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1.
Sci Rep ; 11(1): 12043, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34103615

RESUMO

Alzheimer's disease (AD) is the most common type of dementia characterized by the abnormal accumulation of amyloid-ß (Aß) in the brain. Aß misfolding is associated with neuroinflammation and synaptic dysfunction, leading to learning and memory deficits. Therefore, Aß production and aggregation have been one of the most popular drug targets for AD. Failures of drug candidates regulating the aforementioned Aß cascade stimulated development of immunotherapy agents for clearance of accumulated Aß in the brain. Here, we report that quinacrine, a blood-brain barrier penetrating antimalarial chemical drug, dissociates Aß plaques in the brain of AD transgenic mice. When co-incubated with pre-formed Aß fibrils, quinacrine decreased thioflavin T-positive ß-sheets in vitro, on top of its inhibitory function on the fibril formation. We confirmed that quinacrine induced dissociation of high-molecular-weight Aß aggregates into low-molecular-weight species by dot blots in association with size cut-off filtrations. Quinacrine was then administered to adult 5XFAD transgenic mice via weekly intravenous injections for 6 weeks, and we found a significant reduction of Aß plaques and astrocytosis in their cortex and hippocampus. In western blots of quinacrine-administered mouse brains, amelioration of AD-related biomarkers, glial fibrillary acidic protein, postsynaptic protein 95, phosphorylated cAMP response element-binding protein, phosphorylated c-Jun N-terminal kinase were observed. Lastly, quinacrine-stimulated dissociation of misfolded aggregates induced recovery of synaptic function associated with Aß in excitatory post-synaptic current recordings of primary rat cortical neurons treated with Aß aggregates and quinacrine. Collectively, quinacrine can directly dissociate Aß fibrils and alleviate decreased synaptic functions.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Fragmentos de Peptídeos/metabolismo , Placa Amiloide/metabolismo , Quinacrina , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/genética , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Transgênicos , Fragmentos de Peptídeos/genética , Placa Amiloide/tratamento farmacológico , Placa Amiloide/genética , Placa Amiloide/patologia , Quinacrina/farmacocinética , Quinacrina/farmacologia
2.
Semin Thromb Hemost ; 42(3): 282-91, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26871254

RESUMO

Dense granule disorder is one of the most common platelet abnormalities, resulting from dense granule deficiency or secretion defect. This study was aimed to evaluate the clinical usefulness of the flow cytometric combination of mepacrine uptake/release assay and CD63 expression detection in the management of patients with suspected dense granule disorder. Over a period of 5 years, patients with abnormal platelet aggregation and/or reduced adenosine triphosphate (ATP) secretion suggestive of dense granule disorder were consecutively enrolled. The flow cytometric assays were systematically performed to further investigate dense granule functionality. Among the 26 included patients, 18 cases showed impaired mepacrine uptake/release and reduced CD63 expression on activated platelets, consistent with δ-storage pool deficiency (SPD). Another seven patients showed decrease in mepacrine release and CD63 expression but mepacrine uptake was normal, indicating secretion defect rather than δ-SPD. Unfortunately, ATP secretion could not be measured in 7 out of the 26 patients due to insufficient sample and/or severe thrombocytopenia. This test combination provides a rapid and effective method to detect the heterogeneous abnormalities of platelet dense granule by distinguishing between storage and release defects. This combination is particularly advantageous for severely thrombocytopenic patients and pediatric patients in which only minimal sample is required.


Assuntos
Plaquetas/metabolismo , Citometria de Fluxo/métodos , Deficiência do Pool Plaquetário/diagnóstico , Quinacrina/metabolismo , Tetraspanina 30/metabolismo , Trifosfato de Adenosina/metabolismo , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária , Agregação Plaquetária , Contagem de Plaquetas , Testes de Função Plaquetária/métodos , Deficiência do Pool Plaquetário/metabolismo , Quinacrina/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
3.
Oncotarget ; 5(15): 6497-511, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25153726

RESUMO

Most anticancer drugs are not able to cross the blood-brain barrier (BBB) effectively while surgery and radiation therapy cannot eradicate brain glioma cells and glioma stem cells (GSCs), hence resulting in poor prognosis with high recurrence rates. In the present study, a kind of multifunctional targeting daunorubicin plus quinacrine liposomes was developed for treating brain glioma and GSCs. Evaluations were performed on in-vitro BBB model, murine glioma cells, GSCs, and GSCs bearing mice. Results showed that the multifunctional targeting daunorubicin plus quinacrine liposomes exhibited evident capabilities in crossing the BBB, in killing glioma cells and GSCs and in diminishing brain glioma in mice. Action mechanism studies indicated that the enhanced efficacy of the multifunctional targeting drugs-loaded liposomes could be due to the following aspects: evading the rapid elimination from blood circulation; crossing the BBB effectively; improving drug uptake by glioma cells and GSCs; down-regulating the overexpressed ABC transporters; inducing apoptosis of GSCs via up-regulating apoptotic receptor/ligand (Fas/Fasl), activating apoptotic enzymes (caspases 8, 9 and 3), activating pro-apoptotic proteins (Bax and Bok), activating tumor suppressor protein (P53) and suppressing anti-apoptotic proteins (Bcl-2 and Mcl-1). In conclusion, the multifunctional targeting daunorubicin plus quinacrine liposomes could be used as a potential therapy for treating brain glioma and GSCs.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Lipossomos/administração & dosagem , Células-Tronco Neoplásicas/efeitos dos fármacos , Aglutininas do Germe de Trigo/administração & dosagem , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/química , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Apoptose/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Daunorrubicina/administração & dosagem , Daunorrubicina/química , Daunorrubicina/farmacocinética , Glioma/metabolismo , Glioma/patologia , Lipossomos/química , Lipossomos/farmacocinética , Camundongos , Quinacrina/administração & dosagem , Quinacrina/química , Quinacrina/farmacocinética , Tamoxifeno/administração & dosagem , Tamoxifeno/química , Tamoxifeno/farmacocinética , Aglutininas do Germe de Trigo/química , Aglutininas do Germe de Trigo/farmacocinética
4.
PLoS One ; 7(7): e39112, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22768295

RESUMO

The lipophilic cationic compound quinacrine has been used as an antimalarial drug for over 75 years but its pharmacokinetic profile is limited. Here, we report on the pharmacokinetic properties of quinacrine in mice. Following an oral dose of 40 mg/kg/day for 30 days, quinacrine concentration in the brain of wild-type mice was maintained at a concentration of ∼1 µM. As a substrate of the P-glycoprotein (P-gp) efflux transporter, quinacrine is actively exported from the brain, preventing its accumulation to levels that may show efficacy in some disease models. In the brains of P-gp-deficient Mdr1(0/0) mice, we found quinacrine reached concentrations of ∼80 µM without any signs of acute toxicity. Additionally, we examined the distribution and metabolism of quinacrine in the wild-type and Mdr1(0/0) brains. In wild-type mice, the co-administration of cyclosporin A, a known P-gp inhibitor, resulted in a 6-fold increase in the accumulation of quinacrine in the brain. Our findings argue that the inhibition of the P-gp efflux transporter should improve the poor pharmacokinetic properties of quinacrine in the CNS.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacocinética , Encéfalo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Quinacrina/farmacocinética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Ciclosporina/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Masculino , Camundongos , Camundongos Mutantes , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética
5.
Biomaterials ; 33(2): 565-82, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21983136

RESUMO

Breast cancer stem cells play a crucial role in the relapse of breast cancers because they are resistant to a standard chemotherapy and the residual cancer stem cells are able to proliferate indefinitely. The objectives of present study were to construct a kind of mitochondrial targeting daunorubicin plus quinacrine liposomes for treating and for preventing the recurrence of breast cancer arising from the cancer stem cells. MCF-7 cancer stem cells were identified as CD44(+)/CD24(-) cells and cultured in free-serum medium. Evaluations were performed on MCF-7 cancer stem cells, MCF-7 cancer stem cell mammospheres, and the relapsed tumor by xenografting MCF-7 cancer stem cells into female NOD/SCID mice. The particle size of mitochondrial targeting daunorubicin plus quinacrine liposomes was approximately 98 nm. The mitochondrial targeting liposomes evidently increased the mitochondrial uptake of drugs, were selectively accumulated into mitochondria, activated the pro-apoptotic Bax protein, dissipated the mitochondrial membrane potential, opened the mitochondrial permeability transition pores, released cytochrome C by translocation, and initiated a cascade of caspase 9 and 3 reactions, thereby inducing apoptosis of MCF-7 cancer stem cells. The mitochondrial targeting liposomes showed the strongest efficacy in treating MCF-7 cancer cells in vitro, in treating MCF-7 cancer stem cells in vitro, and in treating the relapsed tumor in mice. Mitochondrial targeting daunorubicin plus quinacrine liposomes would provide a new strategy for treating and preventing the relapse of breast cancers arising from cancer stem cells.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Daunorrubicina/farmacocinética , Lipossomos/química , Células-Tronco Neoplásicas/efeitos dos fármacos , Quinacrina/farmacocinética , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Citocromos c/metabolismo , Feminino , Humanos , Potencial da Membrana Mitocondrial , Camundongos , Camundongos SCID , Mitocôndrias/metabolismo , Recidiva Local de Neoplasia/prevenção & controle , Células-Tronco Neoplásicas/metabolismo , Proteína X Associada a bcl-2/metabolismo
6.
Cancer Biol Ther ; 12(3): 229-38, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21725212

RESUMO

Quinacrine has been widely explored in treatment of malaria, giardiasis, and rheumatic diseases. We find that quinacrine stabilizes p53 and induces p53-dependent and independent cell death. Treatment by quinacrine alone at concentrations of 10-20 mM for 1-2 d cannot kill hepatocellular carcinoma cells, such as HepG2, Hep3B, Huh7, which are also resistant to TRAIL. However, quinacrine renders these cells sensitive to treatment by TRAIL. Co-treatment of these cells with quinacrine and TRAIL induces overwhelming cell death within 3-4 h. Levels of DR5, a pro-apoptotic death receptor of TRAIL, are increased upon treatment with quinacrine, while levels of Mcl-1, an anti-apoptotic member of the Bcl-2 family, are decreased. While the synergistic effect of quinacrine with TRAIL appears to be in part independent of p53, knockdown of p53 in HepG2 cells by siRNA results in more cell death after treatment by quinacrine and TRAIL. The mechanism by which quinacrine sensitizes hepatocellular carcinoma cells to TRAIL and chemotherapies, and the potential for clinical application currently are being further explored. Lastly, quinacrine synergizes with chemotherapeutics, such as adriamycin, 5-FU, etoposide, CPT11, sorafenib, and gemcitabine, in killing hepatocellular carcinoma cells in vitro and the drug enhances the activity of sorafenib to delay tumor growth in vivo.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Doxorrubicina/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Quinacrina/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Animais , Benzenossulfonatos/farmacologia , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Carcinoma Hepatocelular/patologia , Morte Celular/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Sinergismo Farmacológico , Etoposídeo/farmacologia , Feminino , Fluoruracila/farmacologia , Genes p53 , Humanos , Irinotecano , Neoplasias Hepáticas/patologia , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides , Niacinamida/análogos & derivados , Compostos de Fenilureia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Piridinas/farmacologia , Quinacrina/farmacocinética , RNA Interferente Pequeno , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Sorafenibe , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Gencitabina
7.
Pediatr. aten. prim ; 10(38): 261-266, abr.-jun. 2008. ilus
Artigo em Es | IBECS | ID: ibc-68414

RESUMO

Giardia lamblia es uno de los parásitos intestinales patógenos más frecuente, causante de enfermedad tanto autóctona como importada. Aunque la infección es asintomática en la mayoría de los casos, puede cursar con patología digestiva diversa. Los derivados nitroimidazólicos, en especial el metronidazol, continúan siendo el tratamiento de elección. El aumento en el número de resistencias ha hecho necesario la introducción de nuevas pautas terapéuticas. Se presenta un caso de giardiasis resistente a metronidazol, que respondió a tratamiento con quinacrina


Giardia Lamblia is one of the most frequent intestinal pathogen parasite, responsible for autochthonous as well as imported illness. Although the infection is asymptomatic in the majority of the cases, it can be revealed by several digestive conditions. Nitroimidazole derivatives, especially Metronidazole, keep on being the treatment of choice. The increase in the number of resistances has made necessary the introduction of new therapeutical patterns. A case of giardiasis resistant to metronidazole which responded to a quinacrine treatment is presented


Assuntos
Humanos , Feminino , Lactente , Giardíase/tratamento farmacológico , Metronidazol/farmacocinética , Giardia lamblia/patogenicidade , Resistência a Medicamentos , Quinacrina/farmacocinética
8.
DNA Cell Biol ; 27(2): 81-90, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17924822

RESUMO

There is compelling evidence that cellular DNA is the target of many anticancer agents. Consequently, elucidation of the molecular nature governing the interaction of small molecules to DNA is paramount to the progression of rational drug design strategies. In this study, we have compared the binding and thermodynamic aspects of two known DNA-binding agents, quinacrine (QNA) and methylene blue (MB), with calf thymus (CT) DNA. The study revealed noncooperative binding phenomena for both the drugs to DNA with an affinity one order higher for QNA compared to MB as observed from diverse techniques, but both bindings obeyed neighbor exclusion principle. The data of the salt dependence of QNA and MB from the plot of log K versus log [Na+] revealed a slope of 1.06 and 0.93 consistent with the values predicted by theories for the binding of monovalent cations, and have been analyzed for contributions from polyelectrolytic and nonpolyelectrolytic forces. The binding of both drugs was further characterized by strong stabilization of DNA against thermal strand separation in both optical melting and differential scanning calorimetry studies. The binding data analyzed from the thermal denaturation and from isothermal titration calorimetry (ITC) were in close proximity to those obtained from spectral titration data. ITC results revealed the binding to be exothermic and favored by both negative enthalpy and positive entropy changes. The heat capacity changes obtained from temperature dependence of enthalpy indicated -146 and -78 cal/(mol.K), respectively, for the binding of QNA and MB to CT DNA. Circular dichroism study further characterized the structural changes on DNA upon intercalation of these molecules. Molecular aspects of interaction of these molecules to DNA are discussed.


Assuntos
DNA/metabolismo , Substâncias Intercalantes/farmacocinética , Azul de Metileno/farmacocinética , Quinacrina/farmacocinética , Ligação Competitiva , Dicroísmo Circular , DNA/efeitos dos fármacos , Temperatura Alta , Modelos Biológicos , Desnaturação de Ácido Nucleico/efeitos dos fármacos , Termodinâmica , Titulometria
9.
J Toxicol Environ Health A ; 69(11): 1083-95, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16840255

RESUMO

Bacillus anthracis has gained notoriety as a dangerous biological weapon because of its virulence and ability to produce highly resistant spores. In addition, the ability of this organism to produce plasmid-encoded edema toxin (EdTx) and lethal toxin (LeTx) plays a pivotal role in the pathogenesis of anthrax. In this study, the efficacy of quinacrine was evaluated against the effects of anthrax toxins in vitro and its ability to provide protection against challenge with B. anthracis Ames strain spores in an intranasal mouse and guinea pig model. Quinacrine protected murine macrophages in vitro against cytotoxicity and cAMP production induced by LeTx and EdTx, respectively, at concentrations of 40-80 microM, most likely by preventing acidification of the endosomes. However, animals dosed with human equivalent doses of quinacrine were not protected against respiratory spore challenge. The failure of quinacrine to provide protection against inhalation anthrax was attributed to our inability to attain inhibitory concentrations of the drug in the serum or tissues. After daily administration of 43.3 mg quinacrine to guinea pigs (300 g), serum levels after 96 h were only 9.9 microM, a concentration not sufficient to protect macrophages in vitro. Administration of high doses of quinacrine (86.6 mg/kg) was toxic to the animals. These results illustrate some of the difficulties in developing protective therapeutic strategies against inhalation anthrax even when antitoxic drugs appear effective in vitro.


Assuntos
Antraz/prevenção & controle , Bacillus anthracis/efeitos dos fármacos , Bacillus anthracis/patogenicidade , Inibidores Enzimáticos/farmacologia , Quinacrina/farmacologia , Administração Intranasal , Animais , Antraz/etiologia , Bioterrorismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacocinética , Cobaias , Humanos , Injeções Intraperitoneais , Camundongos , Quinacrina/farmacocinética , Esporos
10.
Drug Metab Dispos ; 34(7): 1136-44, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16581945

RESUMO

Quinacrine (QA), an antimalarial drug used for over seven decades, has been found to have potent antiprion activity in vitro. To determine whether QA can be used to treat prion diseases, we investigated its metabolism and ability to traverse the blood-brain barrier in mice. In vitro and in vivo, we identified by liquid chromatography-tandem mass spectrometry the major metabolic pathway of QA as N-desethylation and compared our results with an authentic reference compound. The major human cytochrome (P450) isoforms involved in QA mono-desethylation were identified as CYP3A4/5 by using specific chemical and antibody inhibition as well as cDNA-expressed P450 studies. QA transport from the basolateral to apical side in multidrug resistance protein 1 gene (MDR1)-transfected Madin-Darby canine kidney (MDCK) cells was markedly greater than in control MDCK cells and was inhibited by the potent P-glycoprotein (P-gp) inhibitor GG918 (N-(4-[2-(1,2,3,4-tetrahydro-6,7-dimethoxy-2-iso-1-quinolynyl)-ethyl]-phenyl)-9,10-dihydro-5-methoxy-9-oxo-4-acridine carboxamine). In MDR1-knockout (KO) mice, QA brain levels were 6 to 9 times higher after a single i.v. dose of 2 mg/kg QA and 49 times higher after multiple oral doses of 10 mg/kg/day QA for 7 days, compared with those in wild-type (WT) FVB mice. In contrast, the QA levels in plasma, liver, spleen, and kidney were similar after a single 2 mg/kg i.v. dose and <2 times greater after 10 mg/kg oral doses in MDR1-KO mice compared with WT mice. These results indicate that P-gp plays a critical role in transporting QA from the brain.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antimaláricos/farmacocinética , Encéfalo/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Quinacrina/farmacocinética , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Biotransformação , Barreira Hematoencefálica/metabolismo , Linhagem Celular , Citocromo P-450 CYP3A , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/genética , Cães , Inibidores Enzimáticos/farmacologia , Humanos , Cetoconazol/farmacologia , Fígado/metabolismo , Masculino , Camundongos , Camundongos Knockout , Microssomos Hepáticos , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/metabolismo
11.
Nanomedicine (Lond) ; 1(3): 345-50, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17716164

RESUMO

AIMS: To analyze drug transport at a single cell level, a mast cell line, RBL-2H3, was treated with cell-permeable fluorescent compounds, such as quinacrine, and was monitored by a fluorescence video microscope. METHODS: Small areas in the video that corresponded to granules and part of the cytosol in a cell were chosen and the signal intensity in these areas was monitored sequentially. RESULTS: The initial rate of quinacrine uptake through the cell membrane calculated from the fluorescent signal was correlated with quinacrine concentration, and it decreased at a lower temperature, showing that the transport was an energy-requiring process, such as active transport. The kinetics of the transport through the microgranular membrane did not depend on the temperature but the pH in the cytosol, therefore this process should be passive transport by pH gradient. CONCLUSION: These data indicate that the observation of video microscope-mediated drug transport using fluorescent dye is useful in kinetic analysis at the nanometer scale.


Assuntos
Microscopia de Fluorescência/métodos , Nanotecnologia/métodos , Quinacrina/farmacocinética , Animais , Transporte Biológico , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Citosol/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Modelos Biológicos , Estrutura Molecular , Quinacrina/química , Temperatura
12.
Mol Pharm ; 2(6): 440-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16323951

RESUMO

Many weakly basic drugs incubated with cells have been shown to specifically accumulate in lysosomes. The mechanistic basis and substrate specificity for this sequestration have not been rigorously evaluated; however, conditions are favorable for a pH-partitioning type accumulation. In some circumstances, this compartmentalization can be very extensive, which can impact the therapeutic efficacy of a drug. Despite the pharmaceutical importance, direct quantitative assessments of drug accumulation in lysosomes have not been previously described. We report here a novel magnetic capture technique that allows for quick and efficient isolation of lysosomes from cultured HL-60 cells that have been preincubated with model compounds. The amount of compound associated with the isolated fraction is determined by HPLC. Extensive biochemical and morphological characterizations of isolated lysosomes, together with HPLC data, allowed for estimates to be made regarding the concentration of model compounds in lysosomes. The corresponding theoretically determined concentration values, based on pH-partitioning theory, were also calculated for comparison purposes. Interestingly, experimentally determined values were approximately 3-15 times higher than theoretically predicted values. This finding suggests that mechanisms, in addition to pH-partitioning, may play a significant role in the accumulation of drugs in lysosomes.


Assuntos
Lisossomos/metabolismo , Quinacrina/farmacocinética , Linhagem Celular Tumoral , Células HL-60 , Humanos , Concentração de Íons de Hidrogênio , Leucemia Promielocítica Aguda , Lisossomos/ultraestrutura , Microscopia de Fluorescência
13.
Br J Pharmacol ; 144(3): 386-93, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15655516

RESUMO

Quinacrine was reported to have a marked in vitro antiprion action in mouse neuroblastoma cells. On compassionate grounds, quinacrine was administered to Creutzfeldt-Jakob disease patients, despite the absence of preclinical in vivo studies to evaluate efficacy. Quinacrine failed to provide therapeutic benefit. The aim of the study was to investigate possible pharmacokinetic and/or pharmacodynamic explanations for the discrepancy between the proven action of quinacrine in vitro and its lack of clinical efficacy. We conducted in vitro experiments reproducing the culture conditions in which antiprion effects had been previously observed and recalculated the EC(50) by determining the actual extracellular (120 nM) and intracellular (6713 nM) quinacrine neuroblastoma concentrations with the reported quinacrine EC(50) (300 nM). A randomized clinical trial in scrapie-affected ewes confirmed the absence of therapeutic benefit of quinacrine. The in vivo quinacrine exposure was evaluated in a pharmacokinetic investigation in healthy ewes. Cerebrospinal fluid concentrations (<10.6 and 55 nM after administration of therapeutic and toxic quinacrine doses, respectively) were much lower than the quinacrine extracellular neuroblastoma concentrations corresponding to the reported EC(50). The total brain tissue concentrations (3556 nM) obtained after a repeated therapeutic dosage regimen were within the range of the intracellular neuroblastoma quinacrine concentrations. In conclusion, in order to avoid in vivo trials for which failure can be predicted, the measurement in vitro of the antiprion EC(50) in both intra- and extracellular biophases should be determined. It can then be established if these in vitro antiprion concentrations are achievable in vivo.


Assuntos
Doenças Priônicas/tratamento farmacológico , Doenças Priônicas/veterinária , Quinacrina/uso terapêutico , Scrapie/tratamento farmacológico , Doenças dos Ovinos/tratamento farmacológico , Algoritmos , Animais , Linhagem Celular Tumoral , Meios de Cultura , Espaço Extracelular/metabolismo , Feminino , Injeções Intramusculares , Quinacrina/administração & dosagem , Quinacrina/farmacocinética , Ovinos , Análise de Sobrevida , Falha de Tratamento
14.
BMC Infect Dis ; 4: 53, 2004 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-15569390

RESUMO

BACKGROUND: Prion diseases are caused by the accumulation of an aberrantly folded isoform of the prion protein, designated PrPSc. In a cell-based assay, quinacrine inhibits the conversion of normal host prion protein (PrPC) to PrPSc at a half-maximal concentration of 300 nM. While these data suggest that quinacrine may be beneficial in the treatment of prion disease, its penetration into brain tissue has not been extensively studied. If quinacrine penetrates brain tissue in concentrations exceeding that demonstrated for in vitro inhibition of PrPSc, it may be useful in the treatment of prion disease. METHODS: Oral quinacrine at doses of 37.5 mg/kg/D and 75 mg/kg/D was administered to mice for 4 consecutive weeks. Plasma and tissue (brain, liver, spleen) samples were taken over 8 weeks: 4 weeks with treatment, and 4 weeks after treatment ended. RESULTS: Quinacrine was demonstrated to penetrate rapidly into brain tissue, achieving concentrations up to 1500 ng/g, which is several-fold greater than that demonstrated to inhibit formation of PrPSc in cell culture. Particularly extensive distribution was observed in spleen (maximum of 100 microg/g) and liver (maximum of 400 microg/g) tissue. CONCLUSIONS: The documented extensive brain tissue penetration is encouraging suggesting quinacrine might be useful in the treatment of prion disease. However, further clarification of the distribution of both intracellular and extracellular unbound quinacrine is needed. The relative importance of free quinacrine in these compartments upon the conversion of normal host prion protein (PrPC) to PrPSc will be critical toward its potential benefit.


Assuntos
Encéfalo/metabolismo , Fígado/metabolismo , Doenças Priônicas/tratamento farmacológico , Quinacrina/farmacocinética , Baço/metabolismo , Administração Oral , Animais , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Camundongos , Quinacrina/sangue , Quinacrina/uso terapêutico , Espectrometria de Massas por Ionização por Electrospray
15.
Cell Mol Neurobiol ; 24(2): 205-17, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15176436

RESUMO

1. A clinical trial of quinacrine in patients with Creutzfeldt-Jakob disease is now in progress. The permeability of drugs through the blood-brain barrier (BBB) is a determinant of their therapeutic efficacy for prion diseases. The mechanism of quinacrine transport across the BBB was investigated using mouse brain endothelial cells (MBEC4). 2. The permeability of quinacrine through MBEC4 cells was lower than that of sodium fluorescein, a BBB-impermeable marker. The basolateral-to-apical transport of quinacrine was greater than its apical-to-basolateral transport. In the presence of P-glycoprotein (P-gp) inhibitor, cyclosporine or verapamil, the apical-to-basolateral transport of quinacrine increased. The uptake of quinacrine by MBEC4 cells was enhanced in the presence of cyclosporine or verapamil. 3. Quinacrine uptake was highly concentrative, this event being carried out by a saturable and carrier-mediated system with an apparent Km of 52.1 microM. Quinacrine uptake was insensitive to Na+-depletion and changes in the membrane potential and sensitive to changes in pH. This uptake was decreased by tetraethylammonium and cimetidine, a substrate and an inhibitor of organic cation transporters, respectively. 4. These findings suggest that quinacrine transport at the BBB is mediated by the efflux system (P-gp) and the influx system (organic cation transporter-like machinery).


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Quinacrina/farmacocinética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Barreira Hematoencefálica/fisiologia , Proteínas de Transporte de Cátions/efeitos dos fármacos , Proteínas de Transporte de Cátions/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Polaridade Celular/efeitos dos fármacos , Polaridade Celular/fisiologia , Cimetidina/farmacologia , Ciclosporina/farmacologia , Células Endoteliais/metabolismo , Fluoresceína/farmacocinética , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Camundongos , Doenças Priônicas/tratamento farmacológico , Quinacrina/uso terapêutico , Tetraetilamônio/farmacologia , Verapamil/farmacologia
16.
Proc Natl Acad Sci U S A ; 100(7): 3907-12, 2003 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-12644710

RESUMO

Noncompetitive inhibitors of the nicotinic acetylcholine (ACh) receptors suppress cation flux directly by binding in and blocking the open channel or indirectly by stabilizing closed states of the receptor. The lidocaine derivative QX-314 and the acridine derivative quinacrine act directly as open channel blockers, but can act indirectly as well. The binding site for quinacrine in the open channel of mouse-muscle ACh receptor was mapped in cysteine-substituted mutants of the alpha subunit expressed with wild-type beta, gamma, and delta subunits. In the open state, substituted cysteines in the inner half of the second membrane-spanning segment (M2), but not in the outer half, were protected by quinacrine from reaction with 2-aminoethyl methanethiosulfonate. In addition, an alkylating derivative, quinacrine mustard, affinity labeled a subset of the substituted cysteines in M2, but only in the open state. These results, mapped onto a model of the open channel surrounded by five alpha-helical M2s, imply that quinacrine binds midway down M2 in the same site previously mapped for QX-314. A cysteine substituted for a residue in the outer third of alphaM1, which reacted with 2-aminoethyl methanethiosulfonate only in the presence of ACh, reacted faster in the additional presence of quinacrine or QX-314. It is proposed that channel opening involves both the opening of the resting gate at the inner end of M2 and the removal of an obstruction formed by the outer end of M1 that retards diffusion of blockers into the closed channel. Blocker binding in the open channel causes a further change in structure.


Assuntos
Quinacrina/farmacologia , Quinacrina/farmacocinética , Receptores Colinérgicos/fisiologia , Substituição de Aminoácidos , Animais , Sítios de Ligação , Cisteína , Feminino , Cinética , Camundongos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Oócitos/efeitos dos fármacos , Oócitos/fisiologia , Estrutura Secundária de Proteína , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Quinacrina/química , Mostarda de Quinacrina/farmacocinética , Mostarda de Quinacrina/farmacologia , Receptores Colinérgicos/química , Receptores Colinérgicos/efeitos dos fármacos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Xenopus laevis
17.
Cell Mol Biol Lett ; 8(1): 111-20, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12655364

RESUMO

Quinacrine was used to visualize the intracellular pH changes in the yeast strain Saccharomyces cerevisiae RXII occurring after exposure to four recently-synthesized lysosomotropic drugs: DM-11, PY-11, PYG-12s and DMAL-12s. The cells took up quinacrine, mostly accumulating it in their vacuoles. DM-11 and PY-11 gave rise to diffuse quinacrine fluorescence throughout the cells, with the vacuoles staining to a somewhat greater extent than the cytosol. This quinacrine-detected overall acidification of the cell interior is very probably caused by blocking of plasma membrane H(+)-ATPase. PYG-12s gave rise to a strong vacuolar accumulation of the dye. Like the vacuolar ATPase inhibitor bafilomycin A(1), DMAL-12s strongly lowered the intensity of quinacrine fluorescence. Owing to its low pK(a), it can penetrate rapidly into the cells and may inhibit vacuolar H(+)-ATPase and prevent quinacrine-detectable vacuolar acidification without causing strong cell acidification. Since these drugs were found to penetrate into the cells, their lack of effect may reflect a higher resistance of both plasma membrane H(+)-ATPase and vacuolar ATPase to the drugs. Our data indicate that the lysosomotropic drugs under study have a dual action. On entering the cell, they cause intracellular acidification, very probably by inhibiting plasma membrane H(+)-ATPase and curtailing active proton pumping from the cells. Furthermore, they interfere with the function of V-type ATPase, causing vacuolar alkalinization and eventually cell death.


Assuntos
Antifúngicos/farmacologia , Lisossomos/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Antifúngicos/química , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Corantes Fluorescentes/farmacocinética , Concentração de Íons de Hidrogênio , Líquido Intracelular/efeitos dos fármacos , Líquido Intracelular/metabolismo , Microscopia de Fluorescência , ATPases Translocadoras de Prótons/metabolismo , Quinacrina/farmacocinética , Saccharomyces cerevisiae/metabolismo , ATPases Vacuolares Próton-Translocadoras/metabolismo , Vacúolos/efeitos dos fármacos , Vacúolos/metabolismo
18.
Nihon Rinsho ; 60(8): 1649-57, 2002 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-12187766

RESUMO

Prion diseases are lethal transmissible neurodegenerative illnesses that affect humans and many other animals. Since the accumulation of the pathogenic form of prion protein is a pivotal event in prion diseases, most of the therapeutic strategies are designed to prevent the conformational change of normal prion protein to that of the pathogenic form or to remove the accumulated prion protein. Quinacrine is one of the compounds that can inhibit the accumulation of pathogenic prion protein in cultured neuroblastoma cells. Here we report the results of clinical trials of quinacrine administration to the patients of Creutzfeldt-Jakob disease. In some patients, response to visual and auditory stimulations improved transiently. Lemon-yellow discolorization of skin and liver dysfunction were common side effects by quinacrine.


Assuntos
Antimaláricos/uso terapêutico , Síndrome de Creutzfeldt-Jakob/tratamento farmacológico , Quinacrina/uso terapêutico , Animais , Antimaláricos/efeitos adversos , Antimaláricos/farmacocinética , Barreira Hematoencefálica , Ensaios Clínicos como Assunto , Humanos , Príons , Quinacrina/efeitos adversos , Quinacrina/farmacocinética
19.
J Med Assoc Thai ; 85 Suppl 1: S435-40, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12188448

RESUMO

OBJECTIVE: To compare quinacrine pellets distribution in the uterine cavity between women standing up promptly after insertion and those lying down for a further 30-minutes. DESIGNS: Randomized controlled trial MATERIAL AND METHOD: Twenty women who, desired interval female sterilization, were equally randomized into 2 groups. Quinacrine pellets were inserted twice, one month apart in both groups. Transvaginal ultrasonography (TVS) was performed after insertion in order to locate the position of the quinacrine pellets. In group I, the TVS was performed after the women stood up promptly. In group II, the TVS was performed after the women lay down for 30-minute. The distribution of quinacrine pellets, measured from the uterine fundus to the lowest pellet, were compared. RESULTS: There was no difference at the baseline and 30 minutes measurement of both groups. In the first insertion, there was statistical difference of the distance of the quinacrine pellets when compared in the same group immediately and the 30-minute measurement (Gr 1: 19.10+/-3.28 mm vs 22.30+/-3.50 mm); (Gr 2: 18.70+/-3.40 mm vs 24.40+/-5.95 mm). In the same manner, the authors found statistical difference in the same group of the second insertion (Gr 1: 21.80+/-5.39 mm vs 24.70+/-7.24 mm); (Gr 2 : 20.89+/-4.78 mm vs 28.30+/-7.59 mm) CONCLUSIONS: There was statistical difference of quinacrine pellet distribution in uterine cavity after time. However, body movement did not effect the position of the pellets. The failure rate of quinacrine pellet insertion for non-surgical female sterilization may not be explained by the changes of position after insertion.


Assuntos
Implantes de Medicamento/administração & dosagem , Quinacrina/administração & dosagem , Esterilização Reprodutiva/métodos , Útero/efeitos dos fármacos , Adulto , Esquema de Medicação , Implantes de Medicamento/farmacocinética , Endossonografia , Feminino , Humanos , Recém-Nascido , Postura , Probabilidade , Quinacrina/farmacocinética , Decúbito Dorsal , Tailândia , Fatores de Tempo , Resultado do Tratamento , Útero/diagnóstico por imagem
20.
Surgery ; 128(3): 439-46, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10965316

RESUMO

BACKGROUND: When quinacrine is injected interstitially, an intense migration of leukocytes and accumulation of various lymphokines is obtained locally, and the reaction is followed by cicatricial fibrosis. This property has been used in humans to induce tubal fibrosis in women and pleurodesis in patients with pleural effusion. METHODS: In a controlled study, a single dose of 150 mg of quinacrine was injected interstitially into a C6 glioma implanted in the subcutaneous tissue of Wistar rats. Changes in size, histologic variations, and microscopic characteristics of leukocyte subpopulations infiltrating the tumor were studied by immunohistochemistry. Tumor necrosis factor and interleukin-1 beta were measured at different times in tumor homogenates. RESULTS: The day after the injection of quinacrine, infiltration of leukocytes and macrophages was observed, accompanied by an accumulation of proinflammatory endogenous cytokines. Tumoral necrosis soon ensued; complete tumor disappearance was obtained in 72% of the animals. Cicatrization proceeded without injury of perilesional structures. In all controls injected with the vehicle, a large tumor developed (P <.0001). CONCLUSIONS: Quinacrine, when administered interstitially in a single dose, elicits an intense local recruitment and proliferation of activated immune cells that, at the dose used in this study, induces tissue necrosis within a radius of 1 cm around the site of quinacrine injection, leaving the surrounding tissue unharmed.


Assuntos
Antineoplásicos/uso terapêutico , Glioma/tratamento farmacológico , Quinacrina/uso terapêutico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Cicatriz , Citocinas/análise , Espaço Extracelular , Feminino , Glioma/patologia , Humanos , Injeções , Leucócitos/patologia , Quinacrina/administração & dosagem , Quinacrina/farmacocinética , Ratos , Ratos Wistar , Células Tumorais Cultivadas
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