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1.
Huan Jing Ke Xue ; 44(11): 6172-6180, 2023 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-37973100

RESUMO

The production and use of plastic blends have been gradually increasing owing to their versatility and low cost. However, the photodegradation of plastic blends in seawater and the potential risk to the marine environment are still not well understood. In this study, plastic blends including polypropylene/thermoplastic starch blends(PP/TPS) and polylactic acid/poly(butylene adipate-co-terephthalate)/thermoplastic starch blends(PLA/PBAT/TPS) were investigated. The corresponding neat polymers, namely polypropylene(PP) and polylactic acid(PLA), were set as control groups. We investigated the formation of MPs and the changes in the physicochemical properties of plastic blends after photodegradation in seawater. The size distribution of MPs indicated that PP/TPS and PLA/PBAT/TPS were more likely to produce small-sized particles after photodegradation than PP and PLA owing to their poorer mechanical properties and lower resistance to UV irradiation. Noticeable surface morphology alterations, including cracks and wrinkles, were observed for plastic blends following photodegradation, whereas PP and PLA were relatively resistant. After photodegradation, the ATR-FTIR spectrum of PP/TPS and PLA/PBAT/TPS showed a significant decrease in the characteristic bands of thermoplastic starch(TPS), indicating the degradation of their starch fractions. The C 1s spectra demonstrated that aged plastic blends contained fewer -OH groups than the pristine MPs did, further confirming the photodegradation of TPS. These results indicate that PP/TPS and PLA/PBAT/TPS had a higher degree of photodegradation than PP and PLA and thereby generated more small-sized MPs. In summary, plastic blends may pose a higher risk to the marine environment than neat polymers, and caution should be taken in the production and use of plastic blends.

2.
IEEE Trans Neural Netw Learn Syst ; 34(12): 10203-10212, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35427225

RESUMO

Although neural networks have achieved great success in various fields, applications on mobile devices are limited by the computational and storage costs required for large models. The model compression (neural network pruning) technology can significantly reduce network parameters and improve computational efficiency. In this article, we propose a differentiable network channel pruning (DNCP) method for model compression. Unlike existing methods that require sampling and evaluation of a large number of substructures, our method can efficiently search for optimal substructure that meets resource constraints (e.g., FLOPs) through gradient descent. Specifically, we assign a learnable probability to each possible number of channels in each layer of the network, relax the selection of a particular number of channels to a softmax over all possible numbers of channels, and optimize the learnable probability in an end-to-end manner through gradient descent. After the network parameters are optimized, we prune the network according to the learnable probability to obtain the optimal substructure. To demonstrate the effectiveness and efficiency of DNCP, experiments are conducted with ResNet and MobileNet V2 on CIFAR, Tiny ImageNet, and ImageNet datasets.

3.
IEEE Trans Image Process ; 31: 99-109, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34793302

RESUMO

Remote sensing scene classification (RSSC) is a hotspot and play very important role in the field of remote sensing image interpretation in recent years. With the recent development of the convolutional neural networks, a significant breakthrough has been made in the classification of remote sensing scenes. Many objects form complex and diverse scenes through spatial combination and association, which makes it difficult to classify remote sensing image scenes. The problem of insufficient differentiation of feature representations extracted by Convolutional Neural Networks (CNNs) still exists, which is mainly due to the characteristics of similarity for inter-class images and diversity for intra-class images. In this paper, we propose a remote sensing image scene classification method via Multi-Branch Local Attention Network (MBLANet), where Convolutional Local Attention Module (CLAM) is embedded into all down-sampling blocks and residual blocks of ResNet backbone. CLAM contains two submodules, Convolutional Channel Attention Module (CCAM) and Local Spatial Attention Module (LSAM). The two submodules are placed in parallel to obtain both channel and spatial attentions, which helps to emphasize the main target in the complex background and improve the ability of feature representation. Extensive experiments on three benchmark datasets show that our method is better than state-of-the-art methods.


Assuntos
Algoritmos , Tecnologia de Sensoriamento Remoto , Redes Neurais de Computação
4.
Life Sci ; 241: 117169, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31843524

RESUMO

AIMS: Melanoma is lethal. Constitutively active signal transducer and activator of transcription 3 (STAT3) has been proposed as a pathogenic factor and a therapeutic target of melanoma. Brevilin A, a sesquiterpene lactone isolated from Centipeda minima (L.) A. Br. et Aschers., has been shown to exert antineoplastic effects and inhibit the STAT3 pathway in nasopharyngeal, lung, prostate and breast cancer cells. This study aimed to determine whether brevilin A has anti-melanoma effects, and whether STAT3 signaling is involved in the effects. MAIN METHODS: A mouse A375 xenograft model, as well as A375 and A2058 cell models were employed to assess the in vivo and in vitro anti-melanoma effects of brevilin A. A375 cells stably expressing STAT3C, a constitutively active STAT3 mutant, were used to determine the role of STAT3 signaling in brevilin A's anti-melanoma effects. KEY FINDINGS: Intraperitoneal injection of brevilin A dose-dependently inhibited melanoma growth in mice and suppressed STAT3 phosphorylation in the tumors. In cultured cells, brevilin A reduced cell viability, induced apoptosis, suppressed migration and invasion, decreased protein levels of phospho-JAK2 (Y1007/1008) and phospho-STAT3 (Tyr705), and restrained STAT3 nuclear localization. STAT3 over-activation diminished brevilin A's effects on cell viability and migration. Collectively, brevilin A exerts anti-melanoma effects and these effects are at least in part attributed to the inhibition of the JAK2/STAT3 pathway. SIGNIFICANCE: Our findings provide a pharmacological basis for developing brevilin A as a new phytotherapeutic agent against melanoma.


Assuntos
Crotonatos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Janus Quinase 2/metabolismo , Melanoma/tratamento farmacológico , Fator de Transcrição STAT3/metabolismo , Sesquiterpenos/farmacologia , Animais , Apoptose , Movimento Celular , Proliferação de Células , Humanos , Janus Quinase 2/genética , Masculino , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação , Fator de Transcrição STAT3/genética , Transdução de Sinais , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
5.
J Pharm Biomed Anal ; 174: 360-366, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31202878

RESUMO

An ultra-high performance liquid chromatography coupled with high-resolution Orbitrap mass spectrometry (UPLC-Orbitrap-MS) method has been used to identify sesquiterpene lactones in the methanolic extract of Centipeda minima. Fifteen sesquiterpene lactones were tentatively identified based on retention time and accurate mass of external standards or exact accurate mass searching (within 2 ppm) by comparison of some previous isolated sesquiterpene lactones. Meanwhile, a rapid, sensitive, precise, and reliable ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QQQ-MS) method has been developed to evaluate the quality of Centipeda minima through a simultaneous determination of five sesquiterpene lactones, namely brevilin A, arnicolide C, arnicolide D, microhelenin C, minimolide F. Chromatographic separation was achieved on a Waters Acquilty UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 µm) with a mobile phase consisting of a) 0.1% formic acid and b) a mixture of acetonitrile and methanol 50:50 v/v under an isocratic elution (42:58) manner. Positive electrospray ionization mode with multiple reaction monitoring was applied for the detection of the five sesquiterpene lactones. Method validation for linearity, accuracy and precision was also carried out. Finally, the method was successfully used for the analysis of 10 batches of Centipeda minima samples collected in China. Brevilin A and arnicolide D were the dominant sesquiterpene lactones in Centipeda minima and could be proposed as suitable markers for the quality control of Centipeda minima.


Assuntos
Asteraceae/química , Medicamentos de Ervas Chinesas/análise , Lactonas/análise , Sesquiterpenos/análise , Linhagem Celular Tumoral , China , Cromatografia Líquida de Alta Pressão , Humanos , Limite de Detecção , Modelos Lineares , Espectrometria de Massas , Extratos Vegetais/análise , Controle de Qualidade , Reprodutibilidade dos Testes
6.
Phytomedicine ; 54: 182-194, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30668368

RESUMO

BACKGROUND: Clinical evidence gathered in Chinese communities suggested that acupoint sticking therapy could be an alternative treatment for asthma-related diseases. However, its underlying mechanism is still poorly understood. AIM/HYPOTHESIS: In this study, we aimed to investigate the mechanism of the anti-inflammatory effect of acupoint sticking application with 'Treatment of Winter Disease in Summer' (TWDS) prescription by using metabolomics. METHODS: Allergic asthma in guinea pig was sensitized and challenged by ovalbumin (OVA). Histopathological evaluation of the lung tissue was performed by hematoxylin and eosin (H&E) staining and Masson's trichrome staining. The levels of Th2 cytokine and IgE level in serum were measured using enzyme-linked immunoassay (ELISA). The mRNA expression levels of IL-4, IL-5, IL-13 and orosomucoid-like 3 (ORMDL3) were measured using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Proteins of NF-κB signaling pathway were measured using western blot. The serum metabolomics profiles were obtained by using ultra-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS). RESULTS: The overall results confirmed that AST with TWDS prescription had a significant protective effect against OVA-induced allergic asthma in guinea pig. This treatment not only attenuated airway inflammation and collagen deposition in the airway, but also decreased the levels of IL-4, IL-5, IL-13 and IgE in serum. In addition, metabolomics results indicated that metabolisms of phospholipid, sphingolipid, purine, amino acid and level of epinephrine were restored back to the normal control level. Moreover, results of the gene expression of ORMDL3 in lung tissues indicated that AST using TWDS could alter the sphingolipid metabolism. Further western blotting analysis also showed that its anti-inflammatory mechanism was by decreasing the phosphorylation of p65 and IκB. CONCLUSION: The study demonstrated that metabolomics provides a better understanding of the actions of TWDS acupoint sticking therapy on OVA-induced allergic asthma.


Assuntos
Terapia por Acupuntura/métodos , Antiasmáticos/farmacologia , Asma/terapia , Medicamentos de Ervas Chinesas/farmacologia , Hipersensibilidade/terapia , Animais , Asma/metabolismo , Citocinas/sangue , Citocinas/genética , Citocinas/metabolismo , Cobaias , Hipersensibilidade/metabolismo , Imunoglobulina E/sangue , Pulmão/metabolismo , Pulmão/patologia , Masculino , Proteínas de Membrana/genética , Metabolômica , NF-kappa B/metabolismo , Ovalbumina/efeitos adversos , Transdução de Sinais/efeitos dos fármacos
7.
J Pharm Biomed Anal ; 125: 400-7, 2016 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-27131150

RESUMO

A high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) method in both positive and negative ion modes was established to investigate the major constituents in the ethanolic extract of Centipeda minima (EBSC). Twelve common components including flavones and their glycosides, phenolic and polyphenolic acids, and sesquiterpene lactone were identified in ten batches of samples based on comparison with the retention time and accurate mass of external standards (mass accuracy within 3ppm) or the fragmentation patterns of tandem MS. Meanwhile, a simple, accurate and reliable HPLC-DAD method was also developed to determine the content of 10 chemical markers simultaneously. Results obtained from method validations including linearity, accuracy and precision showed that this new method is reliable and robust. Isochlorogenic acid A and brevilin A were found to be the most abundant in the ethanol extract of EBSC and could be served as markers for quality control of EBSC.


Assuntos
Asteraceae/química , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Espectroscopia de Ressonância Magnética/métodos , Pesquisa Qualitativa
8.
Chin Med ; 11: 1, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26759603

RESUMO

BACKGROUND: Cycloartane triterpenoids exhibited anticancer effects. This study aims to identify any potential novel anticancer cycloartane triterpenoids from Cimicifuga foetida L. rhizome (Sheng ma) and the mode of actions. METHODS: Cycloartane triterpenoids were isolated from the C. foetida rhizome by a series of column chromatography and identified by IR, MS and NMR. Their anticancer effects on several human cancer cell lines, MCF-7, HepG2, HepG2/ADM, HeLa, and PC3, and normal human mammary epithelial cells MCF10A were investigated by colony formation and MTT assays. Morphological analysis of apoptosis induction was performed by acridine orange/ethidium bromide dual-staining and Hoechst 33258 nuclear staining. The cell-cycle profile and annexin V staining were evaluated by flow cytometry. Apoptosis were investigated by measuring changes in mitochondrial membrane potential and analyzing expression of cell cycle- and apoptosis-related proteins in MCF-7 cells by Western blotting. RESULTS: A novel cycloartane triterpenoid, 25-O-acetyl-7,8-didehydrocimigenol-3-O-ß-d-(2-acetyl)xylopyranoside (ADHC-AXpn), together with the known 7,8-didehydrocimigenol-3-O-ß-d-xylopyranoside (DHC-Xpn) were isolated. MCF-7 growth was significantly inhibited by ADHC-AXpn in a dose- and time-dependent manner (IC50: 27.81 µM at 48 h; P = 0.004 vs. control at 25 µM for 48 h treatment), and ADHC-AXpn was selectively cytotoxic for cancerous cells (MCF-7, HepG2/ADM, HepG2 and HELA cells) based on its higher IC50 values for normal cells MCF10A (IC50: 78.63 µM at 48 h) than for tumor cells. In MCF-7 cells, ADHC-AXpn induced G2/M cell cycle arrest by mediating cyclin-B1, and CDK1 and its phosphorylation; and induced apoptosis through the mitochondrial-mediated apoptotic pathway, with inhibition of Akt activation. As ADHC-AXpn suppressed phosphorylation of ERK1/2, Raf and Akt proteins in MCF-7 cells, its apoptotic effect might be associated with Raf/MEK/ERK signaling and Akt activation. CONCLUSIONS: ADHC-AXpn significantly suppressed the growth of MCF-7 cells, induced mitochondrial apoptosis and cell-cycle arrest, and inhibited Raf/MEK/ERK signaling pathway and Akt phosphorylation.

9.
J Sep Sci ; 39(2): 287-95, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26530331

RESUMO

Methods based on triple quadrupole tandem mass spectrometry have been widely used and reported as highly selective and sensitive methods for quantifying substances of herbal medicines. However, most of them were limited to targeted components, due to the difficulties to optimize the multiple reaction monitoring transitions without authentic standards. This study proposed a novel strategy for non-targeted optimization of multiple reaction monitoring method based on the diagnostic ion guided family classifications, tandem mass spectrometry database establishment, and transitions and collision energy screening. Applying this strategy, 59 Fritillaria alkaloids in Fritillariae Ussuriensis Bulbus have been classified, and 51 of these Fritillaria alkaloids were successfully detected by the optimal multiple reaction monitoring method. For semi-quantification, the easy-to-obtain Fritillaria alkaloids of each type, such as verticinone for cevanine type and peimisine for jervine type, were used as the reference standards to calibrate the other Fritillaria alkaloids in the same type. The method was demonstrated a good linearity (R(2) > 0.998) with satisfactory accuracy and precision, and the lower limits of quantification of verticinone and peimisine were estimated to be 0.076 and 0.216 pg, respectively. In addition, the results suggested that the proposed strategy might obtained high quality metabolomics data in discrimination of Fritillaria unibracteata and Fritillaria ussuriensis.


Assuntos
Alcaloides/análise , Medicamentos de Ervas Chinesas/análise , Fritillaria/química , Espectrometria de Massas em Tandem/métodos , Análise Discriminante , Flores/química , Fritillaria/classificação
10.
Chin Med ; 10: 26, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26388933

RESUMO

BACKGROUND: Centipeda minima (Ebushicao) has been used for the treatment of various diseases, such as nasal allergies, rhinitis and sinusitis, nasopharyngeal carcinoma, cough, and headache. This study aims to investigate the anticancer activities of Centipeda minima ethanol extracts (CME) against nasopharyngeal carcinoma cell CNE-1 and their underlying mechanism. METHODS: CNE-1 cells were treated with different concentrations (15-50 µg/mL) of CME for different time intervals (24, 48, and 72 h). Cytotoxicity of CME was determined by MTT assay. Cell morphological changes were observed by fluorescence microscopy after HO 33258 staining. Cell cycle status was evaluated by flow cytometry following propidium iodide staining. Apoptosis was detected by flow cytometry following annexin V-FITC/PI staining. The levels of apoptosis-associated and PI3K-Akt-mTOR signaling related proteins were measured by western blotting analysis. RESULTS: CME (15-50 µg/mL) significantly inhibited the proliferation of CNE-1 in a dose- and time-dependent manner (P = 0.026 for 15 µg/mL, P < 0.001 for 25, 30, 40, and 50 µg/mL, respectively); the IC50 values (µg/mL) were 41.57 ± 0.17, 30.34 ± 0.06 and 24.98 ± 0.08 for 24, 48 and 72 h treatments, respectively. Significant morphological changes of CNE-1 cells displaying apoptosis were observed after CME treatment. CME showed low cytotoxicity toward normal LO2 cells. CNE-1 cells were arrested in the G2/M phase while treated with 15, 25, 40 µg/mL of CME, respectively (P = 0.032, P = 0.0053, P < 0.001). CME (15, 25, 40 µg/mL) down-regulated Bcl-2 expression (P = 0.032, P = 0.0074, P < 0.001), and up-regulated Bax (P = 0.026, P = 0.0056, P < 0.001) with activation of caspase-3, caspase-8, caspase-9, and PARP observed in CNE-1 cells (P = 0.015, P = 0.0067, P < 0.001 for caspase 3; P = 0.210, 0.028, < 0.001 for caspase 8; P = 0.152, 0.082, 0.0080 for caspase 9; P = 0.265, 0.0072, < 0.001 for PARP). CME suppressed the activation of the PI3K-AKT-mTOR pathway (P = 0.03, 0.0007, 0.004, 0.006, 0.022 for p-PI3K, p-Akt-Ser(473), p-Akt-Thr(308), p-mTOR-Ser(2448), p-mTOR-Ser(2481), respectively after 40 µg/mL of CME treated for 24 h). CONCLUSION: CME inhibited the proliferation of CNE-1 cells and activation of the PI3K-AKT-mTOR signaling pathway.

11.
Antioxidants (Basel) ; 4(2): 359-72, 2015 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-26783710

RESUMO

An integrated approach including chemical and biological assessments was developed to investigate the differences between Apocynum venetum L. (AV) and its adulterant, Apocynum pictum Schrenk (AP). Ten flavonoids were tentatively identified by ultra-visible and mass spectra data. The chemical component, hyperoside, was identified as a critical parameter for discrimination of two species from the results of principal component analysis (PCA) and quantitative analysis. The anti-oxidative power of the herbal extracts were determined using 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) assay and H2O2-induced cell damage on LO2 cells. The results of the biological assays suggested that the chemical differences between AV and AP do lead to difference in activity and AV is demonstrated to have higher anti-oxidant activity.

12.
IEEE Trans Cybern ; 45(9): 1744-56, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25312973

RESUMO

Without constructing adjacency graph for neighborhood, we propose a method to learn similarity among sample points of manifold in Laplacian embedding (LE) based on adding constraints of linear reconstruction and least absolute shrinkage and selection operator type minimization. Two algorithms and corresponding analyses are presented to learn similarity for mix-signed and nonnegative data respectively. The similarity learning method is further extended to kernel spaces. The experiments on both synthetic and real world benchmark data sets demonstrate that the proposed LE with new similarity has better visualization and achieves higher accuracy in classification.

13.
J Asian Nat Prod Res ; 15(10): 1094-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23869536

RESUMO

Two new diarylheptanoids, 1-(3',5'-dihydroxy-4'-methoxyphenyl)-7-phenyl-3-heptanone (1) and 1-(2',4'-dihydroxy-3'-methoxyphenyl)-7-(4″-methoxyphenyl)-3-heptanone (2), along with known diarylheptanoid yakuchinone A (3), and five flavanoids, tectochrysin (4), chrysin (5), izalpinin (6), kaempferol 7, 4'-dimethyl ether (7), and kaempferide (8) were isolated from the fruits of Alpinia oxyphylla Miq. Their structures were determined by means of spectroscopic methods. Antioxidant activities of all the isolated compounds were evaluated using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Compounds 1-3 and 6-8 exhibited potent antioxidant activities in the DPPH assay.


Assuntos
Alpinia/química , Antioxidantes/isolamento & purificação , Diarileptanoides/isolamento & purificação , Diarileptanoides/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Compostos de Bifenilo/farmacologia , Diarileptanoides/química , Medicamentos de Ervas Chinesas/química , Flavonoides/química , Frutas/química , Guaiacol/análogos & derivados , Guaiacol/química , Guaiacol/isolamento & purificação , Quempferóis/isolamento & purificação , Quempferóis/farmacologia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Picratos/farmacologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-21785622

RESUMO

Synthetic chemical drugs, while being efficacious in the clinical management of many diseases, are often associated with undesirable side effects in patients. It is now clear that the need of therapeutic intervention in many clinical conditions cannot be satisfactorily met by synthetic chemical drugs. Since the research and development of new chemical drugs remain time-consuming, capital-intensive and risky, much effort has been put in the search for alternative routes for drug discovery in China. This narrative review illustrates various approaches to the research and drug discovery in Chinese herbal medicine. Although this article focuses on Chinese traditional drugs, it is also conducive to the development of other traditional remedies and innovative drug discovery.

15.
J Ethnopharmacol ; 136(1): 279-82, 2011 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-21524699

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Atractylenolide II (AT-II) is a sesquiterpene compound isolated from the dried rhizome of Atractylodes macrocephala (Baizhu in Chinese), which is traditionally prescribed for melanoma treatment by Chinese medicine practitioners. Our previous study showed that AT-II can inhibit B16 cells proliferation. Here we investigate the mechanistic basis for the anti-proliferative activity of AT-II in B16 melanoma cells. MATERIALS AND METHODS: Cell viability was examined by MTT assay. Cell cycle distribution and apoptosis were determined by flow cytometry. Protein expression was determined by Western blotting. RESULTS: AT-II treatment for 48 h dose-dependently inhibited cell proliferation with an IC(50) of 82.3 µM, and induced G1 phase cell cycle arrest. Moreover, treatment with 75 µM AT-II induced apoptosis. These observations were associated with the decrease of the expression of Cdk2, phosphorylated-Akt, phosphorylated-ERK and Bcl-2, the increase of the expression of phosphorylated-p38, phosphorylated-p53, p21, p27, and activation of caspases-8, -9 and -3. In addition, a chemical inhibitor of p53, PFTα, significantly decreased AT-II-mediated growth inhibition and apoptosis. CONCLUSIONS: We demonstrated that the G1-arresting and apoptotic effects of AT-II in B16 cells involve p38 activation as well as ERK and Akt inactivation, and the cytotoxic/apoptotic effects of AT-II are potentially p53 dependent. These findings provided chemical and pharmacological basis for the traditional application of Baizhu in melanoma treatment.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Atractylodes/química , Fase G1/efeitos dos fármacos , Lactonas/farmacologia , Melanoma Experimental/tratamento farmacológico , Fitoterapia , Sesquiterpenos/farmacologia , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Apoptose/fisiologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fase G1/fisiologia , Concentração Inibidora 50 , Lactonas/uso terapêutico , Melanoma Experimental/metabolismo , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Rizoma , Sesquiterpenos/uso terapêutico
16.
J Pharm Pharm Sci ; 13(3): 450-71, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21092716

RESUMO

Despite advances in technology, drug discovery is still a lengthy, expensive, difficult, and inefficient process, with a low rate of success. Today, advances in biomedical science have brought about great strides in therapeutic interventions for a wide spectrum of diseases. The advent of biochemical techniques and cutting-edge bio/chemical technologies has made available a plethora of practical approaches to drug screening and design. In 2010, the total sales of the global pharmaceutical market will reach 600 billion US dollars and expand to over 975 billion dollars by 2013. The aim of this review is to summarize available information on contemporary approaches and strategies in the discovery of novel therapeutic agents, especially from the complementary and alternative medicines, including natural products and traditional remedies such as Chinese herbal medicine.


Assuntos
Produtos Biológicos , Desenho de Fármacos , Descoberta de Drogas , Medicamentos de Ervas Chinesas , Preparações Farmacêuticas , Formas de Dosagem , Humanos
17.
J Sep Sci ; 33(11): 1587-94, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20405484

RESUMO

A sensitive and reliable HPLC-diode-array detector method was developed for the first time to simultaneously determine nine nucleosides and nucleobases including uracil, cytidine, guanine, uridine, thymine, inosine, guanosine, thymidine and adenosine in 13 different Fritillaria species. The analysis was performed on a BaseLine C18 column with a gradient of acetonitrile in water at a flow rate of 0.8 mL/min. The diode-array detector wavelength was set at 260 nm for the UV detection of nucleosides and nucleobases. Satisfactory separation of these compounds was obtained in less than 40 min. The optimized method provided good linear relation (r(2)>0.9995 for all the investigated analytes), satisfactory precision (RSD <1.51%) and good recovery (from 97.64 to 101.16%). The established method was successfully applied to simultaneous determination of nine nucleosides and nucleobases in 61 batches of samples from 13 Fritillaria species collected from different habitats in China, which could be helpful to control the quality of Fritillaria bulbs.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Fritillaria/metabolismo , Nucleosídeos/química , Calibragem , Química , Técnicas de Química Analítica , China , Modelos Químicos , Nucleotídeos/química , Extratos Vegetais/química , Reprodutibilidade dos Testes , Solventes/química , Fatores de Tempo
18.
J Asian Nat Prod Res ; 10(7-8): 673-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18636380

RESUMO

Two new xanthone O-glycosides, polyhongkongenosides A (1) and B (2), together with four known xanthone glycosides, were isolated from the herbs of Polygala hongkongensis Hemsl. Their structures were elucidated on the basis of UV, IR, NMR, and MS spectral data. The antioxidant in vitro activities of 1-6 were determined by the scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and hydroxyl radicals and their reductive activities to Fe3+. Mangiferin, one of the four known xanthone glycosides, showed potential scavenging effect on DPPH and hydroxy radicals and reductive activity to Fe3+ with IC50 values of 4.7, 13.9, 23.7 microM, respectively.


Assuntos
Antioxidantes/química , Glicosídeos/química , Polygala/química , Xantonas/química , Compostos de Bifenilo/química , Hidrazinas/química , Estrutura Molecular , Picratos
19.
Zhongguo Zhong Yao Za Zhi ; 33(5): 521-3, 2008 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-18536373

RESUMO

OBJECTIVE: To study the chemical constituents in the stems of Schisandra propinqua and evaluate their effects on proliferation of vascular smooth muscle cells (VSMCs) in vitro by MTT assay. METHOD: The compounds were isolated and purified by various column chromatographic techniques and their structures were elucidated on the basis of spectral analysis (ESI-MS, 1H-NMR, 13C-NMR). RESULT: Five compounds were isolated and identified as galgravin (1), veraguensin (2), octadecanoic acid 2, 3-dihydroxypropyl ester (3), hexadecanoic acid 2, 3-dihydroxypropy ester (4), tetracosanoic acid 2, 3-dihydroxypropyl ester (5). CONCLUSION: All the compounds were isolated for the first time from the plant. 1, 2, 5 showed inhibiting effects on vascular smooth muscle cell (VSMCs) proliferation in vitro.


Assuntos
Caules de Planta/química , Schisandra/química , Furanos/química , Lignanas/química , Espectroscopia de Ressonância Magnética , Plantas Medicinais/química , Espectrometria de Massas por Ionização por Electrospray
20.
Int J Pharm ; 359(1-2): 35-45, 2008 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-18440736

RESUMO

The aim of the study was to develop and evaluate a new method for the production of puerarin phospholipids complex (PPC) microparticles. The advanced particle formation method, solution enhanced dispersion by supercritical fluids (SEDS), was used for the preparation of puerarin (Pur), phospholipids (PC) and their complex particles for the first time. Evaluation of the processing variables on PPC particle characteristics was also conducted. The processing variables included temperature, pressure, solution concentration, the flow rate of supercritical carbon dioxide (SC-CO2) and the relative flow rate of drug solution to CO2. The morphology, particle size and size distribution of the particles were determined. Meanwhile Pur and phospholipids were separately prepared by gas antisolvent precipitation (GAS) method and solid characterization of particles by the two supercritical methods was also compared. Pur formed by GAS was more orderly, purer crystal, whereas amorphous Pur particles between 0.5 and 1microm were formed by SEDS. The complex was successfully obtained by SEDS exhibiting amorphous, partially agglomerated spheres comprised of particles sized only about 1microm. SEDS method may be useful for the processing of other pharmaceutical preparations besides phospholipids complex particles. Furthermore adopting a GAS process to recrystallize pharmaceuticals will provide a highly versatile methodology to generate new polymorphs of drugs in addition to conventional techniques.


Assuntos
Isoflavonas/química , Fosfolipídeos/química , Tecnologia Farmacêutica/métodos , Dióxido de Carbono/química , Precipitação Química , Química Farmacêutica , Cristalização , Tamanho da Partícula , Pressão , Soluções , Solventes/química , Temperatura
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