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1.
Microorganisms ; 12(8)2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39203510

RESUMO

Salmonella species are causal pathogens instrumental in human food-borne diseases. The pandemic survey related to multidrug resistant (MDR) Salmonella genomics enables the prevention and control of their dissemination. Currently, serotype Mbandaka is notorious as a multiple host-adapted non-typhoid Salmonella. However, its epidemic and MDR properties are still obscure, especially its genetic determinants accounting for virulence and MD resistance. Here, we aim to characterize the genetic features of a strain SMEH pertaining to Salmonella Mbandaka (S. Mbandaka), isolated from the patient's hydropericardium, using cell infections, a mouse model, antibiotic susceptibility test and comparative genomics. The antibiotic susceptibility testing showed that it could tolerate four antibiotics, including chloramphenicol, tetracycline, fisiopen and doxycycline by Kirby-Bauer (K-B) testing interpreted according to the Clinical and Laboratory Standards Institute (CLSI). Both the reproducibility in RAW 264.7 macrophages and invasion ability to infect HeLa cells with strain SMEH were higher than those of S. Typhimurium strain 14028S. In contrast, its attenuated virulence was determined in the survival assay using a mouse model. As a result, the candidate genetic determinants responsible for antimicrobial resistance, colonization/adaptability and their transferability were comparatively investigated, such as bacterial secretion systems and pathogenicity islands (SPI-1, SPI-2 and SPI-6). Moreover, collective efforts were made to reveal a potential role of the plasmid architectures in S. Mbandaka as the genetic reservoir to transfer or accommodate drug-resistance genes. Our findings highlight the essentiality of antibiotic resistance and risk assessment in S. Mbandaka. In addition, genomic surveillance is an efficient method to detect pathogens and monitor drug resistance. The genetic determinants accounting for virulence and antimicrobial resistance underscore the increasing clinical challenge of emerging MDR Mbandaka isolates, and provide insights into their prevention and treatment.

2.
Sci Adv ; 10(25): eadl1896, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38896621

RESUMO

Skin-like soft optical metamaterials with broadband modulation have been long pursued for practical applications, such as cloaking and camouflage. Here, we propose a skin-like metamaterial for dual-band camouflage based on unique Au nanoparticles assembled hollow pillars (NPAHP), which are implemented by the bottom-up template-assisted self-assembly processes. This dual-band camouflage realizes simultaneously high visible absorptivity (~0.947) and low infrared emissivity (~0.074/0.045 for mid-/long-wavelength infrared bands), ideal for visible and infrared dual-band camouflage at night or in outer space. In addition, this self-assembled metamaterial, with a micrometer thickness and periodic through-holes, demonstrates superior skin-like attachability and permeability, allowing close attachment to a wide range of surfaces including the human body. Last but not least, benefiting from the extremely low infrared emissivity, the skin-like metamaterial exhibits excellent high-temperature camouflage performance, with radiation temperature reduction from 678 to 353 kelvin. This work provides a new paradigm for skin-like metamaterials with flexible multiband modulation for multiple application scenarios.

3.
Int J Antimicrob Agents ; 63(2): 107056, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38081548

RESUMO

OBJECTIVES: The increasing emergence of hypervirulent Klebsiella pneumoniae (hv-Kp) and carbapenem-resistant K. pneumoniae (CR-Kp) is a serious and substantial public health problem. The use of the last resort antimicrobials, tigecycline and polymyxin to combat infections is complicated by the expanding repertoire of newly-identified CR-hvKp. The transmission and co-occurrence of the corresponding antimicrobial resistance and virulence determinants are largely unknown. The aim of this study was to investigate the dissemination and dynamics of CR-Kp and its antibiotic resistance in a hospitalised patient. METHODS: Metagenomic next-generation sequencing (mNGS) was conducted for different specimens collected from an elderly male hospitalised patient. CR-Kp strains were examined using antibiotic susceptibility and string testing. Antimicrobial and virulence genes were annotated using whole-genome sequencing (WGS). RESULTS: A clinical case of a patient infected with a variety of CR-Kp isolates was reported. The co-occurrence of KPC-2 and NDM-1 in the patient was revealed. The CR-Kp isolates, such as BALF2, and Sputum T1 and T3, were classified into ST11 and ST147, respectively. The genetic signature (iuc operon) of hypervirulence was identified in strain T1, although string testing indicated its intermediate virulence. CONCLUSIONS: In this study, multiple infections of CR-Kp isolates were revealed by mNGS, and their dissemination was attributed to plasmid variations, mgrB inactivation and integrative conjugative elements (ICEs). Furthermore, the finding indicated one likely convergence to form CR-hvKp, different from acquisition of carbapenem-resistance determinants in hvKp. A combination of mNGS and WGS is beneficial for clinical diagnosis and anti-infection therapy, and facilitates a better understanding of genetic variants conferring antimicrobial and virulence properties.


Assuntos
Infecções por Klebsiella , Klebsiella , Humanos , Masculino , Idoso , Infecções por Klebsiella/tratamento farmacológico , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Klebsiella pneumoniae , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Sequenciamento de Nucleotídeos em Larga Escala
4.
Sheng Wu Gong Cheng Xue Bao ; 39(4): 1314-1331, 2023 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-37154308

RESUMO

Stenotrophomonas species are non-fermentative Gram-negative bacteria that are widely distributed in environment and are highly resistant to numerous antibiotics. Thus, Stenotrophomonas serves as a reservoir of genes encoding antimicrobial resistance (AMR). The detection rate of Stenotrophomonas is rapidly increasing alongside their strengthening intrinsic ability to tolerate a variety of clinical antibiotics. This review illustrated the current genomics advances of antibiotic resistant Stenotrophomonas, highlighting the importance of precise identification and sequence editing. In addition, AMR diversity and transferability have been assessed by the developed bioinformatics tools. However, the working models of AMR in Stenotrophomonas are cryptic and urgently required to be determined. Comparative genomics is envisioned to facilitate the prevention and control of AMR, as well as to gain insights into bacterial adaptability and drug development.


Assuntos
Farmacorresistência Bacteriana , Stenotrophomonas , Stenotrophomonas/genética , Farmacorresistência Bacteriana/genética , Antibacterianos/farmacologia , Bactérias Gram-Negativas , Genômica , Testes de Sensibilidade Microbiana
5.
Sheng Wu Gong Cheng Xue Bao ; 38(12): 4462-4497, 2022 Dec 25.
Artigo em Chinês | MEDLINE | ID: mdl-36593189

RESUMO

Neonicotinoid compounds are usually considered harmless and eco-friendly in terms of their targeted toxicity compared to that of pyrethroids and phosphorus-containing pesticides. However, overuse of neonicotinoid insecticides resulted in the accumulation of its residuals or intermediates in soil and water, which consequently affected beneficial insects as well as mammals, yielding pollution and secondary risks. This review summarized the recent advances in neonicotinoid degrading microorganisms and their metabolic diversity, with the aim to address the urgent need for degrading these insecticides. These advances may facilitate the development of controllable and reliable technologies for efficiently transforming neonicotinoid insecticides into value-added products by synthetic biology and metagenomics.


Assuntos
Inseticidas , Animais , Neonicotinoides/metabolismo , Inseticidas/análise , Inseticidas/metabolismo , Solo , Poluição Ambiental , Redes e Vias Metabólicas , Mamíferos/metabolismo
6.
Sci Total Environ ; 809: 151152, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-34688762

RESUMO

With the rapid growth of population and economy, shortage and mismatch of land and water resources have deepened the need for cropping pattern optimization. In the context of the sustainable development of agriculture, cropping pattern optimization should not only pursue economic benefits, but the consequent environmental effects also deserve equal attention. Meanwhile, climate change increases the complexity of balancing conflicts of economic-environmental system by cropping pattern optimization. Therefore, this paper builds a multi-objective programming model for Economic-Environmental Synergistic Optimization for Cropping Pattern under Climate Change (EESO-CP-CC) model, with the goals of economic benefit increment and environmental pollutants emission reduction. The EESO-CP-CC model couples a non-point source pollution input-output model, a one-dimensional water quality model and an economic benefit function into an integrated framework. Fuzzy method was used to solve the optimization model, and the stochastic uncertainty of water supply under climate change was quantified by the integration of Bayesian approach and interval linear regression. The model was applied to Jinxi Irrigation District (JXID) in Heilongjiang Province, northeast of China. Results show that by adjusting the acreage of rice, corn and soybean, the harmony degree of economy-society-environment system increased by 10.7% compared to the current situation, indicating that the model tends to achieve the best possible economic benefits while ensuring the environmental effects. Compared with actual cropping pattern, the pollutants emissions reduced by 24.7% and 3% from corn and soybean, respectively. However, this led to a decrease of economic benefit by 8% in exchange, showing the trade-off between environmental pollution reduction and economic benefits improvement. The output coefficients of nitrogen and phosphorus pollutants were optimized, with the optimal output reducing by 20% compared to the standard. Cropping pattern and water resources allocation vary with different climate change conditions, however, the amplitude of variation is modest, indicating that the model can cope well with the changing environment. The developed model can help achieve synergistic development of economic benefits and environmental effects, and thus promote sustainable development of irrigation areas, and improve the coping capacity of agricultural water and land under climate change, by cropping pattern optimization and planning.


Assuntos
Agricultura , Hidrologia , Teorema de Bayes , China , Incerteza , Recursos Hídricos
7.
Sci Total Environ ; 755(Pt 1): 142487, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33035987

RESUMO

The adverse impacts of harmful algal blooms (HABs) are increasing worldwide. Lake Erie is a North American Great Lake highly affected by cultural eutrophication and summer cyanobacterial HABs. While phosphorus loading is a known driver of bloom size, more nuanced yet crucial questions remain. For example, it is unclear what mechanisms are primarily responsible for initiating cyanobacterial dominance and subsequent biomass accumulation. To address these questions, we develop a mechanistic model describing June-October dynamics of chlorophyll a, nitrogen, and phosphorus near the Maumee River outlet, where blooms typically initiate and are most severe. We calibrate the model to a new, geostatistically-derived dataset of daily water quality spanning 2008-2017. A Bayesian framework enables us to embed prior knowledge on system characteristics and test alternative model formulations. Overall, the best model formulation explains 42% of the variability in chlorophyll a and 83% of nitrogen, and better captures bloom timing than previous models. Our results, supported by cross validation, show that onset of the major midsummer bloom is associated with about a month of water temperatures above 20 °C (occurring 19 July to 6 August), consistent with when cyanobacteria dominance is usually reported. Decreased phytoplankton loss rate is the main factor enabling biomass accumulation, consistent with reduced zooplankton grazing on cyanobacteria. The model also shows that phosphorus limitation is most severe in August, and nitrogen limitation tends to occur in early autumn. Our results highlight the role of temperature in regulating bloom initiation and subsequent loss rates, and suggest that a 2 °C increase could lead to blooms that start about 10 days earlier and grow 23% more intense.


Assuntos
Cianobactérias , Teorema de Bayes , Clorofila A , Eutrofização , Proliferação Nociva de Algas , Lagos , Fósforo
8.
Org Biomol Chem ; 17(44): 9605-9614, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31681917

RESUMO

Diverse derivatives of amino acids with different steric configurations are important biosynthetic building blocks. In biology, epimerization is an important way to generate steric diversity. MarH catalyzes the epimerization of the ß-position of (3R)-ß-methyl-indolepyruvate (MeInPy), forming (3S)-ß-MeInPy. Both compounds are derivatives of l-tryptophan (l-Trp) and are important precursors of bioactive natural products. Here, we report the crystal structures of MarH and the NMR structure of its complex with l-Trp, an analogue of its native substrate, (3R)-ß-MeInPy. Structural analysis and mutagenesis studies indicated that His25 acts as a base to remove Hß and generate a planar carbanion intermediate, which is then putatively reprotonated on the opposite face by a water molecule to form (3S)-ß-MeInPy in a stereospecific manner. The details of ß-site isomerization at the atomic level provide deeper insights into the epimerization mechanism of MarH and will facilitate further enzyme design to extend the substrate scope.


Assuntos
Racemases e Epimerases/química , Indóis/química , Indóis/metabolismo , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Conformação Proteica , Piruvatos/química , Piruvatos/metabolismo , Racemases e Epimerases/metabolismo
9.
Sci Total Environ ; 695: 133776, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31426003

RESUMO

Harmful algal blooms (HABs) have been increasing in intensity worldwide, including the western basin of Lake Erie. Substantial efforts have been made to track these blooms using in situ sampling and remote sensing. However, such measurements do not fully capture HAB spatial and temporal dynamics due to the limitations of discrete shipboard sampling over large areas and the effects of clouds and winds on remote sensing estimates. To address these limitations, we develop a space-time geostatistical modeling framework for estimating HAB intensity and extent using chlorophyll a data sampled during the HAB season (June-October) from 2008 to 2017 by five independent monitoring programs. Based on the Bayesian information criterion for model selection, trend variables explain bloom northerly and easterly expansion from Maumee Bay, wind effects over depth, and variability among sampling methods. Cross validation results demonstrate that space-time kriging explains over half of the variability in daily, location-specific chlorophyll observations, on average. Conditional simulations provide, for the first time, comprehensive estimates of overall bloom biomass (based on depth-integrated concentrations) and surface areal extent with quantified uncertainties. These new estimates are contrasted with previous Lake Erie HAB monitoring studies, and deviations among estimates are explored and discussed. Overall, results highlight the importance of maintaining sufficient monitoring coverage to capture bloom dynamics, as well as the benefits of the proposed approach for synthesizing data from multiple monitoring programs to improve estimation accuracy while reducing uncertainty.


Assuntos
Monitoramento Ambiental/métodos , Proliferação Nociva de Algas , Modelos Estatísticos , Poluição da Água/estatística & dados numéricos
10.
Materials (Basel) ; 12(6)2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30901888

RESUMO

DNA nanostructures, owing to their controllable and adaptable nature, have been considered as highly attractive nanoplatforms for biomedical applications in recent years. However, their use in the biological environment has been restricted by low cellular transfection efficiency in mammalian cells, weak stability under physiological conditions, and endonuclease degradation. Herein, we demonstrate an effective approach to facilitate fast transfection of DNA nanostructures and enhance their stability by encapsulating DNA origami with a biocompatible cationic protein (cHSA) via electrostatic interaction. The coated DNA origami is found to be stable under physiological conditions. Moreover, the cHSA coating could significantly improve the cellular transfection efficiency of DNA origami, which is essential for biological applications.

11.
Environ Sci Technol ; 52(21): 12484-12493, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30264998

RESUMO

Nearly every summer, a large hypoxic zone forms in the northern Gulf of Mexico. Research on the causes and consequences of hypoxia requires reliable estimates of hypoxic extent, which can vary at submonthly time scales due to hydro-meteorological variability. Here, we use an innovative space-time geostatistical model and data collected by multiple research organizations to estimate bottom-water dissolved oxygen (BWDO) concentrations and hypoxic area across summers from 1985 to 2016. We find that 27% of variability in BWDO is explained by deterministic trends with location, depth, and date, while correlated stochasticity accounts for 62% of observational variance within a range of 185 km and 28 days. Space-time modeling reduces uncertainty in estimated hypoxic area by 30% when compared to a spatial-only model, and results provide new insights into the temporal variability of hypoxia. For years with shelf-wide cruises in multiple months, hypoxia is most severe in July in 59% of years, 29% in August, and 12% in June. Also, midsummer cruise estimates of hypoxic area are only modestly correlated with summer-wide (June-August) average estimates ( r2 = 0.5), suggesting midsummer cruises are not necessarily reflective of seasonal hypoxic severity. Furthermore, summer-wide estimates are more strongly correlated with nutrient loading than midsummer estimates.


Assuntos
Hipóxia , Oxigênio , Golfo do México , Humanos , Estações do Ano , Água
12.
Biomol NMR Assign ; 12(2): 335-338, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30054867

RESUMO

MarH is an essential epimerase that catalyzes the isomerization of 3R-ß-methyl-indolepyruvate (ß-MeInPy) to 3S-ß-MeInPy, which is the important precursor for biosynthesis of Maremycins. Biophysical study of the structure of MarH would be informative for better understanding of its catalytic mechanism and feasible application of the enzyme in isomerization reaction. Here, we report the backbone and side-chain NMR chemical shift assignments of MarH, which lays a foundation for further structural and mechanical study of the enzyme.


Assuntos
Indóis/metabolismo , Ressonância Magnética Nuclear Biomolecular , Racemases e Epimerases/química , Racemases e Epimerases/metabolismo , Streptomyces/enzimologia , Streptomyces/metabolismo
13.
Anal Bioanal Chem ; 410(7): 2011-2018, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29362854

RESUMO

Quantification of endogenous and exogenous plasma glucose can help more comprehensively evaluate the glucose metabolic status. A ratio-based approach using isotope dilution liquid chromatography tandem mass spectrometry (ID LC-MS/MS) with indirect multiple reaction monitoring (MRM) of the derivative tag was developed to simultaneously quantify endo-/exogenous plasma glucose. Using diluted D-[13C6] glucose as tracer of exogenous glucose, 12C6/13C6 glucoses were first derivatized and then data were acquired in MRM mode. The metabolism of exogenous glucose can be tracked and the concentration ratio of endo/exo-genous glucose can be measured by calculating the endo-/exo-genous glucose concentrations from peak area ratio of specific daughter ions. Joint application of selective derivatization and MRM analysis not only improves the sensitivity but also minimizes the interference from the background of plasma, which warrants the accuracy and reproducibility. Good agreement between the theoretical and calculated concentration ratios was obtained with a linear correlation coefficient (R) of 0.9969 in the range of D-glucose from 0.5 to 20.0 mM, which covers the healthy and diabetic physiological scenarios. Satisfactory reproducibility was obtained by evaluation of the intra- and inter-day precisions with relative standard deviations (RSDs) less than 5.16%, and relative recoveries of 85.96 to 95.92% were obtained at low, medium, and high concentration, respectively. The method was successfully applied to simultaneous determination of the endo-/exogenous glucose concentration in plasma of non-diabetic and type II diabetic cynomolgus monkeys. Graphical Abstract The scheme of the proposed ratio-based approach using isotope dilution LC-MS/MS with indirect MRM of the derivative tag for simultaneous quantification of endogenous and exogenous plasma glucose.


Assuntos
Glicemia/análise , Diabetes Mellitus/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Glicemia/metabolismo , Isótopos de Carbono/análise , Isótopos de Carbono/metabolismo , Cromatografia Líquida/métodos , Diabetes Mellitus/metabolismo , Humanos , Técnicas de Diluição do Indicador , Limite de Detecção , Macaca fascicularis , Reprodutibilidade dos Testes
14.
Planta Med ; 84(2): 123-128, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28793356

RESUMO

Eupatorium lindleyanum has traditionally been used as folk medicine in Asian countries for its therapeutic effects on tracheitis and tonsillitis. Investigation of the anti-inflammatory active constituents from E. lindleyanum led to the isolation of two novel sesquiterpene lactones, named eupalinolide L (1: ) and eupalinolide M (2: ), and seven known sesquiterpene lactones (3: -9: ). The structures and configurations of the new compounds were determined on the basis of spectroscopic analysis, especially 2D NMR techniques. In vivo experiments showed that the sesquiterpenes fraction significantly reduced mouse ear edema induced by xylene (18.6%, p < 0.05). In in vitro assays, compounds 1: -9: showed excellent anti-inflammatory activities, as they lowered TNF-α and IL-6 levels in lipopolysaccharide-stimulated murine macrophage RAW 264.7 cells (p < 0.001). The above results suggest that the sesquiterpene lactones from E. lindleyanum can be developed as novel potential natural anti-inflammatory agents.


Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Eupatorium/química , Sesquiterpenos/isolamento & purificação , Animais , Anti-Inflamatórios não Esteroides/farmacologia , China , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Estrutura Molecular , Plantas Medicinais/química , Células RAW 264.7 , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo
15.
Mol Med Rep ; 15(4): 2235-2240, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28260103

RESUMO

As a neurotropic substance, ethanol can damage nerve cells through an increase in the production of free radicals, interference of neurotrophic factor signaling pathways, activation of endogenous apoptotic signals and other molecular mechanisms. Previous studies have revealed that a number of natural drugs extracted from plants offer protection of nerve cells from damage. Among these, arctigenin (ATG) is a lignine extracted from Arctium lappa (L.), which has been found to exert a neuroprotective effect on scopolamine­induced memory deficits in mice with Alzheimer's disease and glutamate-induced neurotoxicity in primary neurons. As a result, it may offer beneficial effects on ethanol-induced neurotoxicity. However, the effects of ATG on ethanol­induced nerve damage remain to be elucidated. To address this issue, the present study used rat pheochromocytoma PC12 cells to investigate the neuroprotective effects of ATG on ethanol-induced cell damage by performing an MTT reduction assay, cell cycle analysis, Hoechst33342/propidium iodide fluorescence staining and flow cytometry to examine apoptosis. The results showed that 10 µM ATG effectively promoted the proliferation of damaged cells, and increased the distribution ratio of the cells at the G2/M and S phases (P<0.05). In addition, the apoptosis and necrosis of the PC12 cells were significantly decreased following treatment with ATG. Therefore, it was concluded that 10 µM ATG had a protective effect on ethanol­induced injury in PC12 cells.


Assuntos
Etanol/toxicidade , Furanos/farmacologia , Lignanas/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Animais , Apoptose/efeitos dos fármacos , Arctium/química , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Furanos/química , Lignanas/química , Neurônios/citologia , Neurônios/patologia , Fármacos Neuroprotetores/química , Células PC12 , Ratos
16.
Biomed Pharmacother ; 79: 254-62, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27044836

RESUMO

As one of the most commonly abused psychotropic substances, ethanol exposure has deleterious effects on the central nervous system (CNS). The most detrimental results of ethanol exposure during development are the loss of neurons in brain regions such as the hippocampus and neocortex, which may be related to the apoptosis and necrosis mediated by oxidative stress. Recent studies indicated that a number of natural drugs from plants play an important role in protection of nerve cells from damage. Among these, it has been reported that chlorogenic acid (CA) has neuroprotective effects against oxidative stress. Thus, it may play some beneficial effects on ethanol-induced neurotoxicity. However, the effects of CA on ethanol-induced nerve damage remain unclear. In order to investigate the protective effects of CA on alcohol-induced apoptosis in rat pheochromocytoma PC12 cells, in the present study, cell viability and the optimal dosage of CA were first quantified by MTT assay. Then, the cell apoptosis and cell cycle were respectively investigated by Hoechst 33258 staining and flow cytometer (FCM). To further clarify the possible mechanism, followed with the test of mitochondria transmembrane potential with Rhodamine 123 (Rho 123) staining, the expression of Bcl-2, Capase-3 and growth associated protein-43 (GAP-43) were analyzed by immunofluorescence assay separately. The results showed that treatment with 500 mM alcohol decreased the cell viability and then significantly induced apoptosis in PC12 cells. However, when pretreated with different concentrations of CA (1, 5, 10, 50 µM), cell viability increased in different degree. Comparatively, CA with the concentration of 10 µM most effectively promoted the proliferation of damaged cells, increased the distribution ratio of the cells at the G2/M and S phases, and enhanced mitochondria transmembrane potential. This appears to be in agreement with up-regulation of the expression of Bcl-2 and GAP-43, and down-regulation of the expression of Capsae-3. Taken together, CA can increase cell viability and promote cell differentiation by preventing alcohol-induced cell from apoptosis. The mechanism may be related to the enhancement of the expression of GAP-43 and the inhibition of mitochondrial apoptotic pathway including promotion of mitochondria transmembrane potential, up-regulation of the expression of Bcl-2, and down-regulation of the expression of Capsae-3.


Assuntos
Ácido Clorogênico/farmacologia , Etanol/toxicidade , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ácido Clorogênico/química , Proteína GAP-43/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Células PC12 , Substâncias Protetoras/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos
17.
J Sep Sci ; 39(11): 2068-78, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27062005

RESUMO

Flavonoids, including flavones, isoflavones, flavanones, chalcones, and isoflavans, have long been recognized as the main active ingredients in licorice. A method combining liquid chromatography with photodiode array detection and quadrupole time-of-flight mass spectrometry was developed to characterize components in three Glycyrrhiza species, and to expound the characteristic fragmentation behaviors in the positive ion mode. Based on the fragmentation patterns of reference compounds, a total of 39 compounds, including 37 flavonoid aglycones and two coumestans, were identified or tentatively identified. Besides, some common features, such as H2 O, CO, and CH2 O2 losses, together with retro-Diels-Alder fragmentation, were observed in these compounds. Furthermore, diagnostic fragmentations of C-ring cleavages and UV absorption on the skeleton groups were observed to structurally characterize flavonoid aglycones. In addition, typical losses of different substituent groups were detected: Neutral losses of 56 (C4 H8 ) and 68 Da (C5 H8 ) were yielded from a prenyl chain; neutral losses of 42 (C3 H6 ), 54 (C4 H6 ), and 70 Da (C4 H6 O) were generated by a pyran ring. Particularly, neutral losses of 18 (H2 O), 16 (CH4 ), 112 (C8 H16 ), and 98 Da (C7 H14 ) predicted a hydroxyl, a methoxyl, double prenyl chains, and a prenyl chain with a pyran ring, respectively.


Assuntos
Flavonoides/análise , Glicosídeos/análise , Glycyrrhiza/química , Cromatografia Líquida , Espectrometria de Massas , Estrutura Molecular , Especificidade da Espécie , Fatores de Tempo
18.
Molecules ; 20(4): 6273-83, 2015 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-25859783

RESUMO

Two novel oleanane-type triterpene saponins, licorice-saponin P2 (1) and licorice-saponin Q2 (3), together with nine known compounds 2, 4-11, have been isolated from the water extract of the roots of Glycyrrhiza inflata. The structures of these compounds were elucidated on the basis of spectroscopic analysis, including 2D-NMR experiments (1H-1H COSY, HSQC, HMBC and ROESY). In in vitro assays, compounds 2-4, 6 and 11 showed significant hepatoprotective activities by lowering the ALT and AST levels in primary rat hepatocytes injured by D-galactosamine (D-GalN). In addition, compounds 2-4, 6, 7 and 11 were found to inhibit the activity of PLA2 with IC50 values of 6.9 µM, 3.6 µM, 16.9 µM, 27.1 µM, 32.2 µM and 9.3 µM, respectively, which might be involved in the regulation of the hepatoprotective activities observed.


Assuntos
Glycyrrhiza/química , Fígado/efeitos dos fármacos , Saponinas/farmacologia , Triterpenos/química , Animais , Galactosamina/toxicidade , Hepatócitos/efeitos dos fármacos , Extratos Vegetais/química , Raízes de Plantas/química , Cultura Primária de Células , Ratos , Saponinas/química , Triterpenos/farmacologia
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