Leticia Maria Siqueira

Mrs. Leticia Maria Siqueira

Universidade Federal do Pará

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 March 2021 in Foods
Verified
Journal Article
Open access
PDF file
FPFlávia Cristina Seabra Pires
Flávia Cristina Seabra Pires
JOJoicy Corrêa de Oliveira
Joicy Corrêa de Oliveira
Eduardo Gama Ortiz MenezesEduardo Gama Ortiz Menezes
Eduardo Gama Ortiz Menezes
ASAna Silva
Ana Silva
Maria FerreiraMaria Ferreira
Maria Ferreira
RJRaul Carvalho Junior
Raul Carvalho Junior
The use of clean technologies in the development of bioactive plant extracts has been encouraged, but it is necessary to verify the cytotoxicity and cytoprotection for food and pharmaceutical applications. Therefore, the objective of this work was to obtain the experimental data of the supercritical sequential extraction of murici pulp, to determine the main bioactive compounds obtained and to evaluate the possible cytotoxicity and cytoprotection of the extracts in models of HepG2 cells treated with H2O2. The murici pulp was subjected to sequential extraction with supercritical CO2 and CO2+ethanol, at 343.15 K, and 22, 32, and 49 MPa. Higher extraction yields were obtained at 49 MPa. The oil presented lutein (224.77 µg/g), oleic, palmitic, and linoleic, as the main fatty acids, and POLi (17.63%), POO (15.84%), PPO (13.63%), and LiOO (10.26%), as the main triglycerides. The ethanolic extract presented lutein (242.16 µg/g), phenolic compounds (20.63 mg GAE/g), and flavonoids (0.65 mg QE/g). The ethanolic extract showed greater antioxidant activity (122.61 and 17.14 µmol TE/g) than oil (43.48 and 6.04 µmol TE/g). Both extracts did not show cytotoxicity and only murici oil showed a cytoprotective effect. Despite this, the results qualify both extracts for food/pharmaceutical applications.

5 September 2024 in Foods
Verified
Journal Article
Open access
PDF file
LSLeticia Maria Siqueira
Leticia Maria Siqueira
ACANA LUIZA DE BARROS SOUZA CAMPOS
ANA LUIZA DE BARROS SOUZA CAMPOS
FPFlávia Cristina Seabra Pires
Flávia Cristina Seabra Pires
Maria FerreiraMaria Ferreira
Maria Ferreira
ASAna Silva
Ana Silva
RJRaul Carvalho Junior
Raul Carvalho Junior
For bioactivity studies, it is necessary to use products with a high degree of purity, which may influence the cytotoxic effects. Supercritical technology presents itself as an alternative to obtain these products. Therefore, the objective of this work was to obtain the bioactive compounds of oil and pulp of açaí fat-free supercritical technology and evaluate the cytotoxicity of products in MRC-5 and VERO cells in vitro. The açaí pulp was subjected to extraction with supercritical CO2 to obtain the oil and pulp without fat, under conditions of 323.15 K at 35 MPa, 333.15 K at 42 MPa, and 343.15 K at 49 MPa. The largest yields (51.74%), carotenoids (277.09 µg/g), DPPH (2.55 μmol TE/g), ABTS (2.60 μmol TE/g), and FRAP (15.25 μm of SF/g) of oil and ABTS (644.23 μmol TE/g) of pulp without fat were found in the condition 343.15 K at 49 MPa. The highest levels of compounds phenolics (150.20 mg GAE/g), DPPH (414.99 μmol TE/g), and FRAP (746.2 μm SF/g) of the pulp without fat were found in the condition of 323.15 K to 35 MPa. The fat-free pulp presented high levels of anthocyanins without significant variation in cytotoxicity. The developed process was efficient in obtaining oil rich in carotenoids, and the supercritical technology elucidated an efficient way to obtain açaí fat-free pulp.

12 September 2025 in Plants
Verified
Journal Article
Open access
PDF file
ASAna Paula de Souza e Silva
Ana Paula de Souza e Silva
FPFlávia Cristina Seabra Pires
Flávia Cristina Seabra Pires
Maria FerreiraMaria Ferreira
Maria Ferreira
LSLeticia Maria Siqueira
Leticia Maria Siqueira
Eduardo Gama Ortiz MenezesEduardo Gama Ortiz Menezes
Eduardo Gama Ortiz Menezes
RJRaul Carvalho Junior
Raul Carvalho Junior
Cardiovascular diseases (CVDs) are the leading cause of death worldwide, with cardiac arrhythmias being one of the main factors contributing to morbidity. Currently, several established antiarrhythmic medications with proven efficacy are available. However, frequent use of these medications causes adverse effects with medium- and long-term use. This necessitates the development of new medications, preferably of natural origin and with ethnopharmacological relevance. In this sense, Acmella oleracea presents itself as an alternative for the treatment of arrhythmia, considering studies suggesting its cardioprotective effect. Therefore, the objective of this study was to evaluate the electrophysiological and antiarrhythmic effects of a supercritical extract of Acmella oleracea (SEAO) in rats. The extract was obtained by supercritical CO2 extraction at 70 °C and 320 bar, with an extract yield of 9.72 ± 0.26% (db) and a spilanthol yield of 25.91%. The extract was administered intraperitoneally at doses of 10, 15, and 20 mg/kg in two experimental models: (1) assessment of cardiac electrophysiology and (2) epinephrine-induced arrhythmia. Electrocardiogram (ECG) parameters were measured and compared with controls treated with epinephrine and lidocaine. The SEAO group maintained sinus rhythm and preserved cardiac intervals, with a significant reduction in heart rate and R-R interval compared to the epinephrine group. These findings demonstrate that SEAO exerts dose-dependent antiarrhythmic effects comparable to those of lidocaine. The results corroborate the potential use of SEAO as a natural alternative for arrhythmia management, encouraging further pharmacological and clinical studies.

1 June 2025 in LUMEN ET VIRTUS
Verified
Journal Article
Open access
PDF file
Maria FerreiraMaria Ferreira
Maria Ferreira
LMLeonardo Victor Gomes de Melo
Leonardo Victor Gomes de Melo
ASAna Silva
Ana Silva
LSLeticia Maria Siqueira
Leticia Maria Siqueira
GCGabriela Izane De Almeida Campos
Gabriela Izane De Almeida Campos
RJRaul Carvalho Junior
Raul Carvalho Junior
A espécie Mauritia flexuosa representa grande potencial biotecnológico e econômico para a região amazônica. Seus frutos possuem alto valor nutricional e quantidades significativas de compostos bioativos que podem integrar novas formulações de produtos e aplicações especiais, porém ainda pouco explorados do ponto de vista tecnológico e comercial. Dentre as técnicas emergentes que podem ser aplicadas a essa espécie para gerar produtos de alto valor agregado, destaca-se a extração com fluido supercrítico. Além de altos rendimentos e melhor qualidade dos produtos finais, esse processo elimina a necessidade de solventes orgânicos que costumam tóxicos e prejudiciais ao meio ambiente. A utilização de fluidos supercríticos apresenta-se como uma solução inovadora para introduzir o fruto e seus derivados nas mais variadas indústrias, gerando benefícios não só do ponto de vista tecnológico, mas também sociais, ambientais e econômicos. Estudos relacionados a implementação da tecnologia supercrítica na Amazônia em maior escala com foco em análises técnicas e econômicas já vem sendo desenvolvidos, apresentando soluções promissoras que levam em consideração as características únicas da região, tornando o processo tecnicamente viável, economicamente atrativo e ambientalmente responsável. Contudo, para atender o acréscimo na demanda por produtos do buriti alguns fatores além da tecnologia devem ser considerados em todos os níveis da cadeia produtiva. Nesse contexto, esta pesquisa tem como objetivo investigar o impacto da tecnologia supercrítica aplicada ao fruto do buriti (Mauritia flexuosa) na bioeconomia da Amazônia.