Mangiferin ameliorates aluminium chloride-induced cognitive dysfunction via alleviation of hippocampal oxido-nitrosative stress, proinflammatory cytokines and acetylcholinesterase level

Xanthones as neuroprotective agents: A comprehensive review of their role in the prevention and treatment of neurodegenerative diseases

Over the recent years, numerous research efforts have been focused toward xanthones, a class of heterocyclic compounds characterized by a three-ring core structure and a diverse range of biological activities. Despite extensive studies, no xanthone-based molecule has successfully progressed through clinical trials to reach pharmaceutical applications. Xanthones belong to the class of secondary metabolites that exist naturally, found in various plant species, and their structural diversity has been further expanded through synthetic modifications to enhance their pharmacological efficacy. This review provides a comprehensive description of the therapeutic potential of xanthone derivatives within the scope of neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, and neuroinflammation. Existing literature has been rigorously examined to highlight the pharmacological relevance of xanthones in these disorders. Additionally, the pathophysiological aspects of each disease are discussed in detail to establish a mechanistic understanding of how xanthone derivatives may exert neuroprotective effects. Furthermore, the SAR of xanthones is explored to elucidate key molecular features responsible for their bioactivity, providing insights into rational drug design. By synthesizing and critically analyzing the existing research, this review is focused in highlighting the therapeutic relevance of xanthones in neurodegenerative diseases and their potential as lead candidates for further drug development.

Mangiferin: A natural neuroprotective polyphenol with anti-inflammatory and anti-oxidant properties for depression

Depression is a severe global health problem accompanied by persistent low mood that harms the physical and mental health of people and places a substantial economic burden on society. Mangiferin (MGF), a natural polyphenol in the traditional Chinese herb Anemarrhena asphodeloides Bge., can improve neuronal damage, memory, and cognitive deficits, implicating the therapeutic potential of MGF for depression. MGF has a unique C-glycosyl and phenolic structure that endows it with multiple biological properties, e.g., anti-oxidant, anti-inflammatory, and anti-mitochondrial dysfunction. However, the pharmacological role of MGF in depression remains unclear. Therefore, this review describes the neuroprotective effects and the antidepressant mechanisms of MGF in preclinical depression studies. MGF ameliorates cognitive deficits in depression and neurodegenerative diseases animal models by reducing amyloid-beta deposition, ameliorating cholinergic dysfunction, and increasing neurotrophic factors. Also, MGF regulates molecular mechanisms in depressed animals mainly through anti-inflammation (by inhibiting NLRP3 inflammasome activation, mitogen-activated protein kinase phosphorylation and its downstream nuclear factor-кB signaling pathway, and indoleamine 2,3-dioxygenase activity), anti-oxidant (by increasing levels of anti-oxidant enzymes and inhibiting lipid peroxidation). Notably, the potential mechanisms of MGF in treating depression by modulating neurotransmission (e.g., glutamate, dopamine, norepinephrine, and serotonin) need to be further explored. It is hoped to explore further the potential molecular mechanisms of MGF's biological activity in depression and provide directions for further clinical applications.

Acute Supplementation of Soluble Mango Leaf Extract (Zynamite® S) Improves Mental Performance and Mood: A Randomized, Double-Blind, Placebo-Controlled Crossover Study

Background/Objectives: A mango (Mangifera indica) leaf extract (Zynamite®), rich in the polyphenol mangiferin, has been demonstrated to modulate brain activity, boost cognitive function, and reduce mental fatigue. Research evidence supports that improving the solubility of this extract could significantly enhance its efficacy as an active ingredient. This study examined the effects of a soluble version of Zynamite®, Zynamite® S (Zyn-S), on cognitive function and mood in young adults at low doses. Methods: A total of 119 university students were enrolled in the study. Participants were randomly assigned to receive either 100 mg, 150 mg, or placebo in a double-blind crossover design. Short- and long-term memory were evaluated using the Rey Auditory Verbal Learning Test (RAVLT), executive functions with the Trail Making Test (TMT), processing speed with the Digit Symbol Substitution Test (DSST), and selective attention with the Stroop Color and Word Test. Additionally, mood was assessed using the Spanish short version of the Profile of Mood States (POMS). All these assessments were conducted before taking the product and at 30 min, 3 h, and 5 h post-intake. Results: The results demonstrated that participants who received Zynamite® S experienced significant improvements in reduced tension, depression, and confusion, suggesting an enhancement in mental clarity and overall emotional well-being. Both interventions also improved processing speed and cognitive flexibility. However, no significant differences were observed in short- and long-term verbal memory. Conclusions: In summary, these findings support Zynamite® S as a natural nootropic capable of acutely improving key cognitive functions and emotional balance at low doses in young adults, with sustained efficacy for at least five hours.

WITHDRAWN: In-Depth Analysis of Mangiferin and Its Formulations for Alleviating Neurodegenerative Diseases: A Comprehensive Review

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The effect of azelaic acid on AlCl3-induced neurocognitive impairments and molecular changes in the hippocampus of rats

OBJECTIVES

Cognitive function plays a pivotal role in assessing an individual's quality of life. This research aimed to investigate how azelaic acid (AzA), a natural dicarboxylic acid with antioxidant and anti-inflammatory properties, affects aluminium chloride (AlCl3)-induced behavioural changes and biochemical alterations in the hippocampus of rats.

METHODS

Thirty-two male Wistar rats divided into four groups received distilled water, AzA 50 mg/kg, AlCl3 100 mg/kg and AzA plus AlCl3, respectively, by oral gavage for 6 weeks. Behavioural changes were evaluated using open-field maze, elevated plus maze, novel object recognition (NOR), passive avoidance task, and Morris water maze (MWM) tests. Also, malondialdehyde (MDA), carbonyl protein, tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), nuclear factor-kappa B (NF-κB), C/EBP homologous protein (CHOP), glycogen synthase kinase-3 beta (GSK-3β), brain-derived neurotrophic factor (BDNF) and acetylcholinesterase (AChE) activity were examined.

RESULTS

AzA significantly affected AlCl3-provoked anxiety-like behaviours and learning and memory impairments. It also reduced the toxic effect of AlCl3 on MDA, carbonyl protein, TNF-α, IL-1β, NF-κB and GSK-3β status; however, its beneficial effects on AlCl3-induced changes of CHOP, BDNF and AChE activity were not significant.

CONCLUSION

These findings disclosed that AzA could improve behavioural and cognitive function and almost limit the oxidative stress and neuroinflammation caused by AlCl3.

Rosiridin Protects Against Aluminum Chloride-Induced Memory Impairment via Modulation of BDNF/NFκB/PI3K/Akt Pathway in Rats

Background and Objectives: Rosiridin is a monoterpene with outstanding monoamine inhibitory activity that is useful to treat depressive episodes and rapid-onset dementia. The current investigation aims to evaluate the neurologically protective impact of rosiridin, which opposes aluminum chloride (AlCl3) and causes memory dysfunction in rats. Materials and Methods: Memory impairment was developed in Wistar rats by administering AlCl3 (100 mg/kg p.o.) orally for 42 days and then supplemented with rosiridin at 10 and 20 mg/kg/p.o. Upon completion of the investigation, the behavior factor was performed utilizing the Y-maze, Morris Water Maze, and open field tests. Estimating numerous biological factors, such as nitric oxide (NO), oxidative stress (malondialdehyde MDA), acetylcholinesterase (AChE), butyrylcholinesterase levels (BuChE), antioxidants (glutathione GSH, catalase CAT, and superoxide dismutases SODs) and neurotransmitter (serotonin-5HT, dopamine-DA, acetylcholine-Ach) in the brain. Furthermore, interleukin-6 (IL-6), IL-1β, tumor necrosis factor (TNF-α), brain-derived neurotrophic factor (BNDF), nuclear factor kappa B (NFᴋB), phosphatidylinositol 3-kinase (PI3K), and pAkt were assessed in the diffused brain cells. Results: The rosiridin-treated group significantly improved in terms of behavioral parameters, including in the Y-maze, Morris Water Maze, and open field tests. Further, rosiridin restored biochemical parameters, including NO, oxidative stress AChE, BuChE, antioxidants, neurotransmitters, IL-6, IL-1β, TNF-α, BNDF, NFᴋB, PI3K, and pAkt compared to AlCl3. Conclusions: The current investigation reveals that rosiridin could ameliorate the impairment of memory that AlCl3 causes in rats via improvements in behavioral and restored biochemical parameters.

Mangiferin activates the nuclear factor erythroid 2-related factor pathway to protect SOD1-G93A induced NSC-34 motor neurons from oxidative stress and apoptosis

One of the main factors in the pathophysiology of amyotrophic lateral sclerosis is oxidative stress. Mangiferin (MF), a natural plant polyphenol, has anti-inflammatory and antioxidant effects. The aim of our study was to investigate the protective effects and mechanisms of MF in the hSOD1-G93A ALS cell model. Our result revealed that MF treatment reduced the generation of reactive oxygen species (ROS) and malondialdehyde (MDA), decreased oxidative damage, and reduced apoptosis. Additionally, it was observed that MF significantly increased the synthesis of the antioxidant genes hemeoxygenase-1 and NAD(P)H: quinone oxidoreductase 1, which are downstream of the Nrf2 signaling pathway, and increased the expression and activation of nuclear factor erythroid 2-related factor 2 (Nrf2). Nrf2 knockdown greatly promoted apoptosis, which was reversed by MF treatment. To summarize, MF promoted the Nrf2 pathway and scavenged MDA and ROS to protect the ALS cell model.

The Effect of Trientine on AlCl3-Induced Cognitive Dysfunction and Biochemical Changes in the Hippocampus of Rats

Cognitive impairments affect millions of people worldwide with an increasing prevalence. Research on their etiology and treatment is developing, nevertheless significant gaps remain. Trientine (TETA), as a copper chelator, has been shown to have beneficial effects in different human chronic diseases such as diabetic cardiomyopathy and neuropathy. Here, we examined the impact of TETA on AlCl3-induced neurocognitive dysfunctions and molecular changes in the hippocampus of rats.Thirty-six male Wistar rats (weighing 200-250 g) were randomly divided into four groups including control, TETA (100 mg/kg/day), AlCl3 (100 mg/kg/day), and AlCl3 (100 mg/kg/day)+TETA (100 mg/kg/day), and received chemicals by gavage for 30 days. At the end of the treatment, the open field maze, elevated plus maze, novel object recognition memory test, and shuttle box test were done. Then after, brain-derived neurotrophic factor (BDNF), glycogen synthase kinase-3 β (GSK-3β), acetylcholinesterase activity, oxidative stress markers, and inflammatory mediators were measured in the hippocampus.AlCl3 increased anxiety-like behaviors and impaired recognition and short-term memory. TETA was able to improve AlCl3-induced anxiety-like behaviors and short-term memory dysfunction. In the AlCl3-treated group, there was a significant increase in GSK-3β, oxidative stress, pro-inflammatory and pro-apoptotic markers, and decreased BDNF in the hippocampus. Co-administration of TETA was able to decrease lipid peroxidation, inflammation, GSK-3β, and acetylcholinesterase activity, and increase BDNF in the hippocampus compared with AlCl3-treated rats.It can be concluded that TETA was able to improve neurobehavioral and neurocognitive functions by alleviating oxidative stress, inflammation, and pro-apoptotic pathways leading to the normalization of BDNF and GSK-3β.

Phenolic content of Thai Bao mango peel and its in-vitro antioxidant, anti-cholinesterase, and antidiabetic activities

Plant phenolics have been known for various biological activities. This study aims to extract and examine the presence of phenolics in Bao mango (Mangifera indica L. var.) peel ethanolic extract (MPE). Further, antioxidant, anti-diabetic (α-amylase, and α-glucosidase inhibitory activity), and anti- Alzheimer's disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase (BACE-1) inhibitory activity) efficacy of MPE were determined. The results indicated that mangiferin (8755.89 mg/ 100 g extract) was the major phenolic compound in MPE. An antioxidant mechanism revealed that MPE had a higher radical scavenging ability (4266.70 µmol TE/g extract) compared to reducing power (FRAP) or oxygen radical absorption capacity (ORAC). Further in-vitro enzyme inhibitory assay against diabetic and AD involved enzymes showed that MPE had stronger inhibitory action against an enzyme involved in diabetes compared to their standard drug (Acarbose) (P < 0.05). While a lower IC50 value was observed against AD-involved enzymes compared to their standard drug (donepezil) (P < 0.05). The results show that Thai Bao mango peel byproduct can be a potential source of nutraceuticals to lower diabetes and improve cognitive health.

Acute effects of mango leaf extract on cognitive function in healthy adults: a randomised, double-blind, placebo-controlled crossover study

Introduction

Extracts made from the leaves of the edible mango plant (Mangifera indica L., Anacardiaceae) have a long history of medicinal usage, most likely due to the presence of high levels of mangiferin, a polyphenol compound. Previous research has demonstrated that mango leaf extract (MLE) can beneficially modulate cognitive function in both animals and humans. This study aimed to assess the effects of an acute dose of 300 mg MLE (standardised to contain ≥60% mangiferin) on cognitive performance and mood in healthy adults.

Methods

In this double-blind, placebo-controlled, crossover study, 114 healthy men and women (18-43 years) received either MLE or a matched placebo at each testing visit (separated by at least 7 days). Cognitive performance (including the cognitive demand battery) and mood were measured at 30, 180, and 300 min post-dose.

Results

The results showed that, compared to placebo, the group taking MLE displayed a significant increase in serial 3 s and serial 7 s subtraction errors overall. There were no other significant effects on cognitive performance.

Discussion

The results of the current study suggest that the consumption of 300 mg MLE in the absence of an observed multitasking psychological stressor does not improve cognitive performance or mood at up to 300 min post-dose. Due to the very limited nature of the effects and since they were observed among many analyses, these findings should be treated with caution.Clinical trial registration: http://ClinicalTrials.gov, identifier [NCT05182450].

Pharmacological properties of mangiferin: bioavailability, mechanisms of action and clinical perspectives

This review aims to provide an in-depth analysis of the pharmacological properties of mangiferin, focusing primarily on its bioavailability and mechanisms of action, and its potential therapeutic applications, especially in the context of chronic diseases. We conducted a comprehensive examination of in vitro and in vivo studies, as well as clinical trials involving mangiferin or plant extracts containing mangiferin. The primary source of mangiferin is Mangifera indica, but it's also found in other plant species from the families Anacardiaceae, Gentianaceae, and Iridaceae. Mangiferin has exhibited a myriad of therapeutic properties, presenting itself as a promising candidate for treating various chronic conditions including neurodegenerative disorders, cardiovascular diseases, renal and pulmonary diseases, diabetes, and obesity. Despite the promising results showcased in many in vitro studies and certain animal studies, the application of mangiferin has been limited due to its poor solubility, absorption, and overall bioavailability. Mangiferin offers significant therapeutic potential in treating a spectrum of chronic diseases, as evidenced by both in vitro and clinical trials. However, the challenges concerning its bioavailability necessitate further research, particularly in optimizing its delivery and absorption, to harness its full medicinal potential. This review serves as a comprehensive update on the health-promoting and therapeutic activities of mangiferin.

A supercritical fluid co-extract of turmeric powder and dried coconut shreds shows neuroprotection against AlCl3-induced Alzheimer's disease in rats through nose to brain delivery

This study was aimed at investigating the neuroprotective potential of a co-extract obtained by supercritical fluid extraction (SFE) of turmeric powder and dried coconut shreds against aluminium chloride (AlCl3)-induced Alzheimer's disease (AD) in male Wistar rats. Fifty animals were allocated to five groups, which received saline (vehicle control, group 1), a combination of saline and aluminium chloride (AlCl3) (disease control, group 2), coconut oil (COO) (SFE extracted, treatment group 3), turmeric oleoresin (Cur) (SFE extracted, treatment group 4) and SFE co-extract of turmeric powder and coconut shreds (CurCOO) (treatment group 5). Animals were subjected to behavioural evaluation. In addition, the hippocampal section of the brain from all groups was subjected to biochemical, molecular and histopathological evaluations. The results showed CurCOO administered intranasally improved cognitive abilities, reversed histological alterations in the brain, reduced hippocampus inflammation studied through proinflammatory cytokine markers like TNF-α and IL-6 as compared to the disease control group. The impact of CurCOO on preventive neurodegeneration was also observed through a reduction in protein transcription factor NF-kB in the treated group 5 as compared to a disease control group. The effect of intranasal delivery of CurCOO on the neurons responsible for memory consolidation was evident from low acetylcholinesterase (AChE) enzyme activity in the treated groups with respect to AlCl3 induced group. Summarily, the results demonstrated intranasal delivery of CurCOO to show better efficacy than Cur and COO in preventing neurodegeneration associated with AlCl3 induced Alzheimer's disease.

C-Glucosyl Xanthone derivative Mangiferin downregulates the JNK3 mediated caspase activation in Almal induced neurotoxicity in differentiated SHSY-5Y neuroblastoma cells

INTRODUCTION

C-Glucosyl Xanthone derivatives were assessed to inhibit the JNK3 mediated Caspase pathway in Almal (Aluminum Maltolate) induced neurotoxicity in SHSY-5Y cells.

METHODS

Mangiferin was selected among 200 C-Glucosyl Xanthones based on molecular interaction, docking score (-10.22 kcal/mol), binding free energy (-71.12 kcal/mol), ADME/tox properties and by molecular dynamic studies. Further, it was noticed that glycone moiety of Mangiferin forms H-bond with ASN 194, SER 193, GLY 76, and OH group in the first position of the aglycone moiety shows interaction at Met 149 which is exceptionally crucial for JNK3 inhibitory activity.

RESULTS AND DISCUSSION

Mangiferin (0.5, 1, 10, 20 and 30 µM) and standard SP600125 (20 µM) treatment increased the cell survival rate against Almal 200 µM, with EC50 of Mangiferin (8 µM) and standard SP600125 (4.9 µM) respectively. Mangiferin significantly impedes kinase activation, indicating suppression of JNK3 signaling with IC50 (98.26 nM). Mangiferin (10 and 15 µM) dose-dependently inhibits the caspase 3, 8, and 9 enzyme activation in comparison to Almal group.

CONCLUSION

Mangiferin demonstrated neuroprotection in SHSY-5Y cells against apoptosis induced by Almal by adapting the architecture of the neurons and increasing their density. Among all Xanthone derivatives, Mangiferin could improve neuronal toxicity by inhibiting JNK3 and down-regulating the Caspase activation.

Neuroprotective effect of quercetin nanoparticles: A possible prophylactic effect in cerebellar neurodegenerative disorders

Memory deficit, anxiety, coordination deficit and depression are common neurological disorders attributed to aluminum (Al) buildup in the nervous system. Quercetin nanoparticles (QNPs) are a newly developed effective neuroprotectant. We aimed to investigate the potential protective and therapeutic effects of QNPs in Al induced toxicity in rat cerebellum. A rat model of Al-induced cerebellar damage was created by AlCl3 (100 mg/kg) administration orally for 42 days. QNPs (30 mg/kg) was administered for 42-days as a prophylactic (along with AlCl3 administration) or therapeutic for 42-days (following AlCl3 induced cerebellar damage). Cerebellar tissues were assessed for structural and molecular changes. The results showed that Al induced profound cerebellar structural and molecular changes, including neuronal damage, astrogliosis and tyrosine hydroxylase downregulation. Prophylactic QNPs significantly reduced Al induced cerebellar neuronal degeneration. QNPs is a promising neuroprotectant that can be used in elderly and vulnerable subjects to protect against neurological deterioration. It could be a promising new line for therapeutic intervention in neurodegenerative diseases.

Neuroprotective potency of mangiferin against 3-nitropropionic acid induced Huntington's disease-like symptoms in rats: possible antioxidant and anti-inflammatory mechanisms

Huntington's disease (HD), a neurodegenerative disease, normally starts in the prime of adult life, followed by a gradual occurrence of psychiatric disturbances, cognitive and motor dysfunction. The daily performances and life quality of HD patients have been severely interfered by these clinical signs and symptoms until the last stage of neuronal cell death. To the best of our knowledge, no treatment is available to completely mitigate the progression of HD. Mangiferin, a naturally occurring potent glucoxilxanthone, is mainly isolated from the Mangifera indica plant. Considerable studies have confirmed the medicinal benefits of mangiferin against memory and cognitive impairment in neurodegenerative experimental models such as Alzheimer's and Parkinson's diseases. Therefore, this study aims to evaluate the neuroprotective effect of mangiferin against 3-nitropropionic acid (3-NP) induced HD in rat models. Adult Wistar rats (n = 32) were randomly allocated equally into four groups of eight rats each: normal control (Group I), disease control (Group II) and two treatment groups (Group III and Group IV). Treatment with mangiferin (10 and 20 mg/kg, p. o.) was given for 14 days, whereas 3-NP (15 mg/kg, i. p.) was given for 7 days to induce HD-like symptoms in rats. Rats were assessed for cognitive functions and motor coordination using open field test (OFT), novel object recognition (NOR) test, neurological assessment, rotarod and grip strength tests. Biochemical parameters such as oxidative stress markers and pro-inflammatory markers in brain hippocampus, striatum and cortex regions were evaluated. Histopathological study on brain tissue was also conducted using hematoxylin and eosin (H&E) staining. 3-NP triggered anxiety, decreased recognition memory, reduced locomotor activity, lower neurological scoring, declined rotarod performance and grip strength were alleviated by mangiferin treatment. Further, a significant depletion in brain malondialdehyde (MDA) level, an increase in reduced glutathione (GSH) level, succinate dehydrogenase (SDH), superoxide dismutase (SOD) and catalase (CAT) activities, and a decrease in tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) levels were observed in mangiferin treated groups. Mangiferin also mitigated 3-NP induced histopathological alteration in the brain hippocampus, striatum and cortex sections. It could be inferred that mangiferin protects the brain against oxidative damage and neuroinflammation, notably via antioxidant and anti-inflammatory activities. Mangiferin, which has a good safety profile, may be an alternate treatment option for treating HD and other neurodegenerative disorders. The results of the current research of mangiferin will open up new avenues for the development of safe and effective therapeutic agents in diminishing HD.

Natural activators of AMPK signaling: potential role in the management of type-2 diabetes

Adenosine 5'-monophosphate-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase involved in the homeostasis of cellular energy. AMPK has developed as an appealing clinical target for the diagnosis of multiple metabolic diseases such as diabetes mellitus, obesity, inflammation, and cancer. Genetic and pharmacological studies indicate that AMPK is needed in response to glucose deficiency, dietary restriction, and increased physical activity for preserving glucose homeostasis. After activation, AMPK influences metabolic mechanisms contributing to enhanced ATP production, thus growing processes that absorb ATP simultaneously. In this review, several natural products have been discussed which enhance the sensitivity of AMPK and alleviate sub complications or different pathways by which such AMPK triggers can be addressed. AMPK Natural products as potential AMPK activators can be developed as alternate pharmacological intervention to reverse metabolic disorders including type 2 diabetes.

The Protective Effect of Mangiferin on Formaldehyde-Induced HT22 Cell Damage and Cognitive Impairment

Formaldehyde (FA) has been found to induce major Alzheimer's disease (AD)-like features including cognitive impairment, Aβ deposition, and Tau hyperphosphorylation, suggesting that it may play a significant role in the initiation and progression of AD. Therefore, elucidating the mechanism underlying FA-induced neurotoxicity is crucial for exploring more comprehensive approaches to delay or prevent the development of AD. Mangiferin (MGF) is a natural C-glucosyl-xanthone with promising neuroprotective effects, and is considered to have potential in the treatment of AD. The present study was designed to characterize the effects and mechanisms by which MGF protects against FA-induced neurotoxicity. The results in murine hippocampal cells (HT22) revealed that co-treatment with MGF significantly decreased FA-induced cytotoxicity and inhibited Tau hyperphosphorylation in a dose-dependent manner. It was further found that these protective effects were achieved by attenuating FA-induced endoplasmic reticulum stress (ERS), as indicated by the inhibition of the ERS markers, GRP78 and CHOP, and downstream Tau-associated kinases (GSK-3β and CaMKII) expression. In addition, MGF markedly inhibited FA-induced oxidative damage, including Ca2+ overload, ROS generation, and mitochondrial dysfunction, all of which are associated with ERS. Further studies showed that the intragastric administration of 40 mg/kg/day MGF for 6 weeks significantly improved spatial learning ability and long-term memory in C57/BL6 mice with FA-induced cognitive impairment by reducing Tau hyperphosphorylation and the expression of GRP78, GSK-3β, and CaMKII in the brains. Taken together, these findings provide the first evidence that MGF exerts a significant neuroprotective effect against FA-induced damage and ameliorates mice cognitive impairment, the possible underlying mechanisms of which are expected to provide a novel basis for the treatment of AD and diseases caused by FA pollution.

Mangiferin depresses vesicular glutamate release in synaptosomes from the rat cerebral cortex by decreasing synapsin I phosphorylation

Mangiferin is a glucosyl xanthone that has been shown to be a neuroprotective agent against brain disorders involving excess glutamate. However, the effect of mangiferin on the function of the glutamatergic system has not been investigated. In this study, we used synaptosomes from the rat cerebral cortex to investigate the effect of mangiferin on glutamate release and identify the possible underlying mechanism. We observed that mangiferin produced a concentration-dependent reduction in the release of glutamate elicited by 4-aminopyridine with an IC₅₀ value of 25 μM. Inhibition of glutamate release was blocked by removing extracellular calcium and by treatment with the vacuolar-type H⁺-ATPase inhibitor bafilomycin A1, which prevents the uptake and storage of glutamate in vesicles. Moreover, we showed that mangiferin decreased the 4-aminopyridine-elicited FM1-43 release and synaptotagmin 1 luminal domain antibody (syt1-L ab) uptake from synaptosomes, which correlated with decreased synaptic vesicle exocytosis. Transmission electron microscopy in synaptosomes also showed that mangiferin attenuated the 4-aminopyridine-elicited decrease in the number of synaptic vesicles. In addition, antagonism of Ca²⁺/calmodulin-dependent kinase II (CaMKII) and protein kinase A (PKA) counteracted mangiferin's effect on glutamate release. Mangiferin also decreased the phosphorylation of CaMKII, PKA, and synapsin I elicited by 4-aminopyridine treatment. Our data suggest that mangiferin reduces PKA and CaMKII activation and synapsin I phosphorylation, which could decrease synaptic vesicle availability and lead to a subsequent reduction in vesicular glutamate release from synaptosomes.

Neuro-amelioration of Ficus lyrata (fiddle-leaf fig) extract conjugated with selenium nanoparticles against aluminium toxicity in rat brain: relevance to neurotransmitters, oxidative, inflammatory, and apoptotic events

Aluminium is a non-essential metal, and its accumulation in the brain is linked with potent neurotoxic action and the development of many neurological diseases. This investigation, therefore, intended to examine the antagonistic efficacy of Ficus lyrata (fiddle-leaf fig) extract (FLE) conjugated with selenium nanoparticles (FLE-SeNPs) against aluminium chloride (AlCl3)-induced hippocampal injury in rats. Rats were allocated to five groups: control, FLE, AlCl3 (100 mg/kg), AlCl3 + FLE (100 mg/kg), and AlCl3 + FLE-SeNPs (0.5 mg/kg). All agents were administered orally every day for 42 days. The result revealed that pre-treated rats with FLE-SeNPs showed markedly lower acetylcholinesterase and Na+/K+-ATPase activities in the hippocampus than those in AlCl3 group. Additionally, FLE-SeNPs counteracted the oxidant stress-mediated by AlCl3 by increasing superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione contents in rat hippocampus. Besides, the formulated nanoparticles decreased the hippocampal malondialdehyde, carbonyl protein, and nitric oxide levels of AlCl3-exposed animals. Furthermore, FLE-SeNPs attenuated neural tissue inflammation, as demonstrated by decreased interleukin-1 beta, interleukin-6, nuclear factor kappa B, and glial fibrillary acidic protein. Remarkable anti-apoptotic action was exerted by FLE-SeNPs by increasing B cell lymphoma 2 and decreasing caspase-3 and Bcl-2-associated-X protein in AlCl3-exposed rats. The abovementioned results correlated well with the hippocampal histopathological findings. Given these results, SeNPs synthesized with FLE imparted a remarkable neuroprotective action against AlCl3-induced neurotoxicity by reversing oxidative damage, neuronal inflammation, and apoptosis in exposed rats.

Comprehensive Profiling of Mangiferin Metabolites In Vivo and In Vitro Based on the "Drug Metabolite Clusters" Analytical Strategy

Mangiferin, a natural flavonoid compound with multiple biological activities (e.g., anti-inflammatory, anti-oxidant, anti-diabetic, and anti-tumor), has gained increased research interest in recent years. Nevertheless, the metabolic processing of mangiferin has not been fully investigated. In this study, a rapid and efficient analytical strategy named "Drug Metabolite Clusters" was applied for comprehensive profiling of mangiferin metabolites in rat plasma, urine, and feces samples in vivo following oral administration and liver microsomes in vitro. First, the biological samples were pretreated with methanol, acetonitrile, and solid phase extraction (SPE) for further liquid chromatography-mass spectrometry (LC-MS) analysis. Second, the raw data were acquired using ultra-high performance liquid chromatography quadrupole exactive orbitrap high-resolution mass spectrometry (UHPLC-Q-Exactive Orbitrap HRMS) under the positive and negative full-scan/dd MS² modes. Third, mangiferin and its basic metabolites (norathyriol, trihydroxyxanthone, and dihydroxyxanthone) were selected as mangiferin metabolite cluster centers by referring to the relevant literature. Subsequently, according to the pyrolysis law of mass spectrometry, literature reports, and reference material comparison, especially the diagnostic product ions (DPIs), the candidate metabolites were accurately preliminarily identified, and mangiferin metabolite clusters based on metabolite cluster center changes were formed. As a result, a total of 67 mangiferin metabolites (mangiferin included) were detected, including 29 in plasma, 48 in urine, 12 in feces, and 6 in liver microsomes. Among them, trihydroxyxanthones were first detected in rat urine samples after oral mangiferin. We found that mangiferin mainly underwent deglucosylation, dehydroxylation, methylation, glucuronidation, sulfation, and other composite reactions in rats. Herein, we have elucidated the metabolites and metabolic pathways of mangiferin in vivo and in vitro, which provided an essential theoretical basis for further pharmacological studies of mangiferin and a comprehensive research method for the identification of drug metabolites.

Neuroprotective Efficacy of Edaravone against Arsenic-Induced Behavioral and Neurochemical Deficits in Rats: Amelioration of Cholinergic and Mitochondrial Functions

BACKGROUND

A substantial amount of evidence indicates that long-term arsenic exposure leads to various types of pathological complications, especially cognitive dysfunction.

OBJECTIVE

The present study was designed to assess the neuroprotective potential of edaravone (a potent free radical scavenger) against arsenic-induced neurotoxicity in Wistar rats.

METHODS

Adult male Wistar rats were randomly divided into five groups. Arsenic (20 mg/kg/day; p.o.) and Edaravone (5 and 10 mg/kg/day; i.p.) were administered in different experimental groups for 28 days.

RESULTS

The results of various behavioral test paradigms revealed that arsenic caused significant learning and memory deficits, along with anxiety-like behavior. In biochemical analysis, we found marked elevations of oxidative-nitrosative stress (indicated by augmentation of lipid peroxidation and nitrite) and a reduction of glutathione levels in the hippocampus and frontal cortex region of arsenictreated rats. Moreover, arsenic administration caused mitochondrial complexes impairment and reduction of acetylcholinesterase level. On the other hand, chronic treatment with edaravone (10 mg/kg) significantly ameliorated the arsenic-induced behavioral deficits and neurochemical anomalies.

CONCLUSION

This study suggests that edaravone confers neuroprotection against arsenic-induced memory impairment and anxiety-like behavior, which may be attributed to the inhibition of oxidativenitrosative stress and amelioration of cholinergic and mitochondrial functions.

Antidepressant-Like Effects of Edaravone and Minocycline: Investigation of Oxidative Stress, Neuroinflammation, Neurotrophic, and Apoptotic Pathways

Depression is a very common mental disorder and mechanism that is associated with mitochondrial dysfunction. In the present study, we examined the mechanisms of action of isolated brain mitochondria in rats with depression for the first time. This will help identify the mitochondrial protective pathways of the two drugs and shed light on new therapeutic goals for developing antidepressants. Forced swimming, tail suspension, and sucrose preference tests were used to assess depressive-like behaviors and the oxidative stress factors of brain tissue, and measure the gene expression of apoptotic and anti-apoptotic, neuroplasticity, and neuroinflammatory factors by RT-PCR and acetylcholinesterase (AChE) activity in brain tissue (hippocampus and prefrontal) and the serum levels of corticosterone and fasting blood sugar. The results showed that the separation of neonatal rats from their mothers induced depressive-like behaviors, weight loss, mitochondrial dysfunction, increased expression of genes involved in neuroinflammation, apoptosis, genes involved in the depressive process, and decreased expression of genes involved in mood in both the hippocampus and prefrontal cortex. Maternal separation increased serum corticosterone levels, caused dysfunction of the cholinergic system, and also increased AChE activity. Treatment with different concentrations of minocycline and edaravone (1, 20, and 50 mg/kg), 5MTHF, and citalopram for 14 days showed that these drugs improved depression-like behaviors and mitochondrial function. It also reduced the expression of genes involved in neuroinflammation, apoptosis, and depression and increased the expression of genes involved in mood. In conclusion, minocycline and edaravone have neuroprotective, mitochondrial protective, antioxidant, anti-inflammatory, and anti-apoptotic effects against depressive-like behaviors caused by chronic stress.

Progress in the development of naturally derived active metabolites-based drugs: Potential therapeutics for Alzheimer's disease

Alzheimer's disease (AD) is an extensive age-associated neurodegenerative disorder. In spite of wide-ranging progress in understanding the AD pathology for the past 50 years, clinical trials based on the hypothesis of amyloid-beta (Aβ) have reserved worsening particularly at late-stage human trials. Consequently, very few old drugs are presently used for AD with inadequate clinical consequences and various side effects. We focus on widespread pharmacological and beneficial principles for existing as well as future drugs. Multitargeting approaches by means of general antioxidant and anti-inflammatory mechanisms allied with particular receptor and/or enzyme-mediated actions in neuroprotection and neurodegeneration. The plant kingdom comprises a vast range of species with an incredible diversity of bioactive metabolites with diverse chemical scaffolds. In recent times, an increasing body of facts recommended the use of phytochemicals to decelerate AD's onset and progression. The definitive goal of AD investigation is to avert the onset of neurodegeneration, thereby allowing successful aging devoid of cognitive decline. At this point, we discussed the neurological protective role of natural products and naturally derived therapeutic agents for AD from various natural polyphenolic compounds and medicinal plants. In conclusion, medicinal plants act as a chief source of different bioactive constituents.

Molecular dynamics and structure-based virtual screening and identification of natural compounds as Wnt signaling modulators: possible therapeutics for Alzheimer's disease

Wnt signaling pathway is an evolutionarily conserved pathway responsible for neurogenesis, axon outgrowth, neuronal polarity, synapse formation, and maintenance. Downregulation of Wnt signaling has been found in patients with Alzheimer's disease (AD). Several experimental approaches to activate Wnt signaling pathway have proven to be beneficial in alleviating AD, which is one of the new therapeutic approaches for AD. The current study focuses on the computational structure-based virtual screening followed by the identification of potential phytomolecules targeting different markers of Wnt signaling like WIF1, DKK1, LRP6, GSK-3β, and acetylcholine esterase. Initially, screening of 1924 compounds from the plant-based library of Zinc database was done for the selected five proteins using docking approach followed by MM-GBSA calculations. The top five hit molecules were identified for each protein. Based on docking score, and binding interactions, the top two hit molecules for each protein were selected as promising molecules for the molecular dynamic (MD) simulation study with the five proteins. Therefore, from this in silico based study, we report that Mangiferin could be a potential molecule targeting Wnt signaling pathway modulating the LRP6 activity, Baicalin for AChE activity, Chebulic acid for DKK1, ZINC103539689 for WIF1, and Morin for GSk-3β protein. However, further validation of the activity is warranted based on in vivo and in vitro experiments for better understanding and strong claim. This study provides an in silico approach for the identification of modulators of the Wnt signaling pathway as a new therapeutic approach for AD.

Antiamnesic Potential of Malvidin on Aluminum Chloride Activated by the Free Radical Scavenging Property

Objectives: Malvidin, a dietary anthocyanin can be a potent drug for the treatment of neuronal toxicity. The investigation was aimed to study the antioxidant role of malvidin against aluminum chloride (AlCl₃)-induced neurotoxicity in rats. Methods: To evaluate the neuroprotective role of malvidin, the rats were divided into four different groups: group I received saline, group II received AlCl₃, and groups III and IV were administered with 100 and 200 mg/kg malvidin after AlCl₃ for 60 days. During the evaluation period, all the groups were subjected to a behavioral test. On the 61st day of the study, rat brains were removed and used for a neurochemical assay. Results: From the present study, malvidin ameliorated the effects of AlCl₃ on behavioral parameters. Biochemical investigation revealed that oral treatment of malvidin shows neuroprotective effects through regulation of antioxidant levels and neuroinflammation in the AlCl₃-exposed rats. Conclusion: The results indicate that malvidin possesses antioxidant activity via acetylcholinesterase inhibition and regulation of oxidative stress in neuronal cells. Hence, malvidin could be a potential drug in correcting Alzheimer's disease.

Neuroprotective effect of Bryophyllum pinnatum flavonoids against aluminum chloride-induced neurotoxicity in rats

Toxic metals such as aluminum accumulation in the brain have been associated with the pathophysiology of several neurodegenerative disorders. Bryophyllum pinnatum leaves contain a vast array of polyphenols, particularly flavonoids, that may play a role in the prevention of toxic and degenerative effects in the brain. This study assessed the neuro-restorative potential of leaves of B. pinnatum enriched flavonoid fraction (BPFRF) in aluminum-induced neurotoxicity in rats. Neurotoxicity was induced in male Wistar rats by oral administration of 150 mg/kg body weight of aluminum chloride (AlCl₃) for 21 days. Rats were grouped into five (n = 6); Control (untreated), Rivastigmine group, AlCl₃ group and BPFRF group (50 and 100 mg/kg b.wt.) for 21 days. Neuronal changes in the hippocampus and cortex were biochemically and histologically evaluated. Expression patterns of acetylcholinesterase (AChE) mRNA were assessed using semi-quantitative reverse-transcription-polymerase chain reaction protocols. Molecular interactions of BPFRF compounds were investigated in silico. The results revealed that oral administration of BPFRF ameliorated oxidative imbalance by augmenting antioxidant systems and decreasing lipid peroxidation caused by AlCl₃. BPFRF administration also contributed to the down-regulation of AChE mRNA transcripts and improved histological features in the hippocampus and cortex. Molecular docking studies revealed strong molecular interactions between BPFRF compounds, catalase, superoxide dismutase and glutathione peroxidase Overall, these findings suggest the neuroprotective effect of Bryophyllum pinnatum against aluminum-induced neurotoxicity.

SIRT1/PGC-1α signaling activation by mangiferin attenuates cerebral hypoxia/reoxygenation injury in neuroblastoma cells

Ischemia reperfusion injury (IRI) is associated with poor prognoses in the setting of ischemic brain diseases. Silence information regulator 1 (SIRT1) is a member of the third class of nicotinamide adenine dinucleotide (NAD+)-dependent sirtuins. Recently, the role of SIRT1/peroxisome proliferators-activated receptor-γ coactivator 1α (PGC-1α) pathway in organ (especially the brain) protection under various pathological conditions has been widely investigated. Mangiferin (MGF), a natural C-glucosyl xanthone polyhydroxy polyphenol, has been shown to be beneficial to several nervous system diseases and the protective effects of MGF can be achieved through the regulation of SIRT1 signaling. This study is designed to investigate the protective effects of MGF treatment in the setting of cerebral IRI and to elucidate the potential mechanisms. We first evaluated the toxicity of MGF and chose the safe concentrations for the following experiments. MGF exerted obvious neuroprotection against hypoxia/reoxygenation (HR)-induced injury, indicated by restored cell viability and cell morphology, decreased lactate dehydrogenase (LDH) release and reactive oxygen species generation. MGF also restored the protein expressions of SIRT1, PGC-1α, Nrf2, NQO1, HO-1, NRF1, UCP2, and Bcl2 down-regulated by HR treatment. However, SIRT1 siRNA could reverse MGF-induced neuroprotection and decrease the expressions of molecules mentioned above. Taken together, our findings suggest that MGF treatment exerts neuroprotection against HR injury via activating SIRT1/PGC-1α signaling. These findings may provide a theoretical basis for the exploitation of MGF as a potential neuroprotective drug candidate, which may be beneficial for the ischemic stroke patients in clinic.

The Protection of Lactic Acid Bacteria Fermented-Mango Peel against Neuronal Damage Induced by Amyloid-Beta

Mango peels are usually discarded as waste; however, they contain phytochemicals and could provide functional properties to food and promote human health. This study aimed to determine the optimal lactic acid bacteria for fermentation of mango peel and evaluate the effect of mango peel on neuronal protection in Neuron-2A cells against amyloid beta (Aβ) treatment (50 μM). Mango peel can be fermented by different lactic acid bacteria species. Lactobacillus acidophilus (BCRC14079)-fermented mango peel produced the highest concentration of lactic acid bacteria (exceeding 10⁸ CFU/mL). Mango peel and fermented mango peel extracts upregulated brain-derived neurotrophic factor (BDNF) expression for 1.74-fold in Neuron-2A cells. Furthermore, mango peel fermented products attenuated oxidative stress in Aβ-treated neural cells by 27%. Extracts of L. acidophilus (BCRC14079)-fermented mango peel treatment decreased Aβ accumulation and attenuated the increase of subG1 caused by Aβ induction in Neuron-2A cells. In conclusion, L. acidophilus (BCRC14079)-fermented mango peel acts as a novel neuronal protective product by inhibiting oxidative stress and increasing BDNF expression in neural cells.

Environmental toxicants, oxidative stress and health adversities: interventions of phytochemicals

OBJECTIVES

Oxidative stress is the most common factor mediating environmental chemical-induced health adversities. Recently, an exponential rise in the use of phytochemicals as an alternative therapeutics against oxidative stress-mediated diseases has been documented. Due to their free radical quenching property, plant-derived natural products have gained substantial attention as a therapeutic agent in environmental toxicology. The present review aimed to describe the therapeutic role of phytochemicals in mitigating environmental toxicant-mediated sub-cellular and organ toxicities via controlling cellular antioxidant response.

METHODS

The present review has covered the recently related studies, mainly focussing on the free radical scavenging role of phytochemicals in environmental toxicology.

KEY FINDINGS

In vitro and in vivo studies have reported that supplementation of antioxidant-rich compounds can ameliorate the toxicant-induced oxidative stress, thereby improving the health conditions. Improving the cellular antioxidant pool has been considered as a mode of action of phytochemicals. However, the other cellular targets of phytochemicals remain uncertain.

CONCLUSIONS

Knowing the therapeutic value of phytochemicals to mitigate the chemical-induced toxicity is an initial stage; mechanistic understanding needs to decipher for development as therapeutics. Moreover, examining the efficacy of phytochemicals against mixer toxicity and identifying the bioactive molecule are major challenges in the field.

Neuroprotective mechanisms of mangiferin in neurodegenerative diseases

The central nervous system (CNS) regulates and coordinates an extensive array of complex processes requiring harmonious regulation of specific genes. CNS disorders represent a large burden on society and cause enormous disability and economic losses. Traditional Chinese medicine (TCM) has been used for many years in the treatment of neurological illnesses, such as Alzheimer's disease, Parkinson's disease, stroke, and depression, as the combination of TCM and Western medicine has superior therapeutic efficacy and minimal toxic side effects. Mangiferin (MGF) is an active compound of the traditional Chinese herb rhizome anemarrhenae, which has antioxidant, anti-inflammation, anti-lipid peroxidation, immunomodulatory, and anti-apoptotic functions in the CNS. MGF has been demonstrated to have therapeutic effects in CNS diseases through a multitude of mechanisms. This review outlines the latest research on the neuroprotective ability of MGF and the diverse molecular mechanisms involved.

Neuropharmacological studies of ethanolic extract of Vaccinium corymbosum on Alzheimer’s type dementia and catatonia in Swiss albino mice

Introduction: Neuroactive herbal drugs enriched with antioxidants are valuable in treating neurocognitive dysfunction and Vaccinium corymbosum, enriched with antioxidant phytochemicals, is used for treating memory disorders. Hence, the present study evaluated the neuroprotective effects of ethanolic extract of Vaccinium corymbosum (EEVC) on aluminium chloride(AlCl3)-induced Alzheimer’s type of dementia and haloperidol-induced catalepsy-associated behavioural changes. Methods:In vitro antioxidant potential was evaluated using 1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The total phenolic content (TPC) was quantified. For in vivo studies, AlCl3 (100 mg/kg) was orally administered for 42 days, whereas the EEVC was administered on the 21st day until the 42nd day in two doses (200 mg/kg and 400 mg/kg). In the haloperidol-induced group, EEVC was treated for 21 days, and haloperidol (1 mg/kg) was administered to induce behavioural changes. Open-field, Y-Maze and traction tests were performed, and the mice brain acetylcholinesterase (AChE) enzyme was determined. Results: IC50 values in DPPH and ABTS assays were 85.5 μg/mL and 80 μg/mL, respectively and the total phenolic content of EEVC was found to be 0.166 mg. In a behavioral study, animals treated with 200 mg/kg and 400 mg/kg of EEVC exhibited a neuroprotective impact on AlCl3-induced neurodegeneration and haloperidol-induced behavioral changes with significant inhibition (P < 0.05 and P < 0.01, respectively) in acetylcholinesterase enzyme. Conclusion: The neuroprotection by EEVC postulated that it is a promising therapeutic agent for treating behavioral and cognitive dysfunctions. Further investigations on pro-inflammatory cytokine and neuroendocrine regulation in transgenic Alzheimer’s disease (AD)models complement the therapeutic value of V. corymbosum.

Therapeutic potential of mangiferin in the treatment of various neuropsychiatric and neurodegenerative disorders

Xanthones are important chemical class of bioactive products that confers therapeutic benefits. Of several xanthones, mangiferin is known to be distributed widely across several fruits, vegetables and medicinal plants. Mangiferin has been shown to exert neuroprotective effects in both in-vitro and in-vivo models. Mangiferin attenuates cerebral infarction, cerebral edema, lipid peroxidation (MDA), neuronal damage, etc. Mangiferin further potentiate levels of endogenous antioxidants to confer protection against the oxidative stress inside the neurons. Mangiferin is involved in the regulation of various signaling pathways that influences the production and levels of proinflammatory cytokines in brain. Mangiferin cosunteracted the neurotoxic effect of amyloid-beta, MPTP, rotenone, 6-OHDA etc and confer protection to neurons. These evidence suggested that the mangiferin may be a potential therapeutic strategy for the treatment of various neurological disorders. The present review demonstrated the pharmacodynamics-pharmacokinetics of mangiferin and neurotherapeutic potential in several neurological disorders with underlying mechanisms.

Protective effect of mangiferin on memory impairment: A systematic review

Memory impairment (MI) is one of the predominant criteria generally used to identify schizophrenia, dementia and amnesia that are associated with neurodegenerative disorders by evaluating patient’s cognitive symptoms. To date, there is no available treatment that can completely mitigate MI. Currently, there is a trend in recent investigations towards symptomatic therapy approaches using a variety of natural compounds. Mangiferin is one of them that have been investigated extensively. Mangiferin is a naturally occurring potent glucoxilxanthone and is mainly isolated from the Mangifera indica (Mango) plant. This review is aimed at providing a comprehensive overview on the efficacy of mangiferin on MI, based on in-vivo animal studies. After screening through articles identified from Scopus and PubMed based on the inclusion and exclusion criteria, a total of 11 articles between 2009 and 2019 were included. The minimum and maximum dose of mangiferin were 10 and 200 mg/kg respectively and administered over the period of 12–154 days. The results of 11 articles showed that mangiferin effectively improved spatial recognition, episodic aversive events, short- and long-term memories primarily occurring via its antioxidant and anti-inflammatory effects. The outcomes of the review revealed that mangiferin improves memory and cognitive impairment in different animal models, indicating that it has potential preventive and therapeutic roles in MI.

Mangiferin ameliorates intracerebroventricular-quinolinic acid-induced cognitive deficits, oxidative stress, and neuroinflammation in Wistar rats

INTRODUCTION:

Mangiferin (MGF), a xanthonoid polyphenol, confers neuroprotection via combating oxidative stress and inflammation. The current investigation aimed to assess the neuroprotective potential of MGF on behavioral and neurochemical anomalies evoked by administration of quinolinic acid (QA) through intrastriatal injection in male Wistar rats and to reveal the associated mechanisms.

MATERIALS AND METHODS:

QA (300 nm/4 μl saline) was administered intracerebroventricular in the striatum (unilaterally) once. Thereafter, MGF 20 and 40 mg/kg (peroral) was administered to the animals for 21 days.

RESULTS:

QA administration caused marked alteration in motor activity (rotatod), footprint analysis, and cognitive function (Morris water maze test, and novel object recognition test). Furthermore, oxido-nitrosative stress (increased nitrite content, lipid peroxidation, with reduction of GSH), cholinergic dysfunction, and mitochondrial complex (I, II, and IV) dysfunction were observed in hippocampus and striatal region of QA-treated rats in comparison to normal control. Pro inflammatory mediators (tumor necrosis factor-alpha TNF-α and interleukin-1β) were noted to increase in the hippocampus and striatum of QA-treated rats. In addition, we observed BDNF depletion in both the hippocampus and striatum of QA-treated animals. MGF treatment significantly ameliorated memory and motor deficits in QA-administered rats. Moreover, MGF treatment (40 mg/kg) restored the GSH level and reduced the MDA, nitrite level, and pro-inflammatory cytokines in striatum and hippocampus. Furthermore, QA-induced cholinergic dysfunction (AChE), BDNF depletion and mitochondrial impairment were found to be ameliorated by MGF treatment.

CONCLUSION:

The results suggest that MGF offers the neuroprotective potential that may be a promising pharmacological approach to ameliorate cognitive deficits associated with neurodegeneration.

Central nervous system activities of extract Mangifera indica L

ETHNOBOTANICAL RELEVANCE

Leaves of Mangifera indica L. have folk-uses in tropical regions of the world as health teas, as a remedy for exhaustion and fatigue, as a vegetable, and as a medicine. Mangifera indica leaf extract (MLE) had previously been demonstrated to alter brain electrical activity in-vivo. The aim of the present series of studies was to investigate whether mangiferin, a major compound in leaves and in MLE, is responsible for the neurocognitive activity of MLE, and if the CNS activities of MLE have translational potential.

MATERIALS AND METHODS

MLE, tradename Zynamite, is produced by Nektium Pharma, Spain. Isolated mangiferin was tested in-vitro in radioligand binding and enzyme inhibition studies against 106 CNS targets. Changes in the electroencephalograms (EEG's) of MLE and mangiferin were recorded in-vivo from four brain regions. Two double blind randomized placebo-controlled crossover clinical trials were conducted, each with 16 subjects. At 90 min and at 60 min respectively, after oral intake of 500 mg MLE, EEG recordings, psychometric tests, mood state, and tolerability were studied.

RESULTS

Isolated mangiferin is a selective inhibitor of catechol-O-methyltransferase (COMT) with an IC50 of 1.1 μM, with no activity on the CNS targets of caffeine. Both mangiferin and MLE induce similar changes in long-term potentiation (LTP) in the hippocampus in-vitro, and induce a similar pattern of EEG changes in-vivo. In both translational clinical trials MLE was well tolerated, with no cardiovascular side-effects. In both studies MLE caused significant spectral changes in brain electrical activity in cortical regions during cognitive challenges, different to the attenuated spectral changes induced by caffeine. There were no significant changes in the psychometric tests other than reaction time for all groups. In the second study there was a trend to faster reaction time within group for MLE (p = 0.066) and the percentage improvement in reaction time for MLE compared to placebo was significant (p = 0.049). In the first study MLE improved all scores for Profile of Mood States (POMS), with the score for "fatigue" significantly improved (p = 0.015); in the second study the POMS score for "dejection" was improved in the caffeine group, p = 0.05.

CONCLUSIONS

Mangiferin is a COMT inhibitor of moderate potency and is the major CNS-active compound in MLE. Both mangiferin and MLE increase hippocampal LTP in-vitro, and induce a similar pattern of changes in brain electrical activity in-vivo. While the translational clinical trials of MLE are limited by being single dose studies in a small number of subjects, they provide the first clinical evidence that the extract is well tolerated with no cardiovascular side-effects, can induce changes in brain electrical activity, may give a faster reaction time, and decrease fatigue. These CNS activities support the reported folk-uses use of mango leaf tea as a substitute for tea and as a traditional remedy for fatigue and exhaustion. Extract Mangifera indica L., Zynamite, has nootropic potential, and larger clinical studies are needed to realise this potential.

Mangiferin offers protection against deleterious effects of pharmaceuticals, heavy metals, and environmental chemicals

Mangiferin (MGF) is a polyphenolic C-glucosyl-xanthone extracted from the mango tree (Mangifera indica). MGF has shown diverse effects such as antioxidant, antiapoptotic, radical scavenging, and chelating properties. MGF also has been shown to modulate inflammatory pathways. In this review, we examined and evaluated the literature dealing with the protective effects of MGF against various chemical toxicities. Our literature review indicated that the MGF-induced protective effects against the toxic effects of pharmaceuticals, heavy metals and environmental chemicals were mainly mediated via suppression of lipid peroxidation, oxidative stress (along with enhancement of the antioxidant enzyme), inflammatory factors (TNF-α, IL-6, IL-10, and IL-12), and activation of PI3K/Akt and the MAPK survival signaling pathway.

Acute Effects of a Polyphenol-Rich Leaf Extract of Mangifera indica L. (Zynamite) on Cognitive Function in Healthy Adults: A Double-Blind, Placebo-Controlled Crossover Study

Extracts made from the leaves of the mango food plant (Mangifera indica L., Anacardiaceae) have a long history of medicinal usage, most likely due to particularly high levels of the polyphenol mangiferin. In rodent models, oral mangiferin protects cognitive function and brain tissue from a number of challenges and modulates cerebro-electrical activity. Recent evidence has confirmed the latter effect in healthy humans following a mangiferin-rich mango leaf extract using quantitative electroencephalography (EEG). The current study therefore investigated the effects of a single dose of mango leaf extract, standardised to contain >60% mangiferin (Zynamite®), on cognitive function and mood. This study adopted a double-blind, placebo-controlled cross-over design in which 70 healthy young adults (18 to 45 years) received 300 mg mango leaf extract and a matched placebo, on separate occasions, separated by at least 7 days. On each occasion, cognitive/mood assessments were undertaken pre-dose and at 30 min, 3 h and 5 h post-dose using the Computerised Mental Performance Assessment System (COMPASS) assessment battery and the Profile of Mood States (POMS). The results showed that a single dose of 300 mg mango leaf extract significantly improved performance accuracy across the tasks in the battery, with domain-specific effects seen in terms of enhanced performance on an 'Accuracy of Attention' factor and an 'Episodic Memory' factor. Performance was also improved across all three tasks (Rapid Visual Information Processing, Serial 3s and Serial 7s subtraction tasks) that make up the Cognitive Demand Battery sub-section of the assessment. All of these cognitive benefits were seen across the post-dose assessments (30 min, 3 h, 5 h). There were no interpretable treatment related effects on mood. These results provide the first demonstration of cognition enhancement following consumption of mango leaf extract and add to previous research showing that polyphenols and polyphenol rich extracts can improve brain function.

7,8-Dihydroxyflavone alleviated the high-fat diet and alcohol-induced memory impairment: behavioral, biochemical and molecular evidence

RATIONALE

Alcoholism and obesity impart a deleterious impact on human health and affects the quality of life. Chronic consumption of alcohol and western diet has been reported to cause memory deficits. 7,8-dihydroxyflavone (7,8-DHF), a TrkB agonist, comprises antioxidant and anti-inflammatory properties in treating various neurological disorders.

OBJECTIVES

The current study was aimed to determine the protective effect and molecular mechanism of 7,8-DHF against alcohol and high-fat diet (HFD)-induced memory deficits in rats.

METHODS

The adult male Wistar rats were given alcohol (3-15%) and HFD ad libitum for 12 weeks in different experimental groups. 7,8-DHF (5 mg/kg) was intraperitoneally injected daily for the last 4 weeks (9th-12th week).

RESULTS

The alcohol and HFD administration caused cognitive impairment as evaluated through the Morris water maze (MWM) test in alcohol, HFD, and alcohol + HFD-fed animals. The last 4-week treatment of 7,8-DHF (5 mg/kg; i.p.) attenuated alcohol and HFD-induced memory loss. 7,8-DHF treatment also restored the glutathione (GSH) level along with attenuation of nitrite, malondialdehyde content (markers of oxidative and nitrosative stress), and reduction of the acetylcholinesterase activity in the hippocampus of alcohol and HFD-fed animals. Furthermore, the administration of 7,8-DHF caused downregulation of NF-κB, iNOS, and caspase-3 and upregulation of Nrf2, HO-1, and BDNF mRNA level in rat hippocampus.

CONCLUSION

7,8-DHF administration conferred beneficial effects against alcohol and HFD-induced memory deficit via its unique antioxidant, anti-inflammatory, anti-apoptotic potential, along with the activation of TrkB/BDNF signaling pathway in the hippocampus.

Cassia tora extract alleviates Aβ1-42 aggregation processes in vitro and protects against aluminium-induced neurodegeneration in rats

OBJECTIVES

To examine the ability of Cassia tora extract to produce, in vitro and in vivo, beneficial effects with respect to events occurring during Alzheimer's disease.

METHODS

Previously characterised methanol extract of C. tora was tested for its ability to lessen Aβ₄₂ aggregation processes in vitro and to alleviate aluminium-induced impairments in vivo in rats.

KEY FINDINGS

Cassia tora extract prevents the aggregation of monomeric, oligomeric and fibrillary Aβ_1-42 in vitro. Moreover, the daily ingestion of 100 and 400 milligrams of the extract per kilogram of body weight for 60 days ameliorates the neurobehavioral and cognitive abilities of aluminium-treated rats in vivo. Importantly, treatments with the extract trigger a significant recovery of antioxidant enzymes function, a diminution of lipid peroxidation and acetylcholinesterase activity, a decrease of pro-inflammatory cytokines expression and an increase of brain-derived neurotrophic factor levels in both the hippocampus and the frontal cortex. Finally, we evidence that the extract is able to ameliorate the aluminium-dependent loss of neuronal integrity in the CA1 and CA3 regions of the hippocampus.

CONCLUSIONS

Altogether, our results reveal that methanol extract of C. tora is able to prevent typical AD-related events and therefore stands as a promising mild and natural anti-AD multitarget compound.

Dietary Polyphenols: A Multifactorial Strategy to Target Alzheimer's Disease

Ageing is an inevitable fundamental process for people and is their greatest risk factor for neurodegenerative disease. The ageing processes bring changes in cells that can drive the organisms to experience loss of nutrient sensing, disrupted cellular functions, increased oxidative stress, loss of cellular homeostasis, genomic instability, accumulation of misfolded protein, impaired cellular defenses and telomere shortening. Perturbation of these vital cellular processes in neuronal cells can lead to life threatening neurological disorders like Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, Lewy body dementia, etc. Alzheimer's Disease is the most frequent cause of deaths in the elderly population. Various therapeutic molecules have been designed to overcome the social, economic and health care burden caused by Alzheimer's Disease. Almost all the chemical compounds in clinical practice have been found to treat symptoms only limiting them to palliative care. The reason behind such imperfect drugs may result from the inefficiencies of the current drugs to target the cause of the disease. Here, we review the potential role of antioxidant polyphenolic compounds that could possibly be the most effective preventative strategy against Alzheimer's Disease.

Protective Role of Epigallocatechin Gallate in a Rat Model of Cisplatin-Induced Cerebral Inflammation and Oxidative Damage: Impact of Modulating NF-κB and Nrf2

Cisplatin is a widely used chemotherapeutic agent in treating various types of cancers. However, it can induce neurotoxicity and nephrotoxicity, limiting its dose and clinical use. Although previous studies indicated the direct link between cisplatin-induced central neurotoxicity and oxidative stress, the exact mechanism is not completely understood. Therefore, herein we investigated the effects of prophylactic and concurrent treatment with (-)-epigallocatechin-3-gallate (EGCG), a natural polyphenolic neuroprotective antioxidant, on cisplatin-induced brain toxicity in rats to delineate its molecular mechanism of action. We found that cisplatin initiated a cascade of genetic, biological, and histopathological changes in the brain cortex, inducing inflammatory cytokines, appearance of scattered inflammatory cells, nitro-oxidative stress, and apoptotic proteins in the cerebral cortex. However, EGCG not only protected against cisplatin-induced inflammatory burden but also ameliorated the induction of nitro-oxidative stress and apoptotic proteins triggered by cisplatin in the cerebral cortex of pre- and co-treated rats with respect to their unprotected counterparts. EGCG anti-inflammatory effect here may be attributed to the downregulation of nuclear factor kappa B (NF-κB). Additionally, this natural polyphenol significantly ameliorated cisplatin-elicited reduction in cerebral cortex brain-derived neurotrophic factor and acetylcholine esterase. Upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream heme oxygenase-1 (HO-1) by EGCG prophylactic and concurrent administration here seems also to play a key role in the protective impact of EGCG against cisplatin toxicity through enhancing total antioxidant capacity. Thus, EGCG can be used as a promising prophylactic adjuvant for preventing the development of brain inflammation and oxidative damage associated with cisplatin chemotherapy.

Mangiferin: A multipotent natural product preventing neurodegeneration in Alzheimer's and Parkinson's disease models

Alzheimer's disease (AD) and Parkinson's disease (PD) are recognized as the universal neurodegenerative diseases, with the involvement of misfolded proteins pathology, leading to oxidative stress, glial cells activation, neuroinflammation, mitochondrial dysfunction, and cellular apoptosis. Several discoveries indicate that accumulation of pathogenic proteins, i.e. amyloid β (Aβ), the microtubule-binding protein tau, and α-synuclein, are parallel with oxidative stress, neuroinflammation, and mitochondrial dysfunction. Whether the causative factors are misfolded proteins or these pathophysiological changes, leading to neurodegeneration still remain ambiguous. Importantly, directing pharmacological researches towards the prevention of AD and PD seem a promising approach to detect these complicating mechanisms, and provide new insight into therapy for AD and PD patients. Mangiferin (MGF, 2-C-β-D-glucopyranosyl-1, 3, 6, 7-tetrahydroxyxanthone), well-known as a natural product, is detached from multiple plants, including Mangifera indica L. With the structure of C-glycosyl and phenolic moiety, MGF possesses multipotent properties starting from anti-oxidant effects, to the alleviation of mitochondrial dysfunction, neuroinflammation, and cellular apoptosis. In particular, MGF can cross the blood-brain barrier to exert neuronal protection. Different researches implicate that MGF is able to protect the central nervous system from oxidative stress, mitochondrial dysfunction, neuroinflammation, and apoptosis under in vitro and in vivo models. Additional facts support that MGF plays a role in improving the declined memory and cognition of rat models. Taken together, the neuroprotective capacity of MGF may stand out as an agent candidate for AD and PD therapy.

Egg White Hydrolysate as a functional food ingredient to prevent cognitive dysfunction in rats following long-term exposure to aluminum

Aluminum (Al), which is omnipresent in human life, is a potent neurotoxin. Here, we have tested the potential for Egg White Hydrolysate (EWH) to protect against changes in cognitive function in rats exposed to both high and low levels of Al. Indeed, EWH has been previously shown to improve the negative effects induced by chronic exposure to heavy metals. Male Wistar rats received orally: Group 1) Low aluminum level (AlCl3 at a dose of 8.3 mg/kg b.w. during 60 days) with or without EWH treatment (1 g/kg/day); Group 2) High aluminum level (AlCl3 at a dose of 100 mg/kg b.w. during 42 days) with or without EWH treatment (1 g/kg/day). After 60 or 42 days of exposure, rats exposed to Al and EWH did not show memory or cognitive dysfunction as was observed in Al-treated animals. Indeed, co-treatment with EWH prevented catalepsy, hippocampal oxidative stress, cholinergic dysfunction and increased number of activated microglia and COX-2-positive cells induced by Al exposure. Altogether, since hippocampal inflammation and oxidative damage were partially prevented by EWH, our results suggest that it could be used as a protective agent against the detrimental effects of long term exposure to Al.

Ameliorative effect of fisetin against lipopolysaccharide and restraint stress-induced behavioral deficits via modulation of NF-κB and IDO-1

BACKGROUND

Fisetin, a plant active polyphenol, is well known for its antioxidant and free radical scavenging activities. The present study was designed to explore the detailed molecular mechanism underlying its neuroprotective effects.

METHODS

The young male mice were either administered a single dose of lipopolysaccharide (0.83 mg/kg) or subjected to restraint stress (6 h per day for 28 days) to induce behavioral deficits in different groups. Fisetin (15 mg/kg) was orally administered for the last 14 days of the study.

RESULTS

Lipopolysaccharide (LPS) as well as restraint stress (RS) exposure caused behavioral alterations (anxiety and depressive-like behavior). Gene expression analysis showed upregulation of nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) and indoleamine 2,3-dioxygenase (IDO)-1 gene expression along with downregulation of Nrf-2 (nuclear factor erythroid 2-related factor 2), HO-1 (heme oxygenase-1), and ChAT (choline acetyltransferase) gene expression level in RS and RS+LPS groups. Fisetin administration significantly ameliorated behavioral and neurochemical deficits in LPS, RS, and RS+LPS groups.

CONCLUSION

These findings clearly indicated that fisetin administration improved behavioral functions and suppressed the NF-κB and IDO-1 (indoleamine 2,3-dioxygenase) activation along with their antioxidant effect, suggesting fisetin as an intriguing nutraceutical for the management of inflammation-associated neurological disorders.

Voluntary alcohol consumption exacerbated high fat diet-induced cognitive deficits by NF-κB-calpain dependent apoptotic cell death in rat hippocampus: Ameliorative effect of melatonin

Modern sedentary lifestyle with altered dietary habits imposes the risk of human health towards several metabolic disorders such as obesity. The metabolic insults negatively affect the mental health status and quality life of affected individuals. Melatonin is a potent antioxidant with anti-inflammatory and neuroprotective properties. The aim of the present study was to investigate the protective effect of melatonin on the cognitive and neurochemical deficits induced by the high-fat diet (HFD) and alcohol (ALC) alone or in combination (HFD + ALC) in rats. Male Wistar rats were given ALC (3-15% i.e. increased gradually) and HFD for 12 weeks in different experimental groups. After 12 weeks, we found that simultaneous consumption of HFD and ALC exacerbates cognitive dysfunction and neurochemical anomalies. However, melatonin (10 mg/kg/day, i.p.) treatment for four weeks significantly prevented memory deficits, oxidative stress and neuroinflammation in HFD, ALC and HFD + ALC groups. RT-PCR analysis showed down-regulation of nuclear factor erythroid 2-related factor 2 (Nrf-2) and heme oxygenase-1 (HO-1) in ALC and HFD + ALC groups. Moreover, caspase-3 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) mRNA expression level were found up-regulated in hippocampus of HFD, ALC and HFD + ALC groups. However, calpain expression was found up-regulated only in the hippocampus of HFD + ALC group. Chronic treatment with melatonin significantly restored the aberrant gene expression level in HFD, ALC and HFD + ALC group. In conclusion, our findings indicated that melatonin can mitigate the HFD and ALC-induced cognitive deficits via attenuation of oxidative stress and calpain-1 dependent as well as independent caspase-3 mediated neuronal cell death.