Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 83
Filtrar
1.
J Clin Invest ; 86(6): 1954-60, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2123888

RESUMO

Tumor necrosis factor-alpha (TNF-alpha) decreased the expression of pulmonary surfactant proteins SP-A and SP-B in human pulmonary adenocarcinoma cell lines. The effect of TNF alpha on SP-A content and mRNA in the pulmonary adenocarcinoma cell line, H441-4, was concentration and time dependent. TNF alpha decreased the cellular content of SP-A to less than 10% of control 48 h after addition. TNF alpha decreased de novo synthesis of SP-A and decreased the accumulation of SP-A in media. SP-A mRNA was decreased within 12 h of addition of TNF alpha, with nearly complete loss of SP-A mRNA observed after 24 h. Inhibitory effects of TNF alpha on SP-A mRNA were dose-related with nearly complete inhibition of SP-A mRNA caused by 25 ng/ml TNF alpha. The effects of TNF alpha on SP-A were distinct from the effects of interferon gamma which increased SP-A content approximately twofold in H441-4 cells. TNF alpha also decreased the content of SP-B mRNA. In contrast to the inhibitory effect of TNF alpha on SP-A and SP-B mRNA, TNF alpha increased mRNA encoding human manganese superoxide dismutase (Mn-SOD). TNF alpha did not inhibit growth, alter cell viability or beta-actin mRNA in either cell line. These in vitro studies demonstrate the marked pretranslational inhibitory effects of the cytokine, TNF alpha, on the expression of pulmonary surfactant proteins, SP-A and SP-B. The results support the concept that macrophage-derived cytokines may control surfactant protein expression.


Assuntos
Pulmão/metabolismo , Proteolipídeos/metabolismo , Surfactantes Pulmonares/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Northern Blotting , Epitélio/metabolismo , Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Interferon gama/farmacologia , Pulmão/citologia , Proteolipídeos/genética , Proteína A Associada a Surfactante Pulmonar , Proteínas Associadas a Surfactantes Pulmonares , Surfactantes Pulmonares/genética , RNA Mensageiro/genética , Superóxido Dismutase/genética , Células Tumorais Cultivadas
2.
Food Chem Toxicol ; 45(3): 472-85, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17084499

RESUMO

The root bark of Anisophyllea dichostyla R. Br. is traditionally used in the Democratic Republic Congo for the treatment of several conditions such as anorexia, fatigue and intestinal infections. We have identified and quantitated several polyphenol antioxidants in the methanol extract of the root bark (120g). The polyphenol content (3.32g/kg) was predominantly ellagitannins (25%) and polyhydroxyflavan-3-ols (catechins and procyanidins, 75%) with 3'-O-methyl-3,4-methylenedioxo ellagic acid 4'-O-beta-d-glucopyranoside and (-)-epicatechin as the major species in each class. These two compounds and the following species were identified unequivocally by NMR spectroscopy: (+)-catechin, (-)-epicatechin 3-O-gallate, 3-O-methyl ellagic acid, 3,3'-di-O-methyl ellagic acid, 3'-O-methyl-3,4-methylenedioxo ellagic acid, 3'-O-methyl-3,4-methylenedioxo ellagic acid 4'-O-beta-d-glucopyranoside, and 3'-O-methyl ellagic acid 4-O-beta-d-xylopyranoside. The following additional compounds were purified by semi-preparative HPLC and tentatively identified on the basis of UV spectra, HPLC-ESI-MS and nano-ESI-MS-MS: (+)-catechin-3-O-beta-d-glucopyranoside, epicatechin-(4beta-->8)-catechin (procyanidin B(1)), epicatechin-(4beta-->8)-epicatechin (procyanidin B(2)), an (epi)catechin trimer, 3-O-methyl ellagic acid 4-O-beta-d-glucopyranoside, (-)-epicatechin 3-O-vanillate, 3,4-methylenedioxo ellagic acid 4'-O- beta-d-glucopyranoside, and 3,3'-di-O-methyl ellagic acid 4-O-beta-d-xylopyranoside. Fractionation of the raw extract by column chromatography on silicic acid yielded 10 fractions. In the hypoxanthine/xanthine oxidase antioxidant assay system, CC-9 which contained a range of polyphenols dominated by (-)-epicatechin-O-gallate proved to be the most potent antioxidant fraction (IC(50)=52 micro g/mL) in terms of ROS scavenging. In terms of XO inhibition CC-8, dominated by (epi)catechin trimer and which also contained appreciable amounts of 3'-O-methyl ellagic acid 4'-O-beta-d-xylopyranoside, as well as the catechins (+)-catechin-3-O-beta-d-glucopyranoside, epicatechin-(4beta-->8)-catechin (procyanidin B(1)), and (-)-epicatechin 3-O-gallate, proved to be the most potent (IC(50)=36 micro g/mL).


Assuntos
Catequina/química , Cucurbitaceae , Ácido Elágico/química , Fitoterapia , Proantocianidinas/química , República Democrática do Congo , Humanos , Medicinas Tradicionais Africanas , Extratos Vegetais/química , Raízes de Plantas
3.
Food Chem Toxicol ; 44(7): 1038-49, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16488523

RESUMO

A method involving the coupling of high-performance liquid chromatography with electrospray ionisation mass spectrometry (HPLC-ESI-MS) for the quantitative determination of the mammalian lignans enterolactone and enterodiol in human blood and urine has been developed. In contrast to techniques previously published, the method allows direct measurement of free enterolignans as well as their monoglucuronide conjugates in human biofluids with minimal sample preparation. Thereby the method is suitable for large-scale intervention, case-control and epidemiologic studies. Comprehensive, high-precision (1)H and (13)C nuclear magnetic resonance data (CD3OD as solvent) obtained at 11.7 T in combination with polarimetric data show that the major form of lignan precursor in the linseeds used is (-)-secoisolariciresinol diglucoside ((2R,3R)-2,3-bis(4'-hydroxy-3'-methoxy-benzyl)-1,4-butanediyl-bis-beta-d-glucopyranoside) which is transformed by human intestinal bacteria into (+)-enterodiol and (+)-enterolactone. However, these metabolites are mono-glucuronidated after absorption and are detected as (-)-enterodiol 3'-beta-d-glucuronide=(2R,3R)-2-(3'-O-(beta-d-glucopyranosyluronic acid)benzyl)-3-(3''-hydroxybenzyl)-butane-1,4,diol and (-)-enterolactone 3'-beta-d-glucuronide=(2R,3R)-2-(3'-O-(beta-d-glucopyranosyluronic acid)benzyl)-3-(3''-hydroxybenzyl)-beta-butyrolactone in blood and urine.


Assuntos
Linho/química , Lignanas/análise , Cromatografia Líquida de Alta Pressão , Fermentação , Cromatografia Gasosa-Espectrometria de Massas , Glucuronídeos , Humanos , Lignanas/sangue , Lignanas/urina , Padrões de Referência , Sementes/química , Espectrometria de Massas por Ionização por Electrospray
4.
Cancer Res ; 48(6): 1680-8, 1988 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-3125967

RESUMO

19F NMR spectroscopy at 470 MHz (11.7 Tesla) has been used to directly measure the levels of 5-fluorouracil (FU) and its fluorine-containing catabolites in plasma and urine of colon cancer patients after i.v. infusion (10 min) of 60-230 mumol (8-30 mg) FU/kg, either with or without pretreatment with methotrexate (5.1-12.5 mg/kg). With a 1.5-ml sample the minimum metabolite concentration that can be quantified is approximately 15 +/- 5 microM within 30 min and 3 +/- 1 microM within 12 h of data acquisition. The first and second catabolites of FU, dihydrofluorouracil and alpha-fluoro-beta-ureidopropanoic acid, exhibit steady-state behavior with dose-dependent plasma concentrations of 5-40 microM for approximately 10-90 min after infusion (12 patients, 16 treatments). The final catabolite alpha-fluoro-beta-alanine (FBAL) was detected in plasma after 5-15 min, and the rate at which its concentration increased was independent of FU dose, while the maximum concentration reached at about the time FU disappeared (FU less than 5 microM in 1-2 h) was dose-dependent. The area under the time curve for FU in plasma increased more than linearly with dose. Several patients showed elevated levels of free fluoride anion (F-) in plasma (63 samples: median, 5 microM; maximum, 33 microM). In urine all of the above catabolites and F- could be observed. In samples with pH greater than or equal to 7.3 (methotrexate patients, due to bicarbonate infusion) N-carboxy-FBAL was also found in significant amounts. Urinary excretion of FU and catabolites amounted to 2.6-30% of the dose within 2 h (14 patients, 18 treatments) and 60-66% within 24 h (three patients). The ratio FU/creatinine in 2-h urine increased more than linearly with FU dose. Urinary fluoride concentration reached a maximum during the first day after FU infusion and returned to normal background levels after 2-3 days (four patients). The pattern of FU catabolites observed in plasma or urine did not differ significantly between responders and nonresponders to therapy or between patients with FU monotherapy and patients with methotrexate pretreatment. Cytotoxic FU anabolites, i.e., nucleotides, were not detected in plasma or urine (i.e., are less than 3 microM). Their detection in tumor tissue will be required for an assessment of individual responsiveness to FU. Possible toxic metabolic products derivable from FBAL, e.g., 2-fluoroacetate or 2-fluorocitrate, were not detected (i.e., are less than 3 microM) in plasma or urine.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Fluoruracila/metabolismo , Metotrexato/farmacologia , Neoplasias/metabolismo , Idoso , Proteínas Sanguíneas/metabolismo , Cromatografia Líquida de Alta Pressão , Feminino , Fluoretos/metabolismo , Humanos , Cinética , Espectroscopia de Ressonância Magnética , Masculino , Metotrexato/uso terapêutico , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Ligação Proteica , beta-Alanina/análogos & derivados , beta-Alanina/metabolismo
5.
Cancer Res ; 50(18): 5790-4, 1990 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-2118420

RESUMO

Gastrointestinal malignancy may spread to peritoneal surfaces in the absence of lymphatic or hematogenous metastases. To treat peritoneal carcinomatosis, a uniformly lethal disease process, extensive cytoreductive surgery and i.p. chemotherapy were combined. Early postoperative i.p. chemotherapy was instilled in the first few days after the surgical procedure in an attempt to treat anatomic sites that would be sealed off by postoperative adhesions. Mitomycin C was given on the first postoperative day at two doses, 10 and 12 mg/m2. 5-Fluorouracil was given on postoperative days 2-5 at 15 and 20 mg/kg, respectively. Median area under the curve ratio i.p./i.v. was 117 for 5-fluorouracil and 21.6 for mitomycin C. Elevated intraportal levels of drug were observed for i.p. 5-fluorouracil but not for mitomycin C. The marked pharmacokinetic advantage of postoperative i.p. suggests that this treatment strategy should be considered in a clinical trial in patients at risk for progression of peritoneal carcinomatosis.


Assuntos
Fluoruracila/administração & dosagem , Neoplasias Gastrointestinais/terapia , Mitomicinas/administração & dosagem , Neoplasias Peritoneais/terapia , Cromatografia Líquida de Alta Pressão , Terapia Combinada , Fluoruracila/farmacocinética , Humanos , Injeções Intraperitoneais , Espectroscopia de Ressonância Magnética , Mitomicina , Mitomicinas/farmacocinética
6.
Food Chem Toxicol ; 43(11): 1673-82, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16000233

RESUMO

Although it is already known that Tamarind (Tamarindus indica L.) seeds contain phenolic substances, the individual components of the seeds have not been fully identified and quantitated, and in the case of Tamarind pericarp not reported. Therefore, major polyphenolic compounds were extracted using organic solvents and the metabolites were isolated by semi-preparative high performance liquid chromatography. Their structures were elucidated by liquid chromatography-electrospray-ionisation-mass spectrometry (LC-ESI-MS), nano-electrospray-ionisation mass spectrometry (ESI-MS), and where possible by gas chromatography-mass spectrometry (GC-MS) and 1H and 13C NMR. Quantitative analysis of polyphenolic compounds in Tamarind seeds and pericarp was conducted by analytical high performance liquid chromatography (HPLC), calculated against standard curves of authentic compounds. The yields of total phenolic compounds after Soxhlet extraction with methanol were 6.54 and 2.82 g/kg (dry weight) in the seeds and pericarp respectively. The profile (%) of polyphenolics in Tamarind pericarp was dominated by proanthcyanidins (73.4) in various forms (+)-catechin (2.0), procyanidin B2 (8.2), (-)-epicatechin (9.4), procyanidin trimer (11.3), procyanidin tetramer (22.2), procyanidin pentamer (11.6), procyanidin hexamer (12.8) along with taxifolin (7.4), apigenin (2.0), eriodictyol (6.9), luteolin (5.0) and naringenin (1.4) of total phenols, respectively. The content of Tamarind seeds comprised only procyanidins, represented (%) mainly by oligomeric procyanidin tetramer (30.2), procyanidin hexamer (23.8), procyanidin trimer (18.1), procyanidin pentamer (17.6) with lower amounts of procyanidin B2 (5.5) and (-)-epicatechin (4.8). Extraction of Tamarind pericarp and seeds using acetone:methanol:acetic acid gave only procyanidin oligomers, but in much higher yield and variety. The antioxidant capacities of the Soxhlet methanolic extracts were determined, and indicates that Tamarind may be an important source of cancer chemopreventive natural products in tropical regions.


Assuntos
Antioxidantes/química , Fenóis/química , Tamarindus/química , Antioxidantes/isolamento & purificação , Biflavonoides/química , Biflavonoides/isolamento & purificação , Catequina/química , Catequina/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Desoxiguanosina/química , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Fenóis/isolamento & purificação , Extratos Vegetais/química , Proantocianidinas/química , Proantocianidinas/isolamento & purificação , Sementes/química , Espectrometria de Massas por Ionização por Electrospray , Taninos/química , Taninos/isolamento & purificação , Xantina Oxidase/química
7.
Eur J Cancer ; 36(10): 1235-47, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10882862

RESUMO

In our ongoing studies on the chemoprevention of cancer we have a particular interest in the health benefits of the Mediterranean diet, of which olive oil is a major component. Recent studies have shown that extravirgin olive oil contains an abundance of phenolic antioxidants including simple phenols (hydroxytyrosol, tyrosol), aldehydic secoiridoids, flavonoids and lignans (acetoxypinoresinol, pinoresinol). All of these phenolic substances are potent inhibitors of reactive oxygen species attack on, e.g. salicylic acid, 2-deoxyguanosine. Currently there is growing evidence that reactive oxygen species are involved in the aetiology of fat-related neoplasms such as cancer of the breast and colorectum. A plausible mechanism is a high intake of omega-6 polyunsaturated fatty acids which are especially prone to lipid peroxidation initiated and propagated by reactive oxygen species, leading to the formation (via alpha,beta-unsaturated aldehydes such as trans-4-hydroxy-2-nonenal) of highly pro-mutagenic exocyclic DNA adducts. Previous studies have shown that the colonic mucosa of cancer patients and those suffering from predisposing inflammatory conditions such as ulcerative colitis and Crohn's disease generates appreciably higher quantities of reactive oxygen species compared with normal tissue. We have extended these studies by developing accurate high performance liquid chromatography (HPLC) methods for the quantitation of reactive oxygen species generated by the faecal matrix. The data shows that the faecal matrix supports the generation of reactive oxygen species in abundance. As yet, there is a dearth of evidence linking this capacity to actual components of the diet which may influence the colorectal milieu. However, using the newly developed methodology we can demonstrate that the antioxidant phenolic compounds present in olive oil are potent inhibitors of free radical generation by the faecal matrix. This indicates that the study of the inter-relation between reactive oxygen species and dietary antioxidants is an area of great promise for elucidating mechanisms of colorectal carcinogenesis and possible future chemopreventive strategies.


Assuntos
Antioxidantes/isolamento & purificação , Neoplasias da Mama/prevenção & controle , Neoplasias Colorretais/prevenção & controle , Fenóis/uso terapêutico , Óleos de Plantas/química , Antioxidantes/uso terapêutico , Cromatografia Líquida de Alta Pressão/métodos , Dieta , Feminino , Humanos , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Azeite de Oliva , Fenóis/isolamento & purificação , Óleos de Plantas/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo
8.
J Med Chem ; 43(21): 3913-22, 2000 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-11052796

RESUMO

Several radioiodinated N-(dialkylaminoalkyl)benzamides have been used for planar scintigraphy and single-photon emission computed tomography (SPECT) of melanoma metastases. In a quest for improved melanoma uptake and tissue selectivity, structure-activity studies for N-(2-diethylaminoethyl)benzamides with variation of phenyl substituents were performed using C57Bl/6 mice bearing B16 melanoma. Compounds 2 (4-amino-5-bromo-N-(2-diethylaminoethyl)-3-[(131)I]iodo-2-methoxybenz amide) and 6 (4-acetamido-N-(2-diethylaminoethyl)-5-[(131)I]iodo-2-methoxybenzamid e) showed at 6 h post iv injection, for example, melanoma uptake of 16.6 and 23.2% ID/g, respectively (mean values, n = 3). Uptake was 3-5 times higher (P < 0.01) than observed with benzamides known from the literature and was probably facilitated by the relatively slow urinary excretion of 2 or 6. In contrast, analogues lacking either the MeO, Ac, AcNH, or Br substituents exhibited reduced tumor uptake and high urinary excretion of radioactivity in various benzamide metabolites. Uptake of radioiodinated benzamides in B16 melanoma is not mediated by a specific mechanism such as sigma-receptor binding. 2 and 6 exhibited similar melanoma uptake values but quite different sigma(1)-receptor affinities of K(i) = 0.278 +/- 0.018 and 5.19 +/- 0.40 microM, respectively. Uptake studies with IMBA (N-(2-diethylaminoethyl)-3-[(131)I]iodo-4-methoxybenzamide) or BZA (N-(2-diethylaminoethyl)-4-[(131)I]iodobenzamide) showed that with increasing dose of unlabeled compound the measured uptake of label was unchanged (IMBA) or even enhanced (BZA) while receptor binding of label decreased. Differential and equilibrium density-gradient centrifugation revealed that most of the radioactivity from labeled IMBA was associated with fractions containing melanin granules. Thus, structure-activity studies indicate that blood clearance rates and metabolic stability are the main determinants for benzamide uptake in melanoma. The high uptake and slow clearance of 6 offer considerable potential for melanoma imaging in patients, and this compound may also prove to be useful for radionuclide therapy.


Assuntos
Benzamidas/síntese química , Meios de Contraste/síntese química , Iodobenzenos/síntese química , Melanoma/metabolismo , Animais , Benzamidas/química , Benzamidas/metabolismo , Benzamidas/urina , Encéfalo/metabolismo , Centrifugação com Gradiente de Concentração , Cromatografia Líquida de Alta Pressão , Meios de Contraste/química , Meios de Contraste/metabolismo , Cobaias , Técnicas In Vitro , Radioisótopos do Iodo , Iodobenzenos/química , Iodobenzenos/metabolismo , Fígado/metabolismo , Espectrometria de Massas , Melaninas/metabolismo , Melanoma/patologia , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Receptores sigma/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
9.
J Med Chem ; 44(24): 4050-61, 2001 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-11708909

RESUMO

A series of potential inhibitors of the human DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT) were synthesized, characterized in detail by NMR, and tested for their ability to deplete MGMT activity in vitro. The new compounds, omega-[O(6)-R-guan-9-yl]-(CH(2))(n)-beta-d-glucosides with R = benzyl or 4-bromothenyl and omega = n = 2, 4,. 12, were compared with the established inhibitors O(6)-benzylguanine (O(6)-BG), 8-aza-O(6)-benzylguanine (8-aza-BG), and O(6)-(4-bromothenyl)guanine (4-BTG), which exhibit in an in vitro assay IC(50) values of 0.62, 0.038, and 0.009 microM, respectively. Potential advantages of the glucosides are improved water solubility and selective uptake in tumor cells. The 4-BTG glucosides with n = 2, 4, 6 show moderate inhibition with an IC(50) of ca. 0.5 microM, while glucosides derived from BG and 8-aza-BG showed significantly poorer inhibition compared to the parent compounds. The 4-BTG glucosides with n = 8, 10, 12 were effective inhibitors with IC(50) values of ca. 0.03 microM. To understand this behavior, extensive molecular modeling studies were performed using the published crystal structure of MGMT (PDB entry: ). The inhibitor molecules were docked into the BG binding pocket, and molecular dynamics simulations with explicit water molecules were carried out. Stabilization energies for the interactions of specific regions of the inhibitor and individual amino acid residues were calculated. The alkyl spacer is located in a cleft along helix 6 of MGMT. With increasing spacer length there is increasing interaction with several amino acid residues which play an important role in the proposed nucleotide flipping mechanism required for DNA repair.


Assuntos
Inibidores Enzimáticos/síntese química , Glucosídeos/síntese química , Guanina/análogos & derivados , Guanina/síntese química , Monossacarídeos/química , O(6)-Metilguanina-DNA Metiltransferase/antagonistas & inibidores , Sistema Livre de Células , Cristalografia por Raios X , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Guanina/química , Guanina/farmacologia , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , O(6)-Metilguanina-DNA Metiltransferase/química , Solubilidade , Relação Estrutura-Atividade
10.
J Nucl Med ; 38(1): 127-33, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8998166

RESUMO

UNLABELLED: The development of an effective radiopharmaceutical with affinity for malignant melanoma has been a research goal for some time. The early detection of melanoma metastases would greatly improve the therapy outcome for this disease. This article describes the synthesis of radioiodinated IMBA, N-(2-diethylaminoethyl)-3-[123I/131I]iodo-4-methoxybenzamide 8, its organ distribution, its comparison with BZA and other benzamides, and demonstrates the scintigraphic efficacy of the title compound with three melanoma patients. METHODS: The syntheses and radioiodination of eight benzamide derivatives are described. After intravenous injection into C57B16-mice subcutaneously transplanted with B16 melanoma, the organ distribution of the respective benzamides were investigated at 1 and 6 hr. n-octanol/phosphate buffer partition coefficients. The wholebody retention, erythrocyte and serum protein bound fractions of radioiodinated benzamides were measured. RESULTS: While structural changes in the amide substituents of N-(2-dialkylaminoalkyl)-4-iodobenzamides 2-7 resulted in no improvement in organ distribution compared with BZA, the 3-iodo-4-methoxyphenyl form of IMBA showed high melanoma uptake with significantly higher melanoma/nontarget tissue ratios. Compared with BZA the average ratio improved after 1 hr by a factor of eight and was still four times better after 6 hr. BZA and IMBA exhibit almost identical n-octanol/ phosphate buffer partition coefficients, however, IMBA has a faster urinary excretion facilitated by a lower affinity to erythrocytes and serum proteins; this could explain the improved tissue partinioning observed. Scintigraphy of patients with melanoma metastases confirmed the promising characteristics derived from the animal studies. CONCLUSION: Due to rapid background clearance and high melanoma affinity, IMBA showed high tumor contrast already at 4 hr after injection which makes it a promising new radiopharmaceutical for the scintigraphic detection of melanoma metastases.


Assuntos
Benzamidas/farmacocinética , Meios de Contraste , Radioisótopos do Iodo/farmacocinética , Melanoma/metabolismo , Compostos Radiofarmacêuticos/farmacocinética , Animais , Feminino , Humanos , Marcação por Isótopo/métodos , Masculino , Melanoma/diagnóstico por imagem , Melanoma/secundário , Melanoma Experimental/diagnóstico por imagem , Melanoma Experimental/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Cintilografia , Distribuição Tecidual
11.
J Nucl Med ; 38(12): 1864-9, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9430459

RESUMO

UNLABELLED: PHIPA 3-10 [13-(4'-iodophenyl)-3-(p-phenylene)tridecanoic acid] is a p-phenylene-bridged, radioiodinated omega-phenyl fatty acid that has recently been developed to study coronary artery disease or cardiomyopathies. Here, we demonstrate that PHIPA 3-10 exhibits the characteristics of a long-chain fatty acid, including its ability to be efficiently taken up by myocytes and to function as a substrate for beta-oxidation before it is trapped. METHODS: Myocardial metabolism of carrier-added and carrier-free 131I-PHIPA 3-10 preparations were investigated in rats in vivo and in isolated Langendorff rat hearts. Heart extracts were analyzed by high-performance liquid chromatography, negative-ion electrospray mass spectrometry and investigation of intracellular distribution using density-gradient centrifugation. RESULTS: A single, rapidly formed metabolite was found in the heart extract and also, surprisingly, in the hydrolyzed lipids. The total amount of metabolite increased from 43% to 51% between 15 and 60 min postinjection. By high-performance liquid chromatography comparison with synthetic potential catabolites, the metabolite was assigned the name PHIPA 1-10 [11-(4'-iodophenyl)-1-(p-phenylene)undecanoic acid] and was the product of one beta-oxidation cycle. Additional proof was obtained from the mass spectrometric analysis of the metabolite formed in vivo. The formation of this metabolite could be suppressed by Etomoxir, a carnitine palmitoyl transferase I inhibitor, indicating beta-oxidation of 131I-PHIPA 3-10 in mitochondria. Final evidence for the involvement of mitochondria in the degradation of 131I-PHIPA 3-10 was obtained by density-gradient centrifugation of homogenized rat heart tissue. The position of the labeled free PHIPA 3-10 and free metabolite peaked within the fraction containing mainly mitochondria. CONCLUSION: In spite of its bulky structure, 131I-PHIPA 3-10 is extracted by the myocardium in a manner similar to the extraction of the unmodified fatty acid analog, IPPA. The retention of PHIPA 3-10 in heart muscle results from the presence of the p-phenylene group, which prevents more than one beta-oxidation cycle. Intracellular free PHIPA 3-10 and free PHIPA 1-10 are present in the mitochondria, whereas most of the esterified metabolite was found in the cytosolic lipid pool. Hence, the rapid appearance of PHIPA 1-10 in the lipid pool must be accounted for by mitochondrial leakage or by an unknown in-out transport system.


Assuntos
Coração/diagnóstico por imagem , Radioisótopos do Iodo , Miocárdio/metabolismo , Fenilpropionatos , Animais , Meios de Contraste/química , Meios de Contraste/farmacocinética , Radioisótopos do Iodo/farmacocinética , Masculino , Fenilpropionatos/química , Fenilpropionatos/farmacocinética , Cintilografia , Ratos , Ratos Sprague-Dawley
12.
J Cancer Res Clin Oncol ; 117(4): 295-304, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1829730

RESUMO

The influence of infusion time and dose on the anticancer efficacy of 5-fluoro-2'-deoxyuridine (FdUrd) was investigated using a locoregional therapy model: Novikoff hepatoma transplanted i.m. into the thigh of Wistar rats and FdUrd infusion via a catheter implanted in the femoral artery. In experiment A the FdUrd dose (five daily doses of 12, 19 and 30 mg/kg) and the duration of administration (bolus, 1 h, 5 h, and 24 h) were varied. The change in tumor volume following treatment and the number of rats showing regression vs progression served as indicators of therapy response. The results showed a clear dose dependence, and for each infusion time the 30 mg/kg dose was the most effective, without any signs of general toxicity. At this dose the longest infusion time (24 h) was less effective (regression in three of six rats) compared with 1-h or 5-h treatments (four of five in regression). In experiment B either one or five daily FdUrd doses (15, 30, 60 mg/kg) were administered i.a. for the same infusion times used in experiment A. After treatment, tumors were explanted ex vivo and approximately 1-g tissues samples were immediately frozen in liquid nitrogen for storage. 19F-NMR spectroscopy at 11.7 T was used to quantify FdUrd metabolites [5-fluorouracil (FUra), alpha-fluoro-beta-alanine (F beta Ala), 5-fluorouracil nucleosides and nucleotides (F-Nuc)] in the solid tumor tissue samples (maintained at 4 degrees C) with a detection threshold of about 5 nmol/g. The metabolite signal pattern indicated that FdUrd is first converted to FUra, followed by anabolism primarily to nucleotides in the oxy form (e.g. FUTP). The total amount of fluorine detected in tumor tissue increased with dose and decreased with infusion time. For all treatments FNuc could be detected, even after 24 h infusion, and their levels showed a good linear correlation with the total F. The major catabolite F beta Ala was present in tumor at low levels that correlated poorly with total F, indicating recirculation from other organs (e.g. liver) as the main source. Thus, the NMR method can provide detailed information regarding the efficiency of locoregional treatment (catheter function, drug uptake and metabolism). Initial results of non-invasive in vivo NMR experiments are also presented.


Assuntos
Floxuridina/administração & dosagem , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Animais , Esquema de Medicação , Feminino , Floxuridina/metabolismo , Floxuridina/farmacologia , Flúor , Infusões Intra-Arteriais , Neoplasias Hepáticas Experimentais/metabolismo , Espectroscopia de Ressonância Magnética , Transplante de Neoplasias , Ratos , Ratos Endogâmicos
13.
Cancer Chemother Pharmacol ; 38(4): 355-65, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8674159

RESUMO

beta-D-Glucosylisophosphoramide mustard (beta-D-Glc-IPM) is a new, potential chemotherapeutic agent currently under investigation. Its pharmacokinetics in plasma and elimination of the parent drug and its metabolites via urine, bile, and exhaled air were studied in female Sprague-Dawley rats after bolus injection of 315 mg/kg. Typically, the drug's disposition from plasma follows a linear two-compartment model with half-lives (t1/2) of 1.8 (t1/2 alpha) and 32 min (t1/2 beta). The rate of clearance is 0.0046 (range 0.0030-0.0071) 1 min-1 kg-1, and the steady-state volume of distribution (Vss) is 0.18 (0.08-0.042) 1/kg (mean +/- inter-individual standard deviation). In human plasma, 28.1 +/- 2.6% (mean +/- SD) of the drug (concentration range 0.5-5 mg/ml) is bound to plasma proteins (predominantly to albumin). Biliary excretion of the parent drug accounts for 2.9 +/- 1.7% of the dose; its elimination in the form of 14CO2 via exhaled air is less than 1%. Within 24 h, 63.5 +/- 4.9% of the 14C-labeled drug is excreted unchanged in the urine, whereas 17.5 +/- 5.1% is excreted in the urine as metabolites. In addition, beta-D-Glc-[14C]-IPM was given as a bolus injection to female Sprague-Dawley rats at dose levels of 315 and 56.2 mg/kg. The distribution of radioactivity into tissue was examined qualitatively by whole-body autoradiography (WBA). Parallel experiments were carried out using the high dose of the L-derivative. After dosing with the D-compound, the highest levels of radioactivity were found in the liver, kidneys, thymus, thyroid gland, and central nervous system, including the brain. A similar distribution pattern was observed for the L-compound, except in the brain, which contained negligible levels of radioactivity. The distribution of the D-compound (high dose) was also investigated in male Copenhagen rats bearing a Dunning prostate tumor. The results were similar to those obtained in healthy Sprague-Dawley rats. Additionally, radioactivity was found in the tumor at 1 h after dosing with the drug and remained there even after 24 h. The effects of beta-D-Glc-IPM on the incorporation of [methyl-3H]-thymidine into the DNA of the liver, kidneys, thymus, spleen, esophagus, and bone marrow of the rat were examined following tissue excision and liquid scintillation counting at 2, 8, and 24 h after administration of the drug. beta-D-Glc-IPM showed no effect on the incorporation of [methyl-3H]-thymidine in the liver and an insignificant reduction in kidney DNA (maximal reduction: -27.3%). However, after 8 h there was a marked reduction in the incorporation rate in the thymus (-83.7%), spleen (-74.6%), and esophagus (-87.2%), with a tendency toward recovery within 24 h. In bone marrow cells a reduction of -75.5% (8 h) and -73.3% (24 h) was observed.


Assuntos
Antineoplásicos/farmacocinética , Glucose/análogos & derivados , Ifosfamida/análogos & derivados , Timidina/análogos & derivados , Animais , Antineoplásicos/metabolismo , Autorradiografia , Bile/metabolismo , DNA de Neoplasias/metabolismo , Feminino , Glucose/metabolismo , Glucose/farmacocinética , Meia-Vida , Humanos , Ifosfamida/metabolismo , Ifosfamida/farmacocinética , Masculino , Taxa de Depuração Metabólica , Neoplasias da Próstata/metabolismo , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Albumina Sérica/metabolismo , Estereoisomerismo , Timidina/metabolismo , Distribuição Tecidual , Trítio
14.
Adv Enzyme Regul ; 30: 231-42, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2403033

RESUMO

The metabolism of 2-deoxy-2-fluoro-D-galactose (dGalF) was studied in rodents using HPLC, enzymatic methods, and 19F-NMR spectroscopy in vivo and in vitro. The liver took up the major part of the administered dose of the 14C-labeled D-galactose analog. This was confirmed in vivo by use of the 18F-labeled sugar (1.5 mCi/kg; 25 mumol/kg) and examination by positron emission tomography. After a dose of 1 mmol/kg, dGalF-1-phosphate accumulated rapidly (5.3 +/- 0.4 mmol/kg after 30 min), followed by formation of UDP-dGalF and UDP-2-deoxy-2-fluoro-D-glucose (0.7 +/- 0.1 and 1.8 +/- 0.1 mmol/kg, respectively, after 5 hr). Good quantitative agreement was obtained between the measurements by HPLC and enzymatic analyses and by 19F-NMR. The noninvasive in vivo 19F-NMR technique is particularly advantageous, since it allows the simultaneous analysis of all dGalF metabolites. The diversion of uridylate, due to the accumulation of UDP-2-deoxy-2-fluoro-D-hexoses, was associated with a rapid depletion of hepatic UTP, UDP-glucose, and UDP-galactose. The UTP content was decreased to 11 +/- 6% of normal within 15 min after administration of dGalF at a dose of 1 mmol/kg. The UTP-depleting action was minimal, however, at a dose of 25 mumol/kg or less, indicating that interference in uridylate metabolism will be negligible at the doses required for positron emission tomography of the liver using the 18F-labeled compound. At higher doses the UTP deficiency induced by dGalF may be useful in the chemotherapy of D-galactose-metabolizing tumors such as hepatocellular carcinoma. At moderate doses of dGalF, 19F-NMR spectroscopy in vivo or in vitro could be used to pinpoint defects of the enzymes that cause galactosemia, i.e. of galactokinase, uridyltransferase, or 4-epimerase.


Assuntos
Encéfalo/metabolismo , Fucose/análogos & derivados , Rim/metabolismo , Fígado/metabolismo , Uridina Trifosfato/metabolismo , Bexiga Urinária/metabolismo , Animais , Encéfalo/diagnóstico por imagem , Cromatografia Líquida de Alta Pressão , Feminino , Flúor , Radioisótopos de Flúor , Fucose/metabolismo , Fucose/farmacologia , Galactose , Hidrogênio , Rim/diagnóstico por imagem , Cinética , Fígado/diagnóstico por imagem , Espectroscopia de Ressonância Magnética/métodos , Camundongos , Camundongos Endogâmicos , Ratos , Ratos Endogâmicos , Tomografia Computadorizada de Emissão , Bexiga Urinária/diagnóstico por imagem
15.
Anticancer Res ; 16(3B): 1365-74, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8694503

RESUMO

31P magnetic resonance spectroscopy has been used to determine phosphate metabolite profiles in five human tumor cell lines in culture and as solid tumor xenografts in nude mice. Significant differences between cell lines, in particular in their phospholipid metabolite levels, were observed. The largest differences between metabolite profiles in vivo and in culture were observed for cell lines which exhibit low phosphoethanolamine levels in culture. One of these lines, the colon carcinoma CX-1, was studied in more detail in both incubated and perfused DMEM cultures with variation of the concentrations of glucose, choline and ethanolamine. Highly significant alterations of phospholipid metabolite concentrations and UDP-hexoses (primarily UDP-GlcNAc and UDP-GalNAc) were observed as a function of the precursor concentrations, culture time or perfusion time. A strong interaction between phospholipid metabolic pathways and UDP-hexose pathways could be demonstrated.


Assuntos
Neoplasias/metabolismo , Fosfolipídeos/metabolismo , Animais , Colina/farmacologia , Meios de Cultura , Etanolamina , Etanolaminas/farmacologia , Glucose/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Camundongos , Células Tumorais Cultivadas , Uridina Difosfato Glucose/metabolismo
16.
Food Chem Toxicol ; 41(5): 703-17, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12659724

RESUMO

Because olives represent an important component of the Mediterranean diet, it is necessary to establish unequivocal identification and quantitation of the major potential antioxidant phenolic compounds they contain. The major phenolic antioxidants in two types of brined olives were isolated and purified by semi-preparative high performance liquid chromatography. Structural analysis was conducted using UV spectrophotometry, mass spectrometry and nuclear magnetic resonance spectroscopy. In particular, completely assigned 1H and 13C NMR data are presented and errors in literature data are corrected. The data show that tyrosol, hydroxytyrosol, 3-(3, 4-dihydroxyphenyl) propanoic acid (dihydrocaffeic acid), dihydro-p-coumaric acid (phloretic acid), the phenylpropanoid glucosides acteoside (verbascoside) and isoacteoside, along with the flavonoids luteolin and apigenin are major components of the phenolic fraction of brined black olives. Brined green olives contain only hydroxytyrosol and traces of other minor phenolics. Brined olives contain even higher concentrations of phenolic antioxidants than olive oil and may, therefore, be more important modulators of cancer chemopreventive activity.


Assuntos
Antioxidantes/farmacologia , Flavonoides/farmacologia , Olea/química , Fenóis/farmacologia , Antioxidantes/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Flavonoides/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Fenóis/química , Fenóis/isolamento & purificação , Extratos Vegetais , Espécies Reativas de Oxigênio , Espectrofotometria Ultravioleta
17.
Food Chem Toxicol ; 41(12): 1727-38, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14563398

RESUMO

Although it is already known that carob fibre contains several classes of polyphenolic substances, a comprehensive analysis of these has not been conducted to date. Therefore, the major polyphenolic compounds were extracted with organic solvents, and, following fractionation by normal-phase column chromatography on silicic acid, their structures were elucidated by liquid-chromatography electrospray-ionisation mass spectrometry (LC-ESI), nano-electrospray-ionisation mass spectrometry (ESI-MS), and gas-chromatography mass spectrometry (GC-MS). In addition, complete 1H and 13C NMR assignments were obtained for the isolated gallotannins 1,6-di-, 1,2,6-tri- and 1,2,3,6-tetra-O-galloyl-beta-D-glucose. Carob fibre was found to contain a rich variety of phenolic antioxidants. A total of 24 polyphenol compounds were identified with a yield of 3.94 g/kg (dry weight). The profile was dominated by gallic acid in various forms: free gallic acid (42% of polyphenols by weight), gallotannins (29%), and methyl gallate (1%), while simple phenols, mainly cinnamic acid, made up about 2% of the total. Flavonoids represented 26% of the polyphenols, and the major components were identified as the glycosides myricetin- and quercetin-3-O-alpha-L-rhamnoside (ca. 9% and 10%, respectively). These data indicate that carob fibre is rich in both amount and variety of phenolic antioxidant substances, and its inclusion in the diet may have chemopreventive properties.


Assuntos
Fibras na Dieta/análise , Flavonoides/química , Fenóis/química , Polissacarídeos/química , Cromatografia por Troca Iônica , Flavonoides/isolamento & purificação , Galactanos , Cromatografia Gasosa-Espectrometria de Massas , Hidrólise , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Mananas , Fenóis/análise , Fenóis/isolamento & purificação , Gomas Vegetais , Polifenóis , Ácido Silícico/química , Espectrometria de Massas por Ionização por Electrospray
18.
Food Chem Toxicol ; 38(8): 647-59, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10908812

RESUMO

The aim of this study was to evaluate the phenolic antioxidant and squalene content in a range of olive and seed oils. A mean of 290 +/- 38 (SEM) mg squalene/100 g was detected. However, while there was a weak significant difference between extra virgin (424 +/- 21 mg/kg) and refined virgin (340 +/- 31 mg/100 g; P<0.05) olive oils, highly significant differences were evident between extra virgin olive oils (P<0.0001) refined virgin olive oils (P<0.0001) and seed oils (24 +/- 5 mg/100 g). While seed oils were devoid, on average, the olive oils contained 196 +/- 19 mg/kg total phenolics as judged by HPLC analysis, but the value for extra virgin (232 +/- 15 mg/kg) was significantly higher than that of refined virgin olive oil (62 +/- 12 mg/kg; P<0.0001). Appreciable quantities of simple phenols (hydroxytyrosol and tyrosol) were detected in olive oils, with significant differences between extravirgin (41.87 +/- 6.17) and refined virgin olive oils (4.72 +/- 215; P<0.01). The major linked phenols were secoiridoids and lignans. Although extra virgin contained higher concentrations of secoiridoids (27.72 +/- 6.84) than refined olive oils (9.30 +/- 3.81) this difference was not significant. On the other hand, the concentration of lignans was significantly higher (P<0.001) in extra virgin (41.53 +/- 3.93) compared to refined virgin olive oils (7.29 +/- 2.56). All classes of phenolics were shown to be potent antioxidants. In future epidemiologic studies, both the nature and source of olive oil consumed should be differentiated in ascertaining cancer risk.


Assuntos
Antioxidantes/análise , Gorduras Insaturadas na Dieta/análise , Glucosídeos/análise , Lignanas/análise , Fenóis/análise , Óleos de Plantas/análise , Piranos/análise , Esqualeno/análise , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Cromatografia Gasosa-Espectrometria de Massas , Iridoides , Espectroscopia de Ressonância Magnética , Azeite de Oliva , Sementes/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA