Banca de DEFESA: NAYARA NÁGILA NEVES ALVES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : NAYARA NÁGILA NEVES ALVES
DATE: 18/03/2026
TIME: 15:00
LOCAL: Microsoft Teams: https://teams.microsoft.com/meet/25998421084694?p=4rdCP3dG62lYWtLv2y ID da Reunião:
TITLE:

Metabolomic profile of Brazil nut (Bertholethia excelsa) teas and their therapeutic potential against Plasmodium falciparum

KEY WORDS:

Keywords: Bioactives; Amazonian Chestnut; Ethnobotany; Malaria; Metabolomics.

PAGES: 90
BIG AREA: Ciências Biológicas
AREA: Farmacologia
SUBÁREA: Etnofarmacologia
SUMMARY:

Malaria and leishmaniasis are diseases with a significant socioeconomic impact, exacerbated by the resistance and toxicity of available treatments, which drives the search for new therapeutic alternatives. Traditional communities use Brazil nut (Bertholletia excelsa) tea for liver treatment and as an antimalarial agent, constituting a valuable starting point for scientific investigations into its bioactive compounds. The objective of this study was to evaluate the susceptibility of Plasmodium falciparum and Leishmania amazonensis to the action of metabolites present in crude extracts of different plant structures of B. excelsa. Based on the results obtained, a scientific article was prepared, structured according to the institutional norms for academic work of this type. Samples consisting of stem bark, fruit, and operculum (the structure inside the fruit) were collected from native Amazonian trees in Porto Velho/RO. The plant samples, dried in an oven, had their metabolites extracted using water at room temperature (25°C), water at 100°C, and methanol. Once dried, the crude extracts were analyzed by ultra-high performance liquid chromatography coupled to high-resolution tandem mass spectrometry (UHPLC/HRMSn) using a C18 column and electrospray ionization in positive (ESI+) and negative (ESI-) modes. Analyte identification was performed using MS Dial 5.1 software. The results reveal an abundance of secondary metabolites, described for the first time in B. excelsa, belonging to the classes of flavonoids, coumarins, and terpenes (triterpenes, diterpenes, sesquiterpenes, and monoterpenes), expanding knowledge about the diversity and chemical richness of this species. The identified metabolites, aligned with the biological activities described in the literature, confirm the biological potential of this species. Biological assays demonstrated significant antioxidant activity against the DPPH free radical, with minimum IC50 values of 1.48 µg/mL for the stem bark extract, 14.15 µg/mL for the fruit extract, and 13.25 µg/mL for the operculum extract. Additionally, they exhibited potent inhibitory activity against chloroquine-resistant P. falciparum, with inhibitions between 80 and 100% at a concentration of 100 µg/mL. The minimum IC50 values for this antiplasmodial activity were 2.38 µg/mL for the stem bark extract, 9.41 µg/mL for the fruit extract, and 30.36 µg/mL for the operculum extract, scientifically validating the traditional use of Brazil nut. It was also found that the crude extracts of stem bark and fruit showed greater selectivity for the parasite than for the HePG2 and VERO cell lines, justifying further studies. However, no relevant minimum inhibitory activities were observed against the tested L. amazonensis species. These results highlight the importance of ethnobotanical knowledge as a guide for bioprospecting, demonstrate the potential and importance of Amazonian biodiversity as a source of new bioactive compounds, and reinforce the need for the preservation of plant species in the region.

COMMITTEE MEMBERS:
Presidente - ***.359.608-** - LUCIA HELENA DE OLIVEIRA WADT - EMBRAPA
Interna - ***.324.392-** - MARCELA ALVARES OLIVEIRA - UNIR
Externa ao Programa - 1348799 - MARIANGELA SOARES DE AZEVEDO - UNIRExterna ao Programa - 2245719 - SHEILA BARRETO GUTERRES - UNIRExterna à Instituição - STEFANIE COSTA PINTO LOPES
Externa à Instituição - CAMILA FABBRI