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Electrochemical carbon-capture technologies, with renewable electricity as the energy input, are promising for carbon management but still suffer from low capture rates, oxygen sensitivity or system complexity1-6. Here we demonstrate a continuous electrochemical carbon-capture design by coupling oxygen/water (O2/H2O) redox couple with a modular solid-electrolyte reactor7. By performing oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) redox electrolysis, our device can efficiently absorb dilute carbon dioxide (CO2) molecules at the high-alkaline cathode-membrane interface to form carbonate ions, followed by a neutralization process through the proton flux from the anode to continuously output a high-purity (>99%) CO2 stream from the middle solid-electrolyte layer. No chemical inputs were needed nor side products generated during the whole carbon absorption/release process. High carbon-capture rates (440 mA cm-2, 0.137 mmolCO2 min-1 cm-2 or 86.7 kgCO2 day-1 m-2), high Faradaic efficiencies (>90% based on carbonate), high carbon-removal efficiency (>98%) in simulated flue gas and low energy consumption (starting from about 150 kJ per molCO2) were demonstrated in our carbon-capture solid-electrolyte reactor, suggesting promising practical applications.
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BACKGROUND: The accumulation of CD4+Foxp3+ regulatory T cells (Tregs) in the tumor microenvironment (TME) dampens anti-tumor immune responses and promotes tumor progression. Therefore, the elimination of Tregs has become a strategy to enhance the efficacy of tumor immunotherapy, although it is still a daunting challenge. Rhododendron brachypodum (R. brachypodum) is a perennial shrub mainly distributed in Southwestern China, whereas the chemical constituents in this plant remain elusive. PURPOSE: To identify small-molecule inhibitors of Tregs from R. brachypodum. METHODS: Meroterpenoids in R. brachypodum were isolated by column chromatography under the guidance of LCMS analyses. The structures of isolates were identified by spectroscopic data and quantum calculations. The activities of compounds were first evaluated on CD4+ T cell differentiation by flow cytometry in Th1, Th2, Th17, and Treg polarizing conditions, and then on CT26 and MC38 murine colorectal carcinoma cells-allografted mice models. The mechanism of action was first investigated by determining Foxp3 degradation in Jurkat T cells transfected with pLVX-TetOne-Puro-Foxp3-tGFP, and then through analyses of Foxp3 expression on several pre-transcriptional signaling molecules. RESULTS: Two new prenylated phenolic acids (1 and 2) and a chromane meroterpenoid, rubiginosin B (RGB, 3) were obtained from R. brachypodum. The structure of S-anthopogochromene C (1) was rectified according to the electronic circular dichroism (ECD) experiment, and rhodobrachypodic acid (2) was proposed as the precursor of RGB by photochemical transformation. In this investigation, we first found that RGB (3) selectively suppressed the de novo differentiation of TGFß-induced CD4+Foxp3+ regulatory T cells (iTregs), overcome the immunosuppressive TME, and consequently inhibited the growth of tumor in mouse models. The mechanistic study revealed that RGB could target calcineurin, inhibited the nuclear factor of activated T cells (NFAT) dephosphorylation, and down-regulated Foxp3 expression. The hypothetical binding modes of RGB with calcineurin were predicted by molecular docking, and the interactions were mainly hydrophobic effects and hydrogen bonds. CONCLUSION: These results suggest that RGB enhances anti-tumor immune responses by inhibiting Treg cell differentiation through calcineurin-NFAT signaling pathway, and therefore RGB or its analogs may be used as adjuvant agents meriting further investigation.
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Neoplasias , Linfocitos T Reguladores , Ratones , Animales , Calcineurina/metabolismo , Simulación del Acoplamiento Molecular , Neoplasias/patología , Diferenciación Celular , Transducción de Señal , Activación de Linfocitos , Factores de Transcripción Forkhead/metabolismo , Microambiente TumoralRESUMEN
Iridium-based electrocatalysts remain the only practical anode catalysts for proton exchange membrane (PEM) water electrolysis, due to their excellent stability under acidic oxygen evolution reaction (OER), but are greatly limited by their high cost and low reserves. Here, we report a nickel-stabilized, ruthenium dioxide (Ni-RuO2) catalyst, a promising alternative to iridium, with high activity and durability in acidic OER for PEM water electrolysis. While pristine RuO2 showed poor acidic OER stability and degraded within a short period of continuous operation, the incorporation of Ni greatly stabilized the RuO2 lattice and extended its durability by more than one order of magnitude. When applied to the anode of a PEM water electrolyser, our Ni-RuO2 catalyst demonstrated >1,000 h stability under a water-splitting current of 200 mA cm-2, suggesting potential for practical applications. Density functional theory studies, coupled with operando differential electrochemical mass spectroscopy analysis, confirmed the adsorbate-evolving mechanism on Ni-RuO2, as well as the critical role of Ni dopants in stabilization of surface Ru and subsurface oxygen for improved OER durability.
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BACKGROUND: CD4+Foxp3+ regulatory T cells (Tregs) represent the primary cellular mechanism of tumor immune evasion. Elimination of Treg activity by the pharmacological agent may enhance anti-tumor immune responses. However, Treg-eliminating agents, especially those with small molecules, are rarely reported. PURPOSE: To identify small molecule inhibitors of Treg cells from natural products. METHODS: Compounds from Diploclisia glaucescens were isolated by column chromatography, and structures were identified by spectroscopic evidence and quantum calculations. The tet-On system for Foxp3-GFP expression in Jurkat T cells was generated to screen Treg inhibitors based on Foxp3 expression. The effect of the compound on TNF-induced proliferative expansion of naturally occurring Tregs (nTregs) and TGF-ß-induced generation of Tregs (iTregs) from naive CD4+ Tcells was further examined. RESULTS: A novel dimeric proaporphine alkaloid, designated as distepharinamide (DSA) with a symmetric structure isolated from the stems of D. glaucescens, restrained the doxycycline (Doxy)-induced Foxp3-tGFP expression, decreased the half-life of Foxp3 mRNA as well as reduced the mRNA levels of chemokine receptors (CCR4, CCR8 and CCR10) in Jurkat T cells with inducible Foxp3-tGFP expression. In lymphocytes or purified Tregs from wild-type C57BL/6 mice or from C57BL/6-Tg(Foxp3-DTR/EGFP)23.2Spar/Mmjax mice, DSA markedly inhibited TNF-induced proliferative expansion of Tregs present in the unfractionated CD4+ T cells, accompanied by the down-regulation of TNFR2, CD25 and CTLA4 expression on Tregs. Furthermore, DSA potently inhibited TGF-ß-induced differentiation of Foxp3-expressing iTregs. Importantly, the expression of Foxp3 mRNA by both nTregs and iTregs was decreased by DSA treatment. Nevertheless, DSA at the same concentrations did not inhibit the proliferation of conventional CD4+ and CD8+ T cells stimulated by anti-CD3/CD28 antibodies. CONCLUSION: DSA, a novel dimeric proaporphine alkaloid, potently inhibited the expansion of nTregs and generation of iTregs. Therefore, DSA or its analogs may merit further investigation as novel immunotherapeutic agents.
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Alcaloides , Antineoplásicos , Productos Biológicos , Alcaloides/metabolismo , Alcaloides/farmacología , Animales , Antineoplásicos/farmacología , Productos Biológicos/farmacología , Antígenos CD28/metabolismo , Linfocitos T CD8-positivos , Antígeno CTLA-4/metabolismo , Doxiciclina/metabolismo , Doxiciclina/farmacología , Factores de Transcripción Forkhead/metabolismo , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/metabolismo , Receptores de Quimiocina/metabolismo , Receptores Tipo II del Factor de Necrosis Tumoral/metabolismo , Receptores Tipo II del Factor de Necrosis Tumoral/farmacología , Linfocitos T Reguladores , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
AIM: To obtain promising immunosuppressants from endophytic fungus. METHODS AND RESULTS: The endophytic fungus Mycosphaerella nawae (ZJLQ129) was isolated from the plant Smilax china L. and its secondary metabolites extracted and fractionated through column chromatography. The metabolites were further modified by a derivatization reaction with ammonium hydroxide. After isolation and derivatization, a new dibenzofuran named as (+)isomycousnine enamine (iME) was obtained. The structures of the derivatives were determined based on chemical evidences and extensive spectroscopic methods including 2D-NMR, DEPT and HRESI-MS spectra. The immune activities of iME were first evaluated on the proliferation and cytokines (IL-2 and IFN-γ) production of T and B cells by using MTT and ELISA methods respectively. Then, its effects on the proliferation of T-cell subsets (CD4+ and CD8+ T cells), as well as CD25 and CD69 expressions were also determined by flow cytometry. Finally, by using Cytometric Bead Array (CBA), the impacts of iME on the secretion of Th1/Th2/Th17 cytokines from purified CD4+ T cells were assayed. The results showed that iME not only selectively suppressed the immune responses of T cells, but also preferentially inhibited the activation and proliferation of CD4+ T cells. CONCLUSION: A novel dibenzofuran derived from endophytic fungus Mycosphaerella nawae preferentially inhibits CD4+ T-cell activation and proliferation. SIGNIFICANCE AND IMPACT OF THE STUDY: This work obtained iME, a new dibenzofuran derived from endophytic fungus. iME has the capacity to inhibit CD4+ T-cell activation and therefore is a novel potential immunosuppressant for development in the future.
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Linfocitos T CD8-positivos , Mycosphaerella , Células Th17 , Citocinas/metabolismo , Proliferación Celular , Dibenzofuranos/metabolismo , Dibenzofuranos/farmacologíaRESUMEN
Electrochemically converting nitrate ions, a widely distributed nitrogen source in industrial wastewater and polluted groundwater, into ammonia represents a sustainable route for both wastewater treatment and ammonia generation. However, it is currently hindered by low catalytic activities, especially under low nitrate concentrations. Here we report a high-performance Ru-dispersed Cu nanowire catalyst that delivers an industrial-relevant nitrate reduction current of 1 A cm-2 while maintaining a high NH3 Faradaic efficiency of 93%. More importantly, this high nitrate-reduction catalytic activity enables over a 99% nitrate conversion into ammonia, from an industrial wastewater level of 2,000 ppm to a drinkable water level <50 ppm, while still maintaining an over 90% Faradaic efficiency. Coupling the nitrate reduction effluent stream with an air stripping process, we successfully obtained high purity solid NH4Cl and liquid NH3 solution products, which suggests a practical approach to convert wastewater nitrate into valuable ammonia products. Density functional theory calculations reveal that the highly dispersed Ru atoms provide active nitrate reduction sites and the surrounding Cu sites can suppress the main side reaction, the hydrogen evolution reaction.
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Nanocables , Purificación del Agua , Amoníaco/análisis , Nitratos , Aguas ResidualesRESUMEN
Electrochemically converting nitrate, a widespread water pollutant, back to valuable ammonia is a green and delocalized route for ammonia synthesis, and can be an appealing and supplementary alternative to the Haber-Bosch process. However, as there are other nitrate reduction pathways present, selectively guiding the reaction pathway towards ammonia is currently challenged by the lack of efficient catalysts. Here we report a selective and active nitrate reduction to ammonia on Fe single atom catalyst, with a maximal ammonia Faradaic efficiency of ~ 75% and a yield rate of up to ~ 20,000 µg h-1 mgcat.-1 (0.46 mmol h-1 cm-2). Our Fe single atom catalyst can effectively prevent the N-N coupling step required for N2 due to the lack of neighboring metal sites, promoting ammonia product selectivity. Density functional theory calculations reveal the reaction mechanisms and the potential limiting steps for nitrate reduction on atomically dispersed Fe sites.
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Dendrobium devonianum has been used as herbal medicines and nutraceutical products since ancient time in China. However, its chemical composition and pharmacological mechanisms are not fully known. In present studies, by chemical purification and characteristic identification, we discovered a novel polysaccharide from D. devonianum, which was designated as DvP-1 with molecular weights of 9.52â¯×â¯104â¯Da. DvP-1 is a homogeneous heteropolysaccharide consisting of D-mannose and d-glucose in the molar ration of 10.11: 1. The main glycosidic linkages were ß-1, 4-Manp, which were substituted with acetyl groups at the O-2, O-3 and/or O-6 positions. DvP-1 was found to directly stimulate the activation of macrophages in vitro, as evidenced by inducing morphologic change, thereby promoting the production of cytokines TNF-α, IL-6 and NO, and enhancing the pinocytic activity of macrophages. By establishing a zebrafish model, we also found that DvP-1 could alleviate vinorelbine-induced decrease of macrophages in vivo. Further findings indicated that DvP-1 activated macrophages through several toll-like receptors (TLRs), but mainly through TLR4. DvP-1 served as a TLR4 agonist and induced ERK, JNK, p38, and IκB-α phosphorylation, suggesting the activation of MAPK and NFκB signaling pathways downstream of TLR4. These findings could help us further understand the immunomodulating effects of D. devonianum in Chinese medicines or health foods for immunocompromised persons. They also show the medicinal value of DvP-1 for the treatment of cancer and infectious diseases caused by TLR4 dysfunction.
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Dendrobium/química , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Polisacáridos/farmacología , Receptor Toll-Like 4/agonistas , Animales , Proliferación Celular/efectos de los fármacos , Citocinas/biosíntesis , Macrófagos/citología , Ratones , Monosacáridos/análisis , Polisacáridos/química , Células RAW 264.7 , Bazo/inmunología , Vinorelbina/farmacología , Pez CebraRESUMEN
Uncontrolled excessive activation of Hedgehog (Hh) signaling pathway is linked to a number of human malignant tumorigenesis. To obtain valuable Hh pathway inhibitors from natural product, in present study, a pair of novel epimers, Cynanbungeigenin C (CBC) and D (CBD) from the plant Cynanchum bungei Decne were chemically characterized by multiple spectroscopic data and chemical derivatization, and evaluated for their inhibition on Hh pathway. Mechanistically, CBC and CBD block Hh pathway signaling not through targeting Smo and Sufu, but at the level of Gli. In addition, both eipmers significantly suppress Hh pathway-dependent Ptch+/-; p53-/- medulloblastoma in vitro and in vivo. Furthermore, both CBC and CBD inhibited two Smo mutants induced Hh pathway activation, which suggested that they are potential compounds for the treatment of medulloblastoma with primary or acquired resistance to current Smo inhibitors. These results highlight the potential of CBC and CBD as effective lead compounds in the treatment of medulloblastoma and other Hh-dependent malignancy.
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Neoplasias Cerebelosas/tratamiento farmacológico , Cynanchum/química , Meduloblastoma/tratamiento farmacológico , Fitosteroles/administración & dosificación , Fitosteroles/aislamiento & purificación , Transducción de Señal/efectos de los fármacos , Animales , Neoplasias Cerebelosas/metabolismo , Células HEK293 , Proteínas Hedgehog/metabolismo , Humanos , Meduloblastoma/metabolismo , Ratones , Células 3T3 NIH , Fitosteroles/química , Fitosteroles/farmacología , Extractos Vegetales/análisis , Ensayos Antitumor por Modelo de Xenoinjerto , Proteína con Dedos de Zinc GLI1/metabolismoRESUMEN
An endophytic fungus, Mycosphaerella nawae ZJLQ129, was isolated from the leaves of the traditional Chinese medicine Smilax china. From the fermentation broth and mycelium, a dibenzofurane compound (-)mycousnine (1) was isolated. Chemical modification of it to the amide derivative (-)mycousnine enamine (2), which is new to science, was found to have high and selective immunosuppressive activity: similar to cyclosporin A, (-)mycousnine enamine (2) selectively inhibited T cell proliferation, suppressed the expression of the surface activation antigens CD25 and CD69 and the formation and expression of the cytokines interleukin-2 as well as interferon γ in activated T cells, but did not show any effect on the proliferation of B cells and cancer cells (PANC-1 and A549) and the activation of macrophages. Furthermore, the cytotoxicity of (-)mycousnine enamine was lower than that of cyclosporin A, and its therapeutic index (TC50/EC50) was 4,463.5, which is five-fold higher than that of cyclosporin A. We conclude that (-)mycousnine enamine (2), the semi-synthestic product prepared from the native product (-)mycousnine (1) of the endophyte M. nawae is a novel effective immunosuppressant showing low toxicity and high selectivity.
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Two new 13, 14/14, 15-disecopregnane-type skeleton C21 steroidal aglycones, neocynapanogenin G (1) and neocynapanogenin H (2), were isolated from the hydrolyzed extract of the CHCl3 soluble extract of the roots of Cynanchun paniculatum. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods, including 1D and 2D NMR spectroscopy. Compound 1 displayed signifidant inhibition of the Hedgehog signaling pathway in vitro.
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Cynanchum/química , Medicamentos Herbarios Chinos/química , Iridoides/química , Raíces de Plantas/química , Esteroides/química , Animales , Línea Celular , Erizos/genética , Erizos/metabolismo , Humanos , Estructura Molecular , Transducción de Señal/efectos de los fármacosRESUMEN
Stemucronatoside K (SMK) and its aglycone stephanthraniline A (STA) are the most representative of a series of novel C21 steriodal compounds that we have previously isolated from Asclepiadaceae plants. The objectives of this study were to investigate the antitumor activity of SMK and STA, and clarify the effect of the sugar chain at the C(3) position. Our results showed that both SMK and STA decreased the growth of HT-29 cells in a dose- and time-dependent manner. Meanwhile, STA showed much stronger inhibitory effect than SMK. Treatment of HT-29 cells with STA increased the apoptotic cell numbers and the protein expression of cleaved caspase 3 and cleaved-PARP. G1 phase cell cycle arrest and decreased expression of cyclin D1 and cyclin-dependent kinases 4 were also observed after STA treatment. Furthermore, STA reduced the mRNA levels of four Hedgehog pathway components (GLI1, GLI2, GLI3, and PTCH1) and suppressed Shh-induced Hedgehog pathway activation in a concentration-dependent manner. These results indicated that SMK and STA could inhibit the growth of HT-29 cells by inducing apoptosis, cell cycle arrest, and hedgehog pathway inhibition. The loss of sugar chain at C(3) position could enhance SMK's activity. This study is beneficial to understand the use of natural C21 steroids as antitumor lead compounds.
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Apoptosis/efectos de los fármacos , Carbohidratos/química , Puntos de Control del Ciclo Celular/efectos de los fármacos , Saponinas/farmacología , Transducción de Señal/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Células HT29 , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Humanos , Conformación Molecular , Saponinas/química , Relación Estructura-ActividadRESUMEN
Stephanthraniline A (STA), a C21 steroid isolated from Stephanotis mucronata (Blanco) Merr., was previously shown to inhibit T cells activation and proliferation in vitro and in vivo. The purpose of this study was to further evaluate the in vivo immunosuppressive activity of STA and to elucidate its potential mechanisms. The results showed that pretreatment with STA significantly attenuated concanavalin A (Con A)-induced hepatitis and reduced CD4(+) T cells activation and aggregation in hepatic tissue in mice. STA directly suppressed the activation and proliferation of Con A-induced CD4(+) T cells, and inhibited NFAT, NFκB and MAPK signaling cascades in activated CD4(+) T cells in vitro. Moreover, it was proved that STA inhibited T cells activation and proliferation through proximal T cell-receptor (TCR) signaling- and Ca(2+) signaling-independent way. The molecular docking studies predicted that STA could tight bind to PKCθ via five hydrogen. The further findings indicated STA directly inhibited PKCθ kinase activity, and its phosphorylation in activated CD4(+) T cells in vitro. Collectively, the present study indicated that STA could protect against CD4(+) T cell-mediated immunological hepatitis in mice through PKCθ and its downstream NFAT, NFκB and MAPK signaling cascades. These results highlight the potential of STA as an effective leading compound for use in the treatment of CD4(+) T cell-mediated inflammatory and autoimmune diseases.
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Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Diterpenos/farmacología , Hepatitis/tratamiento farmacológico , Hepatitis/inmunología , Isoenzimas/antagonistas & inhibidores , Activación de Linfocitos/efectos de los fármacos , Proteína Quinasa C/antagonistas & inhibidores , Animales , Señalización del Calcio/efectos de los fármacos , Dominio Catalítico , Agregación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Diterpenos/metabolismo , Diterpenos/uso terapéutico , Femenino , Hepatitis/metabolismo , Hepatitis/patología , Isoenzimas/química , Isoenzimas/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Simulación del Acoplamiento Molecular , FN-kappa B/metabolismo , Factores de Transcripción NFATC/metabolismo , Fosforilación/efectos de los fármacos , Proteína Quinasa C/química , Proteína Quinasa C/metabolismo , Proteína Quinasa C-theta , Proteínas Quinasas/metabolismoRESUMEN
Two new 8, 14-seco skeleton C(21) steroidal aglycones, cynanbungeigenin A (1) and cynanbungeigenin B (2), were isolated from the hydrolyzed extract of the EtOAc soluble extract of the roots of Cynanchum bungei. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods, including 1D and 2D NMR spectroscopy.
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Cynanchum/química , Pregnanos/aislamiento & purificación , Animales , Espectroscopía de Resonancia Magnética con Carbono-13 , Proteínas Hedgehog/antagonistas & inhibidores , Ratones , Células 3T3 NIH , Extractos Vegetales/química , Raíces de Plantas/química , Pregnanos/química , Pregnanos/farmacología , Espectroscopía de Protones por Resonancia MagnéticaRESUMEN
Two novel steroidal aglycones, together with four known ones, were isolated from the hydrolysis extract of the CHCl3 soluble extract of the stems of Marsdenia tenacissima. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods, including 1D and 2D NMR spectroscopy. These compounds displayed inhibition of the Hedgehog signaling pathway in vitro.
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Proteínas Hedgehog/antagonistas & inhibidores , Marsdenia/química , Transducción de Señal/efectos de los fármacos , Esteroides/aislamiento & purificación , Extractos Vegetales/análisis , Tallos de la Planta/química , Esteroides/farmacologíaRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: The larvae of Musca domestica (Diptera: Muscidae) have been used traditionally for malnutritional stagnation, decubital necrosis, osteomyelitis, ecthyma and lip scald and also to treat coma and gastric cancer in the traditional Chinese medicine. Its in vitro antitumor activity and immunomodulatory effect in naïve mice in relation to the traditional uses were also reported. However, the in vivo antitumor effect of this insect and its mechanism of action have not yet been well studied. The objectives of this study were to evaluate the in vivo antitumor potential of the peptide fraction from Musca domestica larvae (MDPF) and to elucidate its immunological mechanisms. MATERIALS AND METHODS: The mice inoculated with sarcoma S180 cells were orally administered with MDPF at three doses for 10 days. The effects of MDPF on the growth of mouse S180 sarcoma, splenocyte proliferation, the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTLs), production and mRNA expression of cytokines from splenocytes, and serum antigen-specific antibody levels in tumor-bearing mice were measured. RESULTS: MDPF could significantly not only inhibit the growth of mouse transplanted S180 sarcoma, but also promote splenocytes proliferation, NK cell and CTL activity from splenocytes, and enhance serum antigen-specific IgG, IgG2a and IgG2b antibody levels in S180-bearing mice. MDPF also significantly promoted the production of IFN-γ and up-regulated the mRNA expression levels of IFN-γ and Th1 transcription factors T-bet and STAT-4 in splenocytes from the S180-bearing mice. However, Th2 cytokine IL-10 and transcription factors GATA-3 and STAT-6 were not significantly changed both at transcriptional and protein levels following MDPF treatment. CONCLUSIONS: MDPF significantly inhibit the growth of transplantable tumor in mice and its in vivo antitumor activity might be achieved by switching-on of Th1-based protective cell-mediated immunity. MDPF could act as antitumor agent with immunomodulatory activity.
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Antineoplásicos , Productos Biológicos , Moscas Domésticas , Factores Inmunológicos , Péptidos , Sarcoma 180/tratamiento farmacológico , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Productos Biológicos/farmacología , Productos Biológicos/uso terapéutico , Línea Celular Tumoral , Femenino , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Factores Inmunológicos/farmacología , Factores Inmunológicos/uso terapéutico , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-10/genética , Células Asesinas Naturales/efectos de los fármacos , Células Asesinas Naturales/inmunología , Larva/química , Masculino , Ratones Endogámicos ICR , Péptidos/farmacología , Péptidos/uso terapéutico , ARN Mensajero/metabolismo , Sarcoma 180/inmunología , Bazo/citología , Bazo/inmunología , Linfocitos T Citotóxicos/efectos de los fármacos , Linfocitos T Citotóxicos/inmunología , Factores de Transcripción/genéticaRESUMEN
Three novel and one known C21 steroidal glycosides were isolated from the stems of Stephanotis mucronata. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods. The four C21 steroidal glycosides displayed significant immunosuppressive activities in vitro.
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Apocynaceae/química , Glicósidos/farmacología , Inmunosupresores/farmacología , Esteroides/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Cromatografía en Capa Delgada , Concanavalina A/farmacología , Relación Dosis-Respuesta a Droga , Glicósidos/aislamiento & purificación , Inmunosupresores/aislamiento & purificación , Lipopolisacáridos/farmacología , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Ratones , Tallos de la Planta/química , Bazo/efectos de los fármacos , Bazo/inmunología , Esteroides/aislamiento & purificaciónRESUMEN
The total crude polysaccharides (CADPs), isolated from the roots of Angelica dahurica by H(2) O extraction, EtOH precipitation, and dialysis, and the four fractions ADP1, ADP2, ADP3, and ADP4, obtained by gel filtration of the CADPs, were analyzed to characterize their composition and evaluated for their antioxidant activity using different in vitro tests such as the malondialdehyde (MDA)-production, the ferrous ion (Fe(2+) )-chelating, and the HO(.) radical-scavenging assays. The predominant neutral monosaccharides in the four fractions were identified as arabinose, galactose, and glucose, while the composition and ratio of the monosaccharides were different between the fractions. The CADPs and its fractions were found to significantly inhibit lipid peroxidation, chelate Fe(2+) , and scavenge HO(.) radicals, indicating that these polysaccharides possessed antioxidant activity. Among the four fractions, ADP4 exhibited the strongest antioxidant activity, which was stronger than that of the control antioxidant vitamin E (Vit E). Taken together, the chemical composition of these polysaccharides might affect their antioxidant activity, and ADP4 could be explored as a source of potential novel natural antioxidants for food and pharmaceutical purposes.
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Angelica/química , Depuradores de Radicales Libres/química , Polisacáridos/química , Cromatografía en Gel , Depuradores de Radicales Libres/aislamiento & purificación , Depuradores de Radicales Libres/farmacología , Quelantes del Hierro/química , Quelantes del Hierro/aislamiento & purificación , Quelantes del Hierro/farmacología , Malondialdehído/metabolismo , Raíces de Plantas/química , Polisacáridos/aislamiento & purificación , Polisacáridos/farmacologíaRESUMEN
3beta,6beta-dihydroxyolean-12-en-27-oic acid (1) is a pentacyclic triterpenoid isolated from the rhizomes of Astilbe chinensis. To evaluate the in vivo antitumor potential and to elucidate its immunological mechanisms, effect of 1 on the growth of mouse-transplantable tumors, and the immune response in naive and tumor-bearing mice were investigated. The mice inoculated with mouse tumor cell lines were orally treated with 1 at the doses of 40, 60, and 80 mg/kg for 10 days. The effects of 1 on the growth of mouse-transplantable S180 sarcoma and H22 hepatoma, splenocyte proliferation, cytotoxic T lymphocyte (CTL) activity, natural killer (NK) cell activity, and production of interleukin-2 (IL-2) from splenocytes in S180-bearing mice were measured. Furthermore, the effect of 1 on 2,4-dinitrofluorobenzene (DNFB)-induced delayed-type hypersensitivity (DTH) reactions and the sheep red blood cell (SRBC)-induced antibody response in naive mice were also studied. Compound 1 could not only significantly inhibit the growth of mouse transplantable S180 sarcoma and H22 hepatoma, increase splenocytes proliferation, CTL and NK cell activity, and the level of IL-2 secreted by splenocytes in tumor-bearing mice, but also remarkably promote the DTH reaction and enhance anti-SRBC antibody titers in naive mice. These results suggested that 1 could improve both cellular and humoral immune response, and could act as antitumor agent with immunomodulatory activity.
Asunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Factores Inmunológicos/uso terapéutico , Ácido Oleanólico/análogos & derivados , Animales , Femenino , Hipersensibilidad Tardía/tratamiento farmacológico , Interleucina-2/metabolismo , Masculino , Ratones , Ácido Oleanólico/uso terapéutico , Sarcoma 180/tratamiento farmacológicoRESUMEN
AIM OF THE STUDY: The roots of Actinidia eriantha Benth (Actinidiaceae) have been used for cancers in the Chinese folk medicine. The present study aimed at evaluating the antitumor potentials of the polysaccharides from the roots of Actinidia eriantha and elucidating their immunological mechanisms by determining the effects on the growth of tumor transplanted in mice and the immune response in tumor-bearing mice. MATERIALS AND METHODS: The total polysaccharide AEP and fours purified polysaccharides AEPA, AEPB, AEPC and AEPD were isolated and purified from the roots of Actinidia eriantha by hot water extraction, ethanol precipitation, dialysis and gel filtration. Their effects on the growth of mouse transplantable tumor, splenocyte proliferation, the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL), production of cytokines from splenocytes, and serum antigen-specific antibody levels in tumor-bearing mice were measured. RESULTS: AEP and four purified polysaccharides could not only significantly inhibit the growth of mouse transplantable tumor, but also remarkably promote splenocytes proliferation, NK cell and CTL activity, IL-2 and IFN-gamma production from splenocytes, and serum antigen-specific antibody levels in tumor-bearing mice. CONCLUSIONS: The antitumor activity of AEP and four purified polysaccharides might be achieved by improving immune response, and the composition of the monosaccharides, uronic acid contents and molecular weight could affect their antitumor and immunomodulatory activity.