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Exposure to cadmium, a heavy metal distributed in the environment is a cause of concern due to associated health effects in population around the world. Continuing with the leads demonstrating alterations in brain cholinergic signalling in cadmium induced cognitive deficits by us; the study is focussed to understand involvement of N-Methyl-D-aspartate receptor (NMDA-R) and its postsynaptic signalling and Nrf2-ARE pathways in hippocampus. Also, the protective potential of quercetin, a polyphenolic bioflavonoid, was assessed in cadmium induced alterations. Cadmium treatment (5 mg/kg, body weight, p.o., 28 days) decreased mRNA expression and protein levels of NMDA receptor subunits (NR1, NR2A) in rat hippocampus, compared to controls. Cadmium treated rats also exhibited decrease in levels of NMDA-R associated downstream signalling proteins (CaMKIIα, PSD-95, TrkB, BDNF, PI3K, AKT, Erk1/2, GSK3ß, and CREB) and increase in levels of SynGap in hippocampus. Further, decrease in protein levels of Nrf2 and HO1 associated with increase in levels of Keap1 exhibits alterations in Nrf2/ARE signalling in hippocampus of cadmium treated rats. Degeneration of pyramidal neurons in hippocampus was also evident on cadmium treatment. Simultaneous treatment with quercetin (25 mg/kg body weight p.o., 28 days) was found to attenuate cadmium induced changes in hippocampus. The results provide novel evidence that cadmium exposure may disrupt integrity of NMDA receptors and its downstream signaling targets by affecting the Nrf2/ARE signaling pathway in hippocampus and these could contribute in cognitive deficits. It is further interesting that quercetin has the potential to protect cadmium induced changes by modulating Nrf2/ARE signaling which was effective to control NMDA-R and PI3K/AKT cell signaling pathways.
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Proteínas Proto-Oncogênicas c-akt , Quercetina , Ratos , Animais , Quercetina/farmacologia , Quercetina/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , N-Metilaspartato/metabolismo , Cádmio/toxicidade , Cádmio/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais , Receptores de N-Metil-D-Aspartato/genética , Hipocampo , CogniçãoRESUMO
The risk to develop neurobehavioural abnormalities in humans on exposure to lambda-cyhalothrin (LCT) - a type II synthetic pyrethroid has enhanced significantly due to its extensive uses in agriculture, homes, veterinary practices and public health programs. Earlier, we found that the brain dopaminergic system is vulnerable to LCT and affects motor functions in rats. In continuation to this, the present study is focused to unravel the role of neuroinflammation in LCT-induced neurotoxicity in substantia nigra and corpus striatum in rats. Increase in the mRNA expression of proinflammatory cytokines (TNF- α, IL-1ß, IL-6) and iNOS whereas decrease in anti-inflammatory cytokine (IL-10) was distinct both in substantia nigra and corpus striatum of rats treated with LCT (0.5, 1.0, 3.0 mg/kg body weight, p.o, for 45 days) as compared to control rats. Further, LCT-treated rats exhibited increased levels of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adapter molecule 1 (Iba-1), the glial marker proteins both in substantia nigra and corpus striatum as compared to controls. Exposure of rats to LCT also caused alterations in the levels of heat shock protein 60 (HSP60) and mRNA expression of toll-like receptors (TLR2 and TLR4) in the substantia nigra and corpus striatum. An increase in the phosphorylation of key proteins involved in NF-kß (P65, Iκß, IKKα, IKKß) and JAK/STAT (STAT1, STAT3) signaling and alteration in the protein levels of JAK1 and JAK2 was prominent in LCT-treated rats. Histological studies revealed damage of dopaminergic neurons and reactive gliosis as evidenced by the presence of darkly stained pyknotic neurons and decrease in Nissl substance and an increase in infiltration of immune cells both in substantia nigra and corpus striatum of LCT-treated rats. Presence of reactive microglia and astrocytes in LCT-treated rats was also distinct in ultrastructural studies. The results exhibit that LCT may damage dopaminergic neurons in the substantia nigra and corpus striatum by inducing inflammation as a result of stimulation of neuroglial cells involving activation of NF-κß and JAK/STAT signaling.
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Piretrinas , Humanos , Ratos , Animais , Piretrinas/metabolismo , Substância Negra/metabolismo , Neurônios Dopaminérgicos/metabolismo , Citocinas/genética , Citocinas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Inflamação/metabolismo , RNA Mensageiro/metabolismo , Corpo Estriado/metabolismoRESUMO
Early-life viral infections critically influence the brain development and have been variously reported to cause neuropsychiatric diseases such as Schizophrenia, Parkinson's diseases, demyelinating diseases, etc. To investigate the alterations in the dopaminergic system, myelination and associated behavioral impairments following neonatal viral infection, the viral immune activation model was created by an intraperitoneal injection of Poly I:C (5 mg/kg bw/ip) to neonatal rat pups on PND-7. The DA-D2 receptor binding was assessed in corpus striatum by using 3H-Spiperone at 3, 6 and 12 weeks of age. MOG immunolabelling was performed to check myelination stature and myelin integrity, while corpus callosum calibre was assessed by Luxol fast blue staining. Relative behavioral tasks i.e., motor activity, motor coordination and neuromuscular strength were assessed by open field, rotarod and grip strength meter respectively at 3, 6 and 12 weeks of age. Following Poly I:C exposure, a significant decrease in DA-D2 receptor binding, reduction in corpus callosum calibre and MOG immunolabelling indicating demyelination and a significant decrease in locomotor activity, neuromuscular strength and motor coordination signify motor deficits and hypokinetic influence of early life viral infection. Thus, the findings suggest that early life poly I:C exposure may cause demyelination and motor deficits by decreasing DA-D2 receptor binding affinity.
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Comportamento Animal/efeitos dos fármacos , Bainha de Mielina/efeitos dos fármacos , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Poli I-C/toxicidade , Receptores de Dopamina D2/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Corpo Caloso/citologia , Corpo Caloso/efeitos dos fármacos , Masculino , Atividade Motora/efeitos dos fármacos , Força Muscular/efeitos dos fármacos , Desempenho Psicomotor/efeitos dos fármacos , Ratos , Ratos Wistar , Espiperona/farmacologiaRESUMO
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with no cure. The reports showed the role of nearby astrocytes around the motor neurons as one among the causes of the disease. However, the exact mechanistic insights are not explored so far. Thus, in the present investigations, we employed the induced pluripotent stem cells (iPSCs) of Cu/Zn-SOD1L39R linked ALS patient to convert them into the motor neurons (MNs) and astrocytes. We report that the higher expression of stress granule (SG) marker protein G3BP1, and its co-localization with the mutated Cu/Zn-SOD1L39R protein in patient's MNs and astrocytes are linked with AIF1-mediated upregulation of caspase 3/7 and hyper activated autophagy. We also observe the astrocyte-mediated non-cell autonomous neurotoxicity on MNs in ALS. The secretome of the patient's iPSC-derived astrocytes exerts significant oxidative stress in MNs. The findings suggest the hyperactive status of autophagy in MNs, as witnessed by the co-distribution of LAMP1, P62 and LC3 I/II with the autolysosomes. Conversely, the secretome of normal astrocytes has shown neuroprotection in patient's iPSC-derived MNs. The whole-cell patch-clamp assay confirms our findings at a physiological functional level in MNs. Perhaps for the first time, we are reporting that the MN degeneration in ALS triggered by the hyper-activation of autophagy and induced apoptosis in both cell-autonomous and non-cell autonomous conditions.
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Esclerose Lateral Amiotrófica/patologia , Astrócitos/metabolismo , Autofagia , Neurônios Motores/patologia , Superóxido Dismutase-1/genética , Esclerose Lateral Amiotrófica/fisiopatologia , Apoptose/genética , Autofagia/genética , Diferenciação Celular , Fenômenos Eletrofisiológicos , Regulação da Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Lisossomos/metabolismo , Metaloproteinases da Matriz/metabolismo , Modelos Biológicos , Células-Tronco Neurais/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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The original version of this article unfortunately contained an error at Fig. 10.
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BACKGROUND: Exposure to adverse environmental conditions such as toxic chemicals, viral infections, and even stress during pregnancy or early life may disrupt the development of normal brain and its functioning leading to incidence of neurodevelopmental disorders at later stages of life. Recently, we reported that poly (I:C) exposure altered synaptic plasticity protein level and impaired memory through activation of microglia cells. PURPOSE: As epigenetic modifications are involved in memory formation, we have studied methylation of DNA and acetylation of histone at promoters of synaptic plasticity genes in the brain of rats exposed to poly (I:C) during early life. METHODS: One dose of poly (I:C) (5 mg/kg bw) was intraperitoneally injected to rat pups on postnatal seventh day. A set of pups exposed to vehicle was included as control. In order to assess methylation of DNA and acetylation of histone at synaptic plasticity gene promoter, we performed qPCR after methylated DNA immunoprecipitation and chromatin immunoprecipitation. RESULTS: Poly (I:C) exposure reduced the level of 5-methylcytosine (5mC) at synaptic plasticity gene (bdnf, arc, and egr1) promoters in the frontal cortex (FC) and hippocampus of 3-week rats, although increased it later in both regions of 12-week rats as compared to respective controls. On contrary, poly (I:C) exposure enhanced acetylation of histone H3K9 (H3K9Ac) at promoters of these genes in both regions of 3-week rats but decreased in 12-week rats. CONCLUSION: Poly (I:C) exposure altered 5mC and H3K9Ac at synaptic plasticity gene promoters resulting in memory impairment of rats at later life.
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Viral infection during early stage of life influences brain development and results in several neurodevelopmental disorders such as schizophrenia, autism and behavioral abnormalities. However, the mechanism through which infection causes long-term behavioral defects is not well known. To elucidate this, we have used synthetic polyinosinic-polycytidylic acid [poly (I:C)] which acts as a dsRNA molecule and interacts with toll-like receptor-3 (TLR-3) of microglia cells to evoke the immune system, thus mimicking the viral infection. Rat pups of postnatal day (PND) 7 were infused with a single dose of poly (I:C) (5â¯mg/kg BW) and vehicle alone to controls. When these pups grew to 3, 6 and 12â¯weeks, their spatial and fear conditioning memory were impaired as assessed by Morris water maze and passive avoidance test, respectively. We checked the immune activation by staining of TNF-α in the hippocampus and observed that poly (I:C) exposure elevated the number of TNF-α positive cells immediately after 12â¯h of infusion in one week rat and it persisted up to postnatal age of 3 and 12â¯weeks. Moreover, poly (I:C) significantly decreased the binding of 3H-QNB to the cholinergic receptors in the frontal cortex and hippocampus of 3 and 6â¯weeks rats as compared to control but did not change significantly in 12â¯weeks rats. RT-PCR and immunoblotting results showed that poly (I:C) exposure upregulated the expression of memory associated genes (BDNF, Arc, EGR1) at mRNA and protein level in frontal cortex and hippocampus of 3â¯weeks rats as compared to control. However, long-time persistence of poly (I:C) effects significantly decreased the expression of these genes in both brain regions of 12â¯weeks rats. Taken together, it is evident that early life exposure to poly (I:C) has a long-term effect and impairs learning and memory, probably through TNF-α mediated neuroinflammation and alteration in the expression of memory associated genes in frontal cortex and hippocampus of rats.
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Encéfalo/crescimento & desenvolvimento , Encéfalo/imunologia , Memória/fisiologia , Plasticidade Neuronal/genética , Plasticidade Neuronal/imunologia , Aprendizagem Espacial/fisiologia , Animais , Encéfalo/efeitos dos fármacos , Condicionamento Clássico/efeitos dos fármacos , Condicionamento Clássico/fisiologia , Feminino , Lobo Frontal/efeitos dos fármacos , Lobo Frontal/imunologia , Expressão Gênica , Hipocampo/efeitos dos fármacos , Hipocampo/imunologia , Masculino , Memória/efeitos dos fármacos , Plasticidade Neuronal/efeitos dos fármacos , Poli I-C/administração & dosagem , Ratos Wistar , Receptores Muscarínicos/metabolismo , Aprendizagem Espacial/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Cholinergic system has an important role in memory and learning. Abnormal cognitive and behavioral changes have been reported in Japanese encephalitis (JE), but their basis has not been comprehensively evaluated. In this study, we report memory and learning and its association with acetylcholinesterase (AChE) activity, JE virus titer, and with histopathological observations in a rat model of JE. Wistar rats were intracerebrally inoculated on 12th day with 3 × 106 pfu/ml of JE virus. Memory and learning were assessed by the active and passive avoidance tests on 10, 33, and 48 days post inoculation (dpi). After 10, 33, and 48 dpi AChE activity, Japanese encephalitis virus (JEV) titer and histopathological changes were studied in the frontal cortex, thalamus, midbrain, cerebellum, and hippocampus. There was significant impairment in memory and learning on 10 dpi which started improving from 33 dpi to 48 dpi by active avoidance test. Passive avoidance test showed decrease in transfer latency time of retention trial compared to acquisition on first, second, and third retention day trial compared to controls. AChE inhibition was more marked in the hippocampus, frontal cortex, and cerebellum on 10 dpi. However, AChE activity started improving from 33 dpi to 48 dpi. AChE activity in the thalamus and midbrain correlated with active avoidance test on 10 dpi and 33 dpi. Histopathological studies also revealed improvement on 33 and 48 compared to 10 dpi. The present study demonstrates transient memory and learning impairment which was associated with reduction in AChE, JEV titer, and damage in different brain regions of JEV infected rats.
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Acetilcolinesterase/metabolismo , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Encefalite Japonesa/enzimologia , Encefalite Japonesa/fisiopatologia , Memória , Animais , Aprendizagem da Esquiva , Encéfalo/enzimologia , Encéfalo/patologia , Encéfalo/fisiopatologia , Encéfalo/virologia , Encefalite Japonesa/patologia , Encefalite Japonesa/virologia , Ratos WistarRESUMO
The plethora of literature has supported the potential benefits of Resveratrol (RV) as a life-extending as well as an anticancer compound. However, these two functional discrepancies resulted at different concentration ranges. Likewise, the role of Resveratrol on adult neurogenesis still remains controversial and less understood despite its well documented health benefits. To gather insight into the biological effects of RV on neurogenesis, we evaluated the possible effects of the compound on the proliferation and survival of neural progenitor cells (NPCs) in culture, and in the hippocampus of aged rats. Resveratrol exerted biphasic effects on NPCs; low concentrations (10 µM) stimulated cell proliferation mediated by increased phosphorylation of extracellular signal-regulated kinases (ERKs) and p38 kinases, whereas high concentrations (>20 µM) exhibited inhibitory effects. Administration of Resveratrol (20 mg/kg body weight) to adult rats significantly increased the number of newly generated cells in the hippocampus, with upregulation of p-CREB and SIRT1 proteins implicated in neuronal survival and lifespan extension respectively. We have successfully demonstrated that Resveratrol exhibits dose dependent discrepancies and at a lower concentration can have a positive impact on the proliferation, survival of NPCs and aged rat hippocampal neurogenesis implicating its potential as a candidate for restorative therapies against age related disorders.
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Envelhecimento/efeitos dos fármacos , Células-Tronco Neurais/citologia , Neurogênese/efeitos dos fármacos , Estilbenos/administração & dosagem , Células A549 , Envelhecimento/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Humanos , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Fosforilação/efeitos dos fármacos , Ratos , Resveratrol , Sirtuína 1/metabolismo , Estilbenos/farmacologiaRESUMO
Cognitive changes have been known in encephalitis but in Japanese encephalitis (JE) such studies are limited. This study aims at evaluating the spatial memory and learning and correlate with markers of cholinergic activity in the brain.12day old Wistar rats were inoculated with dose of 3×10(6)pfu/ml of JE virus. On 10, 33 and 48days post-inoculation (dpi), spatial memory and learning was assessed by Y maze. Brain biopsies from frontal cortex, corpus striatum, hippocampus and cerebellum were taken. Muscarinic cholinergic receptor was assayed by Quinuclidinyl benzylate (H3-QNB) binding, CHRM2 gene expression by real time PCR and choline acetyl transferase (ChAT) by Western blot. Spatial learning and memory showed significant decline in rats inoculated with JEV on 10 and 33dpi (47.5%, p<0.01; 30.2%, p<0.01). It started recovering on 48dpi. Muscarinic cholinergic receptors showed significant decrease in frontal cortex (31%, p=0.001; 26%, p=0.003), hippocampus (57%, p=0.001; 39.9%, p=0.002) and cerebellum (31.2%, p=0.008; 21.6%, p=0.007) but not in corpus striatum as compared to control. The mRNA expression of CHRM2 receptor gene showed significant decrease in the expression in frontal cortex (48%, p<0.001; 38%, p<0.01), hippocampus (43%, p<0.001; 37%, p<0.05) and cerebellum (46%, p<0.001; 42%, p<0.05) on 10 and 33dpi. ChAT showed significant fold decrease in the expression in frontal cortex (2.11, p<0.01, 1.12, p<0.05) and hippocampus (2.2, p<0.01, 1.41, p<0.05) on 10 and 33dpi. Correlation between ChAT, CHRM2 and total muscarinic receptor activity with spatial memory were found at different dpi. There was transient spatial learning and memory impairment which was associated with reduction of total muscarinic receptor binding, CHRM2 gene and ChAT expression in different brain region of rat infected with JE Virus.
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Acetilcolina/metabolismo , Encéfalo/metabolismo , Colina O-Acetiltransferase/metabolismo , Encefalite Japonesa/psicologia , Memória/fisiologia , Aprendizagem Espacial/fisiologia , Animais , Modelos Animais de Doenças , Vírus da Encefalite Japonesa (Subgrupo)/isolamento & purificação , Encefalite Japonesa/genética , Encefalite Japonesa/metabolismo , Hipocampo/metabolismo , Masculino , Ratos , Ratos Wistar , Receptores Muscarínicos/metabolismoRESUMO
Oral administration of low doses of cypermethrin to pregnant Wistar rats led to a dose-dependent differences in the induction of xenobiotic-metabolizing cytochrome P450s (CYPs) messenger RNA (mRNA) and protein in brain regions isolated from the offsprings postnatally at 3 weeks that persisted up to adulthood. Similar alterations were observed in the expression of rate-limiting enzymes of neurotransmitter synthesis in brain regions of rat offsprings. These persistent changes were associated with alterations in circulating levels of growth hormone (GH), cognitive functions, and accumulation of cypermethrin and its metabolites in brain regions of exposed offsprings. Though molecular docking studies failed to identify similarities between the docked conformations of cypermethrin with CYPs and neurotransmitter receptors, in silico analysis identified regulatory sequences of CYPs in the promoter region of rate-limiting enzymes of neurotransmitter synthesis. Further, rechallenge of the prenatally exposed offsprings at adulthood with cypermethrin (p.o. 10 mg/kg × 6 days) led to a greater magnitude of alterations in the expression of CYPs and rate-limiting enzymes of neurotransmitter synthesis in different brain regions. These alterations were associated with a greater magnitude of decrease in the circulating levels of GH and cognitive functions in rechallenged offsprings. Our data has led us to suggest that due to the immaturity of CYPs in fetus or during early development, even the low-level exposure of cypermethrin may be sufficient to interact with the CYPs, which in turn affect the neurotransmission processes and may help in explaining the developmental neurotoxicity of cypermethrin.
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Encéfalo/patologia , Sistema Enzimático do Citocromo P-450/metabolismo , Neurotransmissores/biossíntese , Efeitos Tardios da Exposição Pré-Natal/enzimologia , Efeitos Tardios da Exposição Pré-Natal/patologia , Piretrinas/efeitos adversos , Xenobióticos/metabolismo , Animais , Animais Recém-Nascidos , Biocatálise , Encéfalo/enzimologia , Simulação por Computador , Feminino , Regulação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Aprendizagem/efeitos dos fármacos , Masculino , Metaboloma/genética , Simulação de Acoplamento Molecular , Gravidez , Efeitos Tardios da Exposição Pré-Natal/sangue , Efeitos Tardios da Exposição Pré-Natal/genética , Piretrinas/química , Piretrinas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Análise de Sequência de DNA , Memória Espacial/efeitos dos fármacos , Homologia Estrutural de ProteínaRESUMO
We demonstrate the role of molecular switching of TrkA/p75(NTR) signaling cascade in organophosphate pesticide-Monocrotophos (MCP) induced neurotoxicity in stem cell derived cholinergic neurons and in rat brain. Our in-silico studies reveal that MCP followed the similar pattern of binding as staurosporine and AG-879 (known inhibitors of TrkA) with TrkA protein (PDB ID: 4AOJ) at the ATP binding sites. This binding of MCP to TrkA led to the conformational change in this protein and triggers the cell death cascades. The in-silico findings are validated by observing the down regulated levels of phosphorylated TrkA and its downstream molecules viz., pERK1/2, pAkt and pCREB in MCP-exposed cells. We observe that these MCP induced alterations in pTrkA and downstream signaling molecules are found to be associated with apoptosis and injury to neurons. The down-regulation of TrkA could be linked to increased p75(NTR). The in-vitro studies could be correlated in the rat model. The switching of TrkA/p75(NTR) signaling plays a central role in MCP-induced neural injury in rBNSCs and behavioral changes in exposed rats. Our studies significantly advance the understanding of the switching of TrkA/p75(NTR) that may pave the way for the application of TrkA inducer/p75(NTR) inhibitor for potential therapeutic intervention in various neurodegenerative disorders.
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Inibidores da Colinesterase/farmacologia , Inseticidas/farmacologia , Monocrotofós/farmacologia , Receptor trkA/metabolismo , Receptores de Fator de Crescimento Neural/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Inibidores da Colinesterase/química , Inibidores da Colinesterase/toxicidade , Inseticidas/química , Inseticidas/toxicidade , Modelos Moleculares , Conformação Molecular , Simulação de Acoplamento Molecular , Monocrotofós/química , Monocrotofós/toxicidade , Proteínas do Tecido Nervoso , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Receptor trkA/antagonistas & inibidores , Receptor trkA/química , Receptores de Fatores de Crescimento , Relação Estrutura-AtividadeRESUMO
Sustained and safe delivery of dopamine across the blood brain barrier (BBB) is a major hurdle for successful therapy in Parkinson's disease (PD), a neurodegenerative disorder. Therefore, in the present study we designed neurotransmitter dopamine-loaded PLGA nanoparticles (DA NPs) to deliver dopamine to the brain. These nanoparticles slowly and constantly released dopamine, showed reduced clearance of dopamine in plasma, reduced quinone adduct formation, and decreased dopamine autoxidation. DA NPs were internalized in dopaminergic SH-SY5Y cells and dopaminergic neurons in the substantia nigra and striatum, regions affected in PD. Treatment with DA NPs did not cause reduction in cell viability and morphological deterioration in SH-SY5Y, as compared to bulk dopamine-treated cells, which showed reduced viability. Herein, we report that these NPs were able to cross the BBB and capillary endothelium in the striatum and substantia nigra in a 6-hydroxydopamine (6-OHDA)-induced rat model of PD. Systemic intravenous administration of DA NPs caused significantly increased levels of dopamine and its metabolites and reduced dopamine-D2 receptor supersensitivity in the striatum of parkinsonian rats. Further, DA NPs significantly recovered neurobehavioral abnormalities in 6-OHDA-induced parkinsonian rats. Dopamine delivered through NPs did not cause additional generation of ROS, dopaminergic neuron degeneration, and ultrastructural changes in the striatum and substantia nigra as compared to 6-OHDA-lesioned rats. Interestingly, dopamine delivery through nanoformulation neither caused alterations in the heart rate and blood pressure nor showed any abrupt pathological change in the brain and other peripheral organs. These results suggest that NPs delivered dopamine into the brain, reduced dopamine autoxidation-mediated toxicity, and ultimately reversed neurochemical and neurobehavioral deficits in parkinsonian rats.
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Barreira Hematoencefálica/metabolismo , Dopamina/química , Dopamina/metabolismo , Nanopartículas/química , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/fisiopatologia , Animais , Linhagem Celular Tumoral , Dopamina/efeitos adversos , Neurônios Dopaminérgicos/metabolismo , Portadores de Fármacos/efeitos adversos , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Liberação Controlada de Fármacos , Humanos , Ácido Láctico/química , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Oxirredução , Oxidopamina/química , Oxidopamina/farmacologia , Oxidopamina/uso terapêutico , Doença de Parkinson/metabolismo , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Wistar , Receptores Dopaminérgicos/metabolismo , Segurança , Regulação para Cima/efeitos dos fármacosRESUMO
A novel analytical approach based on molecularly imprinted solid phase extraction (MISPE) coupled with dispersive liquid-liquid microextraction (DLLME), and injector port silylation (IPS) has been developed for the selective preconcentration, derivatization and analysis of 3-phenoxybenzoic acid (3-PBA) using gas chromatography-tandem mass spectrometry (GC-MS/MS) in complex biological samples such as rat blood and liver. Factors affecting the synthesis of MIP were evaluated and the best monomer and cross-linker were selected based on binding affinity studies. Various parameters of MISPE, DLLME and IPS were optimized for the selective preconcentration and derivatization of 3-PBA. The developed method offers a good linearity over the calibration range of 0.02-2.5ngmg(-1) and 7.5-2000ngmL(-1) for liver and blood respectively. Under optimized conditions, the recovery of 3-PBA in liver and blood samples were found to be in the range of 83-91%. The detection limit was found to be 0.0045ngmg(-1) and 1.82ngmL(-1) in liver and blood respectively. SRM transition of 271â227 and 271â197 has been selected as quantifier and qualifier transition for 3-PBA derivative. Intra and inter-day precision for five replicates in a day and for five, successive days was found to be less than 8%. The method developed was successfully applied to real samples, i.e. rat blood and tissue for quantitative evaluation of 3-PBA. The analytical approach developed is rapid, economic, simple, eco-friendly and possess immense utility for the analysis of analytes with polar functional groups in complex biological samples by GC-MS/MS.
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Benzoatos/análise , Benzoatos/sangue , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microextração em Fase Líquida/métodos , Fígado/química , Impressão Molecular , Animais , Cromatografia Gasosa-Espectrometria de Massas/economia , Limite de Detecção , Microextração em Fase Líquida/economia , Ratos , Ratos Wistar , Espectrometria de Massas em Tandem/economia , Espectrometria de Massas em Tandem/métodosRESUMO
BACKGROUND: Vitamin B12 deficiency is a well recognized cause of posterolateral myelopathy. In Indian subcontinent, it may coexist with nutritional copper deficiency producing partial response of patients to B12 supplementation. Hence the study was planned to look for association of hypocupremia and B12 deficiency. METHODS: Twenty-three patients with posterolateral myelopathy (Romberg sign positive) were enrolled and investigated for levels of vitamin B12, copper and zinc and followed up for six months. RESULT: In three patients, copper deficiency alone was found to be the cause. In another three, both copper and vitamin B12 were deficient. In all these six patients, ceruloplasmin and 24h urinary copper were found to be low suggesting dietary copper deficiency. Hyperzincemia was found in four of these patients. Magnetic resonance imaging of spine was normal in lone Cu deficient patients but showed T2 hyperintensity of posterior column in lone B12 or combined B12 and copper deficiency. CONCLUSION: In cases of B12 deficiency myelopathy not responding to supplementation, copper deficiency must be sought at the earliest to avoid and treat persistent neurological disability.
Assuntos
Ataxia/complicações , Cobre/sangue , Doenças da Medula Espinal/sangue , Doenças da Medula Espinal/complicações , Vitamina B 12/sangue , Zinco/sangue , Potenciais de Ação/fisiologia , Adulto , Análise de Variância , Ataxia/sangue , Encéfalo/patologia , Avaliação da Deficiência , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Medula Espinal/patologia , Estatísticas não Paramétricas , Deficiência de Vitamina B 12/complicaçõesRESUMO
This study was undertaken to ascertain the antipsychotic properties of Rauwolfia tetraphylla L. leaves and to isolate and characterize the antipsychotic constituents. Among the MeOH extract and some alkaloidal fractions at different pHs, the alkaloidal CHCl(3) fraction at pH-9 (2C) showed the highest antipsychotic activity against dopaminergic (DA-D(2)) and serotonergic (5-HT(2A)) receptors in-vitro and amphetamine induced hyperactive mouse model in-vivo. The activity guided isolation of CHCl(3) fraction (2C) afforded six indole alkaloids: 10-methoxytetrahydroalstonine (1), isoreserpiline (2), an isomeric mixture of 11-demethoxyreserpiline (3) and 10-demethoxyreserpiline (4), α-yohimbine (5) and reserpiline (6). Given orally, alkaloids 3-6 showed significant antipsychotic activity in a dose dependent manner. None of the extract, alkaloidal fractions or alkaloids showed any extra pyramidal symptoms at the tested doses. It was also observed that MeOH extract was behaving similar to other clinically used novel atypical antipsychotics in having 5-HT(2A) occupancy greater than the DA-D(2) receptor at the tested doses. Further toxicity and safety evaluation studies of MeOH extracts of R. tetraphylla leaves at different doses (10, 100, 300 and 2000 mg/kg) on female Swiss albino mice showed that MeOH extract is non toxic. The isolated alkaloids, 3-6 could serve as a promising lead structure for drug development of treating psychotic conditions in human.