Search results for " Phytogenic"
showing 10 items of 225 documents
SYNTHESIS, CHARACTERIZATION AND IN VITRO CYTOTOXICITY STUDIES OF A MACROMOLECULAR CONJUGATE OF PACLITAXEL BEARING OXYTOCIN AS TARGETING MOIETY.
2007
The present study describes the experimental synthetic procedure and the characterization of a new polyaspartamide macromolecular prodrug of paclitaxel, bearing oxytocin residues as targeting moieties. In vitro stability studies of bioconjugate, performed in media mimicking biological fluids (buffer solutions at pH 7.4 and 5.5) and in human plasma, evidenced the high stability of the targeting portion (oxytocin)-polymer linkage and the ability of this conjugate to release linked paclitaxel in a prolonged way in plasma. Moreover, preliminary in vitro antiproliferative studies, carried out on MCF-7 cells, that are oxytocin receptor positive cells, showed that the polymeric conjugate has the s…
Stability of irinotecan-loaded drug eluting beads (DC BeadTM) used for transarterial chemoembolization
2009
Purpose. The aim of this study was to determine the loading efficiency, physicochemical stability, and release of irinotecan-loaded DC BeadsTM (bead size 100—300 μm, 300—500 μm) before and after mixing with nonionic contrast medium (Accupaque® 300, Imeron® 300, Ultravist ® 300) during a prolonged period of time (28 days) when stored at room temperature or refrigerated. Methods. DC Beads TM were loaded with 50 mg irinotecan (Campto®) per milliliter beads in a 2 h loading period. Drug loading efficiency and stability were determined by measuring the irinotecan concentration in the excess solution. A free-flowing in vitro elution method for a period of 2 h and phosphate buffered solution (PBS…
Paclitaxel and beta-lapachone synergistically induce apoptosis in human retinoblastoma Y79 cells by downregulating the levels of phospho-Akt.
2009
Paclitaxel (PTX) and beta-lapachone (LPC) are naturally occurring compounds that have shown a large spectrum of anticancer activity. In this article we show for the first time that PTX/LPC combination induces potent synergistic apoptotic effects in human retinoblastoma Y79 cells. Combination of suboptimal doses of PTX (0.3 nM) and LPC (1.5 microM) caused biochemical and morphological signs of apoptosis at 48 h of treatment. These effects were accompanied by potent lowering in inhibitor of apoptosis proteins and by activation of Bid and caspases 3 and 6 with lamin B and PARP breakdown. PTX/LPC combination acted by favoring p53 stabilization through a lowering in p-Akt levels and in ps166-MDM…
Acrylamide catalytically inhibits topoisomerase II in V79 cells.
2010
The vinyl monomer acrylamide is characterized by the presence of an alpha,beta-unsaturated carbonyl group that makes it reactive towards thiol, hydroxyl or amino groups and towards the nucleophilic centers in DNA. The ability of acrylamide to chemically modify protein thiols has prompted us to consider topoisomerase II as one possible target of acrylamide, since agents targeting protein sulfhydryl groups act as either catalytic inhibitors or poisons of topoisomerase II. Nuclear extracts from V79 Chinese hamster cells incubated with acrylamide reduced topoisomerase II activity as inferred by an inability to convert kinetoplast DNA to the decatenated form. Nuclear extracts incubated with acry…
Cytotoxic activity of secondary metabolites derived from Artemisia annua L. towards cancer cells in comparison to its designated active constituent a…
2010
Artemisia annua L. (sweet wormwood, qinhao) has traditionally been used in Chinese medicine. The isolation of artemisinin from Artemisia annua and its worldwide accepted application in malaria therapy is one of the showcase success stories of phytomedicine during the past decades. Artemisinin-type compounds are also active towards other protozoal or viral diseases as well as cancer cells in vitro and in vivo. Nowadays, Artemisia annua tea is used as a self-reliant treatment in developing countries. The unsupervised use of Artemisia annua tea has been criticized to foster the development of artemisinin resistance in malaria and cancer due to insufficient artemisinin amounts in the plant as c…
Antileukemic ancistrobenomine B and related 5,1′-coupled naphthylisoquinoline alkaloids from the Chinese liana Ancistrocladus tectorius
2017
A striking feature of the metabolite pattern of the Southeast Asian liana Ancistrocladus tectorius (Ancistrocladaceae) is the predominance of 5,1′-coupled naphthylisoquinoline alkaloids. About 20 alkaloids of this coupling type have so far been discovered in this plant species. Here, we report on the isolation of four new 5,1′-linked naphthylisoquinolines from the twigs and stems of A. tectorius. Two of them, the ancistrobenomines B (5) and C (6), belong to the very rare group of alkaloids with a fully dehydrogenated isoquinoline portion. Likewise unusual for naphthylisoquinoline alkaloids is the presence of a hydroxymethylene group at C-3. Within the large class of meanwhile ca. 180 such n…
Antiproliferative activity against leukemia cells of sesquiterpene lactones from the Turkish endemic plant Centaurea drabifolia subsp. detonsa
2017
The apolar organic extract obtained from aerial parts of Centaurea drabifolia Sibth. & Sm. subsp. detonsa (Bornm.) Wagenitz, growing wild in Turkey, was investigated for the first time for its secondary metabolite composition. Seven sesquiterpene lactones belonging to the guaiane class (1-7), including the new compound 4, along with a fatty acid lactone derivative (8), were isolated. The structures of these compounds were established by spectroscopic analysis, including 2D NMR spectroscopic techniques, with the stereostructure of the new guaiane 4 determined with the help of MTPA derivatization. Cytotoxic activities of compounds 1-7 were evaluated against two cancer cell lines, namely acute…
Synthesis of Combretastatin A-4 and 3′-Aminocombretastatin A-4 derivatives with Aminoacid Containing Pendants and Study of their Interaction with Tub…
2020
Natural product combretastatin A-4 (CA-4) and its nitrogenated analogue 3&prime
Cytotoxic glycosides from the roots of Weigela x “Bristol Ruby”
2019
International audience; Seven oleanane-type glycosides were extracted and isolated by various chromatographic methods from the roots of Weigela x "Bristol Ruby" (1-7), six previously undescribed (1-6) and a known one (7). Their structures were assigned by spectroscopic analysis mainly 2D NMR and mass spectrometry (ESIMS). Selected triterpenoid glycosides (1-3, 6, 7) displayed a good cytotoxic activity against a mouse colon cancer cell line CT26.
Cytotoxicity and modes of action of three naturally occurring xanthones (8-hydroxycudraxanthone G, morusignin I and cudraxanthone I) against sensitiv…
2014
Abstract Background Resistance of cancer to chemotherapy remains a challenging issue for scientists as well as physicians. Naturally occurring xanthones possess a variety of biological activities such as anti-inflammatory, anti-bacterial, and anti-cancer effects. The present study was aimed at investigating the cytotoxicity and the modes of action of three naturally occurring xanthones namely, morusignin I (1), 8-hydroxycudraxanthone G (2) and cudraxanthone I (3) against a panel of nine cancer cell lines, including various sensitive and drug-resistant phenotypes. Methods The cytotoxicity of the compounds was determined using a resazurin reduction assay, whereas the caspase-Glo assay was use…