RESUMEN
BACKGROUND: DNA topoisomerase (Topo) inhibition plays key role in breast cancer treatment. Stephania hainanensis H. S. Lo et Y. Tsoong (S. hainanensis), a Li nationality plant that has abundant aporphine alkaloids, can inhibit Topo. PURPOSE: To identify a dual Topo inhibitor, a deep and systematic study of active aporphine alkaloids in S. hainanensis and their mechanisms of inhibiting breast cancer proliferation and Topo activity are essential. STUDY DESIGN: This study aimed to assess the anti-breast cancer and Topo inhibitory activities of oxocrebanine and explore the underlying mechanisms. METHODS: The growth inhibitory activities of 12 compounds in S. hainanensis were screened by MTT assay in MCF-7, SGC-7901, HepG-2 cells, and compared with the effects on human normal mammary epithelial MCF-10A cells as non cancer control cells. The Topo inhibitory activity was assessed by DNA relaxation and unwinding assays, kDNA decatenation assay and western blot. Cell cycle and autophagy analyses were carried out with flow cytometry and staining. Acridine orange staining and α-tubulin morphology were observed by fluorescence microscopy. Western blot was used to examine microtubule assembly dynamics and the expression levels of key proteins associated with DNA damage, autophagy and mitotic arrest. RESULTS: Oxocrebanine was the anti-breast cancer active alkaloid in S. hainanensis. It exhibited the best inhibitory effect on MCF-7 cells with an IC50 of 16.66 µmol/l, and had only weak effect on the proliferation of MCF-10A cells. Oxocrebanine inhibited Topo I and II α in a cell-free system and in MCF-7 cells. The DNA unwinding assay suggested that oxocrebanine intercalated with DNA as a catalytic inhibitor. Oxocrebanine regulated the levels of Topo I and IIα and DNA damage-related proteins. Oxocrebanine led to the mitotic arrest, and these effects occurred through both p53-dependent and p53-independent pathways. Oxocrebanine induced autophagy, abnormal α-tubulin morphology and stimulated enhanced microtubule dynamics. CONCLUSION: Oxocrebanine was the anti-breast cancer active aporphine alkaloid in S. hainanensis. Oxocrebanine was a Topo I/IIα dual inhibitor, catalytic inhibitor and DNA intercalator. Oxocrebanine caused DNA damage, autophagy, and mitotic arrest in MCF-7 cells. Oxocrebanine also disrupted tubulin polymerization. Accordingly, oxocrebanine held a great potential for development as a novel dual Topo inhibitor for effective breast cancer treatment.
Asunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Aporfinas/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Inhibidores de Topoisomerasa/uso terapéutico , Alcaloides/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Aporfinas/química , Aporfinas/farmacología , Neoplasias de la Mama/patología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Daño del ADN , ADN-Topoisomerasas de Tipo I/metabolismo , ADN-Topoisomerasas de Tipo II/metabolismo , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Células MCF-7 , Mitosis/efectos de los fármacos , Inhibidores de Topoisomerasa/química , Inhibidores de Topoisomerasa/farmacologíaRESUMEN
Bioassay-guided fractionation of an ethanolic extract of Ochrosia borbonica led to the isolation of two known pyridocarbazole alkaloids, ellipticine (1) and 9-methoxyellipticine (2), and six known monoterpenoid indole alkaloids (3-8). Lipid-lowering assay in 3T3-L1 cell model revealed that 1 and 2 could significantly inhibit the lipid droplet formation (EC50 = 0.41 and 0.92 µmol·L-1, respectively) and lower triglyceride levels by 50%-60% at the concentration of 1 µmol·L-1, being more potent than the positive drug luteolin (EC50 = 2.63 µmol·L-1). A mechanistic study indicated that 1 and 2 could intercalate into supercoiled DNA, which consequently inhibited the mitotic clonal expansion of 3T3-L1 cells at the early differentiation phase, leading to the retardance of following adipogenesis and lipogenesis. These findings suggest that 1 and 2 may serve as promising leads for further development of anti-obesity drugs.
Asunto(s)
Adipogénesis/efectos de los fármacos , Carbazoles/farmacología , Proliferación Celular/efectos de los fármacos , ADN Superhelicoidal/química , Hipolipemiantes/farmacología , Ochrosia/química , Células 3T3-L1 , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Adipocitos/patología , Animales , Carbazoles/química , Carbazoles/metabolismo , Daño del ADN , Elipticinas/química , Elipticinas/metabolismo , Elipticinas/farmacología , Hipolipemiantes/química , Hipolipemiantes/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , Ratones , Estructura Molecular , Extractos Vegetales/química , Inhibidores de Topoisomerasa/química , Inhibidores de Topoisomerasa/metabolismo , Inhibidores de Topoisomerasa/farmacologíaRESUMEN
A novel anthraquinone, 2-(dimethoxymethyl)-1-hydroxyanthracene-9,10-dione (1), together with nine known compounds (2-10), were isolated from the fermentation of Aspergillus versicolor derived from deep sea sediment. Their structures were established through spectroscopic methods. Compound 1 exhibited strong inhibitory activities against MRSA ATCC 43300 and MRSA CGMCC 1.12409 (with MIC values of 3.9 and 7.8 µg/mL respectively) and moderate activities against tested strains of Vibrio (with MIC values ranging from 15.6 to 62.5 µg/mL). Compound 1 was subjected to molecular docking studies for inhibition of topoisomerase IV and AmpC ß-lactamase enzymes indicating its usefulness as antimicrobial agent.
Asunto(s)
Antraquinonas/química , Antiinfecciosos/química , Antiinfecciosos/farmacología , Aspergillus/química , Organismos Acuáticos , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/metabolismo , Topoisomerasa de ADN IV/antagonistas & inhibidores , Evaluación Preclínica de Medicamentos , Fermentación , Sedimentos Geológicos/microbiología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Estructura Molecular , Inhibidores de Topoisomerasa/química , Inhibidores de Topoisomerasa/farmacología , Vibrio/efectos de los fármacos , beta-Lactamasas/metabolismoRESUMEN
Three new compounds, a sesquilignan (1) and two glucosylated phenylpropanoids (2, 3), and seven known compounds (4-10), were isolated from the fruits of Illicium verum HOOK. FIL. (Illiciaceae). The structures of 1-3 were determined based on one and two dimensional (1D- and 2D-) NMR data and electronic circular dichroism (ECD) spectra analyses. Compounds 3, 5, 6, and 8-10 exhibited potent inhibitory activities against topoisomerase II with IC50 values of 54.6, 25.5, 17.9, 12.1, 0.3 and 1.0 µM, respectively, compared to etoposide, the positive control, with an IC50 of 43.8 µM.
Asunto(s)
Alcanos/química , ADN-Topoisomerasas/metabolismo , Frutas/química , Illicium/química , Extractos Vegetales/farmacología , Alcanos/metabolismo , Alcanos/toxicidad , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Dicroismo Circular , ADN-Topoisomerasas/química , Frutas/metabolismo , Glucósidos/química , Glucósidos/metabolismo , Glucósidos/farmacología , Humanos , Illicium/metabolismo , Concentración 50 Inhibidora , Espectroscopía de Resonancia Magnética , Conformación Molecular , Fenilpropionatos/química , Fenilpropionatos/metabolismo , Fenilpropionatos/farmacología , Extractos Vegetales/química , Inhibidores de Topoisomerasa/química , Inhibidores de Topoisomerasa/metabolismo , Inhibidores de Topoisomerasa/farmacologíaRESUMEN
Natural products have been used for medical applications since ancient times. Commonly, natural products are structurally complex chemical compounds that efficiently interact with their biological targets, making them useful drug candidates in cancer therapy. Here, we used cell-based phenotypic profiling and image-based high-content screening to study the mode of action and potential cellular targets of plants historically used in Saudi Arabia's traditional medicine. We compared the cytological profiles of fractions taken from Juniperus phoenicea (Arar), Anastatica hierochuntica (Kaff Maryam), and Citrullus colocynthis (Hanzal) with a set of reference compounds with established modes of action. Cluster analyses of the cytological profiles of the tested compounds suggested that these plants contain possible topoisomerase inhibitors that could be effective in cancer treatment. Using histone H2AX phosphorylation as a marker for DNA damage, we discovered that some of the compounds induced double-strand DNA breaks. Furthermore, chemical analysis of the active fraction isolated from Juniperus phoenicea revealed possible anti-cancer compounds. Our results demonstrate the usefulness of cell-based phenotypic screening of natural products to reveal their biological activities.
Asunto(s)
Antineoplásicos/farmacología , Ensayos Analíticos de Alto Rendimiento/métodos , Preparaciones de Plantas/farmacología , Inhibidores de Topoisomerasa/farmacología , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Brassicaceae/química , Caspasa 9/metabolismo , Supervivencia Celular/efectos de los fármacos , Citrullus colocynthis/química , Roturas del ADN de Doble Cadena/efectos de los fármacos , Daño del ADN , Células HeLa , Histonas/metabolismo , Humanos , Juniperus/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas/métodos , Estructura Molecular , Fosforilación/efectos de los fármacos , Preparaciones de Plantas/química , Arabia Saudita , Inhibidores de Topoisomerasa/química , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
In the present study, 300 plant derived secondary metabolites (100 each of alkaloid, flavonoid, and terpenoid), have been screened for their anti-cancerous activity through inhibition of selected key enzymatic targets, namely cyclooxygenases (COXs), topoisomerases (Topos), and aromatase by molecular docking approach. Furthermore, the stability of the complexes of top hits, from each class of secondary metabolites, with their respective enzymatic targets was analyzed using molecular dynamics (MD) simulation analyses and binding free energy calculations. Analysis of the results of the docking in light of the pharmacokinetically screened 18 alkaloids, 26 flavonoids, and 9 terpenoids, revealed that the flavonoid, curcumin, was the most potent inhibitor for all the selected enzymatic targets. The stability of the complexes of COX-1, COX-2, Topo I, Topo IIß and aromatase with the most potent inhibitor curcumin and those of the respective drugs, namely ibuprofen, aspirin, topotecan, etoposide, and exemestane were also analyzed through MD simulation analyses which revealed better stability of curcumin complexes than those of respective drugs. Binding energy calculations of the complexes of the curcumin with all the targets, except those of Topos, exhibited lower binding energies for the curcumin complexes than those of respective drugs which corroborated with the results of molecular docking analyses. Thus, the present study affirms the versatile and multipronged nature of curcumin, the traditionally used herbal medicine, as anti-cancer molecule directed against these enzymatic targets.
Asunto(s)
Antineoplásicos Fitogénicos/química , Inhibidores de la Aromatasa/química , Inhibidores de la Ciclooxigenasa/química , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Extractos Vegetales/química , Plantas/química , Inhibidores de Topoisomerasa/química , Antineoplásicos Fitogénicos/farmacología , Aromatasa/química , Aromatasa/farmacología , Inhibidores de la Aromatasa/farmacología , Inhibidores de la Ciclooxigenasa/farmacología , Flavonoides/química , Flavonoides/farmacología , Extractos Vegetales/farmacología , Plantas/metabolismo , Unión Proteica , Inhibidores de Topoisomerasa/farmacologíaRESUMEN
Iron depletion and stimulation of iron-dependent free radical damage is a rapidly developing field for chelation therapy, but the iron mobilization from ferritin by chelators has received less attention. In this study, the di-2-pyridylketone 2-pyridine carboxylic acid hydrazone (DPPCAH) and its copper complex was prepared and characterized by NMR and MS spectra. The proliferation inhibition assay showed that both DPPCAH and its copper complex exhibited selectively proliferation inhibition for HepG2 (IC50, 4.6 ± 0.2 µM for DPPACH and 1.3 ± 0.2 µM for its copper complex), but less inhibition for HCT-116 cell line (IC50, >100 µM for DPPACH and 7.8 ± 0.4 µM for its copper complex). The mechanistic studies revealed that DPPACH could remove iron from ferritin in a oxygen-catalytic manner, and contributed to redox activity of labile iron pool (LIP), that is less reported for the chelators that possess significant biological activity. The reactive oxygen species (ROS) generation and DNA cleavage assay in vitro and in vivo showed that both DPPACH-Fe(II) and DPPACH-Cu were redox-active species, indicating that ROS may mediate their antitumor activity. Further study revealed that both DPPACH and its copper complex displayed certain degree of inhibition of type II topoisomerase (Top) which contributed to their antitumor activity. Thus, the mechanism that iron mobilization by DPPACH from ferritin contributed to LIP was proposed, and both DPPACH and its copper complex were involved in ROS generation and Top II inhibition for their antitumor activities.
Asunto(s)
Proliferación Celular/efectos de los fármacos , Hidrazonas/administración & dosificación , Neoplasias Hepáticas/tratamiento farmacológico , Especies Reactivas de Oxígeno/metabolismo , Catálisis , Cobre/química , ADN-Topoisomerasas/efectos de los fármacos , Células Hep G2 , Humanos , Hidrazonas/química , Hierro/química , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Oxígeno/química , Inhibidores de Topoisomerasa/administración & dosificación , Inhibidores de Topoisomerasa/químicaRESUMEN
Oxabicyclooctane linked 1,5-naphthyridinyl-pyridoxazinones are novel broad-spectrum bacterial topoisomerase inhibitors (NBTIs) targeting bacterial DNA gyrase and topoisomerase IV at a site different than quinolones. Due to lack of cross-resistance to known antibiotics they present excellent opportunity to combat drug-resistant bacteria. A structure activity relationship of the pyridoxazinone moiety is described in this Letter. Chemical synthesis and activities of NBTIs with substitutions at C-3, C-4 and C-7 of the pyridoxazinone moiety with halogens, alkyl groups and methoxy group has been described. In addition, substitutions of the linker NH proton and its transformation into amide analogs of AM-8085 and AM-8191 have been reported. Fluoro, chloro, and methyl groups at C-3 of the pyridoxazinone moiety retained the potency and spectrum. In addition, a C-3 fluoro analog showed 4-fold better oral efficacy (ED50 3.9 mg/kg) as compared to the parent AM-8085 in a murine bacteremia model of infection of Staphylococcus aureus. Even modest polarity (e.g., methoxy) is not tolerated at C-3 of the pyridoxazinone unit. The basicity and NH group of the linker is important for the activity when CH2 is at the linker position-8. However, amides (with linker position-8 ketone) with a position-7 NH or N-methyl group retained potency and spectrum suggesting that neither basicity nor hydrogen-donor properties of the linker amide NH is essential for the activity. This would suggest likely an altered binding mode of the linker position-7,8 amide containing compounds. The amides showed highly improved hERG (functional IC50 >30 µM) profile.
Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Ciclooctanos/química , Evaluación Preclínica de Medicamentos/métodos , Relación Estructura-Actividad , Inhibidores de Topoisomerasa/química , Administración Oral , Animales , Antibacterianos/administración & dosificación , Técnicas de Química Sintética , Topoisomerasa de ADN IV/antagonistas & inhibidores , Canal de Potasio ERG1 , Canales de Potasio Éter-A-Go-Go/metabolismo , Compuestos Heterocíclicos con 2 Anillos/química , Compuestos Heterocíclicos con 2 Anillos/farmacología , Ratones , Pruebas de Sensibilidad Microbiana , Naftiridinas/química , Naftiridinas/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/patogenicidad , Inhibidores de Topoisomerasa/farmacologíaRESUMEN
Complexes of yttrium(III) and dysprosium(III) with the traditional Chinese medicine active ingredient oxoglaucine (OG), namely [Y(OG)2(NO3)3]·CH3OH (1) and [Dy(OG)2(NO3)3]·H2O (2), were synthesized and characterized by elemental analysis, IR, ESI-MS, (1)H and (13)C NMR as well as single-crystal X-ray diffraction analysis. In vitro the complexes exhibited higher anticancer activity than the free ligand OG against the tested cancer cell lines. Among the tested cell lines, HepG2 is the most sensitive to the complexes. Complex 2 can trigger DNA damage in HepG2 cells, resulting in cell cycle arrest in the S phase and leading to cell apoptosis. The S phase cell-cycle arrest is caused via the ATM (ataxia-telangiectasia mutated)-Chk2-Cdc25A pathway. Chk2 is phosphorylated and activated in an ATM-dependent manner. It, in turn, phosphorylates Cdc25A phosphatise on serine124, causing the inactivation of Cdc25A in ubiquitin-mediated proteolytic degradation. The cyclin-Cdk complexes of the S phase could also be inhibited by limited supply of cyclins A and E. This irreversible cell cycle arrest process ultimately induces mitochondria-involved apoptotic cell death via the activation of Bcl-2 protein. Complex e2 ffectively inhibited tumour growth in the BEL-7402 xenograft mouse model and exhibited higher safety in vivo than cisplatin.
Asunto(s)
Antineoplásicos , Apomorfina/análogos & derivados , Complejos de Coordinación , Disprosio , Inhibidores de Topoisomerasa , Itrio , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Apomorfina/química , Apomorfina/farmacología , Apomorfina/uso terapéutico , Apoptosis/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Complejos de Coordinación/uso terapéutico , ADN/metabolismo , Daño del ADN , Disprosio/química , Disprosio/farmacología , Disprosio/uso terapéutico , Humanos , Medicina Tradicional China , Ratones , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Fase S/efectos de los fármacos , Solubilidad , Inhibidores de Topoisomerasa/química , Inhibidores de Topoisomerasa/farmacología , Inhibidores de Topoisomerasa/uso terapéutico , Carga Tumoral/efectos de los fármacos , Agua/química , Difracción de Rayos X , Itrio/química , Itrio/farmacología , Itrio/uso terapéuticoRESUMEN
Low molecular weight (LMW) polyphenolics containing a polyhydroxylated benzyl moiety are abundant in medicinal plants. In the present study, we report on the activities of seven LMW polyphenolics isolated from Inonotus obliquus, a medicinal mushroom. The isolated compounds included caffeic acid (CA), 3,4-dihydroxybenzalacetone (DBL), gallic acid, syringic acid, protocatechuic acid, 3,4-dihydroxybenzaldehyde and 2,5-dihydroxyterephthalic acid. We analyzed their inhibitory effects on DNA polymerase (pol) and DNA topoisomerase (topo), and their effects on human cancer cell growth. All isolated compounds inhibited human topo II activity; the most potent were DBL and CA, which contain a catechol propanoid moiety. CA and DBL inhibited the activity of human topo I, whereas other compounds had no effect. No compound modulated the activities of 11 mammalian pol species or other DNA metabolic enzymes, including T7 RNA polymerase, mouse IMP dehydrogenase (type II), T4 polynucleotide kinase and bovine deoxyribonuclease I. CA and DBL markedly suppressed the proliferation of human colon HCT116 carcinoma cells with an LD50 of 70.0 and 49.4 µM, respectively, and halted the cell cycle in the G2/M phase. The suppressive effect of these compounds on cancer cell growth correlated with their ability to inhibit topo II. These results suggest that CA- and DBL-dependent decreases in cell proliferation are due to the inhibition of cellular topo II. The mechanism of action of these catechol propanoid compounds and the implication for their use as anticancer agents are discussed.
Asunto(s)
Antineoplásicos/farmacología , Basidiomycota/química , Polifenoles/farmacología , Inhibidores de Topoisomerasa/farmacología , Animales , Antineoplásicos/química , Bovinos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Computadores Moleculares , ADN Polimerasa I/metabolismo , ADN Polimerasa beta/metabolismo , ADN-Topoisomerasas de Tipo I/metabolismo , Activación Enzimática/efectos de los fármacos , Células HCT116 , Humanos , Concentración 50 Inhibidora , Modelos Moleculares , Peso Molecular , Polifenoles/química , Ratas , Inhibidores de Topoisomerasa/químicaRESUMEN
Pyrimidine compounds were identified as inhibitors of DNA topoisomerase IV through high-throughput screening. This study was designed to exemplify the in vitro activity of the pyrimidines against Gram-positive and Gram-negative microorganisms, to reveal the mode of action of these compounds and to demonstrate their in vivo efficacy. Frequencies of resistance to pyrimidines among Staphylococcus aureus and Streptococcus pneumoniae were <10(-10) at four times their minimum inhibitory concentrations (MICs). These compounds exhibited a dual mode of action through inhibition of the ParE subunit of DNA topoisomerase IV as well as the GyrB subunit of DNA gyrase, a homologue of DNA topoisomerase IV. Pyrimidines were shown to have MIC(90) values (MIC that inhibited 90% of the strains tested) of ≤2 mg/L against Gram-positive pathogens, including meticillin-resistant S. aureus, quinolone- and meticillin-resistant S. aureus, vancomycin-resistant enterococci, penicillin-non-susceptible S. pneumoniae and Streptococcus pyogenes, and MIC(90) values of 2- to >16 mg/L and ≤0.5 mg/L against the Gram-negative pathogens Haemophilus influenzae and Moraxella catarrhalis, respectively. The pyrimidines were bactericidal and exhibited a ca. 1000-fold reduction of the bacterial counts at 300 mg/kg in a S. pneumoniae lung infection model. The microbiological properties and in vivo efficacy of pyrimidines underscore their potential as candidates for the treatment of soft-tissue infections and hospital-acquired pneumonia.
Asunto(s)
Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Topoisomerasa de ADN IV/antagonistas & inhibidores , Bacterias Gramnegativas/efectos de los fármacos , Cocos Grampositivos/efectos de los fármacos , Neumonía Neumocócica/tratamiento farmacológico , Inhibidores de Topoisomerasa/farmacología , Inhibidores de Topoisomerasa/uso terapéutico , Animales , Antibacterianos/química , Topoisomerasa de ADN IV/química , Modelos Animales de Enfermedad , Femenino , Humanos , Ratones , Pruebas de Sensibilidad Microbiana/normas , Modelos Moleculares , Neumonía Neumocócica/microbiología , Streptococcus pneumoniae/efectos de los fármacos , Inhibidores de Topoisomerasa II , Inhibidores de Topoisomerasa/química , Resultado del TratamientoRESUMEN
In this study, the inhibitory activities against DNA polymerases (pols) and DNA topoisomerases (topos) by eight major green tea catechin derivatives (flavan-3-ols) were investigated. Some catechins inhibited mammalian pols (α and ß) and human topos (I and II), with (-)-epigallocatechin gallate (EGCg) the strongest inhibitor of both enzyme types, showing IC(50) values of 3.8-21.5 and 2.0-20.0 µM, respectively. EGCg did not affect the activities of plant (cauliflower) pol α or prokaryotic pols and showed no effect on the activities of other DNA metabolic enzymes tested. Next, a method was established for assay of mouse one-cell zygote development inhibition, the catechin derivatives screened for bioactivity, and the inhibition was assessed and their effects ranked as: EGCg > GCg > Cg >> others. In the mouse one-cell zygote assay, EGCg at 50 µM increased abnormal cells and 75 µM of EGCg-induced apoptosis. The observed ranking of catechin derivative inhibition effects against mouse one-cell zygote development in vivo was similar to their ranking by topo inhibition in vitro rather than by pol inhibition; therefore, topo inhibition might have been effecting zygote development inhibition. These results suggested that catechin derivatives indeed reached the nuclear DNA where topo inhibition can occur, thus causing the observed cellular effects. From these findings, this zygote development inhibition assay will be useful as an anti-pregnant agent screening.
Asunto(s)
Catequina/análogos & derivados , Inhibidores de la Síntesis del Ácido Nucleico , Inhibidores de Topoisomerasa/farmacología , Cigoto/efectos de los fármacos , Animales , Apoptosis , Catequina/química , Catequina/farmacología , Bovinos , ADN/metabolismo , ADN Polimerasa Dirigida por ADN/metabolismo , Humanos , Ratones , Ratas , Té/química , Inhibidores de Topoisomerasa/química , Cigoto/citología , Cigoto/crecimiento & desarrolloRESUMEN
New N-alkylaminoacridine derivatives attached to nitrogen heterocycles were synthesized, and their antimalarial potency was examined. They were tested in vitro against the growth of Plasmodium falciparum, including chloroquine (CQ)-susceptible and CQ-resistant strains. This biological evaluation has shown that the presence of a heterocyclic ring significantly increases the activity against P. falciparum. The best compound shows a nanomolar IC(50) value toward parasite proliferation on both CQ-susceptible and CQ-resistant strains. The antimalarial activity of these new acridine derivatives can be explained by the two mechanisms studied in this work. First, we showed the capacity of these compounds to inhibit heme biocrystallization, a detoxification process specific to the parasite and essential for its survival. Second, in our search for alternative targets, we evaluated the in vitro inhibitory activity of these compounds toward Sulfolobus shibatae topoisomerase VI-mediated DNA relaxation. The preliminary results obtained reveal that all tested compounds are potent DNA intercalators, and significantly inhibit the activity of S.â shibatae topoisomerase VI at concentrations ranging between 2.0 and 2.5 µM.
Asunto(s)
Acridinas/química , Antimaláricos/síntesis química , Antimaláricos/farmacología , Aminacrina/química , Antimaláricos/química , Antimaláricos/farmacocinética , Línea Celular , Cloroquina/farmacología , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Farmacorresistencia Microbiana , Hemo/metabolismo , Hemoproteínas/antagonistas & inhibidores , Humanos , Concentración de Iones de Hidrógeno , Concentración 50 Inhibidora , Células KB/efectos de los fármacos , Estructura Molecular , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/crecimiento & desarrollo , Sulfolobus/enzimología , Inhibidores de Topoisomerasa/química , Inhibidores de Topoisomerasa/farmacologíaRESUMEN
Three new compounds of Ga(III), Au(III), Sn(IV) with matrine (MT), [H-MT][GaCl(4)] (1), [H-MT][AuCl(4)] (2) and [Sn(H-MT)Cl(5)] (3), have been synthesized and characterized by elemental analysis, IR, ESI-MS and single crystal X-ray diffraction methods. The crystal structural analyses indicate that 1 and 2 are ionic compounds, whereas 3 is a tin(IV) complex formed by the monodentate MT via its carbonyl oxygen atom of MT coordinating to Sn(IV). Their in vitro cytotoxicity towards eight selected tumour cell lines has been evaluated by MTT (3-[4,5-Dimentylthiazole-2-yl]-2,5-diphenpyltetra-zolium bromide) method, and compounds 1 and 2 exhibit enhanced activity, such as 1 to SW480, 2 to HeLa, HepG2 and MCF-7, which exceeds matrine and cisplatin, and display synergistic contribution of their components. The cell cycle analyses show that compounds 1, 3 and MT exhibit cell cycle arrest at the G(2)/M phase. Interactions of these compounds with calf thymus DNA (ct-DNA) have been investigated by spectroscopic analyses. The planar extension of the intercalative metal-matrine compounds increases the interaction of the metal-matrine with DNA, indicating that the cationic metal ions and configuration of the intercalated metal-matrine will affect the extent of interaction. Compound 2, [H-MT][AuCl(4)], exhibits more intensive binding ability to DNA, which may correlate with intercalation and other action mode. The circular dichroism spectra of the ct-DNA bound with metal-MT compounds also suggest that ct-DNA interacted with 1, 2, 3 does not influence its secondary structure. Furthermore, both compounds 1 and 2 exhibit effective inhibition ability to topoisomerase (TOPO I) at concentration of 50 µM, while matrine and compound 3 do not.