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1.
PLoS One ; 15(5): e0231948, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32369483

RESUMEN

In our search for bioactive mushrooms native to British Columbia, we determined that the ethanol extracts from fruiting bodies of the terrestrial polypore Albatrellus flettii had potent anti-cell viability activity. Using bioassay-guided fractionation, mass spectrometry and nuclear magnetic resonance, we successfully isolated three known compounds (grifolin, neogrifolin and confluentin). These compounds represent the major anti-cell viability components from the ethanol extracts of A. flettii. We also identified a novel biological activity for these compounds, specifically in down-regulating KRAS expression in two human colon cancer cell lines. Relatively little is known about the anti-cell viability activity and mechanism of action of confluentin. For the first time, we show the ability of confluentin to induce apoptosis and arrest the cell cycle at the G2/M phase in SW480 human colon cancer cells. The oncogenic insulin-like growth factor 2 mRNA-binding protein 1 (IMP1) has been previously shown to regulate KRAS mRNA expression in colon cancer cells, possibly through its ability to bind to the KRAS transcript. Using a fluorescence polarization assay, we show that confluentin dose-dependently inhibits the physical interaction between KRAS RNA and full-length IMP1. The inhibition also occurs with truncated IMP1 containing the KH1 to KH4 domain (KH1to4 IMP1), but not with the di-domain KH3 and KH4 (KH3&4 IMP1). In addition, unlike the control antibiotic neomycin, grifolin, neogrifolin and confluentin do not bind to KRAS RNA. These results suggest that confluentin inhibits IMP1-KRAS RNA interaction by binding to the KH1&2 di-domains of IMP1. Since the molecular interaction between IMP1 and its target RNAs is a pre-requisite for the oncogenic function of IMP1, confluentin should be further explored as a potential inhibitor of IMP1 in vivo.


Asunto(s)
Basidiomycota/química , Neoplasias del Colon/genética , Fenoles/farmacología , Proteínas Proto-Oncogénicas p21(ras)/genética , Resorcinoles/farmacología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/metabolismo , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HT29 , Humanos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Terpenos/farmacología
2.
Int J Med Mushrooms ; 21(7): 629-643, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31679298

RESUMEN

Wild mushrooms, while largely explored for their ecological significance, have not been systematically studied for their medicinal properties. This is the first report of biological activities of mushrooms from Haida Gwaii, British Columbia, Canada. The 17 mushroom species in this study were collected from multiple locations on Haida Gwaii and were screened for antiproliferative, immunostimulatory, and anti-inflammatory activities. Prior to screening, mushrooms were genetically identified and then sequentially fractionated into four crude extracts using 80% ethanol, 50% methanol, water, and 5% sodium hydroxide. We report here the strong antiproliferative and antiinflammatory activities of Amanita augusta, Phellodon atratus, Guepinia helvelloides, Chroogomphus tomentosus, Laetiporus conifericola, and Inocybe sp. In addition, A. augusta, G. helvelloides, and Inocybe sp. showed potent immunostimulatory activity. Two other species (Ganoderma tsugae and Pleurotus ostreatus) displayed strong immunostimulatory activity consistent with previous reports by others, suggesting that similar constituents are present in the same species from Haida Gwaii. For nine species (Russula paludosa, Hygrophoropsis aurantiaca, Tricholomopsis rutilans, Tyromyces chioneus, Hydnum repandum, Hypholoma fasciculare, Clavulina cinerea, P. ostreatus and Ramaria cystidiophora), we describe antiproliferative, immunostimulatory, and/or anti-inflammatory activities that have never been reported before. The new findings serve as a platform for future investigations into the potentially novel bioactive constituents of these mushrooms, as well as an incentive to further study a wider array of wild mushrooms for medicinal properties.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Agaricales/química , Antiinflamatorios/farmacología , Mezclas Complejas/farmacología , Animales , Colombia Británica , Proliferación Celular/efectos de los fármacos , Mezclas Complejas/aislamiento & purificación , Células HeLa , Humanos , Ratones , Células RAW 264.7
3.
Int J Med Mushrooms ; 19(6): 485-497, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29199559

RESUMEN

Wild mushrooms, especially from North America, have not been systematically explored for their medicinal properties. Here we report screening for the growth-inhibitory and immunomodulatory activities of 12 species collected from multiple locations in north-central British Columbia, Canada. Mushrooms were characterized using morphology and DNA sequencing, followed by chemical extraction into 4 fractions using 80% ethanol, 50% methanol, water, and 5% sodium hydroxide. Growth-inhibitory, immunostimulatory, and anti-inflammatory activities of 5 mushrooms (Leucocybe connata, Trichaptum abietinum, Hydnellum sp., Gyromitra esculenta, and Hericium coralloides) are reported here, to our knowledge for the first time. Growth-inhibitory effects were assessed using the cytotoxic MTT assay. Immunostimulatory activity was assessed by tumor necrosis factor-α production in Raw 264.7 macrophages, whereas anti-inflammatory activity was assessed based on the inhibition of lipopolysaccharide-induced tumor necrosis factor-α production. The ethanol and aqueous extracts of Hydnellum sp. were potent growth inhibitors, with a half-maximal inhibitory concentration of 0.6 mg/mL. All 5 fungi displayed strong immunostimulatory activity, whereas only L. connata and T. abietinum showed strong anti-inflammatory activity. For the 7 other fungi investigated, which included well-known medicinal species such as Inonotus obliquus, Phellinus igniarius, and Ganoderma applanatum, the remarkable similarities in the biological activities reported here, and by others for specimens collected elsewhere, suggest that mushrooms can produce similar metabolites regardless of their habitat or ecosystem. This is to our knowledge the first study to explore wild mushrooms from British Columbia for biological activities that are relevant to cancer, and the results provide an initial framework for the selection of mushroom species with the potential for discovery of novel anticancer compounds.


Asunto(s)
Antiinflamatorios/farmacología , Ascomicetos/química , Basidiomycota/química , Factores Inmunológicos/farmacología , Lipopolisacáridos/farmacología , Animales , Ascomicetos/clasificación , Ascomicetos/genética , Basidiomycota/clasificación , Basidiomycota/genética , Colombia Británica , Supervivencia Celular/efectos de los fármacos , Células HeLa , Humanos , Inmunomodulación/efectos de los fármacos , Ratones , Células RAW 264.7
4.
Carbohydr Res ; 343(2): 179-88, 2008 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-18022609

RESUMEN

A tetrasaccharide corresponding to a sequence of the rhamnogalacturonan I backbone has been synthesized. This synthesis relies on only two protected monosaccharides and proceeds through a common disaccharide intermediate. Synthesis of this tetrasaccharide has been designed to allow for the addition of branching elements at the 4-positions of the rhamnosyl units, or further chain elongation at the 2-position.


Asunto(s)
Oligosacáridos/síntesis química , Pectinas/química , Secuencia de Carbohidratos , Disacáridos/química
5.
Carbohydr Res ; 339(15): 2507-13, 2004 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-15476711

RESUMEN

A disaccharide portion of the A-side chain of the rhamnogalacturonan II oligosaccharide has been prepared. Glycosylation of methyl (methyl 3,4-O-isopropylidene-alpha-D-galactopyranosid)uronate with p-tolyl 2,3-di-O-acetyl-3-C-(benzyloxymethyl)-1-thio-alpha/beta-D-erythrofuranoside was carried out using N-iodosuccinimide as promoter and silver trifluoromethanesulfonate as catalyst. Removal of the protecting groups gave the beta-d-Apif-(1-->2)-alpha-D-GalpA-OMe disaccharide.


Asunto(s)
Disacáridos/síntesis química , Pectinas/química , Conformación de Carbohidratos , Secuencia de Carbohidratos , Pared Celular/química , Glicosilación , Plantas/química
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