RESUMEN
To assess the toxic potential of the alkaloids, a quantification method is necessary. An ion pair extraction method was used for quantitative fluorometric determination of vincamine, protopine and all contained alkaloids in the mother tinctures of Vinca minor and Fumaria officinalis. The non-fluorescent alkaloids were transformed into an ion pair with sodium-9,10-dimethoxy-anthracene-sulfonate and then fluorometrically determined and quantified in this study. The applicable ion pair was extracted in a suitable organic solvent, where dichloromethane has proven to be beneficial. Conditions for the ion pairing and fluorometric quantification are given. The recovery rate was used to investigate the quality of determinability and the influence of the mother tincture matrix. The method was applied to determine the concentration of protopine in the range 0.1 - 15 µg/ml and of vincamine in the range of 0.5 - 20 µg/ml. The limit of detection was < 0.3 µg/ml, and the limit of quantification < 0.9 µg/ml for both alkaloids.
Asunto(s)
Alcaloides , Fumaria , Vinca , Vincamina , Femenino , Humanos , MadresRESUMEN
All aerobes are dependent on enzymatic and non-enzymatic antioxidants to withstand the presence of reactive oxygen species (ROS). Superoxide dismutase (SOD) is a part of the enzymatic antioxidant system. It is one of the most important antioxidant enzymes, enabling organisms to survive in an oxygen containing atmosphere. A disorder in the oxidative and antioxidative balance can be associated with the occurrence of diseases in human organisms. Little data exist on the relevance of SOD in plants. Moreover, it is not known whether there is any association between a plant's origin and its SOD activity. Our screening of 27 different plant species was intended to expose whether there is a connection. The highest SOD activities were found for extremophile plants. Especially the Crassulaceae Aeonium haworthii Salm-Dyck Ex Webb & Berthel. and Crassula multiflora Schönland & Baker F. were highly active. Nevertheless, we did not find unambiguous evidence for a correlation between extremophilicity and SOD activity.
Asunto(s)
Extremófilos/química , Extractos Vegetales/farmacología , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/metabolismo , Antioxidantes/metabolismo , Humanos , Plantas/químicaRESUMEN
BACKGROUND/OBJECTIVE: Consumption of green tea has become increasingly popular, particularly because of claimed reduction in body weight. We recently reported that animals with pharmacological inhibition (by candoxatril) or genetic absence of the endopeptidase neprilysin (NEP) develop an obese phenotype. We now investigated the effect of green tea extract (in drinking water) on body weight and body composition and the mediating role of NEP. SUBJECTS/METHODS: To elucidate the role of NEP in mediating the beneficial effects of green tea extract, 'Berlin fat mice' or NEP-deficient mice and their age- and gender-matched wild-type controls received the extract in two different doses (300 or 600 mg kg-1 body weight per day) in the drinking water. RESULTS: In 'Berlin fat mice', 51 days of green tea treatment did not only prevent fat accumulation (control: day 0: 30.5% fat, day 51: 33.1%; NS) but also reduced significant body fat (green tea: day 0: 27.8%, day 51: 20.9%, P<0.01) and body weight below the initial levels. Green tea reduced food intake. This was paralleled by a selective increase in peripheral (in kidney 17%, in intestine 92%), but not central NEP expression and activity, leading to downregulation of orexigens (like galanin and neuropeptide Y (NPY)) known to be physiological substrates of NEP. Consequently, in NEP-knockout mice, green tea extract failed to reduce body fat/weight. CONCLUSIONS: Our data generate experimental proof for the assumed effects of green tea on body weight and the key role for NEP in such process, and thus open a new avenue for the treatment of obesity.
Asunto(s)
Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Neprilisina/biosíntesis , Extractos Vegetales/farmacología , Té , Animales , Modelos Animales de Enfermedad , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/fisiología , Ratones , Ratones Noqueados , Neprilisina/deficiencia , Obesidad/metabolismo , Obesidad/patología , Obesidad/prevención & control , Termogénesis/efectos de los fármacos , Termogénesis/fisiología , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Inflammation does not only lead to pain and functio laesa in the affected tissue but is also implicated in the onset and progression of cardiovascular diseases and cancer. Many medicinal plants show anti-inflammatory properties yet plant-constituents and their effect on molecular pathways involved in the attenuation of inflammation as well as cell migration are only poorly understood. Harpagophytum procumbens DC. ex MEISN. is a potent plant used as an immune modulator in traditional herbal medicine. Aim of this study was to investigate the influence of harpagoside and harpagide on TNFα-secretion in undifferentiated and differentiated THP-1 cells under inflammatory conditions as well as their implication in cellular migration into inflamed tissue. We found that both iridoids decrease TNFα-secretion in PMA-differentiated THP-1 cells whereas undifferentiated cells were poorly affected. Yet, in undifferentiated cells harpagoside and harpagide induced mRNA-expression of certain proteins involved in leukocyte transmigration. Especially TNFα and ICAM-1 mRNA-expression was positively affected after 3h and expression could be maintained on high levels even after 48h. L-selectin and PSGL-1 were strongly induced after 48h of stimulation. This ambiguous effect of harpagoside and harpagide highlights their immune modulatory function by facilitating cell migration into the inflamed tissue, whereby in consequence the anti-inflammatory activity of the resident macrophages was also found to be promoted.
Asunto(s)
Antiinflamatorios/química , Glicósidos/química , Glicósidos Iridoides/química , Monocitos/efectos de los fármacos , Piranos/química , Factor de Necrosis Tumoral alfa/metabolismo , Diferenciación Celular , Línea Celular , Movimiento Celular , Harpagophytum/química , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Interferón gamma , Selectina L/metabolismo , Lipopolisacáridos , Macrófagos/efectos de los fármacos , Glicoproteínas de Membrana/metabolismo , Plantas Medicinales/químicaRESUMEN
The latex of Euphorbia papillosa A.St.-Hil. and Sapium glandulosum (L.) Morong was phytochemically investigated by liquid chromatography/mass spectrometry. The results reveal the presence of tigliane-type diterpenoid compounds, particularly 12-deoxyphorbol esters, in both species. In addition, ingenane-type diterpene esters were found in the latex of E. papillosa. The latex of S. glandulosum showed only tigliane-type diterpenes, confirming the literature data on this genus. According to mass data, we are proposing the presence of 10 compounds derived from 12-deoxyphorbol monoesters and diesters, from one 12-deoxyphorbaldehyde, from two ingenol derivatives and from one nitrogen-containing phorbol ester in the latex of the analysed species. Considering that 12-deoxy tigliane diterpenes are described as antitumour and antiviral agents, these results indicate a pharmacological potential for these two Euphorbiaceae species.
Asunto(s)
Cromatografía Liquida/métodos , Diterpenos/análisis , Euphorbiaceae/química , Látex/análisis , Espectrometría de Masa por Ionización de Electrospray/métodosRESUMEN
OBJECTIVES: Osteosarcoma is the most common type of malignant bone tumour in children and adolescents; it has poor prognosis, is highly metastatic and is resistant to current therapeutic approaches. In this study, different herbal extracts used in phytotherapy have been screened after searching innovative natural anti-cancer components. MATERIALS AND METHODS: Twenty steroid glycosides were examined for accordance to their potential of inhibiting cell proliferation and inducing apoptosis in the osteosarcoma cell line 143B. Cell proliferation was examined using a CASY counter. Effects of cardiac glycosides on induction of apoptosis were evaluated by Annexin V-APC and flow cytometry, caspase activity assay and measurement of mitochondrial membrane potential. RESULTS: The study revealed that various steroid glycosides suppress cell proliferation in a concentration-dependent manner. Further investigations indicated apoptotic induction by 17 of the 20 tested cardenolides and bufadienolides. Bufadienolide proscillaridin A, arenobufagin, and cardenolides evomonoside, convallatoxol and ouabain waged strongest apoptotic induction, associated with breakdown of mitochondrial membrane potential and activation of caspases -8 and -9. In contrast, the bufadienolide resibufogenin and cardenolide uzarin had no effect on proliferation inhibition, apoptotic induction or change in mitochondrial membrane potential. CONCLUSION: These results indicate that bufadienolides proscillaridin A and arenobufagin and cardenolide evomonoside, or related natural compounds might be promising new starting points for development of novel anti-cancer agents for treatment of osteosarcoma.
Asunto(s)
Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Glicósidos/farmacología , Neoplasias Óseas/metabolismo , Neoplasias Óseas/patología , Caspasa 8/metabolismo , Caspasa 9/metabolismo , Línea Celular Tumoral , Glicósidos/química , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Osteosarcoma/metabolismo , Osteosarcoma/patología , Esteroides/químicaRESUMEN
Monocytes play a major role in modulating inflammation and can be found as circulating blood cells or, after extravasation, as differentiated tissue specific macrophages. The activation of TLRs (Toll-like receptors) modulates their action and contributes considerably to the eradication of pathogens. Aim of this study was to investigate the influence of TLR-agonists on TNF-alpha secretion and lysozyme activity in a comparative assay. To explore the importance of differentiation the monocytic cell line THP-1 was pre-treated with PMA and IFNy. Stimulation of undifferentiated cells with various bacterial antigens had almost no effect on TNFalpha secretion and lysozyme activity but influenced adhesion molecule expression clearly. Differentiated THP-1 cells were much more sensitive to further stimulation with TLR-agonists yet revealed an opposing effect on lysozyme activity and TNF-alpha secretion. The results suggest a coordinated activation of intercellular adhesion molecule expression and cytokine secretion in the differentiation process from monocytes to macrophages.
Asunto(s)
Adhesión Celular/efectos de los fármacos , Muramidasa/metabolismo , Receptores Toll-Like/agonistas , Factor de Necrosis Tumoral alfa/metabolismo , Diferenciación Celular/efectos de los fármacos , Línea Celular , ADN/análisis , ADN/biosíntesis , Ensayo de Inmunoadsorción Enzimática , Humanos , Monocitos/efectos de los fármacos , Monocitos/metabolismo , ARN/biosíntesis , ARN/genética , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
The liver plays an essential role in xenobiotic metabolism including alcohol and drugs. Oxidative stress that usually occurs during the hepatic metabolism participates in the pathogenesis of liver disease. Inflammatory cytokines that exist in liver in both physiological and pathophysiological conditions may change the hepatic toxic response to hepatotoxicants. The human hepatoma cell line HepG2 is frequently used as in vitro model for biomedical studies. In this work, HepG2 cells were pre-incubated with or without TNF-alpha, and then treated with ethanol, acetaldehyde, acetaminophen and tert-butyl hydroperoxide, respectively. Cell viability was measured by MTT assay. The data showed that HepG2 cells were generally resistant to xenobiotic compounds, especially to alcohol and acetaldehyde, which may be partially caused by the absence of specific cytochrome P450 systems in these cells. TNF-alpha could sensitize the toxic response of HepG2 cells to those exogenous compounds, indicating the important role of TNF-alpha in the pathogenesis of alcohol, drugs and oxidant related liver diseases.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Acetaldehído/toxicidad , Acetaminofén/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Depresores del Sistema Nervioso Central/toxicidad , Colorantes , Etanol/toxicidad , Humanos , Sales de Tetrazolio , Tiazoles , terc-Butilhidroperóxido/toxicidadRESUMEN
The bark of Daphne mezereum L. is known as toxic drug due to the presence of diterpene esters. The phytochemical analysis of the bark used for preparation of homeopathic mother tinctures showed that gniditrin was the main diterpene constituent, only in the fruits of D. mezereum mezerein could be detected. The complete NMR data of gniditrin are published for the first time.
Asunto(s)
Antineoplásicos Fitogénicos/análisis , Daphne/química , Diterpenos/análisis , Antineoplásicos Fitogénicos/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Diterpenos/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Materia Medica , Corteza de la Planta/química , Extractos Vegetales/análisis , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Lysozyme is an important factor of innate immunity and a unique enzybiotic in that it exerts not only antibacterial activity, but also antiviral, anti-inflammatory, anticancer, and immunomodulatory activities. The purpose of the present study was to investigate whether in vitro exposure to microbial preparations can affect the release and production of lysozyme activity in human monocytic cell line THP-1. Lysozyme activity levels in cell culture fluids were measured using highly sensitive fluorescence-based lysozyme activity assay. Different preparations of bacteria and ascomycetes stimulated lysozyme release result in a higher lysozyme activity after one hour exposure. The demonstrated ability of selected microbial preparations to enhance the release of lysozyme activity can present a new mechanism contributing to explaining biological characteristics of microbial preparations, including their antibacterial and immune-stimulating properties.
Asunto(s)
Bacterias/química , Hongos/química , Muramidasa/metabolismo , Adyuvantes Inmunológicos/farmacología , Antiinflamatorios/farmacología , Antivirales/farmacología , Recuento de Células , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Lipopolisacáridos/farmacología , Monocitos/efectos de los fármacos , Monocitos/enzimología , Juego de Reactivos para Diagnóstico , Estándares de Referencia , Espectrometría de Fluorescencia , Estimulación QuímicaRESUMEN
There is increasing evidence that endogenously produced toxins may be involved in the development of a number of neurodegenerative diseases such as Alzheimer's, Parkinson's or Huntington's disease and that the mechanisms leading to cell loss are a combination of oxidative stress, mitochondrial dysfunction and a decrease in antioxidant defenses. The purpose of this study was to investigate the effects of glutathione on 3-hydroxykynurenine, 6-hydroxydopamine and salsolinol mediated neurotoxicity in the human neuroblastoma SH-SY5Y cell line in order to find a possible therapeutic application of this compound to neurodegenerative disorders. In this study, we tested the protective effect of glutathione on SH-SY5Y cells against 3-hydroxykynurenine, 6-hydroxydopamine and salsolinol induced cytotoxicity and demonstrated that glutathione inhibits cell death and adenosine-5'triphosphate depletion caused by 3-hydroxykynurenine and 6-hydroxydopamine. However, unexpectedly salsolinol neurotoxicity toward SH-SY5Y cells was potentiated during treatment with concentrations of glutathione below 250 µM, whereas glutathione concentrations above 250 µM resulted in protection against salsolinol induced neuronal cell death. We also report that the incubation of salsolinol and low concentrations of glutathione led to increased apoptosis. Hence, salsolinol in the presence of low glutathione concentration may be involved in neurodegeneration. These data may provide new promising insights into the pathophysiology of neudegenerative disorders such as Parkinson's disease.
Asunto(s)
Glutatión/metabolismo , Isoquinolinas/toxicidad , Neuroblastoma/patología , Neuronas/efectos de los fármacos , Adenosina Trifosfato/metabolismo , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Caspasa 7/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Humanos , Quinurenina/análogos & derivados , Quinurenina/toxicidad , Degeneración Nerviosa , Neuroblastoma/metabolismo , Neuronas/metabolismo , Neuronas/patología , Oxidopamina/toxicidad , Factores de TiempoRESUMEN
Forskolin (7beta-acetoxy-1alpha,6beta,9alpha-trihydroxy-8,13-epoxy-labd-14-en-11-one) is the first main labdane diterpenoid isolated from the roots of the Indian Plectranthus barbatus ANDREWS and one of the most extensively studied constituents of this plant. The unique character of forskolin as a general direct, rapid and reversible activator of adenylyl cyclase not only underlies its wide range of pharmacological effects but also renders it as a valuable tool in the study of the role of cAMP. The purpose of this review is to provide data presenting the utility of forskolin--as a cAMP activator--for studying the function of cAMP from different biological viewpoints as follows: 1) Investigation on the role of cAMP in various cellular processes in different organs such as gastrointestinal tract, respiratory tract, reproductive organs, endocrine system, urinary system, olfactory system, nervous system, platelet aggregating system, skin, bones, eyes, and smooth muscles. 2) Studies on the role of cAMP activation and inhibition to understand the pathogenesis (e.g. thyroid autoimmune disorders, leukocyte signal transduction defect in depression, acute malaria infection, secretory dysfunction in inflammatory diseases) as well as its possibly beneficial role for curing diseases such as the regulation of coronary microvascular NO production after heart failure, the attenuation of the development or progression of fibrosis in the heart and lungs, the augmentation of myo-protective effects of ischemic preconditioning especially in the failing hearts after myocardial infarction, the stimulation of the regeneration of injured retinal ganglion cells, the curing of glaucoma and inflammatory diseases, the reducing of cyst formation early in the polycystic kidney disease, and the management of autoimmune disorders by enhancing Fas-mediated apoptosis. 3) Studies on the role of cAMP in the mechanism of actions of a number of drugs and substances such as the effect of the protoberberine alkaloid palmatine on the active ion transport across rat colonic epithelium, the inhibitory effect of retinoic acid on HIV-1-induced podocyte proliferation, the whitening activity of luteolin, the effect of cilostazol on nitric oxide production, an effect that is involved in capillary-like tube formation in human aortic endothelial cells, the apoptotic effect of bullatacin, the effects of paraoxon and chlorpyrifos oxon on nervous system. Moreover, cAMP was found to play a role in acute and chronic exposure to ethanol, in morphine dependence and withdrawal and in behavioral sensitization to cocaine as well as in the protection against cisplatin-induced oxidative injuries.
Asunto(s)
Colforsina/análogos & derivados , AMP Cíclico/fisiología , Animales , Fenómenos Fisiológicos Celulares , Colforsina/uso terapéutico , Interacciones Farmacológicas , Humanos , FarmacocinéticaRESUMEN
Quinolinic acid (QUIN), kynurenine acid (KYNA) and 3-hydroxykynurenine (3-HK) - metabolites of the kynurenine pathway are considered to be associated with many central nervous system diseases. However, in neuroscience research in order to test neurotoxicity or neuroprotection against these compounds only primary cell models are available. In this investigation we aimed to develop a simple, rapid and accurate cellular in vitro model using immortalized human neuroblastoma cell lines, namely SK-N-SH and SH-SY5Y differentiated by treatment with various agents. In order to alter the cell response to the neurotoxins, tumor necrosis factor-alpha and retinoic acid (RA) as differentiating agents and modulation of the cellular metabolism through changing the sugar composition from galactose to glucose in media were used. Our results indicated that although RA-differentiation of both cell lines induced the expression of neuronal features, cell vulnerability after exposure to control neurotoxicants (salsolinol, 6-hydroxydopamine) and 3-HK was decreased in comparison to untreated cells and was not influenced after exposure to QUIN and KYNA. Interestingly, the same observations were done in cells grown in galactose containing media.
Asunto(s)
Quinurenina/metabolismo , Neurotoxinas/metabolismo , Neoplasias Encefálicas/metabolismo , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Colorantes , Técnica del Anticuerpo Fluorescente , Humanos , Hidroxidopaminas/toxicidad , Isoquinolinas/toxicidad , Quinurenina/análogos & derivados , Quinurenina/farmacología , Neuroblastoma/metabolismo , Ácido Quinolínico/farmacología , Sales de Tetrazolio , Tiazoles , Tretinoina/farmacologíaRESUMEN
Saponinum album (Merck) is a complex composite of triterpene saponins. It was shown that Saponinum album (Merck) dramatically enhances the toxicity of the N-glycosylase saporin from the seeds of Saponaria officinalis L. as well as the toxicity of a saporin based anti-tumor toxin. This study was intended to chromatographically profile the saponins present in Saponinum album (Merck) in order to identify saponins that determine the cytotoxicity enhancing properties of Saponinum album (Merck) on saporin. For this purpose a liquid-chromatographic profiling (HPLC) followed by ESI-TOF-MS analysis and evaluation of cytotoxicity enhancer effects of saponins from Saponinum album (Merck) was performed. This is the first study describing a liquid-chromatographic profiling of saponins from Saponinum album (Merck). Ten different saponins were isolated. There was a lot of variation observed in the cytotoxicity enhancing properties of different isolated saponins, 8 out of 10 isolated saponins showed an enhancer effect on the toxicity of saporin. Based on these results it was concluded that the cytotoxicity enhancer effect of Saponinum album (Merck) is not attributable to a single, activity determining saponin.
Asunto(s)
Antineoplásicos Fitogénicos/análisis , Saponinas/análisis , Triterpenos/análisis , Antineoplásicos Fitogénicos/farmacología , Secuencia de Carbohidratos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Humanos , Datos de Secuencia Molecular , Saponaria/química , Saponinas/farmacología , Espectrometría de Masa por Ionización de Electrospray , Triterpenos/farmacologíaRESUMEN
Sialidases are very common in biological systems. They are found particularly in diverse virus families and bacteria, but also in protozoa, some invertebrates and mammalian. The enzymes differ in their biochemical properties, e.g., kinetics, binding affinity or substrate preference. Nevertheless, they have conserved domains and structural similarities. Their functions offer a wide spread spectrum in nutrition, pathomechanisms and communication in mammalian. In pathogen organisms sialidases give insight in coevolution and interaction between pathogen or commensale and host. As well the enzymes are of interest in drug targeting, like neuraminidase inhibitors of influenza viruses.
Asunto(s)
Neuraminidasa/fisiología , Animales , Bacterias/enzimología , Infecciones Bacterianas/enzimología , Infecciones Bacterianas/microbiología , Humanos , Invertebrados/fisiología , Mamíferos/fisiología , Neuraminidasa/metabolismo , Orthomyxoviridae , Ácidos Siálicos/metabolismo , Virus/enzimologíaRESUMEN
Eighteen species of the genus Euphorbia are known to have proteolytic enzymes in their latices, 9 of them are characterized by the type of endopeptidases (Cysteine-, Serine-, Metallo- or Aspartatic-endopeptidase) which are responsible for the activity, and all nine are serine endopeptidases. In our study we examined the latices of 64 different species of the genus Euphorbia concerning proteolytic activity and serine protease activity, five of them are mentioned in the literature to be proteolytic active and four are known to contain at least one serine endopeptidase. All tested samples were able to degrade labelled casein, the activity of six latices were completely inhibited by specific serine protease inhibitors, 15 samples were not influenced, and in 43 latices a remaining activity was measured, indicating that other types of endopeptidases seem to be involved.
Asunto(s)
Endopeptidasas/química , Euphorbia/clasificación , Euphorbia/enzimología , Látex/análisis , Biomarcadores , Caseínas/química , Clasificación/métodos , Indicadores y Reactivos , Inhibidores de Proteasas/farmacología , Serina Proteasas/análisis , Serina Proteasas/metabolismo , Inhibidores de Serina Proteinasa/farmacologíaRESUMEN
BACKGROUND AND PURPOSE: Certain saponins synergize with antitumour drugs to enhance their efficacy, but the mechanisms underlying this synergy in vivo are not well studied. Here, we describe the distribution of Saponinum album (Spn) from Gypsophila paniculata L. in mice after subcutaneous injection. EXPERIMENTAL APPROACH: The [(3)H]-labelled Spn used for in vivo experiments was biologically active, as it still increased the cytotoxicity of a chimeric toxin in vitro. Distribution of [(3)H]-Spn was measured in BALB/c mice, with or without subcutaneous tumours in the flank. Labelled Spn was subcutaneously injected in the neck, and samples of organs, blood, urine and tumour tissue were analysed for radioactivity, 5-240 min after the injection. KEY RESULTS: The majority of [(3)H]-Spn distributed within 10 min throughout the entire animal, with high levels of radioactivity in the urine by 30 min. No preferential accumulation in tumour tissue or other organs was observed. In tumour-bearing mice, using a sequential combination of Spn (given first) and a chimeric toxin against the epidermal growth factor receptor, ErbB1, we tested two different pretreatment times for Spn. There was high antitumour efficacy (66% inhibition of tumour growth) after 60 min pre treatment with Spn, but no significant inhibition after 10 min pre treatment with Spn. CONCLUSIONS AND IMPLICATIONS: [(3)H]-Spn was rapidly cleared from the mice after s.c. injection, and antitumour synergy with chimeric toxins was correlated with the removal of excess Spn from tissues. Disposition of Spn in vivo may critically determine antitumour synergy with chimeric toxins.
Asunto(s)
Antineoplásicos/farmacocinética , Receptores ErbB/biosíntesis , Inmunotoxinas/farmacocinética , Saponinas/farmacocinética , Animales , Antineoplásicos/farmacología , Caryophyllaceae , Línea Celular , Línea Celular Tumoral , Sinergismo Farmacológico , Factor de Crecimiento Epidérmico/genética , Receptores ErbB/genética , Femenino , Humanos , Inmunotoxinas/genética , Inmunotoxinas/farmacología , Ratones , Ratones Endogámicos BALB C , Trasplante de Neoplasias , Proteínas Inactivadoras de Ribosomas Tipo 1/genética , Saponinas/genética , Saponinas/farmacología , Saporinas , Distribución Tisular , TritioRESUMEN
In Traditional Chinese Medicine a number of herbs are used to alleviate age-related diseases including memory impairment and dementia, among them stems of Cynomorium songaricum, Cynomoriaceae. In this study, we evaluated the protective effect of different extracts of aerial parts of C. songaricum on amyloid-beta peptide (Abeta) and hypoxanthine/xanthine oxidase induced cell death in SK-N-SH neuroblastoma cells. Abeta (20 microM) as well as superoxide anions generated by the hypoxanthine/xanthine oxidase system both reduced cell viability to about 60%. The methanolic extract of C. songaricum attenuated Abeta induced cell death at concentrations of 100 and 10 microg/ml, an even stronger effect was observed for the ethyl acetate fraction obtained from the crude methanolic extract. On the other hand, the dichloromethane as well as water fractions showed no protective effects. In order to further analyze the protective mode of action, the ability of extracts to protect against superoxide anions induced cell death was also evaluated. In this system, cell viability could again be restored by methanol and ethyl acetate extracts, the latter showingsignificant protective effects even at concentrations as low as 0.1 microg/ml.
Asunto(s)
Péptidos beta-Amiloides/antagonistas & inhibidores , Péptidos beta-Amiloides/toxicidad , Cynomorium/química , Fármacos Neuroprotectores , Oxidantes/toxicidad , Fragmentos de Péptidos/antagonistas & inhibidores , Fragmentos de Péptidos/toxicidad , Superóxidos/toxicidad , Acetatos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Metanol , Extractos Vegetales/farmacología , Solventes , Xantina Oxidasa/toxicidadRESUMEN
Saporin is a type I ribosome-inactivating protein with N-glycosidase activity. It removes adenine residues from the 28S ribosomal RNA resulting in inhibition of protein synthesis. Recently we have shown that saporin exerts no cytotoxicity on seven human cell lines. However, the combination of saporin with a special mixture of Gypsophila saponins (Soapwort saponins) from Gypsophila paniculata L. (baby's breath) rendered saporin to a potent cytotoxin comparable to viscumin, a highly toxic type II ribosome-inactivating protein. In this study we investigated whether the enhancement of the saporin-cytotoxicity by Gypsophila saponins is mediated by a saponin-triggered modulation of endocytosis, exocytosis or impaired degradation processes of his-tagged saporin ((his)saporin) in ECV-304 cells. For this purpose (his)saporin was labelled with tritium and cytotoxicity of the toxin alone and in combination with Gypsophila saponins was scrutinized. The transport and degradation processes of (his)saporin were not different in Gypsophila saponin-treated and control cells. However, after ultracentrifugation of a post-nuclear supernatant the amount of cytosolic (his)saporin was significantly higher in saponin-treated cells than in cells, which were only incubated with (his)saporin. This indicates a saponin mediated endosomal escape of saporin.
Asunto(s)
Caryophyllaceae/química , Endocitosis/efectos de los fármacos , Extractos Vegetales/farmacología , Proteínas Inactivadoras de Ribosomas Tipo 1/farmacología , Saponinas/farmacología , Secuencia de Carbohidratos , Línea Celular , Sinergismo Farmacológico , Humanos , Datos de Secuencia Molecular , Saponinas/química , Saporinas , Fracciones Subcelulares/químicaRESUMEN
Saponins are plant glycosides that consist of a steroid, steroid alkaloid or triterpenoid aglycone and one or more sugar chains that are covalently linked by glycosidic binding to the aglycone. Glucose, galactose, glucuronic acid, xylose and rhamnose are commonly bound monosaccharides. Saponins are found in all organs of a variety of higher plants. Due to the great variability of their structures, diverse functions have been described for distinct saponins; including foaming and pore forming properties as well as selective removal of protozoa from the rumen. The most interesting properties are, however, favorable anti-tumorigenic effects. Several saponins inhibit tumor cell growth by cell cycle arrest and apoptosis with half maximal inhibitory concentrations of down to 0.2 microM. A drawback of saponins in tumor therapy is the non-targeted spreading throughout the whole body. Surprisingly, certain saponins were identified that drastically enhance the efficacy of targeted chimeric toxins bearing the ribosome-inactivating protein saporin as cell-killing moiety. It was demonstrated that this effect is substantially more pronounced on target cells than on non-target cells, thus not only preserving the target specificity of the chimeric toxin but also broadening the therapeutic window with simultaneous dose lowering. This review describes the role of saponins as drug in general, their use as single drug treatment in tumor therapy, their combination with conventional tumor treatment strategies and the synergistic effects with particular targeted tumor therapies that are based on recombinant proteins.