RESUMO
Neural-tumor interactions drive glioma growth as evidenced in preclinical models, but clinical validation is limited. We present an epigenetically defined neural signature of glioblastoma that independently predicts patients' survival. We use reference signatures of neural cells to deconvolve tumor DNA and classify samples into low- or high-neural tumors. High-neural glioblastomas exhibit hypomethylated CpG sites and upregulation of genes associated with synaptic integration. Single-cell transcriptomic analysis reveals a high abundance of malignant stemcell-like cells in high-neural glioblastoma, primarily of the neural lineage. These cells are further classified as neural-progenitor-cell-like, astrocyte-like and oligodendrocyte-progenitor-like, alongside oligodendrocytes and excitatory neurons. In line with these findings, high-neural glioblastoma cells engender neuron-to-glioma synapse formation in vitro and in vivo and show an unfavorable survival after xenografting. In patients, a high-neural signature is associated with decreased overall and progression-free survival. High-neural tumors also exhibit increased functional connectivity in magnetencephalography and resting-state magnet resonance imaging and can be detected via DNA analytes and brain-derived neurotrophic factor in patients' plasma. The prognostic importance of the neural signature was further validated in patients diagnosed with diffuse midline glioma. Our study presents an epigenetically defined malignant neural signature in high-grade gliomas that is prognostically relevant. High-neural gliomas likely require a maximized surgical resection approach for improved outcomes.
Assuntos
Neoplasias Encefálicas , Epigênese Genética , Glioma , Humanos , Prognóstico , Glioma/genética , Glioma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Metilação de DNA/genética , Animais , Camundongos , Masculino , Feminino , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/patologia , Pessoa de Meia-Idade , Neurônios/patologia , Neurônios/metabolismo , Adulto , Análise de Célula Única , Linhagem Celular Tumoral , Transcriptoma , Gradação de TumoresRESUMO
Persistent central nervous system (CNS) immune dysregulation and consequent dysfunction of multiple neural cell types is central to the neurobiological underpinnings of a cognitive impairment syndrome that can occur following traditional cancer therapies or certain infections. Immunotherapies have revolutionized cancer care for many tumor types, but the potential long-term cognitive sequelae are incompletely understood. Here, we demonstrate in mouse models that chimeric antigen receptor (CAR) T cell therapy for both CNS and non-CNS cancers can impair cognitive function and induce a persistent CNS immune response characterized by white matter microglial reactivity and elevated cerebrospinal fluid (CSF) cytokines and chemokines. Consequently, oligodendroglial homeostasis and hippocampal neurogenesis are disrupted. Microglial depletion rescues oligodendroglial deficits and cognitive performance in a behavioral test of attention and short-term memory function. Taken together, these findings illustrate similar mechanisms underlying immunotherapy-related cognitive impairment (IRCI) and cognitive impairment following traditional cancer therapies and other immune challenges.
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Neurogenetic disorders, such as neurofibromatosis type 1 (NF1), can cause cognitive and motor impairments, traditionally attributed to intrinsic neuronal defects such as disruption of synaptic function. Activity-regulated oligodendroglial plasticity also contributes to cognitive and motor functions by tuning neural circuit dynamics. However, the relevance of oligodendroglial plasticity to neurological dysfunction in NF1 is unclear. Here we explore the contribution of oligodendrocyte progenitor cells (OPCs) to pathological features of the NF1 syndrome in mice. Both male and female littermates (4-24 weeks of age) were used equally in this study. We demonstrate that mice with global or OPC-specific Nf1 heterozygosity exhibit defects in activity-dependent oligodendrogenesis and harbor focal OPC hyperdensities with disrupted homeostatic OPC territorial boundaries. These OPC hyperdensities develop in a cell-intrinsic Nf1 mutation-specific manner due to differential PI3K/AKT activation. OPC-specific Nf1 loss impairs oligodendroglial differentiation and abrogates the normal oligodendroglial response to neuronal activity, leading to impaired motor learning performance. Collectively, these findings show that Nf1 mutation delays oligodendroglial development and disrupts activity-dependent OPC function essential for normal motor learning in mice.
Assuntos
Aprendizagem , Neurofibromina 1 , Plasticidade Neuronal , Oligodendroglia , Animais , Camundongos , Oligodendroglia/metabolismo , Masculino , Aprendizagem/fisiologia , Plasticidade Neuronal/fisiologia , Plasticidade Neuronal/genética , Feminino , Neurofibromina 1/genética , Mutação , Atividade Motora/fisiologia , Atividade Motora/genética , Diferenciação Celular/fisiologia , Camundongos Endogâmicos C57BL , Camundongos TransgênicosRESUMO
The role of the nervous system in the regulation of cancer is increasingly appreciated. In gliomas, neuronal activity drives tumour progression through paracrine signalling factors such as neuroligin-3 and brain-derived neurotrophic factor1-3 (BDNF), and also through electrophysiologically functional neuron-to-glioma synapses mediated by AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors4,5. The consequent glioma cell membrane depolarization drives tumour proliferation4,6. In the healthy brain, activity-regulated secretion of BDNF promotes adaptive plasticity of synaptic connectivity7,8 and strength9-15. Here we show that malignant synapses exhibit similar plasticity regulated by BDNF. Signalling through the receptor tropomyosin-related kinase B16 (TrkB) to CAMKII, BDNF promotes AMPA receptor trafficking to the glioma cell membrane, resulting in increased amplitude of glutamate-evoked currents in the malignant cells. Linking plasticity of glioma synaptic strength to tumour growth, graded optogenetic control of glioma membrane potential demonstrates that greater depolarizing current amplitude promotes increased glioma proliferation. This potentiation of malignant synaptic strength shares mechanistic features with synaptic plasticity17-22 that contributes to memory and learning in the healthy brain23-26. BDNF-TrkB signalling also regulates the number of neuron-to-glioma synapses. Abrogation of activity-regulated BDNF secretion from the brain microenvironment or loss of glioma TrkB expression robustly inhibits tumour progression. Blocking TrkB genetically or pharmacologically abrogates these effects of BDNF on glioma synapses and substantially prolongs survival in xenograft models of paediatric glioblastoma and diffuse intrinsic pontine glioma. Together, these findings indicate that BDNF-TrkB signalling promotes malignant synaptic plasticity and augments tumour progression.
Assuntos
Adaptação Fisiológica , Glioma , Plasticidade Neuronal , Sinapses , Animais , Criança , Humanos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proliferação de Células , Progressão da Doença , Glioma/metabolismo , Glioma/patologia , Ácido Glutâmico/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Receptor trkB/genética , Receptor trkB/metabolismo , Receptores de AMPA/metabolismo , Transdução de Sinais , Sinapses/metabolismo , Microambiente Tumoral , OptogenéticaRESUMO
Neural-tumor interactions drive glioma growth as evidenced in preclinical models, but clinical validation is nascent. We present an epigenetically defined neural signature of glioblastoma that independently affects patients' survival. We use reference signatures of neural cells to deconvolve tumor DNA and classify samples into low- or high-neural tumors. High-neural glioblastomas exhibit hypomethylated CpG sites and upregulation of genes associated with synaptic integration. Single-cell transcriptomic analysis reveals high abundance of stem cell-like malignant cells classified as oligodendrocyte precursor and neural precursor cell-like in high-neural glioblastoma. High-neural glioblastoma cells engender neuron-to-glioma synapse formation in vitro and in vivo and show an unfavorable survival after xenografting. In patients, a high-neural signature associates with decreased survival as well as increased functional connectivity and can be detected via DNA analytes and brain-derived neurotrophic factor in plasma. Our study presents an epigenetically defined malignant neural signature in high-grade gliomas that is prognostically relevant.
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Gliomas synaptically integrate into neural circuits1,2. Previous research has demonstrated bidirectional interactions between neurons and glioma cells, with neuronal activity driving glioma growth1-4 and gliomas increasing neuronal excitability2,5-8. Here we sought to determine how glioma-induced neuronal changes influence neural circuits underlying cognition and whether these interactions influence patient survival. Using intracranial brain recordings during lexical retrieval language tasks in awake humans together with site-specific tumour tissue biopsies and cell biology experiments, we find that gliomas remodel functional neural circuitry such that task-relevant neural responses activate tumour-infiltrated cortex well beyond the cortical regions that are normally recruited in the healthy brain. Site-directed biopsies from regions within the tumour that exhibit high functional connectivity between the tumour and the rest of the brain are enriched for a glioblastoma subpopulation that exhibits a distinct synaptogenic and neuronotrophic phenotype. Tumour cells from functionally connected regions secrete the synaptogenic factor thrombospondin-1, which contributes to the differential neuron-glioma interactions observed in functionally connected tumour regions compared with tumour regions with less functional connectivity. Pharmacological inhibition of thrombospondin-1 using the FDA-approved drug gabapentin decreases glioblastoma proliferation. The degree of functional connectivity between glioblastoma and the normal brain negatively affects both patient survival and performance in language tasks. These data demonstrate that high-grade gliomas functionally remodel neural circuits in the human brain, which both promotes tumour progression and impairs cognition.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Vias Neurais , Humanos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patologia , Trombospondina 1/antagonistas & inibidores , Gabapentina/farmacologia , Gabapentina/uso terapêutico , Progressão da Doença , Cognição , Taxa de Sobrevida , Vigília , Biópsia , Proliferação de Células/efeitos dos fármacosRESUMO
COVID survivors frequently experience lingering neurological symptoms that resemble cancer-therapy-related cognitive impairment, a syndrome for which white matter microglial reactivity and consequent neural dysregulation is central. Here, we explored the neurobiological effects of respiratory SARS-CoV-2 infection and found white-matter-selective microglial reactivity in mice and humans. Following mild respiratory COVID in mice, persistently impaired hippocampal neurogenesis, decreased oligodendrocytes, and myelin loss were evident together with elevated CSF cytokines/chemokines including CCL11. Systemic CCL11 administration specifically caused hippocampal microglial reactivity and impaired neurogenesis. Concordantly, humans with lasting cognitive symptoms post-COVID exhibit elevated CCL11 levels. Compared with SARS-CoV-2, mild respiratory influenza in mice caused similar patterns of white-matter-selective microglial reactivity, oligodendrocyte loss, impaired neurogenesis, and elevated CCL11 at early time points, but after influenza, only elevated CCL11 and hippocampal pathology persisted. These findings illustrate similar neuropathophysiology after cancer therapy and respiratory SARS-CoV-2 infection which may contribute to cognitive impairment following even mild COVID.
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COVID-19 , Influenza Humana , Neoplasias , Animais , Humanos , Influenza Humana/patologia , Camundongos , Microglia/patologia , Bainha de Mielina , Neoplasias/patologia , SARS-CoV-2RESUMO
Survivors of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection frequently experience lingering neurological symptoms, including impairment in attention, concentration, speed of information processing and memory. This long-COVID cognitive syndrome shares many features with the syndrome of cancer therapy-related cognitive impairment (CRCI). Neuroinflammation, particularly microglial reactivity and consequent dysregulation of hippocampal neurogenesis and oligodendrocyte lineage cells, is central to CRCI. We hypothesized that similar cellular mechanisms may contribute to the persistent neurological symptoms associated with even mild SARS-CoV-2 respiratory infection. Here, we explored neuroinflammation caused by mild respiratory SARS-CoV-2 infection - without neuroinvasion - and effects on hippocampal neurogenesis and the oligodendroglial lineage. Using a mouse model of mild respiratory SARS-CoV-2 infection induced by intranasal SARS-CoV-2 delivery, we found white matter-selective microglial reactivity, a pattern observed in CRCI. Human brain tissue from 9 individuals with COVID-19 or SARS-CoV-2 infection exhibits the same pattern of prominent white matter-selective microglial reactivity. In mice, pro-inflammatory CSF cytokines/chemokines were elevated for at least 7-weeks post-infection; among the chemokines demonstrating persistent elevation is CCL11, which is associated with impairments in neurogenesis and cognitive function. Humans experiencing long-COVID with cognitive symptoms (48 subjects) similarly demonstrate elevated CCL11 levels compared to those with long-COVID who lack cognitive symptoms (15 subjects). Impaired hippocampal neurogenesis, decreased oligodendrocytes and myelin loss in subcortical white matter were evident at 1 week, and persisted until at least 7 weeks, following mild respiratory SARS-CoV-2 infection in mice. Taken together, the findings presented here illustrate striking similarities between neuropathophysiology after cancer therapy and after SARS-CoV-2 infection, and elucidate cellular deficits that may contribute to lasting neurological symptoms following even mild SARS-CoV-2 infection.
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Basing on the wavelengths with consistent and stable spectral signals between spectrometers, wavelength combinations were screened by different methods to obtain robust and simple near infrared spectra (NIR) calibration models that can be shared by slave spectrometers directly. Firstly, the wavelength set of Usc, at which the spectral signals between spectrometers are consistent and stable, was obtained by the method of screening the wavelengths with consistent and stable signals between spectrometers (SWCSS for short). Then, the wavelength set of Uscr whose spectral responses are correlated with dependent variables strongly was selected from Usc. Basing on Uscr, the methods of uninformative variable elimination (UVE), variable importance in projection (VIP) and selectivity ratio (SR) were applied to further screen optimal wavelength sets to obtain better NIR calibration models. These sets were recorded as UscrUVE, UscrVIP and UscrSR, respectively. The NIR partial least squares (PLS) models for predicting total alkaloids content of tobacco leaves were built on the three optimal wavelength sets, and named as UscrUVE-PLS, UscrVIP-PLS, UscrSR-PLS, respectively. Both UscrUVE-PLS and UscrVIP-PLS give satisfactory prediction errors for master and slave samples, and work better than the PLS model built on the whole wavelengths (WW-PLS) after piecewise direct standardization (PDS) calibration. The results show that further optimizing wavelength combinations based on consistent and stable spectral information cannot only simplify PLS models and improve the models' efficiency, but also ensure the models' accuracy when they are transferred to slave spectrometers. Wavelength selection based on the whole wavelengths without considering spectra consistency between spectrometers can improve the performance of the calibration models on the master spectrometer but cannot ensure the prediction accuracy of the slave samples.
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Diffuse midline gliomas (DMGs) are universally lethal malignancies occurring chiefly during childhood and involving midline structures of the central nervous system, including thalamus, pons, and spinal cord. These molecularly related cancers are characterized by high prevalence of the histone H3K27M mutation. In search of effective therapeutic options, we examined multiple DMG cultures in sequential quantitative high-throughput screens (HTS) of 2706 approved and investigational drugs. This effort generated 19,936 single-agent dose responses that inspired a series of HTS-enabled drug combination assessments encompassing 9195 drug-drug examinations. Top combinations were validated across patient-derived cell cultures representing the major DMG genotypes. In vivo testing in patient-derived xenograft models validated the combination of the multi-histone deacetylase (HDAC) inhibitor panobinostat and the proteasome inhibitor marizomib as a promising therapeutic approach. Transcriptional and metabolomic surveys revealed substantial alterations to key metabolic processes and the cellular unfolded protein response after treatment with panobinostat and marizomib. Mitigation of drug-induced cytotoxicity and basal mitochondrial respiration with exogenous application of nicotinamide mononucleotide (NMN) or exacerbation of these phenotypes when blocking nicotinamide adenine dinucleotide (NAD+) production via nicotinamide phosphoribosyltransferase (NAMPT) inhibition demonstrated that metabolic catastrophe drives the combination-induced cytotoxicity. This study provides a comprehensive single-agent and combinatorial drug screen for DMG and identifies concomitant HDAC and proteasome inhibition as a promising therapeutic strategy that underscores underrecognized metabolic vulnerabilities in DMG.
Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos , Glioma/tratamento farmacológico , Ensaios de Triagem em Larga Escala/métodos , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias do Tronco Encefálico/tratamento farmacológico , Morte Celular , Linhagem Celular Tumoral , Sinergismo Farmacológico , Feminino , Glioma/genética , Glioma/metabolismo , Humanos , Lactonas/farmacologia , Lactonas/uso terapêutico , Masculino , Metabolômica , Camundongos , Panobinostat/farmacologia , Panobinostat/uso terapêutico , Pirróis/farmacologia , Pirróis/uso terapêutico , Reprodutibilidade dos Testes , Análise de Sequência de RNA , Transcrição Gênica/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
High-grade gliomas are lethal brain cancers whose progression is robustly regulated by neuronal activity. Activity-regulated release of growth factors promotes glioma growth, but this alone is insufficient to explain the effect that neuronal activity exerts on glioma progression. Here we show that neuron and glioma interactions include electrochemical communication through bona fide AMPA receptor-dependent neuron-glioma synapses. Neuronal activity also evokes non-synaptic activity-dependent potassium currents that are amplified by gap junction-mediated tumour interconnections, forming an electrically coupled network. Depolarization of glioma membranes assessed by in vivo optogenetics promotes proliferation, whereas pharmacologically or genetically blocking electrochemical signalling inhibits the growth of glioma xenografts and extends mouse survival. Emphasizing the positive feedback mechanisms by which gliomas increase neuronal excitability and thus activity-regulated glioma growth, human intraoperative electrocorticography demonstrates increased cortical excitability in the glioma-infiltrated brain. Together, these findings indicate that synaptic and electrical integration into neural circuits promotes glioma progression.
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Encéfalo/fisiopatologia , Sinapses Elétricas/patologia , Fenômenos Eletrofisiológicos , Glioma/fisiopatologia , Animais , Encéfalo/citologia , Membrana Celular/patologia , Proliferação de Células , Junções Comunicantes/patologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Neurônios/patologia , Optogenética , Potássio/metabolismo , Transmissão Sináptica , Células Tumorais CultivadasRESUMO
Abstract Purpose: To investigate the impact of Ramipril (RAM) on the expressions of insulin-like growth factor-1 (IGF-1) and renal mesangial matrix (RMM) in rats with diabetic nephropathy (DN). Methods: The Sprague Dawley rats were divided into normal control (NC) group (n = 12), DN group (n = 11), and DN+RAM group (n = 12). The ratio of renal weight to body weight (RBT), fasting blood glucose (FBG), HbA1c, 24-h urine protein (TPU), blood urea nitrogen (BUN), creatinine (Cr), renal pathological changes, the levels of IGF-1, fibronectin (FN), type IV collagen (Col-IV), and matrix metalloproteinases (MMP)-2 were compared among the groups. Results: Compared with NC group, the RBT, FBG, HbA1c, TPU, BUN, Cr, and RMM in DN group were significantly increased (P < 0.05), the IGF-1, FN, and Col-IV were significantly upregulated (P < 0.05), while MMP was significantly downregulated (P < 0.05). Compared with DN group, the indexes except for the FBG and HbA1c in DN+RAM group were significantly improved (P < 0.05), among which IGF-1 exhibited significant positive correlation with TPU(r=0.937), FN(r=0.896) and Col-IV(r=0.871), while significant negative correlation with MMP-2 (r=-0.826) (P<0.05). Conclusion: RAM may protect the kidneys by suppressing IGF-1 and mitigating the accumulation of RMM.
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Animais , Masculino , Ratos , Fator de Crescimento Insulin-Like I/antagonistas & inibidores , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Ramipril/farmacologia , Nefropatias Diabéticas/tratamento farmacológico , Células Mesangiais/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/metabolismo , Imuno-Histoquímica , Fibronectinas/efeitos dos fármacos , Fibronectinas/metabolismo , Ratos Sprague-Dawley , Metaloproteinases da Matriz/efeitos dos fármacos , Metaloproteinases da Matriz/metabolismo , Colágeno Tipo IV/efeitos adversos , Colágeno Tipo IV/metabolismo , Nefropatias Diabéticas/metabolismo , Células Mesangiais/metabolismoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Yaotongning (YTN) is a traditional Chinese Medicine (TCM) that contains ten component medicinal materials (CMMs) and uses Chinese rice wine as a vehicle to enhance its efficacy. YTN has been used for rheumatoid arthritis (RA) treatment in China for decades and has been reported to have anti-inflammatory and analgesic effects, as well as to strengthen the immune system. AIM OF THE STUDY: The present work quantitatively evaluated the in vitro effects of active fractions from the ten CMMs that make up YTN and eight additional herbs commonly used in TCM formulas for RA treatment, as well as different combinations of these active fractions, on cellular immune response; the findings were used to determine which active fractions are responsible for promoting an immune response, and to assess whether YTN is superior to other similar formulas and whether YTN can be improved by simplifying its formula from the point of its cellular immunomodulatory activity. MATERIALS AND METHODS: Using the YTN formulation principles and some concepts in combinatorial chemistry, 27 TCM samples were designed by combining some or all of the active fractions of YTN and other eight herbs used for RA treatment. Release of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) from ANA-1 murine macrophages was measured using an enzyme-linked immunosorbent assay (ELISA). The immunoregulatory effects of the TCM samples were evaluated by comparing their half-effective concentrations (EC50) for stimulating the release of these cytokines. RESULTS: Among the investigated active fractions, the flavonoids from Carthamus tinctorius (Fct), Davallia mariesii (Fdm), and Cinnamomum cassia Twig volatile oils (Vca) from the eight selected herbs effectively promoted IL-1ß and IL-6 release from ANA-1 cells. Saponins from the YTN CMM Glycyrrhiza uralensis (Sgu) were the most potent promoters of IL-1ß and TNF-α release. The aqueous extract of YTN CMM Eupolyphaga sinensis (Ves) strongly enhanced the release of IL-1ß, IL-6, and TNF-α from ANA-1 cells. The EC50 values for stimulating the secretion of IL-1ß, IL-6, and TNF-α could be determined for only six samples. The full YTN formula and the sample containing 50% Glycyrrhiza uralensis saponins, 25% of the mixture of alkaloids, and 25% of the mixture of all flavonoids exhibited good comprehensive cellular immunomodulatory activity. The immunomodulatory activity of the complete YTN formula was better than that of the sample containing all active fractions of YTN without Chinese rice wine (the YTN vehicle). CONCLUSIONS: Sgu and Ves are the primary active fractions of YTN involved in stimulating immune responses. The YTN prescription was reasonably effective at promoting cellular immune responses. Chinese rice wine, the YTN vehicle, strengthened the immunoregulatory activity of YTN. The results of this study demonstrate that the YTN recipe could be improved by reducing the number of CMMs and altering some active fractions without reducing its activity to promote cellular immune responses.
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Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Medicamentos de Ervas Chinesas/isolamento & purificação , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Mediadores da Inflamação/metabolismo , Camundongos , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/farmacologia , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Saponinas/isolamento & purificação , Saponinas/farmacologiaRESUMO
OBJECTIVE: To investigate the effect of technologies and conditions on volatile oil yield extracted from Rhizoma Curcumae. METHODS: Water Extraction coupling Rectification (WER) and Steam Distillation (SD) technologies were applied to extract the volatile oils based on orthogonal table L9 (3(3)) to find out optimized condition. RESULTS: Variance and range analysis of orthogonal experiment results showed that the best conditions of WER and SD were as follows: ultrasound 0 h, extract 12 h with 8 (or 12 fold water for SD) fold water amount. Paired T test on the yields of the oils indicated that the oil yields prepared by WER and SD were significantly different. GC-MS analysis characterized 12 common compounds,which occupied 97.19% (SD) and 92.25% (WER) of the ones identified, respectively. Moreover, the relative percentage of the common constituents were almost the same. CONCLUSION: Ultrasound is not good for extracting volatile oil from Rhizoma Curcumae. WER could not only increase the oil yield of Rhizoma Curcumae, but also keep the quality of the oils accord with that extracted by SD.
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Curcuma/química , Destilação/métodos , Medicamentos de Ervas Chinesas/isolamento & purificação , Óleos Voláteis/isolamento & purificação , Cicloexanóis/análise , Medicamentos de Ervas Chinesas/análise , Eucaliptol , Cromatografia Gasosa-Espectrometria de Massas , Monoterpenos/análise , Óleos Voláteis/análise , Rizoma/química , Sesquiterpenos/análise , Tecnologia Farmacêutica/métodos , Ultrassom , Água/químicaRESUMO
In tobacco industry of China, tobacco leaves are classified and managed in terms of their cultivation areas and plant parts of tobacco-stalks. However, sometimes intentionally or involuntary mislabeling cultivation areas, blending tobacco plant parts would occur into tobacco market. The error will affect the style and quality of cigarettes. In the present work, more than 1000 Chinese flue-cured tobacco leaf samples, which have 12 genotypes and cultivated from 5 to 10 regions of China in 2003 and 2004, have been discriminated by means of an improved and simplified KNN classification algorithm (IS-KNN) based on near infrared (NIR) spectra. An original method of optimizing number of significant principal components (PCs) based on analysis of error and cross-validation was advanced. Compared with conventional pattern recognition methods KNN, NN, LDA and PLS-DA, IS-KNN exhibits good adaptability in discrimination of complicated Chinese flue-cured tobaccos. The practice in this work shows that optimized number of PCs and performance of classification models are closely relative to complicated extent of samples but not to number of categories or samples. The results demonstrated the usefulness of NIR spectra combined with chemometrics as an objective and rapid method for the authentication and identification of tobacco leaves or other kinds of powder samples.
Assuntos
Algoritmos , Nicotiana/química , Folhas de Planta/classificação , China , Reconhecimento Automatizado de Padrão , Reprodutibilidade dos Testes , Espectroscopia de Luz Próxima ao Infravermelho , Nicotiana/anatomia & histologiaRESUMO
In the present paper, an IR/NIR spectrometry based on the pattern recognition using Mahalanobis distance method in the principal component analysis (PCA) space was established for the discrimination of plant parts of tobaccos. Effects of the type of IR/NIR spectrometers, calibration region of the spectra, model parameters and pretreatment of the spectra on the accuracy of discrimination were investigated using tobaccos cultivated in Yunan Province in 2003 and 2005 as case study. The recognition model shows the internal relationships between the information of spectra and the plant parts of tobaccos. The results indicate that both IR and NIR could be successfully used to recognize plant parts of the tobaccos, but the latter was better because it involves more sample information. It was found that the highest recognition accuracy, 94.11%, was obtained by using apparatus A with the second derivative spectra, while recognition accuracy of 88.24% and 82.35% was respectively given by apparatus B with with the first derivative SNV spectra and IR spectrometer with first derivative spectra. For the same spectrometer, the optimal calibration region and principal component number were changed with samples and the spectral pretreatment method.