RESUMO
(1) Background: Spermidine is a biogenic polyamine that plays a crucial role in mammalian metabolism. As spermidine levels decline with age, spermidine supplementation is suggested to prevent or delay age-related diseases. However, valid pharmacokinetic data regarding spermidine remains lacking. Therefore, for the first time, the present study investigated the pharmacokinetics of oral spermidine supplementation. (2) Methods: This study was designed as a randomized, placebo-controlled, triple-blinded, two-armed crossover trial with two 5-day intervention phases separated by a washout phase of 9 days. In 12 healthy volunteers, 15 mg/d of spermidine was administered orally, and blood and saliva samples were taken. Spermidine, spermine, and putrescine were quantified by liquid chromatography-mass spectrometry (LC-MS/MS). The plasma metabolome was investigated using nuclear magnetic resonance (NMR) metabolomics. (3) Results: Compared with a placebo, spermidine supplementation significantly increased spermine levels in the plasma, but it did not affect spermidine or putrescine levels. No effect on salivary polyamine concentrations was observed. (4) Conclusions: This study's results suggest that dietary spermidine is presystemically converted into spermine, which then enters systemic circulation. Presumably, the in vitro and clinical effects of spermidine are at least in part attributable to its metabolite, spermine. It is rather unlikely that spermidine supplements with doses <15 mg/d exert any short-term effects.
Assuntos
Espermidina , Espermina , Animais , Adulto , Humanos , Espermidina/análise , Espermina/análise , Putrescina/metabolismo , Cromatografia Líquida , Saliva/química , Espectrometria de Massas em Tandem , Poliaminas/metabolismo , Plasma/química , Suplementos Nutricionais/análise , Mamíferos/metabolismoRESUMO
Infections with Helicobacter pylori are a global challenge. Currently, H. pylori infections are treated systemically, but the eradication rates of the different therapy regimens are declining due to the growing number of bacterial strains resistant to major antibiotics. Here, we present a strategy for the local eradication of H. pylori by the use of Penicillin G sodium (PGS). In vitro experiments revealed that PGS shows high antibiotic activity against resistant strains of Helicobacter pylori with a minimum inhibitory concentration (MIC) of 0.125 µg/ml. In order to provide luminal concentrations above the MIC for longer periods of time, an extended release tablet was developed. Alkalizers were included to prevent acidic degradation of PGS within the tablet matrix. Out of the tested alkalizers MgO, l-Lysine, NaHCO3, and Na2CO3 NaHCO3 provided the strongest rise in pH inside the hydrated matrix when tested in simulated gastric fluid. Better PGS stability can mainly reasoned from that, addition of MgO resulted in high pH values within the matrix, causing basic degradation of PGS. This work is a first step towards the use of extended release tablets containing PGS for the local treatment of H. pylori as a safe and cost-effective alternative to common systemic treatment regimens.
Assuntos
Infecções por Helicobacter , Helicobacter pylori , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções por Helicobacter/tratamento farmacológico , Humanos , Testes de Sensibilidade MicrobianaRESUMO
The health benefit through the control of lipid levels in hyperlipidaemic individuals is evident from a large number of studies. The pharmacological options to achieve this goal shall be as specific and personalized as the reasons for and co-factors of hyperlipidaemia. It was the goal of this study to reveal the impact of leoligin on cholesterol levels and to define its mechanism of action. Oral application of leoligin in ApoE-/- mice led to significantly reduced total serum cholesterol levels and a reduction in postprandial blood glucose peak levels. In the absence of biochemical signs of toxicity, leoligin treatment resulted in reduced weight gain in mice. The effects of leoligin on serum cholesterol levels may be due to a direct inhibition of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR) by a unique, non-statin-like binding mode. Postprandial serum glucose peaks may be reduced by a mild peroxisome proliferator-activated receptor-gamma (PPAR-γ) agonistic activity of leoligin. No effect on atherosclerotic plaque size was observed. As a non-toxic, cholesterol-, peak glucose-, and weight gain-lowering compound, leoligin continues to fulfil characteristics of a potential agent for the treatment of cardiovascular disease (CVD). The counterregulatory overexpression of hepatic HMGCR in leoligin treated animals possibly explains the missing permanent anti-atherosclerotic effect.
Assuntos
Apolipoproteínas E/deficiência , Colesterol/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Lignanas/farmacologia , Extratos Vegetais/farmacologia , Animais , Colesterol/sangue , Feminino , Glucose/metabolismo , Ligação de Hidrogênio , Hidroximetilglutaril-CoA Redutases/química , Hidroximetilglutaril-CoA Redutases/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Lignanas/administração & dosagem , Lignanas/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Knockout , Modelos Moleculares , Conformação Molecular , PPAR gama/agonistas , PPAR gama/química , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Relação Estrutura-Atividade , Fatores de TempoRESUMO
AIMS: Atorvastatin blunts the response of cardiomyocytes to catecholamines by reducing isoprenylation of G gamma subunits. We examined whether atorvastatin exerts similar effects in vivo and protects the rat heart from harmful effects of catecholamines. METHODS AND RESULTS: Rats were treated with atorvastatin (1 or 10 mg/kg x day) or H(2)O for 14 days per gavage. All three animal groups were subjected to restraint stress on day 10 and to infusions of isoprenaline (ISO; 1 mg/kg x day) or NaCl via minipumps for the last 4 days. Heart rate was measured by telemetry, left ventricular atrial natriuretic peptide (ANP) transcript levels by RT-PCR, and left atrial contractile function in organ baths. Heart rate was similar in all six study groups. In animals pre-treated with water, infusion of ISO induced an increase in heart-to-body weight ratio (HW/BW) by approximately 20%, an increase in ANP mRNA by approximately 350%, and a reduction in the inotropic effect of isoprenaline in left atrium by approximately 50%. In animals pre-treated with high-dose atorvastatin, the effects of ISO on HW/BW, ANP, and left atrial force were approximately 40, 50, and 40% smaller, respectively. Low dose atorvastatin had similar, albeit smaller effects. Atorvastatin treatment of NaCl-infused rats had only marginal effects. In cardiac homogenates from atorvastatin-treated rats (both NaCl- and ISO-infused), G gamma and G alpha(s) were partially translocated from the membrane to the cytosol. CONCLUSION: In the rat heart, treatment with atorvastatin results in translocation of cardiac membrane G gamma and G alpha(s) to the cytosol. This mechanism might contribute to protecting the heart from harm induced by chronic isoprenaline infusion without affecting heart rate.
Assuntos
Agonistas Adrenérgicos beta/toxicidade , Frequência Cardíaca/efeitos dos fármacos , Coração/efeitos dos fármacos , Ácidos Heptanoicos/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Isoproterenol/toxicidade , Contração Miocárdica/efeitos dos fármacos , Pirróis/farmacologia , Agonistas Adrenérgicos beta/administração & dosagem , Animais , Atorvastatina , Fator Natriurético Atrial/genética , Fator Natriurético Atrial/metabolismo , Cardiomegalia/induzido quimicamente , Cardiomegalia/prevenção & controle , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Ritmo Circadiano , Citosol/metabolismo , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Coração/fisiopatologia , Bombas de Infusão Implantáveis , Isoproterenol/administração & dosagem , Masculino , Miocárdio/metabolismo , Transporte Proteico , RNA Mensageiro/metabolismo , Ratos , Ratos WistarRESUMO
BACKGROUND: Idiopathic dilated cardiomyopathy (DCM) is characterized by ventricular wall remodeling and an increased frequency of cardiac cell apoptosis. Apollon is a 528kD cell membrane-anchored protein that inhibits apoptosis by ubiquitinylation facilitating the degradation of Smac/Diablo and caspase-9. The present study tested the hypothesis that the Apollon/Smac system may mediate programmed cell death in DCM. METHODS: Apollon and caspase-9 protein expression was assessed in left ventricular biopsies of explanted failing hearts using Western blotting in 36 DCM patients undergoing cardiac transplantation and in 10 controls. Human cardiac cells were transfected with a plasmid containing the human Apollon complementary DNA or control vector and were subsequently stressed by hypoxia. Apollon, Smac/Diablo, and caspase-9 expression were then examined in cell lysates by real-time polymerase chain reaction and a transferase-mediated dUTP nick-end labeling assay was used to determine the apoptotic index. RESULTS: In DCM myocardial tissue, Apollon messenger (m)RNA and protein expression was down-regulated compared with control hearts (p < 0.001 and p < 0.005, respectively) concomitant with an increase in activated caspase-9 protein levels (p < 0.001). Cell stress resulted in increased apoptosis in cardiac cells in vitro and down-regulation of Apollon mRNA expression compared with control cells (p < 0.001). Transfection increased Apollon mRNA expression in cell lysates (p < 0.001) and completely prevented hypoxia-induced apoptosis associated with reduced expression of Smac/Diablo and activated caspase-9. CONCLUSIONS: These results suggest that Apollon down-regulation plays a role in programmed cell death associated with DCM. Up-regulation of Apollon might therefore represent a novel therapeutic strategy in the treatment of DCM.