Banca de QUALIFICAÇÃO: RAYSSA LOURENNA TRIGUEIRO NOBREGA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : RAYSSA LOURENNA TRIGUEIRO NOBREGA
DATE: 07/07/2025
TIME: 08:30
LOCAL: remota
TITLE:

In vitro, in vivo and in silico evaluation of xylan toxicity extracted from corn cobs

KEY WORDS:

Xylan, corn cob, polysaccharide, Mysidopis juniae, CHO cells

PAGES: 88
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUBÁREA: Química de Macromoléculas
SPECIALTY: Glicídeos
SUMMARY:

Corncob xylan (XSM) is an abundant polysaccharide with a linear backbone composed of xylose units and side chains containing arabinose and glucuronic acid. Its extraction via ultrasound is both efficient and environmentally sustainable. Studies have demonstrated the antioxidant, immunomodulatory, antimicrobial, and antiproliferative activities of this polysaccharide. Enriched fractions and silver nanoparticles functionalized with xylan have shown enhanced therapeutic potential. These findings highlight XSM as a promising biopolymer for pharmaceutical applications. XSM was evaluated in terms of its composition, physicochemical properties, antioxidant activity, and toxicological safety. The study aimed to determine whether XSM exhibits low toxic potential and promising bioactive properties. Extraction was carried out through alkaline treatment, followed by physicochemical characterization using chemical analyses, UV-Vis and FTIR spectroscopy, X-ray diffraction, and electron microscopy. Biological activities were assessed through metal chelation assays, cytotoxicity (MTT), nuclear morphology (DAPI), clonogenicity, genotoxicity (CBMN and Comet assays), toxicity in zebrafish embryos, and bioassays with Mysidopsis juniae. In silico tests complemented the toxicological evaluation. Results showed that XSM contains a high sugar content (97.4%) and low levels of contaminants. It exhibited strong antioxidant capacity and did not show significant cytotoxicity in L929 and CHO cell lines. Morphological and genotoxic analyses indicated no nuclear alterations or DNA damage. In in vivo models, XSM did not induce mortality, malformations, or cardiac abnormalities. In silico predictions confirmed low toxicity and favorable pharmacokinetic safety. In conclusion, XSM presents antioxidant activity and a satisfactory safety profile, suggesting its potential use in pharmaceutical or food formulations

COMMITTEE MEMBERS:
Presidente - 2962496 - RAFAEL BARROS GOMES DA CAMARA
Externa ao Programa - 2477216 - NAISANDRA BEZERRA DA SILVA FARIAS - UFRNExterno à Instituição - MOACIR FERNANDES DE QUEIROZ NETO - UFPB