Banca de DEFESA: NATHÁLIA CRISTINA LOPES DE JORGE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : NATHÁLIA CRISTINA LOPES DE JORGE
DATE: 11/11/2023
TIME: 09:00
LOCAL: Videoconferência - Link para acesso: https://meet.google.com/wqr-eneh-hkq
TITLE:

Chemical, antioxidant and toxicological prospecting of Marine Sponges Suberites aurantiacus, Mycale angulosa and Halichondrida from the Potiguar Basin – RN.

KEY WORDS:

Antioxidant activity. Bioprospecting. Metabolites from marine sponges.

PAGES: 81
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUBÁREA: Química de Macromoléculas
SPECIALTY: Proteínas
SUMMARY:

Marine sponges are very promising organisms in the search for bioactive molecules with a range of biological activities already reported in the scientific literature, with an emphasis on antioxidant agents. Knowing that oxidative stress is associated with various health conditions, such as cancer, Parkinson's, Alzheimer's, among others, the search for compounds that act on oxidative control becomes a key element in the quest for new treatments. The Potiguar Basin of RN has a vast coastline with a rich diversity of marine sponge species, but, on the other hand, it is little explored in terms of its biotechnological potential. In this work, we conducted chemical, antioxidant, and toxicological prospecting of three species of sponges collected on the coast of the Potiguar Basin: Suberites aurantiacus, Mycale (Zygomycale) angulosa, and Halichondrida. Sequential extractions were carried out with n-hexane (HE) and chloroform/methanol, and the extracts obtained only with HE were named HESUB, HEMYC, and HEHALI, while the extracts obtained only with CM were named CMSUB, CMMYC, and CMHALI for S. aurantiacus, M. angulosa, and Halichondrida, respectively. The yield of the extracts was the determining factor for choosing the CM extracts that would be chemically characterized by GC/MS and evaluated for their antioxidant activity using the following methods: Total Antioxidant Capacity (CAT), Reducing power, ion sequestration (superoxide, DPPH, Hydroxyl Radical (OH)) and Ion Chelating activity (Ferrous (Fe²⁺) and Cuprous (Cu²⁺)). CM extracts from the three sponges were also subjected to toxicological tests in vitro with human erythrocytes and in vivo with Tenebrio molitor larvae. Chemical characterization by GC/MS revealed the presence of alcohols, alkaloids, phenolic compounds, and lipids (mainly sterol classes). In in vitro antioxidant tests, the extracts showed the ability to scavenge DPPH radicals (CMHALI 60.91% ± 3.05; CMSUB 59.32% ± 3.71 and CMMYC 53.78% ± 6.96 at 1000 µg/mL) and hydroxyl radicals (CMSUB 96% ± 0.04 at a concentration of 2000 µg/mL; CMMYC 37% ± 0.17 and CMHALI 54% ± 0.086 with 1000 µg/mL of extract) and chelating copper ions (CMHALI 113.5% ± 1.93; CMSUB 112.1% ± 5.81 and CMMYC with 110.6% ± 3.19 activity with 25 µg/mL of the sample), with a particular emphasis on the copper chelating activity for three extracts. In vitro and in vivo toxicological tests revealed that, in both tests, at different concentrations, the samples did not exhibit toxic effects. Furthermore, antibacterial tests were conducted against the pathogenic bacteria Staphylococcus aureus and Escherichia coli, but no such activity was observed. The results presented here suggest that marine sponges from this coast have pharmacological properties that can be investigated with a view to isolating the metabolites responsible for the antioxidant activities presented. Furthermore, there is the possibility of investigating the potential of these metabolites in relation to other biological activities.

COMMITTEE MEMBERS:
Externa à Instituição - DAYANNE LOPES GOMES - IFPI
Presidente - 1149356 - ELIZEU ANTUNES DOS SANTOS
Interno - 2195251 - HUGO ALEXANDRE DE OLIVEIRA ROCHA