Resveratrol attenuates MPP+-induced mitochondrial dysfunction and cell apoptosis via AKT/GSK-3β pathway in SN4741 cells

Mechanism and Clinical Application Prospects of Mitochondrial DNA Single Nucleotide Polymorphism in Neurodegenerative Diseases

Mitochondrial dysfunction is well recognized as a critical component of the complicated pathogenesis of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. This review investigates the influence of mitochondrial DNA single nucleotide polymorphisms on mitochondrial function, as well as their role in the onset and progression of these neurodegenerative diseases. Furthermore, the contemporary approaches to mitochondrial regulation in these disorders are discussed. Our objective is to uncover early diagnostic targets and formulate precision medicine strategies for neurodegenerative diseases, thereby offering new paths for preventing and treating these conditions.

Resveratrol: A Natural Compound Targeting the PI3K/Akt/mTOR Pathway in Neurological Diseases

Neurological diseases (NDs), including neurodegenerative disorders and acute injuries, are a significant global health concern. The PI3K/Akt/mTOR pathway, a crucial signaling cascade, is responsible for the survival of cells, proliferation, and metabolism. Dysregulation of this pathway has been linked to neurological conditions, indicating its potential as a vital target for therapeutic approaches. Resveratrol (RSV), a natural compound found in berries, peanuts, and red grapes, has antioxidant, anti-cancer, and anti-inflammatory effects. Its ability to modulate the PI3K/Akt/mTOR pathway has been interesting in NDs. Studies have shown that RSV can activate the PI3K/Akt pathway, promoting cell survival and inhibiting apoptosis of neuronal cells. Its impact on mTOR, a downstream effector of Akt, further contributes to its neuroprotective effects. RSV's ability to restore autophagic flux presents a promising avenue for therapeutic intervention. Its anti-inflammatory properties suppress inflammatory responses by inhibiting key signaling molecules within the pathway. Additionally, RSV's role in enhancing mitochondrial function contributes to its neuroprotective profile. This study highlights RSV's potential as a multifaceted therapeutic agent in NDs, specifically by PI3K/Akt/mTOR pathway modulation. Additional investigation is required to optimize its therapeutic capacity in diverse neurological conditions.

Multidimensional biological activities of resveratrol and its prospects and challenges in the health field

Resveratrol (RES) is a naturally occurring polyphenolic compound. Recent studies have identified multiple potential health benefits of RES, including antioxidant, anti-inflammatory, anti-obesity, anticancer, anti-diabetic, cardiovascular, and neuroprotective properties. The objective of this review is to summarize and analyze the studies on the biological activities of RES in disease prevention and treatment, as well as its metabolism and bioavailability. It also discusses the challenges in its clinical application and future research directions. RES exhibits significant potential in the prevention and treatment of many diseases. The future direction of RES research should focus on improving its bioavailability, conducting more clinical trials to determine its effectiveness in humans, and investigating its mechanism of action. Once these challenges have been overcome, RES is expected to become an effective health intervention.

Phytomedicine for neurodegenerative diseases: The road ahead

Neurodegenerative disorders (NDs) are among the most common causes of death across the globe. NDs are characterized by progressive damage to CNS neurons, leading to defects in specific brain functions such as memory, cognition, and movement. The most common NDs are Parkinson's, Alzheimer's, Huntington's, and amyotrophic lateral sclerosis (ALS). Despite extensive research, no therapeutics or medications against NDs have been proven to be effective. The current treatment of NDs involving symptom-based targeting of the disease pathogenesis has certain limitations, such as drug resistance, adverse side effects, poor blood-brain barrier permeability, and poor bioavailability of drugs. Some studies have shown that plant-derived natural compounds hold tremendous promise for treating and preventing NDs. Therefore, the primary objective of this review article is to critically analyze the properties and potency of some of the most studied phytomedicines, such as quercetin, curcumin, epigallocatechin gallate (EGCG), apigenin, and cannabinoids, and highlight their advantages and limitations for developing next-generation alternative treatments against NDs. Further extensive research on pre-clinical and clinical studies for developing plant-based drugs against NDs from bench to bedside is warranted.

Exposure estimation and neurotoxicity inhibition of dioxins in sensitive populations near domestic waste incineration plant through adverse outcome pathway

The neurotoxicity induced by dioxins has been recognized as a serious concern to sensitive population living near waste incineration plants. However, investigating the intracellular neurotoxicity of dioxin in humans and the corresponding mitigation strategies has been barely studied. Thus, a domestic waste incineration plant was selected in this study to characterize the neurotoxicity risks of sensitive populations by estimating the ratio of dioxin in human cells using membrane structure dynamics simulation; and constructing a complete dioxin neurotoxicity adverse outcome pathway considering the binding process of AhR/ARNT dimer protein and dioxin response element (DRE). Six dioxins with high neurotoxicity risk were identified. According to the composite neurotoxicity risk analysis, the highest composite neurotoxicity risk appeared when the six dioxins were jointly exposed. Dietary schemes were designed using 1/2 partial factor experimental design to mitigate the composite neurotoxicity risk of six dioxins and No. 16 was screened as the optimum combination which can effectively alleviate the composite neurotoxicity risk by 29.52%. Mechanism analysis shows that the interaction between AhR/ARNT dimer protein and DRE was inhibited under the optimal dietary scheme. This study provides theoretical feasibility and reference significance for assessing composite toxicity risks of pollutants and safety mitigation measures for toxic effects.

Corydaline alleviates Parkinson's disease by regulating autophagy and GSK-3β phosphorylation

BACKGROUND

Jitai tablet, a traditional Chinese medicine, has a neuroprotective effect on 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mice. As one of the main active ingredients in the Jitai tablet, corydaline (Cory) has analgesic and anti-allergic effects, but it has not been studied in PD. Here, we investigated the role and mechanism of Cory in PD.

METHODS

The PD model was induced by MPTP. Cell viability was measured by 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide assay. The Pole test and traction test were performed to detect the behaviors of mice. The expression of tyrosine hydroxylase (Th) was detected by immunohistochemistry and Western blot. Immunofluorescence staining, monodansylcadaverine staining, and Western blot were conducted to assess autophagy. A lactic dehydrogenase release assay was used to detect cytotoxicity. Network pharmacology was used to screen the targets.

RESULTS

There existed cytotoxicity when the concentration of Cory reached 40 μg/mL. Cory (not exceeding 20 μg/mL) could alleviate MPTP-induced cell damage. In vivo experiments indicated that Cory could improve the motor coordination of mice with PD. Besides, Cory could increase LC3-II/LC3-I levels both in vivo and in vitro. In addition, the Th levels reduced in the striatum and middle brain tissues of Parkinson's mice were recovered by Cory injection. We also found that Cory decreased the phosphorylation of glucogen synthase kinase-3 beta (GSK-3β) at Tyr216 and increased the phosphorylation of GSK-3β at Ser9 not only in primary neurons and SH-SY5Y cells but also in the striatum and middle brain tissues. Furthermore, Cory increased LC3-II/LC3-I levels and decreased p62 levels by regulating GSK-3β.

CONCLUSION

Cory enhanced autophagy, attenuated MPTP-induced cytotoxicity, and alleviated PD partly through the regulation of GSK-3β phosphorylation.

Unveiling the interplay of AMPK/SIRT1/PGC-1α axis in brain health: Promising targets against aging and NDDs

The escalating prevalence of neurodegenerative diseases (NDDs) within an aging global population presents a pressing challenge. The multifaceted pathophysiological mechanisms underlying these disorders, including oxidative stress, mitochondrial dysfunction, and neuroinflammation, remain complex and elusive. Among these, the AMPK/SIRT1/PGC-1α pathway emerges as a pivotal network implicated in neuroprotection against these destructive processes. This review sheds light on the potential therapeutic implications of targeting this axis, specifically emphasizing the promising role of flavonoids in mitigating NDD-related complications. Expanding beyond conventional pharmacological approaches, the exploration of non-pharmacological interventions such as exercise and calorie restriction (CR), coupled with the investigation of natural compounds, offers a beacon of hope. By strategically elucidating the intricate connections within these pathways, this review aims to pave the ways for novel multi-target agents and interventions, fostering a renewed optimism in the quest to combat and manage the debilitating impacts of NDDs on global health and well-being.

The Molecular and Biological Function of MEF2D in Leukemia

Myocyte enhancer factor 2 (MEF2) is a key transcription factor (TF) in skeletal, cardiac, and neural tissue development and includes four isoforms: MEF2A, MEF2B, MEF2C, and MEF2D. These isoforms significantly affect embryonic development, nervous system regulation, muscle cell differentiation, B- and T-cell development, thymocyte selection, and effects on tumorigenesis and leukemia. This chapter describes the multifaceted roles of MEF2 family proteins, covering embryonic development, nervous system regulation, and muscle cell differentiation. It further elucidates the contribution of MEF2 to various blood and immune cell functions. Specifically, in B-cell precursor acute lymphoblastic leukemia (BCP-ALL), MEF2D is aberrantly expressed and forms a fusion protein with BCL9, CSF1R, DAZAP1, HNRNPUL1, and SS18. These fusion proteins are closely related to the pathogenesis of leukemia. In addition, it specifically introduces the regulatory effect of MEF2D fusion protein on the proliferation and growth of B-cell acute lymphoblastic leukemia (B-ALL) cells. Finally, we detail the positive feedback loop between MEF2D and IRF8 that significantly promotes the progression of acute myeloid leukemia (AML) and the importance of the ZMYND8-BRD4 interaction in regulating the IRF8 and MYC transcriptional programs. The MEF2D-CEBPE axis is highlighted as a key transcriptional mechanism controlling the block of leukemic cell self-renewal and differentiation in AML. This chapter starts with the structure and function of MEF2 family proteins, specifically summarizing and analyzing the role of MEF2D in B-ALL and AML, mediating the complex molecular mechanisms of transcriptional regulation and exploring their implications for human health and disease.

Evaluating the mouse neural precursor line, SN4741, as a suitable proxy for midbrain dopaminergic neurons

To overcome the ethical and technical limitations of in vivo human disease models, the broader scientific community frequently employs model organism-derived cell lines to investigate disease mechanisms, pathways, and therapeutic strategies. Despite the widespread use of certain in vitro models, many still lack contemporary genomic analysis supporting their use as a proxy for the affected human cells and tissues. Consequently, it is imperative to determine how accurately and effectively any proposed biological surrogate may reflect the biological processes it is assumed to model. One such cellular surrogate of human disease is the established mouse neural precursor cell line, SN4741, which has been used to elucidate mechanisms of neurotoxicity in Parkinson disease for over 25 years. Here, we are using a combination of classic and contemporary genomic techniques - karyotyping, RT-qPCR, single cell RNA-seq, bulk RNA-seq, and ATAC-seq - to characterize the transcriptional landscape, chromatin landscape, and genomic architecture of this cell line, and evaluate its suitability as a proxy for midbrain dopaminergic neurons in the study of Parkinson disease. We find that SN4741 cells possess an unstable triploidy and consistently exhibits low expression of dopaminergic neuron markers across assays, even when the cell line is shifted to the non-permissive temperature that drives differentiation. The transcriptional signatures of SN4741 cells suggest that they are maintained in an undifferentiated state at the permissive temperature and differentiate into immature neurons at the non-permissive temperature; however, they may not be dopaminergic neuron precursors, as previously suggested. Additionally, the chromatin landscapes of SN4741 cells, in both the differentiated and undifferentiated states, are not concordant with the open chromatin profiles of ex vivo, mouse E15.5 forebrain- or midbrain-derived dopaminergic neurons. Overall, our data suggest that SN4741 cells may reflect early aspects of neuronal differentiation but are likely not a suitable proxy for dopaminergic neurons as previously thought. The implications of this study extend broadly, illuminating the need for robust biological and genomic rationale underpinning the use of in vitro models of molecular processes.

Targeting Nrf2 signaling pathway and oxidative stress by resveratrol for Parkinson's disease: an overview and update on new developments

Parkinson's disease (PD) as a prevalent neurodegenerative condition impairs motor function and is caused by the progressive deterioration of nigrostriatal dopaminergic (DAergic) neurons. The current therapy solutions for PD are ineffective because they could not inhibit the disease's progression and they even have adverse effects. Natural polyphenols, a group of phytochemicals, have been found to offer various health benefits, including neuroprotection against PD. Among these, resveratrol (RES) has neuroprotective properties owing to its capacity to protect mitochondria and act as an antioxidant. An increase in the formation of reactive oxygen species (ROS) leads to oxidative stress (OS), which is responsible for cellular damage resulting in lipid peroxidation, oxidative protein alteration, and DNA damage. In PD models, it's been discovered that RES pretreatment can diminish oxidative stress by boosting endogenous antioxidant status and directly scavenging ROS. Several studies have examined the involvement of RES in the modulation of the transcriptional factor Nrf2 in PD models because this protein recognizes oxidants and controls the antioxidant defense. In this review, we have examined the molecular mechanisms underlying the RES activity and reviewed its effects in both in vitro and in vivo models of PD. The gathered evidence herein showed that RES treatment provides neuroprotection against PD by reducing OS and upregulation of Nrf2. Moreover, in the present study, scientific proof of the neuroprotective properties of RES against PD and the mechanism supporting clinical development consideration has been described.

Signaling pathways in Parkinson's disease: molecular mechanisms and therapeutic interventions

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide, and its treatment remains a big challenge. The pathogenesis of PD may be related to environmental and genetic factors, and exposure to toxins and gene mutations may be the beginning of brain lesions. The identified mechanisms of PD include α-synuclein aggregation, oxidative stress, ferroptosis, mitochondrial dysfunction, neuroinflammation, and gut dysbiosis. The interactions among these molecular mechanisms complicate the pathogenesis of PD and pose great challenges to drug development. At the same time, the diagnosis and detection of PD are also one of obstacles to the treatment of PD due to its long latency and complex mechanism. Most conventional therapeutic interventions for PD possess limited effects and have serious side effects, heightening the need to develop novel treatments for this disease. In this review, we systematically summarized the pathogenesis, especially the molecular mechanisms of PD, the classical research models, clinical diagnostic criteria, and the reported drug therapy strategies, as well as the newly reported drug candidates in clinical trials. We also shed light on the components derived from medicinal plants that are newly identified for their effects in PD treatment, with the expectation to provide the summary and outlook for developing the next generation of drugs and preparations for PD therapy.

Evaluating the mouse neural precursor line, SN4741, as a suitable proxy for midbrain dopaminergic neurons

To overcome the ethical and technical limitations of in vivo human disease models, the broader scientific community frequently employs model organism-derived cell lines to investigate of disease mechanisms, pathways, and therapeutic strategies. Despite the widespread use of certain in vitro models, many still lack contemporary genomic analysis supporting their use as a proxy for the affected human cells and tissues. Consequently, it is imperative to determine how accurately and effectively any proposed biological surrogate may reflect the biological processes it is assumed to model. One such cellular surrogate of human disease is the established mouse neural precursor cell line, SN4741, which has been used to elucidate mechanisms of neurotoxicity in Parkinson disease for over 25 years. Here, we are using a combination of classic and contemporary genomic techniques - karyotyping, RT-qPCR, single cell RNA-seq, bulk RNA-seq, and ATAC-seq - to characterize the transcriptional landscape, chromatin landscape, and genomic architecture of this cell line, and evaluate its suitability as a proxy for midbrain dopaminergic neurons in the study of Parkinson disease. We find that SN4741 cells possess an unstable triploidy and consistently exhibits low expression of dopaminergic neuron markers across assays, even when the cell line is shifted to the non-permissive temperature that drives differentiation. The transcriptional signatures of SN4741 cells suggest that they are maintained in an undifferentiated state at the permissive temperature and differentiate into immature neurons at the non-permissive temperature; however, they may not be dopaminergic neuron precursors, as previously suggested. Additionally, the chromatin landscapes of SN4741 cells, in both the differentiated and undifferentiated states, are not concordant with the open chromatin profiles of ex vivo , mouse E15.5 forebrain- or midbrain-derived dopaminergic neurons. Overall, our data suggest that SN4741 cells may reflect early aspects of neuronal differentiation but are likely not a suitable a proxy for dopaminergic neurons as previously thought. The implications of this study extend broadly, illuminating the need for robust biological and genomic rationale underpinning the use of in vitro models of molecular processes.

Evaluating the mouse neural precursor line, SN4741, as a suitable proxy for midbrain dopaminergic neurons

To overcome the ethical and technical limitations of in vivo human disease models, the broader scientific community frequently employs model organism-derived cell lines to investigate of disease mechanisms, pathways, and therapeutic strategies. Despite the widespread use of certain in vitro models, many still lack contemporary genomic analysis supporting their use as a proxy for the affected human cells and tissues. Consequently, it is imperative to determine how accurately and effectively any proposed biological surrogate may reflect the biological processes it is assumed to model. One such cellular surrogate of human disease is the established mouse neural precursor cell line, SN4741, which has been used to elucidate mechanisms of neurotoxicity in Parkinson disease for over 25 years. Here, we are using a combination of classic and contemporary genomic techniques - karyotyping, RT-qPCR, single cell RNA-seq, bulk RNA-seq, and ATAC-seq - to characterize the transcriptional landscape, chromatin landscape, and genomic architecture of this cell line, and evaluate its suitability as a proxy for midbrain dopaminergic neurons in the study of Parkinson disease. We find that SN4741 cells possess an unstable triploidy and consistently exhibits low expression of dopaminergic neuron markers across assays, even when the cell line is shifted to the non-permissive temperature that drives differentiation. The transcriptional signatures of SN4741 cells suggest that they are maintained in an undifferentiated state at the permissive temperature and differentiate into immature neurons at the non-permissive temperature; however, they may not be dopaminergic neuron precursors, as previously suggested. Additionally, the chromatin landscapes of SN4741 cells, in both the differentiated and undifferentiated states, are not concordant with the open chromatin profiles of ex vivo , mouse E15.5 forebrain- or midbrain-derived dopaminergic neurons. Overall, our data suggest that SN4741 cells may reflect early aspects of neuronal differentiation but are likely not a suitable a proxy for dopaminergic neurons as previously thought. The implications of this study extend broadly, illuminating the need for robust biological and genomic rationale underpinning the use of in vitro models of molecular processes.

Circulating (Poly)phenol Metabolites: Neuroprotection in a 3D Cell Model of Parkinson's Disease

SCOPE

Diets rich in (poly)phenols have been associated with positive effects on neurodegenerative disorders, such as Parkinson's disease (PD). Several low-molecular weight (poly)phenol metabolites (LMWPM) are found in the plasma after consumption of (poly)phenol-rich food. It is expected that LMWPM, upon reaching the brain, may have beneficial effects against both oxidative stress and neuroinflammation, and possibly attenuate cell death mechanisms relate to the loss of dopaminergic neurons in PD.

METHODS AND RESULTS

This study investigates the neuroprotective potential of two blood-brain barrier permeant LMWPM, catechol-O-sulfate (cat-sulf), and pyrogallol-O-sulfate (pyr-sulf), in a human 3D cell model of PD. Neurospheroids were generated from LUHMES neuronal precursor cells and challenged by 1-methyl-4-phenylpyridinium (MPP⁺ ) to induce neuronal stress. LMWPM pretreatments were differently neuroprotective towards MPP⁺ insult, presenting distinct effects on the neuronal transcriptome. Particularly, cat-sulf pretreatment appeared to boost counter-regulatory defense mechanisms (preconditioning). When MPP⁺ is applied, both LMWPM positively modulated glutathione metabolism and heat-shock response, as also favorably shifting the balance of pro/anti-apoptotic proteins.

CONCLUSIONS

Our findings point to the potential of LMWPM to trigger molecular mechanisms that help dopaminergic neurons to cope with a subsequent toxic insult. They are promising molecules to be further explored in the context of preventing and attenuating parkinsonian neurodegeneration.

New Insights on the Role of Bioactive Food Derivatives in Neurodegeneration and Neuroprotection

Over the last three decades, neurodegenerative diseases have received increasing attention due to their frequency in the aging population and the social and economic burdens they are posing. In parallel, an era's worth of research in neuroscience has shaped our current appreciation of the complex relationship between nutrition and the central nervous system. Particular branches of nutrition continue to galvanize neuroscientists, in particular the diverse roles that bioactive food derivatives play on health and disease. Bioactive food derivatives are nowadays recognized to directly impact brain homeostasis, specifically with respect to their actions on cellular mechanisms of oxidative stress, neuroinflammation, mitochondrial dysfunction, apoptosis and autophagy. However, ambiguities still exist regarding the significance of the influence of bioactive food derivatives on human health. In turn, gut microbiota dysbiosis is emerging as a novel player in the pathogenesis of neurodegenerative diseases. Currently, several routes of communication exist between the gut and the brain, where molecules are either released in the bloodstream or directly transported to the CNS. As such, bioactive food derivatives can modulate the complex ecosystem of the gut-brain axis, thus, targeting this communication network holds promises as a neuroprotective tool. This review aims at addressing one of the emerging aspects of neuroscience, particularly the interplay between food bioactive derivatives and neurodegeneration. We will specifically address the role that polyphenols and omega-3 fatty acids play in preventing neurodegenerative diseases and how dietary intervention complements available pharmacological approaches.

N-isopropylbenzylamine, a methamphetamine mimics, produces toxicity via increasing nitric oxide in vitro

N-isopropylbenzylamine, an isomer of methamphetamine, has been used to adulterate methamphetamine, and distributed as fake "Ice" methamphetamine by illicit manufacturers, leading to a world problem of N-isopropylbenzylamine exposure. Though it is unclear whether N-isopropylbenzylamine has addictive potential like methamphetamine, N-isopropylbenzylamine users reported side effects such as headaches and confusion. However, the pharmacological targets and cytotoxicity of this chemical remained unknown. In this study, in vitro toxicity of N-isopropylbenzylamine and its toxicity-related targets were investigated in SN4741, SH-SY5Y or PC12 cell lines that model neurons. The cell viability was analyzed by using MTT assay after incubation with N-isopropylbenzylamine for 24 h in cells. N-isopropylbenzylamine caused cell death with IC₅₀ values at around 1-3 mM in these cell lines. N-isopropylbenzylamine time- and concentration-dependently facilitated the expression of neuronal nitric oxide synthase (nNOS), and increased intracellular nitric oxide (NO) in SN4741 cells. Furthermore, 7-nitroindazole, a specific inhibitor of nNOS, significantly prevented N-isopropylbenzylamine-induced toxicity in vitro. These results suggested that N-isopropylbenzylamine-induced toxicity is at least partially related to the increased intracellular NO levels and the activated nNOS. Considering the circumstances that N-isopropylbenzylamine was used to adulterate and mimic methamphetamine, and the side effects associated with N-isopropylbenzylamine in abusers, our findings sounded an alarm for abuser and warn the dangerousness of N-isopropylbenzylamine for public health.

The Impact of Oxidative Stress and AKT Pathway on Cancer Cell Functions and Its Application to Natural Products

Oxidative stress and AKT serine-threonine kinase (AKT) are responsible for regulating several cell functions of cancer cells. Several natural products modulate both oxidative stress and AKT for anticancer effects. However, the impact of natural product-modulating oxidative stress and AKT on cell functions lacks systemic understanding. Notably, the contribution of regulating cell functions by AKT downstream effectors is not yet well integrated. This review explores the role of oxidative stress and AKT pathway (AKT/AKT effectors) on ten cell functions, including apoptosis, autophagy, endoplasmic reticulum stress, mitochondrial morphogenesis, ferroptosis, necroptosis, DNA damage response, senescence, migration, and cell-cycle progression. The impact of oxidative stress and AKT are connected to these cell functions through cell function mediators. Moreover, the AKT effectors related to cell functions are integrated. Based on this rationale, natural products with the modulating abilities for oxidative stress and AKT pathway exhibit the potential to regulate these cell functions, but some were rarely reported, particularly for AKT effectors. This review sheds light on understanding the roles of oxidative stress and AKT pathway in regulating cell functions, providing future directions for natural products in cancer treatment.

Evaluating the neuroprotective activities of vinpocetine, punicalagin, niacin and vitamin E against behavioural and motor disabilities of manganese-induced Parkinson's disease in Sprague Dawley rats

The current study investigated the neuroprotective activity of some drugs and nutriceuticals with antioxidant and anti-inflammatory potential on the pathogenesis of Parkinson's disease (PD). Rats were categorized into seven groups: Rats received tween80 daily for 5 weeks as a control group, MnCl₂ (10 mg/kg, i.p) either alone (group II) or in combination with vinpocetine (VIN) (20 mg/kg) (group III), punicalagin (PUN) (30 mg/kg) (group IV), niacin (85 mg/kg) (group V), vitamin E (Vit E) (100 mg/kg) (group VI) or their combination (group VII). Motor activities was examined using open-field and catalepsy. Striatal monamines, acetylcholinesterase, excitatory/inhibitory neurotransmitters, redox status, pro-oxidant content, brain inflammatory, apoptotic and antioxidant biomarkers levels were assessed. Besides, histopathological investigations of different brain regions were determined. Groups (IV -GVII) showed improved motor functions of PD rats. Applied drugs significantly increased the brain levels of monoamines with the strongest effect to PUN. Meanwhile, they significantly decreased levels of acetylcholinesterase with a strongest effect to PUN. Moreover, they exhibited significant neuronal protection and anti-inflammatory abilities through significant reduction of the brain levels of COX2, TNF-α and Il-1β with a strongest effect to the PUN. Interestingly; groups (IV - GVII) showed restored glutamate/GABA balance and exhibited a pronounced decrease in caspase-3 content and GSK-3β protein expression levels. In addition, they significantly increased Bcl2 mRNA expression levels with a strongest effect for PUN. All these findings were further confirmed by the histopathological examinations. As a conclusion, we propose VIN and PUN to mitigate the progression of PD via their antioxidant, anti-inflammatory, anti-apoptotic, neurotrophic and neurogenic activities.

Evidence for Oxidative Pathways in the Pathogenesis of PD: Are Antioxidants Candidate Drugs to Ameliorate Disease Progression?

Parkinson’s disease (PD) is a progressive neurodegenerative disorder that arises due to a complex and variable interplay between elements including age, genetic, and environmental risk factors that manifest as the loss of dopaminergic neurons. Contemporary treatments for PD do not prevent or reverse the extent of neurodegeneration that is characteristic of this disorder and accordingly, there is a strong need to develop new approaches which address the underlying disease process and provide benefit to patients with this debilitating disorder. Mitochondrial dysfunction, oxidative damage, and inflammation have been implicated as pathophysiological mechanisms underlying the selective loss of dopaminergic neurons seen in PD. However, results of studies aiming to inhibit these pathways have shown variable success, and outcomes from large-scale clinical trials are not available or report varying success for the interventions studied. Overall, the available data suggest that further development and testing of novel therapies are required to identify new potential therapies for combating PD. Herein, this review reports on the most recent development of antioxidant and anti-inflammatory approaches that have shown positive benefit in cell and animal models of disease with a focus on supplementation with natural product therapies and selected synthetic drugs.

Mammalian AKT, the Emerging Roles on Mitochondrial Function in Diseases

Mitochondrial dysfunction may play a crucial role in various diseases due to its roles in the regulation of energy production and cellular metabolism. Serine/threonine kinase (AKT) is a highly recognized antioxidant, immunomodulatory, anti-proliferation, and endocrine modulatory molecule. Interestingly, increasing studies have revealed that AKT can modulate mitochondria-mediated apoptosis, redox states, dynamic balance, autophagy, and metabolism. AKT thus plays multifaceted roles in mitochondrial function and is involved in the modulation of mitochondria-related diseases. This paper reviews the protective effects of AKT and its potential mechanisms of action in relation to mitochondrial function in various diseases.

Neuroprotective Effects of Resveratrol in In vivo and In vitro Experimental Models of Parkinson's Disease: a Systematic Review

Parkinson's disease (PD) is currently the second most common neurodegenerative disease, being characterized by motor and non-motor symptoms. The therapeutic options available for its treatment are limited, do not slow the progression of the disease, and have serious side effects. For this reason, many studies have sought to find compounds with neuroprotective properties that bring additional benefits to current therapy. In this context, resveratrol is a phenolic compound, found in many plant species, capable of crossing the blood-brain barrier and having multiple biological properties. Experimental studies in vitro and in vivo have shown that it can prevent or slow the progression of a variety of diseases, including PD. In this systematic review, we summarize the effects of resveratrol in experimental in vivo and in vitro models of PD and discuss the molecular mechanisms involved in its action. The bibliographic search was performed in the databases of PubMed, Web of Science, SciELO, and Google Scholar, and based on the inclusion criteria, 41 articles were selected and discussed. Most of the included studies have demonstrated neuroprotective effects of resveratrol. In general, resveratrol prevented behavioral and/or neurological disorders, improved antioxidant defenses, reduced neuroinflammatory processes, and inhibited apoptosis. In summary, this systematic review offers important scientific evidence of neuroprotective effects of resveratrol in PD and also provide valuable information about its mechanism of action that can support future clinical studies.

Contribution of Mitochondrial Dysfunction Combined with NLRP3 Inflammasome Activation in Selected Neurodegenerative Diseases

Alzheimer's disease and Parkinson's disease are the most common forms of neurodegenerative illnesses. It has been widely accepted that neuroinflammation is the key pathogenic mechanism in neurodegeneration. Both mitochondrial dysfunction and enhanced NLRP3 (nucleotide-binding oligomerization domain (NOD)-like receptor protein 3) inflammasome complex activity have a crucial role in inducing and sustaining neuroinflammation. In addition, mitochondrial-related inflammatory factors could drive the formation of inflammasome complexes, which are responsible for the activation, maturation, and release of pro-inflammatory cytokines, including interleukin-1β (IL-1β) and interleukin-18 (IL-18). The present review includes a broadened approach to the role of mitochondrial dysfunction resulting in abnormal NLRP3 activation in selected neurodegenerative diseases. Moreover, we also discuss the potential mitochondria-focused treatments that could influence the NLRP3 complex.

Neuroprotective Effects of B-Type Cinnamon Procyanidin Oligomers on MPP+-Induced Apoptosis in a Cell Culture Model of Parkinson's Disease

Cinnamon procyanidin oligomers (CPOs) are water-soluble components extracted from cinnamon. This study aims to explore the neuroprotection of B-type CPO (CPO-B) against 1-methyl-4-phenylpyridinium (MPP⁺)-mediated cytotoxicity and the molecular mechanisms underlying its protection. The results demonstrated that CPO-B showed protection by increasing cell viability, attenuating an intracellular level of reactive oxygen species, downregulating cleaved caspase-3 expression, and upregulating the Bcl-2/Bax ratio. Moreover, CPO-B completely blocked the dephosphorylation of extracellular, signal-regulated kinase 1 and 2 (Erk1/2) caused by MPP⁺. Treatment with an Erk1/2 inhibitor, SCH772984, significantly abolished the neuroprotection of CPO-B against MPP⁺. Taken together, we demonstrate that CPO-B from cinnamon bark provided protection against MPP⁺ in cultured SH-SY5Y cells, and the potential mechanisms may be attributed to its ability to modulate the dysregulation between pro-apoptotic and anti-apoptotic proteins through the Erk1/2 signaling pathway. Our findings suggest that the addition of cinnamon to food or supplements might benefit patients with PD.

Flavonoids modulate AMPK/PGC-1α and interconnected pathways toward potential neuroprotective activities

As progressive, chronic, incurable and common reasons for disability and death, neurodegenerative diseases (NDDs) are significant threats to human health. Besides, the increasing prevalence of neuronal gradual degeneration and death during NDDs has made them a global concern. Since yet, no effective treatment has been developed to combat multiple dysregulated pathways/mediators and related complications in NDDs. Therefore, there is an urgent need to create influential and multi-target factors to combat neuronal damages. Accordingly, the plant kingdom has drawn a bright future. Among natural entities, flavonoids are considered a rich source of drug discovery and development with potential biological and medicinal activities. Growing studies have reported multiple dysregulated pathways in NDDs, which among those mediator AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) play critical roles. In this line, critical role of flavonoids in the upregulation of AMPK/PGC-1α pathway seems to pave the road in the treatment of Alzheimer's disease (AD), Parkinson's disease (PD), aging, central nervous system (brain/spinal cord) damages, stroke, and other NDDs. In the present study, the regulatory role of flavonoids in managing various NDDs has been shown to pass through AMPK/PGC-1α signaling pathway.

Mechanism for antiParkinsonian effect of resveratrol: Involvement of transporters, synaptic proteins, dendrite arborization, biochemical alterations, ER stress and apoptosis

The present study was undertaken to evaluate the mechanism for antiParkinsonian effect of resveratrol employing 6-hydroxydopamine (6-OHDA) induced experimental model of Parkinson's disease (PD). Resveratrol treatment significantly protects the PD related pathological markers like level of tyrosine hydroxylase, dopamine and apoptotic proteins (Bax and cleaved caspase-3). Disease pathology involves significantly decreased level of dopamine transporter, synaptophysin and postsynaptic density protein 95 (PSD-95) along with augmented level of vesicular monoamine transporter and considerably affected the dendrite arborization. Such affected neuronal communication was significantly restored with resveratrol treatment. Biochemical alterations include the depleted level of glutathione (GSH), mitochondrial complex-I activity with concomitant increased level of lipid peroxidation, nitrite level and calcium levels, which were also significantly inhibited with resveratrol treatment. Altered calcium level induces the endoplasmic reticulum (ER) stress related signalling and phosphorylated Nuclear factor erythroid 2-related factor 2 (Nrf2), and with resveratrol treatment the level of phosphorylated Nrf2 was further increased. The concurrent depleted level of proteasome activity was observed which was attenuated with resveratrol treatment. Proinflammatory cytokines and activated astrocytes were observed which was inhibited with resveratrol treatment. In conclusion, findings suggested that resveratrol exhibits the interference in neuronal communication, oxidative stress, mitochondrial pathophysiology, ER stress, protein degradation mechanism and inflammatory responses and could be utilize in clinics to treat the PD patients.

Natural products attenuate PI3K/Akt/mTOR signaling pathway: A promising strategy in regulating neurodegeneration

BACKGROUND

As common, progressive, and chronic causes of disability and death, neurodegenerative diseases (NDDs) significantly threaten human health, while no effective treatment is available. Given the engagement of multiple dysregulated pathways in neurodegeneration, there is an imperative need to target the axis and provide effective/multi-target agents to tackle neurodegeneration. Recent studies have revealed the role of phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) in some diseases and natural products with therapeutic potentials.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating various neuronal disorders via the PI3K/Akt/mTOR signaling pathway.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was done based on the PubMed, Scopus, Web of Science, and Cochrane electronic databases. Two independent investigators followed the PRISMA guidelines and included papers on PI3K/Akt/mTOR and interconnected pathways/mediators targeted by phytochemicals in NDDs.

RESULTS

Natural products are multi-target agents with diverse pharmacological and biological activities and rich sources for discovering and developing novel therapeutic agents. Accordingly, recent studies have shown increasing phytochemicals in combating Alzheimer's disease, aging, Parkinson's disease, brain/spinal cord damages, depression, and other neuronal-associated dysfunctions. Amongst the emerging targets in neurodegeneration, PI3K/Akt/mTOR is of great importance. Therefore, attenuation of these mediators would be a great step towards neuroprotection in such NDDs.

CONCLUSION

The application of plant-derived secondary metabolites in managing and/or treating various neuronal disorders through the PI3K/Akt/mTOR signaling pathway is a promising strategy towards neuroprotection.

Role of Flavonoids in Neurodegenerative Diseases: Limitations and Future Perspectives

BACKGROUND

Flavonoids, a group of natural dietary polyphenols, are known for their beneficial effects on human health. By virtue of their various pharmacological effects, like anti-oxidative, antiinflammatory, anti-carcinogenic and neuroprotective effects, flavonoids have now become an important component of herbal supplements, pharmaceuticals, medicinals and cosmetics. There has been enormous literature supporting neuroprotective effect of flavonoids. Recently their efficacy in various neurodegenerative diseases, like Alzheimer's disease and Parkinson diseases, has received particular attention.

OBJECTIVE

The mechanism of flavanoids neuroprotection might include antioxidant, antiapoptotic, antineuroinflammatory and modulation of various cellular and intracellular targets. In in-vivo systems, before reaching to brain, they have to cross barriers like extensive first pass metabolism, intestinal barrier and ultimately blood brain barrier. Different flavonoids have varied pharmacokinetic characteristics, which affect their pharmacodynamic profile. Therefore, brain accessibility of flavonoids is still debatable.

METHODS

This review emphasized on current trends of research and development on flavonoids, especially in neurodegenerative diseases, possible challenges and strategies to encounter using novel drug delivery system.

RESULTS

Various flavonoids have elicited their therapeutic potential against neurodegenerative diseases, however by using nanotechnology and novel drug delivery systems, the bioavailability of favonoids could be enhanced.

CONCLUSION

This study bridges a significant opinion on medicinal chemistry, ethanopharmacology and new drug delivery research regarding use of flavonoids in management of neurodegeneration.

Potential therapeutic effects of polyphenols in Parkinson's disease: in vivo and in vitro pre-clinical studies

Parkinson’s disease is a neurodegenerative disorder characterized by a combination of severe motor and non-motor symptoms. Over the years, several factors have been discovered to play a role in the pathogenesis of this disease, in particular, neuroinflammation and oxidative stress. To date, the pharmacological treatments used in Parkinson’s disease are exclusively symptomatic. For this reason, in recent years, the research has been directed towards the discovery and study of new natural molecules to develop potential neuroprotective therapies against Parkinson’s disease. In this context, natural polyphenols have raised much attention for their important anti-inflammatory and antioxidant properties, but also for their ability to modulate protein misfolding. In this review, we propose to summarize the relevant in vivo and in vitro studies concerning the potential therapeutic role of natural polyphenols in Parkinson’s disease.

Exploring the multimodal role of phytochemicals in the modulation of cellular signaling pathways to combat age-related neurodegeneration

Neurodegeneration is the progressive loss of neuronal structures and functions that lead to copious disorders like Alzheimer's (AD), Parkinson's (PD), Huntington's (HD), amyotrophic lateral sclerosis (ALS), and other less recurring diseases. Aging is the prime culprit for most neurodegenerative events. Moreover, the shared pathogenic factors of many neurodegenerative processes are inflammatory responses and oxidative stress (OS). Unfortunately, it is very complicated to treat neurodegeneration and there is no effective remedy. The rapid progression of the neurodegenerative diseases that exacerbate the burden and the concurrent absence of effective treatment strategies force the researchers to investigate more therapeutic approaches that ultimately target the causative factors of the neurodegeneration. Phytochemicals have great potential to exert their neuroprotective effects by targeting various mechanisms, such as OS, neuroinflammation, abnormal protein aggregation, neurotrophic factor deficiency, disruption in mitochondrial function, and apoptosis. Therefore, this review represents the molecular mechanisms of neuroprotection by multifunctional phytochemicals to combat age-linked neurodegenerative disorders.

Enhancement of oral bioavailability and anti-Parkinsonian efficacy of resveratrol through a nanocrystal formulation

Resveratrol (RES), a non-flavonoid polyphenol extracted from a wide variety of plants, exhibits neuroprotective activities against Parkinson's disease (PD). However, undesirable water solubility of RES reduces its oral bioavailability and demonstrates low efficacy in blood and brain, thus limiting its application. In present study, a nanocrystal formulation of RES (RES-NCs) was developed to enhance its oral bioavailability and delivery into brain for PD treatment. RES-NCs were fabricated with hydroxypropyl methylcellulose (HPMC) stabilizer via antisolvent precipitation approach. The obtained RES-NCs displayed the particle size of 222.54 ± 1.66 nm, the PDI of 0.125 ± 0.035, the zeta potential of -9.41 ± 0.37 mV, and a rapid in vitro dissolution rate. Molecular dynamics simulation of RES and HPMC revealed an interaction energy of -68.09 kJ/mol and a binding energy of -30.98 ± 0.388 kJ/mol, indicating that the spontaneous binding between the two molecules is through van der Waals forces. RES-NCs conferred enhanced cellular uptake as well as improved permeability relative to pure RES. In addition, RES-NCs were able to protect neurons against cytotoxicity induced by MPP+. Meanwhile, RES-NCs exerted no significant toxic effects on zebrafish embryos and larvae, and did not influence their survival and hatching rates. When orally administered to rats, RES-NCs exhibited more favorable pharmacokinetics than pure RES, with higher plasma and brain concentrations. More importantly, MPTP-induced PD mice showed notable improvements in behavior, attenuated dopamine deficiency, and elevated levels of dopamine and its metabolites after the treatment with RES-NCs. Furthermore, immunoblot analysis revealed that the neuroprotective role of RES-NCs may be at least partially mediated by Akt/Gsk3β signaling pathway. Taken altogether, RES-NCs can serve as a potential treatment modality for PD, offering means of improving RES oral bioavailability and brain accumulation.

Neuroprotective effects of Ginkgo biloba dropping pills in Parkinson's disease

Parkinson’s disease (PD) is the second most common neurodegenerative disease in the world; however, it lacks effective and safe treatments. Ginkgo biloba dropping pill (GBDP), a unique Chinese G. biloba leaf extract preparation, exhibits antioxidant and neuroprotective effects and has a potential as an alternative therapy for PD. Thus, the aims of this study were to evaluate the effects of GBDP in in vitro and in vivo PD models and to compare the chemical constituents and pharmacological activities of GBDP and the G. biloba extract EGb 761. Using liquid chromatography tandem-mass spectrometry, 46 GBDP constituents were identified. Principal component analysis identified differences in the chemical profiles of GBDP and EGb 761. A quantitative analysis of 12 constituents showed that GBDP had higher levels of several flavonoids and terpene trilactones than EGb 761, whereas EGb 761 had higher levels of organic acids. Moreover, we found that GBDP prevented 6-hydroxydopamine-induced dopaminergic neuron loss in zebrafish and improved cognitive impairment and neuronal damage in methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced PD mice. Although similar effects were observed after EGb 761 treatment, the neuroprotective effects were greater after GBDP treatment on several endpoints. In addition, in vitro results suggested that the Akt/GSK3β pathway may be involved in the neuroprotective effects of GBDP. These findings demonstrated that GBDP have potential neuroprotective effects in the treatment of PD.

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GBDP is composed of 46 constituents.

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Content of 12 constituents were different between GBDP and EGb 761.

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GBDP attenuated neurological deficits in zebrafish and mice PD models.

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GBDP prevented PD through anti-apoptosis and Akt/GSK3β signaling pathways.

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GBDP might be a potential therapeutic agent for PD.

Delayed treatment with an autophagy inhibitor 3-MA alleviates the progression of hyperuricemic nephropathy

Autophagy is a cell self-renewal process that relies on the degradation of the cytoplasmic proteins or organelles of lysosomes and is associated with development of numerous diseases. However, the therapeutic effect of autophagy inhibition on hyperuricemic nephropathy (HN) and the underlying mechanisms are still unknown. Here, we investigated the effect of delayed treatment with 3-methyladenine (3-MA), a specific autophagy inhibitor, on the development of HN in a rat model. Administration of 3-MA at 21 days following after uric acid injury protected kidney from hyperuricemic-related injuries, as demonstrated by improving renal dysfunction and architecture damage, blocking Beclin-1 and LC3II/I and decreasing the number of autophagic vacuoles. Late treatment with 3-MA was also effective in attenuating renal fibrosis as evidenced by reducing ECM protein deposition, blocking epithelial-to-mesenchymal transition (EMT) and decreasing the number of renal epithelial cells arrested at the G2/M phase of cell cycle. Injury to the kidney resulted in increased expression of TGFβ receptor I, and phosphorylation of Smad3, 3-MA significantly abrogated all these responses. Moreover, inhibition of autophagy suppressed mitochondrial fission, downregulated the expression of Dynamin-related protein 1 (Drp-1), Cofilin and F-actin, and alleviated cell apoptosis. Finally, 3-MA effectively blocked STAT3 and NF-κB phosphorylation and suppressed infiltration of macrophages and lymphocytes as well as release of multiple profibrogenic cytokines/chemokines in the injured kidney. Taken together, these findings indicate that hyperuricemia-induced autophagy is critically involved in the activation of renal fibroblasts, EMT, mitochondrial fission and apoptosis of tubular epithelial cells and development of renal fibrosis. Thus, this study provides evidence for autophagy inhibitors as the treatment of HN patients.

Ruta graveolens as a potential source of neuroactive compounds to promote and restore neural functions

Nutraceuticals had always been known for their therapeutic effects in ancient medicine and had been the primary healing remedy until the introduction of modern chemistry and pharmacology. However, their use has not been dismissed but actually is acquiring a new acclamation among the scientific community especially for their efficacy on the Central Nervous System (CNS). Molecular mechanisms of the most common neurodegenerative diseases are now being uncovered and along with that the molecules that drive the neurodegenerative processes. It is not surprising that some natural compounds can interact with those molecules and interfere with the pathological pathways halting the cascades that ultimately lead to neuronal cell death. The plant Ruta graveolens has gained increased attention in medicinal chemistry due to its beneficial role to treat a variety of human diseases and also because of the presence of a huge number of compounds belonging to different classes of natural products, including neuroactive compounds potentially able to promote neuroprotection. Among all the components of the plant extract, rutin – which is highly, if not the most, abundant – positively interacts with the neurophysiology of the CNS too, being particularly efficient against neurotoxicity. Rutin, has proven to be protective in a variety of experimental settings of neurodegeneration. Finally, it has been shown that the water extract of Ruta graveolens (RGWE) induces death of glioblastoma cells but not of neuronal cells. Moreover, it also fosters cell cycle re-entry and differentiation of neuronal cells. This peculiarity represents a promising tool to promote neural plasticity in pathological conditions.

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Traditional therapeutic use of the plant Ruta graveolens in a large variety of illnesses.

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It has been used, together with its main component rutin to treat some neurodegenerative diseases.

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It might own compounds able to foster plasticity in neural cells.

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It is able to kill neural cancer cells but not neurons.

Potential implications of polyphenols on aging considering oxidative stress, inflammation, autophagy, and gut microbiota

Naturally occurring compounds polyphenols are secondary metabolites of plants, comprised several categories, namely, flavonoids, phenolic acids, lignans and stilbenes. The biological aging process is driven by a series of interrelated mechanisms, including oxidative stress, inflammation status, and autophagy function, through diverse signaling pathways. Moreover, the crucial role of gut microbiota in regulating aging and health status was widely demonstrated. In recent years, the potential anti-aging benefits of polyphenols have been gaining increasing scientific interest due to their capability to modulate oxidative damage, inflammation, autophagy, and gut microbiota. This review highlights the influence of polyphenols in preventing aging disorders and augmenting lifespan based on the influence of oxidative stress, inflammation, autophagy, and gut microbiota, and encourages research on novel polyphenol-based strategies and clinical trials to develop a nutrition-oriented holistic anti-aging therapy.

Resveratrol Derivatives as Potential Treatments for Alzheimer's and Parkinson's Disease

Neurodegenerative diseases are characterized by the progressive loss of neurons in different regions of the nervous system. Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the two most prevalent neurodegenerative diseases, and the symptoms associated with these pathologies are closely related to the regions that are most affected by the process of neurodegeneration. Despite their high prevalence, currently, there is no cure or disease-modifying drugs for the treatment of these conditions. In the last decades, due to the need for the development of new treatments for neurodegenerative diseases, several authors have investigated the neuroprotective actions of naturally occurring molecules, such as resveratrol. Resveratrol is a stilbene found in several plants, including grapes, blueberries, raspberries, and peanuts. Studies have shown that resveratrol presents neuroprotective actions in experimental models of AD and PD, however, its clinical application is limited due to its rapid metabolism and low bioavailability. In this context, studies have proposed that structural changes in the resveratrol molecule, including glycosylation, alkylation, halogenation, hydroxylation, methylation, and prenylation could lead to the development of derivatives with enhanced bioavailability and pharmacological activity. Therefore, this review article aims to discuss how resveratrol derivatives could represent viable molecules in the search for new drugs for the treatment of AD and PD.

The Potential for Natural Antioxidant Supplementation in the Early Stages of Neurodegenerative Disorders

The neurodegenerative process is characterized by the progressive ultrastructural alterations of selected classes of neurons accompanied by imbalanced cellular homeostasis, a process which culminates, in the later stages, in cell death and the loss of specific neurological functions. Apart from the neuronal cell impairment in selected areas of the central nervous system which characterizes many neurodegenerative diseases (e.g., Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, etc.), some alterations may be found in the early stages including gliosis and the misfolding or unfolding accumulation of proteins. On the other hand, several common pathophysiological mechanisms can be found early in the course of the disease including altered oxidative metabolism, the loss of cross-talk among the cellular organelles and increased neuroinflammation. Thus, antioxidant compounds have been suggested, in recent years, as a potential strategy for preventing or counteracting neuronal cell death and nutraceutical supplementation has been studied in approaching the early phases of neurodegenerative diseases. The present review will deal with the pathophysiological mechanisms underlying the early stages of the neurodegenerative process. In addition, the potential of nutraceutical supplementation in counteracting these diseases will be assessed.

Bioactive Polyphenols and Neuromodulation: Molecular Mechanisms in Neurodegeneration

The interest in dietary polyphenols in recent years has greatly increased due to their antioxidant bioactivity with preventive properties against chronic diseases. Polyphenols, by modulating different cellular functions, play an important role in neuroprotection and are able to neutralize the effects of oxidative stress, inflammation, and apoptosis. Interestingly, all these mechanisms are involved in neurodegeneration. Although polyphenols display differences in their effectiveness due to interindividual variability, recent studies indicated that bioactive polyphenols in food and beverages promote health and prevent age-related cognitive decline. Polyphenols have a poor bioavailability and their digestion by gut microbiota produces active metabolites. In fact, dietary bioactive polyphenols need to be modified by microbiota present in the intestine before being absorbed, and to exert health preventive effects by interacting with cellular signalling pathways. This literature review includes an evaluation of the literature in English up to December 2019 in PubMed and Web of Science databases. A total of 307 studies, consisting of research reports, review articles and articles were examined and 146 were included. The review highlights the role of bioactive polyphenols in neurodegeneration, with a particular emphasis on the cellular and molecular mechanisms that are modulated by polyphenols involved in protection from oxidative stress and apoptosis prevention.

Differences in serum proteins in traditional Chinese medicine constitutional population: Analysis and verification

Traditional Chinese medicine assigns individuals into different categories called "constitutions" to help guide the clinical treatment according to subjective physiologic, psychologic analyses, large-scale clinical observations, and epidemiologic studies. To further explore more objective expressions of constitutions, antibody microarrays were used to analyze the serologic protein profiles of two different constitutions, a balanced (or healthy) constitution (BC) and the dampness constitution (DC) comprising phlegm-dampness and damp-heat constitutions. The profiles of changing constitutions across time were also analyzed. Nineteen differentially expressed proteins between the two groups were identified, with known biologic functions involved in immunity and inflammation. This proteomic study may provide a biologic explanation why the BC is different than the dampness constitution.

Nutraceuticals: An integrative approach to starve Parkinson's disease

The therapeutic approach of multifactorial complex diseases is always a challenge; Parkinson's disease (PD) is a heterogeneous neurodegenerative disorder triggered by genetic and environmental factors, contributing to its etiology. Indeed, several pathogenic mechanisms lead to selective dopaminergic neuronal injury, including oxidative stress, mitochondrial dysfunction, alteration of endoplasmic reticulum-to-Golgi protein trafficking, excitotoxicity, and neuroinflammation. Current treatment approaches include mainly dopamine replacement therapy or optimizing dopaminergic transmission; however, these strategies that do not counteract the pathogenic mechanisms underlying PD symptoms and often are less effective over time. Recently, there has been growing interest in the therapeutic use of nutraceuticals, that could represent an integrative approach to the pharmacological standard therapy and specifically affect one or more pathogenic pathways. The intake of nutraceuticals or nutritional modifications are generally safe and can be combined with current common drug therapy in most cases to improve the patient's quality of life and/or mitigate PD symptoms. The current review focuses on several key nutritional compounds and dietary modifications that are effective on several pathogenic pathways involved in PD onset and progression, and further highlights the rationale behind their potential use for the prevention and treatment of PD.

Polyphenols in the management of brain disorders: Modulation of the microbiota-gut-brain axis

The modulation of the microbiota-gut-brain axis with a view to preventing and treating brain disorders became recently a hot topic for the scientific community. Dietary polyphenols are multifaceted compounds that have demonstrated to be highly advantageous to counteract inflammation, oxidative stress, and neurodegeneration, among other pathological conditions, being useful in the prevention and treatment of several chronic disorders. The potential of these compounds to prevent and treat brain disorders has not been only related to their capacity to reach the brain, depending on their chemical structure, and interact directly with brain cells, but also to their ability to modulate the communication between the brain and the gut, interfering with multiple branches of this axis. Preclinical studies have demonstrated the potential of these food bioactive compounds in brain diseases, namely, neurodevelopmental, such as Down's syndrome and Autism spectrum disorder, neurodegenerative, such as Parkinson's disease and Alzheimer's disease, and psychiatric disorders, such as depression and anxiety. Until now, dietary polyphenols have been recognized as promising nutraceuticals to combat brain disorders. However, the impact of these compounds on the gut-brain interconnection remains poorly elucidated. Also, clinical assays are crucial to further support the beneficial effects of these compounds as demonstrated in preclinical research.

Da-Bu-Yin-Wan and Qian-Zheng-San Ameliorate Mitochondrial Dynamics in the Parkinson's Disease Cell Model Induced by MPP. Front Pharmacol 2019;10:372. [PMID: 31068806 PMCID: PMC6491701 DOI: 10.3389/fphar.2019.00372]

To investigate the effect of Da-Bu-Yin-Wan and Qian-Zheng-San (DBYW and QZS) on mitochondrial mass in Parkinson’s disease (PD) cell model induced by 1-Methyl-4-phenylpyridinium Ion (MPP⁺). The SH-SY5Y cell was selected and treated with MPP⁺. The PD model was intervened with DBYW and QZS. CCK-8 method was used to detect the survival rate of cells in each group. Mitochondria was labeled by mitoTracker^®Red CMXRos probe and observed by laser scanning confocal microscope, and ImageJ software was used to process images and measure mitochondrial form factors; Tetramethylrhodamine methyl ester was used to detect mitochondrial membrane potential (ΔΨm); Luciferase method was used to detect cellular ATP levels; Western-Blot technique was applied to detect the expression levels of Parkin protein, and the expression levels of Mfn1, Mfn2, OPA1, Drp1, and Fis1. We found that DBYW and QZS treatment significantly increased the cell survival rate, form factor (F-factor), mitochondrial activity and ΔΨm after MPP⁺ treatment, while the increase of ATP levels was not significant. In addition, the results of western blot analysis showed that the MPP⁺ induced increase in the expression of Drp1 and Fis1, as well as decrease in Parkin, Mfn1, Mfn2, and OPA1 were all partially revised by DBYW and QZS. In summary, our data strongly suggested that DBYW and QZS treatment can exert protective effects against PD related neuronal injury through regulation the homeostasis between mitochondrial fission and fusion.

MEF-2 isoforms' (A-D) roles in development and tumorigenesis

Myocyte enhancer factor (MEF)-2 plays a critical role in proliferation, differentiation, and development of various cell types in a tissue specific manner. Four isoforms of MEF-2 (A-D) differentially participate in controlling the cell fate during the developmental phases of cardiac, muscle, vascular, immune and skeletal systems. Through their associations with various cellular factors MEF-2 isoforms can trigger alterations in complex protein networks and modulate various stages of cellular differentiation, proliferation, survival and apoptosis. The role of the MEF-2 family of transcription factors in the development has been investigated in various cell types, and the evolving alterations in this family of transcription factors have resulted in a diverse and wide spectrum of disease phenotypes, ranging from cancer to infection. This review provides a comprehensive account on MEF-2 isoforms (A-D) from their respective localization, signaling, role in development and tumorigenesis as well as their association with histone deacetylases (HDACs), which can be exploited for therapeutic intervention.

Neuroprotection of multifunctional phytochemicals as novel therapeutic strategy for neurodegenerative disorders: antiapoptotic and antiamyloidogenic activities by modulation of cellular signal pathways

In neurodegenerative disorders, including Alzheimer's and Parkinson's disease, neuroprotection by diet and natural bioactive compounds has been proposed to prevent the onset and progress of neurodegeneration by modification of pathogenic factors. Plant food-derived phytochemicals protect neurons via targeting oxidative stress, mitochondrial dysfunction, neurotrophic factor deficit, apoptosis and abnormal protein accumulation. This review presents the molecular mechanism of neuroprotection by phytochemicals: direct regulation of mitochondrial apoptotic machinery, modification of cellular signal pathways, induction of antiapoptotic Bcl-2 protein family and prosurvival neurotrophic factors, such as brain- and glial cell line-derived neurotrophic factor, and prevention of protein aggregation. Multitargeted neuroprotective agents are under development based on the structure of blood–brain barrier-permeable phytochemicals to ameliorate brain dysfunction and prevent neurodegeneration.

Senkyunolide H protects against MPP+-induced apoptosis via the ROS-mediated mitogen-activated protein kinase pathway in PC12 cells

Senkyunolide H (SNH) is a phthalide isolated from the rhizome of Ligusticum chuanxiong Hort. that has been reported to have several pharmacological activities, including anti-atherosclerotic, antiproliferative, and cytoprotective effects. In this study, we investigated the neuroprotective effects and potential mechanisms of SNH against 1-methyl-4-phenylpyridinium (MPP⁺)-induced oxidative stress. We demonstrated that SNH pretreatment significantly attenuated MPP⁺-induced neurotoxicity and apoptosis in PC12 cells. In addition, SNH attenuated the effect of MPP⁺ on the expression of the pro-apoptotic factors Bax and caspase-3. Meanwhile, SNH prevented oxidative stress by reducing reactive oxygen species generation, mitochondrial membrane potential loss, cytochrome C release, and malondialdehyde levels while increasing antioxidant enzyme activity (e.g., superoxide dismutase, catalase, and glutathione peroxidase). In addition, SNH inhibited nuclear accumulation of nuclear factor-κB and c-Jun N-terminal kinase and phosphorylation p38 mitogen-activated protein kinases (MAPKs). Overall, this investigation provides novel evidence that SNH exerts neuroprotective effects via the ROS-mediated MAPK pathway and represents a potential preventive or therapeutic agent for neuronal disorders.

Current Drugs and Potential Future Neuroprotective Compounds for Parkinson's Disease

The research progress of understanding the etiology and pathogenesis of Parkinson's disease (PD) has yet lead to the development of some clinical approaches intended to treat cognitive and behavioral symptoms, such as memory and perception disorders. Despite the major advances in different genetic causes and risk factors for PD, which share common pathways to cell dysfunction and death, there is not yet a complete model of PD that can be used to accurately predict the effect of drugs on disease progression. Clinical trials are also important to test any novel neuro-protective agent, and recently there have been great advances in the use of anti-inflammatory drugs and plant flavonoid antioxidants to protect against specific neuronal degeneration and its interference with lipid and cholesterol metabolism. The increasing knowledge of the molecular events underlying the degenerative process of PD has stimulated research to identify natural compounds capable of halting or slowing the progress of neural deterioration. Polyphenols and flavonoids, which play a neuroprotective role in a wide array of in vitro and in vivo models of neurological disorders, emerged from among the multi-target bio-agents found mainly in plants and microorganisms. This review presents a detailed overview of the multimodal activities of neuroprotective bio-agents tested so far, emphasizing their neurorescue/neuroregenerative activity. The brain-penetrating property of bioagents may make these compounds an important class of natural drugs for the treatment of neurodegenerative diseases. Although there are numerous studies demonstrating beneficial effects in the laboratory by identifying critical molecular targets, the clinical efficacy of these neuroprotective treatments remains to be proven accurately.

Resveratrol Brain Delivery for Neurological Disorders Prevention and Treatment

Resveratrol (RES) is a natural polyphenolic non-flavonoid compound present in grapes, mulberries, peanuts, rhubarb and in several other plants. Numerous health effects have been related with its intake, such as anti-carcinogenic, anti-inflammatory and brain protective effects. The neuroprotective effects of RES in neurological diseases, such as Alzheimer's (AD) and Parkinson's (PD) diseases, are related to the protection of neurons against oxidative damage and toxicity, and to the prevention of apoptotic neuronal death. In brain cancer, RES induces cell apoptotic death and inhibits angiogenesis and tumor invasion. Despite its great potential as therapeutic agent for the treatment of several diseases, RES exhibits some limitations. It has poor water solubility and it is chemically instable, being degraded by isomerization once exposed to high temperatures, pH changes, UV light, or certain types of enzymes. Thus, RES has low bioavailability, limiting its biological and pharmacological benefits. To overcome these limitations, RES can be delivered by nanocarriers. This field of nanomedicine studies how the drug administration, pharmacokinetics, and pharmacodynamics are affected by the use of nanosized materials. The role of nanotechnology, in the prevention and treatment of neurological diseases, arises from the necessity to mask the physicochemical properties of therapeutic drugs to prolong the half-life and to be able to cross the blood-brain barrier (BBB). This can be achieved by encapsulating the drug in a nanoparticle (NP), which can be made of different kinds of materials. An increasing trend to encapsulate and direct RES to the brain has been observed. RES has been encapsulated in many different types of nanosystems, as liposomes, lipid and polymeric NPs. Furthermore, some of these nanocarriers have been modified with targeting molecules able to recognize the brain areas. Then, this article aims to overview the RES benefits and limitations in the treatment of neurological diseases, as the different nanotechnology strategies to overcome these limitations.

GSK-3β Inhibitor Alsterpaullone Attenuates MPP+-Induced Cell Damage in a c-Myc-Dependent Manner in SH-SY5Y Cells

Mitochondrial dysfunction plays significant roles in the pathogenesis of Parkinson’s Disease (PD). The inactivation of c-Myc, a down-stream gene of Wnt/β-catenin signaling, may contribute to the mitochondria dysfunction. Inhibition of glycogen synthase kinase 3β (GSK-3β) with Alsterpaullone (Als) can activate the down-stream events of Wnt signaling. Here, we investigated the protective roles of Als against MPP⁺-induced cell apoptosis in SH-SY5Y cells. The data showed that Als effectively rescued c-Myc from the MPP⁺-induced decline via Wnt signaling. Furthermore, Als protected SH-SY5Y cells from the MPP⁺-induced mitochondrial fission and cell apoptosis. However, the protective roles of Als were lost under β-catenin-deficient conditions. These findings indicate that Als, a GSK-3β inhibitor, attenuated the MPP⁺-induced mitochondria-dependent apoptotic via up-regulation of the Wnt signaling.