Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
Cancer Immunol Immunother ; 72(2): 351-369, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35895109

RESUMO

BACKGROUND: Immunotherapy is an emerging cancer therapy with potential great success; however, immune checkpoint inhibitor (e.g., anti-PD-1) has response rates of only 10-30% in solid tumor because of the immunosuppressive tumor microenvironment (TME). This affliction can be solved by vascular normalization and TME reprogramming. METHODS: By using the single-cell RNA sequencing (scRNAseq) approach, we tried to find out the reprogramming mechanism that the Fc-VEGF chimeric antibody drug (Fc-VFD) enhances immune cell infiltration in the TME. RESULTS: In this work, we showed that Fc-VEGF121-VEGF165 (Fc-VEGF chimeric antibody drug, Fc-VFD) arrests excess angiogenesis and tumor growth through vascular normalization using in vitro and in vivo studies. The results confirmed that the treatment of Fc-VFD increases immune cell infiltration including cytotoxic T, NK, and M1-macrophages cells. Indeed, Fc-VFD inhibits Lon-induced M2 macrophages polarization that induces angiogenesis. Furthermore, Fc-VFD inhibits the secretion of VEGF-A, IL-6, TGF-ß, or IL-10 from endothelial, cancer cells, and M2 macrophage, which reprograms immunosuppressive TME. Importantly, Fc-VFD enhances the synergistic effect on the combination immunotherapy with anti-PD-L1 in vivo. CONCLUSIONS: In short, Fc-VFD fusion normalizes intratumor vasculature to reprogram the immunosuppressive TME and enhance cancer immunotherapy.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Microambiente Tumoral , Fator A de Crescimento do Endotélio Vascular , Imunoterapia , Antineoplásicos/farmacologia , Imunossupressores/farmacologia
2.
J Virol ; 96(6): e0214121, 2022 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-35044216

RESUMO

Due to the high mutation rate of influenza virus and the rapid increase of drug resistance, it is imperative to discover host-targeting antiviral agents with broad-spectrum antiviral activity. Considering the discrepancy between the urgent demand of antiviral drugs during an influenza pandemic and the long-term process of drug discovery and development, it is feasible to explore host-based antiviral agents and strategies from antiviral drugs on the market. In the current study, the antiviral mechanism of arbidol (ARB), a broad-spectrum antiviral drug with potent activity at early stages of viral replication, was investigated from the aspect of hemagglutinin (HA) receptors of host cells. N-glycans that act as the potential binding receptors of HA on 16-human bronchial epithelial (16-HBE) cells were comprehensively profiled for the first time by using an in-depth glycomic approach based on TiO2-PGC chip-Q-TOF MS. Their relative levels upon the treatment of ARB and virus were carefully examined by employing an ultra-high sensitive qualitative method based on Chip LC-QQQ MS, showing that ARB treatment led to significant and extensive decrease of sialic acid (SA)-linked N-glycans (SA receptors), and thereby impaired the virus utilization on SA receptors for rolling and entry. The SA-decreasing effect of ARB was demonstrated to result from its inhibitory effect on sialyltransferases (ST), ST3GAL4 and ST6GAL1 of 16-HBE cells. Silence of STs, natural ST inhibitors, as well as sialidase treatment of 16-HBE cells, resulted in similar potent antiviral activity, whereas ST-inducing agent led to the diminished antiviral effect of ARB. These observations collectively suggesting the involvement of ST inhibition in the antiviral effect of ARB. IMPORTANCE This study revealed, for the first time, that ST inhibition and the resulted destruction of SA receptors of host cells may be an underlying mechanism for the antiviral activity of ARB. ST inhibition has been proposed as a novel host-targeting antiviral approach recently and several compounds are currently under exploration. ARB is the first antiviral drug on the market that was found to possess ST inhibiting function. This will provide crucial evidence for the clinical usages of ARB, such as in combination with neuraminidase (NA) inhibitors to exert optimized antiviral effect, etc. More importantly, as an agent that can inhibit the expression of STs, ARB can serve as a novel lead compound for the discovery and development of host-targeting antiviral drugs.


Assuntos
Indóis , Sialiltransferases , Sulfetos , Antivirais/farmacologia , Antivirais/uso terapêutico , Linhagem Celular , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Células Epiteliais , Glicômica , Hemaglutininas , Humanos , Indóis/farmacologia , Indóis/uso terapêutico , Neuraminidase/farmacologia , Polissacarídeos/metabolismo , Sialiltransferases/antagonistas & inibidores , Sulfetos/farmacologia , Sulfetos/uso terapêutico
3.
PLoS Pathog ; 17(8): e1009758, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34379705

RESUMO

Since the pandemic of COVID-19 has intensely struck human society, small animal model for this infectious disease is in urgent need for basic and pharmaceutical research. Although several COVID-19 animal models have been identified, many of them show either minimal or inadequate pathophysiology after SARS-CoV-2 challenge. Here, we describe a new and versatile strategy to rapidly establish a mouse model for emerging infectious diseases in one month by multi-route, multi-serotype transduction with recombinant adeno-associated virus (AAV) vectors expressing viral receptor. In this study, the proposed approach enables profound and enduring systemic expression of SARS-CoV-2-receptor hACE2 in wild-type mice and renders them vulnerable to SARS-CoV-2 infection. Upon virus challenge, generated AAV/hACE2 mice showed pathophysiology closely mimicking the patients with severe COVID-19. The efficacy of a novel therapeutic antibody cocktail RBD-chAbs for COVID-19 was tested and confirmed by using this AAV/hACE2 mouse model, further demonstrating its successful application in drug development.


Assuntos
COVID-19 , Doenças Transmissíveis Emergentes , Modelos Animais de Doenças , Células 3T3 , Enzima de Conversão de Angiotensina 2/genética , Animais , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/uso terapêutico , COVID-19/imunologia , COVID-19/patologia , COVID-19/fisiopatologia , Chlorocebus aethiops , Dependovirus/genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transdução Genética , Células Vero
4.
Appl Microbiol Biotechnol ; 107(23): 7197-7211, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37741939

RESUMO

Tetanus toxin (TeNT) and botulinum neurotoxins (BoNTs) are neuroprotein toxins, with the latter being the most toxic known protein. They are structurally similar and contain three functional domains: an N-terminal catalytic domain (light chain), an internal heavy-chain translocation domain (HN domain), and a C-terminal heavy chain receptor binding domain (Hc domain or RBD). In this study, fusion functional domain molecules consisting of the TeNT RBD (THc) and the BoNT/A RBD (AHc) (i.e., THc-Linker-AHc and AHc-Linker-THc) were designed, prepared, and identified. The interaction of each Hc domain and the ganglioside receptor (GT1b) or the receptor synaptic vesicle glycoprotein 2 (SV2) was explored in vitro. Their immune response characteristics and protective efficacy were investigated in animal models. The recombinant THc-linker-AHc and AHc-linker-THc proteins with the binding activity had the correct size and structure, thus representing novel subunit vaccines. THc-linker-AHc and AHc-linker-THc induced high levels of specific neutralizing antibodies, and showed strong immune protective efficacy against both toxins. The high antibody titers against the two novel fusion domain molecules and against individual THc and AHc suggested that the THc and AHc domains, as antigens in the fusion functional domain molecules, do not interact with each other and retain their full key epitopes responsible for inducing neutralizing antibodies. Thus, the recombinant THc-linker-AHc and AHc-linker-THc molecules are strong and effective bivalent biotoxin vaccines, protecting against two biotoxins simultaneously. Our experimental design will be valuable to develop recombinant double-RBD fusion molecules as potent bivalent subunit vaccines against bio-toxins. KEY POINTS: • Double-RBD fusion molecules from two toxins had the correct structure and activity. • THc-linker-AHc and AHc-linker-THc efficiently protected against both biotoxins. • Such bivalent biotoxin vaccines based on the RBD are a valuable experimental design.


Assuntos
Toxinas Botulínicas Tipo A , Toxina Tetânica , Animais , Toxina Tetânica/genética , Toxina Tetânica/metabolismo , Toxinas Botulínicas Tipo A/genética , Toxinas Botulínicas Tipo A/metabolismo , Ligação Proteica , Anticorpos Neutralizantes , Vacinas de Subunidades Antigênicas/genética
5.
Nucleic Acids Res ; 49(1): 38-52, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33290562

RESUMO

Acquired drug resistance is a major obstacle in cancer therapy. Recent studies revealed that reprogramming of tRNA modifications modulates cancer survival in response to chemotherapy. However, dynamic changes in tRNA modification were not elucidated. In this study, comparative analysis of the human cancer cell lines and their taxol resistant strains based on tRNA mapping was performed by using UHPLC-MS/MS. It was observed for the first time in all three cell lines that 4-demethylwyosine (imG-14) substitutes for hydroxywybutosine (OHyW) due to tRNA-wybutosine synthesizing enzyme-2 (TYW2) downregulation and becomes the predominant modification at the 37th position of tRNAphe in the taxol-resistant strains. Further analysis indicated that the increase in imG-14 levels is caused by downregulation of TYW2. The time courses of the increase in imG-14 and downregulation of TYW2 are consistent with each other as well as consistent with the time course of the development of taxol-resistance. Knockdown of TYW2 in HeLa cells caused both an accumulation of imG-14 and reduction in taxol potency. Taken together, low expression of TYW2 enzyme promotes the cancer survival and resistance to taxol therapy, implying a novel mechanism for taxol resistance. Reduction of imG-14 deposition offers an underlying rationale to overcome taxol resistance in cancer chemotherapy.


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Paclitaxel/farmacologia , Processamento Pós-Transcricional do RNA/genética , RNA Neoplásico/química , RNA de Transferência de Fenilalanina/química , Células A549 , Sequência de Bases , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/fisiologia , Feminino , Regulação Enzimológica da Expressão Gênica , Técnicas de Silenciamento de Genes , Guanosina/análogos & derivados , Guanosina/química , Guanosina/metabolismo , Células HeLa , Humanos , Estrutura Molecular , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Conformação de Ácido Nucleico , Neoplasias Ovarianas/patologia , RNA Neoplásico/fisiologia , RNA de Transferência de Fenilalanina/fisiologia , Espectrometria de Massas em Tandem , Ensaio Tumoral de Célula-Tronco
6.
J Proteome Res ; 19(4): 1470-1480, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32129075

RESUMO

Due to its relatively small size, homology to humans, and susceptibility to human viruses, the tree shrew becomes an ideal alternative animal model for the study of human viral infectious diseases. However, there is still no report for the comprehensive glycan profile of the respiratory tract tissues in tree shrews. In this study, we characterized the structural diversity of N-glycans in the respiratory tract of tree shrews using our well-established TiO2-PGC chip-Q-TOF-MS method. As a result, a total of 219 N-glycans were identified. Moreover, each identified N-glycan was quantitated by a high sensitivity and accurate MRM method, in which 13C-labeled internal standards were used to correct the inherent run-to-run variation in MS detection. Our results showed that the N-glycan composition in the turbinate and lung was significantly different from the soft palate, trachea, and bronchus. Meanwhile, 28 high-level N-glycans in turbinate were speculated to be correlated with the infection of H1N1 virus A/California/04/2009. This study is the first to reveal the comprehensive glycomic profile of the respiratory tract of tree shrews. Our results also help to better understand the role of glycan receptors in human influenza infection and pathogenesis.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Tupaiidae , Animais , Glicômica , Humanos , Espectrometria de Massas , Polissacarídeos , Titânio
7.
BMC Cancer ; 18(1): 799, 2018 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-30089463

RESUMO

BACKGROUND: Resistance to chemotherapy drugs (e.g. taxol) has been a major obstacle in successful cancer treatment. In A549 human lung adenocarcinoma, acquired resistance to the first-line chemotherapy taxol has been a critical problem in clinics. Sphingolipid (SPL) controls various aspects of cell growth, survival, adhesion, and motility in cancer, and has been gradually regarded as a key factor in drug resistance. To better understand the taxol-resistant mechanism, a comprehensive sphingolipidomic approach was carried out to investigate the sphingolipid metabolism in taxol-resistant strain of A549 cell (A549T). METHODS: A549 and A549T cells were extracted according to the procedure with optimal condition for SPLs. Sphingolipidomic analysis was carried out by using an UHPLC coupled with quadrupole time-of-flight (Q-TOF) MS system for qualitative profiling and an UHPLC coupled with triple quadrupole (QQQ) MS system for quantitative analysis. The differentially expressed sphingolipids between taxol-sensitive and -resistant cells were explored by using multivariate analysis. RESULTS: Based on accurate mass and characteristic fragment ions, 114 SPLs, including 4 new species, were clearly identified. Under the multiple reaction monitoring (MRM) mode of QQQ MS, 75 SPLs were further quantified in both A549 and A549T. Multivariate analysis explored that the levels of 57 sphingolipids significantly altered in A549T comparing to those of A549 (p < 0.001 and VIP > 1), including 35 sphingomyelins (SMs), 14 ceramides (Cers), 3 hexosylceramides (HexCers), 4 lactosylceramides (LacCers) and 1 sphingosine. A significant decrease of SM and Cer levels and overall increase of HexCer and LacCer represent the major SPL metabolic characteristic in A549T. CONCLUSIONS: This study investigated sphingolipid profiles in human lung adenocarcinoma cell lines, which is the most comprehensive sphingolipidomic analysis of A549 and A549T. To some extent, the mechanism of taxol-resistance could be attributed to the aberrant sphingolipid metabolism, "inhibition of the de novo synthesis pathway" and "activation of glycosphingolipid pathway" may play the dominant role for taxol-resistance in A549T. This study provides insights into the strategy for clinical diagnosis and treatment of taxol resistant lung cancer.


Assuntos
Células A549 , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/metabolismo , Paclitaxel/farmacologia , Esfingolipídeos , Células A549/química , Células A549/efeitos dos fármacos , Células A549/metabolismo , Cromatografia Líquida , Biologia Computacional , Humanos , Espectrometria de Massas , Análise de Componente Principal , Esfingolipídeos/análise , Esfingolipídeos/química , Esfingolipídeos/metabolismo
8.
Zhongguo Zhong Yao Za Zhi ; 42(18): 3557-3563, 2017 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-29218942

RESUMO

In this study, we used Ultra Performance Liquid Chromatography-Time-of-Flight Mass Spectrometry(UPLC-TOF-MS)to identify the chemical constituents in both ethanol and water extract of Polygonum capitatum. A Waters ACQUITY UPLC BEH C18 column(2.1 mm×100 mm,1.7 µm) was used for separation. The mobile phase was consisted of(A) 0.10% formic acid in water and(B)0.10% formic acid in acetonitrile, and the flow rate was 0.35 mL•min⁻¹. ESI source in negative ion mode was used for MS detection. Structural identification was carried out according to the accurate mass and matching with database. The results showed that flavonoids, polyphenols and lignans were the main components in both extracts. However, the chemical compositions of both extracts were different, e.g. there are less hydrolyzable tannins, loss of ellagic acid and more anthocyanins in ethanol extract. In a conclusion, this study provides an important scientific basis for identifying the active ingredients in P. capitatum, which also help to reveal the pharmacological effect of P. capitatum.


Assuntos
Medicamentos de Ervas Chinesas/análise , Extratos Vegetais/análise , Polygonum/química , Cromatografia Líquida de Alta Pressão , Etanol , Flavonoides/análise , Lignanas/análise , Polifenóis/análise , Espectrometria de Massas em Tandem , Água
9.
Chem Pharm Bull (Tokyo) ; 64(10): 1505-1508, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27725504

RESUMO

Phytochemical investigation of the root of Baphicacanthus cusia (NEES) BREMEK afforded two new alkaloids, baphicacanthin A (1) and baphicacanthin B (2), along with 28 known compounds. The chemical structures of these compounds were elucidated on the basis of one and two dimensional (1D/2D)-NMR and high resolution (HR)-MS spectral evidence.


Assuntos
Acanthaceae/química , Alcaloides/química , Alcaloides/isolamento & purificação , Benzoxazinas/química , Glucosídeos/química , Alcaloides Indólicos/química , Compostos Fitoquímicos/química , Raízes de Plantas/química , Benzoxazinas/isolamento & purificação , Glucosídeos/isolamento & purificação , Alcaloides Indólicos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação
10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(2): 316-21, 2016 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-27209722

RESUMO

The development of terahertz technology is attracting broad intention in recent years. The quality identification is important for the quality control of Chinese medicine production. In the present work, terahertz time-domain spectroscopy (THz-TDS) combined with partial least squares (PLS) were used for the identification model building and studied based on 41 official and unofficial rhubarb samples. First, the THz-TDS spectra of rhubarb samples were collected and were preprocessed by using chemometrics methods rather than transformed to absorption spectra. The identification models were then established based on the processed terahertz time domain spectra. The spectral preprocessing methods include Savitzky-Golay (S-G) first derivative, detrending, standard normal transformation (SNV), autoscaling, and mean centering. The identification accuracy of 90% was accomplished by using proper pretreatment methods, which was higher than the classified accuracy of 80% without any preprocessing for the time domain spectra. The component number of the PLS model was evaluated by leave-one-out cross-validation (LOOCV). The minimum values of the root-mean squared error of cross-validation (RMSECV) and root-mean squared error of prediction (RMSEP) were 0.076 6 and 0.169 0 by using mean centering method, respectively. The results of this work showed that the combination of terahertz time domain spectroscopy technology with chemometrics methods, as well as PLS can be applied for the recognition of genuine and counterfeit Chinese herbal medicines, as well as official and unofficial rhubarbs. The advantage of using terahertz time domain spectra directly with no transformation into absorption spectra is: (1) the thickness of samples could not be considered in the model establishment, and (2) the spectral processing was simplified. The proposed method based on the combination of THz-TDS and chemometrics proved to be rapid, simple, non-pollution and solvent free, suitable to be developed as a promising tool for quality control of many other Chinese herbal medicines.


Assuntos
Medicamentos de Ervas Chinesas/química , Rheum/química , Análise Espectral , Plantas Medicinais/química , Controle de Qualidade
11.
Molecules ; 20(3): 3496-514, 2015 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-25699594

RESUMO

Mutant huntingtin aggregation is highly associated with the pathogenesis of Huntington's disease, an adult-onset autosomal dominant disorder, which leads to a loss of motor control and decline in cognitive function. Recent literature has revealed the protective role of autophagy in neurodegenerative diseases through degradation of mutant toxic proteins, including huntingtin or a-synuclein. Through the GFP-LC3 autophagy detection platform, we have  identified  neferine,  isolated  from  the  lotus  seed  embryo  of Nelumbo nucifera, which is able to induce autophagy through an AMPK-mTOR-dependent pathway. Furthermore, by overexpressing huntingtin with 74 CAG repeats (EGFP-HTT 74) in PC-12 cells, neferine reduces both the protein level and toxicity of mutant huntingtin through an autophagy-related gene 7 (Atg7)-dependent mechanism. With the variety of novel active compounds present in medicinal herbs, our current study suggests the possible protective mechanism of an autophagy inducer isolated from Chinese herbal medicine, which is crucial for its further development into a potential therapeutic agent for neurodegenerative disorders in the future.


Assuntos
Autofagia/efeitos dos fármacos , Benzilisoquinolinas/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Doença de Huntington/patologia , Proteínas Mutantes/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Adulto , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Proliferação de Células/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Citometria de Fluxo , Humanos , Proteína Huntingtina , Doença de Huntington/tratamento farmacológico , Doença de Huntington/genética , Proteínas Mutantes/genética , Proteínas do Tecido Nervoso/genética , Células PC12 , RNA Mensageiro/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
12.
Anal Chem ; 86(12): 5688-96, 2014 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-24844867

RESUMO

The emerging field of sphingolipidomics calls for accurate quantitative analyses of sphingolipidome. Existing analytical methods for sphingolipid (SPL) profiling often suffer from isotopic/isomeric interference, leading to the low-abundance, but biologically important SPLs being undetected. In the current study, we have developed an improved sphingolipidomic approach for reliable and sensitive quantification of up to 10 subclasses of cellular SPLs. By integratively utilizing high efficiency chromatographic separation, quadrupole time-of-flight (Q-TOF) and triple quadrupole (QQQ) mass spectrometry (MS), our approach facilitated unambiguous identification of several groups of potentially important but low-abundance SPLs that are usually masked by isotopic/isomeric species and hence largely overlooked in many published methods. The methodology, which featured a modified sample preparation and optimized MS parameters, permitted the measurement of 86 individual SPLs in PC12 cells in a single run, demonstrating great potential for high throughput analysis. The improved characterization, along with increased sensitivity for low-abundance SPL species, resulted in the highest number of SPLs being quantified in a single run in PC12 cells. The improved method was fully validated and applied to a lipidomic study of PC12 cell samples with or without amyloid ß peptide (Aß) treatment, which presents a most precise and genuine sphingolipidomic profile of the PC12 cell line. The adoption of the metabolomics protocol, as described in this study, could avoid misidentification and bias in the measurement of the analytically challenging low-abundance endogenous SPLs, hence achieving informative and reliable sphingolipidomics data relevant to discovery of potential SPL biomarkers for Aß-induced neurotoxicity and neurodegenerative disease.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Neurônios/efeitos dos fármacos , Esfingolipídeos/química , Animais , Limite de Detecção , Células PC12 , Ratos , Testes de Toxicidade
13.
Molecules ; 19(4): 4466-78, 2014 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-24727418

RESUMO

The standard extract of Ginkgo biloba leaves (EGb761) is used clinically in Europe for the symptomatic treatment of impaired cerebral function in primary degenerative dementia syndromes, and the results of numerous in vivo and in vitro studies have supported such clinical use. The abnormal production and aggregation of amyloid ß peptide (Aß) and the deposition of fibrils in the brain are regarded as key steps in the onset of Alzheimer's Disease (AD), and the inhibition of Aß aggregation and destabilization of the preformed fibrils represent viable approaches for the prevention and treatment of AD. Flavonoid glycosides and terpene trilactones (TTLs) are the two main components of EGb761 which represent 24 and 6% of the overall content, respectively. In our research, seven abundant flavonoid glycosides 1-7 were isolated from the extract of Ginkgo biloba leaves and characterized by spectroscopic analysis. Furthermore, an ultra-high performance liquid chromatography method was established for the simultaneous quantification of these seven flavonoids. The inhibitory activities of these flavonoids, as well as four TTLs, i.e., ginkgolides A, B, and C and bilobalide (compounds 8-11), were evaluated towards Aß42 fibril formation using a thioflavin T fluorescence assay. It was found that three flavonoids 1, 3 and 4 exhibited moderate inhibitory activities, whereas the other four flavonoids 2, 5, 6 and 7, as well as the four terpene trilactones, showed poor activity. This is the first report of the inhibition of Aß fibril formation of two characteristic acylated flavonoid glycosides 6, 7 in Ginkgo leaves, on the basis of which the structure-activity relationship of these flavonoids 1-7 was discussed.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Flavonoides/química , Ginkgo biloba/química , Glicosídeos/química , Lactonas/química , Fragmentos de Peptídeos/antagonistas & inibidores , Extratos Vegetais/química , Terpenos/química , Peptídeos beta-Amiloides/química , Benzotiazóis , Flavonoides/isolamento & purificação , Glicosídeos/isolamento & purificação , Humanos , Lactonas/isolamento & purificação , Fragmentos de Peptídeos/química , Folhas de Planta/química , Espectrometria de Fluorescência , Relação Estrutura-Atividade , Terpenos/isolamento & purificação , Tiazóis
14.
Molecules ; 19(4): 5119-34, 2014 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-24759072

RESUMO

Catechins and procyanidins, together with flavonoid glycosides and terpene trilactones, are three important categories of components in the standard extract of Ginkgo biloba leaves (EGb761). In this research, catechins and proanthocyanidins were found to exist in both the extract of Ginkgo leaves and Ginkgo products. By comparing with reference compounds, six of them were identified as (+)-catechin, (-)-epicatechin, (-)-gallocatechin, (-)-epigallocatechin and procyanidins B1 and B3. The activities of these polyphenols in the inhibition of Aß42 aggregation and the destabilization of preformed fibrils were evaluated using biochemical assays, which showed that all six of the polyphenols, as well as a fraction of the extract of Ginkgo biloba leaves (EGb) containing catechins and procyanidins, exerted potent inhibitory activities towards Aß42 aggregation and could also destabilize the performed fibrils. Catechins and procyanidins can therefore be regarded as the potent active constituents of EGb761 in terms of their inhibition of Aß42 aggregation and destabilization of the fibrils. Although quantitative mass spectroscopic analysis revealed that the catechins and procyanidins are only present in low concentrations in EGb761, these components should be studied in greater detail because of their potent inhibitory effects towards Aß42 aggregation and their ability to destabilize preformed fibrils, especially during the quality control of Ginkgo leaves and the manufacture of Ginkgo products.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Benzopiranos/química , Ginkgo biloba/química , Fragmentos de Peptídeos/antagonistas & inibidores , Extratos Vegetais/química , Folhas de Planta/química , Peptídeos beta-Amiloides/química , Benzopiranos/isolamento & purificação , Biflavonoides/química , Biflavonoides/isolamento & purificação , Catequina/análogos & derivados , Catequina/química , Catequina/isolamento & purificação , Humanos , Fragmentos de Peptídeos/química , Proantocianidinas/química , Proantocianidinas/isolamento & purificação , Relação Estrutura-Atividade
15.
Front Pharmacol ; 15: 1421130, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38962315

RESUMO

Background: Desmopressin acetate (DDAVP) and behavioral interventions (BI) are cornerstone treatments for nocturnal enuresis (NE), a common pediatric urinary disorder. Despite the growing body of clinical studies on massage therapy for NE, comprehensive evaluations comparing the effectiveness of Tuina with DDAVP or BI are scarce. This study aims to explore the efficacy of Tuina in the management of NE. Methods: A systematic search of international databases was conducted using keywords pertinent to Tuina and NE. The inclusion criteria were limited to randomized controlled trials (RCTs) that evaluated NE treatments utilizing Tuina against DDAVP or BI. This meta-analysis included nine RCTs, comprising a total of 685 children, to assess both complete and partial response rates. Results: Tuina, used as a combination therapy, showed enhanced clinical efficacy and improved long-term outcomes relative to the control group. The therapeutic efficacy of Tuina was not directly associated with the number of acupoints used. Instead, employing between 11 and 20 acupoints appeared to have the most significant effect. Conclusion: The findings of this meta-analysis support the potential of Tuina as an adjunct therapy to enhance the sustained clinical efficacy of traditional treatments for NE. However, Tuina cannot completely replace DDAVP or BI in the management of NE. While this study illuminates some aspects of the effective acupoint combinations, further research is crucial to fully understand how Tuina acupoints contribute to the treatment of NE in children. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=442644, identifier CRD42023442644.

16.
Anal Biochem ; 443(1): 27-33, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23938773

RESUMO

Peptide isoelectric focusing (IEF) is a common technique used in two-dimensional liquid chromatography tandem mass spectrometry (2D-LC-MS/MS) proteomic workflow, in which the tryptic peptide is first pre-fractionated based on pI values before being subjected to reverse phase LC-MS analysis. Although this method has been widely used by many research groups, a systemic study on the optimal conditions and fundamental parameters influencing the experimental outcomes has been lacking, including the effect of peptide extraction methods, the extent of pre-fractionation, and the choice of pH range. In this study, we compared the effect of different parameters on the numbers of peptides and proteins identified using two complex mouse proteomes. The results indicated that extraction of peptides from immobilized pH gradient (IPG) strips by sequential elution of increasingly organic solvents provided the highest number of peptide identification. In addition, we showed that approximately 45 more unique proteins were identified for every additional fraction collected during peptide IEF. Although narrow pH ranges provided higher resolution in peptide separation as expected, different pH ranges yielded similar numbers of peptide and protein identification. Overall, we demonstrated that the extraction solvent influenced the numbers of peptide and protein identification and quantitatively demonstrated the advantage of extensive fractionation and the performance of different pH ranges in practice.


Assuntos
Carcinoma Pulmonar de Lewis/química , Fragmentos de Peptídeos/isolamento & purificação , Proteoma/análise , Animais , Linhagem Celular Tumoral , Cromatografia Líquida , Concentração de Íons de Hidrogênio , Focalização Isoelétrica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Força Próton-Motriz , Microextração em Fase Sólida , Espectrometria de Massas em Tandem , Tripsina/química
17.
Chin Med ; 18(1): 65, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37264387

RESUMO

BACKGROUND: Baphicacanthis Cusiae Rhizoma et Radix, commonly known as Nan-Ban-Lan-Gen (NBLG), is an essential traditional Chinese medicine that possesses diverse bioactivities, particularly noteworthy for its antiviral properties. Although NBLG has been listed in the Chinese Pharmacopoeia as an independent Chinese medicine, the establishment of a comprehensive quality standard for NBLG remains elusive. The absence of assay for marker compound in its quality standards has led to the lack of corresponding quality control measures for NBLG-containing preparations, and its discrimination from adulterant species in the market which thereby can significantly impact the efficacy and safety of NBLG-containing products. METHODS: Ultra-high performance liquid chromatography (UHPLC) coupled with quadrupole-time-of-flight mass spectrometry (Q-TOF-MS) was employed for comprehensive profiling of the chemical constituents of NBLG, the stem of Baphicacanthus cusia (Nees) Bremek (NBLJ), and the roots of Isatis indigotica Fort. (Bei-Ban-Lan-Gen, BBLG). Additionally, multivariate analysis was conducted to compare the chemical components of NBLG with those of NBLJ and BBLG. Furthermore, we established an optimized and validated HPLC method to obtain the fingerprint of NBLG and quantify the content of 2-benzoxazolinone and acteoside in the samples. RESULTS: A total of 73 compounds belonging to six classes were assigned in NBLG, with alkaloids being the most abundant and diverse species. High compositional similarities with significant differences in content were observed between NBLG and NBLJ. Moreover, the chemical profile of BBLG markedly differed from that of NBLG. An informative high performance liquid chromatography (HPLC) fingerprint of NBLG comprising seven characteristic peaks that can be used for quality assessment was established. Notably, we propose a quality control standard for NBLG, stipulating that the limit of content in dry weight for both 2-benzoxazolinone and acteoside should not be less than 0.010%. CONCLUSION: This study provides the most comprehensive chemical information to date on NBLG, offering valuable insights into its authentication and quality control. Our findings highlight the importance of comprehensive chemical profiling to differentiate potential substitutions and adulterations of herbal medicines, particularly when the original source is scarce or unavailable. These results can aid in the development of quality control measures for NBLG-containing preparations, ensuring their safety and efficacy.

18.
Talanta ; 256: 124264, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36689895

RESUMO

Gangliosides (GAs) and sulfatides (STs) are acidic glycosphingolipids that are particularly abundant in the nervous system and are closely related to aging and neurodegenerative disorders. To explore their roles in brain diseases, in-depth molecular profiling, including structural variations of sphingoid backbone, fatty acyl group, and sugar chain of GAs and STs was performed. A total of 210 GAs and 38 STs were characterized in the inferior frontal gyrus (IFG) of human brain, with 90 GAs discovered in brain tissues for the first time. Influential MS parameters for detecting GAs and STs in multiple reaction monitoring (MRM) mode were systematically examined and optimized to minimize in-source fragmentation, resulting in remarkable signal intensity enhancement for GAs and STs, especially for polysialylated species. To eliminate analytical variations, isotopic interference-free internal standards were prepared by simple and fast reduction reaction. The final established method facilitated the simultaneous quantitation of 184 GAs and 30 STs from 25 subtypes, which represents the highest number of GAs quantitated among all quantitation methods recorded in literature so far. The method was further validated and applied to reveal the aberrant change of GAs and STs in the IFG of 12 Alzheimer's disease (AD) patients. Four GAs exhibited high classification capacity for AD (AUC ≥0.80) and were thereby considered the most promising signatures for AD. These findings suggested the close correlation between GAs and the pathogenesis of AD, highlighting the achievements of our robust method for investigating the roles of GAs and STs in various physiological states and diseases.


Assuntos
Doença de Alzheimer , Gangliosídeos , Humanos , Sulfoglicoesfingolipídeos/química , Cromatografia Líquida de Alta Pressão/métodos , Encéfalo
19.
J Thorac Dis ; 15(10): 5534-5548, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37969309

RESUMO

Background: Pulmonary cryptococcosis (PC) contributes to the ongoing global disease burden in human immunodeficiency virus (HIV)-negative populations. Since some PC patients are misdiagnosed under existing diagnostic guidelines, new diagnostic markers are needed to improve diagnostic accuracy and therapeutic efficacy and reduce disease risk. Methods: Our previously established sphingolipidomic approach was employed to explore the use of serum sphingolipids (SPLs) in diagnosing HIV-negative patients with PC. A clinical cohort of PC, pulmonary aspergillosis (PA), and tuberculosis (TB) patients and healthy controls was assessed to identify SPL biomarkers. Results: A total of 47 PC, 27 PA, and 18 TB patients and 40 controls were enrolled. PC and TB patients had similar clinical features, laboratory test results and radiological features, excluding plural effusion. The serum ceramide [Cer (d18:1/18:0)] level showed a significant increase in PC patients compared to controls and PA and TB patients (P<0.05). Cer (d18:1/18:0) was identified as a specific diagnostic biomarker for PC. The optimal cut-off value of greater than 18.00 nM showed a diagnostic sensitivity of 76.60% and a specificity of 95.00% and better distinguished PC patients from PA and TB patients. Furthermore, the serum Cer (d18:1/18:0) level gradually decreased after 3 and 6 months of treatment, suggesting the prediction potential for therapeutic efficacy of this biomarker. In addition, Cer (d18:1/18:0) analysis presented a higher sensitivity than the cryptococcal antigen (CrAg) assay. Conclusions: This is the first study to report the use of the SPL Cer (d18:1/18:0) as a serum biomarker for diagnosing Cryptococcus spp. infection in HIV-negative patients.

20.
Drug Metab Dispos ; 40(8): 1538-44, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22584255

RESUMO

Ginsenosides are hydrolyzed extensively by gut microflora after oral administration, and their metabolites are pharmacologically active against lung cancer cells. In this study, we measured the metabolism of various ginsenosides by gut microflora and determined the mechanisms responsible for the observed pharmacokinetic behaviors of its active metabolite, Compound K (C-K). The results showed that biotransformation into C-K is the major metabolic pathway of ginsenosides after the oral administration of the red ginseng extract containing both protopanaxadiol and protopanaxatriol ginsenosides. Pharmacokinetic studies in normal mice showed that C-K exhibited low oral bioavailability. To define the mechanisms responsible for this low bioavailability, two P-glycoprotein (P-gp) inhibitors, verapamil and cyclosporine A, were used, and their presence substantially decreased C-K's efflux ratio in Caco-2 cells (from 26.6 to <3) and significantly increased intracellular concentrations (by as much as 40-fold). Similar results were obtained when transcellular transport of C-K was determined using multidrug resistance 1 (MDR1)-overexpressing Madin-Darby canine kidney II cells. In MDR1a/b(-/-) FVB mice, its plasma C(max) and AUC(0-24h) were increased substantially by 4.0- and 11.7-fold, respectively. These increases appear to be due to slower elimination and faster absorption of C-K in MDR1a/b(-/-) mice. In conclusion, C-K is the major active metabolite of ginsenosides after microflora hydrolysis of primary ginsenosides in the red ginseng extract, and inhibition/deficiency of P-gp can lead to large enhancement of its absorption and bioavailability.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Ginsenosídeos/farmacocinética , Intestinos/microbiologia , Panax/química , Extratos Vegetais/farmacologia , Administração Oral , Animais , Disponibilidade Biológica , Células CACO-2 , Ginsenosídeos/administração & dosagem , Humanos , Camundongos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA