Leandro De Santis Ferreira

Dr. Leandro De Santis Ferreira

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Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

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

Representative Publications

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EAEdilane Rodrigues Dantas De Araújo
Edilane Rodrigues Dantas De Araújo
GGGerlane Coelho Bernardo Guerra
Gerlane Coelho Bernardo Guerra
DADaline Araujo
Daline Araujo
AAAurigena Araújo
Aurigena Araújo
JFJulia MORAIS FERNANDES
Julia MORAIS FERNANDES
Silvana Maria LangassnerSilvana Maria Langassner
Silvana Maria Langassner
Kalanchoe brasiliensis and Kalanchoe pinnata are used interchangeably in traditional medicine for treating peptic ulcers and inflammatory problems. In this context, this study aims to characterize the chemical constituents and evaluate the gastroprotective activity of the leaf juices of the two species in acute gastric lesions models. Thin Layer Chromatography (TLC) and Ultra High Performance Liquid Chromatography coupled to Mass Spectrometer (UHPLC-MS) were performed for chemical characterization. Wistar rats were pre-treated orally with leaf juices (125, 250 and 500 mg/kg) or ranitidine (50 mg/kg). The peaks observed in the chromatogram of K. brasiliensis showed similar mass spectra to flavonoid glycosides derived from patuletin and eupafolin, while K. pinnata showed mass spectra similar to compounds derived from quercetin, patuletin, eupafolin and kaempferol. K. brasiliensis at all doses and K. pinnata at doses of 250 mg/kg and 500 mg/kg significantly reduced the lesions in the ethanol induction model. In the indomethacin induction model, both species showed significant results at doses of 250 and 500 mg/kg. Also, the pre-treatment with leaf juices increased the antioxidant defense system, glutathione (GSH), whereas malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) levels were significantly decreased. Treatment with leaf juices led to the upregulation of zone occludes-1 (ZO-1) and the downregulation of inducible nitric oxide synthase (iNOS) and factor nuclear-κβ transcription (NF-κB-p65), while also showing a cytoprotective effect and maintaining mucus production. These findings show that the leaf juices of the two species showed gastroprotective effects on ethanol and gastric indomethacin injury which were a consequence of gastric inflammation suppression, antioxidant activity and the maintenance of cytoprotective defenses and mucosal structure architecture.

1 May 2019 in Biomedicine & Pharmacotherapy
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EAEdilane Rodrigues Dantas de Araújo
Edilane Rodrigues Dantas de Araújo
Juliana Felix-SilvaJuliana Felix-Silva
Juliana Felix-Silva
JXJacinthia Beatriz Xavier-Santos
Jacinthia Beatriz Xavier-Santos
JFJulia MORAIS FERNANDES
Julia MORAIS FERNANDES
GGGerlane Coellho Bernardo Guerra
Gerlane Coellho Bernardo Guerra
Silvana Maria LangassnerSilvana Maria Langassner
Silvana Maria Langassner
Kalanchoe brasiliensis and Kalanchoe pinnata are used interchangeably in traditional medicine in the treatment of wound healing. In this context, the objective of the present study was to evaluate the local anti-inflammatory activity of a topical formulation containing aqueous extract of both species. The in vivo model used was ear edema induced by croton oil and paw edema induced by carrageenan. The Swiss mice treatments use formulations containing aqueous extract at different concentrations (1.25%, 2.5%, and 5%) or dexamethasone (1 mg/g), all administered topically and immediately after edema induction. The treatment with formulations containing aqueous extract of both species reduced ear and paw edema, besides that, the decrease in edema was evidenced by reduction of myeloperoxidase activity, IL-1β, and TNF-α levels and increase IL-10 levels. In conclusion, the two species showed local anti-inflammatory activity; however K. brasiliensis showed a better result in both edematogenic models since it had activity in the lowest concentration.

4 April 2020 in Planta Medica
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ESEmerson M. da S. Siqueira
Emerson M. da S. Siqueira
TLTábata L. C. Lima
Tábata L. C. Lima
LBLaurita Boff
Laurita Boff
SLSarah G. M. Lima
Sarah G. M. Lima
ELEstela M. G. Lourenço
Estela M. G. Lourenço
Silvana Maria LangassnerSilvana Maria Langassner
Silvana Maria Langassner
Spondias mobin leaves have been traditionally used for treating cold sores. The study investigated the mechanism of antiherpes action of S. mombin extract, fractions, and geraniin. Different concentrations of samples were used to evaluate the in vitro antiherpes activity (anti-HSV-1) in virucidal, post-infection, attachment, and penetration assays. The mechanism of action of geraniin was investigated considering the glycoproteins gB and gD of HSV-1 surface as potential molecular targets. Molecular docking simulations were carried out for both in order to determine the possible binding mode position of geraniin at the activity sites. The binding mode position was posteriorly optimized considering the flexibility of the glycoproteins. The chemical analysis of samples was performed by LC-MS and revealed the presence of 22 substances, which are hydrolysable tannins, O-glycosylated flavonoids, phenolic acids, and a carbohydrate. The extract, tannin-rich fraction and geraniin showed important in vitro virucidal activity through blocking viral attachment but showed no relevant inhibition of viral penetration. The in silico approaches demonstrated a high number of potential strong intermolecular interactions as hydrogen bonds between geraniin and the activity site of the glycoproteins, particularly the glycoprotein gB. In silico experiments indicated that geraniin is at least partially responsible for the anti-herpes activity through interaction with the viral surface glycoprotein gB, which is responsible for viral adsorption. These results highlight the therapeutic potential of S. mombin anti-herpes treatment and provides support for its traditional purposes. However, further studies are required to validate the antiviral activities in vivo, as well as efficacy in humans.

21 April 2020 in Pharmaceutics
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JAJovelina Samara Ferreira Alves
Jovelina Samara Ferreira Alves
ASAlaine Maria dos Santos-Silva
Alaine Maria dos Santos-Silva
RSRodrigo Moreira da Silva
Rodrigo Moreira da Silva
PTPamella Rebeca Fernandes Tiago
Pamella Rebeca Fernandes Tiago
Thais CarvalhoThais Carvalho
Thais Carvalho
Silvana Maria LangassnerSilvana Maria Langassner
Silvana Maria Langassner
A variety of neuroactive flavonoids can be found in the species of the Passiflora genus; however, their difficulty in crossing the blood–brain barrier limits their in vivo neuropharmacological activity. In this study, cationic nanoparticles were developed as a novel nanocarrier for improving the antidepressant activity of Passiflora edulis f. flavicarpa leaf extract. Formulations obtained using Eudragit E PO polymethylmethacrylate copolymer, as polymeric matrix had their physicochemical properties investigated. The analytical content of the flavonoids vicenin-2, orientin, isoorientin, vitexin, and isovitexin was determined in the plant extract. Small-sized and spherical nanoparticles loaded with Passiflora edulis f. flavicarpa were obtained with positive zeta potential and high encapsulation efficiency. In addition, the nanosystems were shown to be stable for at least 6 months. The antidepressant activity of P. edulis extract (50 and 100 mg/kg) as well as the extract-loaded nanoparticles (5 mg/kg) were investigated in mice using the forced swimming test, where the latter increased the potency of the former by 10-fold. In addition, histopathological and biochemical analysis confirmed the biocompatibility of the extract-loaded nanoparticles. This study demonstrated that the Eudragit cationic nanoparticles were able to improve the antidepressant activity of P. edulis in the central nervous system of mice.

12 February 2021 in Marine Drugs
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NSNayara Sousa da Silva
Nayara Sousa da Silva
NANathalia Araujo
Nathalia Araujo
ASAlessandra Silva
Alessandra Silva
JOJohny Olivera
Johny Olivera
JDJulia M M Dantas
Julia M M Dantas
MPMatheus Pedrosa
Matheus Pedrosa
The global rise of infectious disease outbreaks and the progression of microbial resistance reinforce the importance of researching new biomolecules. Obtained from the hydrolysis of chitosan, chitooligosaccharides (COSs) have demonstrated several biological properties, including antimicrobial, and greater advantage over chitosan due to their higher solubility and lower viscosity. Despite the evidence of the biotechnological potential of COSs, their effects on trypanosomatids are still scarce. The objectives of this study were the enzymatic production, characterization, and in vitro evaluation of the cytotoxic, antibacterial, antifungal, and antiparasitic effects of COSs. NMR and mass spectrometry analyses indicated the presence of a mixture with 81% deacetylated COS and acetylated hexamers. COSs demonstrated no evidence of cytotoxicity upon 2 mg/mL. In addition, COSs showed interesting activity against bacteria and yeasts and a time-dependent parasitic inhibition. Scanning electron microscopy images indicated a parasite aggregation ability of COSs. Thus, the broad biological effect of COSs makes them a promising molecule for the biomedical industry.

2 October 2018 in Molecules
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Larissa SilvaLarissa Silva
Larissa Silva
JAJovelina Samara Ferreira Alves
Jovelina Samara Ferreira Alves
ESEmerson Michell Da Silva Siqueira
Emerson Michell Da Silva Siqueira
MNManoel André De Souza Neto
Manoel André De Souza Neto
Lucas AbreuLucas Abreu
Lucas Abreu
Silvana Maria LangassnerSilvana Maria Langassner
Silvana Maria Langassner
Genipa americana is a medicinal plant popularly known as “jenipapo”, which occurs in Brazil and belongs to the Rubiaceae family. It is a species widely distributed in the tropical Central and South America, especially in the Cerrado biome. Their leaves and fruits are used as food and popularly in folk medicine to treat anemias, as an antidiarrheal, and anti-syphilitic. Iridoids are the main secondary metabolites described from G. americana, but few studies have been conducted with their leaves. In this study, the aim was to chemical approach for identify the main compounds present at the extract of G. americana leaves. The powdered leaves were extracted by maceration with EtOH: water (70:30, v/v), following liquid-liquid partition with petroleum ether, chloroform, ethyl acetate and n-butanol. A total of 13 compounds were identified. In addition three flavonoids were isolated from the ethyl acetate fraction: quercetin-3-O-robinoside (GAF 1), kaempferol-3-O-robinoside (GAF 2) and isorhamnetin-3-O-robinoside (GAF 3) and, from n-butanol fraction more two flavonoids were isolated, kaempferol-3-O-robinoside-7-O-rhamnoside (robinin) (GAF 4) and isorhamnetin-3-O-robinoside-7-rhamnoside (GAF 5). Chemical structures of these five flavonoids were elucidated using spectroscopic methods (MS, 1H and 13C-NMR 1D and 2D). These flavonoids glycosides were described for the first time in G. americana.