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1.
Arch. endocrinol. metab. (Online) ; 65(1): 49-59, Jan.-Feb. 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1152879

RESUMO

ABSTRACT Objectives: To evaluate the effectiveness of adding dapagliflozin as an intensification strategy for the treatment of patients with uncontrolled type 2 diabetes mellitus (T2DM). Materials and methods: A historical cohort study was conducted in 123 adult patients over 18 years old who were diagnosed with uncontrolled T2DM, who received dapagliflozin add-on to their dual base treatment: metformin plus glibenclamide (n = 32), metformin plus saxagliptin (n = 29), metformin plus exenatide (n = 28), or metformin plus insulin (n = 34). The endpoints were evaluated using analysis of variance. Results: All the patients completed a 52-week follow-up. Overall, 52.85% of patients were female, the Hispanic population represented the largest proportion of patients in all groups (60.98%), and the mean ± SD patient age and body weight were 55.05 ± 7.58 years and 83.55 ± 9.65 kg, respectively. The mean ± SD duration of T2DM, glycated hemoglobin (HbA1c), and fasting plasma glucose (FPG) were 5.93 ± 2.98 years, 8.1 ± 0.53%, and 166.03 ± 26.80 mg/dL, respectively. The grand mean changes of HbA1c, FPG, body weight and blood pressure showed a decreasing trend during the study period and it was statistically significant in all groups (p-value = <0.001). The proportion of patients achieving HbA1c target (<7%) was highest in the group that used a dapagliflozin add-on to metformin plus saxagliptin. Conclusion: The addition of dapagliflozin as an alternative for intensification of dual therapy consistently improved, not only FPG and HbA1c, but also body weight and blood pressure, with statistically significant results.


Assuntos
Humanos , Feminino , Adulto , Compostos Benzidrílicos/uso terapêutico , Diabetes Mellitus Tipo 2 , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucosídeos/uso terapêutico , Hipoglicemiantes , Hipoglicemiantes/uso terapêutico , Glicemia , Hemoglobinas Glicadas , Estudos de Coortes , Resultado do Tratamento , Colômbia , Quimioterapia Combinada , Insulina/uso terapêutico , Metformina/uso terapêutico
3.
Acta cir. bras ; 36(11): e361106, 2021. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1360062

RESUMO

ABSTRACT Purpose: To delve into the influence of paeoniflorin (PA) on abating primary biliary cholangitis (PBC)-induced liver fibrosis and its causative role. Methods: Our team allocated the mice to control group, PA group, PBC group and PBC+PA group. We recorded the weight change of mice in each group. We used Masson staining for determining liver fibrosis, immunofluorescence staining for measuring tumor necrosis factor-α (TNF-α) expression, quantitative real-time polymerase chain reaction (qRT-PCR) for assaying related gene expression, as well as Western blot for testing related protein expression. Results: The weight of PBC model mice declined. Twenty-four weeks after modeling, the positive rate of anti-mitochondrial antibody-M2 (AMA-M2) in PBC mice reached 100%. Alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), hydroxyproline (HYP), laminin (LN), procollagen type III (PC III), and malondialdehyde (MDA) contents saliently waxed (p<0.01). Meanwhile, superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) activity patently waned (p<0.01). Liver fibrosis levels were flagrantly higher (p<0.01), and TNF-α, NOD-like receptor protein 3 (NLRP3), caspase-1, interleukin-18 (IL-18), and interleukin-1β (IL-1β) protein or gene expression were manifestly up-regulated (p<0.01). PA could restore the weight of PBC mice, strikingly restrain the positive expression of AMA-M2, and down-regulate serum ALP, ALT, AST, HYP, LN, PC III, MDA in PBC mice (p<0.01). PA could also significantly up-regulate SOD and GSH-px levels (p<0.01), down-regulate IL-1β, IL-18, caspase-1, NLRP3, and TNF-α protein or gene expression in PBC mice (p<0.01) and inhibit liver fibrosis levels (p<0.01). Conclusions: PA can reduce PBC-induced liver fibrosis in mice and may function by curbing the formation of NLRP3.


Assuntos
Animais , Camundongos , Monoterpenos/farmacologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Glucosídeos/farmacologia , Cirrose Hepática/prevenção & controle , Cirrose Hepática/tratamento farmacológico , Aspartato Aminotransferases , Fígado/patologia
4.
Rev. Assoc. Med. Bras. (1992) ; 66(supl.1): s17-s24, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1057108

RESUMO

SUMMARY Type 2 diabetes mellitus is an important public health problem, with a significant impact on cardiovascular morbidity and mortality and an important risk factor for chronic kidney disease. Various hypoglycemic therapies have proved to be beneficial to clinical outcomes, while others have failed to provide an improvement in cardiovascular and renal failure, only reducing blood glucose levels. Recently, sodium-glucose cotransporter-2 (SGLT2) inhibitors, represented by the empagliflozin, dapagliflozin, and canagliflozin, have been showing satisfactory and strong results in several clinical trials, especially regarding the reduction of cardiovascular mortality, reduction of hospitalization due to heart failure, reduction of albuminuria, and long-term maintenance of the glomerular filtration rate. The benefit from SGLT2 inhibitors stems from its main mechanism of action, which occurs in the proximal tubule of the nephron, causing glycosuria, and a consequent increase in natriuresis. This leads to increased sodium intake by the juxtaglomerular apparatus, activating the tubule glomerular-feedback and, finally, reducing intraglomerular hypertension, a frequent physiopathological condition in kidney disease caused by diabetes. In addition, this class of medication presents an appropriate safety profile, and its most frequently reported complication is an increase in the incidence of genital infections. Thus, these hypoglycemic agents gained space in practical recommendations for the management of type 2 diabetes mellitus and should be part of the initial therapeutic approach to provide, in addition to glycemic control, cardiovascular outcomes, and the renoprotection in the long term.


Assuntos
Humanos , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/tratamento farmacológico , Transportador 2 de Glucose-Sódio/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Hipoglicemiantes/farmacologia , Nefropatias/prevenção & controle , Compostos Benzidrílicos/uso terapêutico , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/mortalidade , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/prevenção & controle , Transportador 2 de Glucose-Sódio/uso terapêutico , Canagliflozina/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Taxa de Filtração Glomerular , Glucose/metabolismo , Glucosídeos/uso terapêutico , Hipoglicemiantes/uso terapêutico , Rim/efeitos dos fármacos , Rim/fisiopatologia , Rim/metabolismo , Nefropatias/etiologia , Nefropatias/metabolismo
5.
Braz. j. med. biol. res ; 53(12): e10109, 2020. graf
Artigo em Inglês | LILACS, Coleciona SUS | ID: biblio-1132504

RESUMO

Psoriasis is a chronic inflammatory skin disorder in humans, and the inflammatory reaction plays an important role in development and onset of psoriasis. 4'-O-β-D-glucosyl-5-O-methylvisamminol (4GMV) is one of the major active chromones isolated from Saposhnikoviae divaricata (Turcz.) Schischk, which has been reported to exhibit excellent anti-inflammatory activities. However, the possible therapeutic effect on psoriasis and underlying mechanism has not been reported. Thus, the aim of this study was to investigate the protective effect of 4GMV on the imiquimod (IMQ)-induced psoriasis-like lesions in BALB/c mice and the anti-inflammatory effect on the lipopolysaccharide (LPS)-induced inflammation in RAW264.7 macrophages. The results demonstrated that 4GMV decreased IMQ-induced keratinocyte proliferation and inflammatory cell infiltration. Moreover, 4GMV treatment significantly inhibited the production of NO, PEG 2, and cytokines such as interleukin (IL)-1β, IL-6, interferon (IFN)-γ, and IL-22 in LPS-stimulated RAW264.7 macrophages. 4GMV also suppressed the LPS-upregulated protein expressions of iNOS and COX-2 in a dose-dependent manner. Furthermore, qRT-PCR analysis showed that 4GMV down-regulated the mRNA level of IL-1β and IL-6 expression. Further studies by western blot indicated that 4GMV inhibited the activation of upstream mediator NF-κB by suppressing the expression of TLR4 and the phosphorylation of IκBα and p65. The phosphorylation of JNK, p38, and ERK were also markedly reversed by 4GMV in LPS-treated RAW264.7 macrophages. Taken together, these results demonstrated that 4GMV showed a protective effect in IMQ-induced psoriasis-like mice and inhibited inflammation through the NF-κB and MAPK signaling pathways, indicating that 4GMV might be a potential therapeutic drug for psoriasis.


Assuntos
Animais , Coelhos , Psoríase/induzido quimicamente , Psoríase/tratamento farmacológico , Dermatite , Lipopolissacarídeos , Citocinas , NF-kappa B , Cromonas , Sistema de Sinalização das MAP Quinases , Imiquimode , Glucosídeos , Inflamação , Camundongos Endogâmicos BALB C
7.
Rev. MVZ Córdoba ; 24(3): 7291-7296, sep.-dic. 2019. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1115253

RESUMO

RESUMEN Objetivo. Evaluar el efecto de dosis crecientes del glucósido cianogénico Linamarina, en la reducción de metano ruminal in vitro. Materiales y Métodos. Se empleó líquido ruminal de dos ovejas fistuladas de la raza Merino Precoz, con el que se inoculó un sustrato fermentativo constituido por heno de alfalfa (Medicago sativa) y grano de avena molido (Avena sativa L.), se adicionó solución buffer y Linamarina (pureza de ≥98%) en dosis crecientes, lo que se llevó a incubación por ocho horas in vitro. El metano se midió cada hora, con un monitor de gases infrarrojo. Resultados. De acuerdo con el incremento de las dosis de Linamarina (0, 6, 13, 20 y 26 mg/L), la concentración de metano disminuyó de forma lineal (p≤0.05) en (9.7, 9.2, 18.1 y 29.4%) respectivamente. Se observó una reducción significativa de metano con la dosis más alta de Linamarina. Conclusión. La Linamarina, en su estado puro, fue eficaz en la reducción de metano durante la fermentación ruminal in vitro. Por lo tanto, este estudio constituye una base para futuros experimentos que incluyan fuentes vegetales de Linamarina y otras variables ruminales, lo que puede conducir a encontrar estrategias para reducir los gases de efecto invernadero.


ABSTRACT Objective. To assess the effect of rising doses of the cyanogenic glucoside Linamarin on the reduction of in vitro rumen methane. Materials and methods. Rumen fluid from two fistulated Merino Precoz sheep, inoculated with a fermentation substrate comprising alfalfa hay (Medicago sativa) and ground oat grain (Avena sativa L.), and added with buffer solution and Linamarin (purity ≥98%) in rising doses, was incubated for eight hours in vitro. Methane was measured each hour with an infrared gas monitor. Results. According Linamarin doses were increased (0, 6, 13, 20 and 26 mg/L), the methane concentration fell in a linear manner (p≤0.05) by (9.7, 9.2, 18.1 and 29.4%), respectively. A significant reduction of methane was seen whit the highest dose of Linamarin. Conclusions. Linamarin, in pure state, was effective to reduce methane during in vitro ruminal fermentation. Therefore, this study constitutes a basis for future experiments including vegetable sources of Linamarin as well as other rumen variables, leading to find a strategy for reducing greenhouse gases.


Assuntos
Técnicas In Vitro , Aditivos Alimentares , Glucosídeos , Metano , Fermentação
8.
Rev. Assoc. Med. Bras. (1992) ; 65(2): 246-252, Feb. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-990338

RESUMO

SUMMARY Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are drugs that act by maintaining glycosuria. Recent studies have shown promising effects of these in the treatment of type 2 diabetes mellitus (DM2). However, there may be an increased risk of developing urinary tract infections (UTIs) in patients treated with these. Our study aims to analyze the association between the risk of UTI in patients treated with SGLT2i. A systematic review of the literature was carried out by randomized clinical trials, totalizing at the end of the selection 23 articles that were statistically evaluated. The incidence of UTI was generally demonstrated in articles and in different subgroups: patients on SGLT2i monotherapy or on combination therapy; according to specific comorbidities of each sample or according to the drug used. They noticed an increase in the chance of UTI in the SGLT2i groups compared to the control groups on placebo or other oral antidiabetic agents. This increased chance was found predominantly with the use of Dapagliflozin, Canagliflozin, and Tofogliflozin, regardless of the dosing. Lastly, stands out that the dimension of UTI chances for DM2 patients who use SGLT2i remains to be more strictly determined.


RESUMO Os inibidores do cotransportador de sódio-glicose do tipo 2 (SGLT2i) são medicamentos que atuam mantendo a glicosúria. Estudos recentes têm demonstrado efeitos promissores desses no tratamento de diabetes mellitus tipo 2 (DM2). No entanto, pode haver um risco aumentado de desenvolver infecções do trato urinário (UTI) em pacientes tratados com essa classe de medicação. Nosso estudo tem como objetivo analisar a associação entre o risco de desenvolver UTI em pacientes tratados com SGLT2i. Uma revisão sistemática da literatura foi realizada por ensaios clínicos randomizados, totalizando, ao final da seleção, 23 artigos que foram avaliados estatisticamente. A incidência de UTI foi demonstrada genericamente de acordo com os dados dos artigos e em diferentes subgrupos: pacientes em monoterapia com SGLT2i ou em terapia combinada, de acordo com as comorbidades específicas de cada amostra ou de acordo com a droga utilizada. Verificou-se um aumento na chance de UTI nos grupos SGLT2i em comparação com os grupos de controle em placebo ou outros agentes antidiabéticos orais. Essa chance aumentada foi encontrada predominantemente com uso de Dapagliflozina, Canagliflozina e Tofoglifozina, independentemente da dosagem. Por fim, ressaltou-se que as chances de UTI em pacientes com DM2 em uso de SGLT2i ainda precisam ser mais bem determinadas.


Assuntos
Humanos , Infecções Urinárias/etiologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversos , Compostos Benzidrílicos/efeitos adversos , Compostos Benzidrílicos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Diabetes Mellitus Tipo 2/complicações , Canagliflozina/efeitos adversos , Canagliflozina/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Glucosídeos/efeitos adversos , Glucosídeos/uso terapêutico
9.
Braz. j. med. biol. res ; 52(12): e8834, 2019. graf
Artigo em Inglês | LILACS | ID: biblio-1055472

RESUMO

Polydatin (PD), a monocrystalline polyphenolic drug mainly found in the roots of Polygonum cuspidatum, has various pharmacological activities. Long non-coding RNAs (lncRNA) DiGeorge syndrome critical region gene 5 (DGCR5) was found to participate in the suppression of multiple cancers. Here, we proposed to study the effect of PD on myocardial infarction (MI) by inducing DGCR5. CCK-8 assay was performed to detect the viability of H9c2 cells. Flow cytometry was utilized to test apoptosis of H9c2 cells. These results determined the optimal concentration and effect time of hypoxia as well as PD. Si-DGCR5 was transfected into cells and the expression level was determined by qRT-PCR. Western blot was utilized to evaluate the expression of apoptosis-related proteins, Bcl-2, Bax, and cleaved-caspase-3, as well as autophagy-associated proteins including Beclin-1, p62, and LC3-II/LC3-I. As a result, PD efficiently attenuated hypoxia-induced apoptosis and autophagy in H9c2 cells. The expression of DGCR5 was down-regulated by hypoxia and up-regulated by PD. Besides, knocking-down the expression of DGCR5 inhibited the protection of PD in H9c2 cells. In addition, PD up-regulated the accumulation of DGCR5, DGCR5 decreased the expression of Bcl-2 and p62, raised the expression of Bax and cleaved-caspase-3, and the proportion of LC3-II/LC3-I. PD stimulated the PI3K/AKT/mTOR and MEK/ERK signaling pathways via up-regulating the expression of DGCR5. Our data demonstrated that PD reduced cell apoptosis and autophagy induced by hypoxia in cardiomyocytes. Moreover, PD activated PI3K/AKT/mTOR and MEK/ERK signaling pathways by up-regulating the expression of DGCR5.


Assuntos
Animais , Ratos , Estilbenos/farmacologia , Hipóxia Celular/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , RNA Longo não Codificante/efeitos dos fármacos , Glucosídeos/farmacologia , Transdução de Sinais , Regulação para Cima/efeitos dos fármacos , Linhagem Celular , Citoproteção , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia
10.
Arch. endocrinol. metab. (Online) ; 62(4): 424-430, July-Aug. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-950077

RESUMO

ABSTRACT Objective: This analysis compared the efficacy and safety of the sodium-glucose cotransporter-2 (SGLT2) inhibitor, dapagliflozin, and the dipeptidyl peptidase-4 (DPP4) inhibitor, saxagliptin, both added on to metformin. Materials and methods: This was a post-hoc analysis from a double-blind, randomized, 24-week clinical trial (NCT01606007) of patients with type 2 diabetes (T2D) inadequately controlled with metformin. We compared the dapagliflozin 10 mg (n = 179) and saxagliptin 5 mg (n = 176) treatment arms. Results: Dapagliflozin showed significantly greater mean reductions versus saxagliptin in HbA1c (difference versus saxagliptin [95% CI]: −0.32% [-0.54, −0.10]; p < 0.005), fasting plasma glucose (-0.98 [-1.42, −0.54] mmol/L; p < 0.0001), body weight (-2.39 [-3.08, −1.71] kg; p < 0.0001) and systolic blood pressure (SBP) (-3.89 [-6.15, −1.63] mmHg; p < 0.001). More dapagliflozintreated than saxagliptin-treated patients achieved the composite endpoint of HbA1c reduction ≥ 0.5%, weight loss ≥ 2 kg, SBP reduction ≥ 2 mmHg and no major/minor hypoglycemia (24% versus 7%). No major events of hypoglycemia were reported. More patients on dapagliflozin (6%) versus saxagliptin (0.6%) experienced genital infections. Conclusion: Dapagliflozin demonstrated greater glycemic efficacy than saxagliptin with additional benefits on weight and SBP, and the safety profile was consistent with previous studies.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Compostos Benzidrílicos/uso terapêutico , Adamantano/análogos & derivados , Diabetes Mellitus Tipo 2/tratamento farmacológico , Dipeptídeos/uso terapêutico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Glucosídeos/uso terapêutico , Compostos Benzidrílicos/efeitos adversos , Glicemia/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Adamantano/efeitos adversos , Adamantano/uso terapêutico , Método Duplo-Cego , Diabetes Mellitus Tipo 2/sangue , Dipeptídeos/efeitos adversos , Transportador 2 de Glucose-Sódio/uso terapêutico , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico
11.
Int. j. morphol ; 36(2): 584-591, jun. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-954158

RESUMO

Among the neurodegenerative disorders, Parkinson disease (PD) is ranked as second most common. The pathological hallmark is selective degeneration of the dopaminergic neurons in the nigro-striatal regions of brain with appearance of the Lewy bodies. Present study explores the neuro-protective potential of polydatin in terms of amelioration of degeneration of dopaminergic neurons in nigro-striatal regions of brain and distorted neuromotor behavior in the rotenone model of Parkinson's disease. Thirty-six male Sprague Dawley rats were divided into three groups. Group A (control), Group B (rotenone treated) and Group C (rotenone+polydatin treated). Rotenone was administrated intraperitoneally (i.p) at a dose of 3 mg/kg/body weight while polydatin was given i.p. at a dose of 50 mg/ kg/body weight for four weeks. Then, animals were sacrificed; substantia nigra (SN) & striatum isolated from brain and five micron thick sections were prepared. Cresyl violet (CV), H&E and Immuno-histochemical staining using anti-TH antibody was done. Motor behavior was assessed weekly throughout the experiment using five different methods. Rotenone treated parkinsonian animals showed deterioration of motor behavior, weight loss, loss of dopaminergic neurons and diminished immune-reactivity in the sections from the nigrostriatal regions of these animals Polydatin+rotenone treatment showed contradicting effects to parkinsonism, with amelioration in weight loss, neuro-motor behavior, dopaminergic loss and immune-reactivity against dopaminergic neurons. Present study revealed a neuro-protective potential of polydatin in animal model of PD by ameliorating the neuro-motor abnormalities and degeneration of dopaminergic neurons in nigrostriatal regions.


Entre los trastornos neurodegenerativos, la enfermedad de Parkinson (EP) se clasifica como la segunda más común. El sello patológico es la degeneración selectiva de las neuronas dopaminérgicas en las regiones nigro-estriatales del cerebro, con la aparición de los cuerpos de Lewy. El presente estudio explora el potencial de protección neuronal de la polidatina en términos de la mejora de la degeneración de las neuronas dopaminérgicas en las regiones nigro-estriatales del cerebro y el comportamiento neuromotor distorsionado en el modelo de rotenona de la enfermedad de Parkinson. Treinta y seis ratas macho Sprague Dawley se dividieron en tres grupos: Grupo A (control), Grupo B (tratado con rotenona) y Grupo C (tratamiento con rotenona + polidatina). La rotenona se administró por vía intraperitoneal (i.p.) a una dosis de 3 mg/kg/peso corporal, mientras que la polidatina se administró i.p. a una dosis de 50 mg/kg/ peso corporal durante cuatro semanas. Posteriormente, los animales fueron sacrificados. Se aislaron la substantia nigra (SN) y cuerpo estriado de los cerebros y se realizaron secciones de cinco micras de espesor. Se realizó una tinción de violeta de cresilo (CV), H&E y tinción inmunohistoquímica usando anticuerpo anti-TH. El comportamiento motriz se evaluó semanalmente durante todo el experimento utilizando cinco métodos diferentes. Los animales parkinsonianos tratados con rotenona mostraron deterioro del comportamiento motriz, pérdida de peso, pérdida de neuronas dopaminérgicas y disminución de la reactividad inmune en las secciones de las regiones nigroestriadas. El tratamiento con polidatina + rotenona mostró efectos contrarios al parkinsonismo, con mejoría en la pérdida de peso, en el comportamiento motor, en la pérdida dopaminérgica y en la reactividad inmune contra las neuronas dopaminérgicas. El presente estudio reveló un potencial de protección neuronal de la polidatina en el modelo animal de la EP al mejorar las anomalías neuro-motoras y la degeneración de las neuronas dopaminérgicas en las regiones nigroestriatales.


Assuntos
Animais , Masculino , Ratos , Doença de Parkinson/tratamento farmacológico , Estilbenos/administração & dosagem , Glucosídeos/administração & dosagem , Doença de Parkinson/patologia , Rotenona/toxicidade , Imuno-Histoquímica , Dopamina , Ratos Sprague-Dawley , Fármacos Neuroprotetores , Modelos Animais de Doenças , Transtornos dos Movimentos/prevenção & controle , Degeneração Neural/prevenção & controle
12.
Braz. j. med. biol. res ; 51(4): e6867, 2018. graf
Artigo em Inglês | LILACS | ID: biblio-889068

RESUMO

Polydatin, a small molecule from Polygonum cuspidatum, has many biological functions, particularly anti-cancer effects. However, the anti-cancer effects of polydatin in hepatocellular carcinoma (HCC) have not been examined yet. In the present study, MTT assay, BrdU assay, transwell invasion assay, and wound healing assay were performed to determine cell proliferation, invasion and migration. Flow cytometry and TUNEL assay were used to measure cell apoptosis. Quantitative real-time PCR and western blotting assays were used to determine mRNA and protein expression levels. Xenograft experiment was performed to determine the in vivo anti-tumor effect of polydatin. Immunostaining was performed to analyze the expression of caspase-3 and Ki-67. Our results showed that polydatin inhibited cell proliferation in a concentration-dependent and time-dependent manner in the HCC cell lines. Polydatin also induced cell apoptosis in a concentration-dependent manner possibly via increasing the caspase-3 activity, and up-regulating the protein expression of caspase-3, caspase-9, Bax, and down-regulating the protein expression of Bcl-2. In addition, polydatin treatment had an inhibitory effect on cell proliferation, invasion and migration in HCC cell lines. Polydatin treatment also suppressed the Wnt/beta-catenin signaling activities in HCC cells. Polydatin treatment significantly reduced tumor growth in nude mice inoculated with HepG2 cells, suppressed the expression of Ki-67, and increased caspase-3 expression and TUNEL activity. Our data indicated the important role of polydatin for the suppression of HCC progression.


Assuntos
Animais , Masculino , Camundongos , Estilbenos/farmacologia , Movimento Celular/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Glucosídeos/farmacologia , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Medicamentos de Ervas Chinesas , Western Blotting , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Reação em Cadeia da Polimerase em Tempo Real , Citometria de Fluxo , Neoplasias Hepáticas Experimentais/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica
13.
Braz. j. med. biol. res ; 51(10): e7439, 2018. graf
Artigo em Inglês | LILACS | ID: biblio-951707

RESUMO

Nuclear factor erythroid-related factor 2 (Nrf2) has been implicated in several detoxifying and antioxidant defense processes. Nrf2-mediated heme oxygenase-1 (HO-1) expression was demonstrated to play a key role against oxidative stress. Gastrodin (GSTD) is a well-known active compound isolated from the roots of Rhizoma gastrodiae, a plant used in ancient Chinese traditional medicine. The aim of this work was to investigate whether GSTD could alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells (LSECs). In LSECs exposed to 1 mM H2O2, treatment with GSTD (1, 10, or 50 µM) resulted in higher cell viability than the untreated control. Treated cells maintained a higher Bcl2/Bax ratio and suppressed caspase-9 expression compared with untreated cells, reducing cell apoptosis. GSTD was protective for H2O2-induced oxidative injury by reducing the generation of intracellular reactive oxygen species and malondialdehyde. HO-1 and Nrf2 expressions were synergistically upregulated by GSTD. Inhibition of HO-1 by 10 µM zinc protoporphyrin resulted in less protective effects on cell viability and malondialdehyde reduction by GSTD treatment in H2O2-exposed LSECs. Additionally, phosphorylated p38 in LSECs exposed to H2O2 was elevated by GSTD. Inhibition of p38 phosphorylation by SB203580 did not induce Nrf2 and HO-1 expression after 1 or 10 µM GSTD treatment and the protective effect on cell viability and malondialdehyde reduction in H2O2-exposed LSECs was reduced. The data conclusively demonstrated that GSTD-induced HO-1 and Nrf2 expression is involved in protection of LSECs from H2O2-induced oxidative injury, which may be regulated by p38 phosphorylation.


Assuntos
Animais , Coelhos , Álcoois Benzílicos/farmacologia , Células Endoteliais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Heme Oxigenase-1/metabolismo , Glucosídeos/farmacologia , Peróxido de Hidrogênio/farmacologia , Regulação para Cima/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Fígado/citologia , Fígado/efeitos dos fármacos , Malondialdeído/metabolismo , Modelos Teóricos
14.
Rev. medica electron ; 39(5): 1153-1159, set.-oct. 2017.
Artigo em Espanhol | CUMED, LILACS | ID: biblio-1127720

RESUMO

La estevia [Stevia rebaudiana (Bertoni)] es un arbusto de tipo perenne de la familia de las Asteraceas que crece en áreas tropicales y subtropicales de Suramérica. Hoy en día, su cultivo se ha extendido a otras regiones del mundo, incluyendo Canadá y algunas partes de Asia, Europa y México, donde sus hojas se han utilizado tradicionalmente como edulcorante natural durante cientos de años. En la actualidad, el uso potencial y las implicaciones prácticas de la estevia como un edulcorante se muestran en una serie de alimentos procesados, ya que contiene glucósidos de esteviol como ingrediente activo, que puede ser bajo o no calórico, y hasta 100-300 veces más dulce que la sacarosa. Además, las hojas secas de estevia contienen también minerales, vitaminas, compuestos fenólicos, flavonoides y otros compuestos antioxidantes, con propiedades antimicrobianas y antioxidantes. Stevia acumula hasta un 30 % de los glucósidos de esteviol (SGs por su sigla en inglés) del peso seco de las hojas. El esteviósido y el rebaudiósido A son las principales SGs. Desde diciembre de 2011, los SGs (E 960) se han autorizado como aditivo alimentario y edulcorante en Estados Unidos. Su uso en diversas categorías de alimentos está regulado como por ejemplo en suplementos alimenticios y alimentos dietéticos para propósitos médicos especiales y control de peso. Sin embargo, la información ofrecida al consumidor es engañosa y dista de ser confiable. Este artículo ofrece al público interesado, datos que deben de ser evaluados al comprar productos adicionados con estevia (AU).


Stevia [Stevia rebaudiana (Bertoni)] is a perennial shrub belonging to the Asteraceae family that grows in tropical and subtropical areas of South America. Today its cultivation has spread to other regions of the world, including Canada and some parts of Asia, Europe and México, where its leaves have been used traditionally as a natural sweetener for hundreds of years. Nowadays, the potential use and practical implications of Stevia as a sweetener are shown in a number of processed foods, because it contains steviol-glycosides, which are low- or non-caloric ingredients, up to 100­300 times sweeter than sucrose. In addition, dry Stevia leaves also contain minerals, vitamins, phenolic compounds, flavonoids and other antioxidant compounds, with antimicrobial and antioxidant properties. Stevia accumulates up to 30% of diterpenoid steviol glycosides (SGs) of the leaf dry weight. Stevioside and rebaudioside A are the major SGs. Since December 2011, SGs (E 960) have been permitted for use as food additive and a sweetener in the United States. Its use in various food categories is regulated, e.g. food supplements and dietary foods for special medical purposes and weight control. However, the information offered to the consumers is misleading and far from reliable. This article offers the interested public, data that should be evaluated when buying products added with Stevia (AU).


Assuntos
Humanos , Masculino , Feminino , Stevia/classificação , Glucosídeos/administração & dosagem , Sacarose/administração & dosagem , Edulcorantes/administração & dosagem , Comentário , Obesidade/complicações , Obesidade/prevenção & controle
15.
Rev. Assoc. Med. Bras. (1992) ; 63(7): 636-641, July 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-896368

RESUMO

Summary Introduction: Diabetes mellitus is one of the most common chronic diseases in the world, with high morbidity and mortality rates, resulting in a greatly negative socioeconomic impact. Although there are several classes of oral antidiabetic agents, most of the patients are outside the therapeutic goal range. Objective: To review the use of SGLT-2 inhibitors in the treatment of type 2 diabetes mellitus, focusing on their favorable and unfavorable effects, as well as on cardiovascular profile. Method: A literature search on Pubmed database was performed using the following keywords: "SGLT-2 inhibitors," "dapagliflozin," "empagliflozin," "canagliflozin." Results: SGLT-2 inhibitors are a class of oral antidiabetic drugs directed to the kidney. Their mechanism of action is to reduce blood glucose by inducing glycosuria. Extra-glycemic benefits have been described, such as weight loss, decline in blood pressure and levels of triglycerides and uric acid, and they can slow the progression of kidney disease. Genitourinary infections are the main side effects. There is a low risk of hypotension and hypoglycemia. Diabetic ketoacidosis is a serious adverse effect, although rare. Empagliflozin has already had its cardiovascular benefit demonstrated and studies with other drugs are currently being performed. Conclusion: SGLT-2 inhibitors are a new treatment option for type 2 diabetes mellitus, acting independently of insulin. They have potential benefits other than the reduction of blood glucose, but also carry a risk for adverse effects.


Resumo Introdução: O diabetes mellitus é uma das doenças crônicas mais frequentes no mundo, com altas taxas de morbimortalidade, resultando em um grande impacto negativo socioeconômico. Apesar de existirem diversas classes de antidiabéticos orais, a maioria dos pacientes acometidos está fora da meta terapêutica. Objetivo: Revisar o uso dos inibidores da SGLT-2 no tratamento do diabetes mellitus tipo 2, com enfoque nos efeitos favoráveis, desfavoráveis e no perfil cardiovascular. Método: Foi realizada uma pesquisa bibliográfica transversal com artigos científicos obtidos da base de dados Pubmed, utilizando os descritores: "SGLT-2 inhibitors", "dapagliflozin", "empagliflozin", "canagliflozin". Resultados: Os inibidores da SGLT-2 são uma classe de antidiabéticos orais com atuação no rim. O mecanismo de ação é reduzir a glicemia induzindo glicosúria. Benefícios extraglicêmicos já foram descritos, como redução de peso, pressão arterial, triglicerídeos e ácido úrico, além de retardar a progressão da doença renal. O principal efeito colateral é a infecção geniturinária, com baixo risco de hipotensão e hipoglicemia. Cetoacidose diabética é um efeito adverso grave, mas infrequente. A empagliflozina já teve seu benefício cardiovascular demonstrado, e estudos com outras drogas estão em andamento. Conclusão: Os inibidores da SGLT-2 são uma nova opção de tratamento do diabetes mellitus tipo 2, que atua de forma insulino-independente e com potenciais benefícios adicionais, além da redução da glicemia, mas também com risco de efeitos adversos.


Assuntos
Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose , Hipoglicemiantes/uso terapêutico , Compostos Benzidrílicos/uso terapêutico , Glicemia/efeitos dos fármacos , Transportador 2 de Glucose-Sódio , Canagliflozina/uso terapêutico , Glucosídeos/uso terapêutico , Hipoglicemiantes/efeitos adversos , Rim/efeitos dos fármacos
16.
Rev. chil. pediatr ; 88(3): 404-410, jun. 2017. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-899995

RESUMO

Dapaglifozina, un inhibidor del cotransportador de sodio-glucosa 2 (I-SGLT2) induce glucosuria y reduce la glicemia en adultos con diabetes tipo 2. Objetivo: Presentar una cetosis diabética “normoglicémica” en una adolescente con diabetes tipo 1 (DM1) que recibía dapaglifozina y alertar sobre el riesgo del uso I-SGLT2 que parece promisorio, pero no está aprobado en niños ni en DM1. Caso clínico: Paciente de 17 años sin cetosis durante 9 años con DM1, inició dapaglifozina 10 mg/día para reducir la insulina y el peso. Durante 11 meses de tratamiento tuvo cetonas capilares indetectables, redujo el índice de masa corporal 23,9 a 21,1 kg/m², la insulina basal 40 a 17 U, la hemoglobina glicosilada 8,3 a 7,5%, la glicemia capilar 175 a 161 mg/dl y la variabilidad de la glucosa (desvío estándar 85 a 77). Inesperadamente aparecieron náuseas y vómitos. La paciente portaba bomba de insulina con monitorización continua de glucosa, bien calibrada (glucosas intersticiales concordantes con glicemias), que mostraba glucosa estable bajo 200 mg/dl. Recibió insulina pero los vómitos persistieron; en tres horas, aparecieron deshidratación y desmayos, con cetonas 4,6 nmol/l y glicemia 224 mg/dl. Recibió suero fisiológico, ondansetrón, carbohidratos y varias dosis de insulina con pronta recuperación del estado general e hidratación, sin embargo, la cetosis continuó durante 24 horas. Cabe destacar que la bomba estaba funcionando bien y no se cambió la cánula. Al superar la cetosis, continuó con la misma cánula con buen control metabólico. Conclusión: Es importante sospechar la cetosis diabética normoglicémica por ser de riesgo vital.


Dapagliflozin, an insulin-independent sodium-glucose cotransporter 2 inhibitor (SGLT2-I) induces glycosuria and reduces hyperglycemia in adults with type 2 diabetes. Objective: To present an “euglycemic” diabetic ketosis in an adolescent with type 1 diabetes (T1D) receiving dapagliflozin, to alert about the risk of a drug not approved in children nor in T1D. Case report: A 17 years old adolescent with T1D during 9 years, was started on dapagliflozin 10 mg / day to reduce insulin dose and weight. During 11 months on treatment, capillaries ketones were undetectable and she exhibited a reduction in body mass index 23.9 to 21.1 kg/m2, basal insulin 40 to 17 U, glycated hemoglobin 8.3 to 7.5%, capillary glucose 175 to 161 mg/dl and glucose variability (standard deviation) 85 to 77. Suddenly nausea and vomits appeared. The patient was on an insulin pump and well calibrated continuous glucose monitoring, showing stable glucose levels under 200 mg/dl, and an insulin bolus was delivered. Vomiting without hyperglycemia persisted; three hours later, she was severely dehydrated and fainting, with ketones 4.6 nmol/l and glucose 224 mg/dl. She received IV saline fluids, ondansetron, carbohydrates and several insulin boluses. Hydration and general condition improved soon, however despite several insulin doses, ketosis continued for 24 hours. It is remarkable that the pump was working well and the cannula was not changed. After the ketosis was resolved, she continued using the same cannula with good metabolic control. Conclusion: Euglycemic ketosis is a life-threatening condition that must be suspected.


Assuntos
Humanos , Feminino , Adolescente , Compostos Benzidrílicos/efeitos adversos , Cetoacidose Diabética/induzido quimicamente , Diabetes Mellitus Tipo 1/tratamento farmacológico , Glucosídeos/efeitos adversos , Hipoglicemiantes/efeitos adversos , Insulina/uso terapêutico , Compostos Benzidrílicos/uso terapêutico , Glicemia/metabolismo , Biomarcadores/sangue , Cetoacidose Diabética/diagnóstico , Cetoacidose Diabética/sangue , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/sangue , Quimioterapia Combinada , Glucosídeos/uso terapêutico , Hipoglicemiantes/uso terapêutico
17.
Ann. hepatol ; 16(2): 308-311, Mar.-Apr. 2017. tab
Artigo em Inglês | LILACS | ID: biblio-887237

RESUMO

ABSTRACT A 75-year old male patient had been regularly visiting our hospital for the management of his type 2 diabetes mellitus since he was diagnosed at age 64 years. When he developed hypoglycemic episodes with sulfonylurea, ipragliflozin (50 mg/day) was started to replace the sulfonylurea therapy. However, 49 days after starting ipragliflozin, his AST increased from 13 to 622 U/L, ALT increased from 9 to 266 U/L, ALP increased from 239 to 752 U/L, and γ-GTP increased from 19 to 176 U/L. ZTT was 3.5 U, TTT was 0.4 U, and total bilirubin was 0.7 mg/dL. IgM hepatitis A antibody, hepatitis B antigen, hepatitis C virus antibody, IgM CMV antibody, and IgM EB VCA antibody were negative, whereas a lymphocyte transformation test for ipragliflozin was positive. Abdominal CT scan showed mild fatty liver but no sign of nodular lesions. Following admission to our hospital, he received liver supportive therapy with the discontinuation of ipragliflozin therapy. He was discharged from the hospital 18 days later with AST and ALT levels reduced to 20 U/L and 13 U/L, respectively. Based on the clinical presentation of this patient, it is highly important to monitor liver function along with other possible clinical complications (e.g., dehydration, ketosis, and urinary tract infection) associated with SGLT2 inhibitor therapy.


Assuntos
Humanos , Masculino , Idoso , Ativação Linfocitária/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/imunologia , Glucosídeos/efeitos adversos , Hipoglicemiantes/efeitos adversos , Tiofenos/efeitos adversos , Valor Preditivo dos Testes , Fatores de Risco , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/sangue , Doença Hepática Induzida por Substâncias e Drogas/terapia , Testes de Função Hepática
18.
Bol. latinoam. Caribe plantas med. aromát ; 15(5): 288-300, Sept. 2016. ilus
Artigo em Inglês | LILACS | ID: biblio-907546

RESUMO

Ultraviolet radiation (UVR) is involved in both sunburn and the development of skin cancer, which has a high incidence worldwide. Strategies to reduce these effects include the use of photoprotective substances. The aim of this work was to investigate the photoprotective effect of verbascoside isolated from the methanolic extract of Buddleja cordata (BCME) in SKH-1 mice exposed to acute and chronic UV-B radiation. The mouse dorsal area was evaluated macroscopically and microscopically for diagnosis; verbascoside penetration into mouse skin was investigated in vivo by the tape stripping method. After acute UV-B exposure, 100 percent of irradiated mice that had been protected with verbascoside showed no signs of sunburn or of inflammatory processes. After chronic exposure, 100 percent of unprotected mice showed skin carcinomas; in contrast, in mice topically treated with either BCME or verbascoside, the presence of lesions was decreased by 90 percent. These results prove that verbascoside penetrates through the skin of mice and suggest that verbascoside and BCME may potentially prevent photodamage on mice’s skin after acute and chronic UVR exposure.


La radiación ultravioleta (RUV) provoca quemaduras solares y el desarrollo de cáncer de piel. El objetivo de este trabajo fue investigar el efecto fotoprotector del verbascósido obtenido del extracto metanólico de Buddleja cordata (EMBC) en ratones SKH-1 expuestos a RUV-B de manera aguda y crónica. El diagnóstico histológico se llevó a cabo en la piel de la zona dorsal de los ratones. La penetración del verbascósido fue cuantificada mediante la técnica de la cinta adhesiva. En el experimento agudo, el 100 por ciento de los ratones protegidos con verbascósido no evidenciaron signos de quemadura ni procesos inflamatorios. En el experimento crónico los ratones sin protección e irradiados presentaron carcinomas cutáneos. En contraste en los ratones protegidos con EMBC o verbascósido las lesiones disminuyeron un 90 por ciento en ambos grupos. El verbascósido penetró en la piel del ratón. Los resultados sugieren que el EMBC y el verbascósido previenen el fotodaño en la piel de ratones expuestos de forma aguda o crónica a la RUV.


Assuntos
Animais , Camundongos , Buddleja/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Pele , Pele/efeitos da radiação , Eritema/prevenção & controle , Glucosídeos/farmacologia , Camundongos Pelados , Pele/patologia , Queimadura Solar/prevenção & controle , Raios Ultravioleta/efeitos adversos
19.
J. bras. pneumol ; 41(1): 16-22, Jan-Feb/2015. tab
Artigo em Inglês | LILACS | ID: lil-741568

RESUMO

Objective: To evaluate the impact of asthma on patients in Brazil, by age group (12-17 years, 18-40 years, and ≥ 41 years). Methods: From a survey conducted in Latin America in 2011, we obtained data on 400 patients diagnosed with asthma and residing in one of four Brazilian state capitals (São Paulo, Rio de Janeiro, Curitiba, and Salvador). The data had been collected using a standardized questionnaire in face-to-face interviews. For the patients who were minors, the parents/guardians had completed the questionnaire. The questions addressed asthma control, number of hospitalizations, number of emergency room visits, and school/work absenteeism, as well as the impact of asthma on the quality of life, sleep, and leisure. We stratified the data by the selected age groups. Results: The proportions of patients who responded in the affirmative to the following questions were significantly higher in the 12- to 17-year age group than in the other two groups: "Have you had at least one episode of severe asthma that prevented you from playing/exercising in the last 12 months?" (p = 0.012); "Have you been absent from school/work in the last 12 months?" (p < 0.001); "Have you discontinued your asthma relief or control medication in the last 12 months?" (p = 0.008). In addition, 30.2% of the patients in the 12- to 17-year age group reported that normal physical exertion was very limiting (p = 0.010 vs. the other groups), whereas 14% of the patients in the ≥ 41-year age group described social activities as very limiting (p = 0.011 vs. the other groups). Conclusions: In this sample, asthma had a greater impact on the patients between 12 and 17 years of age, which might be attributable to poor treatment compliance. .


Objetivo: Avaliar o impacto da asma em pacientes segundo as faixas etárias de 12-17 anos, 18-40 anos e ≥ 41 anos no Brasil. Métodos: Os dados de 400 pacientes com asma diagnosticada por um médico e residentes de quatro capitais estaduais brasileiras (São Paulo, Rio de Janeiro, Curitiba e Salvador) foram obtidos em um inquérito realizado em países da América Latina em 2011. Os dados foram coletados por meio de um questionário padronizado em entrevista presencial com os pacientes ou com os pais/responsáveis daqueles < 18 anos. As questões abordavam controle da asma, número de hospitalizações, número de consultas de urgência, absenteísmo na escola/trabalho e impactos da asma na qualidade de vida, sono e lazer. Os dados foram estratificados pelas faixas etárias selecionadas. Resultados: Em comparação com os grupos de pacientes adultos, houve uma proporção significativamente maior no grupo 12-17 anos em relação a ter ao menos um episódio de asma grave que impediu o paciente a continuar a jogar ou a se exercitar nos últimos 12 meses (p = 0,012), absenteísmo escolar/trabalho nos últimos 12 meses (p < 0,001), e interrupção de medicação para controle ou prevenção da asma nos últimos 12 meses (p = 0,008). Além disso, 30,2% dos pacientes na faixa etária 12-17 anos relataram que esforços físicos normais eram atividades muito limitantes (p = 0,010 vs. outros grupos), enquanto 14% dos pacientes do grupo ≥ 41 anos descreveram as atividades sociais como muito limitantes (p = 0,011 vs. outros grupos). Conclusões: Nessa amostra, o impacto da asma foi maior nos pacientes com idade entre 12 e 17 anos do que nos adultos, e isso pode ser atribuído à baixa aderência ao tratamento. .


Assuntos
Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Benzidrílicos/uso terapêutico , Glicemia/metabolismo , /tratamento farmacológico , Glucosídeos/uso terapêutico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Pressão Sanguínea , Peso Corporal , Ensaio Clínico , Estudos de Coortes , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , /sangue , Seguimentos , Hemoglobinas Glicadas/análise , Fatores de Tempo
20.
Braz. j. microbiol ; 45(4): 1139-1144, Oct.-Dec. 2014. ilus
Artigo em Inglês | LILACS | ID: lil-741263

RESUMO

Bacteria have evolved various mechanisms to extract utilizable substrates from available resources and consequently acquire fitness advantage over competitors. One of the strategies is the exploitation of cryptic cellular functions encoded by genetic systems that are silent under laboratory conditions, such as the bgl (β-glucoside) operon of E. coli. The bgl operon of Escherichia coli, involved in the uptake and utilization of aromatic β-glucosides salicin and arbutin, is maintained in a silent state in the wild type organism by the presence of structural elements in the regulatory region. This operon can be activated by mutations that disrupt these negative elements. The fact that the silent bgl operon is retained without accumulating deleterious mutations seems paradoxical from an evolutionary view point. Although this operon appears to be silent, specific physiological conditions might be able to regulate its expression and/or the operon might be carrying out function(s) apart from the utilization of aromatic β-glucosides. This is consistent with the observations that the activated operon confers a Growth Advantage in Stationary Phase (GASP) phenotype to Bgl+ cells and exerts its regulation on at least twelve downstream target genes.


Assuntos
Escherichia coli/enzimologia , Escherichia coli/genética , Regulação da Expressão Gênica , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Arbutina/metabolismo , Álcoois Benzílicos/metabolismo , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Glucosídeos/metabolismo , Óperon
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