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1.
ACS Biomater Sci Eng ; 7(6): 2496-2507, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-33825438

RESUMO

Protecting the body from radiation damage is a huge medical challenge. Amifostine and curcumin are both effective radioprotectants, but their use has been greatly restricted due to various reasons including low bioavailability. Nanoscale drug delivery systems of poly(ethylene glycol)-poly(ε-caprolactone) copolymers can improve the bioavailability of drugs due to excellent biocompatibility, biodegradability, and long circulation characteristics. In this study, a new reactive oxygen species-sensitive nanocarrier fabricated by linking curcumin and thioketal to poly(ethylene glycol)-poly(ε-caprolactone) polymer was used for delivery of WR-1065 (the active ingredient of amifostine). The content of curcumin in this polymer was about 7.6%, and the drug loading of WR-1065 was 44%. The WR-1065-loaded nanoparticles (NPs) had an average size of 128.6 nm and uniform spherical morphology. These WR-1065-loaded NPs reduced the metabolism of curcumin and WR-1065 in the gastrointestinal tract and could be well absorbed by cells and distributed to multiple organs. Compared with a single drug, oral administration of WR-1065-loaded NPs demonstrated obvious radioprotective effects on the hematopoietic system and prevented intestinal injury. The 30-day survival rate after half-lethal dose (7.2 Gy) of total body irradiation was 100%. In general, WR-1065-loaded NPs improved the oral bioavailability of WR-1065 and curcumin. This multifunctional nanocarrier provides a possibility for combination therapy in treating ionizing radiation damage.


Assuntos
Curcumina , Mercaptoetilaminas , Nanopartículas , Curcumina/farmacologia , Espécies Reativas de Oxigênio
2.
Exp Neurol ; 341: 113705, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33753139

RESUMO

Anticancer therapeutics can provoke severe side effects that impair the patient's quality of life. A frequent dose-limiting side effect of platinum-based anticancer therapy is neurotoxicity. Its pathophysiology is poorly understood, and effective preventive or therapeutic measures are missing. Therefore, elucidation of the molecular mechanism of platinating drug-induced neurotoxicity and the development of preventive strategies is urgently needed. To this end, we aim to use C. elegans as a 3R-compliant in vivo model. The 3R principles were conceived for animal welfare in science concerning animal experiments, which should be replaced, reduced or refined. We can analytically demonstrate dose-dependent uptake of cisplatin (CisPt) in C. elegans, as well as genotoxic and cytotoxic effects based on DNA adduct formation (i.e., 1,2-GpG intrastrand crosslinks), induction of apoptosis, and developmental toxicity. Measuring the impairment of pharyngeal pumping as a marker of neurotoxicity, we found that especially CisPt reduces the pumping frequency at concentrations where basal and touch-provoked movement were not yet affected. CisPt causes glutathione (GSH) depletion and RNAi-mediated knockdown of the glutamate-cysteine ligase GCS-1 aggravates the CisPt-induced inhibition of pharyngeal pumping. Moreover, N-acetylcysteine (NAC) mitigated CisPt-triggered toxicity, indicating that GSH depletion contributes to the CisPt-induced pharyngeal damage. In addition to NAC, amifostine (WR1065) also protected the pharynx of C. elegans from the toxic effects of CisPt. Measuring pharyngeal activity by the electrophysiological recording of neurotransmission in the pharynx, we confirmed that CisPt is neurotoxic in C. elegans and that NAC is neuroprotective in the nematode. The data support the hypothesis that monitoring the pharyngeal activity of C. elegans is a useful surrogate marker of CisPt-induced neurotoxicity. In addition, a low GSH pool reduces the resistance of neurons to CisPt treatment, and both NAC and WR1065 are capable of attenuating platinum-induced neurotoxicity during post-incubation in C. elegans. Overall, we propose C. elegans as a 3R-compliant in vivo model to study the molecular mechanisms of platinum-induced neurotoxicity and to explore novel neuroprotective therapeutic strategies to alleviate respective side effects of platinum-based cancer therapy.


Assuntos
Antineoplásicos/toxicidade , Cisplatino/toxicidade , Modelos Animais de Doenças , Síndromes Neurotóxicas/prevenção & controle , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans , Quimioprevenção/métodos , Relação Dose-Resposta a Droga , Mercaptoetilaminas/farmacologia , Mercaptoetilaminas/uso terapêutico , Síndromes Neurotóxicas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Compostos de Platina/toxicidade
3.
Cell Mol Neurobiol ; 39(5): 619-636, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30874981

RESUMO

Chemotherapy-induced peripheral neuropathy (CIPN) is a side effect of platinum-based chemotherapy and decreases the quality of life of cancer patients. We compared neuroprotective properties of several agents using an in vitro model of terminally differentiated human cells NT2-N derived from cell line NT2/D1. Sodium azide and an active metabolite of amifostine (WR1065) increase cell viability in simultaneous treatment with cisplatin. In addition, WR1065 protects the non-dividing neurons by decreasing cisplatin caused oxidative stress and apoptosis. Accumulation of Pt in cisplatin-treated cells was heterogeneous, but the frequency and concentration of Pt in cells were lowered in the presence of WR1065 as shown by X-ray fluorescence microscopy (XFM). Transition metals accumulation accompanied Pt increase in cells; this effect was equally diminished in the presence of WR1065. To analyze possible chemical modulation of Pt-DNA bonds, we examined the platinum LIII near edge spectrum by X-ray absorption spectroscopy. The spectrum found in cisplatin-DNA samples is altered differently by the addition of either WR1065 or sodium azide. Importantly, a similar change in Pt edge spectra was noted in cells treated with cisplatin and WR1065. Therefore, amifostine should be reconsidered as a candidate for treatments that reduce or prevent CIPN.


Assuntos
Antioxidantes/farmacologia , Cisplatino/efeitos adversos , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Mercaptoetilaminas/farmacologia , Crescimento Neuronal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Azida Sódica/farmacologia
4.
Sci Rep ; 9(1): 1949, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30760738

RESUMO

Unresectable pancreatic cancer is almost universally lethal because chemotherapy and radiation cannot completely stop the growth of the cancer. The major problem with using radiation to approximate surgery in unresectable disease is that the radiation dose required to ablate pancreatic cancer exceeds the tolerance of the nearby duodenum. WR-2721, also known as amifostine, is a well-known radioprotector, but has significant clinical toxicities when given systemically. WR-2721 is a prodrug and is converted to its active metabolite, WR-1065, by alkaline phosphatases in normal tissues. The small intestine is highly enriched in these activating enzymes, and thus we reasoned that oral administration of WR-2721 just before radiation would result in localized production of the radioprotective WR-1065 in the small intestine, providing protective benefits without the significant systemic side effects. Here, we show that oral WR-2721 is as effective as intraperitoneal WR-2721 in promoting survival of intestinal crypt clonogens after morbid irradiation. Furthermore, oral WR-2721 confers full radioprotection and survival after lethal upper abdominal irradiation of 12.5 Gy × 5 fractions (total of 62.5 Gy, EQD2 = 140.6 Gy). This radioprotection enables ablative radiation therapy in a mouse model of pancreatic cancer and nearly triples the median survival compared to controls. We find that the efficacy of oral WR-2721 stems from its selective accumulation in the intestine, but not in tumors or other normal tissues, as determined by in vivo mass spectrometry analysis. Thus, we demonstrate that oral WR-2721 is a well-tolerated, and quantitatively selective, radioprotector of the intestinal tract that is capable of enabling clinically relevant ablative doses of radiation to the upper abdomen without unacceptable gastrointestinal toxicity.


Assuntos
Amifostina/farmacologia , Mercaptoetilaminas/farmacologia , Protetores contra Radiação/uso terapêutico , Administração Oral , Amifostina/metabolismo , Animais , Feminino , Intestino Delgado/efeitos dos fármacos , Masculino , Mercaptoetilaminas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Pancreáticas/tratamento farmacológico , Doses de Radiação , Proteção Radiológica/métodos
5.
Med Chem ; 14(6): 585-594, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29663895

RESUMO

BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) usually invalidate powerful antibiotics in the clinic. Pleuromutilin derivatives have been reported to possess antibacterial activity against MRSA. OBJECTIVE: The antibacterial activities against MRSA of a series of thirteen synthetic pleuromutilin derivatives were investigated through in vitro models. METHODS: A series of novel thioehter pleuromutilin derivatives incorporating various aromatic substituents into the C14 side chain have been reported. The in vitro antibacterial activities of these derivatives against MRSA and Escherichia coli were tested by the broth dilution method. RESULTS: Twelve pleuromutilin derivatives were designed, synthesized and evaluated for in vitro antibacterial activities against four Staphylococcus aureus strains. From structure-activity relationship studies, compound 11c was identified as promising compounds with the most potent in vitro antibacterial activity among the series (MIC = 0.0625-0.125 µg/ml) against Staphylococcus aureus strains. The binding of compound 11c to the 50s ribosome was investigated by molecular modeling. CONCLUSION: It was found that there is a reasonable correlation between the binding free energy and the antibacterial activity.


Assuntos
Antibacterianos/farmacologia , Mercaptoetilaminas/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Diterpenos/síntese química , Diterpenos/química , Diterpenos/farmacologia , Escherichia coli/efeitos dos fármacos , Mercaptoetilaminas/síntese química , Mercaptoetilaminas/química , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Compostos Policíclicos , Subunidades Ribossômicas Maiores de Bactérias/química , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade
6.
J Dent Res ; 97(11): 1252-1259, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29634396

RESUMO

Radiotherapy for head and neck cancers commonly causes damage to salivary gland tissue, resulting in xerostomia (dry mouth) and numerous adverse medical and quality-of-life issues. Amifostine is the only Food and Drug Administration-approved radioprotective drug used clinically to prevent xerostomia. However, systemic administration of amifostine is limited by severe side effects, including rapid decrease in blood pressure (hypotension), nausea, and a narrow therapeutic window. In this study, we demonstrate that retroductal delivery of amifostine and its active metabolite, WR-1065, to murine submandibular glands prior to a single radiation dose of 15 Gy maintained gland function and significantly increased acinar cell survival. Furthermore, in vivo stimulated saliva secretion was maintained in retrograde-treated groups at levels significantly higher than irradiated-only and systemically treated groups. In contrast to intravenous injections, retroductal delivery of WR-1065 or amifostine significantly attenuated hypotension. We conclude that localized delivery to salivary glands markedly improves radioprotection at the cellular level, as well as mitigates the adverse side effects associated with systemic administration. These results support the further development of a localized delivery system that would be compatible with the fractionated dose regimen used clinically.


Assuntos
Amifostina/administração & dosagem , Protetores contra Radiação/administração & dosagem , Glândulas Salivares/efeitos da radiação , Células Acinares/efeitos dos fármacos , Células Acinares/efeitos da radiação , Amifostina/uso terapêutico , Animais , Feminino , Imunofluorescência , Injeções , Mercaptoetilaminas/administração & dosagem , Mercaptoetilaminas/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/prevenção & controle , Protetores contra Radiação/uso terapêutico , Glândulas Salivares/efeitos dos fármacos , Glândulas Salivares/patologia , Glândula Submandibular/efeitos dos fármacos , Glândula Submandibular/efeitos da radiação
7.
Pharm Res ; 35(5): 99, 2018 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-29556791

RESUMO

PURPOSE: Amifostine (AMF), a radioprotectant, is FDA-approved for intravenous administration in cancer patients receiving radiation therapy (XRT). Unfortunately, it remains clinically underutilized due to adverse side effects. The purpose of this study is to define the pharmacokinetic profile of an oral AMF formulation potentially capable of reducing side effects and increasing clinical feasibility. METHODS: Calvarial osteoblasts were radiated under three conditions: no drug, AMF, and WR-1065 (active metabolite). Osteogenic potential of cells was measured using alkaline phosphatase staining. Next, rats were given AMF intravenously or directly into the jejunum, and pharmacokinetic profiles were evaluated. Finally, rats were given AMF orally or subcutaneously, and blood samples were analyzed for pharmacokinetics. RESULTS: WR-1065 preserved osteogenic potential of calvarial osteoblasts after XRT to a greater degree than AMF. Direct jejunal AMF administration incurred a systemic bioavailability of 61.5%. Subcutaneously administrated AMF yielded higher systemic levels, a more rapid peak exposure (0.438 vs. 0.875 h), and greater total systemic exposure of WR-1065 (116,756 vs. 16,874 ng*hr/ml) compared to orally administered AMF. CONCLUSIONS: Orally administered AMF achieves a similar systemic bioavailability and decreased peak plasma level of WR-1065 compared to intravenously administered AMF, suggesting oral AMF formulations maintain radioprotective efficacy without causing onerous side effects, and are clinically feasible.


Assuntos
Amifostina/farmacocinética , Mercaptoetilaminas/farmacocinética , Osteogênese/efeitos dos fármacos , Lesões Experimentais por Radiação/prevenção & controle , Protetores contra Radiação/farmacocinética , Administração Intravenosa , Administração Oral , Amifostina/administração & dosagem , Animais , Disponibilidade Biológica , Linhagem Celular , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Injeções Subcutâneas , Jejuno/efeitos dos fármacos , Jejuno/metabolismo , Jejuno/efeitos da radiação , Masculino , Mercaptoetilaminas/administração & dosagem , Osteoblastos/efeitos dos fármacos , Osteoblastos/efeitos da radiação , Osteogênese/efeitos da radiação , Lesões Experimentais por Radiação/etiologia , Protetores contra Radiação/administração & dosagem , Ratos , Crânio/citologia , Resultado do Tratamento
8.
Artigo em Inglês | MEDLINE | ID: mdl-29482122

RESUMO

Hypotension is the dose-limiting side effect of the radio-protective drug Amifostine and results from relaxation of the vascular smooth muscle, which is directly mediated by the active metabolite, WR-1065, of Amifostine. The route of administration (currently FDA-approved only for intravenous administration) and the rapid metabolic conversion of Amifostine combine to yield high systemic levels of WR-1065 and facilitate the onset of hypotension. Research efforts aiming to optimize the delivery of WR-1065 to maintain efficacy while reducing its peak, systemic concentration below levels that induce hypotension are underway. To fully characterize the effect of reduced dose levels and alternative routes of administration of Amifostine on systemic WR-1065 concentrations, improved analytical techniques are needed. We have developed and evaluated a highly sensitive method for measuring WR-1065 in rat plasma that employs chemical derivatization, protein precipitation and UPLC-MS/MS analysis. The method exhibits a limit of quantification (LOQ) of 7.4 nM in plasma, which is a significant improvement over conventional approaches that utilize LC-electrochemical detection (ECD) (LOQ 150 nM or higher). The method was assessed in a pharmacokinetics study in rats administered Amifostine intravenously and via direct jejunal injection (10 mg/kg each route). The bioavailability of WR-1065 was 61.5% after direct jejunal injection indicating rapid conversion and absorption of the metabolite in the intestinal tract. This demonstrates that an oral formulation of Amifostine designed for site-specific release of the drug in the upper GI tract can deliver systemic absorption/conversion to WR-1065, provided that the formulation protects the therapeutic from gastric decomposition in the stomach.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Mercaptoetilaminas/sangue , Protetores contra Radiação/análise , Espectrometria de Massas em Tandem/métodos , Animais , Estabilidade de Medicamentos , Modelos Lineares , Masculino , Mercaptoetilaminas/química , Mercaptoetilaminas/farmacocinética , Protetores contra Radiação/química , Protetores contra Radiação/farmacocinética , Ratos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Neurosci Lett ; 627: 7-12, 2016 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-27222379

RESUMO

Over production of reactive oxygen species (ROS) is postulated to be the main contributor in degeneration of nigrostriatal dopaminergic neurons. In this study we investigated the effects of WR1065, a free radical scavenger, on motor imbalance, oxidative stress parameters and inflammatory cytokines in CSF and brain of hemi-parkinsonian rats. Lesion of dopaminergic neurons was done by unilateral infusion of 6-hydroxydopamine into the central region of the substentia nigra pars compacta (SNc) to induce hemi-parkinsonism and motor imbalance in rats. WR1065 (20, 40 and 80µg/2µl/rat) was administered three days before 6-OHDA administration. After three weeks behavioral study was performed and then brain and CSF samples were collected to assess tumor necrosis factor (TNFα), interlukin (IL-1ß), reduced glutathione (GSH), and malondialdehyde (MDA). WR1065 pre-treatment in rats before receiving 6-OHDA, improved significantly motor impairment and caused reduction of MDA and inflammatory cytokines TNFα and IL-1ß levels, while GSH level significantly increased when compared with lesioned rats. Our study indicated that WR1065 could improve 6-OHDA-induced motor imbalance. Furthermore, it decreased lipid peroxidation and inflammatory cytokines and restored the level of GSH up to normal range. We suggest that WR1065 can be proposed as a potential neuroprotective agent in motor impairments of PD. However to prove this hypothesis more clinical trial studies should be done.


Assuntos
Inflamação/metabolismo , Mercaptoetilaminas/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Transtornos Parkinsonianos/prevenção & controle , Transtornos Parkinsonianos/fisiopatologia , Animais , Modelos Animais de Doenças , Glutationa/líquido cefalorraquidiano , Interleucina-1beta/líquido cefalorraquidiano , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Malondialdeído/líquido cefalorraquidiano , Atividade Motora/efeitos dos fármacos , Oxidopamina , Transtornos Parkinsonianos/líquido cefalorraquidiano , Transtornos Parkinsonianos/induzido quimicamente , Parte Compacta da Substância Negra/efeitos dos fármacos , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/líquido cefalorraquidiano
10.
J Med Chem ; 59(7): 3003-17, 2016 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-26978566

RESUMO

Amifostine protects normal cells from DNA damage induction by ionizing radiation or chemotherapeutics, whereas cancer cells typically remain uninfluenced. While confirming this phenomenon, we have revealed by comet assay and currently the most sensitive method of DNA double strand break (DSB) quantification (based on γH2AX/53BP1 high-resolution immunofluorescence microscopy) that amifostine treatment supports DSB repair in γ-irradiated normal NHDF fibroblasts but alters it in MCF7 carcinoma cells. These effects follow from the significantly lower activity of alkaline phosphatase measured in MCF7 cells and their supernatants as compared with NHDF fibroblasts. Liquid chromatography-mass spectrometry confirmed that the amifostine conversion to WR-1065 was significantly more intensive in normal NHDF cells than in tumor MCF cells. In conclusion, due to common differences between normal and cancer cells in their abilities to convert amifostine to its active metabolite WR-1065, amifostine may not only protect in multiple ways normal cells from radiation-induced DNA damage but also make cancer cells suffer from DSB repair alteration.


Assuntos
Amifostina/farmacologia , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Protetores contra Radiação/farmacologia , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Amifostina/farmacocinética , Ensaio Cometa , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/efeitos da radiação , Raios gama , Histonas/genética , Histonas/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células MCF-7/efeitos dos fármacos , Células MCF-7/efeitos da radiação , Mercaptoetilaminas/farmacocinética , Microscopia de Fluorescência/métodos , Proteína 1 de Ligação à Proteína Supressora de Tumor p53
11.
Anal Bioanal Chem ; 408(22): 5973-84, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26973237

RESUMO

Enzyme-linked immunosorbent assay (ELISA) is commonly used to determine food allergens in food products. However, a significant number of ELISAs give an erroneous result, especially when applied to highly processed food. Accordingly, an improved ELISA, which utilizes an extraction solution comprising the surfactant sodium lauryl sulfate (SDS) and reductant 2-mercaptoethanol (2-ME), has been specially developed to analyze food allergens in highly processed food by enhancing analyte protein extraction. Recently, however, the use of 2-ME has become undesirable. In the present study, a new extraction solution containing a human- and eco-friendly reductant, which is convenient to use at the food manufacturing site, has been established. Among three chemicals with different reducing properties, sodium sulfite, tris(3-hydroxypropyl)phosphine, and mercaptoethylamine sodium sulfite was selected as a 2-ME substitute. The protein extraction ability of SDS/0.1 M sodium sulfite solution was comparable to that of SDS/2-ME solution. Next, the ELISA performance for egg, milk, wheat, peanut, and buckwheat was evaluated by using model-processed foods and commercially available food products. The data showed that the SDS/0.1 M sulfite ELISA significantly correlated with the SDS/2-ME ELISA for all food allergens examined (p < 0.01), thereby establishing the validity of the SDS/0.1 M sulfite ELISA performance. Furthermore, the new SDS/0.1 M sulfite solution was investigated for its applicability to the lateral-flow (LF) test. The result demonstrated the successful analysis of food allergens in processed food, showing consistency with the SDS/0.1 M sulfite ELISA results. Accordingly, a harmonized analysis system for processed food comprising a screening LF test and a quantitative ELISA with identical extraction solution has been established. The ELISA based on the SDS/0.1 M sulfite extraction solution has now been authorized as the revised official method for food allergen analysis in Japan.


Assuntos
Alérgenos/isolamento & purificação , Fracionamento Químico/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Análise de Alimentos/métodos , Substâncias Redutoras/química , Alérgenos/análise , Animais , Arachis/química , Ovos/análise , Hipersensibilidade Alimentar/diagnóstico , Humanos , Mercaptoetilaminas/química , Leite/química , Fosfinas/química , Sulfitos/química , Triticum/química
12.
Talanta ; 144: 1059-64, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26452927

RESUMO

In this study, we reported a simple and sensitive fluorescence nanosensor for rapid detection of amifostine and alkaline phosphatase (ALP). The novel nanosensor was based on the fluorescence "turn on-off" of CdS quantum dots (QDs). Firstly, Cd(2+) cation could react with S(2-) anion to generate fluorescent CdS QDs in the presence of amifostine. The fluorescence (FL) intensity of amifostine-capped CdS QDs (Amifostine-CdS QDs) was increased with the increasing amounts of amifostine, and could be used for amifostine detection. However, amifostine could be converted to 2-(3-aminopropylamino) ethanethiol (WR1065) in the presence of ALP based on the dephosphorylation of ALP. Under the optimum conditions, the affinity of WR1065 to CdS QDs was weaker than that of amifostine. Therefore the new generation of WR1065-CdS QDs would reduce the FL intensity with the increase of ALP concentration, and the fluorescence of CdS QDs was turn off. The metabolic process of amifostine in the presence of alkaline phosphatase could be also studied via the change of FL intensity of CdS QDs. The present method was cost-effective, convenient, and does not require any complicated synthetic procedures.


Assuntos
Fosfatase Alcalina/análise , Amifostina/análise , Compostos de Cádmio/química , Limite de Detecção , Nanotecnologia/instrumentação , Pontos Quânticos/química , Sulfetos/química , Fosfatase Alcalina/sangue , Fosfatase Alcalina/metabolismo , Amifostina/química , Humanos , Hidrólise , Mercaptoetilaminas/química , Ácidos Fosfóricos/química , Fosforilação , Espectrometria de Fluorescência , Fatores de Tempo
13.
Health Phys ; 109(3): 242-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26222219

RESUMO

Acute radiation syndrome results from radiation exposure, such as in accidental nuclear disasters. Safe and effective radioprotectants, mitigators, and treatment drugs must be developed as medical countermeasures against radiation exposure. Here, the authors evaluated CCM-Ami, a novel polyethylene glycol micelle encapsulated with amifostine, for its radioprotective properties after total-body irradiation from a 60Co source. Male C57BL/6 mice (6-8 wk old) were intravenously injected with 45 mg kg(-1) of CCM-Ami 90 min before exposure to 7.2 and 8.5 Gy irradiation at a dose rate of 0.04 Gy min(-1). Both survival benefit and hematopoietic protection were observed after prophylactic CCM-Ami administration when compared with the effects measured in excipient control and amifostine groups. Pharmacokinetic results showed that after the intravenous injection, the plasma concentration of WR-1065, the active form of amifostine, was higher in CCM-Ami-treated mice than in amifostine-treated mice. These findings suggest that CCM-Ami-mediated hematopoietic protection plays a key role in enhancing survival of mice exposed to radiation toxicity and thus indicate that CCM-Ami is a radioprotectant that can be used safely and effectively in nuclear disasters.


Assuntos
Síndrome Aguda da Radiação/prevenção & controle , Amifostina/administração & dosagem , Protetores contra Radiação/administração & dosagem , Síndrome Aguda da Radiação/sangue , Amifostina/farmacocinética , Animais , Modelos Animais de Doenças , Relação Dose-Resposta à Radiação , Masculino , Mercaptoetilaminas/sangue , Camundongos , Camundongos Endogâmicos C57BL , Micelas , Polietilenoglicóis , Protetores contra Radiação/farmacocinética , Irradiação Corporal Total
14.
Redox Biol ; 6: 73-79, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26188467

RESUMO

Exposure to radiation can damage endothelial cells in the irradiated area via the production of reactive oxygen species. We synthesized phosphine-borane complexes that reduce disulfide bonds and had previously been shown to interfere with redox-mediated signaling of cell death. We hypothesized that this class of drugs could interfere with the downstream effects of oxidative stress after irradiation and rescue endothelial cells from radiation damage. Cultured bovine aortic endothelial cells were plated for clonogenic assay prior to exposure to varying doses of irradiation from a (137)Cs irradiator and treated with various concentrations of bis(3-propionic acid methyl ester)phenylphosphine borane complex (PB1) at different time points. The clone-forming ability of the irradiated cells was assessed seven days after irradiation. We compared the radioprotective effects of PB1 with the aminothiol radioprotectant WR1065 and known superoxide scavengers. PB1 significantly protected bovine aortic endothelial cells from radiation damage, particularly when treated both before and after radiation. The radioprotection with 1 µM PB1 corresponded to a dose-reduction factor of 1.24. Radioprotection by PB1 was comparable to the aminothiol WR1065, but was significantly less toxic and required much lower concentrations of drug (1 µM vs. 4 mM, respectively). Superoxide scavengers were not radioprotective in this paradigm, indicating the mechanisms for both loss of clonogenicity and PB1 radioprotection are independent of superoxide signaling. These data demonstrate that PB1 is an effective redox-active radioprotectant for endothelial cells in vitro, and is radioprotective at a concentration approximately 4 orders of magnitude lower than the aminothiol WR1065 with less toxicity.


Assuntos
Boranos/farmacologia , Células Endoteliais/efeitos dos fármacos , Raios gama/efeitos adversos , Fosfinas/farmacologia , Protetores contra Radiação/farmacologia , Superóxidos/antagonistas & inibidores , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aorta/efeitos da radiação , Bovinos , Células Cultivadas , Células Clonais , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Células Endoteliais/efeitos da radiação , Humanos , Mercaptoetilaminas/farmacologia , Metaloporfirinas/farmacologia , Oxirredução , Polietilenoglicóis/farmacologia , Transdução de Sinais , Superóxido Dismutase/farmacologia , Superóxidos/metabolismo
15.
Chem Biol Drug Des ; 86(2): 163-72, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25407396

RESUMO

The guardian of the genome, p53, is the most mutated protein found in all cancer cells. Restoration of wild-type activity to mutant p53 offers promise to eradicate cancer cells using novel pharmacological agents. Several molecules have already been found to activate mutant p53. While the exact mechanism of action of these compounds has not been fully understood, a transiently open pocket has been identified in some mutants. In our study, we docked twelve known activators to p53 into the open pocket to further understand their mechanism of action and rank the best binders. In addition, we predicted the absorption, distribution, metabolism, excretion and toxicity properties of these compounds to assess their pharmaceutical usefulness. Our studies showed that alkylating ligands do not all bind at the same position, probably due to their varying sizes. In addition, we found that non-alkylating ligands are capable of binding at the same pocket and directly interacting with Cys124. The comparison of the different ligands demonstrates that stictic acid has a great potential as a p53 activator in terms of less adverse effects although it has poorer pharmacokinetic properties.


Assuntos
Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/metabolismo , Alquilação , Amifostina/química , Amifostina/farmacocinética , Amifostina/toxicidade , Compostos Aza/química , Compostos Aza/farmacocinética , Compostos Aza/toxicidade , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Compostos Bicíclicos Heterocíclicos com Pontes/toxicidade , Avaliação Pré-Clínica de Medicamentos , Elipticinas/química , Elipticinas/farmacocinética , Elipticinas/farmacologia , Elipticinas/toxicidade , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacocinética , Compostos Heterocíclicos de 4 ou mais Anéis/toxicidade , Humanos , Cinética , Ligantes , Mercaptoetilaminas/química , Mercaptoetilaminas/farmacocinética , Mercaptoetilaminas/toxicidade , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Mutação , Oxepinas/química , Oxepinas/farmacocinética , Oxepinas/toxicidade , Ligação Proteica , Pirimidinas/química , Pirimidinas/farmacologia , Pirimidinas/toxicidade , Quinuclidinas/química , Quinuclidinas/farmacocinética , Quinuclidinas/toxicidade , Proteína Supressora de Tumor p53/genética
16.
Environ Mol Mutagen ; 55(7): 566-72, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24833597

RESUMO

The cytokinesis-block micronucleus cytome (CBMN) assay, introduced by Fenech, was used to demonstrate different types of DNA damage in MOLT-3 human lymphoblastoid cells exposed to 10 µM zidovudine (AZT). In addition, we explored the cytoprotective potential of two antioxidants, WR-1065 and Tempol, to decrease AZT-induced genotoxicity. Binucleated cells, arrested by Cytochalasin B (Cyt B), were evaluated for micronuclei (MN), caused by DNA damage or chromosomal loss, and chromatin nucleoplasmic bridges (NPBs), caused by telomere attrition. Additionally, nuclear buds (NBUDs), caused by amplified DNA, and apoptotic and necrotic (A/N) cells were scored. We hypothesized that AZT exposure would increase the frequency of genotoxic end points, and that the antioxidants Tempol and WR-1065 would protect against AZT-induced genotoxicity. MOLT-3 cells were exposed to 0 or 10 µM AZT for a total of 76 hr. After the first 24 hr, 0 or 5 µM WR-1065 and/or 0 or 200 µM Tempol were added for the remainder of the experiment. For the last 28 hr (of 76 hr), Cyt B was added to arrest replication after one cell division, leaving a predominance of binucleated cells. The nuclear division index (NDI) was similar for all treatment groups, indicating that the exposures did not alter cell viability. MOLT-3 cells exposed to AZT alone had significant (P < 0.05) increases in MN and NBs, compared to unexposed cells. Both Tempol and WR-1065 protected against AZT-induced MN formation (P < 0.003 for both), and WR-1065, but not Tempol, reduced the levels of A/N (P = 0.041). In cells exposed to AZT/Tempol there were significantly reduced levels of NBUDs, compared to cells exposed to AZT alone (P = 0.015). Cells exposed to AZT/WR-1065 showed reduced levels of NPBs, compared to cells exposed to AZT alone (P = 0.037). Thus WR-1065 and Tempol protected MOLT-3 cells against specific types of AZT-induced DNA damage.


Assuntos
Antioxidantes/química , Cromatina/química , Óxidos N-Cíclicos/química , Dano ao DNA , Mercaptoetilaminas/química , Zidovudina/química , Apoptose , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Proliferação de Células , Sobrevivência Celular , Cromossomos/ultraestrutura , Citocalasina B/química , Humanos , Testes para Micronúcleos , Mutagênicos/química , Necrose , Protetores contra Radiação/química , Marcadores de Spin
17.
Redox Biol ; 2: 590-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24688895

RESUMO

Many carbonyl species from either lipid peroxidation or glycoxidation are extremely reactive and can disrupt the function of proteins and enzymes. 4-hydroxynonenal and methylglyoxal are the most abundant and toxic lipid-derived reactive carbonyl species. The presence of these toxics leads to carbonyl stress and cause a significant amount of macromolecular damages in several diseases. Much evidence indicates trapping of reactive carbonyl intermediates may be a useful strategy for inhibiting or decreasing carbonyl stress-associated pathologies. There is no rapid and convenient analytical method available for the assessment of direct carbonyl scavenging capacity, and a very limited number of carbonyl scavengers have been identified to date, their therapeutic potential being highlighted only recently. In this context, we have developed a new and rapid sensitive fluorimetric method for the assessment of reactive carbonyl scavengers without involvement glycoxidation systems. Efficacy of various thiol- and non-thiol-carbonyl scavenger pharmacophores was tested both using this screening assay adapted to 96-well microplates and in cultured cells. The scavenging effects on the formation of Advanced Glycation End-product of Bovine Serum Albumin formed with methylglyoxal, 4-hydroxynonenal and glucose-glycated as molecular models were also examined. Low molecular mass thiols with an α-amino-ß-mercaptoethane structure showed the highest degree of inhibitory activity toward both α,ß-unsaturated aldehydes and dicarbonyls. Cysteine and cysteamine have the best scavenging ability toward methylglyoxal. WR-1065 which is currently approved for clinical use as a protective agent against radiation and renal toxicity was identified as the best inhibitor of 4-hydroxynonenal.


Assuntos
Aldeídos/farmacologia , Cisteamina/farmacologia , Cisteína/farmacologia , Ensaios de Triagem em Larga Escala/métodos , Aldeído Pirúvico/farmacologia , Aldeídos/antagonistas & inibidores , Animais , Células CACO-2 , Linhagem Celular Tumoral , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Mercaptoetilaminas/farmacologia , Camundongos , Aldeído Pirúvico/antagonistas & inibidores , Sensibilidade e Especificidade , Soroalbumina Bovina/metabolismo
18.
Pharmacology ; 91(5-6): 281-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23736649

RESUMO

BACKGROUND/AIMS: We have undertaken this study to investigate the feasibility of topical application of the radioprotective compound WR-2721 to the buccal mucosa. METHODS: Saliva samples were collected from 5 volunteers and were reconstituted in 3 amifostine solutions. Measurements of amifostine and WR-1065 contents were performed at 6 different time points. Young-adult guinea pigs were topically administered amifostine 50 and 100 mg to each buccal mucosa. At 0, 15 and 30 min after application, the blood samples obtained from the heart and the buccal tissues were prepared for the analysis of amifostine and WR-1065. RESULTS: There was no significant difference between the 3 concentrations of amifostine in saliva in vitro at any of the 6 study time points (p > 0.05). No WR-1065 was detected in saliva. In the guinea pigs from groups A and B, there were significant differences in concentrations of amifostine and WR-1065 in the tissues between the 0-min and 15-min subgroups and between the 0-min and 30-min subgroups (p < 0.05). The concentrations of amifostine and WR-1065 from the 15-min and 30-min subgroups did not differ statistically (p > 0.05). CONCLUSIONS: It is feasible to administer topical amifostine (WR-2721) to mucosa to prevent radiation-induced oral mucositis, and systemic absorption is negligible. Relatively high concentrations of amifostine in human saliva in vitro were maintained, although some inconsistent changes are observed.


Assuntos
Amifostina/administração & dosagem , Amifostina/farmacocinética , Mucosa Bucal/metabolismo , Protetores contra Radiação/administração & dosagem , Protetores contra Radiação/farmacocinética , Administração Bucal , Animais , Estudos de Viabilidade , Cobaias , Humanos , Mercaptoetilaminas/metabolismo , Miocárdio/metabolismo , Saliva/metabolismo
19.
Eur J Pharm Sci ; 49(4): 499-504, 2013 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-23643735

RESUMO

This study shows the effect of ion pair formation on intestinal absorption and oral bioavailability of amifostine. Amifostine is a prodrug used as a highly potent and selective radiotherapy and chemotherapy protectant but due to its low lipophilicity and charge at physiological pH range, its trans epithelial transport and its potential for oral drug delivery is very low. Ion pair formation with negatively charged counter ions was evaluated by in situ rat perfusion studies as a possible strategy to enhance intestinal absorption of amifostine. Succinic acid, phthalic acid and benzoic acid were used as counter ions. Rat intestinal perfusion studies confirmed a statistically significant increase in amifostine permeability in the presence of the counter ions in the order of succinic>phthalic>benzoic. Rat pharmacokinetic studies in vivo were performed to calculate oral absolute bioavailability of amifostine alone and with ion pairs in order to confirm the in situ perfusion results and the applicability of the ion pair approach. Intravenous and intraduodenal administrations were done in rats using a permanent jugular vein cannulation technique and a duodenal cannulation method to avoid drug degradation in stomach. In vivo oral bioavailability studies demonstrated a 20-30-fold increase in amifostine bioavailability with succinic acid depending on counter ion ratio and 10-fold increase with phthalic acid as ion pair. In summary ion pair strategy with succinic acid could enable amifostine oral administration on enteric coated formulations.


Assuntos
Amifostina/administração & dosagem , Absorção Intestinal , Ácidos Ftálicos/administração & dosagem , Protetores contra Radiação/administração & dosagem , Ácido Succínico/administração & dosagem , Administração Oral , Amifostina/farmacocinética , Animais , Ácido Benzoico/administração & dosagem , Disponibilidade Biológica , Intestino Delgado/metabolismo , Masculino , Mercaptoetilaminas/sangue , Perfusão , Pró-Fármacos , Protetores contra Radiação/farmacocinética , Ratos , Ratos Wistar
20.
Radiat Res ; 179(2): 115-24, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23237540

RESUMO

Very low doses of ionizing radiation, 5 to 100 mGy, can induce adaptive responses characterized by elevation in cell survival and reduction in micronuclei formation. Utilizing these end points, RKO human colon carcinoma and transformed mouse embryo fibroblasts (MEF), wild-type or knockout cells missing TNF receptors 1 and 2 (TNFR1(-)R2(-)), and C57BL/6 and TNFR1(-)R2(-) knockout mice, we demonstrate that intact TNF signaling is required for induction of elevated manganese superoxide dismutase (SOD2) activity (P < 0.001) and the subsequent expression of these SOD2-mediated adaptive responses when cells are challenged at a later time with 2 Gy. In contrast, amifostine's free thiol form WR1065 can directly activate NF-κB giving rise to elevated SOD2 activity 24 h later and induce an adaptive response in both MEF wild-type and TNF signaling defective TNFR1(-)R2(-) cells. Transfection of cells with SOD2 siRNA completely abolishes both the elevation in SOD2 activity and expression of the adaptive responses. These results were confirmed in vivo using a micronucleus assay in splenocytes derived from C57BL/6 and TNFR1(-)R2(-) knockout mice that were exposed to 100 mGy or 400 mg/kg amifostine 24 h prior to exposure to a 2 Gy whole-body dose. A dose of 100 mGy also conferred enhanced protection to C57BL/6 mice exposed 24 h later to 100 mg/kg of N-Ethyl-N-nitrosourea (ENU). While very low radiation doses require an intact TNF signaling process to induce a SOD2-mediated adaptive response, amifostine can induce a similar adaptive response in both TNF receptor competent and knockout cells, respectively.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/efeitos da radiação , Superóxido Dismutase/metabolismo , Alquilantes/farmacologia , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Etilnitrosoureia/farmacologia , Feminino , Instabilidade Genômica/efeitos dos fármacos , Instabilidade Genômica/efeitos da radiação , Humanos , Mercaptoetilaminas/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação
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