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 Regulação fisiológica da butirilcolinesterase através do uso de aditivos alimentares e sua aplicação em rações para camarão marinho(2023-04-19) Souza, Douglas Lemos de; Santos, Juliana Ferreira dos; http://lattes.cnpq.br/6621907859216486; http://lattes.cnpq.br/2715233041393261Litopenaeus vannamei is the most cultivated crustacean species in the world, representing 51.7% of total production. In Brazil, the species leads the national shrimp farming earning about R$1.6 million. Seeking to optimize cultures, new methods of physiological regulation can generate important results. The investigation of the modulation of the action of enzymes in the endocrine/digestive systems is an alternative with the potential to obtain significant results. Recently, it was proposed that the enzyme butyrylcholinesterase (BChE) plays a role in the metabolism of ghrelin, known as the “hunger hormone” and may influence feed intake and productive performance. The present study aimed to investigate the in vitro effect of BChE inhibitors as a physiological tool using food additives and their application in marine shrimp diets. Juveniles of L. vannamei in the fattening phase (2g, 4g and 6g) were obtained from a local producer and enzyme activity tests were carried out in different tissues (eye, muscle and hepatopancreas) using the IC50 parameter (concentration that inhibits the enzymatic activity by 50%). Tests were carried out to evaluate the inhibitory effect of the following plants: arugula (Eruca sativa), Swiss chard (Beta vulgaris) and spinach (Spinacea oleracea). The best inhibition results were arugula IC50: 0.019μg/mL in 6g shrimp; chard IC50: 0.14μg/mL in 4g shrimp and spinach IC50: 0.20μg/mL in 4g shrimp, chard showed better results for use as an additive. The feed was processed, and inhibitor extracts were added to the feed, in different samples, using grain alcohol as an incorporating vehicle. The physical and bromatological evaluations were then conducted, in the physical tests the repelletized rations showed a difference only in apparent density, even the repelletized rations being denser the buoyancy was not affected, for the bromatological tests they only showed lower humidity, due to the time in the oven. It can be concluded that individuals of average weight (4 g) have greater BChE activity, suggesting that this phase is ideal for introducing feeds with BChE inhibitors and that the inclusion of additives in shrimp feed, using the repellent method, can be used without impairing the nutritional and physical quality of the feed.Item Estudo in silico de derivados naftoquinônicos potenciais inibidores da principal protease do SARS-CoV-2(2020-11-05) Alencar, Natanael Ferreira de; Camara, Celso de Amorim; http://lattes.cnpq.br/4500025814149366; http://lattes.cnpq.br/7715134143959483