RESUMO
En el presente estudio se evaluó el efecto del propóleos sobre el metabolismo de la glucosa en ratones C57/BL-6 con diabetes mellitus tipo 2 inducida por dieta alta en grasa. Se midieron los cambios en las concentraciones séricas de lípidos, glucosa e insulina, y el efecto sobre la captación de 2-deoxi-[2,6-3H]-D-glucosa, síntesis de [14C]-glicógeno y descarboxilación de [U-14C]-D-glucosa inducida por insulina en músculo aislado. Los resultados muestran que en ratones diabéticos, el tratamiento con propóleos (150 mg/kg/día) reduce los niveles de insulina e índice HOMA (P<0.05). También disminuyó la obesidad abdominal de estos animales (P<0.05). Por otro lado, no modificó las concentraciones plasmáticas de glucosa, colesterol total y triglicéridos. Se observó también que la captación de 2-deoxi-[2,6-3H]-D-glucosa, síntesis de [14C]-glicógeno y descarboxilación de [U-14C]-D-glucosa inducida por insulina en músculo sóleo de ratones tratados con propóleos fue significativamente superior al grupo control (P<0.05). En resumen, nuestros datos confirman que el propóleos es capaz de modular el metabolismo de glucosa en ratones C57/BL-6 con diabetes mellitus tipo 2 inducida por dieta alta en grasa. Los datos obtenidos constituyen un importante antecedente que avala el posible uso del propóleos como fuente de polifenoles con actividad antidiabetogénica.
In the current study, we investigated the effect of propolis on diabetic mice undergoing propolis treatment (150 mg/kg/day) for a 6 week period. We also evaluated serum lipids, glucose, insulin levels and the effect on glucose uptake of 2-deoxy-D-[2,6-3H] glucose, [14C]-glycogen synthesis and [U-14C]-D-glucose decarboxylation induced by insulin in muscle tissue. Our results show that treatment with propolis (150 mg/kg/day) reduced insulin and HOMA index (P<0.05). Propolis also lowered abdominal obesity (P<0.05). No effects over serum glucose, total cholesterol and triglycerides levels were observed. We also observed that uptake of 2-deoxy-D-[2,6-3H] glucose, [14C]-glycogen synthesis and [U-14C]-D-glucose decarboxylation induced by insulin in soleus muscle of mice treated with propolis were significantly greater than control group (P<0.05). In summary, our data establishes that propolis modulates glucose metabolism. This result constitutes important data indicating that propolis can be used as a polyphenols source with antidiabetogenic activity.
Assuntos
Ratos , /induzido quimicamente , /metabolismo , Própole/administração & dosagem , Própole/metabolismo , Glucose/antagonistas & inibidores , Ratos/metabolismoRESUMO
OBJECTIVE: Nitro-fatty acids (NO(2)-FAs) are emerging as a new class of cell signaling mediators. Because NO(2)-FAs are found in the vascular compartment and their impact on vascularization remains unknown, we aimed to investigate the role of NO(2)-FAs in angiogenesis. METHODS AND RESULTS: The effects of nitrolinoleic acid and nitrooleic acid were evaluated on migration of endothelial cell (EC) in vitro, EC sprouting ex vivo, and angiogenesis in the chorioallantoic membrane assay in vivo. At 10 µmol/L, both NO(2)-FAs induced EC migration and the formation of sprouts and promoted angiogenesis in vivo in an NO-dependent manner. In addition, NO(2)-FAs increased intracellular NO concentration, upregulated protein expression of the hypoxia inducible factor-1α (HIF-1α) transcription factor by an NO-mediated mechanism, and induced expression of HIF-1α target genes, such as vascular endothelial growth factor, glucose transporter-1, and adrenomedullin. Compared with typical NO donors such as spermine-NONOate and deta-NONOate, NO(2)-FAs were slightly less potent inducers of EC migration and HIF-1α expression. Short hairpin RNA-mediated knockdown of HIF-1α attenuated the induction of vascular endothelial growth factor mRNA expression and EC migration stimulated by NO(2)-FAs. CONCLUSION: Our data disclose a novel physiological role for NO(2)-FAs, indicating that these compounds induce angiogenesis in an NO-dependent mechanism via activation of HIF-1α.
Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Ácidos Linoleicos/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Nitrocompostos/farmacologia , Ácidos Oleicos/farmacologia , Animais , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Transportador de Glucose Tipo 1/genética , Humanos , Masculino , Óxido Nítrico/fisiologia , Ratos , Ratos Wistar , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
The vascular effects of nitrolinoleate (LNO2), an endogenous product of linoleic acid (LA) nitration by nitric oxide-derived species and a potential nitrosating agent, were investigated on rat endothelial-leukocyte interactions. Confocal microscopy analysis demonstrated that LNO2 was capable to deliver free radical nitric oxide (*NO) into cells, 5 min after its administration to cultured cells, with a peak of liberation at 30 min. THP-1 monocytes incubated with LNO2 for 5 min presented nitrosation of CD40, leading to its inactivation. Other anti-inflammatory actions of LNO2 were observed in vivo by intravital microscopy assays. LNO2 decreased the number of adhered leukocytes in postcapillary venules of the mesentery network. In addition to this, LNO2 reduced mRNA and protein expression of beta2-integrin in circulating leukocytes, as well as VCAM-1 in endothelial cells isolated from postcapillary venules, confirming its antiadhesive effects on both cell types. Moreover, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, a nitric oxide scavenger, partially abolished the inhibitory action of LNO2 on leukocyte-endothelium interaction, suggesting that the antiadhesion effects of LNO2 involve a dual role in leukocyte adhesion, acting as a nitric oxide donor as well as through nitric oxide-independent mechanisms. In conclusion, LNO2 inhibited adhesion molecules expression and promoted *NO inactivation of the CD40-CD40L system, both important processes of the inflammatory response.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antígenos CD40/metabolismo , Ligante de CD40/metabolismo , Moléculas de Adesão Celular/metabolismo , Ácidos Linoleicos/farmacologia , Nitrocompostos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Anti-Inflamatórios não Esteroides/síntese química , Adesão Celular/efeitos dos fármacos , Moléculas de Adesão Celular/genética , Linhagem Celular Tumoral , Células Endoteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Ácidos Linoleicos/síntese química , Masculino , Microscopia de Vídeo/métodos , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Nitrocompostos/síntese química , Nitrosação , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Vênulas/metabolismoRESUMO
OBJECTIVES: To evaluate biomarkers of endothelial dysfunction and oxidative stress in glucose intolerance (GI) compared to overt diabetes (DM2). DESIGN AND METHODS: 140 volunteers including 96 with DM2, 32 with GI and 12 controls (C) were studied. (*)NO metabolites, (*)NO synthase inhibitors, thiols and N-acetyl-beta-glucosaminidase (NAGase) activity were analyzed by chemiluminescence, capillary electrophoresis, ELISA and colorimetric assay, respectively. RESULTS: (*)NO metabolites were higher in GI (NOx: p=0.03; S-nitrosothiols: p=0.001) and DM2 (p=0.006; p=0.0006) groups in relation to group C, while nitrotyrosine was higher only in the DM2 group in comparison to the other groups. NAGase activity was elevated in GI (p=0.003) and DM2 (p=0.0004) groups in relation to group C, as well as, ADMA (p=0.01; p=0.003) and GSSG (p=0.01; p=0.002). CONCLUSIONS: (*)NO metabolites, (*)NO synthase inhibitors, thiols and NAGase are biomarkers suitable to indicate endothelial dysfunction and oxidative stress in the early stages of impaired response to insulin.
Assuntos
Biomarcadores/sangue , Diabetes Mellitus Tipo 2/metabolismo , Endotélio/metabolismo , Intolerância à Glucose/metabolismo , Estresse Oxidativo , Arginina/análogos & derivados , Arginina/sangue , Arginina/química , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Intolerância à Glucose/fisiopatologia , Glutationa/química , Glutationa/metabolismo , Hexosaminidases/metabolismo , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Nitratos/metabolismo , Óxido Nítrico/metabolismo , Nitritos/metabolismoRESUMO
A atividade dos receptores ativados por proliferadores de peroxissoma (PPAR) e receptor X hepático (LXR) são regulados por ácidos graxos. Entretanto, o papel do LNO2, um produto endógeno da nitração do ácido linoléico por espécies reativas derivadas de óxido nítrico (NO), na via de sinalização que regula a ativação destes receptores ainda não está elucidada. Assim, considerando a propriedade do LNO2 como doador de NO, nós investigamos a participação da via de sinalização p21Ras/Raf/ERK na ativação de PPAR e LXR por LNO2. Os resultados obtidos demonstraram que LNO2, na concentração de 0.01µM, foi um potente ativador de PPAR quando comparado ao ligante natural ácido linoléico, o qual apresentou ativação equivalente do PPAR na concentração de 0.01µM. O LN02, contudo não teve efeito na ativação de LXR. LNO2 foi um potente ativador de p21Ras quando comparado ao ácido linoléico. A ativação de Ras ocorreu após 5 minutos de incubação com LNO2 em células parentais. Entretanto, em células transfectadas com p21RasC118S, o LNO2 não foi capaz de ativar Ras. A ativação de Ras e PP AR foi dependente da liberação de NO a partir de LN02, o que foi evidenciado na presença de C-PTIO, um seqüestrador de NO. LNO2 ativou ERK, mas não demonstrou efeito relevante na ativação de p38 MAP kinase...
Assuntos
Camundongos , Anti-Inflamatórios , Ácidos Graxos/fisiologia , Ácidos Graxos/metabolismo , Aterosclerose/metabolismo , Técnicas In Vitro , Inflamação/metabolismo , Metabolismo dos Lipídeos , Óxido Nítrico/fisiologia , Óxido Nítrico/metabolismo , Proliferadores de Peroxissomos , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Western Blotting/métodosRESUMO
Oxidative modifications of proteins are fundamental biochemical events that regulate cellular signaling, protein expression, and function. The redox status is balanced by reductants in which GSH plays a major role. This study investigated whether or not p21Waf1 expression and TNFalpha biosynthesis in macrophage differentiation/activation were regulated by GSH modulators and whether or not the JNK and ERK pathway were involved. We observed an increase of p21Waf1 expression and TNFalpha biosynthesis in the THP1 monocyte/macrophage cell line treated with PMA. Treatment of THP1 cultures with NAC prior to adding PMA abrogates the expression of p21Waf1 mRNA and decreases the level of TNFalpha whereas GSH depletion by BSO enhances the levels of TNFalpha with minor effects on p21Waf1 expression. To assess whether or not ERK and JNK were involved in the redox mechanism of p21Waf1 and TNFalpha, we used pharmacological inhibitors for JNK and ERK. Both PD98095 and dicoumarol were capable of blocking TNFalpha production but had only a small effect on p21Waf1 expression. We next observed that activation of JNK was significantly inhibited in cells pretreated with NAC with no effect on ERK. Taken together, our findings suggest that the modulation of GSH regulate the magnitude the cell response to PMA in which JNK and ERK have a particular role in redox signaling.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glutationa/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Fator de Necrose Tumoral alfa/biossíntese , Biomarcadores , Linhagem Celular , Inibidor de Quinase Dependente de Ciclina p21/genética , Ativação Enzimática/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/genéticaRESUMO
OBJECTIVE: To assess the effect of endogenous estrogens on the bioavailability of nitric oxide (.NO) and in the formation of lipid peroxidation products in pre- and postmenopausal women. METHODS: NOx and S-nitrosothiols were determined by gaseous phase chemiluminescence, nitrotyrosine was determined by ELISA, COx (cholesterol oxides) by gas chromatography, and cholesteryl linoleate hydroperoxides (CE18:2-OOH), trilinolein (TG18:2-OOH), and phospholipids (PC-OOH) by HPLC in samples of plasma. RESULTS: The concentrations of NOx, nitrotyrosine, COx, CE18:2-OOH, and PC-OOH were higher in the postmenopausal period (33.8+/-22.3 microL; 230+/-130 nM; 55+/-19 ng/microL; 17+/-8.7 nM; 2775+/-460 nM, respectively) as compared with those in the premenopausal period (21.1+/-7.3 microM; 114+/-41 nM; 31+/-13 ng/microL; 6+/-1.4 nM; 1635+/-373 nM). In contrast, the concentration of S-nitrosothiols was lower in the postmenopausal period (91+/-55 nM) as compared with that in the premenopausal p in the premenopausal period (237+/-197 nM). CONCLUSION: In the postmenopausal period, an increase in nitrotyrosine and a reduction of S-nitrosothiol formation, as well as an increase of COx, CE18:2-OOH and PC-OOH formation occurs. Therefore, NO inactivation and the increase in lipid peroxidation may contribute to endothelial dysfunction and to the greater risk for atherosclerosis in postmenopausal women.
Assuntos
Estrogênios/fisiologia , Peroxidação de Lipídeos , Óxido Nítrico/metabolismo , Pós-Menopausa/metabolismo , Tirosina/análogos & derivados , Adulto , Idoso , Arteriosclerose/etiologia , Colesterol/sangue , Estradiol/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Óxido Nítrico/sangue , Pós-Menopausa/sangue , Pré-Menopausa/sangue , Pré-Menopausa/metabolismo , S-Nitrosotióis/sangue , Tirosina/sangue , VasodilataçãoRESUMO
OBJECTIVE: To assess the effect of endogenous estrogens on the bioavailability of nitric oxide ( NO) and in the formation of lipid peroxidation products in pre- and postmenopausal women. METHODS: NOx and S-nitrosothiols were determined by gaseous phase chemiluminescence, nitrotyrosine was determined by ELISA, COx (cholesterol oxides) by gas chromatography, and cholesteryl linoleate hydroperoxides (CE18:2-OOH), trilinolein (TG18:2-OOH), and phospholipids (PC-OOH) by HPLC in samples of plasma. RESULTS: The concentrations of NOx, nitrotyrosine, COx, CE18:2-OOH, and PC-OOH were higher in the postmenopausal period (33.8±22.3 mM; 230±130 nM; 55±19 ng/mL; 17±8.7 nM; 2775±460 nM, respectively) as compared with those in the premenopausal period (21.1±7.3 mM; 114±41 nM; 31±13 ng/mL; 6±1.4 nM; 1635±373 nM). In contrast, the concentration of S-nitrosothiols was lower in the postmenopausal period (91±55 nM) as compared with that in the premenopausal p in the premenopausal period (237±197 nM). CONCLUSION: In the postmenopausal period, an increase in nitrotyrosine and a reduction of S-nitrosothiol formation, as well as an increase of COx, CE18:2-OOH and PC-OOH formation occurs. Therefore, òNO inactivation and the increase in lipid peroxidation may contribute to endothelial dysfunction and to the greater risk for atherosclerosis in postmenopausal women
Assuntos
Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Peroxidação de Lipídeos , Pós-Menopausa , Estrogênios , Óxido Nítrico , Arteriosclerose , Tirosina , Vasodilatação , Colesterol , Pré-Menopausa , Pós-Menopausa , Estradiol , Óxido Nítrico , S-Nitrosotióis/sangueRESUMO
Verificou-se o efeito dos fitoestrógenos da soja e da terapia de reposição hormonal sobre a concentração dos metabólitos do óxido nítrico(NOx), homocisteína e óxidos de colesterol(COx) em mulheres pós-menopausa em mulheres hipercolesterolêmicas que receberam placebo por um mês e posteriormente gérmen de soja (F, n=11), 17 beta estradiol (E, n=12) ou 17 beta estradiol associado ao acetato de noretisterona (E + P, n=11). Determinou-se os Nox e S nitrosotióis por quimioluminiscência em fase gasosa, a homocisteína por eletroforese capilar e os COx por cromatografia gasosa. O gérmen de soja reduziu as concentrações de NOx (34 +- 16 para 22 +- 9µM, p=0,048) e de homocisteína (13 +- 4 para 9 +- 4µM, p+0,036) e aumentou a concentração de S-nitrosotióis (87 +- 45 para 180 +- 92µM, p+ 0,007), em relação ao placebo. Não foi encontrada diferença significativa para as terapias E e E + P sobre os NOx, homocisteína e S-nitrosotióis. A concentração de óxidos de colesterol foi reduzida nos grupos F e E (96,97 +- 41,74 para 28,52 +- 11,47ng/µL, p=0,00002 e 88,7 +- 56,9 para 33,9 +- 15,8ng/µL, p= 0,027, respectivamente). O uso de fitoestrógenos do gérmen da soja reduziu a concentração de homocisteína, aumentou a concentração de S-nitrosotióis e, associada ao 17 beta estradiol, reduziu a formação de Cox. Portanto, estes dados indicam um efeito protetor dos fitoestrógenos em relação à disfunção endotelial e ao risco de aterosclerose na pós-menopausa.
The effect of phytoestrogens and hormone replacement therapy on nitric oxide metabolites (Nox), homocysteine and cholesterol oxides concentration was evaluated in hypercholesterolemic postmenopausal women that received placebo for 1 month followed by soy germen (F, n=11)...