Banca de DEFESA: STELLA MARIA ANDRADE GOMES BARRETO
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : STELLA MARIA ANDRADE GOMES BARRETO
DATE: 20/12/2022
TIME: 13:30
LOCAL: Link de acesso para videoconferência: http://meet.google.com/wav-hzgc-ztk
TITLE:
In Vitro and In Vivo Antioxidant Activity of Agave sisalana Agro-Industrial Residue
KEY WORDS:
Agave sisalana, antioxidant, cosmetics, nanoemulsions.
PAGES: 199
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:
Agave sisalana (sisal) is a plant extensively cultivated in the northeast region to obtain
a hard fiber. However, a large amount of residue is generated in the process to obtain
that fiber. In view of this, the aim of study was to obtain and characterize
polysaccharides-rich fractions from A. sisalana agro-industrial residue, to evaluate the
antioxidant potential in vitro and in vivo and to develop a nanoemulsion containg those
fractions for application as a prevent product of skin aging sings. From the residue, a
polysaccharides-rich fraction (FRE) was received, and, from the FRE, another fraction
was received through ultrafiltration by size (FREP). The qualitative composition of the
fractions was evaluated using Nuclear Magnetic Resonance (NMR) and liquid
chromatography coupled to mass spectrometry (LC-MS). Fractions were evaluated for
their antioxidant activity in vitro using different spectrophotometric techniques and in
culture medium and, also in vivo by means of intracellular quantification of reactive
oxygen species (ROS), oxidative stress survival and quantification of gst-4::GFP gene
expression in Caenorhabditis elegans models. A factorial experimental design
(2³+3PC) was designed to obtain a nanoemulsion system and its evaluations. The
fractions consist mainly of terpenoids and O-glycosyl metabolites, with β-Glcp, α-
ManNH2p and α-GalNH2p as the main sugars. FRE showed greater ability to
scavenging DPPH and ABTS radicals, while FREP showed better metal chelating
activity (Cu2+ and Fe2+). FRE and FREP were able to promote a protective effect
against oxidative stress in 3T3 cells. In C. elegans, FRE and FREP promoted
intracellular reduction of ROS and increased survival variation by up to 21% and 26%,
respectively. The expression of gst-4:GFP was positive for FRE whereas, for FREP, a
reduction in expression was observed. The nanoemulsion consisting of 20% oil phase,
5% surfactants and 75% aqueous phase was considered stable for 90 days at different
temperatures. The use of agro-industrial residue as a new antioxidant cosmetic raw
material for skin care and prevention of signs of skin aging can bring environmental
benefits and contribute to the socioeconomic development of the region.
COMMITTEE MEMBERS:
Interno - 1789788 - ADLEY ANTONINI NEVES DE LIMA
Externo à Instituição - EDEMILSON CARDOSO DA CONCEIÇÃO - UFG
Externo à Instituição - JOSEAN FECHINE TAVARES - UFPB
Presidente - 1714294 - MARCIO FERRARI
Externa à Instituição - VERA LUCIA BORGES ISAAC - UNESP