RESUMO
The MnSOD Ala16Val single nucleotide polymorphism (SNP) has shown to be associated to risk factors of several metabolic and vascular diseases. However, little is known about interaction between MnSOD Ala16Val SNP in stroke, a frequent neurologic disease that involves clinic manifestations such as motor deficits and spasticity. In this sense, we decided to investigate the relationship between MnSOD Ala16Val SNP with spasticity in stroke and also its influence on interleukin levels, BDNF, and glycolipid parameters. Eighty post-stroke subjects and 80 healthy controls were investigated. We showed a higher spasticity, levels of total cholesterol, LDL, IL-1ß, IL-6, and INF-γ in VV post-stroke group. Interesting, we found a correlation between IL-1ß levels and spasticity in VV post-stroke. Triglycerides, glucose levels and caspases (1 and 3) activation were significantly higher, as well as BDNF levels were lower in VV and AV post-stroke. DNA damage was higher in post-stroke group. Thus, we can suggest that the V allele has a worse glycolipid profile, which would facilitate changes in neurovascular homeostasis. These events associated with an increase in inflammatory markers and a reduction in BDNF can contribute with the stroke and a worse clinical evolution in relation to spasticity in patients with VV genotype.
Assuntos
Interleucina-6 , Acidente Vascular Cerebral , Fator Neurotrófico Derivado do Encéfalo/genética , Caspases/genética , LDL-Colesterol/genética , Genótipo , Glucose , Glicolipídeos , Humanos , Interleucina-1beta/genética , Interleucina-6/genética , Espasticidade Muscular/genética , Polimorfismo de Nucleotídeo Único , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/genética , Superóxido Dismutase/genética , TriglicerídeosRESUMO
PURPOSE: 5'-methoxynobiletin (5'-MeONB), a polymethoxyflavone isolated from A. conyzoides, has shown anti-inflammatory property. Nevertheless, the antinociceptive activity and pre-clinical pharmacokinetics (PK) characteristics of 5'-MeONB remain unknown. Considering the anti-inflammatory potential of the 5'-MeONB, this study aimed to investigate the pre-clinical PK behavior of 5'-MeONB, as well as its time course antinociceptive activity. METHODS: 5'-MeONB plasma concentrations were determined in Wistar rats after intravenous (i.v.) (10 mg/kg) and oral (50 mg/kg) administration, and in Swiss mice after oral administration (100 mg/kg). Plasma samples were deproteinization and 5'-MeONB quantified by a validated UPLC-MS method. Additionally, the antinociceptive activity of 5'-MeONB was evaluated after 15, 30, 60, 180 and 360 min following oral administration on the acute nocifensive behavior of mice induced by formalin. RESULTS: 5'-MeONB rats and mice plasma concentration-time profiles were best one-compartment model. After i.v. administration to rats, a short half-life, a high clearance and moderate volume of distribution at steady state were observed. Similar results were obtained after oral administration. The oral bioavailability ranged from 8 to 11%. Additionally, 5'-MeONB exhibited antinociceptive activity in both formalin phases, especially in the inflammatory phase of the model, inhibiting 68% and 91% of neurogenic and inflammatory responses, respectively, after 30 min of oral administration. CONCLUSIONS: The results described here provide novel insights on 5'-MeONB pharmacokinetics and pharmacodynamic effect, serving as support for future studies to confirm this compound as anti-nociceptive and anti-inflammatory effective agent.
Assuntos
Ageratum , Administração Oral , Analgésicos/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Cromatografia Líquida , Formaldeído , Camundongos , Ratos , Ratos Wistar , Espectrometria de Massas em TandemRESUMO
The association between chronic kidney disease (CKD) and pulmonary pathophysiological changes is well stablished. Nevertheless, the effects of aerobic exercise (AE) on lungs of CKD need further clarification. Thus, Swiss mice were divided in control, AE, CKD, and CKD + AE groups. CKD was induced by 0.2% adenine intake during 8 weeks (4 weeks of CKD induction and 4 weeks of AE). AE consisted in running on treadmill, at moderate intensity, 30 min/day, 5 days/week, during 4 weeks. Twenty-four hours after the last training day, functional capacity test was performed, and 48 h after the test, mice were euthanized. CKD mice showed a significant increase in urine output, serum urea, and creatinine concentrations, and decreased body weight and urine density, besides oxidative damage (p = 0.044), edema area (p < 0.001), leukocyte infiltration (p = 0.040), and collagen area in lung tissue (p = 0.004). AE resulted in an increase of distance traveled (p = 0.049) and maximum speed (p = 0.046), increased activity of catalase (p = 0.031) and glutathione peroxidase (p = 0.048) in lungs, increased levels of nitric oxide (NOx) in serum (p = 0.001) and bronchoalveolar lavage fluid (p = 0.047), and decreased kidney histological injury (p = 0.018) of CKD mice. However, AE also increased oxidative damage (p = 0.003) and did not change collagen content or perivascular edema in lungs (p > 0.05) of CKD mice. Therefore, AE attenuated kidney injury and improved antioxidants defenses in lungs. Despite no significant changes in pulmonary damage, AE significantly improved physical performance in CKD mice.
Assuntos
Antioxidantes , Insuficiência Renal Crônica , Adenina/farmacologia , Animais , Antioxidantes/farmacologia , Catalase/metabolismo , Creatinina , Glutationa Peroxidase , Rim/patologia , Pulmão/metabolismo , Camundongos , Óxido Nítrico , Estresse Oxidativo , Desempenho Físico Funcional , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/patologia , Ureia/farmacologiaRESUMO
Adipose tissue accumulation, resulting from the consumption of hypercaloric foods, can cause a dysfunction of the endocrine system. Such endocrine changes can influence the expression of various neurochemicals including brain-derived neurotrophic factor (BDNF) - associated with cognitive and emotional problems. Here, we investigated the effects of a hypercaloric diet on depression- and anxiety-like behaviors in young rats along with concomitant changes in BDNF expression levels in the hippocampus. Eight week-old Wistar rats (n = 20) were divided in: control diet (CD) group which received industrial food (n = 8) and hypercaloric diet (HD) group which received animal fat and soybean oil (n = 12). After 45 days on the diet, the animals were evaluated: body weight and blood biochemical analisys. Changes in mood disposition were evaluated using forced swim test and the elevated plus-maze, whereas hippocampal BDNF expression levels were quantified by ELISA. After 45 weeks, the CD group showed a significant increase in body weight relative to the HD group. However, the HD rats had a body fat percentage and exhibited increased level of the biochemical markers. Furthermore, the animals in the HD group presented increased immobility time in the forced swimming test, as well as reduced response to plus-maze test suggesting a depression- and anxiety-like emotional state. In addition, the HD group also showed lower BDNF expression levels in the hippocampus. This study demonstrates that a hypercaloric diet induced increase in adipose tissue concentration in young rats was associated with reduced hippocampal BDNF expression and resulted in an increase in depression- and anxiety-like behaviors. Graphical abstract.
Assuntos
Afeto/fisiologia , Ansiedade/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Depressão/metabolismo , Dieta Hiperlipídica , Hipocampo/metabolismo , Animais , Peso Corporal/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Ratos , Ratos Wistar , NataçãoRESUMO
This study presents the development and validation of a fast and simple bioanalytical ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) method intended for quantifying the anti-inflammatory candidate 5'-methoxynobiletin (5'-MeONB) in rat plasma. Standard of 5'-MeONB was purified from A. conyzoides extract by using preparative HPLC. After a pretreatment of plasma samples with acetonitrile, chromatographic separations were efficiently achieved with a C18 column using a 9 min gradient system of 0.1% aqueous formic acid and acetonitrile as eluent. Drug candidate 5'-MeONB and chrysin (internal standard, IS) detection were carried out using ESI+ through the extracted ion chromatograms approach, monitored at m/z 433.1494 (for 5'-MeONB, tR:1.78 min) and m/z 255.0657 (for IS, tR:1.57 min). Method was validated according to US FDA guidelines, presenting linearity (R2 > 0.999) over concentration range of 30-750 ng/mL. Relative standard deviation (RSD) of repeatability and intermediary precision respectively ranged between 1.93-3.65% and 2.16-7.54%, considering lower limit of quantitation (30 ng/mL) and quality control (90, 360 and 600 ng/mL) samples, while accuracy was between 82.51 and 109.44%. Moreover, no interference from plasma endogenous substances, no carryover effect, and no influence of extraction method even in hemolyzed blood samples were observed. Sample stability in auto-sampler and long-term -80 °C storage, as well as matrix effect were within acceptable limits. For the first time, using the validated UPLC-MS bioanalytical method, the plasma pharmacokinetics of 5'-MeONB following 2 mg/kg intravenous bolus dosing to Wistar rats was characterized allowing the determination of the parameters describing drug distribution and elimination.
Assuntos
Anti-Inflamatórios/sangue , Cromatografia Líquida de Alta Pressão/métodos , Flavonas/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacocinética , Flavonas/química , Flavonas/farmacocinética , Limite de Detecção , Modelos Lineares , Masculino , Ratos , Ratos Wistar , Reprodutibilidade dos TestesRESUMO
Upper limb nerve injuries are common, and their treatment poses a challenge for physicians and surgeons. Experimental models help in minimum exploration of the functional characteristics of peripheral nerve injuries of forelimbs. This study was conducted to characterize the functional recovery (1, 3, 7, 10, 14, and 21 days) after median and ulnar nerve crush in mice and analyze the histological and biochemical markers of nerve regeneration (after 21 days). Sensory-functional impairments appeared after 1 day. The peripheral nerve morphology, the nerve structure, and the density of myelin proteins [myelin protein zero (P0) and peripheral myelin protein 22 (PMP22)] were analyzed after 21 days. Cold allodynia and fine motor coordination recovery occurred on the 10th day, and grip strength recovery was observed on the 14th day after injury. After 21 days, there was partial myelin sheath recovery. PMP22 recovery was complete, whereas P0 recovery was not. Results suggest that there is complete functional recovery even with partial remyelination of median and ulnar nerves in mice.
Assuntos
Nervo Mediano/fisiopatologia , Recuperação de Função Fisiológica , Remielinização , Nervo Ulnar/fisiopatologia , Animais , Masculino , Nervo Mediano/lesões , Nervo Mediano/metabolismo , Camundongos , Proteína P0 da Mielina/metabolismo , Proteínas da Mielina/metabolismo , Compressão Nervosa , Nervo Ulnar/lesões , Nervo Ulnar/metabolismoRESUMO
While chronic high-fat feeding has long been associated with the rising incidence of obesity/type 2 diabetes, recent evidence has established that it is also associated with deficits in hippocampus-dependent memory. In this regard, environmental enrichment (EE) is an animal housing technique composed of increased space, physical activity, and social interactions, which in turn increases sensory, cognitive, motor, and social stimulation. EE leads to improved cerebral health as defined by increased neurogenesis, enhanced learning and memory and resistance to external cerebral insults. In the present study, the impacts of environmental enrichment (EE) on Swiss mice fed a high-fat, cholesterol-enriched diet (HFECD; 20% fat and 1.5% cholesterol) were investigated. Here, we demonstrated that EE, when initiated 4 weeks after the beginning of HFECD in mice, prevents HFECD-induced spatial memory and object recognition impairment, which were tested in T-maze and object recognition tests. Although EE did not affect HFECD-induced weight gain or hypercholesterolaemia, it improved glucose tolerance. On the other hand, EE was unable to mitigate a decrease in brain-derived neurotrophic factor (BDNF) and IL-6 hippocampal levels induced by the HFECD. Overall, while our results reinforce the positive and neuroprotective effects of EE on cognition they do not support a role for EE in preventing the neurochemical changes induced by the HFECD. Based on clinical observations that nondiabetic individuals with mild forms of impaired glucose tolerance have a higher risk of cognitive impairments, one can speculate about the connection between the effects of EE on glucose intolerance and its effects on cognition.
Assuntos
Colesterol/efeitos adversos , Disfunção Cognitiva/terapia , Dieta Hiperlipídica/efeitos adversos , Meio Ambiente , Abrigo para Animais , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/patologia , Modelos Animais de Doenças , Intolerância à Glucose/etiologia , Intolerância à Glucose/metabolismo , Intolerância à Glucose/patologia , Intolerância à Glucose/terapia , Hipocampo/metabolismo , Hipocampo/patologia , Hipercolesterolemia/etiologia , Hipercolesterolemia/metabolismo , Hipercolesterolemia/patologia , Hipercolesterolemia/psicologia , Interleucina-6/metabolismo , Masculino , Camundongos , Obesidade/etiologia , Obesidade/metabolismo , Obesidade/patologia , Obesidade/psicologia , Distribuição Aleatória , Reconhecimento Psicológico , Memória EspacialRESUMO
AIM: To investigate the mechanism of action of sulfonyl(thio)urea derivative (SD) on glycemia and on insulin secretion in pancreatic islets. METHODS: Wistar rats were divided into hyperglycemic control group, rats received 4 g/kg body weight glucose plus sitagliptin 10 mg/kg (p.o.); hyperglycemic plus SD 10 mg/kg (p.o.); hyperglycemic plus SD plus sitagliptin. Blood was collected before glucose overloading (zero time), and at 15, 30, 60, and 180 min after glucose, from the afore mentioned groups for glycemia and glucagon-like peptide 1 (GLP-1) measurements and intestinal disaccharidases activity. Pancreatic islets were isolated for the calcium influx and insulin secretion in in vitro studies. RESULTS: SD reduced glycemia and increased GLP-1 secretion, while inhibited sucrase and lactase activity. This SD (1.0 and 10.0 µM) stimulated calcium influx in a similar percentile to that of glibenclamide, and in a nonsynergic manner. In addition, the trigger effect of SD on calcium influx was through the K+ -ATP-dependent channels, and partially by activating voltage-dependent K + channels and voltage-dependent calcium channels. Furthermore, SD-stimulated Na + and Ca 2+ entry, induced by the transient receptor potential ankyrin 1 and by modulation of Na + /Ca 2+ exchange. The activation of these pathways by SD culminated in in vitro insulin secretion, reinforcing the critical role of K + -ATP channels in the secretagogue effect of SD. CONCLUSIONS: SD diminish glycemia by inducing GLP-1 secretion and inhibiting disaccharidases. To our knowledge, this is the first report of an insulin secretagogue effect of SD that is mediated by potassium and calcium, as well as sodium, signal transduction.
Assuntos
Hipoglicemiantes/farmacologia , Secreção de Insulina/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Compostos de Sulfonilureia/farmacologia , Animais , Canais de Cálcio/efeitos dos fármacos , Canais de Cálcio/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hiperglicemia/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Masculino , Canais de Potássio de Abertura Dependente da Tensão da Membrana/efeitos dos fármacos , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Ratos , Ratos Wistar , Fosfato de Sitagliptina/farmacologia , Canais de Sódio Disparados por Voltagem/efeitos dos fármacos , Canais de Sódio Disparados por Voltagem/metabolismoRESUMO
In sepsis, greater understanding of the inflammatory mechanism involved would provide insights into the condition and into its extension to the muscular apparatus in critically ill patients. Therefore, this study evaluates the inflammatory profile of pneumosepsis induced by Klebsiella pneumoniae (K.p.) in lungs and skeletal muscles during the first 72â¯h. Male BALB/c mice were divided into 4 groups, submitted to intratracheal inoculation of K.p. at a concentration of 2â¯×â¯108 (PS) or PBS, and assessed after 24 (PS24), 48 (PS48) and 72 (PS72) hours. The Maximum Physical Capacity Test (MPCT) was performed before and after induction. Pulmonary inflammation was assessed by total cell number, nitric oxide levels (NOx), IL-1ß and TNF-α levels in bronchoalveolar lavage fluid (BALF); inflammation and muscle trophism were evaluated by the levels of TNF-α, IL-6, TGF-ß and BDNF by ELISA and NF-κB by western blotting in muscle tissue. Cells and colony forming units (CFU) were also analyzed in blood samples. The PS groups showed an increase in total cells in the BALF (pâ¯<â¯0.05), as well in the number of granulocytes in the blood (pâ¯<â¯0.05) and a decrease in performance in the MPCT (pâ¯<â¯0.05). NOx levels showed significant increase in PS72, when compared to Control group (pâ¯=â¯0.03). The PS24 showed a significant increase lung in TNF-α levels (pâ¯<â¯0.001) and in CFU (pâ¯=â¯0.013). We observed an increase in muscular IL-6 and nuclear NF-κB levels in PS24 group, when compared to PS48 and Control groups (pâ¯<â¯0.05). Nevertheless, mild signs of injury in the skeletal muscle tissue does not support the idea of an early muscular injury in this experimental model, suggesting that the low performance of the animals during the MPCT may be related to lung inflammation.
Assuntos
Biomarcadores/metabolismo , Inflamação/patologia , Pulmão/patologia , Músculos/patologia , Sepse/patologia , Animais , Contagem de Células , Citocinas/metabolismo , Granulócitos/metabolismo , Klebsiella pneumoniae/fisiologia , Pulmão/microbiologia , Masculino , Camundongos Endogâmicos BALB C , Músculos/microbiologia , Sepse/microbiologia , Análise de Sobrevida , Fatores de TempoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Discaria americana (Rhamnaceae) root bark infusion have been used in traditional medicine as antipyretic, tonic, ameliorative of stomach and skin diseases and diabetes. This study was designed to investigate whether the methanolic extract of the root bark of Discaria americana (MEDa) exhibits antinociceptive effects in mice. Furthermore, it was investigated the involvement of the opioidergic system in MEDa mechanism of action as well the interactions with TRP/ASIC channels in its effect. MATERIALS AND METHODS: The antinociceptive effect of intra-gastric gavage (i.g.) of MEDa (0.3-300â¯mg/kg) was evaluated in mice subjected to acute chemical (acetic-acid, formalin, glutamate, capsaicin, cinnamaldehyde, and acidified saline) or thermal (hot plate) tests of pain. The involvement of opioid system was evaluated in the formalin test. A nonspecific effect of MEDa was observed by measuring locomotor activity and exploratory behavior in open field test. RESULTS: MEDa significantly reduced the number of writhing induced by acetic acid and inhibited the nociception in the two phases of formalin. These effects were inhibited by pretreatment with naloxone. The nociception induced by hot plate and intraplantar injection of glutamate, capsaicin, cinnamaldehyde and acidified saline were significantly inhibited by MEDa. Only the dose of 300â¯mg/kg altered the locomotor activity. CONCLUSIONS: Our results demonstrated, for the first time, that the methanolic extract of the root bark of Discaria americana presents antinociceptive effect in chemical and thermal stimuli and its analgesic properties can be due activation of the opioidergic system. These results support the use of Discaria americana in traditional medicine and demonstrate that this plant presents a therapeutic potential for the development of phytomedicines with antinociceptive profile.
Assuntos
Analgésicos Opioides/uso terapêutico , Dor/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Rhamnaceae , Bloqueadores do Canal Iônico Sensível a Ácido/farmacologia , Analgésicos Opioides/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Masculino , Camundongos , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Fitoterapia , Casca de Planta , Extratos Vegetais/farmacologia , Raízes de Plantas , Canais de Potencial de Receptor Transitório/antagonistas & inibidoresRESUMO
Species of the Byrsonima genus are widely used in Brazil, especially for the treatment of gastrointestinal disorders. However, species from the Amazonian region are still poorly studied. Thus, we studied the antioxidant, antinociceptive, and anti-inflammatory activities of for Amazonian species, Byrsonima crispa, Byrsonima duckeana, Byrsonima garcibarrigae, and Byrsonima incarnata. Phenolic composition was determined by chemical and chromatographic methods. The aqueous extracts were evaluated in DPPH⢠, ABTS+⢠, and superoxide (O2â¢- ) tests, LPS-activated macrophage assay, and formalin test. All species contained a high phenolic and flavonoid content. We identified 15 phenolic compounds, including phenolic acids, hydroxycinnamic acids, flavonoids, and catechins. The extracts showed high antioxidant activity and were more active than quercetin at inhibiting nitric oxide release in the LPS-activated macrophage assay. B. duckeana and B. garcibarrigae showed higher in vivo antinociceptive and anti-inflammatory activities. B. garcibarrigae presented significant effect on the early phase of the formalin test, pointing to an antinociceptive mechanism distinct from traditional anti-inflammatory medicines. In conclusion, the pharmacological potential of these species is closely related to their flavonoid-rich chemical composition, which seems to act through antioxidant mechanisms. Copyright © 2017 John Wiley & Sons, Ltd.
Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Malpighiaceae/química , Extratos Vegetais/farmacologia , Células 3T3-L1 , Animais , Brasil , Feminino , Macrófagos/efeitos dos fármacos , Malpighiaceae/classificação , Camundongos , Óxido Nítrico/análise , Medição da Dor , Fenóis/farmacologiaRESUMO
Pramipexole (PPX), a dopamine D2/3 receptor preferring agonist, is currently in use for the treatment of Parkinson's disease symptoms and restless legs syndrome. Recently, anti-inflammatory properties of PPX have been shown in an autoimmune model of multiple sclerosis, and case reports indicate PPX ameliorates depressive symptoms. Since peripheral inflammation is known to induce depression-like behavior in rodents, we assessed the potential antidepressant effect of PPX in an inflammatory model of depression induced by LPS. Repeated (daily for 7days, 1mg/kg, i.p.), but not acute (1h before LPS) treatment with PPX abolished the depression-like behavior induced by LPS (0.1mg/kg, i.p.) in the forced swim test, and the anhedonic behavior in the splash test. Interestingly, PPX per se decreased interleukin 1ß levels and reversed LPS-induced increase in its content in mice hippocampusâ Repeated PPX treatment also prevented the increase in hippocampal levels of the 3-nitrotyrosine protein adducts induced by LPS. Haloperidol (0.2mg/kg, i.p.) and sulpiride (50mg/kg, i.p.) were unable to prevent the antidepressant-like effect of PPX in LPS-treated mice. Altogether, these results suggest that the observed antidepressant-like effect of PPX in LPS-treated mice may be dependent on its anti-inflammatory properties and may not be related to dopamine D2 receptor activation.
Assuntos
Benzotiazóis/uso terapêutico , Depressão/tratamento farmacológico , Depressão/etiologia , Agonistas de Dopamina/uso terapêutico , Inflamação/complicações , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Comportamento de Doença/fisiologia , Inflamação/induzido quimicamente , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Lipopolissacarídeos/toxicidade , Locomoção/efeitos dos fármacos , Malondialdeído/metabolismo , Camundongos , Pramipexol , Natação/psicologia , Fatores de Tempo , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMO
The effect of 3ß-hidroxihop-22(29)ene (3-BHO) on insulin and glucagon-like peptide 1 (GLP-1) secretion as well as the mechanism of action of the compound in pancreatic islet on glucose homeostasis was investigated. The data from in vivo treatment show that 3-BHO significantly reduces the hyperglycemia by increasing the insulin and GLP-1 secretion, as well as by accumulating hepatic glycogen in hyperglycemic rats. In rat pancreatic ß-cell, 3-BHO stimulates the glucose uptake, insulin vesicles translocation to the plasma membrane and thus the insulin secretion through the involvement of potassium channels (ATP- and Ca(2+)-dependent K(+) channels) and calcium channels (L-type voltage-dependent calcium channels (L-VDCC)). Furthermore, this study also provides evidence for a crosstalk between intracellular high calcium concentration, PKA and PKC in the signal transduction of 3-BHO to stimulate insulin secretion. In conclusion, 3-BHO diminishes glycaemia, stimulates GLP-1 secretion and potentiates insulin secretion and increase hepatic glycogen content. Moreover, this triterpene modulates calcium influx characterizing ATP-K(+), Ca(2+)-K(+) and L-VDCC channels-dependent pathways as well as PKA and PKC activity in pancreatic islets underlying the signaling of 3-BHO for the secretory activity and contribution on glucose homeostasis.
Assuntos
Canais de Cálcio Tipo L/metabolismo , Peptídeo 1 Semelhante ao Glucagon/sangue , Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Canais KATP/metabolismo , Canais de Potássio Cálcio-Ativados/metabolismo , Triterpenos/farmacologia , Animais , Transporte Biológico , Cálcio/metabolismo , Canais de Cálcio Tipo L/genética , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulação da Expressão Gênica , Peptídeo 1 Semelhante ao Glucagon/genética , Glucose/metabolismo , Teste de Tolerância a Glucose , Glicogênio/metabolismo , Homeostase/genética , Humanos , Insulina/sangue , Secreção de Insulina , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Canais KATP/genética , Masculino , Canais de Potássio Cálcio-Ativados/genética , Proteína Quinase C/genética , Proteína Quinase C/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais , Técnicas de Cultura de TecidosRESUMO
BACKGROUND: This study was conducted to test whether the IBB Forelimb Scale (Irvine et al., 2010) which was originally developed for rats with spinal cord injury, is also capable of measuring the functional performance of Swiss mice with lesions of the median and ulnar nerves inflicted via crushing with standardized strength. NEW METHOD: This test was performed at days 1, 3, 7, 10, 14 and 21 after surgery and each animal gives a score of 9, where 0 represented the worst functionality and 9 represented the habitual behavior. RESULTS: The control animals usually exhibited movements in the task that were scored as 9 during the experimental period. The lesion group began with a score of 2 on the 1st and 3rd post-operative days. On the 7th and 10th postoperative days, respectively, they scored 7, and on the 14th post-operative day, they achieved a score of 8. Only on the 21st post-operative day, did they exhibit habitual skillful behaviors. COMPARISON WITH EXISTING METHOD(S): IBB Forelimb Scale is effective for determining how the animals perform the movements in detail, which is not readily revealed by other methods. Furthermore, this test show similar recovery periods with grasping test, staircase test and seems to be more sensitive than paw print analysis for this type of lesion. CONCLUSIONS: Our data demonstrate that IBB scale was capable of measuring gradual improvements in motor forelimb functions in this model and may be a new and effective assessment tool for peripheral nerve injury.
Assuntos
Avaliação da Deficiência , Membro Anterior , Nervo Mediano/lesões , Traumatismos dos Nervos Periféricos/diagnóstico , Recuperação de Função Fisiológica , Nervo Ulnar/lesões , Animais , Fenômenos Biomecânicos , Diagnóstico Diferencial , Modelos Animais de Doenças , Membro Anterior/fisiopatologia , Masculino , Camundongos , Destreza Motora/fisiologia , Traumatismos dos Nervos Periféricos/fisiopatologia , Distribuição Aleatória , Índice de Gravidade de Doença , Análise e Desempenho de Tarefas , Fatores de TempoRESUMO
OBJECTIVES: In this study, we evaluated the effect of the proanthocyanidins-rich fraction (PRF) obtained from Croton celtidifolius bark in an experimental animal model of spinal cord injury and cell death induced by glutamate. METHODS: Experiments were conducted using adult male Wistar rats (10 weeks old and weighing 270-300g). Experimental groups were randomly allocated into the following groups: spinal cord injury (SCI) + vehicle group: rats were subjected to SCI plus intraperitoneal administration of vehicle (saline 10 ml/kg); SCI + PRF: rats were subjected to SCI plus intraperitoneal administration of PRF (10 mg/kg) at 1 and 6 h after injury and sham operated. KEY FINDINGS: The treatment with the proanthocyanidin-rich fraction significantly improved not only motor recovery and grip force but also H2 O2 or glutamate-induced cell death and reactive oxygen species generation induced by glutamate in dorsal root ganglion cells. In this study we demonstrate that the neuroprotective effect triggered by the proanthocyanidins-rich fraction appears to be mediated in part by the inhibition of N-methyl-D-aspartate-type glutamate receptors. CONCLUSIONS: Taken together, our results demonstrate that PRF treatment ameliorates spinal cord injury and glutamatergic excitotoxicity and could have a potential therapeutic use.
Assuntos
Croton/química , Ácido Glutâmico/efeitos adversos , Fármacos Neuroprotetores/uso terapêutico , Fitoterapia , Proantocianidinas/uso terapêutico , Receptores de Glutamato/metabolismo , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Morte Celular/efeitos dos fármacos , Modelos Animais de Doenças , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Masculino , Movimento/efeitos dos fármacos , Força Muscular/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Casca de Planta , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Proantocianidinas/farmacologia , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Traumatismos da Medula Espinal/fisiopatologiaRESUMO
RATIONALE: There are evidences indicating the role of kinins in pathophysiology of traumatic brain injury, but little is known about their action on memory deficits. OBJECTIVES: Our aim was to establish the role of bradykinin receptors B1 (B1R) and B2 (B2R) on the behavioral, biochemical, and histologic features elicited by moderate lateral fluid percussion injury (mLFPI) in mice. METHODS: The role of kinin B1 and B2 receptors in brain damage, neuromotor, and cognitive deficits induced by mLFPI, was evaluated by means of subcutaneous injection of B2R antagonist (HOE-140; 1 or 10 nmol/kg) or B1R antagonist (des-Arg9-[Leu8]-bradykinin (DAL-Bk; 1 or 10 nmol/kg) 30 min and 24 h after brain injury. Brain damage was evaluated in the cortex, being considered as lesion volume, inflammatory, and oxidative damage. The open field and elevated plus maze tests were performed to exclude the nonspecific effects on object recognition memory test. RESULTS: Our data revealed that HOE-140 (10 nmol/kg) protected against memory impairment. This treatment attenuated the brain edema, interleukin-1ß, tumor necrosis factor-α, and nitric oxide metabolites content elicited by mLFPI. Accordingly, HOE-140 administration protected against the increase of nicotinamide adenine dinucleotide phosphate oxidase activity, thiobarbituric-acid-reactive species, protein carbonylation generation, and Na⺠K⺠ATPase inhibition induced by trauma. Histologic analysis showed that HOE-140 reduced lesion volume when analyzed 7 days after brain injury. CONCLUSIONS: This study suggests the involvement of the B2 receptor in memory deficits and brain damage caused by mLFPI in mice.
Assuntos
Bradicinina/análogos & derivados , Lesões Encefálicas/complicações , Lesões Encefálicas/tratamento farmacológico , Transtornos da Memória/etiologia , Transtornos da Memória/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Animais , Bradicinina/metabolismo , Bradicinina/farmacologia , Antagonistas de Receptor B1 da Bradicinina/farmacologia , Antagonistas de Receptor B2 da Bradicinina/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Edema Encefálico/etiologia , Edema Encefálico/metabolismo , Edema Encefálico/patologia , Edema Encefálico/prevenção & controle , Lesões Encefálicas/metabolismo , Lesões Encefálicas/patologia , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Camundongos , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , NADPH Oxidases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Reconhecimento Psicológico/efeitos dos fármacos , Reconhecimento Psicológico/fisiologia , Fatores de TempoRESUMO
The methylmalonic acidemia is an inborn error of metabolism (IEM) characterized by methylmalonic acid (MMA) accumulation in body fluids and tissues, causing neurological dysfunction, mitochondrial failure and oxidative stress. Although neurological evidence demonstrate that infection and/or inflammation mediators facilitate metabolic crises in patients, the involvement of neuroinflammatory processes in the neuropathology of this organic acidemia is not yet established. In this experimental study, we used newborn Wistar rats to induce a model of chronic acidemia via subcutaneous injections of methylmalonate (MMA, from 5th to 28th day of life, twice a day, ranged from 0.72 to 1.67 µmol/g as a function of animal age). In the following days (29th-31st) animal behavior was assessed in the object exploration test and elevated plus maze. It was performed differential cell and the number of neutrophils counting and interleukin-1 beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) levels in the blood, as well as levels of IL-1ß, TNF-α, inducible nitric oxide synthase (iNOS) and 3-nitrotyrosine (3-NT) in the cerebral cortex were measured. Behavioral tests showed that animals injected chronically with MMA have a reduction in the recognition index (R.I.) when the objects were arranged in a new configuration space, but do not exhibit anxiety-like behaviors. The blood of MMA-treated animals showed a decrease in the number of polymorphonuclear and neutrophils, and an increase in mononuclear and other cell types, as well as an increase of IL-1ß and TNF-α levels. Concomitantly, MMA increased levels of IL-1ß, TNF-α, and expression of iNOS and 3-NT in the cerebral cortex of rats. The overall results indicate that chronic administration of MMA increased pro-inflammatory markers in the cerebral cortex, reduced immune system defenses in blood, and coincide with the behavioral changes found in young rats. This leads to speculate that, through mechanisms not yet elucidated, the neuroinflammatory processes during critical periods of development may contribute to the progression of cognitive impairment in patients with methylmalonic acidemia.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/imunologia , Erros Inatos do Metabolismo dos Aminoácidos/psicologia , Córtex Cerebral/metabolismo , Mediadores da Inflamação/metabolismo , Transtornos da Memória/induzido quimicamente , Ácido Metilmalônico/toxicidade , Comportamento Espacial/efeitos dos fármacos , Erros Inatos do Metabolismo dos Aminoácidos/induzido quimicamente , Animais , Animais Recém-Nascidos , Biomarcadores/metabolismo , Córtex Cerebral/imunologia , Regulação da Expressão Gênica , Humanos , Interleucina-1beta/metabolismo , Ácido Metilmalônico/administração & dosagem , Neuroimunomodulação , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMO
Cells are endowed with several overlapping peroxide-degrading systems whose relative importance is a matter of debate. In this study, three different sources of neural cells (rat hippocampal slices, rat C6 glioma cells, and mouse N2a neuroblastoma cells) were used as models to understand the relative contributions of individual peroxide-degrading systems. After a pretreatment (30 min) with specific inhibitors, each system was challenged with either H2O2 or cumene hydroperoxide (CuOOH), both at 100 µM. Hippocampal slices, C6 cells, and N2a cells showed a decrease in the H2O2 decomposition rate (23-28%) by a pretreatment with the catalase inhibitor aminotriazole. The inhibition of glutathione reductase (GR) by BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) significantly decreased H2O2 and CuOOH decomposition rates (31-77%). Inhibition of catalase was not as effective as BCNU at decreasing cell viability (MTT assay) and cell permeability or at increasing DNA damage (comet test). Impairing the thioredoxin (Trx)-dependent peroxiredoxin (Prx) recycling by thioredoxin reductase (TrxR) inhibition with auranofin neither potentiated peroxide toxicity nor decreased the peroxide-decomposition rate. The results indicate that neural peroxidatic systems depending on Trx/TrxR for recycling are not as important as those depending on GSH/GR. Dimer formation, which leads to Prx2 inactivation, was observed in hippocampal slices and N2a cells treated with H2O2, but not in C6 cells. However, Prx-SO3 formation, another form of Prx inactivation, was observed in all neural cell types tested, indicating that redox-mediated signaling pathways can be modulated in neural cells. These differences in Prx2 dimerization suggest specific redox regulation mechanisms in glia-derived (C6) compared to neuron-derived (N2a) cells and hippocampal slices.
Assuntos
Catalase/metabolismo , Glutationa/metabolismo , Neurônios/metabolismo , Peróxidos/metabolismo , Peroxirredoxinas/metabolismo , Animais , Derivados de Benzeno/farmacologia , Catalase/antagonistas & inibidores , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Glutationa Redutase/antagonistas & inibidores , Glutationa Redutase/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Peróxido de Hidrogênio/farmacologia , Camundongos , Neurônios/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ratos , Ratos Wistar , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Tiorredoxina Dissulfeto Redutase/metabolismoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Pfaffia glomerata (Spreng) Pedersen (Amaranthaceae) is a medicinal plant known in Brazil as "Paratudo" and "Brazilian ginseng" and is commonly used as tonic, antidiabetic and to treat gastric disorders. AIM OF THE STUDY: This study evaluates the possible mechanism by which hydroalcoholic extract (HE) of Pfaffia glomerata exerts its antinociceptive effect. MATERIALS AND METHODS: The HE was evaluated in acetic acid and glutamate models of pain or by biting behavior following intrathecal (i.t.) administration of agonists of excitatory aminoacids (EAA) receptors glutamate and pro-inflammatory cytokines, IL-1beta and TNF-alpha in mice. RESULTS: Oral administration of HE produced dose-dependent inhibition of acetic acid-induced visceral pain and glutamate-induced pain, with ID(50) of 64.6 (47.7-87.5)mg/kg and ID(50) of 370.8 (253.4-542.7)mg/kg, respectively. The HE (300 mg/kg, p.o.) antinociception, in the acetic acid test, was not affected by i.p. treatment of animals with naloxone. In addition, HE (300 mg/kg, p.o.) inhibited the pain-related behaviors induced by i.t. injection of trans-ACPD and TNF-alpha, but not by NMDA, AMPA, kainate or IL-1beta. CONCLUSIONS: Our results suggest that inhibition of glutamatergic metabotropic receptors and TNF-alpha may account for the antinociceptive action reported for the HE in models of chemical pain used in this study.
Assuntos
Amaranthaceae , Analgésicos/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Dor/tratamento farmacológico , Fitoterapia , Extratos Vegetais/farmacologia , Ácido Acético , Analgésicos/uso terapêutico , Animais , Comportamento Animal/efeitos dos fármacos , Cicloleucina , Modelos Animais de Doenças , Agonistas de Aminoácidos Excitatórios , Feminino , Ácido Glutâmico/metabolismo , Injeções Espinhais , Interleucina-1beta , Camundongos , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Dor/induzido quimicamente , Dor/metabolismo , Extratos Vegetais/uso terapêutico , Raízes de Plantas , Fator de Necrose Tumoral alfa/antagonistas & inibidoresRESUMO
Methylmalonic acidemias consist of a group of inherited neurometabolic disorders caused by deficiency of methylmalonyl-CoA mutase activity clinically and biochemically characterized by neurological dysfunction, methylmalonic acid (MMA) accumulation, mitochondrial failure and increased reactive species production. Although previous studies have suggested that nitric oxide (NO) plays a role in the neurotoxicity of MMA, the involvement of NO-induced nitrosative damage from inducible nitric oxide synthase (iNOS) in MMA-induced seizures are poorly understood. In the present study, we showed a decrease of time spent convulsing induced by intracerebroventricular administration of MMA (2 micromol/2 microL; i.c.v.) in iNOS knockout (iNOS(-/-)) mice when compared with wild-type (iNOS(+/+)) littermates. Visual analysis of electroencephalographic recordings (EEG) showed that MMA injection induced the appearance of high-voltage synchronic spike activity in the ipsilateral cortex which spreads to the contralateral cortex while quantitative electroencephalographic analysis showed larger wave amplitude during MMA-induced seizures in wild-type mice when compared with iNOS knockout mice. We also report that administration of MMA increases NOx (NO(2) plus NO(3) content) and 3-nitrotyrosine (3-NT) levels in a greater extend in iNOS(+/+) mice than in iNOS(-/-) mice, indicating that NO overproduction and NO-mediated damage to proteins are attenuated in iNOS knockout mice. In addition, the MMA-induced decrease in Na(+), K(+)-ATPase activity, but not in succinate dehydrogenase (SDH) activity, was less pronounced in iNOS(-/-) when compared with iNOS(+/+) mice. These results reinforce the assumption that metabolic collapse contributes for the secondary toxicity elicited by MMA and suggest that oxidative attack by NO derived from iNOS on selected target such as Na(+), K(+)-ATPase enzyme might represent an important role in this excitotoxicity induced by MMA. Therefore, these results may be of value in understating the pathophysiology of the neurological features observed in patients with methylmalonic acidemia and in the development of new strategies for treatment of these patients.