Banca de QUALIFICAÇÃO: RAFAEL OLIVEIRA DE ARAUJO COSTA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : RAFAEL OLIVEIRA DE ARAUJO COSTA
DATA : 01/03/2019
HORA: 10:00
LOCAL: Sala de vídeo conferência do Departamento de nutrição (DNUT)
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 trypsin inhibitor isolated from tamarind (Tamarindus indica L.) seeds (TTI), stand 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 potentialized the bioactive effects. However, the safety needs to be evaluated, aiming at possible clinical applications. Thus, the objective of this study was to evaluate the cytotoxicity and blood sub-acute toxicity of the bioactive dose of ECW in overfed Wistar rats with a high glycemic index diet. For this, 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 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 water, through several steps of ultrafiltration in Amicon® 100 K, being monitored by the antitrypsin activity. In addition, cytotoxicity of the ECW was evaluated in different concentrations (0.5, 2.5 and 5.0 mg / mL) by MTT and resazurin using two types of cell culture (Caco-2 and CCD-18Co), as well as toxicity, evaluated in Wistar rats feeding with a high glycemic index diet and administered with ECW (12,5mg/Kg) for 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 of TTI and ECW in water through the evaluation of the antitrypsin activity, it was observed that the TTI retained in Amicon® 100 K did not present antitrypsin activity (0.8%) compared to the aliquots obtained after the three stages of ultrafiltration (p <0.05). For the ECW, the results suggested that it did not cross the membrane when ultrafiltrated, since the antitrypsin activity was not observed in the filtrates (0%), unlike the unfiltered and retained aliquots in Amicon® (p> 0.05), which presented 100% activity. The cytotoxicity assay indicated high cell viability (> 70%) of Caco-2 and CCD-18Co cells when exposed to ECW evaluated at different concentrations. Regarding the sub-acute 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 efficient in protecting TTI when dispersed in water and its concentrations evaluated in cells, and the experimental model did not show signs of toxicity, suggesting a safe application of these particles. Finally, ensuring its use in complementary studies to investigate the efficacy in the treatment of obesity and its complications.

PÁGINAS: 58
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

Encapsulation; nanoparticle; antitrypsin activity; cells; CCD-18Co; Caco-2; Wistar rats.

MEMBROS DA BANCA:
Presidente - 1549705 - ADRIANA FERREIRA UCHOA
Externa à Instituição - CATARINA GONÇALVES
Externa ao Programa - 2275877 - THAIS SOUZA PASSOS