Search results for "RESISTANCE"
showing 10 items of 3641 documents
2015
Multidrug resistance is a prevailing phenomenon leading to chemotherapy treatment failure in cancer patients. In the current study two known cytotoxic pseudoguaianolide sesquiterpene lactones; neoambrosin (1) and damsin (2) that circumvent MDR were identified. The two cytotoxic compounds were isolated using column chromatography, characterized using 1D and 2D NMR, MS, and compared with literature values. The isolated compounds were investigated for their cytotoxic potential using resazurin assays and thereafter confirmed with immunoblotting and in silico studies. MDR cells overexpressing ABC transporters (P-glycoprotein, BCRP, ABCB5) did not confer cross-resistance toward (1) and (2), indic…
Inositols in the ovaries: activities and potential therapeutic applications.
2022
Introduction: Myo-inositol (MI) and D-chiro-inositol (DCI) play a key role in ovarian physiology, as they are second messengers of insulin and gonadotropins. Ex-vivo and in-vitro experiments demonstrate that both isomers are deeply involved in steroid biosynthesis, and that reduced MI-to-DCI ratios are associated with pathological imbalance of sex hormones. Areas covered: This expert opinion provides an overview of the physiological distribution of MI and DCI in the ovarian tissues, and a thorough insight of their involvement into ovarian steroidogenesis. Insulin resistance and compensatory hyperinsulinemia dramatically reduce the MI-to-DCI ratio in the ovaries, leading to gynecological dis…
P-glycoprotein and its inhibition in tumors by phytochemicals derived from Chinese herbs
2011
P-glycoprotein belongs to the family of ATP-binding cassette (ABC) transporters. It functions in cellular detoxification, pumping a wide range of xenobiotic compounds, including anticancer drugs out of the cell. In cancerous cells, P-glycoprotein confers resistance to a broad spectrum of anticancer agents, a phenomenon termed multidrug resistance. An attractive strategy for overcoming multidrug resistance is to block the transport function of P-glycoprotein and thus increase intracellular concentrations of anticancer drugs to lethal levels. Efforts to identify P-glycoprotein inhibitors have led to numerous candidates, none of which have passed clinical trials with cancer patients due to the…
Gold(I) compounds with lansoprazole-type ligands
2014
A number of gold(I) complexes containing the proton pump inhibitor (PPI) lansoprazole and its reduced precursor 2-((3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl)methylthio)-1H-benzo[d]imidazole have been synthesized and their biological effects have been evaluated in human cancer and nontumorigenic cells in vitro. The lansoprazole-based compounds appear to act through a V-H+-ATPase-mediated mechanism.
Cytotoxicity of some Cameroonian spices and selected medicinal plant extracts
2011
Abstract Ethnopharmacological relevance Several medicinal plants and spices are used traditionally to treat cancers in Cameroon. Aim Methanol extracts from thirty-four spices and plants, with related ethnobotanical use were investigated for their in vitro cytotoxicity on the human pancreatic cancer cell line MiaPaCa-2, leukemia CCRF-CEM cells and their multidrug resistant (MDR) subline CEM/ADR5000, and the normal human umbilical vein endothelial cells (HUVECs). In addition the anti-angiogenic properties of the most active extracts were investigated. Material and methods The MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay was used for cyto…
Mathematical models for the management of helminth parasites: from biological processes to the evolution of anthelmintic resistance
2010
International audience; Helminth parasitic diseases are mainly controlled by anthelmintic treatments, but control schemes are now threatened by the large development of anthelmintic resistance. Integrated parasite management needs to be developed but processes underpinning parasite population dynamics and resistant gene evolution are still lacking. Here, we review the mathematical models that have been developed to understand the evolution of anthelmintic resistance in host-helminth parasite models (intestinal helminth parasites of herbivores and human soil-transmitted helminths). A first part is dedicated to generic models that allowed the understanding of processes underlying host-helmint…
Chemical characterisation and cytotoxicity evaluation of Convolvulus pluricaulis Sieb. ex Spreng. (Convolvulaceae) extracts towards sensitive and mul…
2016
Thermische Denaturierung von Kaltblüter-Enzymproteinen
1960
The temperature, which leads to 50% reduction of catalytic activity by heat denaturation, has been determined for 8 different enzymes from cod muscle, as being in the range between 30 and 52°C. Therefore, there are no indications of a generally different heat resistance of enzymes from cold-blooded animals as compared with those from warm-blooded animals. The same conclusion is derived from calculations ofQ10-values, measured between +37 and − 37°C for cathepsin and glycylglycine dipeptidase.
Effects of chemically modified tetracyclines (CMTs) in sensitive, multidrug resistant and apoptosis resistant leukaemia cell lines
2001
Recently discovered chemically modified tetracyclines (CMTs) have shown in vitro and in vivo anti-proliferative and anti-tumour activities. Here, we evaluated in vitro the anti-proliferative and apoptotic activity of six different dedimethylamino chemically modified tetracyclines (CMT-1, CMT-3, CMT-5, CMT-6, CMT-7 and CMT-8) in sensitive and multidrug resistant myeloid leukaemia cells (HL60 and HL60R) in vitro. Three of these compounds (CMT-5, CMT-6, CMT-7) showed low cytotoxic activity both in sensitive and in resistant cells, CMT-3 was endowed with a high anti-proliferative activity only in sensitive cells and was moderately effective as apoptosis inducing agent, with an activity similar …