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1.
Int J Mol Sci ; 22(21)2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34769206

RESUMO

Exposure to metallic nanoparticles (NPs) can result in inadvertent NP accumulation in body tissues. While their subsequent cellular interactions can lead to unintended consequences and are generally regarded as detrimental for health, they can on occasion mediate biologically beneficial effects. Among NPs, cerium oxide nanoparticles (CeO2 NP) possess strong antioxidant properties and have shown to alleviate certain pathological conditions. Herein, we show that the presence of cubic 25 nm CeO2 NP was able to reduce TGF-ß-mediated activation in the cultured hepatic stellate cell line LX2 by reducing oxidative stress levels and TGF-ß-mediated signalling. These cells displayed reduced classical liver fibrosis phenotypes, such as diminished fibrogenesis, altered matrix degradation, decreased cell motility, modified contractability and potentially lowered autophagy. These findings demonstrate that CeO2 NP may be able to ameliorate hepatic fibrosis and suggest a possible therapeutic pathway for an otherwise difficult-to-treat condition.


Assuntos
Antifibróticos/farmacologia , Antioxidantes/farmacologia , Cério/farmacologia , Cirrose Hepática/tratamento farmacológico , Antifibróticos/química , Antioxidantes/química , Linhagem Celular , Cério/química , Humanos , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Cirrose Hepática/metabolismo , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos
2.
Breast Cancer Res Treat ; 183(3): 683-696, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32696315

RESUMO

PURPOSE: Brain-derived neurotrophic factor (BDNF) and the BDNF Val66Met polymorphism (rs6265) have been implicated in neurodegenerative conditions. This study aimed to investigate the associations of plasma BDNF and rs6265 with cancer-related cognitive impairment (CRCI) at the end of chemotherapy, and with persistent and delayed CRCI up to 24 months post chemotherapy, among survivors of early-stage breast cancer. METHODS: A multicenter, longitudinal study involving 174 breast cancer patients was conducted. CRCI was assessed using the FACT-Cog (V3) questionnaire and the CANTAB software. Plasma BDNF levels were quantified using an enzyme-linked immunosorbent assay at serial time points and genotyping was achieved using Sanger sequencing. The associations of BDNF and rs6265 with CRCI were analyzed using logistic regressions. RESULTS: A smaller magnitude of reduction in plasma BDNF between baseline and the end of chemotherapy was correlated with protection from overall subjective CRCI (OR 0.88; 95% CI 0.79-0.99). Furthermore, patients with higher plasma BDNF levels at the end of chemotherapy had lower odds of developing persistent overall subjective CRCI (OR 0.74; 95% CI 0.57-0.97) and persistent CRCI in the functional interference domain (OR 0.62; 95% CI 0.39-0.98). BDNF Met allele carriers were protected against subjective CRCI at the end of chemotherapy in the multitasking and memory domains, and against persistent subjective CRCI in the mental acuity and multitasking domains. CONCLUSION: BDNF plasma level or rs6265 genotype information may facilitate the identification of patients at higher risk of long-term CRCI during survivorship and enable the implementation of early intervention strategies that increase BDNF levels.


Assuntos
Neoplasias da Mama , Disfunção Cognitiva , Fator Neurotrófico Derivado do Encéfalo/genética , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Disfunção Cognitiva/genética , Feminino , Genótipo , Humanos , Estudos Longitudinais , Polimorfismo de Nucleotídeo Único , Sobreviventes
3.
Small ; 16(21): e2000153, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32163668

RESUMO

Metal nanoparticles (NPs) are frequently encountered in daily life, and concerns have been raised about their toxicity and safety. Among which, they naturally accumulate in the liver after introduction into the body, independent of the route of administration. Some NPs exhibit intrinsic pharmaceutical effects that are related to their physical parameters, and their inadvertent accumulation in the liver can exert strong effects on liver function and structure. Even as such physiological consequences are often categorically dismissed as toxic and deleterious, there are cell type-specific and NP-specific biological responses that elicit distinctive pharmacological consequences that can be harnessed for good. By limiting the scope of discussion to metallic NPs, this work attempts to provide a balanced perspective on their safety in the liver, and discusses both possible therapeutic benefits and potential accidental liver damage arising from their interaction with specific parenchymal and nonparenchymal cell types in the liver.


Assuntos
Fígado , Nanopartículas Metálicas , Humanos , Fígado/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade
4.
J Clin Pharm Ther ; 45(1): 52-58, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31670842

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Several Caucasian cohort studies have associated at least one loss-of-function CYP2C19 on Clopidogrel (LoF-Clopidogrel) with major adverse cardiovascular events (MACE), and only a couple have used Clinical Pharmacogenetics Implementation Consortium (CPIC® ) phenotype grouping to study the associations. We primarily aimed to study the impact of use of platelet reactivity testing to escalate antiplatelet therapy and secondarily to study the association of CPIC phenotype with MACE outcomes in South-East Asian Acute Coronary Syndrome (ACS) subjects. METHOD: A retrospective genotype study was performed on 238 percutaneous coronary intervention subjects, originally planned for escalation of antiplatelets using platelet reactivity testing. RESULTS AND DISCUSSION: There was no difference in MACE between the switched and unswitched groups; however, 'all bleeds' and 'clinically significant bleeds' (CSB) were statistically higher in the patients who were switched to prasugrel. The subgroup of patients who remained on clopidogrel (n = 199) were analysed using phenotype categories and MACE. Eleven percent (11.4%) of CYP2C19 poor metabolizers (PM) suffered MACE, compared with 1.3% of extensive metabolizers (EM). LoF-Clopidogrel patients are significantly more likely to experience MACE compared with non-LoF subjects (8.0% vs 5.4%, P: .041). WHAT IS NEW AND CONCLUSION: In our multivariate analysis, LoF-Clopidogrel, malay ethnicity, diabetics and use of proton pump inhibitors were independent predictors of MACE. There were numerically more bleeds in LoF subjects who were on prasugrel compared with Clopidogrel (23.5% vs 11%, P = .082). Our data corroborate with current findings on platelet reactivity testing, suggesting that the assay would not be sensitive enough to pick up sufficient 'at-risk' subjects as compared to the use of CYP2C19 genotyping.


Assuntos
Síndrome Coronariana Aguda/terapia , Citocromo P-450 CYP2C19/genética , Intervenção Coronária Percutânea/métodos , Inibidores da Agregação Plaquetária/administração & dosagem , Idoso , Povo Asiático/genética , Doenças Cardiovasculares/epidemiologia , Clopidogrel/administração & dosagem , Clopidogrel/efeitos adversos , Feminino , Genótipo , Hemorragia/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Farmacogenética , Fenótipo , Inibidores da Agregação Plaquetária/efeitos adversos , Cloridrato de Prasugrel/administração & dosagem , Cloridrato de Prasugrel/efeitos adversos , Estudos Retrospectivos
5.
Chem Soc Rev ; 48(21): 5381-5407, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31495856

RESUMO

The ever-growing use of inorganic nanoparticles (NPs) in biomedicine provides an exciting approach to develop novel imaging and drug delivery systems, owing to the ease with which these NPs can be functionalized to cater to various applications. In cancer therapeutics, nanomedicine generally relies on the enhanced permeability and retention (EPR) effect observed in tumour vasculature to deliver anti-cancer drugs across the endothelium. However, such a phenomenon is dependent on the tumour microenvironment and is not consistently observed in all tumour types, thereby limiting drug transport to the tumour site. On the other hand, there is a rise in utilizing inorganic NPs to intentionally induce endothelial leakiness, creating a window of opportunity to control drug delivery across the endothelium. While this active targeting approach creates a similar phenomenon compared to the EPR effect arising from tumour tissues, its drug delivery applications extend beyond cancer therapeutics and into other vascular-related diseases. In this review, we summarize the current findings of the EPR effect and assess its limitations in the context of anti-cancer drug delivery systems. While the EPR effect offers a possible route for drug passage, we further explore alternative uses of NPs to create controllable endothelial leakiness within short exposures, a phenomenon we coined as nanomaterial-induced endothelial leakiness (NanoEL). Furthermore, we discuss the main mechanistic features of the NanoEL effect that make it unique from conventionally established endothelial leakiness in homeostatic and pathologic conditions, as well as examine its potential applicability in vascular-related diseases, particularly cancer. Therefore, this new paradigm changes the way inorganic NPs are currently being used for biomedical applications.


Assuntos
Antineoplásicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanomedicina , Nanopartículas/química , Neoplasias/irrigação sanguínea , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Antineoplásicos/química , Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias/patologia , Neovascularização Patológica/patologia
6.
Int J Mol Sci ; 21(10)2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32466226

RESUMO

Tuberculosis remains a significant infectious lung disease that affects millions of patients worldwide. Despite numerous existing drug regimens for tuberculosis, drug-induced liver injury is a major challenge that limits the effectiveness of these therapeutics. Two drugs that form the backbone of the commonly administered quadruple antitubercular regimen, that is, pyrazinamide (PZA) and isoniazid (INH), are associated with such hepatotoxicity. Yet, we lack safe and effective alternatives to the antitubercular regimen. Consequently, current research largely focuses on exploiting the hepatoprotective effect of nutraceutical compounds as complementary therapy. Silibinin, a herbal product widely believed to protect against various liver diseases, potentially provides a useful solution given its hepatoprotective mechanisms. In our study, we identified silibinin's role in mitigating PZA- and INH-induced hepatotoxicity and elucidated a deeper mechanistic understanding of silibinin's hepatoprotective ability. Silibinin preserved the viability of human foetal hepatocyte line LO2 when co-administered with 80 mM INH and decreased apoptosis induced by a combination of 40 mM INH and 10 mM PZA by reducing oxidative damage to mitochondria, proteins, and lipids. Taken together, this proof-of-concept forms the rational basis for the further investigation of silibinin's hepatoprotective effect in subsequent preclinical studies and clinical trials.


Assuntos
Antituberculosos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Hepatócitos/efeitos dos fármacos , Isoniazida/toxicidade , Substâncias Protetoras/farmacologia , Pirazinamida/toxicidade , Silibina/farmacologia , Apoptose , Linhagem Celular , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Hepatócitos/metabolismo , Humanos , Estresse Oxidativo , Carbonilação Proteica
7.
Int J Mol Sci ; 21(8)2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32326653

RESUMO

A decline in cognitive function following cancer treatment is one of the most commonly reported post-treatment symptoms among patients with cancer and those in remission, and include memory, processing speed, and executive function. A clear understanding of cognitive impairment as a result of cancer and its therapy can be obtained by delineating structural and functional changes using brain imaging studies and neurocognitive assessments. There is also a need to determine the underlying mechanisms and pathways that impact the brain and affect cognitive functioning in cancer survivors. Exosomes are small cell-derived vesicles formed by the inward budding of multivesicular bodies, and are released into the extracellular environment via an exocytic pathway. Growing evidence suggests that exosomes contribute to various physiological and pathological conditions, including neurological processes such as synaptic plasticity, neuronal stress response, cell-to-cell communication, and neurogenesis. In this review, we summarize the relationship between exosomes and cancer-related cognitive impairment. Unraveling exosomes' actions and effects on the microenvironment of the brain, which impacts cognitive functioning, is critical for the development of exosome-based therapeutics for cancer-related cognitive impairment.


Assuntos
Comunicação Celular/fisiologia , Disfunção Cognitiva/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/fisiopatologia , Exossomos/metabolismo , Neoplasias/metabolismo , Neurônios/metabolismo , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Caquexia/metabolismo , Caquexia/patologia , Comunicação Celular/genética , Tratamento Farmacológico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/psicologia , Exossomos/genética , Fadiga/metabolismo , Fadiga/patologia , Humanos , Neoplasias/genética , Neoplasias/fisiopatologia , Neoplasias/psicologia , Neurônios/patologia , Neuroproteção/genética , Neuroproteção/fisiologia , Doenças do Sistema Nervoso Periférico/metabolismo
8.
J Cell Mol Med ; 23(6): 4281-4289, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31016867

RESUMO

Cancer-related fatigue (CRF) is subjective and has wide inter-individual variability. Given that leptin is commonly associated with fatigue syndrome, its use as a potential biomarker for CRF is being investigated. The primary objective of this study was to evaluate the association between leptin and CRF in early-stage breast cancer patients receiving chemotherapy. In a prospective cohort study, patients completed assessments at baseline (T1), during chemotherapy (T2) and after chemotherapy (T3). Levels of plasma leptin and adipokines were measured using a Luminex bead-immunoassay and CRF was measured using the Multi-Dimensional Fatigue Symptom Inventory-Short Form (MFSI-SF). Data were analysed longitudinally using a generalised estimating equation incorporating clinically relevant parameters and pro-inflammatory adipokines. The analysis included 136 patients (mean age ± SD = 51.5 ± 8.8 years; 69.1% receiving anthracycline-based chemotherapy). More patients experienced CRF at T3 (23.8%) than at T2 (13.8%) compared to baseline. An increase was observed in the median plasma leptin level at T2, followed by a decrease at T3 (T1: 4.07 ng/mL, T2: 4.95 ng/mL and T3: 3.96 ng/mL). In the multivariate model, the change in leptin levels over time was significantly associated with the total MFSI-SF score (ß = -0.15, P = 0.003) after adjusting for the tumour necrosis factor-α (TNF-α) level, anxiety, depression, insomnia, age, menopausal status and type of chemotherapy. This is the first study to report leptin as a biomarker that predicts the onset of CRF over time. Future studies are required to validate the findings.


Assuntos
Adipocinas/sangue , Biomarcadores/sangue , Neoplasias da Mama/complicações , Proteína C-Reativa/análise , Fadiga/diagnóstico , Leptina/sangue , Fadiga/sangue , Fadiga/etiologia , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Prospectivos
10.
Breast Cancer Res Treat ; 168(3): 713-721, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29313215

RESUMO

PURPOSE: Cancer-related fatigue (CRF) and chemotherapy-related cognitive impairment (CRCI) are reported to be associated with mitochondrial dysfunction. Hence, mitochondrial DNA (mtDNA) content, a biomarker of mitochondrial dysfunction, is hypothesized to correlate with the onset of CRF and CRCI. This study aims to evaluate the association between peripheral blood mtDNA content reduction and severity of CRF and CRCI in patients receiving chemotherapy. METHODS: This was a prospective cohort study. Early-stage breast cancer patients receiving anthracycline- or taxane-based chemotherapy were recruited. CRF was assessed using MFSI-SF, and CRCI was assessed using FACT-Cog and CANTAB at two timepoints: baseline (T1; prior to treatment) and 6 weeks after initiation of treatment (T2). mtDNA content was measured at both timepoints using real-time quantitative polymerase chain reaction. Multiple logistic regression was utilized to evaluate the association between mtDNA reduction and worsening of CRF and CRCI, adjusting for age, anxiety, insomnia, plasma cytokines concentrations, and other clinically important covariates. RESULTS: A total of 108 patients (age 52.0 ± 9.2 years; 82.4% Chinese; 64.8% receiving anthracycline-based chemotherapy) were recruited. Proportions of patients with worsening of CRF increased from the lower to the upper quartiles of mtDNA reduction (22.2, 33.3, 55.6, and 63.0% in quartiles 1, 2, 3, and 4, respectively, p = 0.001 for trend). Reduction of mtDNA content was significantly greater among those with worsening of CRF and CRCI compared to those without CRF [mean reduction (± SD): 36.5 (46.1) vs. 9.4 (34.5), p < 0.001]. After adjusting for covariates, every 1-unit reduction of the mtDNA content was associated with a 4% increased risk for worsening of CRF (95% CI, 1-6%; p = 0.009). CONCLUSIONS: This is the first study to show that the reduction of mtDNA content in peripheral blood is associated with the onset of CRF in patients receiving chemotherapy. Further validation studies are required to confirm the findings.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Disfunção Cognitiva/sangue , DNA Mitocondrial/sangue , Fadiga/sangue , Adulto , Idoso , Antraciclinas/administração & dosagem , Antraciclinas/efeitos adversos , Neoplasias da Mama/sangue , Neoplasias da Mama/complicações , Neoplasias da Mama/patologia , Hidrocarbonetos Aromáticos com Pontes/administração & dosagem , Hidrocarbonetos Aromáticos com Pontes/efeitos adversos , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/genética , Disfunção Cognitiva/patologia , DNA Mitocondrial/genética , Fadiga/complicações , Fadiga/genética , Fadiga/patologia , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Taxoides/administração & dosagem , Taxoides/efeitos adversos
11.
Int J Mol Sci ; 20(1)2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30577655

RESUMO

Liver sinusoidal endothelial cells (LSECs) represent the permeable interface that segregates the blood compartment from the hepatic cells, regulating hepatic vascular tone and portal pressure amidst changes in the blood flow. In the presence of pathological conditions, phenotypic changes in LSECs contribute to the progression of chronic liver diseases, including the loss of endothelial permeability. Therefore, modulating LSECs offers a possible way to restore sinusoidal permeability and thereby improve hepatic recovery. Herein, we showed that titanium dioxide nanoparticles (TiO2 NPs) could induce transient leakiness in primary human hepatic sinusoidal endothelial cells (HHSECs). Interestingly, HHSECs exposed to these NPs exhibited reduced protein kinase B (Akt) phosphorylation, an important protein kinase which regulates cell attachment. Using a 3D co-culture system, we demonstrated that TiO2 NPs diminished the attachment of HHSECs onto normal human hepatic cell LO2. To further illustrate the significance of leakiness in liver sinusoids, we showed that NP-induced leakiness promoted Sunitinib transport across the HHSEC layer, resulting in increased drug uptake and efficacy. Hence, TiO2 NPs have the potential to modulate endothelial permeability within the specialized sinusoidal endothelium, especially during events of fibrosis and occlusion. This study highlighted the possible use of inorganic NPs as a novel strategy to promote drug delivery targeting the diseased liver.


Assuntos
Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Fígado/citologia , Fígado/efeitos dos fármacos , Nanopartículas , Titânio/farmacologia , Comunicação Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Fígado/patologia , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Permeabilidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Titânio/química
12.
BMC Cancer ; 17(1): 867, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29258453

RESUMO

BACKGROUND: Preliminary evidence suggests that changes in plasma brain-derived neurotrophic factor (BDNF) levels may contribute to the occurrence of chemotherapy-associated cognitive impairment (CACI), and a previous study suggested that carriers of the BDNF Met homozygous genotype are protected from CACI. METHODS: This multicenter, prospective cohort study involved chemotherapy-receiving early-stage breast cancer (ESBC) patients. Self-perceived cognitive function was longitudinally assessed using the validated FACT-Cog (ver. 3) across three time points: Prior to chemotherapy (T1), during chemotherapy (T2), and at the end of chemotherapy (T3). Plasma BDNF levels were quantified using enzyme-linked immunosorbent assay. Genotyping was performed using Sanger Sequencing. RESULTS: A total of 51 chemotherapy-receiving ESBC patients (mean age: 52.6 ± 9.5 years) were recruited, and 11 patients (21.6%) reported subjective cognitive impairment post-chemotherapy. Overall, there was a reduction in median plasma BDNF levels over time (T1: 5423.0 pg/ml; T2: 5313.6 pg/ml; T3: 4050.3 pg/ml; p < 0.01). After adjusting for confounding factors, longitudinal analysis revealed that BDNF levels were associated with self-reported concentration deficit (p = 0.032). Carriers of Val/Val (p = 0.011) and Val/Met (p = 0.003) BDNF genotypes demonstrated a significant reduction in plasma BDNF levels over time; however, plasma BDNF levels were similar across all time points among Met homozygous carriers (p = 0.107). CONCLUSION: There was a statistically significant change in BDNF levels post-chemotherapy in ESBC patients, and plasma BDNF levels were associated with self-perceived concentration deficit in patients receiving chemotherapy.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Predisposição Genética para Doença , Adulto , Idoso , Fator Neurotrófico Derivado do Encéfalo/sangue , Neoplasias da Mama/sangue , Neoplasias da Mama/patologia , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/patologia , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Polimorfismo de Nucleotídeo Único
13.
Chem Res Toxicol ; 29(7): 1118-31, 2016 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-27245204

RESUMO

Diclofenac and lumiracoxib are two highly analogous 2-phenylaminophenylacetic acid anti-inflammatory drugs exhibiting occasional dose-limiting hepatotoxicities. Prior data indicate that bioactivation and reactive metabolite formation play roles in the observed toxicity, but the exact chemical influence of the substituents remains elusive. In order to elucidate the role of chemical influence on metabolism related toxicity, metabolic stability and electrophilic reactivity were investigated for a series of structurally related analogues and their resulting metabolites. The resulting analogues embody progressive physiochemical changes through varying halogeno- and aliphatic substituents at two positions and were subjected to in vitro human liver microsomal metabolic stability and cell-based GSH depletion assays (to measure electrophilic reactivity). LC-MS/MS analysis of the GSH trapped reactive intermediates derived from the analogues was then used to identify the putative structures of reactive metabolites. We found that chemical modifications of the structural backbone led to noticeable perturbations of metabolic stability, electrophilic reactivity, and structures and composition of reactive metabolites. With the acquired data, the relationships between stability, reactivity, and toxicity were investigated in an attempt to correlate between Phase I metabolism and in vitro toxicity. A positive correlation was identified between reactivity and in vitro toxicity, indicating that electrophilic reactivity can be an indicator for in vitro toxicity. All in all, the effect of substituents on the structures and reactivity of the metabolites, however subtle the changes, should be taken into consideration during future drug design involving similar chemical features.


Assuntos
Acetatos/química , Acetatos/metabolismo , Cromatografia Líquida , Glutationa/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
14.
Biopharm Drug Dispos ; 37(3): 168-81, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26862045

RESUMO

The salivary paraxanthine/caffeine molar ratio has been proposed as a novel dynamic liver function test to guide dose adjustments of drugs hepatically cleared by CYP1A2. Its usability requires an established population norm as well as the factors influencing the ratio and actual concentrations. To address this knowledge gap, salivary caffeine and paraxanthine concentrations were measured at 4 h post caffeine dose in healthy Chinese individuals who had undergone 24 h of caffeine abstinence. The metabolic ratio was calculated and statistical analysis was performed. From the 52 participants (26 males; 30 regular caffeine consumers) recruited, the salivary paraxanthine/caffeine molar ratio was normally distributed with a mean and SD of 0.5 ± 0.2. No statistically significant factors (BMI, body weight, gender and regularity of caffeine intake) affecting the metabolic ratio were found. The caffeine concentration and total caffeine plus paraxanthine concentrations were lower in males than in females, and lower in regular caffeine consumers than in non-regular caffeine consumers. The 4 h salivary metabolic ratio (mean: 0.5) was generally not significantly different from the literature reported salivary, serum and plasma ratios measured at 4-9 h in healthy individuals (mean range 0.4-0.7) but was significantly higher than the literature reported 6 h plasma ratio and salivary ratios measured at 1-6 h in patients with liver disease or mild abnormal liver function tests (mean range 0.03-0.2). Overall, the population norm of the salivary metabolic ratio in a Singaporean Chinese population established in this study is distinct from individuals with liver disease or mild abnormal liver function tests and provides the benchmark for dosage adjustments of drugs metabolized by CYP1A2. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Cafeína/farmacocinética , Saliva/metabolismo , Teofilina/metabolismo , Adulto , Povo Asiático , Citocromo P-450 CYP1A2/metabolismo , Feminino , Humanos , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Adulto Jovem
15.
Anal Chem ; 87(20): 10292-8, 2015 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26382664

RESUMO

The salient optical properties of highly luminescent semiconductor nanocrystals render them ideal fluorophores for clinical diagnostics, therapeutics, and highly sensitive biochip applications. Microfluidic systems allow miniaturization and integration of multiple biochemical processes in a single device and do not require sophisticated diagnostic tools. Herein, we describe a microfluidic system that integrates RNA extraction, reverse transcription to cDNA, amplification and detection within one integrated device to detect histidine decarboxylase (HDC) gene directly from human white blood cells samples. When anisotropic semiconductor nanorods (NRs) were used as the fluorescent probes, the detection limit was found to be 0.4 ng of total RNA, which was much lower than that obtained using spherical quantum dots (QDs) or organic dyes. This was attributed to the large action cross-section of NRs and their high probability of target capture in a pull-down detection scheme. The combination of large scale integrated microfluidics with highly fluorescent semiconductor NRs may find widespread utility in point-of-care devices and multitarget diagnostics.


Assuntos
Histidina Descarboxilase/genética , Técnicas Analíticas Microfluídicas/instrumentação , Nanotubos/química , RNA/análise , RNA/sangue , Semicondutores , Anisotropia , Corantes Fluorescentes/química , Humanos , Pontos Quânticos
16.
Drug Metab Rev ; 47(1): 21-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25639891

RESUMO

Mechanism-based inactivation (MBI) of CYP450 enzymes is a unique form of inhibition in which the enzymatic machinery of the victim is responsible for generation of the reactive metabolite. This precondition sets up a time-dependency for the inactivation process, a hallmark feature that characterizes all MBI. Yet, MBI itself is a complex biochemical phenomenon that operates in different modes, namely, covalent binding to apoprotein, covalent binding of the porphyrin group and also complexation of the catalytic iron. Using lapatinib as a recent example of toxicological interest, we present an example of a mixed-function MBI that can confound clinical drug-drug interactions manifestation. Lapatinib exhibits both covalent binding to the apoprotein and formation of a metabolite-intermediate complex in an enzyme-selective manner (CYP3A4 versus CYP3A5), each with different reactive metabolites. The clinical implication of this effect is also contingent upon genetic polymorphisms of the enzyme involved as well as the co-administration of other substrates, inhibitors or inducers, culminating in drug-drug interactions. This understanding recapitulates the importance of applying isoform-specific mechanistic investigations to develop customized strategies to manage such outcomes.


Assuntos
Citocromo P-450 CYP3A/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Quinazolinas/metabolismo , Animais , Humanos , Lapatinib , Inibidores de Proteínas Quinases/química , Quinazolinas/química
17.
Chem Res Toxicol ; 28(10): 2019-33, 2015 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-26401548

RESUMO

The thiazolidine and imidazolidine heterocyclic scaffolds, i.e., the rhodanines, 2,4-thiazolidinediones, 2-thiohydantoins, and hydantoins have been the subject of debate on their suitability as starting points in drug discovery. This attention arose from the wide variety of biological activities exhibited by these scaffolds and their frequent occurrence as hits in screening campaigns. Studies have been conducted to evaluate their value in drug discovery in terms of their biological activity, chemical reactivity, aggregation-based promiscuity, and electronic properties. However, the metabolic profiles and toxicities have not been systematically assessed. In this study, a series of five-membered multiheterocyclic (FMMH) compounds were selected for a systematic evaluation of their metabolic profiles and toxicities on TAMH cells, a metabolically competent rodent liver cell line and HepG2 cells, a model of human hepatocytes. Our studies showed that generally the rhodanines are the most toxic, followed by the thiazolidinediones, thiohydantoins, and hydantoins. However, not all compounds within the family of heterocycles were toxic. In terms of metabolic stability, 5-substituted rhodanines and 5-benzylidene thiohydantoins were found to have short half-lives in the presence of human liver microsomes (t1/2 < 30 min) suggesting that the presence of the endocyclic sulfur and thiocarbonyl group or a combination of C5 benzylidene substituent and thiocarbonyl group in these heterocycles could be recognition motifs for P450 metabolism. However, the stability of these compounds could be improved by installing hydrophilic functional groups. Therefore, the toxicities and metabolic profiles of FMMH derivatives will ultimately depend on the overall chemical entity, and a blanket statement on the effect of the FMMH scaffold on toxicity or metabolic stability cannot and should not be made.


Assuntos
Hipoglicemiantes/metabolismo , Imidazolidinas/metabolismo , Tiazolidinedionas/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Sistema Enzimático do Citocromo P-450/metabolismo , Avaliação Pré-Clínica de Medicamentos , Glutationa/metabolismo , Meia-Vida , Células Hep G2 , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/toxicidade , Imidazolidinas/química , Imidazolidinas/toxicidade , Microssomos Hepáticos/metabolismo , Relação Estrutura-Atividade , Espectrometria de Massas em Tandem , Tiazolidinedionas/química , Tiazolidinedionas/toxicidade
18.
Br J Clin Pharmacol ; 79(2): 241-53, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25125025

RESUMO

Drug-drug interactions (DDIs) occur when a patient's response to the drug is modified by administration or co-exposure to another drug. The main cytochrome P450 (CYP) enzyme, CYP3A4, is implicated in the metabolism of almost all of the tyrosine kinase inhibitors (TKIs). Therefore, there is a substantial potential for interaction between TKIs and other drugs that modulate the activity of this metabolic pathway. Cancer patients are susceptible to DDIs as they receive many medications, either for supportive care or for treatment of toxicity. Differences in DDI outcomes are generally negligible because of the wide therapeutic window of common drugs. However for anticancer agents, serious clinical consequences may occur from small changes in drug metabolism and pharmacokinetics. Therefore, the objective of this review is to highlight the current understanding of DDIs among TKIs, with a focus on metabolism, as well as to identify challenges in the prediction of DDIs and provide recommendations.


Assuntos
Antineoplásicos/farmacocinética , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacocinética , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Citocromo P-450 CYP3A/efeitos dos fármacos , Citocromo P-450 CYP3A/metabolismo , Interações Medicamentosas , Humanos , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Proteínas Tirosina Quinases/antagonistas & inibidores
19.
Front Genet ; 14: 1199549, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37377593

RESUMO

Background and Aims: Various publications suggested that there is an association between CYP7A1 single nucleotide polymorphisms (SNP) and a reduced response to statin therapy, but the results were inconsistent. This study aimed to collectively review these publications to appraise the effect of statins on cholesterol control in carriers of CYP7A1 variant alleles. Methods: PUBMED, Cochrane and EMBASE were searched systematically to identify reported studies on the lipid responses to statin treatment between carriers of the variant allele versus the non-variant allele of CYP7A1 SNPs. The change from baseline in lipid responses for all included studies were calculated using weighted mean differences (WMD) (with 95% confidence interval (CI)). A meta-analysis was conducted to pool results using either the random-effects model or the fixed effects model. Results: A total of 6 publications comprising of 1,686 subjects for the assessment of total cholesterol, LDL-C and HDL-C and 1,156 subjects for the assessment of triglycerides were included in the meta-analyses. Subjects who were non-carriers of a CYP7A1 SNP (-204 A/C (rs3808607), -278 A/C (rs3808607) and rs8192875) had a greater reduction in total cholesterol (overall WMD -0.17, 95% CI -0.29, -0.06) and LDL-C levels (overall WMD -0.16, 95% CI -0.26, -0.05) as compared with subjects who borne the variant allele of CYP7A1 SNPs when administered a statin. Conclusion: The presence of variant allele of CYP7A1 SNPs may result in suboptimal control of total cholesterol and LDL-C levels as compared with individuals who do not carry the variant allele, when administered an equivalent dose of statin.

20.
Nat Commun ; 14(1): 4269, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37460554

RESUMO

Delivering cancer therapeutics to tumors necessitates their escape from the surrounding blood vessels. Tumor vasculatures are not always sufficiently leaky. Herein, we engineer therapeutically competent leakage of therapeutics from tumor vasculature with gold nanoparticles capable of inducing endothelial leakiness (NanoEL). These NanoEL gold nanoparticles activated the loss of endothelial adherens junctions without any perceivable toxicity to the endothelial cells. Microscopically, through real time live animal intravital imaging, we show that NanoEL particles induced leakiness in the tumor vessels walls and improved infiltration into the interstitial space within the tumor. In both primary tumor and secondary micrometastases animal models, we show that pretreatment of tumor vasculature with NanoEL particles before therapeutics administration could completely regress the cancer. Engineering tumoral vasculature leakiness represents a new paradigm in our approach towards increasing tumoral accessibility of anti-cancer therapeutics instead of further increasing their anti-cancer lethality.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Neoplasias de Tecido Vascular , Neoplasias , Animais , Células Endoteliais/patologia , Ouro , Nanopartículas Metálicas/uso terapêutico , Endotélio/patologia , Neoplasias/patologia
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