Banca de DEFESA: RAYSSA LOURENNA TRIGUEIRO NOBREGA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RAYSSA LOURENNA TRIGUEIRO NOBREGA
DATE: 28/07/2025
TIME: 08:30
LOCAL: Videoconferência
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: 101
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUBÁREA: Química de Macromoléculas
SPECIALTY: Glicídeos
SUMMARY:

Corncob xylan (XSM) is an abundant polysaccharide with a linear structure of xylose and side chains of arabinose and glucuronic acid. Its extraction using ultrasound is efficient and environmentally viable. Previous studies have demonstrated antioxidant, immunomodulatory, antimicrobial, and antiproliferative activities of this polysaccharide. Enriched fractions and silver nanoparticles functionalized with xylan have also shown enhanced therapeutic potential, highlighting XSM as a promising biopolymer for pharmaceutical applications. The use of XSM is supported by its wide availability, low cost, and high sustainability potential. By valorizing an often-discarded agricultural residue, it contributes to reducing environmental impacts. Moreover, the potential pharmacological use of XSM broadens its applicability across different fields. In this study, XSM was evaluated for its composition, physicochemical properties, antioxidant activity, and toxicological safety. XSM extraction was carried out through alkaline treatment, and physicochemical characterizations were performed using 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), zebrafish embryo toxicity, and bioassays with Mysidopsis juniae. In silico analyses complemented the toxicological evaluation. Results showed that XSM contains a high sugar content (97.4%) and low levels of contaminants. It demonstrated strong antioxidant capacity and no significant cytotoxicity in L929 and CHO-K1 cells. Morphological and genotoxic analyses revealed no nuclear alterations or DNA damage. In in vivo models, XSM did not cause mortality, malformations, or cardiac changes. In silico predictions confirmed its low toxicity and favorable pharmacokinetic profile. Therefore, it can be concluded that XSM exhibits antioxidant activity and a satisfactory safety profile, suggesting its potential for use in pharmaceutical or food formulations

COMMITTEE MEMBERS:
Presidente - 2195251 - HUGO ALEXANDRE DE OLIVEIRA ROCHA
Externa à Instituição - ALESSANDRA DANIELE DA SILVA - UFPE
Externo à Instituição - EDVALDO DA SILVA TRINDADE - UFPR