CNS & Neurological Disorders - Drug Targets - Volume 17, Issue 6, 2018

Background: Aluminum (Al) causes neurodegeneration and its toxic effects on cholinergic system in the brain is well documented. However, it is unknown whether and how Al changes oscillation patterns, driven by the cholinergic system, in the hippocampus. Objective: We studied acute effects of Al on nicotinic acetylcholine receptors (nAChRs)-mediated modulation of persistent gamma oscillations in the hippocampus. Method: The field potential recording was done in CA3 area of acute hippocampal slices. Results: Carbachol-induced gamma oscillation peak power increased (1.32±0.09mV2/Hz, P<0.01) in control conditions (without Al) by application of 10μM nicotine as compared to baseline value normalized to 1. This nicotine-induced facilitation of gamma oscillation peak power was found to depend on non-α7 nAChRs. In slices with Al pre-incubation for three to four hours, gamma oscillation peak power was reduced (5.4±1.8mV2/Hz, P<0.05) and facilitatory effect of nicotine on gamma oscillation peak power was blocked as compared to the control (18.06±2.1mV2/Hz) or one hour Al pre-incubated slices (11.3±2.5mV2/Hz). Intriguingly wash-out, after three to four hours of Al incubation, failed to restore baseline oscillation power and its facilitation by nicotine as no difference was observed in gamma oscillation peak power between Al wash-out slices (3.4±1.1mV2/Hz) and slices without washout (3.6±0.9mV2/Hz). Conclusion: This study shows that at cellular level, exposure of hippocampal tissue to Al compromised nAChR-mediated facilitation of cholinergic hippocampal gamma oscillations. Longer in vitro Al exposure caused permanent changes in hippocampal oscillogenic circuitry and changed its sensitivity to nAChR-modulation. This study will help to understand the possible mechanism of cognitive decline induced by Al.

Background & Objective: Medicinal plants have attracted great attention in the recent years and is increasingly applied instead of the chemical drugs. Several documents showed that herbal medicine traditionally and clinically applied in the cure and prevention of several diseases. In the recent years, different medicinal plants and their main components have been chosen in neurological therapy. The less toxic effects, availability, and lower price of medicinal plants versus synthetic substances make them as excellent and simple selection in the treatment of nervous diseases. Nigella sativa (N. Sativa) L. (Ranunculaceae), well recognized as black cumin, has been utilized as a medicinal plant that has a strong traditional background. Thymoquinone (TQ) is one of the main active components of the volatile oil of N. sativa seeds and most effects and actions of N. Sativa are mainly related to TQ. The several pharmacological properties of N. sativa and TQ have been found, for example; anti-tumor, anti-microbial, anti-histaminic, immunomodulatory, anti-inflammatory, and anti-oxidant effects. Many reviews have investigated this valuable plant and its components, but none of them focused on their neuroprotective effects. Therefore, the aim of the present review was to show comprehensive and neuropharmacological properties of N. sativa and TQ. In this review, various studies on scientific databases regarding the effects of N. sativa and TQ in neurological diseases have been introduced. Studies on the neuroprotective effects of N. sativa and TQ which were published between1979 and 2018, were searched using various databases. The results of these studies showed that N. sativa and TQ have the protective effects against neurodegenerative diseases, including; Alzheimer, depression, encephalomyelitis, epilepsy, ischemia, Parkinson, and traumatic brain injury have been discussed in the cell lines and experimental animal models. Although there are many studies indicating the beneficial actions of this plant in the nervous system, the number of research projects relating to the human reports is rare. Conclusion: Therefore, better designed clinical trials in humans are needed to confirm these effects.

Background: Alzheimer's disease (AD) is characterized by the accumulation and deposition of β-amyloid peptides leading to a progressive neuronal damage and cell loss. Besides several hypotheses for explaining the neurodegenerative mechanisms, oxidative stress has been considered to be one of them. Till date, there is no cure for AD, but the pathogenesis of the disease could be delayed by the use of natural antioxidants. In this context, we decided to study the effect of kaempferol against the transgenic Drosophila expressing human amyloid beta-42. Method: The AD flies were allowed to feed on the diet having 10, 20, 30 and 40μM of kaempferol for 30 days. After 30 days of exposure, the amyloid beta flies were studied for their climbing ability and Aversive Phototaxis Suppression assay. Amyloid beta flies head homogenate was prepared for estimating the oxidative stress markers, Caspase and acetylcholinesterase activity. Results: The results of the present study reveal that the exposure of AD flies to kaempferol delayed the loss of climbing ability, memory, reduced the oxidative stress and acetylcholinesterase activity. Conclusion: Kaempferol could be used as a possible therapeutic agent against the progression of the Alzheimer's disease.

Background: Migraine is a disabling neuroinflammatory condition characterized by increasing the levels of interleukin (IL)-6, a proinflammatory cytokine and C-reactive protein (CRP) which considered as a vascular inflammatory mediator, disrupting the integrity of blood-brain barrier and contributing to neurogenic inflammation, and disease progression. Curcumin and ω-3 fatty acids can exert neuroprotective effects through modulation of IL-6 gene expression and CRP levels. The aim of present study is the evaluation of combined effects of ω-3 fatty acids and nano-curcumin supplementation on IL-6 gene expression and serum level and hs-CRP levels in migraine patients. Methods: Eighty episodic migraine patients enrolled in the trial and were divided into four groups as 1) combination of ω-3 fatty acids (2500 mg) plus nano-curcumin (80 mg), 2) ω-3 (2500 mg), 3) nanocurcumin (80 mg), and 4) the control (ω-3 and nano-curcumin placebo included oral paraffin oil) over a two-month period. At the beginning and the end of the study, the expression of IL-6 from peripheral blood mononuclear cells and IL-6 and hs-CRP serum levels were measured, using a real-time PCR and ELISA methods, respectively. Results: The results showed that both of ω-3 and nano-curcumin down-regulated IL-6 mRAN and significantly decreased the serum concentration. hs-CRP serum levels significantly decrease in combination and nano-curcumin within groups (P<0.05). An additive greater reduction of IL-6 and hs-CRP was observed in the combination group suggested a possible synergetic relation. Conclusion: It seems that ω-3 fatty acids and curcumin supplementation can be considered a new promising target in migraine prevention.

Background: Cinnamon polyphenol extract is a traditional spice commonly used in different areas of the world for the treatment of different disease conditions which are associated with inflammation and oxidative stress. Despite many preclinical studies showing the anti-oxidative and antiinflammatory effects of cinnamon, the underlying mechanisms in signaling pathways via which cinnamon protects the brain after brain trauma remained largely unknown. However, there is still no preclinical study delineating the possible molecular mechanism of neuroprotective effects cinnamon polyphenol extract in Traumatic Brain Injury (TBI). The primary aim of the current study was to test the hypothesis that cinnamon polyphenol extract administration would improve the histopathological outcomes and exert neuroprotective activity through its antioxidative and anti-inflammatory properties following TBI. Methods: To investigate the effects of cinnamon, we induced brain injury using a cold trauma model in male mice that were treated with cinnamon polyphenol extract (10 mg/kg) or vehicle via intraperitoneal administration just after TBI. Mice were divided into two groups: TBI+vehicle group and TBI+ cinnamon polyphenol extract group. Brain samples were collected 24 h later for analysis. Results: We have shown that cinnamon polyphenol extract effectively reduced infarct and edema formation which were associated with significant alterations in inflammatory and oxidative parameters, including nuclear factor-ΚB, interleukin 1-beta, interleukin 6, nuclear factor erythroid 2-related factor 2, glial fibrillary acidic protein, neural cell adhesion molecule, malondialdehyde, superoxide dismutase, catalase and glutathione peroxidase. Conclusion: Our results identify an important neuroprotective role of cinnamon polyphenol extract in TBI which is mediated by its capability to suppress the inflammation and oxidative injury. Further, specially designed experimental studies to understand the molecular cross-talk between signaling pathways would provide valuable evidence for the therapeutic role of cinnamon in TBI and other TBI related conditions.

Background & Objective: A series of novel 3-Substituted-1,3,4,5-Tetrahydro-2H-benzo [b] azepine-2-one Derivatives (4, 5, 7, 10, 12, 5a-j, 8a-e) were synthesized from 1,2,3,4-Tetrahydro-1- naphthalenone. The structures of these compounds were confirmed by IR, 1H NMR, 13C NMR, MASS spectra and elemental analysis. Their anticonvulsant activity was evaluated by the maximal electroshock (MES) test, subcutaneous pentylenetetrazol (scPTZ) test, and their neurotoxicity was evaluated by the rotarod neurotoxicity test. Compound 4 showed the maximum anticonvulsant activity against the maximal electroshock test (ED50=26.4, PI =3.2) and against the subcutaneous pentylenetetrazol test (ED50=40.2, PI =2.1). Conclusion: Possible structure-activity relationship was discussed.

Background & Objective: Continuously active neurogenic regions in the adult brain are located in the subventricular zone (SVZ) of the lateral ventricles and subgranular zone of the hippocampal dentate gyrus. Neurogenesis is modulated by many factors such as growth factors, neurotransmitters and hormones. Neuropsychiatric drugs, especially antidepressants, mood stabilizers and antipsychotics may also affect the origin of neuronal cells. Method: The purpose of this study was to determine the effects of chronic olanzapine treatment on adult rat neurogenesis at the level of the SVZ. The number of neuroblasts was evaluated using immunohistochemical and fluorescent detection of sex determining region Y-box 2 and doublecortin expressing cells. Results & Conclusion: The results indicate that olanzapine has proneurogenic effects on the adult rat SVZ, as the mean number of sex determining region Y-box 2 and doublecortin-positive cells increased significantly, while there was a similar tendency in the subgranular zone. Collectively, these results suggest that long-term treatment with olanzapine may stimulate neurogenic stem cell formation in the SVZ which supports adult neurogenesis.

Background: In the lymphocyte migration across the blood-brain barrier (BBB) in multiple sclerosis (MS), matrix metalloproteinases (MMPs) play an important role in the degradation of the basal membrane. Natalizumab (NAT), a monoclonal antibody, binds to the alpha-4 (α4) integrin leading to BBB impermeability. Approximately 30% of NAT-treated patients show clinical or MRI signs of BBB disruption. Objective: To determine whether NAT significantly influences the MMPs serum levels and to what extent these could be used as biomarkers in relapsing-remitting MS (RRMS) patients. Materials and Methods: This prospective study over a period of 8 months of NAT treatment, included 30 RRMS patients (mean age 38 ± 6 years; mean MS duration 12 ± 5 years), of which ten were initially naive to NAT and 15 were healthy controls. We determined the serum levels of the MMPs Panel (MMP1, MMP2, MMP3, MMP7, MMP8, MMP9, MMP10, MMP12, and MMP13) quantified by a multiplex method at the beginning and end of the study. Results: After 8 months of NAT treatment, a statistically significant decrease was found in MMP9, MMP2, MMP3, MMP8, and MMP10 levels. Relapses during the study were correlated with a variation of MMP12 and MMP13 serum levels. MMP9 had the most numerous correlations with the EDSS score, Rio score, and duration of NAT treatment. MMPs signature (the sum of all MMPs) and the MMP9/MMP2 ratio significantly decreased during the study. Conclusion: 1. The serum level of MMP9 significantly decreased by NAT treatment and correlates with MS activity; 2. After eight months of NAT treatment, the MMPs signature and the MMP9/MMP2 ratio decreased; 3. MMP9 might be used as a biomarker in MS patients treated with NAT.

Aim & Objective: To delineate the associations between executive impairments and changes in tryptophan catabolite (TRYCAT) patterning, negative symptoms and deficit schizophrenia. Methods: We recruited 80 schizophrenic patients and 40 healthy controls and assessed 10 key cognitive tests using the Cambridge Neuropsychological Test Automated Battery (CANTAB), IgA/IgM responses to tryptophan catabolites (TRYCATs), the Scale for the Assessment of Negative Symptoms (SANS) and Positive and Negative Syndrome Scale. Results: Partial Least Squares path modeling shows that a large part of the variance in negative symptoms and the deficit phenotype (39-53%) is explained by executive impairments, TRYCAT levels and male sex and that 53.4% of the variance in executive impairments is explained by TRYCATs, lower education, age and a familial history of psychosis. Specific indirect effects of TRYCATs, age and education on negative symptoms are mediated by executive impairments. Nevertheless, sustained attention, memory and emotion recognition also mediate the effects of TRYCATS, lower education and male sex on negative symptoms. Conclusion: Deficit schizophrenia is accompanied by a broader spectrum of cognitive impairments than nondeficit schizophrenia, including executive functions, sustained attention, episodic and semantic memory and emotion recognition. Furthermore, neuro-immune disorders underpin executive impairments, whilst neuro-immune disorders coupled with executive and other cognitive impairments to a large extent determine negative symptoms and the deficit phenotype.