Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Mais filtros

Métodos Terapêuticos e Terapias MTCI
Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Front Endocrinol (Lausanne) ; 12: 774667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34887835

RESUMO

Objective: To characterize the serum metabolomic profile and its role in the prediction of poor ovarian response (POR). Patients: Twenty-five women with normal ovarian reserve (24-33 years, antral follicle count [AFC] ≥5, anti-Müllerian hormone [AMH] ≥1.2 ng/ml) as the control group and another twenty-five women with POR (19-35 years, AFC <5, AMH < 1.2 ng/ml) as the study group were collected in our study. The serum levels of the women in both groups were determined from their whole blood by untargeted liquid chromatography-mass spectrometry (LC-MS). Multivariate statistical analysis and cell signal pathways analysis were used to reveal the results. Results: A total of 538 different metabolites were finally identified in the two groups. Tetracosanoic acid, 2-arachidonoylglycerol, lidocaine, cortexolone, prostaglandin H2,1-naphthylamine, 5-hydroxymethyl-2-furancarboxaldehyde, 2,4-dinitrophenol, and D-erythrulose1-phosphate in POR were significantly different from control as were most important metabolites in support vector machines (p <0.05). Metabolomic profiling, together with support vector machines and pathway analysis found that the nicotinate and nicotinamide metabolism pathway, including L-aspartic acid, 6-hydroxynicotinate, maleic acid, and succinic acid semialdehyde, was identified to have significant differences in POR women compared to control women, which may be associated with ovarian reserve. Conclusion: This study indicated that LC-MS-based untargeted metabolomics analysis of serum provided biological markers for women with POR. The nicotinate and nicotinamide metabolism pathway may offer new insight into the complementary prediction and therapeutic potential of POR. The functional associations of these metabolites need further investigation.


Assuntos
Infertilidade Feminina/diagnóstico , Metaboloma , Reserva Ovariana/fisiologia , Adulto , Hormônio Antimülleriano/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , China , Feminino , Humanos , Infertilidade Feminina/sangue , Redes e Vias Metabólicas , Metabolômica , Niacina/sangue , Niacina/metabolismo , Niacinamida/sangue , Niacinamida/metabolismo , Indução da Ovulação , Prognóstico , Adulto Jovem
2.
Mol Nutr Food Res ; 64(18): e2000489, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32776430

RESUMO

SCOPE: The present study assesses the absorption, pharmacokinetics, and urinary excretion of coffee pyridines and their metabolites after daily regular exposure to specific dosages of coffee or cocoa-based products containing coffee (CBPCC), considering different patterns of consumption. METHODS AND RESULTS: In a three-arm, crossover, randomized trial, 21 volunteers are requested to randomly consume for 1 month: one cup of espresso coffee per day, three cups of espresso coffee per day, or one cup of espresso coffee plus two CBPCC twice per day. The last day of the one-month treatment, blood and urine samples are collected for 24 h. Trigonelline, N-methylpyridinium, N-methylnicotinamide, and N-methyl-4-pyridone-5-carboxamide are quantified. Trigonelline and N-methylpyridinium absorption curves and 24-h urinary excretion reflect the daily consumption of different servings of coffee or CBPCC, showing also significant differences in main pharmacokinetic parameters. Moreover, inter-subject variability due to sex and smoking is assessed, showing sex-related differences in the metabolism of trigonelline and smoking-related ones for N-methylpyridinium. CONCLUSION: The daily exposure to coffee pyridines after consumption of different coffee dosages in a real-life setting is established. This data will be useful for future studies aiming at evaluating the bioactivity of coffee-derived circulating metabolites in cell experiments, mimicking more realistic experimental conditions.


Assuntos
Cacau , Café , Piridinas/farmacocinética , Piridinas/urina , Adulto , Alcaloides/sangue , Alcaloides/urina , Estudos Cross-Over , Feminino , Humanos , Masculino , Niacinamida/análogos & derivados , Niacinamida/sangue , Niacinamida/urina , Piridinas/sangue , Compostos de Piridínio/sangue , Compostos de Piridínio/urina , Fatores Sexuais , Fumar
3.
Mol Syst Biol ; 16(4): e9495, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32337855

RESUMO

The prevalence of non-alcoholic fatty liver disease (NAFLD) continues to increase dramatically, and there is no approved medication for its treatment. Recently, we predicted the underlying molecular mechanisms involved in the progression of NAFLD using network analysis and identified metabolic cofactors that might be beneficial as supplements to decrease human liver fat. Here, we first assessed the tolerability of the combined metabolic cofactors including l-serine, N-acetyl-l-cysteine (NAC), nicotinamide riboside (NR), and l-carnitine by performing a 7-day rat toxicology study. Second, we performed a human calibration study by supplementing combined metabolic cofactors and a control study to study the kinetics of these metabolites in the plasma of healthy subjects with and without supplementation. We measured clinical parameters and observed no immediate side effects. Next, we generated plasma metabolomics and inflammatory protein markers data to reveal the acute changes associated with the supplementation of the metabolic cofactors. We also integrated metabolomics data using personalized genome-scale metabolic modeling and observed that such supplementation significantly affects the global human lipid, amino acid, and antioxidant metabolism. Finally, we predicted blood concentrations of these compounds during daily long-term supplementation by generating an ordinary differential equation model and liver concentrations of serine by generating a pharmacokinetic model and finally adjusted the doses of individual metabolic cofactors for future human clinical trials.


Assuntos
Acetilcisteína/administração & dosagem , Carnitina/administração & dosagem , Metabolômica/métodos , Niacinamida/análogos & derivados , Serina/administração & dosagem , Acetilcisteína/sangue , Adulto , Animais , Carnitina/sangue , Suplementos Nutricionais , Quimioterapia Combinada , Voluntários Saudáveis , Humanos , Masculino , Modelos Animais , Niacinamida/administração & dosagem , Niacinamida/sangue , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Medicina de Precisão , Compostos de Piridínio , Ratos , Serina/sangue
4.
J Agric Food Chem ; 66(22): 5723-5732, 2018 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-29758980

RESUMO

The objective of this study was to evaluate alterations in serum metabolites of transition dairy cows affected by biotin (BIO) and nicotinamide (NAM) supplementation. A total of 40 multiparous Holsteins were paired and assigned randomly within a block to one of the following four treatments: control (T0), 30 mg/day BIO (TB), 45 g/day NAM (TN), and 30 mg/day BIO + 45 g/day NAM (TB+N). Supplemental BIO and NAM were drenched on cows from 14 days before the expected calving date. Gas chromatography time-of-flight/mass spectrometry was used to analyze serum samples collected from eight cows in every groups at 14 days after calving. In comparison to T0, TB, TN, and TB+N had higher serum glucose concentrations, while non-esterified fatty acid in TN and TB+N and triglyceride in TB+N were lower. Adenosine 5'-triphosphate was significantly increased in TB+N. Both TN and TB+N had higher glutathione and lower reactive oxygen species. Moreover, TB significantly increased inosine and guanosine concentrations, decreased ß-alanine, etc. Certain fatty acid concentrations (including linoleic acid, oleic acid, etc.) were significantly decreased in both TN and TB+N. Some amino acid derivatives (spermidine in TN, putrescine and 4-hydroxyphenylethanol in TB+N, and guanidinosuccinic acid in both TN and TB+N) were affected. Correlation network analysis revealed that the metabolites altered by NAM supplementation were more complicated than those by BIO supplementation. These findings showed that both BIO and NAM supplementation enhanced amino acid metabolism and NAM supplementation altered biosynthesis of unsaturated fatty acid metabolism. The improved oxidative status and glutathione metabolism further indicated the effect of NAM on oxidative stress alleviation.


Assuntos
Biotina/sangue , Bovinos/sangue , Suplementos Nutricionais/análise , Niacinamida/sangue , Aminoácidos/sangue , Animais , Biotina/administração & dosagem , Ácidos Graxos Insaturados/sangue , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Glutationa/sangue , Metabolômica , Niacinamida/administração & dosagem , Soro/química
5.
PLoS One ; 12(12): e0186459, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29211728

RESUMO

OBJECTIVES: The co-primary objectives of this study were to determine the human pharmacokinetics (PK) of oral NR and the effect of NR on whole blood nicotinamide adenine dinucleotide (NAD+) levels. BACKGROUND: Though mitochondrial dysfunction plays a critical role in the development and progression of heart failure, no mitochondria-targeted therapies have been translated into clinical practice. Recent murine studies have reported associations between imbalances in the NADH/NAD+ ratio with mitochondrial dysfunction in multiple tissues, including myocardium. Moreover, an NAD+ precursor, nicotinamide mononucleotide, improved cardiac function, while another NAD+ precursor, nicotinamide riboside (NR), improved mitochondrial function in muscle, liver and brown adipose. Thus, PK studies of NR in humans is critical for future clinical trials. METHODS: In this non-randomized, open-label PK study of 8 healthy volunteers, 250 mg NR was orally administered on Days 1 and 2, then uptitrated to peak dose of 1000 mg twice daily on Days 7 and 8. On the morning of Day 9, subjects completed a 24-hour PK study after receiving 1000 mg NR at t = 0. Whole-blood levels of NR, clinical blood chemistry, and NAD+ levels were analyzed. RESULTS: Oral NR was well tolerated with no adverse events. Significant increases comparing baseline to mean concentrations at steady state (Cave,ss) were observed for both NR (p = 0.03) and NAD+ (p = 0.001); the latter increased by 100%. Absolute changes from baseline to Day 9 in NR and NAD+ levels correlated highly (R2 = 0.72, p = 0.008). CONCLUSIONS: Because NR increases circulating NAD+ in humans, NR may have potential as a therapy in patients with mitochondrial dysfunction due to genetic and/or acquired diseases.


Assuntos
Suplementos Nutricionais , Voluntários Saudáveis , NAD/sangue , Niacinamida/análogos & derivados , Administração Oral , Adulto , Feminino , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Niacinamida/administração & dosagem , Niacinamida/efeitos adversos , Niacinamida/sangue , Niacinamida/farmacocinética , Compostos de Piridínio , Adulto Jovem
6.
Anim Sci J ; 88(12): 1970-1978, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28722260

RESUMO

Long-distance transportation is sometimes inevitable in the beef industry because of the geographic separation of major breeding and fattening areas. Long-distance transportation negatively impacts production and health of cattle, which may, at least partly, result from the disturbance of metabolism during and after transportation. However, alteration of metabolism remains elusive in transported cattle. We investigated the effects of transportation on the metabolomic profiles of Holstein steer calves. Non-targeted analysis of serum concentrations of low molecular weight metabolites was performed by gas chromatography mass spectrometry. Transportation affected 38 metabolites in the serum. A pathway analysis suggested that 26, 10, and 10 pathways were affected immediately after transportation, and 3 and 7 days after transportation, respectively. Some pathways were disturbed only immediately after transportation, likely because of feed and water withdrawal during transit. Nicotinate and nicotinamide metabolism, and citric acid cycle were affected for 3 days after transportation, whereas propionate metabolism, phenylalanine and tyrosine metabolism were affected throughout the experiment. Four pathways were not affected immediately after transportation, but were altered thereafter. These results suggested that many metabolic pathways had marked perturbations during transportation. Metabolites such as citric acid, propionate, tyrosine and niacin can be candidate supplements for mitigating transportation-induced adverse effects.


Assuntos
Bovinos/sangue , Bovinos/metabolismo , Ácido Cítrico/metabolismo , Propionatos/metabolismo , Meios de Transporte , Tirosina/metabolismo , Animais , Ácido Cítrico/sangue , Ciclo do Ácido Cítrico , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Peso Molecular , Niacina/sangue , Niacina/metabolismo , Niacinamida/sangue , Niacinamida/metabolismo , Fenilalanina/sangue , Fenilalanina/metabolismo , Propionatos/sangue , Fatores de Tempo , Tirosina/sangue
7.
Pharm Biol ; 55(1): 1863-1867, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28614959

RESUMO

CONTEXT: Combining sorafenib with triptolide could inhibit tumour growth with greater efficacy than single-agent treatment. However, their herb-drug interaction remains unknown. OBJECTIVE: This study investigates the herb-drug interaction between triptolide and sorafenib. MATERIALS AND METHODS: The effects of triptolide (10 mg/kg) on the pharmacokinetics of different doses of sorafenib (20, 50 and 100 mg/kg) in rats, and blood samples were collected within 48 h and evaluated using LC-MS/MS. The effects of triptolide on the absorption and metabolism of sorafenib were also investigated using Caco-2 cell monolayer model and rat liver microsome incubation systems. RESULTS: The results showed that the Cmax (low dose: 72.38 ± 8.76 versus 49.15 ± 5.46 ng/mL; medium dose: 178.65 ± 21.05 versus 109.31 ± 14.17 ng/mL; high dose: 332.81 ± 29.38 versus 230.86 ± 9.68 ng/mL) of sorafenib at different doses increased significantly with the pretreatment of triptolide, and while the oral clearance rate of sorafenib decreased. The t1/2 of sorafenib increased significant (p < 0.05) from 9.02 ± 1.16 to 12.17 ± 2.95 h at low dose with the pretreatment of triptolide. Triptolide has little effect on the absorption of sorafenib in Caco-2 cell transwell model. However, triptolide could significantly decrease the intrinsic clearance rate of sorafenib from 51.7 ± 6.37 to 32.4 ± 4.43 µL/min/mg protein in rat liver microsomes. DISCUSSION AND CONCLUSIONS: These results indicated that triptolide could change the pharmacokinetic profiles of sorafenib in rats; these effects might be exerted via decreasing the intrinsic clearance rate of sorafenib in rat liver.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos/farmacocinética , Diterpenos/farmacologia , Microssomos Hepáticos/efeitos dos fármacos , Niacinamida/análogos & derivados , Fenantrenos/farmacologia , Compostos de Fenilureia/farmacocinética , Inibidores de Proteínas Quinases/farmacocinética , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Antineoplásicos/metabolismo , Biotransformação/efeitos dos fármacos , Células CACO-2 , Citocromo P-450 CYP3A/química , Citocromo P-450 CYP3A/metabolismo , Inibidores do Citocromo P-450 CYP3A/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Enterócitos/efeitos dos fármacos , Enterócitos/metabolismo , Compostos de Epóxi/farmacologia , Feminino , Meia-Vida , Humanos , Absorção Intestinal/efeitos dos fármacos , Masculino , Taxa de Depuração Metabólica/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Niacinamida/administração & dosagem , Niacinamida/sangue , Niacinamida/metabolismo , Niacinamida/farmacocinética , Compostos de Fenilureia/administração & dosagem , Compostos de Fenilureia/sangue , Compostos de Fenilureia/metabolismo , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/sangue , Inibidores de Proteínas Quinases/metabolismo , Ratos Sprague-Dawley , Sorafenibe
8.
Molecules ; 22(7)2017 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-28640225

RESUMO

Sorafenib has been used as a standard therapy for advanced hepatocellular carcinoma (HCC). In Asia, patients with HCC are potentially treated with the combination of sorafenib and Chinese herbal medicines to improve the efficiency and reduce the side effects of sorafenib. However, limited information about the herb-drug interactions is available. We hypothesize that the Chinese herbal medicine may exert hepatoprotective effects on the sorafenib-treated group. The aim of this study is to investigate the pharmacokinetic mechanism of drug-drug interactions of sorafenib including interacting with hepatoprotective formulation, Long-Dan-Xie-Gan-Tang formulation (LDXGT) and with two cytochrome P450 3A4 (CYP3A4) inhibitors, grapefruit juice and ketoconazole. Liver enzyme levels and histopathology of liver slices were used to evaluate sorafenib-induced hepatotoxicity and the potential hepatoprotective effects of the LDXGT formulation on subjects treated with the combination of sorafenib and the herbal medicine. In this study, a validated HPLC-photodiode array analytical system was developed for the pharmacokinetic study of sorafenib in rats. As the result of the pharmacokinetic data, pretreatment with the LDXGT formulation did not significantly interact with sorafenib compared with sorafenib oral administration alone. Furthermore, grapefruit juice and ketoconazole did not significantly affect sorafenib metabolism. Furthermore, pretreatment with variable, single or repeat doses of the LDXGT formulation did not suppress or exacerbate the sorafenib-induced hepatotoxicity and histopathological alterations. According to these results, the LDXGT formulation is safe, but has no beneficial effects on sorafenib-induced hepatotoxicity. A detailed clinical trial should be performed to further evaluate the efficacy or adverse effects of the LDXGT formulation in combination with sorafenib in humans.


Assuntos
Antineoplásicos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Interações Ervas-Drogas , Fígado/efeitos dos fármacos , Medicina Tradicional Chinesa/métodos , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Animais , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/farmacocinética , Fígado/patologia , Masculino , Niacinamida/sangue , Niacinamida/farmacocinética , Niacinamida/farmacologia , Niacinamida/toxicidade , Compostos de Fenilureia/sangue , Compostos de Fenilureia/farmacocinética , Compostos de Fenilureia/toxicidade , Ratos , Ratos Sprague-Dawley , Sorafenibe
9.
PLoS One ; 11(1): e0147028, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26766039

RESUMO

The glucose homeostasis in dairy cattle is very well controlled, in line with the metabolic adaptation during the periparturient period. Former studies showed that nicotinic acid (NA) lowered plasma non-esterified fatty acids (NEFA) concentrations and increased insulin sensitivity in dairy cows. Thus, the purpose of this study was to investigate whether the expression of proteins involved in hepatic and adipose insulin signaling and protein expression of hepatic glucose transporter 2 (GLUT2) were affected by dietary NA and dietary concentrate intake in periparturient dairy cows. Twenty pluriparous German Holstein cows were fed with the same diet from about 21 days before the expected calving date (d-21) to calving. After calving, cows were randomly assigned in 4 groups and fed with diets different in concentrate proportion ("HC" with 60:40% or "LC" with 30:70% concentrate-to-roughage ratio) and supplemented with NA (24 g/day) (NA) or without (CON) until d21. Biopsy samples were taken from the liver, subcutaneous (SCAT) and retroperitoneal (RPAT) adipose tissues at d-21 and d21. Protein expression of insulin signaling molecules (insulin receptor (INSR), phosphatidylinositol-3-kinase (PI3K), protein kinase Cζ (PKCζ)) and hepatic GLUT2 was measured by Western Blotting. The ratio of protein expression at d21/at d-21 was calculated and statistically evaluated for the effects of time and diet. Cows in HC had significantly higher dietary energy intake than cows in LC. In RPAT a decrease in PI3K and PKCζ expression was found in all groups, irrespectively of diet. In the liver, the GLUT2 expression was significantly lower in cows in NA compared with cows in CON. In conclusion, insulin signaling might be decreased in RPAT over time without any effect of diet. NA was able to modulate hepatic GLUT2 expression, but its physiological role is unclear.


Assuntos
Tecido Adiposo/metabolismo , Suplementos Nutricionais , Insulina/metabolismo , Fígado/metabolismo , Niacina/administração & dosagem , Transdução de Sinais , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Glicemia , Bovinos , Ácidos Graxos não Esterificados/sangue , Feminino , Expressão Gênica , Transportador de Glucose Tipo 2/genética , Transportador de Glucose Tipo 2/metabolismo , Insulina/sangue , Niacinamida/sangue , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Período Pós-Parto , Gravidez , Proteína Quinase C/genética , Proteína Quinase C/metabolismo , Receptor de Insulina/genética , Receptor de Insulina/metabolismo
10.
Clin Cancer Res ; 22(10): 2368-76, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26644411

RESUMO

PURPOSE: To assess the safety and tolerability of the small-molecule allosteric MEK inhibitor refametinib combined with sorafenib, in patients with advanced solid malignancies. EXPERIMENTAL DESIGN: This phase I dose-escalation study included an expansion phase at the maximum tolerated dose (MTD). Patients received refametinib/sorafenib twice daily for 28 days, from a dose of refametinib 5 mg plus sorafenib 200 mg to a dose of refametinib 50 mg plus sorafenib 400 mg. Plasma levels of refametinib, refametinib metabolite M17, and sorafenib were measured for pharmacokinetic assessments. Tumors were biopsied at the MTD for analysis of MEK pathway mutations and ERK phosphorylation. RESULTS: Thirty-two patients were enrolled in the dose-escalation cohort. The MTD was refametinib 50 mg twice daily plus sorafenib 400 mg twice daily. The most common treatment-related toxicities were diarrhea and fatigue. Refametinib was readily absorbed following oral administration (plasma half-life of ∼16 hours at the MTD), and pharmacokinetic parameters displayed near-dose proportionality, with less than 2-fold accumulation after multiple dosing. Another 30 patients were enrolled in the MTD cohort; 19 had hepatocellular carcinoma. The combination was associated with significantly reduced ERK phosphorylation in 5 out of 6 patients biopsied, with the greatest reductions in those with KRAS or BRAF mutations. Disease was stabilized in approximately half of patients, and 1 patient with colorectal cancer achieved a partial response at the MTD lasting approximately 1 year. CONCLUSIONS: In this phase I study, refametinib plus sorafenib was well tolerated, with good oral absorption, near-dose proportionality, and target inhibition in a range of tumor types. Clin Cancer Res; 22(10); 2368-76. ©2015 AACR.


Assuntos
Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Difenilamina/análogos & derivados , Neoplasias/tratamento farmacológico , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacocinética , Compostos de Fenilureia/uso terapêutico , Sulfonamidas/farmacocinética , Sulfonamidas/uso terapêutico , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Antineoplásicos/sangue , Terapia Combinada/métodos , Difenilamina/efeitos adversos , Difenilamina/sangue , Difenilamina/farmacocinética , Difenilamina/uso terapêutico , Feminino , Meia-Vida , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/metabolismo , Niacinamida/efeitos adversos , Niacinamida/sangue , Niacinamida/farmacocinética , Niacinamida/uso terapêutico , Compostos de Fenilureia/efeitos adversos , Compostos de Fenilureia/sangue , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/sangue , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/uso terapêutico , Sorafenibe , Sulfonamidas/efeitos adversos , Sulfonamidas/sangue
11.
Tohoku J Exp Med ; 237(3): 173-82, 2015 11.
Artigo em Inglês | MEDLINE | ID: mdl-26477611

RESUMO

Sorafenib, an oral multi-kinase inhibitor, is the final therapy prior to palliative care for advanced hepatocellular carcinoma (HCC). However, due to its adverse effects, 20% of patients must discontinue sorafenib within 1 month after first administration. To identify ways to predict the adverse effects and administer the drug for longer periods, we explored the relationship between the duration of sorafenib treatment and the pharmacokinetics of sorafenib and its major metabolite, sorafenib N-oxide. Twenty-five subjects enrolled in the study were divided into two groups: patients with dosage reduced or withdrawn due to adverse effects (n = 8), and patients with dosage maintained for 1 month after initial administration (n = 17). We evaluated early sorafenib accumulation as the area under the curve of sorafenib and sorafenib N-oxide concentrations during days 1-7 (AUC(sorafenib) and AUC(N-oxide), respectively). Inter-group comparison revealed that AUC(N-oxide) and AUC ratio (AUC(N-oxide)/AUC(sorafenib)) were significantly higher in the dosage reduction/withdrawal group (P = 0.031 and P = 0.0022, respectively). Receiver operating characteristic analysis indicated that AUC(N-oxide) and AUC ratio were reliable predictors of adverse effects. When patients were classified by cut-off points (AUC(N-oxide:) 2.0 µg ∙ day/mL, AUC ratio: 0.13), progression-free survival was significantly longer in patients with AUC(N-oxide) ≤ 2.0 µg ∙ day/mL (P = 0.0048, log-rank test). In conclusion, we recommend to simultaneously monitor serum levels of sorafenib and its N-oxide during the early stage after the first administration, which enables us to provide safe and long-term therapy for each HCC patient with sorafenib.


Assuntos
Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/tratamento farmacológico , Monitoramento de Medicamentos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/tratamento farmacológico , Niacinamida/análogos & derivados , Óxidos/sangue , Compostos de Fenilureia/sangue , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Feminino , Meia-Vida , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Niacinamida/efeitos adversos , Niacinamida/sangue , Niacinamida/farmacocinética , Niacinamida/uso terapêutico , Compostos de Fenilureia/efeitos adversos , Compostos de Fenilureia/farmacocinética , Compostos de Fenilureia/uso terapêutico , Modelos de Riscos Proporcionais , Curva ROC , Sorafenibe , Fatores de Tempo , Suspensão de Tratamento
12.
Diagn Interv Radiol ; 21(3): 235-40, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25835078

RESUMO

PURPOSE: Use of oral sorafenib, an antiangiogenic chemotherapeutic agent for hepatocellular carcinoma (HCC), is limited by an unfavorable side effect profile. Transarterial chemoembolization (TACE) employs targeted intravascular drug administration, and has potential as a novel sorafenib delivery method to increase tumoral concentrations and reduce systemic levels. This study aimed to discern the pharmacokinetics of sorafenib TACE in a rabbit VX2 liver tumor model. METHODS: A 3 mg/kg dose of sorafenib ethiodized oil emulsion was delivered via an arterial catheter to VX2 liver tumors in seven New Zealand white rabbits. Following TACE, serum sorafenib levels were measured at days 0, 1, 2, 3, 7, 10, and 14 until the time of sacrifice, after which rabbit livers were harvested for analysis of sorafenib concentrations within treated tumors and normal liver. Liquid chromatography tandem mass spectrometry was used for drug quantification. RESULTS: Sorafenib uptake within liver tumor and nontumorous liver tissue peaked at mean 3.53 and 0.75 µg/mL, respectively, immediately post-procedure (5:1 tumor to normal tissue drug uptake ratio), before decreasing with a 10-18 hour half-life. Serum sorafenib levels peaked immediately after TACE at a mean value of 58.58 µg/mL before normalizing with a 5.2-hour half-life, suggesting early drug washout from liver into the systemic circulation. Hepatic lab parameters showed transient increase 24 hours post-TACE with subsequent resolution. CONCLUSION: While targeted transarterial delivery of sorafenib ethiodized oil emulsion shows preferential tumor uptake compared to normal liver, systemic washout occurs with a short half-life, resulting in high circulating drug levels.


Assuntos
Inibidores da Angiogênese/farmacocinética , Quimioembolização Terapêutica/métodos , Neoplasias Hepáticas Experimentais/metabolismo , Niacinamida/análogos & derivados , Compostos de Fenilureia/administração & dosagem , Compostos de Fenilureia/farmacocinética , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/sangue , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Modelos Animais de Doenças , Óleo Etiodado/administração & dosagem , Feminino , Injeções Intra-Arteriais , Neoplasias Hepáticas Experimentais/sangue , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Neoplasias Hepáticas Experimentais/patologia , Masculino , Niacinamida/administração & dosagem , Niacinamida/efeitos adversos , Niacinamida/sangue , Niacinamida/farmacocinética , Compostos de Fenilureia/efeitos adversos , Compostos de Fenilureia/sangue , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/sangue , Inibidores de Proteínas Quinases/farmacocinética , Coelhos , Sorafenibe
13.
Anticancer Res ; 35(3): 1803-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25750346

RESUMO

BACKGROUND/AIM: Sorafenib is the medical reference for treatment of hepatocellular carcinoma (HCC). Multiple forms of cytotoxicity are induced by sorafenib in HCC cells in vitro but it is unclear what extent of apoptosis and necrosis is induced in HCC patients receiving sorafenib. PATIENTS AND METHODS: The M30 and M65 biomarkers, which reflect the release of cytokeratin-18 and its apoptotic cleavage fragments, were measured in patients with HCC (n=36) and matched patients with cirrhosis (n=47). A serum sample was collected from 20 patients with HCC four weeks after the onset of treatment with sorafenib. RESULTS: Basal serum levels of M30 and M65 were increased in patients with HCC compared to those with uncomplicated cirrhosis. No statistically significant increase in the level of M30 or M65 was found in the sera of patients with HCC after sorafenib. CONCLUSION: The findings indicate that sorafenib is not a potent inducer of HCC cell death in most patients.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Niacinamida/análogos & derivados , Compostos de Fenilureia/uso terapêutico , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Idoso , Apoptose , Biomarcadores , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Queratina-18/sangue , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/patologia , Masculino , Necrose , Niacinamida/sangue , Niacinamida/uso terapêutico , Compostos de Fenilureia/sangue , Sorafenibe
14.
Cancer Chemother Pharmacol ; 75(1): 161-71, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25413440

RESUMO

Sorafenib (Nexavar®) is currently the only FDA-approved small molecule targeted therapy for advanced hepatocellular carcinoma. The use of structural analogues and derivatives of sorafenib has enabled the elucidation of critical targets and mechanism(s) of cell death for human cancer lines. We previously performed a structure-activity relationship study on a series of sorafenib analogues designed to investigate the inhibition overlap between the major targets of sorafenib Raf-1 kinase and VEGFR-2, and an enzyme shown to be a potent off-target of sorafenib, soluble epoxide hydrolase. In the current work, we present the biological data on our lead sorafenib analogue, t-CUPM, demonstrating that this analogue retains cytotoxicity similar to sorafenib in various human cancer cell lines and strongly inhibits growth in the NCI-60 cell line panel. Co-treatment with the pan-caspase inhibitor, Z-VAD-FMK, failed to rescue the cell viability responses of both sorafenib and t-CUPM, and immunofluorescence microscopy shows similar mitochondrial depolarization and apoptosis-inducing factor release for both compounds. These data suggest that both compounds induce a similar mechanism of caspase-independent apoptosis in hepatoma cells. In addition, t-CUPM displays anti-proliferative effects comparable to sorafenib as seen by a halt in G0/G1 in cell cycle progression. The structural difference between sorafenib and t-CUPM significantly reduces inhibitory spectrum of kinases by this analogue, and pharmacokinetic characterization demonstrates a 20-fold better oral bioavailability of t-CUPM than sorafenib in mice. Thus, t-CUPM may have the potential to reduce the adverse events observed from the multikinase inhibitory properties and the large dosing regimens of sorafenib.


Assuntos
Antineoplásicos/farmacologia , Drogas em Investigação/farmacologia , Neoplasias/tratamento farmacológico , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Quinases raf/antagonistas & inibidores , Administração Oral , Animais , Animais não Endogâmicos , Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Disponibilidade Biológica , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Drogas em Investigação/administração & dosagem , Drogas em Investigação/análise , Drogas em Investigação/farmacocinética , Meia-Vida , Humanos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Neoplasias/sangue , Neoplasias/metabolismo , Neoplasias/patologia , Niacinamida/administração & dosagem , Niacinamida/sangue , Niacinamida/farmacocinética , Niacinamida/farmacologia , Compostos de Fenilureia/administração & dosagem , Compostos de Fenilureia/sangue , Compostos de Fenilureia/farmacocinética , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/sangue , Inibidores de Proteínas Quinases/farmacocinética , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Quinases raf/metabolismo
15.
PLoS One ; 9(5): e98313, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24847987

RESUMO

Administration of pharmacological niacin doses was recently reported to have pronounced effects on skeletal muscle gene expression and phenotype in obese Zucker rats, with the molecular mechanisms underlying the alteration of gene expression being completely unknown. Since miRNAs have been shown to play a critical role for gene expression through inducing miRNA-mRNA interactions which results in the degradation of specific mRNAs or the repression of protein translation, we herein aimed to investigate the influence of niacin at pharmacological doses on the miRNA expression profile in skeletal muscle of obese Zucker rats fed either a control diet with 30 mg supplemented niacin/kg diet or a high-niacin diet with 780 mg supplemented niacin/kg diet for 4 wk. miRNA microarray analysis revealed that 42 out of a total of 259 miRNAs were differentially expressed (adjusted P-value <0.05), 20 being down-regulated and 22 being up-regulated, between the niacin group and the control group. Using a biostatistics approach, we could demonstrate that the most strongly up-regulated (log2 ratio ≥0.5) and down-regulated (log2 ratio ≤-0.5) miRNAs target approximately 1,800 mRNAs. Gene-term enrichment analysis showed that many of the predicted target mRNAs from the most strongly regulated miRNAs were involved in molecular processes dealing with gene transcription such as DNA binding, transcription regulator activity, transcription factor binding and in important regulatory pathways such as Wnt signaling and MAPK signaling. In conclusion, the present study shows for the first time that pharmacological niacin doses alter the expression of miRNAs in skeletal muscle of obese Zucker rats and that the niacin-regulated miRNAs target a large set of genes and pathways which are involved in gene regulatory activity indicating that at least some of the recently reported effects of niacin on skeletal muscle gene expression and phenotype in obese Zucker rats are mediated through miRNA-mRNA interactions.


Assuntos
MicroRNAs/metabolismo , Músculo Esquelético/metabolismo , Niacina/farmacologia , Complexo Vitamínico B/farmacologia , Animais , Peso Corporal , Biologia Computacional , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Masculino , Niacina/administração & dosagem , Niacina/sangue , Niacinamida/sangue , Ácidos Nicotínicos/sangue , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , RNA Mensageiro/metabolismo , Ratos , Ratos Zucker , Transdução de Sinais , Complexo Vitamínico B/administração & dosagem
16.
J Proteome Res ; 12(12): 5520-34, 2013 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-24131325

RESUMO

Inflammation is closely associated with pathogenesis of various metabolic disorders, cardiovascular diseases, and cancers. To understand the systems responses to localized inflammation, we analyzed the dynamic metabolic changes in rat plasma and urine associated with the carrageenan-induced self-limiting pleurisy using NMR spectroscopy in conjunction with multivariate data analysis. Fatty acids in plasma were also analyzed using GC-FID/MS with the data from clinical chemistry and histopathology as complementary information. We found that in the acute phase of inflammation rats with pleurisy had significantly lower levels in serum albumin, fatty acids, and lipoproteins but higher globulin level and larger quantity of pleural exudate than controls. The carrageenan-induced inflammation was accompanied by significant metabolic alterations involving TCA cycle, glycolysis, biosyntheses of acute phase proteins, and metabolisms of amino acids, fatty acids, ketone bodies, and choline in acute phase. The resolution process of pleurisy was heterogeneous, and two subgroups were observed for the inflammatory rats at day-6 post treatment with different metabolic features together with the quantity of pleural exudate and weights of thymus and spleen. The metabolic differences between these subgroups were reflected in the levels of albumin and acute-phase proteins, the degree of returning to normality for multiple metabolic pathways including glycolysis, TCA cycle, gut microbiota functions, and metabolisms of lipids, choline and vitamin B3. These findings provided some essential details for the dynamic metabolic changes associated with the carrageenan-induced self-limiting inflammation and demonstrated the combined NMR and GC-FID/MS analysis as a powerful approach for understanding biochemical aspects of inflammation.


Assuntos
Proteínas de Fase Aguda/metabolismo , Carragenina , Pleurisia/sangue , Pleurisia/urina , Animais , Colina/sangue , Colina/urina , Ciclo do Ácido Cítrico/efeitos dos fármacos , Ácidos Graxos/sangue , Cromatografia Gasosa-Espectrometria de Massas , Glicólise/efeitos dos fármacos , Inflamação/sangue , Inflamação/induzido quimicamente , Inflamação/patologia , Inflamação/urina , Corpos Cetônicos/sangue , Corpos Cetônicos/urina , Lipoproteínas/sangue , Espectroscopia de Ressonância Magnética , Masculino , Niacinamida/sangue , Tamanho do Órgão/efeitos dos fármacos , Pleurisia/induzido quimicamente , Pleurisia/patologia , Ratos , Ratos Sprague-Dawley , Albumina Sérica/metabolismo , Baço/efeitos dos fármacos , Baço/metabolismo , Baço/patologia , Timo/efeitos dos fármacos , Timo/metabolismo , Timo/patologia
17.
J Vasc Interv Radiol ; 24(11): 1657-63.e1, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24060438

RESUMO

PURPOSE: To assess the safety and feasibility of the targeted delivery of the antiangiogenic drug sorafenib to the liver using transarterial chemoembolization methodology as a novel approach to hepatocellular carcinoma (HCC) therapy. MATERIALS AND METHODS: Seven healthy New Zealand white rabbits were used in the study. After placement of a catheter in the common hepatic artery, six rabbits were treated with chemoembolization of sorafenib in iodized oil (Lipiodol) (sorafenib dose 0.1 mg/kg), and one rabbit received Lipiodol only. Liquid chromatography tandem mass spectrometry was used to measure the concentration of sorafenib in the peripheral blood and liver tissue 24 hours and 72 hours after treatment. Histochemical staining of the liver sections and biochemical measurements were performed. RESULTS: The administration of sorafenib in Lipiodol emulsions by transarterial chemoembolization resulted in sorafenib concentrations of 794 ng/g ± 240 and 64 ng/g ± 15 in the liver tissue 24 hours and 72 hours after treatment. The average liver-to-serum ratios 24 hours and 72 hours after treatment were approximately 14 and 22. The histochemical staining of the liver tissue sections and aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase and total bilirubin concentrations indicated no significant liver damage. CONCLUSIONS: Transarterial chemoembolization with sorafenib in Lipiodol is an effective methodology for the localized delivery of this drug to the liver and has possible practical implications in therapeutic interventions for the treatment of hepatocellular carcinoma.


Assuntos
Inibidores da Angiogênese/farmacocinética , Quimioembolização Terapêutica/métodos , Artéria Hepática , Fígado/irrigação sanguínea , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacocinética , Alanina Transaminase/metabolismo , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/sangue , Animais , Bilirrubina/metabolismo , Cromatografia Líquida de Alta Pressão , Óleo Etiodado/administração & dosagem , Estudos de Viabilidade , Fígado/metabolismo , Fígado/patologia , Masculino , Modelos Animais , Niacinamida/administração & dosagem , Niacinamida/sangue , Niacinamida/farmacocinética , Compostos de Fenilureia/administração & dosagem , Compostos de Fenilureia/sangue , Coelhos , Sorafenibe , Espectrometria de Massas em Tandem , gama-Glutamiltransferase/metabolismo
18.
Br J Nutr ; 110(12): 2156-64, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23768418

RESUMO

Ecological evidence suggests that niacin (nicotinamide and nicotinic acid) fortification may be involved in the increased prevalence of obesity and type 2 diabetes, both of which are associated with insulin resistance and epigenetic changes. The purpose of the present study was to investigate nicotinamide-induced metabolic changes and their relationship with possible epigenetic changes. Male rats (5 weeks old) were fed with a basal diet (control group) or diets supplemented with 1 or 4 g/kg of nicotinamide for 8 weeks. Low-dose nicotinamide exposure increased weight gain, but high-dose one did not. The nicotinamide-treated rats had higher hepatic and renal levels of 8-hydroxy-2'-deoxyguanosine, a marker of DNA damage, and impaired glucose tolerance and insulin sensitivity when compared with the control rats. Nicotinamide supplementation increased the plasma levels of nicotinamide, N1-methylnicotinamide and choline and decreased the levels of betaine, which is associated with a decrease in global hepatic DNA methylation and uracil content in DNA. Nicotinamide had gene-specific effects on the methylation of CpG sites within the promoters and the expression of hepatic genes tested that are responsible for methyl transfer reactions (nicotinamide N-methyltransferase and DNA methyltransferase 1), for homocysteine metabolism (betaine-homocysteine S-methyltransferase, methionine synthase and cystathionine ß-synthase) and for oxidative defence (catalase and tumour protein p53). It is concluded that nicotinamide-induced oxidative tissue injury, insulin resistance and disturbed methyl metabolism can lead to epigenetic changes. The present study suggests that long-term high nicotinamide intake (e.g. induced by niacin fortification) may be a risk factor for methylation- and insulin resistance-related metabolic abnormalities.


Assuntos
Metilação de DNA/efeitos dos fármacos , Suplementos Nutricionais/efeitos adversos , Epigênese Genética/efeitos dos fármacos , Doenças Metabólicas/induzido quimicamente , Niacina/efeitos adversos , Niacinamida/efeitos adversos , Complexo Vitamínico B/efeitos adversos , Animais , Betaína/sangue , Colina/sangue , Ilhas de CpG/efeitos dos fármacos , DNA/metabolismo , Dano ao DNA , Intolerância à Glucose/induzido quimicamente , Intolerância à Glucose/genética , Intolerância à Glucose/metabolismo , Homocisteína/genética , Homocisteína/metabolismo , Resistência à Insulina/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Doenças Metabólicas/genética , Doenças Metabólicas/metabolismo , Niacinamida/análogos & derivados , Niacinamida/sangue , Estresse Oxidativo/genética , Regiões Promotoras Genéticas/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Uracila/metabolismo , Aumento de Peso/efeitos dos fármacos
19.
Behav Brain Res ; 224(2): 311-7, 2011 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-21704653

RESUMO

Previous research has demonstrated considerable preclinical efficacy of nicotinamide (NAM; vitamin B(3)) in animal models of TBI with systemic dosing at 50 and 500 mg/kg yielding improvements on sensory, motor, cognitive and histological measures. The current study aimed to utilize a more specific dosing paradigm in a clinically relevant delivery mechanism: continuously secreting subcutaneous pumps. A bilateral frontal controlled cortical impact (CCI) or sham surgery was performed and rats were treated with NAM (150 mg/kg day) or saline (1 ml/kg) pumps 30 min after CCI, continuing until seven days post-CCI. Rats were given a loading dose of NAM (50mg/kg) or saline (1 ml/kg) following pump implant. Rats received behavioral testing (bilateral tactile adhesive removal, locomotor placing task and Morris water maze) starting on day two post-CCI and were sacrificed at 31 days post-CCI and brains were stained to examine lesion size. NAM-treated rats had reductions in sensory, motor and cognitive behavioral deficits compared to vehicle-treated rats. Specifically, NAM-treated rats significantly improved on the bilateral tactile adhesive removal task, locomotor placing task and the reference memory paradigm of the Morris water maze. Lesion size was also significantly reduced in the NAM-treated group. The results from this study indicate that at the current dose, NAM produces beneficial effects on recovery from a bilateral frontal brain injury and that it may be a relevant compound to be explored in human studies.


Assuntos
Comportamento Animal/fisiologia , Lesões Encefálicas/patologia , Lesões Encefálicas/psicologia , Lobo Frontal/lesões , Niacinamida/farmacologia , Complexo Vitamínico B/farmacologia , Animais , Lesões Encefálicas/tratamento farmacológico , Cognição/efeitos dos fármacos , Cognição/fisiologia , Interpretação Estatística de Dados , Lobo Frontal/patologia , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Memória de Curto Prazo/efeitos dos fármacos , Memória de Curto Prazo/fisiologia , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Niacinamida/sangue , Desempenho Psicomotor/efeitos dos fármacos , Desempenho Psicomotor/fisiologia , Ratos , Ratos Sprague-Dawley , Tato/fisiologia , Complexo Vitamínico B/sangue
20.
Carcinogenesis ; 30(1): 101-5, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19028705

RESUMO

Cutaneous immunity, which is a key defence against the development of skin cancers, is suppressed by even small doses of ultraviolet (UV) radiation. Preventing this UV-induced immunosuppression may therefore reduce the incidence of skin cancer. Nicotinamide (vitamin B3) has immune-protective and cancer-preventive effects against UV radiation in mice, and we have shown previously that topical nicotinamide is immune protective in humans. Using the Mantoux model of skin immunity in healthy volunteers, we compared oral nicotinamide to placebo (both administered for 1 week) in a randomized, double-blinded, crossover design against the effects of solar-simulated ultraviolet (ssUV) radiation on delayed-type hypersensitivity to tuberculin purified protein derivative. Discrete areas of the back were irradiated with low doses of ssUV daily for three consecutive days. Immunosuppression, calculated as the difference in Mantoux-induced erythema of irradiated sites compared with unirradiated control sites, was determined in volunteers taking oral nicotinamide and placebo. Significant immunosuppression occurred in an UV dose-dependent manner in the presence of placebo. Oral nicotinamide, at doses of either 1500 or 500 mg daily, was well tolerated and significantly reduced UV immunosuppression with no immune effects in unirradiated skin. Oral nicotinamide is safe and inexpensive and looks promising as a chemopreventive supplement for reducing the immunosuppressive effects of sunlight.


Assuntos
Tolerância Imunológica/efeitos dos fármacos , Tolerância Imunológica/efeitos da radiação , Niacinamida/farmacologia , Raios Ultravioleta , Administração Oral , Adulto , Estudos Cross-Over , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Niacinamida/administração & dosagem , Niacinamida/sangue , Placebos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA