Neuroprotective and anti-inflammatory effects of morin in a murine model of Parkinson's disease

Experimental Parkinson models and green chemistry approach

Parkinson's is the most common neurodegenerative disease after Alzheimer's. Motor findings in Parkinson's occur as a result of the degeneration of dopaminergic neurons starting in the substantia nigra pars compacta and ending in the putamen and caudate nucleus. Loss of neurons and the formation of inclusions called Lewy bodies in existing neurons are characteristic histopathological findings of Parkinson's. The disease primarily impairs the functional capacity of the person with cardinal findings such as tremor, bradykinesia, etc., as a result of the loss of dopaminergic neurons in the substantia nigra. Experimental animal models of Parkinson's have been used extensively in recent years to investigate the pathology of this disease. These models are generally based on systemic or local(intracerebral) administration of neurotoxins, which can replicate many features of Parkinson's mammals. The development of transgenic models in recent years has allowed us to learn more about the modeling of Parkinson's. Applying animal modeling, which shows the most human-like effects in studies, is extremely important. It has been demonstrated that oxidative stress increases in many neurodegenerative diseases such as Parkinson's and various age-related degenerative diseases in humans and that neurons are sensitive to it. In cases where oxidative stress increases and antioxidant systems are inadequate, natural molecules such as flavonoids and polyphenols can be used as a new antioxidant treatment to reduce neuronal reactive oxygen species and improve the neurodegenerative process. Therefore, in this article, we examined experimental animal modeling in Parkinson's disease and the effect of green chemistry approaches on Parkinson's disease.

Flavonoids as Potential Therapeutics Against Neurodegenerative Disorders: Unlocking the Prospects

Neurodegeneration, the decline of nerve cells in the brain, is a common feature of neurodegenerative disorders (NDDs). Oxidative stress, a key factor in NDDs such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease can lead to neuronal cell death, mitochondria impairment, excitotoxicity, and Ca2+ stress. Environmental factors compromising stress response lead to cell damage, necessitating novel therapeutics for preventing or treating brain disorders in older individuals and an aging population. Synthetic medications offer symptomatic benefits but can have adverse effects. This research explores the potential of flavonoids derived from plants in treating NDDs. Flavonoids compounds, have been studied for their potential to enter the brain and treat NDDs. These compounds have diverse biological effects and are currently being explored for their potential in the treatment of central nervous system disorders. Flavonoids have various beneficial effects, including antiviral, anti-allergic, antiplatelet, anti-inflammatory, anti-tumor, anti-apoptotic, and antioxidant properties. Their potential to alleviate symptoms of NDDs is significant.

Polyphenols targeting multiple molecular targets and pathways for the treatment of vitiligo

Vitiligo, a pigmentary autoimmune disorder, is marked by the selective loss of melanocytes in the skin, leading to the appearance of depigmented patches. The principal pathological mechanism is the melanocyte destruction mediated by CD8+ T cells, modulated by oxidative stress and immune dysregulation. Vitiligo affects both physical health and psychological well-being, diminishing the quality of life. Polyphenols, naturally occurring compounds with diverse pharmacological properties, including antioxidant and anti-inflammatory activities, have demonstrated efficacy in managing various dermatological conditions through multiple pathways. This review provides a comprehensive analysis of vitiligo and the therapeutic potential of natural polyphenolic compounds. We examine the roles of various polyphenols in vitiligo management through antioxidant and immunomodulatory effects, melanogenesis promotion, and apoptosis reduction. The review underscores the need for further investigation into the precise molecular mechanisms of these compounds in vitiligo treatment and the exploration of their combination with current therapies to augment therapeutic outcomes.

Effectiveness of Flavonoid-Rich Diet in Alleviating Symptoms of Neurodegenerative Diseases

Over the past decades, there has been a significant increase in the burden of neurological diseases, including neurodegenerative disorders, on a global scale. This is linked to a widespread demographic trend in which developed societies are aging, leading to an increased proportion of elderly individuals and, concurrently, an increase in the number of those afflicted, posing one of the main public health challenges for the coming decades. The complex pathomechanisms of neurodegenerative diseases and resulting varied symptoms, which differ depending on the disease, environment, and lifestyle of the patients, make searching for therapies for this group of disorders a formidable challenge. Currently, most neurodegenerative diseases are considered incurable. An important aspect in the fight against and prevention of neurodegenerative diseases may be broadly understood lifestyle choices, and more specifically, what we will focus on in this review, a diet. One proposal that may help in the fight against the spread of neurodegenerative diseases is a diet rich in flavonoids. Flavonoids are compounds widely found in products considered healthy, such as fruits, vegetables, and herbs. Many studies indicated not only the neuroprotective effects of these compounds but also their ability to reverse changes occurring during the progression of diseases such as Alzheimer's, Parkinson's and amyotrophic lateral sclerosis. Here, we present the main groups of flavonoids, discussing their characteristics and mechanisms of action. The most widely described mechanisms point to neuroprotective functions due to strong antioxidant and anti-inflammatory effects, accompanied with their ability to penetrate the blood-brain barrier, as well as the ability to inhibit the formation of protein aggregates. The latter feature, together with promoting removal of the aggregates is especially important in neurodegenerative diseases. We discuss a therapeutic potential of selected flavonoids in the fight against neurodegenerative diseases, based on in vitro studies, and their impact when included in the diet of animals (laboratory research) and humans (population studies). Thus, this review summarizes flavonoids' actions and impacts on neurodegenerative diseases. Therapeutic use of these compounds in the future is potentially possible but depends on overcoming key challenges such as low bioavailability, determining the therapeutic dose, and defining what a flavonoid-rich diet is and determining its potential negative effects. This review also suggests further research directions to address these challenges.

Neuroprotective effects of flavonoids: endoplasmic reticulum as the target

The incidence of neurological disorders, particularly age-related neurodegenerative pathologies, exhibits an alarming upward trend, while current pharmacological interventions seldom achieve curative outcomes. Despite their diverse clinical presentations, neurological diseases often share a common pathological thread: the aberrant accumulation of misfolded proteins within the endoplasmic reticulum (ER). This phenomenon, known as ER stress, arises when the cell's intrinsic quality control mechanisms fail to cope with the protein-folding burden. Consequently, misfolded proteins accumulate in the ER lumen, triggering a cascade of cellular stress responses. Recognizing this challenge, researchers have intensified their efforts over the past two decades to explore natural compounds that could potentially slow or even reverse these devastating pathologies. Flavonoids constitute a vast and heterogeneous class of plant polyphenols, with over 10,000 identified from diverse natural sources such as wines, vegetables, medicinal plants, and organic products. Flavonoids are generally divided into six different subclasses: anthocyanidins, flavanones, flavones, flavonols, isoflavones, and flavonols. The diverse family of flavonoids, featuring a common phenolic ring backbone adorned with varying hydroxyl groups and additional modifications, exerts its antioxidant activity by inhibiting the formation of ROS, as evidenced by research. Also, studies suggest that polyphenols such as flavonoids can regulate ER stress through apoptosis and autophagy. By understanding these mechanisms, we can unlock the potential of flavonoids as novel therapeutic agents for neurodegenerative disorders. Therefore, this review critically examines the literature exploring the modulatory effects of flavonoids on various steps of the ER stress in neurological disorders.

Therapeutic potential of berries in age-related neurological disorders

Aging significantly impacts several age-related neurological problems, such as stroke, brain tumors, oxidative stress, neurodegenerative diseases (Alzheimer's, Parkinson's, and dementia), neuroinflammation, and neurotoxicity. Current treatments for these conditions often come with side effects like hallucinations, dyskinesia, nausea, diarrhea, and gastrointestinal distress. Given the widespread availability and cultural acceptance of natural remedies, research is exploring the potential effectiveness of plants in common medicines. The ancient medical system used many botanical drugs and medicinal plants to treat a wide range of diseases, including age-related neurological problems. According to current clinical investigations, berries improve motor and cognitive functions and protect against age-related neurodegenerative diseases. Additionally, berries may influence signaling pathways critical to neurotransmission, cell survival, inflammation regulation, and neuroplasticity. The abundance of phytochemicals in berries is believed to contribute to these potentially neuroprotective effects. This review aimed to explore the potential benefits of berries as a source of natural neuroprotective agents for age-related neurological disorders.

Regulation of mitophagy and mitochondrial function: Natural compounds as potential therapeutic strategies for Parkinson's disease

Mitochondrial damage is associated with the development of Parkinson's disease (PD), indicating that mitochondrial-targeted treatments could hold promise as disease-modifying approaches for PD. Notably, natural compounds have demonstrated the ability to modulate mitochondrial-related processes. In this review article, we discussed the possible neuroprotective mechanisms of natural compounds against PD in modulating mitophagy and mitochondrial function. A comprehensive literature search on natural compounds related to the treatment of PD by regulating mitophagy and mitochondrial function was conducted from PubMed, Web of Science and Chinese National Knowledge Infrastructure databases from their inception until April 2023. We summarize recent advancements in mitophagy's molecular mechanisms, including upstream and downstream processes, and its relationship with PD-related genes or proteins. Importantly, we highlight how natural compounds can therapeutically regulate various mitochondrial processes through multiple targets and pathways to alleviate oxidative stress, neuroinflammation, Lewy's body aggregation and apoptosis, which are key contributors to PD pathogenesis. Unlike the single-target strategy of modern medicine, natural compounds provide neuroprotection against PD by modulating various mitochondrial-related processes, including ameliorating mitophagy by targeting the PINK1/parkin pathway, the NIX/BNIP3 pathway, and autophagosome formation (i.e., LC3 and p62). Given the prevalence of mitochondrial damage in various neurodegenerative diseases, exploring the exact mechanism of natural compounds on mitophagy and mitochondrial dysfunction could shed light on the development of highly effective disease-modifying or adjuvant therapies targeting PD and other neurodegenerative disorders.

Therapeutic Potential of Morin Hydrate Against Rifampicin Induced Hepato and Renotoxicity in Albino Wistar Rats: Modulation of Organ Function, Oxidative Stress and Inflammatory Response

Tuberculosis (TB) is a challenging public health issue, particularly in poor and developing countries. Rifampicin (RIF) is one of the most common first-line anti-TB drugs but it is known for its adverse effects on the hepato-renal system. The present study investigated the efficacy of morin hydrate (MH) in protecting hepato-renal damage inflicted by RIF in rats. RIF (50 mg/kg), and a combination of RIF (50 mg/kg) and MH (50 mg/kg) were administered orally for 4 weeks in rats. Silymarin (50 mg/kg) was used as a positive control. Increased levels of serological parameters such as AST, ALT, ALP, LDH, GGT, bilirubin, triglyceride, total cholesterol, urea, uric acid, creatinine, TNF-α, IFN-γ, IL-6 along with the decreased level of IL-10, total protein and albumin were used as markers of hepatic and renal injury. Oxidative damage in the tissues was measured by the increase in lipid peroxidation and decline in GSH, SOD and catalase activities. Histopathology of liver slices was used to study hepatic architecture. Four-week RIF treatment produced altered serological parameters with an increase in pro-inflammatory cytokines in serum suggesting hepatotoxicity and nephrotoxicity. The antioxidant status of the liver and kidney (increased lipid peroxidation and decline in GSH, SOD and catalase) was compromised. Cellular damage and necrosis were observed in liver slices. MH supplementation with RIF improved hepato-renal functions by restoring the serum and tissue markers towards normal values. Histological observations authenticated the results. MH supplementation also reduced the production of pro-inflammatory cytokines. Thus, the results revealed that MH provides protection against RIF-induced hepato-renal injury.

What Can Inflammation Tell Us about Therapeutic Strategies for Parkinson's Disease?

Parkinson's disease (PD) is a common neurodegenerative disorder with a complicated etiology and pathogenesis. α-Synuclein aggregation, dopaminergic (DA) neuron loss, mitochondrial injury, oxidative stress, and inflammation are involved in the process of PD. Neuroinflammation has been recognized as a key element in the initiation and progression of PD. In this review, we summarize the inflammatory response and pathogenic mechanisms of PD. Additionally, we describe the potential anti-inflammatory therapies, including nod-like receptor pyrin domain containing protein 3 (NLRP3) inflammasome inhibition, nuclear factor κB (NF-κB) inhibition, microglia inhibition, astrocyte inhibition, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibition, the peroxisome proliferator-activated receptor γ (PPARγ) agonist, targeting the mitogen-activated protein kinase (MAPK) pathway, targeting the adenosine monophosphate-activated protein kinase (AMPK)-dependent pathway, targeting α-synuclein, targeting miRNA, acupuncture, and exercise. The review focuses on inflammation and will help in designing new prevention strategies for PD.

Solid Lipid Nanoparticles Containing Morin: Preparation, Characterization, and Ex Vivo Permeation Studies

In recent years, bioactive compounds have been the focus of much interest in scientific research, due to their low toxicity and extraordinary properties. However, they possess poor solubility, low chemical stability, and unsustainable bioavailability. New drug delivery systems, and among them solid lipid nanoparticles (SLNs), could minimize these drawbacks. In this work, morin (MRN)-loaded SLNs (MRN-SLNs) were prepared using a solvent emulsification/diffusion method, using two different lipids, Compritol^® 888 ATO (COM) or Phospholipon^® 80H (PHO). SLNs were investigated for their physical-chemical, morphological, and technological (encapsulation parameters and in vitro release) properties. We obtained spherical and non-aggregated nanoparticles with hydrodynamic radii ranging from 60 to 70 nm and negative zeta potentials (about -30 mV and -22 mV for MRN-SLNs-COM and MRN-SLNs-PHO, respectively). The interaction of MRN with the lipids was demonstrated via μ-Raman spectroscopy, X-ray diffraction, and DSC analysis. High encapsulation efficiency was obtained for all formulations (about 99%, w/w), particularly for the SLNs prepared starting from a 10% (w/w) theoretical MRN amount. In vitro release studies showed that about 60% of MRN was released within 24 h and there was a subsequent sustained release within 10 days. Finally, ex vivo permeation studies with excised bovine nasal mucosa demonstrated the ability of SLNs to act as a penetration enhancer for MRN due to the intimate contact and interaction of the carrier with the mucosa.

Morin exhibits a neuroprotective effect in MPTP-induced Parkinson's disease model via TFEB/AMPK-mediated mitophagy

BACKGROUND

Parkinson's disease (PD) is one of the most common neurodegenerative diseases in the world. Mitophagy has been implicated in PD etiology for decades and its pharmacological activation is recognized as a promising treatment strategy for PD. For mitophagy initiation, low mitochondrial membrane potential (ΔΨm) is essential. We identified a natural compound morin that could induce mitophagy without affecting ΔΨm. Morin is a flavonoid that can be isolated from fruits like mulberry.

PURPOSE

To reveal the effect of morin on the PD mice model and their potential underlying molecular mechanism.

METHODS

Mitophagy process induced by morin in N2a cells meditation were measured using flow cytometry and immunofluorescence. JC-1 fluorescence dye used to detect the mitochondrial membrane potential (ΔΨm). The TFEB nuclear translocation were examined by immunofluorescence staining and western blot assay. The PD mice model was induced by MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) intraperitoneal administration.

RESULTS

We found that morin also promoted nuclear translocation of the mitophagy regulator TFEB and activated the AMPK-ULK1 pathway. In MPTP-induced PD in vivo models, morin protected DA neurons from MPTP neurotoxicity and ameliorated behavioral deficit.

CONCLUSION

Although morin was previously reported to be neuroprotective in PD, the detailed molecular mechanisms remain to be elucidated. For the first time, we report morin served as a novel and safe mitophagy enhancer underlying AMPK-ULK1 pathway and exhibited anti-Parkinsonian effects indicating its potential as a clinical drug for PD treatment.

Anti-Inflammatory Effects of Flavonoids in Common Neurological Disorders Associated with Aging

Aging reduces homeostasis and contributes to increasing the risk of brain diseases and death. Some of the principal characteristics are chronic and low-grade inflammation, a general increase in the secretion of proinflammatory cytokines, and inflammatory markers. Aging-related diseases include focal ischemic stroke and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Flavonoids are the most common class of polyphenols and are abundantly found in plant-based foods and beverages. A small group of individual flavonoid molecules (e.g., quercetin, epigallocatechin-3-gallate, and myricetin) has been used to explore the anti-inflammatory effect in vitro studies and in animal models of focal ischemic stroke and AD and PD, and the results show that these molecules reduce the activated neuroglia and several proinflammatory cytokines, and also, inactivate inflammation and inflammasome-related transcription factors. However, the evidence from human studies has been limited. In this review article, we highlight the evidence that individual natural molecules can modulate neuroinflammation in diverse studies from in vitro to animal models to clinical studies of focal ischemic stroke and AD and PD, and we discuss future areas of research that can help researchers to develop new therapeutic agents.

A Comprehensive Review on Anti-Inflammatory Response of Flavonoids in Experimentally-Induced Epileptic Seizures

Flavonoids, a group of natural compounds with phenolic structure, are becoming popular as alternative medicines obtained from plants. These compounds are reported to have various pharmacological properties, including attenuation of inflammatory responses in multiple health issues. Epilepsy is a disorder of the central nervous system implicated with the activation of the inflammatory cascade in the brain. The aim of the present study was to summarize the role of various neuroinflammatory mediators in the onset and progression of epilepsy, and, thereafter, to discuss the flavonoids and their classes, including their biological properties. Further, we highlighted the modulation of anti-inflammatory responses achieved by these substances in different forms of epilepsy, as evident from preclinical studies executed on multiple epilepsy models. Overall, the review summarizes the available evidence of the anti-inflammatory potential of various flavonoids in epilepsy.

Neuroprotective Effect of Swertiamarin in a Rotenone Model of Parkinson's Disease: Role of Neuroinflammation and Alpha-Synuclein Accumulation

Parkinson's disease (PD) is a progressive neurodegenerative disease with no permanent cure affecting around 1% of the population over 65. There is an urgency to search for a disease-modifying agent with fewer untoward effects. PD pathology involves the accumulation of toxic alpha-synuclein (α-syn) and neuronal inflammation leading to the degeneration of dopaminergic (DAergic) neurons. Swertiamarin (SWE), a well-studied natural product, possesses a strong anti-inflammatory effect. It is a secoiridoid glycoside isolated from Enicostemma littorale Blume. SWE showed a reversal effect on the α-syn accumulation in the 6-hydroxydopamine (6-OHDA)-induced Caenorhabditis elegans model of PD. However, there are no reports in the literature citing the effect of SWE as a neuroprotective agent in rodents. The present study aimed to evaluate the anti-inflammatory activity of SWE against lipopolysaccharide (LPS)-induced C6 glial cell activation and its neuroprotective effect in the intrastriatal rotenone mouse PD model. SWE treatment showed a significant reduction in interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) levels in LPS-induced C6 glial cell activation. Further, our studies demonstrated the suppression of microglial and astroglial activation in substantia nigra (SN) after administration of SWE (100 mg/kg, intraperitoneally) in a rotenone mouse model. Moreover, SWE alleviated the rotenone-induced α-syn overexpression in the striatum and SN. SWE ameliorated the motor impairment against rotenone-induced neurotoxicity and mitigated the loss of DAergic neurons in the nigrostriatal pathway. Therefore, SWE has the potential to develop as an adjunct therapy for PD, but it warrants further mechanistic studies.

Molecular understanding of the translational models and the therapeutic potential natural products of Parkinson's disease

Parkinson's disease is the second most prevalent neurodegenerative disease after Alzheimer's disease, mostly happened in the elder population and the prevalence gradually increased with age. Parkinson's disease is a movement disorder that severely affects patients' daily life. The mechanism of Parkinson's disease still remains unknown, however, studies already proved that the damage or absence of dopaminergic neurons located in the substantia nigra and the decreased dopamine in the striatum are significantly related to Parkinson's disease. To date, the mainstream treatment of Parkinson's disease has been achieved by alleviating its associated morbid symptoms, such as the use of levodopa, carbidopa, dopamine receptor agonists, monoamine oxidase type B inhibitors, anticholinergic drugs, etc. However, strong side effects, even toxicity, have been reported after using these drugs, with reduced effectiveness over time. Plant compounds have shown good therapeutic effects in neurodegenerative diseases as a less toxic treatment. In this review, we have compiled several natural plant compounds and classified the currently reported compounds for therapeutic use based on their structural parent nuclei and constituent elements. We wish to inspire new ideas for the treatment of Parkinson's disease by summarizing their mechanisms.

Anti-Inflammatory and Neuroprotective Effects of Morin in an MPTP-Induced Parkinson’s Disease Model

Neurodegenerative diseases such as Parkinson’s disease (PD) are known to be related to oxidative stress and neuroinflammation, and thus, modulating neuroinflammation offers a possible means of treating PD-associated pathologies. Morin (2′,3,4′,5,7-pentahydroxy flavone) is a flavonol with anti-oxidative and anti-inflammatory effects found in wines, herbs, and fruits. The present study was undertaken to determine whether a morin-containing diet has protective effects in an MPTP-induced mouse model of PD. Mice were fed a control or morin diet for 34 days, and then MPTP (30 mg/kg, i.p.) was administered daily for 5 days to induce a PD-like pathology. We found that dietary morin prevented MPTP-induced motor dysfunction and ameliorated dopaminergic neuronal damage in striatum (STR) and substantia nigra (SN) in our mouse model. Furthermore, MPTP-induced neuroinflammation was significantly reduced in mice fed morin. In vitro studies showed that morin effectively suppressed glial activations in primary microglia and astrocytes, and biochemical analysis and a docking simulation indicated that the anti-inflammatory effects of morin were mediated by blocking the extracellular signal-regulated kinase (ERK)-p65 pathway. These findings suggest that morin effectively inhibits glial activations and has potential use as a functional food ingredient with therapeutic potential for the treatment of PD and other neurodegenerative diseases associated with neuroinflammation.

Morin attenuates neurobehavioural deficits, hippocampal oxidative stress, inflammation, and apoptosis in rats co-exposed to bisphenol S and diethyl phthalate

Endocrine-disrupting pollutants (EDPs) remain pervasive in the environment. Bisphenol S (BPS) and diethyl phthalates (DEP) are commonly used to replace the more toxic EDPs. However, it is unclear if they induce neurotoxicity, like their predecessors. Morin possesses relevant neuro-pharmacological activities. Hence, we sought to evaluate the protective effects of morin against the neurotoxic effects previously reported for EDPs. Male Wistar rats were exposed to a mixture of BPS and DEP (MBD) and treated with morin for 21 days. Behavioural assessments were conducted, and the hippocampal tissues were processed for analysis. Rats exposed to MBD presented anxiety-like behaviours, impaired cognitive and motor functions compared to the control group. MBD exposure induced hyperactivity of neurosignalling enzymes (AChE, ADA, MAO-A) and depleted hippocampal antioxidants (SOD, CAT, GPx, and GSH). MBD exposure increased calcium levels and inhibited total Ca²⁺-ATPase activity. Levels of reactive species (NO and H₂O₂) and oxidative damage markers (MDA and AOPP) were significantly (P < 0.05) elevated compared to control. The hippocampal expressions of IL-1β, TNFα, BAX, and APAF-1 in the MBD-exposed rats were significantly higher compared to control. Correspondingly, NF-κB and caspase-3 pathways were activated in the hippocampus of MBD-exposed rats, while the expressions of IL-10 and BDNF were repressed. However, co-treatment with morin improved the neurobehavioral outcomes, alleviated the hyperactivity of neurosignalling enzymes, while suppressing hippocampal oxidative stress, inflammation, and apoptosis. Histological and stereological evaluations supported these findings. In conclusion, co-exposure to BPS and DEP elicit similar neurotoxic outcomes as their predecessors, while morin confers marked protection against these outcomes.

Neuroprotective Effect of Morin Hydrate against Attention-Deficit/Hyperactivity Disorder (ADHD) Induced by MSG and/or Protein Malnutrition in Rat Pups: Effect on Oxidative/Monoamines/Inflammatory Balance and Apoptosis

Monosodium glutamate (MSG) is one of the most widely used food additives. However, it has been linked to protein malnutrition (PM) and various forms of toxicities such as metabolic disorders and neurotoxic effects. The current study is the first to explore the association between MSG, PM, and induced brain injury similar to attention-deficit/hyperactivity disorder (ADHD). Moreover, we determined the underlying mechanistic protective pathways of morin hydrate (MH)―a natural flavonoid with reported multiple therapeutic properties. PM was induced by feeding animals with a low protein diet and confirmed by low serum albumin measurement. Subsequently, rat pups were randomized into seven groups of 10 rats each. Group I, III, and VI were normally fed (NF) and groups II, IV, V, and VII were PM fed. Group I served as normal control NF while Group II served as PM control animals. Group III received NF + 0.4 g/kg MSG, Group IV: PM + 0.4 g/kg MSG, Group V: PM + 60 mg/kg MH, Group VI: NF + 0.4 kg/g MSG + 60 mg/kg MH and Group VII: PM + 0.4 kg/kg MSG + 60 mg/kg MH. At the end of the experimental period, animals were subjected to behavioral and biochemical tests. Our results showed that treatment of rats with a combination of MSG + PM-fed exhibited inferior outcomes as evidenced by deteriorated effects on behavioral, neurochemical, and histopathological analyses when compared to rats who had received MSG or PM alone. Interestingly, MH improved animals’ behavior, increased brain monoamines, brain-derived neuroprotective factor (BDNF), antioxidant status and protein expression of Nrf2/HO-1. This also was accompanied by a significant decrease in brain MDA, inflammatory markers (NF-kB, TNF-α and IL1β), and suppression of TLR4/NLRP3/caspase-1 axis. Taken together, MSG and/or PM are associated with neuronal dysfunction. Our findings suggest MH as a potential neuroprotective agent against brain insults via targeting Nrf2/HO-1 and hindering TLR4/NLRP3 inflammasome signaling pathways.

Morin offsets PTZ-induced neuronal degeneration and cognitive decrements in rats: The modulation of TNF-α/TNFR-1/RIPK1,3/MLKL/PGAM5/Drp-1, IL-6/JAK2/STAT3/GFAP and Keap-1/Nrf-2/HO-1 trajectories

Morin is a bioactive flavonoid with prominent neuroprotective potentials, however, its impact on epilepsy-provoked cognitive dysregulations has not been revealed. Hence, the present investigation aims to divulge the potential anticonvulsant/neuroprotective effects of morin in rats using a pentylenetetrazole (PTZ)-induced kindling model with an emphasis on the possible signaling trajectories involved. Kindling was induced using a sub-convulsive dose of PTZ (35 mg/kg, i.p.), once every other day for 25 days (12 injections). The expression of targeted biomarkers and molecular signals were examined in hippocampal tissues by ELISA, Western blotting, immunohistochemistry, and histopathology. Contrary to PTZ effects, administration of morin (10 mg/kg, i.p., from day 15 of PTZ injection to the end of the experiment) significantly reduced the severity of seizures coupled with a delay in kindling acquisition. It also preserved hippocampal neurons, and diminished astrogliosis to counteract cognitive deficits, exhibited by the enhanced performance in MWM and PA tests. These favorable impacts of morin were mediated via the abrogation of the PTZ-induced necroptotic changes and mitochondrial fragmentation proven by the suppression of p-RIPK-1/p-RIPK-3/p-MLKL and PGAM5/Drp-1 cues alongside the enhancement of caspase-8. Besides, morin inhibited the inflammatory cascade documented by the attenuation of the pro-convulsant receptor/cytokines TNFR-1, TNF-α, I L-1β, and IL-6 and the marked reduction of hippocampal IL-6/p-JAK2/p-STAT3/GFAP cue. In tandem, morin signified its anti-oxidant capacity by lowering the hippocampal contents of MDA, NOX-1, and Keap-1 with the restoration of the impaired Nrf-2/HO-1 pathway. Together, these versatile neuro-modulatory effects highlight the promising role of morin in the management of epilepsy.

Antioxidative role of Traditional Chinese Medicine in Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Neuroprotective Traditional Chinese Medicine (TCM) has been practiced in alternative medicine from early days. TCM-derived neuroprotective compounds, such as Chrysin, Cannabidiol, Toonasinoids, and β-asaron, exert significant effectiveness's towards Parkinson's disease (PD). Further, these neuroprotective TCM showed antioxidative, anti-inflammatory, anti-tumor, anti-septic, analgesic properties. Recent research showed that the reduction in the reactive oxygen species (ROS) decreased the α-synuclein (α-syn) toxicity and enhanced the dopaminergic neuron regenerations, the main hallmarks of PD. Therefore, the neuroprotective effects of novel TCM due to its antiradical activities needed deep investigations.

AIMS OF THE STUDY

This review aims to enlighten the neuroprotective TCM and its components with their antioxidative properties to the scientific community for future research.

METHOD

The relevant information on the neuroprotective TCM was gathered from scientific databases (PubMed, Web of Science, Google Scholar, ScienceDirect, SciFinder, Wiley Online Library, ACS Publications, and CNKI). Information was also gained from MS and Ph.D. thesis, books, and online databases. The literature cited in this review dates from 2001 to June 2, 0201.

RESULTS

Novel therapies for PD are accessible, mostly rely on Rivastigmine and Donepezil, offers to slow down the progression of disease at an early stage but embraces lots of disadvantages. Researchers are trying to find a potential drug against PD, which is proficient at preventing or curing the disease progress, but still needed to be further identified. Oxidative insult and mitochondrial dysfunction are thought to be the main culprit of neurodegenerations. Reactive oxygen species (ROS) are the only causative agent in all interactions, leading to PD, from mitochondrial dysfunctions, α-syn aggregative toxicity, and DA neurons degenerations. It is evident from the redox balance, which seems an imperative therapeutic approach against PD and was necessary for the significant neuronal activities.

CONCLUSION

Our study is explaining the newly discovered TCM and their neuroprotective and antioxidative properties. But also bring up the possible treatment approaches against PD for future researchers.

Therapeutic benefits of flavonoids against neuroinflammation: a systematic review

Flavonoids are an important class of natural polyphenolic compounds reported to exert beneficial effects in cardiovascular and metabolic diseases, cancer, autoimmune and neurological disorders. Flavonoids possess potential antioxidant, anti-inflammatory, antiapoptotic and immuno-modulation properties. Intriguingly, the importance of flavonoids in different neurological disorders is gaining more attention due to the safety, better pharmacokinetic profile and blood-brain barrier penetration, cost-effectiveness and readiness for clinical uses/trials. Many in vitro and in vivo research studies have established the neuroprotective mechanism of flavonoids in the central nervous system (CNS) diseases. The present review summarizes the benefits of various classes of flavonoids (flavones, flavonols, flavanones, anthocyanidins, isoflavones, flavanols), chemical nature, classification, their occurrence and distribution, pharmacokinetics and bioavailability. The manuscript also presents available evidences relating to the role of flavonoids in regulating key signaling pathways such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway, mitogen-activated protein kinase (MAPK) pathway, Janus kinase and signal transducer and activator of transcription proteins (JAK/STAT) pathway, Toll-like receptors (TLR) pathway, nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and cAMP response element-binding protein (CREB) pathway involved in neuroinflammation associated with major neurological disorders. Literature search was conducted using electronic databases like Google Scholar, Scopus, PubMed central, Springer search and Web of science. Chemical structures used in the present analysis were drawn using Chemdraw Professional 15.0 software. This collective information provides comprehensive knowledge on disease pathways and therapeutic benefits of flavonoids in neurological disorders, druggability and future scope for research.

Anti-Inflammatory Effects of the Novel Barbiturate Derivative MHY2699 in an MPTP-Induced Mouse Model of Parkinson's Disease

Parkinson’s disease (PD) is one of the most common neurodegenerative disorders, and is caused by the death of dopamine neurons and neuroinflammation in the striatum and substantia nigra. Furthermore, the inflammatory response in PD is closely related to glial cell activation. This study examined the neuroprotective effects of the barbiturate derivative, MHY2699 [5-(4-hydroxy 3,5-dimethoxybenzyl)-2 thioxodihydropyrimidine-4,6(1H,5H)-dione] in a mouse model of PD. MHY2699 ameliorated MPP⁺-induced astrocyte activation and ROS production in primary astrocytes and inhibited the MPP⁺-induced phosphorylation of MAPK and NF-κB. The anti-inflammatory effects of MHY2699 in protecting neurons were examined in an MPTP-induced mouse model of PD. MHY2699 inhibited MPTP-induced motor dysfunction and prevented dopaminergic neuronal death, suggesting that it attenuated neuroinflammation. Overall, MHY2699 has potential as a neuroprotective treatment for PD.

Further insights for the role of Morin in mRTBI: Implication of non-canonical Wnt/PKC-α and JAK-2/STAT-3 signaling pathways

The slightly available data about the pathogenesis process of mild repetitive traumatic brain injury (mRTBI) indicates to the necessity of further exploration of mRTBI consequences. Several cellular changes are believed to contribute to the cognitive disabilities, and neurodegenerative changes observed later in persons subjected to mRTBI. We investigated glial fibrillary acidic protein (GFAP), the important severity related biomarker, where it showed further increase after multiple trauma compared to single one. To authenticate our aim, Morin (10 mg/kg loading dose, then twice daily 5 mg/kg for 7 days), MK-801 (1 mg/kg; i.p) and their combination were used. The results obtained has shown that all the chosen regimens opposed the upregulated dementia markers (Aβ1-40,p(Thr231)Tau) and inflammatory protein contents/expression of p(Ser53s6)NF-κBp65, TNF-α, IL-6,and IL-1β and the elevated GFAP in immune stained cortex sections. Additionally, they exerted anti-apoptotic activity by decreasing caspase-3 activity and increasing Bcl-2 contents. Saving brain tissues was evident after these therapeutic agents via upregulating the non-canonical Wnt-1/PKC-α cue and IL-10/p(Tyr(1007/1008))JAK-2/p(Tyr705)STAT-3 signaling pathway to confirm enhancement of survival pathways on the molecular level. Such results were imitated by correcting the injury dependent deviated behavior, where Morin alone or in combination enhanced behavior outcome. On one side, our study refers to the implication of two survival signaling pathways; viz.,the non-canonical Wnt-1/PKC-α and p(Tyr(1007/1008))JAK-2/p(Tyr705)STAT-3 in single and repetitive mRTBI along with distorted dementia markers, inflammation and apoptotic process that finally disrupted behavior. On the other side, intervention through affecting all these targets by Morin alone or with MK-801 affords a promising neuroprotective effect.

Anti-Oxidative, Anti-Inflammatory and Anti-Apoptotic Effects of Flavonols: Targeting Nrf2, NF-κB and p53 Pathways in Neurodegeneration

Neurodegenerative diseases are one of the leading causes of disability and death worldwide. Intracellular transduction pathways that end in the activation of specific transcription factors are highly implicated in the onset and progression of pathological changes related to neurodegeneration, of which those related to oxidative stress (OS) and neuroinflammation are particularly important. Here, we provide a brief overview of the key concepts related to OS- and neuroinflammation-mediated neuropathological changes in neurodegeneration, together with the role of transcription factors nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB). This review is focused on the transcription factor p53 that coordinates the cellular response to diverse genotoxic stimuli, determining neuronal death or survival. As current pharmacological options in the treatment of neurodegenerative disease are only symptomatic, many research efforts are aimed at uncovering efficient disease-modifying agents. Natural polyphenolic compounds demonstrate powerful anti-oxidative, anti-inflammatory and anti-apoptotic effects, partially acting as modulators of signaling pathways. Herein, we review the current understanding of the therapeutic potential and limitations of flavonols in neuroprotection, with emphasis on their anti-oxidative, anti-inflammatory and anti-apoptotic effects along the Nrf2, NF-κB and p53 pathways. A better understanding of cellular and molecular mechanisms of their action may pave the way toward new treatments.

Neuroinflammation in neurological disorders: pharmacotherapeutic targets from bench to bedside

Neuroinflammation is one of the host defensive mechanisms through which the nervous system protects itself from pathogenic and or infectious insults. Moreover, neuroinflammation occurs as one of the most common pathological outcomes in various neurological disorders, makes it the promising target. The present review focuses on elaborating the recent advancement in understanding molecular mechanisms of neuroinflammation and its role in the etiopathogenesis of various neurological disorders, especially Alzheimer's disease (AD), Parkinson's disease (PD), and Epilepsy. Furthermore, the current status of anti-inflammatory agents in neurological diseases has been summarized in light of different preclinical and clinical studies. Finally, possible limitations and future directions for the effective use of anti-inflammatory agents in neurological disorders have been discussed.

Neuroprotective and anti-inflammatory effect of pectolinarigenin, a flavonoid from Amazonian Aegiphila integrifolia (Jacq.), against lipopolysaccharide-induced inflammation in astrocytes via NFκB and MAPK pathways

Neurodegenerative diseases affect millions of people worldwide. Regardless of the underlying cause, neuroinflammation is the greatest risk factor for developing any of these disorders. Pectolinarigenin (PNG) is an active flavonoid with several biological properties, anti-metastatic and anti-inflammatory activity. This study investigate the biological effects of PNG in macrophage and astrocyte cultures, with focus on elucidating the molecular mechanisms involved in the PNG activity. J774A.1 murine macrophage or cerebral cortex primary astrocytes primary cultures were treated with different concentration of PNG (1-160 μM) and the inflammatory process was stimulated by LPS (1 μg/ml) and the effect of PNG in different inflammatory markers were determined. PNG did not affect astrocyte or macrophage viability. Moreover, this flavonoid reduced NO• release in macrophages, attenuated astrocyte activation by preventing the overexpression of glial fibrillary acidic protein, and decreased the release of inflammatory mediators, IL-1β and IL-6 induced by LPS by the glial cell, as well as enhanced basal levels of IL-10. In addition, PNG suppressed NFκB, p38MAPK and ERK1/2 phosphorylation in astrocytes culture induced by LPS. The results show clear evidence that this novel flavonoid protects astrocytes against LPS-induced inflammatory toxicity. In conclusion, PNG presents neuroprotective and anti-inflammatory property through the inhibition of inflammatory signaling pathways.

The anticarcinogenic and anticancer effects of the dietary flavonoid, morin: Current status, challenges, and future perspectives

Flavonoids constitute one of the most important classes of polyphenols, which have been found to have a wide range of biological activities such as anticancer effects. A large body of evidence demonstrates that morin as a pleiotropic dietary flavonoid possesses potent anticarcinogenic and anticancer activities with minimal toxicity against normal cells. The present review comprehensively elaborates the molecular mechanisms underlying antitumorigenic and anticancer effects of morin. Morin exerts its anticarcinogenic effects through multiple cancer preventive mechanisms, including reduction of oxidative stress, activation of phase II enzymes, induction of apoptosis, attenuation of inflammatory mediators, and downregulation of p-Akt and NF-κB expression. A variety of molecular targets and signaling pathways such as apoptosis, cell cycle, reactive oxygen species (ROS), matrix metalloproteinases (MMPs), epithelial-mesenchymal transition (EMT), and microRNAs (miRNAs) as well as signal transducer and activator of transcription 3 (STAT3), NF-κB, phosphatidylinositol 3-kinase (PI3K)/Akt, mitogen-activated protein kinase (MAPK), and Hippo pathways have been found to be involved in the anticancer effects of morin. In the adjuvant therapy, morin has been shown to have synergistic anticancer effects with several chemotherapeutic drugs. The findings of this review indicate that morin can act as a promising chemopreventive and chemotherapeutic agent.

Morin protects against acrylamide-induced neurotoxicity in rats: an investigation into different signal pathways

The presented study investigates the effects of morin against toxicity induced by acrylamide (ACR) in the brains of Sprague Dawley rats. In this study, neurotoxicity was induced by orally administering 38.27 mg/kg/b.w ACR to rats through gastric gavage for 10 days. Morin was administered at the same time and at different doses (50 and 100 mg/kg/b.w) with ACR. Biochemical and Western blot analyses showed that ACR increased malondialdehyde (MDA), p38α mitogen-activated protein kinase (p38α MAPK), nuclear factor kappa-B (NF-κB), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2), p53, caspase-3, bcl-2 associated X protein (Bax), Beclin-1, light chain 3A (LC3A), and light chain 3B (LC3B) levels and decreased those of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH), b-cell lymphoma-2 (Bcl-2), mammalian target of rapamycin (mTOR), phosphoinositide 3-kinase (PI3K), and protein kinase B (Akt) in brain tissue and therefore induced neurotoxicity by causing oxidative stress, inflammation, apoptosis, and autophagy. On the other hand, it was determined that morin positively affected the levels of these markers by displaying antioxidant, anti-inflammatory, anti-apoptotic, and anti-autophagic properties and had a protective effect on ACR-induced neurotoxicity. As a result, morin is an effective substance against brain damage caused by ACR, yet further studies are needed to use it effectively.

Acetylcholinesterase Inhibitors in the Treatment of Neurodegenerative Diseases and the Role of Acetylcholinesterase in their Pathogenesis

Acetylcholinesterase (AChE) plays an important role in the pathogenesis of neurodegenerative diseases by influencing the inflammatory response, apoptosis, oxidative stress and aggregation of pathological proteins. There is a search for new compounds that can prevent the occurrence of neurodegenerative diseases and slow down their course. The aim of this review is to present the role of AChE in the pathomechanism of neurodegenerative diseases. In addition, this review aims to reveal the benefits of using AChE inhibitors to treat these diseases. The selected new AChE inhibitors were also assessed in terms of their potential use in the described disease entities. Designing and searching for new drugs targeting AChE may in the future allow the discovery of therapies that will be effective in the treatment of neurodegenerative diseases.

Morin attenuates osteoclast formation and function by suppressing the NF-κB, MAPK and calcium signalling pathways

Morin is a natural compound isolated from moraceae family members and has been reported to possess a range of pharmacological activities. However, the effects of morin on bone-associated disorders and the potential mechanism remain unknown. In this study, we investigated the anti-osteoclastogenic effect of morin in vitro and the potential therapeutic effects on ovariectomy (OVX)-induced osteoporosis in vivo. In vitro, by using a bone marrow macrophage-derived osteoclast culture system, we determined that morin attenuated receptor activator of nuclear factor (NF)-κB ligand (RANKL)-induced osteoclast formation via the inhibition of the mitogen-activated protein kinase (MAPK), NF-κB and calcium pathways. In addition, the subsequent expression of nuclear factor of activated T cells c1 (NFATc1) and c-fos was significantly suppressed by morin. In addition, NFATc1 downregulation led to the reduced expression of osteoclastogenesis-related marker genes, such as V-ATPase-d2 and Integrin β3. In vivo, results provided that morin could effectively attenuate OVX-induced bone loss in C57BL/6 mice. In conclusion, our results demonstrated that morin suppressed RANKL-induced osteoclastogenesis via the NF-κB, MAPK and calcium pathways, in addition, its function of preventing OVX-induced bone loss in vivo, which suggested that morin may be a potential therapeutic agent for postmenopausal osteoporosis treatment.

Genetic Imaging of Neuroinflammation in Parkinson's Disease: Recent Advancements

Parkinson's disease (PD) is one of the most prevalent neurodegenerative aging disorders characterized by motor and non-motor symptoms due to the selective loss of midbrain dopaminergic (DA) neurons. The decreased viability of DA neurons slowly results in the appearance of motor symptoms such as rigidity, bradykinesia, resting tremor, and postural instability. These symptoms largely depend on DA nigrostriatal denervation. Pharmacological and surgical interventions are the main treatment for improving clinical symptoms, but it has not been possible to cure PD. Furthermore, the cause of neurodegeneration remains unclear. One of the possible neurodegeneration mechanisms is a chronic inflammation of the central nervous system, which is mediated by microglial cells. Impaired or dead DA neurons can directly lead to microglia activation, producing a large number of reactive oxygen species and pro-inflammatory cytokines. These cytotoxic factors contribute to the apoptosis and death of DA neurons, and the pathological process of neuroinflammation aggravates the primary morbid process and exacerbates ongoing neurodegeneration. Therefore, anti-inflammatory treatment exerts a robust neuroprotective effect in a mouse model of PD. Since discovering the first mutation in the α-synuclein gene (SNCA), which can cause disease-causing, PD has involved many genes and loci such as LRRK2, Parkin, SNCA, and PINK1. In this article, we summarize the critical descriptions of the genetic factors involved in PD's occurrence and development (such as LRRK2, SNCA, Parkin, PINK1, and inflammasome), and these factors play a crucial role in neuroinflammation. Regulation of these signaling pathways and molecular factors related to these genetic factors can vastly improve the neuroinflammation of PD.

Morin hydrate: A comprehensive review on novel natural dietary bioactive compound with versatile biological and pharmacological potential

Flavonoids are natural plant-derived dietary bioactive compounds having a substantial impact on human health. Morin hydrate is a bioflavonoid mainly obtained from fruits, stem, and leaves of Moraceae family members' plants. Plenty of evidences supported that morin hydrate exerts its beneficial effects against various chronic and life-threatening degenerative diseases. Our current article discloses the recent advances that have been studied to explore the biological/pharmacological properties and molecular mechanisms to better understand the beneficial and multiple health benefits of morin hydrate. Indeed, Morin hydrate exerts free radical scavenging, antioxidant, anti-inflammatory, anti-cancerous, anti-microbial, antidiabetic, anti-arthritis, cardioprotective, neuroprotective, nephroprotective, and hepatoprotective effects. Moreover, morin hydrate exhibits its pharmacological activities by modulating various cellular signaling pathways such as Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-қB), Mitogen-activated protein kinase (MAPK), Janus kinases/ Signal transducer and activator of transcription proteins (JAKs/STATs), Kelch-like ECH-associated protein1/Nuclear erythroid-2-related factor (Keap1/Nrf2), Endoplasmic reticulum (ER), Mitochondrial-mediated apoptosis, Wnt/β-catenin, and Mechanistic target of rapamycin (mTOR). Most importantly, morin hydrate has the potential to modulate a variety of biological networks. Therefore, it can be predicted that this therapeutically potent compound could serve as a dietary agent for the expansion of human health and might be helpful for the development of the novel drug in the future. However, due to the lack of clinical trials, special human clinical trials are needed to address the effects of morin hydrate on various life-threatening disparities to recommend morin and/or morin-rich foods with other foods or bioactive dietary components, as well as dose-response interaction and safety profile.

Neuroprotective and Anti-Inflammatory Effects of Evernic Acid in an MPTP-Induced Parkinson's Disease Model

Oxidative stress, mitochondrial dysfunction, and neuroinflammation are strongly associated with the pathogenesis of Parkinson's disease (PD), which suggests that anti-oxidative and anti-inflammatory compounds might provide an alternative treatment for PD. Here, we evaluated the neuroprotective effects of evernic aid (EA), which was screened from a lichen library provided by the Korean Lichen Research Institute at Sunchon National University. EA is a secondary metabolite generated by lichens, including Ramalina, Evernia, and Hypogymnia, and several studies have described its anticancer, antifungal, and antimicrobial effects. However, the neuroprotective effects of EA have not been studied. We found that EA protected primary cultured neurons against 1-methyl-4-phenylpyridium (MPP+)-induced cell death, mitochondrial dysfunction, and oxidative stress, and effectively reduced MPP+-induced astroglial activation by inhibiting the NF-κB pathway. In vivo, EA ameliorated MPTP-induced motor dysfunction, dopaminergic neuronal loss, and neuroinflammation in the nigrostriatal pathway in C57BL/6 mice. Taken together, our findings demonstrate that EA has neuroprotective and anti-inflammatory effects in PD models and suggest that EA is a potential therapeutic candidate for PD.

Investigation on the Linear and Nonlinear Properties of Morin in Presence of Reverse Micelle and Different Oil Content in Reverse Micelle

We investigate the linear and nonlinear optical property of Morin (MN) at different concentration (1 × 10-6 and 5 × 10-6 M) within AOT reversed micelle prepared by water-in-decane microemulsion having a constant molar ratio of water-to-surfactant molecules of 40 (W = [H2O]/[AOT] = 40) as well as the function of mass fraction of nano-droplet (MFD) values of 0.01,0.04, 0.07, and 0.1 by using UV-Visible, Fluorescence, FTIR, and Z-scan techniques. The steady-state measurement indicates that the presence of microenvironment can greatly affect the tautomeric structure of morin and also Morin property in microenvironment depends upon the amount of oil and Morin concentration. The increase in dipole moment from the ground state to excited state in microenvironment indicate the change in the molecular structure on morin. Morin does not show any nonlinear absorption property but the nonlinear refractive index is observed as a function of Morin concentration as well as MFD values which are due to the thermal agitation of formed dimers. Morin nonlinearity.

Nose-to-brain Delivery of Natural Compounds for the Treatment of Central Nervous System Disorders

BACKGROUND

Several natural compounds have demonstrated potential for the treatment of central nervous system disorders such as ischemic cerebrovascular disease, glioblastoma, neuropathic pain, neurodegenerative diseases, multiple sclerosis and migraine. This is due to their well-known antioxidant, anti-inflammatory, neuroprotective, anti-tumor, anti-ischemic and analgesic properties. Nevertheless, many of these molecules have poor aqueous solubility, low bioavailability and extensive gastrointestinal and/or hepatic first-pass metabolism, leading to a quick elimination as well as low serum and tissue concentrations. Thus, the intranasal route emerged as a viable alternative to oral or parenteral administration, by enabling a direct transport into the brain through the olfactory and trigeminal nerves. With this approach, the blood-brain barrier is circumvented and peripheral exposure is reduced, thereby minimizing possible adverse effects.

OBJECTIVE

Herein, brain-targeting strategies for nose-to-brain delivery of natural compounds, including flavonoids, cannabinoids, essential oils and terpenes, will be reviewed and discussed. Brain and plasma pharmacokinetics of these molecules will be analyzed and related to their physicochemical characteristics and formulation properties.

CONCLUSION

Natural compounds constitute relevant alternatives for the treatment of brain diseases but often require loading into nanocarrier systems to reach the central nervous system in sufficient concentrations. Future challenges lie in a deeper characterization of their therapeutic mechanisms and in the development of effective, safe and brain-targeted delivery systems for their intranasal administration.

Nanoantioxidant-Based Silica Particles as Flavonoid Carrier for Drug Delivery Applications

Nanosystems used in pharmaceutical formulations have shown promising results in enhancing the administration of drugs of difficult formulations. In particular, porous silica nanoparticles have demonstrated excellent properties for application in biological systems; however, there are still several challenges related to the development of more effective and biocompatible materials. An interesting approach to enhance these nanomaterials has been the development of nanoantioxidant carriers. In this work, a hybrid nanoantioxidant carrier based on porous silica nanoplatform with rosmarinic acid antioxidant immobilized on its surface were developed and characterized. Techniques such as dynamic light scattering (DLS), zeta potential, transmission electron microscopy (TEM), N2 adsorption-desorption measurements, differential scanning calorimetry (DSC), Fourier transform-infrared spectroscopy (FT-IR), and 2,2-diphenyl-1-picrylhydrazyl (DPPH●) assay were used to characterize and evaluate the antioxidant activity of nanocarriers. In addition, drug release profile was evaluated using two biorelevant media. The antioxidant activity of rosmarinic acid was maintained, suggesting the correct disposition of the moiety. Kinetic studies reveal that more morin is released in the simulated intestinal fluid than in the gastric one, while an anomalous non-Fickian release mechanism was observed. These results suggest a promising antioxidant nanocarrier suitable for future application in drug delivery.

Neural Glyoxalase Pathway Enhancement by Morin Derivatives in an Alzheimer's Disease Model

The glyoxalase pathway (GP) is an antioxidant defense system that detoxifies metabolic byproduct methylglyoxal (MG). Through sequential reactions, reduced glutathione (GSH), glyoxalase I (glo-1), and glyoxalase II (glo-2) convert MG into d-lactate. Spontaneous reactions involving MG alter the structure and function of cellular macromolecules through the formation of inflammatory advanced glycation endproducts (AGEs). Accumulation of MG and AGEs in neural cells contributes to oxidative stress (OS), a state of elevated inflammation commonly found in neurodegenerative diseases including Alzheimer's disease (AD). Morin is a common plant-produced flavonoid polyphenol that exhibits the ability to enhance the GP-mediated detoxification of MG. We hypothesize that structural modifications to morin will improve its inherent GP enhancing ability. Here we synthesized a morin derivative, dibromo-morin (DBM), formulated a morin encapsulated nanoparticle (MNP), and examined their efficacy in enhancing neural GP activity. Cultured mouse primary cerebellar neurons and Caenorhabditis elegans were induced to a state of OS with MG and treated with morin, DBM, and MNP. Results indicated the morin derivatives were more effective compared to the parent compound in neural GP enhancement and preventing MG-mediated OS in an AD model.

Morin alleviates LPS-induced mastitis by inhibiting the PI3K/AKT, MAPK, NF-κB and NLRP3 signaling pathway and protecting the integrity of blood-milk barrier

Mastitis is a common veterinary clinical disease that restricts the development of dairy farming around the world. Morin, extracted from Mulberry Tree and other herbs, has been reported to possess the function of anti-bacteria, anti-oxidant, and anti-inflammatory. However, whether morin could protect lipopolysaccharide (LPS)-induced mouse mastitis in vivo has not well known. This study firstly aims to evaluate the effects of morin on LPS-induced mouse mastitis in vivo, and then try to illustrate the mechanism involved in the process. Before injected with LPS, mice were intraperitoneally pre-injected with different concentrations of morin, and mice of the control and LPS group were injected with the same amount of saline. Pathologic changes of mammary gland were determined by histopathological examination. Myeloperoxidase (MPO) activities of mammary gland were determined by the MPO kits. The mRNA expressions of inflammatory cytokines including TNF-α, IL-1β and IL-6, and those of chemokine factors CCL2 and CXCL2, and those of tight junctions occludin claudin-3 were examined by qRT-PCR analysis. The activities of IκB, p65, ERK, P38, AKT, PI3K, NLPR3, claudin-1, claudin-3 and occludin were determined by western blotting. The results showed that morin alleviated LPS-induced edema, destructed structures and infiltrated inflammatory cells of mammary gland. Morin administration significantly decreased LPS-induced TNF-α, IL-1β, IL-6, CCL2 and CXCL2 mRNA expressions. Furthermore, western blot analysis also showed that morin significantly reduced LPS-induced phosphorylation of p65, IκB, p38 and ERK, and enhanced LPS-induced phosphorylation of AKT and PI3K. It was also found that LPS-decreased claudin-3 and occludin expressions were also inhibited by morin treatment. In summary, above results suggest that morin indeed protect LPS-induced mouse mastitis in vivo, and the mechanism was through inhibiting the PI3K/AKT, MAPK, NF-κB and NLRP3 signaling pathways and protecting the integrity of blood-milk barrier by regulating the tight junction proteins expressions.

Insights Into the Explication of Potent Tyrosinase Inhibitors with Reference to Computational Studies

Background:

Pigment melanin has primarily a photo defensive role in human skin, its unnecessary production and irregular distribution can cause uneven skin tone ultimately results in hyper pigmentation. Melanin biosynthesis is initiated by tyrosine oxidation through tyrosinase, the key enzyme for melanogenesis. Not only in humans, tyrosinase is also widely distributed in plants and liable for browning of vegetables and fruits. Search for the inhibitors of tyrosinase have been an important target to facilitate development of therapies for the prevention of hyperpigmentary disorders and an undesired browning of vegetables and fruits.

Methods:

Different natural and synthetic chemical compounds have been tested as potential tyrosinase inhibitors, but the mechanism of inhibition is not known, and the quest for information regarding interaction between tyrosinase and its inhibitors is one of the recent areas of research. Computer based methods hence are useful to overcome such issues. Successful utilization of in silico tools like molecular docking simulations make it possible to interpret the tyrosinase and its inhibitor’s intermolecular interactions and helps in identification and development of new and potent tyrosinase inhibitors.

Results:

The present review has pointed out the prominent role of computer aided approaches for the explication of promising tyrosinase inhibitors with a focus on molecular docking approach. Highlighting certain examples of natural compounds whose antityrosinase effects has been evaluated using computational simulations.

Conclusion:

The investigation of new and potent inhibitors of tyrosinase using computational chemistry and bioinformatics will ultimately help millions of peoples to get rid of hyperpigmentary disorders as well as browning of fruits and vegetables.

Morin Hydrate Inhibits TREM-1/TLR4-Mediated Inflammatory Response in Macrophages and Protects Against Carbon Tetrachloride-Induced Acute Liver Injury in Mice

This study aims to investigate the protective effects of morin hydrate (MH) against acute liver injury induced by carbon tetrachloride (CCl₄) in mice and to elucidate the possible molecular mechanism of action. Mice were pretreated with MH (50 mg/kg body weight) or vehicle by oral gavage once daily for 5 days, followed by intraperitoneal injection of a single dose of CCl₄ (1 ml/kg in olive oil). Mice were sacrificed 24 h later; the blood and liver samples were harvested for analysis. We also used the model of lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages in vitro and examined the effects of MH and its mechanism of action on the inflammatory response. Our results revealed that MH remarkably attenuated liver histopathological alterations, serum transaminases, hepatocytes death, and inflammatory response induced by CCl₄. Importantly, MH reduced expression of the triggering receptor expressed on myeloid cells-1 (TREM-1) and toll-like receptor 4 (TLR4) both in vivo and in vitro experiments. This inhibitory effect MH on expression of the TREM-1 and TLR4 in cell culture was further heightened after TREM-1 knockdown with small interfering RNA (siRNA). Moreover, MH dramatically suppressed the inhibitor of kappa B α (IκBα) degradation and subsequent nuclear factor-kappa B (NF-κB) p65 translocation into the nucleus and NF-κB-mediated cytokines, such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6. Additionally, MH also ameliorated CCl₄-induced oxidative stress by enhancing the nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression in the injured livers. Taken together, MH has hepatoprotective activity, and this effect may be elicited by attenuating macrophage-mediated inflammatory responses via inhibition TREM-1/TLR4/NF-κB signaling and by regulating hepatic oxidative stress via enhancement Nrf2/HO-1 antioxidant pathway.

The Potential of Flavonoids for the Treatment of Neurodegenerative Diseases

Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and amyotrophic lateral sclerosis (ALS), currently affect more than 6 million people in the United States. Unfortunately, there are no treatments that slow or prevent disease development and progression. Regardless of the underlying cause of the disorder, age is the strongest risk factor for developing these maladies, suggesting that changes that occur in the aging brain put it at increased risk for neurodegenerative disease development. Moreover, since there are a number of different changes that occur in the aging brain, it is unlikely that targeting a single change is going to be effective for disease treatment. Thus, compounds that have multiple biological activities that can impact the various age-associated changes in the brain that contribute to neurodegenerative disease development and progression are needed. The plant-derived flavonoids have a wide range of activities that could make them particularly effective for blocking the age-associated toxicity pathways associated with neurodegenerative diseases. In this review, the evidence for beneficial effects of multiple flavonoids in models of AD, PD, HD, and ALS is presented and common mechanisms of action are identified. Overall, the preclinical data strongly support further investigation of specific flavonoids for the treatment of neurodegenerative diseases.

Significant roles of neuroinflammation in Parkinson's disease: therapeutic targets for PD prevention

Glial cells outnumber neurons in the brain and play important roles in the neuroinflammation that accompanies brain damage in neurodegenerative diseases. In Parkinson's disease (PD), dopaminergic neuronal loss is accompanied by inflammatory changes in microglia, astrocytes, innate immune cells, and infiltrating peripheral immune cells. Neuroinflammation is probably a fundamental immune response to protect neurons from harm and compensate for neuronal damage, but at the same time, its neurotoxic effects exacerbate neuron damage. Furthermore, neuroinflammatory response is regulated by immune cells, such as microglia, astrocytes, and peripheral immune cells, and by cytokines and chemokines. Accordingly, it is crucial that we understand how such immune cells in the brain regulate neuroinflammatory responses in PD pathology. This review describes the roles played by glia-mediated neuroinflammation in PD, both good and bad, and the therapeutic strategies used to treat PD.

Role of MAPK/NF-κB pathway in cardioprotective effect of Morin in isoproterenol induced myocardial injury in rats

Oxidative stress plays a major role in myocardial injury. Morin, a bioflavonoid has known to possess various biological activities in previous studies. Hence, this study evaluated the cardioprotective mechanism(s) of Morin against isoproterenol induced myocardial necrosis in rats. Male albino Wistar rats were divided into five groups (n = 8) i.e., I (normal), II (ISO-control), III, IV and V (morin 20, 40 and 80 mg/kg respectively). Groups III, IV and V were treated orally with daily doses of Morin accordingly for 28 days. On 26th and 27th day, a single injection of isoproterenol was injected (85 mg/kg s.c.) at 24 h interval to induce myocardial necrosis in group II, III, IV and V. On 28th day, hemodynamic parameters were evaluated, animals were euthanised and heart was excised for measurement of various parameters. In ISO-control rats, there was deterioration of hemodynamic parameters, decreased anti-oxidants levels, increased cardiac injury markers and pro-inflammatory cytokines (TNF-α and IL-6). Also, there was increased level of Bax, Caspase-3, p-JNK, p-38 and NF-κB and decreased expression of Bcl-2 and p-ERK1/2 in ISO-C group. Morin dose-dependently improved hemodynamic profile, increased anti-oxidant levels, normalized myocardial architecture and reduced inflammatory markers and apoptosis. Furthermore, immunoblot analysis of MAPK pathway proteins demonstrated the mechanism responsible for anti-apoptotic and anti-inflammatory potential of morin. Thus, this study substantiated the beneficial effect of Morin by virtue of its modulation of MAPK pathway in myocardial injury.

Mechanisms of DNA damage induced by morin, an inhibitor of amyloid β-peptide aggregation

Morin is a potential inhibitor of amyloid β-peptide aggregation. This aggregation is involved in the pathogenesis of Alzheimer's disease. Meanwhile, morin has been found to be mutagenic and exhibits peroxidation of membrane lipids concurrent with DNA strand breaks in the presence of metal ions. To clarify a molecular mechanism of morin-induced DNA damage, we examined the DNA damage and its site specificity on ³²P-5'-end-labeled human DNA fragments treated with morin plus Cu(II). The formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), an indicator of oxidative DNA damage, was also determined in calf thymus DNA treated with morin plus Cu(II). Morin-induced DNA strand breaks and base modification in the presence of Cu(II) were dose dependent. Morin plus Cu(II) caused piperidine-labile lesions preferentially at thymine and guanine residues. The DNA damage was inhibited by methional, catalase and Cu(I)-chelator bathocuproine. The typical •OH scavengers ethanol, mannitol and sodium formate showed no inhibitory effect on DNA damage induced by morin plus Cu(II). When superoxide dismutase was added to the solution, DNA damage was not inhibited. In addition, morin plus Cu(II) increased 8-oxodG formation in calf thymus DNA fragments. We conclude that morin undergoes autoxidation in the presence of Cu(II) via a Cu(I)/Cu(II) redox cycle and H₂O₂ generation to produce Cu(I)-hydroperoxide, which causes oxidative DNA damage.

Computational and experimental validation of morin as adenosine deaminase inhibitor

Adenosine deaminase (ADA) is one of the major enzymes involved in purin metabolism, it has a significant role in cell growth and differentiation. Over-activity of ADA has been noticed in some pathology, like malignancy and inflammation and makes it an attractive target for the development of drugs for such diseases. In the present study, ADA inhibitory activity of morin, a bioactive flavonoid, was assessed through computational and biophysical methods. The enzyme kinetics data showed that morin is a competitive inhibitor of ADA. Binding energy calculated from ITC analysis was -7.11 kcal/mol. Interaction of morin with ADA was also studied using fluorescence quenching method. Molecular docking studies revealed the structural details of the interaction. Molecular dynamics study in explicit solvent was also conducted to assess the structural stability of protein ligand complex.

Phytochemicals That Influence Gut Microbiota as Prophylactics and for the Treatment of Obesity and Inflammatory Diseases

Gut microbiota (GM) plays several crucial roles in host physiology and influences several relevant functions. In more than one respect, it can be said that you “feed your microbiota and are fed by it.” GM diversity is affected by diet and influences metabolic and immune functions of the host's physiology. Consequently, an imbalance of GM, or dysbiosis, may be the cause or at least may lead to the progression of various pathologies such as infectious diseases, gastrointestinal cancers, inflammatory bowel disease, and even obesity and diabetes. Therefore, GM is an appropriate target for nutritional interventions to improve health. For this reason, phytochemicals that can influence GM have recently been studied as adjuvants for the treatment of obesity and inflammatory diseases. Phytochemicals include prebiotics and probiotics, as well as several chemical compounds such as polyphenols and derivatives, carotenoids, and thiosulfates. The largest group of these comprises polyphenols, which can be subclassified into four main groups: flavonoids (including eight subgroups), phenolic acids (such as curcumin), stilbenoids (such as resveratrol), and lignans. Consequently, in this review, we will present, organize, and discuss the most recent evidence indicating a relationship between the effects of different phytochemicals on GM that affect obesity and/or inflammation, focusing on the effect of approximately 40 different phytochemical compounds that have been chemically identified and that constitute some natural reservoir, such as potential prophylactics, as candidates for the treatment of obesity and inflammatory diseases.

Morin exerts neuroprotection via attenuation of ROS induced oxidative damage and neuroinflammation in experimental diabetic neuropathy

Morin, a bioflavonoid with diverse pharmacological effects against various diseases; in most cases morin protective effects were attributed to its detoxifying effect against reactive oxygen species (ROS). Diabetic neuropathy (DN) is a chronic, debilitating neuronal pain associated with intense generation of free radicals and proinflammatory cytokine accumulation in peripheral neurons. We investigated the pharmacological effect of morin against metabolic excess mediated mitochondrial ROS generation and corresponding effect on Nrf2, NF-κB pathways in Streptozotocin (STZ)-induced diabetic rats and in high glucose insulted Mouse neuroblastoma cell line, Neuro 2A (N2A). Animals were evaluated for nerve function parameters, motor and sensory nerve conduction velocities (MNCV and SNCV) and nerve blood flow (NBF) followed by TUNEL and immunoblot analysis. Mitochondrial function was evaluated by performing JC-1 and MitoSOX assays in high glucose (30 mM) incubated N2A cells. Diabetic animals showed significant impairment in MNCV, SNCV, and NBF as well as increased pain hypersensitivity. However, oral administration of morin at 50 and 100 mg/kg improved SNCV, MNCV, and NBF and reduced sensorimotor alterations (hyperalgesia and allodynia) in diabetic animals. Studies in N2A cells have revealed that morin ameliorated the high glucose-induced mitochondrial superoxide production, membrane depolarization, and total ROS generation. Morin effectively counteracted NF-κB-mediated neuroinflammation by reducing ROS mediated IKK activation and increased Nrf2-mediated antioxidant defenses in high glucose-induced N2A cells. The results of our study suggest that morin has exquisite role in offering neuroprotection in experimental DN and further clinical investigation may reward in finding better alternative for the management of DN. © 2017 BioFactors, 44(2):109-122, 2018.

Nrf2 as a target for prevention of age-related and diabetic cataracts by against oxidative stress

Cataract is one of the most important causes of blindness worldwide, with age-related cataract being the most common one. Agents preventing cataract formation are urgently required. Substantial evidences point out aggravated oxidative stress as a vital factor for cataract formation. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/Kelch-like erythroid-cell-derived protein with CNC homology (ECH)-associated protein 1 (Keap1) system is considered as one of the main cellular defense mechanisms against oxidative stresses. This review discusses the role of Nrf2 pathway in the prevention of cataracts and highlights that Nrf2 suppressors may augment oxidative stress of the lens, and Nrf2 inducers may decrease the oxidative stress and prevent the cataract formation. Thus, Nrf2 may serve as a promising therapeutic target for cataract treatment.

Morin, a novel liver X receptor α/β dual antagonist, has potent therapeutic efficacy for nonalcoholic fatty liver diseases

BACKGROUND AND PURPOSE

Morin is a natural occurring flavonoid in many dietary plants and has a wide range of beneficial effects on metabolism; however, the mechanism underlying its action remains elusive.

EXPERIMENTAL APPROACH

A reporter assay and the time-resolved FRET assay were used to identify morin as a dual antagonist of liver X receptor (LXR)-α and -β. Morin (100 mg^. 100 g^-1 diet) was administered to high-fat diet-induced obese or LXRβ^-/- mice. The pharmacological effects and mechanism of action of morin were evaluated by Western blot and RT-PCR analyses.

KEY RESULTS

From the in vitro assays, morin was shown to be a dual antagonist of LXRα and LXRβ. In vivo, morin blunted the development of liver hepatic steatosis, reduced body weight gains, lowered triglyceride levels and improved glucose and insulin tolerance in mice fed a high-fat diet. Mechanistically, morin inhibited 3T3-L1 adipocyte differentiation and lipid formation in human hepatic HepG2 cells and suppressed the mRNA expression of genes downstream of LXR. Consistently, the effects of morin on metabolic disorders were attenuated in LXRβ^-/- mice.

CONCLUSION AND IMPLICATIONS

Our data reveal that morin is a dual antagonist of LXRα and LXRβ and suggest that morin may alleviate hepatic steatosis and other associated metabolic disorders via the suppression of LXR signalling and, therefore, shows promise as a novel therapy or nutraceutical for nonalcoholic fatty liver disease.