Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Antibiotics (Basel) ; 13(4)2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38667001

RESUMEN

Candida auris is a newly emerging yeast, which is raising public health concerns due to its outbreak potential, lack of protocols for decontamination and isolation of patients or contacts, increased resistance to common antifungals, and associated high mortality. This research aimed to describe the challenges related to identifying the outbreak, limiting further contamination, and treating affected individuals. We retrospectively analyzed all cases of C. auris detected between October 2022 and August 2023, but our investigation focused on a three-month-long outbreak in the department of cardio-vascular surgery and the related intensive care unit. Along with isolated cases in different wards, we identified 13 patients who became infected or colonized in the same area and time, even though the epidemiological link could only be traced in 10 patients, according to the epidemiologic investigation. In conclusion, our study emphasizes the substantial challenge encountered in clinical practice when attempting to diagnose and limit the spread of an outbreak. Therefore, it is crucial to promptly apply contact precaution measures and appropriate environmental cleaning, from the first positive case detected.

2.
J Ethnopharmacol ; 147(1): 42-62, 2013 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-23454683

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The vast genus Rhododendron includes species that have been used in traditional medicine for the treatment of inflammatory conditions, pain, gastro-intestinal disorders, common cold, asthma, skin disease, etc. Rhododendrons are also well known for their toxicity and some species have been traditionally used as poison. AIM OF THE REVIEW: The work reviews and analyses the traditional use, biological activities with the corresponding chemical constituents, and toxicological data on Rhododendron species. The review aims at characterizing the ethnopharmacology of the genus in relation to its toxicity in order to identify the therapeutic potential of Rhododendron species and future directions for research. METHODS: Data regarding Rhododendron spp. was collected using electronic databases (SciFinder, PubMed, Google Scholar) and library search for selected peer-reviewed articles. Plant taxonomy was validated by the databases The Plant List, Tropicos, eFloras, Flora Iberica and Flora Europaea (RBGE). Additional information on traditional use and botany was obtained from published books. The review encompasses literature, mainly regarding biological activity and toxicological data, from 1898 to the end of December 2012. RESULTS: Rhododendrons have been used in Asian, North American and European traditional medicine mainly against inflammation, pain, skin ailments, common cold and gastro-intestinal disorders. In vivo and in vitro testing of plant extracts and isolated compounds determined diverse biological activities including anti-inflammatory, analgesic, anti-microbial, anti-diabetic, insecticidal and cytotoxic activity. Rhododendron spp. can cause intoxications in humans following intake of rhododendron honey or medicinal preparations. The toxicity is due to grayanotoxins, diterpenes which activate voltage-gated sodium channels and lead to gastro-intestinal, cardiac and central nervous system symptoms. CONCLUSION: Rhododendron species are useful traditional remedies for the treatment of inflammation, pain, skin ailments, common cold and gastro-intestinal disorders. Pharmacological data has validated most indications of rhododendrons in ethnomedicine and toxicology studies have confirmed the toxicity observed by traditional use. Ethnopharmacological data point to the therapeutic potential of the genus Rhododendron for the treatment of inflammatory conditions and pain and, thus, research should focus on identification of active compounds and related mechanistic studies. Prolonged and high dose intake of traditional formulations containing rhododendrons should be avoided until more in depth toxicity studies become available.


Asunto(s)
Etnofarmacología , Medicina Tradicional , Fitoterapia , Preparaciones de Plantas/farmacología , Rhododendron , Animales , Humanos , Preparaciones de Plantas/administración & dosificación , Preparaciones de Plantas/química , Preparaciones de Plantas/toxicidad , Plantas Medicinales , Rhododendron/química
4.
Int J Oncol ; 42(1): 338-48, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23135783

RESUMEN

The present study investigates extracts of Neuolaena lobata, an anti-protozoan ethnomedicinal plant of the Maya, regarding its anti-neoplastic properties. Firstly, extracts of increasing polarity were tested in HL-60 cells analyzing inhibition of cell proliferation and apoptosis induction. Secondly, the most active extract was further tested in anaplastic large cell lymphoma (ALCL) cell lines of human and mouse origin. The dichloromethane extract inhibited proliferation of HL-60, human and mouse ALCL cells with an IC50 of ~2.5, 3.7 and 2.4 µg/ml, respectively and arrested cells in the G2/M phase. The extract induced the checkpoint kinases Chk1 and Chk2 and perturbed the orchestrated expression of the Cdc25 family of cell cycle phosphatases which was paralleled by the activation of p53, p21 and downregulation of c-Myc. Importantly, the expression of NPM/ALK and its effector JunB were drastically decreased, which correlated with the activation of caspase 3. Subsequently also platelet derived growth factor receptor ß was downregulated, which was recently shown to be transcriptionally controlled by JunB synergizing with ALK in ALCL development. We show that a traditional healing plant extract downregulates various oncogenes, induces tumor suppressors, inhibits cell proliferation and triggers apoptosis of malignant cells. The discovery of the 'Active Principle(s)' is warranted.


Asunto(s)
Asteraceae/química , Linfoma Anaplásico de Células Grandes/prevención & control , Cloruro de Metileno/química , Fitoterapia , Extractos Vegetales/farmacología , Plantas Medicinales , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Animales , Apoptosis/efectos de los fármacos , Western Blotting , Ciclo Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Humanos , Técnicas para Inmunoenzimas , Linfoma Anaplásico de Células Grandes/metabolismo , Linfoma Anaplásico de Células Grandes/patología , Ratones , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/metabolismo , Células Tumorales Cultivadas
5.
Int J Oncol ; 41(3): 1164-72, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22752086

RESUMEN

Plants have been the source of several effective drugs for the treatment of cancer and over 60% of anticancer drugs originate from natural sources. Therefore, extracts of the rhizome of Smilax spinosa, an ethnomedicinal plant from Guatemala which is used for the treatment of inflammatory conditions, were investigated regarding their anti-neoplastic activities. By using several solvents the methanol extract was by far the most potent against HL60 cell proliferation (50% inhibition at 60 µg/ml). Furthermore, fractionation of this extract yielded fraction F2, which exhibited enforced pro-apoptotic activity, and activated CYP1A1. Proteins that are relevant for cell cycle progression and apoptosis, as well as proto-oncogenes were investigated by western blotting. This revealed that the methanol extract increased the levels of p21 and this may have caused cell cycle attenuation. The derivative fraction F2 induced apoptosis through the intrinsic pathway, which correlated with the inhibition of Stat3 phosphorylation and concomitant induction of caspase 9, then caspase 8 and caspase 3. In summary, the methanol extract and the derivative fraction F2 of S. spinosa showed anti-neoplastic effects in HL-60 cells and CYP1A1 activation in estrogen receptor-positive MCF-7 breast cancer cells but not in estrogen-negative MDA-MB231 breast cancer cells. Based on our data Smilax spinosa may be a promising source for novel anticancer agents.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/farmacología , Smilax , Antiinflamatorios no Esteroideos/farmacología , Apoptosis/efectos de los fármacos , Caspasa 3/biosíntesis , Caspasa 8/biosíntesis , Caspasa 9/biosíntesis , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Citocromo P-450 CYP1A1/metabolismo , Femenino , Células HL-60 , Humanos , Fosforilación/efectos de los fármacos , Factor de Transcripción STAT3/metabolismo , Quinasas p21 Activadas/metabolismo
6.
J Agric Food Chem ; 60(29): 7204-10, 2012 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-22769731

RESUMEN

Sphingolipid metabolites regulate cellular processes such as cell proliferation, differentiation, and apoptosis. In this study, glucocerebrosides (GluCer) from rhizomes of Arisaema amurense and Pinellia ternata were fully characterized using 1- and 2-dimensional nuclear magnetic spin resonance (NMR) and circular dichroism (CD) spectroscopy and tandem collision-induced dissociation mass spectrometry (ESI-MS/CID-MS). Three new acylated and seven known GluCer were elucidated with 4,8-sphingadienine (4,8-SD, d18:2) as backbone. 4,8-SD is a metabolite after enzymatical hydrolysis of GluCer in the gut lumen. In this study, 4,8-SD was hydrolyzed from GluCer and chromatographically purified on silica gel. In contrast to the GluCer, 4,8-SD showed cytotoxic effects in the WST-1 assay. GluCer with 4,8-SD as sphingoid backbone are present in plants consumed as food, such as spinach, soy, and eggplant.


Asunto(s)
Arisaema/química , Etanolaminas/química , Glucosilceramidas/química , Pinellia/química , Animales , Antineoplásicos Fitogénicos/farmacología , Neoplasias de la Mama , Línea Celular Tumoral , Dicroismo Circular , Etanolaminas/metabolismo , Etanolaminas/farmacología , Glucosilceramidas/metabolismo , Células HEK293 , Células HL-60 , Células HeLa , Humanos , Hidrólisis , Macrófagos , Espectroscopía de Resonancia Magnética , Ratones , Estructura Molecular , Valor Nutritivo , Rizoma/química , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en Tándem
7.
Artículo en Inglés | MEDLINE | ID: mdl-22474515

RESUMEN

Introduction. Several studies demonstrated that anti-inflammatory remedies exhibit excellent anti-neoplastic properties. An extract of Pluchea odorata (Asteraceae), which is used for wound healing and against inflammatory conditions, was fractionated and properties correlating to anti-neoplastic and wound healing effects were separated. Methods. Up to six fractionation steps using silica gel, Sephadex columns, and distinct solvent systems were used, and eluted fractions were analysed by thin layer chromatography, apoptosis, and proliferation assays. The expression of oncogenes and proteins regulating cell migration was investigated by immunoblotting after treating HL60 cells with the most active fractions. Results. Sequential fractionations enriched anti-neoplastic activities which suppressed oncogene expression of JunB, c-Jun, c-Myc, and Stat3. Furthermore, a fraction (F4.6.3) inducing or keeping up expression of the mobility markers MYPT, ROCK1, and paxillin could be separated from another fraction (F4.3.7), which inhibited these markers. Conclusions. Wound healing builds up scar or specific tissue, and hence, compounds enhancing cell migration support this process. In contrast, successful anti-neoplastic therapy combats tumour progression, and thus, suppression of cell migration is mandatory.

8.
Int J Oncol ; 40(6): 2131-9, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22446629

RESUMEN

Investigating the bioactivity of traditional medical remedies under the controlled conditions of a laboratory is an option to find additional applications, novel formulations or lead structures for the development of new drugs. The present work analysed the anti­neoplastic activity of increasing polar extracts of the rainforest plant Critonia morifolia (Asteraceae) that has been successfully used as traditional remedy to treat various inflammatory conditions in the long-lasting medical tradition of the Central American Maya, which was here also confirmed in vitro. The apolar petroleum ether extract exhibited the most potent anti­proliferative and pro­apoptotic effects in HL­60 cells and triggered down-regulation of Cdc25C and cyclin D1 within 30 min followed by the inhibition of c-Myc expression and the onset of caspase-3 activation within 2 h. Subsequent to these very rapid molecular responses Chk2 and H2AX became phosphorylated (γ­H2AX) after 4 h. Analysis of the cell cycle distribution showed an accumulation of cells in the G2-M phase within 8 h and after 24 h in S-phase. This was temporally paralleled by the down-regulation of Cdc25A, Cdc25B, Wee1 and Akt. Therefore, the attenuation of cell cycle progression in the G2-M phase was consistent with the known role of Chk2 for G2-M arrest and with the role of Cdc25B in S-phase progression. These findings suggest the presence of two distinct active principles in the petroleum ether extract of C. moriflia. These facilitated the strong apoptotic response evidenced by the rapid activation of caspase-3 that was later enforced by the inhibition of the survival kinase Akt. Importantly, the efficient down-regulation of Akt, which is successfully tested in current clinical trials, is a unique property of C. morifolia.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Asteraceae/química , Proteínas de Ciclo Celular/metabolismo , Extractos Vegetales/farmacología , Alcanos/química , Ciclo Celular/efectos de los fármacos , Puntos de Control del Ciclo Celular , Proteínas de Ciclo Celular/genética , Proliferación Celular/efectos de los fármacos , Ciclina D1/genética , Ciclina D1/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HL-60 , Humanos , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Solventes/química , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo
9.
Artículo en Inglés | MEDLINE | ID: mdl-21837249

RESUMEN

Abnormal Savda Munziq (ASMq) is a herbal preparation used in Traditional Uighur Medicine for the treatment and prevention of diabetes, cardiovascular diseases, chronic asthma and cancer. The recommended dose of this decoction for cancer patients is 500 mL administered orally three times a day. Our approach aimed at reducing the high amount of fluid intake required by fractionation of ASMq guided by the antiproliferative activity on HL-60 cells. The fractionation of ASMq resulted in the preparation of an active extract, Extr-4. Using solid phase extraction, Extr-4 was further fractionated into five fractions (SPE-0, SPE-20, SPE-40, SPE-60 and SPE-80), with SPE-40 showing the strongest antiproliferative activity. Caffeic acid, rutin, isoquercitrin, isorhamnetin 3-O-rutinoside, apigenin 7-O-glucoside, rosmarinic acid, luteolin and formononetin were identified in Extr-4 and fractions thereof by means of TLC, HPLC-DAD and LC-MS. SPE-40 contained the main compounds responsible for the antiproliferative activity on HL-60 cells. Thus, a phenolic fraction with high antiproliferative activity on HL-60 cells was obtained from ASMq through the bioassay-guided fractionation process. This could provide a better pharmaceutical formulation that minimizes the administration inconveniencies of a high volume (1.5 L per day) of ASMq decoction for cancer patients.

10.
Proc Natl Acad Sci U S A ; 108(38): 16062-7, 2011 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-21900605

RESUMEN

Gliomas contain a small number of treatment-resistant glioma stem cells (GSCs), and it is thought that tumor regrowth originates from GSCs, thus rendering GSCs an attractive target for novel treatment approaches. Cancer cells rely more on glycolysis than on oxidative phosphorylation for glucose metabolism, a phenomenon used in 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography imaging of solid cancers, and targeting metabolic pathways in cancer cells has become a topic of considerable interest. However, if GSCs are indeed important for tumor control, knowledge of the metabolic state of GSCs is needed. We hypothesized that the metabolism of GSCs differs from that of their progeny. Using a unique imaging system for GSCs, we assessed the oxygen consumption rate, extracellular acidification rate, intracellular ATP levels, glucose uptake, lactate production, PKM1 and PKM2 expression, radiation sensitivity, and cell cycle duration of GSCs and their progeny in a panel of glioma cell lines. We found GSCs and progenitor cells to be less glycolytic than differentiated glioma cells. GSCs consumed less glucose and produced less lactate while maintaining higher ATP levels than their differentiated progeny. Compared with differentiated cells, GSCs were radioresistant, and this correlated with a higher mitochondrial reserve capacity. Glioma cells expressed both isoforms of pyruvate kinase, and inhibition of either glycolysis or oxidative phosphorylation had minimal effect on energy production in GSCs and progenitor cells. We conclude that GSCs rely mainly on oxidative phosphorylation. However, if challenged, they can use additional metabolic pathways. Therefore, targeting glycolysis in glioma may spare GSCs.


Asunto(s)
Metabolismo Energético , Glioma/metabolismo , Células Madre Neoplásicas/metabolismo , Células Madre/metabolismo , Adenosina Trifosfato/metabolismo , Western Blotting , Línea Celular Tumoral , Células Clonales/metabolismo , Desoxiglucosa/farmacología , Glioma/patología , Glucosa/metabolismo , Glucosa/farmacocinética , Glucólisis/efectos de los fármacos , Humanos , Inmunohistoquímica , Lactatos/metabolismo , Células Madre Neoplásicas/efectos de los fármacos , Oligomicinas/farmacología , Consumo de Oxígeno , Tomografía de Emisión de Positrones/métodos , Complejo de la Endopetidasa Proteasomal/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Células Madre/efectos de los fármacos , Análisis de Matrices Tisulares , Desacopladores/farmacología
11.
Front Biosci (Elite Ed) ; 3(4): 1326-36, 2011 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-21622139

RESUMEN

Natural products continue to represent the main source for therapeutics, and ethnopharmacological remedies from high biodiversity regions are a rich source for the development of novel drugs. Hence, in our attempt to find new anti-neoplastic activities we focused on ethno-medicinal plants of the Maya, who live in the world's third richest area in vascular plant species. Pluchea odorata (Asteraceae) is traditionally used for the treatment of various inflammatory disorders and recently, the in vitro anti-cancer activities of different extracts of this plant were described. Here, we present the results of bioassay-guided fractionations of the dichloromethane extract of P. odorata that aimed to enrich the active principles. The separation resulted in fractions which showed the dissociation of two distinct anti-neoplastic mechanisms; firstly, a genotoxic effect that was accompanied by tubulin polymerization, cell cycle arrest, and apoptosis (fraction F2/11), and secondly, an effect that interfered with the orchestrated expression of Cyclin D1, Cdc25A, and Cdc2 and that also led to cell cycle arrest and apoptosis (fraction F3/4). Thus, the elimination of generally toxic properties and beyond that the development of active principles of P. odorata, which disturb cancer cell cycle progression, are of interest for potential future therapeutic concepts against proliferative diseases.


Asunto(s)
Antineoplásicos Fitogénicos/aislamiento & purificación , Asteraceae/química , Extractos Vegetales/aislamiento & purificación , Western Blotting , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Humanos
12.
J Nat Prod ; 74(4): 712-7, 2011 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-21443171

RESUMEN

Three new compounds, ferruginenes A (1) and B (2) and a mixture of C-5'(R) and C-5'(S) ferruginene C (3) diastereomers, have been isolated from a cytotoxic chloroform-soluble fraction of the leaves of Rhododendron ferrugineum together with 12 known compounds. The structures of these new compounds were elucidated by analyses of NMR spectroscopic and mass spectrometric data. Compounds 1-3 were tested for their cytotoxicity against three human cancer cell lines, namely, HL-60, HeLa-S3, and MCF-7.


Asunto(s)
Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Compuestos de Bifenilo/aislamiento & purificación , Compuestos de Bifenilo/farmacología , Compuestos Heterocíclicos con 3 Anillos/aislamiento & purificación , Compuestos Heterocíclicos con 3 Anillos/farmacología , Antineoplásicos Fitogénicos/química , Austria , Compuestos de Bifenilo/química , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Células HeLa , Compuestos Heterocíclicos con 3 Anillos/química , Humanos , Estructura Molecular , Hojas de la Planta/química , Rhododendron/química , Estereoisomerismo
13.
Mutat Res ; 709-710: 60-6, 2011 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-21392513

RESUMEN

Ikarugamycin (IKA) is an antibiotic with strong antiprotozoal and cytotoxic activity. The purpose of our work was to provide insight into the mechanism of action characterizing the cytotoxic effect of IKA in HL-60 leukemia cells in order to evaluate its potential as an antineoplastic agent. Cell viability was reduced in response to IKA (IC(50) of 221.3nM), while the amount of HL-60 cells with a subdiploid DNA content increased significantly after 24h. Apoptotic cell death was confirmed by the cleavage of caspase-9, -8 and -3 using immunoblotting. Single cell gel electrophoresis pointed to an early genotoxic effect. Monitoring of intracellular calcium ([Ca(2+)](i)) levels by flow cytometric analysis of Fluo-3-AM fluorescence indicated an increase in cytosolic calcium that correlated with the cleavage of caspases. In addition, IKA triggered the activation of p38 MAP kinase which was partly dependent on elevated [Ca(2+)](i) concentrations and contributed to caspase activation. The data demonstrate that IKA induced apoptosis in HL-60 cells through genotoxicity and caspase activation which was in part correlated to an increase in intracellular calcium levels and activation of p38 MAP kinase.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Calcio/metabolismo , Daño del ADN/efectos de los fármacos , Lactamas/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/biosíntesis , Células HL-60 , Humanos
15.
Oncol Rep ; 23(4): 1145-51, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20204303

RESUMEN

The water extract of the lettuce Lactuca sativa, but not the ethyl acetate extract, inhibited the growth of HL-60 leukaemia cells and MCF-7 breast cancer cells. This correlated with the activation of checkpoint kinase 2 (Chk2), the induction of the tumour suppressor p21, and the severe downregulation of the proto-oncogene cyclin D1. The ethyl acetate extract, but not the water extract, induced HL-60 cell death, which correlated with the acetylation of alpha-tubulin. The acetylation of alpha-tubulin is indicative for microtubuli stabilisation such as induced by taxol. The calculated amount for human intake would require approximately 3 kg lettuce to reach the required concentration shown to inhibit 50% HL-60 proliferation.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Proteínas de Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Lactuca/química , Extractos Vegetales/farmacología , Acetilación , Western Blotting , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Quinasa de Punto de Control 2 , Ciclina D1/efectos de los fármacos , Ciclina D1/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Regulación hacia Abajo , Humanos , Proteínas Serina-Treonina Quinasas/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/metabolismo , Proto-Oncogenes Mas , Tubulina (Proteína)/efectos de los fármacos , Tubulina (Proteína)/metabolismo
16.
Int J Mol Med ; 24(4): 513-21, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19724892

RESUMEN

The Aracea Anthurium schlechtendalii and Syngonium podophyllum are traditional remedies for the treatment of severe and chronic inflammatory conditions. We cross-examined these plants regarding their anti-neoplastic properties, because several anti-inflammatory molecular targets are common for both pathologic conditions due to similar signalling pathways. Two malignant cell lines, HL-60 and MCF-7, were treated with increasing concentrations of plant extracts of increasing polarity. The potential of the extracts to inhibit the cell cycle and to induce cell death was investigated, because these are relevant endpoints to assess the anti-cancer potential in vitro and the protein expression and cell cycle distribution upon exposure to the strongest extract was analysed. Extracts from S. podophyllum were rather ineffective, but the freeze-dried (but not air-dried) roots of A. schlechtendalii exhibited strong growth inhibitory and apoptosis-inducing properties. In HL-60 cells 50% proliferation inhibition was achieved by 1.7 microg dichloromethane extract/ml medium and correlated with the activation of Chk2, down-regulation of Cdc25A, suppression of cyclin D1 level, and transient induction of p21. This extract efficiently triggered apoptosis, which was confirmed by caspase 3 activation. The polymerisation of alpha-tubulin and its subsequent degradation that depleted the cells from the G2/M contributed to apoptosis induction, because proper spindle-formation during mitosis is mandatory for survival. In conclusion, we demonstrated that A. schlechtendalii root extract specifically targeted carcinogenic mechanisms, because Cdc25A and cyclin D1 are oncogenes that are frequently overexpressed in a variety of cancer entities and further, this extract affected microtubule function reminiscent of taxol.


Asunto(s)
Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Apoptosis , Araceae/química , Extractos Vegetales/farmacología , Western Blotting , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Quinasa de Punto de Control 2 , Ciclina D1/metabolismo , Citometría de Flujo , Células HL-60 , Humanos , Extractos Vegetales/química , Proteínas Serina-Treonina Quinasas/metabolismo , Fosfatasas cdc25/metabolismo
17.
Int J Oncol ; 34(4): 1117-28, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19287970

RESUMEN

Many traditional healing plants successfully passed several hundred years of empirical testing against specific diseases and thereby demonstrating that they are well tolerated in humans. Although quite a few ethno-pharmacological plants are applied against a variety of conditions there are still numerous plants that have not been cross-tested in diseases apart from the traditional applications. Herein we demonstrate the anti-neoplastic potential of two healing plants used by the Maya of the Guatemala/Belize area against severe inflammatory conditions such as neuritis, rheumatism, arthritis, coughs, bruises and tumours. Phlebodium decumanum and Pluchea odorata were collected, dried and freeze dried, and extracted with five solvents of increasing polarity. We tested HL-60 and MCF-7 cells, the inhibition of proliferation and the induction of cell death were investigated as hallmark endpoints to measure the efficiency of anti-cancer drugs. Western blot and FACS analyses elucidated the underlying mechanisms. While extracts of P. decumanum showed only moderate anti-cancer activity and were therefore not further analysed, particularly the dichloromethane extract of P. odorata inhibited the cell cycle in G2-M which correlated with the activation of checkpoint kinase 2, and down-regulation of Cdc25A and cyclin D1 as well as inactivation of Erk1/2. In HL-60 and MCF-7 cells this extract was a very strong inducer of cell death activating caspase-3 followed by PARP signature type cleavage. The initiating death trigger was likely the stabilization of microtubules monitored by the rapid acetylation of alpha-tubulin, which was even more pronounced than that triggered by taxol. The dichloromethane extract of P. odorata contains apolar constituents which inhibit inflammatory responses and exhibit anti-cancer activity. The strong proapoptotic potential warrants further bioassay-guided fractionation to discover and test the active principle(s).


Asunto(s)
Antineoplásicos/farmacología , Extractos Vegetales/farmacología , Asteraceae , Bisbenzimidazol/farmacología , Línea Celular Tumoral , Separación Celular , Ensayos de Selección de Medicamentos Antitumorales , Selectina E/biosíntesis , Ensayo de Inmunoadsorción Enzimática , Etnofarmacología/métodos , Citometría de Flujo , Guatemala , Células HL-60 , Humanos , Técnicas In Vitro , Fracciones Subcelulares
18.
Oncol Rep ; 19(3): 801-10, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18288419

RESUMEN

The development of chemoresistant breast cancer is poorly understood and second treatment options are barely investigated. The term 'chemoresistance' is ill-defined and thus, our experimental analyses aimed to disentangle the resistance to cell cycle arrest from the resistance to trigger apoptosis, both of which are important mechanisms to be targeted by anticancer therapy. Therefore, an MCF-7 array, which encompassed clones harboring distinct genetically- and pharmacologically-induced stages of resistance, was established. For this, MCF-7 cells were stably transfected with erbB2 cDNA and a dominant negative p53 mutation and the two clones were subjected to long-term treatment with the clinical agents 2'-deoxy-5-fluorouridine (5-FdUrd) or arabinosylcytosine (AraC) to develop specific chemoresistance. This array was tested with 3,4',5-trihydroxy-trans-stilbene (resveratrol) and the methoxylated paired stilbene analogue 3,4',5-trimethoxy-trans-stilbene (M5) to investigate whether these agents can overcome genetically- and pharmacologically-induced chemoresistance and to correlate the structure-activity relationship of resveratrol and M5. In all conditions tested, M5 exhibited stronger anticancer activity than resveratrol, but the cell cycle inhibitory properties of the tested drugs were dependent on the genetic background and the chemoresistant phenotype. In contrast, the proapoptotic properties were rather similar in the distinct genetic backgrounds of the clone array and therefore, apoptotic triggers and cell cycle checkpoints were distinctly affected and are thus independent of each other. The study demonstrates the merits or virtues of the genotypically- and phenotypically-defined clones of the MCF-7 array as a testing tool for novel drugs, which discriminates the two types of chemoresistance mechanisms.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Apoptosis , Neoplasias de la Mama/tratamiento farmacológico , Ciclo Celular/efectos de los fármacos , Estilbenos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/uso terapéutico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Proliferación Celular/efectos de los fármacos , Células Clonales , Resistencia a Antineoplásicos , Femenino , Genes erbB-2 , Genes p53 , Humanos , Resveratrol , Estilbenos/química , Estilbenos/uso terapéutico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...