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Maternal dexamethasone exposure inhibits the gonadotropin-releasing hormone neuronal movement in the preoptic area of rat offspring

Lim WL, Soga T, Parhar IS

Dev Neurosci, 2014;36(2):95-107.
PMID: 24713635 DOI: 10.1159/000360416

Migration and final positioning of gonadotropin-releasing hormone (GnRH) neurons in the preoptic area (POA) is critical for reproduction. It is known that maternal dexamethasone (DEX) exposure impairs reproductive function and behaviour in the offspring. However, it is still not known whether maternal DEX exposure affects the postnatal GnRH neurons in the offspring. This study determined the neuronal movement of enhanced green fluorescent protein (EGFP)-tagged GnRH neurons in slice culture of postnatal day 0 (P0), P5 and P50-60 transgenic male rats. Effect of maternal DEX treatment on EGFP-GnRH neuronal movement and F-actin distribution on GnRH neurons at P0 stage were studied. Time-lapse analysis of P0 and P5 EGFP-GnRH neurons displayed active cellular movement within the POA compared to young adult P50-60 stages, suggesting possible fine-tuning movement for positioning of early postnatal GnRH neurons. The DEX-treated EGFP-GnRH neurons demonstrated decreased motility in the POA and reduced F-actin distribution in the GnRH neurons at 60 h culture compared to the vehicle-treated. These results suggest that the P0 GnRH neuronal movement in the POA is altered by maternal DEX exposure, which possibly disrupts the fine-tuning process for positioning and development of early postnatal GnRH neurons in the brain, potentially linked to reproductive dysfunction in adulthood.

Matched MeSH terms: Neurons/drug effects*
Zinc intake during pregnancy increases the proliferation at ventricular zone of the newborn brain

Azman MS, Wan Saudi WS, Ilhami M, Mutalib MS, Rahman MT

Nutr Neurosci, 2009 Feb;12(1):9-12.
PMID: 19178786 DOI: 10.1179/147683009X388904

Neurogenesis involves cell proliferation, cell cycle arrest, differentiation, migration and the natural developmental death of the neural precursors. These processes are highly co-ordinated and governed by cell-cycle genes and neural transcription factors. Zn plays a crucial role as a functional and structural component of enzymes and transcription factors and components of the intracellular signaling pathway associated with the regulation of cell proliferation. The influence of additional Zn intake during pregnancy on the neuronal proliferation at ventricular zone of the developing fetus has been studied. Pups delivered by the group of mice provided with drinking water with 4.0 mM Zn supplement throughout pregnancy contained an increased number of proliferating neurons in the ventricular zone at P0 compared to those delivered by the mice provided with drinking water without any Zn supplement. This finding provides direct evidence to support the notion that maternal Zn levels influence the development of the nervous system of the offspring.

Matched MeSH terms: Neurons/drug effects
Effect of concurrent application of heat, swim stress and repeated dermal application of chlorpyrifos on the hippocampal neurons in mice

Mitra NK, Nadarajah VD, Siong HH

Folia Neuropathol, 2009;47(1):60-8.
PMID: 19353435

Dermal absorption of chlorpyrifos (CPF), an organophosphate (OP) pesticide, is important because of its popular use. Stress has been reported to exacerbate neurotoxic effects of certain OP pesticides; however, quantitative studies to corroborate this are not reported. This study correlates the changes in acetylcholinesterase (AChE) levels and neuronal counts in areas of the hippocampus to consecutive exposure of stress, heat and CPF. Male mice (60 days) were segregated into six groups: one control, one stress control, and four treated groups (n=10). CPF was applied in doses of 1/2 and 1/5 of dermal LD50 (E1 and E2) over the tail of mice under occlusive bandages for 3 weeks. Stress control [(s) C] mice were subjected to swim stress at 38 degrees C (6 mins/day, 3 weeks). (s) E1 and (s) E2 were subjected to swim stress before CPF application. Blood and brain AChE levels were estimated using a spectrofluorometric method (Amplex Red). Pyramidal neurons of the cornu ammonis of the hippocampus under Nissl stain from histological sections were counted per unit area of section and analyzed statistically using one way ANOVA. Swim stress at 38 degrees C aggravated reduction of serum AChE by dermal exposure to CPF by 19.7%. Neurons of CA3 and CA1 regions of the hippocampus showed significant reduction in neuronal counts in (s) E1 and (s) E2 groups compared to E1 and E2 groups. Whereas application of CPF 1/2 dermal LD50 (E1) showed significant reduction of neuronal counts only in the CA3 area.

Matched MeSH terms: Neurons/drug effects*
Fulltext Neuroprotective Effects of Biochanin A against β-Amyloid-Induced Neurotoxicity in PC12 Cells via a Mitochondrial-Dependent Apoptosis Pathway

Tan JW, Kim MK

Molecules, 2016 Apr 25;21(5).
PMID: 27120593 DOI: 10.3390/molecules21050548

Alzheimer's disease is considered one of the major neurodegenerative diseases and is characterized by the production of β-amyloid (Aβ) proteins and progressive loss of neurons. Biochanin A, a phytoestrogen compound found mainly in Trifolium pratense, was used in the present study as a potential alternative to estrogen replacement therapy via the investigation of its neuroprotective effects against Aβ25-35-induced toxicity, as well as of its potential mechanisms of action in PC12 cells. Exposure of these cells to the Aβ25-35 protein significantly increased cell viability loss and apoptosis. However, the effects induced by Aβ25-35 were markedly reversed in the present of biochanin A. Pretreatment with biochanin A attenuated the cytotoxic effect of the Aβ25-35 protein by decreasing viability loss, LDH release, and caspase activity in cells. Moreover, we found that expression of cytochrome c and Puma were reduced, alongside with the restoration of Bcl-2/Bax and Bcl-xL/Bax ratio in the presence of biochanin A, which led to a decrease in the apoptotic rate. These data demonstrate that mitochondria are involved in the protective effect of biochanin A against Aβ25-35 and that this drug attenuated Aβ25-35-induced PC12 cell injury and apoptosis by preventing mitochondrial dysfunction. Thus, biochanin A might raise a possibility as a potential therapeutic agent for Alzheimer's disease and other related neurodegenerative diseases.

Matched MeSH terms: Neurons/drug effects*
Fulltext Deferoxamine Preconditioning of Neural-Like Cells Derived from Human Wharton's Jelly Mesenchymal Stem Cells as a Strategy to Promote Their Tolerance and Therapeutic Potential: An In Vitro Study

Nouri F, Salehinejad P, Nematollahi-Mahani SN, Kamarul T, Zarrindast MR, Sharifi AM

Cell Mol Neurobiol, 2016 Jul;36(5):689-700.
PMID: 26242172 DOI: 10.1007/s10571-015-0249-8

Transplantation of neural-like cells is considered as a promising therapeutic strategy developed for neurodegenerative disease in particular for ischemic stroke. Since cell survival is a major concern following cell implantation, a number of studies have underlined the protective effects of preconditioning with hypoxia or hypoxia mimetic pharmacological agents such as deferoxamine (DFO), induced by activation of hypoxia inducible factor-1 (HIF-1) and its target genes. The present study has investigated the effects of DFO preconditioning on some factors involved in cell survival, angiogenesis, and neurogenesis of neural-like cells derived from human Wharton's jelly mesenchymal stem cells (HWJ-MSCs) in presence of hydrogen peroxide (H2O2). HWJ-MSCs were differentiated toward neural-like cells for 14 days and neural cell markers were identified using immunocytochemistry. HWJ-MSC-derived neural-like cells were then treated with 100 µM DFO, as a known hypoxia mimetic agent for 48 h. mRNA and protein expression of HIF-1 target genes including brain-derived neurotrophic factors (BDNF) and vascular endothelial growth factor (VEGF) significantly increased using RT-PCR and Western blotting which were reversed by HIF-1α inhibitor, while, gene expression of Akt-1, Bcl-2, and Bax did not change significantly but pAkt-1 was up-regulated as compared to poor DFO group. However, addition of H2O2 to DFO-treated cells resulted in higher resistance to H2O2-induced cell death. Western blotting analysis also showed significant up-regulation of HIF-1α, BDNF, VEGF, and pAkt-1, and decrease of Bax/Bcl-2 ratio as compared to poor DFO. These results may suggest that DFO preconditioning of HWJ-MSC-derived neural-like cells improves their tolerance and therapeutic potential and might be considered as a valuable strategy to improve cell therapy.

Matched MeSH terms: Neurons/drug effects
Fulltext Trans-ancestry genome-wide study of depression identifies 697 associations implicating cell types and pharmacotherapies

Major Depressive Disorder Working Group of the Psychiatric Genomics Consortium. Electronic address: andrew.mcintosh@ed.ac.uk, Major Depressive Disorder Working Group of the Psychiatric Genomics Consortium

Cell, 2025 Feb 06;188(3):640-652.e9.
PMID: 39814019 DOI: 10.1016/j.cell.2024.12.002

In a genome-wide association study (GWAS) meta-analysis of 688,808 individuals with major depression (MD) and 4,364,225 controls from 29 countries across diverse and admixed ancestries, we identify 697 associations at 635 loci, 293 of which are novel. Using fine-mapping and functional tools, we find 308 high-confidence gene associations and enrichment of postsynaptic density and receptor clustering. A neural cell-type enrichment analysis utilizing single-cell data implicates excitatory, inhibitory, and medium spiny neurons and the involvement of amygdala neurons in both mouse and human single-cell analyses. The associations are enriched for antidepressant targets and provide potential repurposing opportunities. Polygenic scores trained using European or multi-ancestry data predicted MD status across all ancestries, explaining up to 5.8% of MD liability variance in Europeans. These findings advance our global understanding of MD and reveal biological targets that may be used to target and develop pharmacotherapies addressing the unmet need for effective treatment.

Matched MeSH terms: Neurons/drug effects
Clitoria ternatea L. root extract ameliorated the cognitive and hippocampal long-term potentiation deficits induced by chronic cerebral hypoperfusion in the rat

Damodaran T, Tan BWL, Liao P, Ramanathan S, Lim GK, Hassan Z

J Ethnopharmacol, 2018 Oct 05;224:381-390.
PMID: 29920356 DOI: 10.1016/j.jep.2018.06.020

ETHNOPHARMACOLOGICAL RELEVANCE: Clitoria ternatea L. (CT), commonly known as Butterfly pea, is used in Indian Ayurvedic medicine to promote brain function and treat mental disorders. Root of CT has been proven to enhance memory, but its role in an animal model of chronic cerebral hypoperfusion (CCH), which has been considered as a major cause of brain disorders, has yet to be explored.
AIM OF THE STUDY: To assess the motor and cognitive effects of acute oral administration of CT root methanolic extract and hippocampal long-term plasticity in the CA1 region of the CCH rat model.
MATERIALS AND METHODS: Male Sprague Dawley rats (200-300 g) were subjected to permanent bilateral occlusion of common carotid arteries (PBOCCA) or sham operation. Then, these rats were given oral administration of CT root extract at doses of 100, 200 or 300 mg/kg on day 28 post-surgery and tested using behavioural tests (open-field test, passive avoidance task, and Morris water maze) and electrophysiological recordings (under urethane anaesthesia).
RESULTS: Treatment with CT root extract at the doses of 200 and 300 mg/kg resulted in a significant enhancement in memory performance in CCH rats induced by PBOCCA. Furthermore, CCH resulted in inhibition of long-term potentiation (LTP) formation in the hippocampus, and CT root extract rescued the LTP impairment. The CT root extract was confirmed to improve the glutamate-induced calcium increase via calcium imaging using primary cultured rat neurons. No significance difference was found in the CaMKII expression. These results demonstrated that CT root extract ameliorates synaptic function, which may contribute to its improving effect on cognitive behaviour.
CONCLUSIONS: Our findings demonstrated an improving effect of CT root extract on memory in the CCH rat model suggesting that CT root extract could be a potential therapeutic strategy to prevent the progression of cognitive deterioration in vascular dementia (VaD) and Alzheimer's disease (AD) patients.

Matched MeSH terms: Neurons/drug effects
Fulltext The Biological Activities of Oleocanthal from a Molecular Perspective

Pang KL, Chin KY

Nutrients, 2018 May 06;10(5).
PMID: 29734791 DOI: 10.3390/nu10050570

Oleocanthal is a minor constituent of olive oil with strong anti-inflammatory activities. Since the pathogenesis of many chronic diseases involves inflammatory and oxidative components, oleocanthal is a promising agent to prevent these conditions. This review aimed to summarise the current beneficial health effects of oleocanthal and the molecular basis of its biological actions. The anti-inflammatory, antioxidative, antimicrobial, anticancer and neuroprotective activities of oleocanthal have been examined by previous studies. Of these, studies on the anticancer effects have been the most extensive. Oleocanthal was reported to suppress melanoma, breast, liver, and colon cancer cells. Neurological studies focused on the effects of oleocanthal against Alzheimer’s disease. Oleocanthal improved clearance of the amyloid beta protein from neurons and reduced the inflammation of astrocytes. Despite the positive results, validation of the biological effects of oleocanthal in animal disease models is limited and should be emphasized in the future. As a conclusion, oleocanthal may act together with other bioactive compounds in olive oil to achieve its therapeutic potential. The use of oleocanthal alone as a single therapeutic measure awaits validation from future studies.

Matched MeSH terms: Neurons/drug effects
Fucosterol exerts protection against amyloid β-induced neurotoxicity, reduces intracellular levels of amyloid β and enhances the mRNA expression of neuroglobin in amyloid β-induced SH-SY5Y cells

Gan SY, Wong LZ, Wong JW, Tan EL

Int J Biol Macromol, 2019 Jan;121:207-213.
PMID: 30300695 DOI: 10.1016/j.ijbiomac.2018.10.021

Alzheimer's disease (AD) is a neurodegenerative disease that leads to progressive loss of neurons which often results in deterioration of memory and cognitive function. The development of AD is highly associated with the formation of senile plaques and neurofibrillary tangles. Amyloid β (Aβ) induces neurotoxicity and contributes to the development of AD. Recent evidences also highlighted the importance of neuroglobin (Ngb) in ameliorating AD. This study assessed the ability of fucosterol, a phytosterol found in brown alga, in protecting SH-SY5Y cells against Aβ-induced neurotoxicity. Its effects on the mRNA levels of APP and Ngb as well as the intracellular Aβ levels were also determined in Aβ-induced SH-SY5Y cells. SH-SY5Y cells were exposed to fucosterol prior to Aβ treatment. The effect on apoptosis was determined using Annexin V FITC staining and mRNA expression was studied using RT-PCR. Flow cytometry confirmed the protective effects of fucosterol on SH-SY5Y cells against Aβ-induced apoptosis. Pretreatment with fucosterol increased the Ngb mRNA levels but reduced the levels of APP mRNA and intracellular Aβ in Aβ-induced SH-SY5Y cells. These observations demonstrated the protective properties of fucosterol against Aβ-induced neurotoxicity in neuronal cells.

Matched MeSH terms: Neurons/drug effects
Chronic cerebral hypoperfusion-induced memory impairment and hippocampal long-term potentiation deficits are improved by cholinergic stimulation in rats

Damodaran T, Müller CP, Hassan Z

Pharmacol Rep, 2019 Jun;71(3):443-448.
PMID: 31003155 DOI: 10.1016/j.pharep.2019.01.012

BACKGROUND: Chronic cerebral hypoperfusion (CCH) can induce the accumulation of reactive oxygen species, which leads to oxidative damage, neuronal injury, and central cholinergic dysfunction in vulnerable regions of the brain, such as the hippocampus and cerebral cortex. These effects can lead to significant cognitive impairments in clinical populations of vascular dementia (VaD). The present studies aimed to investigate the role of the cholinergic system in memory functions and hippocampal long-term potentiation (LTP) impairments induced by CCH in rats.
METHODS: Male Sprague Dawley rats were subjected to permanent bilateral occlusion of common carotid arteries (PBOCCA) or sham surgery. Then, PBOCCA rats received ip injections with, either vehicle (control group), the muscarinic receptor agonist oxotremorine (0.1 mg/kg), or the acetylcholinesterase inhibitor physostigmine (0.1 mg/kg). Cognitive functions were evaluated using a passive avoidance task and the Morris water maze test. In addition, hippocampal LTP was recorded in vivo under anaesthesia.
RESULTS: The PBOCCA rats exhibited significant deficits in passive avoidance retention and spatial learning and memory tests. They also showed a suppression of LTP formation in the hippocampus. Oxotremorine and physostigmine significantly improved the learning and memory deficits as well as the suppression of LTP in PBOCCA rats.
CONCLUSIONS: The present data suggest that the cholinergic system plays an important role in CCH-induced cognitive deficits and could be an effective therapeutic target for the treatment of VaD.

Matched MeSH terms: Neurons/drug effects
Fulltext Prospective role of mitochondrial apoptotic pathway in mediating GMG-ITC to reduce cytotoxicity in H2O2-induced oxidative stress in differentiated SH-SY5Y cells

Jaafaru MS, Nordin N, Rosli R, Shaari K, Bako HY, Noor NM, et al.

Biomed Pharmacother, 2019 Nov;119:109445.
PMID: 31541852 DOI: 10.1016/j.biopha.2019.109445

The antioxidant and neuroprotective activity of Glucomoringin isothiocyanate (GMG-ITC) have been reported in in vivo and in vitro models of neurodegenerative diseases. However, its neuroprotective role via mitochondrial-dependent pathway in a noxious environment remains unknown. The main objective of the present study was to unveil the mitochondrial apoptotic genes' profile and prospectively link with neuroprotective activity of GMG-ITC through its ROS scavenging. The results showed that pre-treatment of differentiated SH-SY5Y cells with 1.25 μg/mL purified isolated GMG-ITC, significantly reduced reactive oxygen species (ROS) production level, compared to H2O2 control group, as evidenced by flow cytometry-based evaluation of ROS generation. Presence of GMG-ITC prior to development of oxidative stress condition, downregulated the expression of cyt-c, p53, Apaf-1, Bax, CASP3, CASP8 and CASP9 genes with concurrent upregulation of Bcl-2 gene in mitochondrial apoptotic signalling pathway. Protein Multiplex revealed significant decreased in cyt-c, p53, Apaf-1, Bax, CASP8 and CASP9 due to GMG-ITC pre-treatment in oxidative stress condition. The present findings speculated that pre-treatment with GMG-ITC may alleviate oxidative stress condition in neuronal cells by reducing ROS production level and protect the cells against apoptosis via neurodegenerative disease potential pathways.

Matched MeSH terms: Neurons/drug effects
PKC inhibitor reversed the suppressive effect of orexin-A on IPSCs of locus coeruleus neurons in naloxone-induced morphine withdrawal

Davoudi M, Vijeepallam K, Azizi H, Mirnajafi-Zadeh J, Semnanian S

J Neural Transm (Vienna), 2019 11;126(11):1425-1435.
PMID: 31493096 DOI: 10.1007/s00702-019-02064-2

The locus coeruleus (LC) as a target of addictive drugs receives a dense projection of orexinergic fibres from the lateral hypothalamus (LH) and is accordingly a candidate site for the expression of the somatic aspects of morphine withdrawal. Recently it has been shown that the inhibitory synaptic currents of LC neurons decrease partly through orexin type 1 receptors in the context of naloxone-induced morphine withdrawal; however, its cellular mechanism remains unclear. In this study, whole-cell patch clamp recordings of LC neurons in brainstem slices were used to investigate the impact of protein kinase C (PKC) on GABAergic inhibitory post-synaptic currents (IPSCs) in the context of naloxone-induced morphine withdrawal. Male Wistar rats (P14-P21) received morphine (20 mg/kg, i.p.) daily for 7 consecutive days to induce morphine dependency. Our results showed that the application of PKC inhibitor (Go 6983; 1 µM) alone did not decrease the probability of GABA release in the LC neurons of the morphine-treated rats in the presence of naloxone. Although, Go 6983 reversed the reduction of the amplitude of evoked IPSCs (eIPSCs) and spontaneous IPSCs (sIPSCs) frequency induced by orexin-A but did not change the sIPSCs amplitude. These results indicate that the suppressive effect of orexin-A on IPSCs is probably reversed by PKC inhibitor in the LC neurons of morphine-treated rats in the context of naloxone withdrawal.

Matched MeSH terms: Neurons/drug effects
Fulltext Review on Cross Talk between Neurotransmitters and Neuroinflammation in Striatum and Cerebellum in the Mediation of Motor Behaviour

Abg Abd Wahab DY, Gau CH, Zakaria R, Muthu Karuppan MK, A-Rahbi BS, Abdullah Z, et al.

Biomed Res Int, 2019;2019:1767203.
PMID: 31815123 DOI: 10.1155/2019/1767203

Neurological diseases particularly Alzheimer's disease (AD), Parkinson's disease (PD), stroke, and epilepsy are on the rise all around the world causing morbidity and mortality globally with a common symptom of gradual loss or impairment of motor behaviour. Striatum, which is a component of the basal ganglia, is involved in facilitating voluntary movement while the cerebellum is involved in the maintenance of balance and coordination of voluntary movements. Dopamine, serotonin, gamma-aminobutyric acid (GABA), and glutamate, to name a few, interact in regulating the excitation and inhibition of motor neurons. In another hand, interestingly, the motor loss associated with neurological diseases is possibly resulted from neuroinflammation induced by the neuroimmune system. Toll-like receptors (TLRs) are present in the central nervous system (CNS), specifically and primarily expressed in microglia and are also found on neurons and astrocytes, functioning mainly in the regulation of proinflammatory cytokine production. TLRs are always found to be associated or involved in the induction of neuroinflammation in neurodegenerative diseases. Activation of toll-like receptor 4 (TLR4) through TLR4 agonist, lipopolysaccharide (LPS), stimulation initiate a signaling cascade whereby the TLR4-LPS interaction has been found to result in physiological and behavioural changes including retardation of motor activity in the mouse model. TLR4 inhibitor TAK-242 was reflected in the reduction of the spinal cord pathology along with the motor improvement in ALS mouse. There is cross talk with neuroinflammation and neurochemicals. For example, TLR4 activation by LPS is noted to release proinflammatory cytokines, IL-1β, from microglia that subsequently suppresses GABA receptor activities at the postsynaptic site and reduces GABA synthesis at the presynaptic site. Glial glutamate transporter activities are also found to be suppressed, showing the association between TLR4 activation and the related neurotransmitters and corresponding receptors and transporters in the event of neuroinflammation. This review is helpful to understand the connection between neurotransmitter and neuroinflammation in striatum- and cerebellum-mediated motor behaviour.

Matched MeSH terms: Motor Neurons/drug effects*
Serotonergic treatment normalizes midbrain dopaminergic neuron increase after periaqueductal gray stimulation

Tan SZK, Temel Y, Chan AY, Mok ATC, Perucho JAU, Blokland A, et al.

Brain Struct Funct, 2020 Sep;225(7):1957-1966.
PMID: 32594260 DOI: 10.1007/s00429-020-02102-w

Electrical stimulation of the dorsolateral periaqueductal gray (dlPAG) in rats has been shown to elicit panic-like behaviour and can be a useful as an unconditioned stimulus for modelling anticipatory fear and agoraphobia in a contextual fear conditioning paradigm. In this study, we further analysed our previous data on the effects of escitalopram (a selective serotonin reuptake inhibitor, SSRI) and buspirone (a 5-HT1A receptor partial agonist) on dlPAG-induced anticipatory fear behaviour in a rat model using freezing as a measure. We then attempted to unravel some of the interactions with dopamine signalling using tyrosine hydroxylase (TH) immunohistochemistry to probe the effects on dopaminergic neurons. We showed that acute treatment of escitalopram, but not buspirone, was effective in reducing anticipatory freezing behaviour, while chronic administrations of both drugs were effective. We found that the dlPAG stimulation induced increase number of dopaminergic neurons in the ventral tegmental area (VTA) which was reversed in both chronic buspirone and escitalopram groups. We further found a strong positive correlation between the number of dopaminergic neurons and freezing in the VTA and showed positive correlations between dopaminergic neurons in the VTA and substantia nigra pars compacta (SNpc) in escitalopram and buspirone groups, respectively. Overall, we showed that chronic treatment with an SSRI and a 5-HT1A agonist reduced anticipatory freezing behaviour which seems to be associated, through correlative studies, with a reversal of dlPAG stimulation induced increase in number of dopaminergic neurons in the VTA and/or SNpc.

Matched MeSH terms: Dopaminergic Neurons/drug effects*
Therapeutic potential of neurogenesis and melatonin regulation in Alzheimer's disease

Mihardja M, Roy J, Wong KY, Aquili L, Heng BC, Chan YS, et al.

Ann N Y Acad Sci, 2020 10;1478(1):43-62.
PMID: 32700392 DOI: 10.1111/nyas.14436

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by the hallmark pathologies of amyloid-beta plaques and neurofibrillary tangles. Symptoms of this devastating disease include behavioral changes and deterioration of higher cognitive functions. Impairment of neurogenesis has also been shown to occur in AD, which adversely impacts new neuronal cell growth, differentiation, and survival. This impairment possibly results from the cumulative effects of the various pathologies of AD. Preclinical studies have suggested that the administration of melatonin-the pineal hormone primarily responsible for the regulation of the circadian rhythm-targets the effects of AD pathologies and improves cognitive impairment. It is postulated that by mitigating the effect of these pathologies, melatonin can also rescue neurogenesis impairment. This review aims to explore the effect of AD pathologies on neurogenesis, as well as the mechanisms by which melatonin is able to ameliorate AD pathologies to potentially promote neurogenesis.

Matched MeSH terms: Neurons/drug effects
Fulltext Neuroprotective effects of Hericium erinaceus (Bull.: Fr.) Pers. against high-dose corticosterone-induced oxidative stress in PC-12 cells

Lew SY, Lim SH, Lim LW, Wong KH

BMC Complement Med Ther, 2020 Nov 11;20(1):340.
PMID: 33176761 DOI: 10.1186/s12906-020-03132-x

BACKGROUND: Hericium erinaceus is a culinary and medicinal mushroom in Traditional Chinese Medicines. It has numerous pharmacological effects including immunomodulatory, anti-tumour, anti-microbial, anti-aging and stimulation of nerve growth factor (NGF) synthesis, but little is known about its potential role in negating the detrimental effects of oxidative stress in depression. The present study investigated the neuroprotective effects of H. erinaceus standardised aqueous extract (HESAE) against high-dose corticosterone-induced oxidative stress in rat pheochromocytoma (PC-12) cells, a cellular model mimicking depression.
METHODS: PC-12 cells was pre-treated with HESAE for 48 h followed by 400 μM corticosterone for 24 h to induce oxidative stress. Cells in complete medium without any treatment or pre-treated with 3.125 μg/mL desipramine served as the negative and positive controls, respectively. The cell viability, lactate dehydrogenase (LDH) release, endogenous antioxidant enzyme activities, aconitase activity, mitochondrial membrane potentials (MMPs), intracellular reactive oxygen species (ROS) levels and number of apoptotic nuclei were quantified. In addition, HESAE ethanol extract was separated into fractions by chromatographic methods prior to spectroscopic analysis.
RESULTS: We observed that PC-12 cells treated with high-dose corticosterone at 400 μM had decreased cell viability, reduced endogenous antioxidant enzyme activities, disrupted mitochondrial function, and increased oxidative stress and apoptosis. However, pre-treatment with HESAE ranging from 0.25 to 1 mg/mL had increased cell viability, decreased LDH release, enhanced endogenous antioxidant enzyme activities, restored MMP, attenuated intracellular ROS and protected from ROS-mediated apoptosis. The neuroprotective effects could be attributed to significant amounts of adenosine and herierin III isolated from HESAE.
CONCLUSIONS: HESAE demonstrated neuroprotective effects against high-dose corticosterone-induced oxidative stress in an in vitro model mimicking depression. HESAE could be a potential dietary supplement to treat depression.

Matched MeSH terms: Neurons/drug effects*
Fulltext Effect of tualang honey against KA-induced oxidative stress and neurodegeneration in the cortex of rats

Mohd Sairazi NS, K N S S, Asari MA, Mummedy S, Muzaimi M, Sulaiman SA

BMC Complement Altern Med, 2017 Jan 09;17(1):31.
PMID: 28068984 DOI: 10.1186/s12906-016-1534-x

Administration of KA on rodents has resulted in seizures, behavioral changes, oxidative stress, and neuronal degeneration on selective population of neurons in the brain. The present study was undertaken to investigate the extent of neuroprotective effect conferred by Malaysian Tualang Honey (TH), an antioxidant agent, in the cerebral cortex of rats against KA-induced oxidative stress and neurodegeneration in an animal model of KA-induced excitotoxicity.

Matched MeSH terms: Neurons/drug effects*
Neuroprotective effect of cerium oxide nanoparticles in a rat model of experimental diabetic neuropathy

Najafi R, Hosseini A, Ghaznavi H, Mehrzadi S, Sharifi AM

Brain Res Bull, 2017 May;131:117-122.
PMID: 28373151 DOI: 10.1016/j.brainresbull.2017.03.013

OBJECTIVE: Neuropathies are a nerve disorders that caused by diabetes. Neuropathy affects over 50% of diabetic patients. High blood glucose and their toxic byproducts are the main causes for nerve dysfunction. In the present study, we examined the neroprotective effects of cerium oxide (CeO2) nanoparticles in diabetic rats.
METHOD: Rats divided into four groups: control group, diabetic group, the diabetic group treated with CeO2nanoparticle at a dose of 65mg/kg and diabetic group received CeO2nanoparticle at a dose of 85mg/kg. Diabetes was induced by single intraperitoneal injection of 65mg/kg streptozotocin (STZ). 8 weeks after the induction of diabetes, body weight and pain sensitivity in all groups were measured. The blood sample was collected for biochemical analysis. The dorsal root ganglion (DRG) neurons were isolated for histopathological stain and morphometric parameters studies.
RESULTS: Reduction of body weight, total thiol molecules (TTM), total antioxidant power (TAP) and ADP/ATP ratio in diabetic rat was reversed by CeO2nanoparticles administration. We showed that lipid peroxidation (LPO) and nociception latency were significantly increased in STZ-treated rats and decreased after CeO2nanoparticles administration. DRG neurons showed obvious vacuole and various changes in diameter, area and the count of A and B cells in STZ-diabetic rat. CeO2nanoparticles improved the histopathology and morphological abnormalities of DRG neurons.
CONCLUSION: Our study concluded the CeO2nanoparticles have a protective effect against the development of DN.

Matched MeSH terms: Neurons/drug effects
Alcohol Addiction- Metabotropic Glutamate Receptor Subtype 5 and its Ligands: How They All Come Together?

Kumar J, Ismail Z, Hatta NH, Baharuddin N, Hapidin H, Get Bee YT, et al.

Curr Drug Targets, 2018;19(8):907-915.
PMID: 28494749 DOI: 10.2174/1389450118666170511144302

In the past decade, many studies have highlighted the role of metabotropic glutamate receptor subtype 5 (mGlu5) modulators in attenuating alcohol-related biological effects such as alcohol consumption, alcohol-seeking and relapse-like behaviors. Taken together, these findings suggest that pharmacological agents acting at mGlu5 could be promising tools in curbing inebriation. mGlu5s are present abundantly in brain regions known to be involved in emotion regulation, motivation and drug administration. On a cellular level, they are primarily located at the postsynaptic part of the neuron where the receptor is functionally linked to various downstream proteins that are involved in cell signaling and gene transcription that mediate the alcohol-induced neuroplasticity. As well, the discovery of a functional link between mGlu5 and a specific isozyme, Protein Kinase C epsilon (PKCε) in mediating the attenuating effects of selective negative allosteric modulators of mGlu5 such as methyl- 6(phenylethynyl)pyridine (MPEP) and 3-((2-methyl-4-thiazolyl)ethynyl)pyridine (MTEP) has sparked interesting speculations. In this article, we shall review the following: the effects of acute and chronic alcohol intake on mGlu5 signaling; the effects of mGlu5 ligands on alcohol-related neurobehavioral changes that are currently being studied both at pre-clinical and clinical stages; and the mechanisms underlying the pharmacological effects of these drugs.

Matched MeSH terms: Neurons/drug effects
Alleviatory effects of Danshen, Salvianolic acid A and Salvianolic acid B on PC12 neuronal cells and Drosophila melanogaster model of Alzheimer's disease

Tan FHP, Ting ACJ, Leow BG, Najimudin N, Watanabe N, Azzam G

J Ethnopharmacol, 2021 Oct 28;279:114389.
PMID: 34217797 DOI: 10.1016/j.jep.2021.114389

ETHNOPHARMACOLOGICAL RELEVANCE: Danshen water extract (DWE), obtained from the Salvia miltiorrhiza Bunge (Family Lamiaceae) root, is usually employed in Chinese traditional medicine as treatment to cardiovascular ailments and cerebrovascular diseases. Intriguingly, the extract was also found to contain vast beneficial properties in Alzheimer's disease (AD) treatment.
AIM OF THE STUDY: Alzheimer's disease is the most significant type of neurodegenerative disorder plaguing societies globally. Its pathogenesis encompasses the hallmark aggregation of amyloid-beta (Aβ). Of all the Aβ oligomers formed in the brain, Aβ42 is the most toxic and aggressive. Despite this, the mechanism behind this disease remains elusive. In this study, DWE, and its major components, Salvianolic acid A (SalA) and Salvianolic acid B (SalB) were tested for their abilities to attenuate Aβ42's toxic effects.
METHODS: The composition of DWE was determined via Ultra-Performance Liquid Chromatography (UPLC). DWE, SalA and SalB were first verified for their capability to diminish Aβ42 fibrillation using an in vitro activity assay. Since Aβ42 aggregation results in neuronal degeneration, the potential Aβ42 inhibitors were next evaluated on Aβ42-exposed PC12 neuronal cells. The Drosophila melanogaster AD model was then employed to determine the effects of DWE, SalA and SalB.
RESULTS: DWE, SalA and SalB were shown to be able to reduce fibrillation of Aβ42. When tested on PC12 neuronal cells, DWE, SalA and SalB ameliorated cells from cell death associated with Aβ42 exposure. Next, DWE and its components were tested on the Drosophila melanogaster AD model and their rescue effects were further characterized. The UPLC analysis showed that SalA and SalB were present in the brains and bodies of Drosophila after DWE feeding. When human Aβ42 was expressed, the AD Drosophila exhibited degenerated eye structures known as the rough eye phenotype (REP), reduced lifespan and deteriorated locomotor ability. Administration of DWE, SalA and SalB partially reverted the REP, increased the age of AD Drosophila and improved most of the mobility of AD Drosophila.
CONCLUSION: Collectively, DWE and its components may have therapeutic potential for AD patients and possibly other forms of brain diseases.

Matched MeSH terms: Neurons/drug effects*

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