Preparing a rat brain tissue samples for acetylcholinesterase activity measurement: The MM method

Background/Aim: Organophosphorus compounds (OP) bind to acetylcholinesterase (AChE) causing an irreversible inhibition of the enzyme. When doing in vivo studies of OP intoxication, to precisely measure AChE activity in the brain tissue it is necessary to remove as much blood from the brain as possible. By doing so, interference of the OPs present in the blood is avoided. Usually this demands expensive equipment, therefore, the aim of this study was to find a simple and economical method to eliminate the blood from brain blood vessels. Methods: Wistar albino rats were divided into four groups named Control (C), Control washout (CW), Paraoxon (Pox) and Paraoxon washout (PoxW) group. Rats in Pox and PoxW were treated with 0.25 mg/kg paraoxon subcutaneously (sc), while C and CW received 1 mL/kg sc saline instead. The "Marinković-Maksimović" ("MM") method was performed in rats from PoxW and CW groups. Activity of AChE was measured both in erythrocyte lysate and in brain tissue using spectrophotometry. Results: Macroscopic examination revealed that the elimination of blood was achieved in CW and PoxW groups. Activity of AChE in homogenised brain tissue was expectedly lower in the Pox and PoxW group, when compared to C and CW group, respectively. The CW group had a lower value of AChE activity in the brain tissue compared to C group, while activity of AChE in the PoxW group was statistically higher than in the Pox group (p = 0.044). Conclusion: The MM method provides good elimination of blood from the brain. Together with blood, present confounding factors that interfere with analysis in homogenised brain tissue, were also eliminated.

Download Full-text

Inhibitory Effects of Sodium Arsenite and Acacia Honey on Acetylcholinesterase in Rats

International Journal of Alzheimer s Disease ◽

10.1155/2015/903603 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Aliyu Muhammad ◽

Oyeronke A. Odunola ◽

Michael A. Gbadegesin ◽

Abdullahi B. Sallau ◽

Uche S. Ndidi ◽

...

Keyword(s):

Ache Activity ◽

Sodium Arsenite ◽

Combined Treatment ◽

Acetylcholinesterase Activity ◽

Mass Spectrometry Analysis ◽

Gas Chromatography Mass Spectrometry ◽

Albino Rats ◽

Spectrometry Analysis ◽

Acacia Honey ◽

The Brain

This study was conducted to investigate the effect of sodium arsenite and Acacia honey on acetylcholinesterase (AChE) activity and electrolytes in the brain and serum of Wistar rats. Male Wistar albino rats in four groups of five rats each were treated with distilled water, sodium arsenite (5 mg/kg body weight), Acacia honey (20% v/v), and sodium arsenite and Acacia honey, daily for one week. The sodium arsenite and Acacia honey significantlyP<0.05decreased AChE activity in the brain with the combined treatment being more potent. Furthermore, sodium arsenite and Acacia honey significantlyP<0.05decreased AChE activity in the serum. Strong correlation was observed between the sodium and calcium ion levels with acetylcholinesterase activity in the brain and serum. The gas chromatography mass spectrometry analysis of Acacia honey revealed the presence of a number of bioactive compounds such as phenolics, sugar derivatives, and fatty acids. These findings suggest that sodium arsenite and/or Acacia honey modulates acetylcholinesterase activities which may be explored in the management of Alzheimer’s diseases but this might be counteracted by the hepatotoxicity induced by arsenics.

Download Full-text

Antimicrobial Agent Triclosan Inhibits Acetylcholinesterase Activity in Vitro in a Dose-Dependent Manner

10.1101/2021.06.11.448059 ◽

2021 ◽

Author(s):

Narasimha Pullaguri ◽

Andrea Kagoo ◽

Anamika Bhargava

Keyword(s):

Antimicrobial Agent ◽

Ache Activity ◽

Acetylcholinesterase Activity ◽

Consumer Products ◽

In Vivo Studies ◽

Dependent Manner ◽

Human Health Effects ◽

Dose Dependent

The antimicrobial agent, Triclosan, is widely used in many consumer products. It has been designated as a "contaminant of emerging concern (CEC)" because its exposure is known to cause adverse ecological and human health effects. Triclosan is not labelled as GRAS/GRAE (generally recognized as safe and effective), but its use is still prevailing. In vivo studies have revealed that exposure to triclosan results in a decreased acetylcholinesterase (AChE) activity. However mechanistic insights into AChE inhibition by triclosan are missing. Using in vitro AChE activity assay with purified AChE, we show that triclosan acts as a direct inhibitor of AChE and inhibits AChE activity in a dose-dependent manner. Given the function of AChE, any alteration in its activity can be neurotoxic. Our results provide important mechanistic insights into triclosan induced neurotoxicity with AChE as a target.

Download Full-text

A Systematic Review of the Literature on the Effects of Dexamethasone on the Brain From In Vivo Human-Based Studies: Implications for Physiological Brain Imaging of Patients With Intracranial Tumors

Neurosurgery ◽

10.1227/neu.0b013e3181fa775b ◽

2010 ◽

Vol 67 (6) ◽

pp. 1799-1815 ◽

Cited By ~ 30

Author(s):

Christina Kotsarini ◽

Paul D Griffiths ◽

Iain D Wilkinson ◽

Nigel Hoggard

Keyword(s):

Systematic Review ◽

Brain Tissue ◽

Database Search ◽

In Vivo Studies ◽

Normal Brain ◽

Review Of The Literature ◽

Eligibility Criteria ◽

Perfusion Studies ◽

The Brain

Abstract BACKGROUND: Among glucocorticoids, dexamethasone is most widely used for treatment of cerebral edema because of its long biological half-life and its low mineralocorticoid activity (sodium retaining). OBJECTIVE: A systematic review of the literature on the effects of dexamethasone on the brain from in vivo studies in humans. METHODS: A MEDLINE database search (via the PubMed interface) and an EMBASE database search (via the Dialog interface) of the past 35 years was performed. Every article relating to human use reported in English was included. In addition, references of all eligible articles were searched to identify other possible sources. RESULTS: Twenty-four articles matched the eligibility criteria. There were disparate methodologies and conflicting results, although they tended to indicate a decrease in blood-tumor barrier permeability, decreased tumoral perfusion, decreased tumoral diffusivity, and the possibility of decreased perfusion in contralateral normal-appearing brain tissue. CONCLUSION: Treatment with dexamethasone may alter imaging parameters from cerebral perfusion studies used in the management of brain tumors. In adequately powered studies, it may be possible to assess the longer term effects of dexamethasone on normal brain tissue to help optimize use with longer term survivors that are emerging as improvements in glioma treatment are made.

Download Full-text

Monocytes as Carriers of Magnetic Nanoparticles for Tracking Inflammation in the Epileptic Rat Brain

Current Drug Delivery ◽

10.2174/1567201816666190619122456 ◽

2019 ◽

Vol 16 (7) ◽

pp. 637-644 ◽

Cited By ~ 4

Author(s):

Hadas Han ◽

Sara Eyal ◽

Emma Portnoy ◽

Aniv Mann ◽

Miriam Shmuel ◽

...

Keyword(s):

Brain Tissue ◽

Ex Vivo ◽

In Vivo Studies ◽

Nanoparticle Distribution ◽

Spontaneous Seizures ◽

Systemic Distribution ◽

Hippocampal Ca1 ◽

Pilocarpine Model

Background: Inflammation is a hallmark of epileptogenic brain tissue. Previously, we have shown that inflammation in epilepsy can be delineated using systemically-injected fluorescent and magnetite- laden nanoparticles. Suggested mechanisms included distribution of free nanoparticles across a compromised blood-brain barrier or their transfer by monocytes that infiltrate the epileptic brain. Objective: In the current study, we evaluated monocytes as vehicles that deliver nanoparticles into the epileptic brain. We also assessed the effect of epilepsy on the systemic distribution of nanoparticleloaded monocytes. Methods: The in vitro uptake of 300-nm nanoparticles labeled with magnetite and BODIPY (for optical imaging) was evaluated using rat monocytes and fluorescence detection. For in vivo studies we used the rat lithium-pilocarpine model of temporal lobe epilepsy. In vivo nanoparticle distribution was evaluated using immunohistochemistry. Results: 89% of nanoparticle loading into rat monocytes was accomplished within 8 hours, enabling overnight nanoparticle loading ex vivo. The dose-normalized distribution of nanoparticle-loaded monocytes into the hippocampal CA1 and dentate gyrus of rats with spontaneous seizures was 176-fold and 380-fold higher compared to the free nanoparticles (p<0.05). Seizures were associated with greater nanoparticle accumulation within the liver and the spleen (p<0.05). Conclusion: Nanoparticle-loaded monocytes are attracted to epileptogenic brain tissue and may be used for labeling or targeting it, while significantly reducing the systemic dose of potentially toxic compounds. The effect of seizures on monocyte biodistribution should be further explored to better understand the systemic effects of epilepsy.

Download Full-text

Electromagnetic field in Alzheimer’s disease: a literature review of recent preclinical and clinical studies

Current Alzheimer Research ◽

10.2174/1567205017666201130085853 ◽

2020 ◽

Vol 17 ◽

Author(s):

Reem Habib Mohamad Ali Ahmad ◽

Marc Fakhoury ◽

Nada Lawand

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Neurodegenerative Disorder ◽

In Vivo Studies ◽

Key Factors ◽

Potential Benefits ◽

Preclinical And Clinical Studies ◽

The Brain

: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the progressive loss of neurons leading to cognitive and memory decay. The main signs of AD include the irregular extracellular accumulation of amyloidbeta (Aβ) protein in the brain and the hyper-phosphorylation of tau protein inside neurons. Changes in Aβ expression or aggregation are considered key factors in the pathophysiology of sporadic and early-onset AD and correlate with the cognitive decline seen in patients with AD. Despite decades of research, current approaches in the treatment of AD are only symptomatic in nature and are not effective in slowing or reversing the course of the disease. Encouragingly, recent evidence revealed that exposure to electromagnetic fields (EMF) can delay the development of AD and improve memory. This review paper discusses findings from in vitro and in vivo studies that investigate the link between EMF and AD at the cellular and behavioural level, and highlights the potential benefits of EMF as an innovative approach for the treatment of AD.

Download Full-text

Safety profile of the transcription factor EB (TFEB)-based gene therapy through intracranial injection in mice

Translational Neuroscience ◽

10.1515/tnsci-2020-0132 ◽

2020 ◽

Vol 11 (1) ◽

pp. 241-250

Author(s):

Zhenyu Li ◽

Guangqian Ding ◽

Yudi Wang ◽

Zelong Zheng ◽

Jianping Lv

Keyword(s):

Gene Therapy ◽

Transcription Factor ◽

Neurodegenerative Diseases ◽

Brain Tissue ◽

Inflammatory Responses ◽

Tissue Samples ◽

Protein Levels ◽

Virus Serotype ◽

Transcription Factor Eb ◽

The Brain

AbstractTranscription factor EB (TFEB)-based gene therapy is a promising therapeutic strategy in treating neurodegenerative diseases by promoting autophagy/lysosome-mediated degradation and clearance of misfolded proteins that contribute to the pathogenesis of these diseases. However, recent findings have shown that TFEB has proinflammatory properties, raising the safety concerns about its clinical application. To investigate whether TFEB induces significant inflammatory responses in the brain, male C57BL/6 mice were injected with phosphate-buffered saline (PBS), adeno-associated virus serotype 8 (AAV8) vectors overexpressing mouse TFEB (pAAV8-CMV-mTFEB), or AAV8 vectors expressing green fluorescent proteins (GFPs) in the barrel cortex. The brain tissue samples were collected at 2 months after injection. Western blotting and immunofluorescence staining showed that mTFEB protein levels were significantly increased in the brain tissue samples of mice injected with mTFEB-overexpressing vectors compared with those injected with PBS or GFP-overexpressing vectors. pAAV8-CMV-mTFEB injection resulted in significant elevations in the mRNA and protein levels of lysosomal biogenesis indicators in the brain tissue samples. No significant changes were observed in the expressions of GFAP, Iba1, and proinflammation mediators in the pAAV8-CMV-mTFEB-injected brain compared with those in the control groups. Collectively, our results suggest that AAV8 successfully mediates mTFEB overexpression in the mouse brain without inducing apparent local inflammation, supporting the safety of TFEB-based gene therapy in treating neurodegenerative diseases.

Download Full-text

Hexagonal boron nitride nanoparticles trigger oxidative stress by modulating thiol/disulfide homeostasis

Human & Experimental Toxicology ◽

10.1177/09603271211002892 ◽

2021 ◽

pp. 096032712110028

Author(s):

F Kar ◽

İ Söğüt ◽

C Hacıoğlu ◽

Y Göncü ◽

H Şenturk ◽

...

Keyword(s):

Oxidative Stress ◽

Boron Nitride ◽

Hexagonal Boron Nitride ◽

Chemical Properties ◽

Heart Tissue ◽

Albino Rats ◽

Dependent Manner ◽

Tissue Samples ◽

Boron Nitride Nanoparticles

Background: Hexagonal boron nitride nanoparticles (hBN NPs) are encouraging nanomaterials with unique chemical properties in medicine and biomedical fields. Until now, the optimal hBN NP’s dosage and biochemical mechanism that can be used for in vivo systems has not been fully revealed. The main aim of this article is to reveal characteristics, serum and tissue interactions and any acute cytotoxic effect of different dose of hBN NPs for the first time. Methods: hBN NPs at concentrations varying between 50–3200 µg/kg was administered by intravenous injection to Wistar albino rats (n = 80) divided into seven dosage and control groups. Blood and tissue samples were taken after 24 hours. Results: Our findings suggested that higher doses hBN NPs caused oxidative stress on the serum of rats dose-dependently. However, hBN NPs did not affect thiol/disulfide homeostasis on kidney, liver, spleen, pancreas and heart tissue of rats. Furthermore, hBN NPs increased serum disulfide formation by disrupting the thiol/disulfide balance in rats. Also, LOOH and MPO levels increased at high doses, while CAT levels decreased statistically. Conclusion: The results revealed that hBN NPs induce oxidative stress in a dose-dependent manner by modulating thiol/disulfide homeostasis in rats at higher concentrations

Download Full-text

Unraveling the neurotoxicity of titanium dioxide nanoparticles: focusing on molecular mechanisms

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.7.57 ◽

2016 ◽

Vol 7 ◽

pp. 645-654 ◽

Cited By ~ 17

Author(s):

Bin Song ◽

Yanli Zhang ◽

Jia Liu ◽

Xiaoli Feng ◽

Ting Zhou ◽

...

Keyword(s):

Dna Methylation ◽

Titanium Dioxide ◽

Molecular Mechanisms ◽

Titanium Dioxide Nanoparticles ◽

Brain Dysfunction ◽

In Vivo Studies ◽

Cell Components ◽

New Perspective ◽

The Brain

Titanium dioxide nanoparticles (TiO2 NPs) possess unique characteristics and are widely used in many fields. Numerous in vivo studies, exposing experimental animals to these NPs through systematic administration, have suggested that TiO2 NPs can accumulate in the brain and induce brain dysfunction. Nevertheless, the exact mechanisms underlying the neurotoxicity of TiO2 NPs remain unclear. However, we have concluded from previous studies that these mechanisms mainly consist of oxidative stress (OS), apoptosis, inflammatory response, genotoxicity, and direct impairment of cell components. Meanwhile, other factors such as disturbed distributions of trace elements, disrupted signaling pathways, dysregulated neurotransmitters and synaptic plasticity have also been shown to contribute to neurotoxicity of TiO2 NPs. Recently, studies on autophagy and DNA methylation have shed some light on possible mechanisms of nanotoxicity. Therefore, we offer a new perspective that autophagy and DNA methylation could contribute to neurotoxicity of TiO2 NPs. Undoubtedly, more studies are needed to test this idea in the future. In short, to fully understand the health threats posed by TiO2 NPs and to improve the bio-safety of TiO2 NPs-based products, the neurotoxicity of TiO2 NPs must be investigated comprehensively through studying every possible molecular mechanism.

Download Full-text

Limitations of studying keloid scars using the nude athymic mouse model

Canadian Journal of Plastic Surgery ◽

10.1177/229255030201000205 ◽

2002 ◽

Vol 10 (2) ◽

pp. 56-61 ◽

Cited By ~ 1

Author(s):

Mp Hillmer ◽

S Salama ◽

Sm Macleod

Keyword(s):

Mouse Model ◽

Scar Tissue ◽

In Vivo Studies ◽

Athymic Mice ◽

Athymic Mouse ◽

Tissue Samples ◽

Keloid Scars ◽

Central Calcification ◽

Sample Identity

Keloid scars are benign fibroproliferative growths that respond poorly to treatment. This study sought to determine the efficacy of three different glucocorticoids (triamcinolone, methylprednisolone and dexamethasone) in altering human keloid scar tissue implanted in athymic mice. Keloid tissue obtained from three patients (one man and two women) who sought cosmetic removal of their scars was implanted into athymic mice for a duration of 15 or 30 days. The keloid tissue was examined histopathologically and evaluated by a dermatopathologist who was blinded to sample identity and who was using predetermined qualitative scoring criteria. The appearance of central calcification, granulation tissue, foreign body granulomatous reaction and acute inflammatory reaction complicated the comparison of the keloid tissue samples. However, on the basis of observations reported in the present paper, it appears that triamcinolone should remain the treatment of choice for keloid scars. The athymic mouse model that is used for studying keloid scars is the best available approach to in vivo studies; however, limitations identified in this study confound the interpretation of experimental data. Ideally, promising and novel therapies should be investigated clinically.

Download Full-text

Scatterometry Measurements With Scattered Light Imaging Enable New Insights Into the Nerve Fiber Architecture of the Brain

Frontiers in Neuroanatomy ◽

10.3389/fnana.2021.767223 ◽

2021 ◽

Vol 15 ◽

Author(s):

Miriam Menzel ◽

Marouan Ritzkowski ◽

Jan A. Reuter ◽

David Gräßel ◽

Katrin Amunts ◽

...

Keyword(s):

Human Brain ◽

Nerve Fiber ◽

Brain Tissue ◽

Scattered Light ◽

Polar Angle ◽

Nerve Fibers ◽

Fiber Architecture ◽

Whole Brain ◽

Tissue Samples ◽

The Brain

The correct reconstruction of individual (crossing) nerve fibers is a prerequisite when constructing a detailed network model of the brain. The recently developed technique Scattered Light Imaging (SLI) allows the reconstruction of crossing nerve fiber pathways in whole brain tissue samples with micrometer resolution: the individual fiber orientations are determined by illuminating unstained histological brain sections from different directions, measuring the transmitted scattered light under normal incidence, and studying the light intensity profiles of each pixel in the resulting image series. So far, SLI measurements were performed with a fixed polar angle of illumination and a small number of illumination directions, providing only an estimate of the nerve fiber directions and limited information about the underlying tissue structure. Here, we use a display with individually controllable light-emitting diodes to measure the full distribution of scattered light behind the sample (scattering pattern) for each image pixel at once, enabling scatterometry measurements of whole brain tissue samples. We compare our results to coherent Fourier scatterometry (raster-scanning the sample with a non-focused laser beam) and previous SLI measurements with fixed polar angle of illumination, using sections from a vervet monkey brain and human optic tracts. Finally, we present SLI scatterometry measurements of a human brain section with 3 μm in-plane resolution, demonstrating that the technique is a powerful approach to gain new insights into the nerve fiber architecture of the human brain.

Download Full-text