Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Aging Neurosci ; 12: 575481, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33328957

RESUMO

Alpha-synuclein (α-Syn) is widely distributed and involved in the regulation of the nervous system. The phosphorylation of α-Syn at serine 129 (pSer129α-Syn) is known to be closely associated with α-Synucleinopathies, especially Parkinson's disease (PD). The present study aimed to explore the α-Syn accumulation and its phosphorylation in the enteric nervous system (ENS) in patients without neurodegeneration. Patients who underwent colorectal surgery for either malignant or benign tumors that were not suitable for endoscopic resection (n = 19) were recruited to obtain normal intestinal specimens, which were used to assess α-Syn immunoreactivity patterns using α-Syn and pSer129α-Syn antibodies. Furthermore, the sub-location of α-Syn in neurons was identified by α-Syn/neurofilament double staining. Semi-quantitative counting was used to evaluate the expression of α-Syn and pSer129α-Syn in the ENS. Positive staining of α-Syn was detected in all intestinal layers in patients with non-neurodegenerative diseases. There was no significant correlation between the distribution of α-Syn and age (p = 0.554) or tumor stage (p = 0.751). Positive staining for pSer129α-Syn was only observed in the submucosa and myenteric plexus layers. The accumulation of pSer129α-Syn increased with age. In addition, we found that the degenerative changes of the ENS were related to the degree of tumor malignancy (p = 0.022). The deposits of α-Syn were present in the ENS of patients with non-neurodegenerative disorders; particularly the age-dependent expression of pSer129α-Syn in the submucosa and myenteric plexus. The current findings of α-Syn immunostaining in the ENS under near non-pathological conditions weaken the basis of using α-Syn pathology as a suitable hallmark to diagnose α-Synucleinopathies including PD. However, our data provided unique perspectives to study gastrointestinal dysfunction in non-neurodegenerative disorders. These findings provide new evidence to elucidate the neuropathological characteristics and α-Syn pathology pattern of the ENS in non-neurodegenerative conditions.

2.
Front Aging Neurosci ; 12: 599246, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33328976

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disorder characterized by dopaminergic neuron death and the abnormal accumulation and aggregation of α-synuclein (α-Syn) in the substantia nigra (SN). Although the abnormal accumulation of α-Syn can solely promote and accelerate the progress of PD, the underlying molecular mechanisms remain unknown. Mounting evidence confirms that the abnormal expression of long non-coding RNA (lncRNA) plays an important role in PD. Our previous study found that exogenous α-Syn induced the downregulation of lncRNA-T199678 in SH-SY5Y cells via a gene microarray analysis. This finding suggested that lncRNA-T199678 might have a potential pathological role in the pathogenesis of PD. This study aimed to explore the influence of lncRNA-T199678 on α-Syn-induced dopaminergic neuron injury. Overexpression of lncRNA-T199678 ameliorated the neuron injury induced by α-Syn via regulating oxidative stress, cell cycle, and apoptosis. Studies indicate lncRNAs could regulate posttranscriptional gene expression via regulating the downstream microRNA (miRNA). To discover the downstream molecular target of lncRNA-T199678, the following experiment found out that miR-101-3p was a potential target for lncRNA-T199678. Further study showed that the upregulation of lncRNA-T199678 reduced α-Syn-induced neuronal damage through miR-101-3p in SH-SY5Y cells and lncRNA-T199678 was responsible for the α-Syn-induced intracellular oxidative stress, dysfunction of the cell cycle, and apoptosis. All in all, lncRNA-T199678 mitigated the α-Syn-induced dopaminergic neuron injury via targeting miR-101-3p, which contributed to promote PD. Our results highlighted the role of lncRNA-T199678 in mitigating dopaminergic neuron injury in PD and revealed a new molecular target for PD.

3.
Zhongguo Zhong Yao Za Zhi ; 38(21): 3709-12, 2013 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-24494559

RESUMO

The concentrations of heavy metals in the extracting solutions of traditional Chinese medicine are usually very low. Furthermore, a vast number of organic components contained in the extracting solutions would be able to coordinate with heavy metals, which might lead to great difficulty in high efficient removal of them from the extracting solutions. This paper was focused on the removal of heavy metals of low concentrations from the extracting solution of Angelica sinensis by applying an EDTA-modified chitosan magnetic adsorbent (EDTA-modified chitosan/SiO2/Fe3O4, abbreviated as EDCMS). The results showed that EDCMS exhibited high efficiency for the removal of heavy metals, such as Cu, Cd and Pb, e.g. the removal percentage of Cd and Pb reached 90% and 94.7%, respectively. Besides, some amounts of other heavy metals like Zn and Mn were also removed by EDCMS. In addition, the total solid contents, the amount of ferulic acid and the HPLC fingerprints of the extracting solution were not changed significantly during the heavy metal removal process. These results indicate that EDCMS may act as an applicable and efficient candidate for the removal of heavy metals from the extracting solution of A. sinensis.


Assuntos
Angelica sinensis/química , Quitosana/química , Contaminação de Medicamentos/prevenção & controle , Ácido Edético/análogos & derivados , Magnetismo/métodos , Metais Pesados/química , Adsorção , Ácido Edético/química , Metais Pesados/isolamento & purificação
4.
Food Chem Toxicol ; 44(7): 1015-23, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16473450

RESUMO

The oxidative modification of low-density lipoprotein (LDL) plays a key role in the pathogenesis of atherosclerosis. Anti-oxidative reagents, which can effectively inhibit LDL oxidation, may prevent atherosclerosis via reducing early atherogenesis, and slowing down the progression to advance stages. As shown in previous studies Hibiscus sabdariffa L. is a natural plant containing a lot of pigments that was found to possess anti-oxidative of activity. Therefore, in this study, we evaluated the anti-oxidative activity of Hibiscus anthocyanins (HAs) by measuring their effects on LDL oxidation (in cell-free system) and anti-apoptotic abilities (in RAW264.7 cells). HAs have been tested in vitro examining their relative electrophoretic mobility (REM), Apo B fragmentation, thiobarbituric acid relative substances (TBARS) and radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity assay. The anti-oxidative activity of HAs was defined by relative electrophoretic mobility of oxLDL (decrease of 50% at 2 mg/ml), fragmentation of Apo B (inhibition of 61% at 1mg/ml), and TBARS assay (IC(50): 0.46 mg/ml) in the Cu(2+)-mediated oxidize LDL. Furthermore, the addition of >0.1 mg/ml of HAs could scavenge over 95% of free DPPH radicals, HAs showed strong potential in inhibiting LDL oxidation induced by copper. In addition, to determine whether oxLDL-induced apoptosis in macrophages is inhibited by HAs, we studied the viability, morphology and caspase-3 expression of RAW 264.7 cells. MTT assay, Leukostate staining analysis and Western blotting reveals that HAs could inhibit oxLDL-induced apoptosis. According to these findings, we suggest that HAs may be used to inhibit LDL oxidation and oxLDL-mediated macrophage apoptosis, serving as a chemopreventive agent. However, further investigations into the specificity and mechanism(s) of HAs are needed.


Assuntos
Antocianinas/farmacologia , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Hibiscus/química , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/toxicidade , Macrófagos/efeitos dos fármacos , Animais , Antocianinas/química , Antioxidantes/química , Apolipoproteínas B/metabolismo , Compostos de Bifenilo , Western Blotting , Caspase 3 , Caspases/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Sulfato de Cobre/antagonistas & inibidores , Sulfato de Cobre/toxicidade , Ensaio de Desvio de Mobilidade Eletroforética , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Lipoproteínas LDL/antagonistas & inibidores , Camundongos , Oxirredução , Picratos/química , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
5.
Toxicol Appl Pharmacol ; 210(3): 236-45, 2006 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-15936790

RESUMO

The biological activities of the polysaccharide have attracted more and more attention in the biochemical and medical areas due to their anti-cancer effects. To estimate the anti-tumor mechanism of MAP, a novel polysaccharide from the loach, Misgurnus anguillicaudatus, the apoptosis effects of the polysaccharide on the human hepatocellular carcinoma cells (SMMC-7721 cells) were studied. The present studies showed that MAP could induce cell apoptosis which was closely accompanied with an increase of intracellular-free calcium concentration ([Ca2+]i), the enhancement of reactive oxygen species (ROS) level, dissipation of mitochondria membrane potential (MMP), up-regulation of p53 mRNA, increase expression of Bax mRNA, and decrease expression of Bcl-2 mRNA. These results suggested that cell apoptosis induced by MAP mainly was mediated by mitochondrial pathways, not involved death receptors (DRs) pathways. The mechanism possibly is that MAP acts on mitochondria and boosts ROS, ROS mediates a release of Ca2+ from the intracellular Ca2+ pool, increasing [Ca2+]i targets the cells a start-up of the apoptosis program. However, further research on the molecular mechanisms of MAP effecting on the cells' mitochondria is necessary.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cipriniformes , Polissacarídeos/farmacologia , Animais , Cálcio/metabolismo , Carcinoma Hepatocelular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Líquido Intracelular/metabolismo , Neoplasias Hepáticas , Potenciais da Membrana/efeitos dos fármacos , Membranas Mitocondriais/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
6.
J Control Release ; 107(3): 513-22, 2005 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-16157412

RESUMO

New unsaturated polyesters of poly(fumaric acid-glycol-dodecanedioic acid) P(FA-GLY-DDDA) copolymers, poly(fumaric acid-glycol-brassylic acid) P(FA-GLY-BA) copolymers, poly(fumaric acid-glycol-tetradecanedioic acid) P(FA-GLY-TA) copolymers and poly(fumaric acid-glycol-pentadecanedioic acid) P(FA-GLY-PA) copolymers were prepared by melt polycondensation of the corresponding mixed monomers: fumaric acid, glycol and one of C(12-15) dibasic acids. The copolymers were characterized by FT-IR, gel permeation chromatography (GPC), and the surface structure of unsaturated polyesters after solidify were studied by atomic force microscopy (AFM). The molecular structure and composition of the unsaturated polyesters were determined by 1H NMR spectroscopy. In vitro studies showed that some of the copolymers are degradable in phosphate buffer at 37 degrees C and have properly drug release rate as drug carriers. The biocompatibility of P(FA-GLY-DDDA) and P(FA-GLY-BA) copolymers under mice skin was also evaluated, macroscopic observation and microscopic analysis demonstrated that the copolymer is biocompatible and well tolerated in vivo. Antitumor efficacy of P(FA-GLY-DDDA) copolymers and P(FA-GLY-BA) copolymers containing 5% adriamycin hydrochloride (ADM) in mice bearing Sarcoma-180 tumor exhibited increased volume doubling time (VDT) (22+/-1.5 days and 24+/-2.5 days) compared to plain subcutaneous injection of ADM (7+/-0.9 days). The antitumor efficacy of injecting P(FA-GLY-DDDA)-ADM inside tumor twice intervened in 22 days exhibited an especially increased cytotoxic effect as revealed by increased VDT (33+/-2.5 days), and the antitumor efficacy of injecting P(FA-GLY-BA)-ADM inside tumor twice intervened in 24 days exhibited an especially increased cytotoxic effect as revealed by increased VDT (35+/-1.5 days). The studies suggested that P(FA-GLY-DDDA) copolymers and P(FA-GLY-BA) copolymers as effective and injectable carriers for antineoplastic drug like adriamycin hydrochloride have a very good foreground in the treatment of noumenon tumor.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Doxorrubicina/administração & dosagem , Doxorrubicina/uso terapêutico , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Sarcoma 180/tratamento farmacológico , Algoritmos , Animais , Fenômenos Químicos , Físico-Química , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Teste de Materiais , Camundongos , Microscopia de Força Atômica , Transplante de Neoplasias , Polímeros/síntese química , Absorção Cutânea/fisiologia , Solubilidade , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Análise de Sobrevida , Viscosidade
7.
J Trace Elem Med Biol ; 18(3): 261-7, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15966575

RESUMO

Many clinical studies reported that diabetic patients had lower glutathione contents in erythrocytes or plasma. Recently, selenium, an essential trace element with well-known antioxidant characteristics, has been found to have insulin-mimetic properties. But seldom information is available about the influence of selenium on glutathione changes induced by diabetes mellitus in animals. Therefore, this study was designed to compare the impacts of selenite treatment on glutathione (GSH) levels of blood and tissues such as brain, kidney, liver, spleen and testis in mice. Four groups were used in this study: a control group, a diabetic group, a selenite-treated normal group and a selenite-treated diabetic group. Selenite was administered to the mice for 4 weeks with an oral dose of 2 mg kg(-1) day(-1) by gavage. The blood glucose level, and GSH level in blood and tissues were determined. The results show that the selenite-treated diabetic group had significantly lower blood glucose levels than the diabetic group. Moreover, alloxan-induced diabetes significantly decreased GSH levels in blood, kidney, liver and testis compared to the controls. Selenite treatment of the diabetic mice only improved the GSH levels in liver and brain. On the other hand, selenite administered to the normal mice reduced GSH levels in the liver compared to the controls. In conclusion, this study suggests that selenite treatment of diabetic mice with an effective dose would be beneficial for the antioxidant system of liver and brain although it exerts a toxic effect on the liver of normal mice.


Assuntos
Antioxidantes/uso terapêutico , Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Glutationa/metabolismo , Hipoglicemiantes/uso terapêutico , Selenito de Sódio/uso terapêutico , Animais , Encéfalo/metabolismo , Insulina/sangue , Rim/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Baço/metabolismo , Testículo/metabolismo
8.
J Ethnopharmacol ; 99(3): 385-90, 2005 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-15935580

RESUMO

This study was designed to determine the anti-proliferative, apoptotic properties of a novel polysaccharide from the loach, Misgurnus anguillicaudatus (MAP), using a human promyelocytic leukemia line (HL-60) as a model system. HL-60 cells were cultured in the presence of MAP at various concentrations (50-800 mg/l) for 5 days and the percentage of cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The results showed that MAP inhibited the cells viability in time and concentration-dependent characteristics. We found that anti-proliferative effect of MAP was associated with apoptosis on HL-60 cells by determinations of morphological changes and oligonucleosomal DNA fragments. In addition, the content of nitric oxide (NO) and activity of lactate dehydrogenase (LDH) release increased when the cells incubated with MAP at various concentrations and times. These investigations suggest that the polysaccharide from loach has the function of anti-proliferation and induction of apoptosis in tumor cells in vitro.


Assuntos
Apoptose/efeitos dos fármacos , Cipriniformes/metabolismo , Muco/química , Polissacarídeos/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HL-60 , Humanos , L-Lactato Desidrogenase/metabolismo , Muco/metabolismo , Nitritos/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo , Fatores de Tempo
9.
Biol Trace Elem Res ; 99(1-3): 241-53, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15235156

RESUMO

Selenium shows insulin-mimic properties in vitro and in vivo. However, in this study, a high dose of 4 mg/kg/d selenite orally administered to the alloxan-induced diabetic Kun-Ming mice for 4 wk failed to reduce hyperglycemia. Se contents in plasma and tissues such as the liver, kidney, spleen, and brain were determined and the thiobarbituric acid-reactive substances (TBARS) levels were investigated. The results showed that alloxan-induced diabetes did not cause a significant decrease in Se levels in plasma and the above tissues compared to the normal control, but selenite treatment significantly increased Se levels in plasma, liver, and brain of the selenite-treated diabetic mice compared to the nontreated diabetic mice. In addition, selenite treatment for diabetic mice reduced the TBARS levels in red blood cells (RBCs) compared to the normal and improved the glutathione peroxidase (GSH-Px) levels in RBCs significantly compared to the diabetic control. In conclusion, this study demonstrated that although oral administration of a high dose of selenite had no hypoglycemic effect on diabetic mice in 4 wk, selenite treatment still maintained the antioxidant beneficial effect on the diabetic mice. This study shed more light on the relationship between Se and diabetes.


Assuntos
Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/metabolismo , Selênio/análise , Selênio/sangue , Aloxano , Animais , Glicemia/análise , Peso Corporal , Diabetes Mellitus Experimental/induzido quimicamente , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Glutationa Peroxidase/sangue , Glutationa Peroxidase/metabolismo , Injeções Intraperitoneais , Peroxidação de Lipídeos , Masculino , Camundongos , Taxa de Sobrevida , Distribuição Tecidual
10.
Biopolymers ; 74(3): 248-55, 2004 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-15150800

RESUMO

Poly(dimer acid-brassylic acid) [P(DA-BA)] copolymers and poly(dimer acid-pentadecandioic acid) [P(DA-PA)] copolymers were prepared by melt polycondensation of the corresponding mixed anhydride prepolymers. The copolymers were characterized by Fourier transform infrared (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), wide angle x-ray powder-diffraction, and thermal gravimetric analysis (TGA). In vitro studies show that all the copolymers are degradable in phosphate buffer at 37 degrees C, and leaving an oily dimer acid residue after hydrolysis for the copolymer with high content of dimer acid. The release profiles of hydrophilic model drug, ciprofloxcin hydrochloride, from the copolymers, follow first-order release kinetics. All the preliminary results suggested that the copolymer might be potentially used as drug delivery devices.


Assuntos
Alcanos/química , Ácidos Dicarboxílicos/química , Ácidos Graxos/química , Polímeros/síntese química , Anti-Infecciosos/farmacocinética , Ciprofloxacina/farmacocinética , Polímeros/farmacocinética , Espectrofotometria Infravermelho , Difração de Raios X
11.
Acta Pharmacol Sin ; 24(4): 306-10, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12676068

RESUMO

AIM: To investigate whether poly (oleic/linoleic acid dimer: sebacic acid)-getamicin [Poly(OAD/LOAD:SA)-gentamicin] delivery system was useful to treat chronic osteomyelitis. METHODS: Drug delivery system consisted of gentamicin sufate dispersed in a copolymer containing oleic/linoleic acid dimer (OAD/LOAD) and sebacic acid (SA) in a 1:1 weight ratio. The gentamicin release from [Poly(OAD/LOAD:SA)-gentamicin] was tested in water, 0.9 % saline, and phosphate buffer 0.1 mol/L. RESULTS: The gentamicin concentration peak was found on d 2, then slowly decreased, considerable amount of gentamicin was still released on d 50. From d 2 to d 50, the gentamicin concentration in the releasing fluids was from 59 to 42128-fold and 1.8 to 1314-fold of the MIC for Staphylococcus aureus and Escherichia coli, respectively. Staphylococcus aureus and Escherichia coli were strongly inhibited by the releasing fluids for 50 d. The gentamicin release and anti-bacterial activity in the three media were similar, only in 0.1 mol/L phosphate buffer, from d 2 to d 14 it was lower. CONCLUSION: Poly(OAD/LOAD:SA)-gentamicin was useful to treat chronic osteomyelitis.


Assuntos
Antibacterianos/administração & dosagem , Sistemas de Liberação de Medicamentos , Escherichia coli/efeitos dos fármacos , Gentamicinas/administração & dosagem , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Ácidos Decanoicos/química , Preparações de Ação Retardada , Ácidos Dicarboxílicos/química , Gentamicinas/química , Gentamicinas/farmacologia , Ácido Linoleico/química , Ácido Oleico/química , Polímeros
12.
Pharmacol Res ; 46(5): 459-67, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12419651

RESUMO

Transmucosal delivery is a suitable route for insulin non-injection administration. In this study, the hypoglycaemic effect of INSULIN BUCCAL SPRAY (IBS), a formulation with soybean lecithin and propanediol combined as absorption enhancer for insulin on diabetic rabbits and rats, were investigated. The hypoglycaemic rate was calculated and the pharmacodynamics and pharmacokinetics of the formulation in rabbits were studied. The results show that when the diabetic rabbits were administrated with IBS in dosages of 0.5, 1.5 and 4.5Ukg(-1), the blood glucose level decreased significantly compared with that of the control group and the hypoglycaemic effect lasted over 5h. The blood glucose decreasing rates are 22.4, 48.1 and 53.5%, respectively. The average bioavailability of IBS by buccal delivery versus subcutaneous injection is 29.2%. Meanwhile, the diabetic rats were administrated with IBS in dosages of 1.0, 3.0 and 9.0Ukg(-1), the blood glucose level decreased significantly compared with that of the control group and the hypoglycaemic effect lasted over 4h. The blood glucose decreasing rates are 24.6, 47.5 and 59.6%, respectively. Furthermore, the penetration of fluorescein isothiocyanate (FITC)-labelled insulin through rabbit buccal mucosa was investigated by scanning the distribution of the fluorescent probe in the epithelium using confocal laser scanning microscopy. The results revealed that FITC-insulin can pass through the buccal mucosa promoted by the enhancer and the passage of insulin across the epithelium includes both intracellular and paracellular routes. From the rabbit and rat experimental results showed that IBS is an effective buccal delivery system, which is promising for clinical trial and the future clinical application.


Assuntos
Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Administração Bucal , Adsorção , Animais , Área Sob a Curva , Disponibilidade Biológica , Glicemia/análise , Diabetes Mellitus Experimental/tratamento farmacológico , Excipientes/química , Feminino , Hipoglicemiantes/química , Hipoglicemiantes/farmacocinética , Insulina/química , Insulina/farmacocinética , Masculino , Mucosa Bucal/metabolismo , Fosfatidilcolinas/química , Propilenoglicóis/química , Coelhos , Ratos , Ratos Sprague-Dawley
13.
Biol Trace Elem Res ; 89(2): 155-63, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12449239

RESUMO

In this study, high-resolution 600-MHz 1H-NMR (nuclear magnetic resonance) spectroscopies were used to compare the urinary metabolic profiles of healthy humans and humans in a high-selenium area of China. NMR biomarkers for renal and liver lesions were observed by comparing the urine 1H-NMR spectra. In urinary excretion, the concentrations in human urine samples of formate, lactate, acetate, hippurate, and alanine in overexposure to selenium were increased, whereas citrate, creatine, and TMAO excretion were decreased compared with that of the healthy human--some of them even disappeared. An interesting result was the appearance of formate in urine, which has previously been shown to lead to acidosis and chronic renal failure and interfere with the lumen and proximal tubular cells. The level of creatine was associated with the seminal activity. The changes of acetate and citrate may explain the disorder of the cellular energy metabolism caused by selenium, and the changes of other amino acids were a result of the reuptake of these compounds that had been blocked in the glomerulus and proximal tubule. The results elucidate the renal/liver lesion in humans in high-selenium area by 1H-NMR spectroscopy and offer the molecular basic of selenium toxicity.


Assuntos
Selênio/administração & dosagem , Selênio/toxicidade , Urina/química , China , Exposição Ambiental , Análise de Alimentos , Cabelo/química , Humanos , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/fisiopatologia , Espectroscopia de Ressonância Magnética , Selênio/análise , Selênio/urina
14.
Acta Pharmacol Sin ; 23(6): 534-8, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12060528

RESUMO

AIM: To investigate the effect of Misgurnus anguillicaudatus polysaccharides (MAP) on immune responses of splenocytes in mice. METHODS: T lymphocyte proliferation (TLP) was measured by [3H]thymidine incorporation assay. Cytotoxic T lymphocyte (CTL) cytotoxicity and natural killer (NK) activity were determined by release of radioactive chromium [51Cr] from pre-labeled target cells. RESULTS: MAP 5 and 10 mg . kg-1 . d-1, ip for 7 d, could increase TLP, enhance the cytotoxicity of CTL and NK cells, and antagonize the effect of concanavalin A (ConA) on TLP suppressed by cyclophosphamide (CP). Inhibitory rates of CTL cytotoxicity were decreased from 51.4 % in CP control mice to 18.2 % and 35.1 % in MAP-treated CP mice, respectively. Furthermore, administration of MAP 10 and 20 mg . kg-1 . d-1, ip for 7 d, restored the reduced NK cell cytotoxicity caused by CP administration in mice. CONCLUSION: MAP has protective effect on augmenting T-cell-mediated immunity and NK activity in normal and CP-treated mice.


Assuntos
Adjuvantes Imunológicos/farmacologia , Cipriniformes , Polissacarídeos/farmacologia , Baço/efeitos dos fármacos , Linfócitos T Citotóxicos/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Ciclofosfamida , Hospedeiro Imunocomprometido , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Camundongos , Baço/citologia , Baço/imunologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T Citotóxicos/imunologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-12050813

RESUMO

The effects of the Misgurnus anguillicaudatus polysaccharide on removal of reactive oxygen species in some modified chemical systems were investigated by chemiluminescence and spectrophotometry. The inhibition of the damage of DNA chain induced by hydroxyl radical by the Misgurnus anguillicaudatus polysaccharide was observed by chemiluminescence. The results showed that the Misgurnus anguillicaudatus polysaccharide could efficiently remove O.(-)(2),.OH, H(2)O(2) and other active compounds of oxygen and significantly protected DNA chains from being damaged by free radicals.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...