Free radicals in brain metabolism and pathology

Role of antioxidants in the neurobiology of drug addiction: An update

Relationships between protective enzymatic and non-enzymatic pro-antioxidant mechanisms and addictive substances use disorders (SUDs) are analyzed here, based on the results of previous research, as well as on the basis of our current own studies. This review introduces new aspects of comparative analysis of associations of pro-antixidant and neurobiological effects in patients taking psychoactive substances and complements very limited knowledge about relationships with SUDs from different regions, mainly Europe. In view of the few studies on relations between antioxidants and neurobiological processes acting in patients taking psychoactive substances, this review is important from the point of view of showing the state of knowledge, directions of diagnosis and treatment, and further research needed explanation. We found significant correlations between chemical elements, pro-antioxidative mechanisms, and lipoperoxidation in the development of disorders associated with use of addictive substances, therefore elements that show most relations (Pr, Na, Mn, Y, Sc, La, Cr, Al, Ca, Sb, Cd, Pb, As, Hg, Ni) may be significant factors shaping SUDs. The action of pro-antioxidant defense and lipid peroxidation depends on the pro-antioxidative activity of ions. We explain the strongest correlations between Mg and Sb, and lipoperoxidation in addicts, which proves their stimulating effect on lipoperoxidation and on the induction of oxidative stress. We discussed which mechanisms and neurobiological processes change susceptibility to SUDs. The innovation of this review is to show that addicted people have lower activity of dismutases and peroxidases than healthy ones, which indicates disorders of antioxidant system and depletion of enzymes after long-term tolerance of stressors. We explain higher level of catalases, reductases, ceruloplasmin, bilirubin, retinol, α-tocopherol and uric acid of addicts. In view of poorly understood factors affecting addiction, analysis of interactions allows for more effective understanding of pathogenetic mechanisms leading to formation of addiction and development the initiation of directed, more effective treatment (pharmacological, hormonal) and may be helpful in the diagnosis of psychoactive changes.

Effect of chronic maternal L-Glu intake during gestation and/or lactation on oxidative stress markers, AMPA Glu1 receptor and adenosine A1 signalling pathway from foetal and neonatal cerebellum

L-Glutamate (L-Glu) is an amino acid present in the diet that plays a fundamental role in the central nervous system, as the main excitatory neurotransmitter participating in learning and memory processes. In addition, the nucleoside adenosine has a crucial role in L-Glu metabolism, by regulating the liberation of this neurotransmitter through four different receptors: A1, A2A, A2B and A3, which activate (A2A and A2B) or inhibit (A1 and A3) adenylate cyclase pathway. L-Glu at high concentrations can act as a neurotoxin and induce oxidative stress. The study of the oxidative stress correlated with an excess of L-Glu consumption during maternity is key to understand its effects on foetuses and neonates. Previous studies have shown that there is a change in the receptor levels in the brain of pregnant rats and their foetuses when mothers are administered L-Glu during gestation; however, its effect on the cerebellum is unknown. Cerebellum is known to be responsible for motor, cognitive and emotional functions, so its possible involvement after L-Glu consumption is an important issue to study. Therefore, the aim of the present work was to study the effect of L-Glu exposure during gestation and lactation on oxidative stress biomarkers and neurotransmitter receptors from the cerebellum of foetuses and neonates. After maternal L-Glu intake during gestation, oxidative stress was increased, as the ionotropic L-Glu receptors, and GluR1 AMPA subunit levels were altered in foetuses. A1 adenosine receptor suffered changes after L-Glu treatment during gestation, lactation or both, in lactating neonate cerebellum, while adenylate cyclase activity remain unaltered. Further studies will be necessary to elucidate the importance of L-Glu intake and its possible excitotoxicity in the cerebellum of Wistar rats during the pregnancy period and their involvement in long-term neurodegeneration.

Circulating Total Extracellular Vesicles Cargo Are Associated with Age-Related Oxidative Stress and Susceptibility to Cardiovascular Diseases: Exploratory Results from Microarray Data

Aging is a risk factor for many non-communicable diseases such as cardiovascular and neurodegenerative diseases. Extracellular vesicles and particles (EVP) carry microRNAs that may play a role in age-related diseases and may induce oxidative stress. We hypothesized that aging could impact EVP miRNA and impair redox homeostasis, contributing to chronic age-related diseases. Our aims were to investigate the microRNA profiles of circulating total EVPs from aged and young adult animals and to evaluate the pro- and antioxidant machinery in circulating total EVPs. Plasma from 3- and 21-month-old male Wistar rats were collected, and total EVPs were isolated. MicroRNA isolation and microarray expression analysis were performed on EVPs to determine the predicted regulation of targeted mRNAs. Thirty-one mature microRNAs in circulating EVPs were impacted by age and were predicted to target molecules in canonical pathways directly related to cardiovascular diseases and oxidative status. Circulating total EVPs from aged rats had significantly higher NADPH oxidase levels and myeloperoxidase activity, whereas catalase activity was significantly reduced in EVPs from aged animals. Our data shows that circulating total EVP cargo-specifically microRNAs and oxidative enzymes-are involved in redox imbalance in the aging process and can potentially drive cardiovascular aging and, consequently, cardiac disease.

Selective neuronal vulnerability to deficits in RNA processing

Emerging evidence indicates that errors in RNA processing can causally drive neurodegeneration. Given that RNA produced from expressed genes of all cell types undergoes processing (splicing, polyadenylation, 5' capping, etc.), the particular vulnerability of neurons to deficits in RNA processing calls for careful consideration. The activity-dependent transcriptome remodeling associated with synaptic plasticity in neurons requires rapid, multilevel post-transcriptional RNA processing events that provide additional opportunities for dysregulation and consequent introduction or persistence of errors in RNA transcripts. Here we review the accumulating evidence that neurons have an enhanced propensity for errors in RNA processing alongside grossly insufficient defenses to clear misprocessed RNA compared to other cell types. Additionally, we explore how tau, a microtubule-associated protein implicated in Alzheimer's disease and related tauopathies, contributes to deficits in RNA processing and clearance.

Antioxidant and neuroprotective effects of dexpanthenol in rats induced with traumatic brain injury

Trauma-induced primary damage is followed by secondary damage, exacerbating traumatic brain injury (TBI). Dexpanthenol has been shown to protect tissues against oxidative damage in various inflammation models. This study aimed to investigate possible antioxidant and neuroprotective effects of dexpanthenol in TBI. Wistar albino male rats were randomly assigned to control (n = 16), trauma (n = 16) and dexpanthenol (500 mg/kg; n = 14) groups. TBI was induced under anesthesia by dropping a 300 g weight from 70-cm height onto the skulls of the rats. Twenty-four hours after the trauma, the rats were decapitated and myeloperoxidase (MPO) levels, luminol- and lucigenin-enhanced chemiluminescence (CL), malondialdehyde (MDA) levels, superoxide dismutase (SOD) levels, and catalase (CAT) and caspase-3 activities were measured in brain tissues. Following transcardiac paraformaldehyde perfusion, histopathological damage was graded on hematoxylin-eosin-stained brain tissues. In the trauma group, MPO level, caspase-3 activity and luminol-lucigenin CL levels were elevated (p < 0.05-0.001) when compared to controls; meanwhile in the dexpanthenol group these increases were not seen (p < 0.05-0.001) and MDA levels were decreased (p < 0.05). Decreased SOD and CAT activities (p < 0.01) in the vehicle-treated TBI group were increased above control levels in the dexpanthenol group (p < 0.05-0.001). in the dexpanthenol group there was relatively less neuronal damage observed microscopically in the cortices after TBI. Dexpanthenol reduced oxidative damage, suppressed apoptosis by stimulating antioxidant systems and alleviated brain damage caused by TBI. Further experimental and clinical investigations are needed to confirm that dexpanthenol can be administered in the early stages of TBI.

Coenzyme Q10 treatment and diazinon exposure in parental male rats: effects of the exposure on their neonatal brains

Prenatal acute and chronic exposure to organophosphorus pesticides may evoke physical and behavioral impairments in offspring development. However, the mechanism of antioxidant consumption repair to cure these impairments remains unclear. This study aimed to investigate the protective effects of COQ10 against DZN toxicity by measuring Malondialdehyde (MDA) level, superoxide dismutase (SOD) activity, the expression of MH2A, DNMT1, H2AZ, and HDAC3, and the histopathology in the brain of neonatal Wistar albino rats whose male parents were exposed to DZN and COQ10. The results showed that COQ10 could significantly decrease MDA level, histopathological alteration, and expression of DNMT1 and HDAC3 in the neonatal brain (P < 0.05). Also, an increase in SOD activity and expression of MH2A and H2AZ were observed in the neonatal brain of this group (P < 0.05). These investigations suggest that COQ10 can reduce the effects of DZN on neuronal oxidative stress and its damage to the neonatal brain.

Bridging the Gap between Nonliving Matter and Cellular Life

A cell, the fundamental unit of life, contains the requisite blueprint information necessary to survive and to build tissues, organs, and systems, eventually forming a fully functional living creature. A slight structural alteration can result in data misprinting, throwing the entire life process off balance. Advances in synthetic biology and cell engineering enable the predictable redesign of biological systems to perform novel functions. Individual functions and fundamental processes at the core of the biology of cells can be investigated by employing a synthetically constrained micro or nanoreactor. However, constructing a life-like structure from nonliving building blocks remains a considerable challenge. Chemical compartments, cascade signaling, energy generation, growth, replication, and adaptation within micro or nanoreactors must be comparable with their biological counterparts. Although these reactors currently lack the power and behavioral sophistication of their biological equivalents, their interface with biological systems enables the development of hybrid solutions for real-world applications, such as therapeutic agents, biosensors, innovative materials, and biochemical microreactors. This review discusses the latest advances in cell membrane-engineered micro or nanoreactors, as well as the limitations associated with high-throughput preparation methods and biological applications for the real-time modulation of complex pathological states.

Acute radiofrequency electromagnetic radiation exposure impairs neurogenesis and causes neuronal DNA damage in the young rat brain

A mobile phone is now a commonly used device for digital media and communication among all age groups. Young adolescents use it for longer durations, which exposes them to radiofrequency electromagnetic radiation (RF-EMR). This exposure can lead to neuropsychiatric changes. The underlying cellular mechanism behind these changes requires detailed investigation. In the present study, we investigated the effect of RF-EMR emitted from mobile phones on young adolescent rat brains. Wistar rats (5 weeks, male) were exposed to RF-EMR signal (2115 MHz) at a head average specific absorption rate (SAR) of 1.51 W/kg continuously for 8 h. Higher level of lipid peroxidation, carbon-centered lipid radicals, and single-strand DNA damage was observed in the brain of rat exposed to RF-EMR. The number of BrdU-positive cells in the dentate gyrus (DG) decreased in RF-EMR-exposed rats, indicating reduced neurogenesis. RF-EMR exposure also induced degenerative changes and neuronal loss in DG neurons but had no effect on the CA3 and CA1 neurons of the hippocampus and cerebral cortex. The activity of Pro-caspase3 did not increase upon exposure in any of the brain regions, pointing out that degeneration observed in the DG region is not dependent on caspase activation. Results indicate that short-term acute exposure to RF-EMR induced the generation of carbon-centered lipid radicals and nuclear DNA damage, both of which likely played a role in the impaired neurogenesis and neuronal degeneration seen in the young brain's hippocampus region. The understanding of RF-EMR-induced alteration in the brain at the cellular level will help develop appropriate interventions for reducing its adverse impact.

Clinical and experimental research progress on neurotoxicity of sulfur mustard and its possible mechanisms

Sulfur mustard (SM), an extremely reactive alkylating toxicant, which poses a continuing threat to both military and civilian populations. SM targets three major organs including skin, eyes and lungs. In recent years, more and more clinical findings have shown that cognitive and emotional disorders in veterans intoxicated with SM, such as anxiety, depression, apathy, cognitive decline and so on, which indicated the long time toxic effects on mental and neurological health of SM. The experimental studies in animal and cell models have also found neurotoxicity which are similar to clinical results. However, these neuropsychological problems are not studied well in victims of SM and the mental and neurological complications are often not subjected to treatment or undertreated. Until now, the exact mechanism of the action of SM toxicity has not been elucidated and no specific therapy for its poisoning exists. Therefore, the studies on neurotoxicity of SM should be strengthened. This review summarizes the main progress of clinical and experimental researches on neurotoxicity of SM for the past few years.

Effects of Phenolic-Rich Pinus densiflora Extract on Learning, Memory, and Hippocampal Long-Term Potentiation in Scopolamine-Induced Amnesic Rats

Alzheimer's disease is the most common type of dementia with cognitive impairment. Various plant-derived phenolics are known to alleviate cognitive impairment in Alzheimer's disease by radical scavenging and strengthening synaptic plasticity activities. Here, we examined the cognition-improving effect of Pinus densiflora Sieb. et Zucc. bark extract (PBE). We identified and quantified phenolics in the PBE using a UHPLC-Orbitrap mass spectrometer. To evaluate the cognition-enhancing effects of PBE, scopolamine-induced amnesic Sprague-Dawley (SD) rats (5 weeks old) and ion channel antagonist-induced organotypic hippocampal slices of SD rats (7 days old) were used. Twenty-three phenolics were tentatively identified in PBE, 10 of which were quantified. Oral administration of PBE to the scopolamine-induced SD rats improved cognitive impairment in behavioral tests. PBE-fed SD rats showed significantly improved antioxidant indices (superoxide dismutase and catalase activities, and malondialdehyde content) and reduced acetylcholinesterase activity in hippocampal lysate compared with the scopolamine group. PBE increased the long-term potentiation (LTP) induction and rescued LTP from blockades by the muscarinic cholinergic receptor antagonist (scopolamine) and N-methyl-D-aspartate channel antagonist (2-amino-5-phosphonovaleric acid) in the organotypic hippocampal slices. These results suggest that polyphenol-rich PBE is applicable as a cognition-improving agent due to its antioxidant properties and enhancement of LTP induction.

Analysis of SOD2 rs4880 Genetic Variant in Patients with Alzheimer’s Disease

A few gene loci that contribute to Alzheimer’s Disease (AD) onset have been identified. Few studies have been published about the relationship between SOD2 rs4880 single nucleotide variant and AD, revealing inconsistent results. Therefore, the aim of the current study is to further examine the role of the SOD2 rs4880 in AD. We performed a case-control study with a total of 641 subjects (320 patients with probable AD, and 321 healthy controls). The statistical analysis was performed assuming five genetic models. The threshold for statistical significance was set at 0.05. The results revealed no association between SOD2 rs4880 and AD in any of the assumed genetic models that were examined [log-additive OR = 0.95 (0.76–1.19), over-dominant OR = 1.15 (0.85–1.57), recessive OR = 0.85 (0.59–1.22), dominant OR = 1.03 (0.72–1.47), and co-dominant OR1 = 1.10 (0.75–1.60) and OR2 = 0.90 (0.58–1.40)]. Adjustment for sex and subgroup analyses based on sex did not reveal any statistically significant results either. Based on our findings, SOD2 rs4880 does not appear to play a determining role in the risk of developing AD. Larger studies are warranted to elucidate the connection between rs4880 and AD.

Long Noncoding RNAs Regulate Hyperammonemia-Induced Neuronal Damage in Hepatic Encephalopathy

Background. Hyperammonemia can result in various neuropathologies, including sleep disturbance, memory loss, and motor dysfunction in hepatic encephalopathy. Long noncoding RNA (lncRNA) as a group of noncoding RNA longer than 200 nucleotides is emerging as a promising therapeutic target to treat diverse diseases. Although lncRNAs have been linked to the pathogenesis of various diseases, their function in hepatic encephalopathy has not yet been elucidated. Research Design and Methods. To identify the roles of lncRNAs in hepatic encephalopathy brain, we used a bile duct ligation (BDL) mouse model and examined the alteration of neuronal cell death markers and neuronal structure-related proteins in BDL mouse cortex tissue. Furthermore, analysis of the transcriptome of BDL mouse brain cortex tissues revealed several lncRNAs critical to the apoptosis and neuronal structural changes associated with hepatic encephalopathy. Results. We confirmed the roles of the lncRNAs, ZFAS1, and GAS5 as strong candidate lncRNAs to regulate neuropathologies in hepatic encephalopathy. Our data revealed the roles of lncRNAs, ZFAS1, and GAS5, on neuronal cell death and neural structure in hyperammonemia in in vivo and in vitro conditions. Conclusion. Thus, we suggest that the modulation of these lncRNAs may be beneficial for the treatment of hepatic encephalopathy.

Synthesis, DFT calculation, pharmacological evaluation, and catalytic application in the synthesis of diverse pyrano[2,3-c]pyrazole derivatives

Pyranopyrazole and its derivatives are classified to be a pharmacologically significant active scaffold for almost all modes of biological activities. In this work, An efficient, green, and facile three-component reaction for preparing pyrano[2,3-c]pyrazole derivatives via the condensation reaction of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, ethyl acetoacetate, and malononitrile in the presence of ZnO Nanoparticle. The products are produced with high yields and in shorter reaction times. It also is mild, safe, green, and environmentally friendly. The geometric parameters such as dipole moment, bond length, dihedral angles, total energy, heat of formation, atomic charges and energies at a highly accurate for prepared compounds were computed by Denisty Functional Theory along with the B3LYP functional. The newly synthesized compounds were screened for their anti-inflammatory and antioxidant activity. Some of the tested compounds displayed promising activities. The newly prepared compounds were found to be potent towards the antioxidant activity. Results indicated that compounds 11 and 12 exhibited significant (p ≥ 0.05) in vitro total antioxidant activity as 44.93 ± 0.15 and 39.60 ± 0.10 U/ML, respectively higher than standard ascorbic acid (29.40 ± 0.62).

Neurotoxicity of methamphetamine: Main effects and mechanisms

Methamphetamine (METH) is an illicit psychostimulant that is abused throughout the world. METH addiction is also a major public health concern and the abuse of large doses of the drug is often associated with serious neuropsychiatric consequences that may include agitation, anxiety, hallucinations, paranoia, and psychosis. Some human methamphetamine users can also suffer from attention, memory, and executive deficits. METH-associated neurological and psychiatric complications might be related, in part, to METH-induced neurotoxic effects. Those include altered dopaminergic and serotonergic functions, neuronal apoptosis, astrocytosis, and microgliosis. Here we have endeavored to discuss some of the main effects of the drug and have presented the evidence supporting certain of the molecular and cellular bases of METH neurotoxicity. The accumulated evidence suggests the involvement of transcription factors, activation of dealth pathways that emanate from mitochondria and endoplasmic reticulum (ER), and a role for neuroinflammatory mechanisms. Understanding the molecular processes involved in METH induced neurotoxicity should help in developing better therapeutic approaches that might also serve to attenuate or block the biological consequences of use of large doses of the drug by some humans who meet criteria for METH use disorder.

Daphnetin, a natural coumarin averts reserpine-induced fibromyalgia in mice: modulation of MAO-A

Fibromyalgia is a common, chronic, and generalized pain syndrome that is often associated with comorbid depression. The etiology of fibromyalgia is complex; most researchers have documented that the hallmark symptoms are due to the central nervous system's abnormal functioning. Neurotransmitters such as serotonin, norepinephrine, and glutamate, have been reported to be key regulators of fibromyalgia syndrome. Daphnetin is a 7, 8 dihydroxy coumarin widely distributed in Thymelaeaceae family plants, possessing various activities such as anti-arthritic, anti-tumor, anti-malarial, and anti-parasitic. The present study was designed to explore the potential of daphnetin against reserpine-induced fibromyalgia in mice. In mice, a fibromyalgia-like state was achieved by injecting reserpine (0.5 mg/kg, s.c) continuously for 3 days. All behavioral tests were conducted on the 4th and 6th day of experimentation. Reserpine administration significantly increased the mechanical hypersensitivity in electronic von Frey (eVF) and pressure application measurement (PAM) tests. It also increased the immobility period and time to reach the platform in force swim test (FST) and Morris water maze (MWM) test, respectively. In the biochemical analysis, reserpine treatment upregulated the monoamine oxidase-A (MAO-A) activity and level of glutamate, tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and thiobarbituric acid reactive substances (TBARS). Whereas, it decreased the level of glutathione (GSH), dopamine, serotonin, and norepinephrine. Daphnetin pretreatment attenuated the behavioral and biochemical changes induced by reserpine. Thus, the current investigation results delineate that daphnetin might exert its protective effect by inhibiting inflammatory stress and MAO-A-mediated neurotransmitter depletion and oxidative stress.

An updated knowledge of Black seed (Nigella sativa Linn.): Review of phytochemical constituents and pharmacological properties

N. sativa (N. sativa) has been used since ancient times, when a scientific concept about the use of medicinal plants for the treatment of human illnesses and alleviation of their sufferings was yet to be developed. It has a strong religious significance as it is mentioned in the religious books of Islam and Christianity. In addition to its historical and religious significance, it is also mentioned in ancient medicine. It is widely used in traditional systems of medicine for a number of diseases including asthma, fever, bronchitis, cough, chest congestion, dizziness, paralysis, chronic headache, back pain and inflammation. The importance of this plant led the scientific community to carry out extensive phytochemical and biological investigations on N. sativa. Pharmacological studies on N. sativa have confirmed its antidiabetic, antitussive, anticancer, antioxidant, hepatoprotective, neuro-protective, gastroprotective, immunomodulator, analgesic, antimicrobial, anti-inflammatory, spasmolytic, and bronchodilator activity. The present review is an effort to explore the reported chemical composition and pharmacological activity of this plant. It will help as a reference for scientists, researchers, and other health professionals who are working with this plant and who need up to date knowledge about it.

Relationship Between Oxidative Stress, Tau Level and Antioxidant Mechanisms of the KEAP-1/NRF-2/HO-1 in Children with Hydrocephalus

BACKGROUND

Hydrocephalus is a complex neurologic disorder which has a widespread impact on the central nervous system, and a multifactor disease which effect the CSF dynamics and causes severe neurological impairments in children. The pathophysiology of hydrocephalus is not fully understood. However, increasing evidence suggests that oxidative stress may be an important factor in the pathogenesis of hydrocephalus.

OBJECTIVE

The purpose of this study is to investigate the relationship of KEAP-1/NRF-2/HO-1 pathway, one of the main regulators of the antioxidant system in the hydrocephalus pathology, on oxidative stress and tau protein level.

METHODS

The study included 32 patients with hydrocephalus and 32 healthy controls. KEAP-1, NRF-2, HO-1, TAU, and MPO levels are measured using ELISA method TAS, TOS, Total THIOL colorimetric method.

RESULTS

KEAP-1, TAS, Total THIOL levels were found significantly low in the hydrocephalus group compared to the control group. Nevertheless, it is identified in the hydrocephalus group that the NRF-2, HO-1, TAU, MPO, TOS, and OSI levels were significantly elevated.

CONCLUSION

In conclusion, although KEAP-1/NRF-2/HO-1 pathway is activated in patients with hydrocephalus, it is identified that the antioxidant defense system is insufficient, and ultimately leads to elevated oxidative stress. The elevation in the tau level may be an indicator of oxidative stress induced neurodegenerative damage.

Quality control, HPTLC analysis, antioxidant and antimicrobial activity of hydroalcoholic extract of roots of qust (Saussurea lappa, C.B Clarke)

OBJECTIVES

Saussurea lappa, CB Clarke (S.lappa) is a perennial herb of the Compositae family. The root of S.lappa has been used for the treatment of various diseases such as hepatitis, jaundice, intestinal worms, bronchial asthma, and a variety of skin diseases. The aim of the study was to ensure quality control of S.lappa and its preparation HAESL (hydroalcoholic extract of S.lappa) along with assessment of HAESL antimicrobial and antioxidant activities in vitro.

METHODS

HAESL was prepared with 50% ethanol, (v/v). Physiochemical analysis of the root of S.lappa, and phytochemical screening, thin-layer chromatography (TLC), high-performance thin-layer chromatography (HPTLC), and in vitro antimicrobial and antioxidant activity of HAESL were performed using the standard protocol.

RESULTS

Physiochemical and phytochemical assessments of S.lappa and HAESL showed the greater quality of the drug. HAESL showed the presence of many phytochemical constituents corresponding to colorful spots, peaks, area under the curve, and corresponding Rf values as evident in the TLC and HPTLC analysis. HAESL showed a concentration-dependent effect on radical scavenging activity against DPHH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radical with IC50 value of 19.10 μg/mL and 82.23 μg/mL, respectively. HAESL exhibited antimicrobial activity against the growth of micro-organisms such as Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Aspergillus flavus, and Candida albicans. HASEL showed no antimicrobial activity against Aspergillus niger.

CONCLUSIONS

The procured and an identified sample of Saussurea lappa was good in quality and the prepared HAESL contained many phytochemical compounds. HAESL substantiated significant antioxidant and antimicrobial activity in vitro.

Soy isoflavones ameliorate the cognitive dysfunction of Goto-Kakizaki rats by activating the Nrf2-HO-1 signalling pathway

Soy isoflavones (SIF) are soybean phytochemicals that are considered to be biologically active components that protect from neurodegenerative diseases. In this study, the therapeutic effect of SIF was evaluated in a diabetic Goto-Kakizaki (GK) rat model. Twenty male GK rats were randomly divided into diabetes mellitus (DM) model group and SIF+DM group (n=10 in each group). Twenty age-matched male Wistar rats were randomly divided into control group (CON group) and CON+SIF group, with 10 rats in each group. The learning and memory functions of the animals were determined by the Morris water maze (MWM) test. Hematoxylin-eosin staining (HE) was performed to examine pyramidal neuron loss in the CA1 area of the hippocampus. Markers of oxidative stress (OS) were measured to evaluate oxidative stress-mediated injury. RT-PCR and western blotting were used to analyze the expression of nuclear factorerythroid2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone1 (NQO1). Treatment with SIF for 4 weeks alleviated the cognitive dysfunction of the GK rats as determined by the MWM test. Moreover, SIF treatment also reduced diabetes-related oxidative reactions. In addition, SIF enhanced the expression of Nrf2, HO-1 and NQO1, suggesting a potential antioxidation mechanism for the effect of SIF. These findings suggest that SIF can be considered candidates for inhibiting the progression of diabetes-induced cognitive dysfunction, provide novel insights into the antioxidant effect of SIF and further strengthen the link between oxidative stress and diabetes.

Synthesis and in vitro evaluation of vanillin derivatives as multi-target therapeutics for the treatment of Alzheimer's disease

A number of novel naphthalimido and phthalimido vanillin derivatives were synthesised, and evaluated as antioxidants and cholinesterase inhibitors in vitro. Antioxidant activity was assessed using DPPH, FRAP, and ORAC assays. All compounds demonstrated enhanced activity compared to the parent compound, vanillin. They also exhibited BuChE selectivity in Ellman's assay. A lead compound, 2a (2-(3-(bis(4-hydroxy-3-methoxybenzyl)amino)propyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione), was identified and displayed strong antioxidant activity (IC₅₀ of 16.67 µM in the DPPH assay, a 25-fold increase in activity compared to vanillin in the FRAP assay, and 9.43 TE in the ORAC assay). Furthermore, 2a exhibited potent BuChE selectivity, with an IC₅₀ of 0.27 µM which was around 53-fold greater than the corresponding AChE inhibitory activity. Molecular modelling studies showed that molecules with bulkier groups, as in 2a, exhibited better BuChE selectivity. This work provides a promising basis for the development of multi-target hybrid compounds based on vanillin as potential AD therapeutics.

Risk factors for osteonecrosis of the femoral head in brain tumor patients receiving corticosteroid after surgery

Purpose

Non-traumatic osteonecrosis of the femoral head (ONFH) is a plausible complication in brain tumor patients. Frequent use of corticosteroid therapy, chemotherapy, and oxidative stress for managing brain tumors may be associated with the development of ONFH. However, there is little knowledge on the prevalence and risk factors of ONFH from brain tumor. This study aimed to investigate the prevalence and risk factors of ONFH in patients with primary brain tumors.

Methods

This retrospective cohort study included data from consecutive patients between December 2005 and August 2016 from a tertiary university hospital in South Korea. A total of 73 cases of ONFH were identified among 10,674 primary brain tumor patients. After excluding subjects (25 out of 73) with missing data, history of alcohol consumption or smoking, history of femoral bone trauma or surgery, comorbidities such as systemic lupus erythematosus (SLE), sickle cell disease, cancer patients other than brain tumor, and previous diagnosis of contralateral ONFH, we performed a 1:2 propensity score-matched, case–control study (ONFH group, 48; control group, 96). Risk factors of ONFH in primary brain tumor were evaluated by univariate and multivariate logistic regression analyses.

Results

The prevalence of ONFH in patients with surgical resection of primary brain tumor was 683.9 per 100,000 persons (73 of 10,674). In this cohort, 55 of 74 patients (74.3%) underwent THA for ONFH treatment. We found that diabetes was an independent factor associated with an increased risk of ONFH in primary brain tumor patients (OR = 7.201, 95% CI, 1.349–38.453, p = 0.021). There was a significant difference in univariate analysis, including panhypopituitarism (OR = 4.394, 95% CI, 1.794–11.008, p = 0.002), supratentorial location of brain tumor (OR = 2.616, 95% CI, 1.245–5.499, p = 0.011), and chemotherapy (OR = 2.867, 95% CI, 1.018–8.069, p = 0.046).

Conclusions

This study demonstrated that the prevalence of ONFH after surgical resection of primary brain tumor was 0.68%. Diabetes was an independent risk factor for developing ONFH, whereas corticosteroid dose was not. Routine screening for brain tumor-associated ONFH is not recommended; however, a high index of clinical suspicion in these patients at risk may allow for early intervention and preservation of the joints.

Biochemical, Toxicological, and Histopathological outcome in rat brain following treatment with NiO and NiO nanoparticles

Nickel oxide nanoparticle (NiO NPs) has been widely used in various fields such as catalysts, radiotherapy, and nanomedicine. The aim of this study was to compare the effects of nickel oxide (NiO) and NiO NPs on oxidative stress biomarkers and histopathological changes in brain tissue of rats. In this study, 49 male rats were randomly divided into one control group and 6 experimental groups (n = 7). The control group received normal saline and the treatment groups received NiO and NiO NPs at doses of 10, 25, and 50 mg/kg intraperitoneally for 8 days. After 8 days, animal was sacrificed, brain excised, homogenized, centrifuged, and then supernatant was collected for antioxidant assays. The results showed that activity of GST in NiO NPs groups with doses of 10, 25, and 50 mg/kg (79.42 ± 4.24, p = 0.035; 78.77 ± 8.49, p = 0.041; 81.38 ± 12.39, p = 0.042 to 47.26 ± 7.17) and catalase in NiO NPs groups with concentrations of 25 and 50 mg/kg (69.95 ± 8.65 to 39.75 ± 5.11, p = 0.02) and (68.80 ± 4.18 to 39.75 ± 5.11 p = 0.027) were significantly increased compared with the control, respectively. Total antioxidant capacity in NiONPs group with doses of 50 mg/kg was significantly decreased (345.00 ± 23.62, p = 0.015 to 496.66 ± 25.77) compared with control. The GSH level in all doses NiO and NiONPs was significantly decreased compared with the control (p = 0.002). MDA level in NiONPs and NiO groups with doses of 50 mg/kg was significantly increased (13.03 ± 1.29, p = < 0.01; 15.61 ± 1.08, p = < 0.001 to 7.32 ± 0.51) compared with the control, respectively. Our results revealed a range of histopathological changes, including necrosis, hyperemia, gliosis, and spongy changes in brain tissue. Thus, increasing level of MDA, GST, and CAT enzymes and decreasing GSH and TAC and also histopathological changes confirmed NiONPs and NiO toxicity.

Minimalistic Principles for Designing Small Molecules with Multiple Reactivities against Pathological Factors in Dementia

Multiple pathogenic elements, including reactive oxygen species, amyloidogenic proteins, and metal ions, are associated with the development of neurodegenerative disorders. We report minimalistic redox-based principles for preparing compact aromatic compounds by derivatizing the phenylene moiety with various functional groups. These molecular agents display enhanced reactivities against multiple targets such as free radicals, metal-free amyloid-β (Aβ), and metal-bound Aβ that are implicated in the most common form of dementia, Alzheimer's disease (AD). Mechanistic studies reveal that the redox properties of these reagents are essential for their function. Specifically, they engage in oxidative reactions with metal-free and metal-bound Aβ, leading to chemical modifications of the Aβ peptides to form covalent adducts that alter the aggregation of Aβ. Moreover, the administration of the most promising candidate significantly attenuates the amyloid pathology in the brains of AD transgenic mice and improves their cognitive defects. Our studies demonstrate an efficient and effective redox-based strategy for incorporating multiple functions into simple molecular reagents.

High concentration of MSG alters antioxidant defence system in lobster cockroach Nauphoeta cinerea (Blattodea: Blaberidae)

Objective

Monosodium glutamate (MSG) is a food additive that has been shown to be toxic to rodents at high concentrations. The available studies in Drosophila melanogaster suggest that MSG toxicity depends on concentration and gender, thus the safety of MSG as a food enhancer still requires further investigation. We have documented impaired locomotor activity and altered oxidative stress markers in cockroaches co-exposed to methylmercury and monosodium glutamate (MSG). We herein examined the susceptibility of Nauphoeta cinerea to high and low concentrations (4% and 1%) of MSG, while monitoring the activities of acetylcholinesterase (AChE), as well as markers of oxidative stress and antioxidant activity over 30 days.

Results

There was no significant alteration in the parameters assessed at 1% MSG while 4% MSG caused an increase in the activity of reactive oxygen and nitrogen species, with a corresponding reduction in the activities of acetylcholinesterase, glutathione-S-transferase and catalase, suggesting the capacity of MSG to alter redox homeostasis in Nauphoeta cinerea.

Neuroprotective effect of Convolvulus pluricaulis Choisy in oxidative stress model of cerebral ischemia reperfusion injury and assessment of MAP2 in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Convolvulus pluricaulis Choisy commonly known as Shankhapushpi, is traditionally prescribed for nerve debility, loss of memory, epilepsy and as nervine tonic. Plant also proved to have diverse pharmacological activity but the neuroprotection in ischemic stroke were not found.

AIM OF THE STUDY

To investigate the effect of Convolvulus pluricaulis against bilateral common carotid artery (BCCA) occlusion induced cerebral ischemic reperfusion injury.

MATERIALS AND METHODS

The neuroprotective activity of Convolvulus pluricaulis against bilateral common carotid artery (BCCA) occlusion induced cerebral ischemic reperfusion (I/S) injury. Sprague-Dawley rats of either sex (200-250 g) were divided into nine groups of 8 rats each. Sham and control group, saline treated 10 ml/kg orally. Third group treated with Quercetin 25 mg/kg orally and fourth to ninth groups treated with chloroform and ethanol extract of Convolvulus pluricaulis 100, 200, and 400 mg/kg (p.o.) respectively. Control, Quercetin and extract treated groups underwent 30 min BCCA occlusion and 24 h reperfusion on 10th day but sham underwent same surgery without BCCA occlusion and 24 h reperfusion on 10th day. The antioxidant enzymatic and non-enzymatic levels were estimated by UV spectroscopic method and cerebral infarction area, Blood brain barrier disruption, microtubule-associated protein 2 immunohistochemical and histopathological studies were carried out.

RESULTS

The results of the study indicate that the chloroform and ethanol extract of Convolvulus pluricaulis showed neuroprotective activity by a significant decrease in lipid peroxidation (p < 0.001) and an increase in superoxide dismutase (p < 0.01, p < 0.001), catalase (p < 0.01, p < 0.001), glutathione (p < 0.001), and total thiol (p < 0.001) levels in extract-treated groups as compared to control group. Measurement of cerebral infarction area, blood brain barrier disruption, microtubule-associated protein 2 immunohistochemical and histopathological studies further supported the protective effect of the extract.

CONCLUSIONS

Present study revile that Convolvulus pluricaulis has potent neuroprotection against bilateral common carotid artery (BCCA) occlusion induced cerebral ischemic reperfusion injury.

Aging protects rat cortical slices against to oxygen-glucose deprivation induced damage

Objective: In present study, we aimed to clarify effect of aging on the susceptibility of brain tissue to neurodegeneration induced by ischemia.Methods: Damage induced by oxygen-glucose deprivation (OGD) followed by reoxygenation (REO) were compared in cortical slices prepared from young (3 months of age) and aged (22-24 months of age) male Sprague Dawley rats.Results: After incubation of the slices in an oxygen and glucose containing control condition, 2,3,5-triphenyl tetrazolium chloride (TTC) staining intensity was found significantly high in aged cortical slices. Although thirty minutes incubation of the slices in OGD medium followed by REO (OGD-REO) caused similar decline in TTC staining in young and aged cortical slices, staining intensity was still significantly higher in the slices prepared from aged animals. Thirty minutes of OGD-REO, on the other hand, also caused more increase in lactate dehydrogenase (LDH) leakage from young slices. While water contents of the slices were almost equal under control condition, it was significantly high in young cortical slices after OGD-REO incubations. In contrary to these findings, OGD and REO caused more increases in S100B output from aged rat cortical slices. S100B levels in brain regions including the cerebral cortex were also found higher in aged rats.Conclusion: All these results indicate that, cortical slices prepared from aged male rats are significantly less responsive to in vitro OGD-REO induced alterations. Since protein S100B outputs were almost doubled from aged cortical slices, a possible involvement of this enhanced S100B output seems to be likely.

Blood total antioxidant status is associated with cortical glucose uptake and factors related to accelerated aging

Identifying cerebral vulnerability in late life is of paramount importance to prevent pathological trajectories of aging before the onset of symptoms. Considerable evidence suggests that impaired antioxidant mechanisms are a fingerprint of aging-related conditions, but there is a lack of human research linking total antioxidant capacity (TAC) measured in peripheral blood to in vivo brain changes and other factors featuring accelerated aging. To address this issue, we have assessed in cognitively normal elderly subjects (N = 100) correlations between serum TAC, using the oxygen radical absorbance capacity assay, surface-based cortical thickness, surface-based 18F-fluorodeoxyglucose positron emission tomography cortical uptake, and different factors associated with accelerated aging [i.e., serum homocysteine (HCY), self-reported memory problems, and self-reported patterns of physical activity]. While no relationship was observed between serum TAC and variations in cortical thickness, decreased TAC level was significantly associated with lower FDG uptake in temporal lobes bilaterally. Remarkably, decreased TAC level was linked to increased HCY concentrations, more subjective memory complaints, and lower frequency of physical activity. Overall, our results suggest that decreased serum TAC level may be helpful to detect vulnerable trajectories of aging.

Neuroprotective and long term potentiation improving effects of vitamin E in juvenile hypothyroid rats

Abstract. Protective effects of vitamin E (Vit E) on long term potentiation (LTP) impairment, neuronal apoptosis and increase of nitric oxide (NO) metabolites in the hippocampus of juvenile rats were examined. The rats were grouped (n=13) as: (1) control; (2) hypothyroid (Hypo) and (3) Hypo-Vit E. Propylthiouracil (PTU) was given in drinking water (0.05%) during 6 weeks. Vit E (20 mg/ kg) was daily injected (IP). To evaluate synaptic plasticity, LTP from the CA1 area of the hippocampus followed by high frequency stimulation to the ipsilateral Schafer collateral pathway was carried out. The cortical and hippocampal tissues were then removed to measure NO metabolites. The brains of 5 animals in each group were removed for apoptosis study. The hypothyroidism status decreased the slope, 10–90% slope and amplitude of field excitatory post synaptic potential (fEPSP) compared to the control group (P<0.01–P<0.001). Injection of Vit E increased the slope, 10–90% slope and amplitude of the fEPSP in the Hypo-Vit E group in comparison to the Hypo group (P<0.05–P<0.01). TUNEL positive neurons and NO metabolites were higher in the hippocampus of the Hypo rats, as compared to those in the hippocampus of the control ones (P<0.001). Treatment of the Hypo rats by Vit E decreased apoptotic neurons (P<0.01–P<0.001) and NO metabolites (P<0.001) in the hippocampus compared to the Hypo rats. The results of the present study showed that Vit E prevented the LTP impairment and neuronal apoptosis in the hippocampus of juvenile hypothyroid rats.

Current and emerging therapeutic targets of alzheimer's disease for the design of multi-target directed ligands

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, and a major cause of death worldwide. The number of people suffering from this debilitating disorder is rising at an unprecedented rate, with a subsequent surge in healthcare costs. Only four drugs are clinically available for the treatment of AD symptoms, but they are not disease-modifying. Consequently, there is an urgent need for a cure. Although the cause of this debilitating condition remains poorly understood, it is believed that several factors may be involved in combination - including, health and lifestyle, environmental, and genetic factors. In recent years, a number of hallmarks of the disease have also been discovered, and it is believed that these factors may play an important role in the development of AD. Amyloid aggregation is one such factor which has been highly investigated, in addition to cholinesterase enzymes and tau aggregation. In the last decade, multi-target drugs have been increasingly investigated for their application to AD treatment. By combining two or more pharmacophores in a single compound, it is possible to synthesise a drug which can target several factors that are involved in AD development. This is a particularly attractive approach as it would avoid the use of combination therapies. As a result, it could reduce the burden on carers and families, and decrease healthcare and social care costs. Many active pharmacophores have been employed for the development of hybrid drugs, due to their abilities to inhibit the factors currently widely recognised to be involved in AD. These compounds have demonstrated promising results; however, research is still required to optimise the pharmacological profiles of the drugs, in addition to their potencies. Meanwhile, extensive research is continuously being performed into other potential targets for the treatment of AD. Based on the results obtained thus far, it is likely that multi-target compounds will continue to be increasingly studied in the future as potential treatments for AD.

Nigella sativa oil and thymoquinone reduce oxidative stress in the brain tissue of rats exposed to total head irradiation

Purpose: To evaluate the antioxidant and radio-protective effects of Nigella sativa oil (NSO) and thymoquinone (TQ) on radiation-induced oxidative stress in brain tissue.Materials and methods: Fifty-four Sprague-Dawley rats were divided into six groups to test the radio-protective effectiveness of Nigella sativa oil and thymoquine administered by either orogastric tube or intraperitoneal injection. Appropriate control groups were also studied.Results: Brain antioxidant capacity, as measured by the levels of total superoxide scavenger activity (TSSA), non-enzymatic superoxide scavenger activity (NSSA), superoxide dismutase, paraoxonase (PON) activities, total antioxidant status and total sulfhydryl (-SH) group, were lower in the irradiation (IR) only group while xanthine oxidase (XO) activity, total oxidant status (TOS), oxidative stress index (OSI) and lipid hydroperoxide (LOOH) levels were higher in the group compared with all other groups. Brain glutathione-S-transferase (GST) activity significantly decreased in the IR only group when compared with the control groups. Glutathione peroxidase (GSH-Px) activity was lower in the IR only, NSO plus IR, TQ plus IR groups when compared with the control group of TQ. Arylesterase (ARYL) activity was not statistically significant in the IR only group compared with all other groups.Conclusions: The results suggest that Nigella sativa oil (NSO) and its active component, TQ, clearly protect brain tissue from radiation-induced oxidative stress.

Neuroprotective effects of mildronate in a rat model of traumatic brain injury

OBJECTIVE

Traumatic brain injury (TBI) is one of the most common preventable causes of mortality and morbidity. Inflammation, apoptosis, oxidative stress, and ischemia are some of the important pathophysiological mechanisms underlying neuronal loss after TBI. Mildronate is demonstrated to be beneficial in various experimental models of ischemic diseases via anti-inflammatory, antioxidant, and neuroprotective mechanisms. This study aimed to investigate possible antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects of mildronate in a rat model of TBI.

METHODS

A total of 46 male rats were divided into three groups of control, saline-treated TBI, and mildronate-treated TBI. Both TBI groups were subjected to closed-head contusive weight-drop injuries followed by treatment with saline or mildronate (100 mg/kg) administered intraperitoneally. The forebrain was removed 24 h after trauma induction, the activities of myeloperoxidase (MPO) and caspase-3, levels of superoxide dismutase (SOD), luminol- and lucigenin-enhanced chemiluminescence were measured, and histomorphological evaluation of cerebral tissues was performed.

RESULTS

Increased MPO and caspase-3 activities in the vehicle-treated TBI group (p < 0.001) were suppressed in the mildronate-treated TBI group (p < 0.001). Similarly, increase in luminol and lucigenin levels (p < 0.001 and p < 0.01, respectively) in the vehicle-treated TBI group were decreased in the mildronate-treated TBI group (p < 0.001). Concomitantly, in the vehicle-treated TBI group, TBI-induced decrease in SOD activity (p < 0.01) was reversed with mildronate treatment (p < 0.05). On histopathological examination, TBI-induced damage in the cerebral cortex was lesser in the mildronate-treated TBI group than that in other groups.

CONCLUSION

This study revealed for the first time that mildronate, exhibits neuroprotective effects against TBI because of its anti-inflammatory, antiapoptotic, and antioxidant activities.

Gut Microbiota Disorder, Gut Epithelial and Blood-Brain Barrier Dysfunctions in Etiopathogenesis of Dementia: Molecular Mechanisms and Signaling Pathways

Emerging evidences indicate a critical role of the gut microbiota in etiopathogenesis of dementia, a debilitating multifactorial disorder characterized by progressive deterioration of cognition and behavior that interferes with the social and professional functions of the sufferer. Available data suggest that gut microbiota disorder that triggers development of dementia is characterized by substantial reduction in specific species belonging to the Firmicutes and Bacteroidetes phyla and presence of pathogenic species, predominantly, pro-inflammatory bacteria of the Proteobacteria phylum. These changes in gut microbiota microecology promote the production of toxic metabolites and pro-inflammatory cytokines, and reduction in beneficial substances such as short chain fatty acids and other anti-inflammatory factors, thereby, enhancing destruction of the gut epithelial barrier with concomitant activation of local and distant immune cells as well as dysregulation of enteric neurons and glia. This subsequently leads to blood-brain barrier dysfunctions that trigger neuroinflammatory reactions and predisposes to apoptotic neuronal and glial cell death, particularly in the hippocampus and cerebral cortex, which underlie the development of dementia. However, the molecular switches that control these processes in the histo-hematic barriers of the gut and brain are not exactly known. This review integrates very recent data on the molecular mechanisms that link gut microbiota disorder to gut epithelial and blood-brain barrier dysfunctions, underlying the development of dementia. The signaling pathways that link gut microbiota disorder with impairment in cognition and behavior are also discussed. The review also highlights potential therapeutic options for dementia.

Protective effect of 6-O-methyl-scutellarein on repeated cerebral ischemia/reperfusion in rats

Scutellarin (1) possesses protective effects against neuronal injury, while 6-O-methyl-scutellarein (3), as the main metabolite of scutellarin in vivo, has not been reported about its protective effects previously. The present study mainly investigated whether the neural injury caused by ischemia/reperfusion would be influenced by different doses of 6-O-methyl-scutellarein (3). The results of behavioral, neurological, and histological examinations indicated that 6-O-methyl-scutellarein (3) could improve neuronal injury, and exhibit significant difference among the various doses. More importantly, 6-O-methyl-scutellarein (3) had better protective effects than scutellarin in rat cerebral ischemia.

Neuro-protective role of nanocapsulated curcumin against cerebral ischemia-reperfusion induced oxidative injury

Cerebral ischemia-reperfusion (CIR) accelerates the progression of neurodegeneration by causing mitochondrial dysfunction to overproduce reactive oxygen species (ROS). Curcumin shows protective effects against CIR-induced oxidative damage. Free curcumin (FC) is effective at high doses due to its poor bioavailability. Also the blood-brain barrier (BBB) limits the passage of substances from circulation into the cerebral region. Thus, formulation of curcumin within polyethylene glycol (PEG)-ylated polylactide-co-glycolide (PLGA) nanoparticles (NC) was applied orally to aged rats to explore its role against CIR injury. Mitochondrial damage was evaluated. The levels of pro-inflammatory cytokines and components of apoptotic pathway were studied. Unlike FC, NC pre-treatment exerted better neuro-protection by ameliorating ROS-mediated oxidative damage and prevented CIR-induced neuronal apoptosis. Therefore, curcumin incorporated PEGylated PLGA nanoparticles may be used as a suitable delivery vehicle to the brain as they can increase curcumin bioavalability and the released curcumin may confer protection to the neurons against CIR-induced oxidative damage.

Current Perspectives and Mechanisms of Relationship between Intestinal Microbiota Dysfunction and Dementia: A Review

BACKGROUND

Accumulating data suggest a crucial role of the intestinal microbiota in the development and progression of neurodegenerative diseases. More recently, emerging reports have revealed an association between intestinal microbiota dysfunctions and dementia, a debilitating multifactorial disorder, characterized by progressive deterioration of cognition and behavior that interferes with the social and professional life of the sufferer. However, the mechanisms of this association are not fully understood.

SUMMARY

In this review, I discuss recent data that suggest mechanisms of cross-talk between intestinal microbiota dysfunction and the brain that underlie the development of dementia. Potential therapeutic options for dementia are also discussed. The pleiotropic signaling of the metabolic products of the intestinal microbiota together with their specific roles in the maintenance of both the intestinal and blood-brain barriers as well as regulation of local, distant, and circulating immunocytes, and enteric, visceral, and central neural functions are integral to a healthy gut and brain.

KEY MESSAGES

Research investigating the effect of intestinal microbiota dysfunctions on brain health should focus on multiple interrelated systems involving local and central neuroendocrine, immunocyte, and neural signaling of microbial products and transmitters and neurohumoral cells that not only maintain intestinal, but also blood brain-barrier integrity. The change in intestinal microbiome/dysbiome repertoire is crucial to the development of dementia.

Computational modeling and biomarker studies of pharmacological treatment of Alzheimer's disease (Review)

Alzheimer's disease (AD) is a complex and multifactorial disease. In order to understand the genetic influence in the progression of AD, and to identify novel pharmaceutical agents and their associated targets, the present study discusses computational modeling and biomarker evaluation approaches. Based on mechanistic signaling pathway approaches, various computational models, including biochemical and morphological models, are discussed to explore the strategies that may be used to target AD treatment. Different biomarkers are interpreted on the basis of morphological and functional features of amyloid β plaques and unstable microtubule‑associated tau protein, which is involved in neurodegeneration. Furthermore, imaging and cerebrospinal fluids are also considered to be key methods in the identification of novel markers for AD. In conclusion, the present study reviews various biochemical and morphological computational models and biomarkers to interpret novel targets and agonists for the treatment of AD. This review also highlights several therapeutic targets and their associated signaling pathways in AD, which may have potential to be used in the development of novel pharmacological agents for the treatment of patients with AD. Computational modeling approaches may aid the quest for the development of AD treatments with enhanced therapeutic efficacy and reduced toxicity.

A Single Primary Blast-Induced Traumatic Brain Injury in a Rodent Model Causes Cell-Type Dependent Increase in Nicotinamide Adenine Dinucleotide Phosphate Oxidase Isoforms in Vulnerable Brain Regions

Blast-induced traumatic brain injury (bTBI) is a leading cause of morbidity in soldiers on the battlefield and in training sites with long-term neurological and psychological pathologies. Previous studies from our laboratory demonstrated activation of oxidative stress pathways after blast injury, but their distribution among different brain regions and their impact on the pathogenesis of bTBI have not been explored. The present study examined the protein expression of two isoforms: nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 and 2 (NOX1, NOX2), corresponding superoxide production, a downstream event of NOX activation, and the extent of lipid peroxidation adducts of 4-hydroxynonenal (4HNE) to a range of proteins. Brain injury was evaluated 4 h after the shock-wave exposure, and immunofluorescence signal quantification was performed in different brain regions. Expression of NOX isoforms displayed a differential increase in various brain regions: in hippocampus and thalamus, there was the highest increase of NOX1, whereas in the frontal cortex, there was the highest increase of NOX2 expression. Cell-specific analysis of changes in NOX expression with respect to corresponding controls revealed that blast resulted in a higher increase of NOX1 and NOX 2 levels in neurons compared with astrocytes and microglia. Blast exposure also resulted in increased superoxide levels in different brain regions, and such changes were reflected in 4HNE protein adduct formation. Collectively, this study demonstrates that primary blast TBI induces upregulation of NADPH oxidase isoforms in different regions of the brain parenchyma and that neurons appear to be at higher risk for oxidative damage compared with other neural cells.

2-(2-benzofuranyl)-2-imidazoline (2-BFI) improved the impairments in AD rat models by inhibiting oxidative stress, inflammation and apoptosis

Alzheimer's Disease (AD) is one of the commonest neural degeneration in aging population, and has become a global health challenge. 2-(2-benzofuranyl)-2-imidazoline (2-BFI) was reported to effectively improved the damage of patients with neuropathological disorders. In the present study, we investigated the effect of 2-BFI on the improvement of antioxidative, inflammation, and apoptosis in AD rats. Sprague-Dawley rats (2 months old, n=40) were used in this study and after injection of Aβ1-42 into hippocampal CA1 (Cornu Ammonis) region, the rats were given high, moderate and low dose of 2-BFI though intraperitoneal (i.p.) injection. Then spatial memory and navigation ability were analyzed by Morrize Water Maze. For the molecular testing, chemical colorimetry, ELISA and immunoblotting were performed to measure the activities of antioxidative enzymes, the abundance of immune cytokines and expression of apoptotic proteins, respectively. Hematoxylin and Eosin staining was used to analyze the pathological changes. We observed that 2-BFI significantly ameliorated the learning and memory abilities in rat models with AD by dosage treatment, as demonstrated by the shorten learning latency and greater times of travel across the platform quadrant. Additionally, reactive oxygen species (ROS) and malondialdehyde (MDA), were decreased after treatment of 2-BFI with dosage dependency, while the activities of superoxidase dismutase (SOD) and (GPX) Glutathione peroxidase were in turn enhanced, suggesting that 2-BFI could protect the antioxidative enzymes and reduce the oxidative stress in the hippocampus. Moreover, the expression of inflammatory factors including TNF-a and IL-1β were decreased after 2-BFI treatment. Additionally, the neuronal apoptosis was also attenuated, as shown by Western blot results. Taken together, the cognitive impairment in AD rats could be significantly improved by 2-BFI in a dose-dependent manner through suppressing oxidants accumulation, inhibiting of inflammatory response, as well as enhancing the neural viability.

Safety assessment of the aqueous extract of the flowers of Nymphaea lotus Linn (Nymphaeaceae): Acute, neuro- and subchronic oral toxicity studies in albinos Wistar rats

Background Nymphaea lotus Linn (N. lotus) is a medicinal plant widely used in Cameroon popular medicine, to treat neuropsychiatric conditions, male sexual disorders or as food supplement. However, scientific data on the pharmacotoxic profile of this plant are not available. The safety of N. lotus was assessed in acute, neuro- and subchronic toxicity studies by following the OECD guidelines. Effectively, no data have been published until now in regard to its safety on the nervous system. Methods Aqueous extract of N. lotus at doses of 200, 400 and 600 mg/kg body weight (BW) was evaluated for nitrites contents and orally administered to rats daily for 28 days (5 male, 5 female per group). The control group received distilled water (10 mL/kg) and a satellite group was used to observe reversal effects. Neurotoxicity of the plant was determined using open field test for motor coordination, ataxia and gait analysis. Clinical signs and state of livelihood were recorded during the 24 h, then for 28 days of treatments. At the end of 28-day period, animals were anesthetized and decapitated. The whole brain was homogenized for neurobiochemical analysis. Blood samples were collected with or without anticoagulant for hematological examinations and serum analysis. Specimens of liver, kidney, testis, ovaries, and brain were fixed in 10 % formalin and processed for histopathological examinations. Results Our findings indicate dose-dependent elevation of nitrites contents in the flowers aqueous extract of N. lotus. Acute toxicity study revealed no signs of toxicity neither at the dose 2,000 mg/kg nor at 5,000 mg/kg. Thus the LD50 value of aqueous extract of N. lotus flowers is superior to 5,000 mg/kg. The repeated administration of N. lotus during 28 days, induced no signs of neurobehavioral changes in male, but female rats exhibited dose-dependent response in the open field test, suggesting sex and dose-relative psychotropic effects of N. lotus. The evaluation of neurobiochemistry revealed consistent rise of brain cholesterol by 44.05 %; 158.10 % and 147.62 % respectively in male rats treated with the doses of 200, 400 and 600 mg/kg. In female rats, these levels were significantly increased (p<0.001) only at the dose of 600 mg/kg compared to control. This trend persisted after 14 days withdrawal. Brain potassium and calcium concentrations were increased in all rats compared to their respective control receiving distilled water, suggesting transmembrane current stabilizing properties of brain cells by our extract. Further, serum biochemical analysis demonstrated that 28-day administration of N. lotus flowers increased depending on the dose and sex, the levels of serum urea, proteins, creatinine and bilirubin and reduced γ-glutamyltransferase (GGT) and alkaline phosphatase (ALP) activities. These results suggest liver alterations that are endowed by lower liver relative weight and histology damages observed in female rats treated with the dose of 600 mg/kg of our extract. We also observed a rise in the low-density lipoprotein (LDL) fraction and AI of male rats undergoing N. lotus treatment. In female rats, the latter remains unaltered, confirming the dose- and sex-dependent response of our extract. The levels of white blood cells (WBC) and granulocytes were higher in male irrespective to their control, revealing stimulatory properties of the male hematopoietic system. Such variations (sex- and dose-dependent) are without biological relevance for the majority of the biochemical parameters evaluated, indicating a wide margin of safety for the traditional use of N. lotus. The alkaloids, nitrites and phytosterols contained in N. lotus flowers extract may probably account for its neuroprotective, anti-oxidant, and immunoboosting properties. Conclusions N. lotus do not possesses neurotoxicity but is able to induce behavioral changes in rats. Therefore, the application of this plant as either drug or supplementary food should be carefully considered.

The Neuroprotective Effects of Thymoquinone: A Review

Thymoquinone (TQ), one of the main components active of Nigella sativa, exhibited very useful biomedical effects such as anti-inflammatory, antioxidant, antimicrobial, antiparasitic, anticancer, hypoglycemic, antihypertensive, and antiasthmatic effects. There are several studies about pharmacological activities of TQ but its neuroprotection effects are not fully described. The literature search has indicated many studies pertaining to the effects of TQ in neurological problems such as epilepsy, parkinsonism, anxiety, and improvement of learning and memory, and so on. In addition, TQ protected brain cells from various injuries due to its antioxidant, anti-inflammatory, and apoptotic effects in cell line and experimental animal models. The present study has been designed to review the scientific literature about the pharmacological activities of TQ to the neurological diseases. This study purposed that although experimental studies indicated the beneficial effects of TQ against nervous system problems, better designed clinical trials in humans are needed to confirm these effects.

Therapeutic Evaluation of Tumor Necrosis Factor-alpha Antagonist Etanercept against Traumatic Brain Injury in Rats: Ultrastructural, Pathological, and Biochemical Analyses

Purpose

The aim of the present study was to investigate the effect of etanercept (ETA) on histopathological and biochemical changes after traumatic brain injury (TBI) in rats.

Materials and Methods

Thirty-six male Wistar albino rats were distributed into three groups (n = 12 each). Control group rats were not subjected to trauma. Trauma group rats were subjected to TBI only. ETA group rats were subjected to TBI plus ETA (5 mg/kg intraperitoneal [i.p.]). The groups were further subdivided into those sacrificed in the hyperacute stage (1 h after TBI) (control-1, trauma-1, and ETA-1 groups) and the acute stage (6 h after TBI) (control-6, trauma-6, and ETA-6 groups). Tissue levels of tumour necrosis factor-alpha, interleukin-1 beta, malondialdehyde, catalase, glutathione peroxidase, and superoxide dismutase were analyzed. Histopathological and ultrastructural evaluations were also performed.

Results

i.p. administration of ETA at 1 and 6 h significantly reduced inflammatory cytokine expression, attenuated oxidative stress and lipid peroxidation, prevented apoptosis, and increased antioxidant defense mechanism activity in comparison to trauma group. Histopathological and ultrastructural abnormalities were significantly reduced in ETA-treated rats compared to closed head injury trauma groups.

Conclusions

ETA significantly improves neural function and prevents post-TBI histopathological damage in rats.

HEK-293 secretome attenuates kainic acid neurotoxicity through insulin like growth factor-phosphatidylinositol-3-kinases pathway and by temporal regulation of antioxidant defense machineries

A major impediment in the success of cell therapy for neurodegenerative diseases is the poor survival of grafted cells in the in vivo milieu, predominantly due to accumulated reactive oxygen species, thus prompting the search for suitable alternatives. Accumulating evidence suggests that the therapeutic potential of transplanted cells is partially attributed to the secretome released by them into the extracellular milieu. Studies that investigated the neuroprotective potential of the secretome attributes to the mere presence of growth factors without addressing other underlying cellular/molecular changes that occur upon post-secretome intervention like re-establishing the host cell's free radical scavenging machineries. In the present study, we investigated the neuroprotective effects of human embryonic kidney (HEK-293) cell line derived secretome (HEK-S) in an in vitro model of kainic acid (KA) induced neurodegeneration and explored the possible neuroprotective mechanism(s) of HEK-S. Murine hippocampal cells were exposed to toxic doses of KA (200μM) for 6hours (H) or 24H to induce excitotoxicity. Kainic acid exposed hippocampal cells were then treated with HEK-S either simultaneously or 6h post-KA exposure. Our results revealed that HEK-S confers significant neuroprotection in early/later stages of neurodegeneration through insulin like growth factor (IGF) - phosphatidylinositol-3-kinases (PI3K) pathway, efficiently restoring the host's free radical scavenging mechanisms at molecular-cellular-biochemical levels and also by modulating kainate receptor subunit expressions in host neurons.

Superoxide Dismutase-Loaded Porous Polymersomes as Highly Efficient Antioxidants for Treating Neuropathic Pain

A highly efficient antioxidant is developed by encapsulating superoxide dismutase (SOD) within the aqueous interior of porous polymersomes. The porous polymersomes provide a permeable membrane that allows free superoxide radicals to pass into the aqueous interior and interact with the encapsulated antioxidant enzyme SOD. In vivo studies in the rat demonstrate that administration of SOD-encapsulated porous polymersomes can prevent neuropathic pain after nerve root compression more effectively than treatment with free antioxidant enzyme alone.

Genetically driven antioxidant capacity in a Caucasian Southeastern European population

Previous studies have underlined the function of specific xenobiotic metabolizing phase-I or phase-II enzymes and endogenous antioxidant-related enzymes in the reduction and/or progression of oxidative stress and consequently the incidence of several diseases. In the present study, 10 polymorphic variants (rs4880, rs1799895, rs660339, rs1050450, rs1001179, rs28665122, rs1695, rs1138272, rs1051740 and rs2234922) were investigated in 1132 individuals of a Caucasian Southeastern European population. The frequency distribution of alleles and genotypes was compared to data of European (Northern, Central, Northwestern and Southwestern) and Global populations, extracted from the ensembl genome browser. The allele frequencies in the case of rs1051740 were similar to the frequencies noted in the global population. The majority of the present study allelic polymorphisms showed similar frequency distribution to those of the European or the Global populations (0.88≤OR≤1.14). The rs1051740 polymorphism demonstrated similar to the Global population frequencies (OR=1.09). In conclusion, observed distributions of the polymorphisms studied in the Southeastern population demonstrate a positive impact (rs4880, rs1799895, rs660339, rs28665122) and a negative impact (rs1050450, rs1138272, rs109179, rs1695) against oxidative stress when compared to other population groups.