Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Phys Chem Chem Phys ; 25(31): 21037-21044, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37522183

RESUMO

The discovery of superconductivity in layered MgB2 has renewed interest in the search for high-temperature conventional superconductors, leading to the synthesis of numerous hydrogen-dominated materials with high critical temperatures (Tc) under high pressures. However, achieving a high-Tc superconductor under ambient pressure remains a challenging goal. In this study, we propose a novel approach to realize a high-temperature superconductor under ambient pressure by introducing a hexagonal H monolayer into the hexagonal close-packed magnesium lattice, resulting in a new and stable few-hydrogen metal-bonded layered magnesium hydride (Mg4)2H1. This compound exhibits superior ductility compared to multi-hydrogen, cuprate, and iron-based superconductors due to its metallic bonding. Our unconventional strategy diverges from the conventional design principles used in hydrogen-dominated covalent high-temperature superconductors. Using anisotropic Migdal-Eliashberg equations, we demonstrate that the stable (Mg4)2H1 compound is a typical phonon-mediated superconductor, characterized by strong electron-phonon coupling and an excellent Tc of 37 K under ambient conditions, comparable to that of MgB2. Our findings not only present a new pathway for exploring high-temperature superconductors but also provide valuable insights for future experimental synthesis endeavors.

2.
Front Neurol ; 14: 1113834, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36908633

RESUMO

Background: Peripheral neuropathy (PN), including numbness, loss of sensation, paresthesia, a burning sensation, and stabbing pain in extremities, is a common complication in people with human immunodeficiency virus (PHIV). Medications commonly used to treat HIV-related PN are not effective and lead to many side effects. HIV-related PN symptoms may be alleviated or treated with a series of therapeutic Chinese foot massages (TCFM), which are non-invasive and relatively safe. However, relevant studies are lacking. Study design: This proposed trial is a prospective, two-arm, parallel, double-blinded, randomized controlled trial. Aim: This proposed trial aims to assess the effectiveness of TCFM on HIV-related PN in people with HIV (PHIV). Outcomes: The primary outcomes, measured at baseline, end of TCFM/placebo, and twelve weeks after, include (1), lower extremity pain, (2) lower extremity functioning, and (3) health-related quality of life. The secondary outcomes, measured throughout the trial process, include (1) recruitment and completion rate (No. of referred, No. of eligible, No. of enrolled, No. of withdrawals, trial recruitment rate, and trial completion rate), (2) participants' safety (No. and severity of adverse events), (3) treatment adherence (average time of each message session, No. of completed sessions, and No. of missed sessions), and (4) compliance (No. of participants completing the trial following the initial group assignment). Sample size: An estimated 142 participants in total, or 71 participants in each arm, will be needed for this trial. Trial status: This trial was registered at ClinicalTrials.gov of the National Institute of Health on Oct 26, 2022 (ClinicalTrials.gov Identifier: NCT05596123). The researchers expect to recruit participants starting in Feb. 2023 and ending in Feb 2025.

3.
Curr Med Sci ; 42(5): 981-990, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35896932

RESUMO

OBJECTIVE: Epidemiology studies indicate that green tea polyphenols (GTP) perform a protective effect on cardiovascular diseases, but the underlying mechanisms are complex. The present study aimed to investigate the effect of GTP on high-fat diets (HFD) induced-early vascular aging. METHODS: Six-week young adult Wistar rats were fed with standard chow or HFD in the presence and absence of GTP (200 mg/kg body weight) for 18 weeks. In vitro experiment, human umbilical vascular endothelial cells (HUVECs) were treated with palmitic acid (PA) and GTP. RESULTS: The results showed that GTP alleviated the disorganized arterial wall and the increased intima-media thickness induced by HFD. In addition, the vascular oxidative injury was suppressed following GTP treatment. Furthermore, GTP elevated the ratio of LC3-II/LC3-I and suppressed expression of p62/SQSTM1, and restored SIRT3 expression in the aorta of HFD rats. Consistently, in cultured HUVECs, GTP inhibited cell senescence indicated by SA-ß-gal and promoted endothelial autophagy compared with the PA treatment group. The activity of SIRT3 was specifically inhibited by 3-TYP, and the protective effect of GTP was consequently abolished. CONCLUSION: The findings indicated that GTP protected against early vascular senescence in young HFD rats via ameliorating oxidative injury and promoting autophagy which was partially regulated by the SIRT3 pathway.


Assuntos
Dieta Hiperlipídica , Sirtuína 3 , Animais , Ratos , Envelhecimento , Antioxidantes/farmacologia , Autofagia , Espessura Intima-Media Carotídea , Dieta Hiperlipídica/efeitos adversos , Células Endoteliais/metabolismo , Guanosina Trifosfato/farmacologia , Ácido Palmítico/farmacologia , Polifenóis/farmacologia , Ratos Wistar , Proteína Sequestossoma-1/metabolismo , Sirtuína 3/metabolismo , Sirtuína 3/farmacologia , Chá/metabolismo
4.
Chemosphere ; 271: 129580, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33460904

RESUMO

In this paper, two level III fugacity models are developed and applied using an environmental system containing six compartments, including air, aerosols, soil, water, suspended particulate matters (SPMs), and sediments, as a "unit world". The first model, assumes equilibrium between air and aerosols and between water and SPMs. These assumptions lead to a four-fugacity model. The second model removes these two assumptions leading to a six-fugacity model. The two models, compared using four PBDE congeners, BDE-28, -99, -153, and -209, with a steady flux of gaseous congeners entering the air, lead to the following conclusions. 1. When the octanol-air partition coefficient (KOA) is less than 1011.4, the two models produce similar results; when KOA > 1011.4, and especially when KOA > 1012.5, the model results diverge significantly. 2. Chemicals are in an imposed equilibrium in the four-fugacity model, but in a steady state and not necessary an equilibrium in the six-fugacity model, between air and aerosols. 3. The results from the six-fugacity model indicate an internally consistent system with chemicals in steady state in all six compartments, whereas the four-fugacity model presents an internally inconsistent system where chemicals are in equilibrium but not a steady state between air and aerosols. 4. Chemicals are mass balanced in air and aerosols predicted by the six-fugacity model but not by the four-fugacity model. If the mass balance in air and aerosols is achieved in the four-fugacity model, the condition of equilibrium between air and aerosols will be no longer valid.


Assuntos
Poluentes Atmosféricos , Aerossóis , Poluentes Atmosféricos/análise , Gases , Solo
5.
Zhongguo Zhong Yao Za Zhi ; 44(3): 546-552, 2019 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-30989921

RESUMO

The aim of this paper was to study the effect and mechanism of alcohol extract from Polygonum cuspidatum(PCE) on acute gouty arthritis in C57 BL/6 mice through NLRP3/ASC/caspase-1 axis. The model mice which injected with ankle joint injection of sodium urate crystals(MSU) were orally administrated with three different concentration of PCE, with colchicine as positive control. HE staining was used for observing the morphological changes of synovial tissue; concentration of IL-1ß, IL-6 and TNF-α secreted by synovial tissue of the ankle joint were detected by ELISA; mRNA and protein expression of NLRP3, ASC and caspase-1 in synovial tissue were detected by RT-PCR and Western blot respectively. The results showed that the swelling degree of ankle joint in model mice were significantly elevated; expression of IL-1ß, IL-6 and TNF-α were significantly increased; mRNA and protein expression of NLRP3, ASC and caspase-1 also significant increase, compared with normal control group. The swelling degree of ankle joint significantly relief; expression of IL-1ß, IL-6 and TNF-α in joint synovium significantly decrease; mRNA and protein expression of NLRP3, ASC and caspase-1 were significantly decrease in PCE treatment group compared with model group. Our research implied that alcohol extract from P. cuspidatum had positive effect on acute gouty arthritis in mice, and the regulation of NLRP3/ASC/caspase-1 axis may be its mechanism.


Assuntos
Artrite Gotosa/tratamento farmacológico , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Caspase 1/metabolismo , Fallopia japonica/química , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Extratos Vegetais/farmacologia , Animais , Articulação do Tornozelo/fisiopatologia , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator de Necrose Tumoral alfa/metabolismo , Ácido Úrico
6.
J Trace Elem Med Biol ; 51: 91-97, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30466945

RESUMO

Little evidence showed the interplay between tea and diet in the regulation of trace metal. Here, we examined the effects of green tea polyphenols (GTPs) on the level of trace elements (TEs) in rats on food restriction or high-fat diet. Thirty-six rats (Wistar, male) were randomly divided into 6 groups and fed on standard diet, food restriction and high-fat diet with or without GTPs (200 mg/kg bw/day) supplementation, respectively. Levels of vanadium (V), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo) and cobalt (Co) in feed, whole blood, femur and urine were measured by inductively coupled plasma mass spectrometry (ICP-MS). Blood glucose, total cholesterol (TC), triglycerides (TG), high and low density lipoprotein-cholesterol (LDL-C, HDL-C) in serum were determined. Decreased daily intakes of TEs were observed in rats on food restriction and high-fat diet. Decreased whole blood level of Zn, femur level of Co and increase urinary excretion of Se were observed in rats fed on high-fat diet. GTPs altered the whole blood level of several TEs in rats on food restriction (V, Zn, Co) or high-fat diet (V, Se), respectively, but not in rats fed on standard diet. The level of several TEs in femur and the daily urinary excretion of V and Mo were altered by GTPs in rats on all of the three diets. In addition, rats fed on high-fat diet developed dyslipidemia, which was ameliorated by GTPs. The data indicated that diet status played a role in the effects of GTPs on TEs and lipid metabolism, and trace elements may play a role in the modulation of lipid metabolic disturbances by high-fat diet and GTPs.


Assuntos
Restrição Calórica , Dieta Hiperlipídica , Metabolismo dos Lipídeos/efeitos dos fármacos , Polifenóis/farmacologia , Chá/química , Oligoelementos/análise , Animais , Masculino , Polifenóis/química , Ratos , Ratos Wistar
7.
Life Sci ; 203: 193-202, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29705350

RESUMO

AIMS: The antihypertensive mechanism (s) of the epigallocatechin-3-gallate (EGCG), a major effective component in green tea, might associate with microRNAs (miRNAs). Here, we aimed to investigate which microRNA in aorta of spontaneously hypertensive rats (SHRs) were modulated by administration of EGCG and its mechanism. MAIN METHODS: The pharmacokinetic behaviors of EGCG and epigallocatechin (EGC) in Sprague-Dawley rats were analyzed by HPLC and DRUG AND STATISTICS software. Blood pressure of SHRs was monitored by the tail-cuff method, the miRNomes of aorta from SHRs was analyzed with deep sequencing, and expression of hypertension-associated miRNAs with significant change and their host genes and target genes were validated by real-time PCR and Western blot. KEY FINDINGS: The plasma deposition of EGCG and EGC best fitted a mono-compartmental model with maximum plasma concentration post-dose (Cmax, 6.65 vs 4.45 µg/ml) and the corresponding time (Tmax, 15 vs 10 min). Systolic blood pressure (SBP) of SHRs decreased to the lowest point by 34.04 mmHg and recovered by 23.39 mmHg after 15 and 30 min of administration at dose of 300 mg/kg BW EGCG, respectively, and it decreased again at 60 min and recovered at time 2 h. Total 35 upregulated and 18 downregulated miRNAs were identified compared to the control group (p < .01) after EGCG administration. Expression of hypertension-associated miRNA-126a-3p and miRNA-150-5p were further validated. In turn, their host gene and target genes were up-regulated and down-regulated, respectively. SIGNIFICANCE: Our results indicated that miRNA-150-5p might be involved in the antihypertensive effect of EGCG through SP1/AT1R pathway.


Assuntos
Anti-Hipertensivos/farmacologia , Aorta/metabolismo , Catequina/análogos & derivados , Regulação da Expressão Gênica/efeitos dos fármacos , Hipertensão/genética , MicroRNAs/genética , Chá/química , Animais , Aorta/efeitos dos fármacos , Biomarcadores/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Catequina/farmacologia , Perfilação da Expressão Gênica , Hipertensão/tratamento farmacológico , Hipertensão/patologia , Masculino , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley
8.
Oxid Med Cell Longev ; 2017: 9032792, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28814987

RESUMO

SCOPE: Several reports in the literature have suggested the renoprotective effects of ketone bodies and green tea polyphenols (GTPs). Our previous study found that GTP consumption could elevate the renal expression of the ketogenic rate-limiting enzyme, which was decreased by a high-fat diet (HFD) in rats. Here, we investigated whether ketogenesis can mediate renoprotection by GTPs against an HFD. METHODS AND RESULTS: Wistar rats were fed a standard or HFD with or without GTPs for 18 weeks. The renal oxidative stress level, kidney function, renal expression, and activity levels of mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase 2 (HMGCS2) and sirtuin 3(SIRT3) were detected. The increased renal oxidative stress and the loss of renal function induced by the HFD were ameliorated by GTPs. Renal ketogenesis and SIRT3 expression and activity levels, which were reduced by the HFD, were restored by GTPs. In vitro, HEK293 cells were transfected with the eukaryotic expression plasmid pcDNA HMGCS2. GTP treatment could upregulate HMGCS2 and SIRT3 expression. Although SIRT3 expression was not affected by HMGCS2 transfection, the 4-hydroxy-2-nonenal (4-HNE) level and the acetyl-MnSOD (K122)/MnSOD ratio were reduced in HMGCS2-transfected cells in the context of H2O2. CONCLUSION: The ketogenesis/SIRT3 pathway mediates the renoprotection of GTPs against the oxidative stress induced by an HFD.


Assuntos
Dieta Hiperlipídica , Rim/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Polifenóis/farmacologia , Sirtuína 3/metabolismo , Chá/química , Aldeídos/química , Aldeídos/metabolismo , Animais , Glicemia/análise , Peso Corporal/efeitos dos fármacos , Colesterol/sangue , Proteína Forkhead Box O3/metabolismo , Células HEK293 , Humanos , Hidroximetilglutaril-CoA Sintase/genética , Hidroximetilglutaril-CoA Sintase/metabolismo , Insulina/sangue , Rim/metabolismo , Rim/patologia , Masculino , Polifenóis/química , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Chá/metabolismo
9.
Nutrients ; 9(5)2017 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-28505110

RESUMO

Epidemiological and experimental studies reveal that Western dietary patterns contribute to chronic kidney disease, whereas dietary restriction (DR) or dietary polyphenols such as green tea polyphenols (GTPs) can ameliorate the progression of kidney injury. This study aimed to investigate the renal protective effects of GTPs and explore the underlying mechanisms. Sixty Wistar rats were randomly divided into 6 groups: standard diet (STD), DR, high-fat diet (HFD), and three diets plus 200 mg/kg(bw)/day GTPs, respectively. After 18 weeks, HFD group exhibited renal injuries by increased serum cystatin C levels and urinary N-acetyl-ß-d-glucosaminidase activity, which can be ameliorated by GTPs. Meanwhile, autophagy impairment as denoted by autophagy-lysosome related proteins, including LC3-II, Beclin-1, p62, cathepsin B, cathepsin D and LAMP-1, was observed in HFD group, whereas DR or GTPs promoted renal autophagy activities and GTPs ameliorated HFD-induced autophagy impairment. In vitro, autophagy flux suppression was detected in palmitic acid (PA)-treated human proximal tubular epithelial cells (HK-2), which was ameliorated by epigallocatechin-3-gallate (EGCG). Furthermore, GTPs (or EGCG) elevated phosphorylation of AMP-activated protein kinase in the kidneys of HFD-treated rats and in PA-treated HK-2 cells. These findings revealed that GTPs mimic the effects of DR to induce autophagy and exert a renal protective effect by alleviating HFD-induced autophagy suppression.


Assuntos
Injúria Renal Aguda/tratamento farmacológico , Autofagia/efeitos dos fármacos , Polifenóis/farmacologia , Chá/química , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Antioxidantes/farmacologia , Glicemia/metabolismo , Catequina/análogos & derivados , Catequina/farmacologia , Linhagem Celular , Colesterol/sangue , Creatinina/sangue , Creatinina/urina , Cistatina C/sangue , Dieta Hiperlipídica/efeitos adversos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Fosforilação , Ratos , Ratos Wistar , Triglicerídeos/sangue
10.
Biomed Environ Sci ; 29(7): 524-8, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27554123

RESUMO

Bovine aortic endothelial cells (BAECs) were cultured with high glucose (33 mmol/L), 4 mg/L green tea polyphenols (GTPs) or 4 mg/L GTPs co-treatment with high glucose for 24 h in the presence or absence of Bafilomycin-A1 (BAF). We observed that high glucose increased the accumulation of LC3-II. Treatment with BAF did not further increase the accumulation of LC3-II. Results also showed an increased level of p62 and decreased Beclin-1. However, GTPs showed inversed trends of those proteins. Furthermore, GTPs co-treatment with high glucose decreased the level of LC3-II and a much higher accumulation of LC3-II was observed in the presence of BAF in comparison with high glucose alone. Results also showed a decreased p62 and increased Beclin-1. The results demonstrated that GTPs alleviated autophagy inhibition induced by high glucose, which may be involved in the endothelial protective effects of green tea against hyperglycemia.


Assuntos
Autofagia/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Glucose/toxicidade , Polifenóis/farmacologia , Chá/química , Animais , Bovinos , Células Cultivadas , Células Endoteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Macrolídeos/farmacologia , Polifenóis/química
11.
Sci Rep ; 6: 24353, 2016 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-27072746

RESUMO

Prospective studies on the association of green tea with risk of coronary heart disease (CHD) incidence were scarce. This study examined whether green tea can reduce CHD incidence and have a beneficial effect on CHD-related risk markers in middle-aged and older Chinese population. We included 19,471 participants who were free of CHD, stroke or cancer at baseline from September 2008 to June 2010, and were followed until October 2013. Cox proportional hazard models were used to examine the hazard ratios (HR) of CHD incidence in relation to green tea consumption. Linear regression models were used to evaluate the effect of green tea on 5-year changes of CHD-related biomarkers. Compared with non-green tea consumers, the multivariable-adjusted HR for CHD was 0.89 (95% CI, 0.81-0.98) in green tea consumers. Particularly, the reduced risk of CHD incidence with green tea consumption was more evident among participants who were male, more than 60 years old, overweight, or with diabetes mellitus. In addition, green tea consumption improved multiple CHD-related risk markers including total cholesterol, HDL-cholesterol, triglycerides, mean platelet volume, and uric acid. In conclusion, green tea consumption was associated with a reduced risk of CHD incidence in the middle-aged and older Chinese populations, and the association might be partly due to altered CHD-related biomarkers.


Assuntos
Biomarcadores/metabolismo , Doença das Coronárias/prevenção & controle , Chá , Idoso , China , Estudos de Coortes , Doença das Coronárias/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Biomed Environ Sci ; 28(6): 455-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26177907

RESUMO

Fifty male Wistar rats were fed a standard chow diet or a high-fat (HF) diet, and different concentrations of green tea polyphenols (GTPs) (0.8, 1.6, and 3.2 g/L) were administered in the drinking water. We found that the malondialdehyde (MDA) level in the HF diet group was significantly higher than that in the control (CON) group (P<0.05). Decreased peroxisome proliferator-activated receptor (PPAR)-α and sirtuin 3 (SIRT3) expression, and increased manganese superoxide dismutase (MnSOD) acetylation levels were also detected in the HF diet group (P<0.05). GTP treatment upregulated SIRT3 and PPARα expression, increased the pparα mRNA level, reduced the MnSOD acetylation level, and decreased MDA production in rats fed a HF diet (P<0.05). No significant differences in total renal MnSOD and PPAR-γ coactivator-1α (PGC1-α) expression were detected. The reduced oxidative stress detected in kidney tissues after GTP treatment was partly due to the higher SIRT3 expression, which was likely mediated by PPARα.


Assuntos
Antioxidantes/farmacologia , Dieta Hiperlipídica/efeitos adversos , Rim/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Polifenóis/farmacologia , Sirtuína 3/metabolismo , Chá/química , Acetilação/efeitos dos fármacos , Animais , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Rim/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
13.
BMC Res Notes ; 7: 120, 2014 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-24580748

RESUMO

BACKGROUND: Hyperglycemia-induced endothelial hyperpermeability is crucial to cardiovascular disorders and macro-vascular complications in diabetes mellitus. The objective of this study is to investigate the effects of green tea polyphenols (GTPs) on endothelial hyperpermeability and the role of nicotinamide adenine dinucleotide phosphate (NADPH) pathway. METHODS: Male Wistar rats fed on a high fat diet (HF) were treated with GTPs (0, 0.8, 1.6, 3.2 g/L in drinking water) for 26 weeks. Bovine aortic endothelial cells (BAECs) were treated with high glucose (HG, 33 mmol/L) and GTPs (0.0, 0.4, or 4 µg/mL) for 24 hours in vitro. The endothelial permeabilities in rat aorta and monolayer BAECs were measured by Evans blue injection method and efflux of fluorescein isothiocyanate (FITC)-dextran, respectively. The reactive oxygen species (ROS) levels in rat aorta and monolayer BAECs were measured by dihydroethidium (DHE) and 2', 7'-dichloro-fluorescein diacetate (DCFH-DA) fluorescent probe, respectively. Protein levels of NADPH oxidase subunits were determined by Western-blot. RESULTS: HF diet-fed increased the endothelial permeability and ROS levels in rat aorta while HG treatments increased the endothelial permeability and ROS levels in cultured BAECs. Co-treatment with GTPs alleviated those changes both in vivo and in vitro. In in vitro studies, GTPs treatments protected against the HG-induced over-expressions of p22phox and p67phox. Diphenylene iodonium chloride (DPI), an inhibitor of NADPH oxidase, alleviated the hyperpermeability induced by HG. CONCLUSIONS: GTPs could alleviate endothelial hyperpermeabilities in HF diet-fed rat aorta and in HG treated BAECs. The decrease of ROS production resulting from down-regulation of NADPH oxidase contributed to the alleviation of endothelial hyperpermeability.


Assuntos
Endotélio Vascular/efeitos dos fármacos , NADPH Oxidases/metabolismo , Polifenóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Chá/química , Animais , Aorta/citologia , Western Blotting , Permeabilidade Capilar/efeitos dos fármacos , Bovinos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Células Cultivadas , Dieta Hiperlipídica , Relação Dose-Resposta a Droga , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/fisiologia , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiologia , Glucose/farmacologia , Masculino , NADH NADPH Oxirredutases/antagonistas & inibidores , NADH NADPH Oxirredutases/metabolismo , NADPH Oxidases/antagonistas & inibidores , Oniocompostos/farmacologia , Ratos , Ratos Wistar
14.
Yao Xue Xue Bao ; 48(4): 541-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23833943

RESUMO

Scutellarin is the main effective constituent of breviscapine, a flavonoid mixture isolated from the dried whole plant of Erigeron breviscapus (Vant.) Hand-Mazz, and valsartan is used as an antihypertensive drug. These two drugs have already been clinically used together to treat diabetic nephropathy (DN) in China, and the combined medications showed some enhanced protection against DN. The aim of this study is to investigate the potential pharmacokinetic interaction between scutellarin and valsartan in rats. Breviscapine injection (20 mg x kg(-1), i.v.) and valsartan (15 mg x kg-, i.g.), either alone or together were given to 18 male Sprague-Dawley rats. Concentrations of scutellarin and valsartan were quantified by HPLC, and pharmacokinetic parameters were calculated by non-compartmental methods. We found that the pharmacokinetic parameters of scutellarin altered significantly after co-administration of oral valsartan. The plasma clearance (CL(p)) and the bile clearance (CL(b)) of scutellarin were reduced significantly in the presence of valsartan. After oral administration of valsartan with or without intravenous scutellarin, however, the pharmacokinetic parameters of valsartan were comparable. In conclusion, our data suggests that the concurrent use of valsartan reduces the biliary excretion of scutellarin, and this may be due to the inhibitory effect of valsartan on the biliary excretion of scutellarin mediated by Mrp2 (Multidrug resistance-associated protein 2).


Assuntos
Anti-Hipertensivos/farmacocinética , Apigenina/farmacocinética , Bile/metabolismo , Glucuronatos/farmacocinética , Valsartana/farmacocinética , Administração Intravenosa , Administração Oral , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/sangue , Apigenina/administração & dosagem , Apigenina/sangue , Apigenina/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Interações Medicamentosas , Erigeron/química , Glucuronatos/administração & dosagem , Glucuronatos/sangue , Glucuronatos/isolamento & purificação , Masculino , Taxa de Depuração Metabólica , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Plantas Medicinais/química , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Valsartana/administração & dosagem , Valsartana/sangue
15.
PLoS One ; 8(1): e53796, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23342006

RESUMO

OBJECTIVE: Hypoadiponectinemia contributes to the development of obesity and related disorders such as diabetes, hyperlipidemia, and cardiovascular diseases. In this study we investigated the effects of green tea polyphenols (GTPs) on adiponectin levels and fat deposits in high fat (HF) fed rats, the mechanism of signaling pathway was explored as well. METHODS AND RESULTS: Male Wistar rats were fed with high-fat diet. GTPs (0.8, 1.6, 3.2 g/L) were administered via drinking water. Serum adiponectin and insulin were measured by ELISA, mRNA levels of adiponectin and PPARγ in visceral adipose tissue (VAT) were determined by Real-time PCR, protein levels of PPARγ, phospho (p) - PPARγ, extracellular signal regulated kinase (erk) 1/2 and p-erk1/2 in VAT were determined by western blot. GTPs treatment attenuated the VAT accumulation, hypoadiponectinemia and the decreased mRNA level of adiponectin in VAT induced by HF. Decreased expression and increased phosphorylation of PPARγ (the master regulator of adiponectin), and increased activation of erk1/2 were observed in HF group, and these effects could be alleviated by GTPs treatment. To explore the underlying mechanism, VAT was cultured in DMEM with high glucose to mimic the hyperglycemia condition in vitro. Similar to the results of in vivo study, decreased adiponectin levels, decreased expression and increased phosphorylation of PPARγ, and elevated erk1/2 phosphorylation in cultured VAT were observed. These effects could be ameliorated by co-treatment with GTPs or PD98059 (a selective inhibitor of erk1/2). CONCLUSION: GTPs reduced fat deposit, ameliorated hypoadiponectinemia in HF-fed rats, and relieved high glucose-induced adiponectin decrease in VAT in vitro. The signaling pathway analysis indicated that PPARγ regulation mediated via erk1/2 pathway was involved.


Assuntos
Adiponectina/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Gordura Intra-Abdominal/efeitos dos fármacos , PPAR gama/metabolismo , Polifenóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Chá/química , Adiponectina/sangue , Adiponectina/genética , Animais , Peso Corporal/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Regulação para Baixo/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Gordura Intra-Abdominal/citologia , Gordura Intra-Abdominal/metabolismo , Masculino , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , PPAR gama/genética , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Wistar
16.
Nutrition ; 26(11-12): 1176-80, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20137896

RESUMO

OBJECTIVE: Increased oxidative stress plays an important role in cardiovascular diseases including hypertension and stroke. Evidence has indicated that ketone bodies could exert antioxidative effects. We explored the role of renal mitochondrial 3-hydroxy-3-methylglutaryl-coenzyme A synthase (HMGCS2) expression, a key control site of ketogenesis, in stroke-prone spontaneously hypertensive rats (SHRSPs) and their ancestral hypertensive but stroke-resistant spontaneously hypertensive rats (SHRs). METHODS: Two groups of SHRSPs were fed a standard chow or standard chow supplemented with clofibrate (an agonist of HMGCS2 promoter), respectively, and SHRs fed with a standard chow were used as controls. The renal levels of HMGCS2, Akt, and phosphorylated protein kinase B (Akt) were measured by western blotting. Malondialdehyde, catalase, superoxide dismutase, and glutathione peroxidase were detected by assay kits. RESULTS: Compared with SHRs, lower HMGCS2 protein expression, enhanced phosphorylated Akt signal, higher malondialdehyde levels, and higher catalase activity were observed in kidney tissues in SHRSPs (P < 0.05). No differences in superoxide dismutase and glutathione peroxidase activities were observed between SHRSPs and SHRs. Clofibrate treatment significantly upregulated renal HMGCS2 expressions, inhibited phosphorylation of Akt, and decreased malondialdehyde levels and catalase activities in SHRSP kidney tissues (P < 0.05). CONCLUSION: These results demonstrated the difference in HMGCS2 expression and oxidative stress in kidney tissues between SHRSPs and their SHR controls. The enhanced oxidative stress was partly due to the lower HMGCS2 expression regulated possibly by the Akt signaling pathway.


Assuntos
Anti-Hipertensivos/farmacologia , Hidroximetilglutaril-CoA Sintase/metabolismo , Hipertensão/enzimologia , Rim/enzimologia , Mitocôndrias/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Acidente Vascular Cerebral/fisiopatologia , Animais , Anti-Hipertensivos/uso terapêutico , Catalase/metabolismo , Clofibrato/farmacologia , Clofibrato/uso terapêutico , Regulação para Baixo/efeitos dos fármacos , Hidroximetilglutaril-CoA Sintase/genética , Hipertensão/metabolismo , Hipertensão/prevenção & controle , Rim/metabolismo , Masculino , Malondialdeído/metabolismo , PPAR gama/agonistas , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Endogâmicos SHR , Acidente Vascular Cerebral/prevenção & controle , Regulação para Cima/efeitos dos fármacos
17.
Blood Coagul Fibrinolysis ; 20(7): 552-7, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19713834

RESUMO

Compelling epidemiological evidence suggests that the consumption of green tea is associated with beneficial effects in prevention of cardiovascular diseases. Plasminogen activator inhibitor-1 (PAI-1) is known to play a pivotal role in cardiovascular diseases including arteriosclerosis and hypertension. Increased PAI-1 was found in atherosclerotic lesions, and high PAI-1 plasma levels were associated with coronary heart disease. To determine the effect and molecular mechanism of green tea polyphenols (GTPs) on the regulation of PAI-1 expression in endothelial cells, bovine aortic endothelial cells were incubated with GTPs, and PAI-1 expressions were measured by western blot and enzyme-linked immunosorbent assay, respectively. GTPs significantly reduced PAI-1 expression and secretion in a time-dependent and dose-dependent manner. Inhibition of phosphatidylinositol 3-kinase (PI3K) with wortmannin markedly reversed GTPs repression of PAI-1 expression. In addition, the GTP-induced inhibitory effect was associated with an increased of activation of the protein kinase Akt. These results suggest that GTPs inhibit PAI-1 expression and its release from endothelial cells through the PI3K/Akt pathway, which may contribute to cardiovascular protection.


Assuntos
Células Endoteliais/efeitos dos fármacos , Flavonoides/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fenóis/farmacologia , Inibidor 1 de Ativador de Plasminogênio/genética , Chá/química , Animais , Aorta/citologia , Bovinos , Relação Dose-Resposta a Droga , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Flavonoides/farmacocinética , Fenóis/farmacocinética , Fosfatidilinositol 3-Quinases/metabolismo , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Polifenóis , Proteínas Proto-Oncogênicas c-akt/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA