first time the RA CNE glioprotective potential, associated with an increase in cell viability and proliferation, a preventive effect on cellular death by necrosis, migratory ability and hypertrophic reactive astrocytes, and the reparation of astrocyte redox state.

Evidence on the Health Benefits of Supplemental Propolis

Propolis is a honey-related product with reported health benefits such as improved immunity, lowered blood pressure, treated allergies and skin conditions. A literature review and narrative synthesis were conducted to investigate the evidence on the reported health benefits and future direction of propolis products. Using a predefined search strategy we searched Medline (OvidSP), Embase and Central for quantitative and qualitative studies (1990-2018). Citation, reference, hand searches and expert consultation were also undertaken. Studies of randomised control trials and observational data on humans with health-related outcomes were included. Collected data were entered into NVivo software (Version 12, QRS International) and analysed using a thematic framework and a narrative synthesis of emergent themes. A total of 63 publications were discussed. The majority were cell-based and animal studies, with a few key human trials conducted. There is significant promise for propolis as an effective antioxidant and anti-inflammatory agent with particular promise in cardiometabolic health.

Neuroprotective effects of glucomoringin-isothiocyanate against H2O2-Induced cytotoxicity in neuroblastoma (SH-SY5Y) cells

Neurodegenerative diseases (NDDs) are pathological conditions characterised by progressive damage of neuronal cells leading to eventual loss of structure and function of the cells. Due to implication of multi-systemic complexities of signalling pathways in NDDs, the causes and preventive mechanisms are not clearly delineated. The study was designed to investigate the potential signalling pathways involved in neuroprotective activities of purely isolated glucomoringin isothiocyanate (GMG-ITC) against H₂O₂-induced cytotoxicity in neuroblastoma (SH-SY5Y) cells. GMG-ITC was isolated from Moringa oleifera seeds, and confirmed with NMR and LC-MS based methods. Gene expression analysis of phase II detoxifying markers revealed significant increase in the expression of all the genes involved, due to GMG-ITC pre-treatment. GMG-ITC also caused significant decreased in the expression of NF-kB, BACE1, APP and increased the expressions of IkB and MAPT tau genes in the differentiated cells as confirmed by multiplex genetic system analysis. The effect was reflected on the expressed proteins in the differentiated cells, where GMG-ITC caused increased in expression level of Nrf2, SOD-1, NQO1, p52 and c-Rel of nuclear factor erythroid factor 2 (Nrf2) and nuclear factor kappa-B (NF-kB) pathways respectively. The findings revealed the potential of GMG-ITC to abrogate oxidative stress-induced neurodegeneration through Nrf2 and NF-kB signalling pathways.

A Narrative Review of Lifestyle Factors Associated with Parkinson's Disease Risk and Progression

Parkinson's disease is a complex slowly progressive neurodegenerative disorder with motor and non-motor symptoms affecting daily living. Despite effective symptomatic treatments, with various degrees of side effects, no disease-modifying therapeutic options presently exist. Symptoms progress, with an accumulating burden, reducing the quality of life and forming the impression that medications are no longer effective. Adopting positive lifestyle behaviours can empower patients, improve the quality of life, alleviate symptoms, and potentially slow disease progression. Lifestyle behaviours including nutrition, cognitive enrichment, physical activity, and stress management have beneficial effects on brain health and quality of life. While some evidence of an association of lifestyle with Parkinson's disease risk and progression exists, the sparse and often conflicting data make it difficult to provide clinical recommendations. Herein, we highlight studies showing promising associations between lifestyle and Parkinson's disease. Given the increasing aging of populations worldwide and the prevalence of neurological disorders, further research into self-management through adoption of positive lifestyle behaviours is clearly warranted to better enable individualized care.

Biologically active compounds from two members of the Asteraceae family: Tragopogon dubius Scop. and Tussilago farfara L

Tragopogon dubius and Tussilago farfara are consumed as vegetables and used in folk medicine to manage common diseases. Herein, the chemical compositions and biological activities of different leaf extracts (ethyl acetate, methanol, and water) of T. dubius and T. farfara were evaluated. The antibacterial, antifungal, and antioxidant abilities of the extracts were tested using different assays including free radical scavenging, reducing power, phosphomolybdenum, and metal chelating assays. Enzyme inhibitory potentials were evaluated against cholinesterases, tyrosinase, α-amylase and α-glucosidase. Complexes of bioactive compounds (chlorogenic and rosmarinic acid) were docked into the enzymatic cavity of α-glucosidase and subjected to molecular dynamic calculation, enzyme conformational stability, and flexibility analysis. T. dubius and T. farfara extracts showed remarkable antioxidant potentials. Ethyl acetate extracts of T. dubius and T. farfara were the most potent inhibitors of acetylcholinesterase and butyrylcholinesterase. T. dubius ethyl acetate extract and T. farfara methanolic extract showed noteworthy activity against α-glucosidase. High performance liquid chromatography analysis revealed the abundance of some phenolic compounds including chlorogenic and rosmarinic acids. Ethyl acetate extract of T. dubius showed notable antifungal activity against all strains. Docking studies showed best pose for chlorogenic acid was stabilized by a network of hydrogen bonds with residues Asp1157, Asp1279, whereas rosmarinic acid showed several hydrogen bonds with Asp1157, Asp1420, Asp1526, Lys1460 and Trp1369. This study further validates the use of T. dubius and T. farfara in traditional medicine, as well as act as a stimulus for further studies for future biomedicine development. Communicated by Ramaswamy H. Sarma.

Mitochondria in Neuroprotection by Phytochemicals: Bioactive Polyphenols Modulate Mitochondrial Apoptosis System, Function and Structure

In aging and neurodegenerative diseases, loss of distinct type of neurons characterizes disease-specific pathological and clinical features, and mitochondria play a pivotal role in neuronal survival and death. Mitochondria are now considered as the organelle to modulate cellular signal pathways and functions, not only to produce energy and reactive oxygen species. Oxidative stress, deficit of neurotrophic factors, and multiple other factors impair mitochondrial function and induce cell death. Multi-functional plant polyphenols, major groups of phytochemicals, are proposed as one of most promising mitochondria-targeting medicine to preserve the activity and structure of mitochondria and neurons. Polyphenols can scavenge reactive oxygen and nitrogen species and activate redox-responsible transcription factors to regulate expression of genes, coding antioxidants, anti-apoptotic Bcl-2 protein family, and pro-survival neurotrophic factors. In mitochondria, polyphenols can directly regulate the mitochondrial apoptosis system either in preventing or promoting way. Polyphenols also modulate mitochondrial biogenesis, dynamics (fission and fusion), and autophagic degradation to keep the quality and number. This review presents the role of polyphenols in regulation of mitochondrial redox state, death signal system, and homeostasis. The dualistic redox properties of polyphenols are associated with controversial regulation of mitochondrial apoptosis system involved in the neuroprotective and anti-carcinogenic functions. Mitochondria-targeted phytochemical derivatives were synthesized based on the phenolic structure to develop a novel series of neuroprotective and anticancer compounds, which promote the bioavailability and effectiveness. Phytochemicals have shown the multiple beneficial effects in mitochondria, but further investigation is required for the clinical application.

Electro-Acupuncture Ameliorated MPTP-Induced Parkinsonism in Mice via TrkB Neurotrophic Signaling

Neurotrophins, such as brain-derived neurotrophic factor (BDNF), have shown promise as neuroprotective agents, indicating their potential in therapeutic strategies for neurodegenerative disease. However, the inherent bioactivity and pharmaceutical limitations of BDNF compromise its clinical efficacy. Research has documented the beneficial effects of electroacupuncture (EA) against neurodegeneration, possibly by BDNF-mediated mechanisms. The present study was designed to clarify whether EA can mount a neuroprotective effect in mice lesioned with MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) via stimulation of the BDNF-TrkB signaling pathway. We found that EA not only ameliorated the motor dysfunction but also restored the dopaminergic neuronal function and upregulated BDNF expression in MPTP-lesioned mice. Interestingly, the TrkB inhibitor K252a abolished the neuroprotective effects of EA. Western blot analyses further demonstrated that EA might recover the level of phospho-Akt, phospho-ERK1/2, and BDNF against MPTP neurotoxicity via reversing the imbalance between TrkB FL and TrkB T1. Taken together, the results of the present study show that EA stimulation can ameliorate MPTP-induced parkinsonism in mice. Such a neuroprotective effect may be partially mediated via restoring TrkB neurotrophic signaling.