01. Universidade Federal Rural de Pernambuco - UFRPE (Sede)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/1
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Resultados da Pesquisa
Item Investigação do extrato de cladódios de Cereus jamacaru quanto à composição química, potencial antimicrobiano contra Staphylococcus aureus e efeito larvicida para Aedes aegypti(2023-09-21) Guimarães, Júlia Maria Rodrigues; Pontual, Emmanuel Viana; Alves, João Victor de Oliveira; http://lattes.cnpq.br/0882174483226946; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/3701748857935689Cereus jamacaru (Cactaceae), mandacaru, is a plant from the Brazilian semi-arid region that has economic importance for livestock farming and use in folk medicine. The use of currently commercialized antibiotics leads to many unwanted effects and has led to the emergence of resistant bacteria, while synthetic insecticides generally have high persistence in the environment and strong non-target toxicity. In this sense, the search for new antimicrobial agents and insecticides has grown. The aim of this work was to investigate the cladode extract of C. jamacaru regarding its chemical composition (presence of lectins, protease inhibitors and secondary metabolites), antimicrobial potential against pathogenic bacteria and larvicidal effect against Aedes aegypti. Cladodes of C. jamacaru were collected in Recife, Pernambuco. The spines were removed and the cladodes were cut into slices and air-dried (28°C, 4 days). Then, the cladodes were crushed and the powder (10 g) was homogenized (28°C, 16 h) with 0.15 M NaCl solution (100 mL) in water, using a magnetic stirrer. The mixture was filtered and centrifuged (3,000 g, 15 min) and the clear supernatant corresponded to cladode extract (CjCE) which was investigated for the presence of lectins using rabbit erythrocytes, protease inhibitor using bovine trypsin (0.1 mg/ mL) and the chromogenic and peptidomimetic substrate BApNA (8 mM), and secondary metabolites by thin layer chromatography. The content of phenolic compounds in CjCE was determined using the Folin-Ciocalteu reagent (10%, v/v) and a gallic acid standard curve, while flavonoids were quantified using the aluminum chloride reagent (20%, m/v) and quercetin as standard. Then, the extract was investigated for antioxidant activity using the DPPH, ABTS and Phosphomolybdenum methods. The antibacterial potential of CjCE was determined using bacterial strains sensitive or resistant to antibiotics by the plate microdilution method. The minimum inhibitory concentration (MIC, lowest concentration of CjCE capable of inhibiting bacterial growth by 50%) was determined. Hemolysis assay by S. aureus was performed using human erythrocytes and the effect of CjCE (128, 64 and 32 µg/mL) on hemolysis was investigated. The larvicidal potential of CjCE (0.40 to 3.5%, m/v) was evaluated by treatment (48 h) of A. aegypti larvae in the third instar (L3). CjCE caused agglutination of rabbit erythrocytes (8 UAH), suggesting the presence of lectins. The extract reduced the hydrolysis of the BApNA substrate by trypsin, indicating the presence of a protease inhibitor. CjCE thin layer chromatography revealed the presence of reducing sugars and qualitative-quantitative analysis showed 40.20±0.97 mgEAG/g of total phenols, among which, 3.36±0.07 mgEAG/g (8, 36%) were flavonoids. CjCE showed relevant oxidant activity, with the ability to scavenge ABTS and DPPH radicals (IC50 of 3,735 µg/mL and 2704.50 µg/mL, respectively), but was not able to cause reduction of phosphomolybdenum. CjCE was toxic only to the Staphylococcus aureus strain (UFPEDA 02), revealing a strong bacteriostatic effect (MIC of 199.09±0.85 µg/mL), and reduced erythrocyte lysis caused by the bacteria by more than 90%, compared to to control. The treatment of L3 of Ae. aegypti with CjCE resulted in dose-dependent mortality (LC50 = 0.68%, m/v). On the other hand, when larvae were treated with CjCE at a concentration 10 times higher than the LC50, the intestinal contents covered by the peritrophic membrane were eliminated in an attempt to eliminate the toxic components of the extract. In conclusion, C. jamacaru cladode extract is a novel antimicrobial agent capable of strongly inhibiting the growth of S. aureus and reducing bacterial toxicity to human erythrocytes. Furthermore, the toxicity to A. aegypti larvae shown here points to the C. jamacaru cladode extract as an interesting starting material for obtaining larvicidal formulations. The antibacterial and insecticidal effects of the extract may be linked to the presence of lectins, protease inhibitors and phenolic compounds.Item Caracterização eletroquímica das interaçôes da lectina de sementes de Cratylia mollis (Cramoll) com glicose e eritrócitos de coelho em biossensor de MOF de [Cu3(BTC)2.(H2O)3]n(2022-05-31) Carvalho, Maryana Hermínio de; Coelho, Luana Cassandra Breitenbach Barroso; Freitas, Kátia Cristina Silva de; http://lattes.cnpq.br/5859266863241551; http://lattes.cnpq.br/2944428818449047; http://lattes.cnpq.br/0134945103585503Biosensors are small devices known for their selectivity, high specificity and sensitivity with the respective analyte even at low concentrations. Thus, we aimed to evaluate the charge transfer and electrochemical potential of the plant popularly known as camaratu bean, a forage native to the Caatinga biome, rich in shrub legumes, from which Cramoll lectin is extracted from Cratylia mollis Mart. electrochemical biosensor using the crystalline polymer MOF- [Cu3(BTC)2.(H2O)3]n.. to immobilize and characterize the physical and chemical properties of C. mollis (Cramoll) seed lectin and its interaction with free carbohydrates (glu-cose) and carbohydrates on the surface of rabbit erythrocytes. Lectin immobilization in MOF was effective for the construction of the electrochemical system, showing itself to be sensi-tive to conformational changes, being able to detect changes in the electrochemical poten-tials of Cramoll promoted in a buffered medium (200 mM potassium phosphate buffer, pH 7.0) with different glucose concentrations, highlighting the concentrations of 10 mM (96 - 121 mV), 15 mM (110 - 126 mV) and 20 mM (107 - 142 mV) in the time of 5 to 30 min. In the cyclic voltammetry, the interaction in the potential range from -0.2 to 0.0 V stood out; with the current reaching 0.0003 A and at peak 2 in the potential range of 0.4 to 0.5 V; with the current reaching 0.0007 A. The interaction of the carbohydrate present on the surface of the rabbit erythrocyte was also monitored by the potentiometric method, detecting changes in the Cramoll-glucose potentials, even in the presence of rabbit erythrocytes. Through SEM, it was possible to observe Cramoll immobilized on the MOF surface, proving the specificity of the ligand (glucose-lectin) through the morphological changes of this protein in this process. This electrochemical model, Cramoll/MOF biosensor, is effective for evalu-ating free lectin/carbohydrate or in the erythrocyte membrane.Item Sistemas eletroquímicos para tratar amostras de água contendo corante têxtil como ferramenta didática para divulgação da poluição hídrica(2021-07-07) Neves, Eloisa Ferreira; Freitas, Kátia Cristina Silva de; http://lattes.cnpq.br/5859266863241551; http://lattes.cnpq.br/9764373408949634Didactic workshops for scientific and technological dissemination, in addition to contributing to motivational aspects for the development of learning, are an interactive strategy that can provide the development of science learning. This research aims to use electrochemical systems to characterize the physicochemical properties of the coagulant lectin from Moringa oleifera seeds (cMoL) in the treatment of water samples containing indigo-type textile dyes as teaching tools for scientific dissemination about water pollution in effluents from the textile industry. The methodological development of this research comprises the development of aluminum piles using aluminum cans and PET bottles for the treatment of indigo-type dye solution; the determination of electrochemical potentials and cyclic voltammograms generated by the agglutination of cMoL immobilized on the MOF with an aqueous solution of indigo carmine dye; the development of potentiometric biosensors for the determination of indigo dye residues in aqueous media. Considerable differences were observed in the electrochemical potentials in relation to the platinum electrode (Pt), MOF coated platinum working electrode (Pt/MOF), MOF coated platinum electrode and immobilized cMoL (Pt/MOF/cMoL) and when interacting Pt /MOF/cMoL with different concentrations of galactose. Cyclic voltammetry showed results with significant differences between the untreated dye sample and the dye samples after treatment. The development of didactic workshops in school spaces to validate the electrochemical system as a didactic tool applied to learning and dissemination about water pollution caused by the disposal of indigo dyes in textile industry effluents is relevant for the construction of concepts related to electrochemistry.Item Investigação do potencial antibiofilme da lectina de folhas de Schinus terebinthifolia Raddi contra Staphylococcus aureus(2019-12-20) Silva, Talyta Naldeska da; Pontual, Emmanuel Viana; Silva, Pollyanna Michelle da; http://lattes.cnpq.br/0563176148137978; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/8762925956752737Biofilms are complex microbial communities that have been associated with the incidence of infections, including in the hospital environment. Its formation is considered a determining factor for virulence in microorganisms and strongly contributes with the microbial resistance to conventional antimicrobials. In this sense, the search for natural compounds with antimicrobial activity that are more effective and less toxic to host cells. Plants are important sources of bioactive compounds, including lectins, a class of carbohydrate-binding proteins whose antimicrobial action has been reported. SteLL is a leaf lectin isolated from Schinus terebinthifolia Raddi (Anacardiaceae) with antimicrobial action that was previously reported. In this work, the antibacterial and antibiofilm potential of SteLL against sensitive (UFPEDA 02) and oxacillin resistant (UFPEDA 670) isolates of Staphylococcus aureus was evaluated. SteLL was a bacteriostatic and bactericidal agent against UFPEDA 02 and UFPEDA 670 isolates with MIC50 (Minimum Inhibitory Concentration) of 12.5 and 25.0 μg/mL and CMB (Minimum Bactericidal Concentration) of 50.0 and 100 μg/mL, respectively. The growth kinetics of the cells treated with SteLL revealed a dose-dependent growth inhibition regarding to control. SteLL caused morphometric alterations in S. aureus cells and inhibited biofilm formation of UFPEDA 02 at concentrations between 400 and 25.0 μg/mL and UFPEDA 670 between 400 and 100 μg/mL. In conclusion, SteLL is an antibacterial agent against Staphylococcus aureus by inhibiting the growth, promoting cell death and inhibiting bacterial biofilm formation.Item Efeito da lectina de folhas de Schinus terebinthifolia sobre a formação de vasos do saco vitelínico e morfologia de embriões de Coturnix japônica(2019-08-13) França, Rayssa Perla Martins; Pontual, Emmanuel Viana; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/4999755464041290Angiogenesis corresponds to the budding of new blood vessels starting from other preexisting ones. This process is of great importance for development of tumor cells. Schinus terebinthifolia (Brazilian Peppertree) leaves express a thermostable and antimicrobial lectin (SteLL). This work reports the effect of SteLL on the angiogenesis process using the in vivo model of yolk sac membrane of Coturnix japonica (Japanese quail) embryos. The fractal analysis by box counting and information dimension indicated that SteLL at 1.35 mg/mL reduced the angiogenesis of C. japonica yolk sac membrane. The inhibition of the vascular network formation in the yolk sac membrane resulted in decreased blood supply to the embryos, and consequently area, perimeter and percentage of cephalic length of embryos were significantly reduced in the group treated with SteLL, corroborating with the antiangiogenic activity. In conclusion, SteLL is an antiangiogenic agent and this result stimulate future investigations about its antitumor activity.