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The key feature of non-contact temperature measurement provided by infrared (IR) cameras underpins their versatility. However, the accuracy of temperature measurements with IR cameras depends on imaging quality due to their non-contact nature, such as the lens, body temperature, and measurement environment. This paper addresses the correction of radial distortion and nonlinear response issues in IR cameras. To address radial distortion, we have designed a passive checkerboard calibration board specifically for infrared cameras. This board is used to calibrate the IR camera and derive the necessary camera parameters. Subsequently, these parameters are applied during the actual measurement process to rectify radial distortion effectively. Building on the radial distortion correction method mentioned above, we propose a multi-point segmented calibration approach that considers different temperature ranges and imaging regions. This method alleviates the issue of reduced temperature measurement accuracy due to variations in camera responses by computing gain and offset coefficient matrices for each temperature range. Experimental results demonstrate the effectiveness of the calibration board in correcting radial distortion in IR cameras, with a mean reprojection error of less than 0.16 pixels. Regarding the nonlinear response problem, the introduced method significantly reduces the relative error in temperature measurement. In the verification phase, spanning from 100 to 500 °C, the average relative error in temperature measurement decreases by 0.49% from 1.61% before and after correction, which highlights a substantial improvement in temperature measurement accuracy. This work gives a useful reference to improve the imaging quality and temperature measurement accuracy using infrared cameras.
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Mitochondria maintain the normal physiological function of nerve cells by producing sufficient cellular energy and performing crucial roles in maintaining the metabolic balance through intracellular Ca2+ homeostasis, oxidative stress, and axonal development. Depression is a prevalent psychiatric disorder with an unclear pathophysiology. Damage to the hippocampal neurons is a key component of the plasticity regulation of synapses and plays a critical role in the mechanism of depression. There is evidence suggesting that mitochondrial dysfunction is associated with synaptic impairment. The maintenance of mitochondrial homeostasis includes quantitative maintenance and quality control of mitochondria. Mitochondrial biogenesis produces new and healthy mitochondria, and mitochondrial dynamics cooperates with mitophagy to remove damaged mitochondria. These processes maintain mitochondrial population stability and exert neuroprotective effects against early depression. In contrast, mitochondrial dysfunction is observed in various brain regions of patients with major depressive disorders. The accumulation of defective mitochondria accelerates cellular nerve dysfunction. In addition, impaired mitochondria aggravate alterations in the brain microenvironment, promoting neuroinflammation and energy depletion, thereby exacerbating the development of depression. This review summarizes the influence of mitochondrial dysfunction and the underlying molecular pathways on the pathogenesis of depression. Additionally, we discuss the maintenance of mitochondrial homeostasis as a potential therapeutic strategy for depression.
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Transtorno Depressivo Maior , Humanos , Transtorno Depressivo Maior/metabolismo , Depressão , Mitocôndrias/metabolismo , Neurônios/metabolismo , Encéfalo/metabolismoRESUMO
Purpose: Corticosteroid insensitivity has become a major barrier in the treatment of chronic obstructive pulmonary disease (COPD). It is known that oxidative stress reduces the expression and activity of histone deacetylase (HDAC)-2 by activating phosphoinositide-3-kinase-δ(PI3Kδ)/Akt pathway, which is a common mechanism. The aim of this study was to investigate whether cryptotanshinone (CPT) can improve corticosteroid sensitivity and to investigate the molecular mechanisms by which this occurs. Patients and Methods: Corticosteroid sensitivity in peripheral blood mononuclear cells (PBMCs) collected from COPD patients, or in human monocytic U937 monocytic cells exposed to cigarette smoke extract (CSE), was quantified as the dexamethasone concentration required to achieve 30% inhibition of tumor necrosis factor-α (TNFα)-induced interleukin 8 (IL-8) production in the presence or absence of cryptotanshinone. PI3K/Akt activity (measured as the relative ratio of phosphorylated Akt at Ser-473 to total Akt) and HDAC2 expression levels were determined by western blotting. HDAC activity was evaluated by a Fluo-Lys HDAC activity assay kit in U937 monocytic cells. Results: Both PBMCs in patients with COPD and U937 cells exposed to CSE were found to be insensitive to dexamethasone, accompanied by increased phosphorylated Akt (pAkt) and decreased HDAC2 protein expression. The pretreatment of cryptotanshinone restored their sensitivity to dexamethasone, and simultaneously downregulated the level of phosphorylated Akt and upregulated the level of HDAC2 protein. Pretreatment with cryptotanshinone or IC87114 reversed the decrease in HDAC activity in CSE-stimulated U937 cells. Conclusion: Cryptotanshinone restores corticosteroid sensitivity induced by oxidative stress via inhibition of PI3Kδ and is a potential treatment for corticosteroid-insensitive diseases such as COPD.
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Doença Pulmonar Obstrutiva Crônica , Humanos , Doença Pulmonar Obstrutiva Crônica/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Leucócitos Mononucleares/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Corticosteroides/farmacologia , Dexametasona/farmacologia , Fosfatidilinositóis/metabolismo , Histona Desacetilase 2/metabolismoRESUMO
In-situ microemulsion flushing is an effective remediation technology for the removal of dense non-aqueous phase liquids (DNAPLs) from aquifers. Nitrobenzene (NB) is a typical DNAPL pollutant that is responsible for the serious contamination of many groundwater systems, while its removal using the flushing method has rarely been studied. In this study, bench scale, 1-D column and 2-D tank experiments were conducted to establish an efficient salt-free sodium dodecyl sulfate (SDS)/1-butanol based in-situ microemulsion flushing system for NB contaminated aquifers. Results showed that the NB/SDS/1-butanol/water microemulsion increased dissolved NB concentrations by more than 15-fold compared to the SDS-only solution. The formulation also presented good solubilization capacity at low temperature (5 â) and with clay media. NB was effectively removed from the aquifer by solubilization and mobilization via the formation of the microemulsion with the injected SDS/1-butanol solution. The flushing system also reduced the tailing phenomenon in later remediation stages, and exhibited weak reagent adsorption onto aquifer media. Furthermore, the vertical DNAPL migration to deeper aquifer was effectively controlled. Therefore, the constructed in-situ microemulsion flushing system is a highly efficient treatment method for NB contaminated aquifers, with this study providing valuable reference information on the optimal reagent parameters and the remediation mechanism.
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Electromagnetic (EM) wave absorber with broad and robust absorption performance over wide incident angle range is persistently desired in specific applications. In this work, we propose and demonstrate a broadband and wide-angle metamaterial absorber (MA) based on a hybrid of stereo spoof surface plasmonic polariton (SSPP) structure and planar resistive metasurface. At first, we design a broadband SSPP absorber by adjusting the dispersion and loss of the artificial plasmonic structure (PS) simultaneously. Furthermore, owing to utilize its spatial phase manipulation ability, we integrate a resistive metasurface on top of the PS to construct a modified circuit analog (CA) absorber with a dispersive metamaterial spacer. The absorption mechanism of the hybrid structure is analyzed theoretically. The results indicate that the hybrid MA is equipped with broad and robust absorption performance over a wide incident angle range due to the synergistic absorption of the PS and metasurface. Finally, a prototype of the hybrid MA is fabricated by silk-printing technic and its absorption performances are measured. The experimental results can verify the theoretic ones and indicate that proposed hybrid MA can achieve 90% absorptivity from 3.9â GHz to 10.6â GHz with thickness of 7.0â mm, which is only 106% times of the ultimate thickness corresponding to the absorption performance of MA. In general, the concept and design offer a distinct approach of utilizing SSPP to design absorbers with excellent performances from radio frequency to optic band, which are promising for extensive applications.
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INTRODUCTION: This study explores the longitudinal and bidirectional relations between paternal/maternal psychological control and adolescent maladjustment (i.e., internalizing symptoms, aggression, and association with deviant peers). METHODS: This longitudinal investigation was conducted at two time points over a one-year interval with participants comprising 543 Chinese adolescents aged 10 to 13 (mean age at Time 1 = 11.29; 51.93% girls). The performed measurements encompassed paternal/maternal psychological control, adolescent internalizing symptoms, aggression, association with deviant peers, and demographic information. RESULTS: The findings of a cross-lagged model analysis revealed that paternal psychological control was longitudinally and positively related to adolescent internalizing symptoms and aggression. Maternal psychological control was not significantly related to any domain of adolescent maladjustment. In turn, adolescent association with deviant peers was longitudinally and positively associated with both parents' psychological control. CONCLUSIONS: Parental psychological control was bidirectionally associated with adolescent maladjustment in general, and paternal psychological control played a crucial role on adolescent maladjustment in the Chinese cultural context. The study's findings supported the reciprocal model of parent-child interaction, and extended it by highlighting the apprehension of the characteristics of parental impact from a cultural perspective. The study results add to the current scholarly understanding of parental psychological control in the non-western cultural context.
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Comportamento do Adolescente , Relações Pais-Filho , Adolescente , Agressão , Feminino , Humanos , Masculino , Pais , Grupo AssociadoRESUMO
Dual modification in which carboxymethyl cellulose (CMC) stabilization and sulfidation are coupled is an effective strategy to solve the insufficient electron selectivity, reactivity, and mobility of nanoscale zerovalent iron (nZVI). We compared the sulfur content, suspension composition, viscosity, zeta potential, and sedimentation of dual-modified nZVI suspensions synthesized in different modification sequences to analyze the interaction among CMC, the sulfidation reagent, and nZVI. The results show that the dissolved CMC does not take up S2-, and the CMC coating on the surface does not block S2- during sulfidation. However, CMC can peel off the FeS shell, resulting in a low sulfur content in nZVI. The Na+ of the sulfidation reagent and the Fe2+ dissolved from the FeS precipitates reduce the CMC viscosity, causing accelerated sedimentation and reduced mobility of nZVI. The peeled off FeS shell increases the free Fe2+ concentration, thereby enhancing nitrobenzene reduction. Additionally, CMC promotes nitrobenzene reduction and hydrogen evolution reactions due to the increased nZVI dispersibility. These findings explain why postsulfidated and one-pot nZVI has higher reactivity and electron selectivity, while presulfidated nZVI has higher mobility. This study highlights the importance of the modification sequence for the dual-modified nZVI properties and provides support for the synthesis method.
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Carboximetilcelulose Sódica , Ferro , Elétrons , Hidrogênio , EnxofreRESUMO
2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) exists in many foods, and its effect on taste is controversial. The aim of this study was to clarify whether DDMP has bitter taste or not. For this purpose, DDMP was synthesized from maltol instead of from glucose for the first time. In contrast, DDMP derived from glucose was also prepared and further purified. Their structures were identified by NMR and MS, and considered to be the same substance. The sensory analysis showed that DDMP derived from maltol was tasteless. Further studies indicated that some impurities in Maillard reaction made DDMP derived from glucose taste bitter.
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Pironas/química , Pironas/síntese química , Paladar , Glucose/química , Humanos , Espectroscopia de Ressonância Magnética , Reação de MaillardRESUMO
It is well known that 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) is usually formed in the Maillard reaction and it contributes to the antioxidant properties of Maillard reaction intermediates. A series of hydroxyl group protected DDMP derivatives were synthesized to further understand the source of antioxidant activity. Antioxidant abilities of the DDMP derivatives were evaluated by scavenging the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTSË+), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively. It was found that the introduction of protecting groups to the free hydroxyl groups of DDMP decreases their reducing abilities. In particular, the hydroxyl group at the olefin position exhibited a remarkable impact on the antioxidant activity of DDMP, indicating that the unstable enol structure in the DDMP moiety is the key factor for its antioxidant activity.
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The uniform migration of remedial amendments in an aquifer was negatively influenced by medium heterogeneity and the density effect of amendment. This study sought to use a polymer (xanthan) to enhance the uniformity of amendment distribution in contamination zones. Visible tank experiments were conducted to investigate the feasibility and performance of xanthan-enhanced KMnO4 delivery in the simulated aquifer. The results showed that the addition of xanthan improved fluid movement into the lower-permeability stratum, so the overall sweeping efficiency was remarkably increased compared to the fluid control test without polymer using. In two layered aquifer systems, the smaller the thickness of the low-permeability layer is, or the greater the permeability contrast between layers is, the more obvious the enhancement of the uniform distribution of remedial fluid by xanthan. The sinking of KMnO4 solution in medium and coarse sand aquifers was obvious, and the effect of KMnO4 concentration and aquifer medium size on the density effect was evaluated. The fluid viscosity increase caused by xanthan addition could stabilize the displacement front and reduce the density effect. Xanthan-KMnO4 applications were more effective at penetrating finer-grained lenses and played a more obvious role in TCE oxidation removal.
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Água Subterrânea , Poluentes Químicos da Água , Oxirredução , Permeabilidade , Polímeros , Dióxido de SilícioRESUMO
Atherosclerosis (AS), a progressive disorder, is one of the tough challenges in the clinic. Scutellarin, an extract from Herba Erigerontis, is found to have oxygen-free radicals scavenging effects and antioxidant effects. In this study, we aimed to investigate the anti-AS effects of scutellarin is related to controlling the Hippo-FOXO3A and PI3K/AKT signal pathway. To establish an AS model, the rats in the scutellarin and model groups were intraperitoneally injected with vitamin D 3 and then fed a high-fat diet for 12 weeks. In addition, in vitro angiotensin II-induced apoptosis of human aortic endothelial cells (HAECs) were used to establish models. Scutellarin significantly reduced blood lipid levels and increased antioxidase levels in both models. Additionally, scutellarin inhibited reactive oxygen species generation and apoptosis in HAECs. The impaired vascular barrier function was restored by using scutellarin in AS rats and in HAECs cells characterized by inhibiting mammalian sterile-20-like kinases 1 (Mst1) phosphorylation, Yes-associated protein (YAP) phosphorylation, forkhead box O3A (FOXO3A) phosphorylation at serine 207, nuclear translocation of FOXO3A, and upregulating protein expression of AKT and FOXO3A phosphorylation at serine 253. Scutellarin significantly reduced Bcl-2 interacting mediator of cell death (Bim), caspase-3, APO-1, CD95 (Fas), and Bax: Bcl-2-associated X (Bax) levels and activated Bcl-2: B-cell lymphoma-2 (Bcl-2). Scutellarin also significantly inhibited the expression of Mst1, YAP, FOXO3A at the messenger RNA level. When Mst1 was overexpressed or phosphoinositide 3-kinases suppressed, the effects of scutellarin were significantly blocked. In conclusion, the results of the present study suggest that scutellarin exerts protective effects against AS by inhibiting endothelial cell injury and apoptosis by regulating the Hippo-FOXO3A and PI3K/AKT signal pathways.
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Antioxidantes/farmacologia , Aorta/efeitos dos fármacos , Doenças da Aorta/prevenção & controle , Apigenina/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Aterosclerose/prevenção & controle , Células Endoteliais/efeitos dos fármacos , Proteína Forkhead Box O3/metabolismo , Glucuronatos/farmacologia , Fator de Crescimento de Hepatócito/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Aorta/enzimologia , Aorta/patologia , Doenças da Aorta/enzimologia , Doenças da Aorta/genética , Doenças da Aorta/patologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/genética , Aterosclerose/enzimologia , Aterosclerose/genética , Aterosclerose/patologia , Células Cultivadas , Modelos Animais de Doenças , Células Endoteliais/enzimologia , Células Endoteliais/patologia , Proteína Forkhead Box O3/genética , Fator de Crescimento de Hepatócito/genética , Humanos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Fosforilação , Placa Aterosclerótica , Proteínas Proto-Oncogênicas/genética , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Proteínas de Sinalização YAPRESUMO
Vascular calcification (VC) is a process in which calcium phosphate crystals deposit within the intima and middle membrane of the vascular wall. Rosmarinic acid (RA) is a common phenolic compound. It possesses antioxidation, anti-inflammatory, antimicrobial effects. Our experiment aims to investigate the role and molecular mechanism of RA in VC. Rats were fed high-fat feed and injected with vitamin D3 to establish a VC model. ß-Glyerophosphate (ß GP) was selected to stimulate rat aortic smooth muscle cells (VSMCs) in order to establish the cell calcification model. Kits were used to detect the antioxidant index and calcification index. RA significantly reduced the levels of ALP, MDA, Ca, and P but increased SOD levels. Quantitative real-time polymerase chain reaction (RT-qPCR) and western blot analysis were used to detect various antioxidant-related genes and calcified genes on an mRNA and protein level. The results showed that nuclear factor red cell-2 related factors (Nrf2), haem oxygenase-1 (HO-1), NAD(P)H quinone dehydrogenase (NQO1), and osteoprotegerin (OPG) were up regulated by RA at both the mRNA and protein levels, but kelch-like ECH-associated protein 1 (Keap1), nuclear factor kappa B(NF-κB), cadherin associated protein (ß-catenin) and osteogenic transcription factor (Runx2) expression at both the mRNA and protein levels was significantly inhibited. Microscopic examination showed that RA significantly decreased the content of calcified nodules and the production of reactive oxygen species (ROS). When Nrf2 is disturbed, the role of RA is significantly blocked. Our results showed that RA can improve VC by regulating the Nrf2 pathway.
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Anti-Inflamatórios não Esteroides/uso terapêutico , Cinamatos/uso terapêutico , Depsídeos/uso terapêutico , Fator 2 Relacionado a NF-E2/metabolismo , Calcificação Vascular/tratamento farmacológico , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Cinamatos/farmacologia , Depsídeos/farmacologia , Humanos , Masculino , Camundongos , Ratos Sprague-Dawley , Transdução de Sinais , Calcificação Vascular/patologia , Ácido RosmarínicoRESUMO
The Chrysanthemum morifolium flower is widely used in China and Japan as a food, beverage, and medicine for many diseases. In our work, two new caffeoylquinic acid derivatives (1, 2), a new flavanone glycoside (3), and six reported flavanones (4â»9) were isolated and identified from the flowers of C. morifolium. The chemical structures of all isolates were elucidated by the analysis of comprehensive spectroscopic data as well as by comparison with previously reported data. The isolated constituents 1â»8 were evaluated for their neuroprotective activity, and compounds 3 and 4 displayed neuroprotective effects against hydrogen peroxide-induced neurotoxicity in human neuroblastoma SH-SY5Y cells.
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Chrysanthemum/química , Flavanonas , Flores/classificação , Glicosídeos , Fármacos Neuroprotetores , Ácido Quínico/análogos & derivados , Flavanonas/química , Flavanonas/farmacologia , Glicosídeos/química , Glicosídeos/farmacologia , Células Hep G2 , Humanos , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Ácido Quínico/química , Ácido Quínico/farmacologiaRESUMO
Contact dermatitis and psoriasis are skin disorders caused by immune dysregulation, yet much remains unknown about their underlying mechanisms. Ghrelin, a recently discovered novel peptide and potential endogenous anti-inflammatory factor expressed in the epidermis, is involved in skin repair and disease. In this study, we investigated the expression pattern and therapeutic effect of ghrelin in both contact dermatitis and psoriasis mouse models induced by oxazolone (OXA) and imiquimod (IMQ), respectively, and in TNF-α-stimulated RAW264.7 macrophages, NHEKs and skin fibroblasts. Ghrelin expression was reduced in both the OXA-induced contact dermatitis and IMQ-induced psoriasis mouse models. Furthermore, treatment with ghrelin attenuated skin inflammation in both the contact dermatitis and psoriasis mouse models. Mice administered PBS after OXA- or IMQ-induced model generation exhibited typical skin inflammation, whereas ghrelin treatment in these mouse models substantially decreased the dermatitis phenotype. In addition, exogenous ghrelin attenuated the inflammatory reaction induced by TNF-α in RAW264.7 cells. Moreover, ghrelin administration limited activation of NF-κB signaling. In summary, ghrelin may represent a potential molecular target for the prevention and treatment of inflammatory skin diseases, including contact dermatitis and psoriasis.
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Dermatite de Contato/genética , Grelina/genética , Doenças do Sistema Imunitário/genética , Inflamação/genética , Psoríase/genética , Animais , Dermatite de Contato/imunologia , Dermatite de Contato/patologia , Modelos Animais de Doenças , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Humanos , Imiquimode/toxicidade , Doenças do Sistema Imunitário/induzido quimicamente , Doenças do Sistema Imunitário/imunologia , Doenças do Sistema Imunitário/patologia , Inflamação/induzido quimicamente , Inflamação/imunologia , Inflamação/patologia , Camundongos , NF-kappa B/genética , Oxazolona/toxicidade , Psoríase/induzido quimicamente , Psoríase/imunologia , Psoríase/patologia , Células RAW 264.7 , Transdução de Sinais , Pele/imunologia , Pele/patologia , Fator de Necrose Tumoral alfa/genéticaRESUMO
Nonalcoholic fatty liver disease (NAFLD) is characterised by excessive accumulation of hepatic lipids and oxidative injury of hepatocytes. Scutellarin is a flavonoid glycoside having antioxidative stress activity. Our current study aims to investigate the molecular mechanism of scutellarin ameliorating NAFLD. Scutellarin treatment was applied to male C57BL/6 mice maintained on a high-fat diet (HFD) and HepG2 cells challenged with oleic acid. The antioxidation biochemical indicators and lipid levels in the liver and cells were detected by kits. Liver pathology was observed by light microscope, Oil Red O staining, and transmission electron microscope (TEM). In addition, quantitative real-time polymerase chain reactions (qRT-PCR) and western blot assays were employed to detect the mRNA and protein levels of various antioxidative-related genes in the presence or absence of peroxisome proliferator-activated receptor gamma (PPARγ); inhibitor GW9662. Our results showed that scutellarin could significantly reduce blood lipid levels and enhance antioxidative capacities in both the models. In addition, scutellarin treatment conspicuously activated PPARγ, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), nuclear factor erythroid-2-related factor (Nrf2), haem oxygenase-1 (HO-1), glutathione S-transferase (GST), and NAD(P)H quinone dehydrogenase one (NQO1), while it significantly inhibited nuclear factor kappa B (NF-κB), Kelch-like ECH-associated protein 1 (Keap1) at both the mRNA and protein levels. However, after interfered by GW9662, scutellarin effect was significantly decreased. The experimental data demonstrated that scutellarin showed strong hypolipidaemic, antioxidative, and liver protective activity which could be attributed to its regulating activity in the PPARγ/PGC-1α-Nrf2 signaling pathway.
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Apigenina/farmacologia , Glucuronatos/farmacologia , Fígado/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Células Hep G2 , Humanos , Hipolipemiantes/farmacologia , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR gama/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismoRESUMO
2-Amino-9H-pyrido[2,3-b]indole (AαC), which has been reported to be 40-258ng per cigarette, was regarded as a probable human carcinogen (Group 2B) and harmful composition in Hoffman list. Thus, it is of great significance to develop an effective method for the accurate identification of AαC and its metabolites. In the present study, we have investigated for the first time the in vivo and in vitro metabolites of AαC using ultra performance liquid chromatography combined with diode array detector and time-of-flight mass spectrometry (UPLC-DAD and UPLC-Q-TOF-MS/MS). A comparative study showed that the metabolic patterns of AαC in beagle, mouse, rat and human liver microsomes were of significant difference with these in rat urine. For the metabolism of AαC in liver microsomes, nine metabolites of AαC, including five hydroxy metabolites, two quinone metabolites and two N-dimer metabolites, have been found. However, metabolism of AαC in rats is a phase II process with complex enzyme catalysis, 23 metabolites including C- and N-oxidation, O- and N-glycosylation, O- and N-sulfonation, and N-acetylation were identified in rat urine. In addition, five new N-acetyl-AαC-OH metabolites were identified for the first time, indicating a possible new pathway for the metabolism. This study significantly enriched our knowledge about the metabolism of AαC, and will be useful for a better understanding of its harmfulness and toxicity.
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Carbolinas/química , Carbolinas/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Microssomos Hepáticos/metabolismo , Espectrometria de Massas em Tandem/métodos , Animais , Carbolinas/análise , Carbolinas/farmacocinética , Feminino , Masculino , Redes e Vias Metabólicas , RatosRESUMO
A sensitive UHPLC-MS/MS method to simultaneously determine fifteen heterocyclic aromatic amines (HAAs) was developed and applied analyze of human urine. The detection limit of the fifteen HAAs was 0.80-6.06 pg/mL and the quantitation limit was 2.65-20.2 pg/mL. The intra-day and inter-day precisions of all HAAs were ≤10%. Based on the high sensitivity and good precision, the method was successively applied to analyze the urine of smokers and nonsmokers. Ten HAAs were detected, analyzed and compared between the two groups, and the analytical results showed that cigarette smoke could increase the exposures to 2-amino-9H-pyrido[2,3-b]indole (AαC) and 2-amino-1,6-dimethylimidazo[4,5-b]-pyridine (DMIP). This work is the first report that ten HAAs were simultaneously detected, and is the first comprehensive study of HAA exposure induced by cigarette smoking.