RESUMEN
In this report, a water-soluble polysaccharide was obtained from the dried stems of Dendrobium officinale Kimura et Migo by hot-water (70-75°C) extraction and 85% ethanol precipitation, and successively purification by DEAE-cellulose anion-exchange chromatography and gel-permeation chromatography. The D. officinale polysaccharide (DOP) has a molecular weight of 8500Da. Monosaccharide composition analysis reveals that DOP is composed of mannose, glucose, and arabinose with a trace of galacturonic acid in a molar ratio of 6.2:2.3:2.1:0.1. Periodate oxidation-smith degradation and 1D and 2D NMR spectroscopy analysis suggest the predominance of mannose and glucose, and it contains a 2-O-acetylglucomannan and (1â4)-linked-ß-d-mannopyranosyl and (1â4)-linked-ß-d-glucopyranosyl residues. Atomic force microscope shows that DOP mainly exists as rod-shaped chains, supporting high degrees of polymerization. The antioxidant activities of the polysaccharide in vitro assay indicate that DOP has good scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, higher scavenging activity of hydroxyl radical, and metal chelating activities.
Asunto(s)
Antioxidantes/química , Compuestos de Bifenilo/antagonistas & inhibidores , Dendrobium/química , Picratos/antagonistas & inhibidores , Polisacáridos/química , Antioxidantes/aislamiento & purificación , Arabinosa/química , Conformación de Carbohidratos , Cromatografía en Gel , Cromatografía por Intercambio Iónico , Glucosa/química , Glicósidos/química , Ácidos Hexurónicos/química , Manosa/química , Peso Molecular , Extractos Vegetales/química , Tallos de la Planta/química , Polisacáridos/aislamiento & purificación , Extracción en Fase SólidaRESUMEN
Multidrug resistance (MDR) is a key element in the failure of chemotherapies, and development of agents to overcome MDR is crucial to improving cancer treatments. The overexpression of glutathione-S-transferases (GSTs) is one of the major mechanisms of MDR. Because some agents used in traditional Chinese medicine have strong antitumor effects coupled with low toxicity; we investigated the ability of N,N-bis(2-chloroethyl)docos-13-enamide (compound J), the synthesized analog of a highly unsaturated fatty acid from Isatis tinctoria L., to reverse the MDR induced by adriamycin (ADM) in TCA8113/ADM cells. We found that compound J significantly increased the cytotoxicity of ADM in TCA8113/ADM cells, with a reversal fold of 2.461. Analysis of the mechanisms through which compound J reversed MDR indicated that compound J significantly decreased the activity of GSTs and enhanced the depletion of GSH in TCA8113/ADM cells, but did not affect the P-glycoprotein (P-gp) efflux. Taken together, our data suggested that compound J was an excellent candidate for reversing MDR in cancer therapy.
Asunto(s)
Antineoplásicos/farmacología , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Ácidos Erucicos/química , Ácidos Erucicos/farmacología , Ácidos Grasos/farmacología , Neoplasias de la Lengua/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Doxorrubicina/farmacología , Glutatión/metabolismo , Glutatión Transferasa/metabolismo , HumanosRESUMEN
OBJECTIVE: To study the best technology of the extraction of triterpenoids from the stems of Hyptis suaveolens with microwave. METHODS: Orthogonal experiment was carried out to investigate 4 influential factors as follows: the time (A), the temperature (B), the solid fluid compared to (C), the NaOH density (D). RESULTS: The optimal conditions for microwave extraction were A1 B2 C3 D2. CONCLUSION: The microwave extraction can extract more triterpenoids from the stems of Hyptis suaveolens in shorter time with less energy. It also shows a promising prospect for leaching the effective constituents from Chinese herbal medicine by using microwave extraction.