RESUMEN
Fucoidan has been reported to have a variety of biological activities. However, different algae species, extraction methods, harvesting seasons, and growth regions lead to the structural variation of fucoidan, which would affect the bioactivities of fucoidan. To date, the anti-inflammatory properties and the underlying mechanism of fucoidan from brown alga Saccharina japonica (S. japonica) remain limited. The aims of the present study were to investigate the structure, the anti-inflammatory properties, and the potential molecular mechanisms of fucoidan isolated from S. japonica (SF6) against lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. SF6 was characterized using high performance liquid gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR), and observed to be rich in fucose, galactose, and sulfate. Additionally, results showed that SF6 remarkably inhibited LPS-induced production of various inflammatory mediators and pro-inflammation cytokines, including nitric oxide (NO), NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-ß (IL-ß), and interleukin-6 (IL-6). A mechanism study showed that SF6 could effectively inhibit inflammatory responses through blocking LPS-induced inflammation pathways, including nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and Janus kinase (JAK)-2 and signal transducer and activator of transcription (STAT)-1/3 pathways. These results suggested that SF6 has the potential to be developed as an anti-inflammatory agent applied in functional food.
Asunto(s)
Antiinflamatorios/farmacología , Inflamación/tratamiento farmacológico , Janus Quinasa 2/metabolismo , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , FN-kappa B/antagonistas & inhibidores , Polisacáridos/farmacología , Factores de Transcripción STAT/antagonistas & inhibidores , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Ciclooxigenasa 2/metabolismo , Citocinas/metabolismo , Lipopolisacáridos/farmacología , Sistema de Señalización de MAP Quinasas , Macrófagos/efectos de los fármacos , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Phaeophyceae/química , Células RAW 264.7 , Factores de Transcripción STAT/metabolismoRESUMEN
There is increasing evidence for a beneficial effect of ginseng on cardiac pathology. Here, we determined whether North American ginseng can modulate the deleterious effects of the ß-adrenoceptor agonist isoproterenol on cardiac hypertrophy and function using in vitro and in vivo approaches. Isoproterenol was administered for 2 weeks at either 25 mg/kg per day or 50 mg/kg per day (ISO25 or ISO50) via a subcutaneously implanted osmotic mini-pump to either control rats or those receiving ginseng (0.9 g/L in the drinking water ad libitum). Isoproterenol produced time- and dose-dependent left ventricular dysfunction, although these effects were attenuated by ginseng. Improved cardiac functions were associated with reduced heart masses, as well as prevention in the upregulation of the hypertrophy-related fetal gene expression. Lung masses were similarly attenuated, suggesting reduced pulmonary congestion. In in vitro studies, ginseng (10 µg/mL) completely suppressed the hypertrophic response to 1 µmol/L isoproterenol in terms of myocyte surface area, as well as reduction in the upregulation of fetal gene expression. These effects were associated with attenuation in both protein kinase A and cAMP response element-binding protein phosphorylation. Ginseng attenuates adverse cardiac adrenergic responses and, therefore, may be an effective therapy to reduce hypertrophy and heart failure associated with excessive catecholamine production.
Asunto(s)
Agonistas Adrenérgicos beta/toxicidad , Cardiomegalia/prevención & control , Extractos Vegetales/uso terapéutico , Saponinas/uso terapéutico , Transducción de Señal/efectos de los fármacos , Disfunción Ventricular Izquierda/prevención & control , Animales , Cardiomegalia/inducido químicamente , Cardiomegalia/diagnóstico por imagen , Relación Dosis-Respuesta a Droga , Isoproterenol/toxicidad , Masculino , Panax , Extractos Vegetales/aislamiento & purificación , Raíces de Plantas , Ratas , Ratas Sprague-Dawley , Saponinas/aislamiento & purificación , Transducción de Señal/fisiología , Disfunción Ventricular Izquierda/inducido químicamente , Disfunción Ventricular Izquierda/diagnóstico por imagenRESUMEN
BACKGROUND: Polysaccharides constituting about 10% by weight of ginseng root are known to stimulate the immune system but have recently been shown to also suppress induced proinflammatory responses. Our study aims to determine whether American ginseng root polysaccharides (AGRPS) stimulates basal innate immune function and at the same time can suppress response to lipopolysaccharide (LPS) induced proinflammatory response. An in vitro mechanistic study was used to identify the bioactive fraction(s) responsible for AGRPS immunomodulatory effects. METHODS: The ex vivo and in vivo immunomodulatory effects after oral administration of AGRPS extract was studied in adult rats by measuring cultured alveolar macrophage production of NO and changes of plasma cytokine level, modification of LPS proinflammatory immune response by AGRPS extract was also examined. To identify the bioactive fraction(s) responsible for AGRPS extract immunomodulatory effects, the immunobioactivities of the extract fractions (isolated by ion exchange and size exclusion chromatography) was investigated in an in vitro mechanistic study. RESULTS: Culture of alveolar macrophages obtained from AGRPS extract treated rats resulted in an increase of ex vivo production of NO and also reduced alveolar macrophage responsiveness to ex vivo LPS challenge. Oral treatment with AGRPS extract elevated plasma TNF-α concentration in vivo. This treatment also suppressed LPS induced elevation of plasma TNF-α in vivo. AGRPS extract immunostimulatory and immunosuppressive effects were mediated primarily by acid PS and its species with molecular weights ≥ 100 kDa and 50-100 kDa. CONCLUSION: AGRPS extract exerted immunostimulation and suppressed LPS immune response under basal and LPS induced proinflammatory conditions respectively.
Asunto(s)
Adyuvantes Inmunológicos/farmacología , Inmunidad Innata/efectos de los fármacos , Inmunosupresores/farmacología , Macrófagos Alveolares/efectos de los fármacos , Panax , Polisacáridos/farmacología , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/aislamiento & purificación , Administración Oral , Animales , Línea Celular , Citocinas/metabolismo , Relación Dosis-Respuesta a Droga , Inmunosupresores/administración & dosificación , Inmunosupresores/química , Inmunosupresores/aislamiento & purificación , Mediadores de Inflamación/metabolismo , Lipopolisacáridos/farmacología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Masculino , Ratones , Óxido Nítrico/metabolismo , Panax/química , Fitoterapia , Raíces de Plantas , Plantas Medicinales , Polisacáridos/administración & dosificación , Polisacáridos/química , Polisacáridos/aislamiento & purificación , Ratas Sprague-DawleyRESUMEN
Extraction of medicinally active components from natural health products has become an emerging source for drug discovery. Of particular interest for this work was the finding and testing of a new ginsenoside from North American ginseng (Panax quinquefolius). In the present study, a large amount of 6â³-O-acetylginsenoside Rb1, compound 7, was found using ultrasonic extraction of North American ginseng with DMSO aqueous solution. This new ginsenoside was well identified with MS, FTIR, and 1D (1H and 13C) and 2D (gCOSY, gHSQC, and gHMBC) NMR. Subsequent bioassay experiments confirmed that compound 7 demonstrated an additional immunosuppressive activity towards inhibiting the production of nitric oxide and tumor necrosis factor alpha in lipopolysaccharide-induced macrophage cells in a dose-dependent manner using murine macrophages. This new ginsenoside is encouraging for the further exploration and development of novel drugs.
Asunto(s)
Ginsenósidos/uso terapéutico , Inmunosupresores/uso terapéutico , Inflamación/tratamiento farmacológico , Macrófagos/efectos de los fármacos , Panax/química , Fitoterapia , Extractos Vegetales/uso terapéutico , Animales , Antiinflamatorios/aislamiento & purificación , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Relación Dosis-Respuesta a Droga , Ginsenósidos/química , Ginsenósidos/aislamiento & purificación , Ginsenósidos/farmacología , Inmunosupresores/química , Inmunosupresores/aislamiento & purificación , Inmunosupresores/farmacología , Inflamación/inducido químicamente , Inflamación/metabolismo , Lipopolisacáridos , Macrófagos/metabolismo , Ratones , Ácido Nítrico/metabolismo , Extractos Vegetales/química , Extractos Vegetales/farmacología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
North American ginseng is known to have immunomodulatory and antipseudomonal properties in vitro. In this study we investigated the effects of aqueous ginseng extract, either alone or in a combination with the antibiotic tobramycin, in an animal model of chronic Pseudomonas aeruginosa lung infection. The lungs of male rats (n = 5) were infected with P. aeruginosa (2 × 10(8) cfu/mL) in agar-beads by intratracheal instillation. Starting on day 7 post-infection, animals were treated daily for 3 consecutive days with saline, tobramycin (300 µg/kg body mass, intratracheal), and (or) ginseng (100 mg/kg body mass, subcutaneous); animals were sacrificed 24 h after the third drug treatment. Lung bacteria counts, cytokine levels in sera, and lung histopathology were examined. The treatment of infected animals with tobramycin [6.6 × 10(4) colony forming units (cfu)], ginseng (5.3 × 10(4) cfu), or tobramycin plus ginseng (2.0 × 10(3) cfu) lessened the lung infection compared with the control group (saline treated) (6.0 × 10(6) cfu). The levels of pro-inflammatory cytokines (IL-2, IL-4, IL-6, IL-12p70, IFN-γ, GM-CSF, TNF-α) in infected animals were significantly increased with co-treatment of ginseng plus tobramycin. These data suggest that co-administration of aqueous ginseng extract and tobramycin stimulated the pro-inflammatory response and promoted the killing of P. aeruginosa.
Asunto(s)
Antibacterianos/farmacología , Inflamación/fisiopatología , Enfermedades Pulmonares/tratamiento farmacológico , Panax/química , Extractos Vegetales/farmacología , Infecciones por Pseudomonas/tratamiento farmacológico , Pseudomonas aeruginosa/efectos de los fármacos , Tobramicina/farmacología , Agar , Animales , Carga Bacteriana , Peso Corporal/efectos de los fármacos , Quimiocinas/análisis , Quimiocinas/metabolismo , Medios de Cultivo , Citocinas/análisis , Citocinas/metabolismo , Pulmón/patología , Enfermedades Pulmonares/microbiología , Enfermedades Pulmonares/patología , Masculino , Tamaño de los Órganos/efectos de los fármacos , Infecciones por Pseudomonas/microbiología , Infecciones por Pseudomonas/patología , Ratas , Ratas Sprague-DawleyRESUMEN
Emerging evidence suggests ginseng has therapeutic potential in cardiovascular disease. The aim of this study was to investigate the role of endothelial nitric oxide synthase (eNOS) in the cardioprotective effects of ginseng during myocardial ischemia and reperfusion (I/R). Treatment with ginseng extract significantly increased Akt phosphorylation and eNOS protein levels in cultured neonatal cardiomyocytes. Upregulation of eNOS was blocked by LY294002, a PI3-kinase inhibitor, suggesting a PI3-kinase/Akt-dependent mechanism. To simulate I/R, cultured neonatal cardiomyocytes from eNOS(-/-) and wild-type (WT) mice were subjected to anoxia and reoxygenation (A/R). Ginseng treatment inhibited A/R-induced apoptosis in WT, but not in either eNOS(-/-) cardiomyocytes or WT cardiomyocytes treated with LY294002. To further study the cardioprotective effects of ginseng in vivo, WT and eNOS(-/-) mice were pretreated with ginseng extract (50mg/kg/day, oral gavage) for 7 days before they were subjected to myocardial I/R. Treatment with ginseng significantly increased Akt phosphorylation and eNOS protein levels in the myocardium. Furthermore, ginseng-induced myocardial eNOS expression was inhibited by LY294002. Strikingly, ginseng treatment significantly decreased infarct size and myocardial apoptosis following I/R in WT mice, but not in either eNOS(-/-) mice or WT mice treated with LY294002. We conclude that ginseng treatment protects the heart from I/R injury via upregulation of eNOS expression. Our study suggests that ginseng may serve as a potential therapeutic agent to limit myocardial I/R injury.
Asunto(s)
Cardiotónicos/uso terapéutico , Daño por Reperfusión Miocárdica/prevención & control , Óxido Nítrico Sintasa de Tipo III/genética , Panax/química , Fitoterapia , Preparaciones de Plantas/uso terapéutico , Regulación hacia Arriba/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Cardiotónicos/aislamiento & purificación , Células Cultivadas , Eliminación de Gen , Corazón/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Daño por Reperfusión Miocárdica/enzimología , Daño por Reperfusión Miocárdica/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/enzimología , Miocitos Cardíacos/patología , América del Norte , Fosforilación/efectos de los fármacos , Preparaciones de Plantas/aislamiento & purificación , Proteínas Proto-Oncogénicas c-akt/metabolismoRESUMEN
Ultraviolet (UV) radiation is known to cause an imbalance of the endogenous antioxidant system leading to an increase in skin cancer. Panax quinquefolium (American ginseng) polysaccharides (GPS) can inhibit such an imbalance due to its anti-oxidative and anti-inflammatory properties. The aim of this study was to investigate the therapeutic effects of topical formulations containing GPS nanoparticles (NPs) to inhibit UVB induced oxidative damage and skin cancer. Photoaging was conducted under UVB irradiation with a dose of 300 mJ/cm2 on SKH1 hairless mice. The treatment groups (n = 5) were as follows: sham control, native GPS, GPS NPs and fluorescent labeled GPS NPs. To compare the photoprotective performance, the topical formulations were applied before and after UVB induction (pre-treatment and post-treatment), followed by sacrificing the animals. Then, skin and blood samples were collected, and inflammatory cytokines production was measured using ELISA. Compared to the sham control, GPS NPs pre-treated mice skin and blood samples exhibited a significant lowering in all cytokine production. In addition, skin histology analysis showed that pre-treatment of GPS NPs prevented epidermal damage and proliferation. The results support that topical formulation containing GPS NPs can inhibit UVB induced oxidative damage and skin cancer.
Asunto(s)
Nanomedicina , Nanopartículas/administración & dosificación , Nanopartículas/uso terapéutico , Panax/química , Polisacáridos/uso terapéutico , Neoplasias Cutáneas/tratamiento farmacológico , Rayos Ultravioleta , Administración Cutánea , Animales , Citocinas/metabolismo , Daño del ADN , Femenino , Ratones Pelados , Nanopartículas/ultraestructura , Tamaño de la Partícula , Polisacáridos/administración & dosificación , Piel/patologíaRESUMEN
Obesity is regarded to be associated with fat accumulation, chronic inflammation, and gut microbiota dysbiosis. Raw and ripened pu-erh tea extract (PETe) have the effect of reducing body weight gain and fat accumulation, which are associated with gut microbiota. However, little is known about the difference of raw and ripened PETe on the regulation of gut microbiota. Here, our results suggested that supplementation of raw and ripened PETe displayed similar anti-obesogenic effect in high fat diet (HFD)-induced obesity mice, by attenuating the body weight gain, fat accumulation, oxidative injury, and low-grade inflammation, improving the glucose tolerance, alleviating the metabolic endotoxemia, and regulating the mRNA and protein expression levels of the lipid metabolism-related genes. 16S rRNA sequencing of fecal samples indicated that raw and ripened PETe intervention displayed different regulatory effect on the HFD-induced gut microbiota dysbiosis at different taxonomic levels. The microbial diversity, the relative abundance of Firmicutes and Bacteroidetes as well as F/B ratio were reversed more closer to normal by ripened PETe. Phylotypes of Bacteroidaceae, Ruminococcaceae, Lachnospiraceae, Muribaculaceae, and Rikenellaceae which are negatively correlated with obesity were enhanced notably by the intervention of ripened PETe, while Erysipelotrichaceae and Lactobacillaceae which have positive correlation with obesity were decreased dramatically. In addition, the treatment of ripened PETe had better effect on the increase of benefical Bacteroides, Alistipes, and Akkemansia and decrease of obesity associated Faecalibaculum and Erysipelatoclostridium (p < 0.05). These findings suggested that pu-erh tea especially ripened pu-erh tea could serve as a great candidate for alleviation of obesity in association with the modulation of gut microbiota.
Asunto(s)
Microbioma Gastrointestinal , Animales , Dieta Alta en Grasa , Ratones , Obesidad , ARN Ribosómico 16S , TéRESUMEN
BACKGROUND: American ginseng (Panax quinquefolius L.) is one of the most widely used herbal remedies in the world. Its major bioactive constituents are the triterpene saponins known as ginsenosides. However, little is known about ginsenoside biosynthesis in American ginseng, especially the late steps of the pathway. RESULTS: In this study, a one-quarter 454 sequencing run produced 209,747 high-quality reads with an average sequence length of 427 bases. De novo assembly generated 31,088 unique sequences containing 16,592 contigs and 14,496 singletons. About 93.1% of the high-quality reads were assembled into contigs with an average 8-fold coverage. A total of 21,684 (69.8%) unique sequences were annotated by a BLAST similarity search against four public sequence databases, and 4,097 of the unique sequences were assigned to specific metabolic pathways by the Kyoto Encyclopedia of Genes and Genomes. Based on the bioinformatic analysis described above, we found all of the known enzymes involved in ginsenoside backbone synthesis, starting from acetyl-CoA via the isoprenoid pathway. Additionally, a total of 150 cytochrome P450 (CYP450) and 235 glycosyltransferase unique sequences were found in the 454 cDNA library, some of which encode enzymes responsible for the conversion of the ginsenoside backbone into the various ginsenosides. Finally, one CYP450 and four UDP-glycosyltransferases were selected as the candidates most likely to be involved in ginsenoside biosynthesis through a methyl jasmonate (MeJA) inducibility experiment and tissue-specific expression pattern analysis based on a real-time PCR assay. CONCLUSIONS: We demonstrated, with the assistance of the MeJA inducibility experiment and tissue-specific expression pattern analysis, that transcriptome analysis based on 454 pyrosequencing is a powerful tool for determining the genes encoding enzymes responsible for the biosynthesis of secondary metabolites in non-model plants. Additionally, the expressed sequence tags (ESTs) and unique sequences from this study provide an important resource for the scientific community that is interested in the molecular genetics and functional genomics of American ginseng.
Asunto(s)
Perfilación de la Expresión Génica/métodos , Ginsenósidos/biosíntesis , Panax/genética , Raíces de Plantas/genética , Etiquetas de Secuencia ExpresadaRESUMEN
Plant polysaccharides (PS) such as American ginseng polysaccharide (GPS) have drawn immense interest in the field of immunoengineering, as they offer a way to actively control immune cell behavior and stimulation. These pharmacological activities have been limited by PS's inherent physicochemical properties including large molecular size, heterogeneity, and poor solubility. In this work, we hypothesized that by nanosizing and encapsulating GPSs, we could enhance their immunomodulation by increased penetration and absorption through the GI tract. Herein, GPS nanoparticles (NPs) of average size 20 nm (± 4 nm) were prepared using a microfluidic approach, then encapsulated within porous nanospheres (diameter 180 ± 10 nm) of biodegradable gelatin to enhance their oral delivery. To locate the GPS NPs inside the gelatin, we encapsulated fluorescent-labeled GPS in gelatin and analyzed using confocal microscopy. An in vitro investigation on tumor induced macrophage cell lines showed a concentration dependent enhanced immunostimulation with the encapsulated GPS NPs. The immunomodulation was then studied for different formulations of GPS through oral gavage in Swiss albino mice. The results showed that the production of proinflammatory mediators in blood samples was significantly increased for the encapsulated GPS in a dose- and time-dependent manner compared to other GPS treatments. This study shows that GPS and potentially other PS systems' immunomodulation properties can be significantly enhanced for use in simple oral drug delivery.
RESUMEN
Polysaccharides are a major active component of American ginseng root showing various biological activities including anti-carcinogenic, anti-aging, immunostimulatory and antioxidant effects. Although their biological activity has been reported by several groups, no research has explored their cellular uptake and biodistribution, owing to the lack of suitable detection techniques in living cells. This work examines a novel, simple and efficient fluorescent labeling procedure of ginseng polysaccharides (PS), in order to examine their cellular distribution using confocal microscopy. This procedure utilized a one-pot strategy with fluorescein-5-thiosemicarbazide (FTSC) to introduce a thiosemicarbazide group onto the aldehyde group at the reducing saccharide end to form a stable amino derivative through reductive amination. This polysaccharide-FTSC derivative was then characterized by GPC, UV, FTIR, photoluminescence and fluorescence microscopy to confirm attachment and any structural changes. The results demonstrated that the labeled ginseng PS nanostructure showed high fluorescence with minimal changes in PS molecular weight. The labeled PS exhibited almost no cytotoxicity effect against tumor induced macrophage cell lines (RAW 264.7) while retaining high immunostimulating activity similar to the non-labeled ginseng PS. Therefore, the developed approach provides a convenient and highly efficient fluorescent labeling procedure for understanding the mechanism of ginseng PS uptake in macrophage cell lines.
Asunto(s)
Factores Inmunológicos/química , Factores Inmunológicos/farmacología , Nanopartículas/química , Panax/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Polisacáridos/química , Polisacáridos/farmacología , Animales , Supervivencia Celular/efectos de los fármacos , Citocinas/metabolismo , Colorantes Fluorescentes , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Imagen Molecular , Nanopartículas/ultraestructura , Óxido Nítrico/metabolismo , Células RAW 264.7 , Espectroscopía Infrarroja por Transformada de Fourier , Coloración y EtiquetadoRESUMEN
A new approach is provided for preparing radiopaque and angiogenic poly(propylene fumarate) (PPF) bone cements by integrating Sr-doped n-TiO2 nanowires and ginsenoside Rg1 suitable for treating osteonecrosis. High aspect ratio radiopaque TiO2 -nanowires are synthesized by strontium doping in supercritical CO2 for the first time, showing a new phase, SrTiO3 . PPF is synthesized using a transesterification method by reacting diethyl fumarate and propylene glycol, then functionalized using maleic anhydride to produce terminal carboxyl groups, which are subsequently linked to the nanowires. The strong interfacial adhesion between functionalized PPF and nanowires is examined by scanning electron microscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, thermal analysis, and mechanical testing. An angiogenic modulator, ginsenoside Rg1 , is integrated into the bone cement formulation with the mechanical properties, radiopacity, drug release, and angiogenesis behavior of the formed composites explored. The results show superior radiopacity and excellent release of ginsenoside Rg1 in vitro, as well as a dose-dependent increase in the branching point numbers. The present study suggests this new methodology provides sufficient mechanical properties, radiopacity, and angiogenic activity to be suitable for cementation of necrotic bone.
Asunto(s)
Cementos para Huesos/farmacología , Fumaratos/farmacología , Ginsenósidos/farmacología , Nanocompuestos/química , Nanocables/química , Neovascularización Fisiológica/efectos de los fármacos , Polipropilenos/farmacología , Estroncio/farmacología , Titanio/farmacología , Dióxido de Carbono/química , Liberación de Fármacos , Módulo de Elasticidad/efectos de los fármacos , Fumaratos/síntesis química , Fumaratos/química , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Ensayo de Materiales , Nanocompuestos/ultraestructura , Nanocables/ultraestructura , Espectroscopía de Fotoelectrones , Polipropilenos/síntesis química , Polipropilenos/química , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
This study was concerned with the role of copper (Cu) and Cu-metallothionein (Cu-MT) in oxidative stress. Hydrogen peroxide (H(2)O(2))-induced oxidative injury was examined in Ehrlich ascites tumour cells isolated from host mice pretreated with 0, 1 or 2mg of CuSO(4) (ip) 24h earlier. Control Ehrlich cells contained low levels of Cu and Cu treatment produced dose-related increases in cellular Cu and Cu-MT levels and corresponding increases in sensitivity to oxidative toxicity of H(2)O(2) (LC(50), cell blebbing, lipid peroxidation, GSH depletion, and increase in intracellular free [Ca(2+)](i)). Hydrogen peroxide treatment also resulted in the oxidation of MT thiolates, reduction in the binding of Cu to MT resulting in translocation of Cu to other subcellular sites. d-penicillamine, a Cu-chelating agent, obliterated the sensitization effect of Cu-pretreatment and reduced the redistribution of MT-bound Cu, suggesting the participation of Cu ions derived from MT in promoting oxidant stress. Additional experiments with desferoxamine and mannitol have revealed the involvement of a Cu-dependent Fenton reaction in the mediation of the prooxidative effect of Cu-MT. These data suggest that cells with high levels of Cu-MT may be particularly susceptible to oxidative stress.
Asunto(s)
Cobre/farmacología , Peróxido de Hidrógeno/toxicidad , Metalotioneína/farmacología , Animales , Calcio/metabolismo , Carcinoma de Ehrlich/metabolismo , Carcinoma de Ehrlich/patología , Supervivencia Celular/efectos de los fármacos , Cobre/química , Cobre/metabolismo , Sulfato de Cobre/farmacología , Deferoxamina/farmacología , Relación Dosis-Respuesta a Droga , Disulfuro de Glutatión/metabolismo , Inyecciones Intraperitoneales , Hierro/química , Hierro/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Masculino , Manitol/farmacología , Metalotioneína/química , Metalotioneína/metabolismo , Ratones , Estrés Oxidativo/efectos de los fármacos , Penicilamina/farmacología , Pinocitosis/efectos de los fármacos , Factores de Tiempo , Células Tumorales Cultivadas , Zinc/química , Zinc/metabolismoRESUMEN
This study was concerned with the role of zinc (Zn) and zinc-metallothionein (Zn-MT) in oxidative stress. Hydrogen peroxide-induced oxidative injury was examined in Ehrlich ascites tumour cells isolated from control host mice, mice pretreated with 10 mg/kg ZnSO4 (i.p.) to increase cellular Zn/Zn-MT levels, and mice exposed to Zn-deficient diet to reduce the cellular Zn/Zn-MT levels. The results of the present study showed that Ehrlich cells with seven-fold differences in Zn-MT concentrations could be obtained by manipulating the Zn status of host mice and that high Zn and Zn-MT levels can make Ehrlich cells more resistant to H2O2-induced oxidative injury (cell viability, lipid peroxidation, [Ca2+]i) while cells with reduced Zn/Zn-MT levels were more susceptible to this treatment. H2O2 treatment resulted in oxidation of MT thiolate groups and loss of its metal binding capacity with translocation of Zn released from oxidized MT to other cellular sites. Preincubation of Ehrlich cells with ZnSO4 in vitro also conferred some degree of resistance to H2O2 toxicity, suggesting the inherent antioxidative property of Zn ions. These data suggested that Zn-MT can be considered as an antioxidant by virtue of its thiolate groups and its Zn ions that are released in the presence of oxidative stress.
Asunto(s)
Antioxidantes/farmacología , Carcinoma de Ehrlich/metabolismo , Peróxido de Hidrógeno/toxicidad , Metalotioneína/farmacología , Zinc/farmacología , Animales , Antioxidantes/metabolismo , Calcio/metabolismo , Carcinoma de Ehrlich/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cobre/farmacología , Citosol/metabolismo , Glutatión/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Masculino , Metalotioneína/metabolismo , Ratones , Trasplante de Neoplasias , Unión Proteica , Factores de Tiempo , Células Tumorales Cultivadas , Zinc/metabolismoRESUMEN
Next generation drug-loaded polymer scaffolds for hard tissue engineering require unique structures to enhance release kinetics while enabling bone cell growth (osteogenesis). This study examined the encapsulation of the pro-angiogenic mediator, ginsenoside Rg1, into biodegradable poly(propylene fumarate) (PPF) microspheres to facilitate osteogenesis, while examining the release mechanism using advanced X-ray absorption near edge structure spectroscopy (XANES). Ginsenoside Rg1-loaded PPF microspheres were prepared using both an emulsion method and a microfluidic device, with the microfluidic technique providing tunable unimodal PPF spheres ranging in size from 3 to 52 µm by varying the flow rates. The morphology and composition of the Rg1-loaded PPF microspheres were characterized using FTIR, XRD, and XANES to examine the distribution of ginsenoside Rg1 throughout the polymer matrix. Encapsulation efficiency and release profiles were studied and quantified by UV-Vis spectrophotometry, showing high encapsulation efficiencies of 95.4 ± 0.8% from the microfluidic approach. Kinetic analysis showed that Rg1 release from the more monodisperse PPF microspheres was slower with a significantly smaller burst effect than from the polydisperse spheres, with the release following Fickian diffusion. The released Rg1 maintained its angiogenic effect in vitro, showing that the PPF microspheres are promising to serve as vehicles for long-term controlled drug delivery leading to therapeutic angiogenesis in bone tissue engineering strategies.
RESUMEN
BACKGROUND: A major challenge in the treatment of heart failure is the ability to reverse already-established myocardial remodeling and ventricular dysfunction, with few available pharmacological agents prescribed for the management of heart failure having demonstrated successful reversal of the remodeling and hypertrophic processes. North American ginseng (Panax quinquefolius) has previously been shown to effectively prevent cardiomyocyte hypertrophy and heart failure. Here, we determined whether North American ginseng can reverse established cardiomyocyte hypertrophy in cultured myocytes as well as hypertrophy and left ventricular dysfunction in experimental heart failure secondary to coronary artery occlusion. METHODS AND RESULTS: Ginseng was administered in drinking water (0.9 g/L) ad libitum to rats after 4 weeks of sustained coronary artery ligation when heart failure was established or to angiotensin II- (100 nmol/L), endothelin-1- (10 nmol/L), or phenylephrine- (10 µmol/L) induced hypertrophic cultured neonatal ventricular cardiomyocytes. Echocardiographic and catheter-based measurements of hemodynamic parameters 4 weeks after starting ginseng treatment (8 weeks postinfarction) revealed nearly complete reversibility of systolic and diastolic abnormalities. Similarly, ginseng administration to hypertrophic cardiomyocytes resulted in a complete reversal to a normal phenotype after 24 hours as determined by cell surface area and expression of molecular markers. The effects of ginseng both in vivo and in cultured cardiomyocytes were associated with reversal of calcineurin activation and reduced nuclear translocation of the transcription factor NFAT3 (nuclear factor of activated T cells 3) in cultured myocytes. Moreover, the beneficial effect of ginseng was associated with normalization in the gene expression of profibrotic markers, including collagen (I and III) and fibronectin. CONCLUSIONS: This study demonstrates a marked ability of ginseng to reverse cardiac hypertrophy, myocardial remodeling, and heart failure, which was associated with and likely mediated by reversal of calcineurin activation. Ginseng may offer a potentially effective approach to reverse the myocardial remodeling and heart failure processes, particularly in combination with other treatment modalities.