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1.
Nat Commun ; 14(1): 2876, 2023 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-37208361

RESUMO

Tumors are comprised of a multitude of cell types spanning different microenvironments. Mass spectrometry imaging (MSI) has the potential to identify metabolic patterns within the tumor ecosystem and surrounding tissues, but conventional workflows have not yet fully integrated the breadth of experimental techniques in metabolomics. Here, we combine MSI, stable isotope labeling, and a spatial variant of Isotopologue Spectral Analysis to map distributions of metabolite abundances, nutrient contributions, and metabolic turnover fluxes across the brains of mice harboring GL261 glioma, a widely used model for glioblastoma. When integrated with MSI, the combination of ion mobility, desorption electrospray ionization, and matrix assisted laser desorption ionization reveals alterations in multiple anabolic pathways. De novo fatty acid synthesis flux is increased by approximately 3-fold in glioma relative to surrounding healthy tissue. Fatty acid elongation flux is elevated even higher at 8-fold relative to surrounding healthy tissue and highlights the importance of elongase activity in glioma.


Assuntos
Ecossistema , Glioblastoma , Animais , Camundongos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Metabolômica/métodos , Glioblastoma/diagnóstico por imagem , Ácidos Graxos/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Microambiente Tumoral
2.
J Anaesthesiol Clin Pharmacol ; 38(3): 399-404, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36505226

RESUMO

Background and Aims: Operation theater (OT) complex is an important area for a hospital as it needs expensive infrastructure, disposable, and reusable resources and a multidisciplinary highly qualified and efficient team, the metrics of which are key in generating revenue, and improved productivity. The efficient utilization of OT ensures maximum output in view of the investment of highly qualified doctors, equipment, and outcomes. Our study aimed to evaluate the utilization of OT functioning stepwise, reasons for delays, case cancellations, and areas of improvement if any. Material and Methods: This prospective observational study was planned in three phases; in phase 1 audit of OT functioning was carried out for 1 month and based on data analysis recommendations were given for improvement. In phase 2, the recommendations would be implemented over 3 months and in phase 3 re-audit will be carried out for 1 month. Data analysis was done on IBM SPSS version 26 software. Descriptive statistics measures were calculated by the mean and standard deviation. Results: The total available resource time was 52920 min and the total time utilized was 37740 min. Overall, raw utilization was 71.31%. OT was started late 63.50% times. Case cancellation occurred on 8.99% occasions. Conclusion: We conclude that utilization of operating room time can be maximized by proper planning and realistic scheduling of elective lists, communication among team members, and resource management. Audit of OT utilization is an important tool to identify problem areas and formulate protocols accordingly.

3.
Biosensors (Basel) ; 12(8)2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35892449

RESUMO

Pramipexole (PMXL) belongs to the benzothiazole class of aromatic compounds and is used in treating Parkinson's disease; however, overdosage leads to some abnormal effects that could trigger severe side effects. Therefore, it demands a sensitive analytical tool for trace level detection. In this work, we successfully developed an electrochemical sensor for the trace level detection of PMXL, using the voltammetric method. For the analysis, graphitic carbon nitride (gCN) was opted and synthesized by using a high-temperature thermal condensation method. The synthesized nanoparticles were employed for surface characterization, using transmission electron microscopy (TEM), X-ray diffraction (XRD), and atomic force microscopy (AFM) techniques. The electrochemical characterization of the material was evaluated by using the electrochemical impedance spectroscopy (EIS) technique to evaluate the solution-electrode interface property. The cyclic voltammetry (CV) behavior of PMXL displayed an anodic peak in the forward scan, indicating that PMXL underwent electrooxidation, and an enhanced detection peak with lower detection potential was achieved for gCN-modified carbon paste electrode (gCN·CPE). The influence of different parameters on the electrochemical behavior was analyzed, revealing the diffusion governing the electrode process with an equal number of hydronium ions and electron involvement. For the fabricated gCN·CPE, good linearity range was noticed from 0.05 to 500 µM, and a lower detection limit (LD) of 0.012 µM was achieved for the selected concentration range (0.5 to 30 µM). Selectivity of the electrode in PMXL detection was investigated by conducting an interference study, while the tablet sample analysis demonstrates the sensitive and real-time application of the electrode. The good recovery values for the analysis illustrate the efficiency of the electrode for PMXL analysis.


Assuntos
Técnicas Eletroquímicas , Grafite , Carbono/química , Técnicas Eletroquímicas/métodos , Eletrodos , Grafite/química , Limite de Detecção , Compostos de Nitrogênio , Pramipexol
4.
Cell Rep Med ; 2(8): 100369, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34308390

RESUMO

There is an urgent need to identify which COVID-19 patients will develop life-threatening illness so that medical resources can be optimally allocated and rapid treatment can be administered early in the disease course, when clinical management is most effective. To aid in the prognostic classification of disease severity, we perform untargeted metabolomics on plasma from 339 patients, with samples collected at six longitudinal time points. Using the temporal metabolic profiles and machine learning, we build a predictive model of disease severity. We discover that a panel of metabolites measured at the time of study entry successfully determines disease severity. Through analysis of longitudinal samples, we confirm that most of these markers are directly related to disease progression and that their levels return to baseline upon disease recovery. Finally, we validate that these metabolites are also altered in a hamster model of COVID-19.


Assuntos
COVID-19/metabolismo , Plasma/metabolismo , SARS-CoV-2/metabolismo , Adulto , Biomarcadores/sangue , Feminino , Humanos , Estudos Longitudinais , Aprendizado de Máquina , Masculino , Metaboloma , Metabolômica/métodos , Pessoa de Meia-Idade , Gravidade do Paciente , Plasma/química , Prognóstico , Índice de Gravidade de Doença
5.
medRxiv ; 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33564793

RESUMO

There is an urgent need to identify which COVID-19 patients will develop life-threatening illness so that scarce medical resources can be optimally allocated and rapid treatment can be administered early in the disease course, when clinical management is most effective. To aid in the prognostic classification of disease severity, we performed untargeted metabolomics profiling of 341 patients with plasma samples collected at six longitudinal time points. Using the temporal metabolic profiles and machine learning, we then built a predictive model of disease severity. We determined that the levels of 25 metabolites measured at the time of hospital admission successfully predict future disease severity. Through analysis of longitudinal samples, we confirmed that these prognostic markers are directly related to disease progression and that their levels are restored to baseline upon disease recovery. Finally, we validated that these metabolites are also altered in a hamster model of COVID-19. Our results indicate that metabolic changes associated with COVID-19 severity can be effectively used to stratify patients and inform resource allocation during the pandemic.

6.
J Nanosci Nanotechnol ; 20(5): 2887-2892, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31635625

RESUMO

A simple cost effective Al-TiO2 thin film electrode was fabricated for urea sensing. Urea is the key end product of nitrogen metabolism in humans. Increased level of urea leads to loss of kidney function. Thus determination of urea is important in analysis of kidney diseases. Al-TiO2 thin films were deposited with different concentration of Al by Spray pyrolysis technique. The X-ray diffraction (XRD) pattern reveals the anatase phase of the Al-TiO2 thin films with tetragonal structure. A shift is observed in the XRD peak position compared to as prepared TiO2 thin film indicates the incorporation of Al ions into Ti ions. The UV-Vis spectroscopy study shows that the absorption increases and the absorption peak shifts towards the visible region for Al-TiO2 thin films compared with that of the as prepared TiO2 thin film. The optical band gap values changes with the change in the Al concentration in TiO2 thin films. The electrochemical analysis for optimized Al-TiO2 thin film electrode was carried out by cyclic voltammetry (CV) method. CV studies of Al-TiO2 thin film electrode show the good stability and linearity which is essential to fabricate biosensor. The sensor response to urea is linear with correlation coefficient of 0.944 and the sensitivity is 3.17 µA mM-1 cm-2.


Assuntos
Pirólise , Ureia , Eletrodos , Humanos , Titânio
7.
J Parasit Dis ; 36(1): 129-34, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23542948

RESUMO

The present study was undertaken to evaluate various disease conditions prevalent in slaughtered pigs and zoonotic importance. The study was conducted on two hundred non-descript pigs slaughtered at an organized slaughter house, Mumbai. The animals included in the study were randomly selected. Post mortem examination of the animals was performed to note various disease conditions and tissues were collected for histopathology. Direct examination of stool was found negative for parasites. Gross and microscopical examination revealed presence of Ascarops strongylina, Sarcocyst, Hydatid cyst, Cysticercus cellulosae, Ascaris suum and Cysticercus tenuicollis, along with bacteria like Salmonella, Pseudomonas, Shigella, Streptococci, Proteus and Pasteurella spp. were isolated. Indirect ELISA was performed for detection of antibody titer in the pig serum against classical swine fever. Studies on hematological and serum biochemical profile revealed decreased total protein concentration and globulin level with leukocytosis and neutrophilia and in parasitic infections eosinophilia was evident.

8.
J Parasit Dis ; 36(1): 99-100, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23543247

RESUMO

The present study was undertaken to survey and study the prevalence of different diseases in pigeons in regions in and around Kolkata, India. About 8,000 pigeons from Kolkata region and 2,000 from semi-urban area surrounding Kolkata were selected and 5,000 fecal specimens were collected from apparently unhealthy pigeons. From the present study, it was evident that star gazing, diarrhea and pox were the major infections. Protozona parasites were also revealed which was caused mainly due to coccidian oocysts. In the present study it was found that the pigeons mainly suffered from star gazing condition and helminthic infection revealed majorly the presence of coccidian oocysts followed by Capillarea and Ascaridia spp.

9.
Anal Chem ; 84(2): 1117-25, 2012 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-22141424

RESUMO

Although acute myocardial infarction (MI) is consistently among the top causes of death in the United States, the spatial distribution of lipids and metabolites following MI remains to be elucidated. This work presents the investigation of an in vivo rat model of MI using mass spectrometric imaging (MSI) and multivariate data analysis. MSI was conducted on cardiac tissue following a 24-h left anterior descending coronary artery ligation to analyze multiple compound classes. First, the spatial distribution of a small metabolite, creatine, was used to identify areas of infarcted myocardium. Second, multivariate data analysis and tandem mass spectrometry were used to identify phospholipid (PL) markers of MI. A number of lysophospholipids demonstrated increased ion signal in areas of infarction. In contrast, select intact PLs demonstrated decreased ion signal in the area of infarction. The complementary nature of these two lipid classes suggests increased activity of phospholipase A(2), an enzyme that has been implicated in coronary heart disease and inflammation.


Assuntos
Vasos Coronários/metabolismo , Vasos Coronários/patologia , Coração/fisiologia , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Animais , Processamento de Imagem Assistida por Computador , Ligadura , Masculino , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem
10.
J Biol Chem ; 285(53): 41255-69, 2010 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-20956542

RESUMO

Myeloperoxidase-derived HOCl targets tissue- and lipoprotein-associated plasmalogens to generate α-chlorinated fatty aldehydes, including 2-chlorohexadecanal. Under physiological conditions, 2-chlorohexadecanal is oxidized to 2-chlorohexadecanoic acid (2-ClHA). This study demonstrates the catabolism of 2-ClHA by ω-oxidation and subsequent ß-oxidation from the ω-end. Mass spectrometric analyses revealed that 2-ClHA is ω-oxidized in the presence of liver microsomes with initial ω-hydroxylation of 2-ClHA. Subsequent oxidation steps were examined in a human hepatocellular cell line (HepG2). Three different α-chlorinated dicarboxylic acids, 2-chlorohexadecane-(1,16)-dioic acid, 2-chlorotetradecane-(1,14)-dioic acid, and 2-chloroadipic acid (2-ClAdA), were identified. Levels of 2-chlorohexadecane-(1,16)-dioic acid, 2-chlorotetradecane-(1,14)-dioic acid, and 2-ClAdA produced by HepG2 cells were dependent on the concentration of 2-ClHA and the incubation time. Synthetic stable isotope-labeled 2-ClHA was used to demonstrate a precursor-product relationship between 2-ClHA and the α-chlorinated dicarboxylic acids. We also report the identification of endogenous 2-ClAdA in human and rat urine and elevations in stable isotope-labeled urinary 2-ClAdA in rats subjected to intraperitoneal administration of stable isotope-labeled 2-ClHA. Furthermore, urinary 2-ClAdA and plasma 2-ClHA levels are increased in LPS-treated rats. Taken together, these data show that 2-ClHA is ω-oxidized to generate α-chlorinated dicarboxylic acids, which include α-chloroadipic acid that is excreted in the urine.


Assuntos
Cloro/química , Ácidos Dicarboxílicos/química , Ácidos Graxos/metabolismo , Animais , Ácidos Dicarboxílicos/metabolismo , Células Hep G2 , Hepatócitos/citologia , Humanos , Espectrometria de Massas/métodos , Microssomos Hepáticos/metabolismo , Oxigênio/química , Ácidos Palmíticos/química , Peroxidase/química , Peroxidases/química , Coelhos , Ratos
11.
J Lipid Res ; 51(5): 1085-92, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20019386

RESUMO

Neutrophils are important in the host response against invading pathogens. One chemical defense mechanism employed by neutrophils involves the production of myeloperoxidase (MPO)-derived HOCl. 2-Chlorohexadecanal (2-ClHDA) is a naturally occurring lipid product of HOCl targeting the vinyl ether bond of plasmalogens. Previous studies have shown that exogenously-added 2-ClHDA is oxidized to 2-chlorohexadecanoic acid (2-ClHA) and reduced to 2-chlorohexadecanol (2-ClHOH) by endothelial cells. These studies show that both 2-ClHA and 2-ClHOH are produced in activated neutrophils in an MPO- and time-dependent manner and are released by neutrophils into media. 2-ClHDA levels peak following 30 min of phorbol 12-myristate-13-acetate stimulation. In contrast, 2-ClHA and 2-ClHOH levels steadily increased over 60 min, suggesting a precursor-product relationship between 2-ClHDA and both 2-ClHA and 2-ClHOH. Additional experiments using wild-type CHO.K1 and CHO.K1 cells deficient in fatty aldehyde dehydrogenase (FALDH), FAA.K1A, demonstrated that 2-ClHDA oxidation to 2-ClHA is dependent on FALDH activity. Furthermore, mice exposed to intranasal Sendai virus displayed lung neutrophil recruitment, as well as elevated 2-ClHA levels in plasma and bronchoalveolar lavage compared with control-treated mice. Taken together, these data demonstrate, for the first time, that metabolites of 2-ClHDA are produced both in vivo as well as in isolated human neutrophils.


Assuntos
Aldeídos/imunologia , Aldeídos/metabolismo , Halogenação , Metabolismo dos Lipídeos/imunologia , Neutrófilos/imunologia , Animais , Lavagem Broncoalveolar , Células CHO , Cricetinae , Cricetulus , Álcoois Graxos/metabolismo , Humanos , Camundongos , Neutrófilos/metabolismo , Ésteres de Forbol/farmacologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/virologia
12.
J Chromatogr B Analyt Technol Biomed Life Sci ; 877(26): 2768-77, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19091635

RESUMO

Plasmalogens are targeted by hypohalous acids resulting in the production of 2-chlorofatty aldehydes, 2-bromofatty aldehydes and chlorohydrin species of lysophosphatidylcholine. These novel lipids may have important roles in the pathophysiological sequelae of cardiovascular diseases as well as serve as biomarkers of cardiovascular disease. Accordingly, the discovery of these new lipid species have required the development of techniques for their purification and quantification. Thin layer chromatography, high performance liquid chromatography (LC) and gas chromatography (GC) of these lipids and their derivatives have provided a battery of tools for their analyses. These lipids have been quantified using flame ionization detection (FID) and mass spectrometry (MS).


Assuntos
Aldeídos/análise , Cloridrinas/análise , Cromatografia/métodos , Lisofosfatidilcolinas/química , Animais , Humanos
13.
Front Biosci ; 12: 2750-60, 2007 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17127277

RESUMO

The development of electrospray ionization mass spectrometry has been critical for the analyses of lipidomes from subcellular organelles. The myocardial nuclear lipidome likely has a key role in the molecular regulation of gene expression. In fact, recent studies have suggested that specific phospholipid classes bind and regulate specific transcription factors. The dynamic regulation of the myocardial nuclear lipidome may be critical in mediating long-term pathological responses to stresses such as ischemia, tachycardia, and hypertension. In this brief review, the preparation of myocardial nuclei is discussed, and the resulting nuclear lipidome from rat and rabbit are shown as examples. The rabbit myocardial nuclear lipidome contains relatively more plasmenylcholine/phosphatidylcholine molecular species in comparison to that ratio observed in the rat myocardial nuclear lipidome. The composition of the rat myocardial nuclear choline glycerophospholipid pool was relatively enriched with molecular species containing arachidonic acid and docosahexaenoic acid in comparison to that in the rabbit myocardial nuclear choline glycerophospholipid pool. While the ethanolamine glycerophospholipids of the rabbit myocardial nuclei are enriched with arachidonic acid and plasmalogens, the ethanolamine glycerophospholipid profile from rat myocardial nuclei show less plasmalogen and more species containing docosahexaenoic acid. Last, significant differences in the ethanolamine glycerophospholipid molecular species were observed in the rabbit heart lipidomes from the nucleus and the mitochondria. Quantitation of these lipid species in hearts subjected to pathophysiological stresses may provide important information on the role of the myocardial nuclear lipidome on long-term cardiac cell function.


Assuntos
Núcleo Celular/química , Lipídeos/química , Miocárdio/química , Animais , Fracionamento Celular , Núcleo Celular/ultraestrutura , Membranas Mitocondriais/química , Miocárdio/ultraestrutura , Membrana Nuclear/química , Plasmalogênios/análise , Coelhos , Ratos , Espectrometria de Massas por Ionização por Electrospray
14.
J Biol Chem ; 281(25): 16849-16860, 2006 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-16611638

RESUMO

Numerous studies have suggested relationships between myeloperoxidase (MPO), inflammation, and atherosclerosis. MPO-derived reactive chlorinating species attack membrane plasmalogens releasing alpha-chloro fatty aldehydes including 2-chlorohexadecanal (2-ClHDA), which have been found to accumulate in activated neutrophils, activated monocytes, infarcted myocardium and human atheromas. The present study employed synthetically prepared 2-Cl-[3H]-HDA as well as stable isotope-labeled 2-ClHDA to elucidate the metabolism of 2-ClHDA. The results herein demonstrate that human coronary artery endothelial cells oxidize and reduce 2-ClHDA to its respective chlorinated fatty acid (alpha-ClFA) and chlorinated fatty alcohol (alpha-ClFOH). Within the first hour of incubations of human coronary artery endothelial cells with 2-Cl-[3H]-HDA, the label was incorporated into the alpha-ClFOH and alpha-ClFA pools. After 1 h, the radiolabel was predominantly found in the alpha-ClFOH pool. Cell-derived alpha-ClFOH and alpha-ClFA were also released into the cell culture medium. Additionally, chlorinated fatty acid was incorporated into complex endothelial cell glycerolipids, including monoglycerides, triglycerides, phosphatidylcholine, and phosphatidylethanolamine. The oxidation and reduction of 2-ClHDA to alpha-ClFA and alpha-ClFOH, respectively, was further supported by mass spectrometric analyses of human coronary artery endothelial cells incubated with either 2-ClHDA or stable isotope-labeled 2-ClHDA (2-Cl-[d4]-HDA). 2-ClHDA was also oxidized to alpha-ClFA and reduced to alpha-ClFOH in both control and phorbol 12-myristate 13-acetate-stimulated neutrophils. Taken together, these results show that a family of chlorinated lipidic metabolites is produced from alpha-chloro fatty aldehydes derived from reactive chlorinating species targeting of plasmalogens. These metabolites are incorporated into complex lipids and their biological roles may provide new insights into MPO-mediated disease.


Assuntos
Aldeídos/metabolismo , Peroxidase/metabolismo , Aldeídos/química , Vasos Coronários/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Ácidos Graxos/metabolismo , Coração/efeitos dos fármacos , Humanos , Lipídeos/química , Modelos Químicos , Miocárdio/patologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Oxigênio/metabolismo , Fosfatidilcolinas/química
15.
Breast Cancer Res Treat ; 81(1): 1-10, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14531492

RESUMO

The present study was conducted to ascertain the modulatory influences of Ferula asafoetida L. (asafoetida, flavoring agent) on the mammary epithelial tissue differentiation, hepatic drug metabolizing enzymes, antioxidant profiles and N-methyl-N-nitrosourea (MNU)-induced mammary carcinogenesis in Sprague-Dawley rats. Feeding with two doses of asafoetida (1.25 and 2.5% w/w in diet) showed a remarkable increase in the development and differentiation of ducts/ductules (p < 0.01-0.005), lobules (p < 0.005) and a decrease in terminal end buds (p < 0.05-0.005) as compared to both normal and MNU-treated control animals. To assess the biochemical parameters, effect of asafoetida on drug-metabolizing enzymes was evaluated in the liver of rats. Asafoetida treatment significantly reduced (p < 0.05) the levels of cytochrome P450 and b5. There was an enhancement in the activities of glutathione S-transferase (p < 0.05-0.005), DT-diaphorase (p < 0.05-0.01), superoxide dismutase (p < 0.01-0.005) and catalase (p < 0.05-0.005) and in the level of reduced glutathione (p < 0.05-0.005), followed by asafoetida treatment. Also, asafoetida significantly restored the level of antioxidant system, depleted by MNU-treatment. The strengthening of antioxidant system by the lower and higher doses of asafoetida in the presence and absence of MNU was further substantiated by a significant inhibition (p < 0.005) in lipid peroxidation as measured by thiobarbituric acid-reactive substances (TBARS) in the liver of rat. Further, in long-term animal studies, where MNU was used to induce mammary carcinogenesis, asafoetida treatment resulted in a significant reduction in the multiplicity (p < 0.001) and size of palpable mammary tumors (p < 0.005-0.001) and a delay in mean latency period of tumor appearance (p < 0.005). Together, these findings indicate the chemopreventive potential of asafoetida against MNU-induced mammary carcinogenesis. Thus, asafoetida needs further investigation with regard to identification and characterization of its active principle(s) and mechanism of action, for this compound to be developed as a potential chemopreventive agent for human cancers.


Assuntos
Anticarcinógenos/farmacologia , Células Epiteliais/efeitos dos fármacos , Ferula , Fígado/efeitos dos fármacos , Fígado/enzimologia , Glândulas Mamárias Animais/efeitos dos fármacos , Neoplasias Mamárias Experimentais , Animais , Carcinógenos , Diferenciação Celular/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Indução Enzimática/efeitos dos fármacos , Feminino , Ferula/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/prevenção & controle , Metilnitrosoureia , Preparações de Plantas/farmacologia , Ratos , Ratos Sprague-Dawley , Xenobióticos/metabolismo
16.
Oncogene ; 21(11): 1759-67, 2002 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-11896607

RESUMO

Prostate cancer (PCA) is one of the most common invasive malignancies of men in the US, however, there have been limited successes so far in its therapy. Even most potent agents (e.g. TNFalpha) are ineffective in killing human PCA cells possibly due to constitutive activation of NF-kappaB that subsequently activates a large number of anti-apoptotic genes. In such a scenario, strong apoptotic agent TNFalpha, further induces NF-kappaB activation rather than inducing apoptosis. In several recent studies, we have demonstrated both cancer preventive and anti-cancer efficacy of silymarin and its constituent silibinin in a variety of experimental tumor models and cell culture systems. Here we examined whether silibinin is effective in inhibiting constitutive NF-kappaB activation in human PCA cells, which would help in overcoming TNFalpha-insensitivity. Our studies reveal that silibinin effectively inhibits constitutive activation of NF-kappaB in advanced human prostate carcinoma DU145 cells. Consistent with this, nuclear levels of p65 and p50 sub-units of NF-kappaB were also reduced. In the studies assessing molecular mechanism of this effect, silibinin treatment resulted in a significant increase in the level of IkappaBalpha with a concomitant decrease in phospho-IkappaBalpha. Kinase assays revealed that silibinin dose-dependently decreases IKKalpha kinase activity. The effect of silibinin on IKKalpha seemed to be direct as evidenced by the in vitro kinase assay, where immunoprecipitated IKKalpha was incubated with silibinin. This shows that silibinin does not necessarily need an upstream event to bring about its inhibitory effect on IKKalpha and downstream effectors. Additional studies showed that silibinin also inhibits TNFalpha-induced activation of NF-kappaB via IkappaBalpha pathway and subsequently sensitizes DU145 cells to TNFalpha-induced apoptosis. These results indicate that silibinin could be used to enhance the effectiveness of TNFalpha-based chemotherapy in advanced PCA.


Assuntos
Apoptose/efeitos dos fármacos , Proteínas I-kappa B , NF-kappa B/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Silimarina/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Transporte Ativo do Núcleo Celular , Proteínas de Ligação a DNA/fisiologia , Humanos , Quinase I-kappa B , Masculino , Inibidor de NF-kappaB alfa , Fosforilação , Neoplasias da Próstata/patologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Células Tumorais Cultivadas
17.
Phytomedicine ; 7(3): 209-19, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11185732

RESUMO

The effect of two doses (30 microl and 60 microl/day/mice daily for 14 days) of the fresh leaf pulp extract of Aloe vera was examined on carcinogen-metabolizing phase-I and phase-II enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase and lipid peroxidation in the liver of mice. The modulatory effect of the pulp extract was also examined on extrahepatic organs (lung, kidney and forestomach) for the activities of glutathione S-transferase, DT-diophorase, superoxide dismutase and catalase. The positive control mice were treated with butylated hydroxyanisole (BHA). Significant increases in the levels of acid soluble sulfhydryl (-SH) content, NADPH-cytochrome P450 reductase, NADH-cytochrome b5 reductase, glutathione S-transferase (GST), DT-diaphorase (DTD), superoxide dismutase (SOD), catalase, glutathione peroxidase (GPX) and glutathione reductase (GR) were observed in the liver. Aloe vera significantly reduced the levels of cytochrome P450 and cytochrome b5. Thus, Aloe vera is clearly an inducer of phase-II enzyme system. Treatment with both doses of Aloe caused a decrease in malondialdehyde (MDA) formation and the activity of lactate dehydrogenase in the liver, suggesting its role in protection against prooxidant-induced membrane and cellular damage. The microsomal and cytosolic protein was significantly enhanced by Aloe vera, indicating the possibility of its involvement in the induction of protein synthesis. BHA, an antioxidant compound, provided the authenticity of our assay protocol and response of animals against modulator. The pulp extract was effective in inducing GST, DTD, SOD and catalase as measured in extrahepatic organs. Thus, besides liver, other organs (lung, kidney and forestomach) were also influenced favorably by Aloe vera in order to detoxify reactive metabolites, including chemical carcinogens and drugs.


Assuntos
Aloe , Anticarcinógenos/farmacologia , Antioxidantes/farmacologia , Fígado/enzimologia , Plantas Medicinais , Animais , Anticarcinógenos/administração & dosagem , Antioxidantes/administração & dosagem , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Citocromos b5/efeitos dos fármacos , Esquema de Medicação , Rim/enzimologia , Peroxidação de Lipídeos/efeitos dos fármacos , Pulmão/enzimologia , Camundongos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Folhas de Planta , Distribuição Aleatória , Estômago/enzimologia
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