Banca de DEFESA: TAÍS DA SILVA ROSA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : TAÍS DA SILVA ROSA
DATA : 06/05/2019
HORA: 09:00
LOCAL: sala 49, prédio PQ
TÍTULO:

EFFECT OF AÇAÍ  (Euterpe oleracea Mart) AND PITANGA (Eugenia uniflora L.) EXTRACTS TOWARD RATS BRAIN AND LIVER BIOTANSFORMATION AND ANTIOXIDANT ENZYMES FOR POTENTIAL PROTECTION AGAINST GENOTÓXIC AGENTS

PALAVRAS-CHAVES:

 GST, Catalase, fruits 

PÁGINAS: 156
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
SUBÁREA: Enzimologia
RESUMO:

Several endogenous or exogenous substances can impair the functioning of the organism directly or induce the formation of other harmful compounds, and therefore need to be eliminated. There are diverse pathways and cellular processes that lead the elimination of these compounds. The elimination process of xenobiotic compounds occurs mainly with the participation of biotransformation enzymes such as those belonging to the Glutathione Stransferase (GST) family. On the other hand, reactive oxygen species are eliminated by other action mechanisms that also involve the performance of enzymes, such as catalase. Bioactive compounds present in plants, particularly fruits, are constantly reported as having antioxidant compounds that can act directly in the cell or act as modulators of both biotransformation enzymes and enzymes responsible for the metabolism of reactive oxygen species. In this work, the objective was to determine the modulator capacity of compounds of two high consumption fruits, açaí and brazilian cherry, in modulating the GST enzyme, its mu isoform and the cerebral and hepatic catalase enzyme, in order to verify the possibility of extracts and compounds of these fruits become promising alternatives for enhancing the body's ability to protect against possibly genotoxic agents.The fruits extracts were obtained, crude extract has being extracted with distilled water and fractional extracts: ethereal (petroleum ether), alcoholic (in ethanol, using solid residue resulting from the ethereal extract) and aqueous distilled water, using solid residue resulting from the extraction of ethereal and alcoholic extract). These were tested in enzymatic assays of cerebral and hepatic cytosolic GSTs and catalases of rats, and the results compared with the control assays performed in the absence of extracts. Studies of the inhibition produced by the extracts at various substrate concentrations, such as Michaelis-Menten curves, from the reciprocal double plots, determined kinetic parameters (Km and Vmax) are important to better understand the enzymatic kinetics in the presence of the extracts. It was possible to observe the modulatory capacity of the compounds present in the extracts obtained from these two fruits, differently and depending on the compound, enzyme and /or isoform. GST and catalase were both activated or inactivated by the different extracts tested. By these results, the most expressive for increased GST and hepatic catalase activity, was found with the use of crude and aqueous extracts of açaí. GST and brain catalase were activated by the compounds of the aqueous extract of brazilian cherry. The results obtained with these extracts allow to relate them to the increase of the cellular capacity of reduction of the concentration of xenobiotic compounds in the organism, as well as the possibility of oxidative stress occurrence. This result becomes more important because the crude and aqueous extracts are directly related to the form of direct consumption of the fruits tested. 

MEMBROS DA BANCA:
Presidente - 1681790 - CRISTIANE MARTINS CARDOSO DE SALLES
Interno - 1844240 - CRISTIANO JORGE RIGER
Externo ao Programa - 2873182 - DIEGO DE MELLO CONDE DE BRITO
Externo ao Programa - 1220298 - ALEXANDRE HERCULANO BORGES DE ARAUJO
Externo à Instituição - EDUARDO DOS SANTOS SILVA - UERJ
Externo à Instituição - FREDERICO FREIRE BASTOS - UERJ
Externo à Instituição - LAILA NATASHA SANTOS BRANDÃO - IFMT