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1.
Psychol Psychother ; 94(1): 33-44, 2021 03.
Article in English | MEDLINE | ID: mdl-31833224

ABSTRACT

OBJECTIVES: Cognitive processing therapy (CPT) is a psychotherapy for post-traumatic stress disorder (PTSD) with a broad evidence base. Change in trauma-related cognitions is considered its primary working mechanism. When trying to integrate a traumatic event into existing cognitive schemas, the adaptive mechanism is changing the schema (accommodation). However, PTSD patients frequently either change their schemas too much (over-accommodation), or cognitively distort the event (assimilation). We aimed to test the hypothesized connections between the three types of cognition and symptom load. DESIGN: This study adds to the literature using 'impact statements', essays on their trauma-related thoughts written by patients at the beginning and end of CPT, to investigate cognitive change and its relationship to symptomatic outcome. METHODS: We analysed statements written by 31 adolescents and young adults who received developmentally adapted CPT (a longer treatment where CPT is the core component) in a randomized controlled trial. RESULTS: As expected, post-CPT statements contained more accommodated and fewer over-accommodated and assimilated clauses than pre-CPT statements. Correlations between cognition frequencies and concurrent symptom load were as expected for assimilation, and, in part, over-accommodation and accommodation. Decreased PTSD and depressive symptoms were correlated with increased accommodated thoughts. For over-accommodation and assimilation, however, expected correlations could not be shown. CONCLUSIONS: Our results support the notion that cognitive change is an important mechanism of change in CPT in a sample of younger, non-English-speaking clients.


Subject(s)
Cognitive Behavioral Therapy , Stress Disorders, Post-Traumatic , Adolescent , Cognition , Humans , Psychotherapy , Stress Disorders, Post-Traumatic/therapy , Treatment Outcome , Young Adult
2.
Cell Chem Biol ; 26(5): 699-710.e6, 2019 05 16.
Article in English | MEDLINE | ID: mdl-30880156

ABSTRACT

Our inability to effectively "drug" targets such as MYC for therapeutic purposes requires the development of new approaches. We report on the implementation of a phenotype-based assay for monitoring MYC expression in multiple myeloma cells. The open reading frame (ORF) encoding an unstable variant of GFP was engineered immediately downstream of the MYC ORF using CRISPR/Cas9, resulting in co-expression of both proteins from the endogenous MYC locus. Using fluorescence readout as a surrogate for MYC expression, we implemented a pilot screen in which ∼10,000 compounds were prosecuted. Among known MYC expression inhibitors, we identified cardiac glycosides and cytoskeletal disruptors to be quite potent. We demonstrate the power of CRISPR/Cas9 engineering in establishing phenotype-based assays to identify gene expression modulators.


Subject(s)
Proto-Oncogene Proteins c-myc/genetics , Small Molecule Libraries/pharmacology , Transcription, Genetic/drug effects , Bufanolides/pharmacology , CRISPR-Cas Systems/genetics , Cardiac Glycosides/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Cytoskeleton/drug effects , Cytoskeleton/metabolism , Eukaryotic Initiation Factor-2/genetics , Eukaryotic Initiation Factor-2/metabolism , Humans , Proto-Oncogene Proteins c-myc/antagonists & inhibitors , Proto-Oncogene Proteins c-myc/metabolism , RNA Interference , RNA, Small Interfering/metabolism
3.
Neurogastroenterol Motil ; 31(1): e13470, 2019 01.
Article in English | MEDLINE | ID: mdl-30238636

ABSTRACT

BACKGROUND: TRPA1 is an excitatory ion channel and is involved in sensory processes including thermal nociception and inflammatory pain. The allicin in garlic is a strong activator of the TRPA1 channel. AIM: To evaluate the effect of intragastric garlic powder containing allicin on perception, gastric tone, and mechanosensitivity. METHODS: An infusion-barostat balloon assembly was used for infusion of test solutions, for distension, and to measure proximal gastric compliance and tone. After an initial open label dose finding with 1 g, 2 g, 3.75 g, and 7.5 g commercially available garlic powder, a bolus of 2 g garlic powder (11 mg allicin)/60 mL H2 O was considered to induce moderate but constant sensation and was used hereafter in a placebo-controlled, single-dose, double-blind, randomized study in 7 volunteers to evaluate gastric sensation, tone, and mechanosensitivity. KEY RESULTS: Bolus injection of garlic caused immediate epigastric symptoms, mean aggregate symptom scores (AUC in 15 minutes) were 106 ± 49 vs. 35 ± 30 after placebo (P = 0.01). Garlic induced significant epigastric pressure, stinging, and warmth (P < 0.01 vs. placebo), while intensity of cramps, satiety, nausea, and pain was not significantly different to placebo (P > 0.05). Garlic induced an immediate, short lived fundic relaxation (balloon volume 627 ± 349 mL vs. -145 ± 120 mL; P < 0.02). No effect of allicin on proximal gastric mechanosensitivity and compliance was observed (NS). CONCLUSION AND INFERENCES: Garlic containing allicin induces immediate epigastric symptoms of pressure, stinging, and warmth and induces fundic relaxation but does not influence mechanosensitivity or compliance. TRPA1 is a receptor that is involved in gastric sensation and motility.


Subject(s)
Muscle, Smooth/drug effects , Stomach/drug effects , Sulfinic Acids/pharmacology , TRPA1 Cation Channel/agonists , TRPA1 Cation Channel/drug effects , Adolescent , Adult , Disulfides , Double-Blind Method , Female , Garlic , Healthy Volunteers , Humans , Male , Middle Aged , Powders , Young Adult
4.
ACS Omega ; 3(9): 10545-10553, 2018 Sep 30.
Article in English | MEDLINE | ID: mdl-30320246

ABSTRACT

Pomace, the press residue from different fruits accumulating as waste product in food industry, contains high amounts of secondary metabolites that could be utilized for health-related applications. This study aims at evaluating the potential of pomaces of apricot, bilberry, and elderberry to serve as a source for endothelial nitric oxide synthase (eNOS)-activating compounds. Five extracts obtained from the lyophilized pomace of apricot and elderberry with solvents of different polarity were found to enhance A23187-stimulated eNOS activity when tested at 50 µg/mL in an [14C]-l-arginine to [14C]-l-citrulline conversion assay in the human endothelium-derived cell line EA.hy926 (p < 0.05). The bioassay-guided fractionation of the extracts obtained with methanol/water (70:30) led to several active fractions from apricot pomace (p < 0.05) and elderberry pomace (p < 0.01). Liquid chromatography-mass spectrometry-based chemical analysis of the extracts and active fractions pointed mainly to triterpenoic acids as active compounds. One particular dihydroxytriterpenoic acid, characteristic for elderberry, was enriched as the main compound in the two most active fractions and might serve as a promising lead structure for further studies.

5.
Fitoterapia ; 131: 182-188, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30339926

ABSTRACT

Secondary metabolites from lichens are known for exhibiting various biological effects such as anti-inflammatory, antioxidant and antibacterial activities. Despite this wide range of reported biological effects, their impact on the formation of advanced glycation end products (AGEs) remains vastly unexplored. The latter are known contributors to lifestyle and age-related diseases such as Alzheimer and Parkinson. Moreover, the development of atherosclerosis and arterial stiffness is causally linked to the formation of AGEs. With this in mind, the present work evaluated the inhibitory effects of secondary lichen metabolites on the formation of pentosidine-like AGEs' by using an in vitro, Maillard reaction based, fluorescence assay. Overall, thirty-seven natural and five synthetically modified compounds were tested, eighteen of which exhibiting IC50 values in the range of 0.05 to 0.70 mM. This corresponds to 2 to 32 fold of the inhibitory activity of aminoguanidine. Targeting one major inhibiting mechanism of AGEs formation, all compounds were additionally evaluated on their radical scavenging capacities in an DPPH assay. Furthermore, as both AGEs' formation and hypertension are major risk factors for atherosclerosis, compounds that were available in sufficient amounts were also tested for their vasodilative effects. Overall, and though some of the active compounds were previously reported cytotoxic, present results highlight the interesting potential of secondary lichen metabolites as anti-AGEs and vasodilative agents.


Subject(s)
Biological Products/pharmacology , Glycation End Products, Advanced/antagonists & inhibitors , Lichens/chemistry , Vasodilator Agents/pharmacology , Animals , Biological Products/isolation & purification , Male , Molecular Structure , Rats, Inbred WKY , Secondary Metabolism , Vasodilator Agents/isolation & purification
8.
Planta Med ; 83(12-13): 994-1010, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28701021

ABSTRACT

Apple pomace is a waste product of the apple manufacturing industry that has been in the focus of life sciences as it represents a low-cost source of fruit-derived compounds. High fruit consumption is associated with beneficial health effects, and therefore, apple pomace and its constituents raise therapeutic interest. The present work reviews (i) the chemical constituents of apple pomace, (ii) optimized extraction methods of apple pomace compounds, and (iii) biological activities of apple pomace. Current evidence of apple pomace influence on digestion and metabolism, cholesterol and triglyceride homeostasis, diabetes, and sex hormones is summarized. Furthermore, studies regarding its antioxidative, anti-inflammatory, antiproliferative, antibacterial and antiviral effects are presented. The review concludes that apple pomace is an underutilized waste product of the apple industry with the potential of being processed for its nutritional and pharmaceutical value.


Subject(s)
Anti-Infective Agents/pharmacology , Anti-Inflammatory Agents/pharmacology , Antioxidants/pharmacology , Biological Products/chemistry , Fruit/chemistry , Malus/chemistry , Anti-Infective Agents/chemistry , Anti-Infective Agents/isolation & purification , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/isolation & purification , Antioxidants/chemistry , Antioxidants/isolation & purification , Biological Products/isolation & purification , Biological Products/pharmacology , Cholesterol/metabolism , Digestion/drug effects , Homeostasis/drug effects , Humans , Metabolism/drug effects , Triglycerides/metabolism
9.
Phytochemistry ; 141: 37-47, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28554035

ABSTRACT

The traditionally used Central American medicinal plant Pluchea odorata, known as an anti-inflammatory and cancer cell growth-inhibiting remedy, was subjected to bioassay-guided isolation. Structure elucidation by 1D- and 2D-NMR and MS techniques supported by ECD and UV spectroscopic data revealed seven structurally previously undescribed and eight known eudesmane-type sesquiterpenes. Furthermore, one previously undescribed and one known phytol-like alcohol were identified. All compounds were tested for their cytotoxicity in cancer cells and for their anti-invasive effects. Among the eudesmanes, 3α-(2',3'-epoxy-2'-methylbutyryloxy)-4α-hydroxy-11-hydroperoxy-eudesm-6-en-8-one exhibited the most potent cytotoxic activity with an IC50 value of 8.8 µM (after 48 h). Also in an in vitro model measuring the tumor-triggered breaching of the adjacent lymph endothelial cell barrier (3S*,4R*,5S*,10S*,2'R*,3'R*)-3-(2',3'-epoxy-2'-methylbutyryloxy)-4,7-dihydroxy-eudesm-11-en-8-one (IC75 = 47 µM) and (3S*,4R*,5R*,10S*,2'R*,3'R*)-3-(2',3'-epoxy-2'-methylbutyryloxy)-4-acetyloxy-6-methoxy-11-hydroxy-eudesm-6-en-8-one (IC75 = 73 µM) showed inhibitory activities. Furthermore, preliminary structure-activity relationships (SARs) of the eudesmanes were developed.


Subject(s)
Asteraceae/chemistry , Sesquiterpenes, Eudesmane/pharmacology , Cell Line, Tumor , Humans , Molecular Structure , Neoplasm Invasiveness , Sesquiterpenes, Eudesmane/isolation & purification , Structure-Activity Relationship
10.
Int J Oncol ; 50(5): 1879-1888, 2017 May.
Article in English | MEDLINE | ID: mdl-28393180

ABSTRACT

Lymph node metastasis of breast cancer is a clinical marker of poor prognosis. Yet, there exist no therapies targeting mechanisms of intravasation into lymphatics. Herein we report on an effect of the antidyslipidemic drug fenofibrate with vasoprotective activity, which attenuates breast cancer intravasation in vitro, and describe the potential mechanisms. To measure intravasation in a 3-dimensional co-culture model MDA-MB231 and MCF-7 breast cancer spheroids were placed on immortalised lymphendothelial cell (LEC) monolayers. This provokes the formation of circular chemorepellent induced defects (CCIDs) in the LEC barrier resembling entry ports for the intravasating tumour. Furthermore, the expression of adhesion molecules ICAM-1, CD31 and FAK was investigated in LECs by western blotting as well as cell-cell adhesion and NF-κB activity by respective assays. In MDA-MB231 cells the activity of CYP1A1 was measured by EROD assay. Fenofibrate inhibited CCID formation in the MDA-MB231/LEC- and MCF-7/LEC models and the activity of NF-κB, which in turn downregulated ICAM-1 in LECs and the adhesion of cancer cells to LECs. Furthermore, CD31 and the activity of FAK were inhibited. In MDA-MB231 cells, fenofibrate attenuated CYP1A1 activity. Combinations with other FDA-approved drugs, which reportedly inhibit different ion channels, attenuated CCID formation additively or synergistically. In summary, fenofibrate inhibited NF-κB and ICAM-1, and inactivated FAK, thereby attenuating tumour intravasation in vitro. A combination with other FDA-approved drugs further improved this effect. Our new concept may lead to a novel therapy for cancer patients.


Subject(s)
Breast Neoplasms/drug therapy , Coculture Techniques , Fenofibrate/administration & dosage , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cytochrome P-450 CYP1A1/genetics , Endothelial Cells/drug effects , Endothelial Cells/pathology , Female , Humans , Intercellular Adhesion Molecule-1/genetics , Lymphatic Metastasis , MCF-7 Cells , NF-kappa B/genetics , Platelet Endothelial Cell Adhesion Molecule-1/genetics , Signal Transduction/drug effects
11.
Wien Med Wochenschr ; 167(7-8): 145-146, 2017 May.
Article in English | MEDLINE | ID: mdl-28357520
12.
Monatsh Chem ; 147: 479-491, 2016.
Article in English | MEDLINE | ID: mdl-27069281

ABSTRACT

ABSTRACT: Inflammation is part of numerous pathological conditions, which are lacking satisfying treatment and effective concepts of prevention. A national research network project, DNTI, involving scientists from six Austrian universities as well as several external partners aimed to identify and characterize natural products capable of combating inflammatory processes specifically in the cardiovascular system. The combined use of computational techniques with traditional knowledge, high-tech chemical analysis and synthesis, and a broad range of in vitro, cell-based, and in vivo pharmacological models led to the identification of a series of promising anti-inflammatory drug lead candidates. Mechanistic studies contributed to a better understanding of their mechanism of action and delivered new knowledge on the molecular level of inflammatory processes. Herein, the used approaches and selected highlights of the results of this interdisciplinary project are presented.

13.
J Agric Food Chem ; 64(1): 185-94, 2016 Jan 13.
Article in English | MEDLINE | ID: mdl-26682617

ABSTRACT

Pomace is an easy-accessible raw material for the isolation of fruit-derived compounds. Fruit consumption is associated with health-promoting effects, such as the prevention of cardiovascular disease. Increased vascular nitric oxide (NO) bioavailability, for example, due to an enhanced endothelial nitric oxide synthase (eNOS) activity, could be one molecular mechanism mediating this effect. To identify compounds from apple (Malus domestica Borkh.) pomace that have the potential to amplify NO bioavailability via eNOS activation, a bioassay-guided fractionation of the methanol/water (70:30) extract has been performed using the (14)C-L-arginine to (14)C-L-citrulline conversion assay (ACCA) in the human endothelium-derived cell line EA.hy926. Phytochemical characterization of the active fractions was performed using the spectrophotometric assessment of the total phenolic content, as well as TLC, HPLC-DAD-ELSD, and HPLC-MS analyses. Eleven triterpenoic acids, of which one is a newly discovered compound, were identified as the main constituents in the most active fraction, accompanied by only minor contents of phenolic compounds. When tested individually, none of the tested compounds exhibited significant eNOS activation. Nevertheless, cell stimulation with the reconstituted compound mixture restored eNOS activation, validating the potential of apple pomace as a source of bioactive components.


Subject(s)
Endothelial Cells/enzymology , Malus/chemistry , Nitric Oxide Synthase Type III/metabolism , Phenols/pharmacology , Plant Extracts/pharmacology , Cell Line , Chromatography, High Pressure Liquid , Endothelial Cells/drug effects , Fruit/chemistry , Humans , Mass Spectrometry , Molecular Structure , Phenols/chemistry , Plant Extracts/chemistry
14.
Biotechnol Adv ; 33(8): 1582-1614, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26281720

ABSTRACT

Medicinal plants have historically proven their value as a source of molecules with therapeutic potential, and nowadays still represent an important pool for the identification of novel drug leads. In the past decades, pharmaceutical industry focused mainly on libraries of synthetic compounds as drug discovery source. They are comparably easy to produce and resupply, and demonstrate good compatibility with established high throughput screening (HTS) platforms. However, at the same time there has been a declining trend in the number of new drugs reaching the market, raising renewed scientific interest in drug discovery from natural sources, despite of its known challenges. In this survey, a brief outline of historical development is provided together with a comprehensive overview of used approaches and recent developments relevant to plant-derived natural product drug discovery. Associated challenges and major strengths of natural product-based drug discovery are critically discussed. A snapshot of the advanced plant-derived natural products that are currently in actively recruiting clinical trials is also presented. Importantly, the transition of a natural compound from a "screening hit" through a "drug lead" to a "marketed drug" is associated with increasingly challenging demands for compound amount, which often cannot be met by re-isolation from the respective plant sources. In this regard, existing alternatives for resupply are also discussed, including different biotechnology approaches and total organic synthesis. While the intrinsic complexity of natural product-based drug discovery necessitates highly integrated interdisciplinary approaches, the reviewed scientific developments, recent technological advances, and research trends clearly indicate that natural products will be among the most important sources of new drugs also in the future.


Subject(s)
Biological Products/therapeutic use , Drug Discovery , Plants, Medicinal/chemistry , Biological Products/chemistry , Drug Industry , Humans
15.
Phytomedicine ; 22(9): 862-74, 2015 Aug 15.
Article in English | MEDLINE | ID: mdl-26220634

ABSTRACT

BACKGROUND: The t(2;5)(p23;q35) chromosomal translocation results in the expression of the fusion protein NPM/ALK that when expressed in T-lymphocytes gives rise to anaplastic large cell lymphomas (ALCL). In search of new therapy options the dichloromethane extract of the ethnomedicinal plant Neurolaena lobata (L.) R.Br. ex Cass was shown to inhibit NPM/ALK expression. PURPOSE: Therefore, we analysed whether the active principles that were recently isolated and found to inhibit inflammatory responses specifically inhibit growth of NPM/ALK+ ALCL, leukaemia and breast cancer cells, but not of normal cells, and the intravasation through the lymphendothelial barrier. METHODS: ALCL, leukaemia and breast cancer cells, and normal peripheral blood mononuclear cells (PBMCs) were treated with isolated sesquiterpene lactones and analysed for cell cycle progression, proliferation, mitochondrial activity, apoptosis, protein and mRNA expression, NF-κB and cytochrome P450 activity, 12(S)-HETE production and lymphendothelial intravasation. RESULTS: In vitro treatment of ALCL by neurolenin B suppressed NPM/ALK, JunB and PDGF-Rß expression, inhibited the growth of ALCL cells late in M phase, and induced apoptosis via caspase 3 without compromising mitochondrial activity (as a measure of general exogenic toxicity). Moreover, neurolenin B attenuated tumour spheroid intravasation probably through inhibition of NF-κB and CYP1A1. CONCLUSION: Neurolenin B specifically decreased pro-carcinogenic NPM/ALK expression in ALK+ ALCL cells and, via the inhibition of NF-kB signalling, attenuated tumour intra/extravasation into the lymphatics. Hence, neurolenin B may open new options to treat ALCL and to manage early metastatic processes to which no other therapies exist.


Subject(s)
Asteraceae/chemistry , Lactones/pharmacology , Lymphoma, Large-Cell, Anaplastic/pathology , NF-kappa B/metabolism , Protein-Tyrosine Kinases/metabolism , Sesquiterpenes, Germacrane/pharmacology , Sesquiterpenes/pharmacology , Apoptosis , Cell Cycle , Cell Line, Tumor/drug effects , Cell Proliferation , Humans , Leukocytes, Mononuclear/drug effects , Molecular Structure , Plants, Medicinal/chemistry , Signal Transduction
17.
Mutat Res ; 777: 79-90, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25989051

ABSTRACT

Pluchea odorata is ethno pharmaceutically used to treat inflammation-associated disorders. The dichloromethane extract (DME) was tested in the carrageenan-induced rat paw oedema assay investigating its effect on inflammation that was inhibited by 37%. Also an in vitro anti-neoplastic potential was reported. However, rather limited information about the bio-activity of purified compounds and their cellular mechanisms are available. Therefore, two of the most abundant eudesmanes in P. odorata were isolated and their anti-neoplastic and anti-intravasative activities were studied. HL-60 cells were treated with P. odorata compounds and metabolic activity, cell number reduction, cell cycle progression and apoptosis induction were correlated with relevant protein expression. Tumour cell intravasation through lymph endothelial monolayers was measured and potential causal mechanisms were analyzed by Western blotting. Compound PO-1 decreased the metabolic activity of HL-60 cells (IC50 = 8.9 µM after 72 h) and 10 µM PO-1 induced apoptosis, while PO-2 showed just weak anti-neoplastic activities at concentrations beyond 100 µM. PO-1 arrested the cell cycle in G1 and this correlated with induction of JunB expression. Independent of this mechanism 25 µM PO-1 decreased MCF-7 spheroid intravasation through the lymph endothelial barrier. Hence, PO-1 inhibits an early step of metastasis, impairs unrestricted proliferation and induces apoptosis at low micromolar concentrations. These results warrant further testing in vivo to challenge the potential of PO-1 as novel lead compound.


Subject(s)
Apoptosis/drug effects , Asteraceae/chemistry , Cell Proliferation/drug effects , Plant Extracts/pharmacology , Sesquiterpenes, Eudesmane/pharmacology , Animals , Antineoplastic Agents, Phytogenic/pharmacology , Cell Cycle/drug effects , HL-60 Cells , Humans , Inhibitory Concentration 50 , Male , Rats , Rats, Sprague-Dawley , Saponins/pharmacology , Spirostans/pharmacology
18.
J Steroid Biochem Mol Biol ; 150: 97-111, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25797029

ABSTRACT

Cardiotonic steroids have long been in clinical use for treatment of heart failure and are now emerging as promising agents in various diseases, especially cancer. Their main target is Na(+)/K(+)-ATPase, a membrane protein involved in cellular ion homeostasis. Na(+)/K(+)-ATPase has been implicated in cancer biology by affecting several cellular events and signaling pathways in both sensitive and drug-resistant cancer cells. Hence, we investigated the cytotoxic activities of 66 cardiotonic steroids and cardiotonic steroid derivatives in sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells. Data were then subjected to quantitative structure-activity relationship analysis (QSAR) and molecular docking into Na(+)/K(+)-ATPase, which both indicated a possible differential expression of the pump in the mentioned cell lines. This finding was confirmed by western blotting, intracellular potassium labeling and next generation sequencing which showed that Na(+)/K(+)-ATPase was less expressed in multidrug-resistant than in sensitive cells.


Subject(s)
Antineoplastic Agents/pharmacology , Cardiac Glycosides/pharmacology , Leukocytes, Mononuclear/drug effects , Sodium-Potassium-Exchanging ATPase/genetics , Antineoplastic Agents/chemistry , Bufanolides/chemistry , Bufanolides/pharmacology , Cardiac Glycosides/chemistry , Cell Line, Tumor , Cell Survival/drug effects , Digoxin/chemistry , Digoxin/pharmacology , Doxorubicin/chemistry , Doxorubicin/pharmacology , Drug Resistance, Multiple , Drug Resistance, Neoplasm/genetics , Gene Expression , Humans , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/enzymology , Molecular Docking Simulation , Primary Cell Culture , Quantitative Structure-Activity Relationship , Signal Transduction , Sodium-Potassium-Exchanging ATPase/antagonists & inhibitors , Sodium-Potassium-Exchanging ATPase/chemistry , Sodium-Potassium-Exchanging ATPase/metabolism , Verapamil/chemistry , Verapamil/pharmacology
19.
Biochem Pharmacol ; 93(1): 11-24, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-25451686

ABSTRACT

P-glycoprotein (ABCB1, MDR1) is capable of extruding chemotherapeutics outside the cell and its overexpression in certain cancer cells may cause failure of chemotherapy. Many attempts were carried out to identify potent inhibitors of this transporter and numerous compounds were shown to exert inhibitory effects in vitro, but so far none were able to make their way to the clinic due to serious complications. Natural compounds represent a great source of therapeutics, which are believed to be safe and effective. Therefore, we have screened a large library of naturally occurring cardiotonic steroids and their derivatives using high throughput flow cytometry. We were able to identify six compounds capable of modulating P-glycoprotein activity. By using P-glycoprotein ATPase assays, molecular docking in silico studies and resazurin reduction assays, the outcome of this high throughput screening platform has been validated. These novel compounds may serve as candidates to reverse doxorubicin resistance in leukemia cells.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors , Cardiac Glycosides/pharmacology , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Cardiac Glycosides/chemistry , Cell Line , Cell Survival/drug effects , Cell Survival/physiology , Dose-Response Relationship, Drug , Doxorubicin/chemistry , Doxorubicin/pharmacology , Humans , Protein Structure, Secondary , Protein Structure, Tertiary
20.
Cancer Lett ; 356(2 Pt B): 994-1006, 2015 Jan 28.
Article in English | MEDLINE | ID: mdl-25444930

ABSTRACT

An apolar extract of the traditional medicinal plant Neurolaena lobata inhibited the expression of the NPM/ALK chimera, which is causal for the majority of anaplastic large cell lymphomas (ALCLs). Therefore, an active principle of the extract, the furanoheliangolide sesquiterpene lactone lobatin B, was isolated and tested regarding the inhibition of ALCL expansion and tumour cell intravasation through the lymphendothelium. ALCL cell lines, HL-60 cells and PBMCs were treated with plant compounds and the ALK inhibitor TAE-684 to measure mitochondrial activity, proliferation and cell cycle progression and to correlate the results with protein- and mRNA-expression of selected gene products. Several endpoints indicative for cell death were analysed after lobatin B treatment. Tumour cell intravasation through lymphendothelial monolayers was measured and potential causal mechanisms were investigated analysing NF-κB- and cytochrome P450 activity, and 12(S)-HETE production. Lobatin B inhibited the expression of NPM/ALK, JunB and PDGF-Rß, and attenuated proliferation of ALCL cells by arresting them in late M phase. Mitochondrial activity remained largely unaffected upon lobatin B treatment. Nevertheless, caspase 3 became activated in ALCL cells. Also HL-60 cell proliferation was attenuated whereas PBMCs of healthy donors were not affected by lobatin B. Additionally, tumour cell intravasation, which partly depends on NF-κB, was significantly suppressed by lobatin B most likely due to its NF-κB-inhibitory property. Lobatin B, which was isolated from a plant used in ethnomedicine, targets malignant cells by at least two properties: I) inhibition of NPM/ALK, thereby providing high specificity in combating this most prevalent fusion protein occurring in ALCL; II) inhibition of NF-κB, thereby not affecting normal cells with low constitutive NF-κB activity. This property also inhibits tumour cell intravasation into the lymphatic system and may provide an option to manage this early step of metastatic progression.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Asteraceae/chemistry , Endothelium, Lymphatic/drug effects , Lymphoma, Large-Cell, Anaplastic/drug therapy , Lymphoma, Large-Cell, Anaplastic/pathology , NF-kappa B/antagonists & inhibitors , Plant Extracts/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Sesquiterpenes/pharmacology , Apoptosis/drug effects , Blotting, Western , Caspases/genetics , Caspases/metabolism , Cell Cycle/drug effects , Cell Proliferation/drug effects , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Endothelium, Lymphatic/pathology , Humans , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/metabolism , Leukocytes, Mononuclear/pathology , Lymphoma, Large-Cell, Anaplastic/metabolism , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondria/pathology , NF-kappa B/genetics , NF-kappa B/metabolism , Neoplasm Invasiveness , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins c-jun/genetics , Proto-Oncogene Proteins c-jun/metabolism , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured
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