17 resultados para efeito proteína
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Analisar se o pré-tratamento com sinvastatina em modelo experimental de sepse abdominal é benéfico em ratos diabéticos. Métodos: Cinquenta e seis ratos Wistar foram aleatoriamente distribuídos em: grupo não diabético (n-28) e grupo diabetes induzido por estreptozotocina (n=28). Sepse abdominal por ligadura e punção do ceco foi induzida em 14 ratos diabéticos e em 14 não diabéticos. Os demais 28 animais foram alocados em grupo sham. Os grupos de ratos com sepse e os sham (cada com sete animais) foram tratados com microemulsão oral de simvastatina (20 mg kg-1 day-1) e solução salina 0,9%, respectivamente. Sangue periférico foi usado para dosagem de TNFa, IL-1b, IL-6, proteína C reativa, procalcitonina, contagem de leucócitos e neutrófilos em todos os animais. A análise estatística foi realizada pela ANOVA e teste de Tukey, com p<0,05. Resultados: A sinvastatina reduziu a mortalidade nos ratos diabéticos. Os valores séricos de TNF-a, IL-1b, IL-6, proteína C reativa, procalcitonina, leucócitos e neutrófilos mostraram-se mais baixos nos ratos diabéticos e não diabéticos com sepse, tratados com sinvastatina, do que nos tratados com solução salina. Conclusão: A sinvastatina teve efeito antiinflamatório, que pode ter resultado em proteção contra a sepse em ratos diabéticos
Resumo:
Linseed is an important oilseed consumed raw as nutritional supplement, that although represents a rich source of nutrients, its nutritional value could be impaired due to the presence of antinutritional factors. In this study, protein fractions from raw linseed flour were extracted and isolated being obtained 12% of albumins, 82% of globulins, 5% of glutelins and 1% of prolamins. These proteins were visualized by SDS-PAGE and albumins showed low molecular mass protein bands around 21 kDa and minor bands, similar to that of trypsin inhibitor; Globulins presented protein bands with high molecular masses, which possibly are constituents of multimeric proteins, such as legumins. After determination of the centesimal composition of raw linseed, it was used as exclusive protein source for young rats to evaluate its effect on animal growth. The results showed negative effects on rat growth (weight gain 73% less than the control group) and reduction of intestinal villus (35%), that could be related with in vitro and in vivo globulin digestibility and proteinaceous antinutritional factors (mammalian digestive enzymes inhibitors and lectins) in albumin fraction. Native globulins showed, by SDS-PAGE, low susceptibility in vitro to trypsin and chymotrypsin, however presented high degradation by pancreatin. Thermal treatment of globulins for 5 and 15 minutes at 100ºC improved considerably its digestibility by trypsin and pancreatin. Globulins presented 93.2% in vivo digestibility, similar to the control protein. Albumin fraction had high trypsin inhibition activity (100%) and chymotrypsin inhibition of 28.3%; haemagglutinating activity was not detected. The results of this study indicate the negative action of trypsin inhibitors on animal growth, but can not be discarded its combined action with other antinutritional factors, which could compromise the raw linseed utilization as an alternative food
Resumo:
In this study, a BCR-ABL expressing human chronic myelogenous leukaemia cell line (K562) was used to investigate the antitumoral potential of a novel lectin (CvL) purified from the marine sponge Cliona varians. CvL inhibited the growth of K562 cells with an IC50 value of 70 g/ml, but was ineffective to normal human peripheral blood lymphocytes in the same range of concentrations tested (180 g/ml). Cell death occurred after 72 h of exposure to the lectin and with sign of apoptosis as analysed by DAPI staining. Investigation of the possible effectors of this process showed that cell death occurred in the presence of Bcl-2 and Bax expression, and involved a caspase-independent pathway. Confocal fluorescence microscopy indicated a major role for the lysosomal protease cathepsin B in mediating cell death. Accordingly, pre-incubation of K562 cells with the cathepsin inhibitor L-trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E-64) abolished the cytotoxic effect of CvL. Furthermore, we found upregulation of tumor necrosis factor receptor 1 (TNFR1) and down-modulation of p65 subunit of nuclear factor kappa B (NFB) expression in CvL-treated cells. These effects were accompanied by increased levels of p21 and downmodulation of pRb, suggesting that CvL is capable of cell cycle arrest. Collectively, these findings suggest that cathepsin B acts as death mediator in CvL-induced cytotoxicity possibly in a still uncharacterized connection with the membrane death receptor pathway
Resumo:
Vitamin A is important in many essential body processes and its deficiency results in serious consequences for human health. Breast milk is the only source of this vitamin for children that are exclusively breastfed. Analysis of vitamin A in mother s milk is important because its concentration is related to maternal vitamin A status and to its ingestion by the mother during pregnancy. The aim of the present study was to assess the effect of maternal supplementation with retynil palmitate on the concentration of colostrum retinol under fasting and postprandial conditions. A total of 149 nursing mothers were recruited at the Januário Cicco Maternity School (Natal, Brazil) and allocated to two groups: Comparison (n = 69) and Test (n = 80). Blood and colostrum (in fasting and postprandial conditions) samples were collected up to 24hs after delivery. Serum retinol and colostrum levels were analyzed by high-performance liquid chromatography. The serum retinol level of 41.6 ± 12.7μg/dL (mean ± standard deviation) indicates adequate biochemical nutritional status. Colostrum retinol level was not influenced by serum retinol levels under any of the conditions established. In the colostrum, the retinol concentration in the unsupplemented test group was 67.3 ± 37.7 μg/dL under fasting and 80.3 ± 35.1 μg/dL under postprandial conditions (p<0.05), showing an increase of 19.3%. In the supplemented test group the values were 102.6 ± 57.3 μg/dL and 133.4 ± 78.3 μg/dL under fasting and postprandial, respectively (p<0.05), representing an increase of 30%. Considering that under fasting conditions most of the vitamin A transported to the milk originates in the retinol binding protein (RBP), the postprandial increase in colostrum retinol suggests a different transport mechanism of retinol to maternal milk from that performed by RBP. This situation becomes more evident under supplementation conditions.
Resumo:
Globulins fractions of legume seeds of Crotalaria pallida, Erytrina veluntina and Enterolobium contortisiliquum were isolated and submitted to assays against serine, cysteine and aspartic proteinases, as also amylase present in midgut of C. maculatus and Z. subfasciatus. Hemagglutination assays indicated presence of a lectin in E. veluntina globulin fractions. This lectin had affinity to human erythrocytes type A, B and O. Vicilins were purified by chromatography on Sephacryl S-300 followed of a chromatography on Sephacryl S-200, which was calibrated using protein markers. Vicilins from C. pallida (CpV) and E. veluntina (EvV) seeds had a molecular mass of 124.6 kDa and E. contortisiliquum a molecular mass of 151kDa. Eletrophoresis in presence of SDS showed that CpV was constituted by four subunities with apparent molecular mass of 66, 63, 57 and 45 kDa, EvV with three subunities with apparent molecular mass of 45kDa and EcV four subunities, two with 37.1 kDa and two with 25.8 kDa. Non denaturantig eletrophoresis displayed single bands with high homogeneity, where CpV had lower acidic behavior. All vicilins are glycoproteins with carbohydrate contents at 1 to1.5%. Bioassays were done to detect deleterious effects of vicilins against C. maculatus and Z. subfasciatus larvae. CpV, EvV and EcV exhibited a WD50 of 0.28, 0.19 and 1.03%; LD50 0.2, 0.26, and 1.11% respectively to C. maculatus. The dose responses of CpV, EvV and EcV to Z. subfasciatus were: WD50 of 0.12, 0.14, 0.65% and LD50 of 0.09, 0.1, and 0.43% respectively. The mechanism of action of these proteins to bruchids should be based on their properties of bind to chitin present in mid gut of larvae associated with the low digestibility of vicilin. In assays against phytopatogenous fungus, only EcV was capable of inhibit F. solani growth at concentrations of 10 and 20 µg and its action mechanism should be also based in the affinity of EcV to chitin present in the fungi wall
Resumo:
Despite advances in antibiotic therapy, bacterial meningitis (BM) remains with high mortality and morbidity rates in worldwide. One important mechanism associated to sequels during disease is the intense inflammatory response which promotes an oxidative burst and release of reactive oxygen species, consequently leading to cell death. Activation of DNA repair enzymes during oxidative stress has been demonstrated in several neurological disorders. APE1/Ref-1 is a multifunctional protein involved in DNA repair and plays a redox function on transcription factors such as NFkB and AP-1.The aim of this study was assess the role of APE1/Ref-1 on inflammatory response and the possibility of its modulation to reduce the sequels of the disease. Firstly it was performed an assay to measure cytokine in cerebrospinal fluid of patients with BM due to Streptococcus pneumoniae and Neisseriae meningitides. Further, a cellular model of inflammation was used to observe the effect of the inhibition of the endonuclease and redox activity of APE1/Ref-1 on cytokine levels. Additionally, APE1/Ref-1 expression in cortex and hippocampus of rat with MB after vitamin B6 treatment was evaluated. Altogether, results showed a similar profile of cytokines in the cerebrospinal fluid of patients from both pathogens, although IFNy showed higher expression in patients with BM caused by S. pneumoniae. On the other hand, inhibitors of APE1/Ref-1 reduced cytokine levels, mainly TNF-α. Reduction of oxidative stress markers was also observed after introduction of inhibitors in the LPS-stimulated cell. In the animal model, BM increased the expression of the protein APE1/Ref-1, while vitamin B6 promoted reduction. Thereby, this data rise important factors to be considered in pathogenesis of BM, e.g., IFNy can be used as prognostic factor during corticosteroid therapy, APE1/Ref-1 can be an important target to modulate the level of inflammation and VIII oxidative stress, and vitamin B6 seems modulates several proteins related to cell death. So, this study highlights a new understanding on the role of APE1/Ref-1 on the inflammation and the oxidative stress during inflammation condition
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Resumo:
Alpha-lipoic acid (ALA) is a potent antioxidant with favourable anti-inflammatory, metabolic and endothelial effects, and has been widely investigated due to its potential against cardiovascular risk factors. This study aimed to evaluate the effect of oral ALA supplementation on oxidative stress biomarkers, inflammation and cardiovascular risk factors in patients with hypertension. This is a double-blind placebo-controlled randomized clinical trial, where the intervention was evaluated prospectively comparing results in both groups. The sample consisted of 64 hypertensive patients who were randomly distributed into ALA group (n = 32), receiving 600 mg / day ALA for twelve weeks and control group (n = 32), receiving placebo for the same period. The following parameters were evaluated before and after intervention: lipid peroxidation, content of reduced glutathione (GSH), enzymatic activities of glutathione peroxidase (GPx) and superoxide dismustase, ultrasensitive C-reactive protein (hs-CRP), triglycerides, total cholesterol and fractions, fasting glucose and anthropometric indicators. There was a statistically significant reduction (p <0.05) in serum concentrations of total cholesterol, very low density lipoprotein (VLDL), high density lipoprotein (HDL), triglycerides and blood glucose. There was a reduction in body weight and waist, abdominal and hip circumferences in the group that received ALA. In addition, there was a statistically significant increase (p <0.05) in the contents of reduced glutathione (GSH) and glutathione peroxidase (GPx) in the group receiving ALA. Oral administration of ALA appears to be a valuable adjuvant therapy, which may contribute to decrease the damage caused by oxidative stress and other risk factors associated with the atherosclerotic process
Resumo:
The cashew, a fruit from Brazilian Northeast is used to produce juice due to its flavor and vitamin C richness. However, its acceptance is limited due to its astringency. Cajuína is a derivate product appreciated by its characteristic flavor, freshness and lack of astringency, due to tannin removal. Cajuína is a light yellow beverage made from clarified cashew juice and sterilized after bottling. It differs from the integral and concentrated juice by the clarification and thermal treatment steps. Many problems such as haze and excessive browning could appear if these steps are not controlled. The objective of this work was divided into two stages with the aim to supply process information in order to obtain a good quality product with uniform characteristics (sensory and nutritional). Polyphenol-protein interaction was studied at the clarification step, which is an empirical process, to provide values on the amount of clarifying solution (gelatin) that must be added to achieve a complete juice clarification. Clarification essays were performed with juice dilutions of 1:2 and 1:10 and the effect of metabissulfite and tannic acid addition was evaluated. It was not possible to establish a clarification point. Metabissulfite did not influenced the clarification process however tannic acid addition displaced the clarification point, showing the difficulty visual monitoring of the process. Thermal treatment of clarified juice was studied at 88, 100, 111 e 121 °C. To evaluate the non-enzymatic browning, vitamin C, 5-hidroximetilfurfural (5-HMF) and sugar variation were correlated with color parameters (reflectance spectra, color difference and CIELAB). Kinetic models were obtained for reflectance spectra, ascorbic acid and 5-HMF. It was observed that 5-HMF introduction followed a first order kinetic rate at the beginning of the thermal treatment and a zero order kinetic at later process stages. An inverse correlation was observed between absorbance at 420 nm and ascorbic acid degradation, which indicates that ascorbic acid might be the principal factor on cajuína non-enzymatic browning. Constant sugar concentration showed that this parameter did not contribute directly to the nonenzymatic browning. Optimization techniques showed showed that to obtain a high vitamin C and a low 5-HMF content, the process must be done at 120 ºC. With the water-bath thermal treatment, the 90 °C temperature promoted a lower ascorbic acid degradation at the expense of a higher 5-HMF level
Resumo:
Neuropeptide S (NPS) is an endogenous 20-aminoacid peptide which binds a G protein-coupled receptor named NPSR. This peptidergic system is involved in the modulation of several biological functions, such as locomotion, anxiety, nociception, food intake and motivational behaviors. Studies have shown the participation of NPSR receptors in mediating the hyperlocomotor effects of NPS. A growing body of evidence suggests the participation of adenosinergic, dopaminergic and CRF systems on the hyperlocomotor effects of NPS. Considering that little is known about the role of dopaminergic system in mediating NPS-induced hyperlocomotion, the present study aims to investigate the locomotor actions of intracerebroventricular (icv) NPS in mice pretreated with α-metil-p-tirosine (AMPT, inhibitor of dopamine synthesis), reserpine (inhibitor of dopamine vesicle storage) or sulpiride (D2 receptor antagonist) in the open field test. A distinct group of animals received the same pretreatments described above (AMPT, reserpine or sulpiride) and the hyperlocomotor effects of methylphenidate (dopamine reuptake inhibitor) were investigated in the open field. NPS and methylphenidate increased the mouse locomotor activity. AMPT per se did not change the locomotion of the animals, but it partially reduced the hyperlocomotion of methylphenidate. The pretreatment with AMPT did not affect the psychostimulant effects of NPS. Both reserpine and sulpiride inhibited the stimulatory actions of NPS and methylphenidate. These findings show that the hyperlocomotor effects of methylphenidate, but not NPS, were affected by the pretreatment with AMPT. Furthermore, methylphenidate- and NPS-induced hyperlocomotion was impaired by reserpine and sulpiride pretreatments. Together, data suggests that NPS can increase locomotion even when the synthesis of catecholamines was impaired. Additionally, the hyperlocomotor effects of NPS and methylphenidate depend on monoamines vesicular storaged, mainly dopamine, and on the activation of D2 receptors. The psychostimulant effects of NPS via activation of dopaminergic system display clinical significance on the treatment of diseases which involves dopaminergic pathways, such as Parkinson s disease and drug addiction
Resumo:
Base excision repair (BER) proteins has been associated with functions beyond DNA repair. Apurynic/apyrimidinic endonuclease 1 (APE1) is a multifunctional protein involved in a plethora of cellular activities, such as redox activation of transcription factors, RNA processing and DNA repair. Some studies have described the action of the protein 8-oxoguanine (OGG1) in correcting oxidized lesions in promoters as a step in the transcription of pro-inflammatory cytokines. Despite being especially important in redox activation of transcription factors such as nuclear factor κB (NF-κB) and AP- 1, the repair activity of APE1 has not yet been associated with the inflammatory response. In this study, experimental and bioinformatic analysis approaches have been used to investigate the relationship between inhibition of the repair of abasic sites in DNA by MX, a synthetic molecule designed to inhibt the repair activity of APE1, and the modulation of the inflammatory response. The results showed that treatment of monocytes with lipopolysaccharide (LPS) and MX reduced the expression of cytokines, chemokines and toll-like receptors, and negatively regulated biological immune processes, as macrophages activation, and NF-κB and tumor necrosis factor (TNF-α) and interferon pathways, without inducing cell death. The transcriptomic analysis suggests that LPS/MX treatment induces mitochondrial dysfunction, endoplasmic reticulum stress and activation of autophagy pathways, probably activated by impairment of cellular energy and/or the accumulation of nuclear and mitochondria DNA damage. Additionally, it is proposed that the repair activity of APE1 is required for transcription of inflammatory genes by interaction with abasic sites at specific promoters and recruitment of transcriptional complexes during inflammatory signaling. This work presents a new perspective on the interactions between the BER activity and the modulation of inflammatory response, and suggests a new activity for APE1 protein as modulator of the immune response in a redox-independent manner.
Resumo:
Analisar se o pré-tratamento com sinvastatina em modelo experimental de sepse abdominal é benéfico em ratos diabéticos. Métodos: Cinquenta e seis ratos Wistar foram aleatoriamente distribuídos em: grupo não diabético (n-28) e grupo diabetes induzido por estreptozotocina (n=28). Sepse abdominal por ligadura e punção do ceco foi induzida em 14 ratos diabéticos e em 14 não diabéticos. Os demais 28 animais foram alocados em grupo sham. Os grupos de ratos com sepse e os sham (cada com sete animais) foram tratados com microemulsão oral de simvastatina (20 mg kg-1 day-1) e solução salina 0,9%, respectivamente. Sangue periférico foi usado para dosagem de TNFa, IL-1b, IL-6, proteína C reativa, procalcitonina, contagem de leucócitos e neutrófilos em todos os animais. A análise estatística foi realizada pela ANOVA e teste de Tukey, com p<0,05. Resultados: A sinvastatina reduziu a mortalidade nos ratos diabéticos. Os valores séricos de TNF-a, IL-1b, IL-6, proteína C reativa, procalcitonina, leucócitos e neutrófilos mostraram-se mais baixos nos ratos diabéticos e não diabéticos com sepse, tratados com sinvastatina, do que nos tratados com solução salina. Conclusão: A sinvastatina teve efeito antiinflamatório, que pode ter resultado em proteção contra a sepse em ratos diabéticos
Resumo:
Linseed is an important oilseed consumed raw as nutritional supplement, that although represents a rich source of nutrients, its nutritional value could be impaired due to the presence of antinutritional factors. In this study, protein fractions from raw linseed flour were extracted and isolated being obtained 12% of albumins, 82% of globulins, 5% of glutelins and 1% of prolamins. These proteins were visualized by SDS-PAGE and albumins showed low molecular mass protein bands around 21 kDa and minor bands, similar to that of trypsin inhibitor; Globulins presented protein bands with high molecular masses, which possibly are constituents of multimeric proteins, such as legumins. After determination of the centesimal composition of raw linseed, it was used as exclusive protein source for young rats to evaluate its effect on animal growth. The results showed negative effects on rat growth (weight gain 73% less than the control group) and reduction of intestinal villus (35%), that could be related with in vitro and in vivo globulin digestibility and proteinaceous antinutritional factors (mammalian digestive enzymes inhibitors and lectins) in albumin fraction. Native globulins showed, by SDS-PAGE, low susceptibility in vitro to trypsin and chymotrypsin, however presented high degradation by pancreatin. Thermal treatment of globulins for 5 and 15 minutes at 100ºC improved considerably its digestibility by trypsin and pancreatin. Globulins presented 93.2% in vivo digestibility, similar to the control protein. Albumin fraction had high trypsin inhibition activity (100%) and chymotrypsin inhibition of 28.3%; haemagglutinating activity was not detected. The results of this study indicate the negative action of trypsin inhibitors on animal growth, but can not be discarded its combined action with other antinutritional factors, which could compromise the raw linseed utilization as an alternative food
Resumo:
In this study, a BCR-ABL expressing human chronic myelogenous leukaemia cell line (K562) was used to investigate the antitumoral potential of a novel lectin (CvL) purified from the marine sponge Cliona varians. CvL inhibited the growth of K562 cells with an IC50 value of 70 g/ml, but was ineffective to normal human peripheral blood lymphocytes in the same range of concentrations tested (180 g/ml). Cell death occurred after 72 h of exposure to the lectin and with sign of apoptosis as analysed by DAPI staining. Investigation of the possible effectors of this process showed that cell death occurred in the presence of Bcl-2 and Bax expression, and involved a caspase-independent pathway. Confocal fluorescence microscopy indicated a major role for the lysosomal protease cathepsin B in mediating cell death. Accordingly, pre-incubation of K562 cells with the cathepsin inhibitor L-trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane (E-64) abolished the cytotoxic effect of CvL. Furthermore, we found upregulation of tumor necrosis factor receptor 1 (TNFR1) and down-modulation of p65 subunit of nuclear factor kappa B (NFB) expression in CvL-treated cells. These effects were accompanied by increased levels of p21 and downmodulation of pRb, suggesting that CvL is capable of cell cycle arrest. Collectively, these findings suggest that cathepsin B acts as death mediator in CvL-induced cytotoxicity possibly in a still uncharacterized connection with the membrane death receptor pathway
Resumo:
Vitamin A is important in many essential body processes and its deficiency results in serious consequences for human health. Breast milk is the only source of this vitamin for children that are exclusively breastfed. Analysis of vitamin A in mother s milk is important because its concentration is related to maternal vitamin A status and to its ingestion by the mother during pregnancy. The aim of the present study was to assess the effect of maternal supplementation with retynil palmitate on the concentration of colostrum retinol under fasting and postprandial conditions. A total of 149 nursing mothers were recruited at the Januário Cicco Maternity School (Natal, Brazil) and allocated to two groups: Comparison (n = 69) and Test (n = 80). Blood and colostrum (in fasting and postprandial conditions) samples were collected up to 24hs after delivery. Serum retinol and colostrum levels were analyzed by high-performance liquid chromatography. The serum retinol level of 41.6 ± 12.7μg/dL (mean ± standard deviation) indicates adequate biochemical nutritional status. Colostrum retinol level was not influenced by serum retinol levels under any of the conditions established. In the colostrum, the retinol concentration in the unsupplemented test group was 67.3 ± 37.7 μg/dL under fasting and 80.3 ± 35.1 μg/dL under postprandial conditions (p<0.05), showing an increase of 19.3%. In the supplemented test group the values were 102.6 ± 57.3 μg/dL and 133.4 ± 78.3 μg/dL under fasting and postprandial, respectively (p<0.05), representing an increase of 30%. Considering that under fasting conditions most of the vitamin A transported to the milk originates in the retinol binding protein (RBP), the postprandial increase in colostrum retinol suggests a different transport mechanism of retinol to maternal milk from that performed by RBP. This situation becomes more evident under supplementation conditions.