Banca de QUALIFICAÇÃO: NAYARA NÁGILA NEVES ALVES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : NAYARA NÁGILA NEVES ALVES
DATE: 17/09/2025
TIME: 08:00
LOCAL: Microsoft Teams ID da Reunião: 258 425 369 308 4 Senha: gz3q6nt6
TITLE:

Bioprospecting of metabolites from Bertholletia excelsa active against Plasmodium and Leishmania amazonensis.

KEY WORDS:

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

PAGES: 91
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, driving the search for new therapeutic
alternatives. Traditional communities use Brazil nut (Bertholletia excelsa) tea for liver
treatment and as an antimalarial agent, providing a valuable starting point for scientific
investigations into its bioactive compounds. The objective of this study was to evaluate the
susceptibility of Plasmodium spp. and Leishmania amazonensis to the action of metabolites
present in crude extracts of different plant structures of B. excelsa. Samples consisting of stem
bark, fruit, and operculum (the structure inside the fruit) were collected from native
Amazonian trees in Porto Velho, Rondonia. The metabolites of the oven-dried plant samples
were extracted with room-temperature (25°C) water, water at 100°C, and methanol. Once
dried, the crude extracts were analyzed by ultra-performance liquid chromatography coupled
with 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 flavonoid, coumarin,
and terpene classes (triterpenes, diterpenes, sesquiterpenes, and monoterpenes), expanding
knowledge about the diversity and chemical richness of this species. The identified
metabolites, in line with the biological activities described in the literature, confirm the
biological potential of this species. The biological assays demonstrated significant antioxidant
activities 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 cap extract.
Additionally, they exhibited potent inhibitory activities 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 cap extract, scientifically
validating the traditional use of Brazil nut. It was also found that the crude extracts of the
stem bark and fruit showed greater selectivity for the parasite than for the HePG2 and VERO
cell lines, justifying further studies. However, no relevant minimal inhibitory activity was
observed against the L. amazonensis species tested. 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 to preserve the region's plant species.

COMMITTEE MEMBERS:
Presidente - ***.324.392-** - MARCELA ALVARES OLIVEIRA - UNIR
Interna - ***.337.517-** - GEISA PAULINO CAPRINI EVARISTO - FIOCRUZ
Interno - 1427035 - WILSON GOMEZ MANRIQUE
Interna - 1387002 - OSVANDA SILVA DE MOURA
Externa ao Programa - 1554302 - ELIETH AFONSO DE MESQUITA - UNIRExterna à Instituição - ROSIMEIRE CRISTINA DALLA MARTHA - CEPEM
Externo à Instituição - JOSEPH ALBERT MEDEIROS EVARISTO - FIOCRUZ