Banca de DEFESA: RAFAEL OLIVEIRA DE ARAUJO COSTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RAFAEL OLIVEIRA DE ARAUJO COSTA
DATA : 29/03/2019
HORA: 09:00
LOCAL: Auditório da Superintendência de Infraestrutura
TÍTULO:

EVALUATION OF CYTOTOXICITY AND BLOOD SUBACUTE TOXICITY OF TRYPSIN INHIBITOR ISOLATED FROM TAMARIND SEEDS NANOENCAPSULATED

 

PALAVRAS-CHAVES:

 

Natural molecules with bioactive action, such as the trypsin inhibitor isolated from tamarind (Tamarindusindica L.) (TTI) stands out among the satietogenic and anti-inflammatory agents currently studied. In this perspective, the encapsulation of TTI in purified chitosan and whey protein isolated (ECW) may be a strategy to prolong the effect of this inhibitor to modulate or potentiate the bioactive effects. However, for this, the safety needs to be evaluated, aiming at possible clinical applications. Thus, the objective of this study was to evaluate the cytotoxicity, and subacute blood toxicity of the bioactive dose of ECW in Wistar rats fed a high glycemic index diet. TTI was obtained from protein fractionation using ammonium sulfate. The fraction with the highest inhibitory activity against trypsin, fractionation of 30-60%, was isolated by Chromatography of Affinity in Trypsin-Sepharose and used for the synthesis of nanoparticles. The ECW was produced by the organic solvent nanoprecipitation method, respecting the ratio of TTI, purified chitosan and whey protein isolated of 1: 2: 2 w/w/w, respectively. The encapsulation was characterized by different physical and chemical analyzes, as well as the interaction between TTI and the encapsulating agents in neutral pH (water) and acidic pH, through several filtration steps in Amicon® 100 K, being monitored antitrypsin activity. In addition, the cytotoxicity of the ECW at different concentrations (0.5, 2.5 and 5 mg / mL) was evaluated by resazurin assay (Caco-2 and CCD-18Co) and blood toxicity (blood count, hepatic and renal function) in male Wistar rats (n = 10) fed a high glycemic index diet and , administered with ECW (12.5 mg / kg) for days 10 days. The ECW presented spherical particles with a smooth surface according to Scanning Electron Microscopy, mean diameter of 118 nm (17.27), a polydispersity index of 0.373 (0.02) and surface charge of -38.26 mV (0.15). Concerning the interaction in water of TTI and the encapsulating agents through the evaluation of the antitrypsin activity, using Amicon® 100 K, it was observed that in water the ECW protected the TTI and kept it entrapped. However, in acidic pH, there was a gradual release of TTI, evidenced by the strong interaction between TTI and the encapsulating agents used in this study. The cytotoxicity assay indicated high cell viability (> 70%) for Caco-2 and CCD-18Co when exposed to the ECW evaluated at different concentrations. As for the subacute blood toxicity of the ECW administered in Wistar rats, no toxic effects were also demonstrated according to the results obtained for the biochemical parameters evaluated. In this study, ECW proved to be effective in protecting TTI when dispersed in water and exposed to acid pH. The concentrations of ECW evaluated in cells, and the experimental model did not show signs of toxicity, suggesting the safe application of these particles and, probably, hepatoprotective effect. Finally, ensuring its application in complementary studies to investigate the efficacy in the treatment of obesity and its complications.

PÁGINAS: 70
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

Encapsulation. Nanoparticle. Antitrypsin activity. CCD18-Co. Caco-2. Wistar rats.

MEMBROS DA BANCA:
Presidente - 1549705 - ADRIANA FERREIRA UCHOA
Externo à Instituição - ALEXANDRE COELHO SERQUIZ - UNI-RN
Interno - 2195251 - HUGO ALEXANDRE DE OLIVEIRA ROCHA